277 research outputs found
Compare motor development of male and female children with consanguineous and in-law parents
زمینه و هدف: مطالعات نشان داده اند ازدواج فامیلی می تواند احتمال بروز مشکلات متعددی در رشد حرکتی را موجب گردد. هدف این تحقیق مقایسه رشد حرکتی کودکان دختر و پسر با والدین نسبی و سببی بوده است. روش بررسی: در این مطالعه مقطعی، رشد حرکتی 15 کودک 4 و 5 ساله و 15 کودک 8 و 9 ساله با والدین نسبی با 15 کودک 4 و 5 ساله و 15 کودک 8 و 9 ساله با والدین سببی که به صورت خوشه ای چند مرحله ای از چهار مدرسه ابتدایی دخترانه و پسرانه و پانزده مهد کودک شهرستان اراک انتخاب شده بودند مقایسه شد. برای سنجش رشد حرکتی از آزمون رشد حرکتی درشت اولریخ-2 استفاده گردید. یافته ها: بین مهارت های دستکاری، جابجایی و رشد حرکتی درشت کودکان دختر و پسر 4- 5 ساله و رشد حرکتی و مهارت های جابجایی و دستکاری کودکان پسر 9-8 ساله و مهارت های جابجایی کودکان دختر 9-8 ساله با والدین نسبی و سببی تفاوت معنی داری وجود نداشت (05/0P>)؛ ولی رشد حرکتی و مهارت های دستکاری کودکان دختر 9-8 ساله با والدین سببی بهتر از کودکان با والدین نسبی بود (05/0
Evaluation of Active aging condition in the elderly in Tehran and its relative factors
Scientific and international assemblies now consider active aging as an important concept in an aging positive approach. The goal of this study is to evaluate active aging condition in the elderly in Tehran and its relative factors. This study is a cross-sectional descriptive research, which is performed in June and July 2018. The sample includes 131 old adults (people with the age of 60 or more than 60) living in Shemiranat area of Tehran. These people are selected via two-stage cluster sampling. Data- gathering tool includes “active aging” questionnaire, “life satisfaction in elderly” questionnaire and demographic data of old adults. Data analysis is performed by SPSS software and also using descriptive statistics, t-test and Pearson correlation. In this study, data suggest that only 9.2 % of case study were at the higher level of aging. According to six index of active aging, most respondent status were weak in “active mind maintenance” and “social-institutional participation” and were average in “agent attitude”, “physical-functional activity”, “social contacts” and “productive engagement”. There were reverse and meaningful relation between age and number of children variables and active aging ( and there were positive and meaningful relation between education, occupation and income level variables ( . However, there were no meaningful relation between sex and marital status . The results of this study also suggest that there is positive and meaningful relation between “life satisfaction of elderly” and “active aging” ( . According to low level of active aging in old adult of Tehran, this issue needs to be addressed by the authorities. Therefore, it is necessary to consider and modify the needed solutions to improve the level of active aging and special services for this group in the future planning of the country. On the other hand, considering the concept of active aging has recently been raised in the scientific community, researchers need to plan and implement more extensive studied in this area.
 
Performance of Steel-Concrete Shear Walls with Two-Sided Reinforced Concrete
This paper deals with the performance of Steel-Concrete Shear Walls (SCSWs) which have reinforced concrete on both sides of the steel plate subjected to cyclic loads. Finite element software ABAQUS is applied to analyze the SCSWs. Accuracy of the finite element modeling is verified by comparison of the theoretical results with those obtained experimentally. Then, various variables are studied in order to evaluate their effects on the performance of the SCSWs. These variables include thickness of concrete, steel plate thickness, number of bolts, gap size between reinforced concrete and steel frame, the percentage of reinforcement in reinforced concrete, and beam and column profiles of the steel frame. It is concluded that the change of the variables influences the ultimate load capacity, ductility, and energy dissipation of the SCSWs. Moreover, buckling of the walls is discussed
Feasibility study for application of the marine coral powder as an adsorbent for Volatile Organic Hydrocarbons
The marine coral has a porous outer surface and it has served in the processes such as water treatment systems, removal of carbon dioxide and adsorption of arsenic. Based on the need for cheap and efficient adsorbents, in sampling, the aim of this study, comparison of the efficiency of marine coral powder and activated charcoal in adsorption of volatile organic hydrocarbons was considered. In this experimental research, a certain concentrations of 8 volatile organic hydrocarbons: (para-Xylene, Chloroform, Carbon tetrachloride, tert-Butanol, Pyridine, Acetone, Ethyl acetate and Diethyl ether) was injected into dynamic atmospheric chamber in the NTP (Normal Temperature and Pressure) conditions. Air sampling was performed with the tube containing marine coral powder as well as the tube of activated charcoal, based on the standard method of NIOSH (National Institute of Occupational Safety and Health) and in the same laboratory conditions. Then samples were injected into the gas Chromatograph apparatus and analytical comparison has been done between the amount of adsorption of hydrocarbons by activated charcoal and coral powder-test and Mann-Whitney were done with SPSS V.20.Findings showed that there was a significant difference between the amount of adsorption of Para-Xylene, carbon tetrachloride, tert-Butanol, Pyridine, acetone and Ethyl acetate hydrocarbons by activated charcoal and coral powder (
Finite Element Analysis of Ultimate Load Capacity of Slender Concrete-Filled Steel Composite Columns
Ultimate load capacity of slender concrete-filled steel composite columns is investigated in this paper. Nonlinear analyses are done by the use of finite element software, LUSAS, to study the ultimate axial load behaviour of the columns. Verification of the finite element modelling is done by comparing the result with the corresponding experimental result reported by other researchers. Analyses are carried out to assess different shapes and number of cold-formed steel sheeting stiffeners with various thicknesses of cold-formed steel sheets and their effects on the behaviour and ultimate axial load capacity of the columns. The results are presented in the form of axial load-normalized axial shortening plots. It is demonstrated that the ultimate axial load capacity of the slender concrete-filled steel composite columns can be accurately predicted by proposed finite element modelling. Obtained results from the study show that various thicknesses of cold-formed steel sheets, and different shapes and number of stiffeners influence the ultimate axial load capacity and behaviour of the columns. Also, the ultimate axial load capacity of the columns is improved by increase of number of stiffeners. Moreover, increase of thickness of cold-formed steel sheet enhances the ultimate axial load capacity
Experimental Evaluation of Eco-friendly Light Weight Concrete with Optimal Level of Rice Husk Ash Replacement
Concrete is a versatile and cost-effective building material whose properties are influenced by age, curing condition, and installation. A number of studies deduced that there should be an association of benefits encouraged the use of partial replacements of cement seems to improve strength and durability properties of concrete. This paper presents a framework for feasibility assessment and determination of optimum percentage of rice husk ash (RHA) replacement. Five mix plans with RHA replacing ratio of 0-20% and constant micro- silica value by 10% were prepared. Tests results indicated that compressive strength increased by 20% with an increase in RHA up to 15%. The similar trend was observed in mix designs made of cement replaced by RHA up to 20% in water absorption coefficient measurement. Higher chloride ion penetration was observed in mix designs containing 25% RHA compared to that of conventional concrete. Mixes developed a slightly higher impact resistance than the control mix
KARTIRANJE LISKUNASTE ŽELJEZNE RUDE I IZRADA PRIMJENJIVIH INDUSTRIJSKIH STANDARDA
The purpose of this study is to determine the appropriate method for micaceous iron ore processing and production per-industrial application standards. After identifying the characteristics of the samples (with XRF, XRD, mineralogical analyzes), gravity and magnetic separation tests were carried out. Quartz and hematite are the main minerals of micaceous hematite ores. Silica grade as the major impurity varies from 10% to 68%. The total iron content of the samples also varies from 15% to 62%. A jig and shaking table did not provide a good result in micaceous hematite beneficiation to achieve the standard of its specific applications. Gravity concentration by the spiral in the size range of -200 and -300 μm has led to the production of iron concentrates with a grade of 62.34% and 64.84%, respectively. The recovery values for the two experiments are 13.50% and 12.60%, respectively. Therefore, the spiral did not provide a good result in the micaceous iron ore beneficiation. High-intensity magnetic separation (1.2 T) has resulted in a product with a grade and recovery of 65.98% and 88.35%, respectively. The experimental design utilizing the Taguchi method considering the increasing of grade or recovery priority indicated that for micaceous iron beneficiation with a priority of recovery increasing, the feeder frequency, roll speed, and adjustable gate angle should be at 6.5 Hz, 95 rpm, and 20°, respectively. However, for micaceous iron beneficiation with a priority of grade increasing, the feeder frequency, roll speed, and adjustable gate angle should be at 2.5 Hz, 135 rpm, and 60°, respectively.Svrha je ovoga istraživanja odrediti prikladnu metodu za oplemenjivanje liskunaste željezne rude te izrada standarda primjenjivih u industriji. Nakon utvrđivanja karakteristika uzoraka (s XRF, XRD, mineraloškim analizama) provedena su ispitivanja gravitacijskom i magnetskom separacijom. Kvarc i hematit glavni su minerali liskunastih hematitnih ruda. Udio silicija kao glavne nečistoće varira od 10 % do 68 %. Ukupni sadržaj željeza u uzorcima također varira od 15 % do 62 %. Plakalica i koncentracijski stol nisu dali dobre rezultate u obogaćivanju liskunastoga hematita za postizanje standar-da njegove specifične primjene. No, gravitacijska koncentracija spiralom veličine zrna -200 i -300 μm rezultirala je kvali-tetom koncentrata željeza od 62,34 odnosno 64,84 %. Vrijednosti iskorištenja bile su 13,50 odnosno 12,60 %. Stoga ni spirala nije dala dobar rezultat u obogaćivanju liskunaste željezne rude. Visokointenzivna magnetska separacija (1,2 T) rezultirala je kvalitetom koncentrata od 65,98 % i iskorištenjem od 88,35 %. Eksperimentalni dizajn prema Taguchiju s obzirom na povećanje kvalitete ili iskorištenja pokazao je da za povećanje iskorištenja frekvencija dodavača, brzina bub-nja i kut separacijskoga noža trebaju biti na 6,5 Hz, 95 o/min i 20°. Međutim, za obogaćivanje liskunaste željezne rude s prioritetom povećanja kvalitete koncentrata frekvencija dodavača, brzina bubnja i kut separacijskoga noža trebaju biti 2,5 Hz, 135 o/min, odnosno 60°
Moisture content on some engineering properties of celery (Apium Graveolens L) seeds
The study was conducted to investigate some physical properties of celery seed at various moisture levels. The average length, width, thickness and 1000-seeds mass were 0.571, 0.429, 0.295 mm and 0.792 g, respectively, at moisture content of 5.24% (d.b). Length, width and thickness distributions of the seeds were modeled using Generalized Extreme Value, lognormal and Weibull distributions. Results showed that to model length of the seeds, lognormal distribution had the best performance while to model the width of the seeds Weibull distribution had the best performance. True density has increase from 892.02 to 931.42 kg/m3 when the moisture content increased from 5.24% to 20.25% (d.b). The angle of static friction increased from 28.45 to 39.66°, 25.15 to 34.84°, 19.57 to 27.07° and 16.72 to 19.720° for plywood, rubber, iron and galvanized metal, respectively, as the moisture content increases from 5.24% to 20.25% (d.b). The pouring angle of repose increased from 34.70 to 39.12°, 33.37 to 36.37°, 30.59 to 33.33° and 27.16 to 29.45° for plywood, rubber, iron and galvanized metal , respectively, as the moisture content increases from 5.24% to 20.25% (d.b). The Hele-Shaw angle of repose increased from 32.65 to 35.25°, 30.35 to 32.77°, 27.81 to 30.03° and 24.72 to 26.61° for plywood, rubber, iron and galvanized metal , respectively, as the moisture content increases from 5.24% to 20.25% (d.b)
Synthesis and characterization of silicon nanorod on n-type porous silicon
This work reports a new method for growing semiconductor nanorods on a porous silicon substrate. After preparation of n-type porous silicon samples, a thin layer of gold was deposited on them. Gold deposited samples were annealed at different temperatures. The structural, thermal, and optical properties of the samples were studied using a field emission scanning electron microscope (FESEM), photoacoustic spectroscopy, and photoluminescence spectroscopy, respectively. FESEM analysis revealed that silicon nanorods of different sizes grew on the annealed samples. Thermal behavior of the samples was studied using photoacoustic spectroscopy. Photoluminescence spectroscopy showed that the emission peaks were degraded by gold deposition and attenuated for all samples by annealing
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