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The working temperature of solar module has a significant effect on the performance. In this paper, the effect of temperature on ideality factor for PERC monofacial solar module was investigated based on single-diode equivalent circuit modelling. It is found that the ideality factor of PERC monofacial solar module decreases with the increasing temperature under different irradiances. The non-ideal behaviour can be reflected in deviation of the ideality factor from unity and its temperature dependence.

SHS-produced TiC–Al2O3 powders were used as a filler of organosilicon polymers and ethoxyline resin to prepare electroconducting polymeric compounds. The electrical conductivity of thus prepared polymeric compounds was found to depend on the amount of added ceramic powder, temperature, and type of polymer binder. A threshold effect observed for the temperature dependence of compound resistance can be used in designing temperature sensors and temperature/current-limiting devices. Our polymeric compounds can also be recommended as a material for film heaters with a working temperature of below 300°С.

In this work, a series of PdO catalytic ZnO/SnO2 (PdO–ZSO) nanoparticles have been synthesized by a two-step approach including a low-temperature (− 10 °C) precipitation followed by a PdO dipping process. The composition, surface morphology, and crystal structure of the as-obtained samples were characterized by multi-techniques. And the gas-sensing properties toward formaldehyde (HCHO) were evaluated. The results indicate that the PdO–ZSO nanoparticles exhibit high sensitivity (5.4) and rapid response (37 s)/recovery (87 s) to 10 ppm HCHO at 140 °C through optimizing the ratio of PdO, ZnO, and SnO2 in nanoparticles. Comparing with the traditional SnO2 sensor without ZnO and PdO, the sensors’ working temperature is much lower and the response–recovery speed is also improved. In addition, the specific sensing mechanism was discussed preliminarily.

The detection of oil-dissolved gases (such as CO, CH4 and H2) in transformers on-line is an important technology to predict and judge the operating status of transformers. Microstructure and gas sensing performance of Au-MoS2 microspheres synthesized by hydrothermal method were investigated in the present research. The results indicated Au-MoS2 based gas sensor has excellent response to CO, CH4 and H2 gases with maximum responses of 25.48, 16.75 and 8.48 at 30 ppm in their optimum working temperature (150 °C, 150 °C, 175 °C). In addition, First-principle calculation was carried out to expound the sensing mechanism in detail. The conclusions of this study suggest that Au-MoS2 monolayer exhibits a promising applicable future in sensor detecting of oil-dissolved gases in power transformer.

In this letter, conductometric sensing devices based on VLS grown NiO nanowires were presented for the detection of low concentrations of NO2. Moreover, the shelf life of sensing devices stored in ambient environmental conditions was tested over a period of 6 months. The VLS grown NiO nanowires were uniform in nature, covering completely the substrate surface area, with diameters ranging from 10 to 50 nm. The sensing devices show excellent performances, such as good stability, high response, outstanding selectivity toward NO2 and low detection limit. The devices were tested toward different analytes such as H2, acetone, NO2, etc. Indeed, at optimal working temperature, they show highly selective behavior towards NO2. Finally, the shelf life study reports that, due the exposure to the atmosphere, NiO nanowires exhibit a decrease in their conductivity, which enhances the response of the sensor.

In this research, microstructure and mechanical properties of stir rheocast AA2024/TiB2 metal matrix composite have been investigated. The working temperature was 640℃, which was the selected semisolid temperature that corresponds to 40% of the solid fraction. Two weight percentage, 4 wt%, and 6 wt% of the TiB2 reinforcements were added to the matrix. The field emission scanning electron microscope micrographs of the developed composites showed a uniform distribution of the particles in the case of the 2 wt% and 4 wt% of the reinforcements. However, the particles agglomerated as the weight percentages of the reinforcement increases to 6%. The optical microscope of the liquid cast sample showed the dendritic structure, whereas the rheocast samples showed a globular structure. The X-ray diffraction analysis confirmed the distribution of the reinforcements in the matrix and the formation of some intermetallic compounds. Mechanical properties significantly improved by the addition of the reinforcements in the matrix. An increase in tensile strength of 13.3%, 40%, 28%, and 5% was achieved for the unreinforced rheocast sample, 2 wt%, 4 wt%, and 6 wt% reinforced rheocast samples respectively, compared to the liquid cast sample. An increase in 20% of hardness was attained for the composite with 2 wt% TiB2 compared to the liquid cast sample. According to the fractography analysis, small dimples were observed on the fractured surface of the unreinforced rheocast sample, whereas small and large voids were dominant on the fractured surface of the 2 wt% composite, which shows the ductile fracture mode.

Thermal energy storage (TES) with phase change materials is a promising approach for combined heat and power plants to enhance the electricity peak regulation capability and maintain stable heat-supply at the same time. Its cyclic performance is important under practical working conditions, however was rarely investigated. An experimental study on the thermocline TES was presented employing encapsulated paraffin wax packed bed as heat storage media and water as heat transfer fluid (HTF). The cyclic characteristics were revealed experimentally with consecutive charging/discharging processes. Convergence behavior was observed during the cyclic operation. It was found that the end-of-charging/discharging temperature distribution, charging/discharging duration and utilization rate of each cycle tend to be stable as the cycle number increases. It is believed that such behavior stems from the difference between the initial status and the end-of-charging/discharging criteria. The influences of flow rate of HTF, working temperature and initial status on the operational performance were investigated. The results indicated that the initial status had no significant impact on the TES performance after the convergence reached. Larger flow rate of HTF resulted in lower utilization rate and longer duration of each cycle. Especially the cyclic operation performance was strongly depended on the completeness of charging/discharging. These results may be helpful to understand such promising thermal energy storage technology, as well as the design and improvement of its auxiliary system.

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.

It is shown that the shape of a sample determines the allowed lower-bound limit of the coercive force of material that can be used for fabrication of magnets with the given shape. Rings with radial magnetization are used as examples to show that such samples can be made of only rare-earth alloys with the coercive force that is sufficiently high to satisfy technical requirements at the maximum allowed working temperature of the magnet.

P-type metal oxide semiconductors with special morphology have received high expectation for their potential application in gas sensors. We have synthesized hollow dodecahedral Cu2O nanocages with exposed (1 1 1) planes by a simple solution growth approach at room temperature. Characterization results indicate that the diameters of Cu2O nanocages are about 200 nm. Gas sensing performance of the Cu2O nanocages is investigated towards ethanol gas. Remarkably, the response of Cu2O reaches 4.6 at a low working temperature of 250 °C when the concentration is 100 ppm. The unique structure of Cu2O benefits the sensing performance owing to its active (1 1 1) planes.

The sandwich-like composite of double-layer Co3O4 and reduced graphene oxide (rGO) is successfully manufactured through a one-step hydrothermal method. The gas sensing test results indicate that the sandwich-like composite of double-layer Co3O4 and rGO (D-Co3O4/rGO) has a five-fold increase in response to 100 ppm triethylamine compared to conventional Co3O4 sensor at the optimum working temperature of 200 °C. The higher response may be attributed to the double-layer structure of Co3O4 in the D-Co3O4/rGO which can effectively utilize the surface areas of Co3O4. It is also capable of detecting a minimum concentration of 1 ppm of triethylamine gas.

Nowadays, many applications are demanding more and more compact, cost effective, and robust electric drives. By using rare earth magnets, it is possible to achieve electrical machines with rather high torque volume ratio, accomplishing this way the compactness requirement. Nevertheless, rare earth permanent magnets are very sensitive to the temperature, so that the risk of being partially demagnetized arises as their working temperature increases. In addition, as it has been seen during the last years, the market of rare earth metals is quite volatile. The price of magnets could rise suddenly, leading to a significant impact on the cost, and so in the competitiveness of permanent magnet machines. Due to this fact, it is essential to reduce the dependency on rare earth market in order to accomplish cost-effective drive solutions. Some key points to face this problem can be to reduce the magnet volume, or to use magnets with worse thermal properties (magnets with less dysprosium). Nevertheless, in both cases, the adopted solution would lead to an increase in the risk of demagnetization, affecting to the robustness of the machine. In this paper, a methodology based on finite element analysis and experimental test is proposed to evaluate the demagnetization risk in permanent magnet machines. By applying this methodology, it is possible to accomplish competitive machine designs, achieving a good tradeoff between cost and robustness. The proposed methodology has been applied in a practical case, for the optimization of ten industrial motors, achieving good results.

Mesin penggerak conveyor terdiri dari motor, gearbox, serta conveyor sebagai alatmemindahkan lumpur dengan motor 2,2 KW putaran 1400 rpm. Rangsangan gaya luarmenyebabkan terjadinya getaran paksa jika rangsangan tersebut berosilasi maka sistemdipaksa bergetar pada frekuensi ransangan. Penelitian memfokuskan pada analisa getaran padabagian block mesin yaitu Seal input gearbox, Gear input dan Seal Output gearbox searahhorizontal dengan mengukur kecepatan getaran dan temperatur yang dihasilkan. Getaran pada daerah3 yaitu seal output gearbox mengalami peningkatan 4,95 mm/s yang tidak stabil sehingga diprediksibahwa elemen tersebut getarannya tidak stabil dibandingkan gear input dan seal ouput gearboxsehingga perlu adanya perbaikan lebih lanjut. Daerah 2 yaitu gear input mengalami peningkatantemperatur 53,6 0C dibanding daerah 1 dan 3 tetapi elemen tersebut masih dalam kondisi stabil.Getaran terjadi pada elemen mesin berbeda beda pada setiap priode waktu serta temperatur kerjasetiap elemen mesin juga mengalami perubahan setiap priode waktu.

Due to changes in the working temperature in a shearer transmission system, it is easy to cause the transmission gear to work abnormally. In this paper, the first gear pair in a cutting transmission system of a permanent magnet semi-direct drive shearer was taken as the research object. The coupling effect of time-varying meshing stiffness, meshing damping, bearing clearance and gear backlash under thermal deformation were fully considered. Then, a three degree of freedom nonlinear dynamic model of the gear pair was established, and a dimensionless analysis was performed. Finally, the Runge-Kutta method was used in the numerical calculations. The motion characteristics of the system were analysed through the gear’s bifurcation diagram of the temperature at different frequencies and the bifurcation diagram of the frequency at different temperatures. The meshing state was analysed at different frequencies and temperatures. For the chaotic motion generated in the system, a periodic resonance excitation was applied to control unstable motion. This study has revealed various specific effects of the temperature on the dynamic characteristics of the system. In addition, the periodic excitation method can effectively control the nonlinear motion in the system and realise the control of the chaos under the temperature effect.

Two dimensional (2D) nanomaterials with porous structure have stimulated much research interest owing to their unique structure and fascinating physical and chemical properties. Here, ultrathin 2D porous nanosheets (PNSs) of pure and SnO2-decorated NiO with uniform hexagonal shape were synthesized by using the pre-synthesized Ni(OH)2 nanosheets precursor. The obtained SnO2/NiO PNSs were about 100∼150 nm in size and their mean thickness was about 7.5 nm. The gas sensing properties of the prepared pure and SnO2-decorated NiO PNSs were investigated intensively. It was found that after decorating with different amount of SnO2, the sensor based on NiO PNSs showed an improved sensing properties to methane (CH4), and the optimal SnO2 content in the composite was determined to be 2 mol%. At the optimum working temperature of 330 °C, the SnO2/NiO-2 sensor showed higher response and faster response/recover speed towards 500 ppm CH4 than the pure NiO sensor. In addition, the SnO2/NiO-2 sensor also exhibited a good long-term stability within 28 days, demonstrating its potential application for CH4 detection. The porous structure and p-n junction related sensing mechanism of SnO2/NiO PNSs was also discussed.

The aims of this research is to study and analysis on furnace walls with variation of hot face lining material types, variation of refractory material types, and variation of thickness of insulating materials to outer wall temperature at furnace with working temperature 1000 oC. This research uses a variety of hot face lining material in the form of ceramic fiber blanket with CR1260, CR1400, and CR1430, variations of refractory material in the form of refractory brick with the type NJM-20, NJM-23, and NJM-26, and using ROCKWOOL as an insulating material with a thickness variation of 50 mm, 75 mm, 100 mm. This research was simulated using Steady State Thermal ANSYS Mechanical (ANSYS Multiphysic) software. The result of the research shows the difference of the outer wall temperature value of the furnace. The highest wall temperature is in interaction with the wall without insulation, hot face lining material using CR1260, and NJM-26 as refractory material is 75.211 oC. While the lowest wall temperature is in the interaction of 100 mm thick insulation, hot face lining material using CR1430, NJM-20 as refractory material is 46.682 oC.

The Ni-Mn-Z (Z = Sn, In, Sb, Ga) based alloys are considered as promising magnetic refrigeration materials due to its giant inverse magnetocaloric effect, simple preparation and low cost. In this work, the transformation behavior and magnetocaloric effect of Ni42Co8Mn37.7In12.3 polycrystalline alloy has been investigated. It is found that both the temperature-induced martensitic transformation and its associated field induced metamagnetic transition occur near the room temperature. The large magnetic entropy change ΔSM of 14.30 J·K−1·kg−1 and large refrigeration capacity RC of 549 J·K−1 are achieved under 6 T within the broad ambient working temperature range of 248–295 K. Its magnetocaloric performance is outstanding among a great number of reported Ni-Mn-Z based alloys.

Zn2SnO4/SnO2(ZTO/SnO2) and Y doped Zn2SnO4/SnO2(ZTO/SnO2) microcubes were synthesized by a hydrothermal route at 130 °C and subsequently used for obtaining gas sensors. To evaluate the structure, morphology, chemical state and optical bandgap, our sensors were characterized by XRD, SEM, XPS and UV–vis analysis. Compared with sensors based on ZTO/SnO2 microcubes, the Y doped ZTO/SnO2 microcubes had an optimum sensing performance to 100 ppm formaldehyde (HCHO), for instance lower working temperature (210 °C) and better response (46.07). In addition, the enhanced sensing mechanism of Y doped ZTO/SnO2 microcubes was discussed in detail.

A novel rolling process characterized by multi-pass bi-axial reduction was proposed. An 800 MPa class low-carbon steel bar with ultrafine elongated-grain structures was fabricated using bi-axial rolling at a warm working temperature, and tensile and three-point bending tests were conducted at a temperature range from 77 K to 473 K. The texture in the developed steel bar was dominated by {0 0 1}〈0 0 1〉 cube orientations. The toughness–strength balance of the developed steel was remarkably improved compared with that of conventional 0.15%C ferrite–pearlite steel and 0.29%C martensitic steel. The toughness reached its maximum when crack branching started to appear upon decreasing the test temperature, and the specimen did not separate into two pieces even at low temperature of 77 K. A microstructural design that improves toughness in steel was demonstrated.

In the article on the basis of the conducted researches and available technical documentation on modern non-contact electric devices the approach to perfect a control system of heating element of equipment for the production of gasified models. The thermophysical features and mode of operation of heating elements used in equipment for the production of gasified models is given. The numerical value of the working temperature of the spiral of heating element is determined. It is shown that application of three phase Solid State Relays (SSR) increased the life of heating elements by an average of 400–450 hours. SSR in the systems for controlling the heating of liquid heat carrier of plants for the production of gasified models are promising.

Palladium film hydrogen sensor based on suspended micro hotplate has been fabricated to operate at elevated temperature with low power consumption. Below 150 °C, the response of the sensor to H2 is represented by an increase in resistance. At higher temperature, the phenomenon of resistance reduction appears when it comes into contact with H2. We have researched the reasons for this phenomenon and proposed that the sensitive mechanism is the redox reaction of Pd film on the suspended structure. The suspended substrate can affect the temperature at which redox of the Pd film occurs, and be sensitive to the changes of the surrounding gas stream. When the working temperature is 400 °C, the magnitude of response (S) changes to −0.4% within 2 s for 200 ppm H2, and S changes to −3% within 10 s for 4000 ppm H2. This micro hotplate based hydrogen sensor can control the range of operating temperature according to the performance requirements.

A series of high-response and fast-response/recovery n-butanol gas sensors was fabricated by adding ZnO to In2O3 in varying molar ratios to form ZnO-In2O3 nanocomposites via a facile co-precipitation hydrothermal method. Morphological characterizations revealed that the shape of pure In2O3 was changed from irregular cubes into irregular nanoparticles, 30–50 nm in size, with the addition of ZnO. Compared with the pure In2O3 gas sensor, the ZnO-In2O3 gas sensor exhibits superior n-butanol sensing performance. With the introduction of ZnO, the response of the sensor to n-butanol was improved from 17 to 99.5 at 180 °C for a [Zn]:[In] molar ratio of 1:1. In addition, the ZnO-In2O3 gas sensors show a reduced optimal working temperature, excellent selectivity to n-butanol, and good repeatability. The response of the ZnO-enhanced In2O3-based sensors showed a strong linear relationship with the n-butanol gas concentration, allowing for the quantitative detection of n-butanol gas.

Surface structure control at the atomic scale is an efficient strategy for improving the performance of gas sensing. Herein, hierarchical hollow MoS2 microspheres with enhanced performance for NO2 gas sensing were synthesized via a facile hydrothermal method. The introduction of micro-nano hierarchical structure improved the exposure of active edge sites of MoS2, and the efficiency of gas and carriers exchange and transportation during the reaction, which synthetically contribute the sensing performance enhancement. With additional optimization of reaction conditions, the hierarchical hollow MoS2 microspheres show excellent sensing performance with 3.1 times enhancement compared with the contrast sample of smooth solid structure. The rapid and sensitive response, decreased working temperature, as well as the prominent selectivity, enable the material with attractive sensing performance for NO2 detection. This study provides new opportunities on the surface morphology control at both the micro- and nanoscale for enhancing the sensing performance of MoS2.

Solar thermoelectric generators (STEGs) is one of the most important technologies for solar energy conversion. However, the inefficiency due to coupling constraints such like low working temperature and dimensionless figure of merit of the thermoelectric materials, also known as material’s ZT value, has been hampering the development of STEGs for a time. Here we demonstrate a high performance STEG system combined with solar concentrators and carbon nanotubes (CNTs) absorber, which can greatly improve the solar-thermal conversion process. The proposed STEG system enables a peak efficiency of 4.3% with solar concentration of 78, and a maximum power of 11.2 W at 106× suns. The enhanced efficiency is ensured by the optimized system thermodynamics due to the combination of solar concentration devices and CNT based solar absorber. Our design provides a universal prototype of solar thermal energy recovery system for distributed energy harvesting and deep-space explorations.

Resumen El objetivo de esta investigación fue estudiar la cinética de secado de la uchuva en un secador de lecho fluidizado, usando temperaturas de 60, 70 y 80°C, con velocidades de aire de 9.5 m/s. Se evaluó el efecto de la temperatura de secado sobre características del producto tales como pH, sólidos solubles (°Bx), acidez, humedad y color. Se estableció la cinética de pérdida de humedad, velocidad de secado y se obtuvo el coeficiente de difusión efectivo para cada temperatura de trabajo. Se ajustó una ecuación tipo Arrhenius para establecer la relación entre el coeficiente de difusión y la temperatura. Los resultados mostraron que el color de la uchuva se vio afectado principalmente por el tratamiento a 80°C. Además, los tiempos de secado para alcanzar un equilibrio fueron de 8, 5.5 y 5 horas para 60, 70 y 80°C respectivamente, con pérdidas de humedad de 92, 85 y 94%. Abstract The objective of this research was to study the drying kinetics of cape gooseberries in a fluidized bed dryer, using temperatures of 60, 70 and 80°C, with air velocities of 9.5 m/s. The effects of the drying temperature on product characteristics such as pH, °Bx, acidity, humidity and color were evaluated. The kinetics of moisture loss and drying rate were established and the effective diffusion coefficient was obtained for each working temperature. An Arrhenius equation was fitted to establish the relationship between the diffusion coefficient and the temperature. The results showed that color of cape gooseberry was affected mainly for the treatment at 80°C. Additionally, the drying times to reach equilibrium were 8, 5.5 and 5 hours for 60, 70 and 80°C respectively; with moisture losses of 92, 85 and 94%.

A novel chain-like nanostructure of Co3O4 was successfully prepared via a facile and reliable oxalate sacrificial template route, in which coralloid cobalt oxalate (CoC2O4·2H2O) precursor was first obtained through a room-temperature precipitation method and then used as sacrificial template to prepare Co3O4 by annealing at 500 °C. Au nanoparticles-decorated Co3O4 nanochains were also prepared by soaking the CoC2O4 precursor in Au+ solution before the annealing process. The prepared samples were characterized by XRD, FESEM, TEM, and N2 adsorption-desorption. Results indicated that the pure and Au-decorated Co3O4 nanochains were constructed by several end-to-end connected nanoparticles, and their specific surface areas were 28.42 m2/g and 37.39 m2/g, respectively. The gas sensing properties of the prepared samples were tested and compared. It was found that after being functionalized with Au nanoparticles, the Co3O4 nanochains showed an improved TEA sensing performance, such as lower optimal working temperature, higher response, and faster response and recover speed. In addition, the Au/Co3O4 sensor can also give a good linearity in the TEA concentration range from 10 to 200 ppm and considerable stability within 7 weeks, suggesting its potential application for quantitative detection of TEA. The improved gas sensing mechanism of the Au/Co3O4 nanochain was discussed.

Ni-Co-Mn-Sb alloys can exhibit large elastocaloric effect characterized as stress-induced entropy change ΔSσ. However, the intrinsic large brittleness of polycrystalline alloys makes it difficult to directly measure the stress-induced temperature change ΔTad. Here, we demonstrate large elastocaloric effect in a directionally solidified Ni45.7Co4.2Mn37.3Sb12.8 alloy with enhanced mechanical properties. Large ΔTad up to 9.4 K was realized through compressive stress-induced martensitic transformation with a low transformation strain of 1.5%. Moreover, with integrating large ΔSσ up to 25.4 Jkg−1 K−1 and wide working temperature window of 46 K, a giant refrigeration capacity RCσ of 930 Jkg−1 was achieved under the compressive stress of 250 MPa.

The compounds La0.67Pb0.33Mn1−xFexO3 (0 ≤ x ≤ 0.10) have been fabricated by ceramic procedures mainly to investigate their structure, magnetic phase transition and magnetocaloric effect. All samples have a rhombohedral structure belonging to $$R\overline {3} C$$ space group by structural analysis. As the Fe concentration x increases up to 0.10, Curie temperature value significantly decreases from 360 to 210 K. The maximum values of MEC (magnetic entropy change) are found to be 4.17, 2.99, 2.58 J kg−1 K−1 under 5 T field change for x = 0, 0.05, 0.10, respectively. The corresponding values of RCP (relative cooling power) are 229.8, 235.4, 216.5 J kg−1. The relatively large MEC, high RCP values and the convenient adjustment of the TC suggest that the prepared La0.67Pb0.33Mn1−xFexO3 compounds could be appropriate materials for magnetic cooling in a wide working temperature range. The analysis of isothermal magnetization using the Arrott curves and Franco’s universal method reveals that the La0.67Pb0.33Mn1−xFexO3 manganites show a second-order ferromagnetic–paramagnetic transition.

A novel cataluminescence (CTL) sensor was firstly fabricated utilizing α-MoO3 nanobelts as sensing material, which possesses lower working temperature of 120 °C for detection of diethyl ether gas. Under optimal conditions (200 mL min−1, 120 °C, 440 nm), as-made CTL sensor shows a wider detection range of 9.0–2000 ppm with a lower limit of detection of 7.5 ppm. The respond and recovery time were 16 s and within 2 s, respectively. Meanwhile, as-made CTL sensor exhibits an outstanding selectivity towards other 11 interferences. Besides, the highly stable signals were also obtained with the relative standard deviation of 2.60%. In general, α-MoO3 nanobelts as a sensing material have the potential application prospect in CTL sensor for detection of diethyl ether.

Compressive ductility of the as-cast AA7075 was nearly doubled by hot compression and by appropriate homogenization treatment. The latter dissolved the 2nd phase, and introduced compositional gradients around the ‘surviving’ precipitates. Direct observations, through split channel die compression, revealed a correlation between particle deformed zone (PDZ: deformed aluminum matrix surrounding coarse 2nd phase particle), the composition gradient and the working temperature. Local misorientation in the PDZ reduced, remarkably, with the introduction of composition gradient and higher working temperature. The generation of PDZ, especially the influence of the composition gradient and the working temperature, was modeled successfully with discrete dislocation dynamics (DDD). More importantly, tailoring the composition gradients around the second phase brought out clear technological possibility of improving the as-cast compressive ductility without sacrificing the particle content and the compressive strength.

This article presents the results of computational experiments aimed at determining the influence of the ambient temperature ( $${{t}_{a}}$$ ), wind speed (v), average working temperature ( $${{\bar {t}}_{{avw}}}$$ ), and emissivity of light-absorbing heat-exchange panels (LAHPs) $$\left( {{{\varepsilon }_{p}}} \right)$$ on their thermal losses through the translucent coating (TC) of the case of flat-plate solar water heating collectors (FSWHC) with a single-layer TC.

The significant Tc enhancement of 110 K in [N-fluoromethyldabconium] triiodide lead caused by the promising design of H/F substitution is the first and unprecedented, opening up an applicable and universal strategy to effectively regulate the Tc working temperature in phase transition materials.

In this paper, a sapphire-based ultra high temperature optical fiber deep ultraviolet (UV) detection system is proposed to detect the deep UV light emitted by the flame for fire alarm. In order to overcome the high temperature and high pressure environment in engine compartment, based on theoretical analysis and simulation, we designed a high temperature sapphire probe for deep ultraviolet light detection which realized the coupling of large incident angle ultraviolet light and transmission fiber. Experiments show that the system can detect 180–260 nm ultraviolet light, with the maximum working temperature of 1373 K and maximum measurement angle of 50° on one side. The system has a simple structure, low false alarm rate, and response speed of 53 ms.

Risk based analysis of temperature and time effects on fracture toughness values is applied to different regions of a welded joint made of low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Heterogeneity of microstructure and properties of welded joint is evaluated by testing standard 3BP specimens with crack tip located at different regions of a joint, including the base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Experiments were performed both at the room temperature and at design working temperature, 540°C. Based on these results, fracture toughness values are determined and used for risk based analysis, including risk matrix presentation as the basis for decision making process.

The influence of temperature on fracture toughness values in different regions of a welded joint is analysed low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Heterogeneity of microstructure and properties of welded joint is evaluated by testing standard 3BP specimens with crack tip located at different regions of a joint, including the base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Experiments were performed both at the room temperature and at design working temperature, 540°C. Based on these results, temperature effect on crack resistance is established for all different regions in a welded joint.

Ferroelectric materials have great potential use for solid-state refrigeration. However, their working temperature is restricted to Curie temperature; the working temperature can be increased by the new component of strain gradient-driven caloric effect or flexocaloric effect (FCE). The FCE relies on the inhomogeneous strain of the crystal lattice to induce polarization in centrosymmetric crystals (flexoelectricity). The strain gradient-induced polarization is defined by flexoelectric polarization coefficient and is utilized to estimate the FCE. As the FCE is a relatively new phenomenon, several ways can be used to calculate it. Different methods of flexocaloric quantification in ferroelectric materials (Pb(Mg1/3Nb2/3)O3 and Ba0.67Sr0.33TiO3) are discussed in the present work. The FCE can be obtained based on the measured properties and combination between the polarization and strain. This allows one to study the actual or net flexocaloric behavior in the material. It was found that the quantification of temperature change varies according to the method used for estimation. The experimental confirmation is required for validation of the proposed methods of estimation. Further, this work also discusses the possibility of other ways that are untouched by the research community. The analysis indicates a substantial untapped potential for solid-state refrigeration and warrants further research.

It is crucial to develop highly energy-efficient and selective sensors for wide concentration range of H2S, a common toxic gas that widely exists in petrochemical industries. In this work, MoO2 nanospheres were rapidly synthesized by microwave-assisted solvothermal method, and were subsequently fabricated into H2S gas sensor. The MoO2 nanospheres-based sensor exhibited excellent response toward H2S with good linearity in a wide concentration range (10–240 ppm). Besides, this sensor presented low working temperature, good repeatability, and selectivity against CH4, H2, and CO. The outstanding sensing performance results from the reaction between H2S and abundant chemisorbed oxygen introduced by oxygen vacancies of MoO2. This result indicates that MoO2 nanosphere synthesized by microwave-assisted solvothermal method is a promising sensing material for H2S detection.

Herein, we utilized molecular dynamic (MD) simulations using LAMMPS software and selecting Tersoff and Lennard-Jones potentials to design and investigate mechanical properties of (8,8), (9,9), (10,10), and (11,11) single-walled and (8,8)@(11,11) double-walled silicon-germanium (SiGe) armchair nanopeapods. The number of encapsulated fullerenes and the working temperature were changed as variables to evaluate the mechanical properties. The larger nanopeapods had lower Young’s modulus and failure strain, but, surprisingly enough, no significant variation was found in failure strain values by increasing the number of Si30Ge30 cages and the temperature (300–900 K). Overall, higher mechanical properties were the case for double-walled SiGe nanopeapods and that the more the number of encapsulated cages, the lower the mechanical properties whatever the nanopeapod. Amazingly, fullerenes remained undamaged even after the SiGe nanopeapods ruptured. Thus, thermally/mechanically stable nanopeapods developed theoretically herein can be considered potential super-carriers for drug and gene encapsulation.

Solid-state molecular rotor-type materials such as host-guest inclusion compounds are very desirable for the construction of molecular ferroelectrics. However, they usually have a low Curie temperature (Tc) and uniaxial nature, severely hindering their practical applications. Herein, by regulating the anion to control "momentum matching" in the crystal structure, we successfully designed a high-temperature multiaxial host-guest inclusion ferroelectric [(MeO-C6H4-NH3)(18-crown-6)][TFSA] (MeO-C6H4-NH3 = 4-methoxyanilinium, TFSA = bis(trifluoromethanesulfonyl)ammonium) with the Aizu notation of mmmFm. Compared to the parent uniaxial ferroelectric [(MeO-C6H4-NH3)(18-crown-6)][BF4] with a Tc of 127 K, the introduction of larger TFSA anions brings a lower crystal symmetry at room temperature and a higher energy barrier of molecular motions in phase transition, giving [(MeO-C6H4-NH3)(18-crown-6)][TFSA] multiaxial ferroelectricity and a high Tc up to 415 K (above that of BaTiO3). To our knowledge, such a record temperature enhancement of 288 K makes its Tc the highest among the reported crown-ether-based ferroelectrics, giving a wide working temperature range for applications in data storage, temperature sensing, actuation, and so on. This work will provide guidance and inspiration for designing high-Tc host-guest inclusion ferroelectrics.

A review the synthesis of thermoelectric materials (TEM) and techniques of their subsequent processing in order to obtain an optimal structure was carried out. TEM on basis of BiTeSe and BiSbTe were obtained by zone melting and extrusion, and PbTe and GeTe were obtained by hot pressing. On basis of X-ray fluorescence analysis, a correlation was established between the concentration of elements in the initial composition and in the manufactured samples. The investigation of thermoelectric parameters of TEM was carried out. The thermoelectric figure of merit in the working temperature range varies from 1.05 to 1.20. Vickers microhardness was established that for BiTeSe and BiSbTe it is from 33.5 HV to 60.2 HV. The microhardness of PbTe and GeTe is 51.7 HV and 125.7 HV, respectively. The obtained results are necessary for the development of techniques for mechanical treatment of TEM and the design of thermoelectric devices.

At present, LED lighting is gradually replacing the traditional lighting and becoming the fourth generation of light source. In the process of LED lighting, a large part of electric energy is converted into heat energy. If it can not dissipate heat in time, the device efficiency will be reduced or even damaged. Therefore, the heat dissipation problem of LED needs to be solved. By testing and recording the working temperature of the existing LED lighting radiator in different positions, the performance of the radiator was compared and tested. The experiment shows that the radiator works best when the light source is downward, and the temperature difference between the top and the bottom of the radiator is the smallest in this case, and the temperature at the top of the radiator is higher than that at the bottom in the working process. When the position of the LED lighting radiator changes, the heat dissipation performance of the top and bottom of the radiator changes.

A Chilean company dedicated to grape juice production used a 696 m2 parabolic trough collector to pre-heat the feed water of a liquefied petroleum gas boiler in a temperature range of 20–90 °C. During 2017 the solar field generated 241 MWhth of heat, a low value for a concentration collector of such dimensions located in a place with high irradiation. This study presents a methodology to identify enhanced scenarios of solar heat integration into a grape juice industry and among them select the best scenario from an energetic perspective. This methodology started with data gathering of the thermal processes of the industry and the solar field (monitoring campaign and logbook of the industry) to generate the annual thermal demand. In a second step, the maximum theoretical generation potential of the solar field (1,107 MWhth) was obtained with simulations in TRNSYS 18. Then, a Pinch Analysis to the process streams was performed to confirm that a higher solar heat integration potential (520 MWhth) existed. The next step consisted of identifying different scenarios to increase the solar heat integration and analyzing them with simulations in TRNSYS 18 to identify the best-case scenario. The main increase on the solar fraction was achieved for the scenario when the collector working temperature was increased up to 140 °C and when heat was integrated at process level. Furthermore, it was concluded that one of the reasons for low solar fraction was the low thermal demand during months with high solar irradiation.

The ZnO/CuO heterostructures were synthesized by two simple methods. The structural and morphological characterizations of the as-deposited samples were well evaluated by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The gas sensing characteristics of the pure CuO and ZnO/CuO heterostructure were discussed. By comparison, the ZnO/CuO heterostructure sensor synthesized by water bath deposition has a higher response than pure CuO obviously. At the optimal working temperature, the response of the CuO-ZnO gas sensor to ethanol (100 ppm) reached 31.2, which was about 4.3 times higher than the original CuO nanoparticles. Besides, this heterojunction also showed good selectivity towards ethanol. The ZnO/CuO heterostructure provides a feasible method for preparing high performance ethanol sensor

Development of thermoelectric materials for extracting electricity from heat has grown at a sweeping pace in the past few decades. Estimation of thermoelectric efficiency of a material requires determination of three parameters, viz., electrical conductivity, Seebeck coefficient, and thermal conductivity. Methodologies required for accurate determination of these three parameters may vary according to the nature of the material, its dimensions, working temperature, etc. Thus, this chapter introduces different methods employed and standard rules for the measurement of the thermoelectric properties of samples. Toward the end of this chapter, we also mention some of the common sources of errors and precautions to be taken to obtain results with minimum ambiguity.

Because of its simple handling and low temperature sensitivity, the direct methanol fuel cell (DMFC) system is very important to the development of energy converters. Also, the factors that inhibit the commercialization of DMFCs have a number of negative effects, such as the sensitivity of the polymer to the osmotic swelling of the electrolyte membrane, the passing of methanol through the membrane, the high cost, and the limited working temperature. The prepared product is based on the production and properties of polymer electrolyte membranes (PEMs) used in DMFC applications. © 2021 Elsevier Inc. All rights reserved.

The strength of a shaft-hub hybrid joint is affected by several factors, such as working temperature, interference level and coupling procedure. The first part of this study deals with temperature effect on the static response of shaft-hub hybrid joints. LOCTITE 648 anaerobic adhesive was applied for coupling 42CrMo4 tempered steel shafts to 16CrNi4Pb hardening steel hubs. The performance up to 100°C was experimentally investigated, involving press-fitted as well as shrink-fitted joints with interference up to 0.2%. Adhesive stripping upon coupling, adhesive degradation at high temperature and also frictional contribution decrease were highlighted. Afterwards, in the second part, the question of the adhesive being teared off under high interference was tackled. A hoop-channeled geometry was proposed, to increase the amount of adhesive remaining trapped at the joint interface. Hoop channels in the shafts proved to act as adhesive reservoir, thus facilitating adhesive dragging over the entire engagement length. Their effects on the joint strength were experimentally determined for both press-fitting and shrink-fitting coupling methods. The results, processed by the statistical tools of Analysis of Variance, orthogonality and pairwise tests, indicate the modified geometry is significantly beneficial for high interference press-fitted joints. Conversely, it may even be detrimental for shrink-fitted ones.

Catalysis is an effective and economical approach to reduce air pollutants and the development of high-performance catalysts is a critical factor in the employment of catalytic pollutant control technology. Considerable efforts have been made to develop catalytic technologies capable of reducing pollutants in flue gas with NH3-SCR being successfully industrialized for NOx abatement since the late 1970s. However, flue gas pollutants vary by fuel and can include varying concentrations of NOx, SOx, VOCs, and heavy metals. When combined with the varying temperature of flue gas and the source of pollutants, the effective removal of pollutants becomes challenging. Additional requirements have thus been suggested for the catalytic technology to efficiently remove multiple pollutants. In this chapter, the basic principles of SCR are first introduced. Some critical issues in SCR development, including the design of poison-resistant catalysts, catalysts exhibiting a wide working temperature window or low-sulfur conversion, and the industrial preparation and regeneration of deactivated catalysts, are then discussed in detail. Finally, research on and applications of simultaneous multi-pollutant catalytic treatments are presented.

11 figures, 3 tables.-- Supplementary information available., The attrition behaviour of several promising oxygen carriers tested in Chemical Looping Combustion (CLC) units has been evaluated using an air-jet apparatus based on ASTM D5757 at 20 and 800 °C. Results were evaluated to determine a general testing procedure that allows estimating the adequacy at working temperature of a potential oxygen carrier. For both fresh and used oxygen carriers, attrition was lower when the temperature of the Air Jet attrition Index (AJI) test was increased. Thus, tests with potential oxygen carriers must be performed close to the temperature they are planned to be used to obtain reliable information. Results indicated that used oxygen carriers with AJI value at hot conditions between 1 and 2% showed long lifetimes under continuous CLC operation., This work was supported by the Spanish National Research Council (CSIC) through the international collaboration project i-LINK+ 1225. The authors would also thank the support of the European Regional Development Fund (ERDF) under the program “Programa Operativo FEDER Aragón 2014-2020 - Construyendo Europa desde Aragón: Proyecto BiosinCO2 (LMP180_18)” and of the ENE2017-89473-R AEI/FEDER, UE. T. Mendiara thanks for the “Ramón y Cajal” post-doctoral contract awarded by the Spanish Ministry of Economy and Competitiveness.