This paper aimed to analyze the properties of rubber agglomerate panel, a heterogeneous material. After making three adjustments using three classical differential fractional models, namely, the Scott-Blair model, the generalized fractional Maxwell model (FMM), and the 1D standard fractional viscoelastic order for fluids (SFVOF), this paper assessed the number of parameters in those models for rubber agglomerate panel, made from rubber grains and urea thermoplastic elastomer (TPE). Combining data published from an undergraduate thesis with Microsoft Excel software and the solver command, this paper obtained better sample results using four parameters, rather than two or three complicated material function equations. Data of Ribeiro Alves in 2019 came from hardness experiments. Then this paper transformed deformation data into creep compliance in accordance with equation $J(t)=\varepsilon / t$ (mm/s), and obtained graphical adjustment representations, parameter values, and eventually adjustment equations. However, results from the modified FMM and 1D SFVOF were more comparable, and certain hypotheses were investigated to choose the better model. It was determined that the generalized FMM fit the data the best for this time period. With a certain margin of error, this model could be used for constructing new recycled materials and rubber agglomerate panel using Salvadori equipment. However, it is suggested that new and recent materials should be tested in order to solve environmental problems.

In an oil-film lubricating system, fit clearance and the different types of lubricating oil can result in changes in the orbit of shaft center, thereby affecting the stability of the system. Subject of this paper is the camshaft lubricating system of airspace engine, to figure out the effects of fit clearance and the type of lubricating oil on the shaft center orbit of camshaft, in this study, a 3D model of the camshaft lubricating system was built for simulation purpose based on Reynolds equation, and the calculation results suggest that, as the fit clearance grows larger, the convergence position of shaft center gradually moves away from the starting position, and the stability of shaft center declines; in terms of the type of lubricating oil, the higher the viscosity of the lubricating oil, the closer of the position of shaft center to the starting point, and the higher the stability. Our research method can be applied to common oil-film lubricating systems and we hope it could provide a theoretical evidence for the selection of fit clearance and type of lubricating oil for such systems.

Turboprop engines are widely used in the commuter or light transport aircraft (LTA) turboprop engines, because they are more fuel efficient than the propeller, which has a low jet velocity, at flight velocities below 0.6 Mach. For short distances, turboprop engines are more fuel efficient than jet engines, because the light weight assures a high power output per unit of weight. In addition, turboprops are known for their efficiency at medium and low altitudes. Turboprop engines require an exhaust stub (or nozzle) to duct the engine exhaust flue gas outboard of the aircraft. The design of these exhaust stubs is dictated primarily by the aircraft configuration. During the exhaust stub design, full flow at bends and in diffusing sections must be realized by following the established practice for the design of internal flow ducts. Otherwise, the flow will separate from the wall, causing unnecessary pressure loss and reducing the effective flow area. This paper discusses some of the many variations in exhaust stub design, and examines how they influence the performance of the engine, the performance of the aircraft, and the manufacturing aspect. The authors carried out a detailed analysis on the influencing parameters, such as the location, orientation, flange dimension, and geometric effective area of exhaust port. On this basis, the authors determined the jet temperature at exhaust stub exit and temperature at exhaust stub exit plane and nacelle midsection were determined at both static and cruise condition, laying the data basis for further analysis on the exhaust temperature effects over the nacelle and aircraft surfaces.

The world is presently confronted with the twin crisis of resource restriction and environmental degradation. The search for solutions that promise a harmonious correlation with sustainable development, energy conservation, efficiency, and environmental preservation has become highly important. The main purpose of innovative studies on fuel refinement and combustion engines is to improve fuel properties by adding fuel additives. In this study, the impact of Titanium dioxide, TiO₂, nanoparticles solution blended with diesel fuel on the performance and emission characteristics of four-stroke combustion engine OM 364 EU III, manufactured by IDEM Co and licensed by Daimler Benz, has been investigated. The selection of TiO₂ nanoparticles is based on the easy access in the market and the gap recognized; in previous literature, these nanoparticles were added to biodiesel or n-butanol blends. The proposed combined fuel in this study contains 2.5 ppm TiO₂ nanoparticles dissolved in 1200 [ml] water and added to 60 [Lit] base diesel fuel. The results of the aforementioned combined fuel have been compared with the base diesel fuel. It has been observed that applying nano-additives improves the mechanical performance of the diesel engine, such as power, torque, brake-specific fuel consumption, and thermal efficiency. Moreover, soot, unburned hydrocarbons, and carbon monoxide have declined by 2.78%, 3.55%, and 3.32%, respectively, due to TiO₂ nanoparticles' catalytic effect on fuel combustion. However, the amount of NOx has increased up to 3.09% because of the high cycle temperature.

Convectional refrigeration is one of the causes of global warming as carbon dioxide is emitted from its refrigerant to the environment. Semiconductor-based refrigeration is one of the alternative technologies that can lower the carbon dioxide emissions to the atmosphere as it uses electron gas instead of a refrigerant as its working fluid. The present work aims to design and construct a semiconductor-based refrigerator and test its performance. The refrigerator was designed to cool 4×10^-3 m^-3 of water from a temperature of 30℃ to 0℃. The tests performed on the refrigerator were retention time of the temperature of the water, change in the water temperature at different intervals of time, and the cooling rate of the water. The results of the tests indicated that the temperature of the water dropped from its initial value of 30℃ to 0℃ after 225 minutes, and maintained the temperature of 0℃ for 15 minutes. After the refrigerator was switched off, the temperature of 0℃ was retained for approximately 30 minutes, and then took 192 minutes to rise from 0℃ to its initial value of 30℃. The average cooling rate for the duration of 225 minutes was 0.133℃/min. The current work widens the studies on the use of alternative technologies for convectional refrigeration.

In the process of robot bone grinding, a large amount of heat is generated, which will cause mechanical and thermal damage to bone tissues and nerves. It is necessary to study the influence of cooling and lubrication parameters on the robot bone grinding temperature and establish the prediction models among them. The FE model of single abrasive bone grinding was established to explore the influence of cooling and lubrication parameters on the bone grinding temperature. Response surface design of experiment was carried out to obtain the simulation results, and Design-Expert was used to establish a multiple regression prediction models of grinding temperature under the condition of different cooling and lubrication. Through the variance and response surface comparative analysis of the prediction model, the influence rules of the bone grinding parameters and the cooling and lubrication parameters on the bone grinding temperature was obtained. A robot bone grinding experiment was performed to prove the accuracy of FE simulation and prediction model. The research results show that the relationship between grinding temperature and cooling lubrication parameters obtained by FE simulation, RSM prediction and experiment verification is consistent, and the simulation model and prediction model of cooling and lubrication parameters are proven to be correct and effective. The influence rules and prediction effects obtained in this study will provide a reasonable scheme for doctors to implement robot bone grinding with high efficiency and low damage, and establish the theoretical basis for the effective control of robot bone grinding force thermal damage.

This study aims to realize continuous, high efficiency defrosting of air-to-air heat pumps using the effect of outdoor warm air recycling, trying to improve the coefficient of performance (COP) and total heat capacity of traditional defrosting methods like hot bypass and Joule heating. The proposed patented method recovers heat from the air change system by mixing the warm discarded air with the incoming air of the external heat exchanger. The fan of the external unit sucks the indoor air with the depression obtained by a Venturi. The warm air is ducted to the Venturi through a hole in the wall. The amount of warm air mixed to the outside air is regulated by a butterfly valve installed on the pipe from the hole to the Venturi. In this way, the air entering the external coil is warm enough to avoid frost. The energy efficiency of the system is assured, for the warm indoor air is heated with the high COP of the heat pump. Our system can achieve defrosting with a limited amount of warm air, and realize a higher overall COP than the best traditional defrosting systems. Finally, the defrosting device can be added as an option to any existing split systems.

Bilinear and bicubic interpolations were often used in digital elevation models (DEMs), image scaling, and image restoration, with the aid of spatial transform techniques. This paper resorts to bilinear and bicubic interpolations, along with the spatial transform of images, to present the temperature distribution on a plate with a circular hole. The Dirichlet boundary conditions were applied, a rectangular grid was created, and the nodal values were calculated using the finite difference method (FDM). These methods were also employed to represent the mechanical stress distribution on a plate with a circular hole, under the presence of uniaxial stress. In this case, the nodal values were calculated using the analytical method. Experimental results show that bicubic interpolation generated continuous contours, while bilinear interpolation had a discontinuity in some cases. The results were comparative to images for similar cases when solved through ANSYS.

Although many fluidized systems are not vertically oriented, little research has been done on fluidization within inclined channels. The fluidization of the gravitational force and the tensile force may be substantially opposing in the vertical system. The theory of gravitational field fluidization, which is related to industrial fluidization processes like coal gasification, iron ore reduction, and catalytic cracking and calls for the use of standing tubes or angled risers, has to be developed in order to encompass various orientations. Without underlying theories, engineers must rely on vertical fluidization equations to build these sloping systems. A significant barrier to improving the design and optimization of new solid circulation systems is the tendency of fluidization. Based on historical developments and theoretical progress, the study presents an overview of recent advancements of liquid-solid fluidized beds in inclined columns. The fluidized bed is investigated as a whole by looking at the governing factors.

This paper intends to improve the hydrogen production efficiency of the electrolysis cells, fully utilize wind energy, and ensure the reliability of power supply. For this purpose, the authors put forward a capacity optimization configuration for non-grid-connected wind-hydrogen hybrid energy storage system, in view of the features of hydrogen production efficiency. The working interval of the electrolytic cell was optimized by analyzing the said features. Considering the features of battery charge/discharge, equipment capacity and power, the authors formulated the energy management strategy applicable to six working conditions, established the quantitative multi-objective function of system cost and reliability, and solved the optimization model by the fast non-dominant sorting genetic algorithm (NSGA)-II. In this way, the optimal combination of energy storage capacity was determined. Next, the wind velocity data of a pastoral area in Inner Mongolia was measured, and analyzed in details. The analysis results show that the electrolytic cell always operates in the optimal working area, and the optimized wind-hydrogen system is economic and reliable in power supply. The research provides a reference for practical engineering applications.

During the operation of the ground source heat pump (GSHP) system, the operations of the chiller system should be controlled by adjusting the difference between water temperature and wet bulb temperature. Therefore, it is important to consider the control strategy for the switch time (ST) and wet bulb temperature difference (WBTD) of the chiller system. This paper sets up two control strategies, namely, the strategy to control the ST of system operations, and the strategy to control the WBTD. Then, theoretical modeling was carried out to compare the system energy consumption and borehole wall temperature under different strategies. The modeling results were referred to optimize the control strategy for composite GSHP systems. It was found that, under the ST control strategy, the best wet bulb temperature is 2℃, and the best chiller operation hours are 3h; under the WBTD control strategy, the best wet bulb temperature is 3.5℃, and the best WBTD is 1.5℃. In addition, the ST control strategy is superior to the WBTD control strategy, in terms of system energy consumption, borehole wall temperature and initial investment.

The atmospheric pressure air plasma technology is based on the general principle of transforming the air into an ideal conductor of plasma energy thanks to the application of an electric potential difference able to ionize the molecules. Applying the principle to the human surgery, it comes to be possible to assure an energy transfer from plasma-generator devices to the human tissue in a relatively simple way: passing through the air, with exceptionally limited effects in terms of tissue heating. Such a condition is very useful to assure effective treatments in surgery: less thermal damage, fewer side effects on the patient. This is also what emerged during the use of innovative devices embedding the Airplasma® technology (by Otech Industry S.r.l.), where temperatures on human tissues were measured stably below 50°C. However, the profiles assumed by the temperature along the different electrodes during the operating conditions are rather unclear. This knowledge is essential to improve the efficiency of the electrodes (through their redesign in shapes and materials) as well as to reduce the invasiveness of surgical interventions. The present work had the purpose of characterizing the most common electrodes thanks to temperature measurements carried out by infrared sensors respect to different operating conditions. A simplified finite element model was also developed to support the optimal redesign of electrodes.