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1
Zhang, Qinghong. "SINTERING BEHAVIOR AND PROPERTIES STUDY IN STOICHIOMETRIC BLENDING BaTiOs." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971278607.
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Ottman, Michael. "Wheat and Barley Varieties for Arizona 2010." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/147013.
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Ottman, Michael J. "Wheat and Barley Varieties for Arizona 2011." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/225875.
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Ottman, Michael J. "Wheat and Barley Varieties for Arizona 2012." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/248911.
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Ottman, Michael J. "Wheat and Barley Varieties for Arizona 2013." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/305109.
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Kalumba, Denis. "Effect of grading and grain size on the friction characteristics of a sand/geotextile inteface." Master's thesis, Faculty of Engineering and the Built Environment, 2020. http://hdl.handle.net/11427/32297.
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Geofabrics are incorporated in geotechnical engineering structures for various reasons and functions. This study addresses the reinforcement function whereby geotextiles are utilised as reinforcing elements in reinforced slopes and fills. It particularly focuses on the soil/geotextile interface behaviour. Geotextile reinforcements transfer a majority of the shear stress from the soil to the reinforcement and vice versa by friction. This interfacing ability manifested by the soil/geotextile frictional contact is very important in the performance of reinforced soil structures, and depends on the physical characteristics of the backfill as well as the geotextile. In this investigation, the interaction behaviour of geotextiles with sand is evaluated by conducting extensive laboratory interface tests both in direct shear and pull-out. A comprehensive test program was established to include a needle punched non-woven geotextile interacting with sands of different grading, grain size distributions and grain shapes namely; Cape Flats, Klipheuwel and Munich sands. The respective responses were primarily presented in terms of shear stress/horizontal displacement and pUll-out resistance/front displacement relationships; showing the frictional performance of the geotextile in these sands of different physical characteristics. Interface shear strength in both test methods was determined using Mohr-Coulomb's law. The ensuing shear strength values were compared with each other and with the direct shear strengths of the respective sands used in this investigation Specific emphasis and detailed analyses went into the pull-out experiments in which local displacements of the geotextile specimens were measured as the test progressed. The measurements enabled the study of the stretching characteristics of the geofabric in the different sands. Applying an extrapolation procedure to approximate the constantly changing deformation modulus of the geotextile as it stretched in the respective sands, allowed the back-prediction of the pull-out force/displacement relationship, and thus enabled the study of skin friction distribution along the geotextile specimen during pull-out. The effect of the grading and grain size on the development of the interface shear stress, the peak values, and the type of interface failure could be demonstrated. The analysis of the skin friction along the geotextile specimen led to the development of a generalised shear stress distribution graph which, if validated in further research, may be adopted in practical design situations. In a design example, it was shown that the assumption of interface shear parameters based on direct shear tests provides too optimistic a factor of safety. This study recommends the use of interface shear parameters derived from pull-out tests. The in-depth analysis of the tests in a variety of sands showed clearly that the shear stress is not uniformly distributed over the embedment length of the reinforcement. This skin friction drops dramatically from a peak value near the loaded end to zero at the free end in all investigated confinements.
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Beucia, Bermane. "Etudes de lien entre écrouissage/restauration et croissance de grains dans les polycristaux métalliques thermomécaniquement transformés." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCD071/document.
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Depuis des décennies, le rôle joué par les joints de grains dans le comportement plastique des matériaux cristallins interroge mécaniciens, métallurgistes, spécialistes des matériaux. Après les avancées décisives de la plasticité individuelle des cristaux et de leur comportement collectif au sein d’agrégats, les effets complexes des interfaces sur le comportement effectif constituent l’enjeu restant à maîtriser. Car si les joints peuvent aussi bien être sites d’endommagement que réseau de consolidation dans une structure polycristalline, ils contribuent toujours fortement aux propriétés macroscopiques de cette dernière. Le travail réalisé est une contribution à l’étude du comportement des joints lors de traitements thermomécaniques induisant leur mobilité. On parle de migration.Nous avons étudié les caractéristiques essentielles de la migration de joints de grains à partir du mécanisme de SIBM (croissance de grains sans germination après faible déformation plastique). La migration des joints de grains sous recuit après déformation a été suivie in situ en MEB. Les évolutions microstructurales sont analysées en MEB et en AFM. Les principales forces et caractéristiques contribuant à la migration des joints sont étudiées. Pour les forces, un diagramme de migration reliant le déplacement des joints à l’énergie de courbure et à l’énergie stockée par déformation plastique a permis d’évaluer la pertinence de l’expression usuelle de la force motrice de migration et d’en discuter de possibles ajustements. Pour les caractéristiques, nous avons confirmé l’effet de surface de la gravure thermique et celui plus intrinsèque des jonctions triples sur la mobilité des joints de grainsFor many decades, the role of grain boundaries in the plastic behavior of crystalline materials questions engineers, metallurgists, materials scientists. After the decisive progress in plasticity of individual crystals and for their collective behavior in aggregates, the complex effects of boundaries on the actual behavior are the remaining challenge to master. If boundaries can as well be considered as damage sites as strengthening network in a poly-crystalline structure, they always contribute greatly to the macroscopic properties of the latter. This work is a contribution to the study of the behavior of boundaries during thermomechanical treatments inducing mobility. We talk about migration.We studied the essential characteristics of the migration of grain boundaries from SIBM mechanism (Strain Induced Boundary Migration). The migration of grain boundaries under annealing after deformation was monitored in situ SEM. Microstructural changes are analyzed by SEM and AFM. The main strengths and characteristics contributing to the boundary migration are studied. For strengths, a migration diagram linking the displacements of grain boundaries to the curvature energy and the stored energy from plastic deformation allowed to assessing of the relevance of the usual expression for the migration driving force and to discussing possible adjustments. For characteristics, we confirmed the surface effect of the thermal grooving and the more intrinsic one of triple junctions on the mobility of grain boundaries
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Luca, Matthieu. "Quality Timber Strength Grading : A prediction of strength using scanned surface grain data and FE-analyses." Thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-14037.
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Goyal, Anchal. "Comportement mécanique d'un alliage d'aluminium à grains ultrafins. Analyse et modélisation du rôle exacerbé des joints de grains." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX091/document.
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Les alliages à grains ultrafins semblent prometteurs, au vu de leur forte résistance en traction et de la possibilité d'une mise en forme superplastique à basse température. Toutefois, leurs mécanismes de déformation, qui comportent une part plus ou moins forte de glissement aux joints de grains restent mal connus, et leurs performances en fatigue ont été peu étudiées. Ce travail vise à comparer et analyser le comportement viscoplastique et les mécanismes de déformation et d'endommagement en traction et en fatigue d’un alliage d’aluminium-magnésium "classique" et à grains ultrafins (600nm en moyenne) obtenu par déformation plastique sévère, selon le procédé ECAP.Des essais de relaxation, fluage et traction à diverses vitesses et températures ont permis de mesurer les évolutions des sensibilités à la vitesse en fonction de ces deux paramètres et de montrer: 1) que le raffinement microstructural accroît sensiblement la sensibilité à la vitesse 2) que ce paramètre augmente avec la vitesse de déformation 3) qu'il contrôle la ductilité du matériau à grains ultrafins, qui s'accroît donc à faible vitesse 4) que cette ductilité devient supérieure à celle du matériau classique lorsque la température s'élève. Les domaines de vitesse et température dans lesquels le raffinement microstructural accroît ou diminue la résistance en traction ont été délimités.Les mécanismes de déformation et d'endommagement des deux matériaux ont été étudiés au moyen d'essais de traction sous MEB accompagnés de mesures des champs de déformation par corrélation d'images à plusieurs échelles: méso et microscopique, grâce à des microgrilles d'or et sub-micrométrique, grâce à un mouchetis très fin obtenu par démouillage d'un film d'or. Le glissement aux joints est d'autant plus actif, dans les deux matériaux, que la température augmente et que la vitesse de déformation diminue. Dans l'alliage à grains ultrafins, il a un caractère coopératif et survient préférentiellement aux joints de forte désorientation. Les champs de déformation sont plus hétérogènes dans le matériau à grains ultrafins, où le taux de déformation dépasse 100% dans des bandes localisées.Un modèle éléments finis 2D intégrant, outre la viscoplasticité au sein des grains, un glissement visqueux des joints, a été identifié dans toute la gamme de température explorée et rend assez bien compte du comportement viscoplastique des deux matériaux et de la contribution beaucoup plus forte du glissement aux joints dans l'alliage à grains ultrafins. Il permet également de préciser comment évolue cette contribution au cours de l'écrouissage.Des essais de traction-compression à déformation plastique imposée ont permis d'étudier la plasticité cyclique et les mécanismes d'endommagement en fatigue oligocyclique et des essais à contrainte imposée, d'explorer la fatigue à grand nombre de cycles. Les essais ont été suivis d'observations des surfaces de rupture et d'une analyse statistique de l'endommagement en surface, ainsi que d'observations au MET des arrangements de dislocations. Les deux matériaux manifestent un durcissement cyclique, plus modeste dans l'alliage à grains ultrafins, qui présente, à forte amplitude, une croissance de ses grains. L'écrouissage isotrope prédomine dans l'alliage classique, où la densité de dislocations augmente fortement avec la plasticité cyclique, alors que l'écrouissage cinématique prédomine dans l'alliage à grains ultrafins, en raison de sa moindre aptitude à stocker des dislocations et de la plus grande hétérogénéité de sa déformation plastique. A même amplitude plastique, ce dernier a une durée de vie plus faible, en raison d'un amorçage bien plus rapide des fissures, à partir de particules intermétalliques. A contrainte imposée, le matériau a grain ultrafins a une durée de vie légèrement supérieure, grâce à une propagation plus lente des microfissures, dont le trajet est transgranulaire dans les plus gros grains et intergranulaire dans les plus petitsUltrafine grained (UFG) alloys seem promising, based on their high tensile properties and the possibility of superplastic forming at relatively low temperature. However, their deformation mechanisms are not fully understood, and their performance in fatigue has not been thoroughly investigated. This work compares the viscoplastic behavior, and the deformation and damage mechanisms in tension and fatigue of a UFG Al-Mg alloy (600 nm mean grain size) obtained by severe plastic deformation (ECAP process) with that of its coarse-grained (CG) counterpart.The strain rate sensitivity (SRS) of both materials has been measured during creep, relaxation and tensile tests run at various strain rates and temperature. Microstructural refinement is shown to increase the SRS, which rises as the strain rate decreases, and controls the ductility. The UFG material becomes softer and more ductile than the CG material at high temperature. The temperature and strain rate domain for which the UFG alloy is stronger or softer has been determined.Tensile tests run in a SEM, with DIC measurements of strain fields at meso/ micro scales (using gold microgrids printed by electron beam lithography) and at sub-micron scale (using a superfine speckle obtained by film remodelling) have shown that grain boundary sliding is more and more active in both materials as the temperature rises and as the strain rate decreases. Grain boundary sliding is cooperative and occurs mostly at high-angle grain boundaries in the UFG alloy, where the strain field is more heterogeneous, and where very high strain levels (> 100%) are often observed in localized bands.A 2D finite element model taking into account the viscoplastic behaviour inside the grains, and viscous sliding at the grain boundaries has been identified other the whole temperature range investigated. It captures well the observed behaviours and the much larger contribution of grain boundary sliding in the UFG alloy. It also provides the evolution of this contribution during strain hardening.Plastic strain-controlled push-pull tests and stress-controlled push-pull tests were run to investigate the cyclic behaviour and damage mechanisms of the two materials in low and high-cycle fatigue. The tests were followed by fractographic observations, statistical analysis of surface damage, as well as TEM observations of dislocations arrangements. Both materials exhibit cyclic hardening, although it is more modest in the UFG alloy, in which grain growth occurs at high amplitude. While isotropic hardening predominates in the CG alloy where the density of dislocation strongly increases during cyclic tests, kinematic hardening predominates in the UFG alloy, because of its limited capacity to store dislocations and its more heterogeneous plastic deformation. For a given plastic strain range, the UFG alloy has a shorter fatigue life than its CG counterpart, because of a much easier crack initiation, mostly from intermetallic particles. For a given stress range, it has a slightly higher life, due to a slower development of microcracks, which have a transgranular path in the largest grains, with some intergranular growth within the smallest grains
10
Dadiotis, Konstantinos. "Improving phase grating and absorption grating diffusers." Thesis, University of Salford, 2010. http://usir.salford.ac.uk/26633/.
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This thesis investigates room acoustic diffusers based on number sequences, exploring their shortcomings and presents improvements. Standard Phase Grating Diffusers display frequencies where they act like flat plates and fail to diffuse. To overcome this, two new sequences (Luke and power residue) are introduced. The diffusers based on these sequences display extended frequency range compared to standard ones such as Quadratic Residue and Primitive Root Diffusers. Their performance is studied using Boundary Element Modelling which shows that they can avoid flat plate phenomena in the audible frequency range. Furthermore, it is shown that by taking advantage of their inner symmetries Quadratic Residue and Primitive Root Diffusers can be created from smaller components thus allowing for the flat plat effect to be mitigated. Next, Absorption Grating Diffusers are investigated. They consist of ideally absorbing and reflecting elements. For their implementation heavily damped Helmholtz Resonators are investigated showing that they give an approximation of the required distribution of admittance on the surface. Then the performance of ideal Absorption Grating Diffusers is investigated using Boundary Element Modelling. Even with idealised completely absorbing elements, the performance of the diffuser is shown not to achieve substantial diffusion. This arises because edge diffraction from the reflecting elements weakens at high frequencies. At frequencies where smaller elements are creating substantial scattering, larger elements are producing specular reflections. Furthermore, due to the lack of cancellation, the specular reflected lobe is insufficiently attenuated, because it can only be changed through absorption. Improvements to the original design are suggested. By changing reflective elements to reactive ones, scattering can be extended to higher frequencies. This allows for a range of frequencies were more reflecting elements display substantial dispersion. Also, implementing the absorbing elements using porous material in a shallow well allows some reflection, resulting in cancellation in the specular reflection lobe due to interference. Measurements of the scattered pressure distribution of absorption grating surfaces are carried out and then compared to Boundary Element Modelling simulations using surface admittance data measured in an impedance tube. The agreement between measurement and simulation is excellent proving the accuracy of this simulation method for these applications. The results show that the samples tested perform as two level Phase Grating Diffusers, with some energy loss, while their diffusion characteristics are shifted to lower frequencies. This arises because of the lower speed of sound in the porous medium. This implementation is shown to absorb 50% of the incident sound while the rest is scattered uniformly but only over a limited bandwidth.
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Hassanabadi, Massoud. "Grain Refinement of Commercial EC Grade 1070 Aluminium Alloy for Electrical Application." Thesis, KTH, Materialvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163402.
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The aluminium alloys for electrical conductivity applications are generally not grain refinedsince the addition of grain refiners drops the electrical conductivity by introducing impuritiesinto the melt. Non-grain refined aluminium may lead to bar fracture and cracks during themetalworking process. The present study focuses to find an optimum balance between the grain refiner addition andthe electrical conductivity of commercial EC grade 1070 aluminium alloy for electricalapplication. In order to reach this goal, the electrical conductivity and the macrostructure ofcommercial EC grade 1070 aluminium (commercial pure aluminium) have been studiedunder a series of controlled lab scale trails. Specific addition levels of different grain refiners(TiBloy, Al-5Ti-1B, Al-3Ti-0.15C, and Al-3Ti-1B) were added to the metal melt and sampleswere taken at specific time intervals. The collected samples were sectioned, ground andmacro-etched. Thereafter, the macrostructure was analysed by the use of a digital camera andthe electrical conductivity was measured at temperature. The obtained result was expressed asa percentage of the International Annealed Copper Standard (IACS %). The macro-structuralanalysis showed that TiBloy, Al-5Ti-1B, and Al-3Ti-1B, with the maximum addition level of0.1%, cannot grin refine commercial pure aluminium. However, at higher grain refiner levelsthe number of columnar grains increased and their size decreased. The Al-3Ti-0.15C master alloy, with the same addition level as the once chosen for the othergrain refiners (up to 0.1%), showed significantly better grain refining. By the addition of0.1% of this grain refiner the macrostructure became very equiaxed already after 30 minutesof grain refiner addition. The fading of the Al-3Ti-0.15 master alloy was, however, observedfor samples with a long holding time. Nevertheless, by maximum addition level (0.1%) and a90 minutes holding time the macrostructure remained as equiaxed grains. The electrical conductivity results showed that none of the applied grain refiners (TiBloy, Al-5Ti-1B, Al-3Ti-0.15C, and Al-3Ti-1B), with the maximum addition level of 0.1%, decreasedthe electrical conductivity of commercial pure aluminium.
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Wade, James C. "Summary of 1990 Estimated Cost of Growing Wheat in Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201346.
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Doerge, T. A., and M. J. Ottman. "Predicting Late Season Nitrogen Fertilizer Requirements of Irrigated Durum Wheat Using Stem Nitrate Analyses." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201347.
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A field experiment was conducted on a Casa Grande sandy loam at the Maricopa Agricultural Center to 1) determine the optimum rates of late season N needed to achieve optimum yield and quality of irrigated dumm wheat in conjunction with varying rates of early season N, and 2) to evaluate the usefulness of stem NO₃⁻N analysis in predicting the late season N rates which optimize grain production but minimize the potential for nitrate pollution of groundwater. The application of 80, 195 and 350 lbs. N/a during vegetative growth resulted in wheat with deficient, sufficient and excessive N status at the boot stage as indicated by stem NO₃⁻N analysis. The application of 60 lbs. N/a at heading to N-deficient wheat and 15 lbs. N/a to N-sufficient wheat resulted in grain protein levels above 14% but had little effect on grain yield. Applications of N at heading to wheat which had previously received excessive N did not affect grain yield or quality. The use of stem NO₃⁻N analysis appears to be a useful tool in predicting the minimum N rate to be applied during the early reproductive period to insure acceptable levels of grain protein at harvest.
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Clark, Lee J., and Eddie W. Carpenter. "Wheat and Barley Rate and Date Studies: Safford Agricultural Center, 1988 to 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201267.
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Seeding rates of wheat and barley varying from 50 to 250 pounds per acre were planted at four or five planting dates from the 1987-88 season to the 1989-90 season. Optimum seeding rates for wheat seemed to be near the upper limit whereas for barley it fell between 150 and 250 pounds per acre. This is considerably higher than what is commonly recommended in other parts of the state.
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Tickes, Barry R., and Stanley Heathman. "An Evaluation of Potential New Treatments for Canarygrass Control in Red Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201268.
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Canarygrass (Phalaris minor) has become an increasingly widespread weed in wheat grown in central and southwestern Arizona. Only two herbicides, Barban and Diclofop, have been used effectively to control this weed. The registration of Barban was dropped in 1989 and the labeled rate of Diclofop was lowered to marginal control levels in 1990. A test was conducted to evaluate potential new treatments for the control of canarygrass. One treatment; Puma at 1.14 lbs./A resulted in excellent control of this weed.
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Clark, Lee J., and Eddie W. Carpenter. "A Comparison of Irrigation Scheduling Methods on Durum Wheat, Safford Agricultural Center, 1988-90." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201348.
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Four irrigation scheduling methods are compared over a three year period on the Safford Agricultural Center. A computerized checkbook method based on the consumptive water use curves of Erie, et al, updated with near real time evapotranspiration data from the AZMET system and utilizing empirical crop coefficients, produced the highest yields and with the highest water use efficiency. Scheduling irrigations with the IR thermometer produced yields higher than the Check when a Stress Index threshold of 2 (similar to a CWSI of 0.2) was used, but not with a threshold value of 3 nor 4. A method of irrigation scheduling using Erie's curves, but not updated for current weather values, yielded less than the check in all years of the study, and was not considered an acceptable method Irrigation inputs from the 1990 season were plugged into new near real time irrigation scheduling software which utilizes AZMET data to determine both evapotranspiration and crop coefficients. This method was found to track the field data quite well and will be utilized in future research.
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Garrot, D. J. Jr, M. J. Ottman, D. D. Fangmeier, S. H. Husman, and J. M. Harper. "Scheduling Wheat Irrigations Using Infrared Thermometers and the Crop Water Stress Index in Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201349.
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Durum wheat (Triticum turgidum L. var. durum ) is grown as a winter annual crop, normally in rotation with cotton, and in 1989, comprised 121,500 acres in Arizona. Winter rainfall is insignificant, therefore water is supplied totally through surface irrigation. The relationship between the timing and amount of irrigation water applied and grain yields have not been well -defined Field plot studies were conducted in 1986 and 1987 to test the feasibility of using the Crop Water Stress Index (CWSI) to time wheat irrigations and also to determine the relationship among the CWSI, grain production, and water applied The study was repeated at the commercial production level with a grower cooperator in 1989 to determine the usefulness of CWSI scheduling on large farms. Highest grain production was attained when irrigations were scheduled when the CWSI averaged 0.37 and 0.30 units on small plots for 1986 and 1987, respectively. At the grower production level, highest yields were attained when irrigations were scheduled when the CWSI averaged 0.17 units. In 1986 and 1987 scheduling irrigations at lower CWSI values did not significantly increase grain production while requiring more applied water than the optimum CWSI values. Scheduling irrigations at CWSI's exceeding the optimum values did significantly reduce grain production from the optimum, but required less applied water in all three years.
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Ottman, Michael J. "Small Grains Variety Evaluation at Maricopa and Yuma, 2009." College of Agriculture, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/203772.
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Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
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Ottman, M. J. "Small Grains Variety Evaluation at Arizona City, Coolidge, Maricopa and Yuma, 2012." College of Agriculture, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/279394.
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Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
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Clark, L. J., and R. E. Cluff. "Feed Wheat Variety Demonstration in Graham County, 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201013.
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Two wheat varieties were grown in Graham county as a follow -up to a previous field demonstration. AC79-97, a red wheat developed by the University of Arizona for the Safford area, yielded 6719 pounds per acre, compared with 6359 pounds per acre for Super-X. The protein differential made the crop values even more important than the yield comparison. AC79-97 produced $454 per acre, compared to $423 for Super-X. Using two year's data, AC79-97 produced 85 more pounds of protein per acre than Super-X, with a protein supplement replacement value of $28 per acre.
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Sheedy, M., M. Ottman, and T. Ramage. "Oat Variety Grain and Forage Yield Trials at the Maricopa Agricultural Center 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201031.
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Sheedy, M., M. Ottman, and T. Ramage. "Small Grain Variety Comparisons at the Maricopa Agriculutral Center, 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201050.
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Sheedy, M., M. Ottman, and T. Ramage. "Forage Production of Four Crops Grown Under Two Different Irrigation Cultures." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201051.
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Winans, S. S., M. J. Ottman, and T. A. Doerge. "Wheat and Durum Variety Trial in Poston, 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201069.
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Sheedy, M., M. Ottman, and T. Ramage. "Oat Variety Grain and Forage Yield Trials at the Maricopa Agricultural Center, 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201345.
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Twelve oat varieties (9 hulled and 3 hull-less) were yield tested for both forage and grain production at the Maricopa Agricultural Center during the '89-90 growing season. Highest forage producing varieties were generally later maturing - Cayuse and Stampede; while lower yields were produced by early maturing varieties - Montezuma and Palestine. Highest grain yields were produced by Swan and FMC400.
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Sheedy, M., M. Ottman, and T. Ramage. "Small Grain Variety Comparisons at the Maricopa Agricultural Center, 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201266.
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Yield trials were conducted at the Maricopa Agricultural Center during the '89 -90 growing season. Barley, durum and wheat varieties as well as experimental lines from various seed companies were tested for yield performance. Gustoe and two experimental lines, 7024 and PHS84-11, were the highest yielding barley entries. Aldura, Turbo and Aldente were the top yielding durum varieties. 911, Probred and BR5738-1 were the top yielding wheat cultivars.
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Sheedy, M., M. Ottman, and T. Ramage. "Forage Production of Four Crops Grown Under Two Different Production Cultures, 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201344.
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Forage trials of four crops grown under high-input and low-input production cultures were performed at the Maricopa Agricultural Center. Six varieties of each crop were grown to evaluate yield potential under both production cultures. Only a preplant irrigation was applied to the low-input culture, but up to four additional irrigations were applied to the high-input culture. No fertilizer application was given to low-input, but a total of 135#N/A and 75#P₂O₅/A was applied to the full production culture. Barley, durum, and wheat cultivars developed for grain yield under a low-input production culture were tested for forage production under both high- and low-input practices. No advantage in forage production was observed by using the following varieties in a low-input production culture: Stampede oats, Westford barley, Mexicali durum, and 911 wheat produced the highest yields in each of the four crops. Yields were greater from crops grown under a high-input culture: Stampede oats, Harlan II barley, Aldura durum, and 911 wheat were highest yielding varieties in each crop.
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Ottman, M. J., and T. A. Doerge. "Durum Quality is Related to Water and Nitrogen Management." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201419.
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Ottman, M. J., and S. H. Husman. "Nitrogen Fertilizer Movement in Wheat Production, Higley." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201420.
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Ottman, M. J., and S. H. Husman. "Nitrogen Fertilizer Movement in Wheat Production, Yuma." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201421.
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Ottman, M. J., and G. Hareland. "Small Grains Variety Evaluation at the Maricopa Agricultural Center, 1993." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201422.
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Ottman, M. J., and G. Hareland. "Small Grains Variety Evaluation at the Maricopa Agricultural Center, 1994 (Preliminary)." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201423.
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Ottman, M. J., and B. R. Tickes. "Nitrogen Fertilizer Movement in Wheat Production, Roll." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201429.
Full textAbstract:
Labeled nitrogen fertilizer (N-15) was applied to wheat to determine fertilizer nitrogen movement in the soil at harvest. Most of the labeled fertilizer recovered in the soil was found in the surface few feet. The amount of nitrogen fertilizer detected below S feet was minimal.
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Ottman, M. J., and N. Vigorito. "Nitrogen Fertilizer Movement in the Soil as Influenced by Nitrogen Rate and Timing in Wheat Production, 1991." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201430.
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Ottman, M. J., and N. Vigorito. "Nitrogen Fertilizer Movement in the Soil as Influenced by Nitrogen Rate and Timing in Wheat Production, 1992." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201431.
Full textAbstract:
Durum wheat was grown with deficient, adequate, and excessive rates of ¹⁵N-labeled nitrogen fertilizer in order to document fertilizer nitrogen movement in the soil with differing nitrogen management. Crop water use increased with nitrogen rate due to increased vegetative growth. The amount of excess water applied increased with a decrease in nitrogen rate. Soil bromide concentrations at harvest suggest that the maximum potential depth of leaching was 3 to 6 feet. Most of the fertilizer applied in this study was recovered in the top 2 to 3 feet of soil. Fertilizer nitrogen rate and timing resulted in some differences in recovery of labeled fertilizer in the soil and plant, but did not contribute significantly to the depth of fertilizer nitrogen leaching.
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Clark, L. J., and E. W. Carpenter. "Barley Variety Trials at the Safford Agricultural Center, 1994." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201432.
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Clark, L. J., and E. W. Carpenter. "Durum Wheat Variety Trials on the Safford Agricultural Center, 1994." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201434.
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Griniova, Livija. "Grūdų produktų riebalų rūgščių sudėties įvertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140618_233053-23857.
Full textAbstract:
Darbo tikslas: išanalizuoti ir įvertinti riebalų rūgščių sudėtį dažniausiai vartojamuose grūdų gaminiuose, įvertinti terminio apdorojimo įtaką riebalų rūgščių sudėčiai kepiniuose su spelta miltais.
Darbo uždaviniai: 1. Atlikti vartotojų apklausą apie grūdų produktų vartojimą, pasirinkimo kriterijus bei žinias apie palankias sveikatai riebalų rūgštis. 2. Atlikti riebalų rūgščių sudėties tyrimus grūdų gaminiuose: kruopose, miltuose, džiūvėsėliuose , palyginti riebalų rūgščių kompozicijas. 3. Įvertinti gautus rezultatus ir nustatyti palankiausia sveikatai sudėtimi pasižyminčius grūdų gaminius. 4. Atlikti terminio apdorojimo įtakos riebalų rūgščių sudėčiai kepiniuose su speltos miltais tyrimus. 5. Pateikti rekomendacijas vartotojams apie saugiausius ir palankiausius sveikatai grūdų produktus.
Atlikus „Riebalų rūgštys žmogaus mityboje“ žmonių apklausą, nustatyta, kad vartotojai vartoja maisto produktus, kuriuose gausu riebalų rūgščių, žino, kad grūdai vieni iš pagrindinių riebalų rūgščių šaltinių, dažnai juos vartoja savo mityboje, žino teigiamą jų poveikį žmogaus organizmui. Atlikti riebalų rūgščių sudėties tyrimai grūdų gaminiuose: kruopose, miltuose, džiūvėsėliuose parodė, iš visų tirtų mėginių duomenų daugiausia sočiųjų riebalų rūgščių nustatyta ryžių dribsniuose su džiovintais vaisiais 89,8 proc. (%), mažiausias kiekis - miltiniame mišinyje speltos miltų blynams su gemalais 13,8 proc. (%), polinesočių riebalų rūgščių didžiausias kiekis nustatytas iškeptų spelta miltų... [toliau žr. visą tekstą]The aim of work: analyze and evaluate the fatty acid’s compositions in commonly consumed grain products, assess the impact of thermal processing fatty acid’s compositions in bakery with spelta flour. Work objectives: 1. Make the survey of users’ about consumption of grain products, criteria of selection and knowledge about positive fatty acid’s influence to the health. 2. Conduct fatty acid’s compositions’ researches in grain products: in grits, flour, breadcrumbs, compare the fatty acid’s compositions. 3. Evaluate the results and determine the most favorable to the health composition, which having the characteristics of grain products. 4. Make the researches of thermal processing impact to fatty acid‘s compositions in bakery with spelta flour. 5. Leave recommendations to the users about the safest and to the most favorable health grain products. Completed "Fatty acids in human dietary" users survey was found that users are eating food rich of fatty acids, they know, that grains are one of the main essential of fatty acids, which often used in our dietary and know their positive effect on human‘s organism. Completed compositions of fatty acid‘s in grain products analysis: in grains, flour, breadcrumbs showed that in all analyzed samples data mainly saturated fatty acids found in rice flakes with dried fruits 89.8 percent (%), and the lowest amount found in flour mixture spelta for pancakes with germs 13.8 percent (%), the maximum amount of polyunsaturated fatty acids were... [to full text]
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Day, A. D., M. A. Solomon, M. J. Ottman, and B. B. Taylor. "High Rates of Sewage Sludge in Wheat Production." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201070.
Full textAbstract:
A greenhouse experiment was conducted at the University of Arizona, Tucson, Arizona, to study the effects of sewage sludge loading rates on the vegetative growth, yield, and heavy metal contents of wheat grain and straw. Vegetative growth, grain and straw yields were similar whether wheat was fertilized with the recommended rate of inorganic N (112 kg/ha) or equivalent amounts of plant-available N from sewage sludge. Sewage sludge loading rates higher than three times the recommended plant- available N level delayed maturity and decreased wheat stands in the seedling stage; however, grain and straw yields were similar for all sewage sludge loading rates. Concentrations of cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn) in wheat grain and straw and in the soil following each harvest were low and similar for all fertilizer treatments.
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Ottman, M. J. "Small Grains Variety Evaluation at Arizona City, Coolidge, Maricopa and Yuma, 2011." College of Agriculture, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/211136.
Full textAbstract:
Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
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Ottman, M. J. "Small Grains Variety Evaluation at Maricopa, Coolidge and Yuma, 2010." College of Agriculture, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/279395.
Full textAbstract:
Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
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Vaugeois, Antoine. "Modélisation de l'influence de la structure des joints de grains sur les phénomènes de ségrégation." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR096/document.
Full textAbstract:
La présente étude porte sur la modélisation de la structure des joints de grains (JG) et sur les phénomènes de ségrégation. Dans les matériaux polycristallins, la ségrégation aux joints de grains a des conséquences importantes sur leurs propriétés structurelles et fonctionnelles : glissement intergranulaire, corrosion intergranulaire et modification des propriétés mécaniques. Ce phénomène devient particulièrement important pour les matériaux irradiés où la ségrégation intergranulaire induite par irradiation peut conduire à une modification locale de la composition des joints de grains et par conséquent, à une évolution parfois néfaste des propriétés macroscopiques de ces matériaux. Dans ce manuscrit, nous nous sommes focalisés sur le développement de la méthode des quasiparticules pour pouvoir modéliser ce phénomène dans des systèmes binaires. La méthode des quasi-particules est un modèle continu qui permet de modéliser les phénomènes physiques à l’échelle atomique. Un des avantages est lié à la possibilité de modéliser les déplacements des atomes dans l’espace continu, tout en permettant de modéliser des transitions diffusives s’étalant sur des temps longs. Dans ce travail la méthode des quasi-particules a été appliquée pour étudier la ségrégation du phosphore aux JG. Le lien entre les différentes structures des JG et la concentration du phosphore aux JG a été établi. Pour modéliser les phénomènes qui ont lieu aux JG dans les matériaux irradiés le modèle des quasi-particules a été développé pour pouvoir inclure des lacunes ou des auto-interstitiels puis décrire leurs cinétiques. Ensuite la diffusion et l’annihilation des lacunes (ou des auto-interstitiels) aux JG ont été modélisées. Il a été montré que lorsque la force de puits du JG est assez importante, les lacunes diffusent vers les JG et des cavités se forment aux JG en ayant une forme allongée, ce qui concorde avec les données expérimentales. Le modèle des quasi-particules a été également appliqué pour étudier la croissance des grains dans un polycristalThis thesis focuses on the modeling of grain boundaries (GB) structure and segregation phenomena. Segregation at GB in polycrystalline materials can have profound consequences on structural and functional properties : intergranular slipping, intergranular corrosion and mechanical properties. Segregation becomes really important in irradiated materials where radiation-induced segregation can change th local composition of GB and sometimes impact the macroscopic properties of materials. In this work, the quasi-particles approach is developed to model these phenomena in binary systems. The quasi-particles approach is a continuous model able to model physical phenomena at atomic scale. One of the insight of this model is the capability to simulate atomic displacement in continuum space and diffusive transitions at mesoscale. In this work, the quasi-particles approach is used to study phosphorus segregation at GB. The link between GB structure and phosphorus concentration is highlighted. Next, vacancies or self-interstitial are introduced into the quasi-particles approach to model some specific phenomena which occur in irradiated materials. In particular, the diffusion and annihilation of vacancies (or self-interstitials) at GB could be modeled. When sink strength of GB is large enough, vacancies diffuse to GB and create voids with elongated shape, consistantly with experimental observation. Finally, the quasi-particles approach is used to study grain growth in polycrystalline materials
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Michaels, Joshua O. "Cross Grain." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1407406914.
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44
Day, A. D., M. A. Solomon, M. J. Ottman, and B. B. Taylor. "High Rates of Sewage Sludge in Barley Production." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201052.
Full textAbstract:
A greenhouse experiment was conducted at the University of Arizona, Tucson, Arizona, to study the effects of liquid sewage sludge loading rates on the vegetative growth, yield, and quality of barley grain and straw. Vegetative growth, grain yields, and straw yields were similar whether barley was grown with inorganic N or equivalent amounts of plant-available N from sewage sludge. Sewage sludge loading rates higher than three times the recommended plant-available N rate decreased barley stands in the seedling stage. The loss of stand was compensated for by higher tillering later in the season. High sludge loading rates tended to delay maturity, increase tillering and increase straw yield; however, they did not affect grain yield. Concentrations of cadmium (Cd), copper, (Cu), lead (Pb), nickel (Ni), and zinc (Zn) in barley grain and straw and the amounts of heavy metals recovered in the soil following each harvest were similar to the control for all sewage sludge treatments.
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Knowles, T., T. Doerge, and M. Ottman. "Interpretation of Basal Stem Nitrate-N Concentrations for Improved Nitrogen Management in Irrigated Durum Wheat Production." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201071.
Full textAbstract:
Attempts to characterize nitrogen (N) status of irrigated spring wheat by using basal stem nitrate - N (NO₃⁻N) tissue tests have shown contradictory results, due to the wide range of agronomic conditions existing in Arizona. Seven N fertility trials were conducted at the Maricopa and Safford Agricultural Centers over the 1985-88 crop years to examine the effects of N rate, N fertilizer form, residual soil N, soil texture and contrasting varieties on basal stem NO₃⁻N concentrations, yield and quality of irrigated durum wheat. Fertilizer N treatments were broadcast at planting then at the 5-6 leaf, boot and anthesis growth stages to simulate fertigation in conjunction with the first four basin irrigation events. Stem tissue samples were taken from all plots at the 3-4 leaf 5-6 leaf joint, boot and anthesis growth stages for NO₃⁻N analysis with a nitrate electrode. Diagnostic levels for durum wheat basal stem tissue NO₃⁻N tests at these growth stages are presented.
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Knowles, T., T. Doerge, L. Clark, and E. Carpenter. "Effects of Residual and Fertilizer Phosphorus on Durum Wheat Production and Wheat Stem Phosphate Levels." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201072.
Full textAbstract:
Collecting additional data to calibrate and refine current guidelines for interpreting soil and plant test values is an ongoing need in Arizona. An experiment was conducted at the Safford Agricultural Center during the 1987 -89 crop years to evaluate the response of 'Aldura' durum wheat to a range of residual soil and fertilizer P levels. Maximum grain yields exceeding 5,500 lbs./A were obtained by banding 50 lbs. P₂O₅/A as triple superphosphate with the seed at planting in 1988. Residual P front phosphorus fertilizer applications up to 80 lbs. P₂O₅/A had no significant effect on grain yields of the succeeding wheat crop. Basal stem PO₄-P tissue analysis seemed reliable in monitoring P nutrition of durum wheat during the vegetative growth period. Observed critical levels of POD P in basal stem tissue for durum wheat at the 3-4 leaf, joint and boot growth stages were 2000, 1200 and 500 ppm, respectively.
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Doerge, T. A., T. C. Knowles, L. Clark, and E. Carpenter. "Effects of Early Season Nitrogen Rates on Stem Nitrate Levels and Nitrogen Fertilizer Requirements During Grain Filling for Irrigated Durum Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201074.
Full textAbstract:
A field experiment was conducted on a Pima clay loam at the Safford Agricultural Center to: 1) determine the optimum rates of late season N needed to achieve optimum yield and quality of irrigated durum wheat in conjunction with varying rates of early season N; and 2) evaluate the usefulness of stern NO₃-N analysis in predicting the late season N rates which optimize grain production but minimize the potential for nitrate pollution of groundwater. The application of 75, 175 and 350 lbs. N/a during vegetative growth resulted in wheat with deficient, sufficient and excessive N status at the boot stage, as indicated by stem NO₃-N analysis. The application of 60 lbs. N/a at heading to N- deficient wheat and 15-20 lbs. N/a to N-sufficient wheat resulted in grain protein levels above 14 %, but the applications had little effecton grain yield. Applications of N at heading to wheat which had previously received excessive N did not affect grain yield or quality. The use of stein NO₃-N analysis appears to be a useful tool in predicting the minimum N rate to be applied during the early reproductive period to insure acceptable levels of grain protein at harvest.
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Clark, L. J., and E. W. Carpenter. "Wheat Irrigation Scheduling at the Safford Agricultural Center, 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201075.
Full textAbstract:
Wheat irrigations were scheduled using two computer models and an infrared thermometer, using three critical threshold values. Yields from these plots were compared with plots scheduled by the farm manager. The highest yield was obtained by the computer model using evapotranspiration data taken from the local AZMET station; this corroborates results from the previous year. The crop coefficients and the irrigation model that have been developed over the past several years are very accurate for this area. The two lower threshold infrared treatments were second and third in yield and had lower water use efficiencies.
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Nordin, Anna. "Tillverkning av grafen-kiselkompositer till litiumjonbatterier." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278844.
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I kommersiella litiumjonbatterier används ofta grafit i anodmaterialet, främst på grund av att det reversibelt kan placeras litiumjoner mellan dess lager. Grafit har dock en begränsad energitäthet och forskning bedrivs därför för att finna metoder som kan öka energitätheten hos anodmaterialet. Kisel, som har en betydigt högre energitäthet, kan interkalleras i grafiten för att öka energitätheten. För att undvika en förstörande volymexpansion som sker under litieringen när kisel tillämpas måste interkalleringen göras med kiselnanopartiklar. En skalbar metod för att framställa kiselnanopartiklar på nanografitflak har tagits fram och presenterats i en artikel av Phadatare et al. Syftet bakom det här arbetet har varit att lägga grund för en storskalig produktion av kiselbaserade anoder avsedda att användas i litiumjonbatterier för att ge dem en ökad kapacitet. Målet med arbetet var att genom laborativa undersökningar presentera hurvida metoden presenterad i artikeln är repeterbar samt hur olika parametrar påverkar resultatet inför en uppskalning. Resultaten bekräftade att metoden presenterad i artikeln är repeterbar och att den tillhörande ugnsprocessen bör utföras i en rörugn. Resultaten visade också att temperaturen för ugnsprocessen inte bör sänkas till så lågt som 600 °C, men att potential finns för att kunna sänka temperaturen från nuvarande 800 °C. Vid nuvarande temperatur bör andelen kisel inte ökas till ≥ 47 %, men bedöms ha potential att kunna ökas från nuvarande 33 %. Resultaten visade endast en liten bildning av kiselnanopartiklar då ett kiselpulver av annan kvalitet än det beskrivet i artikeln användes och visade på att valet av utgångsmaterialet är av stor vikt. Resultaten visade vidare att dispergeringsmedlet polyvinylakohol, PVA, inte kan uteslutas. Resultaten tydde på att det finns potential för att kunna minska andelen PVA, men att det inte bör reduceras till motsvarande en halverad koncerntration av vad som presenterats i artikeln. Resultaten visade också att processen måste utföras i en syrefattig miljö för att inte orsaka oxidaton av nanografiten. Däremot tydde resultaten på att mekanismen för bildningen av kiselnanopartiklar inte är syrekänslig och att mekanismen inte tycks vara beroende av att just PVA utgör den, om teorin stämmer, nödvändiga vätekällan.In commercial lithium ion batteries graphite is often used in the anode material, mainly because it can reversibly contain lithium ions between the layers. However, graphite has a limited energy density and research is therefore being performed to find methods that will increase the energy density of the anode material. Silicon, which has a significantly higher energy density, can be intercalated in the graphite to increase the energy density. However, in order to avoid a destructive volume expansion that occurs during the lithiation, the intercalation must be performed with silicon nanoparticles. A scalable method for producing silicon nanoparticles on nanographite flakes has been developed and presented in an article by Phadatare et al. The purpose behind this work has been to lay the foundation for large-scale production of silicon- based anodes intended to be used in lithium-ion batteries to provide them with increased capacity. The aim of the work was to present whether the method is repeatable and how different parameters affect the results for an upscaling, which was done through laboratory investigations. The results confirmed that the method presented in the article is repeatable and that the process should be carried out using a tube furnace. The results also showed that the temperature of the oven process should not be lowered to 600 °C, but that there is potential to lower it from the current 800 °C. At the current temperature, the percentage of silicon should not be increased to ≥ 47 %, but is considered to have the potential to be increased from the current 33 %. Only a small proportion of silicon nanoparticles was formed when a silicon powder of a different quality than that described in the article was used and showed that the choice of the silicon starting material is of great importance. The results further revealed that the dispersant polyvinyl alcohol, PVA, cannot be excluded. The results showed that there is potential to reduce the proportion of PVA, but that it should not be reduced to as much as half the concentration that is presented in the article. The results showed that the process must be carried out in an oxygen-poor environment in order not to cause oxidation of the nanographite. However, the results also indicated that the mechanism for the formation of silicon nanoparticles is not oxygen sensitive and that the mechanism, if the existing theory is correct, does not appear to be dependent on PVA beeing the source of hydrogen.
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Annis, Margaret Catherine, and n/a. "Extending stored grain research and technology to grain farmers." University of Canberra. Education, 1995. http://erl.canberra.edu.au./public/adt-AUC20060602.115607.
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This thesis is concerned with an investigation into current on-farm grain storage
practice and with ascertaining what educational interventions, if any, are appropriate
for future and more detailed consideration. The Australian grain growing, handling,
and marketing industry has changed in recent times. A few years ago (1989), the grain
growers only essential contact with grain marketing was through the bulk handling
authorities and the Australian Wheat Board. Advice was freely available from state
departments of agriculture, and the only requirement to store grain on-farm was that
necessary for the grower's own needs.
Now (1994), there is a possible advantage that grain stored on-farm may be used for a
wide range of selling options, amongst other reasons, and market requirements are
much more complex and stringent. There is a substantial body of research on grain
storage techniques. At the same time there is a significant gap between researched
knowledge and the use of this knowledge for on-farm storage. A major purpose of this
study is to identify an improved approach to extension and farmer education that may
help to reduce this gap.
This thesis contains a review of the general literature on extension followed by an
overview of extension in the developed world to establish the international context for
Australia. Then the historical context of extension is examined briefly to understand
the current situation in each state. Some educational models are reviewed to identify
relationships between stakeholders and the opportunities available for and constraints
to development of educational strategies. Information channels are reviewed to
comprehend extension interaction and grain storage technologies are reviewed to
ensure comprehension of techniques.
On the basis of the literature review a field study was designed to investigate current
on-farm storage practice, current extension sources for storage information and
preferences for future educational interventions. This was done by a survey using a
stratified random sample of grain growers and cluster selection of individuals for
personal interviews. This information was complemented by informal discussion with
farmers at field days.
The results of the study confirmed the gap between research knowledge and on-farm
implementation of this knowledge. They also demonstrated that grain growers wanted
more information and gave some indicators of how this might be achieved. Major
findings of the research included the need for extension coalitions and the desirability
for active involvement of the grain grower.
Major conclusions, for on-farm storage and extension, are drawn to form a basis for
development of future extension interventions. These are aimed at ensuring grain
growers have available the information needed for good storage practice. This includes
an essential understanding the grain growers' needs and perceptions, early, in any
planning process. It also includes the necessity for coordination of extension/education
activities at local, regional and national levels.
The research has some major implications for an improved approach to extension and
on-farm storage. These include the establishment of a farmers-as-researcher program to
implement grain storage innovations and the recognition that implemented change will
need long term maintenance; often more resource intensive than the original
intervention.