Seismic performance of unbonded post-tensioned precast wall systems subjected to shake table testing

The research in this dissertation was conducted with the primary aim of understanding the seismic response of unbonded post-tensioned precast concrete rocking walls both with and without additional hysteretic energy dissipaters. These wall systems dissipate the seismic input energy mainly through impacts of the wall on top of the foundation during rocking as well as the external hysteretic damping. The behavior of these walls are largely investigated based on experimental tests using quasi-static loading and few numerical studies. A systematic seismic design approach for their application in high seismic regions is still lacking. To date, there are limited large-scale studies that have evaluated the lateral response of these rocking walls using earthquake ground motions of different intensities and there is little published data on quantification of their different energy dissipation components. To address the main objective of overcoming the aforementioned limitations, a series of large-scale experimental shake table tests were conducted on four unbonded post-tensioned precast Single Rocking Walls (SRWs) and four Precast Wall with End Columns (PreWEC) systems by subjecting them to a set of earthquake excitations with varying intensities. These walls were designed by varying key design parameters such as: (i) the initial prestress force, Pi, (ii) base moment to base shear ratio, and (iii) the number and location of additional hysteretic dampers in PreWECs, namely O-connectors. Minimal wall base damage was observed as these wall systems were subjected to the design-level ground motions. As intended, all walls provided the self-centering behavior during ground motions of different intensities and the additional O-connectors started to yield and dissipate the seismic energy at 0.6% wall drifts. The rocking wall tests generally indicated the satisfactorily seismic performance of SRWs and PreWECs in terms of the lateral drift, absolute acceleration, and residual drift during design-level and greater earthquakes; however it was found that walls with reduced resistance responded beyond the allowable limits during such strong ground motions. Further studies were experimentally conducted to evaluate equivalent viscous damping ratios of SRWs and PreWECs and apply them to achieve desirable seismic design forces that ensure their promising seismic response. Participation of different damping components of the walls with and without external hysteretic dampers in energy dissipation of the system was also evaluated. The results revealed the potential of SRWs to remove a part of the seismic energy and dissipate the rest relying on their limited damping capacity. It was highlighted that the additional hysteretic damping provided in PreWECs reduced the maximum drift and decay of the response. An investigation was performed using a simplified single degree of freedom analytical model to emulate the seismic response of SRWs and PreWECs. The nonlinear dynamic analysis results calculated from this model were then verified using the shake table test results. Lastly, the seismic forces recommended for the design of rocking walls with different damping ratios, as prescribed in the preliminary stages of this research, were validated by conducting an extensive numerically based case-study. For this purpose, six, nine, and twelve story buildings were designed using SRWs and PreWECs and the responses were evaluated during a set of near-field and far-field ground motions scaled to represent design-level and maximum considered events. In addition to an excellent performance of both systems designed following the recommendations of this dissertation, PreWECs were shown to be the most economical rocking wall solution for the design of these seismic-resilient buildings

Applying genetic algorithm in selecting providers of supply chain in big stores

Excess competition in offering the goods and services in two previous decades throughout the world, is an undeniable fact. By increasing the number of rivals in the world class, the organizations were forced to improve home processes (processes within the enterprise) to stay in global competition arena. During recent years, determining appropriate suppliers for supply chain has had extreme importance. A lot of manufactures were looking for cooperation with appropriate suppliers to improve the level of management and competitive performance. The main goal in the process of selecting suppliers is to decrease the risk of purchase, maximize the important values of client and create high and close connection between buyer and supplier. Therefore, determining appropriate supplier in supply chain is a strategic key for accessing to organizational competitiveness

Lightweight Rubberized Concrete Slabs for Sustainable Road Pavements Serving Non-Auto Traffic

Non-auto transportation infrastructure, such as bicycle lanes and sidewalks, serves as an efficient means of public mobility. Improving the sustainable design and construction of the concrete slabs that compose such roads promotes environmental and economic benefits, spanning the usage of green sources of materials and reduced maintenance costs. In this study, an investigation into the application of recycled tires, also known as tire-derived aggregate (TDA), combined with rotary-kiln produced expanded clay (EC) as coarse aggregates in concrete, as well as their life-cycle cost assessment, are presented. The mechanical properties of concrete specimens with three different mix designs, i.e.,100% EC (MIX A or control mix), a mixture of 20% EC – 80% TDA (MIX B), and 100% TDA (MIX C) as coarse aggregates, were first derived through experimental tests. Impact-fatigue tests were then conducted on concrete slabs of MIX A, B, and C to evaluate their sustainability under several cycles of bicycle loads. The results showed that the TDA concrete has lower compressive and flexural strength, but it is more ductile than concrete with zero rubber content. Also, the results of impact-fatigue tests combined with a life-cycle cost analysis indicated the long-term benefits of constructing green and durable infrastructure using TDA on future investments in transportation

The effect of a set of submaximal aerobic exercise and ginger on pain duration in the college girls with primary dysmenorrhea

Background and aims: Due to the anti-inflammatory properties of the ginger plant, it has attracted researchers’ attentions for treating menstrual problems. The aim of this study was to investigate the effect of a program which contains submaximal aerobic exercises and ginger on pain duration in the college girls with primary dysmenorrhea. Methods: This quasi-experimental research was performed on 40 female students with primary dysmenorrhea (moderate, severe) who lived in the dormitory of Shahid Rajaei University with average height, weight, age and body mass index of 164.47 ± 4.66 cm, 56.95 ± 6.81 kg, 21.40 ± 1.42 years and 21.07±2.41 kg/m², respectively. The samples were randomly divided into 4 groups (n=10) including exercise, ginger, combined of both exercise and ginger, and control groups. The exercise group performed an eight-week submaximal aerobic exercise. The ginger group used capsules which contain 250 mg ginger, 4 times a day from the third day of bleeding, and both variables were applied for the combined group. The influence of ginger and exercise were evaluated on the duration of dysmenorrheal pain and the data analysis was performed by using one-way ANOVA and Tukey tests. Results: After 8 weeks of ginger usage and sub maximal aerobic exercise, the duration of pain declined in the combined (P=0.001) and practice groups (P=0.04) compared to the control group. Conclusion: Submaximal aerobic exercise along with ginger use is effective in reducing the pain of primary dysmenorrhea

Impacts of Coronavirus Disease 2019 Pandemic on Sleep Pattern

The ongoing coronavirus disease 2019 (COVID-19) pandemic is the third global crisis after two epidemics of severe acute respiratory syndromes. It has affected general public besides health care systems and governments. Confinements and lock downs have changed waking up time and going to bed time, ultimately affecting circadian clocks that can disturb sleep quality which can lead to anxiety, stress, and depression. This puts the most susceptible group -young adults and females- at risk of psychological disorders and even inflammatory events. Several kinds of sleep disorders due to COVID-19 including insomnia, sleep apnea, sleepiness during daytime, post-traumatic-like sleep dysfunction, abnormal dreams, and restless legs syndrome have been reported. As sleep deprivation can alter circadian clock and weaken immunity which makes human more susceptible to pulmonary inflammatory process of COVID-19 and even enhance its manifestations, it should be considered as an urgent complication that needs to be treated. Furthermore, longstanding effects of sleep disturbances during COVID-19 pandemic need to be elucidated

Bidirectional Association Between COVID-19 and Mental Health Disorders: A Narrative Review

Background: Fear, anxiety, and stress are natural reactions of the human body to unpredictable and potentially threatening conditions. Currently, individuals are encountering Coronavirus Disease 2019 (COVID-19) pandemic; it is caused by a virulent, partially unknown pathogen with high transmissibility, recognized as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It is conceivable to experience anxiety, stress, and subsequent mental health disorders during the pandemic. This narrative review provided a brief overview of mechanisms involved in COVID-19 and mental health disorders as well as the bidirectional association between them.Methods: Scientific electronic databases, such as PubMed, Scopus, Web of Science, and Google Scholar were thoroughly searched, based on different keywords in this study.Results: Lifestyle changes and isolation for breaking the chain of infection facilitate mental health disorders development more than before. Since the onset of the pandemic, the prevalence of mental health disorders has significantly increased. Moreover, studies suggested that the incidence of COVID-19 and the progression of the disease to a severe and life-threatening stage is higher in individuals with a history of mental health disorders. Inflammation is caused by, also may cause mental health disorders. Besides, COVID-19 is associated with cytokine storm and subsequent inflammation.Conclusion: There seems to be a bidirectional association between COVID-19 and mental health disorders, in which inflammation acts as an adaptor

Prevalence of Helicobacter pylori and its cagA gene in patients with gastric cancer or peptic ulcer at an Iranian medical center

Background: Iran has a high incidence rate for gastric cancer among the Middle East countries. In addition to gastric cancer, peptic ulcer is also life-threatening; thus, investigating the prevalence of Helicobacter pylori infection and other risk factors are essential. The present study was aimed to assess the frequency of H. pylori and the cagA-positive strains in patients with gastric cancer or peptic ulcer at a teaching hospital in Qom, one of the most populated cities of Iran. Materials and Methods: The presence of H. pylori was investigated in gastric cancer and peptic ulcer biopsy specimens using the standard culture method. PCR analysis was performed to detect the presence of the cagA gene. Results: The frequency of H. pylori isolates among 86 investigated biopsies was 20 (23.2%). Likewise, the rate of H. pylori was the highest when samples were examined from patients with gastric cancer (25.8%), while it was 21.8% when obtained from peptic ulcer patients. The frequency of the cagA gene in H. pylori isolates was 9 (56.2%), as confirmed by PCR. Conclusion: Our results indicated that H. Pylori infection and its virulent strains are frequent and widely spread in Qom city. The cagA gene was present in almost half of H. pylori isolates from peptic ulcer or gastric cancer patients. Therefore, it is necessary to screen it in all cases with H. pylori infection for early detection of gastric cancer

Evaluation of mouse embryos produced in vitro after electromagnetic waves exposure; Morphometric study.

INTRODUCTION Today, the use of electromagnetic waves in medical diagnostic devices, such as magnetic resonance imaging (MRI), has increased, and many of its biological effects have been reported. The aim of the present study was to assess the biological effects of 1.5 Tesla (T) magnetic resonance imaging (MRI) on fertility and reproductive parameters. METHODS Eighty adult male and female NMRI mice (NMRI: Naval Medical Research Institute) of age 6-8 weeks were studied and randomly divided into two study and control groups. After confirmation of pregnancy, the mice in the study group were exposed to the MRI (1.5 T) machine's waves over the next three weeks, once a week for 36 minutes. One day and thirty-five days after the last radiation, the mice were killed in order to do the in vitro fertilization (IVF) by neck beads' displacement and the impact on the evolution of embryos, and its quality was studied. Data were analyzed using SPSS version 20 and the significance level of less than 0.05 was considered. RESULTS Embryo morphometry showed that the total diameter and the cytoplasm diameter of the study group embryos suffered significant reduction compared to the control group, 1 day after the last irradiation (p < 0.05), but the diameter of the perivitelline space of this group's embryos had a significant increase (p < 0.05). The qualitative results during 35 days after irradiation showed that morphologically parameters of the embryos in the study group had no significant differences from the control group. CONCLUSION Exposure to MRI irradiation can transiently disturb the development of mouse embryos and fertility, but these effects are reversible 35 days after the last irradiation

Frequency of Psychiatric Disorders in Children of Opioid or Methamphetamine-Dependent ‎Patients

Background: Addiction is one of the main problems of human societies, which is more common in developing countries. In addition, it causes to personal and social problems and family problem. The aim of this study was to examine the prevalence of psychiatric disorders in children 5-15 years old of opioid or methamphetamine dependence patients. Methods: For this study, three groups including: (1) children of parents addicted to opium, (2) children of parents addicted to methamphetamine, and (3) control group were examined. Child symptom inventory-4 (CSI-4) questionnaires completed by non-hospitalized guardian and control group; then make interviews with the children by the Kiddie-schedule for affective disorders and schizophrenia (K-SADS). Data were analyzed by chi-square test and ANOVA. Findings: Survey showed that the frequency of attention deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), generalized anxiety disorder, obsessive-compulsive disorder, specific phobia (SP), and separation anxiety disorder in children of addicted parents were more than a non-addicted parent. However, there was no significant difference between the two groups in the frequency of conduct disorder, social phobia, and oppositional defiant disorders (ODDs). Conclusion: Parental addiction can lead to an increase in some psychiatric disorders in the children. Therefore follow-up, early diagnosis, treatment, and prevention of these disorders in children of the drug-dependent parent are necessary to reduce health costs and improve the health system

Isolation and Identification of an Alkaliplilic Thermo-tolerant Protease producing Bacillus sp. from Dehloran Hot Spring: Production Optimization and Investigation of the Activity and Stability of the Enzyme

Introduction:Thermophilic proteases can be used in various industries, including detergents, pharmaceuticals, food, etc. These enzymes are produced by thermophilic microorganisms, includingbacteria. Materials and methods: Sampling was carried out from Dehloran hot springs in Ilam province in the west of Iran to find new protease producing bacteria. Then, the effect of pH, temperature and finally the effect of different heating time on the production of protease enzyme were evaluated. Then, Polymerase Chain Reaction (PCR) was performed to detect the strain. Protease was purified through anion exchange using DEAE-sepharose column and its molecular weight was estimated using SDS-PAGE technique. Then, activity and stability of the enzyme were investigated in temperature and pH range. Results: Among isolated strains, bacteria Bacillus sp. DEM07 (registered in the World Gene Bank with access number KY392988) with the highest diameter of the protease clear zone, was selected to produce thermo tolerant alkaline protease. The maximum production of the alkaline protease enzyme was observed at 50 ° C, pH 7 and 48 hours after culture. The protease enzyme was purified by anionic chromatography and its molecular weight was estimated to be about 27.5 kDa after purification. The enzyme was active and stable at the temperature range of 30 to 55 ° C and the optimum temperature of the enzyme activity was observed at 50 ° C. The pH range for activity and its stability was from 4 to 11, and the optimum activity of the enzyme was observed at pH 10. Discussion and conclusion: In this study, the protease enzyme purified from Bacillus sp. DEM07 is a thermo tolerant alkalophilic protease. On the other hand, by creating the optimal conditions for achieving high production of thermo-tolerant alkalophilic protease, this enzyme has a high potential for use in various industries