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In this research, the hot deformation behavior of API X70 steel was investigated by hot compression tests. A temperature range between 950 and 1150 °C was used for experiments with different strain rates of 0.01, 0.1 and 1 s-1. The work hardening rate versus stress curves were used to reveal if dynamic recrystallization (DRX) occurred. The application of constitutive equations to determine the hot working constants for the tested steel was discussed. Using regression analysis, the stress multiplier (α), the apparent stress exponent (n), and the activation energy (Qd) for DRX were calculated as 0.016 and 4.420, and 382 kJ/mol, respectively. Furthermore, the effect of Zener–Hollomon parameter (Z) on the characteristic points of flow curves was investigated using the obtained relations. The dynamic recrystallization (DRX) kinetics of API X70 steel was also studied and its governing equation was derived.

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The API X70 steel is a high-strength low alloy steel which is used in construction of high-pressure long-distance gas and oil transportation pipelines with large-diameter. The pipe used in this study has 1422mm outside diameter and 19.8mm wall thickness, formed by spiral welding. As this steel is totally imported from abroad, the study of continues cooling transformation behavior and the optimum design of thermo-mechanical control processes are important for its domestic production. In this study, dilatometry examination was conducted on API X70 steel in a wide range of cooling rates from 0.5 to 40 °C/s. The optical microscopy observation and microhardness measurement were used to verify the observed microstructures. From the experimental results, the continuous cooling transformation curves (CCT) were constructed for API X70 pipeline steel. Different microstructures including granular bainite, pearlite, acicular ferrite and bainitic ferrite were observed depending on the cooling rate of tested samples. The observed dominant microstructure in 5 and 7.5 °C/s cooling rate was acicular ferrite which is the desired microstructure in energy transportation pipeline steels. These results can be used to design the optimum thermo-mechanical control process (through the selection of proper cooling rate) in domestic manufacturing of the API X70 steel.

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Objective: Different signaling pathways have been identified that are involved in the cellular response to opiates. The mitogen-activated protein kinase pathway is one of the most important signaling pathways underlying the neuronal response to opiates. MicroRNAs (miRNAs) are considered to be post-transcriptional regulators of gene expression with paramount significance, which plays key roles in modulating cellular processes such as neuronal plasticity and synaptic consolidation. The purpose of this study is to identify miRNAs that are differentially expressed in response to chronic morphine treatment, and predict those genes that have a possible role in this process. Because the MAPK pathway in involved in morphine dependence and participates in hypersensitivity to pain, determining miRNAs that modulate this pathway could be insightful in morphine dependence treatment and pain control. Methods: In this study, the BE(2)-C neuroblastoma cell line was chronically treated with morphine sulphate and the changes in expression of 750 miRNAs were analyzed by real time PCR. Results: Two up- and down- regulated groups of  miRNAs were determined to be differentially expressed in response to morphine: i) has-mir-193a-3p, -212, -181c, -362-3p, -639, -646  and ii) has-mir-412, -937, -558, -552, -943, -628-5p, -593, -555, -636, -643, 566, -571, -642, -653, -611, -31, let7-g. Conclusion: The analysis of differentially expressed miRNAs showed that the MAPK signaling pathway could be regarded as a signaling pathway with utmost significance in chronic morphine response. Due to the role played by MAPK pathway in cellular response to morphine exposure, we can propose that protein phosphorylation has a presumable part in this response.

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In this study, we developed a Joint Replenishment Problem (JRP) model; In addition, JRP was introduced through capacitated vehicle to send the parts. The model was developed as an Integer-non linear model. Cost function consists of the major ordering cost, the minor ordering cost and the holding cost. Previous studies had not considered transaction cost; therefore, we considered transaction cost, which depends on the number of different parts in the order. Demand for parts was considered as constant and the model was solved by using a genetic algorithm. For calculating variable, we developed the present algorithm in the literature. We solved the model for two conditions, with dispatch volume restriction and without dispatch volume restriction. The results showed that the dispatch volume increases both the cycle time and the total cost. The model was solved for one of the major manufacturers of SAPCO. We considered the problem with 12 strategic parts of this company. The model was investigated through the real data gathered from the SAPCO Company. Finally, for model validation, the results were compared with the traditional ordering system of SAPCO, in which the parts are ordered separately. It was shown that the proposed system has better performance than the traditional ordering system. Validation of Model was performed by the numerical example that has been solved in the literature. Keywords: Joint replenishment, Automotive parts, Genetic algorithm, Inventory.

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Unglazed transpired solar air heater collectors are relatively new solar technologies that can be used for air heating or pre-heating ventilation air and drying agricultural and industrial products. Passing air through the perforated plate, which is usually metallic is the main mechanism of heat transfer. The cost of buying and preparing the absorber plate is the dominant share of costs allocated to this type of collector. In the present study, performance of non-metallic absorber plates available in the Iranian market, as an alternative to metal absorber plates are examined experimentally and theoretically. Therefore, three collectors with Metallic, Polycarbonate and Compressed-Plastic are designed, fobricated and tested in real conditions. In addition, a thermal modelbased on the first law of thermodynamic is developed for these collectors. In this model, all mood of heat transfer (including conduction, convection and radiation) are considered. Results show that there is a good agreement between experimental and theorical results (For most test condition, average relative error in estimation of the outlet temperature of the collectors is less than 5%). The results showed that the performance of three collector’s, espisially for low mass flow rates, was not too different. However, for considered condition Steel (metallic) collector has the best performance and the polycarbonate collector the worse performance. The performance of the Compress plastic was close to the Steel collector and given the low cost of non-metallic collectors, it can be used as a convenient alternative to metal collectors.

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Objective: Morphine and its derivatives are well-known for their strong analgesic effects in medicine. However, their medical long-term administration is severely restricted because of tolerance and dependence. Morphine fails to induce endocytosis of Mu opioid receptors whereas other encephalin analogues such as DAMGO induce rapid endocytosis of these receptors. Repeated use of opioid drugs alters gene expressions. In current study, we analyze the effects of long-term opioid treatment on Dnm1L and Rab22a genes. Methods: HEK293 cell lines that expressed MOP receptors were treated separately with morphine, methadone, and DAMGO. mRNAs were extracted from the cell suspension and we amplified the cDNA. Next, we analyzed Dnm1L and Rab22a gene expressions compared to control samples by qRT-PCR. Results were statistically validated by Graph Pad software. Results: Amplification graphs from qRT-PCR showed that Dnm1L gene expression was induced by 2.37-fold, whereas Rab22a gene expression decreased by 0.39-fold in response to long-term treatment of cells with morphine compared to control samples. Dnm1L gene expression was not significantly affected by treatment with methadone and DAMGO. Rab22a gene expression decreased by 0.41-fold with methadone treatment and by 0.45-fold in response to DAMGO treatment. Conclusion: The Dnm1L gene could be involved in cellular pathways of morphine-induced tolerance which would indicate the difference between morphine and other similar Mu opioid receptor agonists.

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The study aimed to investigate the frequency of enterotoxin-producing Staphylococcus aureus isolates in hamburgers and meat bites in Mashhad and the frequency of the gene. In this practical descriptive research, the number of 175 meat samples including 70 hamburger samples, 70 kebab bite samples, and 35 handmade hamburger samples in a non-repetitive and cluster sampling method, from the brand various commercial products were collected from the supply centers in Mashhad from April to June 2023. After culturing the samples in a specific medium and isolating the isolates suspected of Staphylococcus aureus, the bacteria were identified using morphological and biochemical characteristics. Then they were confirmed by using a specific primer and polymerase chain reaction (PCR). Using PCR, the frequency of enterotoxin-producing genes was detected and the antibiotic resistance of Staphylococcus aureus isolates was checked by disc diffusion method in food samples. Among the 175 meat products tested, 28 hamburger samples (16%), 12 kebab samples (7%), and 15 handmade hamburger samples (about 9%) were pathogenic bacteria. were infected with Staphylococcus aureus. Compared to kebab samples, hamburger samples showed higher contamination, and more of them were reported as Staphylococcus aureus positive. nuc gene was detected in all bacteria identified by biochemical method. The presence of the sea gene was detected in 45 samples of tested meat products (25.71% of all samples). sec and see genes were found in 4 (2.28%) and 6 (4.08%) food samples, respectively. Genes encoding used and sed were not found in any of the studied samples. In addition, many isolates showed high resistance to tetracycline, clindamycin, and oxacillin; some were resistant to more than one antibiotic. In this study, the results obtained from the SEA-F and SEA-R blast analyses revealed that the sequences had more than 98% agreement with the overlapping results.