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This paper reports the production of micro porous ceramics consisting of TiO 2 and ZrO 2 by direct foaming. ZrO 2 particles in a colloidal suspension were partially hydrophobized using propyl gallate as an amphiphile at a suitable pH range of around 3.5–4.5. A TiO 2 suspension with different mole ratios was added to the surface modified ZrO 2 suspension to obtain ZrTiO 4 -TiO 2 porous ceramics in the sintered sample. The influence of the TiO 2 content and calcination temperature on the phase transformation, microstructure, and thermal properties of the materials was determined by thermal analysis, X-ray diffraction, field emission scanning electron microscopy, and dilatometry. The crystallization of ZrTiO 4 (orthorhombic) was observed at 1100 °C on the thermal hysteresis curve due to anisotropic thermal expansion. The compressive load and displacement of the sintered porous ceramics samples were calculated using the Hertzian indentation method. [ABSTRACT FROM AUTHOR]

The diatom species Fragilariopsis cylindrus produces antifreeze proteins (AFPs) of moderate thermal hysteresis. Two concepts are often used in order to describe a thermal hysteresis, on the one hand the irreversible nucleation growth described by the Gibbs-Thomson relation and on the other hand a nonlinear adsorption kinetics of the ice-binding proteins. We refer to the Landau's phase transition theory and predict a saturation concentration of AFPs for the maximal freezing depression. The derived functional relation between temperature and AFP concentration is more complex than a simple power law as suggested by thermal hysteresis experiments. With the parameter set obtained for Fragilariopsis cylindrus the modelled curve is comparable with the often used square root law. [ABSTRACT FROM AUTHOR]

The La doped ceramics PLZT-0.03/1-x/x (0.43 ≤ x ≤ 0.49) around morphotropic phase boundary (MPB) region were prepared by solid-state reaction. The ceramics exhibited diffused phase transition behavior, while MPB region showed the least degree of diffusion. It has been shown that distinct difference exists between poled and unpoled samples. All the samples exhibited thermal hysteresis behavior characteristic of the first order phase transition. The ferroelectric properties of the samples were also discussed. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) are a unique class of proteins that bind to growing ice crystal surfaces and arrest further ice growth. AFPs have gained a large interest for their use in antifreeze formulations for water-based materials, such as foods, waterborne paints, and organ transplants. Instead of commonly used colligative antifreezes such as salts and alcohols, the advantage of using AFPs as an additive is that they do not alter the physicochemical properties of the water-based material. Here, we report the first comprehensive evaluation of thermal hysteresis (TH) and ice recrystallization inhibition (IRI) activity of all major classes of AFPs using cryoscopy, sonocrystallization, and recrystallization assays. The results show that TH activities determined by cryoscopy and sonocrystallization differ markedly, and that TH and IRI activities are not correlated. The absence of a distinct correlation in antifreeze activity points to a mechanistic difference in ice growth inhibition by the different classes of AFPs: blocking fast ice growth requires rapid nonbasal plane adsorption, whereas basal plane adsorption is only relevant at long annealing times and at small undercooling. These findings clearly demonstrate that biomimetic analogs of antifreeze (glyco)proteins should be tailored to the specific requirements of the targeted application. [ABSTRACT FROM AUTHOR]

The field deployment of a heated distributed temperature sensor (DTS) for over three years has revealed two obstacles to estimating soil moisture (θ) that may hamper subsurface DTS applications as well as use of other subsurface thermal probes. The first observed obstacle was a hysteretic response of the DTS sensor. The relationship between θ and the temperature response (∆T) within the cable was not only dependent on θ of the soil, but also on the previous wetting and drying cycles leading to that state. The second observed obstacle was soil structure healing. Soil structure healing causes the relationship between ∆T and θ to evolve through time; this calibration curve becomes flatter, or less sensitive, as the surrounding soil makes better contact with the cable. Effects of the hysteretic response of the instrument and soil structure healing are largely the result of small gaps between the cable and soil. These small gaps can be approximated by a contact resistance between the cable and soil. In this article we characterize the occurrence of hysteretic and soil structure healing effects from field data and parameterize contact resistance by simulating heat transfer using a numerical modelling approach Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) panel temperature was evaluated by developing theoretical models that are feasible to be used in realistic scenarios. Effects of solar irradiance, wind speed and ambient temperature on the PV panel temperature were studied. The parametric study shows significant influence of solar irradiance and wind speed on the PV panel temperature. With an increase of ambient temperature, the temperature rise of solar cells is reduced. The characteristics of panel temperature in realistic scenarios were analyzed. In steady weather conditions, the thermal response time of a solar cell with a Si thickness of 100–500 μm is around 50–250 s. While in realistic scenarios, the panel temperature variation in a day is different from that in steady weather conditions due to the effect of thermal hysteresis. The heating effect on the photovoltaic efficiency was assessed based on real-time temperature measurement of solar cells in realistic weather conditions. For solar cells with a temperature coefficient in the range of −0.21%∼−0.50%, the current field tests indicated an approximate efficiency loss between 2.9% and 9.0%. [ABSTRACT FROM AUTHOR]

Ice-binding proteins (IBPs) are a diverse class of proteins that assist organism survival in the presence of ice in cold climates. They have different origins in many organisms, including bacteria, fungi, algae, diatoms, plants, insects, and fish. This review covers the gamut of IBP structures and functions and the common features they use to bind ice. We discuss mechanisms by which IBPs adsorb to ice and interfere with its growth, evidence for their irreversible association with ice, and methods for enhancing the activity of IBPs. The applications of IBPs in the food industry, in cryopreservation, and in other technologies are vast, and we chart out some possibilities. [ABSTRACT FROM AUTHOR]

The influence of thermal hysteresis of the comparator on the sensitivity of signal converter and distortions of the zero line at various comparator type equivalent time signal conversion methods is studied. The research is carried out by statistical simulations and physical experiments. In the simulations two sets of parameters of the thermal hysteresis are used: one appropriate to parameters of experimental device, and the second-appropriate to comparator with a stronger thermal hysteresis. [ABSTRACT FROM AUTHOR]

In this paper we report on the integration of micro-rods of the [Fe(Htrz) 2 (trz)](BF 4 ) spin crossover compound into an electronic switch-type device. The device has been fabricated by organizing the micrometric particles between interdigitated gold electrodes using dielectrophoresis and the influence of dielectrophoresis parameters on their integration is also examined. A particular attention was devoted to the investigation of the stability of the spin transition and the associated device properties. The stability of the particles before dielectrophoresis was investigated using variable temperature diffuse reflectivity experiments, which revealed a remarkable stability of the spin crossover even after performing 3000 switching cycles. We show also that the spin transition is not influenced by the solvents used for device fabrication, neither by the atmosphere (ambient air or vacuum) in which the device is used. The spin transition remains reproducible over several tens of cycles even at the device level, but the current in the device decreases continuously. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) are the key biomolecules that protect species from extreme climatic conditions. Studies of AFPs, which are based on recognition of ice plane and structural motifs, have provided vital information that point towards the mechanism responsible for executing antifreeze activity. Importantly, the use of experimental techniques has revealed key information for AFPs, but the exact microscopic details are still not well understood, which limits the application and design of novel antifreeze agents. The present review focuses on the importance of computational tools for investigating (i) molecular properties, (ii) structure–function relationships, and (iii) AFP-ice interactions at atomistic levels. In this context, important details pertaining to the methodological approaches used in molecular dynamics studies of AFPs are also discussed. It is hoped that the information presented herein is helpful for enriching our knowledge of antifreeze properties, which can potentially pave the way for the successful design of novel antifreeze biomolecular agents. [ABSTRACT FROM AUTHOR]

Ceratophysella sigillata (Collembola, Hypogastruridae) has a life cycle which may extend for >2 years in a temperate climate. It exists in two main morphs, a winter-active morph and a summer-dormant morph in central European forests. The winter-active morph often occurs in large aggregations, wandering on leaf litter and snow surfaces and climbing on tree trunks. The summer-dormant morph is found in the upper soil layers of the forest floor. The cryobiology of the two morphs, sampled from a population near Bern in Switzerland, was examined using Differential Scanning Calorimetry to elucidate the roles of body water and the cold tolerance of individual springtails. Mean (SD) live weights were 62 ± 16 and 17 ± 6 µg for winter and summer individuals, respectively. Winter-active springtails, which were two feeding instars older than summer-dormant individuals, were significantly heavier (by up to 4 times), but contained less water (48% of fresh weight [or 0.9 g g-1 dry weight]) compared with summer-dormant animals (70% of fresh weight [or 2.5 g g-1 dry weight]). Summer-dormant animals had a slightly greater supercooling capacity (mean (SD) -16 ± 6°C) compared with winter-active individuals (-12 ± 3°C), and they also contained significantly larger amounts of both total body water and osmotically inactive (unfrozen) water. In the summer morph, the unfrozen fraction was 26%, compared to 11% in the winter morph. The ratio of osmotically inactive to osmotically active (freezable) water was 1 : 1.7 (summer) and 1 : 3.3 (winter); thus unfrozen water constituted 59% of the total body water during summer compared with only 30% in winter. Small, but significant, levels of thermal hysteresis were detected in the winter-active morph (0.15°C) and in summer-dormant forms (0.05°C), which would not confer protection from freezing. However, the presence of antifreeze proteins may prevent ice crystal growth when feeding on algae with associated ice crystals during winter. It is hypothesised that in summer animals a small decrease in freezable water results in a large increase in haemolymph osmolality, thereby reducing the vapour pressure gradient between the springtail and the surrounding air. A similar decrease in freezable water in winter animals will not have such a large effect. The transfer of free water into the osmotically inactive state is a possible mechanism for increasing drought survival in the summer-dormant morph. The ecophysiological differences between the summer and winter forms of C. sigillata are discussed in relation to its population ecology and survival.

In this work, the Casimir suspensions of a nanoplate (gold or Teflon) in a liquid environment are theoretically investigated. The substrate of the system is a three-layer structure of Teflon/vanadium dioxide(VO 2)/Teflon. It is found that stable suspensions of nanoplates can be achieved due to the balances of repulsive Casimir forces, gravity and buoyancy. Remarkably, the suspension positions of gold and Teflon nanoplates are strongly associated with the preceding thermal history of VO 2 , i.e., heating or cooling. The differences in the suspension positions between the heating and cooling can reach tens of nanometers. Finally, a thermal hysteresis of Casimir suspensions via the temperature is shown for gold and Teflon nanoplates. Our findings offer the possibility of designing conceptually new devices in micro and nanoelectromechanical systems (MEMS and NEMS). • The Casimir suspensions of gold and Teflon nano-plates are investigated theoretically in a system containing VO 2. • A strong thermal hysteresis of Casimir suspensions is revealed for both gold and Teflon nano-plates. • The suspension positions depend not only on the temperature but also on the preceding thermal history of VO 2. • The discrepancies of the equilibrium positions between the heating and cooling can reach about tens of nanometers. [ABSTRACT FROM AUTHOR]

• Joule heating phenomenon is incorporated in the AC Josephson effect. • The phase and temperature dynamic states are discussed for various parameters. • Device state diagrams are realized for Josephson weak-link – shunted and unshunted. • A useful thermal model as a guide for the experiments with weak-link-based devices. Superconducting weak-link (WL), behaving like a Josephson junction (JJ), is fundamental to many superconducting devices such as nanoSQUIDs, single-photon detectors, and bolometers. The interplay between unique nonlinear dynamics and inevitable Joule heating in a JJ leads to new characteristics. Here, we report a time-dependent model incorporating thermal effect in the AC Josephson regime for a Josephson WL shunted by a resistor together with an inductor to investigate the dynamics as well as the resulting current-voltage characteristics. We find that the dynamic regime where phase and temperature oscillate simply widens due to a pure resistive shunt. However, a significant inductive time-scale in the shunt loop, competing with the thermal time-scale, introduces high-frequency relaxation oscillations in the dynamic regime. Based on numerical analysis, we present state diagrams for different parameter regimes. Our model is a guide for better controlling the parameters in the experiments of WL-based devices. [ABSTRACT FROM AUTHOR]

Spin state bistability within high spin (HS) and low spin (LS) state is investigated in undoped and (Zn, Mn) doped spin crossover (SCO) complex Fe(phen) 2 (NCS) 2 thin films (thickness ∼ 300 nm) deposited by dip-coating technique at room temperature on the quartz substrate. The X-ray diffraction studies clearly show the formation of crystalline structure of SCO complexes. The growth of the thin films was indisputably confirmed by electron microscopy and optical studies. The optical absorption peak between 535-557 nm was clearly observed, and that corresponds to 1A 1g → 1T 1g ligand field absorption in undoped and metal-doped (Zn, Mn) SCO thin films. The high spin (HS) state of the SCO films at room temperature was confirmed by Raman spectra. The bistability of spin states is clearly revealed by the well pronounced thermal hysteresis loop in magnetization measurements. The spin transition temperature (T 1/2) and loop width are found to be critically dependent on metal doping and suggested the possibility of tuning these parameters in spin-crossover thin films to design future spin-based devices. • The thin films of doped and undoped spin-crossover materials Fe(phen) 2 (NCS) 2 , Fe 1−x Zn x (phen) 2 (NCS) 2 , and Fe 1−x Mn x (phen) 2 (NCS) 2 [x = 0,15 and 30%] are deposited on quartz substrates with using a dip-coater, which is developed in our laboratory. • The lattice parameters increased for Mn doped sample while for Zn doped sample the lattice parameters are found to decrease in comparison to the undoped sample. • The spin transition temperature (T 1/2) and loop width are found to be critically dependent on metal doping. • Details of spin-state switching under metal doping of SCO materials are reported here which may be crucial in designing future spin-based devices. [ABSTRACT FROM AUTHOR]

R 2 Cu 2 O 5 (R = Tb-Lu, Sc, In) (RCO) compounds are interesting magnetic materials due to their quasi-low dimensional crystal structure, which also lacks centro-symmetry. Previous investigations on these compounds indicated antiferromagnetic or canted-antiferromagnetic ground state with Néel temperatures lying below about 30 K. The present work tries to provide finer details of the intricate magnetic characteristics of the RCO compounds, which were not addressed in the previous works. These include thermomagnetic irreversibility, thermal hysteresis, hysteresis in the isothermal magnetization measurements and so on. Most interestingly, we observe large magnetocaloric effect as calculated from our magnetization data and we find that it is primarily connected to the metamagnetic transitions observed in the samples. Our work also recognizes anomalies in the dielectric constant at the magnetic transition temperatures indicating possible multiferroicity in the samples. Efforts have been made to understand the diverse magnetic properties of the RCO samples on the basis of the crystal structure and the rare-earth moment. • A comprehensive magnetic scenario of complete R 2 Cu 2 O 5 series in a single report. • Observation of sizable magnetocaloric effect in R 2 Cu 2 O 5 associated with metamagnetism. • Dielectric anomaly at magnetic transition indicates the magneto-electric coupling. • Studies of thermo-magnetic irreversibility, thermal hysteresis in R 2 Cu 2 O 5 oxides. [ABSTRACT FROM AUTHOR]

[Display omitted] Shape memory alloys (SMAs) are desirable candidates for elastocaloric effect materials, but they all suffer from large thermal hysteresis (T hys). This study analyzes multicomponent TiNi-based SMAs dataset by machine learning (ML) to explore new SMAs with narrow T hys. The second-largest eigenvalue λ 2 of the stretch transformation matrix U is added to the original dataset to guide the ML process as a feature. Firstly, λ 2 is obtained by first-principles calculations combined with ML. XGBoost Regressor (XGBR) combined with Leave-One-Out Cross-Validation (LOO-CV) is selected from four algorithms for modeling with the highest coefficient of determination R 2 of 0.87. The introduction of λ 2 improves the performance of the model. The dataset is divided into 15 groups based on different doping elements (such as Hf, Cu, Zr, etc.), among which TiNiCu is the most predictive component with the R 2 of 0.89. Over 500 TiNiCu components are randomly generated and predicted T hys. Based on the contour maps created from the prediction results, it is found that T hys is likely to decrease with the increase of Cu doping in general, and minimum T hys occurs when the Cu is about 15 at. %, which is consistent with the existing experimental results. Eventually, a potential T hys minimum (1.2 K) region of Ti x Ni y Cu z (58.3%≤ x ≤ 58.5%, 26.5%≤ y ≤ 27%, 14.8%≤ z ≤ 15.3%, x + y + z = 100%) SMA composition is predicted. Our study not only provides a potential selection of narrow T hys TiNi-based SMAs but also indicates combining of XGBoost and DFT calculation is an effective strategy for materials design. [ABSTRACT FROM AUTHOR]

Evaluation of colour change as a function of temperature was studied on twenty eight samples of bulk ternary thermochromic composites using varying concentrations of crystal violet lactone as a colour former, bisphenol A as a developer and tetradecanol as a co-solvent. A number of parameters describing the colour change – reflectance, trichromatic values X and Y , visual colour densities DX and DY , and several parameters in CIELAB space, were obtained as a function of temperature. From these functions, the colour contrast, temperature sensitive interval, rate of colour change and width of hysteresis loop as the characteristics of thermochromic composites were evaluated and compared. The results show that cumulative colour difference Δ E C , representing the length of the path of colour change in CIELAB space, might be the best parameter in such an evaluation. Taking into account both the rate of colour change and the width of hysteresis loop the best performing thermochromic system could be selected. [ABSTRACT FROM AUTHOR]

High latitude waters in the Southern Ocean can be near their freezing point and remain ice-covered throughout the year whereas lower latitude Southern Ocean waters have seasonal ice coverage and comparatively large (6 °C) annual temperature changes. The genus Trematomus (suborder Notothenioidei) is regarded primarily as a high latitude group because of its abundance there, they also inhabit the warmer regions in smaller numbers. Freeze avoidance in the notothenioids is linked to the presence of two antifreeze proteins (AFPs); the antifreeze glycoproteins (AFGPs) and antifreeze potentiating protein (AFPP), both of which adsorb to internal ice crystals inhibiting growth. Both high and low latitude trematomids possess sufficient AFP to lower their blood freezing point below that of seawater (− 1.9 °C). We investigated the contributions of AFGPs and AFPP to the blood freezing point depression to determine how they varied with depth, water temperature, and the presence of ice. High latitude trematomids had lower blood freezing points than those inhabiting lower latitude waters indicating differences in their freeze avoidance capacities. Lower freezing points were associated with higher levels of antifreeze activity due to higher levels of both AFGP and AFPP. Populations of Trematomus hansoni and Trematomus bernacchii from shallow depths appear more freeze avoidant than populations inhabiting deep, ice-free water based on their lower freezing points and higher antifreeze activities. Gel electrophoresis of the trichloroacetic acid-soluble AFGPs indicates that only high molecular weight isoforms, which contribute more to AFGP activity, vary across species as well as between individuals of a species. [ABSTRACT FROM AUTHOR]

The ETS-25-type standard thermometers manufactured by a single company are investigated. It is shown that instability of the thermometers during calibration may be due to the occurrence of stresses in the platinum wire of the sensitive element, and not due to oxidation of the platinum. [ABSTRACT FROM AUTHOR]

The influence of thermal hysteresis of a clocked comparator on the quality of operation of a comparator type equivalent time sampling converter has been studied. The influence of thermal hysteresis is characterized by the noise and distortion of the converter zero line. The studies are carried out based on physical experiments and computer simulation. For physical experiments clocked comparator, based on tunnel diodes, is used. The up-and-down method is used as a sampling conversion method. [ABSTRACT FROM AUTHOR]

For the case of the cold, relative to a gas mixture, walls of an apparatus and radiation heat transfer, an investigation is made of the dependence of the limiting minimum gas mixture temperatures above which catalytic self-ignition and firing of a low-concentration combustible gas on a catalyst particle are possible. The proposed method is based on obtaining the desired dependences in a parametric form. An analysis of the degeneration of critical temperatures and of ignition and extinction diameters is carried out. [ABSTRACT FROM AUTHOR]

The cold tolerance of the Antarctic nematodes Scottnema lindsayae and Plectus murrayi was determined using material freshly isolated from the field. Both species could survive low temperatures but the survival of S. lindsayae was greater than that of P. murrayi. Field soil temperatures in late spring-early summer indicated a minimum temperature of −19.5 °C and a maximum cooling rate of 0.71 °C min. In P. murrayi grown in culture, there was no significant effect of acclimation, nor of the two culture media used, on survival after freezing but survival was greater if freezing was seeded at -1 °C than at lower temperatures. The freezing survival ability of P. murrayi is much less than that of Panagrolaimus davidi CB1, another Antarctic nematode. Cryomicroscopy indicates that P. murrayi can survive low temperatures by either cryoprotective dehydration or freezing tolerance, but that freezing tolerance is the dominant strategy. Measurable thermal hysteresis was detected only in highly concentrated extracts of the nematodes, indicating the presence of an antifreeze protein, but at the concentrations likely to be found in vivo, the major function of the ice active protein involved is probably recrystallization inhibition. [ABSTRACT FROM AUTHOR]