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Various Thicknesses (various + thickness)
Selected AbstractsThermal properties of conduction current and carrier behavior in an organic electroluminescent deviceELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 3 2009Masahiro Minagawa Abstract Organic electroluminescent device (OLED) was fabricated using a vacuum evaporation method and thermal properties were investigated. The OLED has an indium tin oxide (ITO)/N,N,-diphenyl- N,N,-bis(3-methylphenyl)-1,1,-biphenyl-4,4,-diamine (TPD)/tris(8-hydroxyquinoline) aluminum (Alq)/lithium fluoride (LiF)/aluminum (Al) structure. An electron-dominant device of Al/Alq/LiF/Al structure, or a hole-dominant device of ITO/TPD/Al structure was also fabricated in order to study the carrier behavior in the OLEDs. The current density versus voltage (J,V) properties with various thickness of organic layers were investigated in both electron- and hole-dominant devices, and the thermal dependence of J,V properties was observed in the devices. At room temperature, conductions in a wide current region were considered to be due to space-charge-limited current for all of the devices. Especially for the Al/Alq/LiF/Al device and the OLED, relationships were observed across a wide current region. At low temperature, tunnel currents were estimated for the ITO/TPD/Al device. For the Al/Alq/LiF/Al device and the OLED, relationships were observed across a wide current region at low temperature. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(3): 24,31, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10048 [source] Combustion of chlorinated hydrocarbons in catalyst-coated sintered metal fleece reactors,JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2-3 2003K Everaert Abstract Incinerators emit chlorinated hydrocarbons, such as polychlorinated benzenes (PCBz) and phenols (PCPh), polychlorinated biphenyls (PCB) and polychlorinated dibenzodioxins and furans (PCDD/F), as very dilute streams. High temperatures (>1000,°C) are required in traditional oxidizers. From an energy-saving perspective and to avoid de novo synthesis of PCDD/F, exhaust gas clean-up must be performed at low temperatures (250,350,°C). Catalytic combustion can be applied in this temperature range and different reactor layouts are used (eg monoliths, honeycomb). The present investigation uses a novel catalyst-coated sintered metal fleece. Thin metal fibers are sintered (non-woven) to fleece of various thickness, structure and porosity. V,Ti,W catalysts are examined. The paper will briefly review the catalyst coating method suitable to provide a structured fleece reactor with adequate characteristics. Experiments were carried out in the temperature range of 260,340,°C with various hydrocarbons injected in a carrier air stream. The experimental investigations demonstrated: (i) that the conversion of the hydrocarbons (volatile organic compounds, VOC) is independent of the oxygen concentration, corresponding to a zero-order dependence of the reaction rate; (ii) that the conversion of the hydrocarbons is a first-order reaction in the VOC; (iii) that the oxidation of the VOC proceeds to a greater extent with increasing temperature, with chlorine substitution enhancing the reactivity, and (iv) that the reaction rate constant follows an Arrhenius-dependence with activation energies between 37.3 and 58.4,kJ,mol,1. An assessment of the results leads to a model expression with kinetic reaction control. This model can be used in a scale-up strategy. © 2003 Society of Chemical Industry [source] New supplying evaporation precursor method with CVDHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 5 2009Motohiro Oshima Abstract We propose a novel system of chemical vapor deposition (CVD), i.e., flash boiling spray CVD (SF-CVD) to eliminate several kinds of problems, such as the decomposition of precursors in the supply line and evaporator. In this method, liquid precursors are supplied directly to the vacuum chamber through an injector, just like fuel for an automobile engine, without any vaporizers, so as to induce an unsteady and intermittent flash boiling spray in the chamber. However, it is necessary to keep the lowest ambient pressure possible because the saturated vapor pressure of the precursors is very low. Thus, this is very useful for modifying the saturated vapor pressure of the precursors. A technique of lowering the vaporization pressure is proposed by mixing a more saturated vapor-pressure organic solvent with a precursor. To determine the principles underlying FS-CVD, we first formed SiO2 film on the Si substrate. A mixed solution of tetraethylorthosilicate (TEOS) and n-pentane was used as the mixing solution. The film thickness distribution of SiO2 film on a 100-mm-diameter Si wafer was ±4% using this method. Furthermore, this method enabled us to control film with various thicknesses by optimizing the injection duration, cycle, and injection cycle per second. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20235 [source] Novel microwave,freeze drying of onion slicesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2009Soleiman Abbasi Summary The present study aimed to introduce the capability of a novel dehydration technique. To do so, slices with various thicknesses (3.5 and 7 mm) of white onions were dried using commercial freeze drier (abs. pressure 0.005 mbar, temp. 45 °C), our own designed microwave-vacuum drier (abs. pressure down to 300 mbar) under various microwave powers (120,1200 W) and microwave-vacuum,freeze drier (onion slices kept at ,20 °C for 2 h). Then, their dehydration rates and some quality parameters, such as rehydration ratio, colour (L*, a* and b*) and micro-structure were investigated. Our findings showed that microwave-vacuum,freeze drier is practically a rapid, simple, efficient, economic and novel dehydration technique which can be used for dehydration of mainly foodstuffs. The quality properties of slices produced by this novel method were also completely comparable and competitive with commercial freeze drier with over 96% saving on processing time and enormous amount on energy and capital investments. [source] Hardness of Three Resin-Modified Glass-Ionomer Restorative Materials as a Function of Depth and TimeJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2009HOWARD W. ROBERTS DMD ABSTRACT Statement of the Problem:, The polymerization of bulk-placed resin-modified glass-ionomer (RMGI) restoratives is compromised when penetration of the curing light is limited because of the materials' thickness. It is unknown if additional post light-curing resin polymerization and/or glass-ionomer setting occurs over time to ensure adequate polymerization. Purpose:, The primary objective was to evaluate the depth of cure of various thicknesses of RMGI restorative products over 1 year using Knoop hardness (KH) testing. Materials and Methods:, The materials were placed in Delrin molds having an internal diameter of 5.0 mm and heights of 2, 3, 4, and 5 mm and were photopolymerized with a halogen light-curing unit. Five specimens of each depth were prepared for each time period evaluated. Specimens were stored in darkness at 37 ± 2°C and 98 ± 2% humidity until being tested at 24 hours, 1 week, and 1, 3, 6, 9, and 12 months after fabrication. Mean KH values were calculated for the bottom and top surfaces of each thickness group and used to determine bottom/top hardness ratios. Data were compared using two-way analysis of variance (factors of time, thickness) at a 0.05 significance level with Scheffé's post hoc analysis, where required. Results:, The materials had relatively stable top surface KH, which permitted valid assessment of changes in bottom surface KH over time. The bottom surface KH of some RMGIs changed significantly over time (p < 0.001), but degrees of change were material dependent. Certain RMGIs demonstrated a potential for statistically significant post light-activation hardening; however, that too was material dependent. As compared with top surface KH, deeper layers of the thicker RMGI specimens consistently failed to achieve an adequate degree of polymerization. Conclusion:, Although certain RMGI materials demonstrate a potential for post light-activation chemically initiated resin polymerization and/or polyalkenoate acid/base reaction, these reactions may not be sufficient to ensure that the material is adequately polymerized for long-term success. This is particularly true when RMGI materials are placed in thicker layers where curing light penetration may be compromised. CLINICAL SIGNIFICANCE RMGI materials should not be placed in bulk but photopolymerized in layers to ensure adequate light activation. The results of this study suggest that Photac-Fil Quick be placed in layers no thicker than 2 mm while Fuji II LC and Vitremer may be placed in layers up to 3 mm in thickness. [source] EFFECT OF SAMPLE THICKNESS ON THE BITE FORCE FOR APPLESJOURNAL OF TEXTURE STUDIES, Issue 3 2003HARUKA DAN The thickness of a piece of food and its mechanical properties affected the bite force. A multiple-point sheet sensor was used to measure the bite force applied to apple specimens of various thicknesses during the first bite with incisors. The results of wedge penetration tests on the same samples were compared with results of the bite measurements. The maximum bite force increased with the sample thickness for two apple varieties, though the maximum load measured by the wedge penetration test did not change. Therefore, it is important to consider that not only the mechanical properties but also the thickness of the sample affects the required bite force. [source] Effect of cooling field strength and ferromagnetic shell shape on exchange bias in nanoparticles with inverted ferromagnetic,antiferromagnetic core-shell morphologyPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2010Yong Hu Abstract The dependence of exchange bias (EB) effects on cooling field strength and particle shape in nanoparticles with antiferromagnetic (AFM) interfacial coupling and inverted AFM core with a fixed radius and ferromagnetic (FM) shell with various thicknesses are investigated by using a modified Monte Carlo Metropolis method. It is found that with the increase of cooling field, field-cooled exchange bias field (HE) fluctuates in the range of negative values initially, and then has an abrupt jump from the negative value to the positive value, finally levels off. However, HE decreases as the FM shell shape varies from No. 1 to No. 13 regardless of the strength of cooling field. Coercivity is affected by cooling fields and shapes indicating distinct behaviors. Because the AFM core is almost unaffected by shape and frozen completely during measuring hysteresis loops, the effect of ferromagnets on EB, negligible in most of other systems, is ambiguously manifested in such an unconventionally structural system. Moreover, the phenomena are interpreted well by presenting the snapshots of microscopic spin energy distributions, which make us observe directly and vividly the movement of domains and the competition of energies. This work will shed new light into the microscopic origin of peculiar magnetic properties of nanoparticles with special structures. [source] Effects of tool-embedded dielectric sensors on heat transfer phenomena during composite curePOLYMER COMPOSITES, Issue 2 2007A.A. Skordos The present study examines the effects that placement of tool-mounted dielectric sensors in the composite cure assembly has on the local thermal and degree-of-cure fields. A nonlinear heat transfer model, incorporating appropriate thermoset cure and thermal property submodels, is used to simulate the cure of carbon and glass composites of various thicknesses. The model is validated against experimental data obtained during the cure of composite samples in a resin-transfer molding tool. The results of the simulations show that embedding a sensor can have a significant effect on the thermal field, because of the thermal conductivity mismatch between the metal tool and the sensor substrate material. In the heating-up stage of the cure profile, sensors embedded in the heated tool side intensify thermal gradients, which causes a corresponding lag in the progress of the reaction in the area adjacent to the sensor. Exothermic effects are also intensified by the sensor presence, especially in the case of thick composite curing. These results suggest that control strategies based on the utilization of embedded sensors should take these effects into account. POLYM. COMPOS., 28:139,152, 2007. © 2007 Society of Plastics Engineers. [source] Interfacial characteristics of film insert molded polycarbonate film/polycarbonate-acrylonitrile-butadiene-styrene substrate, part 1: Influence of substrate molecular weight and film thicknessPOLYMER ENGINEERING & SCIENCE, Issue 12 2006Y.W. Leong Adhesion properties between a polycarbonate (PC)/acrylonitrile-butadiene-styrene blend substrate and PC films of various thicknesses, bonded through film insert molding, were investigated. The use of various molecular weights of PC and incorporation of PC-oligomer in the blend substrate has been found to severely affect the adhesion strength and alter the delamination characteristics at the film,substrate interface. Thicker films were able to increase film,substrate adhesion, apart from providing added impact resistance to a brittle substrate. Polym. Eng. Sci. 46:1674,1683, 2006. © 2006 Society of Plastics Engineers [source] Atomic Vapor Deposition of Titanium Nitride as Metal Electrodes for Gate-last CMOS and MIM DevicesCHEMICAL VAPOR DEPOSITION, Issue 5-6 2008Mindaugas Lukosius Abstract Pure and diluted Ti[N(Et)2]4 precursors are used to grow TiN layers at 400,600,°C by using atomic vapor deposition (AVD®). The composition, microstructure, and electrical properties of TiN films with various thicknesses are investigated. The determined work function of 4.7,eV indicates the possibility of using AVD®-grown TiN as a metal gate electrode for PMOSFET and metal-insulator-metal (MIM) devices. TiN/HfO2/SiO2 stacks are integrated into gate-last PMOS transistors, and the extracted parameters are compared to poly-Si/SiO2 reference transistors. The optimized films grown at 400,°C with a thickness of 20,nm exhibit a resistivity of 400,µ,,cm. [source] | ||||||||||||||||