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The battery needed to store electricity is an essential element of a photovoltaic energy production system. The place where this system element is located, during its operation, will thermally influence the way the battery works. The specialized literature presents studies on the influence of temperature on the electrical working capacity of the battery, but through this scientific paper we want to study a concrete case of a LiFePO4 battery and quantify the influence of temperature differences in the working space on the differences in the energy capacities generated by the same battery. The experimental setup allowed recording the temperature of the space where the battery is placed for a long time, so we ensured that the temperature of the battery is approximately equal to that of the working space, just like in a real case of a photovoltaic system. The monitoring of the electric power of the battery in operation was carried out only during its discharge, by imposing a constant discharge current simultaneously with the recording of the voltage at the battery terminals throughout this cycle. At the end of the experiments, we associated the average temperatures during the discharge cycles with the average powers discharged by the battery in each thermal frame. The quantification was achieved by relating the power differences generated to the temperature differences of the different thermal situations experienced. The importance of this study resides into the highlighting of importance to maintain an optimal temperature for the space where the batteries are stored, having as technical effect the maintaining the power's functioning optimal rate of these. The design of a photovoltaic system must be oriented to a long term calculus regarding power's rate depending by battery's working space temperature. [ABSTRACT FROM AUTHOR]

Heating is a knotty factor contributing to device degradation of flexible organic solar cells (FOSCs), and thermal regulation plays a crucial role in the realization of long operational lifetime. Herein, a passive cooling strategy for stable FOSCs is proposed by boosting the optical‐thermal radiative transfer to reduce the insufficient thermal dissipation and the elevated temperature caused by irradiation‐induced heating, while retaining their flexibility and portability. A spectrally selective coupling structure consisting of subwavelength hemisphere pattern and distributed Bragg reflector is integrated into FOSCs to collectively enhance out‐coupling of infrared radiation and limit near‐infrared absorption‐induced heat generation, leading to a reduced heat power intensity of 292.5 W cm−2 and the decreased working temperature by 9.6 °C under outdoor sunlight irradiation. The D18:Y6:PC71BM‐based FOSCs achieve a power conversion efficiency of over 17% with a prolonged T80 lifetime as long as one year under real outdoor working conditions. These results represent a new opportunity for enhancing the operational stability of FOSCs. [ABSTRACT FROM AUTHOR]

The main objective of this study is to investigate the adaptation of wind turbines at the Gibara II Wind Farm in Cuba, which operates in a tropical climate that differs from the typical conditions in which these turbines are designed and manufactured in the northern hemisphere. The study utilizes condition monitoring techniques supported by Big Data acquired through a supervisory control and data acquisition (SCADA) system. By statistically processing normalized databases using multiple linear regression equations, the study establishes mathematical models that characterize the behavior of critical variables such as bearing, oil and winding temperatures, electrical generation, and specific climatic conditions unique to the wind farm under analysis. These models are essential for advancing condition-based maintenance (CBM) practices and developing preventive measures to mitigate functional failures. The significance of this research lies in the historical technical performance of the equipment under investigation, highlighting the importance of addressing the challenges posed by different environmental conditions. The study was conducted using the relevant regulatory technical documentation pertaining to the design of the wind turbines at the Gibara II Wind Farm. [ABSTRACT FROM AUTHOR]

• Mixed nitrates with elevated working temperature were obtained by adding KCl/K 2 CO 3. • The eutectic point and composition of NaNO 3 -KNO 3 -KCl were predicted by phase diagram. • BP algorithm combined with GA was used to overcome the shortcoming of calculation software. • The accuracy and credibility of prediction of phase diagram and machine learning were verified. • Specific heat capacity of the mixed molten salts was calculated by using FactSage software. Mixed nitrates with relative low melting point have widely been used as thermal storage medium in the concentrated solar power stations. However, their maximum working temperatures aren't high enough to integrate with more efficient power generation systems such as the supercritical CO 2 cycle. In the present work, mixed nitrates with elevated working temperature were obtained by adding KCl/K 2 CO 3. With the help of FactSage software and back-propagation (BP) algorithm combined with genetic algorithm (GA), the eutectic compositions and melting points of NaNO 3 -KNO 3 -KCl and NaNO 3 -KNO 3 -K 2 CO 3 were predicted, and the validity of BP algorithm combined with GA was verified. Based on DSC and TG curves, the melting points of the as-prepared NaNO 3 -KNO 3 -KCl and NaNO 3 -KNO 3 -K 2 CO 3 are 206.12 °C and 207.24 °C, respectively, which are in agreement with predicted values. Moreover, their decomposition temperatures were increased to more than 640 °C. In addition, the specific heat capacity of both mixed molten salts was measured, and it also was calculated by using FactSage software. This work provides two new ternary molten salts based on nitrates with higher working temperature and develops the prediction method on phase diagram calculation and machine learning. [ABSTRACT FROM AUTHOR]

• A multifunctional direct expansion solar-air source heat pump system is proposed. • Comparison of performance to the system's own air source heat pump to establish switching logic. • The impact of the working temperature on the system performance in different season was studied. Solar energy is the most important renewable energy source for achieving carbon neutrality. The problem of steady and efficient operation must be promptly addressed due to the inconsistent and variable nature of solar energy. This research proposes a multifunctional heat pump using the R417A refrigerant, which combines a direct expansion solar heat pump (DXSHP) with an air source heat pump (ASHP), resulting in a direct expansion sola-air source heat pump (DX-S/AS-HP). The system could operate in three modes: combined cooling and heating, domestic water heating, and space heating. The performance of solar heat pump and air source heat pump in different modes was compared, and the switching logic of different modes was developed accordingly, and the performance of the system at different working temperatures was analyzed. The results demonstrate that in combined cooling and heating mode, the system's average comprehension coefficient of performance (COP) could approach 6.0. In DX-SHP mode, the average COP for domestic water heating and space heating is 3.94 and 4.25, respectively, which is greater than the air source heat pump in similar working conditions. Switching from DX-SHP to ASHP for domestic water heating is only necessary when solar irradiation is less than 300 W m −2, while switching to ASHP for space heating is only necessary when solar irradiation is absent. The greater the working temperature, the lower the COP. While the working temperature has little effect on thermal collecting efficiency. [ABSTRACT FROM AUTHOR]

An effective method to prolong the use time and long-term stability of gas sensors is by lowering the working temperature. However, reducing the working temperature and increasing the sensitivity of a gas sensor is essential to enhance gas-sensing performance. In this work, Sr-doped ferrite bismuth nanomaterial has been synthesized by the facile sol–gel method and their surface morphology, microstructure, and surface chemical composition were characterized. Sr-doped ferrite bismuth is a single-phase nanomaterial with about 50 nm average grain size and rhombohedral crystal structure (Space Group R 3c). The gas-sensing results show that Sr dopant can significantly enhance the sensitivity and reduce the working temperature. Furthermore, the optimum working temperature of Sr-doped BiFeO3 sensor reduces from 244 °C to 208 °C. At the optimum working temperature (208 °C), Sr-doped BiFeO3 gas sensor's sensitivities to 200 ppm ethanol and acetone are nearly the same value (49.5), which are respectively 1.3 and 1.4 times more than BiFeO3 gas sensor at 244 °C. A related gas-sensing mechanism is also discussed.

Many harmful gasses are released during the burning of fossil fuels. Thus, it is essential to create gas sensors with high efficiency and low power consumption. The easy chemical bath deposition approach was used to produce the MnO 2 -incorporated polythiophene (PTh/MnO 2) composite thin film, and its potential application in NO 2 gas sensing at the operating temperature was comprehensively examined. The physicochemical properties were examined using FT-IR, FE-SEM, EDAX, AFM, and other instruments. The effects of adding MnO 2 on the physicochemical and NO 2 -sensing properties were studied. Out of all the oxidizing and reducing gases, the PTh/MnO 2 composite sensor showed the highest NO 2 selectivity when tested at operating temperature (NH 3 , Cl 2 , H 2 S, NO 2 , and methane). Every PTh/MnO 2 composite thin film demonstrated improved NO 2 sensing capabilities, with a maximum sensitivity of 95.67 percent for 100 parts per million of gas and a response of 20.93 percent for 0.5 parts per million of gas. Furthermore, they all reacted remarkably well to decreased NO 2 gas concentrations. [Display omitted] • MnO 2 incorporated polythiophene (PTh/MnO 2) composite thin film for gas sensing applications. • Highest sensitivity of 95.67 % and the shortest response time of 11 sec for NO 2 • Low working temperatures for NO 2 gas sensor. [ABSTRACT FROM AUTHOR]

Nanostructured NiO thin film was prepared by the sol–gel spin-coating technique and used for low-concentration ammonia (NH3) detection at elevated temperatures. The x-ray diffraction (XRD) pattern confirms the cubic phase with a polycrystalline nature. Field-emission scanning electron microscopy (FESEM) shows uniform spherical-shaped grains and substantiates the evident porosity of the film. The film shows 94% of transmittance in the visible region and has an optical band gap of 3.64 eV. Hall measurement confirms the p-type conductivity at room temperature. X-ray photoelectron spectroscopy (XPS) reveals the presence and electronic states of nickel (Ni 2p3/2, 2p½) and oxygen (O 1s). Gas-sensing studies on the NiO film reveal that the response was comparatively deprived at low- (< 250°C), and high-temperature (> 250°C) regimes, demonstrating that the reaction directions are spontaneous, along with the rate of adsorption (and diffusion) being extremely slow, with the desorption process dominating the adsorption, resulting in a positive value of Gibbs free energy ( Δ G ). Especially, at a working temperature of 250°C, the film exhibits the limit of detection (LOD) at 0.2 ppm with a response of 1.91 × 102%, and a maximum response of 4.01 × 10 3 % toward 5 ppm of NH3 concentration. This remarkable response at low concentration is attributed to the smaller crystallite size and porosity. In addition, and more significantly, the working temperature reduces the depletion region between the grains. As a consequence, this lower the potential barrier and accelerates the diffusion rate. Hence, increasing the response. [ABSTRACT FROM AUTHOR]

In this paper, a polymer dispersed liquid crystal (PDLC) film with good electro-optical properties and wide working temperature range was prepared by the UV-polymerization induced phase separation (PIPS) method by optimizing the curing temperature using a LC with wide temperature range. The investigation found that when the polymerization temperature was at the clearing point of the prepolymer/LC mixture, the film had better electro-optical properties and a high contrast ratio of 51 at 90 °C, and the rise time and decay time were respectively as fast as 241.5 ms and 1750 ms at −20 °C. This study provides further methodological guidance for the curing process of PDLC film, and promotes its application in outdoor smart windows. [ABSTRACT FROM AUTHOR]

In this work, luminescence-tunable high-power white light-emitting diodes (WLEDs) were fabricated by printing phosphor-in-silicone on 3-D ceramic substrates with adjusted dam structure. The 3-D ceramic substrate was prepared by a simple and efficient magnetic field-oriented grouting method in which silicate ceramic dam with adjusted height and angle was reliably bonded on a planar direct plating ceramic (DPC) substrate. The phosphor concentration of WLEDs was optimized to realize white light. At the phosphor concentration of 12 wt%, the packaged WLEDs achieve cool white light and high optical consistency. The influence of dam height and angle on the optothermal performances of WLEDs was investigated. As the dam height increases from 0.5 to 1.0 mm, the luminous efficiency (LE) of WLEDs first increases and then decreases, and the correlated color temperature (CCT) gradually decreases. At the dam height of 0.7 mm, the WLED achieves a high LE of 122 lm/W and a suitable CCT of 5008 K. Furthermore, the LE increases from 122 to 132 lm/W and the CCT decreases from 5006 to 4458 K when the dam angle changes from 0° to 40°. Importantly, the dam height and angle have no obvious influence on the surface temperature of WLEDs, and the WLEDs still display a low surface temperature even at high input current due to the effective heat dissipation of dam structure. The results indicate that the fabricated WLEDs achieve the tunable luminescence and low working temperature, which can be treated as an efficient and reliable high-power white source. [ABSTRACT FROM AUTHOR]

The use of ultra-high-strength steels (UHSS) has been growing in recent years, mainly in the automotive industry. Since these steels have high strength and hardness, more applied stresses are required to deform them, probably also impacting friction behaviour. In this article, a variation in the process parameters commonly observed in sheet-metal forming, such as contact pressure, sliding speed, lubrication and working temperature was performed. The material used was TRIP1000. These process parameters were varied, aiming to investigate the friction-coefficient behaviour; however, it was observed that there were no significant variations, indicating that the steel hardness may have contributed to this. Another finding is that, even if the lubricant did not change the average value of the friction coefficient, it contributed to a more stable process, favouring the absence of premature wear of the tools. [ABSTRACT FROM AUTHOR]

Based on experimental study and computer modeling of working temperature influence on the efficiency of Chinese production silicon solar cells identified temperature dependence of efficiency shows the feasibility of using Chinese production Si-SC in the construction of photovoltaic thermal system, which together with the heat pump is part of a combined system for hot water supply, heating and air conditioning. Based on a detailed analysis of the working temperature influence on the efficiency of photovoltaic processes that determine the solar cells work, it has been developed the optimal construction and technological solution of hybrid solar generated module, the main feature of which is the heat exchange block, designed to reduce the solar cells working temperature. The experimental testing of hybrid modules samples equipped with developed cooling system, high-voltage part of power take-off system demonstrates their reliability and high efficiency which allow to achieve the such module efficiency up to 18.5 %.

The existing method of calculating the working temperature of a gear housing is refined by taking account of the contact thermal conductivity, which depends on the materials used in the housing and the frame, the machining quality of the supporting surfaces, and the tightening of the screws that attach the housing to the frame. As an example, the housing temperature of a worm gear is calculated. [ABSTRACT FROM AUTHOR]

In this paper, a polymer dispersed liquid crystal (PDLC) film with good electro-optical properties and wide working temperature range was prepared by the UV-polymerization induced phase separation (PIPS) method by optimizing the curing temperature using a LC with wide temperature range. The investigation found that when the polymerization temperature was at the clearing point of the prepolymer/LC mixture, the film had better electro-optical properties and a high contrast ratio of 51 at 90 °C, and the rise time and decay time were respectively as fast as 241.5 ms and 1750 ms at −20 °C. This study provides further methodological guidance for the curing process of PDLC film, and promotes its application in outdoor smart windows.

Pure WO3 sensors and Mn3O4/WO3 composite sensors with different Mn concentrations (1 atom %, 3 atom % and 5 atom %) were successfully prepared through a facile hydrothermal method. As gas sensing materials, their sensing performance at different temperatures was systematically investigated for gas detection. The devices displayed different sensing responses toward different gases at specific temperatures. The gas sensing performance of Mn3O4/WO3 composites (especially at 3 atom % Mn) were far improved compared to sensors based on pure WO3, where the improvement is related to the heterojunction formed between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 °C, 150 °C and 210 °C, respectively. The demonstrated superior selectivity opens the door for potential applications in gas recognition and detection.

In this work, we proposed a chip on thermoelectric cooler (chip-on-TEC) for the active thermal management of high-power light-emitting diode (LED). The chip-on-TEC was prepared by electroplating a circuit layer on the cold-side substrate of thermoelectric cooling (TEC) and directly attaching LED chips on the circuit layer. Due to the Peltier effect of TE materials and the low thermal resistance of chip-on-TEC structure, the heat generated from the chips can be dissipated to the surrounding environment effectively. The performances of chip-on-TEC were studied by using the thermal simulation and packaging experiment. Compared with the traditional packaging structure, the working temperature of chip-on-TEC is greatly reduced under various chip currents. At the chip current of 1.0 A, the chip-on-TEC can reduce the working temperature from 232 °C to 114 °C (the reduction of 51%). Moreover, the light output power of LED is increased by 35.3%. The chip-on-TEC also can improve the light intensity and the light saturation point of LED. The results demonstrate that the chip-on-TEC is a promising thermal management for high-power LED packaging. [ABSTRACT FROM AUTHOR]

Summary: Utilization of fuel cells as a source of driving power would expose them to dynamic variable loading conditions depending on the driving profile and environmental circumstances. The present research study aims to investigate the dynamic behavior of a single‐cell proton exchange membrane fuel cell (PEMFC) subjected to various loading modes and operation parameters. A fuel cell with hydrogen gas as fuel has been assembled as the test module. Three different voltage load modes were designed and applied to the cell. The corresponding current variation of the cell as its dynamic response was measured. The dynamic behavior of the cell was examined for various control parameters such as the cell working temperature, inlet humidification temperature, and stoichiometry. The experimental results indicated that the working temperature of 65°C provided the best fuel‐cell performance among the three investigated working temperatures of 45°C, 55°C, and 65°C. At different humidification temperatures, the Ta/Tc = 70°C/60°C humidification condition led to the best fuel cell performance due to the adequate wettability of the membrane. However, the humidification temperature might also have induced a minimal impact on the dynamic response of the fuel cell. Although past studies have indicated that higher stoichiometry achieved better cell performance, the experimental data of this study demonstrated that the cell performance of λa/λc = 1.5/2.0 was better than λa/λc = 1.0/1.0 or 3.0/3.0. The influence of the load modes on the performance of the fuel cell was distinguished when the load was high and driving load changed rapidly. Thus, in the present study, the dynamic behavior of a single cell has been investigated and the outcomes can be directly employed for validation of future theoretical models. [ABSTRACT FROM AUTHOR]

Polymer-based dielectric capacitors are widely-used energy storage devices. However, although the functions of dielectrics in applications like high-voltage direct current transmission projects, distributed energy systems, high-power pulse systems and new energy electric vehicles are similar, their requirements can be quite different. Low electric loss is a critical prerequisite for capacitors for electric grids, while high-temperature stability is an essential pre-requirement for those in electric vehicles. This paper reviews recent advances in this area, and categorizes dielectrics in terms of their foremost properties related to their target applications. Requirements for polymer-based dielectrics in various power electronic equipment are emphasized, including high energy storage density, low dissipation, high working temperature and fast-response time. This paper considers innovations including chemical structure modification, composite fabrication and structure re-design, and the enhancements to material performances achieved. The advantages and limitations of these methods are also discussed. [ABSTRACT FROM AUTHOR]

The commercial capacitor using dielectric biaxially oriented polypropylene (BOPP) can work effectively only at low temperatures (less than 105 °C). Polyphenylene oxide (PPO), with better heat resistance and a higher dielectric constant, is promising for capacitors operating at elevated temperatures, but its charge-discharge efficiency (η) degrades greatly under high fields at 125 °C. Here, SiO 2 layers are magnetron sputtered on both sides of the PPO film, forming a composite material of SiO 2 /PPO/SiO 2 . Due to the wide bandgap and high Young's modulus of SiO 2 , the breakdown strength ( E b ) of this composite material reaches 552 MV/m at 125 °C (PPO: 534 MV/m), and the discharged energy density ( U e ) under E b improves to 3.5 J/cm 3 (PPO: 2.5 J/cm 3 ), with a significantly enhanced η of 89% (PPO: 70%). Furthermore, SiO 2 /PPO/SiO 2 can discharge a U e of 0.45 J/cm 3 with an η of 97% at 125 °C under 200 MV/m (working condition in hybrid electric vehicles) for 20,000 cycles, and this value is higher than the energy density (∼0.39 J/cm 3 under 200 MV/m) of BOPP at room temperature. Interestingly, the metalized SiO 2 /PPO/SiO 2 film exhibits valuable self-healing behavior. These results make PPO-based dielectrics promising for high-temperature capacitor applications.

Laser-driven white lighting has been considered as a next-generation high-brightness white lighting source. Thermally stable color converter is an essential down-conversion material for phosphor-converted white laser diodes (pc-wLDs), which inevitably endures high-density laser excitation and huge heat shock from conversion loss. In this work, we proposed a thermally self-managing phosphor-in-glass (PiG) converter to enhance the heat dissipation of reflective pc-wLDs. The PiG converter was prepared by printing and sintering a phosphor glass film on the cold side of thermoelectric cooler (TEC). By controlling the input current of TEC, the heat generated from phosphors under high-power laser excitation was effectively and initiatively dissipated into the ambient environment due to the Peltier effect of TE materials. As the laser power (LP) increases from 0.73 to 5.6 W, the working temperature of PiG film slowly increases from 2.3°C to 6.1°C. The maximum temperature of PiG film is reduced by 61.1 °(~91%) at the LP of 5.6 W. Furthermore, the PiG-TEC-based pc-wLD achieves a cool white light and stable light quality under various LPs. At the LP of 4.5 W, the correlated color temperature (CCT) of pc-wLD is 6449 K, and the chromaticity coordinate of pc-wLD is (0.3139, 0.3274). The results indicate that the proposed PiG-TEC converter enhances the thermal performance of high-brightness laser-driven white lighting. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiO) thin films were deposited on to the glass substrates via chemical bath deposition (CBD) method at various deposition times of 5, 6, 7 and 8 h. The X-ray diffraction (XRD) study showed the cubic crystal structure of NiO. The field emission scanning electron microscopy (FE-SEM) images exhibit the porous structured morphology composed of randomly oriented nanosheets. The atomic force microscopy (AFM) analysis reveals the maximum surface roughness of 107.9 nm for NiO film deposited at 7 h. The X-ray photoelectron spectroscopy (XPS) study reveals the presence of Ni2+ and Ni3+ chemical states. The transmission electron microscopy (TEM) images reveal an average size of 5 nm for NiO nanocrystalline particles. The nitrogen dioxide (NO 2) gas sensing performance was tested at various working temperatures and gas concentrations. The sensing tests showed 45.6 % response to 100 ppm NO 2 at 200 °C with T response = 13 s and T recovery = 146 s. [ABSTRACT FROM AUTHOR]

Copyright of Electrical Engineering & Electromechanics is the property of National Technical University, Kharkiv Polytechnic Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The made research results of the dependence of the film photovoltaic converter efficiency on their operating temperature and their comparison are considered in the paper. The physical mechanisms of temperature influence analysis on output, diode and electronic parameters of photovoltaic converters were conducted. The output parameters determination of the flexible photovoltaic converters was carried out by measurement of light current-voltage characteristics by using illuminator based on powerful semiconductor LEDs with different colors for simulated radiation which is close to the standard ground and ultraviolet solar spectrum. For ensuring effective non-destructive switching of the test specimens of the flexible PVC based on cadmium telluride to the measurement circle, the special contact device was developed and used. The main feature of contact device is four separate vertically moving metal probes in form of semi spheres with polished surfaces, which makes it impossible to puncture the PVC electrodes. These probes have possibility of individual positioning of each probe that is carried out with the help of a hard rotary console of variable length attached to the body and can be pressed with a given effort without impact on the frontal and any rear electrodes of the PVC experiments. The efficiency temperature coefficients of the photovoltaic converter, which make up for devices with a CdTe of 0.14 %/C, CuInSe2 – 0.36 %/C, amorphous silicon -0.21 %/C were obtained. The analytical processing and analysis of the light diode characteristic effect on the PVC efficiency based on the CdTe showed that the temperature stability of their efficiency is ensured by the diode current density, the incision of which increases by 50 % from 1.9·10-9 A to 2.7·10-9 A with the temperature rise from 20 °С to 50 °С. At the same time, it has been established for PVC on the CuInSe and amorphous silicon base that the decrease of short circuit current density, open circuit voltage and fill factor of current-voltage characteristics plays the main role in efficiency reduction with rising temperature. [ABSTRACT FROM AUTHOR]

Abstract Phosphor-in-glass (PiG) is considered as a stable and efficient color converter for high-power white lighting due to its high thermal stability, excellent mechanical strength, and facile preparation process. However, the low thermal conductivity of PiG hinders the heat dissipation of phosphor, which limits its application in high-brightness white laser diodes (LDs). In this work, we proposed a heat-conducting PiG with dual-sapphire plates for laser-driven white lighting. The PiG_sapphire was fabricated by screen-printing and sintering a phosphor glass film between the dual-sapphire plates. In order to avoid the film delamination, a low-melting borosilicate glass matrix with similar expansion coefficient of sapphire was prepared. The optical performances of PiG_sapphire based white LDs were adjusted by varying the thickness of phosphor glass film. Furthermore, the PiG_sapphire exhibits low working temperature (<50 °C) at the up/down surfaces under various laser powers compared with the traditional PiG, which is attributed to the effective heat transfer channels of dual-sapphire plates. The PiG_sapphire maintains high emission intensity and stable luminescence at much higher laser power. The results demonstrate that the heat-conducting PiG_sapphire is a promising color converter for high-brightness laser-driven white lighting. Highlights • The heat-conducting PiG with dual-sapphire plates was fabricated for white LDs. • The borosilicate glass has similar expansion coefficient of sapphire was prepared. • The luminescence of PiG_sapphire were adjusted by varying phosphor film thickness. • The PiG_sapphire has low temperature at both surfaces under various laser powers. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • The low-cycle fatigue behavior of Cr18Mn18N0.6 austenitic steel is studied under strain controlled condition. • Cyclic softening that is affected by the ratio of tensile strength over yield stress is found. • Relationships such as stress-life and strain-life are analyzed with theoretical equations. • Dislocation structures with twins during fatigue test are observed via transmission electron microscopy. • Cr18Mn18N0.6 austenitic steel possesses a higher low-cycle fatigue resistance compared with conventional steel alloys. Abstract Low-cycle fatigue characteristics (e.g. cyclic stress-strain curves, strain-life curves, stress-life curves, and transition fatigue life) of austenitic stainless steel Cr18Mn18N0.6 used for supercritical turbogenerator retaining rings were studied under an axial strain controlled condition with total strain amplitudes ranging from 0.005 to 0.0085 at working temperature 100 °C. Cr18Mn18N0.6 was found to be cyclic softening during low-cycle fatigue with the extent and rate of cyclic softening increasing with strain amplitude. Stress amplitude decreased more rapidly for larger applied total strain amplitude. The transition fatigue life of Cr18Mn18N0.6 was found to be about 2177 cycles. Fatigue crack initiated from a relatively flat zone at the specimen surface due to persistent slip band and surface roughening. Cr18Mn18N0.6 austenitic stainless steel was found to possess a high low-cycle fatigue resistance compared with conventional steel alloys like 304 stainless steel. [ABSTRACT FROM AUTHOR]

Experimentally established, the influence of the working temperature and solar radiation power on the efficiency of industrial production silicon solar cells. Based on the experimental results designed the concept of a hybrid solar generating module equipped with a mirror concentrator of solar radiation and solar cells cooling system for using in high-performance solar energy station. Concentrator of solar radiation provides in 1.5-time increase of electrical power generating by such module, and water-cooling system can reduce the equilibrium temperature of the module up to 10 degrees and twice reduce efficiency losses from solar cells overheating. The proposed concept will reduce the number of modules needed to build solar energy station. [ABSTRACT FROM AUTHOR]

• Oxygen sensors play a crucial role in the effective operation of the Active Oxygen Control System (OCS) in the liquid LBE coolant system of one of the Gen. IV reactors (lead-based reactors). • Using 8 mol% yttrium oxide stabilized zirconia (YSZ) as solid electrolyte, three kinds of gas refence sensors with LSCF, LSMr and Pt electrodes were developed. • Sensors were tested in static LBE saturation environment, and their operating temperature characteristics were obtained. Oxygen sensors play a crucial role in the effective operation of the Active Oxygen Control System (OCS) in liquid LBE systems. In this study, the performance of LSCF/air, LSM/air and Pt/air reference electrode sensors with yttrium stabilized zirconia (YSZ) as the solid electrolyte in the static oxygen saturated liquid lead bismuth eutectic alloy (LBE) was evaluated with varying temperature range by measuring the electromotive force. Compared with the activation temperature of Pt electrode sensor (420 °C), the activation temperature of LSCF electrode and LSM electrode sensor is as low as 320 °C. The LSCF/air and LSM/air sensors show good performance in the high and low temperature tests. However, the electrochemical balance of the Pt/air reference sensor has an irreversible effect at the lowest temperature, leading to the sensor malfunction. During the temperature transient process, the electromotive force (EMF) measured by the sensor shows a deviation from the theoretical value. Besides, the LSCF/air reference sensor has the smallest deviation and the Pt/air reference sensor has the largest deviation. Therefore, the LSCF electrode sensor exhibits best performance in the low operating temperature region. [ABSTRACT FROM AUTHOR]

• The liquid crystal phase temperature ranges of PDLC films are increased by using high clearing-point mesogenic compounds. • The working temperature range of the PDLC film is further expanded. • The effects of different mesogenic compound structures on the performance of PDLC films are studied. • The influence of mesogenic compound structure on the properties of the host liquid crystal is thoroughly investigated. As a type of smart dimming film, polymer dispersed liquid crystal (PDLC) film can meet the functional requirements in fields of displays and smart windows, but its narrow working temperature range is far from satisfactory for outdoor applications. To solve this problem, two types of high-clearing point mesogenic compounds with different end groups were introduced and the effects of their chemical structure on the working temperature range of PDLC film were investigated. Results show that the PDLC film doped with 10 wt% fluorine-containing LC molecule (3F) has a low driving voltage (<36 V) at −20 °C, but its contrast ratio (CR) value at the high temperature is disappointing. Furthermore, by adding 10 wt% cyano LC molecule (3 N), the film maintains an excellent CR value (62) at 90 °C. This work provides theoretical guidance and experimental support for broadening the working temperature of PDLC films, which is an important factor for their applications in automobile smart windows. [ABSTRACT FROM AUTHOR]

Semiconductor oxides with high sensing capacity remain a real challenge from long ago. Several attempts were considered to enhance the sensor's performance factors and achieve high quality requirements. In the present work, we operated a chemical sensor using intrinsic and vanadium doped zinc oxide. These samples were prepared and deposited using low cost spray pyrolysis technique. The structural data revealed good surface morphology and roughness, confirming the existence of ideal environment for oxidizing/reduction reactions. The addition of 4% vanadium minimized the grain size with a diameter lower than 9 nm. The gas testing measurements showed that vanadium doped ZnO presented higher response compared to pure ZnO. V-doped ZnO confirmed an improvement of the optimal operating temperature which varies from 350 °C to 300 °C at 100 ppm of acetone, 50 ppm of ethanol and 500 ppm of H 2 . Furthermore, V-doped ZnO showed a maximum response reaching 100 at 100 ppm, for 450 °C. This high response is attributed to the effect of vanadium impurities that altered ZnO structure which was confirmed by structural data. [ABSTRACT FROM AUTHOR]

Accurate prediction of the remaining useful life (RUL) of lithium-ion batteries is important for battery management systems. Traditional empirical data-driven approaches for RUL prediction usually require multidimensional physical characteristics including the current, voltage, usage duration, battery temperature, and ambient temperature. From a capacity fading analysis of lithium-ion batteries, it is found that the energy efficiency and battery working temperature are closely related to the capacity degradation, which account for all performance metrics of lithium-ion batteries with regard to the RUL and the relationships between some performance metrics. Thus, we devise a non-iterative prediction model based on flexible support vector regression (F-SVR) and an iterative multi-step prediction model based on support vector regression (SVR) using the energy efficiency and battery working temperature as input physical characteristics. The experimental results show that the proposed prognostic models have high prediction accuracy by using fewer dimensions for the input data than the traditional empirical models.