Determination of Material Parameters of E-GlassEpoxy Laminated Composites in ANSYS

Prediction of damage initiation and Evolution in composite materials are of particu- lar importance for the design, production, certification, and monitoring of an increasingly large variety of structures. In this study a methodology is presented to calculate the mate- rial properties for the progressive damage analysis (PDA) and discrete damage mechanics (DDM) in ANSYS RTM by using two sets of experimental data for laminates [0 2/904]S and [0/+/-40 4/01/2]S. The type of laminates to be used for material property determination are chosen based on a sensitivity study.;This method is based on fitting results calculated with PDA and DDM to experimental data by using Design of Experiments and optimization tools in ANSYS Workbench. The method uses experimental modulus-reduction vs. strain data for only two laminates to fitt all the parameters of PDA (F 2t, F6, Gc tm ) and DDM (GIc, GIIc) . Fitted parameters are then used to predict and compare with the experimental behavior of other laminates with the same material system. Mesh sensitivity of both PDA and DDM is studied by performing p- and h-mesh refinement. Choice of damage activation function is justified based on goodness of fit with each proposed equation. Comparison between DDM and PDA predictions is shown

Assessment relationship between agro-morphological traits and grain yield in bread wheat genotypes under drought stress condition

To evaluate the genetic diversity in bread wheat landraces along with six controls (Azar2, Fankang, Trakia, Siosson, Gaspard and Gascogne), an experiment based on randomized complete block design with three replications was carried out under drought stress condition in the Agricultural Research Station of Islamic Azad University, Ardabil, Iran. Analysis of variance indicated that there were highly significant differences among the genotypes in all of the traits. There were significant correlations between yield and all of the studied traits. Principal components (PC) analysis showed that five components explained 69.3% of the total variation among traits. The first PC assigned 29% and the second PC assigned 15% and of total variation between traits. The first PC was more related to tiller numbers, fertile tillers, biological yield, grain yield and volume of seed plants. Therefore, selection based on first component is helpful for a good hybridization breeding program. A principal component biplot showed low distance between grain yield and biological yield, volume of seed, plant height and hectoliter. From this study, it was concluded that a good hybridization breeding program can be initiated by the selection of genotypes from the PC1.Keywords: Bread wheat, biplot, landrace, drought stress, agronomic trait

Anti-bacterial properties of calcium hydroxide in combination with silver, copper, zinc oxide or magnesium oxide

Prevention of bacterial growth among root canal treatment sessions is a prerequisite for successful root canal treatment. The most common way to achieve this is to use calcium hydroxide in the treatment sessions. Some studies have shown calcium hydroxide inefficiency in this field. The aim of this study was to investigate and compare the effects of silver, copper, zinc oxide and magnesium oxide nanoparticles on the inhibitory effects of calcium hydroxide based on Enterococcus faecalis species. Enterococcus faecalis bacteria having 0.5 McFarland concentration were prepared. Plates containing BHI agar medium were prepared. In each plate, four wells were created and the plate was cultured using a sterile swab. Afterwards, calcium hydroxide composition of 1% and 2% concentration from silver, copper, zinc oxide and magnesium oxide nanoparticles were prepared separately, as well as the combination of calcium hydroxide with 1% silver in combination with 1% of copper, zinc oxide and magnesium oxide nanoparticles, which were then transferred to the wells. After 24 hours of incubation, the inhibition zone diameter was measured. Data were analyzed by Mann-Withney test. At 1% concentration, only the combination of copper nanoparticles with calcium hydroxide could significantly create an inhibition zone larger than calcium hydroxide alone (P value<0.5). At 2% concentration, the combination of copper nanoparticles with calcium hydroxide, and the combination of silver nanoparticles with calcium hydroxide, were significantly higher than calcium hydroxide alone (P value<0.5). The calcium hydroxide composition containing 1% silver nanoparticles in combination with 1% copper, zinc oxide and magnesium oxide nanoparticles significantly increased the growth inhibition zone more than calcium hydroxide alone. (P Value<0.5). Copper nanoparticles showed the best antibacterial properties among silver, copper, magnesium oxide and zinc oxide nanoparticles in combination with calcium hydroxide. Also, the combination of 1% of nanoparticles with each other increases antibacterial properties

Seasonal heavy metal monitoring of water, sediment and common carp (Cyprinus carpio) in Aras Dam Lake of Iran

Heavy metal in aquatic ecosystems are monitored by measuring their concentrations in water, sediments and biota. In the presented study, cadmium, copper, lead, mercury, nickel, and zinc concentrations determined in water, sediment and tissues (liver and muscle) of Cyprinus carpio in Aras dam Lake of Iran, during spring, summer, autumn, and winter from 2016 to 2017. The concentration of Pb, Cd, Zn, Cu and Ni of samples were measured using inductively coupled plasma-optical emission spectroscopy. The concentration of Hg was analyzed using Atomic Absorption equipped with MHS 15 CVAAS. The trend in the metal mean concentrations of liver and muscle was Zn&gt;Cu&gt;Pb≈Ni&gt;Cd&gt;Hg, and water and sediment were Cu&gt;Zn&gt;Pb&gt;Cd≈Ni&gt;Hg. Heavy metals concentration was more in sediment than fish tissues and water. This results revealed that heavy metals accumulation of muscle was the highest in summer showing the most contaminated season. Whereas, winter had the lowest contamination in water (Cd،Hg, Cu, Pb, Ni, Zn), sediments (Hg, Cu, Zn, Pb, Ni), and the liver and muscle of fish (Cd, Zn, Ni, Cu). The amount of heavy metals was less or slightly higher than global standards (EPA, WHO).

Effects of Kinesthetic Imagery, Active and Combined Exercises on the Electromyographic Pattern of Hip Hyperextension and Tests of Relation with Lumbar Hyperlordosis

Abstract: Background: Mental exercise uses the same neuronal pathways involved in physical exercise to modify the pattern and function without the stress caused by physical exercise. This study investigated the effects of the three methods of kinesthetic imagery, active, and combined exercise (imagery and active) on the pattern of hip hyperextension and the strength of selected muscle of lumbo-pelvic in women with lumbar hyperlordosis. Method: In this semi-experimental study, 36 women with lumbar hyperlordosis (age: 34.47±3.79, height: 160.48±12.63, weight: 64.46±18.26) were sorted into three groups. The groups practiced three sessions per week for six weeks. The degree of lumbar lordosis using flexible ruler, electromyographic activity of the lumbo-pelvic muscles during hip hyperextension in the prone position using surface electromyogram, the strength of the gluteus maximus during hip hyperextention using dynamometer, the strength of abdominal muscles during lowering two legs test using goniometer, flexibility of hip flexor muscles during the Thomas test using goniometer, and flexibility of erector spine muscles during the Schober test using a meter were measured before and after the intervention. The Shapiro-Wilk test was used for normality of data, and the repeated measures variance test was used for the statistical analysis of data at a significance level of 0.05. Results: The results showed a significant difference between the three methods of kinesthetic imagery, active and combined (p -value = 0.001). There was a significant difference between the method of imagery exercise and the methods of active and combined exercise, but no significant difference was observed between the methods of active and combined exercise. Conclusion: Imagery exercises were effective in modifying the electromyographic activity of some lumbo-pelvic muscles (gluteus maximus and rectus femoris muscles); however, they did not have a significant effect on the strength, flexibility, or degree of lumbar lordosis. Combined exercise was as effective as active exercise in modifying the electromyographic activity of the lumbo-pelvic muscles, the strength of the abdominal and gluteus maximus muscles, and the flexibility of erector spine and hip flexor muscles

Localization of elastic waves in heterogeneous media with off-diagonal disorder and long-range correlations

Using the Martin-Siggia-Rose method, we study propagation of acoustic waves in strongly heterogeneous media which are characterized by a broad distribution of the elastic constants. Gaussian-white distributed elastic constants, as well as those with long-range correlations with non-decaying power-law correlation functions, are considered. The study is motivated in part by a recent discovery that the elastic moduli of rock at large length scales may be characterized by long-range power-law correlation functions. Depending on the disorder, the renormalization group (RG) flows exhibit a transition to localized regime in {\it any} dimension. We have numerically checked the RG results using the transfer-matrix method and direct numerical simulations for one- and two-dimensional systems, respectively.Comment: 5 pages, 4 figures, to appear in Phys. Rev. Let

Gestational diabetes influences the expression of hypertrophic genes in left ventricle of rat’s offspring

Objective(s): Gestational diabetes increases the risk of congenital heart disease in the offspring, but the molecular mechanism underlying this process remains unclear. Therefore, the current study was conducted to assess the effects of induced gestational diabetes on expression of some involved genes in cardiac hypertrophy in the offspring of diabetic rats.Materials and Methods: Diabetes was induced in 40 adult Wistar rats by intraperitoneal injection of 45 mg/kg of streptozotocin. The day of appearance of the vaginal plug was assumed as day zero of gestation for inducing diabetes. After pregnancy, the offspring was maintained until they reach the age of 12 weeks. Then, their hearts were excised and were sectioned for molecular study. We analyzed the expression pattern of some hypertrophic genes by the quantitative real-time RT-PCR.Results: The mRNA expression levels of all studied genes including c-jun, c-fos, c-myc, alpha-myosin heavy chain (α-MHC), atrial natriuretic factor (ANF) and β-MHC, which are important in cardiomyocyte hypertrophy, were higher in the offspring of the diabetic group compared to controls. Significant differences were found for β-MHC and c-myc with PConclusion: Gestational diabetes upregulates expression of c-jun, c-fos c-myc, α-MHC, ANF and β-MHC genes that are involved in cardiac hypertrophy in the offspring of diabetic rats