Temperature-sensitive bridge circuits in automatic compensation of temperature changes at the free ends of thermoelectric transducers

1983 ◽  
Vol 26 (1) ◽  
pp. 38-41
Author(s):  
Yu. V. Pozdnyakov ◽  
V. A. Kochan
Keyword(s):  
Temperature Sensitive ◽  
Automatic Compensation ◽  
Temperature Changes ◽  
Bridge Circuits

scholarly journals Smart Hydrogel Bilayers Prepared by Irradiation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1753
Author(s):  
Weixian Huo ◽  
Heng An ◽  
Shuquan Chang ◽  
Shengsheng Yang ◽  
Yin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Antibacterial Properties ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Temperature Changes ◽  
Smart Hydrogel ◽  
Isopropyl Acrylamide ◽  
Hydrogel Synthesis ◽  
Potential Applications

Environment-responsive hydrogel actuators have attracted tremendous attention due to their intriguing properties. Gamma radiation has been considered as a green cross-linking process for hydrogel synthesis, as toxic cross-linking agents and initiators were not required. In this work, chitosan/agar/P(N-isopropyl acrylamide-co-acrylamide) (CS/agar/P(NIPAM-co-AM)) and CS/agar/Montmorillonite (MMT)/PNIPAM temperature-sensitive hydrogel bilayers were synthesized via gamma radiation at room temperature. The mechanical properties and temperature sensitivity of hydrogels under different agar content and irradiation doses were explored. The enhancement of the mechanical properties of the composite hydrogel can be attributed to the presence of agar and MMT. Due to the different temperature sensitivities provided by the two layers of hydrogel, they can move autonomously and act as a flexible gripper as the temperature changes. Thanks to the antibacterial properties of the hydrogel, their storage time and service life may be improved. The as prepared hydrogel bilayers have potential applications in control devices, soft robots, artificial muscles and other fields.

Temperature Sensitivity of Intracellular and Extracellular Soil Enzyme Activities

2021 ◽  
Author(s):  
Adetunji Alex Adekanmbi ◽  
Laurence Dale ◽  
Liz Shaw ◽  
Tom Sizmur
Keyword(s):  
Enzyme Activity ◽  
Soil Temperature ◽  
Temperature Sensitivity ◽  
Extracellular Enzymes ◽  
Extracellular Enzyme ◽  
Daily Maximum ◽  
Temperature Sensitive ◽  
Intracellular Enzyme ◽  
Temperature Changes ◽  
Som Decomposition

<p>Predicting the pattern of soil organic matter (SOM) decomposition as a feedback to climate change, via release of CO<sub>2</sub>, is extremely complex and has received much attention. However, investigations often do not differentiate between the extracellular and intracellular processes involved and work is needed to identify their relative temperature sensitivities. Samples were collected from a grassland soil at Sonning, UK with average daily maximum and minimum soil temperature of 15 °C and 5 °C. We measured potential activities of β-glucosidase (BG) and chitinase (NAG) (extracellular enzymes) and glucose-induced CO<sub>2 </sub>respiration (intracellular enzymes) at a range of assay temperatures (5 °C, 15 °C, 26 °C, 37<sup>  </sup>°C, and 45 °C). The temperature coefficient Q<sub>10</sub> (the increase in enzyme activity that occurs after a 10 °C increase in soil temperature) was calculated to assess the temperature sensitivity of intracellular and extracellular enzymes activities. Between 5 °C and 15 °C intracellular and extracellular enzyme activities had equal temperature sensitivity, but between 15 °C and 26°C intracellular enzyme activity was more temperature sensitive than extracellular enzyme activity and between 26 °C and 37 °C extracellular enzyme activity was more temperature sensitive than intracellular enzyme activity. This result implies that extracellular depolymerisation of higher molecular weight organic compounds is more sensitive to temperature changes at higher temperatures (e.g. changes to daily maximum summer temperature) but the intracellular respiration of the generated monomers is more sensitive to temperature changes at moderate temperatures (e.g. changes to daily mean summer temperature). We therefore conclude that the extracellular and intracellular steps of SOM mineralisation are not equally sensitive to changes in soil temperature. The finding is important because we have observed greater increases in average daily minimum temperatures than average daily mean or maximum temperatures due to increased cloud cover and sulphate aerosol emission. Accounting for this asymmetrical global warming may reduce the importance of extracellular depolymerisation and increase the importance of intracellular catalytic activities as the rate limiting step of SOM decomposition.</p>

scholarly journals Gut Microbiome Alteration of Cold-adapated Antarctic copepod Tigriopus kingsejongensis with Temperature Changes and Developmental Stages

2021 ◽  
Author(s):  
Han Na Oh ◽  
Myeong Nu Ri ◽  
Taeyune Kim ◽  
Gi-Sik Min ◽  
Sanghee Kim ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Gut Microbiome ◽  
Developmental Stages ◽  
Glycosyl Hydrolase ◽  
Food Resource ◽  
Temperature Sensitive ◽  
Temperature Changes ◽  
Aquatic Microbes ◽  
Different Temperatures ◽  
Stool Samples

Abstract Tigriopus kingsejongensis, a copepod species, reported from the King Sejong Station, Antarctica, serves as a valuable food resource in ecosystems. Some copepods were temperature-sensitive in growth and post-embryonic development. We cultured T. kingsejongensis at three different temperatures (2°C, 8°C, and 15°C) in a laboratory to observe the alterations in the stool microbiome of copepods depending on the cultivation temperature and developmental stages. We observed copepod gut microbiome changes by increasing temperatures: a lower microbial diversity, a higher abundance of aquatic microbes, Vibrio, and a lower abundance of the psychrophilic microbes, Colwellia. Also, the copepod gut microbiome, according to the developmental stage, was changed: a lower microbial diversity in egg-attached copepods than nauplius at 8°C. We further analyzed three shotgun metagenomes from T. kingsejongensis stool samples at different temperatures and obtained 44 metagenome-assembled genomes (MAGs). We noted that MAGs of V. splendidus D contained glycosyl hydrolase (GHs) encoding chitinases and virulence factors with higher relative abundance at 15°C than at lower temperatures. These results that temperature and developmental stages affect the gut microbiome of copepods are helpful to understand the changes in the low-temperature adapted copepod with climate change.

Temperature- and pH- Sensitive Hydrogels for Controlled Release of Antithrombotic Agents

1993 ◽  
Vol 331 ◽  
Author(s):  
Christopher S. Brazel ◽  
Nicholas A. Peppas
Keyword(s):  
Controlled Release ◽  
Methacrylic Acid ◽  
Blood Clot ◽  
Polymer Network ◽  
Temperature Sensitive ◽  
Kinetic Experiment ◽  
Temperature Changes ◽  
Thermally Responsive ◽  
Swelling Characteristics ◽  
Swelling Studies

AbstractPolymeric hydrogels capable of reversible swelling with changes in environmental temperature and pH were synthesized and studied as matrix systems capable of controlled release of antithrombotic drugs to the site of a blood clot. Monomers N-isopropylacrylamide (NIPAAm) and methacrylic acid (MAA) were chosen for the temperature- and pHdependent swelling characteristics of their polymers, respectively. Equilibrium swelling studies were performed as functions of pH and of temperature, and kinetic swelling studies were performed on the thermally responsive gels as a function of time after the gel was subjected to a step-change in temperature. Experimental results indicate that P(NIPAAmco- MAA) hydrogels can be synthesized so that they are either pH- or temperaturesensitive, depending upon the composition of the network. The pure PNIPAAm gels showed a lower critical solubility temperature (LCST) of around 32°C, below which the gel was in its swollen state, and above which the gel collapsed. As the amount of methacrylic acid in the gels was increased, the degree of swelling in deionized water decreased and the temperature sensitivity was lost. The hydrogels containing MAA displayed a transition in swelling behavior between pH 4 and 6. The mesh sizes of the hydrogel networks were calculated from the results of the swelling studies by Flory-Rehner theory. A kinetic experiment on the temperature-sensitive pure PNIPAAm hydrogel showed that the polymer network collapsed rapidly upon temperature changes across the LCST.

scholarly journals Differing pre-industrial cooling trends between tree rings and lower-resolution temperature proxies

2020 ◽  
Vol 16 (2) ◽  
pp. 729-742 ◽  
Author(s):  
Lara Klippel ◽  
Scott St. George ◽  
Ulf Büntgen ◽  
Paul J. Krusic ◽  
Jan Esper
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Ice Core ◽  
Temperature Sensitive ◽  
Global Trends ◽  
Temperature Changes ◽  
Long Term Trends ◽  
Sediment Data ◽  
Common Era

Abstract. The new PAGES2k global compilation of temperature-sensitive proxies offers an unprecedented opportunity to study regional to global trends associated with orbitally driven changes in solar irradiance over the past 2 millennia. Here, we analyze pre-industrial long-term trends from 1 to 1800 CE across the PAGES2k dataset and find that, in contrast to the gradual cooling apparent in ice core, marine, and lake sediment data, tree rings do not exhibit the same decline. To understand why tree-ring proxies lack any evidence of a significant pre-industrial cooling, we divide those data by location (high Northern Hemisphere latitudes vs. midlatitudes), seasonal response (annual vs. summer), detrending method, and temperature sensitivity (high vs. low). We conclude that the ability of tree-ring proxies to detect pre-industrial, millennial-long cooling is not affected by latitude, seasonal sensitivity, or detrending method. Caution is advised when using multi-proxy approaches to reconstruct long-term temperature changes over the entire Common Era.

scholarly journals Evidence of premeiotic control of chromosome pairing in Triticum aestivum

1972 ◽  
Vol 20 (2) ◽  
pp. 201-212 ◽  
Author(s):  
M. W. Bayliss ◽  
Ralph Riley
Keyword(s):  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Sequential Sampling ◽  
Chiasma Formation ◽  
Temperature Sensitive ◽  
Final Temperature ◽  
Similar Time ◽  
Temperature Changes ◽  
Critical Range ◽  
Sensitive Stage

SUMMARYA genotype of wheat deficient for a pair of chromosomes stabilizing chiasma frequency against extremes of temperature was investigated to determine the position and duration of temperature sensitivity with respect to first metaphase of meiosis. Temperature changes over a critical range, followed by sequential sampling and measurement of chiasma frequency, showed a relatively short temperature-sensitive stage, the position and duration of which were dependent on the final temperature used. Comparison with meiotic timings made independently showed that the temperature-sensitive stage occurred in the premeiotic interphase. Euploid wheat was shown to have a stage in chiasma formation sensitive to high-temperature treatments at a similar time.Comparison with the work of others showed that the sensitive stage lay between the last premeiotic mitosis and the start of DNA synthesis. This modification of chromosome pairing at a much earlier stage than has been previously demonstrated is further evidence that the processes of chromosome pairing and crossing-over are probably more complex than formerly envisaged.

scholarly journals Coupling between fast and slow oscillator circuits in Cancer borealis is temperature-compensated

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Daniel Powell ◽  
Sara A Haddad ◽  
Srinivas Gorur-Shandilya ◽  
Eve Marder
Keyword(s):  
Integer Number ◽  
Temperature Sensitive ◽  
Gastric Mill ◽  
Temperature Dependent ◽  
Cancer Borealis ◽  
Cycle Frequency ◽  
Temperature Changes ◽  
Wide Range ◽  
Similar Temperature ◽  
Increasing Temperature

Coupled oscillatory circuits are ubiquitous in nervous systems. Given that most biological processes are temperature-sensitive, it is remarkable that the neuronal circuits of poikilothermic animals can maintain coupling across a wide range of temperatures. Within the stomatogastric ganglion (STG) of the crab, Cancer borealis, the fast pyloric rhythm (~1 Hz) and the slow gastric mill rhythm (~0.1 Hz) are precisely coordinated at ~11°C such that there is an integer number of pyloric cycles per gastric mill cycle (integer coupling). Upon increasing temperature from 7°C to 23°C, both oscillators showed similar temperature-dependent increases in cycle frequency, and integer coupling between the circuits was conserved. Thus, although both rhythms show temperature-dependent changes in rhythm frequency, the processes that couple these circuits maintain their coordination over a wide range of temperatures. Such robustness to temperature changes could be part of a toolbox of processes that enables neural circuits to maintain function despite global perturbations.

scholarly journals Energetically Defining the Thermal Limits of the Snow Crab

1989 ◽  
Vol 145 (1) ◽  
pp. 371-393 ◽  
Author(s):  
TIMOTHY P. FOYLE ◽  
RONALD K. O'DOR ◽  
ROBERT W. ELNER
Keyword(s):  
Food Consumption ◽  
Cold Water ◽  
Caloric Intake ◽  
Oxygen Demand ◽  
Energy Budgets ◽  
Snow Crab ◽  
Temperature Sensitive ◽  
Growth Equation ◽  
Temperature Changes ◽  
Lactate Levels

The snow crab, Chionoecetes opilio, is a cold-water species found naturally at temperatures below 5°C. Its physiology and energetics were examined to understand the metabolic limitations that restrict the snow crab to these temperatures. The species is not confined to cold water because of a limited respiratory system. Routine oxygen demand can be met even at lethal temperatures of 18°C (56 mg O2kg−1h−1, with a Q10 of 2.2). Blood lactate levels remain below 1.5 mmol l−1 and actually decline slightly with temperature. Energy budgets, which were constructed from an examination of oxygen uptake, activity and food consumption in morphometrically mature male animals between 0 and 18°C, indicate that the snow crab is energetically restricted to cold water. Rising metabolic costs overtake caloric intake around 7°C. This is probably due to digestive metabolism which is temperature-sensitive. Food consumption increases up to 6°C but then falls. Crabs stop feeding above 12°C. Although the growth equation is positive between 1 and 7°C, it becomes slightly negative below 1°C. This observation is unexpected since snow crabs are commonly found between 0 and 1°C. Slight temperature changes in the natural environment may, therefore, regulate growth and reproduction in this species.

INVITATION PAPER: BEHAVIOR IN DROSOPHILA MELANOGASTER A GENETICIST'S VIEW

1974 ◽  
Vol 16 (4) ◽  
pp. 713-735 ◽  
Author(s):  
David T. Suzuki
Keyword(s):  
Drosophila Melanogaster ◽  
Sodium Channel ◽  
Temperature Sensitivity ◽  
Temperature Sensitive ◽  
Neuronal System ◽  
Neurological Development ◽  
Temperature Changes ◽  
Early Embryos ◽  
Induced Changes

In screening Drosophila melanogaster for mutations which cause paralysis at 29cC and recovery of mobility at 22cC, 11 temperature-sensitive (ts) mutants were detected among 1.35 × 106 flies screened. These mutations fell into 3 loci, paralytic (parats), shibire (shits) and stoned (stnts). All three loci affect neurological development. The best explanation for parats appears to be an effect on the inhibitory neuronal system. The shi alleles affect an array of developmental events from early embryos to adults. The pattern of heat-induced changes in shits1 electroretinograms (ERG) is consistent with a ts membranal defect. This is supported by a ts resistance of shits flies to tetrodotoxin which specifically blocks the sodium channel of nerves.The final locus, stn, causes sensitivity to the trauma of temperature changes. A jump response observed when a light is turned off is related to a large "offtransient" in ERGs which is correlated with a simultaneous muscle spike. The property of temperature-sensitivity allows greater analytic powers in the study of neurological mutants.

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