... where extreme temperatures are required and (b) how we can engineer enzymes in general to maintain their functionality over a broad range of temperatures In this minireview, we aim to highlight some ... increased yields when the reaction is performed at high temperatures; (e) the reactions kinetics are faster at high temperatures; (f) enzymatic processing at temperatures near or above 100 °C minimizes ... and mesophilic proteins at room temperature and increases with temperature, so as to allow for enzymatic activity near 100 °C It is only upon achieving these high temperatures that sufficient molecular...
... 12.3 Direct and Indirect Internal Reforming 12.3.1 Direct Internal Reforming 12.3.2 Indirect Internal Reforming 12.4 Reformation of Hydrocarbons by Steam, COz and Partial Oxidation 12.5 Direct ... Kendall School of Chemical Engineering, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UIC k.kendall@bham.ac.uk xii HighTemperature SoIid Oxide Fuel Cells: Fundamentals Design and ... Electrons to external circuit Figure 1.1 Oxygen /Porous cathode Oxysen reduction 0+2e 0.- + Electrons from external circuit Schematicofsolidoxidefuel cell (SOFC) 2 HighTemperature Solid Oxide...
... these, historically true, is that higher current density or higher magnetic field is more valuable than higher operating temperature Operating temperatures of 77 K or higher are preferable for all ... high- temperature superconductivity are associated with high currents and high magnetic fields Other unique properties, generally valid at 77 K, promise some entirely different applications First, ... first two 1.5.1 Large Currents in Magnetic Fields Ceramic oxide wires present two problems that were not encountered in the earlier development of low -temperature, intermetallic wires The first...
... operate SiC devices at temperatures as high as 500–600 C, while Si is generally limited to 125 C While the foregoing discussion highlights the advantage of SiC over Si for hightemperature applications, ... small-angle boundaries, and screw dislocations Particularly relevant to high- temperature environments is the bandgap energy of SiC At room temperature, the bandgap of 4H-SiC (the most attractive SiC polytype ... measurement of the phase shift signal, which exhibited higher noise levels at elevated temperatures as indicated by the larger error bars for higher temperatures in the graphical results that follow...
... though their combustion temperatures are quite low As another consequence of the high C concentration, the stoichiometry of these primitively formed TiCx particles in the Fe melt is relatively high ... powder by a self-propagating high- temperature synthesis technique Mater Lett 2004, 58:733-738 13 Khanra AK, Pathak LC, Mishra SK, Godkhindi MM: Self-propagating-hightemperature synthesis (SHS) ... nano-size ZrB2 powder by selfpropagating high- temperature synthesis J Eur Ceram Soc 2009, 29:1501-1506 15 Nersisyan HH, Lee JH, Won CW: Self-propagating high- temperature synthesis of nano-sized titanium...
... process of the formation of catalytically active nanoislands for the growth of Si wire-like crystals Fast anneals at high temperatures of the structures of Si substrates with gold films deposited on ... arrays during the hightemperature anneals Figure shows the contents of oxygen and gold in the subsurface layers of Au/Si structures after 15-s RTA treatments at different temperatures for the ... threshold temperature of about 800°C Besides, a nonlinear increase in the oxygen contents in the subsurface layers was observed with the increase of RTA temperature (by a factor of for the temperature...
... the low temperature drying at 35oC, the mechanical strength of the rice kernels was higher at hightemperature drying (Table 2, Figure 8) This value was significantly higher at 90oC drying temperature ... at low temperature or by ambient air in storage bin (Proctor 1994; Taechapairoj et al 2003) Alternately, a multi-pass fluidized bed drying can be applied as a compact drying process Hightemperature ... thus paddy and air are mixed vigorously (Kunze and Calderwood 2004) Fluidized bed (or fluid bed) drying is applicable in the first stage of drying when paddy is required to decrease high moisture...
... difficult to use in high- temperature or temperature- variable ambient applications To overcome such a thermal problem, which may result in the variation of the operation point, it is desirable to keep ... modulation as a function of temperature, we extracted the channel cross-section profiles containing the on- and off-current density distribution at different temperatures the room temperature value Such ... room temperature up to 150°C; (1) A suitable positive bias VSUB is applied to realize this constant level operation, by enhancing the current level at elevated temperatures to the room temperature...
... nucleated within the c-Fe(B) phase with decreases of the temperature [25] The eutectoid transformation undergoes a similar process at 912 °C As the temperature, is decreased the B solid solution degree ... is associated with the solid solution transform temperature Tss detected at 1135 °C in the solid state, and the second one with the eutectic melt temperature at 1150 °C On further heating Fe2B ... resulting in the third peak For cooling (curve (b)), three exothermic peaks (1134, 1171, and 1198 °C) occur as well, also corresponding to the Tss, eutectic melt and Fe2B melt temperatures, respectively...
... 1,700 lm2) at 10 °C High- temperature operation up to 65 °C was successfully demonstrated from an unbonded GaInNAs QD laser (50 · 1,060 lm2), with high T0 of 79.4 K in the temperature range of ... improvement in performance with hightemperature operation up to 65 °C, high T0 of 79.4 K, and low Jth of 1.05 kA/ cm2 Though these results are still inferior compared to their GaInNAs QW counterparts ... MOCVD-grown GaInNAs QD RWG lasers at room temperature (RT) with emission wavelength at 1078 nm [38] However, their GaInNAs QD RWG laser (4 · 800 lm2) showed relatively high Jth of ~13 kA/cm2 We have recently...
... epitaxy has used low temperatures in an effort to directly crystallize the Ga droplets into GaAs without material redistribution On the other hand, in our approach we used high- temperature to encourage ... accompany the QD pair These are the remnants of the edges along [011] Figure 4b is a 3D presentation of one single QD pair formed after 45 s annealing at 590 °C At this even higher temperature, the ... pairs are bigger and more separated The clear contour lines around each QD pair are steps on the GaAs hill These QD pairs are very stable, as suggested by the observation at different growth temperatures...
... (Continued on next page) Phonon Spectra of HighTemperature Superconductor 62 Table 5–(continued) Symmetry species B1g(R) Eg(R) A2u (IR) TO/LO B2u (IR) Eu (IR) Frequency (cm–1) Using normal Using lattice ... the irreducible representation of the point group for Bi2Sr2Ca2Cu3O10 (2:2:2:3:10) [grouped according to activity] are as follows: ΓTotal = 7A1g(R)+1B1g(R)+8Eg(R)+8A2u (IR) +2B2u (IR) +10Eu (IR) Here, ... experimental results Phonon Spectra of HighTemperature Superconductor 54 An attempt has been made in this paper to study phonon frequencies in Bi2Sr2Ca2Cu3O10 hightemperature superconductor in the...
... at high temperatures and is also of great interest for materials science research and practical applications Mechanical tests were historically the first method of investigating the high- temperature ... Properties 111 Deformation at Lower Temperatures 116 Deformation at Higher Temperatures 124 On the Composition of Superalloys 129 Rafting 130 Effect of Composition and Temperature on γ/γ Misfit Other ... Helicoids 39 Total Combination of Structural Peculiarities of High- temperature Deformation 40 Summary 41 Physical Mechanism of Strain at High Temperatures Physical Model and Theory 43 Velocity of Dislocations...
... nickel, copper, iron, vanadium, niobium and molybdenum Nickel and iron are two of the most important materials for practical use and are applied as the base for numerous alloys for high- temperature ... developed for in situ X-ray investigations of metals and alloys directly during high- temperature deformation The method of measurement of the irradiation intensities, which are diffracted by separate ... determined by the X-ray method at high temperatures Pure metals, solid solutions and nickel-based superalloys have been studied 25 Structural Parameters in High- Temperature Deformed Metals 3.1...
... external conditions (temperature and stress) The substructure formation during high- temperature strain in vanadium is shown in Figs 3.6 and 3.7 The data are obtained at the same temperature 0.6 Tm ... sub-boundary in iron are seen in pattern (b) The regular dislocation networks as low-angle sub-boundaries are found to be typical for the high- temperature tested metals Fig 3.11 Sub-boundaries in α-iron ... specimens after hightemperature tests are associated in sub-boundaries The parallel sub-boundary 3.2 Dislocation Structure Tab 3.2 Average substructure parameters in niobium, vanadium and α-iron at the...
... Strain at High Temperatures Now we can calculate the rate of the steady-state high- temperature deformation ε Three groups of physical parameters are needed: ˙ • • • External parameters: temperature ... subboundary to another is the distinguishing feature of the high- temperature strain Fig 4.1 The physical model of the steady-state strain at hightemperature The sub-boundaries are built of two systems: ... (4.2) HighTemperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright c 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim ISBN: 3-527-313389-9 44 Physical Mechanism of Strain at High Temperatures...
... the dependence of deformation ε on stress σ At room temperature there is a linear dependence, ε ∼ σ At high temperatures he assumes the empirical equation ε = Aσ m to be the most appropriate ... heat-resistant metals, steels and alloys operate at temperatures between 0.40 and 0.75 Tm The area of temperature and stress where the proposed mechanism of hightemperature deformation takes place, is shown ... plays a key role during high- temperature strain, being the process that affects the strain rate The present theory is understood to be valid within certain limitations When the temperature is relatively...
... the applied stress is relatively low 81 83 High- temperature Deformation of Superalloys 6.1 γ Phase in Superalloys The high- temperature strength requirements of materials have increased with new ... engines One of the most important requirements is resistance to high- temperature deformation This has created a need for alloys that can withstand higher stresses and temperatures for the hot zones ... dissolved in the γ phase HighTemperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright c 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim ISBN: 3-527-313389-9 84 High- temperature Deformation...