Quality measurements of an UWB reduced-size CPW-fed aperture antenna

The paper presents a characterization of a compact co-planar waveguide (CPW)-fed slot loaded low return loss planar printed antenna designed for wireless communication and ultra-wideband (UWB) applications. Following a review of the antenna design, which was implemented and simulated using Agilent's Advanced Design System (ADS), the paper presents laboratory measurements of relative gain and impulse response transformed from the frequency domain. An antenna quality metric based on time-domain S21 is discussed and related to antenna quality metrics such as the System Fidelity Factor (SFF)

Electronic Lesson Application Compatible with the Learning Styles of Students With Memetic Pattern

Designing an educational system is costly and a time consuming task, hence, providing electronic learning modules according to the characteristics of each learner in order to reduce the learning time and increase productivity of education is very important. The purpose of this study is to provide an electronic module according to the learning characteristics of each student, using some of the e-Learning standards, learning theories , memetic algorithm and also assess the learning outcomes of this approach. At the stage of subject preparation to teach each concept, a set of maximum possible learning activities is provided with different materials such as slides, lectures, etc. The compatibility between the activities and characteristics of student who want to learn is produced based on the theory of Folder on learning styles and Bloom's theory for knowledge classification. Student learning styles are  designed  based on a questionnaire using Folder approach and testing of his/her  knowledge is extracted based on Bloom's theory and learning path which is include the proper ordering of learning activities is produced based on memetic algorithm. The populations of this study were 40 girls of third-year computer science class of  high school in Zahedan. They were selected randomly.  They have been subdivided into two groups of 20 randomly. The proposed system is trained with 20 people and 20 people have traditionally learned their lesson. Comparison between the proposed approach and traditional method in term of quality of education were  performed. The results indicate that the proposed method has good quality

Enhancement of NMP degradation under UV light by nitrogen-doped TiO2 thin films using a design of experiment

Doping nitrogen within TiO2 is an effective way to enhance visible light photocatalysis due to a direct electron excitation from the N2p states within the band gap. However, nitrogen doping is not always efficient for UV photocatalytic activity. Here, different structures of N-doped TiO2 (TiOxNy) have been prepared by reactive RF (13.56 MHz) magnetron sputtering. The morphological, optical, structural, and photocatalytic properties of the films have been studied in order to investigate the competitive effect of the morphology and the chemical composition on the efficiency of the photocatalytic activity. The variation of surface wettability of the film over time in the dark and under visible and UV irradiation was also studied. The reduction in wettability by dark storage can be explained by the adsorption of hydrocarbon contamination on the thin film’s surface. Additionally, from water contact angle experiments, it was found that these films developed hydrophilic properties upon UV and visible illumination. The photoinduced change in the contact angle of water was due to the removal of hydrocarbon contamination on the surface and also the photo-oxidation of the water droplet. Samples prepared at high pressure gave the best photocatalytic activity, even though the deposition rate was lower at higher pressures (lower film thicknesses), due to the high specific surface area and the optimal presence of TiOxNy crystals in the lattice. However, at low pressure, the TiN crystals became more predominant, and acted as recombination centers for the photo-generated charge carriers. A design of experiments was used in order to optimize the deposition parameters to have the best photocatalytic activity. The high photocatalytic activity under UV light was found to be due to the introduction of discrete energy levels within the band gap, the increased sample wettability, and the higher specific surface area. However, the post annealing process did not effect the activity under UV irradiation. Using the response surface methodology, RSM, based on a design of experiment, DOE, we are able to achieve a good understanding of the complex processes involved in the deposition of the thin films and their effect on the photocatalytic activity. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/930

Detection of hepatitis B virus covalently closed circular DNA in the plasma of Iranian HBeAg-negative patients with chronic hepatitis B

Background: Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is a marker of HBV replication in the liver of patients infected with HBV. Objectives: This study aimed to investigate the association between the presence of cccDNA in the plasma samples of Iranian treatment-naive patients with chronic hepatitis B infection and HBV viral load and HBsAg levels. Patients and Methods: From April 2012 to May 2015, 106 treatment-naive patients with chronic hepatitis B infection were enrolled in this cross-sectional study. The HBsAg titer was measured by the Roche HBsAg II assay on the Cobas e411 system, and HBV DNA quantitation was performed using the COBAS TaqMan 48 kit. Real-time polymerase chain reaction was performed for the detection of HBV cccDNA. Results: The mean (SD) age of the patients was 41.1 ± 12.4 years (range, 20 - 62 years). From a total of 106 study participants, 67 (63.2) were males. The HBV cccDNA was detected in plasma specimens in 19 (17.9) out of the total 106 patients, and a significant relationship was found between the presence of cccDNA in plasma sample of males (23.9) and females (7.7) (P = 0.039). Also, a significant correlation was found between the presence of cccDNA in plasma sample of the patients and HBV viral load level (P < 0.0001) and HBsAg titer (P = 0.0043). Conclusions: This study showed that cccDNA can be detected in the plasma specimen of 17.9 of Iranian treatment-naive patients with chronic hepatitis B infection. Therefore, designing prospective studies focusing on the detection of cccDNA in these patients would provide more information. © 2015, Kowsar Corp

Survey of nutritional and economic values of bighead (Hypophthalmichthys nobilis) in various sizes

Cultured fish are presented in various sizes and prices in market. The present study aimed to investigate the proportion of nutritional value and price of various weight groups of bighead (Hypophthalmichthys nobilis) and to offer two indices for comparing nutritional value in proportion with fish prices. For this purpose, bighead specimens were prepared in market sizes and their dry matter, lipid, protein and ash content and fillet yield were determined. Then, the proportion of nutritional and financial value (NP) and justified price difference based on dry matter content (PDdm) were calculated for each weight group. The results showed that the light weight group has a higher NP index for dry matter, protein, ash and energy than medium and heavy weight group. The NP index was the same between medium and heavy groups. While the price difference between light weight and two other weight groups is more than calculated PDdm index, the light weight group is a proper choice for purchase

Comparison of the Diagnostic Accuracy of Serological and Histology Tests for Helicobacter Pylori in Patients with Dyspepsia and Metabolic Syndrome

Background: Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis, especially in metabolic syndrome patients. The use of a accessible and easy diagnostic method, can speed up the treatment of this infection This study compared two methods of histology and serology for diagnosis of H. pylori in metabolic syndrome patients.Methods: This study was done on 175 metabolic syndrome patients with dyspepsia referred to Shahroud Imam Hossain hospital in 2014. From each patient, standard biopsy and serology tests were taken with endoscopy. This data will be analyzed with sensitivity, specificity, positive and negative predictive value.Results: Of the 175 patients studied, 90 (51.4%) were male and 85 (48.6%) were female. The mean patient age was 46.9±18.6 years. From 175 patients, 114(65.1%)  and 149 (85.3%) patients tested positive by serology and histology, respectively. For the serological test, sensitivity, specificity, positive predictive value and negative predictive value were 66.4%, 42.3%, 86.8%, and 18.1%. It was also found that with IgG values higher than 1.3, there was a sensitivity of 90.7%, and specificity of 72.8%, which was considered a positive test. The cut-off point performance test means that  maximum at this point with 78.3% the area under the curve (AUC),  there is the highest sensitivity and specificity.Conclusions: Due to the relative sensitivity and specificity of serological tests in comparison with other diagnostic methods as well as the simplicity, speed, and low cost, it is recommended that this test be used for screening metabolic syndrome patients

Application of GA in Optimization of Modified Benzene Alkylation Process

A genetic algorithm is used to optimize the modified benzene alkylation process. Based on the previous studies, the modified process increases ethylbenzene selectivity and decreases energy consumption at the same time. The inlet ethylene flow rate of each alkylation reactor is optimized in order to reduce the chance of transalkylation reactions but increase ethylbenzene selectivity. The byproduct trans-ethylbenzene concentration is used as the fitness variable in the optimization process to confine undesired reactions throughout the process. The obtained optimal values of ethylene flow rate for the adiabatic reactors are 3.50, 2.94, 2.58, and 0.36 m3/hr. The ethylbenzene selectivity has been increased by applying the optimized values indicating the current unit is not operating under optimal conditions. Temperature profile within the alkylation reactors and temperature and concentration profiles through the towers of the fraction unit under the optimized conditions of the modified process are also presented.<br /

Comparison of the Diagnostic Accuracy of Serological and Histology Tests for Helicobacter Pylori in Patients with Dyspepsia and Metabolic Syndrome

Background: Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis, especially in metabolic syndrome patients. The use of a accessible and easy diagnostic method, can speed up the treatment of this infection This study compared two methods of histology and serology for diagnosis of H. pylori in metabolic syndrome patients.Methods: This study was done on 175 metabolic syndrome patients with dyspepsia referred to Shahroud Imam Hossain hospital in 2014. From each patient, standard biopsy and serology tests were taken with endoscopy. This data will be analyzed with sensitivity, specificity, positive and negative predictive value.Results: Of the 175 patients studied, 90 (51.4%) were male and 85 (48.6%) were female. The mean patient age was 46.9±18.6 years. From 175 patients, 114(65.1%)  and 149 (85.3%) patients tested positive by serology and histology, respectively. For the serological test, sensitivity, specificity, positive predictive value and negative predictive value were 66.4%, 42.3%, 86.8%, and 18.1%. It was also found that with IgG values higher than 1.3, there was a sensitivity of 90.7%, and specificity of 72.8%, which was considered a positive test. The cut-off point performance test means that  maximum at this point with 78.3% the area under the curve (AUC),  there is the highest sensitivity and specificity.Conclusions: Due to the relative sensitivity and specificity of serological tests in comparison with other diagnostic methods as well as the simplicity, speed, and low cost, it is recommended that this test be used for screening metabolic syndrome patients

Development of a Selective Wet-Chemical Etchant for 3D Structuring of Silicon via Nonlinear Laser Lithography

Recently-demonstrated high-quality three-dimensional (3D) subsurface laser processing inside crystalline silicon (c-Si) wafers opens a door to a wide range of novel applications in multidisciplinary research areas. Using this technique, a novel maskless micro-pillars with precise control on the surface reflection and coverage are successfully fabricated by etching the laser processed region of c-Si wafer. To achieve this, a particular selective wet chemical etching is developed to follow subsurface laser processing of c-Si to reveal the desired 3D structures with smooth surfaces. Here, we report the development of a novel chromium-free chemical etching recipe based on copper nitrate, which yields substantially smooth surfaces at high etch rate and selectivity on the both laser-processed Si surface and subsurface, i.e., without significant etching of the unmodified Si. Our results show that the etch rate and surface morphology are interrelated and strongly influenced by the composition of the adopted etching solution. After an extensive compositional study performed at room temperature, we identify an etchant with a selectivity of over 1600 times for laser-modified Si with respect to unmodified Si. We also support our findings using density functional theory calculations of HF and Cu adsorption energies, indicating significant diversity on the c-Si and laser-modified surfaces