Reliability and Reliability-based Sensitivity Analyses of Steel Moment-Resisting Frame Structure subjected to Extreme Actions

The ground external columns of buildings are vulnerable to the extreme actions such as a vehicle collision. This event is a common scenario of buildings' damages. In this study, a nonlinear model of 2-story steel moment-resisting frame (SMRF) is made in OpenSees software. This paper aims investigating the reliability analysis of aforementioned structure under heavy vehicle impact loadings by Monte Carlo Simulation (MCS) in MATLAB software. To reduce computational costs, meta-model techniques such as Kriging, Polynomial Response Surface Methodology (PRSM) and Artificial Neural Network (ANN) are applied and their efficiency is assessed. At first, the random variables are defined. Then, the sensitivity analyses are performed using MCS and Sobol's methods. Finally, the failure probabilities and reliability indices of studied frame are presented under impact loadings with various collision velocities at different performance levels and thus, the behavior of selected SMRF is compared by using fragility curves. The results showed that the random variables such as mass and velocity of vehicle and yield strength of used materials were the most effective parameters in the failure probability computation. Among the meta-models, Kriging can estimate the failure probability with the least error, sample number with minimum computer processing time, in comparison with MCS

Effect of epsilon-based record selection on fragility curves of typical irregular steel frames with concrete shear walls in Mashhad city

In this paper, the seismic vulnerability of Mashhad city, as the second largest city in Iran, has been investigated using analytical fragility curves. Disaggregation analysis is first performed in order to identify the target epsilon at different hazard levels. The disaggregation results revealed different epsilon values at the first mode period of two representative structures, in the case of 72-, 475-, and 2,475-year return periods. Nonlinear incremental dynamic analyses are then performed for two representative models of a typical steel frame with a concrete shear wall, using independent suites of acceleration time histories that are selected based on the target epsilons. Structural limit states are defined on each incremental dynamic analysis curve, and the corresponding damage measures are estimated. The results show that if ϵ is neglected in the considered simulations, then the predicted median structural capacities is decreased by around 10%, 15%, and 18%, respectively, for the three abovementioned hazard levels

Isoflavones Potentials for the Treatment of Osteoporosis: An Update on In-vivo Studies

Abstract In plant-derived compounds, phytoestrogens are biologically active substances that exhibit various estrogenic and antiestrogenic effects. With the increasing prevalence of osteoporosis among older women caused by estrogen deficiency, identifying natural substances that can potentially treat the disease is of utmost significance. This review study aimed to explore how phytoestrogen metabolites mimic mammalian estrogens and prevent bone loss following menopause. Phytoestrogens derived from plants have gained considerable attention due to their similarity to mammalian estrogens and lower impact on sensitive tissues, such as the uterus and breasts. One well-established approach to simulate postmenopausal conditions is by using ovariectomized rats or mice (OVX). The administration of phytoestrogens in the OVX murine model has inhibited osteoclast differentiation, activation, and Pyridinoline secretion. Furthermore, these compounds have been shown to enhance bone formation and increase bone mineral density and the expression levels of various osteoblast markers, such as alkaline phosphatase, osteocalcin, osteopontin, and alpha-1 collagen. Several natural phytoestrogen compounds in plants possess a chemical structure akin to 17 beta-estradiol, a steroid hormone. In postmenopausal women with osteoporosis, isoflavones, a type of phytoestrogen, can potentially treat the disease by binding to estrogen receptors on the surface of target cells. Mechanistic investigations have demonstrated that phytoestrogens can retard bone resorption and promote bone formation. Novel approaches in phytoestrogen research could involve investigating the synergistic effects of combining different phytoestrogen compounds, exploring their interactions with other signaling pathways, or assessing their effects on various bone types. Furthermore, identifying novel sources of phytoestrogens could lead to the discovery of new compounds with potent osteoprotective effects. https://jlar.rovedar.com/index.php/JLAR/article/view/1

Extracting the innovation policies for Iran based on the approximation of policy implications for comparative economic doctrines

Due to many differences in presumptions and theoretical foundations within neoclassical and evolutionary economics, policy-makers are always confronted with the dilemma of selecting one of these two central models for technology and innovation policy. In light of widely institutionalised ineffectiveness in the field of market and systematic coordination – in Iran as well many other countries – the present investigation presumes that reliance on any of the above doctrines alone is ineffective. An intermediate concept of policy rationales to achieve a comparative structure of policy implications is proposed. Policy rationales (in innovation and technological policy) for neoclassical and evolutionary economics were derived based on a thematic analysis. A spectrum of policy implications of both doctrines was designed and completed in the form of a questionnaire for, together with theoretical foundations and policy rationales by specialists of the field of innovative and technological policy in Iran. Given the institutional conditions and structural frameworks which actually exist, and in spite of wide dissimilarities within the theoretical foundations of neoclassical and evolutionary economics, Clustering of respondents and subsequent test trials show that policy implications of the economics doctrines in the field of innovative and technological policy in Iran are complementary and convergent

Optimization of pulsed ultrasound-assisted technique for extraction of phenolics from pomegranate peel of Malas variety: punicalagin and hydroxybenzoic acids

Pomegranate peel is a rich source of phenolic compounds (such as punicalagin and hydroxybenzoic acids). However, the content of such bioactive compounds in the peel extract can be affected by extraction type and condition. It was hypothesized that the optimization of a pulsed ultrasound-assisted extraction (PUAE) technique could result in the pomegranate peel extract with higher yield and antioxidant activity. The main goal was to optimize PUAE condition resulting in the highest yield and antioxidant activity as well as the highest contents of punicalagin and hydroxybenzoic acids. The operation at the intensity level of 105 W/cm2 and duty cycle of 50% for a short time (10 min) had a high efficiency for extraction of phenolics from pomegranate peel. The application of such short extraction can save the energy and cost of the production. Punicalagin and ellagic acid were the most predominant phenolic compounds quantified in the pomegranate peel extract (PPE) from Malas variety. PPE contained a minor content of gallic acid

Energy, exergy, and economic analysis of a geothermal power plant

The current study aimed at designing a geothermal power plant in the Nonal area in Damavand district for simultaneous generation of thermal energy the electric power in the network of Damavand City and a part of Tehran province, the organic working fluid for the above cycle is R245fa which is a non-flammable fluid of dry type. The values of energy efficiency, exergy, the net rate of entropy change, and the specific output power were calculated as 18.2%, 21.3%, 172.97 kW/K, and 31.43 kJ/kg, respectively. The cost of drilling a well, as well as designing and construction of Damavand’s geothermal power plant, were calculated to be 4.2 and 521.5 million (USD), respectively. Also, the cost per generation of each kW/h of power in Damavand power plant was 17 cents. The estimated payback time is calculated as 15 years. The analysis of the cycle in different months of the year showed that exergy efficiency has little change. The only significant effect of temperature changes was on the exergy efficiency as approximately a change of 2% can be seen during a year.Cited as: Kazemi, H., Ehyaei, M.A. Energy, exergy, and economic analysis of a geothermal power plant. Advances in Geo-Energy Research, 2018, 2(2): 190-209, doi: 10.26804/ager.2018.02.0

Effects of different photoperiods on the survival and growth of beluga sturgeon (huso huso) larvae

Effect of different photoperiodic regimes was evaluated on growth performance and survival rate of the Beluga (Huso huso) prelarvae and larvae. Newly hatched prelarvae were stored in 5 round fiberglass 500‑L tank with different photoperiod (24L:00D, 18L:06D, 12L:12D, 06L:18 D, 00L:24D) till 50 days post hatch with three replicates. Light intensity was 200 lux during the experiment. Feeding was started from 8 days post hatch using live artemia nauplii. Higher total length, survival rates and lower body area, yolk area for beluga prelarvae obtained in long light photoperiods (24L:00D, 18L:06D). Also, higher growth parameters of the beluga larvae observed in long light photoperiods while different photoperiods had no effect on survival rate. The present study indicated that growth performance and survival rates of larvae are significantly influenced by photoperiod. The photoperiod 18L:06D resulted in the best growth performance and survival rate during early development of the beluga

Corporate Life Cycle and the Explanatory Power of Risk Measures versus Performance Measures

The major aim of this paper is to compare the explanatory power of risk measures versus performance measures in different life-cycle stages. To test the hypotheses, first, sample firms were classified into three life-cycle stages (Growth, Mature and Decline). Then, using regression models and Vuong's Z-statistic, the hypotheses were investigated. In this study, financial information of 75 firms which were accepted at Tehran’s Stock Exchange (TSE) from 2003 to 2008 (450 firm-years) was examined. The results of this study show that in growth and decline stages, the explanatory power of risk measures is significantly higher than performance measures and in mature stage, the opposite is true

Phaeoacremonium and Botryosphaeriaceae species associated with cypress (Cupressus sempervirens L.) decline in Kerman province (Iran)

Common cypress (Cupressus sempervirens L.) is an east Mediterranean plant element and one of four native conifers in Iran. During spring and summer of 2012, a field survey was carried out in different areas of Kerman province (south-eastern Iran) to study cypress decline diseases. Samples were collected from crowns, trunks and branches of cypress trees showing yellowing, dieback, canker, wilting of leaves and internal wood discoloration. Isolations were made from symptomatic wood tissues. Based on morphological and molecular characteristics, four species of Phaeoacremonium, namely Phaeoacremonium parasiticum, Pm. aleophilum, Pm. iranianum and Pm. rubrigenum, and two species of the Botryosphaeriaceae, Botryosphaeria dothidea and Neofusicoccum parvum, were isolated and identified. Pathogenicity tests were undertaken to determine the role of these species on 2-year-old potted cypress plants and green shoots of grapevine. Neofusicoccum parvum was more virulent than the other species and caused the largest lesions on both hosts. The fungi were re-isolated from margins of lesions and healthy tissue, thus completing Koch’s postulates. This is the first report of B. dothidea, N. parvum, Pm. aleophilum, Pm. rubrigenum and Pm. iranianum as pathogens on Mediterranean cypress trees

Impact of momordica charantia extract on kidney function and structure in mice

Background: Bitter Melon (BM) is known for its hypoglycemic effect and is commonly used in populations. Objectives: This study examined the effects and safety of bitter melon fruit in laboratory mice. Materials and Methods: In this experimental study 70 male mice (25-30 gr) were randomly divided into 7 groups. The mice were injected intraperitoneally with single doses of 0, 100, 500, 1000, 2000 and 4000 mg/kg and multiple doses 500 mg/kg daily for 7 days. The mice were then observed for 72 hours before sacrificing. Immediately kidneys were taken out for histological examinations. Tubular cell vacuolization and flattening as well as hyaline casts, debris and dilatation of tubular lumen were the morphologic lesions which were assessed with scores from 0 to 4, while zero score addressed normal renal tissue. Serum samples were assayed for kidney function (creatinine; Cr and Blood Urea Nitrogen; BUN). Blood and bitter melon antioxidant activities were measured, too. Data were analyzed with Stata software (Stata Corp. 2011. Stata Statistical Software: Release 12. College Station, TX: Stata Corp LP) using ANOVA and Bonferroni tests. Results: All single dose groups showed normal behavior after the dosing and no statistical changes were observed in blood parameters (p>0.05). Histological examinations revealed normal organ structures, however, the group treated for 7 days showed statistically a significant change in BUN (p=0.002) and a borderline significance in Cr (p=0.051). Conclusions: Administration of up to 4000 mg/kg did not have any effect on the mice kidney function and histology, however chronic administration were nephrotoxic. More studies with different dosage regimens are suggested. © 2014, Society of Diabetic Nephropathy Prevention. All rights reserved