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  • 1.
    Adamopoulos, Stergios
    Technological Educational Institute of Larissa, Greece.
    Fiber analysis techniques for sustainable manufacturing of corrugated board and packaging2006Inngår i: Proceedings of the 2006 Naxos International Conference on Sustainable Management and Development of Mountainous and Island Areas: 29th September - 1st October 2006, Island of Naxos, Greece / [ed] Evangelos I. Manolas, Democritus University of Thrace , 2006, Vol. 1, s. 1-9Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Environmental – economic pressure and associated regulations have led to a significant increase of recycled paper as the main fibrous component of corrugated board the last years. Corrugating packaging industry is facing the challenge to enhance products derived from recycled pulp and to ensure a satisfactory strength of packages. Advanced techniques are highly needed for the evaluation of packaging fiber supply sources as well as for the utilization of the available resources in an optimal manner. As industrial packaging is based on the characteristics of its constituent fibers, information on the fiber composition of the recycled raw materials is of primary importance for a continual control of fiber sources. This paper reports on the usefulness of fiber analysis techniques as diagnostic methods for assessing the potential quality distribution of fibers for sustainable packaging manufacturing.

  • 2.
    Adamopoulos, Stergios
    AIDIMA, Spain.
    Identification of Fibre Components in Packaging Grade Papers2006Inngår i: IAWA Journal, ISSN 0928-1541, Vol. 27, nr 2, s. 153-172Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Environmental and economic issues have led to a significant increase of recycled paper as the main fibrous component of corrugated board the last years. Qualitative data on the different fibre types are needed for the evaluation of packaging fibre supply sources, which are becoming numerous and heterogeneous. Fifteen different packaging grade papers (7 linerboards and 8 corrugating medium) were selected to represent all the variety of papers available on the Spanish market. The origin of virgin and recycled fibres was identified by their morphological characteristics employing light microscopy and standard fibre analysis techniques. The waste-based papers (Waste based-liners and Fluting), Kraft-liners and Test-liner were highly variable containing 9–18 different wood and nonwood components. Semi-chemical, with 5–13 components, was the less variable grade. Hardwoods were identified as the most important fibre component from a quantitative standpoint. All papers contained in their hardwood mix Betula, Eucalyptus and Populus in significant amounts. Fagus sylvatica and Tilia were also frequently observed and in some papers were amongst major hardwood components. Prominent softwood components were found to be Pinus sylvestris, P. pinaster, P. radiata, Picea, Larix and in some papers Pinus nigra. The lower presence of a variety of softwood, hardwood and nonwood (mainly grasses) species and genera was due to the paper recycling process.

  • 3.
    Adamopoulos, Stergios
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Morphology, properties and recyclability of modified fibres and papers with different chemicals at laboratory, pilot plant and industrial trials2015Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 4. Adamopoulos, Stergios
    Quality control of packaging fiber sources2006Konferansepaper (Annet vitenskapelig)
  • 5. Adamopoulos, Stergios
    Quantification of softwood, hardwood and nonwood fibres in packaging grade papers2006Inngår i: TAPPI Journal, ISSN 0734-1415, Vol. 5, nr 3, s. 27-32Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study determined percentages by weight of the fiber components in 15 papers commonly used to produce corrugating packaging in Spain. The papers are manufactured mainly from recycled raw materials. The percentages were determined by means of standard quantitative fiber analysis techniques and use of appropriate weight factors. Hardwoods were the major fiber component in all papers, except kraft liners, varying from 51% to 92% per weight. Kraft liners had greater softwood content (49%-69%)than hardwood, and the most plentiful softwood classes were pines. Douglas-fir was a contaminating fiber component (weight percentage less than 2%) in almost in every paper. Nonwood fibers, entering the papers through the recycling process, were a significant fiber component (2%-9%) in most of the papers, especially the waste-based papers (liners and flutings). Quantitative fiber composition reflects the differences in quality between the papers. Its usefulness could be further explored in the quality control of paper manufacturing for packaging.

    Application: Packaging grade papers incorporate a variety of wood and nonwood fiber types. Manufacturing of papers of consistent and acceptable quality requires knowledge concerning the quantity of each fiber used.

  • 6.
    Adamopoulos, Stergios
    TEI Thessaly, Greece.
    Recovery and utilization of wood and rubber at the end of their lifespan to produce innovative products2014Inngår i: Development and Business Prospects in Thessaly by Symbiotic Utilization of Agricultural and Industrial Solid Waste to Produce Materials and Energy, November 24, Larissa, Greece, 2014Konferansepaper (Annet vitenskapelig)
  • 7.
    Adamopoulos, Stergios
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Birmpilis, D
    Technological Educational Institute of Thessaly.
    Use and properties of recovered paper raw materials for the production of corrugated board2015Inngår i: Proceedings of the 14th International Conference on Environmental Science and Technology Rhodes, Greece, 3-5 September 2015, Global NEST , 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The difficulty of predicting the properties of paper products produced from heterogeneous sources puts several limitations, which therefore lead to severe economic losses and only a comprehensive characterization will enable their better utilization. The project “RF-CORRUG –Quality control of raw materials from recovered fibres for the production of corrugated board”under the NationalStrategic Reference Framework 2007–2013 ARCHIMEDES IIIdeals with this common technical problem of the corrugated board industry. Specifically, the mainobjective of the project is to supportthe competitiveness of the corrugated board companies (mainly SMEs)by creatinga software tool based on practical models that can predict packaging grade paper properties from fibre data (qualitative, quantitative, morphological) used in their production. This paper presents information on the physical and mechanical properties of recovered packaging papers used in corrugated packaging. A number of different category papers (liners, flutings) used for corrugated board production in Greece were examined. The required paper properties included grammage, porosity, bursting strength, SCT, tensile strength and tearing resistance, and were measured by internationally recognized testersand standards. The data will be used to develop predictive models based on advanced statistical methods for the properties and performance of packagingaccording to information of their recovered raw paper materials.

  • 8.
    Adamopoulos, Stergios
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Foti, Dafni
    Aristotle University of Thessaloniki, Greece.
    Voulgaridis, Elias
    Aristotle University of Thessaloniki, Greece.
    Passialis, Costas
    Aristotle University of Thessaloniki, Greece.
    Manufacturing and properties of gypsum-based products with recovered wood and rubber materials2015Inngår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 10, nr 3, s. 5573-5585Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The experimental production of gypsum-based products (cylindrical samples, solid bricks) using different fractions of wood chips and rubber particles was studied. Recovered rubber and wood materials were mixed with gypsum and water in various proportions to fabricate gypsum-wood and gypsum-rubber cylindrical samples and standard solid bricks with six holes using appropriate molds. It was shown that to manufacture gypsum-wood and gypsum-rubber products with good mechanical strength, coarse fractions of wood and rubber should be used, but the proportion of wood or rubber should not exceed 25%. No thermal conductivity differences were found between the wood-and rubber-type of gypsum products, and particle size and material proportion had no effect. Samples with fine wood and rubber particles present at a lower proportion (25%) exhibited similar sound absorption behavior. The solid bricks had slightly higher strength when loaded at the large surface of their lateral upper side than when loaded at the small surface. The bricks provided better thermal insulation than both the extruded and pressed house bricks but lower than that of insulating bricks. The emission of volatile organic compounds out of the bricks was at an acceptable level according to regulations for construction products.

  • 9.
    Adamopoulos, Stergios
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Karageorgos, Anthony
    Technological Educational Institute of Thessaly, Greece.
    Rapti, Elli
    Center for Research and Technology – Hellas (CERTH), Greece .
    Birbilis, Dimitris
    Technological Educational Institute of Thessaly, Greece.
    Predicting the Properties of Corrugated Base Papers Using Multiple Linear Regression and  Artificial Neural Networks2016Inngår i: Drewno, ISSN 1644-3985, Vol. 59, nr 198, s. 61-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The difficulty in predicting the properties and behaviour of paper products produced using heterogeneous raw materials with high percentages of recovered fibres poses restrictions on their efficient and effective use as corrugated packaging materials. This work presents predictive models for the mechanical properties of corrugated base papers (liner and fluting-medium) from fibre and physical property data using multiple linear regression and artificial neural networks. The most significant results were obtained for the prediction of the tensile strength of liners in the cross direction from the origin (wood type, pulp method) of the fibres using linear regression, and the prediction of the compressive strength of fluting-medium in the longitudinal (machine) direction, according to the short-span test, using a neural network with one hidden layer with 6 neurons, with coefficients of determination at 95.14% and 99.28%, respectively

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  • 10.
    Adamopoulos, Stergios
    et al.
    Technological Educational Institute of Larissa, Greece.
    Mai, C
    From wood fibre modification to paper technology: properties of fibres modified with DMDHEU and glutaraldehyde2011Inngår i: 3rd biennial International Fibre Engineering Conference, 24 – 26 May, Barcelona, Spain, 2011Konferansepaper (Annet vitenskapelig)
  • 11.
    Adamopoulos, Stergios
    et al.
    AIDIMA, Spain.
    Martinez, E
    AIDIMA, Spain.
    Ramirez, D.
    AIDIMA, Spain.
    Characterization of packaging grade papers from recycled raw materials through the study of fibre morphology and composition2007Inngår i: Global NEST. International Journal, ISSN 1108-4006, Vol. 9, nr 1, s. 20-28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The restrictions in availability of forest-based raw materials along with favourable environmental policies towards alternative sources of raw materials have forced corrugated packaging industry to shift towards recycled paper and other fibre sources such as non-wood and agro-residues. The variability in raw pulp materials with increasing percentages of recycled fibres is a very common technical problem for the corrugated packaging industry worldwide. Corrugating packaging production is facing the challenge to ensure a satisfactory strength of packages despite the increase of recycled paper as the main fibrous component. Sustainable manufacturing of papers of consistent and acceptable quality requests comprehensive characterization of the fibrous components, which are becoming more heterogeneous. Understanding the influence that heterogeneous recycled raw materials have on packaging grade paper properties offers great potential value to the corrugated board and packaging industry.

    57 linerboards and corrugating medium were selected to represent all the variety of paper grades available on the market at the moment for the production of corrugated board in Spain. The papers were analyzed for their fibre morphology (fibre length, fibre width, lumen diameter, cell wall width and flexibility) and fibre composition (softwood to hardwood and nonwood fibre count and weight) and their strength (compression, bursting and crushing resistance) was evaluated. All the determinations were in accordance with the relevant TAPPI Test Methods. The significant differences found in most of the anatomical characteristics, fibre composition and strength properties among the paper grades reflected the diverse raw materials used for their production as well as their qualitative differences. By means of simple correlation the influence of fibre characteristics and composition on the strength of the papers was determined under two different conditions, at 23 o C and 50% RH and at 20 o C and 90% RH.

    The results demonstrate that besides the physical-mechanical characterization of packaging grade papers, fibre anatomy and composition can be used successfully as a complementary practical test to predict the performance of papers. The application of the predicting correlations is proposed for the evaluation of the fibre supplies for the packaging industry. An enormous potential for cost reduction can be created by the selection of the most appropriate and inexpensive combination of grade papers for a specific packaging use

  • 12. Adamopoulos, Stergios
    et al.
    Mertinez, E
    Ramirez, D
    Characterization of packaging grade papers from recycled raw materials through the study of fibre morphology and composition2005Inngår i: Proceedings of the 9th International Conference on Environmental Science and Technology: Rhodes, Rhodes Island, Greece, 1 - 3 September 2005 ; Volume of Abstracts / [ed] University of the Aegean, 2005, Vol. A, s. 18-25Konferansepaper (Fagfellevurdert)
  • 13.
    Adamopoulos, Stergios
    et al.
    Technological Educational Institute of Karditsa, Greece.
    Oliver, José-Vicente
    AIDIMA, Spain.
    Fiber composition of packaging grade papers as determined by the Graff “C” staining test2006Inngår i: Wood and Fiber Science, ISSN 0735-6161, Vol. 38, nr 4, s. 567-575Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A qualitative and quantitative analysis of the fiber components of 15 representative papers that are used for the production of corrugated board was carried out by the Graff "C" staining test. The method of processing of softwood, hardwood, and nonwood fibers was determined under a light microscope by their color reactions with the stain. All papers, due to the use of recycled pulp raw materials in their manufacturing, were found to incorporate in their furnish fibers that had been produced with a variety of pulping processes: chemical, mechanical, and semi-mechanical. The recycled-based papers (recycled-liner and recycled-medium) were proved to be the most variable comprising 12-15 different fiber components, while in some of the semi-chemicals only up to 7 components were identified. The weight percentages of the fiber components calculated by the application of weight factors showed that in almost all papers the most important fiber component from a quantitative standpoint was hardwood unbleached kraft followed by softwood unbleached kraft. Besides hardwood unbleached semi-chemical pulp and mechanical softwood pulp that were also plentiful in the papers, there was a smaller number of other components which sum, however, accounted for a significant fraction in the total furnish weight. The results taken on the total softwood, hardwood, and nonwood fibers content of the papers demonstrate that Graff "C" staining test is adequate to analyze both the structure and quality of packaging grade papers in practical industrial testing.

  • 14.
    Adamopoulos, Stergios
    et al.
    Democritus University of Thrace, Greece.
    Oliver, José-Vicente
    AIDIMA, Spain.
    Qualitative and quantitative fibre analysis in recycled raw materials for packaging2006Inngår i: Forest products journal, ISSN 0015-7473, Vol. 56, nr 2, s. 58-60Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the influence that heterogeneous recycled raw materials have on packaging-grade paper performance offers great potential value to the corrugated board and packaging industry. Fifty-seven linerboards and corrugating medium were selected to represent all the variety of paper grades available on the Spanish market at the moment for the production of corrugated board. The origin of softwood, hardwood, and nonwood fibers and their percentages by weight were determined with light microscopy and standard fiber analysis techniques.

  • 15. Adamopoulos, Stergios
    et al.
    Passialis, Costas
    Voulgaridis, Elias
    Fibre characteristics of papers used in European corrugated packaging industry2009Inngår i: ATIP. Association Technique de L'Industrie Papetiere, ISSN 0997-7554, Vol. 63, nr 4, s. 14-21Artikkel i tidsskrift (Fagfellevurdert)
  • 16. Adamopoulos, Stergios
    et al.
    Passialis, Costas
    Voulgaridis, Elias
    Fibre characteristics of papers used in European corrugated packaging industry2008Konferansepaper (Fagfellevurdert)
  • 17. Adamopoulos, Stergios
    et al.
    Passialis, Costas
    Voulgaridis, Elias
    Oliver, JV
    Utilization of recycled fibre materials in the European corrugated packaging industrial sector2008Inngår i: 2nd International Conference on Engineering for Waste Valorisation WasteEng08, June 3-5, Patras, Greece, 2008Konferansepaper (Fagfellevurdert)
  • 18. Adamopoulos, Stergios
    et al.
    Voulgaridis, E
    Passialis, C
    Morphology and identification of fibre furnish components of papers used in the production of corrugated board2013Inngår i: Celuloza Si Harti, ISSN 1220-9848Artikkel i tidsskrift (Fagfellevurdert)
  • 19.
    Adamopoulos, Stergios
    et al.
    Technological Educational Institute of Thessaly, Greece.
    Voulgaridis, Elias
    Aristotle University of Thessaloniki, Greece.
    Passialis, Costas
    Aristotle University of Thessaloniki, Greece.
    CARACTERISTICILE MATERIALULUI FIBROS ŞI PROPRIETĂŢILEHÂRTIEI RECICLATE FOLOSITE ÎN FABRICAREA CARTONULUIONDULAT: Morphology and identification of fibre furnish components of papers used in the production of corrugated board2013Inngår i: 7th International Symposium on Advanced Technologies for the Pulp, Paper and Corrugated Board Industry, 2013Konferansepaper (Fagfellevurdert)
    Abstract [ro]

    Fabricarea de ambalaje din carton ondulat (cutii, tăvi, etc) presupune un lanț de producțieintegrat, format din producătorii de hârtie, producătorii de carton ondulat și producătorii decontainere, dintre care, în Europa, majoritatea sunt IMM-uri. În prezent, containerele de cartonondulat sunt în mare parte realizate cu hârtie recuperată. Cea mai mare amenințare cu care seconfruntă lanțul de producție menționat este legat de lipsa de calitate și de disponibilitate a hârtieireciclate ca materie primă. Concret, una dintre cele mai importante proprietăți ale hârtiei deambalaj este rezistența mecanică, care depinde, în principal, de lungimea fibrelor din care estealcătuita hârtia. Aceste fibre sunt mai lungi în celuloza virgină (celuloza obţinută din lemn, adicănereciclată). Cu toate acestea, presiunea mare asupra cererii - precum și restricțiile economice șiecologice actuale referitoare la utilizarea lemnului ca materie primă - a condus la situația în caredoar o foarte mică cantitate de fibre naturale intră în lanțul de reciclare. Acest lucru înseamnă cărezistenţa fibrelor reciclate – si prin extindere – a hârtiilor – scade în mod constant, odată cuciclurile de reciclare aflate în desfăşurare. Suplimentar, hârtia reciclată prezintă o variabilitatefoarte mare, ceea ce constituie un obstacol atunci când vine vorba de a fabrica ambalaje cuproprietăţi omogene, cerute de către clienţi, la costuri fixe.Dificultatea de predicţie a proprietăților produselor din hârtie obţinute din surse eterogenepune mai multe limitări, care, din acest motiv, conduc la pierderi economice grave și numai ocaracterizare completă va permite mai buna lor folosire. Proiectul "RF-CORRUG - Controlulcalității materiilor prime din fibre recuperate pentru producția de carton ondulat", Cadrul NaționalStrategic de referinţă 2007-2013 Arhimede III, tratează această problemă tehnică comună aindustriei de carton ondulat. Concret, obiectivul principal al proiectului este de a sprijinicompetitivitatea companiilor producătoare de carton ondulat (în special IMM-uri), prin creareaunui instrument software bazat pe modele practice, care pot prezice proprietăţile sortimentului dehârtie de ambalaj, pornind de la proprietăţile fibrelor (calitative, cantitative, de structură) utilizateîn producția lor.Această lucrare prezintă informații referitoare la fibre (analiza cantitativă și calitativă,morfologia) și hârtiile de ambalaj (proprietățile fizice și mecanice) folosite în obţinereaambalajelor din carton ondulat. Au fost examinate diferite categorii de hârtii (miez şi capac),utilizate pentru producția de carton ondulat în Grecia. Principalele tehnici de analiză a fibrelor aufost: analiza masei fibroase, analiza morfologica a fibrei, microscopia optică, microscopiaelectronică de baleiaj (SEM). Suplimentar, a fost determinată rezistenţa la tracţiune (zero-spantensile test), pentru a măsura astfel rezistenţa medie a fibrei. Proprietăţile solicitate pentru hârtie au fost măsurate folosind testere şi standarderecunoscute pe plan internaţional. Informaţiile obţinute vor fi folosite pentru a dezvolta modelepredictive, bazate pe metode statistice avansate, pentru proprietăţile şi performanţele hârtiilor deambalaj, în funcţie de informaţiile furnizate de fibrele componente.

  • 20.
    Adamopoulos, Stergios
    et al.
    Greece.
    Voulgaridis, Elias
    Greece.
    Passialis, Costas
    Greece.
    Recycled Waste Paper and the Corrugated Packaging Industry in Europe2009Inngår i: Proceedings of 24th International Conference on Solid Waste Technology and Management: Philadelphia, PA USA, March 15-18, 2009, 2009, s. 400-411Konferansepaper (Fagfellevurdert)
  • 21.
    Addassi, Mouadh
    et al.
    Technical University of Denmark, Denmark.
    Johannesson, Björn
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Wadsö, Lars
    Lund University.
    Inverse analyses of effective diffusion parameters relevant for a two-phase moisture model of cementitious materials2018Inngår i: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 106, s. 117-129Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here we present an inverse analyses approach to determining the two-phase moisture transport properties re-levant to concrete durability modeling. The purposed moisture transport model was based on a continuumapproach with two truly separate equations for the liquid and gas phase being connected by the sorption ki-netics. The moisture properties of ten binder-systems containingfly ash, calcined clay, burnt shale and graymicro-filler, were investigated experimentally. The experiments used were, (i) sorption test (moisturefixation),(ii) cup test in two different relative humidity intervals, (iii) drying test, and, (iv) capillary suction test. Masschange over time, as obtained from the drying test, the two different cup test intervals and the capillary suctiontest, was used to obtain the effective diffusion parameters using the proposed inverse analyses approach. Themoisture properties obtained with the proposed inverse analyses method provide a good description of the testperiod for the ten different binder-systems.

  • 22.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Hansson, Lars
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Distribution of preservatives in thermally modified Scots pine and Norway spruce sapwood2013Inngår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 47, nr 3, s. 499-513Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Studying the impregnation and distribution of oil-based preservative in dried wood is complicated as wood is a nonhomogeneous, hygroscopic and porous material, and especially of anisotropic nature. However, this study is important since it has influence on the durability of wood. To enhance the durability of thermally modified wood, a new method for preservative impregnation is introduced, avoiding the need for external pressure or vacuum. This article presents a study on preservative distribution in thermally treated Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) sapwood using computed tomography scanning, light microscopy, and scanning electron microscopy. Secondary treatment of thermally modified wood was performed on a laboratory scale by impregnation with two types of preservatives, viz. Elit Träskydd (Beckers) and pine tar (tar), to evaluate their distribution in the wood cells. Preservative solutions were impregnated in the wood using a simple and effective method. Samples were preheated to 170 °C in a drying oven and immediately submerged in preservative solutions for simultaneous impregnation and cooling. Tar penetration was found higher than Beckers, and their distribution decreased with increasing sample length. Owing to some anatomical properties, uptake of preservatives was low in spruce. Besides, dry-induced interstitial spaces, which are proven important flow paths for seasoned wood, were not observed in this species.

  • 23.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology, Sweden.
    Morén, Tom
    Luleå University of Technology, Sweden.
    Moisture properties of heat-treated Scots pine and Norway spruce sapwood impregnated with wood preservatives2012Inngår i: Wood and Fiber Science, ISSN 0735-6161, Vol. 44, nr 1, s. 85-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An experiment was conducted on commercially heat-treated (HT) Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst.) sapwood collected from Ht Wood AB, Arvidsjaur, Sweden. Secondary treatment on HT wood was performed in laboratory scale by impregnating with water-repellent preservatives (a commercial one and pine tar) to evaluate their retention and different moisture-related properties. Preservative solutions were impregnated using a simple and effective method. Wood samples were heated at 170°C in a dry oven and were immediately immersed in preservative solutions. Considerable retention was observed in HT wood, particularly in pine. Moisture adsorption properties were measured after conditioning in a high-humidity environmental chamber (4°C and 84% RH). Experimental results showed that secondary treatment enhanced moisture excluding efficiencies by decreasing equilibrium moisture content, suggesting better hydrophobicity. Soaking test in water showed that antiswelling and water repellence efficiencies improved, especially in tar-treated wood. In addition, this type of treatment significantly decreased water absorption. It was also possible to decrease volumetric swellings. Thus, secondary treatment of HT wood with preservative, in particular with tar, improved dimensional stability and water repellency.

  • 24.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Hagman, Olle
    Luleå University of Technology.
    Cloutier, Alain
    Laval University, Canada.
    Fang, Chang-Hua
    Laval University, Canada.
    Elustondo, Diego
    Luleå University of Technology.
    Anatomical properties and process parameters affecting blister/blow formation in densified European aspen and downy birch sapwood boards by thermo-hygro-mechanical compression2013Inngår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 48, nr 24, s. 8571-8579Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Approximately, 13.5 % of the standing volume of productive forest land in Sweden is covered by birch and aspen, which provides the vast potential to produce value-added products such as densified wood. This study shows whether it is possible to densify those species with a thermo-hygro-mechanical (THM) process using heat, steam, and pressure. In this process, transverse compression on thin European aspen (Populus tremula) and downy birch (Betula pubescens) boards was performed at 200 °C with a maximum steam pressure of 550 kPa. To obtain a theoretical 50 % compression set, the press’s maximum hydraulic pressure ranged from 1.5 to 7.3 MPa. Preliminary tests showed that ~75 % of the birch boards produced defects (blisters/blows) while only 25 % of the aspen boards did. Mainly, radial delamination associated with internal checks in intrawall and transwall fractures caused small cracks (termed blisters) while blows are characterized by relatively larger areas of delamination visible as a bumpy surface on the panel. Anatomical investigations revealed that birch was more prone to those defects than aspen. However, those defects could be minimized by increasing the pre-treatment time during the THM processing.

  • 25.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Hansson, Lars
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Evaluation of preservative distribution in thermally modified European aspen and birch boards using computed tomography and scanning electron microscopy2013Inngår i: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 59, nr 1, s. 57-66Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this experiment was to impregnate thermally modified wood using an easy and cost-effective method. Industrially processed thermally modified European aspen (Populus tremula L.) and birch (Betula pubescens Ehrh.) were collected and secondarily treated at the laboratory scale with the preservatives tung oil, pine tar and Elit Träskydd (Beckers) using a simple and effective method. Preservative uptake and distribution in sample boards were evaluated using computed tomography (CT) and scanning electron microscopy (SEM) techniques. Preservative uptake and treatability in terms of void volume filled were found the highest in Beckers and the lowest in tung oil-treated samples. Thermally modified samples had lower treatability than their counterpart control samples. More structural changes after thermal modification, especially in birch, significantly reduced the preservative uptake and distribution. The differences of preservatives uptake near the end grain were high and then decreased near the mid position of the samples length as compared with similar type of wood sample. Non-destructive evaluation by CT scanning provided a very useful method to locate the preservative gradients throughout the sample length. SEM analysis enabled the visualization of the preservative deposits in wood cells at the microstructural level.

  • 26.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Karlsson, Olov
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Uneven distribution of preservative in kiln-dried sapwood lumber of Scots pine: Impact of wood structure and resin allocation2012Inngår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 66, nr 2, s. 251-258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Scots pine (Pinus sylvestris L.) sapwood lumber was collected after kiln drying and preservative treatment with Celcure AC 800 (a copper-amine wood preservative). Distribution of the preservative throughout the lumber was visually examined. Not all, but some samples showed specific localized areas without any preservative distribution throughout their entire length. Those samples were assessed further for anatomical properties, specifically in impregnated and unimpregnated areas. Additional study was conducted on the morphological nature and redistribution of lipophilic extractives using three different histochemical staining methods. Intrinsic wood properties – especially the frequency of axial resin canals and the percentage of canals blocked – were found to be responsible for the irregular distribution of the preservative. Furthermore, the inability to create continuous and frequent interstitial spaces due to the collapse of thin-walled ray cells throughout the lumber resulted in un-even distribution of preservatives. Staining techniques were useful to localize places with more or less abundance of extractives (e.g., fats) in impregnated and unimpregnated wood, which varied considerably. Histochemical observations revealed information pertaining to the kiln dry specific distribution and redistribution of extractives between the areas. Moreover, resin reallocation and modification in ray parenchyma and resin canals induced by kiln drying would be another reason for the impregnation anomalies.

  • 27.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Development of a new rapid method for mould testing in a climate chamber: preliminary tests2013Inngår i: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 71, nr 4, s. 451-461Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to develop fast, simple and robust solid wood mould testing methods for the use in small-scale laboratory tests. The objective was to investigate mould susceptibility of different wood materials within the batches. The proposed method is based on natural contamination of non-sterile surfaces in climates conducive to mould growth. For this purpose, a climate chamber with regulated temperature and relative humidity was used. The conditioning chamber was divided into upper and lower chamber by a thin layer of stainless steel placed horizontally above the fan to minimise air circulation to the sample in the upper compartment. Mould-infected samples from outdoor tests were used as a source of mould inocula, and test trials were conducted on Scots pine (Pinus sylvestris L.) sapwood. Samples were suspended from the top of the upper chamber, and the chamber was exposed to different temperature and humidity levels. Severe mould infestation was observed after 12–14 days of incubation. Visual mould rating was then performed. Regardless of some constraints, this test method was very simple, fast, and effective. More importantly, unlike other test methods, it closely models mould infestation as it would occur under natural condition.

  • 28.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Mould susceptibility of Scots pine (Pinus sylvestris L.) sapwood: Impact of drying, thermal modification, and copper-based preservative2013Inngår i: International Biodeterioration & Biodegradation, ISSN 0964-8305, E-ISSN 1879-0208, Vol. 85, s. 284-288Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of mould on wood surfaces depends on several factors. Although mould does not affect the mechanical properties of wood, it greatly reduces the aesthetic value of wood such as the sapwood of Scots pine (Pinus sylvestris L.), which is very prone to mould. In addition, adverse health effects of mould on humans are a great concern. Different types of dried and treated wood were used to observe whether they had enhanced durability against mould following an accelerated laboratory test method in a climate chamber. Samples were green, air-dried, industrially thermally modified, treated with copper-based preservative, and kiln-dried wood, which were tested within a single test run. The test produced the following main results: The thermal modification increased the durability of the wood, and the protective effectiveness of alternative treatments was comparable to that of commercially available copper-based treatment. However, the initial moisture content of the samples during mould exposure had a great influence on the onset of mould growth. The risk of mould susceptibility of industrial kiln-dried lumber can be reduced by drying using the double-layering technique and planing off the nutrient enriched evaporation surfaces.

  • 29.
    Ahmed, Sheikh Ali
    et al.
    Luleå University of Technology.
    Yang, Qian
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Morén, Tom
    Luleå University of Technology.
    Accelerated Mold Test on Dried Pine Sapwood Boards: Impact of Contact Heat Treatment2013Inngår i: Journal of wood chemistry and technology, ISSN 0277-3813, E-ISSN 1532-2319, Vol. 33, nr 3, s. 174-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We test the hypothesis that the combination of kiln drying of double-stacked boards and contact heat treatment will reduce the susceptibility of treated boards to colonization by mold fungi. Winter-felled Scots pine (Pinus sylvestris L.) sapwood boards were double-stacked in an industrial kiln in ''sapwood out'' and ''sapwood in'' positions. Dried samples were then contact heat-treated using a hot press at three different temperatures (140°C, 170°C, and 200°C) for three different periods (1, 3, and 10 min). An accelerated mold test was performed in a climate chamber where naturally mold-infected samples were used as a source of mold inocula. Contact heat treatment degraded the saccharides that accumulated at dried surfaces, and reduced the mold growth. The threshold temperature and time for inhibiting mold growth were 170°C for 10 min. However, for industrial application, the most feasible combination of temperature and time would be 200°C for 3 min. We concluded that double stacking/contact heat treatment used is an environmentally friendly alternative to chemicals for reducing mold on Scots pine sapwood boards.

  • 30.
    Al-Darwash, Mustafa
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Nuss, Emanuel
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Mechanical characterization of DuraPulp by means of micromechanical modelling2015Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Södra DuraPulp is a relatively new eco-composite, made from natural wood fibers and polylactic acid (PLA), which comes from corn starch. Until now, there are only few applications for DuraPulp, mainly in the area of design. To find new fields of application, more knowledge about its mechanical material properties are of great interest.This study deals with characterizing the mechanical properties of DuraPulp in an analytical way by means of micromechanical modelling and evaluation with help of Matlab. The mechanical properties for PLA were taken from scientific literature. Not all properties of the wood fibers could be found in literature (particularly Poisson’s ratios were unavailable). Therefore, they partly had to be assumed within reasonable boundaries. These assumptions are later validated regarding their influence on the final product.Figures and tables were used to present and compare the in- and out-of-plane E-Moduli, shear moduli and Poisson’s ratios of DuraPulp. The calculated in-plane E-Moduli were then compared to those obtained from an earlier study, where DuraPulp was tested in tension. The results showed that experimental and analytical values are very similar to each other.

    Fulltekst (pdf)
    fulltext
  • 31.
    Alfredsen, Gry
    et al.
    Norwegian Forest and Landscape Institute, Norway.
    Bader, Thomas K.
    Vienna University of Technology, Austria.
    Dibdiakova, Janka
    Norwegian Forest and Landscape Institute, Norway.
    Filbakk, Tore
    Norwegian Forest and Landscape Institute, Norway.
    Bollmus, Susanne
    Georg-August-University of Göttingen, Germany.
    Hofstetter, Karin
    Vienna University of Technology, Austria.
    Thermogravimetric analysis for wood decay characterisation2012Inngår i: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 70, nr 4, s. 527-530Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper focuses on the use of thermogravimetric analysis (TGA) as a fast method for estimating the change of lignocellulosic materials during fungal degradation in laboratory trials. Traditionally, evaluations of durability tests are based on mass loss. However, to gain more knowledge of the reasons for differences in durability and strength between wooden materials, information on the chemical changes is needed. Pinus sylvestris sapwood was incubated with the brown rot fungusGloeophyllum trabeum and the white rot fungus Trametes versicolor. The TGA approach used was found to be reproducible between laboratories. The TGA method did not prove useful for wood deteriorated by white rot, but the TGA showed to be a convenient tool for fast estimation of lignocellulosic components both in sound wood and wood decayed by brown rot.

  • 32.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Glass surface modification by aerosol technique2016Annet (Fagfellevurdert)
    Abstract [en]

    Glass has been a key material for many important advnces in cilivilization.  Currently there is much scientific and technological interest to obtained flat/float glass surface that has extremely highly resistant to abrasion, anti-fingerprint, surface contamination and optical dimming. The aim of current project is to develop new routes to modify the glass surface in order to increase functionality and enhance performance in various existing and future areas of application. This will be achieved by modifying the glass surface by incorporating nitrogen to the flat/float glass surface by deposition of thin coatings of AlN, Si3N4 and TiN. This will be achieved by gas to particle conversion by physiochemical routs. Thin films of elemental nitrides have not been reported previously by aerosol technique and we anticipate that these can be used to enhance the mechanical, optical and chemical properties of flat/float glass surface. Techniques used for structural and physical characterization include, SEM, TEM, AFM, Raman, thermal analysis, mechanical and optical measurements. Areas of applications of these modified surfaces include automotive, architectural, laser optics, camera lenses, optical filters and display technologies.

  • 33.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Hard and Transparent Thin Films2018Inngår i: 4th Nanotechnology Congress and Expo  (GNCE-18), Dubai, UAE (16-18 Apr 2018), 2018, s. 14-Konferansepaper (Fagfellevurdert)
  • 34.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    High temeperature synthesis of nitrogen rich glasses in alkaline-earth silicon oxynitride systems2018Inngår i: Presented at XVI International IUPAC Conference on High Temperature Materials Chemistry, Ekaterinaburg, Russia, 2018, s. 24-Konferansepaper (Fagfellevurdert)
  • 35.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    New Oxynitride Glasses and Thin Films2017Inngår i: 15th International Symposium on Advanced Materials (ISAM), Islamabad, Pakistan, 16-20 Oct 2017, 2017Konferansepaper (Fagfellevurdert)
  • 36.
    Ali, Sharafat
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Nitrogen in Materials2010Konferansepaper (Fagfellevurdert)
  • 37.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Nitrogen rich Glasses and Glass Surfaces for High-tech and Specialty Applications2017Rapport (Fagfellevurdert)
    Abstract [en]

    The aim of this project is to produce more chemical and mechanically durable glasses and glass surfaces having high thermal, mechanical and optical properties. The development of new materials is fundamental for the technological progress; their preparation and characterization lead to breakthrough applications as well as progress in our understanding of basic solid state materials properties. Glasses play an important role in our society and are expected to do so even more in the future. In the current proposed project we would like to extend the M-Si-O-N  ( M= Ca and Sr) system to T-Si-O-N (T= Transition metals e.g. Ti, Zr, Y, Mn etc) and Ln-Si-O-N ( Ln = Lanthanoids e.g. La, Ce, Pr, Eu, Gd, etc) systems. Applications of these nitrogen rich glasses include, as potential materials for use in more light-weight applications in modern communications equipment, in biomedical devices and where reductions in energy usage are critical. Furthermore, these glass materials can be used as a passive coatings on electronic substrates using their higher dielectric constants and elastic moduli to best advantage; special windows where their higher elastic moduli would allow them to remain stiff in thinner sections, thus allowing weight and energy savings; hard disk drives, again making use of higher modulus and lower densities to achieve higher rotation speeds; new bioactive oxynitride glasses and glass-ceramics with better load-bearing properties.

  • 38.
    Ali, Sharafat
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Primary Challenges in the Development of Nitrogen Rich Oxynitride Glasses2018Konferansepaper (Fagfellevurdert)
  • 39.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Bogdonoff, Toni
    Jönköping University.
    Seifeddine, Salem
    Jönköping University.
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Hardness, elastic modulus and refractive index of oxynitride glasses prepared from woody biofuel ashes2017Inngår i: Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B, ISSN 1753-3562, Vol. 58, nr 6, s. 231-236Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper reports the hardness, elastic modulus and refractive index values of the oxynitride glasses prepared from woody biofuel ashes. The glasses were prepared in nitrogen atmosphere at 1350–1500°C with addition of Ca metal as a precursor to the extra addition of this modifier. The glasses were homogenous, but appeared translucent grey to black. They contained up to 23 eq% of Ca and 5 eq% of N. The glass densities vary slightly between 2.76 to 2.92 g/cm3. The molar volume and compactness values vary between 8.01 cm3/mol to 8.31 cm3/mol and 0.446 to 0.462 respectively. Mechanical properties like hardness and reduced elastic modulus show values, up to 10 and 105 GPa, respectively. These properties are strongly correlated with the amount of N in the glass. The refractive index (1.54–1.75) increases with increasing N and Ca contents.

  • 40.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Grins, J.
    Stockholm University.
    Jonson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Raman spectra of Ca-Si-O-N glasses2012Konferansepaper (Fagfellevurdert)
  • 41.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Effect of compactness on oxynitride glasses properties2013Konferansepaper (Fagfellevurdert)
  • 42.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Jonson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Formation of oxynitride glasses from fly ashes2010Inngår i: Abstracts - 10th ESG conference together with 84th annual meeting of the DGG : Glass Trend Seminar "Glass Furnaces and Refractory Materials": Plansee Session "Refractory Methals for the Glass Industry ; Magdeburg, Germany, 30 May - 2 June 2010, 2010, s. 89-Konferansepaper (Fagfellevurdert)
  • 43.
    Ali, Sharafat
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Jonson, Bo
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Nitrogen rich Ca/Sr-Si-O-N glasses crystallization2009Konferansepaper (Fagfellevurdert)
  • 44.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Jonson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Oxidation behavior of nitrogen rich AE-Si-O-N glasses (AE = Ca, Sr, Ba)2011Inngår i: Journal of the Australian Ceramic Society, ISSN 0004-881X, Vol. 47, nr 2, s. 8-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AE-based silicon oxynitride glasses (AE = Ca, Sr, Ba) with high nitrogen content have been synthesized using AE hydrides as primary precursors. The oxidation behavior of AE-Si-O-N glasses in ordinary atmosphere at different temperature has been investigated. These glasses react with air oxygen when heated just above the glass transition temperatures. The oxidation starts with bubble formation on the surface and continued oxidation leads to formation of a white layer on the surface. The oxidation of AE-Si-O-N glasses involves concurrently ongoing inward diffusion of oxygen and outward diffusion of AE elements and nitrogen, resulting in compositional gradient. EDX analysis showed substantial enrichment in AE content at the surfaces of the oxidized layer.

  • 45.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Jonson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Oxynitride glasses2012Konferansepaper (Fagfellevurdert)
  • 46.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Jonson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Preparation and properties of high nitrogen content mixed alkaline-earth oxynitride glasses2011Konferansepaper (Fagfellevurdert)
  • 47.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Thermal and mechanical properties of mixed modifier oxynitride glasses2016Inngår i: Proceeding of International conference on thermal analysis and calorimetry in Russia (RTAC-2016): 16–23 September, 2016 Saint-Petersburg, Russia, Volume I, St. Petersburg: Peter the Great St.Petersburg Polytechnic University , 2016, Vol. 1, s. 136-139Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Nitrogen rich oxynitride glasses in Ca-Sr-Si-O-N system were prepared by the novel synthesis route in which the modifier is used as a metal instead of metal oxide. The results show high values of glass transition (912C), and crystallization temperatures (1140C) and hardness (10.50 GPa). The viscosity increases significantly with the nitrogen content and the apparent viscosity activation energies, ranging from 855 to 2170 kJ/mole. These glasses can be classified as being both very refractory and very fragile.

  • 48.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Thermal properties of calcium silicon oxynitride glasses2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Oxynitride glasses are a branch of high performance glasses, obtained by incorporation of nitrogen atoms into oxide glass network. [1-3]Oxynitride glasses have superior mechanical, rheological and optical properties as compared to their oxide glass counter partner [2-5]. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. Ca- Si-O-N glasses containing high amount of nitrogen and modifiers have been prepared by melting the mixture of CaH2, SiO2 and Si3N4 powder in nitrogen atmosphere. The glasses were characterized by X-ray powder diffraction, differential thermal analysis and scanning electron microscopy. The obtained glasses were found to be homogenous, and having colour opaque black[3]. These glasses show high values of glass transition temperature (1050°C), and crystallization temperatures (1150°C) measured by differential thermal analysis.  Generally the Ca-Si-O-N glasses thermal properties evolve approximately linearly with the nitrogen content. The viscosity increases significantly with the nitrogen content and reaches viscosity values close to reported values for rare-earth silica oxynitride glasses. The apparent viscosity activation energies are very high, ranging from 855 to 2170 kJ/mole. These nitrogen rich glasses can accordingly be classified as being both very refractory and very fragile.

     

  • 49.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Mauro, Jan
    Penn State University, USA.
    Properties of nitrogen rich Mg-Ca-Si-O-N glasses2017Inngår i: 12th  Pacific Rim Conference on Cermics and Glass Technology including Glass & Optical Materials Meeting, Hawii, USA 21-27 May 2017, 2017, s. 180-180, artikkel-id GOMD-S1-061-2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mg-Ca-Si-O-N glasses containing high amount of nitrogen have been prepared by melting the mixture of Mg metal, Ca metal, SiO2 and Si3N4 powders in nitrogen atmosphere using a radio frequency furnace. Chemical composition, surface morphology, glass transition temperature, hardness, reduced elastic modulus and refractive index of the glasses were investigated using X-ray (EDX) point analysis, scanning electron microscopy, differential thermal analysis, nanoindentation, and spectroscopic ellipsometry. Mg was substituted for Ca in these glasses. The obtained glasses were found to be homogenous, and most of them were not transparent in the visible region. These glasses show high values of glass transition temperature (1020°C), and crystallization temperatures (1150°C). The hardness and reduced elastic modulus increases upon substitution by Mg, up to 13 GPa and 150 GPa respectively. The refractive index of the glasses was found to decrease upon increasing substitution by Mg.

  • 50.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Jonsson, Bo
    Eklund, Per
    Birch, Jens
    Modification of float glass surfaces by novel oxy-nitride thin films2015Rapport (Fagfellevurdert)
    Abstract [en]

    Glass is indispensable and innovative material that has plenty of applications. It is an essential component of numerous products that we use every day, most often without noticing it. Glass is widely used in a variety of applications e.g. housing and buildings, automotive and transport, containers, drinking vessels, displays, insulation and optical fibers due to its universal forming ability, transparency, chemical durability, form stability, hardness relatively low price and possibility of recycling. Flat glass is a wide market of the glass industry and generally ninety percent of all flat glass produced worldwide is manufactured using the float forming process. There is a large market strive for thinner and stronger glass in order to reduce costs, save energy, and to find new applications.

    This study comprises the modification of flat/float glass surface by novel oxynitride thin films in the Mg-Si-O-N and Ca-Si-O-N systems prepared by RF magnetron sputtering technique. The aim of this work is to develop a novel process in order to improve the mechanical and optical properties of flat/float glass by deposition of external materials e.g. alkaline earth metals and nitrogen to the surface in a process with the obvious potential to be automatic in industrial processes. Both mechanical and optical properties of the glass surface have been improved by the deposition of thin films. The float glass surface modified with Mg-Si-O-N have high value of hardness of 20 GPa, elastic modulus of 175 GPa and refractive index value of 1.96 compare to the float glass having hardness of 7 GPa, elastic modulus of 72 GPa and refractive index of 1.50.  The method presented here is anticipated to be used in production in the future and would make it possible to produce larger quantities of strong flat glass for smartphone, tablet covers and display technology to a considerably lower cost.

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