83 research outputs found

    Simulation of corrosion protection methods in reinforced concrete by artificial neural networks and fuzzy logic

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    In this study, the effect of protection methods regarding the corrosion decrement of steel in concrete was simulated by artificial neural networks (ANNs) and fuzzy logic (FL) approaches. Hot dip galvanizing as a protective coating, Ferrogard 901 corrosion inhibitor, a pozzolanic component, such as fly ash (FA) and micro-silica (MS), and eventually rebar AISI-304 were employed in concrete. Reinforced concrete samples were held under impres­sed voltage of 30 V in 3.5 % NaCl electrolyte for 350 hours toward a stainless-steel auxiliary electrode. Corrosion currents have been modelled using feed forward back propa­gation ANNs and FL methods. The results demonstrate good consistency between cor­rosion data and simulated models. Furthermore, the correlation coefficient criterion clearly indicates using pozzolanic materials, with a combination of MS and FA, can be introduced as one of the best corrosion protection methods, with a 35 % contribution factor in reinforced concrete

    Digital Encoder Designing for Mobile Robot Control

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    In this paper we present the design of a quadrature decoder/counter interface IC (ASIC) that performs the decoding, counting, and bus interface function in digital motor control systems, employing an Altra FLEX 10KA, 2s150fg456 Xilinx device. The ASIC contains a pair of digital filters, a quadrature decoder, an up/down counter, a latch and inhibit circuit, and an 8-bit bus interface to a digital processing system. The design of digital of the digital filter is based on the finite state machine model with datapath (FSMD). A novel scheme for detecting the motor rotation direction is also proposed. The ASIC can be applied to a digital motor control system forgetting the rotation speed or position of the motor, which is quipped with an optical encoder. The data acquisition can be extended to 16-bit integer format by two continuos reading cycles. Simulation and experimental tests are shown to verify the ASIC function properly.DOI:http://dx.doi.org/10.11591/ijece.v4i4.550

    A Longitudinal Flap of Vena Cava in Live Donor a Safe Option for Adding Elongation at Least 10mm in Vein of Right Kidney

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    Introduction: To treat chronic kidney, kidney transplantation is the most efficient way especially when donor is alive, in such a way that survival tie can be increased in the best possible way. In this regard, major problem is short renal vein resulting in thrombosis. To elongate the vein length, there is a technique that we report in this study. Materials and Methods: The technique of interest is that at the time of dissection of vena cava and renal vein, it should be tried to put vein of vena cava 1cm above and 1cm below of renal vein. In addition, the kidney must be placed in right iliac of kidney done. Results: Patients discharged in good condition after two days. In our cases, there was no tension in the site of anastomosis showing safe condition. Conclusion: Longitudinal flap of vena cava accompanied by a suitable cuff can increase about I cm length of renal vein

    Effects of different coatings, primers and additives on corrosion of steel rebars

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    In this research, methods of increasing the corrosion resistance of reinforced concrete were experimentally investigated. The study used silica fume and fly ash at optimized percentages of 10 and 25% by cement weight, polypropylene fibers at a ratio of 2.5% by volume of concrete, and a commercial corrosion inhibitor, 2-dimethylaminoethanol (Ferrogard 901), at 3% by cement weight. The corrosion resistance of three types of reinforcements, mild steel (STt37), AISI 304 stainless steel, and AISI 316 stainless steel, was investigated. The effects of various coatings, including hot-dip galvanizing, alkyd-based primer, zinc-rich epoxy primer, alkyd top coating, polyamide epoxy top coating, polyamide epoxy primer, polyurethane coatings, a double layer of alkyd primer and alkyd top coating, and a double layer of epoxy primer and alkyd top coating, were evaluated on the reinforcement surface. The corrosion rate of the reinforced concrete was determined through results of accelerated corrosion and pullout tests of steel-concrete bond joints and stereographic microscope images. The samples containing pozzolanic materials, the corrosion inhibitor, and a combination of the two showed significant improvement in corrosion resistance by 7.0, 11.4, and 11.9 times, respectively, compared to the control samples. The corrosion rate of mild steel, AISI 304, and AISI 316 decreased by 1.4, 2.4, and 2.9 times, respectively, compared to the control sample; however, the presence of polypropylene fibers reduced the corrosion resistance by 2.4 times compared to the control

    Providing A Neuromarketing Intelligent Model To Convert Potential Market To Actual Market In The IRAN Mushroom And Its Conversion Industries By Grounded Theory

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    In mushroom industry and its conversion industries, the variety of products (food / pharmaceutical) is very high, the target market is wide, financial and non-financial resources are limited, accurate identification of profitable customers is time consuming, so traditional marketing methods Cognition is not effective enough in attracting and retaining real customers, so adopting smart marketing strategies is a major challenge in industry. The aim of study was to provide a neuromarketing intelligent model to convert potential market to actual market in the IRAN mushroom and its conversion industries. In this applied and qualitative research, through purposive sampling, semi-structured interviewed with 12 experts of neurologist, marketing and mushroom industry. According to Grounded theory, 411 open codes, 246 core codes, 67 sub-categories and 24 main categories were identified as paradigm model. The model validation was confirmed in a quantitative part by SEM in smart-pls. The results showed that main phenomenon consists of three components of senses (physiological characteristics), product personality, product social features. Therefore, through attention and application of the present paradigm model, the emphasis on recognizing the physiological personality and social characteristics of the product leads to a greater understanding of the benefits of neuromarketing applications in the mushroom industry and its conversion industries to turn the potential market into an actual market

    Association of Helicobacter Pylori with Presence of Myocardial Infarction in Iran: A Systematic Review and Meta-Analysis

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    BACKGROUND: Over the past decade, cardiovascular diseases have been recognized as the leading cause of mortality worldwide. Myocardial infarction (MI) is one of the most prevalent types of cardiovascular diseases that is caused by the closure of coronary arteries and ischemic heart muscle. Numerous studies have analyzed the role of H. pylori as a possible risk factor for coronary artery diseases, in most of which the role of infection in coronary artery disease is not statistically significant.METHODS: These contradictory findings made us conduct a systematic review to analyze all relevant studies in Iran through a meta-analysis and report a comprehensive and integrated result. All published studies from September 2000 until September 2016were considered. Using reliable Latin databases like PubMed, Google Scholar, Google search, Scopus, Science Direct and Persian databases like SID, Irandoc, Iran Mede and Magiran. After quality control, these studies were entered into a meta-analysis by using the random effects model. After evaluating the studies, 11 papers were finally selected and assessed.RESULTS: A total of 2517 participants had been evaluated in these studies, including 1253 cases and 1264 controls. Based on the results of meta-analysis and using random effects model, an overall estimate of OR Helicobacter Pylori with Presence of Myocardial Infarction in Iran was OR=2.53 (CI=1.37-4.67).CONCLUSIONS: The results of this review study show that H. pylori are associated with the incidence of MI so that the odds ratio of MI in the patients with helicobacter pylori is twice greater than that of the people without H. pylori. Future studies are recommended to evaluate the mechanisms associated with relation of H. pylori with MI as well as its association with time.KEYWORDS: Myocardial infarction, H. pylori, Meta-analysis, Ira

    Instructional Strategies for Motivating and Engraining Generation Z Students in Their Own Learning Process

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    In the last few years, a number of significant research studies were conducted focusing on identifying and determining the root cause and also factors that critically contribute to students failure and success in higher education. These studies have enabled educators to evaluate the underlying causes by analyzing different perspectives presented by students, faculty and academic leaders. Various studies were conducted and published in the past that have addressed the same issue. For example, in three related studies conducted and presented at the Higher Learning Commission (HLC) conference in Chicago, Illinois, the surveyed participants (students, faculty, and academic leaders) provided concrete root-cause factors for student’s failure at college and university level. Student’s academic readiness, self-motivation, study habits, and students attitude towards education were the most mentioned root-causes by both, faculty and academic leaders (Appendix 1). During the studies, all participants agreed upon the fact that in order to succeed, students should have clear mindsets and should be aware of the reasons and requirements they will need to meet in order to enroll in a specific course. They should be thoroughly aware of their purpose for attending a school beyond just getting passing grades and a degree to get jobs.   However, all three surveyed groups strongly believe that it is not only the student’s responsibility, but also the responsibility of instructors and college administration to keep students motivated after admitting them to their colleges, programs, and courses (Cherif, Movahedzadeh, Adams, Martyn 2013; 2014; 2015).  In this paper, we explore the implementation of some proposed recommendations from various research studies for improving students learning and instructors teaching in a classroom setting. Keywords: Modern students, Motivations; Student academic performance and retention, Student success. DOI: 10.7176/JEP/10-3-0

    Prevalence of diabetes and other cardiovascular risk factors in an Iranian population with acute coronary syndrome

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    BACKGROUND: Coronary artery disease is the leading cause of death in industrialized countries and most patients with diabetes die from complications of atherosclerosis. The objective of this study was to determine the presence of diabetes mellitus and other conventional coronary heart disease risk factors (cigarette smoking, hypertension and hyperlipidemia) in patients with acute coronary events in an Iranian population. METHODS: The study included 514 patients with unstable angina or myocardial infarction (MI) out of 720 patients admitted to CCU ward of a general hospital from March 2003 to March 2005. History of diabetes, hypertension and cigarette smoking, demographic indices, coronary heart disease and diabetes mellitus treatment, myocardial enzymes, serum triglycerides (TG) and cholesterol and fasting and non fasting blood glucose levels and HbA1C of diabetics were recorded of admission sheets. The data were structured to appropriate one way ANOVA, T tests, and chi square test with SPSS 13 product for windows. RESULTS: Out of all patients 35.8% were female, 30% were diabetics (Duration 13.4 ± 8.7 years), 42% were smoker and 91% were hypertensive. Twenty four percent had MI and 76% had unstable angina. MI was significantly higher in diabetic patients (36.4% vs. 19.2%, P < 0.001). Location and extension of MI and myocardial enzymes did not differ between diabetics and non-diabetic patients. Diabetic patients were older than non diabetics (65 ± 11.6 vs. 59.7 ± 12.5 years, p < 0.05). Five (66.7%) out of 9 patients with fatal MI were diabetics (Odds Ratio = 2.98). Age, duration of diabetes and HbA1c levels, did not differ between diabetic patients with or without MI. Hypertension and current smoking was significantly higher in patients with MI compared to patients with unstable angina (p < 0.05). Serum TG, HDL-C, LDL-C and total cholesterol level did not differ between patients with MI and unstable angina. Diabetic patients compare to non diabetic patients were more hypertensive (96% vs. 88.7%, p < 0.005) and had higher serum triglyceride (TG over 200 mg/dl, 35.1% vs. 26.4, p <0.05). Diabetes was more frequent among women than men (36.4% vs. 26.4%, p < 0.05). Women were older than men (65 ± 11.6 vs. 59.2 ± 13 years, p < 0.005) and had higher total serum cholesterol (200 ± 41.8 vs. 192 ± 42.5 mg/dl, p < 0.05) and HDL-C levels (49.7 ± 22 vs. 40 ± 13 mg/dl, p < 0.005). Ninety seven percent of all patients had at least one of cardiovascular risk factors (hypertension, smoking, diabetes, high cholesterol and low HDL-cholesterol levels). CONCLUSION: In this study 19 out of 20 patients with acute coronary event have at least one of conventional cardiac risk factors. Diabetes and hypertension are leading risk factors, which may directly or indirectly interfere and predict more serious complications of coronary heart disease

    Phospholipase A2 activity of the Persian Gulf upside-down jellyfish venom (Cassiopea andromeda)

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    Background: The venomous jellyfish Cassiopea andromeda can produce envenomation and different toxicological and biological effects by their nematocysts. The phospholipase A2 enzymes (PLA2) are toxic and induce various pharmacological effects including neurotoxicity, myotoxicity, and anticoagulant activities. The main aim of the current project was to screen the in vitro PLA2 activity of the C. andromeda crude venom. To better understand the experimental result; a molecular docking study was also performed. Materials and methods: The live specimens were collected from Nayband lagoon, by a trawl net, and separation of their tentacles was done according to Bloom 's et al., method. The PLA2 activity of crude venom was performed according to the acidimetric method of Tan and Tan. The lyophilized venom was subjected to Gas Chromatography/ Mass Spectroscopy, and the obtained structures were used for docking study against PLA2. The indoxam was considered as standard control. Results: The PLA2 activity of the jellyfish crude venom was 413 ±0.08 µmol/min/mg. Analysis of the crude venom detected seven compounds (i-vii) using GC-MS. Docking data was also confirmed the experimental results. According to the docking results, the highest affinity [-6.7 (kcal/mol)] was observed in the compound “Pregn-5-ene-3,11-dione, 17,20:20,21 bis [methylenebis(oxy)]-, cyclic 3-(1,2-ethane diyl acetal”. Conclusions: A high PLA2 level was found in the venom of C. andromeda. There was a good correlation between in vitro and in silico studies

    Potential of Human Umbilical Cord Matrix and Rabbit Bone Marrow–Derived Mesenchymal Stem Cells in Repair of Surgically Incised Rabbit External Anal Sphincter

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    PURPOSE: Anal sphincter defects and fecal incontinence are complicated surgical problems. We investigated the ability of human umbilical cord matrix (hUCM) and rabbit bone marrow (rBM) stem cells to improve anal sphincter incontinence due to induced sphincter defects without surgical repair. METHODS: We harvested hUCM cells from human Wharton’s jelly and rBM stem cells from rabbit femurs and tibias. To induce sphincter defects, we made an incision in the external anal sphincter. Rabbits were randomly allocated to 5 groups to receive either no intervention (n � 3) or injections of 104 hUCM cells in medium (10 �L RPMI-1640), rBM cells in medium, medium only, or normal saline (n � 7 per group), 2 weeks after sphincterotomy. Transplanted cells were tracked in the injured sphincters by prelabeling with bromodeoxyuridine. Electromyography was performed before and 2 weeks after the external anal sphincterotomy, and 2 weeks after cell transplantation. We also evaluated the proliferation and differentiation of injected cells with histopathologic techniques. RESULTS: Electromyography showed significant improvement in sphincter function 2 weeks after local injection of rBM stem cells compared with pretreatment values and controls. Moderate, nonsignificant improvement was observed with hUCM cell injection. Cells with incorporated bromodeoxyuridine were detected at the site of injury after transplantation of hUCM and rBM. Histopathologic evaluation showed normal or muscle-dominant sphincter structure in all animals receiving rBM and fibrous-dominant sphincter structure in most animals receiving hUCM. CONCLUSIONS: Stem cell injection at the site of injury can enhance contractile function of the anal sphincter without surgical repair. Transplantation of stem cells, particularly bone marrow mesenchymal cells, may provide an effective tool for treating anal sphincter injuries in humans
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