Effect of low temperature on oxygen uptake and haemolymph ions in the sandhopper Talitrus saltator (Crustacea: Amphipoda)

1994 ◽  
Vol 74 (2) ◽  
pp. 313-321 ◽  
Author(s):  
John I. Spicer ◽  
David Morritt ◽  
Alan C. Taylor
Keyword(s):  
Low Temperature ◽  
Oxygen Uptake ◽  
Major Ions ◽  
Northern Latitudes ◽  
Talitrus Saltator ◽  
The Common ◽  
Laboratory Exposure ◽  
High Shore

The common sandhopper of European shores, Talitrus saltator (Montagu, 1808) (Crustacea: Amphipoda) remains inactive in high shore burrows for much of the winter in more northern latitudes. In the laboratory exposure to low temperature (2 or 3°C) was accompanied by the onset of inactivity, a precipitous decrease in oxygen uptake and a marked increase in the concentrations of the major ions in the haemolymph. The increase in the concentration of Mg2+ in the haemolymph was particularly pronounced. The possibility that Mg2+ ions are implicated in bringing about a reduction in activity and oxygen uptake is discussed.

Molecule-Based Magnets—An Overview

MRS Bulletin ◽  
2000 ◽  
Vol 25 (11) ◽  
pp. 21-30 ◽  
Author(s):  
Joel S. Miller ◽  
Arthur J. Epstein
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Magnetic Ordering ◽  
Low Density ◽  
Materials Properties ◽  
The Common ◽  
New Processing ◽  
Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

The Effects of Low Temperature Upon the Locomotor Activity Rhythm of Talitrus Saltator (Montagu) (Crustacea: Amphipoda)

1972 ◽  
Vol 57 (2) ◽  
pp. 393-399
Author(s):  
P. K. BREGAZZI
Keyword(s):  
Locomotor Activity ◽  
Low Temperature ◽  
Mode Of Action ◽  
Activity Rhythm ◽  
Inhibitory Factor ◽  
Locomotor Rhythm ◽  
Locomotor Activity Rhythm ◽  
Complete Cessation ◽  
Maximum Delay ◽  
Talitrus Saltator

1. Chilling Talitrus causes a complete cessation of locomotor activity and a delay in the appearance of successive activity peaks following return to normal temperatures. Maximum delay occurs if chilling begins during inactivity and is about equal to the duration of the chill. At other times the delay is less than the duration of the chill. 2. It is postulated that an inhibitory factor is concerned in the control of the locomotor rhythm of Talitrus, and a model is proposed to describe its possible mode of action.

Compatibility of Materials with Cryogens

1983 ◽  
pp. 343-369
Author(s):  
J. C. Moulder ◽  
J. G. Hust
Keyword(s):  
Low Temperature ◽  
Liquid Oxygen ◽  
Hydrogen Environment ◽  
Physical Interactions ◽  
The Common ◽  
Materials Used ◽  
Hydrogen Systems ◽  
Compatibility Of Materials

Abstract This chapter discusses the compatibility problems that arise from chemical or physical interactions between liquefied gases and the common materials used in their production, storage, transportation, distribution, and use. The discussion covers the compatibility of materials with liquid oxygen and liquid fluorine. Hydrogen-environment embrittlement is unique to low-temperature hydrogen systems and is also discussed.

Electroluminescence from GalnN Quantum Wells Grown on Non-(0001) Facets of Selectively Grown GaN Stripes

2004 ◽  
Vol 831 ◽  
Author(s):  
Barbara Neubert ◽  
Frank Habel ◽  
Peter Bruckner ◽  
Ferdinand Scholz ◽  
Till Riemann ◽  
...  
Keyword(s):  
Low Temperature ◽  
Electric Field ◽  
Quantum Wells ◽  
Room Temperature ◽  
Light Emission ◽  
Low Pressure ◽  
Lower Efficiency ◽  
Strong Light ◽  
The Common ◽  
Piezo Electric

ABSTRACTNon (0001) GalnN QWs have been grown by low pressure MOVPE on side facets of triangular shaped selectively grown GaN stripes. By analysing low temperature photo- and cathodoluminescence and room temperature electroluminescence, we found strong indications, that both, In and Mg are less efficiently incorporated on these side facets compared to the common (0001) plane with even lower efficiency for stripes running along (1–100) compared to (11–20). Nevertheless, we observed strong light emission from these quantum wells, supposed to be at least partly caused by the reduced piezo-electric field.

RESPIRATION OF INTACT CELLS OF A LOW-TEMPERATURE BASIDIOMYCETE

1966 ◽  
Vol 44 (8) ◽  
pp. 1077-1086 ◽  
Author(s):  
E. W. B. Ward
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Oxygen Uptake ◽  
Respiratory Quotient ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Endogenous Respiration ◽  
Starvation Period ◽  
Intact Cells ◽  
Exogenous Glucose

Conventional manometric procedures were used to measure oxygen uptake and carbon dioxide evolution by cells of a low-temperature basidiomycete. Total respiration was lowest and, relatively, endogenous respiration was highest in old cells. During starvation, endogenous respiration decreased but did so most rapidly in young cells. Maximum response to exogenous glucose was obtained from young cells after starvation. The respiratory quotient of endogenous respiration fell from 1.0 to approximately 0.7 during starvation, indicating a change in endogenous substrate. Conversely the respiratory quotient for exogenous respiration of added glucose increased with the starvation period. The level of oxidative assimilation of glucose was shown to be high (80-90%) and evidence was obtained that exogenous glucose did not suppress endogenous respiration.The optimum temperature for oxygen uptake was 25 °C, below which the Q10 was approximately 2. At 30 °C the rate, while initially highest, decreased during the 6-hour incubation period.The fungus utilized various compounds as carbon sources, but not sucrose in short-term experiments. Glucose, but not xylose was fermented, although the ratio of carbon dioxide to ethanol was not 1:1. Inhibition by fluoride, arsenite, iodoacetate, fluoroacetate, and malonate suggested that both glucose and xylose are respired at least in part by the Embden-Meyerof pathway and the tricarboxylic acid cycle. Endogenous respiration was only slightly affected by these inhibitors.

Orientation Studies of α-Al(Fe,Mn)Si Dispersoids in 3xxx Al Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 39-44 ◽  
Author(s):  
Astrid Marie Flattum Muggerud ◽  
Yan Jun Li ◽  
Randi Holmestad
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Orientation Relationship ◽  
Aluminum Matrix ◽  
Al Alloys ◽  
Orientation Relationships ◽  
The Matrix ◽  
The Common ◽  
Habit Planes ◽  
Al Matrix

Dispersoids are important in 3xxx Al alloys, influencing mechanical properties, texture and recrystallization. In this work α-Al (Fe,Mn)Si dispersoids have been studied after low temperature homogenisation. The common orientation relationship between dispersoids and Al matrix has been reported in earlier studies. Here a systematic study on the orientation relationship and its exceptions is presented. It is found that most of the dispersoids follow the common orientation relationship, [1-1 1] α //[1-1 1]Al , (5-2 -7 ) α //(0 1 1)Al . Here the dispersoids are semi coherent with the Aluminum matrix. Different morphologies and habit planes are possible. Deviations from the most commonly observed orientation relationships are presented and discussed, to underline the complexity of the phase and its relation to the matrix.

Ash Fusibility Based on Modes of Occurrence and High-Temperature Behaviors of Mineral Matter in Coals

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Xinye Cheng ◽  
Kexin Han ◽  
Zhenyu Huang ◽  
Zhihua Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Melting Process ◽  
Mineral Matter ◽  
Slight Reduction ◽  
Modes Of Occurrence ◽  
Ash Melting ◽  
Ash Fusibility ◽  
Three Stages ◽  
The Common

Complete quantitative data of the chemical (proximate, ultimate, and ash analyses) and mineral (in low-temperature ash (LTA) and various high-temperature ashes (HTA)) compositions of 21 coals were used to investigate the modes of occurrences and high-temperature behaviors of the minerals in coals and their influence on ash fusibility. The common minerals present in the low-temperature ashes (LTA) are kaolinite, quartz, muscovite, calcite, gypsum, pyrite, and siderite. The samples were divided into two groups according to the hemispherical temperature for a comparative study of the behavior of mineral matters. Results show that the average number of mineral species (ANMS) and amorphous substances (AS) in the LTAs of the two groups are essentially the same. The ANMS in both the low and high (ash fusion temperatures, AFT) ash samples go through the same tendency of a slight reduction at first, an increase, and finally, a significant reduction. As the temperature increases, the ANMS in the low-AFT ash is initially higher and then lower than the high-AFT ash, whereas the tendency of the AS is quite the opposite. The ash melting process is divided into three stages, and the AFTs are related to different degrees of the eutectic stage.

scholarly journals Are white dwarf magnetic fields in close binaries generated during common-envelope evolution?

2019 ◽  
Vol 492 (1) ◽  
pp. 1523-1529 ◽  
Author(s):  
Diogo Belloni ◽  
Matthias R Schreiber
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Observational Data ◽  
White Dwarf ◽  
Close Binaries ◽  
Common Envelope ◽  
The Past ◽  
The Common ◽  
M Dwarf ◽  
Dynamo Process

ABSTRACT Understanding the origin of the magnetic fields in white dwarfs (WDs) has been a puzzle for decades. A scenario that has gained considerable attention in the past years assumes that such magnetic fields are generated through a dynamo process during common-envelope evolution. We performed binary population models using an up-to-date version of the bse code to confront the predictions of this model with observational results. We found that this hypothesis can explain only the observed distribution of WD magnetic fields in polars and pre-polars and the low-temperature WDs in pre-polars if it is re-scaled to fit the observational data. Furthermore, in its present version, the model fails to explain the absence of young, close detached WD+M-dwarf binaries harbouring hot magnetic WDs and predicts that the overwhelming majority of WDs in close binaries should be strongly magnetic, which is also in serious conflict with the observations. We conclude that either the common-envelope dynamo scenario needs to be substantially revised or a different mechanism is responsible for the generation of strong WD magnetic fields in close binaries.

Cold Weather Operation of Aircraft

1949 ◽  
Vol 53 (457) ◽  
pp. 1-38
Author(s):  
G. W. Wilson ◽  
E. P. Bridgland
Keyword(s):  
Low Temperature ◽  
Cold Weather ◽  
Aircraft Engines ◽  
Temperature Conditions ◽  
Northern Latitudes ◽  
Medium Type

It is many years since aircraft were first A operated under extreme low temperature conditions, mainly by bush pilots pioneering the northern latitudes of Canada.The aircraft used were of the light and semi—medium type fitted with simple, low—powered engines. Consequently, crude methods could be adopted to keep them operating.With the advent of high—powered boosted—engined aircraft, with their complexity and numerous complicated installations, together with other associated equipments, the difficulties became manifold and the earlier methods used were either impracticable or inadequate.For this reason, some intensive testing and research has been done on the latest type of aircraft, engines and equipment, in an endeavour to solve the problems and, if not entirely successful, find what medium of success can be achieved with the least amount of subsidiary aid.

scholarly journals Relationships between low-temperature fires, climate and vegetation during three late glacials and interglacials of the last 430 kyr in northeastern Siberia reconstructed from monosaccharide anhydrides in Lake El'gygytgyn sediments

2020 ◽  
Vol 16 (2) ◽  
pp. 799-818 ◽  
Author(s):  
Elisabeth Dietze ◽  
Kai Mangelsdorf ◽  
Andrei Andreev ◽  
Cornelia Karger ◽  
Laura T. Schreuder ◽  
...  
Keyword(s):  
Low Temperature ◽  
Boreal Forest ◽  
Biomass Burning ◽  
Boreal Forests ◽  
Vegetation Shifts ◽  
Low Intensity ◽  
Northern Latitudes ◽  
Lake El’Gygytgyn ◽  
Monosaccharide Anhydrides

Abstract. Landscapes in high northern latitudes are assumed to be highly sensitive to future global change, but the rates and long-term trajectories of changes are rather uncertain. In the boreal zone, fires are an important factor in climate–vegetation interactions and biogeochemical cycles. Fire regimes are characterized by small, frequent, low-intensity fires within summergreen boreal forests dominated by larch, whereas evergreen boreal forests dominated by spruce and pine burn large areas less frequently but at higher intensities. Here, we explore the potential of the monosaccharide anhydrides (MA) levoglucosan, mannosan and galactosan to serve as proxies of low-intensity biomass burning in glacial-to-interglacial lake sediments from the high northern latitudes. We use sediments from Lake El'gygytgyn (cores PG 1351 and ICDP 5011-1), located in the far north-east of Russia, and study glacial and interglacial samples of the last 430 kyr (marine isotope stages 5e, 6, 7e, 8, 11c and 12) that had different climate and biome configurations. Combined with pollen and non-pollen palynomorph records from the same samples, we assess how far the modern relationships between fire, climate and vegetation persisted during the past, on orbital to centennial timescales. We find that MAs attached to particulates were well-preserved in up to 430 kyr old sediments with higher influxes from low-intensity biomass burning in interglacials compared to glacials. MA influxes significantly increase when summergreen boreal forest spreads closer to the lake, whereas they decrease when tundra-steppe environments and, especially, Sphagnum peatlands spread. This suggests that low-temperature fires are a typical characteristic of Siberian larch forests also on long timescales. The results also suggest that low-intensity fires would be reduced by vegetation shifts towards very dry environments due to reduced biomass availability, as well as by shifts towards peatlands, which limits fuel dryness. In addition, we observed very low MA ratios, which we interpret as high contributions of galactosan and mannosan from biomass sources other than those currently monitored, such as the moss–lichen mats in the understorey of the summergreen boreal forest. Overall, sedimentary MAs can provide a powerful proxy for fire regime reconstructions and extend our knowledge of long-term natural fire–climate–vegetation feedbacks in the high northern latitudes.

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