Functional monomers, such as 2-acrylamide-2-methylpropionic sulfonic acid (AMPS), N-vinylpyrrolidone (NVP), and acrylamide (AM), were copolymerized into terpolymer microspheres by inverse suspension polymerization. The structure, morphology, swelling, and Temperature resistance of the microspheres were comprehensively characterized through several means, including a 13C nuclear magnetic resonance spectroscope, scanning electron microscope, optical microscope, and laser particle size analyzer (LPSA). The results showed that the AM, AMPS, and NVP monomers were initially polymerized to form smooth and uniformly dispersed terpolymer microspheres. The particle size distribution of the microspheres ranged from 60 to 90 μ, m at a stirring speed of 300 rpm. The microspheres fully absorbed water and swelled to 21. 9 times at 120 °, C compared with dry powder microspheres. The ternary copolymer microsphere/water dispersion system can only withstand a 120 °, C Temperature for 19 days. However, this Temperature resistance of the microspheres can be effectively improved by adding the appropriate stabilizer solution. The microspheres can be stabilized for at least 42 days and 120 days in 0. 1% thiourea--cobalt chloride composite stabilizer solution and 0. 025% LY stabilizer solution, respectively, at 120 °, C. It can be seen that the microspheres, water, and stabilizer systems have excellent long-term thermal stability. The AM/AMPS/NVP microspheres with Temperature resistance will have broad application prospects in high-Temperature reservoirs.

One of the important issues in the production of concrete is environmental variability that affects the concrete and elements constructed from this material. Due to the importance of different characteristics of concrete in short- and long-term conditions, this article aims to investigate the influence of initial Temperature conditions of self-compacting concrete on its long-term characteristics and determine the initial optimal Temperature of concrete. For these purposes, several experiments under three Temperature conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh concrete in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the concrete specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial Temperature in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial Temperature. Moreover, the fluidity of self-compacting concrete increases with increasing initial Temperature.

Asphalt concrete cracking in cold regions is one of the most critical damages of asphalt surfaces. In addition to the cold in some regions, we also see rain that the combined effect of these two factors causes frozen asphalt. In this case, asphalt damages will drastically increase. In this paper, the fracture resistance in saturated hot mix asphalt samples under the influence of freeze and thaw cycles will be studied. For this purpose, a few asphaltic samples that have similar materials, aggregation and construction conditions were made as SCB, then they were saturated. Then different Temperatures (-5 and-15°, C) and cycles (1, 3, 5, 7, 9, 11) were applied to them. The effect of these parameters on the critical stress intensity factor was studied in 4 fracture moods: tensile mood, (tensile mode, shear mode and two mix modes). The result of this study shows that by increasing the number of freeze and thaw cycles, the fracture toughness will be reduced significantly. As it is, until the seventh cycle, the decrease of the fracture toughness will be increased significantly, and after the seventh cycle, its severity will be decreased. The other result of this study is that with a Temperature drop of-15 °,C, the fracture toughness will be increased.

2Background: Antibiotic resistance represents a critical global concern within the medical community, posing significant challenges in the treatment of infections caused by drug-resistant pathogens. Over the years, broad-spectrum fluoroquinolones have been extensively used to treat infections caused by both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa. In this study, we decided to assess the prevalence of plasmid-mediated quinolone resistance mechanisms among clinical isolates of P. aeruginosa in Ardabil hospitals. Methods: We analyzed a total of 200 clinical isolates of P. aeruginosa, collected between June 2019 and May 2023. The antibiotic resistance profiles of these strains against various fluoroquinolone antibiotics were determined using the disk diffusion method. Additionally, we investigated the presence of qnrA, qnrB, qnrC, qnrD, and qnrS genes through polymerase chain reaction (PCR) analysis. Furthermore, we assessed the expression levels of efflux pump genes and outer membrane porin genes using the quantitative reverse transcription PCR (qRT-PCR) in fluoroquinolone-resistant P. aeruginosa strains. Results: Our findings revealed that 69% of P. aeruginosa strains were resistant to fluoroquinolones. The resistance rates for different fluoroquinolones were as follows: ciprofloxacin 55.5%, ofloxacin 62%, norfloxacin 53.5%, lomefloxacin 55.3%, and levofloxacin 55.5%. Notably, 78.9% of these strains exhibited multidrug resistance (MDR). Among the qnr genes, qnrB was the most prevalent (2.9%). No other qnr genes were identified. Interestingly, 75% of P. aeruginosa strains carrying the qnrB gene showed overexpression of efflux pump genes, while 100% exhibited down-regulation of the oprD gene. Conclusion: Given the high prevalence of fluoroquinolone-resistant P. aeruginosa clinical isolates in Ardabil hospitals and the multifactorial nature of resistance, continuous monitoring of antibiotic resistance trends and understanding the underlying resistance mechanisms are crucial for selecting appropriate treatment strategies.

resistance spot welding is an important manufacturing process in the automotive industry for assembling bodies. The quality and strength of the welds and, by extension, the body is mainly defined by the quality of the weld nuggets. The most effective parameters in this process are sheet material, geometry of electrodes, electrode force, current intensity, welding time and sheet thickness. The present research examined the effect of process parameters on nugget formation. A mechanical/ electrical/ thermal coupled model was created in a finite element analysis environment. The effect of welding time and current, electrode force, contact resistivity and sheet thickness was simulated to investigate the effect of these parameters on Temperature of the faying surface. The physical properties of the material were defined as nonlinear and Temperature dependent. The shape and size of the weld nuggets were computed and compared with experimental results from published articles. The proposed methodology allows prediction of the quality and shape of the weld nuggets as process parameters are varied. It can assist in adjusting welding parameters that eliminates the need for costly experimentation. This process can be economically optimized to manufacture quality automotive bodies.

Deep sub-zero treatment is a complementary operation performed on all types of tool steels, carbonized and high-speed steels to improve wear resistance and hardness. Among these tool steels, H13 is a hot work tool steel that have an extended application in industry as a hot deforming tool. This paper investigates the wear behavior of deep cryogenic treated H13 hot work steel at operating Temperature. Two quench-tempered and quench-subzero-tempered samples are compared. The microstructures of the specimens were determined by scanning electron microscopy, and the structures were determined by X-ray diffraction. Vickers hardness used for determining hardness after each treatment. The wear test was carried out at 250° C (mold Temperature on forging of copper base alloys). Finally, the wear surface was examined by scanning electron microscope equipped with EDS analyzer. The results show that the highest hardness was in quench-subzero-tempered condition which is about 26% higher than the quench-tempered in oil conditions. This is due to the formation of fine, dispersed and uniform precipitates and higher martensite percentage in quench-subzero-tempered sample compared to quench-tempered sample. Quench-subzero-temper operation reduced the residual austenite percentage by 10% and improved the wear properties by 36% at 250° C. Examination of wear surfaces indicates the presence of oxidized surfaces adhered to the wear surface in the form of abrasive particles. These oxide levels were lower in quench-subzero-tempered sample than quench-tempered sample.

resistance is one of the fundamental Quranic values in the cause of the development of the Islamic society and the formation of the Islamic civilization, which means standing and resisting against something has upset the balance in internal and external dimensions. The formation of this value in the society as one of the methods of the conventional model of human life in the fields of human life; So that its manifestation can be observed in the totality of social behaviors, it is called the culture of resistance (Problem statement). The purpose of this article is the achievement of the engineering process of this value in a society based on the growth-oriented thought (ideological) system of the Holy Quran (Purpose). Now the question is what process does the Holy Quran propose in order to engineer the culture of resistance in the society? (Question). The necessity of examining this issue is clear considering the emphasis of religious teachings on this value and the need for Islamic societies, especially considering the current conditions of Islam and the need for convergence and coordination between the resistance front (Necessity). The research method in stating the engineering process and its components is qualitative content analysis with an analogy approach (Method). The findings of the research show that the engineering process of resistance culture is based on a self-awareness and purposefulness, according to the idea of Quranic growth, in a three-stage process that leads to the happiness of man and human society (Conclusion).