Дисертації з теми "Low temperature processing"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Low temperature processing".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Mahanama, G. D. K. "Low temperature processing of crystalline silicon solar cells." Thesis, London South Bank University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435235.
Повний текст джерелаBriseno, Murguia Silvia. "Processing of NiTi Shape Memory Alloys through Low Pressure and Low Temperature Hydrogen Charging." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157656/.
Повний текст джерелаJuodawlkis, Paul W. "Low-temperature-grown InGaAs quantum wells for optical device applications." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/13752.
Повний текст джерелаGonzález-León, Juan A. (Juan Antonio). "Low temperature processing of baroplastic core-shell nanoparticles and block copolymers." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/36202.
Повний текст джерелаIncludes bibliographical references (p. 131-144).
Baroplastics are nanophase polymeric materials comprised of two components that can miscibilize under pressure thereby facilitating flow. The possibility of processing these materials at low temperatures was the main focus of this work. Block copolymer baroplastics comprised of a low Tg and a high Tg component that microphase separate, such as polystyrene-block-poly(butyl acrylate) (PS-b-PBA) and polystyrene-b-poly(2-ethyl hexylacrylate) (PS-b-PEHA), were synthesized by ATRP and processed at reduced temperatures by compression molding. The resulting processed specimens were clear and well-defined solid objects. Structural characterization studies on the processed baroplastics showed that the mixing between components during processing is incomplete and distinct hard and soft domains are present even after multiple processing cycles. This suggests that the processing is of a semi-solid nature, where the rigid PS domains are mobilized by the low Tg component. Processing of a control sample exhibiting pressure-induced demixing, polystyrene-block-poly(lauryl methacrylate) (PS-b-PLMA), yielded incompletely processed objects under the same processing conditions and inferior mechanical properties to its acrylate counterparts.
(cont.) Low temperature processing of baroplastics and the proposed semi-solid processing mechanism were further demonstrated with the study of core-shell nanoparticles, where the soft homopolymer (PBA or PEHA) formed the core surrounded by a rigid PS shell. These materials could also be processed at reduced temperatures, displaying a wide range of mechanical properties as a function of their composition, going from tough and rigid materials to soft and rubbery ones comparable to commercial thermoplastic elastomers. Low temperature processing of baroplastics opens a new route to polymer processing, where energy for heating and cooling could be saved, processing times could be reduced and materials with high sensitivity to temperature could be processed.
by Juan A González-León.
Ph.D.
Young, Avery W. "A Study on NiTiSn Low-Temperature Shape Memory Alloys and the Processing of NiTiHf High-Temperature Shape Memory Alloys." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157642/.
Повний текст джерелаGarlapati, Suresh [Verfasser], Horst [Akademischer Betreuer] Hahn, and Heinz von [Akademischer Betreuer] Seggern. "Low Temperature Processing of Printed Oxide Transistors / Suresh Garlapati ; Horst Hahn, Heinz von Seggern." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1126115932/34.
Повний текст джерелаTerry, Mason L. Photovoltaic & Renewable Energy Engineering UNSW. "Post???deposition processing of polycrystalline silicon thin???film solar cells on low???temperature glass superstrates." Awarded by:University of New South Wales. Photovoltaic and Renewable Energy Engineering, 2007. http://handle.unsw.edu.au/1959.4/30498.
Повний текст джерелаMandal, L. "High performance photo-detectors and field effect transistors based on low temperature solution processing routes." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2013. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2200.
Повний текст джерелаZhang, Xinge. "Influence of architecture, materials, and processing on low temperature solid oxide fuel cell (LT-SOFC) performance." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/11262.
Повний текст джерелаZheng, Hanguang. "Processing and Properties of Die-attachment on Copper Surface by Low-temperature Sintering of Nanosilver Paste." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42658.
Повний текст джерелаMaster of Science
Dargan, Richard Alan. "Properties of Low-fat Yogurt Made From Ultrafiltered and Ultra-high Temperature Treated Milk." DigitalCommons@USU, 1992. https://digitalcommons.usu.edu/etd/5389.
Повний текст джерелаSingh, Madhav [Verfasser]. "Low temperature processing and electrochemical characterization of phosphate based cathode materials and electrolytes for Li-ion batteries / Madhav Singh." Aachen : Shaker, 2012. http://d-nb.info/1066197385/34.
Повний текст джерелаShelton, Travis Edward. "Synthesis and Characterization of Crystalline Transition Metal Dichalcogenides onto Stretchable Substrates by Laser Processing." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450405970.
Повний текст джерелаMakhdoom, Atif [Verfasser], Christoph J. [Akademischer Betreuer] Brabec, and Christoph J. [Gutachter] Brabec. "Low Temperature Processing Route of Silicon Nanoparticle Layers for Solar Cell Application / Atif Makhdoom ; Gutachter: Christoph J. Brabec ; Betreuer: Christoph J. Brabec." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2018. http://d-nb.info/1169913245/34.
Повний текст джерелаWang, Xiaoxin. "PROCESSING AND CHARACTERIZATION OF TiB 2 -COLLOIDAL ALUMINA COATING ON CARBON CATHODE IN HALL-HEROULT CELL." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971978030.
Повний текст джерелаBates, Griffin Michael. "Characterizing the Cold Temperature Performance of Guayule (Pathenium argetnatum) Natural Rubber and Improving Processing of Guayule and Agronomic Practices of Taraxacum kok-saghyz." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1448376403.
Повний текст джерелаSandberg, Gary. "Thermal processing of low-acid foods with sub-zero initial temperatures." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30316.
Повний текст джерелаLand and Food Systems, Faculty of
Graduate
Somani, Abhishek. "The responses of lager brewing yeast to low temperatures." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/28783/.
Повний текст джерелаMoussa, Sherif Omar Hassan. "Transient processing and characterizatin of advanced materials /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115572.
Повний текст джерелаWang, Xingang. "Thermal strain of concrete under low temperatures and durability and Processing techniques of concrete with CNTs." Thesis, University of Colorado at Boulder, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1546581.
Повний текст джерелаThis thesis consists of two topics: Thermal strain of concrete under low temperatures, and durability and processing techniques of concrete with CNTs. The low temperature test studies the anti-freezing action of concrete under cooling environment. Concrete mixes using different amounts of air-entraining agent and water/cement ratios were made and cured under different humidity environments. During the cooling process from 10 ºC to -25 ºC, the strain of concrete was measured every 3~5 ºC. The strain-temperature curve of concrete under different mixing proportion was produced from these results. A numerical model was developed based on the theory of the self-consistent model. No knowledge of real pore shapes is needed to apply in the model. The only inputs for the model came from the (Brunauer-Emmett-Teller) BET test, which gave the pore size distribution of concrete sample. The validity of the numerical model was compared to the experimental results, and showed similarity in trend and peak strain. CNT is one of the most popular topics in engineering. CNT has an extremely high strength and Young's modulus. CNT is a nano-scale material, however, and tends to clump together, which makes it difficult to apply. Other research has successfully incorporated CNT into cement paste and polymer materials. This has not yet been done into concrete. This research mainly focuses on the important factors that must be solved to adopt CNT in concrete area. An ultrasonicator was used to aid the dispersion and distribution of CNT in water, while several chemicals were also adopted for this purpose. Both strength and durability were tested for CNT concrete of different mix designs. It is suggested that ultrasonicator can improve the strength of pure CNT concrete (without chemicals) by around 100%. In addition, the sodium polyacrylate treated CNT concrete has showed best durability result and good strength result.
Hassenforder, Philippe. "Preparation et etude de couches minces cristallines de polydiacetylenes." Paris 6, 1988. http://www.theses.fr/1988PA066289.
Повний текст джерелаFrancou, Mireille. "EEtude de la gravure profonde du silicium dans un réacteur haute-densité micro-onde de type propagatif." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10090.
Повний текст джерелаEsmail, Adam Ashiq. "Charge dynamics in superconducting double dots." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/270018.
Повний текст джерелаGarlapati, Suresh. "Low Temperature Processing of Printed Oxide Transistors." Phd thesis, 2017. https://tuprints.ulb.tu-darmstadt.de/5999/1/Low%20Temperature%20Processing%20of%20Printed%20Oxide%20Transistors.pdf.
Повний текст джерелаKwon, Do-Kyun. "Ultra-low temperature processing of barium tellurate dielectrics." 2006. http://www.etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1148/index.html.
Повний текст джерелаChen, Liang-Yu, and 陳良友. "Low Temperature Processing of Tellurate-Base Dielectric Ceramics." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/axrzx2.
Повний текст джерела國立臺北科技大學
材料科學與工程研究所
95
Ceramics, metals and polymers have unique electrical properties that are combined for electronic devices and systems. It necessitates lower processing temperatures for ceramics to be compatible with metal and polymer systems. Pure tellurium dioxide is well known as a networkformer in the glass industry, although pure tellurium dioxide does not form glass, even at high cooling rates. Most tellurium-based oxide materials can be synthesised and sintered at temperatures below 900oC, which makes them potential candidates for use in low-temperature-cofired-ceramics (LTCC) technology. This research divides into two parts of discussions. First part of research was probed into that the influence of dielectric characterisation of ceramics and the change of microstructure from the TiTe3O8 by adding of SiO2. Result reveal that can produce surface volatilize the phenomenon in the process of sintering at 650~750oC. The phenomenon of volatilize can be controlled by adding a few SiO2.The exaggerated grain growth during sintering ofTiTe3O8 with forming additive 1wt%SiO2. The grain size of pure TiTe3O8 is around 5μm. Grain size of the TiTe3O8 by adding of 1wt%SiO2 that grown into 50μm because the liquid phase sintering. The dielectric constant drops as SiO2 adding amount rise in electricity, and the quality factor is improved to 48000 from 25000, measured at ~7GHz. Second part of research is alkaline-earth oxide (Mg、Ca、Sr、Ba)-TeO2 system. the (Mg、Ca、Sr、Ba)-TeO2 system ceramics were prepared by a solid reaction method. In the calcining process, the compounds have an opportunity oxygen to absorb air by long calcined time. Make its compounds(Mg3TeO6/MgTe2O5、CaTeO4、SrTeO4 and BaTeO3/BaTeO4) produce different structure. The compounds were investigated its microstructure and the properties of dielectric. The above-mentioned compounds display the relative permittivity of around 10~20, the quality factor of around 1000~30000 GHz and the temperature coefficient of resonant frequency of around -9~-100ppm /℃.The compounds are sintered in the temperature range of 700 ~ 1100oC.
Huang, Yu-Ting, and 黃郁庭. "Investigation of the low stress TEOS SiO2 films by low temperature PECVD processing." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/61098062573600876958.
Повний текст джерела國立中央大學
光電科學與工程學系
103
Tetra-ethyl-ortho-silicate (TEOS) SiO2 thin films were deposited using low temperature Plasma-enhanced chemical vapor deposition (PECVD) to achieve the performances of low stress and high density. Several process parameters including working pressure, O2 flow rate, TEOS flow rate, high and low frequency power rates, and working temperatures were adjusted to analyze the quality of the films. The results show when the deposition rate is high, the density of the film is low. And the lower density of the film will affect the lower stress. We found out the stress of TEOS SiO2 film has strong correlation by the high film density and slow deposit rates. The working pressure, O2 flow and TEOS flow rate can play important roles for the stress and density of the TEOS SiO2 films. Finally, we found out the high film density and low stress conditions keep the deposition pressure at 4torr, TEOS / O2 ratio at 8.1% and working temperature at 200 degrees. The deposition rate was about 41±2.0Å/sec. the etching rate was about 1100±55Å/sec.The stress of the SiO2 film was compressive and the stress value range was at 300±20Mpa.
Chang, Hsuan, and 掌軒. "Fabrication of TiO2 photocatalyst films using low temperature processing methods." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/49508142029176480463.
Повний текст джерела元智大學
化學工程學系
92
High efficient TiO2 photocatalyst thin films were fabricated in this study using sol-gel method and low temperature treatments. The films were prepared by the sol-gel solution coated on glass using hot water bath, wet-air, and dry-air thermal treatment. The photocatalytic effects of operating variables, such as the temperature, time, and atmosphere of thermal treatments on the films were discussed. The material properties affecting on the photocatalytic ability of the films were measured by different analytical instruments. Results show that thermal processing methods can greatly affect the photocatalytic ability of the TiO2 films. The best quality of photocatalytic films were fabricated by wet air at 100oC. In addition, the quality of the films can not be improved using higher temperature and longer time in thermal process. The presence of PEG added in the sol-gel process was found the important factor to affect the photocatalytic effect of the films. The effects of the thermal treatments on the photocatalytic influences were discussed.
Chen, Yu-Ru, and 陳毓儒. "Study on the Processing of Low Temperature Poly-Si Thin Film." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/44zj8t.
Повний текст джерела國立成功大學
工程科學系碩博士班
92
At present, the Laser annealing method is the most general way to fabricate the poly-Si film of low temperature for LCD industry. In this study, the working pieces primarily include a-Si film and glass substrate. The KrF excimer laser is used to irradiate the amorphous silicon film. The film melts and then solidifies rapidly as a poly-Si one. SEM is used to investigate the resulting poly-Si film. The control parameters of laser energy intensity, pulse number and coverage fraction are considered in this paper. The effects of these control parameters on the average grain size of poly-Si have been studied. The effect of SiO2 layer put between Si film and glass substrate was also investigated. From the experimental results, it can be found that if the molten pool of Si caused by laser energy doesn’t belong to “complete melt”, the more energy obtained from the laser could lead to the larger average grain size. However, if it belongs to “complete melt”, the average grain size would be much smaller than that of the former one (non-complete melt). With the increase of laser energy, the phenomenon becomes more significant.
Chen, You Shen, and 陳宥伸. "Preparation of Perovskite Solar Cells Using Low-temperature Solution Processing techniques." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/f2tg2d.
Повний текст джерела長庚大學
光電工程研究所
104
Solar is a renewable energy, Power generation process does not produce greenhouse gases carbon dioxide emissions, for the protection of the environment is very helpful; from 2012 to the rapid progress of perovskite solar cells, compared with silicon solar cells, which have the advantages of low material cost, Preparation of solution method, low cost manufacturing process, and its photoelectric conversion efficiency of silicon solar cells is expected to catch up, many scientists have also invested in this research effort. Perovskite solar cells perovskite layer made way roughly divided into two types, one is to use the one-step production, is to methylamine iodide (MAI) with lead iodide (PbI2) both Moore and other dissolved proportion after DMF was spin-coated on a substrate; and a two-step rule is the first spin-coated on a substrate PbI2, then soaked after film or iodine drops methylamine grow perovskite crystalline; used in this experiment produced a two-step method. We found that the changed PbI2 standing time will affect their different deposition patterns, the extent of the longer standing PbI2 the aggregation of particles leading to greater perovskite crystal patterns will vary from can be observed on the XRD perovskite films of different PbI2 standing time in the (001) peak characteristic changes significantly, standing at the time when the minimum peak 150s, 150s on behalf of the use of standing time making PbI2 film with 30mg/mL of MAI has the best solution crystalline state. Our success to make efficiency of 10.57% perovskite solar cells, JSC of 16.85mA/cm2, VOC is 1.01V, F.F. of 61.9%, also after continuous measurements found in the first four days up to maximum efficiency 12.65 %. Discussion with the addition of lead iodide standing time of lead iodide with methyl iodide amine concentration both outside, in order to improve the stability of the device, we also try to join the mesoporous layer observation element of the performance, first we direct the dense layer on the ZnO production of mesoporous TiO2 layer, then a two-step method to create elements, we change the spin speed to create different mesoporous layer, only the most efficient battery JSC of 8.89mA/cm2, VOC can reach 1.04V, F.F. of 50.4% efficiency of 4.66%, showed that under these conditions we did not have better cell performance. In addition, we also try to use the TTIP and TiO2(P90) to two different solution volume ratio of production to replace the dense layer of dense ZnO layer found in full without adding TTIP conditions, cell efficiency of up to 7.94%, then this condition further change speed control different mesoporous layer film, you can then create the conditions 1500rpm efficiency of 10.39% of the element JSC up 16.82mA/cm2, VOC is 1.008V, F.F. was 61.3%.
Nahar, Manuj 1985. "Highly conductive, nanoparticulate thick films processed at low processing temperatures." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-08-5967.
Повний текст джерелаtext
Yen, Fu-Cheng, and 顏福成. "Processing and Mechanical Properties of Low-Temperature Sintered Fe-P-C Alloy." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/35374116393421386497.
Повний текст джерела國立臺灣大學
材料科學與工程學研究所
94
Alloyed parts with complicated shape, smooth surface toughness and near net shape can be fabricated in metal injection molding (MIM) process. But green parts made by MIM process just have only 50-60% relative density, it is necessary to use lower than 10μm ultra fine powder as starting powder and sinter at 1200-1300℃ high temperature for 2 horses then 94% relative density can be ontained. Higher equipment cost and energy consumption followed by high temperature sintering result in lower competition for MIM process. So design alloy composition for low temperature sintering to make allying parts sinter at belt furnace with lower cost then have sintered density above 90% and good mechanical properties. It is showed that Fe-0.7P-C sintered at 1080℃ for 30mins can get the value of 7.4g/cm3 in sintered density, 800MPa in ultimate tensile strength, HRB98 in hardness, 12% in elongation in this study, that is superior to standard MIM-4605 counterpart which has better mechanical properties in MPIF. The uniform elemental distribution and ductile dimple structure can be observed by EPMA and SEM equipment even sintered at low temperature Additionally, the possibility of P content causing segregation and its mechanism were also studied in this experiment. According to the experimental results, when P content in Fe-C alloy is more than 0.7wt%, the original ductile dimple structure turning into brittle intergranular structure on fracture surface was observed. Fe-0.7-C alloy sintered at low temperature for short time has optimal mechanical properties as compared to other counterparts in this study.
Lin, Shieh-Chieh, and 林士傑. "Deploying a On-Line Analytical Processing System of Low-Temperature Distribution Center." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/82283250122827073534.
Повний текст джерела元智大學
企業管理學系
93
This thesis is to build up an OLAP application for low-temperature distribution center. We first conducted a thorough study on the business flow of storage processing in a low-temperature logistics center. We then design the system functions, which are related to inventory flows, and create data cubes for efficient information retrieval for stock management. We finally implement a system prototype, with which users can visualize and monitor inventory flows more clearly and easily so as to help improve inventory management.
Chae, Minjung. "Low-temperature post-harvest processing for reducing Vibrio parahaemolyticus and Vibrio vulnificus in raw oysters." Thesis, 2007. http://hdl.handle.net/1957/5705.
Повний текст джерелаGraduation date: 2008
EL-KHAZEN, JOHN. "LOW TEMPERATURE CLEAVAGE FRACTURE OF MICROALLOYED BAINITIC PLATE STEELS." Thesis, 2009. http://hdl.handle.net/1974/2572.
Повний текст джерелаThesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-07-30 19:17:01.25
Tung-Sheng, Lee, and 李東昇. "Low temperature processing of Metal/Ferroelectrics/Insulator/Si structures and their hysteresis loops of conduct current." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/21412083503633544758.
Повний текст джерела國立交通大學
電子工程系
90
SrBi2Ta2O9 (SBT) ferroelectric films have been demonstrated to possess the fatigue-free property to apply in the non-destructive MFISFET,but suffer from the issue of the low remanent polarization and high crystallization temperature。In this thesis,the stoichiometric SBT films prepared by using the metal-organic solution deposition (MOD) method was doped with the Bi3TiTaO3 (BTT) and Bi3TiNbO3 (BTN) for promoting the remanent polarization and achieving the goal of decreasing the process temperature below to 600℃。Moreover,the C-V measurement also reveals the broader memory widows of 1.3V as the sweep voltage in the 5V,and the leakage current density is as low as1E-8 A/ 。On the other hand,the hysteresis loop of conducting current in the MFIS structure also reveals the effect of the polarization behavior of ferroelectric film 。Furthermore,the effect of leakage current on the operation of the MFIS structure is discussed。
Yen, Wen-shiang, and 顏文祥. "Effect of the peroxotitanic acid (PTA) on the Low-temperature paste and High-temperature processing for the performance of Dye-sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/95691941979759458895.
Повний текст джерела中原大學
化學研究所
99
In this study, We use titanium isopropoxide (TTIP) and hydrogen peroxide (H2O2) to prepare a gel (peroxy titanate peroxotitanic acid, PTA). The gel was used as a binder between nanoscale titanium dioxide and nano-level between FTO glass substrate titanium dioxide. In the part of low temperature paste, we use a commercially available nano-titanium dioxide (TiO2) powder (PT-501A and P90) developed a low-temperature slurry production process apply to be fexiable of dye sensitized solar cells (dye-sensitized solar cells). Then use the doctor-blade coating method of titanium dioxide film on glass and plastic substrate with conductive features. Finally, made into a solar cells. In the part of high temperature paste, we use the sol-gel process to prepare a high temperature TiO2 slurry. The solution of PTA in ethanol was sprayed between the FTO glass substrate and the nanoscale titanium dioxide as a pretreatment film. Then the slurry was screen printed above the pretreatment film on the FTO glass substrate. Finally, made into a solar cells.
Chen, Shau-Kang, and 陳孝剛. "The Processing and the Properties of Low temperature High Strain Rate Superplastic Zn-22 wt.% Al Alloys." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/75326344349277768805.
Повний текст джерела大同工學院
材料工程研究所
87
In this study thermal and thermomechanical processings were applied to a monotectoid Zn-22 wt.% Al and a Zn-22 wt.% Al-0.1 wt.% Zr alloys to produce fine grain microstructures for low strain temperature as well as high strain rate superplasticity studies. It was observed in one-step thermal processing that aging at room temperature for a sufficient time period would produce an ultra-fine equiaxed grain mixture of α and β phases by a general precipitation reaction, having proper superplastic behaviors, and that aging at 240℃ would quickly develop a lamellar structure by a discontinuous precipitation reaction, with poor superplastic properties. Two-step aging and for-step thermomechanical processing schedules were designed in this study to produce ultrafine equiaxed grain structures for superplasticity examinations. The results showed that, among many processing routes, a specific 2-step aging process, consisted of natural aging for 2 weeks and artificial aging at 240℃ for 60 minutes, produces a proper grain structure with satisfactory low strain temperature and high strain rate superplasticity properties. Surprisingly, the superplastic properties obtained in the 4-step thermomechanical processed Zn-Al and Zn-Al-Zr alloys were found to be inferior to those in the 2-step aged alloys. A specific 2-step aging process, consisted of natural aging for 2 weeks and artificial aging at 240℃ for 60 minutes, produces a proper grain structure with satisfactory low strain temperature and high strain rate superplasticity properties. The maximum elongations obtained at 250℃ in the 2-step aged Zn-Al alloy is 1240% under an initial strain rate of 1×10-1 s-1, while the maximum elongation obtained in the 2-step aged Zn-Al-Zr alloy is 1120% under an initial strain rate of 5×10-2 s-1.
Shye, Der-Chi, and 史德智. "Low-Temperature Processing Techniques Applied on Barium Strontium Titanate Films for the Applications of DRAM Storage Capacitors." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/85373278879314570415.
Повний текст джерела國立交通大學
電子工程系所
93
The characteristics of (Ba, Sr)TiO3 thin films, prepared by novel techniques of low temperature treatments, were systematically studied in this thesis. Pt/TiN/Ti/Si substrates were applied on each sample to simulate the real capacitor over bit-line (COB) structure of dynamic random access memory (DRAM). (Ba, Sr)TiO3 (BST) films were sputtered by radio frequency (RF) magnetron system with dual targets at low substrate temperature, lower than 450oC (340oC at sample surface), and the effects of the process parameters were also investigated. The work pressure, the sputtering gun power and the gas-mixing ratio are the important parameters in the BST film deposition. Material analyses and electrical testing show that the low temperature BST films are significantly affected by those process parameters. The O2/(Ar+O2) mixing ratio (OMR) is a most critical parameter during BST film sputtering. Plasma emission spectra indicate that the deposition rate declines at a higher OMR due to oxide formation on the target surface. The dielectric constant of the BST films can reach a maximum of 364 at 5% OMR. The ten-year lifetime of the time-dependent dielectric breakdown (TDDB) implies that the reliability of the capacitor can be enhanced at a higher OMR due to the compensation of oxygen vacancies and smaller grain sizes. Current-voltage analysis indicates that the leakage current of the Pt/BST/Pt capacitor is limited by Schottky emission (SE)/Poole-Frenkel emission (PF) at a lower/higher applied field, accordingly. The applied field boundary between SE and PF shifts toward higher field as OMR increases. Moreover, an energy-band model was proposed and this leakage mechanism was also discussed. Post low-temperature treatments were applied on the BST films to further improve their crystallinities and electrical properties. A novel process, KrF excimer laser annealing (ELA) at the wavelength of 248 nm, had been undertaken to implement BST films at a process temperature of 300o C to avoid the steep thermal gradient in thin films. The dielectric constant of the amorphous (α) BST film was remarkably enhanced from 80 to over 250 after ELA treatment. The optical testing and the heat conduction analyses indicate that the underlayer films and devices cannot be damaged during ELA treatment due to a very shallow light absorption depth (20 nm) of the BST film at the wavelength of 248-nm. Besides, the laser energy fluence and film thickness greatly influence the thermal conduction and the temperature distribution within the BST films. In the meanwhile, the as-deposited films revealed (mm0) preferred orientation, and, intriguingly, the preferred orientations changed into (m00) and (mmm) after ELA treatments. The optical and the high frequency properties may be affected by this preferred-orientation change. However, although the ELA can perform “shallow-depth annealing” for BST thin film, the degradation of upper surface is strongly influenced by the laser energy fluence. Hence, the leakage current will be significantly affected by the energy fluence of the laser. The leakage current of the ferroelectric film increases after sputtering process and post ELA treatment, but post oxygen plasma treatment can effectively improve the BST film surface to suppress the leakage at low processing temperature of 250oC. According to the analysis results in this thesis, the oxygen plasma treatment can effectively passivate the oxygen vacancies of BST films, decreasing the leakage currents. The leakage current can be reduced as many as two orders of magnitude under proper control of plasma conditions. The characteristics of the dielectric reliability, TDDB, can be also improved by this treatment due to the compensation of the surface oxygen vacancies. In addition, a nano-scaled chromium (Cr) layer is applied onto (Ba, Sr)TiO3 (BST) thin film capacitor as an inter-layer to enhance thermal stability of capacitance and suppress leakage current. Temperature coefficient of capacitance (TCC) using this BST/Cr/BST (200nm/2nm/200nm) multifilm can achieve 30% lower than that using BST mono-layer (400nm) film. Besides, the leakage current can be also greatly suppressed by applying this nano-scaled Cr layer onto BST thin film capacitor. TCC and leakage current behave as functions of Cr thickness, so the optimal properties can be obtained with the Cr thickness of 2nm. Microstructure analysis suggests that the interfacial continuity strongly influences the TCC and leakage property due to scattering centers and series capacitance formed at imperfect interface. The correlated mechanisms between electric and material properties are systematically investigated in this work. BST thin film can be the most promising candidate for Giga-bit generation cell capacitor, because the low temperature processes can be compatible to the IC’s integration. In this thesis, the optimal properties of the BST films can be obtained by adjusting process parameter, applying post treatments and using thermal stabilization structures to achieve thorough low-temperature processes.
Wang, Mu-Shiun, and 王睦勛. "Reduction of low-temperature induced defects in yellow-green AlGaInP light emitting diodes by post-growth processing." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/65118460336893216977.
Повний текст джерела義守大學
電子工程學系碩士班
96
The improved lifetime in AlGaInP yellow-green light-emitting diodes (YG-LEDs) for low temperature operation by different chip process technologies are reported. For conventional YG-LEDs, light intensity decayed 23% under 20-mA injection current after 20-h testing at ambient temperature of -40℃. By employ different chip process technologies, the light intensity of YG-LEDs decayed within 15% after 160-h testing. The improvement of lifetime characteristic can be attributed to reduced quantity of defects in YG-LEDs. The detail process technologies for improve lifetime in YG-LEDs will be described in this thesis.
Chan, Cheng Tsung, and 鄭宗展. "The Studies of Low Temperature Ploy-Silicon Processing Issue and Thin-Film Grating for Solar Cell Performance Improvement." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/17418528235411953331.
Повний текст джерела南台科技大學
電子工程系
95
This paper is mainly discussing two topics: to improve the method of Low Temperature Ploy-Silicon and enhance the amount of power transforming to efficiency in solar cell. In the part of Low Temperature Ploy-Silicon.The feasibility to transform LPCVD a-Si into Poly-Si by using excimer laser annealing has been approved. More discussion and study on how to make optimization on Poly-Si are also proceeding. Excimer laser annealing (ELA) amorphous silicon (a-Si) to poly-silicon (poly-Si) in different gas environment is studied, i.e. N2 or N2 mixed O2:2%, Influence of laser power on the surface morphology, grain size and height of gibbous grain is investigated. The variation of threshold laser power for the generation of surface ablation in N2 and N2:98% mixed O2:2% environment is also discussed. From experiment, it is found that the combination of O2:2% enhance the threshold laser power for the generation of surface ablation from 320mJ/cm2 to 390mJ/cm2. In the condition of average grain over 0.25um, the process window is 30mJ/cm2 for N2, but is 50mJ/cm2 for N2 mixed O2:2% environment. In the part of improve the power conversion efficiency of solar energy by using the reflection character of grating. Under normal sunlight, light albedo of silicon surface falls between 30% ~ 35%, we can improve the battery power for solar energy by using 30%~35% reflection light. Therefore, the study of this thesis is to use high polymer diffraction grating mold on solar plates by coating with a layer of 212.24 nm depth , 0.52μm circle and grating of 5.9% albedo used for improve the light receiving of solar battery and further enhance the power conversion efficiency.
Urrutia, Benet Gabriel [Verfasser]. "High-pressure low-temperature processing of foods: impact of metastable phases on process and quality parameters / Gabriel Urrutia Benet." 2005. http://d-nb.info/978127013/34.
Повний текст джерела"Novel Low Temperature Processing for Enhanced Properties of Ion Implanted Thin Films and Amorphous Mixed Oxide Thin Film Transistors." Doctoral diss., 2013. http://hdl.handle.net/2286/R.I.17989.
Повний текст джерелаDissertation/Thesis
Ph.D. Materials Science and Engineering 2013
Liau, Jing-Ti, and 廖景義. "Kinetic Analysis of Thermal degradation of Poly(vinyl butyral)/Glass Ceramic/Ag in Low Temperature Co-fired Ceramic processing." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/15164140677399520374.
Повний текст джерела元智大學
化學工程學系
91
Kinetic analysis of thermal degradation of poly(vinyl butyral) (PVB), PVB/glass ceramic, PVB/Ag and PVB/glass ceramic/Ag was investigated in different environment. Dynamic data of the PVB thermal degradation were detected and utilized for the kinetic analysis by thermogravimetry (TG) and Fourier-Transform Infrared (FT-IR) measurements. Results of the kinetic analysis revealed that PVB thermal degradation was little affected by the presence of these inorganic materials in nitrogen. However, the reaction rates and pathways of thermal degradation of PVB with glass ceramic and Ag were obviously altered in air. The results also indicated that the degradation rates were accelerated in lower temperature and the composition of the volatile gas ( reaction pathway) was changed for these cases of PVB with different composition of the inorganic materials. The catalytic effect of glass ceramic and Ag on PVB thermal degradation was verified in air environment.
Wang, Chien-Yu, and 王健宇. "Image Processing and Temperature Correction of Pressure-Sensitive Paint for Airofoil Surface Pressure Measurement in Low Speed Wind Tunnel." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9n7ca7.
Повний текст джерелаDivya, Mitta. "Printed and Low Temperature Processed Oxide Electronics with Superior Electrical Performance and Mechanical Reliability." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5758.
Повний текст джерелаSerrazina, Ricardo Nazaré. "Flash sintering of lead free perovskite oxides towards sustainable processing of materials for energy and related applications." Doctoral thesis, 2021. http://hdl.handle.net/10773/32637.
Повний текст джерелаPiezoelétricos como o K0.5Na0.5NbO3 (KNN) têm uma importância emergente devido à sua natureza livre de chumbo e variada aplicabilidade em componentes como sensores, atuadores, dispositivos de recolha de energia, biossensores, etc. No entanto, o KNN monofásico continua a ser difícil de produzir devido à elevada temperatura e tempo associados ao processo de sinterização convencional. Este doutoramento propõe a utilização de um método alternativo de densificação, a sinterização FLASH, que acima de uma condição limite promove a densificação repentina de cerâmicos por uma combinação de ambiente do forno (atmosfera e/ou temperatura) com a aplicação de campo elétrico diretamente no material. Existem vários mecanismos reportados para explicar a sinterização FLASH. O aquecimento por efeito de Joule é um dos mais reportados e aceites, mas também têm sido sugeridos mecanismos envolvendo a criação e movimento de defeitos por efeito do campo elétrico. Uma compreensão clara do fenómeno continua por ser apresentada, mas muito provavelmente a sinterização por FLASH resulta duma combinação destes dois efeitos, sendo que a energia e condutividade das superfícies das partículas desempenham um papel fundamental. Este trabalho pretende explorar a sinterização por FLASH de cerâmicos, mas também estudar os seus fenómenos fundamentais, mais especificamente, na sinterização FLASH de KNN. O objetivo último deste trabalho é o desenvolvimento de processos de sinterização de cerâmicos que operem à temperatura ambiente, contribuindo para a economia energética e sustentabilidade da indústria cerâmica. A utilização de ferramentas de Modelação por Elementos Finitos (MEF, ou FEM) permitiu estudar o efeito da orientação das partículas na geração de calor por efeito de Joule durante o FLASH, enquanto a modelação da distribuição temperatura local e respetivos gradientes térmicos foram usados para explicar tensões induzidas em cerâmicos densos. A produção de pós de KNN com diferentes tamanhos e pureza permitiu estabelecer a sua relação com a temperatura de FLASH (TF). Em consequência, o estabelecimento de um ciclo térmico apropriado, antes da aplicação do campo elétrico, permitiu obter cerâmicos de KNN com densidade relativa de 95%. A ligação entre os parâmetros de FLASH, como densidade de corrente e tempo, foi determinada, e a relação com a densidade final e tamanho de grão dos cerâmicos foi estudada. Estudos em TEM e FEM permitiram propor um mecanismo para a sinterização por FLASH de KNN, em que o fluxo de corrente pelas superfícies das partículas promove uma fusão parcial nos seus contactos e o rearranjo para a remoção de poros e densificação do compacto. De forma a permitir um decréscimo acentuado na TF do KNN, a sinterização FLASH assistida por atmosfera foi apresentada, e a temperatura foi diminuída para TF ≈ 265 ºC. No entanto, a densificação final foi limitada aos 79%. As propriedades ferroelétricas e dielétricas do KNN sinterizado por FLASH foram estudadas e comparadas com as de cerâmicos sinterizados convencionalmente. Um desempenho semelhante entre ambos foi obtido após um tratamento térmico para cura de elétrodos. No entanto, uma análise detalhada mostrou que as propriedades são afetadas pelo processo de FLASH em cerâmicos tratados ou não termicamente. Este trabalho apresenta uma contribuição clara no desenvolvimento da sinterização FLASH de cerâmicos, especificamente, no piezoelétrico KNN.
Programa Doutoral em Materiais e Processamento Avançados
Kelly, Adrian L., Elaine C. Brown, and Philip D. Coates. "The effect of screw geometry on melt temperature profile in single screw extrusion." 2006. http://hdl.handle.net/10454/3917.
Повний текст джерелаExperimental observations of melt temperature profiles and melting performance of extruder screws are reported. A novel temperature sensor consisting of a grid of thermocouple junctions was used to take multiple temperature readings in real time across melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed melt temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped temperature profile dominated by conduction. At high throughputs, melting performance and measured temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better melting than single flighted screws. Low temperature "shoulder" regions were observed in the temperature profiles of single-flighted screws at high throughput, due to late melting of the solid bed. Stability of the melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in melt pressure and temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the melt at a range of extrusion conditions.
Yang, Hsiu-Ting, and 楊琇婷. "Study on the Photovoltaic Performances of the Hydrothermally- grown ZnO Nanowires Based Perovskite Solar Cells at Low Processing Temperatures." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/16987262067184419177.
Повний текст джерела國立交通大學
電子研究所
105
In recent years, the burning of the fossil fuel causes the aggravating of the global warming due to the increasing energy demand. Development of the renewable energy has attracted worldwide extensive attention, especially solar cells. Perovskite is an emerging material as the active layer of the solar cells, and it has been widely studied by scientists all around the world. The PCEs of perovskite solar cells has surpassed those for the other kinds of solar cells in a relatively short period. Due to the advantages like high absorption coefficient, high carrier mobility, low photo-carriers recombination rate, easy fabrication, capable of large-area preparation, and low-temperature fabrication for the application on flexible substrates and so on, the perovskite solar cells has gradually been paid attention to. In this thesis, the vertically-aligned ZnO nanowires grown via low-temperature hydrothermal growth process are used as the electron transfer layer (ETL) of the perovskite solar cells. Sequentially, the solution-processed perovskite using two-step method is collocated with the hydrothermally-grown ZnO nanowires to form the perovskite solar cells. The main idea of this thesis is utilizing the 3D structures of the hydrothermally-grown ZnO nanowires to increase the junction area to improve the photovoltaic performance of the perovskite solar cells. In the beginning of this thesis, the length effect of the hydrothermally-grown ZnO nanowires on the power conversion efficiencies (PCEs) of the perovskite solar cells is discussed. The infiltration and the surface coverage of the perovskite precursor solution changed as tuning the length of the ZnO nanowires. It is revealed that the devices with ZnO NW of 150 nm demonstrated the best PCE of 8.46 % under the AM 1.5G illumination (100 mW/cm2). However, the surface roughness of the perovskite film on the ZnO nanowires of 150 nm was still room for improvement. For the purpose to improve the surface roughness of the perovskite layer, the substrate preheating method which is heating the substrate to a temperature before dipping the PbI2 solution was carried out to solve the problem. The substrate preheating method prevents PbI2 crystallize too fast and lower the viscosity of the PbI2 solution so that the surface of the PbI2 solution can flow smoothly before the crystallization of the PbI2. From the result of the experiment, it is proved that the surface of the PbI2 spin-coated at a higher temperature might form a smoother surface, fewer pinholes, and higher PbI2 crystallinity. However, there is a trade-off between the crystallinity of PbI2 and the conversion to perovskite. This thesis demonstrated that the surface of PbI2 with the substrate preheating temperature at 200 oC is the smoothest, but the resulting high crystallinity inhibited the conversion of perovskite. Therefore, the best PCE of 10.34% was achieved for the substrate preheating at 150 oC. In this work, perovskite solar cells with hydrothermally-grown ZnO nanowires fabricated at low processing temperature demonstrated the excellent photovoltaic performance, easy fabrication, low-temperature process, and low cost, making it promising for the future developments in the solar cells on flexible substrates.
Wang, Tsai-Hui, and 王彩惠. "Emission Behaviors of CF3-Substituted Triphenyl(triphenylethynyl)benzenes in Different States, Fluoro-Substituted Hexabenzocoronene Derivatives with Low Processing Temperatures, and Biaxial Nematics from Polar Cross-like Liquid Crystals." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/susnqf.
Повний текст джерела淡江大學
化學學系博士班
106
Luminescent behaviors of CF3-substituted triphenyl(triphenylethynyl)benzenes (TPTPEB) in different states and two types of liquid crystalline materials, hexabenzocoronene derivatives and cross-like 1,2,4,5-tetrabiphenylethynylbenzenes, are investigated in this thesis. In the first part, TPTPEB derivatives are designed as a new aggregation-induced emission (AIE) luminogen skeletons. The influence of electronic effect and steric effect, by incorporating CF3 group into ortho-, meta-, para- sites of peripheral phenyls in TPTPEB, are found to influence significantly the materials’ emission in different states. In the second part, fluoro-substituted hexabenzocoronene (HBC) dervatives are designed to be synthesized with eight possible regioisomers as an eutectic composition in one pot to lead to low eutectic transition temperatures. Various oxidation conditions to cyclize peripheral phenyls of fluoro-substituted hexaphenylbenzenes are examined to result in only incomplete cyclization products. Nevertheless, the major cyclization product with two un-cyclized sites are separated to achieve HBC derivatives showing significantly low clearing temperatures (ca. 176 oC) for potential practical applications. In the third part, biaxial nematic cross-like molecules with polar side arms are designed and synthesized. The incorporation of polar groups is expected to lead the molecular packing with parallel molecular long and short axes respectively to enhance biaxiality. Cross-like compound 3-11d shows a very wide nematic liquid crystalline temperature range. Biaxialities of the single crystal and the nematic phase of cross-like 3-11d were investigated by single-crystal X-ray and powder X-ray diffraction on the magnetic-field-aligned sample respectively. Compound 3-14a is a non-polar molecule but with two polar fluoro groups in trans relationship of the central benzene ring to lead to a wide nematic liquid crystalline temperature range (ca. 60 oC) for future biaxial investigations. In summary, a new research direction on biaxial nematics by polar interaction in cross-like liquid crystalline materials is developed.