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  • 251.
    Sandberg, Christer
    et al.
    Holmen Paper AB.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    LC refining combined with screen fractionation – Reduction of system complexity for mechanical pulping2018Ingår i: IMPC 2018, Trondheim, Norway, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Process intensification - a process development method used in the chemical process industry has been appliedto mechanical pulping process design. Process intensification is characterized by significant reduction of energyconsumption and process complexity.A process with single stage high consistency (HC) refining followed by low consistency (LC) refining andscreening was evaluated in mill trials at the Holmen Paper Braviken mill, Sweden. After LC refining, pulp wasscreened and the reject was fed back to LC refining. The process is called HC-LC-S. Two different HC primaryrefiner types were evaluated – single disc (SD) and double disc (DD).High intensity DD chip refining was more suitable than single disc refining for the process due to higher lightscattering and lower shives content of the final pulp. It was also easier to reach high enough tensile index beforeLC refining with the DD refining. The DD-LC-S process required 1940 kWh/adt total specific energy for newsgrade TMP, which was 300 kWh/adt lower than the reference TMP line; DD chip refining and HC rejectrefining. The auxiliary specific energy was reduced with 100 kWh/adt.Six unit operations and three chests with agitators and pumps were omitted compared to a conventional TMPline.

  • 252.
    Sandberg, Christer
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Holmen Paper, Norrköping.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Low consistency refining of mechanical pulp - system design2017Ingår i: TAPPI Journal, ISSN 0734-1415, Vol. 16, nr 7, s. 419-429Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many mechanical pulping mills use low consistency (LC) refining for energy efficient fiber development. In this study, energy efficiency and pulp quality were evaluated for six processes, of which four included LC refining. We studied two different types of chip refiners - single disc (SD) and double disc (DD) - with LC refining in the main and reject lines. All process combinations have been used in the Holmen Paper Braviken mill, Sweden, to make thermomechanical pulp for printing papers. LC refining was more energy efficient than high consistency (HC) refining at certain tensile index increases in all evaluated combinations. LC refining in the main line had somewhat higher energy efficiency than did LC refining in the reject line. The type of chip refiner (DD or SD) did not affect the efficiency or pulp property development in LC refining. The process with a combination of DD chip refining and LC refining had the highest energy efficiency (tensile index at certain specific energy consumption). All processes with LC refining produced pulp with somewhat lower light scattering and fiber length than did the corresponding system with only HC refining. Thus, for printing papers, the best combination was LC refining with DD chip refining. LC refiners seem to have a narrow range in specific energy for maximum energy efficiency and a good balance between tensile index increase and fiber length reduction. Much higher specific energy was applied on reject pulp. However, the reject share was only around 30%. The LC refining specific energy, based on main line production, was around 80 kWh/air-dried metric ton (a.d. metric ton), whereas up to 180 kWh/a.d. metric ton was applied in main line.

  • 253.
    Sandberg, Christer
    et al.
    Holmen Paper AB, Paper Prod Dev, Norrköping.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Mill evaluation of an intensified mechanical pulping process2017Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, nr 2, s. 204-210Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mill-scale demonstration of a process concept inspired by Process Intensification (PI) principles was performed in Holmen Paper Braviken mill, Norrkoping, Sweden. The intensified process consists of wood softening by means of chip pretreatment with sodium sulphite, high intensity refining followed by low consistency refining. This process yields very low shives content and thus the unit operations screening and reject refining can be eliminated and the pulp is fed directly to the paper machine. Thorough evaluation of key paper-and print quality data showed that it is possible to produce pulp for newsprint at 1500 kWh/adt total specific energy (including auxiliary drives such as pumps, screw feeders, etc.). The total specific energy consumption was 900 kWh/adt lower compared to the normal process used for newsprint in Braviken, and 500 kWh/adt lower compared to today's best available technology. The auxiliary equipment energy demand was 120 kWh/adt, which was less than half of that of the reference TMP line. The PIinspired process reduces the number of machines drastically compared to a conventional TMP line, as well as the number of pumps, chests and other auxiliary equipment.

  • 254.
    Sandberg, Christer
    et al.
    Holmen Paper AB, Norrköping.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Process intensification in mechanical pulping2017Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, nr 4, s. 615-622Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Process intensification is a term used in the chemical process industry for major improvements in the process design leading to radical changes in process complexity, equipment size and efficiency. We suggest that a similar approach is applied in the pulp and paper industry. We have focused on the production of mechanical pulp, but a similar approach can be applied to other areas within the pulp and paper industry. Inspired by process intensification methodology, we suggest five principles for development of the mechanical pulping process. Three fundamental principles; 1. Break up the wood and fibre wall structure in the right positions. 2. Give each fibre, of certain morphology, the same processing experience. 3. Optimize the applied mechanical forces and the physiochemical state of the wood and fibre material.  and two system oriented principles; 1. Select wood raw material based on final product specifications. 2. Design the process to facilitate observability, controllability and maintenance. Implications of these principles on process design and future challenges for mechanical pulping are discussed.

  • 255.
    Sandberg, Christer
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Holmen Paper.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    System Aspects on Low Consistency Refining of Mechanical Pulp2016Ingår i: TAPPI 2016 International Mechanical Pulping Conference (IMPC), TAPPI Press, 2016, Vol. 1, s. 485-495Konferensbidrag (Refereegranskat)
    Abstract [en]

    Several combinations of high consistency (HC) and low consistency (LC) refiners were evaluated both in main line and reject line for production of pulp for printing papers. HC-LC processes were compared with processes with only HC refining. Processes with two different types of chip refiners were studied – single disc (SD) and double disc (DD). All process combinations were evaluated during continuous production in the Holmen Paper Braviken mill, Sweden. The purpose of this work was to evaluate energy efficiency and pulp quality for the processes.

    LC refining was more energy efficient than HC refining for certain tensile index increase in all evaluated combinations. The highest energy efficiency was attained when LC refining was utilized in main line, but the difference was small compared to application on reject. Much higher specific energy was applied on reject pulp, but since the reject share was only around 30%, the LC refining specific energy, based on main line production, was around 80 kWh/air dry ton (adt) whereas up to 180 kWh/adt was applied in main line.

    The combination of DD chip refining and LC refining had the highest energy efficiency (tensile index at certain specific energy consumption) and produced pulp with somewhat lower fibre length but higher light scattering and lower shives content compared to a line with only SD HC refining. Thus, for printing papers it seems beneficial to combine LC refining with high intensity HC chip refining. All processes with LC refining had lower light scattering and fibre length compared to the corresponding system with only HC refining.

  • 256.
    Sandberg, Christer
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Holmen Paper.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. StoraEnso.
    Energy efficiency in mechanical pulping2017Konferensbidrag (Refereegranskat)
  • 257.
    Sandberg, Christer
    et al.
    Holmen Paper AB, Norrköping.
    Nelsson, Erik
    HEAD Engineering AB, Nacka strand.
    Engberg, Birgitta A.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Berg, Jan-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Effects of chip pretreatment and feeding segments on specific energy and pulp quality in TMP production2018Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, nr 3, s. 448-459Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Increased wood softening and refining intensity have earlier been utilized to improve refining efficiency in mechanical pulping. We have evaluated a combination of increased softening by low dose sulphite chip pretreatment and increased intensity by feeding segment design in a TMP line for production of high quality printing papers. Norway spruce wood chips were preheated, compressed in an Impressafiner and impregnated with water or sodium sulphite solutions (Na2SO3 charges 3.6 and 7.2 kg/t). Chips were refined in two parallel 68" double disc refiners using two different refining conditions: standard bidirectional segments at normal production rate (9 t/h) and feeding segments at increased production rate (11.1-12.1 t/h). The feeding segments enabled a 30 % increase in production rate. Refining with feeding segments at 12.1 t/h production rate combined with chip pretreatment with 3.6 kg/t sodium sulphite reduced the specific energy 360 kWh/t (19 %) compared to refining with standard segments and no pretreatment. Pulp properties were similar for the two configurations. The combination of feeding segments and chip pretreatment with water reduced the specific energy 180 kWh/t (9 %). Implementation of most of the technology presented has reduced the electrical energy use for the mill by approximately 80 GWh/year.

  • 258.
    Seppälä, Markus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ånga och fjärrvärme från solen: Dimensionering av en värmeväxlarcentral2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta examensarbete har utförts på uppdrag av Absolicon AB, Härnö-sand, med syftet att lösa effektöverföringen från ett planerat solfångarfält. Solfångarfältet ska bestå av en ny typ av koncentrerande solfångare. An-läggningen får en driftstemperatur på 160 grader Celsius för att möjlig-göra demonstration av ångproduktion men effektöverföringen sker dock i huvudsak till ett fjärrvärmenät. Följande konkreta frågeställningar for-mulerades utifrån det övergripande syftet:1. Vilka fysikaliska egenskaper har den tänkta värmebärarfluiden vid avsedd driftstemperatur?2. Vilken flödeskapacitet behöver värmeväxlarcentralen ha för att överföra solfångarfältets effekt?3. Kan en befintlig mobil värmeväxlarcentral som redan finns använ-das för att överföra denna effekt?4. Hur bör effektöverföringen till fjärrvärmenätet genomföras?5. Hur bör anläggningens fluidtemperaturer styras?6. Vilka specifika komponenter behövs för den nya värmeväxlarcen-tralen?7. Hur kan ångproduktionen demonstreras?Metoder som användes för att besvara frågeställningarna var litteratur-studier och beräkningar för dimensionering av en värmeväxlarcentral, undersökning av den befintliga värmeväxlarcentralen, kartläggning av förhållandena på platsen för anläggningen och teoretiskt konstruktions-arbete. Resultatet visar att den befintliga värmeväxlarcentralen inte har flödeskapacitet att överföra effekten från det planerade solfångarfältet och därför dimensionerades en ny värmeväxlarcentral för uppgiften. Re-sultatet innefattar också en utredning på möjliga anslutningar av värme-växlarcentralen till fjärrvärmenätet samt ett förslag på en anläggning som möjliggör demonstration av ångproduktion.

  • 259.
    Sheibani, Amjad
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Energieffektivisering och energibalansberäkningar samt förbättrings förslag på nyproducerade lägenheter.2017Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet: Med arbetet är att utreda en fastighets klimatskal och energiförbrukning med hjälp av energibalansberäkningar. Målet: med rapporten är att upplysa hur fastighetens energiförbrukning kan beskrivas utifrån transmission och ventialtionsberäkningar. Avgränsning: avgränsning till att beräkna energibalanser till en fastighet som består av 46 lägenheter och nästan alla beräkningar är manuella, där energiförbrukningen beräknas. Detta ger en bra överblick över vad som behövs förbättras i dessa lägenheter. Teori: Information om fatigheten samlades in vid ett platsbesök där både in- och utsida undersöktes samt via samtal med företaget PEPA som byggde fastigheten. En ytterligare undersökning gjordes där information om området, byggår, tidigare års energideklarationer och energiberäkningar insamlades samt vilka energibesparingsåtgärder som gjorts i dagsläget. Med hjälp av litteratur, webbaserade källor och artiklar har arbetat granskat och bearbetat till ett sakligt slutresultat.

    Metod: En studie av litteratur undersökning i ämnet har utförts för att hitta relevant och nödvändig information inom området. För att undersöka fastighetens energianvändning, uppvärmning och konstruktion så har ett flertal fastighetsbesök gjorts.

    Utförande: Har undersöks fastighetens energiförbrukning och med hjälp av energibalansförbrukningen upplysas fastighetens elanvändning, fjärrvärme, tappvarmvatten, transmissionsförluster och ventilationsförluster etc. Denna studie har gjorts för att utreda investeringskostnader för solceller på fasader och på taket på en byggnad. Dessutom har studien utförs för att se om dessa bidrar till att minska fastighetens årskostnader och energiförbrukning under ett år.

    Resultat: I resultatdelen visas transmissionsförluster med ett värde på 330 MWh/år och köldbryggor som är 20 % av totala transmissionsförluster. Medan ventilationsförluster är 270 MWh, där luftläckage är 379 W/C. Sammanställningen av U-värde för transmissionsförluster är 0,35 W/m2. C och boverkets krav 0,4 W/m2.C, detta innebär att U-värde uppfyller boverkets krav. Värmeenergi behovet till fastigheten är 647 MWh, medan värmeeffektbehov är 228 kW, där energianvändningen och gränsvärde är 103 kWh/m2.år

    Diskussion: Syftet med arbetet var att studera och titta närmare på vilka energieffektiviserande åtgärder som finns till huset och vilka åtgärder som kan ge ett bra resultat, för att minska energi förbrukningen och ge besparing. Undersökningen har utförts genom manuella beräkningar, via samtal med personal från HSB på plats i Östersund och Sundsvall. Undersökningen har även utförts genom att samla in alla byggnadsritningar, genom kurslitteratur, Boverket, ISO standard samt genom diskussioner med företag som PEAB som har bidragit med viktig information. Ett schablonblad som erhölls av HSB har används vid beräkningar som exempelvis till dörrar, fönster, ytterdörrar, balkonger samt köldbryggor Slutsats: Transmissionsberäkningarna visar att värmegenomgångskoefficienten har ett rimligt värde, vilket är bra i jämförelse med boverkets krav på 0,4 W/m²·K. Vidare visas det i rapporten att ventilationen som används i fastigheten är bra, då FTX system används och värmeåtervinning sker. En annan åtgärd i rapporten, är en beräkning som visar en sänkning av inomhus temperaturen och är på så sätt lönsam. Den sista åtgärden som har utförts är snålspolande kranar som visar ett bra reslutat på en besparing året runt. Solcellernas beräkningar visar två olika resultat, de som är belägna på taket har en livslängd på 12 år och är mer rimlig än de som är på fasaden som har livslängd på 30 år.

  • 260.
    Singh, P.
    et al.
    CQC, University of Coimbra, Department of Chemistry, 3004-535 Coimbra, Portugal.
    Medronho, B.
    Faculty of Sciences and Technology (MeditBio), Ed. 8, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
    Alves, L.
    CQC, University of Coimbra, Department of Chemistry, 3004-535 Coimbra, Portugal.
    da Silva, G. J.
    Faculty of Pharmacy and Center for Neurosciences and Cell Biology, University of Coimbra, Health Sciences Campus, 3000-5548 Coimbra, Portugal.
    Miguel, M. G.
    CQC, University of Coimbra, Department of Chemistry, 3004-535 Coimbra, Portugal.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. CQC, University of Coimbra, Department of Chemistry, 3004-535 Coimbra, Portugal.
    Development of carboxymethyl cellulose-chitosan hybrid micro- and macroparticles for encapsulation of probiotic bacteria2017Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 175, s. 87-95Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel carboxymethyl cellulose-chitosan (CMC-Cht) hybrid micro- and macroparticles were successfully prepared in aqueous media either by drop-wise addition or via nozzle-spray methods. The systems were either physically or chemically crosslinked using genipin as the reticulation agent. The macroparticles (ca. 2 mm) formed are found to be essentially of the core-shell type, while the microparticles (ca. 5 μm) are apparently homogeneous. The crosslinked particles are robust, thermally resistant and less sensitive to pH changes. On the other hand, the physical systems are pH sensitive presenting a remarkable swelling at pH 7.4, while little swelling is observed at pH 2.4. Furthermore, model probiotic bacteria (Lactobacillus rhamnosus GG) was for the first time successfully encapsulated in the CMC-Cht based particles with acceptable viability count. Overall, the systems developed are highly promising for probiotic encapsulation and potential delivery in the intestinal tract with the purpose of modulating gut microbiota and improving human health.

  • 261.
    Singh, Poonam
    et al.
    Univ Coimbra, Dept Chem, Coimbra, Portugal.
    Medronho, Bruno
    Univ Algarve, Fac Sci & Technol MeditBio, Faro, Portugal.
    dos Santos, Tiago
    i3S, Porto, Portugal; Univ Porto, INEB Inst Engn Biomed, Porto, Portugal.
    Nunes-Correia, Isabel
    Univ Coimbra, CNC Ctr Neurosci & Cell Biol, Coimbra, Portugal.
    Granja, Pedro
    i3S, Porto, Portugal; Univ Porto, INEB Inst Engn Biomed, Porto, Portugal; Univ Porto, ICBAS, Porto, Portugal.
    Miguel, Maria G.
    Univ Coimbra, Dept Chem, Coimbra, Portugal.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Univ Coimbra, Dept Chem, Coimbra, Portugal.
    On the viability, cytotoxicity and stability of probiotic bacteria entrapped in cellulose-based particles2018Ingår i: Food Hydrocolloids, ISSN 0268-005X, E-ISSN 1873-7137, Vol. 82, s. 457-465Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Probiotics are increasingly gaining popularity in vast food applications due to their recognized health benefits to the host. However, their passage through the gastrointestinal (GI) tract is not smooth and a significant number of physiological barriers (e.g. low pH, bile salts, enzymes, peristaltic movements, etc.) may considerably affect their viability. The entrapment of probiotics in protective matrices, such as hydrogel particles, is a feasible approach to minimize cell death. Therefore, in this work, novel cellulose/chitosan-based particles have been developed to entrap model probiotic Lactobacillus rhamnosus GG. The particle aging, storing and stability was studied at different temperatures and in simulated GI fluids with and without cross-linking agents or protein and lipid additives. Moreover, the effect of the particles on a model intestinal cell line was evaluated. The formulations containing casein displayed the best bacterial survival/culturability when exposed to the GI fluids. Overall, the storage and viability of the probiotics were observed to be improved in the different biopolymer-based systems, generally presenting a low toxicity profile to the cell line. Thus, the particles, which were based on carboxymethyl cellulose and chitosan, may be regarded as interesting matrices for probiotic encapsulation and delivery in food products. 

  • 262.
    Singh, Poonam
    et al.
    University of Coimbra, Department of Chemistry, Coimbra, Portugal.
    Medronho, Bruno
    University of Algarve, Campus de Gambelas, Faro, Portugal.
    Valente, Artur J. M.
    University of Coimbra, Department of Chemistry, Coimbra, Portugal.
    Miguel, Maria G.
    University of Coimbra, Department of Chemistry, Coimbra, Portugal.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Exploring the prebiotic effect of cyclodextrins on probiotic bacteria entrapped in carboxymetyl cellulose-chitosan particles2018Ingår i: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 168, nr August 2018, s. 156-162Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work the prebiotic effect of different cyclodextrins, CDs, on the viability of model probiotic bacteria (Lactobacillus rhamnosus GG) encapsulated in carboxymethyl cellulose-chitosan (CMC-Cht) hybrid particles was studied. All the CDs tested were observed to considerably improve the viability (quantitatively like common prebiotics, such as corn starch) and encapsulation efficiency when compared to the CD-free particles, as inferred by plate counting method and fluorescence microscopy. The SEM data suggests that the morphology of the particles, the roughness of the surface and porosity, are dependent on the type of CD and may reflect different interactions between the CDs and the matrix components. The aging and stability of the samples with and without β-CD were further evaluated. Remarkably, the viability count of the CD-doped samples was still reasonably high after one month storage at room temperature with acceptable values for practical uses. Moreover, when the CMC-Cht particles were exposed to in vitro simulated digestion fluids, the cell survival was much enhanced when the particles contained β-CD. 

  • 263.
    Sjöberg, Natalia
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    (S)-1,2,3,4-tetrahydroisoquinoline derived chiral auxiliary in diastereoselective alkylationManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A novel chiral auxiliary (S)-2-(1,2,3,4-tetrahydroisoquinolin-3-yl)propan-2-ol 1 was synthesized from (S)-1,2,3,4-tetrahydroisoquinoline acid 2. Alkylation of the propanoylated chiral auxiliary (S)-1-(3-(2-hydroxypropan-2-yl)-3,4-dihydroisoquinolin-2(1H)-yl)-propan-1-one 3 with benzyl bromide or n-butyl iodide caused moderate to high conversion (42–99%) and moderate diastereomeric ratios (up to 89:11). The major diastereomer obtained in the reaction with benzyl bromide was (R,S). Some of the reactions were carried out with LiCl as an enolate coordinating agent, which affected conversion and diastereomeric ratio negatively. 

  • 264.
    Sjöberg, Natalia
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Structure determination and synthesis of natural extracts. (S)-1,2,3,4-tetrahydroisoquinoline derived chiral auxiliary in diastereoselective alkylation: Licentiate thesisManuskript (preprint) (Övrigt vetenskapligt)
  • 265.
    Strömsten, Marcus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Förutsättningar för absorptionskyla i Härnösand: En undersökning av tekniken samt en investeringskalkyl2016Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Denna studie undersöker absorptionstekniken i syfte att ta reda på förutsättningarna för absorptionskyla i Härnösand. En investeringskalkyl har genomförts för att bedöma lönsamheten. I huvudsak har en litteraturstudie genomförts och för investeringskalkylen har nuvärdesmetoden använts samt att produktspecifikationer har efterfrågats från de största leverantörerna i världen. Resultatet visar att det finns två typer av kommersialiserade absorptionskylmaskiner på marknaden, varav den ena är tillämpbar för decentraliserad kylproduktion i fjärrvärmenät vid temperaturer kring 75 °C, och den andra för högre temperaturer kring 120-150 °C och lämpar sig därmed inte för decentraliserad kylproduktion. Det forskas och utvecklas kring andra mer avancerade tekniker och investeringskalkylen visar att en investering är lönsam beroende på storleken på absorptionskylmaskinen och försäljningspriset på kylan som levereras till kunden. Slutsatsen är att säljargument och en motivering måste tas fram varför kunden ska välja att få sin kyla levererad via en absorptionskylmaskin istället för en kompressorkylmaskin.

  • 266.
    Svanedal, Ida
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Fundamental Characterization and Technical Aspects of a Chelating Surfactant2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The purpose of this study was to investigate the fundamental characteristics of a chelating surfactant in terms of solution behaviour, chelation of divalent metal ions, and interaction in mixtures with different foaming agents and divalent metal ion, as well as examining its prospects in some practical applications. Chelating surfactants are functional molecules, with both surface active and chelating properties, which are water soluble and therefore suitable for chelation in many aqueous environments. The dual functionality offers the possibility to recover the chelating surfactant as well as the metals.

    The DTPA (diethylenetriaminepentaacetic acid)-based chelating surfactant 4-C12-DTPA (2-dodecyldiethylenetriaminepentaacetic acid) was synthesized at Mid Sweden University. In the absence of metal ions, all eight donor atoms in the headgroup of 4-C12-DTPA are titrating and the headgroup charge can be tuned from +3 to -5 by altering the pH. The solution properties, studied by surface tension measurements and NMR diffusometry, were consequently found strongly pH dependent. pH measurements of chelating surfactant solutions as a function of concentration was used to extract information regarding the interaction between surfactants in the aggregation process.

    Small differences in the conditional stability constants (log K) between coordination complexes of DTPA and 4-C12-DTPA, determined by competition measurements utilizing electrospray ionization mass spectrometry (ESI-MS), indicated that the hydrocarbon tail only affected the chelating ability of the headgroup to a limited extent. This was further confirmed in hydrogen peroxide bleaching of thermomechanical pulp (TMP) treated with 4-C12-DTPA.

    Interaction parameters for mixed systems of 4-C12-DTPA and different foaming agents were calculated following the approach of Rubingh’s regular solution theory. The mixtures were also examined with addition of divalent metal ions in equimolar ratio to the chelating surfactant. Strong correlation was found between the interaction parameter and the phase transfer efficiency of Ni2+ ions during flotations. Furthermore, a significant difference in log K between different metal complexes with 4-C12-DTPA enabled selective recovery of the metal ion with the highest log K.

    The findings in this study contribute to the understanding of the fundamental characteristics of chelating surfactants, which can be further utilized in practical applications.

  • 267.
    Svanedal, Ida
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Andersson, Fredrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Satija, Sushil K.
    NIST, Ctr Neutron Res, 100 Bur Dr,MS 6100, Gaithersburg, MD 20899 USA.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Univ Coimbra, Dept Chem, Rua Larga, P-3004535 Coimbra, Portugal.
    Rennie, Adrian R.
    Uppsala Univ, Mat Phys, Uppsala, Sweden; Uppsala Univ, Ctr Neutron Scattering, Angstrom Lab, Uppsala, Sweden.
    Molecular Organization of an Adsorbed Layer: A Zwitterionic, pH-Sensitive Surfactant at the Air/Water Interface2016Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, nr 42, s. 10936-10945Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Neutron and X-ray reflection measurements have been used to study the structure of the adsorbed layer of a chelating surfactant at the air/liquid interface. The chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (C-12-DTPA) has a large headgroup containing eight donor atoms that can participate in the coordination of metal ions. The donor atoms are also titrating, resulting in an amphoteric surfactant that can adopt a number of differently charged species depending on the pH. Very strong coordination complexes are formed with metal ions, where the metal ion can be considered as part of the surfactant structure, in contrast to monovalent cations that act as regular counterions to the negative net charge. Adsorption was investigated over a large concentration interval, from well below the critical micelle concentration (cmc) to five times the cmc. The most striking result is the maximum in the surface excess found around the cmc, winch is consistent with previous indications from surface tension measurements. Adding divalent metal ions has a limited effect on the adsorption at the air/liquid interface. The reason is the coordination of the metal ion, resulting in compensating deprotonation of the complex. Small variations in the headgroup area of different metal complexes are found, correlating to the conditional stability constants. Adding sodium chloride has a significant effect on the adsorption behavior, and the results indicate that the protonation equilibrium is more important than the ionic strength effects. From combined fits of the neutron and X-ray data, a model that consists of a thick headgroup region and a relatively thin dehydrated tail region is found, and it indicates that the tails are not fully extended and that the limiting area per molecule is determined by the bulky headgroup.

  • 268.
    Svanedal, Ida
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Boija, Susanne
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Almesåker, Ann
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Persson, Gerd
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Andersson, Fredrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bylund, Dan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Metal Ion Coordination, Conditional Stability Constants and Solution Behavior of Chelating Surfactant Metal Complexes2014Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 30, nr 16, s. 4605-4612Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coordination complexes of some divalent metal ions with the DTPA (diethylenetriaminepentaacetic acid)-based chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) have been examined in terms of chelation and solution behavior. The headgroup of 4-C 12-DTPA contains eight donor atoms that can participate in the coordination of a metal ion. Conditional stability constants for five transition metal complexes with 4-C12-DTPA were determined by competition measurements between 4-C12-DTPA and DTPA, using electrospray ionization mass spectrometry (ESI-MS). Small differences in the relative strength between the coordination complexes of DTPA and 4-C12-DTPA indicated that the hydrocarbon tail only affected the chelating ability of the headgroup to a limited extent. The coordination of Cu2+ ions was investigated in particular, using UV-visible spectroscopy. By constructing Job's plots, it was found that 4-C12-DTPA could coordinate up to two Cu2+ ions. Surface tension measurements and NMR diffusometry showed that the coordination of metal ions affected the solution behavior of 4-C 12-DTPA, but there were no specific trends between the studied divalent metal complexes. Generally, the effects of the metal ion coordination could be linked to the neutralization of the headgroup charge of 4-C 12-DTPA, and the resulting reduced electrostatic repulsions between adjacent surfactants in micelles and monolayers. The pH vs concentration plots, on the other hand, showed a distinct difference between 4-C12-DTPA complexes of the alkaline earth metals and the transition metals. This was explained by the difference in coordination between the two groups of metal ions, as predicted by the hard and soft acid and base (HSAB) theory.

  • 269.
    Svanedal, Ida
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Boija, Susanne
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Headgroup interactions and ion flotation efficiency in mixtures of a chelating surfactant, different foaming agents and divalent metal ions2014Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 30, nr 22, s. 6331-6338Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The correlation between interaction parameters and ion flotation efficiency in mixtures of chelating surfactant metal complexes and different foaming agents was investigated. We have recently shown that chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C-12-DTPA) forms strong coordination complexes with divalent metal ions, and this can be utilized in ion flotation. Interaction parameters for mixed micelles and mixed monolayer formation for Mg2+ and Ni2+ complexes with the chelating surfactant 4-C-12-DTPA and different foaming agents were calculated by Rubingh's regular solution theory. Parameters for the calculations were extracted from surface tension measurements and NMR diffusometry. The effects of metal ion coordination on the interactions between 4-C-12-DTPA and the foaming agents could be linked to a previously established difference in coordination chemistry between the examined metal ions. As can be expected from mixtures of amphoteric surfactants, the interactions were strongly pH-dependent. Strong correlation was found between interaction parameter beta(sigma)for mixed monolayer formation and the phase-transfer efficiency of Ni2+ complexes with 4-C-12-DTPA during flotation in a customized flotation cell. In a mixture of Cu(2+)and Zn2+, the significant difference in conditional stability constants (log K) between the metal complexes was utilized to selectively recover the metal complex with the highest log K (Cu2+) by ion flotation. Flotation experiments in an excess concentration of metal ions confirmed the coordination of more than one metal ion to the headgroup of 4-C-12-DTPA.

  • 270.
    Svanedal, Ida
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Persson, Gerd
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Anomalies in Solution Behavior of an Alkyl Aminopolycarboxylic Chelating Surfactant2013Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, nr 45, s. 13708-13716Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The solution behavior of a DTPA (diethylenetriaminepentaacetic acid)-based chelating surfactant, 4-C12-DTPA, has beenstudied by tensiometry and NMR diffusometry. In the absence of metalions, the eight donor atoms in the headgroup are titrating, and thecharge of the headgroup can thus be tuned by altering the pH. 4-C12-DTPA changes from cationic at very low pH, over a number ofzwitterionic species as the pH is increased, and eventually becomesanionic at high pH. Around the isoelectric point, the chelatingsurfactant precipitated. The solution properties, studied above thesolubility gap, were found strongly pH dependent. When increasing theamount of negative charges in the headgroup, by increasing the pH, theadsorption efficiency was reduced and the cmc was increased. Anoptimum in surface tension reduction was found at pH 5, due to aproper balance between protonated and dissociated groups. Anomaliesbetween surface tension measurements and NMR diffusometry in determination of cmc revealed a more complex relationbetween surface tension, surface coverage, and cmc than usually considered, which is not in line with the common interpretationof the Gibbs adsorption equation. At some of the investigated pH levels, measurements of bulk pH could confirm the location ofcmc, due to the increased protonation of micelles compared to monomers in solution. The adsorption of monomers to the air−water interface showed unusually slow time dependence, evident from decreasing surface tension for several hours. This isexplained by rearrangements of the large head groups to reduce the headgroup area and increase the packing parameter.

  • 271.
    Svanedal, Ida
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Persson, Gerd
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Interactions in Mixed Micellar Systems of an Amphoteric Chelating Surfactant and Ionic Surfactants2014Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 30, nr 5, s. 1250-1256Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mixtures of ionic surfactants and the chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) have been examined in terms of interactions in mixed micellar systems. The amphoteric 4-C12-DTPA is zwitterionic with a negative net charge at the studied pH levels. The investigated ionic surfactants were the cationic dodecyltrimethylammonium chloride (DoTAC), the anionic sodium dodecyl sulfate (SDS), and the zwitterionic dimethyldodecylamine-N-oxide (DDAO). The surfactants all have the same hydrophobic chain lengths, and the results are evaluated in terms of headgroup interactions. 4-C12-DTPA interacts with different ionic surfactants by accepting or donating protons to the aqueous solution to increase the attractive interactions between the two surfactants; i.e., the protonation equilibrium of 4-C12-DTPA is shifted in different directions depending on whether there are predominant repulsions between positively or negatively charged groups in the mixed micelles. This was monitored by measuring pH vs concentration in the mixed systems. By measuring the pH, it was also possible to study the shift in the protonation equilibrium at increasing concentration, as the composition in the micelles approaches the composition in the total solution. Following the approach of Rubingh's regular solution theory, the interaction parameter β for mixed micelle formation was calculated from the cmc values determined by NMR diffusometry. Synergism in mixed micelle formation and negative β parameters were found in all of the investigated systems. As expected, the most negative β parameter was found in the mixture with DoTAC, followed by DDAO and SDS. The self-diffusion in the 4-C12-DTPA/DoTAC system was also discussed. The self-diffusion coefficient vs concentration plots show two distinctly different curves, depending on the surfactant that is present in excess.

  • 272.
    Svensson, G. P.
    et al.
    Department of Biology, Lund University, 223 62 Lund, Sweden .
    Gündüz, E. A.
    Department of Biology, Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey .
    Sjöberg, Natalia
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Lassance, J. -M
    Department of Biology, Lund University, 223 62 Lund, Sweden .
    Wang, H. -L
    Department of Biology, Lund University, 223 62 Lund, Sweden .
    Löfstedt, C.
    Department of Biology, Lund University, 223 62 Lund, Sweden .
    Anderbrant, O.
    Department of Biology, Lund University, 223 62 Lund, Sweden .
    Identification, Synthesis, and Behavioral Activity of 5,11-Dimethylpentacosane, A Novel Sex Pheromone Component of the Greater Wax Moth, Galleria Mellonella (L.)2014Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 40, nr 4, s. 387-395Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The greater wax moth, Galleria mellonella (L.), is a serious and widespread pest of the honeybee, Apis mellifera L. In contrast to most moths, for which long-range mate finding is mediated by female-produced sex pheromones, G. mellonella males attract conspecific females over long distances by emitting large amounts of a characteristic scent in combination with bursts of ultrasonic calls. The male scent for this species was previously identified as a blend of nonanal and undecanal. When these compounds were bioassayed, characteristic short-range sexual behavior, including wing fanning, was triggered in conspecific females, but the aldehyde blend failed to elicit attraction over longer distances. We identified, via analysis and synthesis, a third male-specific compound, 5,11-dimethylpentacosane. We show that it acts as a behavioral synergist to the aldehydes. In wind tunnel experiments, very few female moths responded to the aldehyde blend or to 5,11-dimethylpentacosane tested separately, but consistently showed orientation and source contact when a combination of all three compounds was applied. The level of attraction to the three-component mixture was still lower than that to male extract, indicating that the composition of compounds in the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. The identification of 5,11-dimethylpentacosane is an important step for the development of an efficient long-range attractant that will be integrated with other environmentally safe strategies to reduce damage to beehives caused by wax moths. © 2014 Springer Science+Business Media New York.

  • 273.
    Topic, Sinisa
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Effektivisering av rökgaskondensorn: En undersökning av att kyla inkommande fjärrvärmeretur2016Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This project has been executed as an assignment by Sundsvall Energi AB with the purpose of increasing the efficiency of the flue gas condenser by cooling the incoming district heating return before the flue gas condensing exchanger. The flue gas condenser is part of the heat production. The first production unit is the waste boiler where the steam can be distributed between production of electricity and heat production, depending on how large the costumers needs of electricity and heat are. When the customers’ needs are less than Korstaverkets maximum production, an addition of heat from the flue gas condenser means that a larger portion of the steam can go to the turbine and increase the production of electricity. When the customer’s needs are larger than Korstaverkets maximum capacity, a contribution from the flue gas condenser means that Korstaverket can purchase less heat from SCA (Ostrand and Ortviken). The benefit of cooling the district heating return is that more heat and electricity can be produced.

    In the early stages of the project, literature and the Internet were used to get a basic understanding of the assignment. The supervisor and the staff at Korsta have given drawings and data of the power plant process, and also given advice regarding the process. Product data sheets from suppliers have been used for doing calculations and for getting information about the construction. Scientific articles and literature were used to get facts and formulas. The study has shown that the additional cooling of the district heating return has contributed to an increased efficiency of the flue gas condenser, from 0.9 % with an average flow of the deionized water to 17.2 % with a maximum flow of the deionized water. 

    The exam work has shown how complicated an energy system can be. The process can be more complicated then what the drawings show, because a profitable solution in one part of the process can lead to deterioration in another part of the process. The calculations show that the major factor that’s influencing the cooling is the deionized waters flow into the new heat exchanger. The repayment period can get short. High flows generate a profit after only a couple of months, while low flows of 1 liter/second take up to 3.5 years with KE Therms brazed heat exchangers and 2.5 years with Tranters gasketed heat exchangers.

     

  • 274.
    Tran, Khanh-Quang
    et al.
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
    Klemsdal, Aksel Junge
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sandquist, Judit
    SINTEF Energy Research, Trondheim, Norway.
    Wang, Liang
    SINTEF Energy Research, Trondheim, Norway.
    Skreiberg, Øyvind
    SINTEF Energy Research, Trondheim, Norway.
    Fast Hydrothermal Liquefaction of Native and Torrefied Wood2017Ingår i: Energy Procedia, Elsevier, 2017, Vol. 105, s. 218-223Konferensbidrag (Refereegranskat)
    Abstract [en]

    The work presented in this paper aimed to examine the effect of heating rate on the bio-crude yield of wood hydrothermal liquefaction. Three different heating methods were developed, resulting in heating rates ranging from 66°C/min to 179°C/min. The experiments were conducted using Norway spruce wood as feedstock at an operation temperature of 350°C and with a total reaction time of 15 minutes. The bio-crude product was collected and separated using dichloromethane (DCM) as solvent and a centrifugal separator. The results confirm that heating rate has a clear positive effect on the bio-crude oil yield, increasing from 18.9 wt% for the lower heating rate of 66°C/min to 35.8 wt% for the higher heating rate of 179°C/min. It is also shown that the effect of feedstock pre-treatment via torrefaction on the bio-crude yield is negative.

  • 275.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Complex Matters: Things that matter2016Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, nr 2, s. 213-218Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Complex matters are ubiquitous in everyday life. It is also common in almost every aspect of pulp and paper operation. These are often the problems that have been outstanding for many years. Complexity science is emerging. This is a science of a highly interactive and hierarchical system of a large number of "elements". Elements can be actual materials, such as fibres, colloids, pigments, and cells, or more abstract objects, such as consumers and investors. Complexity science has originally grown from mathematics, computer science, statistical physics, and theoretical biology, but has now spread over many fields of science, engineering, sociology, and economics. In this review we take a few example problems encountered in paper chemistry and paper physics research, and look at how those problems can be seen from the complex science perspective. The objective is to introduce new concepts and approaches of complexity science to solve seemingly very difficult problems in pulp and paper industry. We suggest that many of the challenges that the industry is facing today are in fact the problems of complex systems.

  • 276.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Page'S Theory Of Tensile Strength And The Stress-Strain Properties Of Paper2018Ingår i: Journal of Science & Technology for Forest Products and Processes, ISSN 1927-6311, E-ISSN 1927-632X, Vol. 6, nr 6, s. 13-17Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the most well-known theories in the area of paper is probably Page's theory of tensile strength. The article was published in Tappi Journal in 1969 [1], and written, in a very articulate way, to explain how tensile strength is determined by fibre properties and inter-fibre bond properties. Because this is the area of great interest to papermakers and pulp manufacturers, the theory has attracted great attention since then. In particular, many paper chemists were fascinated by this intuitive way of describing the relationships between bond and fibre parameters so that the theory became a theoretical foundation for many investigations of dry/wet strength agents. Interestingly, Derek himself was not completely happy with the popularity of the theory. As he noted in his paper, it is a semi-empirical theory, intended to provide a picture of the essential factors affecting tensile strength, but not as an analytical equation to predict some of the model parameters. (We will briefly touch upon Derek's concerns later.) In the late 70s, Derek and his colleague, Raj Seth, another legendary scientist from Pulp and Paper Research Institute of Canada (PAPRICAN, currently, FPlnnovations), launched investigations of the tensile stress-strain curves of paper [2,3,4]. The work depicted complex interplays among network structures, fibre properties and inter-fibre bond properties, again, in a very articulate way. This paper has also influenced a number of studies by younger researchers in the areas of paper mechanics and network mechanics. In this short article, I will try to describe how Derek tackled the problem of understanding the tensile properties of paper in the simplest and most articulate way. Based on this review, I will comment on how far we have gone from his ideas, and try to define some outstanding questions.

  • 277.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Performance-based Design of Corrugated Board and Box2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Currently corrugated box and board are designed and manufactured according to the strength specs, such as BCT, SCCT, RCT and SCT. As the market moves toward greener packaging (less-waste, less-cost, and less carbon footprint), the box and board manufacturers are trying to meet both these demands and the strength specs. However, the task is becoming increasingly difficult, because this subject is not new and the industry in fact has already worked on it for decades. The basic question today is what else we can do to improve/maintain strength with reduced weight (and reduced cost).

  • 278.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Variability, non-uniformity, and complexity: From product to process2013Ingår i: Advances in pulp and paper research, Cambridge 2013, Bury, UK: Pulp and Paper Fundamental Research Society , 2013Konferensbidrag (Refereegranskat)
  • 279.
    Uesaka, Tetsu
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Gurnagul, Norayr
    FPInnovat, Pointe Claire, PQ, Canada.
    Keynote Speech By Derek Page At The 2010 Progress In Paper Physics Seminar In Montreal, Canada2018Ingår i: Journal of Science & Technology for Forest Products and Processes, ISSN 1927-6311, E-ISSN 1927-632X, Vol. 6, nr 6, s. 6-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This keynote speech was given at the "Progress in Paper Physics Seminar", which was held in Montreal, Canada in 2010. This was Derek's last speech at an international paper physics conference. The organising committee asked him to send a message to young researchers in the paper physics community. The topic of his talk was "the weakest link in chain" which gives advice that is still timely for researchers that want to make a real difference in the forest products industry. This paper is based on his speaker notes which we were fortunate to find.

  • 280.
    Vallin, Joel
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Åström, Carl
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Energieffektivisering av Midlanda flygplats: Energikartläggning och energieffektivisering av Midlanda terminalbyggnad2016Självständigt arbete på avancerad nivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta är ett examensarbete med inriktning på energieffektivisering av Sundsvall Timrå Airport på C-nivå. Europeiska unionen och Europa parlamentet har satt som mål att till 2020 ska energianvändningen minska med 20 % och komma från förnybara energikällor. Äldre byggnader behöver energieffektiviseras och det kan handla om att tilläggsisolering, byte av uppvärmningssystem, tidsstyrning av ventilation, byte av fönster och byte av belysning. Målet med denna studie har varit att ta fram energieffektiviserande åtgärder genom en energikartläggning av terminalens klimatskal genom transmissionsberäkningar och ventilationsberäkningar.  Ytterligare studier har gjorts för att utreda om solfångare kan bidra till att täcka tappvarmvattenbehovet under juni, juli och augusti. Rapporten har genomförts genom litteraturstudier, kontakt med personal på Midlanda, platsbesök, byggnadsritningar och ovärderlig dokumentation från kontaktperson Petra Schwartz. Transmissionsberäkningarna visar att terminalbyggnadens golv behöver tilläggsisoleras. En tilläggsisolering kommer att sänka energiförbrukningen med 13,7 % enligt beräkningar.  Vidare visar rapporten att ventilationen kan optimeras genom uppgradering av systemet med frekvensstyrd drift. Detta medför lägre flöden och kortare drifttider på ventilationen som bidrar till en minskad energiförbrukning med 18,5 %. Att installera solfångare för att täcka tappvarmvattenbehovet under sommarmånaderna är en alltför kostsam investering för att vara motiverad enligt beräkningar.  Våra beräkningar av en mindre solfångaranläggning för att täcka tappvarmvattenbehovet  ör den sålda värmen visar att detta inte heller är ekonomiskt motiverbart.

  • 281.
    Vickman, Tomas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Integration av solvärme med befintligt fjärrvärmesystem: Ett samarbete med HW hotell och restaurang2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    HW hotell och restaurang värms idag med fjärrvärme från Härnösands energi & miljö AB (HEMAB). Projektets mål är att undersöka möjligheten att kombinera fjärrvärmen med solvärme. Syftet är att visa om det är möjligt att sänka varmvattenkostnaden för verksamheter genom att kombinera befintlig fjärrvärme med solvärme. Solvärmesystemet ska vara dimensionerat så att återbetalningstiden blir så kort som möjligt. Som metod har en fallstudie på HW hotell och restaurang använts. I studien ingår insamling av information genom observation, mätning, intervjuer och litteraturstudier. Informationen har bearbetats och sammanställts till ett slutresultat. Förutsättningarna är att det finns 216 kvadratmeter tak som anses vara mycket lämpligt för solfångare och ytterligare 903 kvadratmeter som kan brukas vid behov. I källaren finns 13 kvadratmeter golvyta för ackumulatortankar där den maximala tankvolymen uppskattas till åtta kubikmeter. Solvärme kan enkelt kopplas ihop med fjärrvärmecentralen och då fungera som förvärmare av vattnet. Årsvärmebehovet är 155 megawattimmar varav 34 megawattimmar är tappvarmvatten. Överskottsvärme kan sommartid säljas till fjärrvärmeleverantören för 400 kronor per megawattimme. Solfångarna dimensioneras efter fastighetens sommarlast och kan stå för ungefär halva tappvarmvattenbehovet. Åtta olika solvärmesystem har jämförts i rapporten. Solfångarnas energiutbyte över året bestäms av globalstrålningens fördelning över året. Solvärmesystemen har olika årsenergiutbyte och investeringskostnader. Årsenergiutbytet ligger mellan 4 och 34 megawattimmar medan investeringskostnaden varierar från 88 560- till 370 291 kronor. Den årliga besparingen ligger mellan 2 825- och 18 288 kronor efter driftkostnader. Utan ränta är Svesol Favorit Max 18 den anläggning som har kortast återbetalningstid (11,6 år). Med en ränta på fem procent krävs 20,4 år att skriva av anläggningen. Därav avråds HW hotell och restaurang från att investera i solvärme.             

  • 282.
    Wallin, Erika
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    The Scents of Nature: Identification and Synthesis of Bioactive Compounds Used in Insect Communication2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Pest insects cause great financial losses in the forest and food industry every year. To fight these pests industries have used insecticides, which are sometimes harmful to nature and humans. One potential way of avoiding insecticides is the use of integrated pest management based on insect communication, which would offer species-specific methods for protecting forest and food resources. Insects use chemicals known as semiochemicals for both intra- and interspecies communication. By learning how insects use these semio-chemicals to talk to each other we can eavesdrop and mimic their communication for our benefit. One research area dealing with these questions is chemical ecology, which is an interdisciplinary area as knowledge in chemistry and biology is required. Collaborations between groups within and outside of Sweden are essential in order to make progress in this field of research.

    This thesis presents the identification and synthesis of semiochemicals from several insect species, most of which are considered to be pests. Synthesised compounds have been sent to collaboration partners around Sweden and Europe for biological evaluations.

    Studies of the African butterfly, Bicyclus anynana, have unravelled particular biological phenomena that may aid in the understanding of the Bicyclus genus, though recognizing individual species variation is crucial. In 2008 the putative male sex pheromone of B. anynana was determined to consist of three compounds: hexadecanal, (Z)-9-tetradecenol and 6,10,14-trimethylpentadecan-2-ol, and the specific stereoisomer for 6,10,14-trimethylpentadecan-2-ol has been determined in this thesis. The ratio of 6,10,14-trimethylpentadecan-2-ol and the corresponding ketone were investigated for seventeen Bicyclus species (including B. anynana) that live in overlapping regions in Africa. The stereochemistry was determined for most of the species and may provide a way to chemically distinguish them.

    The orchid bees, Euglossa spp, are important pollinators of many orchids in Central America. Insight about pollination and conservation of endangered orchid species may be possible by gathering more information about the Euglossa genus. Males of the Euglossa genus have pouch-like structures on their hind legs where they store compounds collected from their surroundings. 6,10,14-Trimethyl-pentadecan-2-one is a common component of leg extracts from Euglossa imperialis, E. crassipunctata and E. allosticta, the specific stereochemistry of which has been determined in this thesis. Another, different compound was found in high amounts in E. viridissima and its structure has been elucidated; several synthetic pathways are under investigation to obtain the target compound.

    Bed bugs (Cimex lectularius and C. hemipterus) are an ectoparasite that feed on human blood, and the number of reported infestations of these parasites has increased considerably during the last decade. Two 5th instar nymph-specific compounds, 4-oxo-hexenal and 4-oxo-octenal, were identified and synthesised.

    Utilizing domestic dogs (Canis lupus familiaris) in the identification of bed bug infestations has become popular during recent years. Their training is usually conducted using live bed bugs, however this thesis describes an alternative method of teaching dogs to find infestations. This alternative method is based on synthetic compounds and dogs trained in this manner have achieved a high positive indication rate.

    Two species of the tiny, Acacia leaf-eating insect pests in Australia known as thrips, Kladothrips nicolsoni and K. rugosus, have been investigated by means of larval extracts and have been shown to contain large amount of (Z)-3-dodecenoic acid which was synthesised and tested in bioassays.

    Fruit flies are common pests on fruit in almost every private household. Even though fruit flies has been investigated extensively, their chemical communication has not been completely elucidated. (Z)-4-undecenal was identified as a compound emitted by females, it was synthesised in high stereoisomeric purity and evaluated in biological assays.

  • 283.
    Wallin, Erika
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Andersson, Annica
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Chemical tools for training domestic dogs (Canis lupus familiaris) to detect bed bugsManuskript (preprint) (Övrigt vetenskapligt)
  • 284.
    Wallin, Erika
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    De Facci, Monica
    Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden .
    Anderbrant, Olle
    Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden .
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    (Z)-3-Dodecenoic Acid Is the Main Component of Full-Body n-Hexane Extracts from Two Acacia Gall-Inducing Thrips (Thysanoptera) and May Function as an Alarm Pheromone2014Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 69C, nr 7-8, s. 335-345Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A major interest in the gall-inducing thrips of Australia began with the discovery that some species have eusocial colonies. The origin of social castes remains one of the outstanding questions in evolutionary biology. The inference of the ancestral stage from study of solitary species is important to understanding the evolutionary history of semiochemicals in the social species. Here we investigated two solitary species, Kladothrips nicolsoni and K. rugosus. Whole body extracts revealed that (Z)-3-dodecenoic acid, here reported for the first time in a thrips species, is the main component. (Z)-3-Dodecenoic acid and (E)-3-dodecenoic acid were synthesized in high stereoisomeric purity (> 99.8 %) and exposed to K. nicolsoni 2nd-instar larvae in a contact chemoreception bioassay to test for potential bioactivity. Both isomers decreased the average time spent in the treated area per entry suggesting repellence at the tested dose. (Z)-3-Dodecenoic acid may function as alarm pheromone. (E)-3-Dodecenoic acid increased also the absolute change in direction of larvae compared to an n-hexane control and could potentially function as a repellent.

  • 285.
    Walter, K.
    et al.
    AkzoNobel Pulp and Performance Chemicals, Bohus, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp and Performance Chemicals, Bohus, Sweden.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Acid hydrogen peroxide treatment of Norway spruce TMP: The effect of chelated ferric ions2014Ingår i: International Mechanical Pulping Conference, IMPC 2014, Paper Engineer's Association (PI) , 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    The effect of treating thermomechanical pulp with Fenton chemistry was evaluated in a model study. Ferrous ions and chelated ferric ions were compared as catalysts while initial pH was varied. The results showed that a catalyst of ferrous sulphate had a greater impact on the pulp (increased total fibre charge and carbonyl groups, more dissolved organic material in filtrate) than ferric ions chelated with EDTA. If using ferric-EDG as catalyst, the hydrogen peroxide consumption was higher and more hydroxyl radicals were detected compared to if using ferrous sulphate. Ferric-EDG, however, gave similar or less effect on the pulp.

  • 286.
    Walter, Karin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    The use of Fenton chemistry for reducing the refining energy during TMP production: the effect of free ferrous and free or chelated ferric ions2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The potential of using acid hydrogen peroxide under Fenton conditions to lowerthe electrical energy consumed during the production of Black spruce (Piceamariana) thermomechanical pulp (TMP) was investigated in pilot scale. Thechemical system, which consisted of ferrous sulphate, hydrogen peroxide andoptionally an enhancer (such as a chelating agent), was evaluated as an inter-stagetreatment. The produced TMPs were thoroughly characterised in order to explainthe effect of the chemical system on fibre development and to be able to propose amechanism for the impact on refining energy reduction. The possibility to improvethe optical properties by washing, chelating and sodium dithionite or hydrogenperoxide bleaching the treated pulps was evaluated. The system of lignocellulosicmaterial, a Norway spruce (Picea abies) TMP, and Fenton chemistry was alsoevaluated in a model study to understand more about how conditions such as e.g.initial pH, dissolved organic material and reaction time affect the reactions.Ferrous and ferric ions (free and chelated) and different anions were evaluated.Moreover, it was examined whether hydroxyl radicals could be detected andmonitored.The results obtained in pilot scale showed that it is possible to significantly reducethe specific energy consumption by approximately 20% and 35% at a freenessvalue of 100 ml CSF or a tensile index of 45 Nm/g by using 1% and 2% hydrogenperoxide respectively. The energy reduction was obtained without any substantialchange to the fractional composition of the pulp, although tear strength wasslightly reduced, as were brightness and pulp yield. No major differences betweenthe reference pulp and the chemically treated pulps were found with respect tofibre length, width or cross-sectional dimensions. However, the acid hydrogenperoxide-treated pulps tended to have more collapsed fibres, higher flexibility, alarger specific surface area and a lower coarseness value. The yield lossiiiaccompanying the treatment was mainly a consequence of degradedhemicelluloses. It was also found that the total charge of the chemically treatedpulps was higher compared to the reference pulps; something that may haveinfluenced the softening behaviour of the fibre wall.A washing or chelating procedure could significantly reduce the metal ion contentof the chemically treated TMPs. The amount of iron could be further reduced to alevel similar to that of untreated pulps by performing a reducing agent-assistedchelating stage with dithionite. The discoloration could not, however, becompletely eliminated. The brightness decrease of the treated pulps was thereforenot only caused by the greater iron content in the pulp, but was also dependent onthe type of iron compound and/or other coloured compounds connected with theacid hydrogen peroxide treatment. Oxidative bleaching using hydrogen peroxidewas more effective than reductive bleaching using sodium dithionite in regainingthe brightness that was lost during the energy reductive treatment.From the model study and by using a chemiluminescence method, it could beconcluded that hydroxyl radicals were present in the system of Fenton chemicalsand lignocellulosic material (TMP). Initial pH, retention time, pulp consistency,type of catalyst (free or chelated) and dissolved organic material had an impact onthe reactions between TMP and acid hydrogen peroxide. Different anions(sulphate, nitrate and chloride) of ferric ion salt gave a similar catalytic effect.There appeared to be more reactions with the TMP when there was less dissolvedorganic material in the liquid phase from the start. A catalyst of ferrous sulphatehad a greater impact on the pulp (increased total fibre charge and carbonyl groups,more dissolved organic material in filtrate) than ferric ions chelated withethylenediaminetetraacetic acid at an initial pH of about 3-7. If using ferric-EDG(ethanol diglycinic acid) as catalyst, the measured effect on the pulp was similar orless compared to using ferrous sulphate. Ferric-EDG, however, gave higherhydrogen peroxide consumption and more detectable hydroxyl radicals than usingferrous sulphate (initial pH 5-8). It is likely that the iron catalyst must bind to theTMP, or be in close proximity to it, for the hydroxyl radicals to be able to react withthe material.A mechanism was proposed: the hydroxyl radicals generated in the Fentonreaction will probably attack and oxidise the available outer fibre surfaces,weakening these layers, and simultaneously dissolve some of the organic material.This can facilitate fibre development, give a better bonding pulp and reduce theelectrical energy required during refining.

  • 287.
    Walter, Karin
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp & Performance Chem, SE-44580 Bohus, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp & Performance Chem, SE-44580 Bohus, Sweden.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Acid Hydrogen Peroxide Treatment of Norway Spruce TMP: The Effect of an Extended pH Range when Catalyzed by Free Ferrous and Free or EDG/EDTA-Chelated Ferric Ions2014Ingår i: Journal of wood chemistry and technology, ISSN 0277-3813, E-ISSN 1532-2319, Vol. 34, nr 2, s. 135-155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of different types of iron salts (i.e., ferrous or ferric cations with sulphate, nitrate or chloride anions) on the reaction between coarse thermomechanical pulp and acid hydrogen peroxide (Fenton chemistry) was studied when the initial pH was 3.2 and 5.3. Also, ferric ions chelated with EDTA or EDG at different molar ratios were compared with ferrous sulphate when the initial pH was extended from about 3 to 8. Different anions of ferric ion salt gave a similar catalytic effect. At an initial pH of 7–8, the ferric-EDTA catalyzed reaction resulted in similar or higher hydrogen peroxide consumption and more detectable hydroxyl radicals than the ferrous sulphate catalyzed reaction, but less reaction with the pulp was indicated. Between pH 5–8, using Fe-EDG as a catalyst gave higher hydrogen peroxide consumption and more detectable hydroxyl radicals than if using ferrous sulphate; however, the measured effect on the pulp was similar or less.

  • 288.
    Westerberg, Elin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sänkt energiförbrukning med byte av energisystem eller energieffektivisering: Ekonomisk analys av fjärrvärme, bergvärme och luft-vatten värmepump i äldre fastigheter kontra energieffektiviseringsåtgärder2017Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Fjärrvärme är det dominerande uppvärmningssättet för flerbostadshus i Sverige och dess konkurrent är värmepumparna som blivit allt mer effektiva och fått en bättre slagkraft på marknaden. Samtidigt har regeringen satt upp 2020 målen, för att sänka och förbättra Sveriges energianvändning. Eftersom att bostadssektorn står för nästan 40 procent av Sveriges totala energianvändning, är rapportens syfte att studera hur energiförbrukningen för äldre hus kan sänkas genom byte av energisystem eller genom att behålla ett befintligt fjärrvärmesystem men utföra energieffektiviseringsåtgärder. De energisystemen som studeras i denna rapport är fjärrvärme, bergvärme och luft-vatten värmepump. Den data som har använts i rapporten har i huvudsak samlats in från ett flerbostads-hyreshus beläget i Vingåker och som ägs av Sjötorps hus AB. För att resultatet ska vara mer generellt har även två typhus studerats; ett småhus och ett större flerbostadshus. Resultatet av studien visar att den största kostnaden för fjärrvärmen ligger i driften och därmed blir detta alternativ också dyrast för de två större husen. Dock är både investeringskostnaden och underhållskostnaderna betydligt större för värmepumpar och varierar beroende på vart i landet de ska installeras, oförutsedda driftstopp och haverier. Resultatet visar också att det inte är lönsamt för ett småhus att byta från ett befintligt fjärrvärmesystem till värmepump. Slutsatsen är att energieffektivisering bör ske i första hand för att sänka en fastighets energiförbrukning, speciellt eftersom att andelen äldre hus kommer att öka och oavsett hur lite energi de nya husen förbrukar kommer de äldre husen utgöra den största andelen av Sveriges totala bostadsbestånd. Att en värmepump använder mindre energi är ingen långsiktig lösning för att sänka energiförbrukningen. Istället bör energieffektiviseringsåtgärder ligga till grund vid en önskan om sänkt energiförbrukning.

  • 289.
    Wickström, Johan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sänkta ventilationsflöden på Sundsvalls sjukhus: Utvärdering av ett energibesparingsinitiativ genom rökförsök och temperaturmätningar2017Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I syfte att sänka energianvändningen på Sundsvalls sjukhus riktas nu fokus mot ventilationssystemet och möjligheterna att där sänka luftflöden. Denna uppsats undersöker detta energibesparingsinitiativ genom att studera vad som händer med luftrörelser och temperaturer i ett rum på sjukhuset vid varierande ventilationsflöden. Metoden är rökförsök med observation och analys av mätdata som jämförs med krav på inomhusklimat och beräkningar av temperatureffektiviteten, ett kvantitativt mått på hur väl tillförd värme kommer rummets vistelsezon tillgodo. Resultaten indikerar bland annat att det kan vara till nackdel för luftkvalitén med alltför drastiska ventilationsflödessänkningar i det observerade rummet, detta fastän mängden tillförd luft är mer än tillräcklig enligt gällande krav. Bäst temperatureffektivitet uppnås då frånluft går via både frånluftsdon och frånluftsfönster vilket pekar mot att bäst förutsättningar för att sänka ventilationsflöden eller tilluftstemperatur finns med denna frånluftsinställning.

  • 290.
    Wiklund, Hanna S.
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Microfluidics of imbibition in random porous media2013Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics, ISSN 1539-3755, E-ISSN 1550-2376, Vol. 87, nr 2, s. 023006-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A free-energy lattice Boltzmann approach has been used to perform simulations of liquid penetration into random porous media. We focus our study on the effects of microstructures, particularly microtopography, on liquid penetration driven by capillary force and external pressure. For this purpose we set up a model structure that consists of a network of interconnected capillaries with varying pore geometries. The results showed that the discontinuities in the solid-surface curvature, as are present as corners on the capillary surfaces, have strong influences on liquid penetration through their pinning effects and interactions with local geometry. DOI: 10.1103/PhysRevE.87.023006

  • 291.
    Yang, Haiping
    et al.
    Huazhong University of Science and Technology, Wuhan, China.
    Wang, Daqian
    Huazhong University of Science and Technology, Wuhan, China.
    Li, Bin
    Huazhong University of Science and Technology, Wuhan, China.
    Zeng, Zhiwei
    Huazhong University of Science and Technology, Wuhan, China.
    Qu, Lei
    Huazhong University of Science and Technology, Wuhan, China.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Chen, Hanping
    Huazhong University of Science and Technology, Wuhan, China.
    Effects of potassium salts loading on calcium oxide on the hydrogen production from pyrolysis-gasification of biomass2018Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 249, s. 744-750Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effects of potassium (K) salts loading on CaO on the H2 production from pyrolysis-gasification of wheat straw were investigated. The loading of 0.25 wt% KCl could significantly enhance the CO2 absorption capability of CaO. The CO2 concentration in the product gas decreased sharply from 20.83 to 11.70 vol%, and the H2 concentration increased from 48.2 to 55.5 vol%. While the loading of 0.25 wt% K2CO3/K2SO4 inhibited the enhancing effect of CaO. Further increasing the loading of KCl on CaO, the CO2 absorption of CaO declined, but the catalytic effect of KCl on the gasification process was promoted. The loading of 0.25 wt% KCl on CaO significantly improved the cyclic performance of CaO during the pyrolysis-gasification process. Higher H2 concentration and more CO2 absorbed by CaO were obtained with the loading of 0.25 wt% KCl even after 5 cycles compared with those of pure CaO in the first cycle. 

  • 292.
    Yang, Jiayi
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Duan, Jiangjiang
    Wuhan University, China.
    Zhang, Lina
    Wuhan University, China.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Spherical nanocomposite particles prepared from mixed cellulose–chitosan solutions2016Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 23, nr 5, s. 3105-3115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel cellulose–chitosan nanocomposite particles with spherical shape were successfully prepared via mixing of aqueous biopolymer solutions in three different ways. Macroparticles with diameters in the millimeter range were produced by dripping cellulose dissolved in cold LiOH/urea into acidic chitosan solutions, inducing instant co-regeneration of the biopolymers. Two types of microspheres, chemically crosslinked and non-crosslinked, were prepared by first mixing cellulose and chitosan solutions obtained from freeze thawing in LiOH/KOH/urea. Thereafter epichlorohydrin was applied as crosslinking agent for one of the samples, followed by water-in-oil (W/O) emulsification, heat induced sol–gel transition, solvent exchange, washing and freeze-drying. Characterization by X-ray photoelectron spectroscopy, total elemental analysis, and Fourier transform infrared spectroscopy confirmed the prepared particles as being true cellulose–chitosan nanocomposites with different distribution of chitosan from the surface to the core of the particles depending on the preparation method. Field emission scanning electron microscopy and laser diffraction was performed to study the morphology and size distribution of the prepared particles. The morphology was found to vary due to different preparation routes, revealing a core shell structure for macroparticles prepared by dripping, and homogenous nanoporous structure for the microspheres. The non-crosslinked microparticles exhibited a somewhat denser structure than the crosslinked ones, which indicated that crosslinking restricts packing of the chains before and under regeneration. From the obtained volume-weighted size distributions it was found that the crosslinked microspheres had the highest median diameter. The results demonstrate that not only the mixing ratio and distribution of the two biopolymers, but also the morphology and nanocomposite particle diameters are tunable by choosing between the different routes of preparation.

  • 293.
    Yang, Jiayi
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Selective separation of wood substances from TMP mill process water by flotation. Analysis of the foam fraction.2013Konferensbidrag (Refereegranskat)
  • 294.
    Zasadowski, Darius
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Strand, Anders
    Laboratory of Wood and Paper Chemistry, Åbo Academy University, Porthansgatan 3, 20500 Turku, Finland .
    Sundberg, Anna
    Laboratory of Wood and Paper Chemistry, Åbo Academy University, Porthansgatan 3, 20500 Turku, Finland .
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Selective purification of bleached spruce TMP process water by induced air flotation (IAF)2014Ingår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 68, nr 2, s. 157-165Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The environmentally benign closure of water systems in paper mills leads to the problem of accumulation of dissolved and colloidal wood substances (DCS) in process water. Notably, pitch affects the pulp and paper production negatively and increases the demand for additional treatment of the process water. In the present article, the purification of thermomechanical pulping process water from the alkaline peroxide bleaching stage has been investigated, with the induced air flotation (IAF) in focus. The following parameters were considered concerning the IAF efficiency to remove detrimental substances: concentration of cationic foaming agent, pH value, calcium concentration, and temperature. The amounts and characteristics of residual DCS were determined by gas chromatography and turbidity measurements. Residual concentrations of the foaming agent dodecyltrimetylammonium chloride were determined by electrospray ionization mass spectrometry. Up to 90% of pitch was removed, whereas hemicelluloses, which are important in preventing pitch problems, remained in the waters. Up to 70% of the pectic acids accounted for the high cationic demand of the process waters were removed by optimization of the IAF parameters. The presented separation process gives new opportunities to a selective purification of the process waters.

  • 295.
    Zasadowski, Dariusz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Mittuniversitetet.
    Selective Separation Of Wood Components In Internal Process Waters Originating From Mechanical Pulping2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Dissolved and Colloidal substances (DSC) and metals are released from woodduring thermomechanical pulp (TMP) production. These components have atendency to accumulate in process waters, as the water circulation systems inintegrated paper mills are closed. Disturbances such as pitch depositions in thepaper machine (pitch problems), specks in the paper, decreased wet and drystrength, interference with cationic process chemicals, and impaired sheetbrightness and friction properties appear when DSC are present. Transition metalions such as manganese results in higher consumption of bleaching chemicals(hydrogen peroxide) and lowers the optical quality of the final product, andaddition of complexing agents, such as EDTA or DTPA, to prevent this is needed.The never ending trends to decrease water consumption and increase processefficiency in pulp and paper production emphasizes that it is very important bothto know the effects of wood substances on pulping and papermaking and to beable to remove them in an efficient way. From a biorefinery point of view, DSCcomponents can be promising renewable raw materials for biofuels, bio‐basedchemicals and materials.In this thesis, a new approach using induced air flotation (IAF) without a cationicpolyelectrolyte addition for the removal of pitch and metal ions from mechanicalpulp mill process waters is presented. The induced air flotation of different processwaters is facilitated by the addition of a chelating surfactant and different foamingagents. The influence of the pH value, temperature and foaming agentconcentration on the flotation efficiency has been investigated. The investigations

    presented show that the disturbing components can be removed from TMP presswater to a high extent. A 90% decrease in turbidity and a 91% removal of lipophilicextractives (i.e. resin and fatty acids, triglycerides, sterols and steryl esters) fromunbleached and bleached TMP process water can be obtained by addition of acationic surfactant as foaming agent during flotation. Lower amount of foamingagent is needed to purify efficiently bleached TMP process water, than unbleached.Additionally, fibres located in TMP press water are not removed with the foamfraction but purified. A retained concentration of hydrophilic extractives (i.e.hemicelluloses and lignans) in the process water indicates that the flotation isselective. Moreover, by introduction of a new recoverable surface activecomplexing agent, a chelating surfactant, manganese ions in the form of chelatescan be successfully removed from the pulp fibres and separated from the processwater in the same flotation process. Furthermore, from the purified unbleachedTMP process water a 90% recovery of dissolved hemicelluloses by anti‐solventprecipitation was obtained.The findings presented above indicate new possibilities for the internal watercleaning stage to decrease DSC emissions to recipient and for recovery of valuableraw materials from purified process water if flotation technology is applied in anintegrated mechanical pulp mill.

  • 296.
    Zasadowski, Dariusz
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Recovery of water-soluble hemicelluloses from TMP process water after selective flotation.2013Ingår i: The 17th International Symposiumon on Wood, Fiber and Pulping Chemistry, 2013Konferensbidrag (Refereegranskat)
  • 297.
    Zasadowski, Dariusz
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Willför, Stefan
    Åbo Akademi, Finland.
    Strand, Anders
    Åbo Akademi, Finland.
    Sundberg, Anna
    Åbo Akademi, Finland.
    Selective froth flotation of pitch components from spruce TMP process water.2013Ingår i: The 17th International Symposiumon on Wood, Fiber and Pulping Chemistry, 2013Konferensbidrag (Refereegranskat)
  • 298.
    Zasadowski, Dariusz
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Yang, Jiayi
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Antisolvent precipitation of water-soluble hemicelluloses from TMP process water2014Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 113, s. 411-419Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the thermomechanical pulping (TMP) of spruce, hemicelluloses (mainly galactoglucomannans, GGMs) are released into the process water at relatively low concentrations that are currently impossible to efficiently recover. This paper examines the recovery of hemicelluloses precipitated from TMP process water via solubility reduction by adding antisolvents such as methanol, ethanol, and acetone. The phase separation was monitored by turbidity measurements. Gravimetric analysis, FTIR, GC–MS, UV spectroscopy, and ICP-OES were used to determine the yield, purity, and composition of the precipitates. Gel permeation chromatography and pulsed field-gradient self-diffusion NMR were used to measure the molecular mass distribution of the precipitates. Acetone was found to be the most efficient antisolvent, giving the highest yield at the lowest addition. The contents of lipophilic extractives and lignin impurities were below 0.5% and 1.6%, respectively, and the metal content was approximately 2% in the precipitates obtained with acetone.

  • 299.
    Zauli, Agnese
    et al.
    Roma Tre Univ, Dept Sci, Rome, Italy.
    Carpaneto, Giuseppe M.
    Roma Tre Univ, Dept Sci, Rome, Italy.
    Chiari, Stefano
    Roma Tre Univ, Dept Sci, Rome, Italy; CREA ABP Consiglio Ric Agr & Anal Econ Agr, Ctr Ric Agrobiol & Pedol, Florence, Italy.
    Mancini, Emiliano
    Roma Tre Univ, Dept Sci, Rome, Italy.
    Nyabuga, Franklin N.
    Lund Univ, Dept Biol, Lund.
    De Zan, Lara Redolfi
    CREA ABP Consiglio Ric Agr & Anal Econ Agr, Ctr Ric Agrobiol & Pedol, Florence, Italy; CFS CNBF Ctr Nazl Studio Conservaz Biodivesita Fo, Marmirolo, Italy.
    Romiti, Federico
    Roma Tre Univ, Dept Sci, Rome, Italy.
    Sabbani, Sunil
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Audisio, Paolo A.
    Sapienza Univ Rome, Dept Biol & Biotechnol Charles Darwin, Rome, Italy.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bologna, Marco A.
    Roma Tre Univ, Dept Sci, Rome, Italy.
    Svensson, Glenn P.
    Lund Univ, Dept Biol, Lund.
    Assessing the taxonomic status of Osmoderma cristinae (Coleoptera Scarabaeidae), endemic to Sicily, by genetic, morphological and pheromonal analyses2016Ingår i: Journal of Zoological Systematics and Evolutionary Research, ISSN 0947-5745, E-ISSN 1439-0469, Vol. 54, nr 3, s. 206-214Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Resolving complexes of closely related and cryptic insect species can be challenging, especially when dealing with rare and protected taxa that are difficult to collect for genetic and morphological analyses. Until recently, populations of the genus Osmoderma (Scarabaeidae), widespread in Europe, were treated as a single species O.eremita (Scopoli, 1763) in spite of observed geographic variation in morphology. A previous survey using sequence data from the mtDNA cytochrome C oxidase I gene (COI) revealed the occurrence of at least two distinct lineages within this species complex: O.eremita in the west and O.barnabita Motschulsky, 1845, in the east. Interestingly, beetles confined to Sicily have been described as a distinct species, O.cristinae Sparacio, 1994, based on morphological traits. Only few Sicilian specimens were included in the former genetic analysis, and the results led to a still questionable taxonomic rank for these populations. To explore the robustness of the previous taxonomic arrangement for O.cristinae, a combination of genetic, morphological and pheromonal analyses was used. A 617-bp fragment of the COI gene, aligned with O.cristinae and O.eremita sequences already available in GenBank, showed a clear genetic divergence between the two species (interspecific mean distance=6.6%). Moreover, results from AFLP markers sustained the distinction of the two species. In addition, geometric morphometric analyses of the shape of male genitalia revealed a clear differentiation between the two species. Via scent analysis and field trapping, we demonstrated the production of the sex pheromone (R)-(+)--decalactone by males of O.cristinae, the attraction by conspecific individuals (mostly females) to this compound, and a lack of antagonistic effect of (S)-(-)--decalactone. The fact that O.eremita and O.eremita use the same compound for mate finding suggests that this sex pheromone has not undergone a differentiation and probably the allopatry of these two species compensates for the absence of a mechanism to avoid cross-attraction. Our genetic and morphological data support the divergence of the two species and confirm the species status for O.cristinae, while sex pheromones are confirmed to be invariant among different species of the genus Osmoderma.

  • 300.
    Zauli, Agnese
    et al.
    Roma Tre Univ, Dept Sci, I-00146 Rome, RM, Italy.
    Chiari, Stefano
    Univ Roma La Sapienza, Dept Biol & Biotechnol Charles Darwin, I-00161 Rome, RM, Italy.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Svensson, Glenn P.
    Lund Univ, Dept Biol, S-22362 Lund, Sweden.
    Carpaneto, Guiseppe M.
    Roma Tre Univ, Dept Sci, I-00146 Rome, RM, Italy .
    Using odour traps for population monitoring and dispersal analysis of the threatened saproxylic beetles Osmoderma eremita and Elater ferrugineus in central Italy2014Ingår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 18, nr 5, s. 801-813Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pheromone-based monitoring could be a very efficient method to assess the conservation status of rare and elusive insect species, but there are still few studies for which pheromone traps have been used to obtain information on presence, abundance, phenology and movements of such insects. We performed a mark-recapture study of two threatened saproxylic beetles, Osmoderma eremita (Scarabaeidae) and its predator Elater ferrugineus (Elateridae), in two beech forests of central Italy using pheromone baited window traps and unbaited pitfall traps. Two lures were used: (1) the male-produced sex pheromone of O. eremita (racemic γ-decalactone) to attract females of both species, and (2) the female-produced sex pheromone of E. ferrugineus (7-methyloctyl (Z)-4-decenoate), to attract conspecific males. In total, 13 O. eremita and 1,247 E. ferrugineus individuals were trapped. For E. ferrugineus, males were detected earlier than females, and 7-methyloctyl (Z)-4-decenoate was much more efficient lure compared to racemic γ-decalactone in detecting its presence. The population size at the two sites were estimated to 520 and 1,369 individuals, respectively. Our model suggests a sampling effort of ten traps checked for 3 days being sufficient to detect the presence of E. ferrugineus at a given site. The distribution of dispersal distances for the predator was best described by the negative exponential function with 1 % of the individuals dispersing farther than 1,600 m from their natal site. In contrast to studies on these beetles in Northern Europe, the activity pattern of the two beetle species was not influenced by variation in temperature during the season.

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