scholarly journals The kinetics of the lysis of Bacterium coli by glycine

1951 ◽  
Vol 49 (2-3) ◽  
pp. 169-174 ◽  
Author(s):  
J. Gordon ◽  
R. A. Hall ◽  
L. H. Stickland
Keyword(s):  
High Temperature ◽  
Latent Period ◽  
Temperature Coefficient ◽  
Maximum Rate ◽  
Bacterial Suspension ◽  
Glycine Concentration ◽  
Wide Range ◽  
Kinetics Of ◽  
Very High

The lysis of Bacterium coli suspensions brought about by glycine shows the following characteristics:(1) There is a latent period of 2 hr., followed by a rapid lysis reaching a maximum in about 8 hr.(2) The extent of the lysis is independent of the dilution of the bacterial suspension over a wide range.(3) The extent of the lysis increases with the glycine concentration up to 10M, but is approaching a limit at this concentration.(4) The lysis is negligible below pH 5 and above pH 10, and shows a maximum rate in the region of pH 6–5–8–5.(5) The rate of lysis has a very high temperature coefficient (Q10 of the order of 5).

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

Robust True LDO Linear Voltage Regulator and Digitally Trimmable Buffered Precision Voltage Reference for High-Temperature, Low-Voltage Applications

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000096-000103
Author(s):  
Yoann Dusé ◽  
Fabien Laplace ◽  
Nicolas Joubert ◽  
Xavier Montmayeur ◽  
Noureddine Zitouni ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Coefficient ◽  
Low Voltage ◽  
Short Circuit ◽  
Silicon On Insulator ◽  
Voltage Regulator ◽  
Voltage Reference ◽  
Soft Start ◽  
Wide Range ◽  
Latch Up

We present in this paper two new products for high-temperature, low-voltage (2.8V to 5.5V) power management applications. The first product is an original implementation of a monolithic low dropout regulator (XTR70010), able to deliver up to 1A at 230°C with less than 1V of dropout. This new voltage regulator can source an output current level up to 1.5A. The regulated output voltage can be selected among 32 preset values from 0.5V to 3.6V in steps of 100mV, or it can be obtained with a pair of external resistors. The circuit integrates complex analog and digital control blocks providing state of the art features such as UVLO protection, chip enable control, soft start-up and soft shut-down, hiccup short-circuit protection, customer selectable thermal shut-down, input power supply protection, output overshoot remover and stability over an extremely wide range of load capacitances. The circuit offers a fair ±2% absolute accuracy and is guaranteed latch-up free. The second product is an advanced high-temperature, low-power, digitally trimmable voltage reference (XTR75020). Thanks to a custom, 1-wire serial interface, the absolute precision and the temperature coefficient can be adjusted in order to obtain an accuracy better than 0.5% with a temperature coefficient bellow ±20ppm/°C. On-chip OTP memory for trimming of absolute value and temperature coefficient makes the circuit extremely accurate and almost insensitive to drifts over time and temperature. The circuit features a class AB output buffer able to source or sink up to 5mA and remains stable with any load capacitance up to 50μF. The XTR75020 has nine preset possible output voltages. The source and sink short circuit current always remains bellow 25mA. The quiescent current consumption is 300μA typical at 230°C while the standby current is, in all cases, under 20μA. Both devices are designed on a latch-up free silicon-on-insulator process.

Chemisorption and catalysis of hydrogen on polycrystalline wires of tungsten and nickel

1972 ◽  
Vol 331 (1586) ◽  
pp. 377-381 ◽  
Keyword(s):  
High Temperature ◽  
Reaction Mechanism ◽  
Metal Surface ◽  
Heat Of Adsorption ◽  
Nearest Neighbour ◽  
Metal Atoms ◽  
Wide Range ◽  
Hydrogen Deuterium ◽  
Adsorption Of Hydrogen ◽  
Kinetics Of

The object of the present programme of work is to correlate the heat of adsorption of hydrogen (and deuterium) as a function of coverage for a metal surface, with the kinetics of the hydrogen-deuterium reaction studied over a wide range of pressures and temperatures, in order to throw further light on reaction mechanism. The metals are studied as polycrystalline wires cleaned by a process of successive treatments with oxygen and hydrogen to remove carbon, followed by flashing to an appropriate high temperature in an apparatus which may be pumped to 10 -8 Pa. Tungsten and nickel have been studied, the first being body-centred cubic and the second face-centred cubic. To estimate the number of metal atoms or sites we assume equal areas of the two lowest energy planes as below: W b. c. c. (110), (100) 12.15 x 10 18 sites m -2 , Ni f. c. c. (111), (100) 17.5 x 18 18 sites m -2 . The most frequent nearest neighbour spacings are W -W = 0⋅315 nm and Ni-Ni = 0.248 nm.

scholarly journals Flexible over-moded resonators based on P(VDF-TrFE) thin films with very high temperature coefficient

2013 ◽  
Vol 60 (10) ◽  
pp. 2039-2043 ◽  
Author(s):  
Van Nguyen ◽  
Laurent Badie ◽  
Emmanuel Sénéchault ◽  
Eloi Blampain ◽  
Brice Vincent ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Temperature Coefficient ◽  
Very High

Use of Electrothermal Explosion and Electro-Thermal Analyser (ETA-100) for the Study the Kinetics of Fast High-Temperature Reactions in SHS-Ceramic Systems

2010 ◽  
Vol 63 ◽  
pp. 203-212
Author(s):  
A.S. Shteinberg ◽  
A.A. Berlin
Keyword(s):  
High Temperature ◽  
Rate Constants ◽  
High Speed ◽  
Dissimilar Materials ◽  
Isothermal Kinetics ◽  
Hard Alloys ◽  
Wide Range ◽  
Static Conditions ◽  
The Impact ◽  
Kinetics Of

Due to the lack of specialty kinetic methods and instruments, the kinetics of fast hightemperature reactions SHS-ceramic systems has not been adequately studied. Recently, we have developed a number of methods of so-called non-isothermal kinetics (NIK) and designed instruments allowing one to obtain information about reactions of ceramic systems in a wide range of practically important temperatures and rates. The use of one of the NIK-methods (called electrothermal analysis based on the phenomena of electro thermal explosion) allows one to study kinetics of SHS of some ceramic materials characterized by the total reaction time ~ 10 μs. In ETE, both samples pressed from reagents powders or cylindrical samples made from tightly rolled foils were studied. The joule heating was accompanied by high-speed scanning of the non-stationary temperature field on its surface. Description and technical characteristics of the specialty device electrothermoanalyzer ETA-100 manufactured by ALOFT are given. Kinetic parameters of fast EM reactions for the temperatures up to 3600 K can be measured by ETE method using ETA-100. New kinetic data for fast high-temperature gasless SHS yielding individual and composite materials (including refractory carbides and borides of transition metals, silicon and boron carbides, some refractory oxides and hard alloys) are presented. At high-speed impact of the samples, the reaction rate constants were found to exceed the combustion rate constants (measured by ETA-100) by many orders of magnitude. It was concluded that the kinetic mechanisms of the corresponding fast reactions in the static conditions and under the impact are dramatically different. It was shown that SHS in ETE mode has a significant potential as a modern practical method to be used for welding of refractory and dissimilar materials, production of coarse superabrasives, etc.

scholarly journals Electrical properties of graphite-glass thick-film resistors

Circuit World ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tomasz Matusiak ◽  
Arkadiusz Dabrowski ◽  
Leszek Golonka
Keyword(s):  
High Temperature ◽  
Temperature Coefficient ◽  
Thick Film ◽  
Sheet Resistance ◽  
Low Cost ◽  
Glass Mass ◽  
Temperature Coefficient Of Resistance ◽  
Content Type ◽  
Wide Range ◽  
Typical Temperature

Purpose The purpose of this paper is to present the properties of thick-film resistors made of novel pastes prepared from glass and graphite. Design/methodology/approach Graphite-based resistors were made of thick-film pastes with different graphite-to-glass mass fraction were prepared and examined. Sheet resistance, temperature coefficient of resistance, impact of humidity and short-term overload were investigated. The properties of the layers fired in atmospheres of air at 550°C and nitrogen at 875°C were compared. Findings Graphite-based resistors with various graphite-to-glass ratios made possible to obtain a wide range of sheet resistance from single O/square to few kO/square. These values were dependent on firing atmosphere, paste composition and the number of screen-printed layers. The samples made of paste with 1:1 graphite-to-glass ratio exhibited the temperature coefficient of resistance of about −1,000 ppm/°C, almost independently on the firing atmosphere and presence of a top coating. The resistors fired in the air after coating with overglaze, exhibited significantly lower sheet resistance, reduced impact of humidity and improved power capabilities. Originality/value In this paper, graphite-based resistors for applications in typical high-temperature cermet thick-film circuits were presented, whereas typical graphite-based resistors were fabricated in polymer thick-film technology. Owing to very low cost of the graphite, the material is suitable for low-power passive circuits, where components are not subjected into high temperature, above the typical temperature of operation of standard electronic components.

Complete Parametric Study of Bagasse Pellets During High-Temperature Steam Gasification

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Hong Nam Nguyen ◽  
Toshiki Tsubota
Keyword(s):  
Weight Loss ◽  
High Temperature ◽  
Parametric Study ◽  
Maximum Rate ◽  
Pyrolysis Temperature ◽  
Steam Gasification ◽  
Operating Conditions ◽  
Energy Yield ◽  
High Temperature Steam ◽  
Kinetics Of

Abstract A complete parametric study of bagasse pellets under high-temperature steam gasification in relevant industrial operating conditions was investigated. Regarding thermal behaviors, the maximum rate of weight loss (Rmax = 0.55%/°C) occurred at the temperature Tmax = 305 °C. The final pyrolysis temperature and heating rate were proportional to the mechanical strength, the bulk density, as well as the char yield and energy yield. However, the changes were not significant after 600 °C. Regarding steam gasification kinetics, an increase from 850 to 1000 °C and from 0.1 to 0.4 atm accelerated 10 times and two times the conversion rate of bagasse pellet char, respectively. Gasification kinetics of a pellet char produced at 2000 °Cmin−1 was 1.4 higher compared with a pellet char produced at 5 °C min−1. An empirical model that takes into account all the changes in the reactive surface could successfully predict the conversion of the bagasse pellet char during high-temperature steam gasification. Experimental results and the kinetic model proposed could be useful for the calculation of industrial or academic codes, necessary for the conception of new efficient gasifiers.

Grain Growth Kinetics of a Ti+Nb Stabilized 12%Cr Ferritic Stainless Steel at High Temperature

2011 ◽  
Vol 66-68 ◽  
pp. 108-113 ◽  
Author(s):  
Chang Jiang Song ◽  
Liang Zhu ◽  
Yuan Yi Guo ◽  
Ke Feng Li ◽  
Feng Mei Sun ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Grain Growth ◽  
Ferritic Stainless Steel ◽  
Growth Exponent ◽  
Growth Behaviour ◽  
Small Particles ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Very High

By using a thermal simulator this work investigated grain growth behaviour of a Ti+Nb stabilized 12%Cr ferritic stainless steel at high temperature. The results showed that the grain growth rate was less than 1.8μm/s at the temperature of 1200°C, but it suddenly became very high and reached about 50μm/s when the temperature was 1250°C. Analysis results indicate that grain growth of this steel is affected by the small particles on the grain boundaries, and grain growth exponent is about 3.3. Moreover, the activation energy of the grain growth is when the temperature is above 1250°C. Compared with a 27Cr ferritic stainless steel containing only 0.14%Nb, the grain growth exponent of this steel is greater, and grain initial rapid growth temperature is higher.

High Temperature Degradation of Co Based Superalloy in Incinerator Environment

2012 ◽  
Vol 585 ◽  
pp. 542-546 ◽  
Author(s):  
Deepa Mudgal ◽  
Pawan K. Verma ◽  
Surendra Singh ◽  
Satya Prakash
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Alkali Metals ◽  
Oxide Scales ◽  
Temperature Oxidation ◽  
Good Oxidation Resistance ◽  
Wide Range ◽  
Metallurgical Furnaces ◽  
Waste Incinerators ◽  
Kinetics Of

Degradation by high temperature oxidation and hot corrosion is the main failure mode of components in the hot section of gas turbines, boilers, industrial waste incinerators, metallurgical furnaces and petrochemical installations etc. Corrosive environment is because of the usage of wide range of fuel containing large amount of Cl and S together with the volatile alkali metals such as K and Na which leads to the degradation of material. To obviate this problem, superalloy Superco 605 has been studied in air as well as in molten salt environment at 900°C for 100cycles. Weight change measurements were taken by a digital electronic weighing balance having accuracy of 1 mg after each cycle (heating at 900°C for 1 hr. and subsequently cooling in air for 20 min.) which was used to determine the kinetics of corrosion. The oxide scales formed on the surface of the superalloy were characterized by various techniques such as FESEM, EDAX and XRD. It was found that superco 605 shows good oxidation resistance in air at 900°C but poor corrosion resistance in simulated incinerator environment.

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