scholarly journals THE DYNAMIC NATURE OF THERMOPHILY

1950 ◽  
Vol 33 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Mary Belle Allen
Keyword(s):  
Temperature Coefficient ◽  
High Temperatures ◽  
Thermophilic Bacteria ◽  
Close Relation ◽  
Enzyme Synthesis ◽  
Dynamic Nature ◽  
Mesophilic Bacteria ◽  
Enzyme Systems ◽  
Higher Temperature ◽  
Synthetic Capacity

1. Evidence for a close relation between thermophilic and mesophilic bacteria is discussed. 2. It is shown that in the absence of nutrients thermophilic bacteria at 55°C. die as rapidly as mesophilic bacteria, and that enzyme systems of the thermophils are rapidly inactivated at this temperature. 3. It is concluded that the thermophils can live at high temperatures because they can synthesize enzymes and other cellular constituents faster than these are destroyed by heat. 4. In order to account for this great synthetic capacity at high temperatures, and for the high minimum temperatures observed for many thermophils, it is postulated that these organisms have a higher temperature coefficient of enzyme synthesis than mesophils.

scholarly journals Cloning and in silico study of an endoglucanase from a thermophilic bacterium isolated from a hydrothermal vent of West Kawio, Sangihe‐Talaud waters, North Sulawesi, Indonesia

2020 ◽  
Vol 24 (2) ◽  
pp. 105
Author(s):  
Edvan Arifsaputra Suherman ◽  
Maelita Ramdani Moeis ◽  
Elvi Restiawaty
Keyword(s):  
Amino Acids ◽  
High Temperatures ◽  
Hydrothermal Vent ◽  
Animal Feed ◽  
Thermophilic Bacteria ◽  
Glycosyl Hydrolase ◽  
Thermophilic Bacterium ◽  
Lower Percentage ◽  
Bacillus Species ◽  
North Sulawesi

Endoglucanase is used in industries that apply high temperatures, such as bioethanol, detergent, paper, and animal feed industries. Most available endoglucanases have very low stability at high temperatures. Therefore, this study aimed to identfy a new thermostable endoglucanase that is able to maintain its actvity at high temperatures. Five isolates of thermophilic bacteria were previously isolated from the hydrothermal vent of West Kawio, Indonesia. Among them, the DSI2 isolate showed the highest endoglucanase actvity, and was identfed and named as Bacillus safensis DSI2. The EgDSI2 gene was cloned from B. safensis DSI2. EgDSI2 is 1851 bp long encoding a protein of 616 amino acids. The encoded protein, EgDSI2, has high sequence identty to other B. safensis endoglucanases and was predicted with the Compute pI/Mw tool to be 69.41 kDa. EgDSI2 was high in hydrophobic amino acids. The enzyme had higher percentage of Ala andPro, and lower percentage of Gly compared to thermolabile endoglucanases from two Bacillus species. EgDSI2 harbored a catalytc domain belonging to glycosyl hydrolase family 9 (GH9) and a type 3 cellulose‐binding domain (CBM3). Propertes of endoglucanases with GH9‐CBM3 modular organizaton include actvity over a wide pH range, high optmum temperature, and thermostablity. Therefore, EgDSI2 has potental applicatons in the industries.

The Regeneration of Legs in Rhodnius Prolixus (Hemiptera)

1948 ◽  
Vol 25 (4) ◽  
pp. 334-343
Author(s):  
MARTIN LÜSCHER
Keyword(s):  
Temperature Coefficient ◽  
Individual Variation ◽  
Rhodnius Prolixus ◽  
Limiting Factors ◽  
Nymphal Instar ◽  
Regenerative Capacity ◽  
Higher Temperature ◽  
Considerable Individual Variation ◽  
Distal Direction ◽  
Regeneration Processes

1. Partial regeneration of the legs is possible in Rhodnius prolixus. 2. The regeneration potencies appear at the level of the femur-tibia joint and increase gradually in a distal direction. 3. Regeneration usually ceases after the fourth post-amputation moult. 4. No striking differences in regenerative capacity can be detected either in the different legs on one nymphal instar or in the legs of different nymphal instars. There is, however, considerable individual variation. 5. Regeneration is dependent on the time which elapses between the amputation and the next moult. 6. The regeneration processes have a higher temperature coefficient than the moulting processes. 7. A conception of two limiting factors is briefly discussed.

scholarly journals Temporal Patterns of Flowering and Pod Set of Determinate Soybean in Response to High Temperature

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 414 ◽  
Author(s):  
Yean-Uk Kim ◽  
Doug-Hwan Choi ◽  
Ho-Young Ban ◽  
Beom-Seok Seo ◽  
Junhwan Kim ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Temporal Distribution ◽  
Temporal Patterns ◽  
Bimodal Distribution ◽  
Flowering Duration ◽  
Sowing Dates ◽  
Glycine Max L ◽  
Higher Temperature ◽  
Pod Number

Global warming is expected to affect yield-determining factors of soybean (Glycine max (L.) Merr.), including the number of flowers and pods. However, little is known about the effects of high temperature on the temporal patterns of flowering and pod set. Experiments in the temperature-controlled greenhouses were conducted to examine the temporal pattern of flowering in determinate soybean cultivar “Sinpaldalkong” and to assess the effects of high temperature on the flower number, pod-set ratio, and pod number of the early- and late-opened-flowers and their contributions to overall pod number. The experiment comprised five sowing dates in 2013–2015 and four temperature treatments, namely ambient temperature (AT), AT + 1.5 °C, AT + 3.0 °C, and AT + 5.0 °C. Flowering duration (i.e., days between the first flowering and the last flowering) was extended by higher temperature and earlier sowing. The temporal distribution of flowering showed a bimodal distribution except for the experiment with the shortest flowering duration, i.e., second sowing in 2014. More flowers were produced in the late flowering period at high temperatures; however, most of these late-opened-flowers failed to reproduce, regardless of temperature conditions, resulting in a negligible contribution to the overall pod number. For the early-opened-flowers, the number of flowers was not significantly affected by temperature, while the pod-set ratio and pod number decreased with high temperatures resulting in a decrease in the overall pod number at temperatures above 29.4 °C.

Preparation of Butadiene

1928 ◽  
Vol 1 (2) ◽  
pp. 208-210
Author(s):  
Stanley Francis Birch
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Liquid Phase ◽  
High Temperatures ◽  
Vapor Phase ◽  
Complex Mixture ◽  
Higher Temperature ◽  
Oil Gas

Abstract OF THE numerous methods available for the preparation of butadiene in the laboratory, those described by Thiele and by Ostromuislenskii are probably the most convenient. Both, however, suffer from the disadvantages which usually characterize operations at comparatively high temperatures; the exact conditions are difficult to find, the process is long and tedious, and finally involves the separation of the required material from a complex mixture. It has long been known that butadiene occurs in the various products obtained when oils are heated to a high temperature. Caventou first isolated butadiene in the form of its tetrabromide from illuminating gas, and Armstrong and Miller definitely established the presence of butadiene in the liquid obtained by compressing oil gas. The work of numerous later investigators has confirmed their results and has shown that the more drastic the heat treatment to which the oil is submitted the greater is the tendency for butadiene to be formed. For this reason vapor-phase cracking of petroleum, which is carried out at a much higher temperature than liquid-phase cracking, yields products specially rich in butadiene.

High-Temperature Adhesives Based on Alder-ene Reaction of Diallyl Bisphenol a Novolac and Bismaleimide: Effect of BMI Structure and Novolac Molar Mass

2003 ◽  
Vol 11 (4) ◽  
pp. 311-320 ◽  
Author(s):  
C. Gouri ◽  
C.P. Reghunadhan Nair ◽  
R. Ramaswamy
Keyword(s):  
Bisphenol A ◽  
High Temperatures ◽  
Molar Mass ◽  
Adhesion Properties ◽  
Ene Reaction ◽  
Network Polymers ◽  
Lap Shear ◽  
Higher Temperature ◽  
Stable Network ◽  
Good Retention

Diallyl bisphenol A formaldehyde novolac (ABPF) resin was cured with four structurally different bismaleimides (BMIs) at high temperatures through an Alder-ene reaction which resulted in thermally stable network polymers. The adhesive characteristics of the different BMI-ABPF systems were evaluated in terms of the lap shear strength (LSS) on aluminium substrates at varying temperatures up to 250°C. The LSS properties were not significantly affected by the structure of the BMI. Although the LSS of BMI-ABPF systems per se were not particularly high due to the brittle nature of the cross-linked structures, all the systems exhibited remarkably good retention of LSS at high temperatures. Replacing ABPF with its monomeric analogue i.e. o,o′- diallyl bisphenol A (DABA) resulted in better adhesion, but in a poorer thermo-adhesive profile. Comparison of DMA and thermo-adhesive profiles implied that in the majority of the cases molecular relaxations at higher temperature are conducive to matrix toughening which results in enhanced adhesion properties.

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 .

Fate of Naturally Occurring Escherichia coli O157:H7 and Other Zoonotic Pathogens during Minimally Managed Bovine Feedlot Manure Composting Processes†

2013 ◽  
Vol 76 (8) ◽  
pp. 1308-1321 ◽  
Author(s):  
ELAINE D. BERRY ◽  
PATRICIA D. MILLNER ◽  
JAMES E. WELLS ◽  
NORASAK KALCHAYANAND ◽  
MICHAEL N. GUERINI
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
High Temperatures ◽  
Thermophilic Bacteria ◽  
Foodborne Illness ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Naturally Occurring ◽  
On Farm ◽  
Campylobacter Spp

Reducing Escherichia coli O157:H7 in livestock manures before application to cropland is critical for reducing the risk of foodborne illness associated with produce. Our objective was to determine the fate of naturally occurring E. coli O157:H7 and other pathogens during minimally managed on-farm bovine manure composting processes. Feedlot pen samples were screened to identify E. coli O157:H7–positive manure. Using this manure, four piles of each of three different composting formats were constructed in each of two replicate trials. Composting formats were (i) turned piles of manure plus hay and straw, (ii) static stockpiles of manure, and (iii) static piles of covered manure plus hay and straw. Temperatures in the tops, toes, and centers of the conical piles (ca. 6.0 m3 each) were monitored. Compost piles that were turned every 2 weeks achieved higher temperatures for longer periods in the tops and centers than did piles that were left static. E. coli O157:H7 was not recovered from top samples of turned piles of manure plus hay and straw at day 28 and beyond, but top samples from static piles were positive for the pathogen up to day 42 (static manure stockpiles) and day 56 (static covered piles of manure plus hay and straw). Salmonella, Campylobacter spp., and Listeria monocytogenes were not found in top or toe samples at the end of the composting period, but E. coli O157:H7 and Listeria spp. were recovered from toe samples at day 84. Our findings indicate that some minimally managed composting processes can reduce E. coli O157:H7 and other pathogens in bovine manure but may be affected by season and/or initial levels of indigenous thermophilic bacteria. Our results also highlight the importance of adequate C:N formulation of initial mixtures for the production of high temperatures and rapid composting, and the need for periodic turning of the piles to increase the likelihood that all parts of the mass are subjected to high temperatures.

Welding Consumables for 2.25Cr-1Mo-V Refining Reactors

2017 ◽  
Author(s):  
Hideaki Takauchi ◽  
Tomoaki Nakanishi ◽  
Hidenori Nako
Keyword(s):  
High Temperatures ◽  
Temper Embrittlement ◽  
Pressure Vessels ◽  
Creep Rupture ◽  
Hydrogen Attack ◽  
Fine Carbide ◽  
Higher Temperature ◽  
Welding Consumables ◽  
Segregation Of Impurities ◽  
Welding Materials

Owing to the demands for larger-capacity reactor vessels in petroleum plants and higher temperature processes for the upgrade of heavy oil, enhanced 2.25Cr-1Mo, 2.25Cr-1Mo-V and 3Cr-1Mo-V steels, which suit both high temperatures and pressure operations, have been developed and used for heavy-wall pressure vessels since the 1990s. 2.25Cr-1Mo-V steel, which has very special mechanical properties, resistant to both hydrogen attack and embrittlement under high temperatures and pressure environments in particular, has been used since 2000. The specifications for 2.25Cr-1Mo-V steel pressure vessels, such as ASME Sec. VIII and API RP 934-A, have been established and reviewed to enhance the contents [1–2]. In this report, the transition of materials, the welding techniques for hydrocracking reactors and 2.25Cr-1Mo-V welding materials are introduced. Particularly, for these welding materials, in order to improve the creep rupture and temper embrittlement properties, the effectiveness of precipitates is discussed. It was found that fine carbide (MC) in crystal grains improves creep rupture lifetime and MC at the prior austenite (γ) grain boundaries inhibits temper embrittlement caused by the segregation of impurities.

scholarly journals The influence of age and development temperature on the temperature-related foraging risk of Formica cinerea ants

2021 ◽  
Vol 75 (7) ◽  
Author(s):  
Piotr Ślipiński ◽  
Gema Trigos-Peral ◽  
István Maák ◽  
Iga Wojciechowska ◽  
Magdalena Witek
Keyword(s):  
High Temperatures ◽  
High Surface ◽  
Foraging Strategy ◽  
Temperate Climate ◽  
Foraging Activity ◽  
Subsequent Increase ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Development Temperature ◽  
Formica Cinerea

Abstract Climate change and the subsequent increase of global temperature are the most current and important threats to biodiversity. Despite the importance of temperature, our knowledge about the level of behavioural and physiological adaptations of ant species from temperate regions to cope with high temperatures is limited compared to the broad knowledge of typical thermal specialists from warmer regions. In the current study, we investigated the temperature-related foraging risk of xerothermic ant species from the temperate climate in Europe, Formica cinerea. Our aims were to check how an increase in external soil temperature affects the foraging activity of workers and how the temperature during development and worker age affects foraging activity in high temperatures. Based on our results, we can draw the following conclusions: (1) the majority of workers utilize a risk-aversive strategy in relation to foraging in high surface temperatures; (2) pupal development temperature affects the risk taken by adult workers: workers that developed in a higher temperature forage more often but for shorter intervals compared to workers that developed in a lower temperature; (3) age is an important factor in temperature-related foraging activity, as with increasing age, workers forage significantly longer at the highest temperatures. Our study is one of the first to assess the potential factors that can affect the foraging risk of ants from a temperate climate in high ambient temperatures. Significance statement Our study is the first direct test of workers' age and the development temperature of pupae on the thermal-related foraging strategy of adult F. cinerea workers. It shows that worker age and the development temperature of pupae interact to promote tolerance of thermal stress. We found that with increasing age, workers are prone to forage significantly longer at the highest and riskiest temperatures. Workers that developed in the high temperature (28°C) foraged more often but for shorter intervals compared to workers that developed in the lower temperature (20°C). Interestingly, the factor of age is more significant for ants that developed in the higher temperature of 28°C; the foraging time of these ants significantly increased with their age.

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