323 research outputs found

    Experimental Study on Size Effect and Fracture Properties of Polypropylene Fiber Reinforced Lightweight Aggregate Concrete

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    In this experimental research, the effects of polypropylene fibers on size effect and fracture properties of lightweight aggregate concrete were studied. Two methods, including size effect method and work of fracture method, were used to investigate and analyze the size effect and fracture properties on different sizes of notched beams. The polypropylene fiber contents were 0.5%, 0.75%, and 1% by volume fraction. The obtained results revealed that increasing the polypropylene fibers in lightweight aggregate concrete relatively decreased the dependence of strength on the size effect parameter, while the addition of polypropylene fibers exhibited significant influence on decreasing the size dependency of ductility and fracture energy in lightweight aggregate concrete. Moreover, the increase of polypropylene fibers improved the total fracture energy (GF), initial fracture energy (Gf), characteristic length (lch), length of fracture process zone (cf), and critical stress intensity factor (KIc) of lightweight aggregate concrete in both size effect method and work of fracture method. This increase was more significant in work of fracture method because of considering the post-peak behavior. The size effect method was suitable and accurate for plain lightweight aggregate concrete. The GF ⁄ Gf ratio increased from 2.88 in plain lightweight aggregate concrete to 12.26 in polypropylene fiber reinforced lightweight aggregate concrete

    Size Effect on Flexural and Fracture Properties of Polypropylene Fiber-reinforced Engineered Cementitious Composite

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    The size effect on flexural properties and fracture behavior of polypropylene fiber-reinforced engineered cementitious composite (PPFECC) containing local waste materials was investigated. Geometrically similar notched beams with dimensions of 190 × 70 × 70 mm (small), 380 × 70 × 140 mm (medium), and 760 × 70 × 280 mm (large) were tested using three-point bending to study the size effect on flexural properties, toughness, and fracture behavior in PPFECC and the influence of tensile ductility of PPFECC on the size effect parameter. Two PPFECC mixtures containing 1% (PPFECC1) and 2% (PPFECC2) volume fraction of polypropylene fibers were prepared. The results indicated clear size effect on ductility, flexural strength, normalized deflection, normalized toughness, and fracture energy for both PPFECCs. The flexural properties and fracture behavior in PPFECC1 were more sensitive to the size effect parameter due to its lower tensile ductility compared to PPFECC2. Moreover, according to Bažant’s size effect curve, the behavior of notched beams in PPFECC2 with higher tensile ductility was closer to the strength criterion compared to PPFECC1

    Investigation of the effective factors on branding in cosmetic and hygienic products (Case study: Ladies consuming cosmetic and hygienic products with local brands)

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    Despite the long history of brands, this concept has been considered in marketing literature for a long time such that it has attracted many experts' attention to this field as one of the most important concepts of modern marketing literature. This concept has become so important that wherever loyalty is mentioned, brand is undoubtedly considered too. This research aims to investigate the effect of marketing mixture (7Ps) on making brands of local hygienic and cosmetic products whose statistical society is ladies consuming hygienic and cosmetic products in Mashhad. The sample under analysis of this research consists of 381 people. It was identified after the analysis of their data using SPSS software and testing the research's assumptions that marketing mixture's factors are effective on making brands. In addition, the severity of the effect of each factor was identified

    Investigation of the effective factors on branding in cosmetic and hygienic products (Case study: Ladies consuming cosmetic and hygienic products with local brands)

    Get PDF
    Despite the long history of brands, this concept has been considered in marketing literature for a long time such that it has attracted many experts' attention to this field as one of the most important concepts of modern marketing literature. This concept has become so important that wherever loyalty is mentioned, brand is undoubtedly considered too. This research aims to investigate the effect of marketing mixture (7Ps) on making brands of local hygienic and cosmetic products whose statistical society is ladies consuming hygienic and cosmetic products in Mashhad. The sample under analysis of this research consists of 381 people. It was identified after the analysis of their data using SPSS software and testing the research's assumptions that marketing mixture's factors are effective on making brands. In addition, the severity of the effect of each factor was identified

    Comparison Of Chloral Hydrate Solution, Hydroxyzine Syrup And Lidocaine/Prilocaine Cream As Premedication For Lumbar Puncture In Children, A Double Blind Study

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      ObjectivesThis study aimed to compare the clinical effectiveness of oral hydroxyzine and chloral hydrate to topical lidocaine/prilocaine 2.5% cream as premedication in pediatric leukemia patients. Material & Methods This double-blind clinical trial study was conducted on 70 leukemic and non-leukemic patients aged 3-11 years old. The patients were divided into 4 groups as follow: in the group A, choral hydrate solution was given in 18 patients, in group B hydroxyzine syrup was used in the same number of patients, in group C, chloral hydrate solution and Lidocaine/Prilocaine cream were used in 17 patients, and in group D hydroxyzine syrup and Lidocaine/Prilocaine cream were given in the same number of patients. These groups were assessed and judged based on visual analog scale (VAS). Side effects of the drugs were also recorded. Results In this study, 54.3% (38) of cases were girls and 45.7% (32) were boys. Patients’ selection was included as follow: ALL in 77%, AML in 7.2% and non-leukemic cases in 15.8% of cases. The VAS test showed no difference in these four groups. Non-Traumatic lumbar puncture (RBC<50) were seen in 97.1% of cases. Conclusion Although the use of pre-medications for lumbar puncture with hydroxyzine syrup and chloral hydrate solution was not statistically effective, it did lead to increased patient and parent satisfaction. Also, adding  the Lidocaine/Prilocane cream does not improve the effectiveness of the drugs. &nbsp

    Bioinformatics methods shows the probability of miR-142, miR-146 & miR-150’s role in differentiation of naïve cd4+ to Th17 cells in multiple sclerosis.

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    Background and aims: MiRNAs are a class of non-coding RNAs that take part in various cellular processes. Recently dysregulation of these small molecules reported in numerous disorders. Unfortunately prevalence of Multiple sclerosis (MS) as an autoimmune disease is rising nowadays in Iran. Th17 cells are the most important cell in this disease. In this study, we have predicted possible role of 3 miRNAs, miR142, miR-146a and miR-150 which could control Th17 differentiation. So, possibly it influences on MS onset and progress. Methods: Using miRwalk database as an integrative database which utilizes 10 different algorithms to predict miRNA-mRNA interaction, it was investigated probable interaction of miRNAs and genes that participate in Th17 differentiation. Results: Based on this study, 3 distinct miRNAs, miR-142, miR-146a and miR-150, were predicted to have a potential role in induction of Th17 differentiation. Therefore, control of these miRNAs could reduce MS symptoms. Conclusion: Conclusively, miR-142, miR-146a and miR-150 may be up-regulated in Th17 of MS patients, since bioinformatics data have shown that these miRNAs suppress negative regulator genes in Th17 differentiation. Thus, several therapeutic approaches may be considered for these miRNAs besides of their application as the valuable prognostic/diagnostic biomarkers in detection of various stages of MS

    Does Dietary Intake by Tehranian Adults Align with the 2005 Dietary Guidelines for Americans? Observations from the Tehran Lipid and Glucose Study

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    The aim of this study was to compare dietary intakes by Tehranian adults with recent dietary guidelines for the Americans. The study made a cross-sectional assessment of the dietary patterns of Tehranian adults using a validated food-frequency questionnaire. It included 2,510 subjects (1,121 men and 1,389 women) aged 19-70 years. They were the participants of the third follow-up survey of the Tehran Lipid and Glucose Study (2005-2008). The dietary patterns were assessed using the latest World Health Organization (WHO)'s nutritional goals and Dietary Guidelines for the Americans Adherence Index (DGAI) 2005. The mean [standard deviation (SD)] DGAI score for this population was 8.31 (1.9). Participants in the highest quartile category of DGAI were more likely to be female, older, non-smoking, and physically active than those in the lowest quartile category (p<0.001). Percentage of participants meeting the DGA recommendations waslow, especially for starchy vegetables (2.3%), orange vegetables (16.2%), lean meat (9.2%), grains (12.0%), and legumes (6.4%). Over-consumption of grains was observed in almost half of the participants while approximately 20% of the subjects over-consumed milk and meat groups. Intakes of most nutrients examined were significantly associated with the DGAI 2005 score (p<0.001), except for vitamin E, vitamin B12, and vitamin D. The least adherence with the WHO goals was observed with n-3 PUFAs, sodium, fruit, and vegetable intakes. The results revealed that the dietary patterns of most Tehranian adults did not comply with the 2005 DGA and nutritional goals of WHO/Food and Agriculture Organization

    Determininig the validity and reliability of the physical literacy knowledge and motivation questionnaire for 8 to 10 year old children of isfahan

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    Introduction: It is essential to become physically literate to develop movement skills, as the knowledge and motivation necessary to lead an active lifestyle. The aim of this study was to determine the validity and reliability of Canadian physical literacy knowledge and motivation questionnaires among 8-10-year-old children in Isfahan.Methods: These questionnaires were translated using the translation–back-translation methodology into Persian and adapted to the Iranian context. A Persian version of these questionnaires was evaluated for its psychometric properties by 384 students aged 8 to 10 in Isfahan city (Iran). The construct validity of the questionnaires was determined using exploratory and confirmatory factor analyses based on structural equation modeling, and the internal consistency was checked using Cronbach's alpha coefficient. The test-retest method determined the temporal reliability of the questionnaires.Results: Face validity was confirmed by five experts in the field of motor behavior. According to the obtained thresholds, the construct validity was acceptable based on the goodness of fit index. A Cronbach's alpha coefficient greater than 0.85 was obtained for the knowledge and motivation questionnaire as its dimensions. The test-retests within two weeks showed that the intragroup correlation coefficients for all five components were acceptable for both boys and girls.Conclusion: Based on the results, the Persian version of Canadian Physical Literacy Knowledge and Motivation Questionnaires for 8-10-year-old children had good validity and reliability. Therefore, it is appropriate to use these tools to measure the children's physical literacy in Isfahan city
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