Multiband monopole antenna for mobile applications

— In this paper, a multiband monopole antenna has been proposed for mobile applications. The monopole antenna has simple structure with a physical size of 15 cm × 7 cm. The antenna consists of monopole shape loaded by a set of folded arms with a varying length which lead to a better impedance matching result and multiband performance. The simulated results show that the proposed antenna provide multiband frequency operation of 0.8 GHz, 1.8 GHz 2.1 GHz, 2.6 GHz and 3.5 GHz which covers the range from 0 to 4 GHz. The antenna is designed to operate at sub-6 GHz which proposed as lower frequency band to deliver 5G in early stage. The designed antenna has been fabricated and measured to validate the simulated results. RF Coaxial U.FL Connector was used as the port connector. The measurement results agrees well with the simulated ones for all frequency bands

Simulation of Coating -Visco-Elastic liquid in the Mico-Nip of Metering Size Press

For a set of operating conditions and coating color formulations, undesirable phenomena like color spitting and coating ribs may be triggered in the Micro-nip during the coating process. Therefore, our interest in this work focus on another parameter affect on the undesirable phenomena as the vortices in the Micro-nip. The problem deals with the flow through the Micro-nip of metering size press. The flow enters and exits at a tangential velocity of 20 m/s between two rollers with diameter 80 cm and 60 -m apart. In the upper and bottom part of the domain the angular velocity is 314 rad /s. It has one sub-domain. Previous studies focus on the Micro-nip without considering the inertia and the viscoelasticity of the material. Roll coating is a technique commonly used in the coating industry to meter a thin fluid film on a moving substrate. During the film formation, the fluid is subjected to very high shear and extensional rates over a very short period of time. The fluid domain changes as a function of the hydrodynamic pressure within the nip as a result of the deformable cover usually used on one of the rolls. The free surface also adds more complexity to the flow due to the force equilibrium in the fluid gas interface. Last of all, the rheological behavior of the coating fluid is usually non-Newtonian, so the metering flow hydrodynamics is finally very difficult to describe. It is concluded that the normal forces of micro-nip increases with increasing the inhibitors. Therefore, it affects on the smoothness and creates defects. On the other hand, it can be concluded that the creation of big vortex in the middle of micro-nip affects on the coating liquid behavior

Recent progress in understanding immune activation in the pathogenesis in HIV-TB coinfection

Purpose of review Tuberculosis is the leading infectious cause of death worldwide, and HIV-1 the best recognized risk factor for active TB. This review focuses on immune complex formation; the interplay of type I and II interferon signaling; and T-cell activation in HIV–TB pathogenesis. Recent findings Circulating immune complexes and complement, and Fcγ signaling in whole blood act as early markers of TB disease in HIV-1-infected persons. HIV-1 is associated with a type I interferon response in whole blood, reducing the specificity of TB biomarkers dependent on type I and II interferon genes. Type I and type II interferons are implicated in both protection and TB disease, a protective outcome may depend on modulating these pathways. Whilst M. tuberculosis-specific CD4 T cells are preferentially depleted during HIV-1 infection, activation markers on M. tuberculosis-specific CD4 T cells, in particular HLA-DR, reflect immune activation and have promise as biomarkers of M. tuberculosis disease activity in individuals with HIV-1. Summary TB pathogenesis in HIV-1 involves a complex interaction of underlying activation of both the innate and adaptive immune systems. Further research is required to understand whether biomarkers of activation could be used to predict or quantify TB disease in the context of HIV-1 infection

A comparison of the professional qualifications among teachers graduated from Farhangian University, former Teacher Education Centers and other universities

Background and Objectives:In the ideals proposed by experts for education systems in the twenty-first century, the teacher is mentioned as the fulcrum of any change. Competence is a set of knowledge, skills and abilities of a particular job that makes a person successful in performing tasks. In recent educational research, the term professional competence is used to describe the specific prerequisites that teachers need to succeed in their work. It is assumed that this professional competence can be learned and taught. Professional competence includes having professional knowledge as well as motivational and emotional aspects. Professional knowledge is divided into different types such as content knowledge, pedagogical content knowledge and pedagogical-psychological knowledge. A teacher's competence refers to his or her ability to adequately meet the demands and requirements of the teaching profession, using an integrated set of knowledge, skills, and attitudes that manifest in the teacher's performance and response. Based on the growth model of teachers' professional competence, the psychological characteristics of the teacher seem to play an important role in gaining learning opportunities. In addition, it has been suggested that beyond specific subject knowledge, more aspects of the teacher, such as teachers' beliefs and motivational and emotional characteristics, are important prerequisites for educating and motivating students. The aim of this study is to investigate professional qualifications among teachers graduated from Farhangian University, former Teacher Education Centers and other universities. Methods: The method of the study is causal-comparative. The sample was comprised of 210 teachers in three groups that graduated from Farhangian University, former Teacher Education Centers and other universities such that the groups were similar in demographic factors. All subjects assessed by teacher professional qualifications questionnaire. The results of two-way analysis of variance show that teachers’ professional qualifications in three groups are different. Findings: The results of the cognitive qualification show that Farhangian University’s graduates have the best state. In management qualification, the difference between Farhangian University’s graduates and former Teacher Education Centers’ graduates is not significant but this difference is significant when other universities’ graduates are considered. Attitude qualification difference is not significant between the groups. Conclusion: The results of this study showed that the professional competence of teachers is significantly different. The cognitive competence of Farhangian University graduates is higher than other graduates. Graduates of teacher training centers also have higher cognitive competencies compared to graduates of other universities. In terms of managerial competence, the graduates of Farhangian University have not shown a significant difference with the graduates of teacher training centers, but they are in a better position compared to the group of graduates of other universities. In this case, the difference between former teacher training graduates and other universities is not significant. In attitudinal competence, the difference between groups of teachers is not significant, meaning that these three categories have equally developed attitudinal competence in their graduates

Construction material selection criteria for timber gridshell application: a literature review

Timber gridshells have the potential to be a sustainable and cost-effective solution for long-span applications and free-form architecture. Despite this, their overall use has been limited, and there is a lack of research focusing on their construction materials. This literature review aims to investigate timber gridshells and their construction materials to identify the criteria used in selecting suitable materials for gridshell applications. A review of peer-reviewed scientific articles, books, and theses was conducted to gather information on timber gridshells, construction materials used in gridshells, timber used in active bending structures, and building standards. The research findings identified six main factors that are important when selecting a suitable material for timber gridshell application: structural strength and strength grading, bending strength and behaviour, bending strength/bending elasticity ratio, durability, commercial availability, and cost. These findings are also discussed to identify the characteristics that make a material suitable for timber gridshell applications, depending on the gridshell’s context, whether in a tropical or international context. This review serves as a necessary reference for architects and engineers when selecting materials for their timber gridshell projects, providing insight into the selection criteria for construction materials and sharing information on the material properties of suitable timber gridshell materials

Azides in the Synthesis of Various Heterocycles

In this review, we focus on some interesting and recent examples of various applications of organic azides such as their intermolecular or intramolecular, under thermal, catalyzed, or noncatalyzed reaction conditions. The aforementioned reactions in the aim to prepare basic five-, six-, organometallic heterocyclic-membered systems and/or their fused analogs. This review article also provides a report on the developed methods describing the synthesis of various heterocycles from organic azides, especially those reported in recent papers (till 2020). At the outset, this review groups the synthetic methods of organic azides into different categories. Secondly, the review deals with the functionality of the azido group in chemical reactions. This is followed by a major section on the following: (1) the synthetic tools of various heterocycles from the corresponding organic azides by one-pot domino reaction; (2) the utility of the chosen catalysts in the chemoselectivity favoring C−H and C-N bonds; (3) one-pot procedures (i.e., Ugi four-component reaction); (4) nucleophilic addition, such as Aza-Michael addition; (5) cycloaddition reactions, such as [3+2] cycloaddition; (6) mixed addition/cyclization/oxygen; and (7) insertion reaction of C-H amination. The review also includes the synthetic procedures of fused heterocycles, such as quinazoline derivatives and organometal heterocycles (i.e., phosphorus-, boron- and aluminum-containing heterocycles). Due to many references that have dealt with the reactions of azides in heterocyclic synthesis (currently more than 32,000), we selected according to generality and timeliness. This is considered a recent review that focuses on selected interesting examples of various heterocycles from the mechanistic aspects of organic azides

Легочный туберкулез у больных с нормальной рентгенограммой легких в районе с высокой заболеваемостью туберкулезом

The objective was to describe early symptoms of pulmonary tubeculosis (T) when the chest radiograph (CXR) is normal.Seventy patients with culture-positive pulmonary T and normal CXR were selected from a review of 377 consecutive patients with smear- or culture-positive pulmonary T in Babol (Iran) in 1994-2000. Patients with abnormal CXR at the time of the diagnosis were excluded from the analysis.Sixty-eight of the 70 patients (98%) were symptomatic at the time of the diagnosis with cough and sputum production being reported most commonly (97%). Two patients were examined due to contact tracing of a case of infectious pulmonary T, while other 68 patients were tested because of symptoms presence. Sixtyeight patients (97%) had cough longer that 1 month, sputum production was in 63 patients (90%), fever for more than 1 week was in 18 patients (25%), haemoptysis was in 28 patients (40%), weight loss was in 21 patients (30%), hoarseness was in 1 patient (1,4%), dyspnea was in 5 patients (7%). The sputum smears of 5 patients (7 % ) were positive. No-one of patients had underlying diseases. Fifty-six patients (80%) had positive Mantoux skin test. The incidence of culture-positive pulmonary T with a normal chest radiograph was less than 1% in the period from 1988 to 1989 and steadily increased to 10% in the period from 1996 to 1997.The culture-positive pulmonary T with abnormal CXR is not uncommon and the incidence of such presentation is increasing. Patients with this presentation of T are typically symptomatic and/or are detected by contact tracing of infectious pulmonary T cases. The results suggest that patients presenting cough for more than 1 month, a fever longer than 1 week or documented weight loss after known exposure to infectious T should undergo sputum examination for a mycobacterium tuberculosis despite a normal CXR.Цель работы — описать ранние симптомы легочного туберкулеза (Т) при нормальной рентгенограмме легких (РГЛ).70 больных с подтвержденным бактериологически легочным Т и нормальной РГЛ были отобраны из 377 с подтвержденным посевом мокроты или бактериоскопией мазка легочным Т в Баболе (Иран) в 1994-2000 г. Больные, имевшие патологические изменения на РГЛ в период постановки диагноза, были исключены из анализа.68 (98%) из 70 больных в период постановки диагноза имели различные симптомы заболевания, наиболее часто отмечался кашель с мокротой (97%). Два пациента обследовались по поводу контакта с больными легочным Т, в то время как остальные 68 были обследованы в связи с имевшимися жалобами.68 (97%) больных жаловались на кашель длительностью более 1 мес, 63 (90%) — на продукцию мокроты, 18 (25%) — на лихорадку более 1 нед, 28 (40%) — на кровохарканье, 21 (30%) — на снижение массы тела, 1 (1,4%) пациент жаловался на хрипы, 5 (7%) — на одышку. В мазке мокроты у 5 (7 % ) больных определялись микобактерии туберкулеза (МБТ). Никто из больных не имел сопутствующей патологии. 56 (80%) пациентов имели положительную пробу Манту. Частота легочного Т, подтвержденного посевом мокроты, при нормальной РГЛ составила менее 1% в период с 1988 по 1989 г. и возросла до 10% в период 1996 по 1997 г.Легочный Т, подтвержденный бактериологически, при нормальной РГЛ встречается не так редко, и его частота возрастает. Больные с такой формой Т обычно имеют клинические проявления заболевания и/или контакт с больными легочным Т. Результаты свидетельствуют, что у пациентов с кашлем продолжающемся, 1 мес, лихорадкой более 1 нед либо документированной потерей массы тела после известного контакта с больным Т необходимо исследовать мокроту на МБТ независимо от нормальной РГЛ