Dissertations / Theses on the topic 'Granule properties'
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Heinze, Karsta. "From grain to granule : the biomechanics of wheat grain fractionation with a focus on the role of starch granules." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS072/document.
Full textThe wheat grain is a natural composite material of worldwide importance. The major part of the grain is the starchy endosperm. To obtain food products, such as flour, the endosperm’s compact structure needs to be disintegrated, which is achieved by milling the grains under high forces. The quantity and quality of the milling products notably depend on the fragmentation behaviour of the endosperm.Due to the endosperm’s composite nature, this behaviour depends strongly on the mechanical properties of its components and their interaction. The main components of the endosperm are carbohydrates and proteins. The carbohydrates are deposited as starch in the form of granules of micro-meter size, whereas proteins form a network (gluten), which surrounds the starch granules. The interactions between starch and proteins is believed to be influenced by certain non-gluten proteins (puroindolines), whose presence and allelic state are genetically controlled. If puroindoline genes are present in the wild-type form, grain hardness is low, which have been related to low starch-protein adhesion. The complete absence of puroindolines in the durum wheat species leads to very high grain hardness and indicates a strong adhesion.The aim of this thesis was to investigate the biomechanics of wheat grain fractionation with a focus on the role of the starch granules therein, which was pursued with a multi-disciplinary approach. Different size scales were considered, from the micro meter-sized structures of starch and protein, the complexity of their arrangement in the endosperm, up to the millimeter-sized grains. In this work, grain-scale milling experiments were combined with nano-mechanical measurements by atomic force microscopy (AFM) and numerical simulations.The milling behaviour of a transgenic durum wheat line, which contained puroindoline genes, was determined by grain scale milling experiments and compared to the milling behavior of non-modified durum wheat. A significant change of milling behavior of the transformed durum wheat grains was observed in terms of milling energy, flour yield and starch damage, which was solely attributable to the presence of puroindolines. The observed changes were consistent with the hypothesis of a lower adhesion between starch granules and protein matrix due to the presence of puroindolines and confirmed the significant effect of puroindolines on the fragmentation behaviour, independent of the grain’s genetic background.The change of fragmentation behaviour is a result of modifications of the mechanical properties of the endosperm’s components and/ or their interaction. Such modifications can be investigated by AFM nano-mechanical measurements. Based on previous work illuminating the global nano-mechanical properties of starch and gluten, contact-resonance AFM (CR-AFM) was applied to obtain maps of the nano-mechanical properties inside the grains. Due to the high topography variations of grain section surfaces and the non-trivial correlation between surface slope and contact resonance-frequency, which hindered a straight-forward interpretation of CR-AFM measurements, a practical method based on existing analytical models of the cantilever vibration was developed to correct the measurements. CR-AFM studies of the endosperm were then focused specifically on the mechanical properties of starch granules and the link to starch structure, and applied to the study of starches from wheat in comparison to plants from different botanical origin (other cereals and legumes).Finally, the role of starch granules, their size distribution, and mechanical properties on endosperm fragmentation was analysed by parametric numerical studies. The influence of the bi-modal size distribution of granules on the mesoscale mechanical properties was shown, as well as the governing role of granule toughness and interface adhesion on the granule damage
Sims, Robert. "On the transmission properties of synapses made between granule cells and cerebellar Purkinje cells." Thesis, Aston University, 2003. http://publications.aston.ac.uk/11071/.
Full textChan, Yuen Cheung. "Quality evaluation and anti-chronic glomerulonephritis properties of a patent herbal drug yi-shen-hua-shi granule." HKBU Institutional Repository, 2020. https://repository.hkbu.edu.hk/etd_oa/825.
Full textLiu, Jing. "EFFECT OF AMYLOSE AND PROTEIN OXIDATION ON THE THERMAL, RHEOLOGICAL, STRUCTURAL, AND DIGESTIVE PROPERTIES OF WAXY AND COMMON RICE FLOURS AND STARCHES." UKnowledge, 2013. http://uknowledge.uky.edu/animalsci_etds/23.
Full textJayakody, J. A. Luckshman Priyadharshana. "The effect of acid hydrolysis on granular morphology and physicochemical properties of native cereal starch granules." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62392.pdf.
Full textPaine, A. C. "Elastic properties of granular materials." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245957.
Full textStewart, James Alexander. "Engineering the properties of spray-dried detergent granules." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548673.
Full textGriffith, J. D. "The drying and absorption properties of surfactant granules." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599715.
Full textUthus, Lillian. "Deformation Properties of Unbound Granular Aggregates." Doctoral thesis, Norwegian University of Science and Technology, Department of Civil and Transport Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1628.
Full textThis thesis discusses the resilient and permanent deformation properties of unbound granular aggregates for use in road structures. One of the objectives of the thesis is to identify the influence of the physical properties of the aggregate grains, such as grain size, grain shape, surface texture, mineralogy and mechanical strength through cyclic load triaxial testing. A second objective is to study the effect of water on the deformation properties of materials as well as their frost susceptibility. The third objective is to study the effect of micromechanical properties using a discrete element model (DEM).
Deformation in unbound granular materials under cyclic loading is divided into a resilient (recoverable) part and a plastic part that does not recover. The elastic strain represents the denominator in the resilient modulus and the non-recoverable strain results in permanent deformations over time. As the resilient response is non-linear, the resilient deformations may be interpreted using several models for curve fitting. Two of the simplest models are the k-θ model and Uzans model. The interpretation of the permanent deformation behaviour of unbound aggregates is complicated, as there is a need for a failure criterion to define when the material is at a failure stage. Two methods used for interpretation of the permanent deformations are mentioned in Chapter 3 of this thesis; the Shakedown approach and the “Coulomb approach”.
Many factors are known to affect the deformation properties in unbound materials. In this thesis the effect of most of these factors is investigated in the six papers. In Chapter 4 the influence of the different factors is discussed on the basis of the results from the papers and findings in the literature. Cyclic load triaxial testing has been the main method to test the deformation properties of the selected unbound materials. This is so far one of the best methods for laboratory simulation of traffic loading.
Discrete element modelling is performed to gain a better understanding of the deformation properties of unbound aggregates tested in a triaxial apparatus under cyclic loading. This method provides useful information about the contact mechanics between neighbouring particles and the interaction of the grains. In addition, unbound spherical aggregates have been tested in the laboratory using a triaxial apparatus.
The main factors studied in this thesis are the influence of grain shape, grain size distribution, fines content, mineralogy, dry density and water content. Useful information about these key factors has been obtained. However, there is still work to do in order to utilize the conclusions directly in a pavement design system.
The dry density, degree of saturation and stress level seem to be key parameters for determining the deformation behaviour, but mineralogy, fines content and grain size distribution are also of importance. Regarding the practical consequences, the results show that mineralogy, fines content and grain size distribution must be given more attention in the pavement design manuals. More effort should also be placed on the compaction control phase in situ, in order to avoid initial rutting in the road structure.
Diaz, Begoña Ruiz. "Magnetic properties of granular magnetic materials." Thesis, University of York, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428429.
Full textOates, Colin John. "Magnetic studies of cobalt based granular thin films." Thesis, University of St Andrews, 2002. http://hdl.handle.net/10023/12928.
Full textZheng, Li-Yang. "Granular monolayers : wave dynamics and topological properties." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1035/document.
Full textGranular crystals are spatially periodic structures of elastic particles arranged in crystal lattices. The interactions between particles take place via their elastic interconnections, which are of much smaller dimensions and weights than the beads. This induces propagation of elastic waves in granular structures at significantly slower velocities than in the individual grains. In addition, due to the existence of non-central shear forces, rotations of particles can be initiated, leading to extra phononic modes in the crystals. In the manuscript, wave dynamics in two-dimensional monolayer granular crystals with either out-of-plane or in-plane particle motion is studied. The phononic properties are investigated, including Dirac points, zero-frequency modes, zero-group-velocity modes and their transformation into slow propagating phononic modes. Furthermore, in the presence of edges/boundaries, zero-frequency and extremely slow elastic edge waves can be also predicted in mechanical granular honeycomb crystals (granular graphene). In addition, topological properties of rotational edge waves in a granular graphene are theoretically demonstrated. By inducing topological transition, which turns the topological order of granular graphene from trivial to nontrivial, topological edge transport in the granular graphene can be observed. The developed theories could promote the potential applications of designed granular structures with novel elastic wave propagation properties
Dai, Beibing, and 戴北冰. "Micromechanical investigation of the behavior of granular materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45700680.
Full textDawson, Janet Caroline. "The electronic properties of granular and amorphous materials." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318097.
Full textBray, David Jonathan. "Statistical properties of a randomly excited granular fluid." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11041/.
Full textHsiau, Shu-San Hunt Melany L. Hunt Melany L. "Shear-induced transport properties of granular material flows /." Diss., Pasadena, Calif. : California Institute of Technology, 1993. http://resolver.caltech.edu/CaltechETD:etd-08292007-090134.
Full textKarim, Mohammad. "SURPRISING PROPERTIES OF STATIC AND FLOWING GRANULAR MATTER." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22655.
Full textZhang, Jiajie, and 张家杰. "Laboratory investigation of loosely compacted completely decomposed granite for slope design." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47055601.
Full textSalahuddin, Mohammed 1959. "Dilatancy effects on the constitutive modeling of granular soils." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276825.
Full textEkblad, Jonas. "Influence of Water on Coarse Granular Road Material Properties." Doctoral thesis, Stockholm : Byggvetenskap, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4329.
Full textMcGuire, Cameron. "Granular flow properties of food powders in extrusion processing." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38220.
Full textDepartment of Grain Science and Industry
Sajid Alavi
This study relates raw material particulate rheology to the granular flow in a single screw food extruder. Raw materials based on corn (i.e. meal, flour, and starch), wheat (i.e. farina, flour and starch), and sucrose (i.e. granulated, superfine, and powdered) were used as model particulate systems for the study. Various particulate-scale characteristics and flow parameters of these nine materials were determined using a powder rheometer. Properties such as basic flow energy, cohesion, flow function, and effective angle of internal friction were good indicators of flowability in an extruder. Corn meal exhibited lower energy requirements and a higher propensity for flow than corn flour (6.7mJ/g versus 10.7mJ/g, and “free-flowing” versus “cohesive,” according to Flow Function classifications), with wheat farina showing similar results when compared to wheat flour (5.8mJ/g versus 7.9mJ/g, and “highly free-flowing” versus “cohesive”), although both wheat systems showed lower energy requirements than their comparable corn systems. Sugar, being of a different base material and particle shape, behaved differently than these starch-based materials—flow energy decreased and propensity to flow increased as particle size decreased (51.7mJ/g versus 8.0mJ/g, and “free flowing” versus “highly free-flowing”). This large energy requirement for coarse sugar particles was attributed more to particle shape than composition, as the sharp edges of sugar can interlock and restrict movement through the sample. The starch-based results were validated in a particulate flow study involving the above model systems (corn meal, corn flour, wheat farina, and wheat flour) in a pilot-scale single screw extruder. Visualization data, obtained using a transparent plexiglass window during extrusion, confirmed that the flours exhibited higher flow energy requirements and a lower flow factor compared to coarser-particle size during extrusion, seen by the increased peak heights and barrel fill. Additionally, moisture changes were analyzed, showing an increase in energy required for starch-based materials as moisture increases and a decrease in energy for sucrose. Due to the hygroscopic nature of sucrose, moisture was absorbed more rapidly than starch products and the edges of individual particles softened, forming a soft solid. These physiochemical differences resulted in decreased energy requirements for sucrose as moisture was increased (51.7mJ/g to 13.6mJ/g), while corn meal and wheat farina yielded increased energy requirements (6.7mJ/g to 9.1mJ/g and 5.8mJ/g to 9.5mJ/g, respectively). Again, results of starch-based materials were validated using a plexiglass cover during extrusion, clearly showing an increase in barrel fill as moisture content increased for both materials, with corn meal flowing more readily than farina. Lastly, temperature of corn meal and farina was increased to show the difference in behavior of starch-based materials, where farina decreased in energy as temperature increased (14.4mJ/g to 12.1mJ/g ) while corn meal energy requirements increased (12.9mJ/g to 17.2mJ/g). With the results developed from these three experiments, and validated where physically possible, it was concluded that offline powder rheometry is a useful tool for predicting the behavior of food powders. These results were then developed into a computer-simulated model to allow for virtual and visual representation of the conveying action inside an enclosed steel barrel.
Ellis, Matthew. "Simulations of magnetic reversal properties in granular recording media." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/12215/.
Full textArowosola, Babatunde Clement. "Influence of particle-scale properties and gravitational field on flow properties of granular materials." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13295/.
Full textChen, Bingran. "Effects of Chemical Properties of Cyanotoxins on Transport through Granular Activated Carbons." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535374137804276.
Full textRoy, Debasis. "Mechanical properties of granular deposits from self-boring pressuremeter tests." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25149.pdf.
Full textBouvier, Philippe. "The magnetic and magneto-optic properties of sputtered granular layers." Thesis, Coventry University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318531.
Full textHaeberle, Jan [Verfasser], and Matthias [Gutachter] Sperl. "Properties of Tailored Granular Media / Jan Haeberle ; Gutachter: Matthias Sperl." Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1179356039/34.
Full textGu, Xiaoqiang, and 顾晓强. "Dynamic properties of granular materials at the macro and microscales." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47752622.
Full textpublished_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
Evans, T. Matthew. "Microscale Physical and Numerical Investigations of Shear Banding in Granular Soils." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7576.
Full textАртюхов, Артем Євгенович, Артем Евгеньевич Артюхов, and Artem Yevhenovych Artiukhov. "The prospects of granules getting with the specific properties in small-sized vortex devices." Thesis, Государственный институт подготовки и переподготовки кадров промышленности, 2011. http://essuir.sumdu.edu.ua/handle/123456789/26420.
Full textНаиболее простым в производстве и применении взрывчатым веществом является пористая аммиачная селитра (ПАС). ПАС также является основой для производства других взрывчатых веществ. Целью работы является обоснование возможности создания в Украине современного высокоэффективного и экономичного производства ПАС, которое в настоящее время отсутствует. В результате сравнительного анализа потребительских свойств полученного безбашенным способом продукта с российским аналогом показано, что удерживающая способность ПАС по солярового масла колеблется в пределах 9-17% при прочности гранул до 500 гр/гранулу, а удерживающая способность российского аналога - 6,8% при средней прочности гранул 300 гр/гранулу. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/26420
The most simple in manufacture and using of industrial explosive agent is porous ammonium nitrate (PAN). PAN is also a basic for production of other explosives. The purpose of the work is a feasibility study for the establishment in Ukraine of modern highly efficient and economical production of PAN, which is currently absent. As a result, the comparative study of consumer properties of the product received by no-tower method with the Russian analogue is shown that the keeping ability of PAN on solar oil ranges from 9-17% at the strength of granules to 500 g/granule, and the keeping ability of Russian analogue – 6,8% at average strength of granules 300 g/granule. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/26420
O'Reilly, Michael Patrick. "Mechanical properties of granular materials for use in thermal energy stores." Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353925.
Full textNeugebauer, Adam (Adam Halbert). "Thermal properties of granular silica aerogel for high-performance insulation systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85213.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 65-67).
Based on mounting evidence in support of anthropogenic global climate change, there is an urgency for developments in high-performance building techniques and technologies. New construction projects provide substantial opportunities for energy efficiency measures, but they represent only a small portion of the building stock. Conversely, while existing buildings are plentiful, they typically have a much narrower range of feasible energy efficiency options. Therefore, there will continue to be a need for the development of new and improved energy efficiency measures for new building construction and even more so for deep retrofits of existing buildings. This thesis provides an overview of the research performed into the on-going development at MIT of a high-performance panelized insulation system based on silica aerogel. Two test methods were used for measuring the thermal conductivity of the granules: the transient hot-wire technique and the guarded hot-plate system. Utilizing the hot-wire set-up, it was demonstrated that compressing a bed of granules will decrease the thermal conductivity of the system until a minimum point is reached around the monolithic density of the aerogel. For the Cabot granules, this was seen at 13 mW/m-K and about 150 kg/m3. The MIT granules showed equal performance to the Cabot granules at bed densities 20-30 kg/m3 lower. The hot-plate testing was able to experimentally evaluate previous analytical predictions regarding the conductivity impact of the internal panel truss and the under-prediction of radiant heat transfer in the hot-wire method. Hot-wire testing was also done in a vacuum chamber to quantify potential performance improvements at reduced air pressures. Since a vacuum would require the incorporation of a barrier film into the panel system, some analyses were done into the thermal bridging potential and gas diffusion requirements of such a film. Additionally, physical prototyping was done to explore how the film would be incorporated into the existing panel design. The aerogel-based insulation panel being developed at MIT continues to show promise, though there are still plenty of opportunities remaining in the development cycle.
by Adam Neugebauer.
S.M. in Building Technology
Amitai, Shahar. "Statistical mechanics, entropy and macroscopic properties of granular and porous materials." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/54766.
Full textTran, Duc Long. "Impact of intrinsic granular porosity on the durability properties of concrete." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30021.
Full textThe preservation of natural resources and the limitation of CO2 emissions are a contribution to sustainable development. In the context of the concrete design, this contribution consists in using local or recycled aggregates. However, local or recycled aggregates can be porous and of low quality.The scientific community agrees that the intrinsic porosity of aggregates changes the transport properties of concrete, but to what extent is still a question. The objective of the thesis is to analyze the impact of intrinsic coarse aggregate porosity on mainly the durability properties of concrete. In a preliminary understanding and with a view to accentuating phenomena occurring in the concrete, an experimental program is designed for elementary model (EM), which is composed of paste and gravel. The impact of the aggregate nature (porous and non-porous), moisture state and volume together with the binder nature, is analyzed on i) the water porosity of EM, ii) the structuration of the paste-aggregate interface. Next, at concrete scale, materials were designed with the same skeleton of aggregates (same sand) and the same equivalent binder content. The designs varied by the aggregate nature, moisture state, the binder nature, the variation of water/cement ratio and the incorporation of chemical admixtures (plasticizer or superplasticizer). The impact of coarse aggregate porosity on properties in the fresh state (slump, apparent density and entrapped air content) and in the hardened state (compressive strength, water porosity, water absorption, gas permeability, chloride migration, accelerated carbonation and Portlandite content) was studied. The main results show that the moisture state of aggregate and the binder nature are the first factors that condition the structuring of the paste/aggregate interface within the elementary model. The necessity to use porous aggregates in saturated surface dry is particularly highlighted. At the scale of concrete, the properties in the fresh state are influenced by the aggregate porosity and the water/binder (W/B) ratio. However, for a fixed W/B ratio corresponding to fluid consistency, the variations in the fresh properties measured when porous aggregates are incorporated do not depend on the binder nature. In hardened concrete, porosity of aggregate plays an important role in water porosity and air permeability of concrete whatever the nature of binder. For other durability properties (water absorption, Clo migration, carbonation and compressive strength), the nature of binder overcome leading in comparison to the porosity of aggregate
Hughes, Graeme David. "The dynamical properties of percolating structures." Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302931.
Full textTo, Chiu-yin, and 杜昭彥. "A unified elasto-plastic model for saturated loosely compacted completely decomposed granite." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203554.
Full textShertzer, Richard Hayden. "Fabric tensors and effective properties of granular materials with application to snow." Diss., Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/shertzer/ShertzerR0811.pdf.
Full textAl-Awad, Khabeer. "The effect of biological exudates on the mechanical properties of granular soil." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/110599/.
Full textJones, Jay Walter IV. "An examination of scale-dependent electrical resistivity measurements in Oracle granite." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184887.
Full textGamon, T. I. "The influence of weathering on the engineering properties of the Hong Kong Granite." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370155.
Full textШабельник, Юрій Михайлович, Юрий Михайлович Шабельник, Yurii Mykhailovych Shabelnyk, Ірина Володимирівна Чешко, Ирина Владимировна Чешко, Iryna Volodymyrivna Cheshko, Ірина Михайлівна Пазуха, et al. "Electrophysical Properties of Granular Film Alloys Based on Fe and Ag or Au." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42780.
Full textGumbe, Lawrence O. "Mechanical properties of granular materials as related to loads in cylindrical grain silos." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1203011493.
Full textGumbe, Lawrence Otweyo-Migire. "Mechanical properties of granular materials as related to loads in cylindrical grain silos /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487331541710474.
Full textRahmanian, Nejatollah. "Influence of Scale-up of High Shear Mixer Granulators on the Evolved Structure and Properties of Granules." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515389.
Full textMahmoodi, Foad. "Compression Mechanics of Powders and Granular Materials Probed by Force Distributions and a Micromechanically Based Compaction Equation." Doctoral thesis, Uppsala universitet, Institutionen för farmaci, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-171874.
Full textKarmakar, Somnath [Verfasser], and Ralf [Akademischer Betreuer] Seemann. "Experimental investigations of mechanical properties of wet granular materials / Somnath Karmakar. Betreuer: Ralf Seemann." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2014. http://d-nb.info/1072418525/34.
Full textNewton, Nichola. "Preparation and properties of granular ferric hydroxide as an adsorbent in potable water treatment." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/7866.
Full textYan, Luke, Rongrong Huang, Jian Xiao, Huiyun Xia, Min Chao, and Sven Wieβner. "Preparation and properties of a composite made by barium sulfate-containing polytetrafluoroethylene granular powder." Sage, 2016. https://tud.qucosa.de/id/qucosa%3A35550.
Full textAnsharullah, of Western Sydney Hawkesbury University, Faculty of Environmental Management and Agriculture, and School of Food Science. "Characterisation and extrusion of Metroxylon sago starch." THESIS_FEMA_SFS_Ansharullah_X.xml, 1997. http://handle.uws.edu.au:8081/1959.7/490.
Full textDoctor of Philosophy (PhD)
Chmelar, Juraj. "Size Reduction and Specification of Granular Petrol Coke with Respect to Chemical and Physical Properties." Doctoral thesis, Norwegian University of Science and Technology, Department of Geology and Mineral Resources Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1719.
Full textCarbon required for the reduction of alumina by electrolysis in the Hall-Héroult process is supplied by the anode. Anodes are produced from a mixture of petroleum coke with coal tar pitch as the binder. The minimum theoretical carbon consumption is 0.334 kg C/kg Al. But due to current efficiency and oxidation losses the consumption is typically 400 kg C/kg Al.
Petroleum coke is a by-product from crude oil refineries, but as its value represents only about 2 per cent of the overall production it has a limited interest to the producers. Mechanical and physical properties of coke are influenced by the crude oil, processes within the refineries and calcining of the coke. Continuous high demand for calcined coke by aluminium smelters has created a difficult situation with respect to quality and availability, leading to the use of lower quality coke in aluminium smelters and potential disturbances in the production.
Understanding the consequences of varying calcined coke qualities is crucial for to possibly compensate and adjust process parameters in the subsequent use of the coke, in order to obtain economical production of aluminium.
In the present work, the subject of study was four different petroleum coke types, where three were derived from a single source (SSA, SSB and SSC) and one was from a blend of different cokes. All of the cokes had different chemical and physical properties. Single source cokes have homogenous chemical and physical composition in the whole size range while the blended coke had heterogeneous composition due to the mixture of different coke types used. The blended coke consisted of several different coke types (25) in order to meet the required specification.
This work also describes new characterisation/measurement methods which can contribute to a better understanding of variations in material properties due to physical and mechanical changes in the calcined coke feed materials.
Each step in the production of pilot scale anodes is described. A new method was developed for the characterisation of the mechanical strength of calcined coke. This method, the drop test, originates from the study of materials for road construction for the determination of the grain stability of rock materials. The method determines the coke grain strength in the entire size distribution. On the other hand, established measuring methods for calcined coke, HGI (ASTM D5003-95) and grain stability (ISO 10142), determine only the mechanical strength in a specific size range, +0.6-1.18 mm and +4-8 mm, respectively. In other words, both methods give limited information about coke mechanical strength distribution throughout the whole size range, which is especially important when blended cokes are used. Additionally, the results from the drop test are expressed in volume reduction, size reduction, impact force and amount of fines below 148 μm generated during the test. A good correlation between ISO 10142 and the drop test was found. The results show good correlation between the size and volume reduction and the specific grinding energy. The method can also determine the grain strength of a specific size fraction which might be critical to further processing during anode production.
Totally, about 8 tons of four calcined coke types were processed during this work. The majority of this material was ground in the air swept ball mill, for production of the finest fraction, dust. The pilot scale air swept ball mill circuit is identical to the equipment used in industry today. This investigation showed the importance of process optimisation for the stable production of dust with the required specification (particle size and Blaine). Each coke exhibited different behaviour in the grinding circuit, due to different mechanical strengths, which is reported as a specific grinding energy. The mechanically weakest coke produced dust with the lowest specific grinding energy. The particle size variation in the coke used in the mill produced a significant disturbance in the product quality. It was found that the sweeping speed through the mill influences the particle size distribution in terms of the proportion of the finest particles. It also affected the particle roundness of the produced dust, which can influence the flowability of the coke when mixed with pitch. The ratio of ball sizes and the rotational speed of the mill influenced the particle size distribution, Blaine and specific grinding energy.
On-line particle size control was utilised during the dust production. This system allowed continuous control of the product size by regulation of the air classifier rotor speed. Three different dust sizes were produced in the air swept ball mill, which were all below about 200 μm but contained different proportions of material below 63 μm.
Sieved coke fractions together with dust were weighed according to a specified recipe and blended in a sigma blade mixer together with coal tar pitch. A vibration compactor was used for the production of green anodes under optimal conditions. The anodes were produced with three different pitch contents (15, 18 and 20 wt%) and three different dust sizes (45, 63 and 94 %, -63 μm).
Core samples of green anodes were investigated in an improved dilatometer for the determination of thermal expansion and shrinkage during baking. Improvements made to the dilatometer during this work contributed to better reproducibility, increased precision and a healthier working environment. An increase in the heating rate influenced the initial expansion, shrinkage and baking loss of the anode. The heterogeneous pitch distribution throughout the anode due to the forming force, friction between coke particles and between the paste and mould showed the importance of selecting a consistent sampling position. The results showed that the bottom samples have greater expansion due to a thicker pitch bridge layer while the top samples have reduced expansion. The sample packing material contributed to a higher initial expansion due to the reduced free surface area for binder volatiles release, and the shrinkage was reduced because of the radial thrusts from the packing material. Thermal dilation results showed differences between samples with varying pitch, dust size and coke type, which can be used to indicate the final properties of baked anodes. A good correlation was found between the thermal dilation after the pitch expansion and the dust content.
Green anodes were baked under controlled conditions and then characterised. The baked apparent density showed a good correlation with the pitch content and dust size. The results showed that 18 % pitch content and 63 % -63 μm produced the highest baked densities. The variation in coke type exhibited differences in baked density, specific electrical resistance, air permeability, CO2 and air reactivity and modulus of elasticity.