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Aspartic proteases (APs) (EC 3.4.23.X) catalyze the hydrolysis of peptide bonds, a reaction that is fundamental to many biological processes. All of the vertebrate and most of the fungal APs are synthesized as zymogens. Porcine pepsin (EC 3.4.23.1) belongs to the aspartic protease family. Pepsin is a gastric aspartic protease and one of the three principal protein degrading enzymes in the digestive system. Pepsin is an industrial enzyme in the food industry. In this study, thermal stability of pepsin investigated in the different concentrations of aluminium in presence and absence of organic solvents ) butanol, ethanol, 1,4-Butanediol and glycerol). Thermal stability of pepsin increased in the presence of aluminium and decreased in presence of organic solvents ) butanol, ethanol, 1,4-butanediol ) and unchanged in presence of glycerol .Thermal stability of pepsin increased in presence organic solvents with adding of aluminium to its absence. possibly aluminum ions through electrostatic and dative interactions with carboxylate groups of Aspartic acid and Glutamic acid residues are bonded to pepsin structure, and causing to condense enzyme structure which leading to increasing thermal stability of pepsin. Mechanism of increasing thermal stability of pepsin is unknown in presence of aluminium. Therefore, we can reduce the instability of pepsin in presence of organic solvents by
Aluminium.

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Objective: Toxoplasmosis can lead to severe pathological effects in both infected humans and animals. The various DNA vaccines against Toxoplasma compose of single or cocktail antigens have been investigated but they have partial protective against disease. In this study, we used pcROP1 as a DNA vaccine and aluminium phosphate and aluminium hydroxide to compare their efficacy as mineral adjuvants. Materials and Methods: BALB/c mice immunized with pcROP1 alone or with co-administration of Alpo4 or Alum and the effectiveness of these two adjuvants were compared using lymphocyte proliferation assay, cytokine and antibody assay and survival time. Results: The group co-administered alum elicited stronger humoral and Th1-type cellular immune responses than the group co-administered Alpo4, while immune response in group administered with pcROP1 alone is higher than them. When challenged with Toxoplasma gondii RH strain, mice immunized with or without alum had significantly higher survival rates, whereas there was no notable enhancement of survival rate in Alpo4 group (P≤0.05). Conclusions: Our result suggest that pcROP1 plus alum and aluminium phosphate not strongly potentiate the efficacy of this DNA.

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Laser Forming (LF) process is one of the thermal forming processes; which uses laser beam irradiation as a forming factor. In this process, temperature gradient along the sheet thickness produces the final bending angle. So far, various investigations are carried out on laser forming of low carbon steel sheets. However, LF process can be utilised in other metallic and non-metallic sheets. High surface reflectivity and thermal conductivity of aluminium sheets, compared to steel sheets, make them more difficult and more complicated to be laser formed than that of steel sheets. In this Article, using LF process simulation with the finite element software, effects of several process parameters such as laser power, scan speed, laser beam diameter and sheet thickness on final bending angle are investigated. Numerical results are validated with the same parameter assigned experimental results. This comparison shows a very good accordance between simulation and experimental results. Also, an equation is derived to predict the final bending angle correspond to the variations of mentioned parameters. This is derived by the use of Design of Experiment (DOE) and full factorial approach.

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The equations of Lamb wave propagation in an infinite isotropic micro plate with finite thickness on the basis of consistent coupled stress theory is presented in this study. By employing the characteristic length scale parameter, the effect of micro-plate size is considered, and thereby the effects of different plate dimensions on the dispersion of Lamb waves is illustrated. Lamb wave propagation velocity in aluminum nitride micro-plates has received many interests due to its applications in surface acoustic resonators. In the current work, at first, the dimensionless relations are developed through the definition of dimensionless parameters where the extracted curves can be applied to all thicknesses, propagation wavelengths and characteristic length scale parameters of a micro-plate. In addition, using the quasi-static approximation, the Lamb wave dispersion curves in both symmetric and asymmetric modes for an aluminum nitride micro plate are plotted and compared with the results from the classical theory. The integrity of the present formulation is verified by comparing the obtained results with the experimental data in the literature. Finally, by employing the dispersion curves and the reported experimental data, a novel method has been proposed to determine the size of characteristic length parameter in the consistent coupled stress theory.

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During the bleaching of edible oil, the color and many oil impurities are removed through the adsorbent which is usually the bleaching earth.  Although adsorbents containing silica have high bleaching capacity, the purpose of this study was to investigate the role of aluminium and magnesium oxides along with silica as the main component of adsorbent. The process was carried out with 1 and 2% of adsorbents consisting of different ratios of silica, aluminium and magnesium oxides. The amount of peroxide and acid values, chlorophyll, carotenoid, red and yellow colors, amounts of copper and iron of the bleached samples were determined. The results indicated that the effect of 2% of adsorbents was more effective than 1%  in reducing all of the investigated factors. The amount of 2% of the adsorbent containing 90% silica and 10% magnesium oxide reduced the peroxide value by 74.82% and the adsorbent containing 70% silica and 30% aluminium oxide reduced the acid value up to 50% (p˂0.05).  Combined adsorbents containing aluminium and magnesium oxides, especially those with 10 or 15% magnesium oxide reduced chlorophyll content significantly.  Adsorbents consisting of higher amounts of aluminium oxide were more effective to reduce carotenoids. Addition of aluminium and magnesium oxides had significant effect on reducing the amount of red color compared to the blank sample. The amount of copper decreased by about 50% compared to the blank sample (p˂0.05). The highest reduction in iron content was obtained using the adsorbent containing 70% silica, 10% aluminium oxide and 20% magnesium oxide. The results of this study showed that the adsorbents had a good performance during the bleaching process of soybean oil and the difference in bleaching depends on the consumed amount, the compounds of the adsorbent, especially aluminium and magnesium oxides, and the type of impurity.

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Metal and especially aluminum mirrors have wide applications in the optical industry due to their desirable properties, hence requiring very high polished surfaces. One of the methods of preparing aluminum mirrors is single-point diamond turning. In this research, the manufacturing process of 6061-grade aluminum mirrors has been studied using diamond turning and consequent polishing process in order to reach surfaces with acceptable optical properties. In the first part, the effective range of turning parameters was determined. The results showed that the feed values less than 5 µm/rev, the cutting-edge radius between 0.2 and 0.8 mm, and the rotational speed of 2250 rpm have a greater effect on the surface roughness. In the second part of the research, initially, the turning process was performed with effective parameters and then the polishing process was applied as the final finishing process. Surface finish is evaluated by surface roughness and surface interferometry parameters. The results showed that the smaller surface roughness after the diamond tool turning process led to higher optical properties after the final polishing process. The lowest PV value equal to 0.293 µm was obtained by diamond turning with 3 µm/rev and a cutting-edge radius of 0.8 mm.
 

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Metal and especially aluminum mirrors have wide applications in the optical industry due to their desirable properties, hence requiring very high polished surfaces. One of the methods of preparing aluminum mirrors is single-point diamond turning. In this research, the manufacturing process of 6061-grade aluminum mirrors has been studied using diamond turning and consequent polishing process in order to reach surfaces with acceptable optical properties. In the first part, the effective range of turning parameters was determined. The results showed that the feed values less than 5 µm/rev, the cutting edge radius between 0.2 and 0.8 mm, and the rotational speed of 2250 rpm have a greater effect on the surface roughness. In the second part of the research, initially, the turning process was performed with effective parameters and then the polishing process was applied as the final finishing process. Surface finish is evaluated by surface roughness and surface interferometry parameters. The results showed that the smaller surface roughness after the diamond tool turning process led to higher optical properties after the final polishing process. The lowest PV value equal to 0.293 µm was obtained by diamond turning with 1.5 µm/rev and a cutting edge radius of 0.8 mm.
 

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Today, various military, aerospace, automotive, etc. industries need materials with a high strength-to-weight ratio. The use of metal-based composite materials, especially aluminum-based composites, has increased greatly. Machining is needed to achieve high dimensional accuracy in products made with aluminum-based composites. Due to the presence of reinforcing material such as silicon carbide, machining of this type of material is difficult. Therefore, it is important to study the parameters affecting the machining of aluminum-based composites. In this study, the effect of spindle speed, feed rate, depth of cut and percentage of reinforcing particles were discussed using experimental and statistical test methods. The responses of surface roughness and material removal rate were investigated. The behavior of the input parameters on the responses of the process has been carefully investigated quantitatively and qualitatively. Answers have also been optimized. According to the obtained results, the spindle speed has the greatest effect on the surface roughness. Also, feed rate 33%, spindle speed 28%, depth of cut 26% and the percentage of reinforcing particles 13% have an effect on the chipping rate.

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 The cylinder head is one of the fundamental and challenging components in the engine, in which the thermo-mechanical stresses due to the fatigue effectively impart in its damage and reduction of its fatigue life. The present study aims to evaluate the low cycle fatigue (LCF) life of the cylinder head by altering its material from A356 aluminium alloy to AZ91 magnesium alloy. The present study used the finite element method to analyze the LCF life. The ANSYS software was also used to predict the temperature, stresses, and LCF life through Morrow theory and nCode Design Life software. The LCF tests were conducted at different temperatures to obtain the Kinematic and isotropic hardening constants of AZ91magnesium alloy. LCF tests were simulated by ANSYS software, showing a very good fit between the experimental and simulation results of LCF tests. According to the thermal analysis results, the substitution of AZ91 magnesium alloy leads to an increment in the cylinder head temperature by approximately 23ºC. The thermo-mechanical analysis suggested that even though the magnesium cylinder head tolerates higher temperatures, its toleration of Von-Mises stress is lower than the aluminiu m one (by about 13 MPa). Therefore, the AZ91 magnesium alloy can be considered an appropriate substitute for the A356 aluminium alloy. The low cycle fatigue life of aluminium and magnesium cylinder heads was predicted as 1799 and 1930 cycles in the critical area between the inlet valves, respectively. The low cycle fatigue life analysis of the cylinder head demonstrated that substituting AZ91 magnesium alloy with A356 aluminium alloy can increase the cylinder head's LCF life by about 7.3%.