Parameter Retrieval of Samples on a Substrate From Reflection-Only Waveguide Measurements

A microwave method has been proposed for constitutive parameters' extraction of samples on a known substrate. The advantage of this method is that it relies on noniterative reflection-only (air- and metal-backed) scattering (S-) parameters so that it is a good candidate for the characterization of samples when only one-port measurements are available. It is validated by the X-band (8.2-12.4 GHz) waveguide S-parameter measurements. A sensitivity analysis is followed to evaluate and improve the performance of our method. IEE

Temperature change in pulp chamber of primary teeth during curing of coloured compomers: An in vitro study using pulpal blood microcirculation model

Introduction: An increase in the temperature of the pulp chamber occurs during polymerisation of all types of light-curing resin-containing restorative materials, due to both the exothermic reaction of the material and the energy absorbed during the curing process. Increase in temperature of the pulp chamber of primary teeth during the curing process or the thermal conductivity properties of coloured compomers (CCs) have not yet been investigated in detail. The aim of the present study was to investigate the increase in pulpal temperature in primary teeth during curing of CCs. Materials and Methods: A Class-II cavity was prepared on the extracted primary mandibular second molar. Pulpal microcirculation of the tooth was performed using an experimental mechanism. The study included 15 groups and 10 experiments in each. Seven different CCs: Pink, blue, gold, silver, orange, lemon, green, respectively from two different manufacturers (Groups 1-7: Twinky Star; VOCO, Cuxhaven, Germany. Groups 8-14: Nova Rainbow; IMICRYL, Konya, Turkey.) and a tooth-CC (Group 15: Dyract XP; DENTSPLY, Weybridge, UK.) were applied in prepared cavity. In all groups the compomers were light cured for 40 s. Intrapulpal temperature changes (Δt) in 20th and 40th second were recorded. In Group-15 the Δt values in 10th second were also recorded as per the manufacturer's instructions. The Kruskal-Wallis test and the Mann-Whitney-U test were used for statistical analyses. Results: At the end of 40-s irradiation time, the orange, lemon and green colours of Nova Rainbow resulted in significantly lower Δt values than the same colours of Twinky Star (p =0.0001), and silver, blue, lemon, green, orange, and pink CCs of Nova Rainbow and the blue and silver shades of Twinky Star demonstrated lower Δt values than the reported critical temperature increase (5.5 °C). Conclusion: An increase in the irradiation time consequently led to an increase in the intrapulpal temperature. Therefore, manufacturers should focus on production of new CCs with shorter polimerization time. © 2019 Ertuǧrul and Ertuǧrul

An improvement of current driving and electrical conductivity properties incovetics

: Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 107 A/m2 , for 1000 A current at a temperature of 1073.2 K, this value is a constant while temperature is changing up to 1573.2 K. We measured the conductivity of the proposed covetic materials at various carbon nanotube densities at room temperature. Experimental results show the lowest resistivity value accomplished after mixing and temperature annealing as a value of 1.78 10−8 Ω.m, where the covetic sample has 1.27% carbon nanotube density, and that the electrical conductivity is superior to that of Cu-carbon nanotube composites previously report

The perspectives on iso 9000 quality Management of smes (small and medium sized Enterprises) that manufacture textile Productions in denizli

Nowadays, small and medium sized enterprises which play an important role in providing employment and also development, commonly called SMEs, have been seen as the driving forces of the local and regional developments. Especially it's thought that SMEs can adopt the environmental conditions quickly, so they are more fortunate in catching the market oppurtunities because of their strong and suitable structures for development and also because of their flexibilities. However, SMEs face a fierce competition with the effect of globalization like big companies. The competition increased by the rate of variation has forced companies to develop strategies like low cost and large product range. Quality Management System is one of the most important ones of these strategies. Quality management systems outline the past of company, show their level today and give reliable information about future. This study presents a research about perspective on quality of small, medium Enterprises in textile industry in Denizli and researchs the differences between companies which have ISO 9000 certificate and which don't have ISO 9000 certificate. And results of the research are shown by SPSS program

Fuzzy Group Decision Making for the Selection of Facility Location

In this paper, fuzzy group decision making based on extension of TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method which was proposed by Chen (Fuzzy Sets Syst, 114:1-9, 2000) is adopted for facility location selection. In this method, the ratings of various alternatives versus various subjective criteria and the weights of all criteria are assessed in linguistic variables represented by fuzzy numbers. By fuzzy numbers, it has been tried to resolve the ambiguity of concepts that are associated with human being's judgments. To determine the order of the alternatives, closeness coefficient is defined by calculating the distances to the fuzzy positive ideal solution (FPIS) and fuzzy negative ideal solution (FNIS). In Chen's approach, the distance between two fuzzy numbers is calculated with vertex method. But in this study, different distance measurement methods are used and the results are compared. Finally the proposed method has been applied to a facility location selection problem of a textile company in Turkey. © 2010 Springer Science+Business Media B.V

Ocular and Periorbital Anthropometry in the Newborn

To provide standard reference values relating to a number of ocular and periorbital anthropometric parameters in the newborn, inner canthal, outer canthal and outer orbital distances were measured in 625 healthy newborns of gestational ages 27-44 weeks. Mean and SD values for these measurements and for inner canthal, canthal and length of palpebral fissure indices derived from these measurements were calculated for boy and girl infants and for infants of different degrees of prematurity. Boy infants showed significantly higher values for inner canthal, outer canthal and periorbital distances (p \u3c 0.01, p \u3c 0.05, p \u3c 0.01). No significant sex differences were observed for palpebral fissure length nor for the inner canthal and canthal indices. Inner canthal, canthal indices and length of palpebral fissure were also found to be essentially comparable in term, preterm and small for gestational age infant groups while significant dif­ferences (p \u3c 0.001) were established among inner canthal, outer canthal and periorbital distance measurements.Our results also indicate that in the newborn, a value exceeding 7.5% for inner canthal index indicates hypertelorism and a value over 43% for canthal index is compatible with a diagnosis of ocular pseudohypertelorism

A practical physical-layer security method for precoded OSTBC-based systems

In this work, we investigate the security performance obtained by employing a practical precoded orthogonal space time block coding method (POSTBC) in MISO wireless networks. In particular, space time codewords are precoded with an optimum matrix that minimizes the error rate at only the legitimate user (Bob). The acquired results depict that there exists a security gap region in the resulting BER performance as a consequence of using POSTBC. Moreover, we enhance the performance more by developing a new hybrid and green security method called precoding along with partial pre-equalizing (PCPPE). In this method, the transmitted symbols are precoded by a new precoder composed of both the original precoder and a new designed unitary matrix that maps Bob's channel amplitudes or phases estimated over the transmitting antennas into 2D orthonormal matrix. Additionally, three issues associated with the proposed security method have been tackled. Including: The slight increase in the transmit power, the appropriate selection process of the optimal precoding matrix, and the effect of imperfect channel estimation and reciprocity. The comparative simulation results prove that PCPPE method provides a secure link among the legitimate parties without sacrificing Bob's reliability although an eavesdropper is assumed to be fully aware of the used method and the original selected precoding matrix indicator (PMI)

Performance evaluation of Turkish cement firms with fuzzy analytic hierarchy process and TOPSIS methods

In today's competitive environment evaluating firms' performance properly, is an important issue not only for investors and creditors but also for the firms that are in the same sector. Determining the competitiveness of the firms and evaluating the financial performance of them is also crucial for the sector's development. The aim of this study is developing a fuzzy model to evaluate the performance of the firms by using financial ratios and at the same time, taking subjective judgments of decision makers into consideration. Proposed approach is based on Fuzzy Analytic Hierarchy Process (FAHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) methods. FAHP method is used in determining the weights of the criteria by decision makers and then rankings of the firms are determined by TOPSIS method. The proposed method is used for evaluating the performance of the fifteen Turkish cement firms in the Istanbul Stock Exchange by using their financial tables. Then the rankings of the firms are determined according to their results. © 2007 Elsevier Ltd. All rights reserved