Stress-strain analysis of a (0/90)sub 2 symmetric titanium matrix laminate subjected to a generic hypersonic flight profile

Cross ply laminate behavior of Ti-15V-3Cr-3Al-3Sn (Ti-15-3) matrix reinforced with continuous silicon carbide fibers (SCS-6) subjected to a generic hypersonic flight profile was evaluated experimentally and analytically. Thermomechanical fatigue test techniques were developed to conduct a simulation of a generic hypersonic flight profile. A micromechanical analysis was used. The analysis predicts the stress-strain response of the laminate and of the constituents in each ply during thermal and mechanical cycling by using only constituent properties as input. The fiber was modeled using a thermo-viscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate the fiber matrix interface failure. Excellent correlation was found between measured and predicted laminate stress-strain response due to generic hypersonic flight profile when fiber debonding was modeled

Non-genomic actions of steroid hormones in pregnant and non-pregnant uterine tissues: in vivo and vitro studies

It is known that the results of the non-genomic action can be the same as or even different from the effects mediated through the genomic pathway. For example, in the cardiovascular system and diabetes mellitus, the outcome of both signaling pathways is the same 27–30, but in breast cancer cell lines, their actions can be the opposite 26. Since the prompt actions of steroids on uterine contractility are not fully explored yet, we aimed to investigate the fast, non-genomic action of sex steroids (E2, progesterone (P4), T) and corticosteroids (MC fludrocortisone (FLD) and GC (DEX)) on uterine contractions and signaling pathways both late (22-day) pregnant and non-pregnant rats in vitro and in vivo as well

Donot Ignore Pulmonary Hypertension Any Longer. It's Time to Deal with it!

<p>Pulmonary hypertension (PH) is a condition that,not only by itself causes many problems for those suffering from it,but also, it can exacerbate and complicate many other disease. PH can be responsible of mortality in many patients.</p><p>Tackling PH is not exclusively related to the field of cardiovascular diseases. Many other disease in other fields of medicine may interfere with PH. Pulmonary diseases ,renal,hepatic,collagen vascular disease,infectious and hematologic disease may be deal with PH. In patients&rsquo; suffering from aforementioned diseases, PH can exacerbate primary disorder and even cause mortality. Pregnant women afflicted with PH have 30%-50% mortality rate.(1) Newborns and children with pulmonary or cardiovascular disorder can be later afflicted by PH. PH drastically increases risk in surgeries and in anesthesia and can be the cause of mortalities.(2) or detoriated outcome of patients after surgery.(3)</p><p>According to the latest guidelines,(4) there are 5 categories of PH(table1):</p><p>&nbsp;1-Pulmonary arterial hypertension</p><p>&nbsp;2-Pulmonary venous hypertension(previously named pulmonary hypertension due to left heart disease)</p><p>&nbsp;3-Pulmonaey hypertension associated with hypoxemic lung disease</p><p>&nbsp;4- Pulmonary hypertension caused by chronic thromboembolic disease</p><p>&nbsp;5-Pulmonary hypertension from conditions with uncertain mechanisms</p><p>&nbsp;</p><p>For a long time, the science of medicine had no remedy for PH and physicians could only stand by and watch PH patients die .</p><p>After some time factors which complicate PH are known and it were shown that control of these factors are helpful. Patients are advised, for instance, to refrain from heavy exertion, to avoid pregnancy, and to be vaccinated against flu and pneumococcal infections. PH patients&rsquo; life expectancy has increased drastically as a result of this newly acquired knowledge.</p><p>As PH was becoming better known, symptomatic cures came to patients&rsquo; help. Diuretic drugs were used to control edema and anticoagulants were used to put tromboembolic attacks in check.</p><p>Then,It was time of revolution in pulmonary hypertension management,With the emergence of Advanced PH treatment science of medicine became able to seriously deal with &nbsp;PH.</p><p>This new strategy were showed to be able preventing mortality in PH patients&rsquo;(5),Figure1</p><p>Prostacycline showed that it is possible to enhance PH patients&rsquo; chance of survival. Phosphodiasterase inhibitor drugs, which were used for treating impotency for a long time, were demonstrated to be effective for reducing pulmonary pressure.</p><p>&nbsp;Eventually, endotheline receptors were targeted.</p><p>By the advent of endothelin receptor blockers such as Brosentan, physicians&rsquo; chances of helping PH patients were further improved.</p><p>Today, with advanced PH treatment, PH is not counted as before and the science of medicine as a failed discipline.</p><p>It is important to not forgetting PH in patients,especially ill patients or intractable to traditional treatment, in surgery wards or obstetric,pediatric,internal medicine,ICU or CCU wards of hospitals.</p><p>&nbsp;By timely diagnosis, it will be possible to control &nbsp;PH patients in an effective way and to enhance their chance of survival.</p><p><em>So,It is time now to pay more attention to PH,</em></p><p><em>Don&rsquo;t ignore it any longer and it&rsquo;s time to deal with it</em></p

Secular trends in the relationship between caloric intake, carbohydrate intake, and physical activity with obesity

The prevalence of obesity has increased dramatically over the past several decades. A number of factors contributing to obesity are well established; however, the etiology of obesity remains unclear. We set out to examine how caloric intake, carbohydrate intake, and physical activity associate with obesity, and whether this association has changed over time using data from the National Health and Nutrition Survey (NHANES). Linear regression was conducted to determine secular changes in the association between physical activity, caloric intake, and carbohydrate intake with BMI. The interaction of relative caloric intake (kcal/kg) and time on BMI was significant after adjusting for physical activity and carbohydrate intake, as the difference between the predicted BMI for any two relative caloric intakes increased over time (P<0.0001). The main effects of time on BMI was significant, indicating that a given relative caloric intake predicted a greater BMI over time (P<0.0001). The association between carbohydrate intake and time revealed significant main effects of time, as a given carbohydrate intake predicted a greater BMI over time (P<0.05). The interaction between exercise frequency (times/week) and time on BMI was significant for females; the difference between the predicted BMI for two physical activity levels increased over time (P=0.0006). The main effects of time on BMI was significant for both sexes, indicating that a given physical activity level predicted a greater BMI over time (P<0.0001). Our results indicate that neither caloric intake nor physical activity consistently predicted BMI over time. We speculate that additional factors may be influencing how physical activity and dietary factors relate with obesity

An Ordinal factor analysis of requirements and challenges of information and communication technology system to train private agricultural insurance brokers in Iran

This study was conducted to identify challenges and requirements of an information and communication technology (ICT) system to train brokers. Using the ordinal factor analysis, the challenges and requirements have been classified into six factors (Human, Organisational, Technical,Social, Financial, and Legal) and four factors (instructional,technical, organisational, and cultural) respectively. Finally a conceptual framework is presented for the challenges and requirements of the ICT training system

Fatigue of continuous fiber reinforced metallic materials

The complex damage mechanisms that occur in fiber reinforced advanced metallic materials are discussed. As examples, results for several layups of SCS-6/Ti-15-3 composites are presented. Fatigue tests were conducted and analyzed for both notched and unnotched specimens at room and elevated temperatures. Test conditions included isothermal, non-isothermal, and simulated mission profile thermomechanical fatigue. Test results indicated that the stress in the 0 degree fibers is the controlling factor for fatigue life for a given test condition. An effective strain approach is presented for predicting crack initiation at notches. Fiber bridging models were applied to crack growth behavior

Identification of appropriate tools of information and communication technologies (ICT) in the improvement of food security of Iran's rural households

Access to sufficient and desirable food is one of the principles of any developing and healthy society. One of the important means for attainment of food security is information and communication technologies (ICT). The purpose of the research was to identify appropriate tools of ICT in improving food security of Iran's rural households. The population for this research was 253 extension experts from eight provinces, out of this population, 170 were selected as sample by proportion stratified sampling between 2006 and 2007. This is an applied research with descriptive-survey methodology. The main tool for collecting data was questionnaire. After data extraction, statistical analysis was carried out using SPSS version 13. The results showed that from the view point of the experts, the situation of food security was unfavorable (81.2%). However, ICT can improve food security of rural households. From the viewpoint of experts, rural households have more accessibility to radio, television, phone, face to face interaction and audio cassettes. Radio, television, audio cassettes, workshop and scientific trips are more cost effective than other tools. In addition to television, workshop, scientific trips, exhibition and printed materials are more relevant to rural households needs. Rural households also have more access to old technologies; these technologies are more cost effective and more relevant to the households needs.Key words: Information andcommunication technologies (ICT), tools, food security, rural households, agricultural extension experts

Prediction of stress-strain response of SCS-6/Timetal-21S subjected to a hypersonic flight profile

Thermomechanical response of a cross-ply SCS-6/Timetal-21S composite subjected to a generic hypersonic flight profile with the temperature ranging from -130 C to 816 C was evaluated experimentally and analytically. A two dimensional micromechanical anlaysis, VISCOPLY, was used to predict the stress-strain response of the laminate and of the constituents in each ply during thermomechanical loading conditions. In the analysis, the fiber was modeled as elastic with transverse orthotropic and temperature dependent properties and the matrix was modeled using a thermoviscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate fiber-matrix interface failure. Reasonable agreement was found between measured and predicted laminate stress-strain response when fiber-matrix debonding was modeled

Survey Study of Lipid Effect on Nisin Nanoliposome Formation and Application in Pasteurized Milk as a Food Model

The use of bacteriocins, mainly nisin, is one of the most significant preservation technologies in the food industry. Nisin encapsulation can improve stability and homogenous distribution in food matrices. In this study, liposomes of four various lipids (lipoid S 100, lipoid S PC-3, lipoid S PC, and lipoid PC (DPPC)) were prepared by dehydration-rehydration method, and compared for entrapment efficiency, and lipid with the highest entrapment efficiency (DPPC) was characterized. The inhibitory effects of encapsulated (DPPC nanoliposomes) and free nisin on the spoilage of pasteurized milk were also studied. All experiments were performed in triplicate. Entrapment efficiency ranged from 14% (lipoid S 100) to 49% (DPPC). DPPC nanoliposomes were large unilamellar vesicles (LUV), and had an asymmetric oval shape (elliptical) with a mean diameter of 136 nm. It was revealed that pasteurized milk spoilage was delayed by both free and encapsulated nisin, but free nisin (with 38 days) was significantly more efficient in comparison with encapsulated nisin (14 days)

The perception of Agricultural Researchers about the Role of Nanotechnology in Achieving Food Security

Agricultural researchers in the Province of Isfahan were surveyed in order to explore their perception about role of nanotechnology in food security. The methodology used in this study involved a combination of descriptive and quantitative research and included the use of correlation, regression and descriptive analysis as data processing methods. The total population for this study was 76 agriculture researchers in the Isfahan Province. Data were collected through interview schedules. Based on the results of the mean score, researchers did not agree that nanotechnology could help in achieving food security, although they believed this technology could have more impact on affordability and safety of food products than other dimension of food security. As regression analysis showed, necessary conditions for application of nanotechnology, producing agricultural products, consuming nanotechnology products and constraints in application of nanotechnology caused 21% of variance on the perception of researchers regarding the role of nanotechnology in achieving food security. Based on the perception of respondents, the main constraint in application of nanotechnology in agricultural sector was regulatory constraints.Key words: Agricultural researchers, nanotechnology, Isfahan Province, food security