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Niloufar Shashaani,1 Reza Shiari,2 Abdullah Karimi,3 Shima Salehi,4 Roxana Ghanaei,3 Mehrnoush Hassas Yeganeh,2 Sara Shiari,1 Khosro Rahmani,2 Vadood Javadi Parvaneh2 1Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Department of Pediatric Rheumatology, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 3Department of Infectious Diseases, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 4Faculty of Medicine, Ali Asghar Children’s Hospital, Iran University of Medical Sciences, Tehran, IranCorrespondence: Reza Shiari Tel +98-21-22227033Email shiareza@yahoo.comIntroduction: Kawasaki disease (KD) is a systemic vasculitis that occurs mostly in children under five years old. Kawasaki affects the middle-size arteries, especially the coronary arteries. Therefore, without adequate treatment, it may cause coronary artery aneurysm in 25% of patients. The purpose of this study was to investigate the relationship between Kobayashi, Sano, and Egami criterions with coronary artery aneurysm in KD patients during the last ten years and to identify risk factors in patients with intravenous immunoglobulin (IVIG)-resistant and coronary artery aneurysms.Methodology: Medical records of 363 Kawasaki patients referred during 2008– 2017 were reviewed. Patients’ demographic data and Kobayashi, Sano, and Egami scores of each patient were calculated. Based on echocardiographic findings, cases of coronary artery aneurysm were determined. Sensitivity, specificity, positive and negative predictive value, and the accuracy of each criterion were determined to predicting IVIG resistance and detect coronary artery aneurysm.Results: There was a slight relationship between IVIG-resistance in Kawasaki children and its prediction based on the Kobayashi risk score, but no relationship was found between the Egami and Sano criteria. Sixty-three patients (17.4%) had coronary artery lesions (CALs) on time of diagnosis. There were no statistically significant differences between gender and mean age of children with and without CALs. Also, there was no significant relationship between coronary artery aneurysm in Kawasaki children and its prediction based on the above three risk factors. The area under the ROC-curve of all three risk measures of Kobayashi, Egami, and Sano indicated that all three criteria were not useful in predicting CALs.Conclusion: Despite the low accuracy of the three above criteria to predictive of patients with IVIG resistance, it seems that the variables of age, duration of fever, and C-reactive protein (CRP) are more useful than other variables and may be utilized to evaluate patients by establishing a more appropriate cut-off point.Keywords: Kawasaki disease, coronary artery aneurysm, IVIG-resistant, Kobayashi, Sano, Egami

Background and Aim: Screening of neonates for early detection and timely treatment of congenital hypothyroidism (CH) is one of the most important public health programs in the world. The purpose of this study was to review the structures, processes and achievements of the CH Screening program in Iran. Materials and Methods: Data were obtained from the surveillance program of the noncommunicable diseases office, review of records, documents, books, published articles and also interviews with process owners and experts of CH screening program in Iran in 2019. Results: TSH measurements on the 3 rd to 5 th days after birth, supplementary and confirmatory testsfor children with TSH ≥ 5 mu/L,timely treatment of hypothyroid children using levothyroxine tablets and assessment of the program by follow-up and continuous monitoring were the most important parts of the national neonatal screening program for congenital hypothyroidism in Iran. Conclusion: The present study provides an overview of the principles and implementation of the CH screening program in Iran, and can be used as an educational and research source for policymakers, researchers, and health providers who work in the field of neonatal metabolic disorders.

Vadood Javadi,1 Reza Shiari,1 Khosro Rahmani,1 Nazanin Farahbakhsh2 1Pediatric Rheumatology Department, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Pediatric Pulmonology Department, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IranCorrespondence: Reza ShiariMofid Children’s Hospital, Shariati Ave, Tehran, IranTel/Fax +982122227033Email shiareza@yahoo.comAbstract: Kawasaki disease is a mysterious childhood vasculitis. It presents with multi-systemic involvement in which the prolonged high-grade fever and mucocutaneous and lymph node manifestations are the prominent features. Sometimes, the disease has an unusual, atypical or incomplete presentation. Herein, we present a child with hilar lymphadenopathy as a manifestation of Kawasaki disease.Keywords: Kawasaki disease, children, lymphadenopathy, pulmonary, mediastinum

Vadood Javadi Parvaneh, Mohsen Jari, Saeideh Qhasemi, Mohammad Mahdi Nasehi, Khosro Rahmani, Reza ShiariMofid Children’s Hospital, Shahid Beheshti Medical University of Sciences, Tehran, IranBackground: Systemic lupus erythematosus (SLE) is an autoimmune disease which involves multiple organs, including peripheral nervous system.Case presentation: We describe a 12-year-old boy with progressively worsening neurological symptoms as first manifestation. Legs pain, loss of balance, and lower extremity weakness were the reason for his admission in neurologic ward. The patient was started on intravenous immunoglobulin therapy due to the possibility of Guillain–Barre syndrome and acute inflammatory demyelinating polyneuropathy (AIDP). However, there was no appropriate response and he developed recurrent attacks of polyneuropathy again with diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). Then, he received intravenous pulse of methylprednisolone for 5 consecutive days followed by oral prednisolone for 3 months. One month after withdrawal of corticosteroid he admitted again with the same manifestations. Rheumatologic workup revealed the presence of leukopenia, hemolytic anemia, hematuria, proteinuria, positive antinuclear antibodies, and ds-DNA antibodies. On the basis of the American College of Rheumatology and Systemic Lupus International Collaborating Clinics Classification Criteria for SLE, the patient had underlying diagnosis of SLE. Eventually, he was treated by the pulse of methylprednisolone and cyclophosphamide, and oral hydroxychloroquine and prednisolone. His neurological and physical symptoms improved and complete neurological recovery occurred several months later.Conclusion: SLE and AIDP/CIDP are different entities, but ADP/CIDP can be part of the neurologic manifestations of the SLE. Although the association between AIDP/CIDP and SLE is very rare especially as a first manifestation of SLE, it should be early recognized for rapid appropriate treatment.Keywords: Guillain–Barre syndrome, chronic inflammatory demyelinating polyneuropathy, systemic lupus erythematosus, nerve disorders

Vadood Javadi Parvaneh, Mohsen Jari, Sheri Motahari, Khosro Rahmani, Reza ShiariDepartment of Pediatric Rheumatology, Shahid Beheshti University of Medical Sciences, Tehran, IranIntroduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a wide, various, and sometimes deceptive clinical and serological manifestations. Environmental factors such as ultraviolet radiation, viral infections, drugs, hormones, and chemicals could trigger SLE flares in genetically predisposed patients.Case report: We presented a 13-year-old girl with the first presentation of systemic lupus erythematosus triggered by a mosquito bite. She presented with a malar rash started after a mosquito bite on her left cheek. She had oral ulcers, photosensitivity, lymphopenia, proteinuria, and positive serologic tests for SLE. Renal biopsy revealed class II lupus nephritis.Conclusion: Environmental factors can trigger the onset of SLE in genetically susceptible cases. Besides microbial agents, UV radiation, hormones, drugs, emotional stresses, immunization, and chemicals are some of the published examples. We presented a case with a mosquito bite as the possible environmental trigger.Keywords: mosquito bite, systemic lupus erythematosus, children, pediatrics, etiology, case report

In developing countries, broiler farmers often use imbalanced energy diets, hence our study aims to evaluate the combined effect of addition of commercial exogenous enzymes (CEE), in low energy level corn/soybean meal based-diet on performance, serum biochemical parameters, meat characteristics in male and female of broiler chickens. A total of 120 one day old Hubbard F15 broiler chickens were divided on 2 groups (60 animals/group) with 5 replicates/group. The control group received a standard diet, while CEE group received the same diet supplemented with enzymes (250 g/ton). Addition of enzymes reduced significantly feed (p

INTRODUCTION: Respiratory Distress Syndrome (RDS) is the most common respiratory disorder among premature infants. The use of surfactant has significantly reduced respiratory complications and mortality. There are two conventional methods for administering surfactant: Intubate-Surfactant-Extubate (INSURE) and Less Invasive Surfactant Administration (LISA). This study aims to compare the effects of surfactant administration using these two methods on the treatment outcomes of premature newborns. MATERIALS AND METHODS: In this retrospective cohort study, we included 100 premature newborns with RDS and spontaneous breathing who were admitted to the Neonatal Intensive Care Unit of Besat Hospital in Sanandaj city in 2021. Exclusion criteria comprised congenital anomalies and the needing for intubation for resuscitation at birth. The outcomes of empirically treated with two methods were compared: the LISA (50 neonates) and the INSURE (50 neonates). Our interesting outcomes were needing for mechanical ventilation, duration of medical ventilation, pneumothorax, pulmonary hemorrhage, severe retinopathy, CPAP duration, and bronchopulmonary dysplasia. Finally, we entered the data into STATA-14 statistical software and analyzed it using chi-square and t-tests. RESULTS: In this study, 69% of the neonates were boys. The LISA group exhibited significantly lower rates of need for mechanical ventilation (P = 0.003) and ventilation duration (P < 0.001) compared to the INSURE group. Conversely, there were no significant differences between the two groups (P > 0.05) in terms of pneumothorax, pulmonary hemorrhage, severe retinopathy, CPAP duration, and bronchopulmonary dysplasia rates. CONCLUSION: The results of this study suggest that the LISA method is a safe and non-invasive approach for surfactant administration. Notably, it resulted in a reduced need for mechanical ventilation and decreased ventilation duration compared to the INSURE method. [ABSTRACT FROM AUTHOR]

In this study, the effect of the compaction velocity as well as the size and volume content of the reinforcing particles on the thermal properties of Mg-B4C composites were evaluated. B4C reinforcing particles at various percentages (0, 5, 10%) and two sizes (micron-scale and nanoscale) were added to the magnesium matrix using a planetary ball mill and compacted at 450 °C and three different compaction velocities. The Instron device was utilized for the quasi-static compaction of the powder particles while a drop-hammer and a Split-Hopkinson bar were used for the dynamic compaction of composite powders at medium and high strain rates, respectively. The thermal behavior of the composites was studied by measuring their thermal conductivity and coefficient of thermal expansion. The results showed improvement in dimensional stability of the composites with increasing the volume percentage of the reinforcing particles. Higher compaction velocities led to higher thermal conductivity and coefficient of thermal expansion. Besides, further addition of the reinforcing particles to the matrix resulted in a decrease in the thermal properties. Magnesium samples reinforced with B4C nanoparticles exhibited superior thermal properties compared to those reinforced with micron-sized particles. [ABSTRACT FROM AUTHOR]

In this study, three-dimensional simulations were conducted on a new passive micromixer to assess the thermal and hydrodynamic behaviors of Newtonian and non-Newtonian fluids subjected to low generalized Reynolds numbers (0.1 to 50) and shear-thinning properties. To acquire a more profound comprehension of the qualitative and quantitative fluctuations in fluid fraction using the CFD Fluent Code, the mass mixing index, rheological behavior, performance index, mixing energy cost, mass fraction distributions, temperature contours, and pressure drop were compared to illustrate the importance of the mixer geometry in the context of two miscible fluids with varying inlet temperatures. The selected geometry is characterized by a robust chaotic flow that substantially enhances thermal and hydrodynamic performance across all Reynolds numbers. A mass mixing exceeding 72.5% is obtained when Re = 5, reaching 93.5% when Re = 50. Furthermore, the evolution of thermal mixing for all behavior indexes reaches a step of 98% with minimal pressure losses. This work enabled the demonstration of a chaotic geometry in a highly efficient mixing system, leading to enhanced thermal performance for both Newtonian and non-Newtonian fluids. The results of the hydrodynamic and thermal characterization of the mixing of shear-thinning fluids within the micromixers under investigation are conclusive.

The objective of this paper focuses on optimizing the performance of solar systems. These systems play an essential role in the production of electricity worldwide. They are sources of clean energy which can be exploited in areas rich with solar potential. In this paper, the goal is to optimize the heat flow absorbed by the receiver. To do this, genetic algorithms are proposed as an approach able of solving the problematic subject with constraints that are countable and interlinked. These constraints are inspired from the energy balance of the solar tower concentrator under study. The results obtained by numerical analysis based on these constraints and the objective functions (maximizing the heat flow received and minimizing the losses of the heat flow) shows the existence of an optimal receiver efficiency value for the heliostat surface total, the receiver temperature, the molten salt temperature, the receiver opening surface, the receiver surface, the diameter, the thickness, the tubes thermal conductivity of the receiver and the steam flow at turbine inlet. In addition, the energy efficiency of the solar tower system improves better depending on the power cycle chosen such as the Hirn cycle with reheating and racking used in our case. [ABSTRACT FROM AUTHOR]

The effect of reinforcing particle size on microstructure, relative density and indentation of Mg reinforced by 0, 1.5, 3, 5 and 10% volume fractions of nano- and micro-sized B4C was investigated. The composites were fabricated through powder compaction technique at strain rates of 1.6 × 103 s−1, 8 × 102 s−1 and 8×103 s−1 using split Hopkinson bar, drop hammer and Instron, respectively. The results indicated that the size of B4C and loading rate had significant effect on relative density. For example, the relative density of Mg-10 vol.% B4C nanocomposite was around 2.5% higher than that of its corresponding microcomposites. The relative density of the samples produced at high rate of loading was in average 1.2% higher than that of the samples fabricated quasi-statically. The results of indentation tests on the produced nanocomposite and microcomposite samples also revealed that loading rate and B4C particle size had significant effect on strength of specimens. For example, for Mg-5 vol.% B4C, the maximum load in load–depth curve of the specimens produced by split Hopkinson bar increased from 530 N for micron-sized B4C to 780 N for nano-sized B4C, around 45% improvement. Moreover, nanocomposites had better indentation resistance compared to similar micro composites fabricated using the three methods. [ABSTRACT FROM AUTHOR]

In this study, effective parameters for Polymer Concrete (PC) based on epoxy resin such as filler, hardener, and solvent are investigated. Rice husk and broom stem ashes as fillers with a mixture of 50-50% acetone-toluene as solvent in the preparation of PC samples were used. According to experimental results, the addition of fillers improved compressive, flexural, and chemical strengths of the PC samples. In the sample with 18.4% polymer, given the addition of rice husk ash with a ratio of filler-aggregate 0.075, compressive strength improved by 21%. For the sample with the broom stem ash ratio of filler-aggregate 0.09, the flexural strength improved by 27%. In addition, experimental data proved that the addition of optimum amount of solvent improved the performance and enhanced the compressive and flexural strengths. However, the excess amount of solvent may reduce the adhesiveness of the polymer; therefore, it may have negative impact on PC. The combination of hardener-resin may affect the strength of PC. Amine type of hardener with a low equivalent weight improved by 27% and 13% on compressive and flexural strengths. Moreover, elasticity modulus increased compared with the samples having a high equivalent weight of amine type hardener. [ABSTRACT FROM AUTHOR]

Mg–SiC nanocomposite samples were fabricated using split Hopkinson pressure bar for different SiC volume fractions and under different temperature conditions. The microstructures and mechanical properties of the samples including microhardness and stress–strain curves were captured from quasi-static and dynamic tests carried out using Instron and split Hopkinson pressure bar, respectively. Nanocomposites were produced by hot and high-rate compaction method using split Hopkinson pressure bar. Temperature also significantly affects relative density and can lead to 2.5% increase in density. Adding SiC-reinforcing particles to samples increased their Vickers microhardness from 46 VH to 68 VH (45% increase) depending on the compaction temperature. X-ray diffraction analysis showed that by increasing temperature from 25℃ to 450℃, the Mg crystallite size increases from 37 nm to 72 nm and decreases the lattice strain from 45% to 30%. In quasi-static tests, the ultimate compressive strength for the compaction temperature of 450℃ was improved from 123% for Mg–0 vol.% SiC to 200% for the Mg–10 vol.% SiC samples compared with those of the compaction at room temperature. In dynamic tests, the ultimate strength for Mg–10 vol.% SiC sample compacted at high strain rate increased remarkably by 110% compared with that for Mg–0 vol.% SiC sample compacted at low strain rate. [ABSTRACT FROM AUTHOR]

The binding energy of an exciton in a cubic quantum dot has been calculated with and without including the electron (hole)-confined longitudinal optical phonon interactions, using a variational approach and within the effective mass approximation. The quantum confinement effect is described by an infinitely deep well in the envelope-function approximation. The charge carrier phonon coupling is treated within the adiabatic approximation. As the dot size increases, the results show that the contribution of the confined longitudinal optical phonon on the binding energy decreases and the correction to the excitonic state increases. [ABSTRACT FROM AUTHOR]

Résumé : Cet article utilise une méthode analytique descriptive pour étudier l'influence du e-learning sur la qualité de l'enseignement supérieur, en se concentrant sur la formation doctorale en Algérie. L'article explore l'historique de l'évolution de cet enseignement, ses différents types, ainsi que sa relation et son influence sur le fonctionnement de l'université en tant qu'institution. Il examine également les moyens d'adopter ce système dans les pays en voie de développement, en particulier en Algérie, ainsi que les obstacles potentiels à cette adoption. L'analyse conclut que le e-learning est un système d'enseignement prometteur pour surmonter de nombreux problèmes rencontrés par les universités dans les pays en voie de développement. Mots-clés : e-learning ; formation doctorale ; qualité de l’enseignement supérieur

The longitudinal optical phonon effects on the exciton binding energy in a cubic quantum dot by using a modified Lee-Low-Pines variation method are studied. The results show that the longitudinal optical phonons effect is higher for the HH-exciton than for the LH-exciton.

• Novel methodology for obtained length to diameter ratio (L/D) in TSHB. • L/D is validated by experiments and obtained from FEM and Lagrange diagram are the same. • The difference between the theoretical value of velocity and numerical was 0.9%. • The shear strain compatibility was satisfied by the numerical wavelengths gained for L / D > 80. • Measurement uncertainly and repeatability are important factors in the analysis. Split Hopkinson bar is a well-known device for mechanical characterization of materials under dynamic loading. The device can be compressive, tensile, and torsional or shear. The effect of dimensions of SHB in particular the length to diameter ratio, L / D , of the bars has been the subject of some investigations over the past several decades. However, no work has so far been performed on the forgoing ratio in torsional Split Hopkinson bar (TSHB). In this work, the length to diameter ratio of the input or output bar, L / D , is studied by numerical simulation, theory through Lagrange diagram of the TSHB and experiment. It has been found that for L / D > 80 , the incident, reflected and transmitted wavelengths obtained from simulations and Lagrange diagram are the same. This value of L / D is quite consistent with that usually recommended for compressive and tensile versions of SHB. The numerical model of TSHB is validated by Lagrange diagram and experiment. [ABSTRACT FROM AUTHOR]

In this paper, fabrication and characterisation of Mg-SiC nanocomposite are investigated. Micrometre-sized Mg powder with the different volume fraction of SiC nano particles were dynamically compacted using a modified Split Hopkinson Pressure Bar. Moreover, the compaction process was simulated using AUTODYN commercial software to demonstrate that the stress in the powder sample was sufficient for consolidation. To achieve the best quality samples, the effects of lubrication and compaction velocity on dynamic compaction process were initially studied by experiment. It was observed that the temperature of 450°C and the compaction velocity of 15.5 m/s led to the best samples with relative density more than 99%. The effects of reinforcing phase content on the relative density, micro-hardness, and compressive behaviour of the compacted samples along with their microstructures were investigated. The results showed that the micro-hardness and the compressive strength of the samples fabricated at 450°C increased about 70% and 50%, respectively. [ABSTRACT FROM AUTHOR]

The use of various additives (admixtures) in concrete and cement products has been considered by various researchers in recent years. Microsilica (Silica fume) can also be considered as one of the most widely used additives (admixtures) in this section. In this study, 120 concrete specimens were constructed using a mix design based on ACI in the laboratory with an overview of records and advantages of using microsilica in concrete. The microsilica used in concrete specimens has been considered 2%, 5.5% and 7.5% by weight of cement. Finally impact permeability, tension and uniaxial compressive strength tests were done on concrete specimens and their mechanical properties were evaluated. The results show that microsilica improves the mechanical properties of concrete. The results also show that the use of microsilica in ordinary concrete has a very positive effect in controlling the surface cracks and increasing some strength parameters such as tensile and compressive strength of concrete. [ABSTRACT FROM AUTHOR]

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The present study presents a numerical prediction of residual stresses (RS) using the single-pass tungsten inert gas (TIG) welding process for stainless steel plates and the two-pass TIG welding process for stainless steel pipes. The effect of heat exchange between welding material and the environment was studied. The work consists of two parts: The first one is based on the determination of the existence of residual stresses numerically using Cast3M software, which has been validated by literature results. The second part addresses the means envisaged to attenuate the amplitudes of these residual stresses by practical methods. Two parameters with significant influence on the residual stresses have been chosen: the welding bead thickness and the torch displacement speed. The finite element model used has been validated experimentally, and the results obtained for the residual stresses have been compared with those given by the numerical study. The results obtained were found to be in agreement with references results. In addition, the microstructural analysis of different areas after welding of the solder joint (base metal, heat-affected zone and solder zone) was carried out using optical microscopy analysis.

The development of important materials for photovoltaic applications is rapidly advancing, particularly in the field of perovskite materials. This study investigates the optical and electronic characteristics of CH 3 NH 3 Pb I3 and analyzes the influence of doping in perovskite CH 3 NH 3 Pb I3 with different concentrations of sodium ions Na+. In this study, we employed Density Functional Theory to assess the optical and electronic properties of both pure and Na+ ion-doped CH 3 NH 3 Pb I3, with Na+ concentrations of 12.5 %, 25 %, and 37.5 %. The bandgap energy of pure CH 3 NH 3 Pb I3 rises from 1.205 eV to 1.573 eV as the concentration of Na+ ions increases from 0 % to 37.5 %, respectively. Doping with Na+ ions leads to an increase in the absorption coefficient of pristine CH 3 NH 3 Pb I3 perovskite in both UV and visible ranges. Doping likewise affects the density of states, dielectric function, and the refractive index of CH 3 NH 3 Pb I3 material. These findings offer vital insights into modulating the electronic and optical characteristics of CH 3 NH 3 Pb I3 through Na+ ion doping.

The present work concerns the study of Numerical analysis on the fluid flow and heat transfer in corrugated channel with various geometry configurations, under constant heat flux conditions is considered. This is largely studied both experimentally and numerically due to their wide industrial application in various fields such as nuclear reactor urgency, solar boiler, heat exchangers and thermo siphon solar capturers, etc. A great deal of relevant research work consists of numerical simulations of forced convection mechanisms with turbulent flows in corrugated channel. We are interested in determining the flow for various amplitudes and periods. The influence of geometry on several factors such as: temperature, the local Nusselt number, friction number, turbulent kinetic energy k and its dissipation ε are considered. Based on the Navier-Stokes equations, these equations were solved by a CFD technique using the Finite Volume Method. The results show that when we gradually increase the amplitudes of the protuberance part (say a 0.03, a=0.06) the maximal temperature increases with the increase of amplitude. This is due to the rise of the heat transfer surface of the modified wall. Regarding heat transfer parameters, the results show that the number of local Nusselt varies accordingly with the amplitudes and number of periods. This explains that the modified wall is affected locally by a pure conduction. The results of this study are expected to lead to guidelines which will allow the selected wavy channel geometry configuration for designing heat exchanger that increase thermal performance. [ABSTRACT FROM AUTHOR]

Background: Fatty acids are the main compounds in edible oils. Oil thermal stability depends on the composition of fatty acids. So, this study was conducted to investigate the effect of fatty acid composition on the oxidative stability of extra virgin olive oil during heating process. Methods: Totally, eight virgin olive oil samples, including five imported oils from market place of Mahabad and three local ones from Qazvin were analyzed to evaluate their thermal stability. Samples were heated at 120 °C for 4 h. Sampling was carried out in 2 h intervals, then fatty acid composition, peroxide, anisidine and totox values were assessed according to Iran national standards. All determinations were carried out in triplicates, and data were subjected to analysis of compare means (t test) and spearman correlation coefficients using SPSS 16.0. Results: Results show that there is a significant correlation between palmitoleic acid and totox index in 2 h (r=0.786) and 4 h (r=0.762), and the same result is observed between linoleic and totox index in 2 h (r=0.643) and 4 h (r=0.786). But, there is an inverse relationship between oleic acid and totox index in 4 h (r=-0.833). Conclusion: Results indicated that linoleic acid and palmitoleic acid have a reducing effect on thermal stability of extra virgin olive oil in 2 h, but oleic acid increases it in 4 h. [ABSTRACT FROM AUTHOR]

This qualitative study aimed to identify the health-care problems of people living with HIV (PLHIV) in 2 large cities: Tehran and Kermanshah. Two main groups of stakeholders — service providers (policy-makers, managers, physicians and counsellors) and service recipients (PLHIV and their relatives) — participated in focus group discussions and in-depth interviews. We identified 24 themes covering the major health problems of PLHIV, including: incomplete and inadequate coverage of health-care services; patients' substance abuse; patients' fear of stigma; occupational burnout of certain service providers; patients' dissatisfaction with some of the services provided by counselling centres/clinics; medical staff's failure to observe confidentiality; and patients' lack of access to required specialized services. The problems and needs identified can inform the design and implementation of health programmes in our country and elsewhere in the Eastern Mediterranean Region. [ABSTRACT FROM AUTHOR]

Industrial applications need to use different systems for the problem of gas cleaning. A lot of processes have been developed, such as the use of a venturi for gas cleaning and pollution reduction. Additionally, several studies have been developed especially in terms of pressure drop because it is one of the main parameters to determine its efficiency. While the phenomenon of mass transfer in a venturi scrubber has not found much attention, in the present study, a mass transfer two-dimensional simulation is developed for gasification gas cleaning through a venturi scrubber with boundary conditions represented in air inlet velocities of 10, 15, and 20 m/s and water inlet mass flow of 0.02, 0.04 and 0.06 kg/s. In this work, Navier–Stokes equations are solved numerically and the mass transfer technique is treated by the volume of fluid (VOF) model, using CFD software. The obtained results were analyzed by presenting the mass fraction, velocity and pressure contours, and profiles. The probability density function (PDF) of mass transfer is studied too, showing how the removal efficiency of the venturi scrubber increases with a decrease in the liquid flow rate and an increase in the gas velocity. Therefore, the results show that the proposed venturi has the best mass transfer performance with a PDF that reaches 97.6 for velocity liquid of 20 m/s and the removal efficiency showed higher values at low liquid flow rates.

At present, Organic-inorganic hybrid methylammonium lead halide perovskites MAPbX3 (MA= CH3NH3; X = Cl, Br) have recently attract attention scientific researchers, as a promising candidate for photovoltaic and optoelectronic devices. We have studied the electronic structures and optical properties of perovskites CH3NH3PbBr3 and CH3NH3PbCl3, using density functional theory (DFT). These physical properties are calculated by CASTEP code, such as the band structures, total density of states (TDOS), absorption coefficient, refractive index and optical conductivity. The analysis of band gap shows that these two perovskites are semiconducting materials. Calculated absorption coefficient of CH3NH3PbBr3 and CH3NH3PbCl3 shows an absorption peak around 3.87 eV and 2.04 eV, respectively. The above results provide good agreement with experimental work for optoelectronic properties of CH3NH3PbBr3 and CH3NH3PbCl3 materials.

The paper investigates the electronic and optical properties of graphene, under the external electric field (Eext) according to perpendicular direction, using density functional theory (DFT). Applying the Eext to the graphene sheet modifies its electronic and optical properties, including the band gap energy, total density of states (TDOS), absorption coefficient, dielectric function, and refractive index. Graphene’s band gap is opened by the application of Eext to its structure. As a result of the effect of Eext on graphene layer, its absorption coefficient increases in the ultraviolet (UV) range and decreases in the visible range. We found that the electronic and optical properties of graphene material, can be altered by a perpendicular excitation applied to its structure.

This work concerns the study of heat transfer by means of natural convection with fluids circulating in enclosures. This is largely studied both experimentally and numerically due to their wide industrial application in various fields such as nuclear energy, the heating and cooling of buildings, solar collectors, etc. A great deal of relevant research work consists of numerical simulations of natural convection mechanisms with laminar flows in closed cavities. In this context, the present study comes as a contribution in numerical form of investigating the turbulent natural convection in a vertical enclosure which has sinusoidal protuberances on one of its vertical walls. Both the top and bottom of the enclosure are open to allow the fluid flow. The horizontal walls are supposed to be adiabatic. We are interested in determining the flow for various amplitudes and periods. The influence of geometry on several factors such as: temperature, the local Nusselt number, turbulent kinetic energy k and its dissipation ε are considered. Based on the Navier-Stokes equations and Boussinesq approximation, the equations were solved by a CFD technique using the Finite Volume Method in the case of enclosures having the form ratio equal to 0.6 (A=0.6). Given the steady conditions of heat flow on the vertical walls and the pressures at the entry and exit of the cavity, the results show that when we gradually increase the amplitudes of the protuberance wall (say a=0.005 m, a=0.010, a=0.015, a= 0.02, and a=0.025), the maximal temperature increases with the increase of amplitude. This is due to the rise of the heat transfer surface of the modified wall. Regarding heat transfer parameters, the results show that the number of local Nusselt varies accordingly with the amplitudes. This explains that the modified wall is affected locally by a pure conduction. The results obtained in this study are in agreement with recent works of several authors. [ABSTRACT FROM AUTHOR]

Background and Aim: Provision of timely healthcare for children under 5 years of age specially children with congenital hypothyroidism and also regular monitoring of growth through measuring weight, height and head circumference have been of great importance. The aim of this study was to make a comparison between healthy children and children with congenital hypothyroidism in regard to health-care coverage in Iran. Materials and Methods: This study was conducted in five provinces in different geographical areas of Iran in 2015. 240 children with congenital hypothyroidism and 240 healthy children were entered into the study. Children with congenital hypothyroidism were selected randomly from the national registere database. The children in the control group were matched with the children with hypothyroidism in regard to age, gender and place of residence. Anthropometric indices including weight, height and head circumference of the children of less than 3 years of age were recorded as the health care indices. STATA software version 13 was used for data analysis. Results: The mean percentage of measurement and record of weight, height and head circumference in children below 3 years of age with congenital hypothyroidism were 82.1, 78.7 and 55.4%, respectively. The mean percentage of measurement and record of weight, height and head circumference in healthy children (control group) below 3 years of age were 82.2%, 80.9 and 55.1%, respectively. There was a statistically significant difference between the two groups in relation to the percentage of height measurement (P =0.02). Conclusion: According to the results of this study, percentage of measurement and record of the anthropometric indices in Iranian children of less than 3 years of age is low. More attention to the measurement and record of these physical growth indices in children of less than 3 years of age specially children with congenital hypothyroidism who need regular follow up, is essential.