Large Temperature Increase Research Articles

A systematic review of the role of heat therapy for patients with intermittent claudication due to peripheral artery disease.

Intermittent claudication (IC) is associated with impairments in quality of life and walking ability. Heat therapy is an emerging cardiovascular therapy, which may improve walking in patients with IC. We undertook a systematic review to establish current evidence for heat therapy for patients with IC. We searched five databases (Ovid Medline / PubMed, Embase, Scopus / Web of Science, Cochrane Library and Health Technology Assessment Databases). A total of 6751 records were screened with 76 full-text articles assessed for eligibility. We included three randomised control trials and three acute interventions. For chronic interventions, three different heat therapy interventions were used. The 6-minute walk distance significantly improved following whole-body immersion (p = 0.03; ES 0.94, 95% CI: 0.06–1.82), but not after Waon therapy or a water-perfused garment. Ankle–brachial pressure indices were significantly improved following whole-body immersion (p = 0.01; ES 1.10, 95% CI: 0.20–1.99) but not after other therapies. No form of heat therapy demonstrated statistical improvements in quality of life or brachial blood pressure. Acute interventions were characterised by large increases in limb blood flow and core temperature, and transient reductions in blood pressure post-heating. At present there are only three randomised controlled trials assessing heat therapy for patients with IC. Moreover, each of those randomised controlled trials utilised different heat therapies. There is also very limited study of the acute physiological responses to different heat therapy interventions in these populations. Future research should establish appropriate heat therapy protocols and implement more randomised trials to understand its effectiveness. PROSPERO: CRD42020187941

Near-infrared light-controllable bufalin delivery from a black phosphorus-hybrid supramolecular hydrogel for synergistic photothermal-chemo tumor therapy

Bufalin is efficacious in treating various tumors, however, the clinical application of which is restricted by the myocardial toxicity. Developing a smart synergetic delivery system is widely considered as a promising therapeutic strategy. To address this issue, a black phosphorus hybrid polypeptides hydrogel was designed to highly load bufalin, and achieved near-infrared (NIR)-controllable drug release with synergistic photothermal-chemo therapeutic effect. Black phosphorus nanosheets (BPNSs) and bufalin were co-loaded in temperature-sensitive supramolecular hydrogel to receive smart hybridization (BP-bufalin@SH). With NIR irradiation (1 W·cm−2), BP-bufalin@SH exhibited a rapid and large temperature increase and released bufalin via light-controllable manner, with which the side effects of bufalin were greatly decreased. Combined with photothermal-chemo therapeutic effect, BP-bufalin@SH could collapse the mitochondrial transmembrane potential resulting in the irreversible apoptosis of tumor cells, and realize a highly efficient in vivo tumor elimination with good biosafety and biocompatibility. This work provides a new hydrogel platform for controlling bufalin release, and thus further promotes the practical application on antitumor therapy.

The Influence of the Drawing Process on the Mechanical Properties of TRIP Steel Wires with 0.4% C Content.

In the work, the results of the research concerned with the TRIP (Transformation Induced Plasticity) steel wire drawing process in experimental and theoretical ways are shown. The wire drawing process tests on the experimental way were conducted in both laboratories as well as industrial conditions, with the use of two drawing speeds (1.6 and 6 m/s) and two drawing schemes (low and high single reductions). The mechanical properties of wires drawn with high drawing speed equal to 6 m/s showed higher values of mechanical properties for wires drawn with low single reductions than for wires drawn with high single reductions. Such a phenomenon contradicts the theory of drawing wires from steel with a ferritic-pearlitic structure and must be related to TRIP structure and the presence of retained austenite in it, which is transformed into martensite during the deformation process. In order to explain this phenomenon, the theoretical wire drawing process analysis was conducted with the use of the Drawing 2D program based on the finite element method. On the base of the simulation, a large increase in temperature was found on the surface for wires drawn with high drawing speed and low single reductions, which can cause the blocking of transformation retained austenite into martensite and thus a decrease in Rm. To confirm this thesis, further studies will include tests of the amount of retained austenite in wires obtained during experimental tests.

Future Crop Yield Projections Using a Multi-model Set of Regional Climate Models and a Plausible Adaptation Practice in the Southeast United States

Since maize, peanut, and cotton are economically valuable crops in the southeast United States, their yield amount changes in a future climate are attention-grabbing statistics demanded by associated stakeholders and policymakers. The Crop System Modeling—Decision Support System for Agrotechnology Transfer (CSM-DSSAT) models of maize, peanut, and cotton are, respectively, driven by the North American Regional Climate Change Assessment Program (NARCCAP) Phase II regional climate models to estimate current (1971–2000) and future (2041–2070) crop yield amounts. In particular, the future weather/climate data are based on the Special Report on Emission Scenarios (SRES) A2 emissions scenario. The NARCCAP realizations show on average that there will be large temperature increases (~2.7 °C) and minor rainfall decreases (~−0.10 mm/day) with pattern shifts in the southeast United States. With these future climate projections, the overall future crop yield amounts appear to be reduced under rainfed conditions. A better estimate of future crop yield amounts might be achievable by utilizing the so-called weighted ensemble method. It is proposed that the reduced crop yield amounts in the future could be mitigated by altering the currently adopted local planting dates without any irrigation support.

Unusual relationship between extrusion temperature and tensile strength of extruded Mg–Al–Zn–Ca–Y–MM alloy

This study investigates the effects of extrusion temperature on the microstructural characteristics and mechanical properties of an extruded Mg–9Al–0.8Zn–0.9Ca–0.6Y–0.5MM (AZXWMM91100) alloy and the resulting unusual relationship between the extrusion temperature and the tensile strength of the extruded material. All the extruded materials, i.e., alloy samples extruded at 325 °C, 350 °C, and 400 °C, have a fully recrystallized grain structure and contain abundant undissolved Al8Mn4Y, Al2Ca, and Al2Y particles. A small number of spherical nanosized Mg17Al12 precipitates are formed during extrusion, and their number density decreases with increasing extrusion temperature. The undissolved-particle bands, which are distributed parallel to the extrusion direction, act as obstacles to the growth of recrystallized grains during and after extrusion, which prevents excessive coarsening of grains at high extrusion temperatures. As a result, despite a large increase in the extrusion temperature from 325 °C to 400 °C, the average grain size of the extruded material increases only slightly, from 17.6 µm to 23.0 µm. Concurrently, the tensile strength of the extruded material increases from 183 MPa to 224 MPa; this directly proportional relationship between temperature and strength contrasts with the general inverse relationship between extrusion temperature and tensile strength. An increase in the extrusion temperature leads to an increase in the texture intensity of the extruded material; this increase is attributed to the following phenomena: (i) transition of the dominant dynamic recrystallization (DRX) mechanism from twinning-induced DRX and continuous DRX to discontinuous DRX, (ii) weakening of DRX through particle-stimulated nucleation, and (iii) promotion of the activation of prismatic slip. Therefore, the unusual extrusion temperature–tensile strength relationship for the AZXWMM91100 alloy is a combined result of the grain coarsening suppressed by the undissolved particles and strengthening of the texture hardening effect with the variation in the DRX behavior during extrusion.

Understanding global spatio-temporal trends and the relationship between vegetation greenness and climate factors by land cover during 1982–2014

Analysis of the correlation between vegetation greenness and climate variable trends is important in the study of vegetation greenness. Our study used Normalized Difference Vegetation Index-3rd generation data from the Advanced Very High-Resolution Radiometer - Global Inventory Modeling and Mapping Studies (AVHRR-GIMMS NDVI3g), land cover data from the Climate Change Initiative (CCI-LC), and climate data from the Climatic Research Unit global time series (CRU TS) of climate variables (temperature and precipitation, solar radiation) over the past 33 years. First, we estimated the overall trends for vegetation greenness and climate variables over five time periods. Second, we subjected the data to correlation, regression, and residual analyses to detect correlations between vegetation greenness and different climate variables. Third, we extracted trends and correlation results by primary land cover types for each climate zone. Our study was focused at the global scale, and findings indicate that the largest decreasing trend of vegetation greenness and grasslands occurred in the mid-latitude regions of the Northern Hemisphere and in parts of South America, Africa, Saudi Arabia, and south and northeast Asia. In particular, the cold climatic zones of forest (36.6%), cropland (36.6%), and grassland (14.1%) suffered significant decline in vegetation greenness. Anthropogenic activities are mainly responsible for declining vegetation greenness particularly in northern Africa, central and western Asia. However, residual analysis shows an increase in vegetation greenness in some parts of western Europe, southern Australia, and the northern part of South America. The study also identified temperature and precipitation as the main factors responsible for controlling vegetation growth. Hot-spot areas with the largest temperature increases were found in the Amazon, Central America, southern Greenland, east Africa, south-east Asia, and other areas. However, temperatures decreased in the western part of South America, Angola, the Philippines, Indonesia, and Papua New Guinea. Precipitation decreased the most from March to May over most parts of the world with high correlation (r = 0.88) in Russia Canada, northeast Asia, and central Africa. In general, climate factors were the principal drivers of the variation in vegetation greenness globally in recent years.

Temperature Elevation in an Instrumented Phantom Insonated by B-Mode Imaging, Pulse Doppler and Shear Wave Elastography

Diagnostic ultrasound is the gold standard for obstetric scanning and one of the most important imaging techniques for perinatal and neonatal monitoring and diagnosis. Ultrasound provides detailed real-time anatomic information, including blood flow measurements and tissue elasticity. The latter is provided through various techniques including shear wave elastography (SWE). SWE is increasingly used in many areas of medicine, especially in detection and diagnosis of breast, thyroid and prostate cancers and liver disease. More recently, SWE has found application in gynaecology and obstetrics. This method mimics manual palpation, revealing the elastic properties of soft biological tissues. Despite its rising potential and expanding clinical interest in its use in obstetrics and gynaecology (such as for assessment of cervical ripening or organ development and structure during pregnancy), its effects on and potential risks to the developing fetus remain unknown. Risks should be evaluated by regulatory bodies before recommendations are made on the use of SWE. Because ultrasound is known to produce thermal and mechanical effects, this study measured the temperature increase caused by B-mode, pulse Doppler (PD) and SWE, using an instrumented phantom with 11 embedded thermocouples. Experiments were performed with an Aixplorer diagnostic ultrasound system (Supersonic Imagine, Aix-en-Provence, France). As expected, the greatest heating was detected by the thermocouple closest to the surface in contact with the transducer (2.9°C for SWE, 1.2°C for PD, 0.7°C for B-mode after 380-s excitation). Both conduction from the transducer face and direct heating owing to ultrasound waves contribute to temperature increase in the phantom with SWE associated with a larger temperature increase than PD and B-mode. This article offers a methodological approach and reference data for future safety studies, as well as initial recommendations about SWE safety in obstetrics and gynaecology.

Thermal metamorphic history of Antarctic CV3 and CO3 chondrites inferred from the first- and second-order Raman peaks of polyaromatic organic carbon

AbstractParent body thermal metamorphism is an important process that alters the structure of organic matter in the parent asteroid of meteorites. Increasing and progressing thermal metamorphism results in carbonization and graphitization of carbonaceous matter in the parent body. Such modifications in the carbon structures can be studied by Raman microspectroscopy, thanks to its high sensitivity to structure and bonding within carbonaceous molecules. We have characterized polyaromatic carbonaceous matter in a total of 24 Antarctic CV3 and CO3 chondrites using micro-Raman imaging spectroscopy in an effort to better understand parent body thermal metamorphism and assess its effects on the carbon structures. Raman spectral parameters of the first-order carbon peaks (D and G) were extracted from at least 200 spectra for each meteorite and were compared to deduce relationships that yield information regarding the thermal metamorphism conditions. We also show, for the first time, spectral trends and relations of the second-order carbon peaks (2D and D+G) within the 2500–3200 cm−1 with thermal metamorphic history. The second-order peaks appear to contain information that is lacking in the first-order peaks. Based on the second-order carbon peak parameters, we tentatively classify four CV3 chondrites into subtypes, and reclassify another. Peak metamorphic temperatures of the investigated meteorites have been estimated based on the width of the D band as well as the calculated Raman spectral curvature. Estimated temperatures appear to correlate well with the assigned petrologic types. We have calculated higher peak metamorphic temperatures for the CV3 chondrites than for the considered CO3 chondrites and further showed that the peak metamorphic temperatures of CV3oxA chondrites are higher than those of CV3oxB, indicating possibly different metamorphic conditions for the two oxidized subtypes. We observe that there is a relatively larger temperature increase going from CO3.2 to CO3.4 (150 °C increase) compared to CO3.4–CO3.6 (20 °C), which may indicate that the graphitization and structural ordering of carbon reach a critical temperature regime around petrologic type CO3.3.

Recent trends in atmospheric evaporative demand in Southwest Iran: implications for change in drought severity

This study evaluates trends in climatic variables, atmospheric evaporative demand (AED) and meteorological drought between 1988 and 2018 over the southwest of Iran, where the Karkheh Basin is located. For this purpose, we used monthly time series of meteorological variables (precipitation, air temperature, wind speed and sunshine duration). The AED was estimated by the FAO-56 Penman-Monteith equation and drought severity by the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). There have been significant changes in the climate over the study domain, including a large increase in air temperature and wind speed and a decrease in relative humidity, which have driven a positive trend in the AED. The SPEI for the region has fallen, with the decrease being larger than the magnitude of change observed with the SPI. This suggests an increase in drought severity mostly associated with the rise in AED. The implications for water availability and climate change processes in the region are discussed.

Study on the effect of laser-assisted machining on tool wear based on molecular dynamics simulation

During the nanometric cutting of single crystal silicon, the wear of the diamond tool is rapid. Despite laser-assisted machining (LAM) has been used to mitigate tool wear, the specific mechanism is not clear. In this paper, molecular dynamics simulations have been successfully used to explain the effect of LAM on tool wear. The long-range carbon bond order potential (LCBOP) is used to describe the interaction of atoms in the diamond tool. The simulation results show that it has the ability to accurately simulate the graphitization of diamond. LAM enhances ductile response of silicon and reduces the cutting force. But only at the appropriate laser power, LAM will inhibit the formation of silicon carbide and mitigate tool wear. The effect of laser power on the tool rake face and clearance face is different. When the laser power is about 50 eV/ps, the wear of tool clearance face is significantly suppressed, which is attributed to the reduction of frictional resistance. When the laser power is about 150 eV/ps, the reduction in cutting forces and silicon carbide results in smaller tool wear of the rake face. At other laser powers, a large increase in chip temperature may promote tool wear to some extent. Therefore, proper laser power is necessary during LAM.

Projections of Precipitation and Temperature over the South Asian Countries in CMIP6

The latest Coupled Model Intercomparison Project phase 6 (CMIP6) dataset was analyzed to examine the projected changes in temperature and precipitation over six South Asian countries during the twenty-first century. The CMIP6 model simulations reveal biases in annual mean temperature and precipitation over South Asia in the present climate. In the historical period, the median of the CMIP6 model ensemble systematically underestimates the annual mean temperature for all the South Asian countries, while a mixed behavior is shown in the case of precipitation. In the future climate, the CMIP6 models display higher sensitivity to greenhouse gas emissions over South Asia compared with the CMIP5 models. The multimodel ensemble from 27 CMIP6 models projects a continuous increase in the annual mean temperature over South Asia during the twenty-first century under three future scenarios. The projected temperature shows a large increase (over 6 °C under SSP5-8.5 scenario) over the northwestern parts of South Asia, comprising the complex Karakorum and Himalayan mountain ranges. Any large increase in the mean temperature over this region will most likely result in a faster rate of glacier melting. By the end of the twenty-first century, the annual mean temperature (uncertainty range) over South Asia is projected to increase by 1.2 (0.7–2.1) °C, 2.1 (1.5–3.3) °C, and 4.3 (3.2–6.6) °C under the SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios, respectively, relative to the present (1995–2014) climate. The warming over South Asia is also continuous on the seasonal time scale. The CMIP6 models projected higher warming in the winter season than in the summer over South Asia, which if verified will have repercussions for snow/ice accumulations as well as winter cropping patterns. The annual mean precipitation is also projected to increase over South Asia during the twenty-first century under all scenarios. The rate of change in the projected annual mean precipitation varies considerably between the South Asian countries. By the end of the twenty-first century, the country-averaged annual mean precipitation (uncertainty range) is projected to increase by 17.1 (2.2–49.1)% in Bangladesh, 18.9 (−4.9 to 72)% in Bhutan, 27.3 (5.3–160.5)% in India, 19.5 (−5.9 to 95.6)% in Nepal, 26.4 (6.4–159.7)% in Pakistan, and 25.1 (−8.5 to 61.0)% in Sri Lanka under the SSP5-8.5 scenario. The seasonal precipitation projections also shows large variability. The projected winter precipitation reveals a robust increase over the western Himalayas, with a corresponding decrease over the eastern Himalayas. On the other hand, the summer precipitation shows a robust increase over most of the South Asia region, with the largest increase over the arid region of southern Pakistan and adjacent areas of India, under the high-emission scenario. The results presented in this study give detailed insights into CMIP6 model performance over the South Asia region, which could be extended further to develop adaptation strategies, and may act as a guideline document for climate change related policymaking in the region.

Timing alters how a heat shock affects a host-parasitoid interaction.

Abiotic factors' effects on species are now well-studied, yet they are still often difficult to predict, especially for strongly interacting species. If these altered abiotic factors and species interactions occur as discrete events in time, such complications may occur because of the events' relative timing. One such discrete abiotic factor is the short-duration, large magnitude increase in temperature called a heat shock. This study investigates how the timing of heat shocks affects the successful attack and reproduction of a parasitoid wasp (Aphidius ervi) attacking its host, the pea aphid (Acyrthosiphon pisum). We tested three relative timings: 1) heat shock before the wasp attacks hosts, 2) heat shock while the wasp is foraging, and 3) heat shock after the wasp has attacked hosts. In each scenario we compared wasp mummy production (pupal stage) with and without a heat shock. Our results showed that a heat shock had the largest effect when it occurred while wasps actively foraged, with fewer mummies produced when exposed to a heat shock compared to the no heat shock control. Follow-up behavioral tests suggest this was caused by wasps becoming inactive during heat shocks. In contrast, when heat shocks were applied three days before or after foraging, we found no difference in mummy production between the heat shock treatment and no heat shock control. These results show the potential importance of timing when considering the ramifications of an altered abiotic factor, especially with relatively discrete abiotic events and interactions.

A basal heat stress test to detect military operational readiness after a 14-day operational heat acclimatization period

ABSTRACT A basal heat stress test (HST) to predict the magnitude of adaptive responses during heat acclimatization (HA) would be highly useful for the armed forces. The aim was to identify physiological markers assessed during a HST (three 8-min running sets at 50% of the speed at VO2max) performed just before a 14-day HA period that would identify participants still at “risk” at the end of HA. Individuals that responded poorly (large increases in rectal temperature [Trec] and heart rate [HR]) during the initial HST were more likely to respond favorably to HA (large reductions in Trec and HR). However, they were also more likely to exhibit lower tolerance to HST at D15. Basal Trec was found to efficiently discriminate participants showing a Trec > 38.5°C after HA, who are considered to be “at risk”. Finally, participants were classified by quartiles based on basal Trec and HR at the end of the HST and physiological strain index (PSI). Most of the participants “at risk” were among the upper quartile (i.e. the least tolerant) of Trec and PSI (p = 0.011 for both). Overall, these results show that the individuals who are less tolerant to a basal HST are very likely to benefit the most from HA but they also remain less tolerant to heat at the end of HA than those who better tolerated the basal HST. A basal HST could therefore theoretically help the command to select the most-ready personnel in hot conditions while retaining those who are less tolerant 6.

Focus on the role of forests and soils in meeting climate change mitigation goals: summary

It is clear that reducing greenhouse gas emissions alone is insufficient to avoid large global temperature increases. To avoid atmospheric concentrations of greenhouse gases that result in dangerous alterations of the climate, large reductions in carbon dioxide emissions from fossil fuel combustion and land use changes must be accompanied by an increase in atmospheric carbon dioxide sequestration. Natural Climate Solutions have become a major focus of climate policy. Land and ocean ecosystems remove and store atmospheric carbon, and forests play a major role. This focus collection includes papers that address three important aspects of the role for forests in meeting climate change mitigation goals: (i) Carbon Accounting of forest sinks and reservoirs, process emissions and carbon storage in forest products, (ii) the carbon dioxide dynamics of using Forest Bioenergy and (iii) the carbon cycle of Tropical Forests.

Detection of subclinical Harlequin syndrome in pediatric patients.

Harlequin syndrome presents as differences in facial coloring due to unilateral flushing. This is the result of the inability to flush on the affected side due to the disruption of vasomotor and sudomotor sympathetic activity. The neurologically intact side appears flushed. A 2°C temperature difference between the flushed and nonflushed sides of the face has been detected in patients presenting with Harlequin syndrome. This difference in temperature might be detectable even in the absence of unilateral flushing, and this subclinical manifestation of the syndrome may occur more often than realized. To measure and compare the difference in the change in temperature on both sides of the face in patients with a thoracic epidural. Fifteen pediatric patients receiving thoracic epidurals for the correction of pectus excavatum via Nuss procedure were enrolled. Temperature measurements on each side of the face were collected at three time points: prior to epidural placement in the holding area, one hour after epidural analgesia had been instituted, and after the patient awakened in the recovery area. The primary outcome is whether or not a temperature difference occurred between the two sides of the face over time. Comparing the pre-op temperature change to post-op temperature change for each side of the face, patient 2 had a large increase in temperature on the left side of the face with a decrease in temperature on the right side of the face. The largest observed difference between the changes in temperature from pre-op to post-op between the right and left sides of the face was 1.85°C in patient 2. This was more than two standard deviations from the mean difference in the patient population. Patient 15 also had a large difference in change in temperature from pre-op to post-op between the right and left sides of the face with an observed difference of 1.14°C, although this was not more than two standard deviations from the mean. None of the patients had unilateral facial flushing. Asymmetric effects or distribution of local anesthetic used in thoracic epidurals may result in asymmetric blockade of efferent sympathetic nervous system activity. This may cause differences in temperature between the two sides of the face without unilateral flushing. This phenomenon has previously been termed subclinical Harlequin syndrome. Subclinical Harlequin syndrome may be more common than anticipated and may be detected by comparing temperature differences in patients.

Draining Over Blocking: Nano-Composite Janus Separators for Mitigating Internal Shorting of Lithium Batteries.

Catastrophic battery failure due to internal short is extremely difficult to detect and mitigate. In order to enable the next-generation lithium-metal batteries, a "fail safe" mechanism for internal short is highly desirable. Here, a novel separator design and approach is introduced to mitigate the effects of an internal short circuit by limiting the self-discharge current to prevent cell temperature rise. A nano-composite Janus separator-with a fully electronically insulating side contacting the anode and a partially electronically conductive (PEC) coating with tunable conductivity contacting the cathode-is implemented to intercept dendrites, control internal short circuit resistance, and slowly drain cell capacity. Galvanostatic cycling experiments demonstrate Li-metal batteries with the Janus separator perform normally before shorting, which then results in a gradual increase of internal self-discharge over >25 cycles due to PEC-mitigated shorting. This is contrasted by a sudden voltage drop and complete failure seen with a single layer separator. Potentiostatic charging abuse tests of Li-metal pouch cells result in dendrites completely penetrating the single-layer separator causing high short circuit current and large cell temperature increase; conversely, negligible current and temperature rise occurs with the Janus separator where post mortem electron microscopy shows the PEC layer successfully intercepts dendrites.

Climate change adaptation strategies of small-scale farmers in Ngamiland East, Botswana

Climate change and variability threaten the sustainability of agricultural and food production, especially in agrarian communities. In Southern Africa, rainfall is expected to decline by almost 10% by the year 2050 and the largest increase in temperature can be experienced. Despite the potential risks of climate change on agricultural productivity, Botswana does not have a dedicated policy to respond to climate change. Furthermore, there is a dearth of research done in Botswana to provide an understanding of factors that shape farmers’ adaptation to climate change and institutional link to the adaptive capacity of farming households. Therefore, the aim of this article is to analyse institutions that influence farmers’ adaptation strategies of farmers in Botswana, using Ngamiland East as a case study. The paper relies on empirical data collected from purposively selected key informants and 300 households. The results show that the majority of farmers who have climate variability adaptation strategies in place are largely influenced by indigenous knowledge. Women and low-income earners are less likely to employ climate change adaptation strategies in order to improve their agricultural productivity. This article gives a better perspective of the strengths, weaknesses, opportunities and threats facing institutions designed to enable agricultural productivity. It recommends that macro-level and local government institutions should acknowledge the indigenous knowledge, community-level institutions and farmers’ adaptive capacity in policy formulation processes.

Effects of Mid‐Infrared Graphene Plasmons on Photothermal Heating

Herein, the plasmonic heating of graphene‐based systems under the mid‐infrared laser irradiation is theoretically investigated, where periodic arrays of graphene plasmonic resonators are placed on dielectric thin films. Optical resonances are sensitive to structural parameters and the number of graphene layers. Under mid‐infrared laser irradiation, the steady‐state temperature gradients are calculated. It is found that graphene plasmons significantly enhance the confinement of electromagnetic fields in the system and lead to a large temperature increase compared with the case without graphene. The correlations between temperature change and the optical power, laser spot, and thermal conductivity of dielectric layer in these systems are discussed. The numerical results are in accordance with experiments.

Analysis of conductive and convective transfers in a double salience switched reluctance machine by analytical coupling-2D finite elements

The work presented in this paper concerns the study of the thermal behavior due to copper losses and iron losses of a switched reluctance machine with double salience (SRM6/4) by analytical coupling - 2D finite elements. Calculation by analytical methods of the conduction coefficients in the radial and axial direction as well as the convection coefficients in the air gap of this machine are presented. The values of these found coefficients are used to solve the transient thermal problem for this device using the ADEMEF2D software. The obtained results show a very large increase in temperature at the winding. Heat conduction in both radial and axial directions has a very large effect on the temperature value in all regions of the SRM6/4.

Evaluating the Impact of Climate Change on Water Quality and Quantity in an Urban Watershed Using an Ensemble Approach

Considerable efforts are underway to restore watersheds and estuaries downstream impacted by urban development; however, climate change (CC) may be undermining them. Current methods are limited in their ability to predict hydrology and water quality with CC and assess its effect on the efficiency of stormwater control measures (SCMs). We developed a method using downscaled global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to project precipitation and temperatures; these were used to force a Storm Water Management Model (SWMM). Three scenarios, a historical and two Representative Concentration Pathways (RCP 4.5 and 8.5) with five GCMs, were used to produce ensemble results. All GCMs in both RCP scenarios projected increases in precipitation and temperature compared to historical conditions. Both RCPs exhibited their largest increases in precipitation, streamflow, total suspended solids (TSS), total nitrogen (TN), and total phosphorous (TP) loads in the winter, summer exhibited the largest increase in temperature. Median loads of TSS, TN, and TP increased 3.1%, 2.5%, and 9.9%, respectively, for RCP 4.5, and increased 3.8%, 3.1%, and 10.4%, respectively, for RCP 8.5. Median reductions in TSS, TN, and TP SCM efficiency for RCP 4.5 were projected to be 6%, 7%, and 11%, respectively; and 11%, 12%, and 17% for RCP 8.5, respectively. Thus, it is likely that additional efforts will be needed to meet water quality goals in the future. Methods such as these can help create climate resilient watershed improvement strategies and guide urban stormwater planning against likely future changes as a result of CC.