SOME LETHAL TEMPERATURE RELATIONS OF TWO MINNOWS OF THE GENUS CHROSOMUS

1966 ◽  
Vol 44 (3) ◽  
pp. 349-364 ◽  
Author(s):  
Albert V. Tyler
Keyword(s):  
Thermal Shock ◽  
High Temperatures ◽  
The Other ◽  
Lethal Temperature ◽  
Lethal Temperatures ◽  
Equal Temperature

The resistance and tolerance of Chrosomus eos and Chrosomus neogaeus to high temperatures were examined. Tests were conducted with C. neogaeus in winter and with C. eos in winter and summer. For both species, death at high temperatures could be separated into three lethal patterns or "effects". The first effect seemed to be associated, at least in part, with thermal shock. Factors generating the other effects were not apparent.Both species showed about the same degree of tolerance and resistance to high temperatures when they were acclimated to 15 °C or higher. At 9 °C, C. eos was less tolerant to high lethal temperatures than was C. neogaeus.When equal temperature acclimations were compared, C. eos was more resistant to high lethal temperatures in summer than in winter.

Temperature Tolerance of Bloater (Coregonus hoyi)

1970 ◽  
Vol 27 (11) ◽  
pp. 2047-2052 ◽  
Author(s):  
Thomas A. Edsall ◽  
Donald V. Rottiers ◽  
Edward H. Brown
Keyword(s):  
Young Adult ◽  
High Temperatures ◽  
Thermal Tolerance ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Temperature Tolerance ◽  
Lethal Temperature ◽  
Lethal Temperatures ◽  
Coregonus Artedii ◽  
Coregonus Hoyi

Juvenile and young adult bloaters (Coregonus hoyi) were tested for tolerance to high temperatures. The ultimate upper lethal temperature of juvenile bloaters (26.75 C) appeared to be slightly higher than that of young adult bloaters, but was similar to that of juvenile ciscoes, Coregonus artedii (26.0 C), the only other North American coregonine for which a detailed description of temperature tolerance has been published.Regression equations are given that permit estimation of the thermal tolerance when the lethal temperatures are incompletely known. The estimated thermal tolerance of juvenile bloaters (617 units) was slightly less than that of the brook trout (Salvelinus fontinalis; 625 units), but was higher than that of other Salmonidae.

UPPER LETHAL TEMPERATURE RELATIONS OF THE GUPPY, LEBISTES RETICULATUS

1954 ◽  
Vol 32 (6) ◽  
pp. 393-407 ◽  
Author(s):  
M. Beatrice Gibson
Keyword(s):  
High Temperatures ◽  
Thermal History ◽  
Inbred Lines ◽  
Genetic Composition ◽  
Lethal Temperature ◽  
Rearing Temperature ◽  
Lethal Temperatures ◽  
General Response ◽  
Lebistes Reticulatus

Guppies, Lebistes reticulatus, of inbred and unselected stocks, were tested for their variability in resistance to upper lethal temperatures. Unselected fish were maintained in constant temperatures of 20°, 25°, and 30 °C. from birth and were subjected to lethal temperatures either without further treatment or acclimated to 30 °C. before testing. Inbred lines were reared at 25 °C. and acclimated to 30 °C. Resistance times were determined at constant temperatures ranging from 33° to 38 °C. Acclimation has a moderate influence on the resistance times at the higher lethal temperatures, but the effect is lessened at 35 °C. and disappears at 34 °C. There is an indication of an optimum rearing temperature in the neighborhood of 25 °C. for resistance to the higher temperatures. General response to high lethal temperatures is similar to that reported for other fish, but heterogeneity is exhibited at 37° and 34 °C. Both genetic composition and early thermal history influence resistance to high temperatures as well as acclimation just prior to experiment. The upper incipient lethal temperature is slightly above 32 °C. over the biokinetic range of the guppy.

scholarly journals Effects of Heating Rate on Formation of Globular and Acicular Austenite during Reversion from Martensite

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 266 ◽  
Author(s):  
Xianguang Zhang ◽  
Goro Miyamoto ◽  
Yuki Toji ◽  
Tadashi Furuhara
Keyword(s):  
Heating Rate ◽  
High Temperatures ◽  
The Other ◽  
Growth Mode ◽  
High Heating Rate ◽  
Heating Rates ◽  
Other Hand ◽  
High Heating ◽  
Martensite Matrix

The effects of heating rate on the formation of acicular and globular austenite during reversion from martensite in Fe–2Mn–1.5Si–0.3C alloy have been investigated. It was found that a low heating rate enhanced the formation of acicular austenite, while a high heating rate favored the formation of globular austenite. The growth of acicular γ was accompanied by the partitioning of Mn and Si, while the growth of globular γ was partitionless. DICTRA simulation revealed that there was a transition in growth mode from partitioning to partitionless for the globular austenite with an increase in temperature at high heating rate. High heating rates promoted a reversion that occurred at high temperatures, which made the partitionless growth of globular austenite occur more easily. On the other hand, the severer Mn enrichment into austenite at low heating rate caused Mn depletion in the martensite matrix, which decelerated the reversion kinetics in the later stage and suppressed the formation of globular austenite.

scholarly journals An electric furnace for experiments in vacuo at temperatures

1912 ◽  
Vol 87 (598) ◽  
pp. 519-524
Keyword(s):  
High Temperatures ◽  
Electric Furnace ◽  
Cuprous Oxide ◽  
The Other ◽  
Resistance Furnace ◽  
Heterogeneous Equilibrium ◽  
Other Hand ◽  
Large Current ◽  
Dissociation Pressures ◽  
Reduction Of Oxides

This furnace was designed with a view to investigating at temperatures up to 1500° C. certain cases of heterogeneous equilibrium in which the equilibrium is defined by the pressure of the system. Instances are the dissociation of certain oxides, nitrides, and carbonates, and the reduction of oxides by carbon. The furnace could not be constructed of carbon, as carbon would react with some of the gases of which the pressure had to be measured, and also because it is almost impossible to remove the adsorbed gases from large quantities of carbon. Tubes of Royal Berlin porcelain in a platinum-wound resistance furnace may be used for temperatures up to 1200°, but at about this temperature they become soft, while the glaze runs and combines with any boat or other substance in the furnace. Tubes of silica are not suitable, because they are porous at high temperatures, and because they disintegrate owing to crystallisation taking place. It was decided to make the furnace of a platinum tube and to heat it by passing a large current through it. As some of the substances which it would be necessary to place in the furnace react with platinum, e. g . copper formed by the dissociation of cuprous oxide, it was necessary to make the furnace sufficiently large to take a boat or crucible of magnesia large enough to contain the reacting substance and thick enough to protect the tube. On the other hand, the tube ought to be as small as possible, in order that in determining the dissociation pressures all the charge should not be decomposed before the equilibrium is attained.

New Catalytic Combustion Technology for Very Low Emissions Gas Turbines

1994 ◽  
Author(s):  
R. A. Dalla Betta ◽  
J. C. Schlatter ◽  
S. G. Nickolas ◽  
D. K. Yee ◽  
T. Shoji
Keyword(s):  
Thermal Shock ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Combustion Process ◽  
Combustion System ◽  
Gas Turbine Combustors ◽  
Homogeneous Combustion ◽  
Combustion Technology

A catalytic combustion system has been developed which feeds full fuel and air to the catalyst but avoids exposure of the catalyst to the high temperatures responsible for deactivation and thermal shock fracture of the supporting substrate. The combustion process is initiated by the catalyst and is completed by homogeneous combustion in the post catalyst region where the highest temperatures are obtained. This has been demonstrated in subscale test rigs at pressures up to 14 atmospheres and temperatures above 1300°C (2370°F). At pressures and gas linear velocities typical of gas turbine combustors, the measured emissions from the catalytic combustion system are NOx < 1 ppm, CO < 2 ppm and UHC < 2 ppm, demonstrating the capability to achieve ultra low NOx and at the same time low CO and UHC.

John Hugh Chesters, O.B.E. 6 October 1906 – 14 December 1994

2000 ◽  
Vol 46 ◽  
pp. 37-48
Author(s):  
G.W. Greenwood
Keyword(s):  
Heat Flow ◽  
Thermal Shock ◽  
High Temperatures ◽  
Refractory Materials ◽  
Steel Melting ◽  
Structure And Properties ◽  
Corrosive Environments ◽  
Efficiency And Reliability

John Hugh Chesters, fulfilling his ambitions as a schoolboy, had a lifelong involvement in the application of science to solve practical and industrially important problems. His major contributions relate mainly to the efficiency and reliability of furnaces for steel melting. These were accomplished through research on refractory materials for furnace linings and on heat flow. His work led to great improvements in the processing and use of ceramics in bulk and in the characterization of the structure and properties of these materials. As a result, the capability of appropriate refractory materials to withstand stresses, sudden thermal shock, and corrosive environments for the long periods at high temperatures that arise in iron and steelmaking processes was substantially increased.

scholarly journals On a new register-pyrometer, for measuring the expansions of solids, and determining the higher degrees of temperature upon the common thermometric scale

1833 ◽  
Vol 2 ◽  
pp. 404-406
Keyword(s):  
Melting Point ◽  
High Temperatures ◽  
The Other ◽  
Royal Institution ◽  
Guyton De Morveau ◽  
Higher Temperature ◽  
The Subject ◽  
The Common ◽  
The One ◽  
Universal Application

In the year 1821, the author published in the Journal of the Royal Institution an account of a new pyrometer, and of some determinations of high temperatures, in connexion with the scale of the mercurial thermometer, obtained by its means. The use of the instrument then described was, however, limited; and the author was subsequently led to the invention of a pyrometer of a more universal application, both to scientific researches and to various purposes of art. Fie introduces the subject by an account of the late attempt of M. Guyton de Morveau, to employ the expansions of platina for the admeasurement of high temperatures, and for connecting the indications of Wedgwood’s pyrometer with the mercurial scale, and verifying its regularity. The experiments of that philosopher were by the contraction of porcelain, and by actual comparison with those of the platina pyrometer, at no higher temperature than the melting point of antimony; but they are sufficient to establish the existence of a great error in Wedgwood’s original estimation of his degrees up to that point. This he carries on by calculation, on the hypothesis of uniform progression of expansion, up to the melting point of iron; the construction of his instrument not admitting of its application to higher temperatures than a red heat, in which platina becomes soft and ductile. Mr. Daniell shows, by an examination of M. Guyton’s results, that he has failed in establishing the point he laboured to prove; namely, the regularity of the contraction of the clay pieces. The pyrometer of the author consists of two distinct parts; the one designated the register , the other the scale .

High Temperature Implantation in Graphite

1983 ◽  
Vol 27 ◽  
Author(s):  
G. Braunstein ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
High Temperature ◽  
Radiation Damage ◽  
High Temperatures ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
Rutherford Backscattering ◽  
The Other ◽  
Highly Oriented Pyrolytic Graphite ◽  
Graphite Lattice ◽  
Partial Annealing

ABSTRACTIn previous studies it was found that when highly oriented pyrolytic graphite (HOPG) is implanted at room temperature, the damage caused by the implantation could be completely annealed by heating the sample to temperatures higher than ∼ 2500°C. However at these high temperatures, the implanted species was found to diffuse out of the sample, as evidenced by the disappearance of the impurity peak in the Rutherford backscattering (RBS) spectrum. If, on the other hand, the HOPG crystal was held at a high temperature (≥ 600°C) during the implantation, partial annealing could be observed. The present work further shows that it is possible to anneal the radiation damage and simultaneously to retain the implants in the graphite lattice by means of high temperature implantation (Ti ≥ 450°C) followed by annealing at 2300°C.

Characteristics of proteinases of 3 strains ofStaphylococcus lactisisolated from Cheddar cheese

1964 ◽  
Vol 31 (2) ◽  
pp. 147-153 ◽  
Author(s):  
I. J. McDonald
Keyword(s):  
High Temperatures ◽  
Culture Supernatant ◽  
Cheddar Cheese ◽  
Maximum Activity ◽  
The Other ◽  
Alkaline Ph ◽  
Temperature Characteristics ◽  
Β Lactoglobulin

SummaryProteinase systems of 3 strains ofStaphylococcus lactisfrom Cheddar cheese have been studied. Proteinase of one organism was found in the culture supernatant, those of the other two were obtained in significant amounts only by disruption of the cells of the organisms. All 3 proteinases possessed maximum activity at alkaline pH (about 9·0–10·0). They were most active at relatively high temperatures (45–55 °C) and possessed temperature characteristics (μ) of 7000–8000 cals. Casein, ²-lactoglobulin and haemoglobin were hydrolysed by the proteinases; casein most readily and β-lactoglobulin more readily than haemoglobin. Because of their characteristics, such proteinases are considered potentially capable of contributing to the ripening of Cheddar cheese.

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