Thermal Window Research Articles

The roles of partial melting of metasomatised mantle, magma mixing at continental crust level and fractionation in calc-alkaline minette genesis, SE Spain

ABSTRACT Detailed textural and compositional study of calc-alkaline lamprophyres and minettes from Zeneta, SE Spain Neogene Volcanic Province (NVP) are used to unravel the magma sources and differentiation processes involved in their formation. The presence of xenocrysts of various origins indicates a hybrid nature involving mantle-derived alkaline lamproitic and continental crust-derived granitic parental magmas. A new U-Th-Pb zircon age of Zeneta minettes allows contextualizing their generation in time and space during regional lamproite magma intrusion and crustal anatexis in the NVP. Interaction and mixing of these compositionally contrasted magmas resulted in the formation of hybrid calc-alkaline lamprophyre minette. This process is reflected by the phases that crystallized from the hybrid magma, particularly phlogopite, and by the whole-rock composition of the less fractionated rocks. The calculated contribution of lamproitic and crustal-derived magma end-members in minette formation are 30–40% and 60–70%, respectively. Mixing of end-member magmas of contrasting rheological properties was possible only in a calculated thermal-window of 1025–1125°C, after cooling of intruding lamproitic magma and heating of host granitic anatectic region. The calculated thermal window fits with the estimated rheological properties of Zeneta minettes and the crystallization temperature of early minette-derived phlogopite. Furthermore, fractional crystallization was identified for the first time in the Zeneta minettes, based on the observed whole-rock line of descent from the less evolved mixed magmas through intermediate to felsic minettes and associated textural and compositional features of late crystallized phases. Polytope Vector Analysis allowed an integrated quantitative characterization of magma differentiation, including magma mixing and subsequent fractional crystallization. The identification of mixing and fractionation processes in calc-alkaline minettes genesis, which otherwise does not show spatial and temporal association in the field with granitic bodies, opens a new scenario to be considered in understanding the petrogenesis of these rocks.

Spatially selective, solid state etching of diamond using lithographically patterned FeCoB

Nanocrystalline layers of FeCoB (Fe:Co:B = 60:20:20 at atom ratio) enable spatially selective, microstructurally agnostic removal of diamond through a solid-state diffusion reaction. Lithographically fabricated 100-300 nm thick films of FeCoB are deposited on polycrystalline diamond substrates. Heat treatment at temperatures ranging from 700 °C–900 °C for 30 min–90 min are used to trigger the conversion of sp3 to sp2 carbon at the diamond-transition metal interface. The integrity of the solid-state etchant within the thermal processing window underpins the spatial selectivity with which the diamond is removed. Removal of the reaction products using solvothermal etching in an acid solution enables the recovery of the structured diamond surfaces. FeCoB offers material removal rates, which exceeds that possible with just Fe or Co – pointing to the key role of B. The interaction zone was excised using focused ion beam milling and characterized using electron microscopy. In addition, XRD and Raman spectroscopy were performed to study the phase composition of the interaction zone. The role of the transition metal-diamond interface is key to controlling the material removal; the stability of the interface determines the ability to faithfully replicate the ultrafine features that were lithographically patterned in the FeCoB.

Experimental Applications and Factors Involved in Validating Thermal Windows Using Infrared Thermography to Assess the Health and Thermostability of Laboratory Animals.

Simple SummaryLaboratory animals are fundamental in biomedical science and monitoring their health and metabolic processes is essential to ensure their welfare and the quality of the research conducted. Infrared thermography (IRT) is a tool that can assess pathological or stressful states by measuring changes in the amount of heat that bodies dissipate. To date, some thermal windows have been utilized to evaluate animals’ thermoregulatory capacity, such as the orbital region, the auricle or ear pavilion region, the tail, and the interscapular zone where brown adipose tissue (BAT) is stored. However, the sensitivity and specificity of these windows are still subject to controversy because the scientific evidence that is available differs regarding the thermal information reported. Therefore, this paper aims to discuss the neurophysiological mechanisms of the vasomotor and thermogenesis responses (using BAT) in laboratory animals, the scientific usefulness of IRT, and the various thermal windows that are currently being used with laboratory animals.Evaluating laboratory animals’ health and thermostability are fundamental components of all experimental designs. Alterations in either one of these parameters have been shown to trigger physiological changes that can compromise the welfare of the species and the replicability and robustness of the results obtained. Due to the nature and complexity of evaluating and managing the species involved in research protocols, non-invasive tools such as infrared thermography (IRT) have been adopted to quantify these parameters without altering them or inducing stress responses in the animals. IRT technology makes it possible to quantify changes in surface temperatures that are derived from alterations in blood flow that can result from inflammatory, stressful, or pathological processes; changes can be measured in diverse regions, called thermal windows, according to their specific characteristics. The principal body regions that were employed for this purpose in laboratory animals were the orbital zone (regio orbitalis), auricular pavilion (regio auricularis), tail (cauda), and the interscapular area (regio scapularis). However, depending on the species and certain external factors, the sensitivity and specificity of these windows are still subject to controversy due to contradictory results published in the available literature. For these reasons, the objectives of the present review are to discuss the neurophysiological mechanisms involved in vasomotor responses and thermogenesis via BAT in laboratory animals and to evaluate the scientific usefulness of IRT and the thermal windows that are currently used in research involving laboratory animals.

Temperature, diffusion, and stress modeling in filament extrusion additive manufacturing of polyetherimide: An examination of the influence of processing parameters and importance of modeling assumptions

Fused filament fabrication (FFF), a form of filament-based material extrusion additive manufacturing (AM), is an extremely useful technique for the rapid production of highly customized products; however, empirical evidence is heavily relied upon for understanding of the process. Initial modeling attempts have traditionally focused on predicting heat transfer and either interlayer diffusion and adhesion or stress development but have not taken a combined approach to analyze all three components simultaneously in a multiphysics model. In this study, we implement finite difference models to examine the combined heat transfer, polymer diffusion represented as degree of healing (Dh), and residual stress development in FFF of poly(ether imide) (PEI). Printing with PEI is of great interest because of its desirable mechanical properties and high use temperatures, but it also creates a more challenging modeling problem with higher thermal gradients and greater potential thermal processing window compared to traditionally modeled AM materials, such as acrylonitrile-butadiene-styrene (ABS) and polylactic acid (PLA). The larger processing window can potentially allow for more processing options but can also significantly complicate the optimization process. In this study, experimental analyses including trouser tear tests and part warpage measurements provide correlation to predicted Dh and stress levels. The models suggest that the temperature of a layer is influenced by the subsequent printing of up to at least three layers in the geometry studied. The results of this study further demonstrate the sensitivity of the molecular mobility and degree of healing to the reptation time (τrep), such that a small change in the τrep on the order of 2–3x can result in an order of magnitude difference in the time before interfacial healing can begin, culminating in significantly less healing occurring. Furthermore, the reptation time and subsequent healing predictions are highly reliant on the extrapolation method used to extend the reptation time to temperatures below those at which it was measured resulting in significantly different predictive results, even if the same experimental data is used.

The thermal tolerance of a tropical population of blue crab (Callinectes sapidus) modulates aerobic metabolism during hypoxia.

The blue crab Callinectes sapidus is a widespread ectothermic species that supports large fisheries. Physiology of temperate and subtropical populations of blue crabs are well studied; however, a lack of information exists on tropical populations. Given the low locomotion capabilities of C. sapidus adult blue crabs, natural selection should favor traits that shape a particular thermal niche reflected through tolerance modulation to dissolved oxygen (DO). This study was designed to evaluate the thermal window and hypoxia sensitivity of the blue crab population in the southern Gulf of Mexico. The effect of acclimation temperatures from 20°C to 34°C on thermal preference (TP), critical thermal limits (CT), and thermal metabolic scope (TMS) was assessed in normoxia. Metabolic rate regulation over oxygen partial pressure (pO2) gradient was evaluated through oxygen consumption measurements at different degrees of acute hypoxia. Callinectes sapidus was observed tending to specialize towards higher temperatures, showing a mean TP from 26°C to 33°C. The lowest performance of aerobic pathways was observed at the coldest regimes and the highest at the warmest ones with mean TMS value being 35 % greater at 34°C than 20°C. Patterns for metabolic regulation were dependent on the interaction between environmental temperature and DO, in which the interval from 29°C to 34°C provoked a 50 % reduction in oxygen consumption when exposed to ∼20% air saturation levels. The results obtained showed that blue crabs distributed in the southern Gulf of Mexico could be close to their oxygen-temperature tolerance limits, which has important implications when climate change effects on species re-distribution is considered.

Application of a Convolutional Neural Network for the Detection of Sea Ice Leads

Despite accounting for a small fraction of the surface area in the Arctic, long and narrow sea ice fractures, known as “leads”, play a critical role in the energy flux between the ocean and atmosphere. As the volume of sea ice in the Arctic has declined over the past few decades, it is increasingly important to monitor the corresponding changes in sea ice leads. A novel approach has been developed using artificial intelligence (AI) to detect sea ice leads using satellite thermal infrared window data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS). In this new approach, a particular type of convolutional neural network, a U-Net, replaces a series of conventional image processing tests from our legacy algorithm. Results show the new approach has a high detection accuracy with F1 Scores on the order of 0.7. Compared to the legacy algorithm, the new algorithm shows improvement, with more true positives, fewer false positives, fewer false negatives, and better agreement between satellite instruments.

The thermoregulatory role of relative bill and leg surface areas in a Mediterranean population of Great tit (Parus major).

There is growing evidence on the role of legs and bill as ‘thermal windows’ in birds coping with heat stress. However, there is a lack of empirical work examining the relationship between the relative bill and/or leg surface areas and key thermoregulatory traits such as the limits of the thermoneutral zone (TNZ) or the cooling efficiency at high temperatures. Here, we explored this relationship in a Mediterranean population of Great tit (Parus major) facing increasing thermal stress in its environment. The lower and upper critical limits of the TNZ were found to be 17.7 ± 1.6ºC and 34.5 ± 0.7°C, respectively, and the basal metabolic rate was 0.96 ± 0.12 ml O2 min−1 on average. The evaporative water loss (EWL) inflection point was established at 31.85 ± 0.27°C and was not significantly different from the value of the upper critical limit. No significant relationship was observed between the relative bill or tarsi size and TNZ critical limits, breadth, mass‐independent VO2, or mass‐independent EWL at any environmental temperature (from 10 to 40°C). However, Great tit males (but not females) with larger tarsi areas (a proxy of leg surface area) showed higher cooling efficiencies at 40°C. We found no support for the hypothesis that the bill surface area plays a significant role as a thermal window in Great tits, but the leg surface areas may play a role in males’ physiological responses to high temperatures. On the one hand, we argue that the studied population occupies habitats with available microclimates and fresh water for drinking during summer, so active heat dissipation by EWL might be favored instead of dry heat loss through the bill surface. Conversely, male dominance behaviors could imply a greater dependence on cutaneous EWL through the upper leg surfaces as a consequence of higher exposure to harsh environmental conditions than faced by females.

Characterizing SOFC Stack Electrochemical Performance at Elevated Pressure

Pressurized operation of high temperature fuel cell stacks is of increasing interest for a variety of applications, including high efficiency, hybrid solid-oxide fuel cell power generation systems. In this presentation, we report on our efforts to characterize the electrochemical performance of 1-kWeand 5-kWe Ceres Power SteelCell solid-oxide fuel cell stacks, with a focus on elevated pressure operation in the range of 2-5 barg. Increased pressure operation requires particular attention to pressure differentials across both the membrane electrode assembly and between the stack and surrounding atmosphere. The effort is part of a five-year U.S. DoE ARPA-E INTEGRATE program to combine the high efficiency of solid-oxide fuel cells with the high efficiency balance-of-plant equipment to demonstrate a 70%-efficient distributed power generator. In this architecture, the highly efficient solid-oxide fuel cells (SOFCs) are placed upstream of an internal combustion engine, where the anode tail gas, consisting of partially converted steam-reformed natural gas, is further utilized by the engine to produce electricity. The stacks are operated between 2-5 barg to maximize overall system efficiency and to increase SOFC power density.Few studies have been reported on SOFC stack operation at elevated pressures. The team at the Colorado School of Mines has designed and operated the pressurized stack test stand shown in the figure to characterize electrochemical performance of various kW-scale SOFC stack test modules developed by Ceres Power, Ltd. Minimizing pressure differentials across the anode and cathode during elevated-pressure operation is of primary concern. Excessive pressure on one side of the cell can cause substantial mechanical stress to the metal-supported membrane-electrode assemblies. Pressure differentials in this work are maintained below the manufacturer’s specifications of +/- 25 mbar at operating pressures of 0-5 barg. In addition to performance measurements at elevated pressures, studies have also been conducted on diluted fuel streams representative of high anode tail-gas recycle and various amounts of internal reforming. The stacks show steady, stable performance over all conditions tested.A fuel feed is produced with mass flow controllers that represents partially, steam-reformed natural gas with anode tail-gas recycle. A natural gas fuel processor will be incorporated into the stand at a later stage of the research program. Reactant gas feeds are preheated in multiple zones to properly control stack temperatures. The insulated stack test module is housed inside of a pressure vessel that has individual pressure control in order to minimize the pressure differentials between the internal flow channels of the stack and the surrounding environment. Exhaust gases exit the pressure vessel where heat exchangers are utilized to partially cool the 600°C gases before reaching back-pressure regulators.Stack operation is challenging because of the combination of a tight thermal operating window and the long system response time to changes in inlet conditions. These time constants become even larger at low air flow rates. Lower air flow (while maintaining required oxygen utilization) is desired in order to reduce the power required by the balance of plant, especially when operating at higher pressures. In order to mitigate this, a model predictive controller is being implemented. A dynamic model of the fuel cell was first tuned and validated against experimental transient response data. Then the resulting model was linearized at multiple operating points. The linearizations were then utilized within a gain-scheduled moving-horizon predictor that can take past input and output data, along with a proposed future input, and predict the future output response. The predictor performance has been validated, and then inserted into a model-predicative controller. Optimization algorithms select the input temperatures, flow rates, and electric current required to quickly reach a desired operating condition while meeting all operational constraints, including thermal constraints.In this talk, we will present our findings on the electrochemical performance of 1 and 5-kWe Ceres Power SteelCell stack test modules and the effects of pressure, fuel composition, anode recycle, and degree of internal reforming on stack performance. Results influence the design and net efficiency of the hybrid system. The trajectory of the research will be discussed. Figure 1

Protic Ionic Liquid Based 3D Printable Ionogels for Applications As Electrolytes

When disregarding the current COVID19 crisis the climate change is one of the most pressing global issues with its well-known challenges concerning the energy economy and climate policy. In this context due to their many benefits, fuel cells and batteries are being discussed as potential applications. These technologies are not without some disadvantages themselves, though. Most polymer electrolyte membrane (PEM) fuel cells work with Nafion®, a sulfonated fluorocopolymer, as their membrane, which loses conductivity at higher temperatures due to dehydration, which limits the operation temperature to around 80 °C at ambient pressure. [1] As a result alternative membrane materials are needed which can preferably be designed with defined geometries and sizes and show high ion mobilities and corresponding ionic conductivities at elevated temperatures.As promising components in energy devices such as fuel or solar cells and batteries ionic liquids (ILs) are discussed due to their promising properties. These salts with melting points below 100 °C show high thermal and electrochemical stability, non-flammability and high ionic conductivities. For the applications mentioned above the immobilization of the ILs is necessary to realize proper function and prevent leaking. [2] The immobilization of the ILs can be realized in three different ways: 1. swelling of polymers in the IL, 2. polymerization of polymerizable ILs and 3. polymerization of vinyl-monomers in an IL. [3] The resulting ionogels (IGs) can then combine for example the characteristics of the respective IL with the useful properties of the polymer, i.e. its mechanical stability. To realize precise shapes and geometries for the membrane materials stereolithography and 3D-printing of the respective IGs provide a suitable method. [4]The aim of this study is the synthesis and characterization of ILs for proton-conduction. The ionic conductivities of these compounds range between 10-2 - 10-4 S/cm at elevated temperatures. Moreover, these ILs exhibit wide electrochemical (e. g. ΔE up to 3 V) and thermal stability windows (Td ≥ 230 °C) and are therefore promising for ion transport at elevated temperatures. NMR-studies also provide information about their ion mobility. Furthermore the ILs are immobilized via two of the aforementioned methods to provide flexible and transparent IGs that contain up to 80 wt% of IL. These IGs display promising thermal and mechanical stability and reach ionic conductivities of up to 10-3 S/cm at elevated temperatures. Successful 3D-printing and therefore structuring of IGs can also be demonstrated.[1] Martinez, et al., Journal of Power Sources, 2010, 195, 5829–5839.[2] Le Bideau, L. Viau, A. Vioux, Chem. Soc. Rev., 2011, 40, 907–925.[3] Lu, F. Yan, J. Texter, Progress in Polymer Science, 2009, 34, 431-448.[4] Zehbe, A. Lange, A. Taubert, Energy Fuels, 2019, 33, 12885-12893.

Beekeeping in the Desert: Foraging Activities of Honey Bee during Major Honeyflow in a Hot-Arid Ecosystem

This study investigated the outgoing and pollen-gathering foraging activities of Apis mellifera jemenitica (AMJ) and Apis mellifera carnica (AMC) under a hot-arid environment in the presence of nectar-rich melliferous Ziziphus nummularia flora. The data revealed the differential effects of weather conditions and Z. nummularia flora on the foraging activities of the studied honey bee subspecies in the Rawdat-Khuraim oasis in central Saudi Arabia. Z. nummularia exhibited two flowering seasons, from June–July (season I) and August–October (season II), with a significantly higher mean flowering density observed during season II (404 flowers/m2) than during season I (235 flowers/m2). AMJ showed significantly higher foraging activities (outgoing and pollen-gathering) than AMC (exotic bees) during all months in each flowering season. The mean outgoing and pollen-gathering foraging rates of AMJ (32.40 ± 0.67 and 4.88 ± 0.40 workers/colony/min, respectively) were significantly higher than those of AMC (15.93 ± 1.20 and 2.39 ± 0.23 workers/colony/min, respectively). The outgoing and pollen-gathering foraging activities of the two subspecies fluctuated throughout the different times of day. Foraging activities were considerably high at sunrise (SR) and low at noon (N) during both flowering seasons. We also observed seasonal variations in the foraging activities of both bee subspecies. The mean foraging activities (outgoing and pollen-gathering) were slightly higher in season I (27.43 ± 1.21 and 4.46 ± 0.45 workers/colony/min, respectively) than in season II (21.71 ± 0.86 and 3.02 ± 0.22 workers/colony/min, respectively). The thermal window analysis revealed a significant difference between the flight activities (bees exiting and returning to the nest throughout the day) of AMJ and AMC; AMJ had a higher temperature threshold than AMC. The outgoing and pollen-gathering foraging activities within each bee subspecies were positively correlated. The present study can help researchers understand the performances of honeybees and the association of their performances with weather and nectar-rich flora conditions.

Heat waves affect an invasive herbivore and its parasitoid differentially with impacts beyond the first generation

AbstractHeat waves are becoming more frequent with climate change, and their impact on lower and higher trophic levels can differ. Higher trophic levels, such as predators and parasitoids, are predicted to be more strongly affected by heat waves than herbivores because they may have smaller thermal windows and because of altered ecological interactions with lower trophic levels. We tested the effects of heat waves of varying intensity (36–42°C), imposed for 4 h during five consecutive days on the egg stage of an invasive herbivore, the brown marmorated stink bug (Halyomorpha halys), and on various developmental stages of its parasitoid,Trissolcus japonicus.Halyomorpha halyseggs had lower hatching success and fewer nymphs emerging with increasing intensity of heat stress, while exposure during the egg and larval stages ofT. japonicusdid not decrease adult emergence rates. Heat waves increased developmental time of parasitoids and decreased adult emergence when pupal stages were exposed. Adult parasitoids experiencing heat stress had lower survival, but their parasitism success overall was not affected. In addition, we detected transgenerational effects, whereas emergence success and the number of adult parasitoids emerging in the second generation declined when the parental generation was exposed to 42°C. Contrary to expectations, the results suggest thatH. halysmay be more sensitive to heat stress thanT. japonicus, at least during early development. Our findings indicate that biological control services provided byT. japonicuscan be maintained in the face of increasing heat wave events and point to the importance of following populations beyond the first generation to better understand the long‐term consequences of heat stress.

Toward Low-Temperature Solid-Source Synthesis of Monolayer MoS2

Two-dimensional (2D) semiconductors have been proposed for heterogeneous integration with existing silicon technology; however, their chemical vapor deposition (CVD) growth temperatures are often too high. Here, we demonstrate direct CVD solid-source precursor synthesis of continuous monolayer (1L) MoS2 films at 560 °C in 50 min, within the 450-to-600 °C, 2 h thermal budget window required for back-end-of-the-line compatibility with modern silicon technology. Transistor measurements reveal on-state current up to ∼140 μA/μm at 1 V drain-to-source voltage for 100 nm channel lengths, the highest reported to date for 1L MoS2 grown below 600 °C using solid-source precursors. The effective mobility from transfer length method test structures is 29 ± 5 cm2 V-1 s-1 at 6.1 × 1012 cm-2 electron density, which is comparable to mobilities reported from films grown at higher temperatures. The results of this work provide a path toward the realization of high-quality, thermal-budget-compatible 2D semiconductors for heterogeneous integration with silicon manufacturing.

Clinical Applications and Factors Involved in Validating Thermal Windows Used in Infrared Thermography in Cattle and River Buffalo to Assess Health and Productivity.

Simple SummaryInfrared thermography is a clinically useful method for detecting physiopathological alterations in animals through microvascular changes. It has been adapted for applications with large species, as a support tool in evaluating animal welfare, and can also contribute to productive and reproductive evaluations. This review discusses the thermal windows currently in use and characterizes their differences and limitations as resources for early detection and diagnosis in cattle and river buffaloes.Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the comfort levels of animals, a topic of concern due to the growing interest in determining the state of health and welfare of production animals. The operating principle of IRT is detecting the heat irradiated in anatomical regions characterized by a high density of near-surface blood vessels that can regulate temperature gain or loss from/to the environment by modifying blood flow. This is essential for understanding the various vascular thermoregulation mechanisms of different species, such as rodents and ruminants’ tails. The usefulness of ocular, nasal, and vulvar thermal windows in the orbital (regio orbitalis), nasal (regio nasalis), and urogenital (regio urogenitalis) regions, respectively, has been demonstrated in cattle. However, recent evidence for the river buffalo has detected discrepancies in the data gathered from distinct thermal regions in these large ruminants, suggesting a limited sensitivity and specificity when used with this species due to various factors: the presence of hair, ambient temperature, and anatomical features, such as skin thickness and variations in blood supplies to different regions. In this review, a literature search was conducted in Scopus, Web of Science, ScienceDirect, and PubMed, using keyword combinations that included “infrared thermography”, “water buffalo”, “river buffalo” “thermoregulation”, “microvascular changes”, “lacrimal caruncle”, “udder”, “mastitis”, and “nostril”. We discuss recent findings on four thermal windows—the orbital and nasal regions, mammary gland in the udder region (regio uberis), and vulvar in the urogenital region (regio urogenitalis)—to elucidate the factors that modulate and intervene in validating thermal windows and interpreting the information they provide, as it relates to the clinical usefulness of IRT for cattle (Bos) and the river buffalo (Bubalus bubalis).

Fish and flows: Abiotic drivers influence the recruitment response of a freshwater fish community throughout a regulated lotic system of the Murray‐Darling Basin, Australia

Abstract Fish assemblages in dryland rivers have life‐history strategies that have evolved in response to environmental conditions and triggers, particularly water temperatures and flow regimes. The regulation of rivers through the construction of dams, weirs and other water diversion structures has altered natural flow regimes and the associated ecological processes of river systems worldwide. Over a 3‐year period, using standardized fish sampling and daily otolith ageing, the recruitment of eight freshwater fish species was monitored in response to various abiotic drivers, including hydrology and water temperatures, throughout the Macquarie River, a large regulated river system of the Australian Murray‐Darling Basin. A data‐driven statistical classification system is provided that groups species into reproductive guilds, based on their recruitment response to hydrology and water temperature, specifically designed for use in environmental flow management. The eight species were grouped into three distinct reproductive guilds that showed similar recruitment responses to the abiotic drivers. Murray‐Darling rainbowfish, Murray cod, and eel‐tailed catfish were considered as a single guild, characterized by seasonal recruitment during a relatively narrow thermal window under low to moderate stable discharges. The second group included common carp, bony herring, and golden perch, which recruited primarily in association with larger flow events. Un‐specked hardyhead and Australian smelt formed a more differentiated guild, recruiting over a broad range of temperatures and discharges. Limitations associated with using a reproductive guild approach to simplify water management are discussed. This study highlighted important relationships among hydrology, water temperatures, and successful recruitment that can, in turn, be used to inform development of adaptive flow management plans and effective use of environmental water for the conservation management of native fish communities. Important considerations in the design of studies that aim to examine relationships between recruitment and abiotic drivers are also discussed.

Effect of thermal mass, night ventilation and window shading on summer thermal comfort of buildings in a temperate climate

Night ventilation and external blinds are the most commonly used passive methods to protect buildings from overheating during high summer temperatures. Another recommended measure is high thermal inertia of buildings. The aim of the study was to compare the effectiveness of night ventilation, external blinds and thermal mass during a heat wave on the thermal performance of a building during a heat wave in a temperate climate. Increasing the thermal mass of the room from light to very heavy without night ventilation resulted in a reduction of the average peak temperature by 3.7 K in a day and 1.2 K by night. The activation of night ventilation in a light room resulted in a reduction of the average value of the peak temperature by 1.5 K during the day and 5.9 K at night. Increase of thermal mass from light to heavy and night ventilation from 0.6 to 10 ACH led to decrease of average peak temperature by 4.7 K in a day and 4.6 K by night. The simultaneous increase of thermal mass, activation of night ventilation and closing of external blinds resulted in lowering the average peak temperature by 7.4 K in a day and 6.3 K by night. The analysis of the test results indicates that the high thermal mass and the closing of the external blinds reduces the diurnal variations of the indoor temperature, while the activation of nighventilation increases it significantly, especially for lightweight construction.

Effects of recent thermal history on thermal behaviour, thermal tolerance and oxygen uptake of Yellowtail Kingfish (Seriola lalandi) juveniles.

This study determined the physiological and metabolic responses of cultivated Yellowtail Kingfish (Seriola lalandi) juveniles in accordance with their recent thermal history. The fish were acclimated at 20, 23, 26, 29 and 32°C for 21 days to determine the final preferred temperature, thermal tolerance and the effect of acclimation temperatures on their oxygen uptake and aerobic scope. The final preferred temperature of juveniles was established at 26°C. The critical thermal maximum (CTmax) ranged from 34.2 to 36.9°C, while the critical thermal minimum (CTmin) ranged from 10.9 to 17.3°C, depending on acclimation temperature. With the CTmax and CTmin values, the thermal window was determined to have an area of 258°C2, which is characteristic of subtropical organisms. Although, the metabolic rate was relatively constant (ranging 390.6-449.8mg O2 kg-0.8 h-1) between 20 and 26°C (Q10=1.6, 1.0), an increase to 544.8mg O2 kg-0.8h-1at 29°C (Q10=1.9) and decrease of 478.4mg O2 kg-0.8h-1at 32°C (Q10=0.6) were observed. The maximum value obtained for aerobic scope was 310.9mg O2 kg-0.8h-1at 26°C. These results suggest that the acclimation temperature of 26°C is an optimum thermal condition for a physiological and metabolic performance of yellowtail kingfish juveniles. On the contrary, the response observed during the evaluation of critical temperatures, oxygen uptake and aerobic scope indicated that yellowtail kingfish in the juvenile state could be vulnerable when it experiences for long periods (e.g., >21 days) temperatures above 29°C. According to our results, the thermoregulatory behaviour of yellowtail kingfish in the juvenile stages could be one of the most important mechanisms to maintain its optimal physiological performance by actively selecting a stable thermal environment close to 26°C. In addition, it was determined the limits of the pejus state of juvenile yellowtail kingfish at 29°C, where an increase of oxygen uptake to maintain the aerobic energy metabolism was observed, this could certainly affect the growth of juveniles in culture systems if they do not return in a thermal range of 23-26°C. These results can contribute to infer the different effects of acclimation temperature on the growth, thermal tolerance and respiratory capacity of S. lalandi juveniles on aquaculture systems.

From Street to Road: An Innovative Approach to Explore Discarded Chewing Gum as a Performance-Enhancing Modifier for Road Pavement Applications.

To uncover the potential benefits of discarded chewing gum (DCG) as a performance-enhancing modifier for road pavement applications, its influence on the asphalt binder’s attributes was profoundly examined. The base AP-5 asphalt along with its specimens dosed with various fractions of DCG (e.g., 3, 6, and 9 wt%) were analyzed by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thin-layer chromatography-flame ionization detection (TLC-FID), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Brookfield viscometer, ring and ball softening point, needle penetration, and dynamic shear rheometer (DSR) tests were adopted to inspect the physical and rheological changes of asphalt cement after DCG incorporation. FT-IR disclosed that the asphalt-gum interaction was not chemical but physical in nature, whilst XRD demonstrated the existence of talc filler in DCG, which may confer the bituminous mixes with exceptional engineering properties. Iatroscan analysis evinced that the gum treatment particularly altered the aromatic and resin fractions; meanwhile, the content of saturates and asphaltenes remained relatively unchanged. SEM divulged that the DCG has a complete dissolution within the bitumen matrix, which becomes rougher due to higher dose administration. AFM revealed that the steady gum introduction amplified the size of bee-like structures, shrunk their peri-phase domains, and wiped out the para-phase domains entirely. TGA/DTGA/DSC data highlighted that the high-temperature-stable additive slightly affected the thermal properties of blends. DSR and empirical rheological tests showed that the waste gum made the bitumen less vulnerable to heat and tender, thereby boosting its resistance against fatigue cracking at intermediate service temperatures. On top of that, DCG widened the thermal window of bitumen performance grade (PG), and preserved its viscosity at standard temperatures, leading to maintaining an appropriate workability for asphalt mix. In brief, the use of discarded chewing gum as an asphalt modifier is feasible and could mitigate plastic pollution and provide durable roadways by delivering superior performance.

Variation in thermal tolerance response associated with geographic location during early development of the neogastropod Ocenebra erinaceus (Linnaeus, 1758)

Environmental temperature plays an important role in shaping the distribution and abundance of marine ectothermic organisms. As a general rule, larvae and juveniles are more sensitive to thermal stress than adults and, as a consequence, represent key life stages that determine in part the geographic range of a species. Identifying critical thermal limits during ontogeny allows for the prediction of the potential impacts of climate warming on the distribution of marine ectotherms. However, thermal tolerance - and therefore the potential to meet the challenge of warming- is known to vary at population scale for many species. In order to fully appreciate a species' future under climate warming, multiple populations studies from different thermal environments are necessary. In this study, we compared the thermal tolerance response during the intracapsular development of the marine gastropod Ocenebra erinaceus between two geographically separated populations: one from the middle (Solent, UK) and another from the south of the species' geographic range (Arcachon, France). The results show that the thermal tolerance response was influenced by geographic origin. Embryos from the relatively warm-water southern population (France) show a warm-eurythermal tolerance window with optimal temperatures between 12 and 18 °C. On the contrary, embryos from the cold-water northern population (UK) exhibit a narrow, warm-stenothermal, thermal tolerance window with optimal temperatures between 14 and 16 °C. In both populations, temperatures outside of the thermal range cause lethal and sub-lethal effects. Importantly, previously observed dispersal polymorphism was not observed at hatching time in either population in our study. Our study demonstrates that during early developmental stages, embryos are adapted to local thermal conditions and that they live very close to their upper thermal limits. Temperatures outside this range cause detrimental and contrasting effects on embryonic development of O. erinaceus, implying that the effects of future warming will depend on the population response to local environmental history. Our results suggest that global warming could shift the geographical distribution range of O. erinaceus poleward.

Antioxidant Efficiency of Irganox® 1010 on Processing and Properties of Plasticized Poly(3-Hydroxybutyrate) Films

Polyhydroxybutyrate (PHB) is one of the few biopolymers that can be processed at industrial scale. Nevertheless, PHB applications in film form are limited, mainly due to the high biopolymer crystallinity and its narrow thermal processing window. In this work, it was studied the effect of glycerol tributyrate (GTB) incorporation as plasticizer, in addition to Irganox® 1010 (I) as phenolic antioxidant on the processability and final properties of PHB-based films. PHB was melt processed in the presence of GTB (5-30 %w/w, PHB basis) and Irganox® (0.3 %w/w, PHB basis) and films were obtained by thermo-compression. PHB films without the plasticizer and the antioxidant were used as control sample. Thermal properties of films demonstrated that PHB thermal processing window was increased due to a synergistic effect of both additives. Improvement can be attributed to changes in the crystalline structure corroborated by X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). Oxygen Transmission Rate (OTR) of PHB films increased in the presence of GTB and Irganox due to the crystalline changes induced by both additives.

New cosmological bounds on hot relics: axions and neutrinos

ABSTRACT Axions, if realized in nature, can be copiously produced in the early universe via thermal processes, contributing to the mass-energy density of thermal hot relics. In light of the most recent cosmological observations, we analyse two different thermal processes within a realistic mixed hot dark matter scenario which includes also massive neutrinos. Considering the axion–gluon thermalization channel, we derive our most constraining bounds on the hot relic masses ma < 7.46 eV and ∑mν < 0.114 eV both at 95 per cent CL; while studying the axion–pion scattering, without assuming any specific model for the axion–pion interactions, and remaining in the range of validity of the chiral perturbation theory, our most constraining bounds are improved to ma < 0.91 eV and ∑mν < 0.105 eV, both at 95 per cent CL. Interestingly, in both cases, the total neutrino mass lies very close to the inverted neutrino mass ordering prediction. If future terrestrial double beta decay and/or long-baseline neutrino experiments find that the nature mass ordering is the inverted one, this could rule out a wide region in the currently allowed thermal axion window. Our results therefore, strongly support multi messenger searches of axions and neutrino properties, together with joint analyses of their expected sensitivities.