Range Of Environmental Temperatures Research Articles

Thermal stability of light transmission on tapered plastic optical fibre coated with PMMA/zircon composites

Abstract A study on thermal stability of light transmission on tapered plastic optical fibre (TPOF) due to PMMA/zircon composites coating has been performed. The zircon filler was obtained from purified local zircon sand. The PMMA/zircon composites were produced utilizing acetone at a temperature of 50°C. The TPOF was subjected to a dip coating procedure to apply composite coatings at varying zircon of 0, 0.5, and 1 wt.%. The characterization of light transmission on coated the TPOF, investigated at an environmental temperature range of 30 to 60°C, was conducted using an optical power meter (OPM) and a spectrometer. Based on the OPM measurements, it is known that the output power of the composite coated TPOF exhibits a high degree of linearity, even when subjected to varying environmental temperatures. The coated composite material also exhibits the capability to withstand wavelength peak shift. Therefore, it can be inferred that the composites could resist fluctuations in external temperatures. To fulfil additional objectives, the composite material can be employed as a protective layer for TPOF applications, particularly while operated at temperatures exceeding the ambient conditions.

The impact of IEQ in the university lecture theatres on students’ concentration levels in London

PurposeUniversity students’ lecture theatre concentration levels are significantly related to indoor environmental quality (IEQ). The purpose of this study is to investigate the relationship between indoor environmental quality (IEQ) and the self-reported concentration levels of university students during the winter at University College London (UCL), UK.Design/methodology/approachA questionnaire survey and physical measurements were used to assess the IEQ factors affecting students’ concentration levels.FindingsThe lecture theatre design factor was the most significant factor influencing students’ concentration levels, and the facility environment was more important than the thermal environment, indoor air quality, and acoustic environment in influencing students’ concentration levels in this winter investigation at UCL, UK. Additionally, students prefer a colder thermal environment. The concentration level of students was positively correlated with the indoor air quality and negatively correlated with the acoustic environment.Practical implicationsBased on model application, this research could provide lecture theatre IEQ design. This research additionally provides an acceptable indoor thermal environment temperature range based on a large sample, which can be used to calibrate a student performance benchmark.Originality/valueAs this study evaluates the IEQ factors that influence the concentration levels of university students, interior designers and engineers should consider the rational layout of these factors. Therefore, this study may provide a reference for the interior environmental design of lecture theatres in educational buildings.

Combinatorial Quantification of Multi-Features of Coda Waves in Temperature-Affected Concrete Beams.

Coda waves are highly sensitive to changes in medium properties and can serve as a tool for structural health monitoring (SHM). However, high sensitivity also makes them susceptible to noise, leading to excessive dispersion of monitoring results. In this paper, a coda wave multi-feature extraction method is proposed, in which three parameters, the time shift, the time stretch, and the amplitude variation of the wave trains within the time window, are totally derived. These three parameters are each mapped to the temperature variations of concrete beams, and then combined together with their optimal weight coefficients to give a best-fitted temperature-multi-parameter relationship that has the smallest errors. Coda wave signals were collected from an ultrasonic experiment on concrete beams within an environmental temperature range of 14 °C~21 °C to verify the effectiveness of the proposed method. The results indicate that the combination of multi-features derived from coda wave signals to quantify the medium temperature is feasible. Compared to the relationship established by a single parameter, the goodness-of-fit is improved. During identification, the method effectively reduces the dispersion of identification errors and mitigates the impact of noise interference on structural state assessment. Both the identification accuracy and stability are improved by more than 50%, and the order of magnitude of the identification accuracy is improved from 1 °C to 0.1 °C.

CNN-BiLSTM: A Novel Deep Learning Model for Near-Real-Time Daily Wildfire Spread Prediction

Wildfires significantly threaten ecosystems and human lives, necessitating effective prediction models for the management of this destructive phenomenon. This study integrates Convolutional Neural Network (CNN) and Bidirectional Long Short-Term Memory (BiLSTM) modules to develop a novel deep learning model called CNN-BiLSTM for near-real-time wildfire spread prediction to capture spatial and temporal patterns. This study uses the Visible Infrared Imaging Radiometer Suite (VIIRS) active fire product and a wide range of environmental variables, including topography, land cover, temperature, NDVI, wind informaiton, precipitation, soil moisture, and runoff to train the CNN-BiLSTM model. A comprehensive exploration of parameter configurations and settings was conducted to optimize the model’s performance. The evaluation results and their comparison with benchmark models, such as a Long Short-Term Memory (LSTM) and CNN-LSTM models, demonstrate the effectiveness of the CNN-BiLSTM model with IoU of F1 Score of 0.58 and 0.73 for validation and training sets, respectively. This innovative approach offers a promising avenue for enhancing wildfire management efforts through its capacity for near-real-time prediction, marking a significant step forward in mitigating the impact of wildfires.

The kainate receptor GluK2 mediates cold sensing in mice.

Thermosensors expressed in peripheral somatosensory neurons sense a wide range of environmental temperatures. While thermosensors detecting cool, warm and hot temperatures have all been extensively characterized, little is known about those sensing cold temperatures. Though several candidate cold sensors have been proposed, none has been demonstrated to mediate cold sensing in somatosensory neurons in vivo, leaving a knowledge gap in thermosensation. Here we characterized mice lacking the kainate-type glutamate receptor GluK2, a mammalian homolog of the Caenorhabditis elegans cold sensor GLR-3. While GluK2 knockout mice respond normally to heat and mechanical stimuli, they exhibit a specific deficit in sensing cold but not cool temperatures. Further analysis supports a key role for GluK2 in sensing cold temperatures in somatosensory DRG neurons in the periphery. Our results reveal that GluK2-a glutamate-sensing chemoreceptor mediating synaptic transmission in the central nervous system-is co-opted as a cold-sensing thermoreceptor in the periphery.

Textile‐Based Flexible Temperature Sensors for Wearable and Sports Applications

Flexible textile‐based sensors are versatile alternatives that can be comfortably worn and can detect a broad range of body and environment temperatures. Furthermore, they become more essential due to the recent rise in the use of wearable customized gadgets, wearable clothing, sports, medical, and soft robotics. Typically made from rigid materials like metals or semiconductors, traditional temperature sensors are heavy, inflexible, and difficult to wear since they can only endure very slight variations in their physical shape to be placed on any irregularly shaped object. In this review, developments in textile temperature sensors are discussed with a focus on their performance, fabrication techniques, advances in various materials, and applications, such as wearable monitoring and sports. Moreover, an in‐depth analysis of different performance parameters is also presented. Lastly, to provide useful guidance and directions for future study, it is concluded by outlining the current limitations of this field, and future recommendations for the scientific community to further explore other facets of textile temperature devices.

Single-molecule FRET observes opposing effects of urea and TMAO on structurally similar meso- and thermophilic riboswitch RNAs.

Bacteria live in a broad range of environmental temperatures that require adaptations of their RNA sequences to maintain function. Riboswitches are regulatory RNAs that change conformation upon typically binding metabolite ligands to control bacterial gene expression. The paradigmatic small class-I preQ1 riboswitches from the mesophile Bacillus subtilis (Bsu) and the thermophile Thermoanaerobacter tengcongensis (Tte) adopt similar pseudoknot structures when bound to preQ1. Here, we use UV-melting analysis combined with single-molecule detected chemical denaturation by urea to compare the thermodynamic and kinetic folding properties of the two riboswitches, and the urea-countering effects of trimethylamine N-oxide (TMAO). Our results show that, first, the Tte riboswitch is more thermotolerant than the Bsu riboswitch, despite only subtle sequence differences. Second, using single-molecule FRET, we find that urea destabilizes the folded pseudoknot structure of both riboswitches, yet has a lower impact on the unfolding kinetics of the thermodynamically less stable Bsu riboswitch. Third, our analysis shows that TMAO counteracts urea denaturation and promotes folding of both the riboswitches, albeit with a smaller effect on the more stable Tte riboswitch. Together, these findings elucidate how subtle sequence adaptations in a thermophilic bacterium can stabilize a common RNA structure when a new ecological niche is conquered.

Transcriptomic analyses of juvenile Striped Bass (Morone saxatilis) exposed to chronic and acute temperature change.

Striped Bass are economically important, migratory fishes, which occur across a wide range of latitudes. Given their wide-ranging nature, Striped Bass can cope with a broad range of environmental temperatures, yet the mechanisms underlying this ability have not been thoroughly described. Heat shock proteins (HSPs) are inducible molecular chaperones, which help mitigate protein damage resulting from increased temperatures. The importance of HSPs has been demonstrated in a number of fish species, but their role in Striped Bass is poorly understood. This study characterizes changes in gene expression in juvenile Striped Bass, following acute and chronic temperature change. Fish were acclimated to one of three temperatures (15, 25 or 30°C) and sampled at one of two treatments (control or after CTmax), following which we assessed differential gene expression and gene ontology in muscle. It is clear from our differential expression analyses that acclimation to warm temperatures elicits more robust changes to gene expression, compared to acute temperature increases. Our differential expression analyses also revealed induction of many different heat shock proteins, including hsp70, hsp90, hsp40 and other small HSPs, after both acute and chronic temperature increase in white muscle. Furthermore, the most consistent gene ontology pattern that emerged following both acclimation and CTmax was upregulation of transcripts involved in "protein folding", which also include heat shock proteins. Gene ontology analyses also suggest changes to other processes after acclimation, including decreased growth pathways and changes to DNA methylation. Overall, these data suggest that HSPs likely play a major role in the Striped Bass's ability to tolerate warm waters.

Theoretical investigation of the temperature characteristics and output parameters of an industrial crystalline silicon solar cell with a microfluidic cooling system

Operating temperature is a key factor affecting the output power of a crystalline silicon solar cell (c-Si SC). Based on solving basic semiconductor equations, Maxwell equations and heat flow equations by finite difference method, this work has theoretically investigated the influences of microfluidic cooling system on the temperature distributions and output parameters of an industrial c-Si SC packaged as a module form, where the cooling system is installed the interface between the aluminum electrode and back ethylene vinyl acetate layer and the cooling medium flowing through microchannel is selected as water. Under the influences of the cooling system, the back surface temperature of the c-Si SC is fixed at about water temperature and the front surface temperature will decrease with the water temperature decreasing. The temperature distributions of c-Si active layer and aluminum layer decrease approximately linearly along the two layer’s thickness directions. The cooling effects of the cooling system are mainly determined by water temperature and when the filling factor of microchannel is larger than 0.1, its influences on the temperature distribution of the c-Si SC are small. In the environmental temperature range from −15 °C to 60 °C, the increase rates of Voc, FF and η per degree Celsius with the water temperature decreasing are about 0.0014 V, 0.036% and 0.05%, respectively.

The Eco-Immunological Relevance of the Anti-Oxidant Response in Invasive Molluscs.

Reactive oxygen species (ROS) are volatile and short-lived molecules playing important roles in several physiological functions, including immunity and physiological adaptation to unsuitable environmental conditions. In an eco-immunological view, the energetic costs associated with an advantageous metabolic apparatus able to cope with wide changes in environmental parameters, e.g., temperature range, water salinity or drought, could be further balanced by the advantages that this apparatus may also represent in other situations, e.g., during the immune response. This review provides an overview of molluscs included in the IUCN list of the worst invasive species, highlighting how their relevant capacity to manage ROS production during physiologically challenging situations can also be advantageously employed during the immune response. Current evidence suggests that a relevant capacity to buffer ROS action and their damaging consequences is advantageous in the face of both environmental and immunological challenges, and this may represent a trait for potential invasiveness. This should be considered in order to obtain or update information when investigating the potential of the invasiveness of emerging alien species, and also in view of ongoing climate changes.

The Influence of Roost Type and Diet on Energy Expenditure in Bats

Bats spend most of their lives resting, socializing, and raising their young in roosts. Roost conditions may affect the lifetime energy expenditure of bats, and this could, in turn, influence fitness of individuals. Different kinds of roosts impose different microclimatic conditions that can affect the thermal balances of bats that use them. Bats thermoregulate by using both physiological mechanisms (such as changes in conductance) and behavioral responses (huddling or active search of certain microclimates). We hypothesized that the contribution of these thermoregulatory strategies would differ depending on the roost type that bats use. To test this idea, we collated data from the literature on metabolic rate (MR), body temperature (Tb), ambient temperature at which MR and Tb were collected, roost type, and diet for 43 species of bats spanning eleven families. From these data, we calculated, for each species, the wet conductance and the area of the thermoregulatory polygon (TRP) as a proxy for the physiological thermoregulatory capabilities of bats. We found that, after controlling for phylogeny, wet conductance and the area of the TRP were higher in bats that use more exposed roosts than in those bats who use roosts that can buffer environmental conditions. Our results suggest that energy expenditure is similar for all species, but in bats that live in more exposed roosts, the contribution of physiological responses was more important than behavior at the entire range of environmental temperatures, whereas bats in more protected roosts seem to rely more on behavioral responses to thermoregulate. Considering that roosts represent valuable resources, the availability of roosts with the proper microclimatic conditions could determine the patterns of distribution of bat populations.

Alternative CO2-based blends for transcritical refrigeration systems

The extensive use of CO2 in commercial refrigeration system has grown in the last two decade thanks to the development of new components and configurations that allows working in transcritical conditions efficiently. However, using these arrangements increases the cost and complexity of the refrigerating plant, making it challenging to implement them in medium or low-capacity systems. As an alternative, CO2-based binary mixtures report attractive improvements that allow for enhancing the COP of the system by minimising its complexity and maintaining the safety and environmental conditions of CO2. This manuscript analyses five binary mixtures of CO2 with the refrigerants R32, R152a, R1234yf, R1234ze(E) and R1270, determining the optimal mixture composition for maximising the COP of a CO2 transcritical refrigeration plant in a wide range of environmental temperatures (0 to 40°C). Fixing the operating conditions for a medium-temperature application, the binary mixtures of CO2/R32 (81/19% in mass) and CO2/R1270 (92.5/7.5% in mass) reported the best COP enhancements results with increments up to +21.4% and +8.7%, respectively, at high environmental temperatures.

The effect of temperature on haemoglobin-oxygen binding affinity in regionally endothermic and ectothermic sharks.

Haemoglobin (Hb)-O2 binding affinity typically decreases with increasing temperature, but several species of ectothermic and regionally endothermic fishes exhibit reduced Hb thermal-sensitivity. Regionally endothermic sharks, including the common thresher shark (Alopias vulpinus) and lamnid sharks such as the shortfin mako shark (Isurus oxyrinchus), can maintain select tissues and organs warmer than ambient temperature by retaining metabolic heat with vascular heat exchangers. In the ectothermic bigeye thresher shark (Alopias superciliosus), diurnal movements above and below the thermocline subject the tissues, including the blood, to a wide range of operating temperatures. Therefore, blood-O2 transport must occur across internal temperature gradients in regionally endothermic species, and over the range of environmental temperatures encountered by the ectothermic bigeye thresher shark. While previous studies have shown temperature-independent Hb-O2 affinity in lamnid sharks, including shortfin mako, the Hb-O2 affinity of the common and bigeye thresher sharks is unknown. Therefore, we examined the effect of temperature on whole blood Hb-O2 affinity in common thresher shark and bigeye thresher shark. For comparison, analyses were also conducted on the shortfin mako shark and two ectothermic species, blue shark (Prionace glauca) and spiny dogfish (Squalus acanthias). Blood-O2 binding affinity was temperature-independent for common thresher shark and shortfin mako shark, which should prevent internal temperature gradients from negatively affecting blood-O2 transport. Blue shark and spiny dogfish blood-O2 affinity decreased with increasing temperature, as expected, but bigeye thresher shark blood exhibited both a reduced temperature-dependence and a high Hb-O2 affinity, which likely prevents large changes in environment temperature and low environmental oxygen from affecting O2 uptake.

Early detection of cold stress to prevent hypothermia: A narrative review.

Temperature monitoring is essential for assessing neonates and providing appropriate neonatal thermal care. Thermoneutrality is defined as the environmental temperature range within which the oxygen and metabolic consumptions are minimum to maintain normal body temperature. When neonates are in an environment below thermoneutral temperature, they respond by vasoconstriction to minimise heat losses, followed by a rise in metabolic rate to increase heat production. This condition, physiologically termed cold stress, usually occurs before hypothermia. In addition to standard axillary or rectal temperature monitoring by a thermometer, cold stress can be detected by monitoring peripheral hand or foot temperature, even by hand-touch. However, this simple method remains undervalued and generally recommended only as a second and lesser choice in clinical practice. This review presents the concepts of thermoneutrality and cold stress and highlights the importance of early detection of cold stress before hypothermia occurs. The authors suggest systematic clinical determination of hand and foot temperatures by hand-touch for early detection of physiological cold stress, in addition to monitoring core temperature for detection of established hypothermia, particularly in low-resource settings.

Theoretical prediction of temperature difference between prefrontal cortex and forehead skin for fever screening

To improve reliability of fever screening, many studies have been conducted on the relationship between forehead skin and core temperatures. However, all studies thus far were based on only statistical analyses of temperature data, and it remains unsolved how forehead skin temperature is determined and controlled by environmental temperature as well as face details of individual. This study examined heat transfer in a free convection thermal boundary layer on the human forehead theoretically and experimentally to propose a theoretical model describing the relationship between prefrontal cortex (PFC) and forehead skin temperatures. Temperature distributions across the forehead boundary layer measured using a resistance thermometer probe showed that the convective heat flux on the forehead, including the case of wearing face mask, could be estimated similarly to that in a laminar free convection boundary layer on a heated vertical plate. It was also shown that the difference between PFC and forehead skin temperatures measured using a zero-heat-flux core-temperature monitoring probe and a thermocouple attached to the forehead was well represented by a simple formula derived from analyses of radiative and convective heat fluxes over a normal range of environmental temperature. Wearing a face mask little affected the temperature difference between PFC and forehead skin. These results provide a scientific basis for fever screening from thermo- and fluid-dynamics viewpoints.

Phylogeny and Morphology Determine Vulnerability to Global Warming in Pristimantis Frogs

Global warming is a great threat to biodiversity with negative impacts spanning the entire biological hierarchy. One of the main species’ traits determining survival at higher temperature is the thermal point at which an animal loses its ability to escape from deadly conditions (critical thermal maximum—CTmax). Variation in CTmax across species is the outcome of environmental and evolutionary factors, but studies do not typically measure the degree to which environment or phylogeny influences the variation in trait values. Here, we aim to elucidate whether local environmental variables or phylogeny influence CTmax in highly climate change-threatened amphibians in the Tropical Andes. We measured CTmax from 204 individuals belonging to seven Pristimantis frog species encountered in primary and secondary forests, and cattle pastures. We recorded their habitat, elevation, and the range of environmental temperatures they experienced over one year. Using phylogenetic analyses, we demonstrate that physiological thermal tolerance is related to phylogeny, positively related to body length, but not affected by environmental factors. We suggest that both phylogeny and morphology determine vulnerability to global warming.

Genome size does not influence extinction risk in the world's amphibians

AbstractVariation in genome size spans multiple orders of magnitude among animals. Despite the longstanding debate regarding the adaptive value or costs of genomic complexity, genome size has been proposed to influence extinction risk under the rapidly changing environments of the Anthropocene.The main hypothesis suggests that genome enlargement increases the accumulation of deleterious mutations while reducing rates of organismal growth and development. These combined effects of larger genome size are predicted to trigger population declines that can lead to extinction, especially under rapidly changing environments that disrupt demographic resilience.Comparative evidence from terrestrial plants and across vertebrates has provided mixed support for this hypothesis. However, large‐scale comparative studies based on explicit phylogenetic approaches remain lacking. Using a global‐scale amphibian dataset and two recognised proxies of extinction risk (International Union for Conservation of Nature IUCN conservation categories and population trends), we test the prediction that genomes are larger (as estimated by C‐value) in species facing extinction risk. We combine these analyses with life‐history traits widely known to be implicated with extinctions (body size, fecundity), along with a range of environmental factors.Our phylogenetic analyses consistently failed to identify an effect of genome size on either of the two proxies for extinction risk. The only consistent predictor of extinction risk observed across models performed for amphibians combined and for orders separately was decreasing geographical range size. We also identified a role for larger body size, decreasing range of environmental temperature (for anurans) and increasing levels of UV‐B radiation (for salamanders) as drivers of increasing threat.Our study provides no support for the prediction that species with larger genomes suffer heightened risk of extinction. We discuss some fundamental limitations underlying the genome size‐extinction hypothesis, and suggest that it is not a promising avenue to elucidate the causes of biodiversity declines in the Anthropocene.Read the freePlain Language Summaryfor this article on the Journal blog.

Influence of Season and Food Type on Bacterial and Entero-Toxigenic Prevalence of Staphylococcus aureus.

Staphylococcus (S.) aureus is a coagulase-positive pathogen of interest for human health and food safety in particular. It can survive in a wide environmental temperature range (7–48 °C, optimum 37 °C). Its enterotoxins are thermostable, which increases the risk of potential contamination in a variety of food products. Here we investigated the influence of seasonality and food type on bacterial count and presence of S. aureus enterotoxins. To do this, we analyzed 3604 food samples collected over a 5-year period (2016–2020). Ordinal logistic regression showed an influence of both seasonality and food type on the bacterial count. Regarding bacterial counts, winter was found to be the season with the highest risk, while with regards to enterotoxin production, the highest risk was found in autumn, specifically in October. The risk of contamination with S. aureus was greatest for dairy products. Our findings may inform food epidemiologists about foodborne illness prevention and risk to human health.

The effect of temperature change on metabolism: separating biological and chemical reactions

Life-detection experiments carried out in extraterrestrial locations provided inconclusive results whether processes observed were biological or chemical. In this study, the typical effect of temperature on metabolic rates is described and a life-detection method that is easy to perform is proposed. The method comprises observing changes in microbial metabolic rates after temperature shift. The method was demonstrated by experiments on aquatic microorganisms in the Gulf of Gdansk (Baltic Sea). First experiment, in which temperature was shifted within the temperature range encountered at the sampling site, demonstrated a typical Q10 coefficient (2.84). The experiment in which temperature was shifted beyond the environmental temperature range provided an unexpectedly low Q10 coefficient (1.44), which indicated that excessive temperature exerted an inhibitory effect on metabolism. This response is not expected for chemical reactions, but it is typical for biological processes. In summary, a pair of properly-tailored experiments permitted separating biological and chemical reactions.

Temperature-tolerant flexible supercapacitor integrated with a strain sensor using an organohydrogel for wearable electronics

Due to the increased demand for wearable devices, there has been extensive research on flexible energy storage devices (e.g., batteries and supercapacitors) and bio-signal monitoring sensors. For the practical application of wearable devices, stable operation regardless of the environmental temperature is required. In this study, we report a temperature-tolerant flexible supercapacitor based on a synthesized novel organohydrogel electrolyte designed to power an integrated strain sensor for the monitoring of bio-signals. The fabricated supercapacitor exhibits a remarkable gravimetric capacitance of 123.4F g−1, 147.0F g−1, and 156.2F g−1 at temperatures of − 20 °C, 25 °C, and 80 °C, respectively. After three repetitive cycles shifting from − 20 °C to 80 °C, the initial capacitance is almost fully recovered. In addition, after 1000 cycles of bending deformation, the capacitance remains almost the same, thus verifying the flexibility of the device. A strain sensor fabricated using the same organohydrogel exhibits a change in resistance with stretching deformation, with a gauge factor of 1.77, 1.61, and 1.50 at 25 °C, −20 °C, and 80 °C. By vertically integrating the supercapacitor and strain sensor, various bio-signals, including finger bending and swallowing are successfully detected using the stored energy of the supercapacitor. As a whole, the results highlight the potential of our proposed temperature-tolerant flexible device fabricated based on a single organohydrogel for use in wearable applications that are stable over a wide range of environmental temperatures.