Distinguishing polymeric insulators PD sources through RF PD measurement

A better performance and consequently the widespread use of polymeric insulators in different parts of the power grid can increase their role in the grid reliability. The accumulation of contamination and housing-erosion are the two most effective factors in undermining the performance of this type of insulators. Therefore, electric utilities need to identify contaminated insulators for washing and cracks in polymeric housing to replace them with healthy specimens. This paper discusses the impact of contamination layer and housing-erosion of polymeric insulators on the partial discharges (PD) at the insulator surface, through RF-PRPD (phase resolved partial discharge) patterns. The existence of different sources of PDs in a real environment (transmission line or station) makes it difficult to use the PRPD patterns to distinguish them from each other. Therefore, using a conical monopole antenna, the simultaneous PD signals and the related RF-PRPD pattern of samples under test are captured. The grayscale image was obtained using the time-frequency matrix of the PD signals transform, by wavelet. Then, features are extracted and selected from grayscale image. By clustering of the PD signals, the resulted RF-PRPD sub-patterns are well separated and provided the necessary means to distinguish among the status of different samples under test

An empirical study for measure the relative performance of banking operations

Structure analysis plays an important role on increasing the efficiency of banking industry. A change in structure of business in this industry could change the profitability, significantly. The proposed study of this paper aims at structural analysis and comparative advantages for a governmental bank in a province of Semnan, Iran called Melli bank. The proposed study considers the effectiveness of four saving plans including current, loaned with no interest, short and long term based in three periods. It applies the change of location-share model, which includes provincial growth influence, structural growth and competitive growth as the determinant variables in saving rate. Findings indicate the disproportionate growth of saving rate in the Melli bank toward the other banks of the province in every 3 terms of the study. The research results show that short time saving in 2001 and 2004, loaned without interest and short term savings in 2001 and 2008, loaned without interest and long term savings in 2004 and 2008 had negative structural changes which indicate that the combination of discussed saving wasn’t desirable, but other savings benefits of desirable combination

On the performance of equiangular mascon solution in GRACE-like missions

Mass concentration (mascon) solutions for GRACE (Gravity Recovery and Climate Experiment) data are widely used in various regional-to-global mass change studies. The current advances in the mascon solution have mainly concentrated on improving the spatial resolution of the solution, enhancing the applied least-squares regularization, and the characterization of the solution errors. Most of the mascon solutions are obtained on the equal-area grid, inducing complexities in creating the grid and its presentation. In this regard, estimation of the mascon solutions on equiangular grids can be appealing. Furthermore, in the equal-area methods, there is no global criterion to determine the size of the mascon areas. The mascon size is usually chosen in a subjective manner which hampers the objective application of different mascon solutions. In view of these challenges, two main questions are addressed in this study: i) what kind of modifications should be made in computation scheme of the mascon solution if equiangular grids are used to account for different areas of the grid patches, and ii) in case of non-equiangular solutions, how to define an objective criterion for the patch sizes based on the resolution of both the observation and the signal of interest. We investigate the performance of the high-resolution mascon-based approach, proposed by Abedini et al. [2021], which uses GRACE-like observations similar to level-1 data for a period of one month over the Greenland region. Two main practical issues are studied on the estimation of the surface density changes as follows. First, we show that for equiangular grids, the area of the patches should be accounted for in the regularization by introducing area-affected weights for the unknown parameters. We investigate the effect of three different area-affected weighting strategies on the derived solution. Secondly in order to obtain proper size for the patches, a novel approach is presented to investigate the performance of the mascon solution using the analysis of the resolution matrix entries. The proposed resolution analysis is used to obtain the optimal patch size for the discretization of the area of interest. Based on the results, it is demonstrated that the minimum legible patch size in the Greenland area for the current settings of the GRACE observations is 0.5 degree in the NS direction and a latitude-adaptive grid-size rather than equiangular grids at high latitude regions in the EW direction

Comparison of Two Marketed Hydroxypropyl Methylcellulose Based Artificial Tear Drops in Young Patients with Dry Eye Syndrome

Background: Artificial tears have been among the first line of therapy in management of Dry Eye Syndrome (DES). This study was conducted to compare a local artificial tear with an imported one in reduction of DES. This comparison would help to evaluate the cost and benefits of each drop in the proper management of DES.Materials and Methods: In this double-blind randomized clinical trial study, a total 65 students meeting our inclusion criteria for DES entered the study. The OSDI questionnaire, TBUT, corneal and conjunctival staining and Schirmer test, were performed. The patients were divided into two groups by block randomization. Group 1 received first drop and group 2 received second drop. Both groups were instructed to use the drops 4 times a day for 14 days. The same tests were performed by the same examiner who was blind to the treatment type after two weeks. Repeated measured ANOVA was used to analyze the data.Results: A total of 58 patients completed the study. In both groups, after the intervention, the OSDI scores (P<0.001), TBUT score (P=0.041), corneal (P<0.001) and conjunctival staining scores (P<0.001) showed improvement in compare to those before the intervention. However, the Schirmer test score did not show significantly difference before and after intervention. In comparing two groups the OSDI scores, the TBUT score, the corneal and conjunctival staining scores and the Schirmer scores did not show statistically significant difference.Conclusion: The two artificial tears equally reduced the symptoms and signs of DES in two weeks

Procalcitonin and white blood cell count (WBC), erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) alterations in children with systemic inflammatory response syndrome before and after treatment

Systemic inflammatory response syndrome (SIRS) due to infection is an important cause of morbidity and  mortality in children. The present prospective observational study aimed to determine the correlation  between  procalcitonin (PCT) and white blood cell count (WBC), erythrocyte sedimentation rate (ESR) and  C-reactive protein (CRP) in toddlers before and after treatment. Moreover, 50 patients aged 1 to 36 months who were hospitalized at the Pediatrics Ward in Besat Hospital, Sanansaj city, Kurdistan province Western  Iran through a census sampling method were recruited. The complete blood count (CBC) was measured via  cell counter; ESR by the Westergren method, CRP via semi quantitative method and PCT via semi quantitative  immune-chromatography method. Pearson correlation coefficient was used to estimate correlation between  WBC, ESR, CRP and PCT before and after treatment of SIRS. The results obtained show correlation coefficients between PCT and CRP as well as between PCT and ESR in the first day of trial before treatment were  determined as ‘good’ and ‘moderate’, respectively. However, there was no significant correlation between PCT and WBC. No significant correlation was found between PCT and WBC count, ESR and CRP at the third day of  treatment. It was concluded that procalcitonin and CRP is the most favorable values for confirming SIRS  diagnosis in the onset of treatment. PCT can be considered as the marker of choice for following up purposes.Key words: Systemic inflammatory response syndrome (SIRS), procalcitonin, toddlers, treatment

Barriers, Facilitators, Process and Sources of Evidence for Evidence- Based Management among Health Care Managers: A Qualitative Systematic Review

BACKGROUND: Evidence-based management (EBMgt) improves managerial decisions as a bridge from theory to practice. For reason that it has a critical impact on organization performance. The purpose of this study was to identify factors affecting EBMgtamong managers.METHODS: The following electronic databases were used: PubMed, Web of Science, Cochrane, ProQuest, Embase and Scopus. In addition, we searched Google Scholar, Emerald, Academy of Management (AOM), and the website for the Center nfor Evidence-Based Management (CEBMa) for articles related to EBMgt. We used data sources published up to September 2017, without language restriction. We appraised the methodologicalquality of studies using the checklists of SRQR and MMAT. The synthesis involved interpretative analysis based on the principles of meta-synthesis.RESULTS: Of 26,011 identified studies, 26 met the full inclusion criteria. Of the 26 studies assessed, the frequency of qualitative studies and mixed-methods were 20 and 6, respectively, and the quality of 3 studies was weak. A total of 23 studies from 7 countries were included: Canada (n=8), USA (n=6), Australia (n=4), UK (n=3), Iran (n=1, Brazil (n=1); none were from Africa. Meta-synthesis findings of 23 studies identified four main factors: facilitators (5 main themes), barriers (5 main themes), sources of evidence (4 main themes), and the process of decision making in EBMgt (1 main theme).CONCLUSIONS: EBMgt is crucial to improve the quality of management decisions, and hence, to improve service delivery, effectiveness and efficiency. Furthermore, to increase the benefit and utilization of EBMgt, training organizations and research institutes must more actively involve managers in setting research plans

Application of lanthanides tetrad effect as a geochemical indicator to identify fluorite generations: A case study from the Laal-Kan fluorite deposit, NW Iran

The Laal-Kan fluorite deposit situated in north margin of the Sanandaj-Sirjan metamorphic belt and Urmia-Dokhtar magmatic arc, NW Iran. The fluorite mineralization in the form of open-space filling, veins and veinlets have been deposited in the contact zone between highly metamorphosed schist, gneiss, amphibolite of the Paleozoic age and the Jangutaran limestone of the Precambrian age. The occurrence of convex tetrad effect and the calculated tetrad values indicate that early and late stage fluorite mineralization display various geochemical behavior, which are supported by the bivariate diagrams including T1, T3 and T4 versus each other and some geochemical parameters such as La/Ho, Y/Ho and Zr/Hf ratios. It can, therefore, deduced that fluorite have been probably formed during two stages from hydrothermal fluids with a relatively constant composition. The fluid-rock interaction during deposition of fluorite and REE-F complex were likely the main mechanisms for the occurrence of tetrad effect

Production of titanium tetrachloride (TiCl4) from titanium ores: A review

Titanium (Ti) is the ninth most abundant element on earth. The titanium mineral ores are widely distributed in different parts of the world. The two main ores of titanium include rutile (TiO2) and ilmenite (FeO.TiO2). It is aimed to provide the readers with an insight to the main processes currently employed to extract and recover titanium tetrachloride (TiCl4) from different titanium ores. Due to the crucial importance of TiCl4 catalyst in the synthesis and polymerization of polyolefins, the present work examines the literature and developments made in the processing of ilmenite and rutile ores for the extraction of TiCl4. The attention has been paid to the chlorination processes and the main parameters affecting the recovery of TiCl4. Different approaches developed to date are reviewed. Different processes, reaction mechanisms and conditions as well as the kinetic models developed for extraction and purification of TiCl4 in fluidized bed reactors are also reviewed. A literature survey on the combined fluidized bed reactor systems developed for achieving a high-grade synthetic rutile via selective chlorination of low-grade titanium ores having high metal oxides content such as magnesium oxide (MgO) and calcium oxide (CaO) is also reported. Different strategies adopted to avoid agglomeration process during the extraction process are discussed too

Application of lanthanides tetrad effect as a geochemical indicator to identify fluorite generations: A case study from the Laal-Kan fluorite deposit, NW Iran

The Laal-Kan fluorite deposit situated in north margin of the Sanandaj-Sirjan metamorphic belt and Urmia-Dokhtar magmatic arc, NW Iran. The fluorite mineralization in the form of open-space filling, veins and veinlets have been deposited in the contact zone between highly metamorphosed schist, gneiss, amphibolite of the Paleozoic age and the Jangutaran limestone of the Precambrian age. The occurrence of convex tetrad effect and the calculated tetrad values indicate that early and late stage fluorite mineralization display various geochemical behavior, which are supported by the bivariate diagrams including T1, T3 and T4 versus each other and some geochemical parameters such as La/Ho, Y/Ho and Zr/Hf ratios. It can, therefore, deduced that fluorite have been probably formed during two stages from hydrothermal fluids with a relatively constant composition. The fluid-rock interaction during deposition of fluorite and REE-F complex were likely the main mechanisms for the occurrence of tetrad effect

A new method of fuzzy clustering by using the combination of the firefly algorithm and the particle swarm optimization algorithm

Abstract: Fuzzy clustering algorithm is one of the data mining methods that is applied in different fields. According to the fuzzy clustering algorithm, each object is allocated to the clusters regarding its percentage of belonging to each of the clusters. Finding the cluster centers is one of the main objectives of the clustering and it is possible to apply the swarm intelligence methods in order to accurately find the cluster centers. The swarm intelligence algorithms have separately been applied for clustering and they received the optimized solution. In order to solve the problems of the fuzzy clustering algorithm, the combined method based on the firefly algorithm and the particle swarm optimization algorithm is applied. In order to determine the validity, the suggested method is tested on four standard data collections received from the valid site of UCI. The simulation results shows that the combination of two algorithms do the clustering more accurately than applying each of them separately