Scattering and absorption sections of Schwarzschild-anti de Sitter with quintessence

In this paper, we study the scattering and absorption sections of the Schwarzschild--anti de Sitter black hole surrounded by quintessence. The critical values of the cosmological constant and the normalization factor are obtained. We describe the event horizons and the extremal condition of the black hole surrounded by quintessence. The effects of quintessence on the classical and semi--classical scattering cross--sections have been estimated. Also, the absorption section is studied with the sinc approximation in the eikonal limit. We consider the quintessence state parameter in the particular cases ω = -2/3 and ω = -1/2.

Thermodynamic Investigation of Integrated Air Cycle Refrigeration Systems

An analysis of air cycle refrigeration (ACR) systems based on the first and second laws of thermodynamics has been carried out. Cooling the gas cooler outlet enhances the system efficiency, hence the use of integrated refrigeration systems (IRSs). The IRS consists of an ACR, an absorption chiller and a prime mover. The waste heat from the prime mover operates the absorption chiller, which provides additional cooling that is used to cool down the air exiting the gas cooler. LiBr-H2O and NH3-H2O are used as fluid pairs in absorption section. The prime mover can either be gas turbine or solid oxide fuel cell (SOFC). Results indicate that an IRS with NH3-H2O and two recuperators has a better first and second law efficiency compared to other considered systems. It is also concluded that the energy utilization factor and second law efficiency are higher for the system with SOFC as a prime mover.

Preparation of Tb³⁺-doped K₂GdF₅ Used to Neutron Dosimetry

The neutron absorption section of gadolinium atom is very high, so that the K2GdF5 crystals doped with Tb3+ ions have been studied for neutron dosimetry by the thermoluminescence (TL) method. The K2GdF5 crystals doped 2%, 3% and 5% concentrations of Tb3+ ions were synthesized by solid state reaction method. The TL properties were studied after the exposure of the samples to neutron source. The experimental results showed that the TL glow-curves of K2GdF5:Tb3+ has the simple, suitable shape for the dosimetry applications. The TL sensitivity of this material is higher than that of commercial TLD-100 and TLD-900 dosimeters. The thermal fading effect of Tb3+-doped K2GdF5 is very low. The glow curve consists of the main peak at temperature of 202oC. The glow curve deconvolution into individual the peaks showed that the curve had a main peak at 202oC, and kinetic order b = 2. The study results indicated that the K2GdF5 doped with Tb3+ is very remarkable material can be applied in neutron dosimetry field.

EXERGY ANALYSIS OF A VAPOR COMPRESSION–VAPOR ABSORPTION CASCADE SYSTEM

In this paper, second law analysis has been done for the vapor compression–vapor absorption (VC–VA) cascade system. Ammonia–water is considered as the working pair in absorption section and R407C is dealt as the working fluid in VC section. Exergy destruction or the irreversibility rate is determined in each components of VC–VA cascade system, for a wide range of cooling capacity by considering a variable speed reciprocating compressor. Further in this, Coefficient of structural bond (CSB) analysis is carried out to quantify the effect of varying the generator temperature, effectiveness of solution heat exchanger, inlet temperature of external fluids in evaporator/condenser and some other variables. Solution heat exchanger and the condenser are reported to have high CSB value, so have a great scope of improvement to reduce the irreversibility rate of the whole system.

A Contrastive Analysis of the Crashworthiness between 22MnB5 and DP590 Front Bumper Inner Plates

The front bumper inner plate was researched based on contrastive analysis of the crashworthiness considering using 22MnB5, a typical hot forming AHSS (Advanced High Strength Steel) and DP590, a kind of general high strength steel. In this paper, we contrasted energy absorption, section force, and maximum displacement of the two different front bumper systems in low-speed collision. The analysis shows the front bumper inner plate using hot forming AHSS can improve the crashworthiness of automobiles and make it more balanced and reasonable to transfer collision energy and force. As a result, the maximum displacement of the front bumper system decreases and other parts such as front side rails can be safer. Thus, using hot forming AHSS in designing a front bumper inner plate can improve the passive safety of automobiles.

Study on Sintering Red Mud Desulphurization Characteristics in Liquid-Column Impingement Scrubber

The feasibility of sintering red mud as wet desulphurization sorbent was studied in this paper. The comparative study of desulphurization efficiency by using sintering red mud and traditional desulphurization sorbent-limestone had done in Liquid-column impingement Scrubber apparatus. The effects of gas velocity, liquid-gas ratio and pH value on desulphurization efficiency were studied. Results show that the desulphurization efficiency of sintering red mud is lower than that of limestone in the same slurry mass concentration, while the sintering red mud can be used as desulphurization sorbent when increase its slurry solid content in appropriate way. The gas and droplets can mix well in absorption section when the gas velocity is upper than 2.7m/s. The desulphurization efficiency higher than 80% can be obtained when L/G ratio higher than 15L/m3 and the pH values between 5.2- 7.