Novel method doped carbon with nanoparticle Cr2O3 and thin film has been studied in much thought in wavelength range, the doping can help new excellent physical and chemical properties for carbon, this application has a semiconductor feature. Nanocomposite thin film deposited on copper and glass substrates have been created by utilizing Spray Pyrolysis method. The precursor solution for the nanocomposite (Cr2O3/C) was blended with the polyethylene glycol as a colloidal. The optical band gap is a crucial property for the nanocomposite, for instance, nanocomposite thin film of Cr2O3/C was kept by shower process on glass and copper substrates. The band gap for the nanocomposite photo-catalytic has been finished using X-ray diffraction, UV-Vis spectrometer. The assessed optical band gaps for direct and indirect transition values determined and were 3. 5, 3. 25 eV and photon energy 1. 65 eV to carbon doped by nanoparticle Cr2O3. Thin film thickness ranging between 45-160 μ m This paper achieved the doped carbon by nanoparticles of Cr2O3 for thin layer coating in flat plate collector. New coating activity may be given by novel nanocomposite Cr2O3/C structure as a semiconductor. Results showed a new nanocomposite to enhance the absorption of the solar energy light activity. Prog. Color Colorants Coat. 13 (2020), 143-154© Institute for Color Science and Technology.

The performance of a water-ammonia air-cooled absorption chiller cycle is evaluated using a low temperature source of solar thermal energy in accordance with Tehran's climatic conditions in different working conditions. energy and exergy analysis of an absorption chiller with computer code written in EES software is performed. Exergy analysis showed that 71% of the exergy loss in the system is related to the generator and 24% is related to the absorber. The results showed that with increasing the generator temperature to a certain temperature, the coefficient of performance increased. The generator temperature of 70 degrees at low absorber temperatures performs better than other generator temperatures. As the generator temperature rises to about 70, the exergy efficiency increases and then the exergy efficiency decreases with increasing temperature. As the temperature of the generator decreases, the circulation ratio increases, and at temperatures below 70 degrees, this increase is seen as exponential and so undesirable that it makes it practically impossible to use the cycle at temperatures below 70 degrees. With the other negative effects seen at temperatures above 80 to reduce the exergy efficiency, the generator temperature between 70 and 80 seems appropriate for the proposed absorption cooling system.

The first and second laws of thermodynamics have been employed to evaluate energy and exergetic efficiency of the single effect absorption chiller which is used for air conditioning purpose. The performance analysis has been carried out by developing a computer program in EES and modeling the chiller and its components. To evaluate entropy of the water/lithium bromide solution at any point, an empirical correlation has been utilized. Exergy destruction and thermodynamic properties at any point in the cycle are evaluated by using related equations or build in property data. The results showed that maximum exergy destruction was occurred in the generator and the absorber at various operating conditions and these components had greater effect on the energy and exergetic efficiency rather than condenser and evaporator. Thus, it can be clearly stated that the generator and absorber are the most important components of the absorption chiller. The results also showed the exergetic efficiency was less than the energy efficiency due to exergy destruction taking place within the absorption chiller. Therefore, it can be concluded that the exergy analysis has been proven to be a more powerful tool in pinpointing real losses and can be used as an effective tool in designing an absorption chiller and obtaining optimum operating conditions.

Thin-walled tubes play a significant role in increasing the energy absorption in energy absorbing systems. Holed thin-walled tubes are a suitable option for use in these systems due to the ease of production and the lack of geometry complexity. In this paper, a new geometric pattern for holed thin-walled cylindrical tubes made of aluminum alloy 6061 is presented, to improve the energy absorption characteristics. To this aim, the Taguchi design of experiment method has been used to find the optimal levels of the geometrical parameters of the tube to achieve the maximum energy-to-weight ratio and the minimum effective equivalent strain. The number of rows of holes, the number of holes in each row, the diameter of the small hole and the diameter coefficient of the small hole were considered as the geometric (input) parameters of the tubes. The initial crushing force, the total absorbed energy, the ratio of energy to weight and the ratio of the maximum initial force to the average force were compared for the optimal layouts. Examining the results showed that the arrangement of the holes in the middle with 3 rows of holes, 8 holes in each row, diameter of the small hole of 5 mm and the diameter coefficient of 1. 2 (the large diameter is 6 mm) will lead to the best energy absorption result.

An ever-increasing number of fatal and severe injury road crashes have made road safety a long-lasting worldwide challenge. Behind any traffic conflict indicators are assumptions that take them away from the real road crashes. To relax the inelastic assumption, we conducted road crash analysis using multi-body elastoplastic dynamic finite element simulations in Ls-Dyna. We considered different crash scenarios defined by collision angle, relative velocities of vehicles involved, and the area of impact on vehicle bodies. Analyzing vehicle crashes using the law of conservation of energy, we calculated the amount of dissipated energy during a crash. The dissipated energy is revealed as the extent of damage to vehicle bodies during a crash. For each crash scenario, the amount of absorbed energy was calculated, and different modes of failure were observed.

In most engineering structures the energy absorption systems are used to prevent or reduce damages. In this paper, performance of a crushing element of ER24PC locomotive is investigated. The numerical modeling of this crushing element, after introducing its operation, is performed using the Abaqus finite element software in order to evaluate its crushing characteristics. Since the shape of crushing element of ER24PC locomotive is tapered, an analytical solution has been used to validate the numerical results. Because of the thickness of crushing element, rupture may be occur in this element and using of a proper damage model is essential in order to simulate this rupture. From three damage models introduced in this paper, one damage model is already provided in Abaqus and the other two models have been coded. By comparing numerical results with experimental test results, proper damage model in software is developed and used in order to properly simulate the crashing process of considered element. The desirable damage model is verified by using ECE R66 standard. Finally in order to improve the energy absorption capacity metallic foam is used as a filler in energy absorber element. Through comparing the energy absorption behavior of foam filled crushing element with the non-filled element the foam performance in crushing element is evaluated.

absorption systems have been in the spotlight of scientists due to their capability to utilize excess energy and heat produced by other working systems. One of the inhibitory factors in using these systems is their low efficiency. This inhibitory factor has been a reason for scientists to propose different configurations for these systems. Investigation of these systems using the second law of thermodynamics could lead to understanding of the reasons behind their low efficiency. In this paper, variations of coefficient of performance and exergetic efficiency of single, double and triple effect parallel and series water-lithium bromide absorption systems with generator temperature in different evaporator temperatures are analyzed using a code written in Engineering Equation Solver (EES). The obtained results demonstrate the excellence of triple effect absorption systems in comparison to double and single effects. Exergetic efficiency increases 10 to 18 percent for each increase of complexity of system. These results also depicts the excellence of parallel systems to series ones. Also, the rate of refrigerant fluid working in the cycle to heat delivered to the high temperature generator is higher for parallel systems compared to series ones and is higher for triple effect systems.

Sound is one of the forms of mechanical energy and the two main characteristics of sound are intensity or power and frequency or wavelength of sound.their performance against the incoming sound wave, industrial silencers can be divided into two general groups of resonating and absorption silencers, the main difference between these silencers is the release of sound energy from the channeling system, which is one of the common examples of the use of resonating type silencers, their use in It is the internal combustion engines that distinguish absorption silencers from the resonator type based on the fact that the main and visible part of the act of muting the sound is achieved by changing sound energy to heat energy.The goal of this article is to design a muffler based on the breaking of sound frequencies resulting from the movement of fluid in the exhaust output of vehicles, which leads to a reduction of at least 50 db of sound and gives the operator enough peace and concentration. In this article, after examining three types of mufflers, absorbent mufflers that use the properties of porous absorbent material to absorb passing sound and are the simplest form of mufflers, have been selected, analyzed and reviewed and are suitable for the OM457 engine of Idem Industrial Company. It designed for maximum inlet exhaust temperature is 520 and for the maximum kW power is 315 with the maximum discharge relative pressure of 185 mbar for homogenization with the standard atmosphere.