Non-linear damping of visco-resistive Alfven waves in solar spicules

Interaction of Alfven waves with plasma inhomogeneities generates phase mixing which can lead to dissipate Alfven waves and to heat the solar plasma. Here we study the dissipation of Alfven waves by phase mixing due to viscosity and resistivity variations with height. We also consider nonlinear magnetohydrodynamic (MHD) equations in our theoretical model. Non-linear terms of MHD equations include perturbed velocity, magnetic field, and density. To investigate the damping of Alfven waves in a stratified atmosphere of solar spicules, we solve the non-linear MHD equations in the x-z plane. Our simulations show that the damping is enhanced due to viscosity and resistivity gradients. Moreover, energy variations is influenced due to nonlinear terms in MHD equations.Comment: Accepted for publication in Astrophysics and Space Science Journal. arXiv admin note: substantial text overlap with arXiv:1304.776

Spring search algorithm for simultaneous placement of distributed generation and capacitors

Purpose. In this paper, for simultaneous placement of distributed generation (DG) and capacitors, a new approach based on Spring Search Algorithm (SSA), is presented. This method is contained two stages using two sensitive index Sv and Ss. Sv and Ss are calculated according to nominal voltageand network losses. In the first stage, candidate buses are determined for installation DG and capacitors according to Sv and Ss. Then in the second stage, placement and sizing of distributed generation and capacitors are specified using SSA. The spring search algorithm is among the optimization algorithms developed by the idea of laws of nature and the search factors are a set of objects. The proposed algorithm is tested on 33-bus and 69-bus radial distribution networks. The test results indicate good performance of the proposed methodЦель. В статье для одновременного размещения распределенной генерации и конденсаторов представлен новый подход, основанный на "пружинном" алгоритме поиска (Spring Search Algorithm, SSA). Данный метод состоит из двух этапов с использованием двух показателей чувствительности Sv и Ss. Показатели чувствительности Sv и Ss рассчитываются в соответствии с номинальным напряжением и потерями в сети. На первом этапе определяются шины-кандидаты для установки распределенной генерации и конденсаторов согласно Sv и Ss. Затем, на втором этапе размещение и калибровка распределенной генерации и конденсаторов выполняются с использованием алгоритма SSA. "Пружинный" алгоритм поиска входит в число алгоритмов оптимизации, разработанных на основе идей законов природы, а факторы поиска представляют собой набор объектов. Предлагаемый алгоритм тестируется на радиальных распределительных сетях с 33 и 69 шинами. Результаты тестирования показывают хорошую эффективность предложенного метода

Designing and Psychometric Evaluation of the Competency Inventory for Postgraduate Students of Intensive Care Nursing

Background: Today, the role of expert clinical nurses is highlighted because their presence is necessary for guaranteeing the quality of nursing care provided for the patients. However, there are no proper instruments for measuring the clinical competence of postgraduate students in intensive care nursing. Objectives: The present study aimed at development and psychometric evaluation of the clinical-competence inventory for postgraduate students of intensive care nursing. Patients and Methods: A methodological study was conducted at state nursing schools of Iran. The participants were postgraduate students of intensive care nursing, who were being trained at 16 nursing schools throughout Iran, during year 2014. After examining some relevant texts, the first draft of the inventory was designed with 60 items. In order to confirm its face and content validity, a panel of experts and students examined the inventory. The final draft, which contained 44 items, was distributed among postgraduate students of intensive care nursing, and 217 students answered the inventory. The construct validity was verified using exploratory factor analysis. The reliability of the inventory was verified using consistency tests. Results: Firstly an instrument with 60 items was developed. Next, the face and content validity of the instrument was assessed by 15 students and 11 experts. Overall, 16 items were removed through validity assessment and 44 items remained in the final draft. The content validity index of the final draft was 0.90. Moreover, the content validity ration of 44 items ranged between 0.75 and 1. The Cronbach’s alpha coefficient of the inventory was 0.95 and the intraclass correlation coefficient (ICC) of the test-retest results was 0.96. To examine the construct validity of the final draft, it was administered for 217 postgraduate students of intensive care nursing and five factors, with Eigenvalues above one and loading level equal to or above 0.4, were extracted through exploratory factor analysis. Conclusions: The inventory developed in this study is a suitable index for evaluating the efficacy of postgraduate students in the field of intensive care nursing

Characterization of Iranian grapevine cultivars using microsatellite markers

Sixty-two grapevine (Vitis spp.) accessions from Iran and the USA were characterized at 9 highly polymorphic microsatellite loci using fluorescent primers and a capillary electrophoresis fragment sizing system. The number of alleles observed per locus ranged from 4 to 16 and heterozygosity values ranged from 0.47 to 0.86. Genetic similarity was estimated for each pair of accessions as the proportion of shared alleles. A phenogram constructed from genetic dissimilarity values revealed three clusters, one each for table grapes, wine grapes and rootstocks. The phenogram also revealed three clonal sets (Askari, Bidane and Yaghoti) as well as some synonyms and homonyms among Iranian table grape cultivars.

Genetic Relationships among Pistacia Species Studied By Morphological Characteristics and RAPD Marker

Abstract: The aim of this research was to study 33 Pistachio accessions and determine their genetic relationships. Thirty-one morphological characters (17 quantitative and 14 qualitative) together with Randomly Amplified Polymorphic DNA (RAPD) marker data were used for this purpose. Factor analysis was used to determine the effective characteristics and the number of main factors which determined seven main factors. Grouping of pistachio accessions by these factors was performed by Ward's method. Among 77 random decamer primers tested, 12 showed good amplification and polymorphism, and a total of 130 markers were produced that 118 were polymorphism. Grouping by morphological characteristics was compared with the results from RAPD analysis which did not produce a significant correlation