Effect of Takaful Models on Performance of Takaful Operators

Purpose of this study is to analyze the performance in terms of profit of different takaful models being used in different countries in the world. It is both quantitative and qualitative research. In qualitative research, literatures is reviewed by using content analysis technique. Many takaful models are being used by many takaful operators i.e. Wakala, Wakal-Waqf, Mudharabah, Mudharabah-Wakla. For examining performance of different takaful models of five takaful operators, Secondary data on profit earning from 2008 to year 2017 is taken. Results and graphs represent the higher performance of Abu Dhabi National Takaful working on Mudharabah and Wakala Model which showed higher profit as compared to all takaful operators. The finding of this study is essential for Accounting and Auditing Organization for Islamic Financial Institutions (AAOIFI) for ensuring the standardization of the services and structures that could be given within the frame of mutual help. Takaful operators who can also use the above model i.e. Mudharabah and Wakala Model for enhancing their performance in financial market of insurance. Governments should enact a law for operations and rulings of standardized takaful models adopted by takaful operators and liberalize the takaful market via removal of tariff

Coupling between time series: a network view

Recently, the visibility graph has been introduced as a novel view for analyzing time series, which maps it to a complex network. In this paper, we introduce new algorithm of visibility, "cross-visibility", which reveals the conjugation of two coupled time series. The correspondence between the two time series is mapped to a network, "the cross-visibility graph", to demonstrate the correlation between them. We applied the algorithm to several correlated and uncorrelated time series, generated by the linear stationary ARFIMA process. The results demonstrate that the cross-visibility graph associated with correlated time series with power-law auto-correlation is scale-free. If the time series are uncorrelated, the degree distribution of their cross-visibility network deviates from power-law. For more clarifying the process, we applied the algorithm to real-world data from the financial trades of two companies, and observed significant small-scale coupling in their dynamics

Quality of Root Canal Obturation Performed by Senior Undergraduate Dental Students

Introduction: There is a direct relationship between the quality of root canal obturation and success of endodontic therapy. The aim of the present study was to assess the quality of canal obturation performed by undergraduate dental students at the Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Materials and Methods: Records of 200 endodontically treated teeth from patients who were visited by undergraduate students between 2009 and 2010, at the Endodontic department, Faculty of Dentistry, Mashhad University of Medical Sciences, were randomly selected for evaluation. Periapical radiographs of all treated teeth were assessed in terms of canal obturation quality (i.e. adequate density and length). Statistical analysis of data was carried out using SPSS software and chi-square test. The Statistical significance level was set at P=0.05. Results: Forty-five percent of teeth fulfilled the criteria of an acceptable root canal obturation. Adequate length and density of root filling was found in 89% and 34% of teeth, respectively. There was a significant difference between maxillary and mandibular teeth regarding the length of root canal obturation (P=0.004). A significant difference was observed between molars and other tooth types. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth compared to premolars or molars. Conclusion: The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal

Effect of adding letrozole to gonadotropin on in vitro fertilization outcomes: An RCT Running

Background: Aromatase inhibitors prevent the aromatization of androgens into estrogens, which reduces the negative feedback of estrogen on the hypothalamicpituitary axis. It is clear that increasing the secretion of follicle-stimulating hormones results in an increased follicular growth. Objective: This study aimed to evaluate the effect of adding letrozole to gonadotropin on in vitro fertilization outcomes in normal responders. Materials and Methods: In this randomized clinical trial, 100 normal responder women candidate for controlled ovarian stimulation were randomly enrolled in two groups (n = 50/each). In the case group letrozole was added to gonadotropin in the antagonist protocol. The control group received the conventional antagonist protocol. The main outcome was clinical and chemical pregnancy; and the second outcomes were the number of mature oocytes, the fertilization rate, estradiol level, and the total dose of gonadotropins. Results: Basic clinical and demographic features were comparable between the groups. Estradiol level on the day of human-chorionic-gonadotropin administration and the total gonadotropin consumption were significantly higher in the control group than the case group (p = 0.045). In addition, the number of MII oocytes was higher (but not significantl) in the case group than the control group (p = 0.09). Moreover, the endometrial thickness was significantly lower in the case group. There were no significant differences in fertilization rate and chemical and clinical pregnancy rates between the two groups. Conclusion: Although adding letrozole to gonadotropin in normal responders reduces the total dose of gonadotropin, it does not improve the pregnancy outcomes. Key words: Letrozole, Ovarian stimulation, Pregnancy

Power Allocation and Cooperative Diversity in Two-Way Non-Regenerative Cognitive Radio Networks

In this paper, we investigate the performance of a dual-hop block fading cognitive radio network with underlay spectrum sharing over independent but not necessarily identically distributed (i.n.i.d.) Nakagami-$m$ fading channels. The primary network consists of a source and a destination. Depending on whether the secondary network which consists of two source nodes have a single relay for cooperation or multiple relays thereby employs opportunistic relay selection for cooperation and whether the two source nodes suffer from the primary users' (PU) interference, two cases are considered in this paper, which are referred to as Scenario (a) and Scenario (b), respectively. For the considered underlay spectrum sharing, the transmit power constraint of the proposed system is adjusted by interference limit on the primary network and the interference imposed by primary user (PU). The developed new analysis obtains new analytical results for the outage capacity (OC) and average symbol error probability (ASEP). In particular, for Scenario (a), tight lower bounds on the OC and ASEP of the secondary network are derived in closed-form. In addition, a closed from expression for the end-to-end OC of Scenario (a) is achieved. With regards to Scenario (b), a tight lower bound on the OC of the secondary network is derived in closed-form. All analytical results are corroborated using Monte Carlo simulation method

Evaluation of Some Organic Inhibitors for Stainless Steel Corrosion Using Different Electrochemical and Surface Techniques

Stainless steels have been extensively used in automotive, industrial, electronics, etc., applications. Iron (Fe) and chromium (Cr) are the main elements with weight percentage contribution of 60-75% and 10-25% respectively. Other elements, such as Ni, Co, Mo, Mn, C etc. are also present with variable concentrations. The purpose of this work is to use different electrochemical and surface techniques to study the corrosion behavior of stainless steel type 316 (percent composition of different chemical elements are listed in table 1) in acid media in presence and absence of different thiophene derivatives (list of inhibitors in figure 1). Moreover, other important goals were to study the effect of adding chloride ion to the acidic media on the corrosion behavior of stainless steel, protection efficiency of ihibitors studied, and to determine the temperature coefficient and the adsorption isotherm of the inhibitor on the stainless steel type 316. Electrochemical techniques such as potentiodynamic polarization, Tafel experiments, polarization resistance and electrochemical spectroscopy were used to evaluate the effect of the inhibitors on the corrosion of stainless steel type 316. Surface analyses were employed to study the surface morphology and structural analysis of the surface using scanning electron microscope(SEM), Fourier Transform infrared(FT-IR), and x-ray diffraction techniques EDAX. The results showed distinct effects for the different inhibitors used that depend on the molecular structure and the electron density on the sulfur atom of the thiophene ring. The order of inhibition efficiency was 2-thiophene carboxylic hydrazide \u3e 2-thiophene carboxylic acid \u3e 3- thiophene caroxaldhyde \u3e 2-acetyl thiophene. It was concluded that the inhibitors studied were of the mixed type. The adsorption pattern for the inhibitors at the stainless steel surface followed a Langmuir isotherm model. The thermodynamic parameters of adsorption were calculated. It was concluded that a thin layer of inhibitor is formed at the surface of steel preventing the corrosion of the specimen in the acid medium. It was also suggested that anchoring of the sulfur atom of the thiophene ring to the surface of the stainless steel takes place that allowed a blanket of the inhibitor molecule to cover the surface. Surface reflectance FT-IR proved the adsorption of the inhibitor molecule at the stainless steel surface. Scanning electron microscopy showed that the presence of inhibitor protected the surface of the stainless steel against pitting in chloride-containing sulfuric acid electrolyte

The impact of liquidity and transparency in the financial markets: A case study in Tehran stock exchange

One of the topics addressed in the capital market is liquidity and transparency in the financial markets. Transparency is one of the major issues in Trading based on the forum, and electronics system. The purpose of this study was to investigate the effect of access to transparent stock information for decision-making. Qualitative approach was used for sample selection, data collection, analysis and conclusions. Data collection methods and instruments are in-depth interviews. Sampling method was purposive, useful and was used for determining the size of the sample theory saturation. Results obtained from this study indicate that liquidity and transparency are effective in information about quality increase

The impact of liquidity and transparency in the financial markets: A case study in Tehran stock exchange

One of the topics addressed in the capital market is liquidity and transparency in the financial markets. Transparency is one of the major issues in Trading based on the forum, and electronics system. The purpose of this study was to investigate the effect of access to transparent stock information for decision-making. Qualitative approach was used for sample selection, data collection, analysis and conclusions. Data collection methods and instruments are in-depth interviews. Sampling method was purposive, useful and was used for determining the size of the sample theory saturation. Results obtained from this study indicate that liquidity and transparency are effective in information about quality increase

The investigation of the relationship between managers’ applied skills and entrepreneurship development: A case study in West Azerbaijan’s food industrial firms

Today, management and managers’ skills have two wide domains: psychological dimension through which managerial skills are considered as personality characters and empirical studies which have studied this construct comprehensively and precisely and have offered valid evaluation methods for its assessment. The current research is applied regarding its aim, descriptive with respect to subject characteristics, survey in terms of time and field study considering data collection. In this research, questionnaires are used to collect data. Research population consists of managers working in firms active in food industry of West Azerbaijan, Iran. Regarding that all-counting method is not possible, sample size calculated as 228 using Cochran method. The present research aims at investigating 3 hypotheses tested through Spearman correlation coefficient and SPSS. Results obtained from hypotheses test indicate that there is a positive significant relationship between managers’ applied skills (self-awareness, self-motivation and social awareness) and entrepreneurship development