506 research outputs found

    A Fuzzy-FMEA Risk Assessment Approach for Offshore Wind Turbines

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    Failure Mode and Effects Analysis (FMEA) has been extensively used by wind turbine assembly manufacturers for risk and reliability analysis. However, several limitations are associated with its implementation in offshore wind farms: (i) the failure data gathered from SCADA system is often missing or unreliable, and hence, the assessment information of the three risk factors (i.e., severity, occurrence, and fault detection) are mainly based on experts’ knowledge; (ii) it is rather difficult for experts to precisely evaluate the risk factors; (iii) the relative importance among the risk factors is not taken into consideration, and hence, the results may not necessarily represent the true risk priorities; and etc. To overcome these drawbacks and improve the effectiveness of the traditional FMEA, we develop a fuzzy-FMEA approach for risk and failure mode analysis in offshore wind turbine systems. The information obtained from the experts is expressed using fuzzy linguistics terms, and a grey theory analysis is proposed to incorporate the relative importance of the risk factors into the determination of risk priority of failure modes. The proposed approach is applied to an offshore wind turbine system with sixteen mechanical, electrical and auxiliary assemblies, and the results are compared with the traditional FMEA

    Bell's Theorem and Chemical Potential

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    Chemical potential is a property which involves the effect of interaction between the components of a system, and it results from the whole system. In this paper, we argue that for two particles which have interacted via their spins and are now spatially separated, the so-called Bell's locality condition implies that the chemical potential of each particle is an individual property. Here is a point where quantum statistical mechanics and the local hidden variable theories are in conflict. Based on two distinct concepts of chemical potential, the two theories predict two different patterns for the energy levels of a system of two entangled particles. In this manner, we show how one can distinguish the non-separable features of a two-particle system.Comment: 11 pages,1 figure, To appear in J. Phy. A: Math. Gen., Special Issue: Foundations of Quantum Theor

    Relationship between Human Resource Accounting in Management Decision Mand Behavior of Employees in Company Stock Based on Structural Equation Modeling

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    Nowadays, in many countries, human resources is being used as a source of property by many social an economical organizations in order to enhance the level of their operation. Investors and other related groups in order to make better decisions need to use some expressions related to the value of human resources. Using human resource accounting organizations seeking to improve the efficiency and effectiveness of human resource management and human resources. The main objective of this paper is to evaluate the effect of accounting, human resources managers in decision-making and behavior of employees in the company's stock. This cross-sectional study with a survey approach and applied research are considered. The population of the study in 1394 are some of the companies stock. The results showed accounting, human resources component of research and finally decided Miran is also significant effect. Keywords: Human resource accounting, Human resource Management, Decision makin

    Overexpression of microRNA-16 declines cellular growth, proliferation and induces apoptosis in human breast cancer cells

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    MicroRNAs (miRNA) are a large family of small single-stranded RNA molecules found in all multicellular organisms. Early studies have been shown that miRNA are involved in cancer development and progression, and this role can be done by working as an oncogenes and tumor suppressor genes, so manipulation of this molecules can be a promising approach in cancer therapy, and experimental results represented that the modification in breast cancer phenotype is possible by miRNA expression alteration. miR-16, which is located in 13q14 chromosome, plays critical roles as a tumor suppressor by targeting several oncogenes which regulate cell cycle and apoptosis. Hence, in the present study, we investigated whether miR-16 could decline growth and survival of MCF-7 cell line as model of human breast cancer. MCF-7 cell line was infected with lentiviruses containing miR-16 precursor sequence. The effects of ectopic expression of miR-16 on breast cancer phenotype were examined by cell cycle analysis and apoptosis assays. miR-16 cytotoxicity effect was measured by the MTT assay. We showed that the miR-16 overexpression reduces Cyclin D1 and BCL2 at messenger RNA (mRNA) and protein levels in MCF-7 cell line. In addition, this is found that enforced expression of miR-16 decreases cell growth and proliferation and induces apoptosis in MCF-7 cells. In conclusion, our results revealed that upregulation of miR-16 would be a potential approach for breast cancer therapy. © 2015, The Society for In Vitro Biology

    Isokinetic Knee Strength in Females with Fibromyalgia

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    Objectives: To compare knee flexors and extensors muscle strength, total work, and power between females with fibromyalgia (FM) and matched healthy controls. Methods: This is the first study to measure knee muscle power and total work in females with FM. Thirty-one females with FM and thirty-one healthy females completed isokinetic testing of knee flexors and extensors of their dominant leg using a Cybex Norm Isokinetic Dynamometer. Two knee muscle groups (flexors and extensors) at two angular velocities (607sec and 1807sec) were tested for both groups. Both muscle groups were assessed continuously using five reciprocal concentric-concentric cycles, followed by five eccentric-eccentric cycles. Results:Females with FM exhibited significant decreases in voluntary muscle strength ranging from 18%-24% and average power ranging from 25%-30%, more pronounced for knee flexors than knee extensors. The strength and power deficits were not uniform during all test arrangements: 1) Maximum eccentric muscle strength for knee flexors and extensors at an angular velocity of 60 /sec in females with FM was reduced compared to the control group (p = .005 and .007, respectively), 2) Maximum concentric muscle strength for knee flexors at an angular velocity of 180 /sec in females with FM was reduced compared to the control group (p = .002), and 3) Average power for knee flexors at an angular velocity of 607sec for eccentric muscle action and 1807sec for concentric muscle action in females with FM was reduced compared to the control group (p =.006 and .001, respectively). No differences in total work at the two different velocities for the two muscle actions were found. Conclusion: We found decreased knee muscle strength and power in females with FM compared to healthy females. This may be due to muscle soreness from unhealed microtraumas, slow deformation of collagen and periarticular connective tissue of the knee joint, hypoxia, or decreased content of high energy metabolites

    Consequences of AphanizomenonFlos-aquae(AFA) extract (StemtechTM) on metabolic profile of patients with type 2 diabetes

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    Background: Blue- green algae is one of the most nutrient dense foods which is rich in substances that have useful effects on human health. The purpose of this study was to evaluate the effectiveness of a water- soluble extract of the cyanophyta Aphanizomenon Flos-aquae (StemtechTM) as a functional supplement on CD markers, lipid profile, glucose levels as well as its side effects in Iranian patients with type 2 diabetes. Methods: During this randomized, double-blind, placebo-controlled trial 49 type 2 diabetic patients, aged between 20 and 60years with a HbA1C�7.5, were allocated. Patients were divided into two groups of placebo and treated with an equal ratio 1:1. The subjects in StemtechTM group received one capsule of StemFlo (508mg) before breakfast and two capsules of StemEnhance (500mg) after each meal for a period of 12weeks, and placebo group was instructed to take placebo with the same pattern. During the intervention period, subjects were asked to keep usual diet and prohibited to take any functional foods or dietary supplements. Metabolic panel has been measured as the primary outcome of study at the beginning and end of the intervention period via blood sampling. Results: StemtechTM supplementation for 12weeks decreased fasting blood glucose (FBG) and Glycatedhemoglobin (HbA1c). Mean serum chemistry parameters (Triglyceride, Total Cholesterol, LDL, HDL, CRP, AST, ALT, BUN and Creatinine) as well as CD 34+, IL-6, TNF-aα in treated and control groups before and after the study showed no considerable dissimilarities. Conclusion: StemtechTM intervention brought in positive consequence on blood glucose levels in Iranian patients with type 2 diabetes, consequently suggests the StemtechTM as a functional food for the management of diabetes. © 2015 Sanaei et al

    Information and The Brukner-Zeilinger Interpretation of Quantum Mechanics: A Critical Investigation

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    In Brukner and Zeilinger's interpretation of quantum mechanics, information is introduced as the most fundamental notion and the finiteness of information is considered as an essential feature of quantum systems. They also define a new measure of information which is inherently different from the Shannon information and try to show that the latter is not useful in defining the information content in a quantum object. Here, we show that there are serious problems in their approach which make their efforts unsatisfactory. The finiteness of information does not explain how objective results appear in experiments and what an instantaneous change in the so-called information vector (or catalog of knowledge) really means during the measurement. On the other hand, Brukner and Zeilinger's definition of a new measure of information may lose its significance, when the spin measurement of an elementary system is treated realistically. Hence, the sum of the individual measures of information may not be a conserved value in real experiments.Comment: 20 pages, two figures, last version. Section 4 is replaced by a new argument. Other sections are improved. An appendix and new references are adde

    An Overview of Solar Thermal Power Generation Systems

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    In the world today, fossil fuels as conventional energy sources have a crucial role in energy supply since they are substantial drivers of the “Industrial Revolution”, as well as the technical, social, and economic developments. Global population growth along with high levels of prosperity have resulted in a significant increase in fossil fuels consumption. However, fossil fuels have destructive impacts on the environment, being the major source of the local air pollution and emitter of greenhouse gases (GHGs). To address this issue, using renewable energy sources especially solar energy as an abundant and clean source of energy, has been attracted considerable global attention, which can provide a large portion of electricity demand. To make the most of solar energy, concentrated solar power (CSP) systems integrated with cost effective thermal energy storage (TES) systems are among the best options. A TES system has the ability to store the thermal energy during sunshine hours and release it during the periods with weak or no solar radiation. Thus, it can increase the working hours as well as the reliability of a solar system. In this paper, the main components of the solar thermal power systems including solar collectors, concentrators, TES systems and different types of heat transfer fluids (HTFs) used in solar farms have been discusse
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