Experimental and numerical behavior of anisotropic laminated FRP thin-walled web beams under different loading and boundary parameters

Master of ScienceDepartment of Civil EngineeringHayder A RasheedStructural elements made of fibrous composites are increasingly used in aerospace, automotive, civil and marine engineering applications due to their high stiffness and strength-to-weight ratio and corrosion resistance properties. Most of the composite structural elements are thin-walled and their design is often controlled by stability considerations mainly due to slenderness effects. Hence, for thin-walled slender composite beams, lateral torsional buckling (LTB) is the dominant failure mode regardless of the fiber orientations. In this study, combined numerical and experimental investigations for lateral torsional buckling of laminated composite web-cantilever and simply support beams are presented. A total of twelve carbon-fiber beams with six different anisotropic layups having a nominal length to height (/ℎ) ratio of 10 and four glass-fiber reinforced polymer beams with varying /ℎ ratios were experimentally tested for cantilever and simply support conditions respectively. The experimental response is compared against a non-linear numerical solution using Static Riks Analysis (SRA) to compare the predicted vs. actual load-displacement curve. An analytical approach, developed in an earlier study, was used to find the critical buckling load. Eigen value analysis was performed to benchmark the analytical buckling load using Abaqus

Epigenetic Modifications in Plants under Abiotic Stress

Plants face a plethora of biotic and abiotic stresses ranging from extreme temperatures to salinity, drought, nutritional deficiencies, chemical toxicity, and pathogen attacks. As a consequence, plants have acquired several sophisticated regulatory mechanisms that allow them to cope with such adverse conditions. Epigenetic regulation plays a key role in the mechanisms of plant response to the environment, without altering DNA sequences. Epigenetics refers to heritable alterations in chromatin architecture that do not involve changes in the underlying DNA sequence but alter gene expression through DNA methylation or histone modifications. The epigenetic regulation of the plant genome is a highly dynamic process that fine-tunes the expression of a pertinent set of genes under certain environmental or developmental conditions. Over the past two decades rapid advancements in the field of high throughput sequencing unveil epigenetic information at genome wide level in various plant species. In view of the adverse effects of global climatic change, utilizing epigenetic differences for developing improved crop varieties is of paramount importance

Triple Frequency Operated Microstrip Patch Antenna for Communication in Multibands

Volume 1 Issue 1 (March 2013

Novel approaches for evaluating brassica germplasm for insect resistance

Brassica crops are grown worldwide for food, oil, medicinal and crop rotation properties. They suffer from insect pests which cause large yield and economic losses. Application of insecticides is the preferred way of dealing with insect problems, but it is not only hazardous to the environment, it also affects humans as the chemicals easily get incorporated into the food chain. As a result, new more resistant varieties are urgently needed to meet the demand of growing populations. A set of 200 accessions were classified as resistant (non-preferred) or susceptible (preferred) in response to cabbage aphid feeding in the field. Fifteen accessions were further assessed to characterize and identify the level and location of resistance factors by investigating feeding behaviour of cabbage aphid using the Electrical Penetration Graph (EPG) technique. The feeding behaviour assessment revealed the presence of interspecific & intraspecific variation and presence of resistance factors at multiple levels. The transcriptional response of these accessions under presence and absence of aphid feeding for 24h showed that gene expression is highly regulated in response to aphid feeding. Gene ontology (GO) enrichment study helped identify strong candidate genes for aphid resistance. In addition to this, the gene expression differences between CWR and landraces indicated adaptations of landraces during the process of domestication. Lastly, Gene expression data was used to develop models to predict insect resistance status. In conclusion, the combination of EPG and transcriptomics provides an opportunity to assess brassica germplasm for further research into defence mechanisms of cabbage aphids

Outcome of vaginal sildinafil in assisted reproductive technology cycles

Background: The present study assessed the role of sildenafil in endometrial blood flow and successful pregnancy in IVF done in surrogate mothers.Methods: In the present study surrogate mothers were included. Thirty patients were randomized to receive sildenafil 25 mg thrice a day vaginally in addition to standard drugs and technique and another 30 were not given sildenafil.Results: Mean age, anthropometry, duration of infertility and pre-treatment endometrial thickness was similar in the two study groups.  After treatment completion, it was observed that the endometrial pattern in ultrasound was similar in the two study groups (p value=0.58). Heterogenic endometrial pattern was observed in 6.7% of the Sildenafil patients and 3.3% in the control patients, while echogenic pattern was seen in 10% of the sildenafil patients and 6.7% of the control patients. Similarly, endometrial thickness was 10.2±1.7 and 9.7±1.8 mm in sildenafil and control group respectively, p value=0.62. Using doppler ultrasound, uterine artery PI was significantly lower in Sildenafil group patients as compared to control group patients. Similarly, we found uterine artery RI was also significantly lower in the Sildenafil group patients as compared to control group patients. We followed the patients and found that clinical pregnancy rate was significantly higher among Sildenafil group (60%) as compared to control group (26.6%), p value<0.05.Conclusions: Vaginal sildenafil resulted in significantly higher pregnancy rates in our study population. The uterine artery PI and RI were significantly lower in patients taking sildenafil

Correlation of mature mean follicle on transvaginal ultrasound and serum estradiol levels on day of trigger injection of ovulation in ovarian stimulation cycle of in vitro fertilization with retrieved oocytes

Background: Controlled ovarian hyperstimulation aims to obtain mature follicles. The present study was conducted to assess the correlation of mature follicle in transvaginal ultrasound scanning (TVS) and serum estradiol levels on day of trigger injection in ovarian stimulation cycle for IVF with the oocyte yield.Methods: In this prospective study, we evaluated oocyte donor 19 to 45 years of age who underwent oocyte retrieval at our clinic. Outcome variables like number of mature follicles visualized on TVS on the last day of stimulation was noted for all patients. On the same day, serum estradiol levels and number of mature follicles seen on TVS were noted and correlated with the number of oocytes retrieved. Ultrasound guided transvaginal oocyte retrieval was performed and total number of oocytes were noted.Results: During the study period, 20 oocytes donors were included. Mean age of the patients was 27.9±4.7 years. Mean BMI was 26.8±2.3 kg/m2. Mean FSH level was 6.89±1.79 IU/L and mean antral follicle count on day 3 was 14.06±3.56. On the day of trigger, mean mature follicle count seen on TVS was 20.4±13.8, ranging from 8 to 50. On an average, 17.2 oocytes were retrieved. On the day of trigger, mean estradiol level was 4970±203, ranging from 500 to 15,665 pg/ml. It was observed that the number of retrieved oocytes correlated significantly with the serum estradiol levels, (Pearson’s coefficient 0.94, p value<0.001) and number of mature follicles seen on TVS ((Pearson’s coefficient 0.92, p value<0.001).Conclusions: Number of retrieved oocytes correlated significantly with the serum estradiol levels and number of mature follicles seen on TVS on the day of trigger

Ecofriendly Repellent-A Study of Control of Mosquito Vectors

Repellents such as Allethrin,Diethyltoluimide etc are widely used in India to combat mosquito nuisance and malaria. These repellent is commonly used in different formulations like mats ,coils,lotions and aerosols under different company brand names,are posing tremendous health hazards.Looking to the health hazard problem, a field study was carried out to evaluate the mosquito repellent action of essential oils viz,Citrus sinensis oil,Cymbopogon winterianus oil,Cymbopogon flexuosus oil and Azadirachta indica oil in a large room against mosquito vectors. Azadirachta indica oil and Cymbopogon winterianus oil show the remarkable most effective repellent properties and other essential oil are also show effective effect. These essential oils was then employed as active ingredients in the preparation of cream and tested on 40 human volunteers of the age group between 18-40 years. Most of the volunteers reported 80% mosquito repellency. This study demonstrates the potential of essential oils as repellents against both day and night biting of mosquitoes. It was found to be safe and suitable alternative to DEET (N, Ndiethyl-3-methyl Benzamide), the most common currently available repellent KEY WORDS:- DEET, Clevenger Apparatus, Repellent Crea