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The hot spot temperature inside the windings of the oil-immersed power transformers may exceed 200 °C due to some winding deficiencies, posing negative impact on the paper insulation. A series of heating experiments are deliberately conducted with oil-paper insulation samples to study the influence of the hot spot temperature ranging from 120 to 280 °C, and the insulation degradation is characterized by the breakdown voltage (BDV) and the degree of polymerization (DP). Furthermore, surface morphology, water content and cellulose degradation mechanism are analyzed so as to reveal the causes of the above phenomena. The experimental results indicate that with increase of the hot spot temperature, the breakdown voltage increases after the first drop, while the DP continues to decline in the tested temperature range. No obvious linear relationship is observed between the hot spot temperature and the DP or the BDV. Regarding the test samples the authors have studied, the inflection point of the hot spot temperature for the insulation deterioration is found to be between 240 and 260 °C. The proposed research presents a fundamental reference for assessment of the winding insulation degradation from the viewpoint of hot spot temperature. [ABSTRACT FROM AUTHOR]

Abstract: Carbon paper is commonly used as the gas diffusion layer (GDL) in polymer electrolyte membrane (PEM) fuel cells as it exhibits high chemical and mechanical durability. This diffusion medium is also anisotropic, which directly affects its transport properties and specifically the thermal conductivity. In this study, the in-plane thermal conductivity of the carbon paper GDL was determined using thermal diffusivity measurements for a temperature range from −20 to +120°C and four Teflon loadings (0, 5, 20 and 50wt.%). It is important to understand the effect of temperature on the thermal conductivity since PEM fuel cells are designed to operate under various temperatures depending on the application of use. Further, Teflon is used to change the hydrophobic properties of the carbon paper GDL with 20wt.% as the most widely used percentage. In this study, the Teflon loadings were chosen to gain a comprehensive understanding of the thermal resistance due to Teflon. In this study, a quasi-steady method was used to measure the thermal properties of the carbon paper; hence, the phase transformation in the presence of PTFE was investigated. The thermal conductivity decreases with an increase in temperature for all samples. The addition of as little as 5wt.% Teflon resulted in high thermal resistance decreasing the overall thermal conductivity of the sample. Further addition of Teflon did not have major effects on the thermal conductivity. For all treated samples, the thermal conductivity lies in the range of 10.1–14.7W/mK. Finally, empirical relations for the thermal diffusivity and conductivity with temperature were deduced. [Copyright &y& Elsevier]

The research is to explore the changes in solar heating buildings under energy-saving structural design. This paper analyzes the changes in solar heating buildings under energy-saving structural design by constructing a numerical simulation method. It mainly studies the effects of the space temperature of the house, different thermal insulation methods, and wall thermal resistance on solar heating buildings. The energy-saving structural design mainly includes expanding the area of exterior windows, increasing heat retainers, adopting energy-saving walls, and improving the building envelope. The results show that after the energy-saving structural design, the indoor temperature of the solar heating building after the renovation has been greatly increased, with an average increase of about 6 ℃. Compared with the external insulation and internal insulation modes, the solar heating building under the sandwich insulation mode has the best effect, and the room temperature increases the most. Also, it shows that the east wall, west wall, and north wall of the building are increasing the energy saving per unit area of the wall as the wall thermal resistance increases. The difference is that the increasing range of the north wall has significant advantages over the east wall and the west wall. The energy-saving structural design for solar heating buildings under the numerical simulation method has significantly improved the utilization efficiency of solar energy. It reduces the consumption of traditional fossil resources and improves the quality of the environment. This paper's research has a positive effect on subsequent research. [ABSTRACT FROM AUTHOR]

A person's body temperature is an important indicator of their health status. A deviation of that temperature by just 2 °C already has or can lead to serious consequences, such as fever or hypothermia. Hence, the development of a temperature-sensing and heatable yarn is an important step toward enabling and improving the monitoring and regulation of a person's body temperature. This technology offers benefits to several industries, such as health care and sports. This paper focuses on the characterization and development of a hybrid yarn, which can measure and visualize temperature changes through a thermoresistive and thermochromic effect. Moreover, the yarn is able to serve as a flexible heating element by connecting to a power source. The structure of the yarn is designed in three layers. Each layer and component ensures the functionality and flexibility of the yarn and additional compatibility with further processing steps. A flexible stainless steel core was used as the heat-sensitive and heat-conducting material. The layer of polyester wrapped around the stainless steel yarn improves the wearing comfort and serves as substrate material for the thermochromic coating. The resulting hybrid yarn has a reproducible sensory function and changes its resistance by 0.15 Ω between 20 and 60 °C for a length of 30 cm. In addition, the yarn has a uniform and reproducible heating power, so that temperature steps can be achieved at a defined length by selecting certain voltages. The thermochromic color change is clearly visible between 28 and 29 °C. Due to its textile structure, the hybrid sensory and actuating yarn can easily be incorporated into a woven fabric or into a textile by means of joining technology sewing. [ABSTRACT FROM AUTHOR]

Sudden stratospheric warmings (SSWs) are impressive events that occur in the winter hemisphere's polar stratosphere and are capable of producing temperature anomalies upward of +50 K within a matter of days. While much work has been dedicated toward determining how SSWs occur and their ability to interact with the underlying troposphere, one underexplored aspect is the role of radiation, especially during the recovery phase of SSWs. Using a radiative transfer model and a heating rate analysis for distinct layers of the stratosphere averaged over the 60°–90°N polar region, this paper accounts for the radiative contribution to the removal of the anomalous temperatures associated with SSWs. In total 17 events are investigated over the 1979–2016 period. This paper reveals that in the absence of dynamical heating following major SSWs, longwave radiative cooling dominates and often results in a strong negative temperature anomaly. The polar winter stratospheric temperature change driven by the radiative cooling is characterized by an exponential decay of temperature with an increasing e-folding time of 5.7 ± 2.0 to 14.6 ± 4.4 days from the upper to middle stratosphere. The variability of the radiative relaxation rates among the SSWs was determined to be most impacted by the initial temperature of the stratosphere and the combined dynamic and solar heating rates following the onset of the events. We also found that trace-gas anomalies have little impact on the radiative heating rates and the temperature evolution during the SSWs in the mid- to upper stratosphere. [ABSTRACT FROM AUTHOR]

The conventional wisdom on peak-duty drive design leads to vastly oversized machines, following design strategies that are based on continuous ratings. This paper investigates induction machine time ratings that allow peak electrical capabilities to be fully attained. The machine transient thermal response is used to identify four heating regimes based on the dominant heat-transfer mode: subtransient, transition, transient, and temperature creep. A strong connection between the subtransient mode and i^2 t ratings is presented. The impacts of stator and rotor losses on the end-winding temperature are independently identified. This information is combined into a transient thermal impedance characteristic, which provides time ratings as a function of stator and rotor losses with less than 10% error. This method is also adapted for unbalanced supply conditions and rotor-related excess heating conditions with similar error. An implementation of time rating information on a drive system is shown to exploit machine peak ratings. The presented characterizations inform the short-term peak energy density of induction machines. [ABSTRACT FROM AUTHOR]

This paper deals with the setting-parameter optimization procedure for a multiphase induction heating system considering transverse flux heating. This system is able to achieve uniform static heating of different thin/size metal pieces without movable inductor parts, yokes, or magnetic screens. The goal is reached by the predetermination of the induced power-density distribution using an optimization procedure that leads to the required inductor supplying currents. The purpose of the paper is to describe the optimization program with the different solution obtained and to show that some compromise must be done between the accuracy of the temperature profile and the energy consumption, with the calculation of the losses. [ABSTRACT FROM PUBLISHER]

An accurate thermal rating of an overhead transmission line must take into account the higher temperatures present at the interior of the conductor. In this paper, we present our experimental study of the radial temperature profile of an all aluminum alloy conductor. We have monitored the temperature of every conductor layer as a function of electrical current, line tension, and time. We have analyzed the data using a continuous model and a layer model of the conductor. Both models closely reproduce the experimental data in the steady and transient state. Also, we discuss the effect of the higher core temperature in the thermal rating of a transmission line. [ABSTRACT FROM AUTHOR]

When a liquid is placed on a surface acoustic wave (SAW) propagation surface, a longitudinal wave is radiated into the liquid, and the liquid begins to vibrate stream, jet, and atomize. This phenomenon is known as SAW streaming. In this paper, we describe experimental results concerning the temperature of a thin liquid layer during SAW generation. The results reveal that the temperature of the liquid is a function of the SAW amplitude, which is determined by the applied voltage. This means that the liquid temperature can be controlled by the applied voltage. We conclude that a novel microliquid heating system can be realized using the SAW device. [ABSTRACT FROM AUTHOR]

Heating, ventilating and air-conditioning systems have a significant share in the energy consumed by buildings. Modeling of room temperature dynamics is the first-step in designing an efficient air-conditioning system. In this regard, this paper proposes a semi-nonlinear thermal model: ordinary differential equation, with parameters as nonlinear functions of ambient temperature and cooling air flow-rate. To validate the performance of the model, a three-roomed building, equipped with an air-conditioning system is modeled, and Navier–Stokes equations are solved to simulate the temporal evolution of temperatures for different ambient temperatures and cooling air flow-rates. The steady-state temperature and transient solution parameters of the thermal model are assumed to be polynomial functions of ambient temperature and flow-rate, and are determined by minimizing the errors between the thermal model- and the computational fluid dynamics-based solutions of final and transient temperatures, respectively. The proposed thermal model of third-order and nonlinear type transient coefficients is shown to predict the temporal evolution of temperature accurately. Further increase in prediction accuracy is achieved by recursively updating the parameters online using extended Kalman filter. The high prediction accuracy of the proposed thermal model makes it a potential candidate for the design of an optimal temperature regulator. [ABSTRACT FROM AUTHOR]

Li-ion batteries have been widely used in electric vehicles, and battery internal state estimation plays an important role in the battery management system. However, it is technically challenging, in particular, for the estimation of the battery internal temperature and state-of-charge (SOC), which are two key state variables affecting the battery performance. In this paper, a novel method is proposed for realtime simultaneous estimation of these two internal states, thus leading to a significantly improved battery model for realtime SOC estimation. To achieve this, a simplified battery thermoelectric model is first built, which couples a thermal submodel and an electrical submodel. The interactions between the battery thermal and electrical behaviors are captured, thus offering a comprehensive description of the battery thermal and electrical behavior. To achieve more accurate internal state estimations, the model is trained by the simulation error minimization method, and model parameters are optimized by a hybrid optimization method combining a metaheuristic algorithm and the least-square approach. Further, time-varying model parameters under different heat dissipation conditions are considered, and a joint extended Kalman filter is used to simultaneously estimate both the battery internal states and time-varying model parameters in realtime. Experimental results based on the testing data of LiFePO$_4$ batteries confirm the efficacy of the proposed method. [ABSTRACT FROM PUBLISHER]

Lithium (Li)-ion battery cells suffer from significant performance degradation at subzero temperatures. This paper presents a predictive control-based technique that exploits the increased internal resistance of Li-ion cells at subzero temperatures to increase the cell’s temperature until the desired power can be delivered. Specifically, the magnitude of a sequence of bidirectional currents is optimized such as to minimize total energy discharged. The magnitude of current is determined by solving an optimization problem that satisfies the battery manufacturer’s voltage and current constraints. Drawing bidirectional currents necessitates that a temporary energy reservoir for energy shuttling, such as an ultracapacitor or another battery, be available. When compared with the case when no penalty on energy withdrawn is imposed, simulations indicate that reductions of up to 20% in energy dispensed as heat in the battery as well as in the size of external storage elements can be achieved at the expense of longer warm-up operation time. [ABSTRACT FROM PUBLISHER]

Synchronous reluctance motors (SynRMs) are gaining in popularity in industrial drives due to their permanent magnet-free, competitive performance, and robust features. This paper studies the power losses in a 90-kW converter-fed SynRM drive by a calorimetric method in comparison of the traditional input–output method. After the converter and the motor were measured simultaneously in separate chambers, the converter was installed inside the large-size chamber next to the motor and the total drive system losses were obtained using one chamber. The uncertainty of both measurement methods is analyzed and discussed. [ABSTRACT FROM AUTHOR]

Optimization of light-emitting diode (LED) design is highly dependent on the relationship between photometric, electric, and thermal parameters of the device. The photoelectrothermal (PET) theory connects all the features of LED device. In this paper, wall-plug efficiency equations of PET theory were extended to estimate heat-dissipation factor and optical power of low-power surface-mounted device (SMD) LED. The wall-plug efficiency as a function of ambient temperature and injection current is used to predict the heat-dissipation factor and the optical power of the SMD LED. The TeraLED and T3ster systems were utilized to provide optical and thermal test reports of the LED parameters at a certain range of injection current and ambient temperature. The presented equations were verified by testing on low-power SMD LED. Results demonstrate that the estimated and measured values were in good agreement for all the considered parameters. This validates the extension of PET theory equations for low-power SMD LED. [ABSTRACT FROM AUTHOR]

This paper describes a constant switching frequency variable duty cycle control strategy that adjusts the current in a vortex water-wall argon arc lamp to achieve wafer temperature tracking in response to a temperature ramp request. The control system includes a model for the following: 1) the outer loop temperature controller; 2) the inner loop current controller; 3) the wafer temperature; and 4) the irradiation produced by the arc lamp in response to arc current changes. The controller design is able to provide a well-behaved arc current and good temperature tracking performance that accommodates for no temperature feedback below 300 °C and a bumpless transfer once temperature feedback is available. [ABSTRACT FROM PUBLISHER]

Recently, one main trend in the development of high-power gas circuit breakers (GCBs) has been to review and reapply the current interruption principle of self-blast GCBs because GCBs need to be compact in size and interrupt high current with low driving energy. A simulation algorithm was designed to analyze arc gas flow during the current interruption in an self-blast GCB. One model of self-blast GCBs was chosen as the test subject in order to validate the results of the algorithm. This paper shows that the simulation algorithm calculated and visualized the entire arc quenching process, and nozzle ablation has been taken into account. Pressure rise in the cylinder presented a great difference between considering the arc radiation effect and not. Both arc temperatures have a range of 13 000–28 000 K, except near the current zero point. Based on the development of the algorithm, the other two results were proposed to clearly validate precision in calculation. One had the results calculated by varying the radius of the nozzle throat in the self-blast GCB and another calculated arc gas flow of a hybrid puffer GCB with piston compression. [ABSTRACT FROM AUTHOR]

A 240-MVA, 165-GRDY/20-kV generator step-up transformer was insulated with Envirotemp FR3 fluid. The transformer was energized during a cold temperature period in mid-December 2010. This is believed to be the largest generator step-up transformer filled with a natural ester fluid that was energized at low temperatures. The lack of cold start experience of natural ester-filled power transformers created questions and at least some uncertainty as to the outcome. This paper describes the instrumentation used and data collected during the cold startup procedure. In addition, a computational fluid dynamics analysis of this transformer design was performed that provided calculated temperatures and elapsed times until steady-state temperatures were achieved. Comparisons were made between the actual and calculated values. The results indicate that the cold startup procedures for a power transformer are the same whether filled with mineral oil or natural ester fluid of similar characteristics as used for this paper. [ABSTRACT FROM PUBLISHER]

This paper presents the frequency and temperature-dependence complex permittivity (ε = ε' + jε") of three layers (the mesocarp, shell and kernel) in palm fruit var. Tenera. The complex permittivity was measured and reported at frequencies between 0.5-6 GHz from 10-70?C. Dominated by the frequency characteristic of free water in these three layers, the ε' and ε" decreased significantly with the increase in temperature at the measured frequencies. The temperature characteristic of ε at 2.45 GHz was investigated. It was found that ε', ε" and the loss tangent for the mesocarp layer were higher than those of the kernel and shell layer. This was especially so for the loss tangent case; this means that the mesocarp layer can absorb microwave energy and convert it to heat more readily than the other two layers. The penetration depth,Dp, for each layer at 2.45 GHz between 10-70°C was computed and confirms volumetric heating does occur in all three layers. Temperature-dependence models for εof all three layers at 2.45 GHz were formulated by applying regression analysis to the measured ε with a 95% confidence interval. The three models were applied to form a multilayer concentric model for palm fruit and can be applied for microwave heating. The temperature distribution profiles in the palm fruit predicted from the model and the experimental results showed good agreement. [ABSTRACT FROM AUTHOR]

The aim of this paper has been the development of a new type of temperature microsensor/microactuator working on the principle of the thermo-elastic (TE) deformation of multilayer magnetic microwire consisting of a glass-coated Co76Si11B13 metallic core and an electroplated Co90Ni10 external shell. The application of an electrical current along the microwire in the range 20–35 mA results in the TE mechanical bending of fixed sample, which is recorded. That mechanical deformation is interpreted to be a consequence of the resulting Joule heating, and its amplitude is directly proportional to the applied dc current in the mentioned range. Moreover, the direct proportionality between TE deformation and the resulting increase of temperature was experimentally confirmed. In this way, the new type of temperature microsensor/microactuator working on the principle of TE deformation has been developed. This opens new technological application of microwires as temperature microsensors and temperature-driven microactuators for micro-electro-mechanical system devices. [ABSTRACT FROM PUBLISHER]

The need for continuous temperature monitoring and thermal management is unquestionable as operating temperature is a critical factor affecting many electrical/electronic components and devices, including energy storage such as batteries and supercapacitors (SCs). On the other hand, many applications require the battery or SC cells to be stacked up to meet the required voltage or power level which introduces uneven temperature distribution among the cells. Hence, thermal-model-based temperature monitoring and management has been widely utilized, using state estimation to allow the use of minimum number of temperature sensors. This paper explores the performance of multiple-model-based abnormal overheating detection in a SCs string with minimum number of sensors based on simulation and experimental results. The performance of the estimator/detector system is evaluated for the case of an abnormally overheating cell as well as for different values of the estimator parameters. Preliminary indication from the experimental results shows satisfying performance of the estimator/detector system. [ABSTRACT FROM PUBLISHER]

Cold weather is an important matter for electric and hybrid-electric vehicles (EV/HEVs), because the electro-chemical process is slowed at low temperatures, hence inducing a loss of power and energy. To prevent it from happening, battery packs are heated via a battery thermal management system (BTMS). However, in some cases, HEVs/EVs are not connected to the grid, so the BTMS uses energy from the battery pack, thus impacting total autonomy. Strategies exist, but must be optimized. Therefore, this paper proposes the design of a HEV strategy that is parked outside and unplugged from the electrical grid. Its objective is to find a compromise between the cost in energy contained in the battery and the aging of the cells. The optimization is based on dynamic programming and utilizes an electro-thermal battery model including aging. Simulation results are then compared with other strategies, underlining that parking outside at work or overnight without plugging in are issues with the actual strategies of common EVs/HEVs, mainly because aging as a result of cold temperatures is not considered. [ABSTRACT FROM PUBLISHER]

Many factors affect the loading of the underground power cables, such as ambient temperature, depth of laying of cable, number of parallel circuits of cable, and thermal resistivity of the surrounding soil. One important factor, usually ignored, is the formation of dry zones around the underground power cables. Dry zones are usually formed around underground power cables under loading conditions due to the migration of moisture within the soil. In this paper, the effect of the formation of the dry zone on the ampacity of underground power cables is investigated. The derating factor for the formation of dry zones around underground power cables is suggested and calculated for different types of natural backfill soil. IEC 60287-1-3 is taken as a reference. Experimental work was conducted to study the phenomena of the dry zone as related to different types of soils. [ABSTRACT FROM AUTHOR]

It is necessary to find alternative regenerator materials for lead because lead is toxic and prohibited in any device by Restriction of Hazardous Substances (RoHS). In this paper, the low temperature heat capacities and mechanical properties of the multiphase Er3+xNi alloys are studied. The results show that Er3+xNi alloys consist of Er and Er3Ni phases. The specific heat capacities of Er10.819Ni and Er4.436Ni are higher than lead from 5 to 90 K. The addition of Er makes Er3+xNi alloys have much more excellent mechanical properties than pure Er3Ni. The compressive strength of Er4.436Ni, Er6.351Ni, and Er10.819Ni alloys as measured are all more than six times larger than Er3Ni. And there is a convert from brittle fracture to ductile fracture along with the increase in the content of Er. The study of mechanism of fracture of Er3+xNi alloys reveals that the fractures of the alloys are cleavage fracture and quasi-cleavage fracture. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate the effect of various temperatures, room, 37 and 50°C, on formaldehyde emission from floor materials, such as laminate and plywood floorings, and furniture materials, such as MDF and particleboard veneered with decorative paper foil, by desiccator's method. The temperature conditions were set up by, measuring the temperature in a Korean under heating system. To maintain an indoor air temperature of 20°C, the temperature of the flooring surface was about 37°C and the temperature of the cement mortar was 50°C. The initial formaldehyde emission of the laminate flooring and plywood flooring was 1.44 and 0.63 mg/l, and for MDF and particleboard it was 4.73 and 4.95 mg/l, respectively. Floor materials were under E1 grade while furniture materials were under E2 grade in terms of formaldehyde emission. Because of the under heating system, the flooring materials were exposed to 37 and 50°C, while the furniture materials mostly existed at room temperature. At 37 and 50°C, the formaldehyde emission level of the flooring materials was already under 0.3 ppm (F☆☆☆☆ level by JIS A 1460, application possibility without area limit) after 10 days and the emission had decreased further (0.03–0.10 mg/l) after 28 days. These levels are not injurious to the human body and will not cause sick house syndrome (SHS). The problem, however, is the furniture materials such as MDF and particleboard. As these materials are not exposed to high temperature (50°C in this experiment) in living condition, it was still E2 grade of formaldehyde emission level at room temperature remained even after 28 days. Although there will be variations with the volume of furniture materials and the indoor conditions, furniture materials are the principal cause of indoor air quality pollution in Korean with the under heating system. Koreans spend most of their time sitting on ONDOL (heated) floors, with their buttocks always in contact with the floor surface. The flooring materials are exposed to high temperatures (37–50°C ) why the effect of bake-out is rapid. The emission of formaldehyde from furniture materials are more important for the IAQ because usually MDF and particleboard of E2 grade are being used as furniture materials in Korea. [ABSTRACT FROM AUTHOR]

This paper presents an improved mixed-integer model for the thermal unit commitment problem. By introducing new variables for the temperature of each thermal unit, the off-time-dependent start-up costs are modeled accurately and with a lower integrality gap than state-of-the-art formulations. This new approach significantly improves computational efficiency compared to existing formulations, even if they only model a rough approximation of the start-up costs. Our findings were validated on real-world test cases using CPLEX. [ABSTRACT FROM PUBLISHER]

In this paper, a GaN light-emitting diode (LED) with sapphire structure and a thin-film LED without sapphire structure are characterized in the photoelectrothermal modeling framework for comparison. Starting from the analysis and modeling of internal quantum efficiency as a function of current and temperature of blue LED, this work develops the thin-film LED device model and derives its optical power and the heat dissipation coefficient. The device parameters of the two LED devices with different structural designs are then compared. Practical optical power measurements are compared with theoretical predictions based on the two types of fabricated devices. It is shown that the thin-film LED device has much lower thermal resistance and optical power loss. [ABSTRACT FROM PUBLISHER]

In this paper, a quick and efficient approach is proposed to estimate in vivo RF-induced heating from small medical implants under MRI procedure. An efficient methodology is developed to correlate the incident electric field to the induced temperature rise for stents of arbitrary shapes. A 10-cm-long titanium rod and a 6-cm-long intestine stent are used as examples to validate the approach under in vitro testing conditions. In vivo temperature rise estimations are then performed on an anatomically corrected adult male model. Numerical and experimental studies demonstrate the efficiency and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Anode material seriously influences the characteristics of vacuum arc and further affects the performance of medium-voltage vacuum switches when the interruption current is high. There are many materials used for electrode manufacture, and different materials are selected for different switches. For a pure metal, its performance usually cannot satisfy the actual requirement. To improve switch’s performance, an alloy is usually used as an electrode material. In this paper, thermal processes of six kinds of metal anodes (including pure metal and alloy anodes) are simulated and researched. The physical parameters of the pure metals all come from experiment results directly or are fitted by the experimental data. The physical parameters of the CuCr alloys are derived from Cu and Cr parameters. Two kinds of temperature calculation methods are used, which are called melting and solidification model and equivalent specific heat method, respectively. Simulation results show that W and Mo anodes have the higher temperature than Cu, Cr, CuCr25, and CuCr50 anodes. A pure Cr anode has the largest melting width and highest saturated vapor pressure and evaporation energy. A Cu anode has the biggest melting depth. A W anode has the smallest melting width and depth. Axial temperature gradient is related to the thermal conductivity, and the Cr anode has the largest axial temperature gradient. The thermal characteristics of CuCr25 and CuCr50 anodes are located between the pure Cu and Cr anodes. There are two melting points appearing in the results of CuCr alloys, and between the two melting points, the alloy anodes are in solid–liquid mixture state. [ABSTRACT FROM PUBLISHER]

Background: Periprosthetic joint infection is a serious complication following joint replacement. The development of bacterial biofilms bestows antibiotic resistance and restricts treatment via implant retention surgery. Electromagnetic induction heating is a novel technique for antibacterial treatment of metallic surfaces that has demonstrated in-vitro efficacy. Previous studies have always employed stationary, non-portable devices. This study aims to assess the in-vitro efficacy of induction-heating disinfection of metallic surfaces using a new Portable Disinfection System based on Induction Heating. Methods: Mature biofilms of three bacterial species: S. epidermidis ATCC 35,984, S. aureus ATCC 25,923, E. coli ATCC 25,922, were grown on 18 × 2 mm cylindrical coupons of Titanium-Aluminium-Vanadium (Ti6Al4V) or Cobalt-chromium-molybdenum (CoCrMo) alloys. Study intervention was induction-heating of the coupon surface up to 70ºC for 210s, performed using the Portable Disinfection System (PDSIH). Temperature was monitored using thermographic imaging. For each bacterial strain and each metallic alloy, experiments and controls were conducted in triplicate. Bacterial load was quantified through scraping and drop plate techniques. Data were evaluated using non-parametric Mann-Whitney U test for 2 group comparison. Statistical significance was fixed at p ≤ 0.05. Results: All bacterial strains showed a statistically significant reduction of CFU per surface area in both materials. Bacterial load reduction amounted to 0.507 and 0.602 Log10 CFU/mL for S. aureus on Ti6Al4V and CoCrMo respectively, 5.937 and 3.500 Log10 CFU/mL for E. coli, and 1.222 and 0.372 Log10 CFU/mL for S. epidermidis. Conclusions: Electromagnetic induction heating using PDSIH is efficacious to reduce mature biofilms of S aureus, E coli and S epidermidis growing on metallic surfaces of Ti6Al4V and CoCrMo alloys. [ABSTRACT FROM AUTHOR]

Cadmium zinc telluride (CZT) possesses excellent material properties for a wide range of applications where room temperature operability, durability, and high efficiency are required. However, because CZT is a challenging material to produce in useful quantities, the growth and fabrication costs have remained high, creating an economic challenge for vendors. While the traveling heater method (THM) is the predominant means of commercial CZT crystal growth, the vertical Bridgman method (VB) is an attractive alternative due to its relatively fast growth rate. However, VB grown CZT has yet to compete with THM grown CZT, particularly in terms of charge collection efficiencies, where the charge collection efficiency is characterized by the single carrier electron mobility lifetime (μτe) product. Despite efforts to overcome this discrepancy, the μτe product in VB grown CZT has remained an order of magnitude lower than THM. Eliminating this difference would bring VB one step closer to outpacing THM in terms of economic feasibility. This paper discusses the development of a unique technique that combines the advantages of both growth methods to better understand this discrepancy and the underlying mechanisms behind it. CZT ingots were grown from melt via VB with highly off-stoichiometric concentrations of tellurium (Te). Melt mixing via accelerated crucible rotation (ACRT) was applied to compensate for any negative effects associated with off-stoichiometry, i.e. flux inclusions. CZT material has been produced at growth rates commensurate with VB (one ingot/week) and with charge collection efficiencies commensurate with THM (mid 10−2 cm2/V) in long bars typical of commercial applications. [ABSTRACT FROM AUTHOR]

Heating procedures dramatically influence the physical-mechanical properties of rock. In this paper, via both numerical simulation and laboratory experiments, we examine the influence of constant temperature period (CTP, from 0.5 to 5 h) and predetermined temperature (PDT, from room temperature to 1,000℃) on the tensile mechanical properties of the Qinling granite, China. Results indicate that: CTP has a significant impact on the tensile mechanical properties of granite. For different PDTs, the density, longitudinal wave velocity (LWV) and tensile strength (TS) of granite decrease with increasing CTP. When CTP reaches the constant temperature turning-point (CTT), heating has fully affected the granite samples. The variation in LWV and TS versus temperature can be divided into four stages: 25–200℃, 200–600℃, 600–800℃ and 800–1,000℃. LWV and TS are negatively related to temperature and are more sensitive to temperature at higher PDTs. In addition, TS is more sensitive to temperature than LWV when PDT increases. The effects of CTP and PDT on LWV are similar to that of TS. Since the measurement of LWV is lossless, researchers can safely determine the appropriate CTP or CTT for any PDT and predict the tensile mechanical properties of rock by LWV analysis. [ABSTRACT FROM AUTHOR]

Magnetic hyperthermia uses the therapeutic heat given by the magnetic particles (MPs) in the alternating magnetic field for the healing of various cancers. The low Curie temperature particles are intelligent tools for the malignant cell destruction. These magnetic systems are used in the magnetic hyperthermia due to their special magnetic properties as high magnetization and magnetic permeability/susceptibility and low Curie temperature ( \(T_{c}\) ) within the range of 42 °C–46 °C. Capability of the Fe–Cr–Nb–B systems to heat uniformly in the hyperthermia range, a complex region with multiple metastases (two spherical metastatic tumors) surrounded by a cubic healthy tissue was the main purpose of this paper. The temperature inside as well as outside the region was computed by finite element method. A significant blood vessel (BV) is located at different distances from tumors. The cooling effect produced by blood flowing in a BV was considered. The presence of the BV induces the thermal gradients within tumors. Their values depend on the tumor–BV distance. The frequency and amplitude of magnetic field and MP concentration are optimized to get the temperature therapeutic range 40 °C–42 °C within tumors as liver, lung, and breast. The heating is automatically stopped when the temperature reaches \(T_{c} = 42\) °C within tumors. Low particle concentrations inserted in the small injection sites are able to heat the tumor to the therapeutic range. [ABSTRACT FROM AUTHOR]