Дисертації з теми "Melt transfer"
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1
Chakraborty, Sanjib. "Melt flow and heat transfer in continuous casting ladles and tundishes /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487694389392267.
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2
Dyck, Brendan. "Textural and petrological studies of anatexis and melt transfer in the Himalayan Orogen." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:98cc1d84-d552-447d-a54a-0f028eecf0f7.
Повний текст джерелаАнотація:
Mineral textures, preserved in the metamorphosed sedimentary sequences that are exposed in orogenic hinterlands, are crucial to understanding the architecture and evolution of collisional mountain belts. In this thesis the textural record of anatexis and melt transfer in the Himalayan metamorphic core is decoded and the controls that these processes exert on the tectonic evolution of the Himalaya are explored. The problem is divided into two parts, corresponding to variations in protolith lithostratigraphy: melt source - the pelitic region where melt was first generated, and melt sink - the psammitic region where melt accumulated and crystallised. Dehydration melting of muscovite has long been recognized as a critical reaction for the generation of anatectic melt in the Himalaya, but a textural understanding of how this reaction progresses is limited by the inherent difficulties in identifying specific reaction products. Using samples collected from the Langtang area in central Nepal, a mechanistic model for muscovite dehydration melting was constructed, and a set of textural criteria were developed, which were used to distinguish peritectic K-feldspar from K-feldspar grains formed during melt crystallisation. Melt is transferred from the source to the sink in two stages: firstly along a pervasive network of mineral grain boundaries, and secondly via a channelised network of sills and dykes in the melt sink where it solidified as leucogranite. Variation in the primary mineral assemblage and appearance of leucogranite bodies reflect the degree of interaction that occurred between the melt and metasedimentary country rock, rather than a change in primary melt composition. The modal proportion of K-feldspar in the melt source requires vapour-absent conditions during muscovite dehydration melting and leucogranite formation, indicating that the generation of large volumes of granitic melts in orogenic belts is not necessarily contingent on an external source of fluids. The crystallisation of hydrous minerals in leucogranite consumes <15.5 % of water released by the breakdown of muscovite. These results indicate that anatexis efficiently dehydrates the middle crust and suggests that the continents have limited potential to store water over geological time.
3
Hsiao, Hsien-Fu. "Mechanical behavior and heat transfer in polymer fiber melt-spinning and drawing processes." Connect to resource, 1997. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osuosu1243349868.
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4
Zhao, Yuer. "A Numerical Study of Melt Pool Heat Transfer in the IVR of a PWR." Thesis, KTH, Fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297867.
Повний текст джерелаАнотація:
This thesis aims to provide the thermal condition of melt pool convection by CFD simulation, which is important to the assessment of the invessel melt retention (IVR) strategy widely adopted in Generation III pressurized water reactors (PWRs). As a severe accident mitigation measure, the IVR strategy is realized through external cooling of the lower head of a reactor pressure vessel (RPV). To achieve the coolability and retention of the corium pool in the RPV lower head, the heat flux at the outer surface of the vessel should be less than the critical heat flux (CHF) of boiling around the lower head. Under such condition, the integrity of the RPV is guaranteed by the adequate thickness of the unmelted vessel wall. The thesis work starts from the selection and validation of a turbulence model in the CFD computational tool chosen (Fluent). Afterwards a numerical model is set up for estimation of melt pool heat transfer of a reference PWR with the power capacity of 1000 MWe, including a mesh sensitivity study. Based on the numerical model of a twolayer melt pool, four tasks are carried out to investigate the effects of Zr oxidation ratio, Fe content, and radiation emissivity on heat flux profiles, as well as the focus effect under extreme conditions. Selection and validation of the turbulence model are conducted by comparing the simulation results of different turbulence models with the DNS data on the convection of volumetrically heated fluid layer bounded by rigid isothermal horizontal walls at equal temperature. The internal Rayleigh numbers of the flow reach up to 10e6. The comparison shows a good agreement of the SST k-ω turbulence model results with the DNS data. The simulations with the Zr oxidation ratio of 0, 0.2 and 0.5, correspondingly, the oxide layer of 1.389m, 1.467m and 1.580m, and the metal layer of 0.705m, 0.646m and 0.561m in height, show that, the temperature of the oxide layer will increase with Zr oxidation ratio, while the temperature of the metal layer will decrease resulting in more heat transfer through the oxide layer sidewall and less top radiation. Nevertheless, the effect of the Zr oxidation ratio is not pronounced in the range of 00.5. The simulations with the Fe mass of 22t, 33t and 45t, and respective height of the metal layer of 0.462m, 0.568m and 0.646m, show that, the inner metal layer will significantly increase the temperatures of both the metal layer and the oxide layer. The percentage of heat transfer at the oxide layer sidewall will increase to supplement the reduction of that at the metal layer. The simulations with the radiation emissivity of 0.2, 0.35, 0.45 and 0.7 show that, the emissivity below 0.45 has an impact on heat transfer, and the temperatures and sidewall heat flux of both the oxide layer and the metal layer will increase with decreasing emissivity. The impact is negligible when the emissivity is above 0.45. The simulations under the hypothetically extreme conditions with either an adiabatic top boundary or a very thin metal layer show the focusing effect may occur, i.e., the heat flux through the metal sidewall is larger than that in the oxide layer. But the local high heat flux is flattened by the vessel wall with good heat conductivity. In summary, the simulations demonstrate that, except for the cases under extreme conditions, the heat fluxes of the melt pools in all other cases are significantly lower than the CHF of external cooling of the lower head. Therefore, the safety margin of the IVR strategy of the PWR chosen is seems sufficient. However, due to some limitations (e.g., simplification and assumptions) in the simulation cases and coupling of different influential factors, as indicated by the present study, the precise predictions of heat flux under all scenarios are still difficult. Therefore, the conclusions could not be generalized to the other conditions or other configurations of the molten pools. By discussing the model and simplifications/assumptions adopted in this work, the improvement directions of the numerical model and other perspectives are proposed at the end of the thesis.Denna avhandling syftar till att tillhandahålla det termiska tillståndet för smältbassängskonvektion genom CFD-simulering, vilket är viktigt för bedömningen av IVR-strategin som allmänt antagits i tryckvattenreaktorer (PWR) i Generation III. Som en åtgärd för att mildra allvarliga olyckor realiseras IVR-strategin genom extern kylning av det nedre huvudet av ett reaktortryckkärl (RPV). För att uppnå kylbarhet och kvarhållning av koriumbassängen i det nedre RPV-huvudet bör värmeflöde vid den yttre ytan av kärlet vara mindre än det kritiska värmeflödet (CHF) som kokar runt det nedre huvudet. Under sådant tillstånd garanteras RPV: s integritet av den osmälta kärlväggens tillräckliga tjocklek. Examensarbetet startar från valet och valideringen av en turbulensmodell i det valda CFD-beräkningsverktyget (Fluent). Därefter sätts en numerisk modell upp för uppskattning av smältbassängens värmeöverföring av en referens PWR med en effektkapacitet på 1000 MWe, inklusive en nätkänslighetsstudie. Baserat på den numeriska modellen för en tvålagers smältbassäng utförs fyra uppgifter för att undersöka effekterna av Zr-oxidationsförhållande, Fe-innehåll och strålningsemissivitet på värmeflödesprofiler, liksom fokuseffekten under extrema förhållanden. Val och validering av turbulensmodellen utförs genom att jämföra simuleringsresultaten för olika turbulensmodeller med DNS-data för konvektionen av volymetriskt uppvärmt fluidskikt avgränsat av styva isoterma horisontella väggar vid lika temperatur. De interna Rayleigh-siffrorna i flödet når upp till 10e6. Jämförelsen visar att SST k-ω turbulensmodellresultaten överensstämmer med DNS-data. Simuleringarna med Zr-oxidationsförhållandet 0, 0,2 och 0,5, motsvarande oxidskiktet på 1,389 m, 1,467 m och 1,580 m, och metallskiktet på 0,705 m, 0,664 m och 0,561 m i höjd, visar att temperaturen av oxidskiktet kommer att öka med Zr-oxidationsförhållandet, medan metallskiktets temperatur kommer att minska vilket resulterar i mer värmeöverföring genom oxidskiktets sidovägg och mindre toppstrålning. Ändå är effekten av Zr-oxidationsförhållandet inte uttalad i intervallet 00,5. Simuleringarna med Fe-massan på 22t, 33t och 45t och respektive höjd av metallskiktet på 0,462m, 0,568m och 0,664m visar att det inre metallskiktet avsevärt kommer att öka temperaturerna för både metallskiktet och oxiden lager. Andelen värmeöverföring vid oxidskiktets sidovägg ökar för att komplettera minskningen av den vid metallskiktet. Simuleringarna med strålningsemissiviteten 0,2, 0,35, 0,45 och 0,7 visar att emissiviteten under 0,45 påverkar värmeöverföringen, och temperaturerna och sidoväggens värmeflöde för både oxidskiktet och metallskiktet kommer att öka med minskande emissivitet. Effekten är försumbar när strålningen är över 0,45. Simuleringarna under de hypotetiskt extrema förhållandena med antingen en adiabatisk övre gräns eller ett mycket tunt metallskikt visar att fokuseringseffekten kan uppstå, dvs. värmeflödet genom metallsidan är större än det i oxidskiktet. Men det lokala höga värmeflödet plattas ut av kärlväggen med god värmeledningsförmåga. Sammanfattningsvis visar simuleringarna att, förutom fall under extrema förhållanden, är värmeflödet från smältpoolerna i alla andra fall betydligt lägre än CHF för extern kylning av nedre huvudet. Därför verkar säkerhetsmarginalen för IVR-strategin för den valda PWR tillräcklig. På grund av vissa begränsningar (t.ex. förenkling och antaganden) i simuleringsfall och koppling av olika inflytelserika faktorer, vilket indikeras av den aktuella studien, är de exakta förutsägelserna av värmeflöde under alla scenarier fortfarande svåra. Därför kunde slutsatserna inte generaliseras till de andra förhållandena eller andra konfigurationer av de smälta poolerna. Genom att diskutera modellen och förenklingar / antaganden som antagits i detta arbete föreslås förbättringsriktningarna för den numeriska modellen och andra perspektiv i slutet av avhandlingen.
5
Konovalikhin, Maxim. "Investigations of Melt Spreading and Coolability in a LWR Severe accident." Doctoral thesis, KTH, Energy Technology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3244.
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6
Kotze, Tyrone. "The influence of heat transfer limitations on the properties of PET yarn produced by melt spinning." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5304.
Повний текст джерелаАнотація:
Includes abstract.Includes bibliographical references (leaves 121-126).
The production of synthetic yarns requires a cost efficient process whilst simultaneously incorporating process methods which ultimately lead to a high quality fibre. A critical part of the production process is the spinning of the molten polymer into individual filaments which are brought together to form the filament bundle. During this process a quench air stream is blown across the filament bundle to aid in cooling the molten polymer. Here, heat transfer limitations may cause inter-filament property variations, which will adversely affect the quality of the yarn. This thesis focuses on the development of a model which allows for an a priori prediction of the influence of major process variables on the degree of fibre property uniformity. Fibre quality is characterised by the high degree of uniformity in the properties which affect the structural features of the yarn. Yarn morphology is dictated by the degree of crystallinity and molecular alignment of the polymer macro-molecules parallel to the fibre axis. These properties are strongly influenced by online tensile stress and local temperature which are, in turn, affected by heat transfer effects between the quench air and filament surface. A model that predicts the influence of heat transfer limitations on the uniformity of the as-spun fibre is therefore needed. Previous research in this field is limited with most work focussed on single filament model development. In this investigation, a monofilament model developed by previous workers (Jarecki et al., 2000) is integrated into a multifilament framework. This model assumes Newtonian behaviour of the polymer with viscosity strongly dependent on local temperature and crystallinity. The development of the multifilament model involves dividing the spinning zone into a number of cells, in which the filament properties are modelled using the monofilament model. The change in quench air temperature is estimated by means of an energy balance incorporating air flow terms and heat transfer through forced convection from the filament surface. A novel iteration approach is proposed in which the temperature of the quench air exiting each cell is iterated for until convergence is met. In simplifying the model, it was found that uniform quench air flow profile could be assumed, since the quench flow channel length was found to fall far short of the length required for turbulent flow to develop. However, it is known that increased contact time for heat transfer would occur if air were dragged down with the filament. Although modelling this effect is beyond the scope of the project, the heat transfer gradients are worsened by air-dragging and hence the model presented in this thesis reveals whether polymer uniformity is possible even under the best possible flow patterns. A negative result therefore indicates that non-uniformity will definitely occur.
7
Zajacz, Zoltán. "Mass transfer during volatile exsolution in magmatic systems : insights trough methodological developments in melt and fluid inclusion analysis /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17254.
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8
Di, Ciano Massimo. "Measurement of primary region heat transfer in horizontal direct chill continuous casting of aluminum alloy re-melt ingots." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/32372.
Повний текст джерелаАнотація:
Thermal-fluid modeling of the Horizontal Direct Chill (HDC) casting process has been
used to aid in process optimization and development of HDC casting of aluminum foundry alloy
re-melt ingots. Characterization of the heat transfer conditions present in the process is
essential to accurate model development. In this study, the heat transfer conditions in the
primary cooling region of an HDC casting machine were characterized using mould
temperature measurements taken during plant trials. Steady state mould heat flux distributions
were determined for various casting conditions through inverse heat conduction modeling. The
calculated heat fluxes are of comparable magnitude to values reported in DC casting literature.
Mould heat fluxes were affected by casting speed but relatively insensitive to casting
temperature and mould water flow rates. To compliment the plant trial approach, an apparatus
was built to replicate primary cooling region heat transfer phenomenon. Mould temperatures
taken from the casting simulator were used to determine mould heat fluxes during lab tests.
Comparing lab results and plant trial results confirm the applicability of the lab tests to in-plant
operating conditions. These preliminary lab results suggest that use of a casting simulator
could suffice as a means for characterizing primary cooling heat transfer in HDC casting, thus
avoiding the need for extensive plant trials.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
9
Xue, Boran. "Heat transfer characterization of secondary cooling in the horizontal direct chill casting process for aluminum alloy re-melt ingot." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/26877.
Повний текст джерелаАнотація:
Horizontal direct chill (HDC) casting is a continuous process used to produce extrusion billet and re-melt aluminum ingot. As in vertical DC casting, secondary cooling, where water directly impinges on the cast surface, is an important process that can affect cast quality and production rates. During HDC casting, secondary cooling is further complicated by horizontal water flow and the water spray conditions. Characterizing the heat transfer during the secondary cooling process is necessary for improved understanding of the process. Since the accessibility of the HDC casting machine is limited and the direct measurement of heat transfer in secondary cooling are difficult, numerical modeling thus becomes a good approach for process development.
In this research, the heat transfer occurring in secondary cooling of an HDC ingot has been studied. Water spray conditions on three different casting surface were simulated separately by quenching the blocks of HDC cast A356 aluminum alloy which was cut from a T-ingot. The temperature history during the cooling within the blocks was recorded by sub-surface thermocouples. An inverse heat transfer model was developed and used to calculate the heat fluxes on the casting surfaces using measured temperature data. The heat fluxes were characterized via boiling curves, which are the functions of surface temperatures, in each spray configuration.
The effects of operational parameters, including the casting speed and the water cooling rate, were investigated by comparing the characteristic features of the calculated boiling curves. The spray configuration effect was also studied with the calculated results from the stationary tests in a qualitative fashion.
Then a fitting technique was developed to idealize the calculated boiling curves. The idealized boiling curves were summarized into the functions,
which provide practical database for application of the results in this research.
All in all, the simulation apparatus and the IHC model provide the ability of characterizing the heat transfer occurring in secondary cooling region of HDC casting with lab-scale experiments. Consequently, the expensive and risky plant trials can be avoided.
10
Nourgaliev, Robert R. "Modeling and analysis of heat and mass transfer processes during in-vessel melt progression stage of light water reactor (LWR) severe accidents /." Stockholm : Tekniska högsk, 1998. http://www.lib.kth.se/abs98/nour0427.pdf.
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11
Tran, Chi Thanh. "The Effective Convectivity Model for Simulation and Analysis of Melt Pool Heat Transfer in a Light Water Reactor Pressure Vessel Lower Head." Doctoral thesis, Stockholm : Division of Nuclear Power Safety, Royal Institute of Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10671.
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12
Liang, Yongxuan. "Fabrication and Characterization of Superconducting Core Fibers with Fused Silica Cladding." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/78101.
Повний текст джерелаАнотація:
Since the discovery of superconductivity, its fantastic properties have fascinated the scientific community. The discovery of high critical temperature (Tc) superconducting compositions further inspires the wide applications of superconductors with relatively inexpensive liquid nitrogen cooling. Recently, the integration of superconductivity and optical waveguides has put forward the potential for ultrasensitive, ultra-fast and ultralow noise light detectors. However, simple and cost effective superconductor designs and fabrication processes are still required to enable wide implementation. The objective of this research was to study the fabrication of the superconductor core fibers with a fused silica cladding via the melt-draw approach, as well as develop appropriate characterization techniques to describe the fibers produced. In addition, a further objective was to determine the cooling efficiency of ordered holes around a superconductor core and construction of a one dimensional (1-D) single-phase steady state model to predict the heat transfer during cryogenic liquid transfer inside glass tube. In this thesis, both Pb and YBCO superconductor core fibers with fused silica cladding have been demonstrated. The fibers were fabricated via the melt-draw technique and maintained overall diameters ranging from 200-900 μm and core diameters of 100-800 μm. Surface morphology, chemical composition, interface effect, and superconductivity were further investigated. Surface morphology analysis confirmed that the Pb and YBCO core fibers possessed good circularity and clean interfaces between the core and cladding. Both the Pb and YBCO cores were relatively dense after the melt-draw process. The melt-draw process avoided contamination during fabrication as indicated by the composition analysis. Limited PbO was examined on the Pb core surface but further action will be required to detect the source of oxygen. The YBCO core maintained a stoichiometric ratio comparable to the superconducting phase even after the melt forming process. The elemental mapping showed that limited cross-diffusion occurred between the Pb core and fused silica cladding. Conversely significantly more elemental cross interaction between the core and cladding was noted for the YBCO core fiber. Superconductivity of the Pb core was verified by a custom designed four-probe technique in liquid helium. The YBCO core was also confirmed to be superconductive after heat treatment with O₂ present. The feasibility of efficient cooling by the holey glass tubes was confirmed. A 1-D single-phase steady state model was constructed to evaluate the heat transfer mechanism. The experimental results are in reasonable agreement to the theoretical calculation.Master of Science
13
Arnoux, Gillean. "Novel Insights into Mass and Energy Transfer and Mid-Ocean Ridges from Seismic Imaging of the East Pacific Rise and Juan de Fuca Ridge." Thesis, University of Oregon, 2019. http://hdl.handle.net/1794/24532.
Повний текст джерелаАнотація:
In this dissertation, I use seismic imaging and waveform modeling methods to investigate melt migration processes and the structure of the magma plumbing system beneath the East Pacific Rise (EPR) and Endeavour segment of the Juan de Fuca Ridge, respectively. This work begins by studying shallow mantle reflections beneath the EPR. I find the amplitude versus offset and waveform characteristics of the reflections to be consistent with a sub-horizontal dunite channels located up to 20 km off-axis. The depth of the dunite channels correlate with patterns of mantle melt delivery and the predicted base of the thermal lithosphere, suggesting the channels are thermally controlled and may have formed in situ via dissolution by focused flow at the base of the lithosphere. This interpretation is consistent with field observations in ophiolites and numerical modeling of melt-focusing channels. The three-dimensional velocity structure of the Endeavour segment is then investigated to identify how patterns of mantle melt delivery influence the segment-scale distribution of crustal melt and crustal accretion. The results from this study indicate that the mantle magmatic system is skewed relative to the ridge-tracking crustal magmatic system and that this skew exerts primary control on magmatic, tectonic, and hydrothermal activity at the Endeavour segment. In regions where mantle melt delivery is axis-centered, mantle-derived melts are efficiently transported from the mantle to the crust, resulting in frequent crustal melt replenishment, associated seismogenic cracking, and enhanced crustal melt content that drives vigorous hydrothermal activity. Conversely, sites of off-axis melt delivery are characterized by less efficient vertical melt transport, resulting in infrequent crustal melt injection and hence, reduced crustal melt content and hydrothermal activity. Next, I focus on how along-axis variations in magma replenishment modulate crustal permeability and the intensity of hydrothermal circulation. Using full-waveform inversion, I show that sites of localized magma replenishment to the axial magma lens, along with induced seismogenic cracking, coincide with enhanced permeability. I conclude that the frequency of magma injection governs hydrothermal circulation patterns and heat flux at mid-ocean ridges.
This dissertation includes previously published and unpublished coauthored material.
14
Tran, Chi Thanh. "Development, validation and application of an effective convectivity model for simulation of melt pool heat transfer in a light water reactor lower head." Licentiate thesis, Stockholm : Fysik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4559.
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15
Neogi, Swati. "Modeling high viscosity melt phase polycondensation reactors using direct inclusion of experimental mixing data." Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1173754996.
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16
Beck, Susan Ashley. "Copolymerizing Acrylonitrile and Methyl Acrylate by RAFT for Melt Processing Applications: A Synthetic Investigation of the Effects of Chain Transfer Agent, Initiator, Temperature, and Solvent." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/49104.
Повний текст джерелаАнотація:
Statistical copolymers of acrylonitrile (AN) and methyl acrylate (MA) were successfully prepared and characterized using reversible addition-fragmentation chain transfer (RAFT) copolymerization. A typical copolymer was charged with 15 wt. % MA content. This thesis describes a systematic variation of the RAFT copolymerization variables to optimize this system. In particular, the effects of chain transfer agent, initiator, temperature, and solvent on the copolymer properties were studied.Master of Science
17
Druet, Pierre-Etienne. "Analysis of a coupled system of partial differential equations modeling the interaction between melt flow, global heat transfer and applied magnetic fields in crystal growth." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2009. http://dx.doi.org/10.18452/15893.
Повний текст джерелаАнотація:
Hauptthema der Dissertation ist die Analysis eines nichtlinearen, gekoppelten Systems partieller Differentialgleichungen (PDG), das in der Modellierung der Kristallzüchtung aus der Schmelze mit Magnetfeldern vorkommt. Die zu beschreibenden Phenomäne sind einerseits der im elektromagnetisch geheizten Schmelzofen erfolgende Wärmetransport (Wärmeleitung, -konvektion und -strahlung), und andererseits die Bewegung der Halbleiterschmelze unter dem Einfluss der thermischen Konvektion und der angewendeten elektromagnetischen Kräfte. Das Modell besteht aus den Navier-Stokeschen Gleichungen für eine inkompressible Newtonsche Flüssigkeit, aus der Wärmeleitungsgleichung und aus der elektrotechnischen Näherung des Maxwellschen Systems. Wir erörtern die schwache Formulierung dieses PDG Systems, und wir stellen ein Anfang-Randwertproblem auf, das die Komplexität der Anwendung widerspiegelt. Die Hauptfrage unserer Untersuchung ist die Wohlgestelltheit dieses Problems, sowohl im stationären als auch im zeitabhängigen Fall. Wir zeigen die Existenz schwacher Lösungen in geometrischen Situationen, in welchen unstetige Materialeigenschaften und nichtglatte Trennfläche auftreten dürfen, und für allgemeine Daten. In der Lösung zum zeitabhängigen Problem tritt ein Defektmaß auf, das ausser der Flüssigkeit im Rand der elektrisch leitenden Materialien konzentriert bleibt. Da eine globale Abschätzung der im Strahlungshohlraum ausgestrahlten Wärme auch fehlt, rührt ein Teil dieses Defektmaßes von der nichtlokalen Strahlung her. Die Eindeutigkeit der schwachen Lösung erhalten wir nur unter verstärkten Annahmen: die Kleinheit der gegebenen elektrischen Leistung im stationären Fall, und die Regularität der Lösung im zeitabhängigen Fall. Regularitätseigenschaften wie die Beschränktheit der Temperatur werden, wenn auch nur in vereinfachten Situationen, hergeleitet: glatte Materialtrennfläche und Temperaturunabhängige Koeffiziente im Fall einer stationären Analysis, und entkoppeltes, zeitharmonisches Maxwell für das transiente Problem.The present PhD thesis is devoted to the analysis of a coupled system of nonlinear partial differential equations (PDE), that arises in the modeling of crystal growth from the melt in magnetic fields. The phenomena described by the model are mainly the heat-transfer processes (by conduction, convection and radiation) taking place in a high-temperatures furnace heated electromagnetically, and the motion of a semiconducting melted material subject to buoyancy and applied electromagnetic forces. The model consists of the Navier-Stokes equations for a newtonian incompressible liquid, coupled to the heat equation and the low-frequency approximation of Maxwell''s equations. We propose a mathematical setting for this PDE system, we derive its weak formulation, and we formulate an (initial) boundary value problem that in the mean reflects the complexity of the real-life application. The well-posedness of this (initial) boundary value problem is the mainmatter of the investigation. We prove the existence of weak solutions allowing for general geometrical situations (discontinuous coefficients, nonsmooth material interfaces) and data, the most important requirement being only that the injected electrical power remains finite. For the time-dependent problem, a defect measure appears in the solution, which apart from the fluid remains concentrated in the boundary of the electrical conductors. In the absence of a global estimate on the radiation emitted in the cavity, a part of the defect measure is due to the nonlocal radiation effects. The uniqueness of the weak solution is obtained only under reinforced assumptions: smallness of the input power in the stationary case, and regularity of the solution in the time-dependent case. Regularity properties, such as the boundedness of temperature are also derived, but only in simplified settings: smooth interfaces and temperature-independent coefficients in the case of a stationary analysis, and, additionally for the transient problem, decoupled time-harmonic Maxwell.
18
Liu, Yao. "Heat transfer process between polymer and cavity wall during injection molding." Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-157361.
Повний текст джерелаАнотація:
Injection molding is one of the most commonly applied processing methods for plastic components. Heat transfer coefficient (HTC), which describes the heat conducting ability of the interface between a polymer and cavity wall, significantly influences the temperature distribution of a polymer and mold during injection molding and thus affects the process and quality of plastic products. This thesis focuses on HTC under diverse processing situations. On the basis of the heat conducting principle, a theoretical model for calculating HTC was presented. Injection mold specially used for measuring and calculating HTC was designed and fabricated. Experimental injection studies under different processing conditions, especially different surface roughness, were performed for acquiring necessary temperature data. The heat quantity across the interface and HTC between a polymer and cavity wall was calculated on the basis of experimental results. The influence of surface roughness on HTC during injection molding was investigated for the first time. The factors influencing the HTC were analyzed on the basis of the factor weight during injection molding. Subsequently FEM (Finite element method) simulations were carried out with observed and preset value of HTC respectively and the relative crystallinity and part density were obtained. In the comparison between results from simulation and experiment, the result calculated with observed HTC shows better agreement with actually measured value, which can verify the reliability and precision of the injection molding simulation with observed HTC. The results of this thesis is beneficial for understanding the heat transfer process comprehensively, predicting temperature distribution, arranging cooling system, reducing cycle time and improving precision of numerical simulationDas Spritzgießen ist eines der am häufigsten angewandten Verarbeitungsverfahren zur Herstellung von Kunststoffkomponenten. Der Wärmedurchgangskoeffizient (WDK), welcher den Wärmeübergang zwischen Kunststoff und Werkzeugwand beschreibt, beeinflusst während des Spritzgießens maßgeblich die Temperaturverteilung im Bauteil und dem Werkzeug und folglich den Prozess und die Qualität der Kunststoffprodukte. Der Inhalt dieser Arbeit beschäftigt sich mit dem WDK unter verschiedenen Prozessbedingungen. Auf Grundlage des Wärmeleitungsprinzips wurde ein theoretisches Modell für die Berechnung des WDK vorgestellt. Es wurde dazu ein Spritzgießwerkzeug konstruiert und hergestellt, welches Messungen zur späteren Berechnung des WDK ermöglicht. Praktische Spritzgießversuche unter verschiedenen Prozessbedingungen, insbesondere unterschiedlicher Oberflächenrauheit, wurden für die Erfassung der erforderlichen Temperaturdaten durchgeführt. Auf Grundlage der experimentellen Ergebnisse wurde der Wärmeübergang zwischen dem Polymer und der Werkzeugwand berechnet. Der Einfluss der Oberflächenrauhigkeit auf den WDK wurde hierbei zum ersten Mal untersucht. Auf Grundlage des Bauteilgewichtes wurden anschließend die Faktoren, die den WDK beeinflussen, berechnet. Des Weiteren wurden FEM-Simulationen (Finite Element Methode) mit dem gemessenen und dem voreingestellten WDK durchgeführt und daraus der Kristallinitätsgrad und die Bauteildichte gewonnen. Der Vergleich zwischen den realen Ergebnissen und der Simulation zeigt, dass die Berechnungen mit dem gemessenen WDK eine bessere Übereinstimmung mit den realen Werten aufweist, was die Zuverlässigkeit und Präzision der Spritzgusssimulation bestätigt. Die Ergebnisse dieser Arbeit tragen zum umfassenden Verständnis des Wärmeübergangs im Spritzgießprozess, zur Vorhersage der Temperaturverteilung, zur Auslegung des Kühlsystems, zur Reduzierung der Zykluszeit und zur Verbesserung der Genauigkeit der numerischen Simulation bei
19
Wang, Shuang. "Novel approaches for patterning hierarchical hydrogels." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/121231/1/Shuang_Wang_Thesis.pdf.
Повний текст джерелаАнотація:
Synthetic hydrogels featuring tunable biological functionalities and hierarchical structures are of compelling interest as scaffolds for tissue engineering applications. With the expectation of regulating cell fate within the soft materials, many efforts have been placed on creating niches that can mimic the complexity of the native extracellular matrix. In this study, a sacrificial moulding process was used to produce porous hydrogels, while two patterning approaches were developed to site-specifically immobilize molecules inside the hydrogels, resembling natural extracellular matrix networks in terms of geometrical interconnectivity and cell-guidance functionalization. The simple approaches allow reproducible control over the size and architecture of the channels, as well as the spatial distribution and concentration of the patterning molecules, enabling controlled study of cell-substrate behaviour.
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Liu, Yao. "Heat transfer process between polymer and cavity wall during injection molding." Doctoral thesis, Universitätsverlag der Technischen Universität Chemnitz, 2014. https://monarch.qucosa.de/id/qucosa%3A20165.
Повний текст джерелаАнотація:
Injection molding is one of the most commonly applied processing methods for plastic components. Heat transfer coefficient (HTC), which describes the heat conducting ability of the interface between a polymer and cavity wall, significantly influences the temperature distribution of a polymer and mold during injection molding and thus affects the process and quality of plastic products. This thesis focuses on HTC under diverse processing situations.
On the basis of the heat conducting principle, a theoretical model for calculating HTC was presented. Injection mold specially used for measuring and calculating HTC was designed and fabricated. Experimental injection studies under different processing conditions, especially different surface roughness, were performed for acquiring necessary temperature data. The heat quantity across the interface and HTC between a polymer and cavity wall was calculated on the basis of experimental results. The influence of surface roughness on HTC during injection molding was investigated for the first time. The factors influencing the HTC
were analyzed on the basis of the factor weight during injection molding. Subsequently FEM (Finite element method) simulations were carried out with observed and preset value of HTC respectively and the relative crystallinity and part density were obtained. In the comparison between results from simulation and experiment, the result calculated with observed HTC shows better agreement with actually measured value, which can verify the reliability and precision of the injection molding simulation with observed HTC. The results of this thesis is beneficial for understanding the heat transfer process comprehensively, predicting
temperature distribution, arranging cooling system, reducing cycle time and improving precision of numerical simulation.Das Spritzgießen ist eines der am häufigsten angewandten Verarbeitungsverfahren zur Herstellung von Kunststoffkomponenten. Der Wärmedurchgangskoeffizient (WDK), welcher den Wärmeübergang zwischen Kunststoff und Werkzeugwand beschreibt, beeinflusst während des Spritzgießens maßgeblich die Temperaturverteilung im Bauteil und dem Werkzeug und folglich den Prozess und die Qualität der Kunststoffprodukte. Der Inhalt dieser Arbeit beschäftigt sich mit dem WDK unter verschiedenen Prozessbedingungen. Auf Grundlage des Wärmeleitungsprinzips wurde ein theoretisches Modell für die Berechnung des WDK vorgestellt. Es wurde dazu ein Spritzgießwerkzeug konstruiert und hergestellt, welches Messungen zur späteren Berechnung des WDK ermöglicht. Praktische Spritzgießversuche unter verschiedenen Prozessbedingungen, insbesondere unterschiedlicher Oberflächenrauheit, wurden für die Erfassung der erforderlichen Temperaturdaten durchgeführt. Auf Grundlage der experimentellen Ergebnisse wurde der Wärmeübergang zwischen dem Polymer und der Werkzeugwand berechnet. Der Einfluss der Oberflächenrauhigkeit auf den WDK wurde hierbei zum ersten Mal untersucht. Auf Grundlage des Bauteilgewichtes wurden anschließend die Faktoren, die den WDK beeinflussen, berechnet. Des Weiteren wurden FEM-Simulationen (Finite Element Methode) mit dem gemessenen und dem voreingestellten WDK durchgeführt und daraus der Kristallinitätsgrad und die Bauteildichte gewonnen. Der Vergleich zwischen den realen Ergebnissen und der Simulation zeigt, dass die Berechnungen mit dem gemessenen WDK eine bessere Übereinstimmung mit den realen Werten aufweist, was die Zuverlässigkeit und Präzision der Spritzgusssimulation bestätigt. Die Ergebnisse dieser Arbeit tragen zum umfassenden Verständnis des Wärmeübergangs im Spritzgießprozess, zur Vorhersage der Temperaturverteilung, zur Auslegung des Kühlsystems, zur Reduzierung der Zykluszeit und zur Verbesserung der Genauigkeit der numerischen Simulation bei.
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Desai, Dipen. "Solid-state plasticizers for melt extrusion /." View online ; access limited to URI, 2007. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3276980.
Повний текст джерела
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Sharedeh, Diaa. "Analyse du transfert de matière et des modifications biochimiques et structurales du tissu musculaire lors du marinage, saumurage et malaxage des viandes." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22573/document.
Повний текст джерелаАнотація:
Le marinage et le saumurage améliorent la durée de conservation, la tendreté et la jutosité de la viande et du poisson. En complément, un malaxage ou « barattage » est souvent appliqué aux pièces de viande préalablement à la cuisson. Le but principal de cette étude était d’évaluer l’impact des conditions de traitement sur les modifications biochimiques et structurales du tissu musculaire ; une grande partie concerne le malaxage. Les essais relatifs au marinage ont permis de fixer le pH et la teneur en NaCl de petits échantillons de Semitendinosus de bœuf respectivement à 6,5, 5,4 ou 4,3 et à 0,9 ou 2 % en masse ; une ANOVA a révélé les effets de ces 2 paramètres sur la taille des cellules et des espaces extracellulaires, l’oxydation des lipides et des protéines et l’hydrophobie de surface de ces dernières. Un simulateur de saumurage-malaxage conçu par le laboratoire a permis d’imposer des successions de déformations contrôlées (nombre de 350 à 2500, taux de compression de 10 à 30%) à des muscles Semimembranosus (SM) ou Rectus femoris (RF) de porc. Des traitements mécaniques semblables à ceux existant dans des barattes industrielles de tailles différentes ont ainsi été reproduits. Les principales conclusions sont : (1) le malaxage augmente nettement la diffusivité apparente du NaCl, d’une part, en altérant la structure tissulaire (+ 20 %), et d’autre part, en induisant une convection s’ajoutant à la diffusion (+200 %) ; (2) le traitement mécanique entraine en lui-même une augmentation de la solubilité des protéines, connue pour moduler les qualités des viandes transformées, de 20 à 50% par rapport à des échantillons non malaxés, qu’ils soient salés ou non ; (3) il entraine aussi une augmentation modérée de l’hydrophobie des protéines ; (4) la dégradation de l’endomysium, servant d’indicateur des modifications structurales, est plus marquée au milieu qu’en périphérie du muscle malaxé et d’autant plus importante que le traitement mécanique est fort et longMarinating and brining improve shelf-life, tenderness and juiciness of meat and fish. As a supplement massaging or tumbling is often applied to meat pieces before cooking. The main aim of this study was to assess the impacts of the processing conditions on the biochemical and structural changes in the meat tissue; a great part is focused on massaging. In the marinating trials the pH and NaCl content of thin samples of beef Semimembranosus muscle were set at 6.5, 5.4 or 4.3 and at 0,9 or 2 % (w/w), respectively; an ANOVA have shown the effect of these two parameters on the cells and extra cellular space sizes, the oxidation of lipids and proteins and the protein surface hydrophobicity. A brining-massaging simulator built by the laboratory was used to apply controlled successions of deformations (number from 350 to 2500, compression ratio from 10 to 30 %) to Semimembranosus (SM) ou Rectus femoris (RF) pork muscles. Mechanical treatments similar to those existing in industrial tumblers of various diameters were so reproduced. The main conclusions are: (1) massaging clearly increases the NaCl apparent diffusivity, on the one hand, by a modifying the tissue structure (+20%) and, on the other hand, by adding convection to diffusion (+200%); (2) the mechanical treatment promotes by itself an increase in protein solubility, known to affect processed meat quality, from 20 to 50 % in comparison with salted or unsalted reference samples; (3) it also increases moderately protein hydrophobicity; (4) the endomysium degradation, used as an indicator of structural changes, was more pronounced in the muscle periphery than in the middle and all the more marked than massaging was strong and long
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Ayele, Yohannes Haileyesus. "Region-Based Contrast Transfer Function correction for Electron Microscopy Images." Thesis, KTH, Skolan för teknik och hälsa (STH), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119305.
Повний текст джерелаАнотація:
Electron crystallography is one of the methods for determining the structure of membrane proteins. However, the resolution that we get from electron crystallography of membrane proteins is limited by crystal disorder and inaccurate determination of contrast transfer function (CTF) parameters. To overcome these problems, we applied single particle refinement with local averaging for long range variation of the crystals and local region-based CTF correction for the tilted images. These two corrections are done on the Melibiose Permease (MelB) data sets and a resolution of 8.6Å is reported.Elektronkristallografi är en av metoderna för att bestämma strukturen av membranproteiner.Den upplösning vi kan få från elektronkristallografi av membranproteiner begränsas av oordning i kristallen och felaktig bestämning av kontrastöverföringsfunktioner (CTF). För att lösa dessa problem tillämpade vi single particle refinement for lokala medelvärden av kristaller och lokala regionsbaserad CTF korrigering av tiltade dataset. Dessa två korrektioner görs på bilder av melibiospermeas (Melb) kristaller och en upplösning på 8.6Å erhölls.
It has been very good presentation with some comments on CTF measurment
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Olivier, Anandi. "Die oordrag van ondernemings met verwysing na uitkontraktering / deur A. Olivier." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2057.
Повний текст джерела
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Paganelli, Emanuele. "Melt percolation and stagnation in a cold suboceanic mantle (Andrew Bain transform fault, southwest indian ridge)." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10026/document.
Повний текст джерелаАнотація:
Les processus pétrologiques profonds, qui précèdent ou accompagnent la décompression du manteau sous les dorsales océaniques, tendent à être oblitérés par la fusion partielle. Les régions de dorsales à vitesse d'expansion très lente et/ou anormalement froides exposent des domaines mantelliques qui ont subi un degré de fusion extrêmement faible et donc permettent d'accéder à ces processus. La zone de fracture de Andrew Bain, située à la limite des plaques Africaine et Antarctique, en est un exemple remarquable. Son massif d'intersection avec la dorsale sud-ouest indienne a été exploré au cours de l'expédition océanographique italo-russe S23-AB06. Les échantillons qui ont été prélevés sont principalement des péridotites mantelliques à spinelle ± plagioclase, contenant des plages et des veinules enrichies en pyroxènes ± plagioclase, et montrant des textures de réquilibrages minéralogiques. Les concentrations en éléments majeurs et en traces des pyroxènes, mesurés in situ par EMPA et LA-ICP-MS, montrent une grande variabilité de compositions, identique à toutes les échelles, du massif à la lame mince. La modélisation des compositions des pyroxènes des péridotites indique (1) une cristallisation à partir de liquides de fusion de lithologies enrichies en éléments incompatibles, générés dans un large intervalle de pression débutant dans le faciès à grenat, (2) un rééquilibrage progressif à des conditions de P-T décroissantes, par interaction péridotite - liquide et diffusion à l'état solide. Le modèle est celui d'une refertilisation d'un manteau lithosphérique épais, similaire à celui qui caractérise les domaines de transition continent-océanAndrew Bain Fracture Zone represents one of the largest transform faults in the ridge system. Located on the South West Indian Ridge, it constitutes part of the plate margin between Africa and Antarctica. In this area, the lithosphere is thick and mainly constituted by ultramafic rocks; the system is characterized by a negative thermal anomaly. During the Italian-Russian expedition S23-AB06, the seafloor in the Southern Ridge Transform Intersection has been sampled and almost only ultramafic material has been recovered. The sampled spinel and plagioclase peridotites show hybrid textures and are characterized by deep spinel-field impregnation assemblages and by plagioclase-field equilibrated patches and mineral trails marked by crystallization of newly formed plagioclase-field equilibrated trails and formation of plagioclase coronas around pristine spinel. Major and trace element data composition have been collected. Both spinel- and plagioclase-peridotite pyroxenes and spinels follow a main melting trend accompanied by a progressive re-equilibration to lower P/T facies. Thin section-scale variability matches inter-site compositional variability. Progressive re-equilibration to lower P/T conditions can be accounted for by the presence of percolating melts and solid diffusion. Major and trace element shows that percolating melts are generated over a wide pressure range and modeling suggests melting started in garnet stability field but stopped early due to the lithospheric cooling. Thus, this mantle seems to be a thermically “normal” mantle cooled down from above by the anomalous thickness of the old lithosphere, similar to those characterizing continent-ocean transition
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Mann, David. "Collaborative Software Development and Sustaining Engineering: An Improved Method to Meet the NASA Mission." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/607321.
Повний текст джерелаАнотація:
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, NevadaThis paper reports on the Space Shuttle, Record and Playback Subsystem (RPS) upgrade project turnaround brought about through extensive collaborative software development. The new project and systems engineering methodologies employed on this project resulted in many positive effects over the status quo method employed to develop and upgrade systems. These effects include; 1) a reduction in the initial software development costs, 2) a reduction in the development timeline, 3) improved marketability of the software technology developed, 4) improved product quality deployed to operations, and 5) improved maintainability. Attributes within each of the aforementioned are examined in support of these assertions. Prior to implementing this new method, the RPS upgrade project had been under development for seven years using the standard software development method. This involves developing custom applications using Commercial Off The Shelf (COTS) hardware, operating systems and compilers. A change in strategy was effected on this pathfinder project by adopting a COTS telemetry ground station software package to provide basic ground station functionality and building additional required capabilities to complete the project. The merits of having employed this methodology are explored using the probable outcome of continued custom software development as a basis for comparison . This collaboration between the United Space Alliance (USA) and AP Data Systems Inc.(an AP Labs company), resulted in software innovations in FM and PCM processing software as well as general ground station management software. The four technology transfer submittals for new software innovations resulting from this collaboration are discussed.
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Goli, Thierry. "Comportements des matrices protéiques acidifiées par immersion en solution concentrée." Thesis, Montpellier, SupAgro, 2012. http://www.theses.fr/2012NSAM0006.
Повний текст джерелаАнотація:
Ce travail avait pour objectif d'améliorer la compréhension du déterminisme des propriétés de la viande soumise à un marinage acide. Il s'est articulé autour de trois objectifs : (i) identifier les mécanismes de transferts de matière, (ii) améliorer la compréhension de l'évolution du pH en fonction des transferts, et (iii) évaluer l'influence du marinage sur les propriétés fonctionnelles de la viande traitée. Des cubes de viande de poitrine de dinde ont été soumis à des traitements de marinage par immersion en solutions sel-eau-acide. Dans le cas d'immersion en solutions diluées en sel (< 0,3 M) on a pu observer des gains en eau importants, corrélés positivement à la teneur en acide de la solution. Au-delà de cette teneur en sel dans la solution, on observe un régime de déshydratation, indépendamment de la teneur en acide de la solution d'immersion. Ces observations nous ont amené à proposer un schéma dans lequel, en solutions diluées en sel, la migration du sel et de l'acide par diffusion moléculaire se superpose à une entrée de marinade intense par infiltration. Une méthode de prédiction du pH de tissus musculaires acidifiés a été testée avec succès dans le domaine de pH de 4 à 5. Son application à la prédiction du pH de pièces de viande marinées s'est heurtée à la baisse très importante de la capacité de fixation de protons de la viande par fuite de constituants réactifs au cours du marinage. Le marinage de cubes de poitrine de dinde en solutions eau-acide ou eau-acide-sel montre que le pH est une variable très influente sur la texture de la viande cuite. La baisse du pH, indépendamment de l'imprégnation en sel, provoque un durcissement des échantillons traités dès les premières minutes d'immersion. Pour des durées plus importantes, on assiste, uniquement en absence de sel, à un attendrissement significatif par rapport au témoin non mariné. L'établissement de la texture et des propriétés de rétention d'eau est sous l'effet de mécanismes complexes liés à la dénaturation et à la solubilisation protéiqueThe objective of this work was to improve understanding of the mechanisms determining the properties of meat subjected to acidic marination. It was based on three objectives: (i) identifying the matter transfer mechanisms, (ii) improving understanding of pH evolution as a function of acid transfer, and (iii) evaluating the influence of marination on the functional properties of treated meat.Turkey breast cubes were subjected to immersion treatments in water-salt-acid solutions. In the case of immersion in dilute salt solutions (< 0.3 M), we observed big water gains, which were positively correlated with the acid content of the solution. Beyond this salt content in the solution, we encountered a state of dehydration, regardless of the acid content of the immersion solution. These observations led us to suggest a system whereby, in solutions dilute in salt, salt and acid migration via molecular diffusion is superimposed onto intense marinade inflow via infiltration. A method for predicting the pH of acidified muscle tissues was tested successfully within the pH region 4 to 5. Its application in predicting the pH of marinated meat pieces was impeded by the very large fall in the proton binding capacity of the meat through the leak of reactive constituents in the course of marination. Marination of turkey breast cubes in water-acid or water-acid-salt solutions demonstrated that pH is a highly influential variable on cooked meat texture. The fall in pH, regardless of salt impregnation, caused hardening of the samples treated from the first minutes of immersion. For longer durations, in the absence of salt only can we see significant tenderization in comparison to the non-marinated control. The establishment of the texture and water holding properties is affected by complex mechanisms linked to denaturation and solubilization of proteins
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Dion, Bruno J. "Application of high-pressure homogenization for the proximate analysis of meat and meat products by Fourier transform infrared (FTIR) spectroscopy." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36912.
Повний текст джерелаАнотація:
An industrial Fourier transform infrared (FTIR) milk analyser has been adapted for the proximate analysis of fresh or cooked meat and meat products. Stable freeze-dried samples of ground beef and bologna were prepared for the calibration of an FTIR spectrometer equipped with a 37-mum transmission cell maintained at a constant temperature of 65°C and were analysed for fat, protein, moisture, and ash by the official methods of analysis of the Association of Official Analytical Chemists (AOAC) prior to instrumental measurement. The requirement to prepare a "milk-like" emulsion of meat for FTIR analysis led to the development of two prototype high-pressure homogenizers specifically designed to produce analytical volumes of emulsions in which the largest residual colloids present in suspension would have dimensions smaller than 1 mum. Emulsified samples were examined by transmission electron microscopy and laser light scattering spectroscopy to determine the size distribution of fat globules and the dimensions of the residual insoluble fragments of protein."Milk-like" emulsions of meat passed three times through a high-pressure homogenizer operating at 20,000 psi (138 MPa) had an average fat globule diameter of less than 320 nm. Also, the use of high-pressure homogenization eliminated the need to filter out insoluble proteins from connective tissues prior to the infrared analysis, resulting in a more accurate determination of the protein content in the meat samples. The results of validation studies conducted with both fresh and freeze-dried samples demonstrated that it is possible to analyse meat samples simultaneously for fat, protein, carbohydrates and moisture with good accuracy in approximately 7½; minutes per sample employing existing FTIR instrumentation used for the routine analysis of milk and dairy products.
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Jahan, Musarrat. "Virulence characteristics of enterococci from cured meat and potential for inter-genetic transfer of antibiotic resistance determinants." Elsevier Limited, 2015. http://hdl.handle.net/1993/30656.
Повний текст джерелаАнотація:
The genus Enterococcus has an exceptional ability to acquire and transmit antibiotic resistance genes and is considered to be a major vector in their dissemination. Enterococci are part of the normal gut microbiota of humans and animals and are frequently encountered in food products including dry fermented sausage. Since fermented sausages are not heat-treated before consumption they might be a vehicle for transmitting resistance and virulence traits of enterococci by conjugation with commensal bacteria present in the human gut and pathogenic bacteria that might be present, such as Listeria species. A PCR-based assay was developed to detect enterococci in dry fermented sausage meat at the generic level by targeting a 16S rRNA sequence and a total of 29 Enterococccus strains (15 E. faecalis, 13 E. faecium, and one E. gallinarum) were identified. The susceptibility of these enterococci to antibiotics was tested and it was found that 27/29 were resistant to more than one antibiotic and possessed antibiotic resistance determinants. All strains were positive for at least one virulence gene. Strong biofilm formation occurred at lower than optimum temperature in all three species of enterococci and probably contributed to their survival in the harsh conditions experienced during dry sausage fermentation and drying. SmaI pulsed-field gel electrophoresis (PFGE) patterns exhibited genomic heterogeneity within and between the two larger groups of isolates. In spite of this heterogeneity, the phenotypic similarities observed suggested that food could still be a vehicle for distribution of antibiotic resistant bacteria among humans. In vitro conjugation experiments demonstrated transfer of the tetracycline resistant determinant, tet(M), from E. faecium S27 isolated from fermented sausage to clinical isolates of both E. faecium and E. faecalis. The streptomycin resistance of E. faecium S27 was also transferred to a clinical strain, E. faecalis 82916, which was confirmed by the presence of the streptomycin resistance gene, aadA, in the donor and transconjugant strains. E. faecium S27 also transferred tet(M) and streptomycin resistance to Listeria monocytogenes GLM-2 by in vitro mating. Evidence suggests that enterococci in fermented meats may contribute to the spread of resistance determinants.October 2015
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Keskinen, Lindsey Ann. "Impact of biofilm formation and sublethal injury of listeria monocytogenes on transfer to delicatessen meats." Diss., Connect to online resource - MSU authorized users, 2006.
Знайти повний текст джерелаАнотація:
Thesis (Ph. D.)--Michigan State University. Dept. of Food Science and Human Nutrition, 2006.Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 209-220). Also issued in print.
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Amen, Tonya Sue. "Birth, weaning, carcass, and meat traits in Bos indicus-Bos taurus reciprocal backcross calves produced through embryo transfer." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1335.
Повний текст джерелаАнотація:
Angus - Bos indicus (Brahman or Nellore) reciprocal backcross embryo transfer
calves belonging to 28 full-sib families were evaluated for differences in birth weight
(BW), gestation length (GL), weaning weight (WW), carcass weight (HCW),
longissimus muscle area (REA), fat thickness (adjusted (ADJFAT) and
actual(ACTFAT)), intramuscular fat (MARB), and Warner-Bratzler shear force
tenderness (WBSF).
Family types with a greater proportion of Bos indicus in the sire in relation to the
amount in the dam (F1 x A and B x F1) averaged longer GL and heavier BW than their
respective reciprocal crosses (A x F1 and F1 x B). Calves had longer GL when the F1
parent was BA as opposed to AB. Small differences (statistically insignificant) were
detected for BW, but no consistent difference was found between offspring of AB and
BA parental types, with the exception of male F1-sired calves.
F1 x A and B x F1 crosses also showed a large BW difference between males and
females (about 5.0 kg), while A x F1 and F1 x B crosses showed no BW difference
between males and females. Further examination within each sex showed a difference
between male reciprocals that was two times that of females.
Calves with a higher percentage of Bos indicus in the sire compared to the
proportion in the dam showed the same trend, as they were still heavier at weaning, and
produced heavier carcasses than the reciprocal crosses, though these differences were
not significant.
As a whole, A backcross calves had more ACTFAT, more ADJFAT, larger REA,
more MARB, and lower WBSF than B backcross calves, though no significant
differences were detected between reciprocal crosses for any of these traits.
These results suggest that for weight related traits, especially BW, both the breed
constitution of the calf and the cross that produces the calf play an important role in its
ultimate performance for Bos indicus crossbred calves. For carcass and meat related
traits, it appears that the breed make-up of the calf itself is more significant in
influencing performance than the cross used to produce the calf.
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Neidhöfer, Thorsten. "Fourier-transform rheology on anionically synthesised polymer melts and solutions of various topology." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971983321.
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Xu, Xinfu [Verfasser], Hermann [Akademischer Betreuer] Winner, and Tobias [Akademischer Betreuer] Melz. "Incidence and transfer behaviors of high-order hot judder in passenger cars / Xinfu Xu ; Hermann Winner, Tobias Melz." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2016. http://d-nb.info/1122286392/34.
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Frenger, Tobias, and Johan Häggmark. "Transfer learning between domains : Evaluating the usefulness of transfer learning between object classification and audio classification." Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-18669.
Повний текст джерелаАнотація:
Convolutional neural networks have been successfully applied to both object classification and audio classification. The aim of this thesis is to evaluate the degree of how well transfer learning of convolutional neural networks, trained in the object classification domain on large datasets (such as CIFAR-10, and ImageNet), can be applied to the audio classification domain when only a small dataset is available. In this work, four different convolutional neural networks are tested with three configurations of transfer learning against a configuration without transfer learning. This allows for testing how transfer learning and the architectural complexity of the networks affects the performance. Two of the models developed by Google (Inception-V3, Inception-ResNet-V2), are used. These models are implemented using the Keras API where they are pre-trained on the ImageNet dataset. This paper also introduces two new architectures which are developed by the authors of this thesis. These are Mini-Inception, and Mini-Inception-ResNet, and are inspired by Inception-V3 and Inception-ResNet-V2, but with a significantly lower complexity. The audio classification dataset consists of audio from RC-boats which are transformed into mel-spectrogram images. For transfer learning to be possible, Mini-Inception, and Mini-Inception-ResNet are pre-trained on the dataset CIFAR-10. The results show that transfer learning is not able to increase the performance. However, transfer learning does in some cases enable models to obtain higher performance in the earlier stages of training.
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Djekic, Uros V. "Coupling selection of the HIV-1 tRNA primer used for reverse transcription with viral translation and encapsidation." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2008r/djekic.pdf.
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Debeaujon, Isabelle. "Contribution a la mise au point d'une methode de transfert de genes par hybridation somatique asymetrique chez le melon (cucumis melo l)." Paris 11, 1991. http://www.theses.fr/1991PA112248.
Повний текст джерелаАнотація:
Un protocole conduisant a la regeneration de plantes entieres a partir de protoplastes (p) de melon (cucumis melo) cantaloup charentais est decrit. Les protoplastes sont isoles a partir de feuilles et de cotyledons preleves sur des plantes cultivees in vitro. La sequence de culture comprend quatre milieux (m) destines a l'induction des divisions des protoplastes (m. 1), a la croissance des microcolonies (m. 2), a l'induction morphogenetique (m. 3) et au developpement des structures neoformees (m. 4). L'inclusion des protoplastes dans l'agarose ameliore les taux de viabilite et de divisions. Ces derniers, releves apres 14 jours de culture en m. 1 a une densite de 10#5 p. Ml##1, sont en moyenne de 60% et 30% quel que soit l'organe. La modulation de l'equilibre auxine/cytokinine exogene au niveau du m. 3 permet d'orienter la morphogenese vers une embryogenese somatique (4,5 m de 2,4-d et 0,4 m de bap) ou une caulogenese (2,2 m de bap et 2,3 m de kin). Le maltose se montre superieur au saccharose pour le developpement des nodules caulogenes en bourgeons sur m. 4. Des conditions d'electrofusion de protoplastes de c. Melo avec des protoplastes de c. Metuliferus ou de cucurbita pepo prealablement irradies aux rayons gamma ont ete mises au point. Trois plantes tetraploides ont ete regenerees a l'issu d'une experience de fusion entre c. Melo et c. Metuliferus. Leur morphologie ainsi que les zymogrammes des peroxydases, de la glutamate oxaloacetate transaminase, de la phosphoglucomutase et de la malate deshydrogenase sont identiques a ceux du parent melon. Les origines possibles de ces plantes sont discutees
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Caplan, Jamie Fay. "College Orientation for the First-Year and Transfer Student Populations: How can the needs of both groups be simultaneously met during orientation and beyond?" Oberlin College Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1212177109.
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Bros, Manuela. "Fermentation de surface d’une viande pré-traitée par Déshydratation-Imprégnation par Immersion : étude cinétique sur aliment réel et milieu modèle." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20028/document.
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Les procédés de fabrication de produits carnés stables à température ambiante s'articulent autour de la théorie des barrières et du couplage d'opérations unitaires telles que le salage, le séchage, la fermentation, le fumage. Dans les pays du Nord, ces procédés traditionnels ou industrialisés, aboutissent à des produits finis à la fois stables à température ambiante et prêts-à-consommer. Pour contrecarrer l'altération de la viande, accrue en conditions tropicales ou en conditions d'hygiène non maîtrisées, les procédés traditionnels du Sud mettent en œuvre des traitements plus drastiques et aboutissent à des produits nécessitant une préparation ultérieure pour être consommés (cuisson, dessalage).L'objectif général de ce travail est de proposer un procédé innovant adapté aux pays du Sud aboutissant à un produit carné salé/séché/fermenté stable à température ambiante et prêt-à-consommer. L'innovation consiste à traiter des morceaux de viande en couplant une pré-stabilisation par Déshydratation-Imprégnation par Immersion (DII) à une étape maîtrisée de fermentation de surface. Par une stratégie expérimentale progressive associée à la modélisation, cette thèse étudie le couplage DII/fermentation de surface et détermine quels leviers sont à disposition pour optimiser ce couplage. Les réponses apportées s'appuient sur trois parties. Une première étude sur aliment réel a validé le couplage de la DII avec une fermentation de surface par Lactobacillus sakei. Dans un deuxième temps, une étude en milieu modèle a mis en évidence l'influence des facteurs environnementaux d'intérêt (activité en eau, teneur en sel, pH et teneur en acide lactique) sur la croissance en surface de L. sakei. Enfin, un modèle global a été construit pour analyser le couplage entre les transferts de matière (eau, sel, sucres et acide) entre la surface et le cœur de l'aliment, et le métabolisme fermentaire à la surface du produit.Mots-clés : produits carnés, Déshydratation-Imprégnation par Immersion, fermentation de surface, Lactobacillus sakei, cinétiques de croissance, transferts de matièreThe fabrication of shelf-stable cured meat products is based on the hurdle technology and on the coupling of unit-operations such as salting, drying, fermentation and smoking. In Northern countries, these processes whether traditional or industrialized, lead to end-products which are both shelf-stable and ready-to-eat. Meat spoilage is accelerated in tropical conditions or when the general hygiene is not controlled. In order to counteract it, traditional processes in these conditions use more drastic treatments leading to end-products which require an additional preparation step before being consumed (cooking, desalting).The general objective of this work is to propose an innovative process adapted to Southern countries and leading to a salted/dried/fermented meat product which is shelf-stable and ready-to-eat. The innovation consists in treating meat pieces by coupling a pre-stabilization by Dehydration-Impregnation by Soaking (DIS) with a controlled surface fermentation step. By means of a progressive experimental strategy associated with modelization, this thesis studies the DIS/surface fermentation coupling and determines which levers are available to optimize it.The answers comprised three parts. Firstly, a study on the real food product validated the coupling of DIS with a surface fermentation by Lactobacillus sakei. Secondly, a study on a model device showed the influence of relevant environmental factors (water activity, salt content, pH and lactic acid content) on the surface growth of L. sakei. Finally, a global model was built to analyze the coupling of mass transfers (water, salt, sugars, acid) between the surface and the core of the product, and the fermentative metabolism at the surface of the product.Keywords: meat products, Dehydration-Impregnation by Soaking, surface fermentation, , Lactobacillus sakei, growth kinetics, mass transfers
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Durin, Bertrand. "Transfert et transport colloïdal de polluants métalliquesApplications en assainissement routier." Phd thesis, Université de Nantes, 2006. http://tel.archives-ouvertes.fr/tel-00104567.
Повний текст джерелаАнотація:
L'impact des infrastructures de transport sur l'environnement est une des préoccupations du ministère en charge de l'environnement. Le ruissellement des eaux de pluie sur les surfaces urbanisées engendre un effluent complexe plus ou moins pollué. L'objet de ce travail était de préciser le rôle de la fraction colloïdale sur la mobilité des éléments traces en assainissement routier. Pour cela nous avons procédé à deux échelles, d'une part d'une manière globale en instrumentant un bassin d'infiltration des eaux pluviales, afin de collecter et de qualifier l'effluent au cours de la chaîne d'infiltration depuis la route jusqu'aux eaux interstitielles ; d'autre part en simulant à l'échelle de la colonne de laboratoire, les sollicitations subies par le sédiment au cours de l'année, c'est à dire des variations de force ionique et des variations de charge hydraulique. L'isolement de la fraction colloïdale a été assurépar un protocole d'ultrafiltration et la caractérisation a été réalisée en couplant les analyses physicochimiques (ICP-AES, SAA, MEB, MEBE, MET, XPS) et un code de calcul géochimique. Les résultats obtenus sur le terrain mettent en évidence l'existence et la grande variabilité de la fraction colloïdale. Seul le cuivre y est toujours présent entre 4 et 59 % de sa concentration totale. Une méthodologie visant à réduire l'incertitude a été mise au point. La chute de la force ionique entraîne une mobilisation colloïdale d'aluminium, de cuivre, de plomb et de matière organique, alors que les cycles d'arrêt-reprise du débit mobilisent le cuivre, le fer, le zinc, le nickel et des composés organiques. La caractérisation colloïdale des éluats montre que les éléments traces sont associés à des oxydes d'aluminium et de fer accompagnés de substances organiques issues de la dégradation biologique mais qui sont à identifier.
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Andersson, Josefin, and Ebba Lindmark. "Är det möjligt att uppnå kraven för FEBY Guld oavsett en byggnads placering i Sverige? : Is it possible to meet the requirements for FEBY Gold regardless of location in Sweden?" Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-82741.
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I dag sätts flera åtgärder in för att bromsa klimatförändringarna, både inom Sverige och på internationell nivå. ‘Forum för energieffektivt byggande’, FEBY, är en organisation som arbetar med att driva utvecklingen av lågenergibyggnader framåt. FEBY har tagit fram ett certifieringssystem som ska hjälpa byggherrar uppföra byggnader med lägre energianvändning. För att en byggnad ska bli certifierad krävs det att den uppfyller vissa krav, bland annat på värmeförlusttal. Sedan starten 2008 har ca 50 småhus certifierats enligt systemet, vilket väcker frågan om varför så få småhus har certifierats och om detta kan bero på hur kraven är ställda.Syftet med rapporten är att undersöka om de krav som FEBY ställer på värmeförlusttal är rimliga vid byggande av ett småhus oavsett vart i Sverige det är placerat. Undersökningen har gjorts för tre orter i olika delar av Sverige; Lund, Falun och Boden. Byggnadens utformning är densamma på alla tre orter, med undantag för isolertjocklek i ytterväggen. Parametrarna fönsterglasarea, U-värde på fönster, luftläckning och köldbrygga varierades i beräkningarna för att få ett bredare och mer trovärdigt resultat.Undersökningen görs enligt de beräkningar som FEBY hänvisar till i dokumentet FEBY18 med utgångspunkt i krav för värmeförlusttal på nivå FEBY Guld.Rapporten avgränsas till en enplansvilla på 100 m2 uppvärmd golvarea. Ingen hänsyn tas till faktorer så som ljud, sol, fukt, årsvärmefaktor eller värmebalans för luftvärmd byggnad. Inte heller beaktas bärförmåga, motstånd mot brand eller fönstrens läge.Resultatet visar att negativa U-värden uppstår vid flera parametervariationer i Boden och Falun. Negativa U-värden indikerar att ytterväggen måste producera värme, vilket i det här fallet inte är möjligt. I flera fall i Falun och Boden förekommer även så pass låga U-värden att isoleringen behöver anta en tjocklek på över en meter medan isolertjockleken i Lund aldrig överstiger 500 mm. Vid de mest gynnsamma förutsättningarna visar resultatet att det fortfarande är svårt att nå en rimlig isolertjocklek, eller ett positivt U-värde, i Boden och delvis Falun.Slutsatsen är att det går att konstruera en byggnad som når kraven för nivå FEBY Guld i södra Sverige, men att det blir svårare ju längre upp i landet som byggnaden ska uppföras. Tjockare isolering verkar inte göra kraven uppnåeliga i Sveriges norra delar utan med de förutsättningar som undersöks skulle väggen behöva skapa värme om värmeförlusttalet för FEBY Guld ska nås.In the current political climate, several measures are implemented to prevent climate change both in Sweden and internationally. ‘Forum för Energieffektict Byggande’, FEBY, is an 6rganization that aims to contribute to the development and expansion of low-energy buildings. To this end, FEBY has created a certification scheme to help contractors develop buildings with lower energy consumption. To certify a building, the contractor must ensure that certain requirements are met, for example heat loss figures. Since the conception of the certification, only about 50 small houses have been certified. This raises the question of why so few small houses have been certified, and whether this is due to how the requirements are set.The purpose of this report is to investigate whether the heat loss figures that features in FEBY’s certification are reasonable in reference to the construction of small houses regardless of its location in Sweden. To examine this, this study features small house construction in Lund, Falun, and Boden. The overall building design is the same in all three locations, apart from the insulation thickness in the outer wall. The examined parameters for this study include window glass area, U-value of windows, air leakage, and thermal bridges varied in the calculations to ensure a more relevant and reliable result.This study is based on the calculations referred to in the document named FEBY18 which is based on the requirements for heat loss figures according to the FEBY Gold level.The report is limited to a single-floor house of 100 m2 of heated floor area. Factors such as sound, sun, moisture, annual heat factor, or heat balance for air-heated buildings are not considered. Nor is bearing capacity, resistance to fire, or the position of the windows, considered within the study.The result shows that negative U-values occur in several parameter variations in Boden and Falun. Negative U-values indicate that the outer wall must produce heat, which is not possible due to the construction of the wall. In several cases in Falun and Boden the U-values were so low that the insulation would need a thickness of more than one meter, while the insulation thickness in Lund never has to exceed 500 mm. Even during the most favorable conditions, the results still show the difficulty of achieving reasonable insulation thickness, as well as a positive U-value. This is especially true with regards to Boden, but in part also Falun.In conclusion, while it is possible to construct a small house that meet the requirements for the level FEBY Gold in the south of Sweden, it is increasingly challenging the further north you attempt to construct such a building. Even using thicker insulation, the requirements are difficult, if not impossible, to achieve in the north of Sweden. Under current conditions, the wall would need to generate its own heat to meat the heat loss figure demanded by the FEBY Gold standard.
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Mollex, Gaëlle. "Architecture de la plomberie du volcan carbonatitique Oldoinyo Lengai : nouvelles contraintes sur la source, les transferts hydrothermaux, et la différenciation magmatique dans la chambre active." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0123/document.
Повний текст джерелаАнотація:
La particularité de l’Oldoinyo Lengai à émettre des laves natrocarbonatitiques fait de ce volcan un laboratoire naturel pour l’étude de la genèse de ces magmas. De nouvelles mesures isotopiques en hélium nous ont permis de constater que la signature des fumerolles est constante depuis 1988 malgré le changement morphologique considérable du cratère sommital lors de la dernière éruption subplinienne de 2007-2008. L’alternance des éruptions explosives et effusives n’engendre donc aucune modification majeure dans l’organisation du système hydrothermal qui est par conséquent profondément enraciné. Les xénolites cogénétiques qui ont été émis lors de l’éruption de 2007-2008 permettent d’étudier directement les processus magmatiques qui se déroulent dans la chambre magmatique active. La comparaison des signatures isotopiques des gaz rares (hélium) de la chambre magmatique et des volcans silicatés de la région d’Arusha montre que les deux types de magmatisme ont une source analogue identifiée comme un manteau lithosphérique subcontinental préalablement métasomatisé par des fluides asthénosphériques. De plus, ces signatures isotopiques confirment l’absence de contaminations crustale lors de la remontée du magma entre le manteau source et la surface. Une description pétrographique de détail couplée à une approche thermobarométrique, ainsi qu’à la détermination des modèles de solubilité des volatils dans les liquides phonolitiques, nous a permis d’identifier l’évolution du liquide dans la chambre magmatique et ses paramètres de stockage. Les résultats nous révèlent que le magma injecté en 2007 a une composition phonolitique et des teneurs élevées en volatils (3.2 wt.% de H2O et 1.4 wt.% de CO2) ainsi qu’une température d'environ 1060° C. Ce magma évolue ensuite dans la chambre magmatique crustale se trouvant à 11.5±3.5 km de profondeur jusqu’à atteindre une composition de néphélinite et une température de 880°C. Pendant sa différenciation, le magma silicaté s’enrichit en calcium, sodium, magnésium et fer alors que sa concentration en silice, potassium et aluminium décroit. Ces résultats concordent avec les précédents relatifs à cette éruption, ou aux produits volcaniques plus anciens émis tout au long de la vie du volcan. Cette similarité suggère qu’aucun changement majeur n’ait eu lieu dans l’organisation de la plomberie du volcan Oldoinyo Lengai au cours de son évolution. Les mesures en éléments traces (REE, HFSE et LILE) dans les minéraux cristallisés lors de cette séquence de différenciation, et les inclusions magmatiques associées montrent un enrichissement pouvant atteindre de 100 à 1000 fois la composition du manteau primitif. Une étude expérimentale préliminaire s’appuyant sur la composition du liquide de recharge (phonolite) et les conditions (P, T) identifiées pour la chambre magmatique nous a permis de reproduire l'immiscibilité entre un liquide silicaté et carbonatitique, processus à l’origine de la formation des carbonatites de l’Oldoinyo Lengai. La poursuite de ces travaux expérimentaux permettra de mieux contraindre la genèse des magmas carbonatitiques et ainsi comprendre les processus en jeux dans l’enrichissement en éléments traces des magmas carbonatitiquesThe uniqueness of Oldoinyo Lengai to emit natrocarbonatite lavas makes this volcano a natural laboratory to study the genesis of these magmas. New helium isotopic data permit to assert that the signature of the fumaroles has been constant since 1988 despite the radical morphological change of the summit crater after the last sub-Plinian eruption in 2007-2008. The alternation of the effusive and explosive eruptions does not cause major modifications in the hydrothermal system architecture, which is inferred to be deeply rooted. Cognate xenoliths that were emitted during the eruption in 2007-2008 represent a unique opportunity to document the igneous processes occurring within the active magma chamber. The comparison between the noble gas (helium) isotopic compositions of the active magma chamber and those of the other silicate volcanoes of the Arusha region indicates that both types of magmatism have similar sources, identified as being a typical sub-continental lithospheric mantle, which was previously metasomatized by asthenospheric fluids. Moreover, these isotopic signatures confirm that no crustal contamination has occurred during the magma ascent from the mantle to the surface. Detailed petrographic descriptions coupled to a thermo-barometric approach, and to the determination of volatile solubility models for a phonolite composition, allow us to identify the melt evolution at magma chamber conditions and the storage parameters. These results indicate that the magma injected in 2007 has a phonolitic composition and contains a high amount of volatiles (3.2 wt.% H2O and 1.4 wt.% CO2) as well as a temperature around 1060° C. This magma subsequently evolved in the crustal magma chamber located at 11.5 ± 3.5 km depth until reaching a nephelinite composition and a temperature of 880°C. During the differentiation in the magma chamber, the silicate magma is enriched in calcium, sodium, magnesium and iron, whereas the content of silicate, potassium and aluminum decreases. Our results support previous studies related to this eruption, and are similar to the historical products emitted during the whole volcano history, permitting the suggestion that no major modification in the plumbing system has occurred during the Oldoinyo Lengai evolution. The trace elements (REE, LILE and HFSE) measured in the minerals and melt inclusions reveal a concentration reaching 100 to 1000 times the primitive mantle composition. A preliminary experimental study based on the recharge melt composition (phonolite) and identified magma chamber conditions (P, T) permits to reproduce the immiscibility between silicate and carbonatite liquids, key processes at the origin of the Oldoinyo Lengai carbonatites. The continuation of this experimental study will lead to a better comprehension of the carbonatite genesis, thus improving our understanding of the processes that are responsible for the enrichment in trace elements
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BERA, ALEXANDRE. "Efeitos nas caracteristicas fisico-quimicas, microbiologicas e sensoriais em amostras de mel de abelhas submetidas a radiacao gama." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9527.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Andrade, Augusto Fernandes Cordeiro de. "Influ?ncia da corrente de pulso, do tempo de pulso e di?metro de gota sobre a estabilidade da transfer?ncia met?lica no processo MIG-P." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15692.
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Previous issue date: 2012-09-17To obtain a process stability and a quality weld bead it is necessary an adequate parameters set: base current and time, pulse current and pulse time, because these influence the mode of metal transfer and the weld quality in the MIG-P, sometimes requiring special sources with synergistic modes with external control for this stability. This work aims to analyze and compare the effects of pulse parameters and droplet size in arc stability in MIG-P, four packets of pulse parameters were analysed: Ip = 160 A, tp = 5.7 ms; Ip = 300 A and tp = 2 ms, Ip = 350 A, tp = 1.2 ms and Ip = 350 A, tp = 0.8 ms. Each was analyzed with three different drop diameters: drop with the same diameter of the wire electrode; droplet diameter larger drop smaller than the diameter of the wire electrode. For purposes of comparison the same was determined relation between the average current and welding speed was determined generating a constant (Im / Vs = K) for all parameters. Welding in flat plate by simple deposition for the MIG-P with a distance beak contact number (DBCP) constant was perfomed subsequently making up welding in flat plate by simple deposition with an inclination of 10 degrees to vary the DBCP, where by assessment on how the MIG-P behaved in such a situation was possible, in addition to evaluating the MIG-P with adaptive control, in order to maintain a constant arc stability. Also high speed recording synchronized with acquiring current x voltage (oscillogram) was executed for better interpretation of the transfer mechanism and better evaluation in regard to the study of the stability of the process. It is concluded that parameters 3 and 4 exhibited greater versatility; diameters drop equal to or slightly less than the diameter of the wire exhibited better stability due to their higher frequency of detachment, and the detachment of the drop base does not harm the maintenance the height of the arc
Para obter a estabilidade no processo e uma boa qualidade no cord?o de solda ? necess?rio um bom ajuste nos par?metros: corrente e tempo de base e corrente e tempo de pulso e Va, pois estes influenciam no modo de transfer?ncia met?lica e sobre a qualidade da solda no processo MIG-P, ?s vezes, sendo necess?rio um aux?lio ?s fontes com os modos sin?rgicos com controle externo para obter esta estabilidade. Este trabalho tem como objetivo analisar e comparar os efeitos dos par?metros de pulso e o di?metro de gota na estabilidade do arco voltaico no processo MIG-P, sendo analisados quatro pacotes de par?metros de pulso: Ip=160 A, tp=5,7 ms; Ip=300 A e tp=2 ms; Ip=350 A, tp=1,2 ms; e Ip=350 A, tp=0,8 ms. Cada um foi analisado com tr?s diferentes di?metros, calculados, de gota: gota com o mesmo di?metro do arame-eletrodo; gota com di?metro de gota maior e menor que o di?metro do arame eletrodo. Para fins de compara??o foi determinada a mesma rela??o entre a corrente m?dia e a velocidade de soldagem gerando uma constante (Im/Vs=K) para todos os par?metros. Realizou-se a soldagem em chapa plana por simples deposi??o para o processo MIG-P com uma dist?ncia bico contato pe?a (DBCP) constante; e posteriormente, efetuando-se a soldagem em chapa plana por simples deposi??o com uma inclina??o de 10? para variar o DBCP, p?de-se avaliar como o MIG-P se comportou em tal situa??o, al?m de avaliar o MIG-P com controle adaptativo, com o objetivo de manter constante a estabilidade do arco voltaico. Tamb?m executou-se a filmagem de alta velocidade sincronizadamente a aquisi??o da corrente x tens?o (oscilograma) para melhor interpreta??o do mecanismo de transfer?ncia e melhor avalia??o no que se refere ao estudo da estabilidade do processo. Conclu?mos que os par?metros 3 e 4 apresentaram uma maior versatilidade; os di?metros de gota igual ou ligeiramente menos que o di?metro do arame apresentaram uma melhor estabilidade, devido a sua maior frequ?ncia de destacamento; e o destacamento da gota na base n?o prejudicou a manuten??o da altura do arco voltaico
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Vallet, Maxime. "Étude des défauts bidimensionnels à base d'hélium dans le silicium - Application au transfert de films minces." Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2277/document.
Повний текст джерелаАнотація:
Le procédé Smart CutTM, utilisé pour le transfert de films minces sur substrat est basé sur la fissuration du silicium. La propagation des fissures est initiée à partir de défauts bidimensionnels induits par implantation d'hydrogène, les « H-platelets ». Des études précédentes ont montré que la fissuration du Si peut également être obtenue à partir de défauts nommés « He-plates » qui ont la particularité d'avoir un diamètre dix fois supérieur. L'objectif de ce travail était d'étudier la formation de ces défauts et leur évolution sous flux d'hydrogène jusqu'à la propagation des fissures. Dans une première partie, la formation des « He-plates » a été étudiée pour différentes orientations de substrats et discutée par rapport à la contrainte compressive bi-axiale induite par l'implantation. Les résultats montrent que les mécanismes qui gouvernent la formation des « He-plates » sont les mêmes que pour les « H-platelets ». Dans une seconde partie, l'évolution des « He-plates » en présence d'H a été étudiée en utilisant une approche expérimentale originale qui couple implantations d'hydrogène et observations par microscopie électronique en transmission. Les expériences montrent que la croissance des « He-plates » est gouvernée par la diffusion de l'hydrogène qui dépend de la température et du taux d'endommagement. Enfin, leur croissance est décrite à l'aide d'un modèle cinétique et, leur coalescence a été analysée en relation avec un modèle élastique. La propagation rectiligne de fissures à partir de ces précurseurs offre des perspectives intéressantes pour une utilisation industrielleThe Smart CutTM process, used in the transfer of thin films on substrates is based on the cracking of silicon. The crack propagation is initiated from bi-dimensional defects induced by H-implantation, the H-platelets. Previous studies showed that the propagation of cracks in Si can also be triggered from defects named He-plates which have the particular feature of having a diameter ten times larger. The aim of this work was to study the formation of these defects and their evolution until the crack propagation under H supply.In a first part, the formation of He-plates was studied for different substrate orientations and discussed regarding the bi-axial compressive stress induced by implantation. Results show that the mechanisms that govern the He-plate formation are the same than for H-platelet formation. In a second part, the evolution of He-plates under H supply was studied by using an original experimental approach that combines H-implantation and transmission electron microscopy observations. Experiments show that the growth of He-plates is controlled by the diffusion of hydrogen which depends on temperature and damage rate. Finally, the growth is described by a kinetic model and their coalescence was analyzed with regard to an elastic model. The straight propagation of cracks from He-plates offers promising outlook for an industrial use
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Vladimir, Filipović. "Uticaj procesa osmotske dehidratacije na prenos mase i kvalitet mesa svinja." Phd thesis, Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, 2013. http://dx.doi.org/10.2298/NS20130523FILIPOVIC.
Повний текст джерелаАнотація:
Ispitivan je proces osmotske dehidratacije mesasvinja u tri osmotska rastvora (vodeni rastvornatrijum hlorida i saharoze, kombinacijavodenog rastvora natrijum hlorida i saharoze imelase i melasa šećerne repe) različitihkoncentracija, na tri temperature (20°C, 35°C i50°C) i pri tri vremena trajanja procesa (1, 3 i5h). Mereni i računati odzivi procesa osmotskedehidratacije bili su: sadržaj suve materije,gubitak vode, prirast suve materije, indeksefiksanosti procesa, vrednost aktivnosti vode.Rezultati ispitivanja pokazuju da povećanjetehnoloških parametara temperature i vremenaprocesa, kao i koncentracije osmotskih rastvoradovode do intenziviranja prenosa mase uprocesu i povećanja vrednosti odzivnihparametara procesa, u oba slučaja, istostrujne iprotivstrujne osmotske dehidratacije.Na osnovu dobijenih rezultata razvijeni sumodeli zavisnosti odziva procesa odprimenjenih tehnoloških parametara zaistostrujne i protivstrujne procese osmotskedehidratacije. “Score” analizom određene suvrednosti tehnoloških parametara koje su zarezultat dale optimalnu efiksanost procesa.U radu je ispitan enegetski bilans procesaosmotske dehidratacije i upoređen sakonvektivnim sušenjem, gde su se kaoenergentski najefikasniji pokazali procesi natemperaturi od 20°C.Karakteristike osmotski dehidriranog svinjskogmesa su pokazale da dolazi do poboljšanjamikrobiološkog, hemijskog i nutritivnog profilamesa nakon procesa, kao i promene boje iteksture, gde je melasa šećerne repe kaoosmotski rastvor, iskazala najbolje uticaje napromene karakteristika dehidiranog mesa.Na osnovu svih ispitanih uticaja variranihparametara kao optimalni parametri procesamogu da se definišu: protivstrujni proces, utrajanju od 5 časova na temperaturi od 20°C, umelasi kao osmotskom rastvoru. Ovakav procesdovodi do sveukupnog poboljšanjakarakteristika svinjskog mesa uvodeći nutritivnapoboljšanja iz hemijskog sastava melase uljudsku ishranu.Process of osmotic dehydration of pork meat inthree different osmotic solutions (sodiumchloride and sucrose dissolved in water, mixtureof sodium chloride, sucrose dissolved in waterand molasses and sugar beet molasses) ofdifferent concentrations, at three temperatures(20°C, 35°C & 50°C) and three different timesof duration of the process (1, 3 & 5h) wasinvestigated.Measured and calculated responses of theosmotic dehydration process were: dry mattercontent, water loss, solid gain, dehydrationefficiency index and value of water activity.The results showed that the increase oftechnological parameters: time and temperatureof the process, as well as the concentration ofthe osmotic solutions led to the intensified masstransfer in the process and increased values ofprocess responses, in either co-counter orcurrent processes of osmotic solutions.Based on obtained results mathematical modelsof dependence of process responses fromapplied technological parameters for co- andcounter-current processes of osmoticdehydrations were developed. By the means of“Score” analyses the values of technologicalparameters which produced optimal efficiencyof the process were calculated.In this research process energy balance wasinvestigated by comparison to the convectivedrying, where the highest energy efficiency wasdetermined in the processes at the temperatureof 20°C.Characteristics of osmo-dehydrated pork meatwere also investigated, pointing at theimprovement of microbiological, chemical andnutritive profile of the meat after the process, aswell as the change of color and texture, wheresugar beet molasses, as an osmotic solution, hadshown the best effects on changes of dehydratedmeat characteristics.Based on all investigated effects of variedparameters, the optimal process parameters canbe defined as: counter-current process, of 5hours duration, at 20°C, in molasses as anosmotic solution. Process like that leads to thetotal improvement of pork meat characteristicsintroducing nutritive benefit from molasseschemical composition into human nutrition.
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Kellermann, Guillaume. "Applications de la transduction des protéines : transfert de TPr-Met pour la transplantation cellulaire : identification d'un domaine de transduction dans la sous unité catalytique de la télomérase." Paris 7, 2009. http://www.theses.fr/2009PA077028.
Повний текст джерелаАнотація:
Certaines protéines comme l'onconase ou le facteur TAT du virus du SIDA ont l'étonnante capacité de pouvoir pénétrer à l'intérieur des cellules malgré leur forte taille. Ces protéines, peuvent être internalisées spontanément par les cellules, car elles possèdent dans leur séquence, un domaine particulier appelé domaine de transduction. Dans la première partie de cette thèse, nous avons utilisé le domaine de transduction de TAT (VIH) pour vectoriser Tpr-Met, une protéine kinase qui agit sur la prolifération, la survie, la migration des cellules. Nous avons construit, exprimé et purifié une protéine chimérique TAT-Tpr-Met et avons mis au point sa renaturation in vitro. TAT-Tpr-Met pénètre dans plusieurs types cellulaires en culture et augmente la prolifération, la survie et la mobilité des cellules. Nous avons ensuite montré que le prétraitement de progéniteurs hépatiques avec cette molécule améliorait leur prise de greffe, après transplantation dans le foie de souris. Ce travail montre qu'il est possible d'utiliser un domaine de transduction pour modifier transitoirement les capacités d'intégration des cellules, sans altérer le génome. Dans la deuxième partie de cette thèse, nous avons construit une protéine fusion entre le domaine de transduction de TAT et la sous-unité catalytique de la télomèrase (hTERT). Au cours de ce travail, nous avons identifié un domaine de transduction naturel dans hTERT. Nous avons fait synthétisé ce domaine sous forme d'un peptide lié à FITC, et avons pu montrer qu'il avait la capacité d'être internalisé par les cellules humaines in vitro. Nous avons produit la sous unité catalytique de la télomèrase à partir de cellules d'insectes infectées par des baculovirus recombinants, et avons également mis au point un protocole pour purifier plusieurs milligrammes de cette protéine, ainsi que son variant dominant négatif, en l'exprimant dans la levure. Les études menées avec la protéine recombinante ont démontré que la protéine hTERT avait une capacité d'internalisation naturelle. Cette propriété suggère que la protéine hTERT, et son variant dominant négatif pourraient respectivement être utilisés comme activateur et inhibiteur de la télomèraseSome proteins such as onconase or TAT from the HIV have an amazing ability to penetrate inside the cells, despite their heavy size. These proteins can be internalized by the cells spontaneously, as they have in their sequence, a field called transduction domain. In the first part of this thesis, we used the domain of transduction from TAT (HIV) to vectorize TPR-Met, a protein kinase that acts on the proliferation, survival, cell migration. We built, expressed and purified chimeric protein TAT-TPR-Met and have developed its renaturation in vitro. TAT-TPR-Met enter s several cell types in culture and increases the proliferation, survival and mobility of cells. We then showed that pretreatment with liver progenitors of this molecule improved their presence into the liver after transplantation in the mouse. This work shows that it is possible to use a domain of transduction to change temporarily the integration capacity of cells, without altering the genome. In the second part of this thesis, we built a protein fusion between the protein transduction domain of TAT and the catalytic subunit of telomerase (hTERT) gene. During this work, we have identified a natural transduction domain in hTERT. We have made this area synthesized form of a peptide linked to FITC, and were able to show he had the ability to be internalized by human cells in vitro. We produced the catalytic subunit of telomerase from insect cells infected with recombinant baculovirus, and have also developed a protocol to purify several milligrams of this protein and its variant dominant negative, expressing in yeast. Studies with the recombinant protein showed that the protein hTERT had a natural ability to internalize. This property suggests that the protein hTERT and its dominant negative variant respectively could be used as activator and inhibitor of telomerase
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Bouhrara, Mustapha. "Caractérisation locale des déformations et des transferts de matière dans le muscle sous contraintes thermiques par imagerie RMN." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00777881.
Повний текст джерелаАнотація:
La cuisson est un procédé universel de transformation de la matière première carnée en aliment. Le chauffage de la matrice musculaire conditionne diverses qualités organoleptiques, technologiques, sanitaires et nutritionnelles des viandes cuites. La cuisson étant appliquée de plus en plus fréquemment en conditions industrielles standardisées, il est pertinent de modéliser certains mécanismes clés dans le déterminisme de ces qualités afin d'optimiser le procédé. Pour cela, une démarche expérimentale originale a été mise en place fondée sur une analyse quantitative, locale, dynamique et in situ de la viande pendant la cuisson. Cette démarche ne fait pas d'hypothèse réductionniste en étudiant un échantillon intact à l'échelle de l'aliment consommé, ni d'hypothèse simplificatrice en prenant en compte les variations spatiales de la température dans l'échantillon. Elle s'appuie sur des développements originaux en imagerie par résonance magnétique nucléaire à haut champ et en traitement d'images pour cartographier la déformation et la quantité d'eau. Des modèles robustes liant température, déformation et quantité d'eau ont été obtenus pour des muscles de teneur variable en tissu conjonctif. Les résultats montrent principalement une augmentation de la déformation avec la température en plusieurs phases dont les caractéristiques dépendent de la composition du muscle, et une diminution de la quantité d'eau avec la température. Tous ces résultats sont discutés et interprétés au regard du comportement à la température des différents composants du muscle. Ce travail montre d'abord que l'imagerie dynamique, quantitative et multiparamétrique permet de décrypter des mécanismes intervenant lors de la cuisson des viandes sans établir des hypothèses réductrices lors de l'interprétation de ces phénomènes. Elle a conduit de plus, à des développements méthodologiques applicables à d'autres champs et ouvre la voie à d'autres investigations dans le domaine de l'optimisation qualitative des produits carnés transformés.
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Hui, Daniel Jason. "The Mechanism of Protein Synthesis Inhibition by the P56 Family of Viral Stress Inducible Proteins." Connect to text online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1104848977.
Повний текст джерела
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Guyomar, Charlotte. "Études structurales de la trans-traduction, cible privilégiée pour le développement de nouveaux antibiotiques." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B039.
Повний текст джерелаАнотація:
Le travail retranscrit dans cette thèse porte sur un processus biologique impliqué dans le contrôle qualité de la synthèse protéique bactérienne : la trans-traduction. Ce processus permet de libérer les ribosomes bloqués sur des ARNm défectueux tout en détruisant les peptides et ARNm problématiques impliqués dans le blocage. Il nécessite deux acteurs principaux qui interagissent avec le ribosome: l’ARN transfert-messager (ARNtm) et la protéine SmpB. Dans un premier chapitre, une étude en cryo-microscopie électronique à transmission (cryo-MET) a permis d’obtenir deux structures à l’échelle atomique impliquant le ribosome et différents acteurs de la trans-traduction. La première structure met en évidence l’interaction entre la RNase R, enzyme responsable de la destruction des ARNm défectueux, et le ribosome bactérien. La deuxième structure a mené à la caractérisation des deux premiers états de la trans-traduction à une résolution quasi-atomique. De nouvelles interactions sont notamment observées entre la protéine SmpB et l’hélice H5 de l’ARNtm. Dans un second chapitre, la trans-traduction est exploitée comme cible pour le développement de nouveaux antibiotiques. En effet, cette voie de sauvetage est souvent vitale ou alors indispensable à la virulence bactérienne. Dans l’objectif de découvrir de nouvelles molécules antibiotiques inhibant la trans-traduction, nous avons mis au point un système de détection de la trans-traduction in vitro. Ce système est simple et rapide, basé sur la mesure de la fluorescence d’une GFP tronquée, réassemblée par un ARNtm muté. La validation du système a conduit à la détection de nouveaux composés anti-trans-traductionThis work is focused on a biological process which controls bacterial protein synthesis, trans-translation. This all-in-one process allows the rescuing of ribosomes stalled on defective mRNA, the degradation of the problematic peptides and mRNA. It is driven by two principal actors that interact with the ribosome: transfer-messenger RNA (tmRNA) and Small protein B (SmpB). In a first chapter, by a cryo-electron microscopic (cryo-EM) study, two near-atomic resolution structures, involving the ribosome and various trans-translation actors, were obtained. The first one highlights the interactions between RNase R, an enzyme responsible for mRNA degradation during trans-translation, and the bacterial ribosome. The second one corresponds to the characterization of two early trans-translation states at a near-atomic resolution. New interactions have been observed between SmpB and tmRNA H5 helix. In a second chapter, trans-translation is used as a target for the development of new antibiotic molecules. Indeed, this pathway is often necessary for bacterial survival and pathogenicity. Towards this aim, we designed and set up a new in vitro assay for high-throughput screening assays. This efficient system is based on fluorescence measurements of a GFP reassembled through trans-translation by a mutated tmRNA. This system has been validated and will be used for the discovery of new anti-trans-translation compounds
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Davoust, Laurent. "Convection naturelle MHD dans une cavité horizontale élancée." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0139.
Повний текст джерелаАнотація:
Lors de la croissance des monocristaux semi-conducteurs a partir d'un bain fondu, la convection naturelle gouverne de maniere determinante les transferts de masse et de chaleur. Comme la micro-gravite, l'imposition d'un champ magnetique permanent sur le bain - electro-conducteur - est un moyen de stabiliser, de reorganiser l'ecoulement de convection naturelle et, finalement, de le freiner afin de s'approcher au mieux des conditions ideales d'un transport diffusif des especes chimiques. Dans un premier temps, une synthese des connaissances acquises sur les ecoulements thermogravitaires, magnetohydrodynamiques (mhd) ou non, est presentee. Puis, sur la base du dispositif experimental mascot (magnetic stabilisation of convection and turbulence), les phenomenes qui gouvernent l'ecoulement thermogravitaire mhd du mercure dans une cavite cylindrique horizontale elancee, soumise a la fois a un champ magnetique uniforme et a un gradient de temperature horizontal, sont mis en evidence puis interpretes a l'aide de la mhd. Dans cette configuration particuliere, les couches de hartmann demeurent electriquement inactives. L'inertie n'influence l'ecoulement que localement (aux extremites de la cavite), et surtout dans le cas ou la convection est intense (a grand nombre de grashoff). Ailleurs, le couplage entre courants electriques induits et distribution de temperature est illustre par l'equilibre entre le rotationnel de la force de laplace et le rotationnel de la force de flottabilite. Cet equilibre pilote l'ecoulement pour un nombre de rayleigh modifie, dit effectif, suffisamment faible. Une simulation numerique 3-d aux elements finis de cet ecoulement (laminaire) apporte une confirmation satisfaisante de ces resultats experimentaux. Ce memoire est l'etude de la transition de cet ecoulement vers la turbulence, a l'aide de l'experience mascot. Trois ondes oscillantes progressives ou stationnaires sont clairement identifiees pendant la transition. Si la convention est intense, ces ondes interagissent avec des instabilites stationnaires evoluant faiblement dans le temps. Le couplage non-lineaire associe au terme de convection dans l'equation de l'energie engendre une bifurcation sous-critique. Puis, si le regime d'ecoulement est faiblement convectif, le chaos survient a la suite d'une bifurcation supercritique de hopf. Ces resultats ouvrent des perspectives de developpement technologique pour le procede bridgman de croissance cristalline. Et plus generalement, ce progres dans la comprehension de la convection naturelle mhd pourrait s'appliquer dans d'autres situations: en genie metallurgique ou dans les couvertures tritigenes du futur reacteur de fusion thermonucleaire