A small scale energy harvester from wind induced vibrations

In this study, a new device for wind energy harvesting on a small-scale was proposed. This system is well suited for powering remote wireless sensors as a cheaper, more environmentally friendly alternative to conventional dry cell batteries which is a need that is being addressed by many recent research studies. The device consists of a cantilever beam with the free end attached to a square section box that is subjected to the air stream inducing aero-elastic flutter. Flutter is a coupled torsion, plunge instability that has been historically studied to be avoided by aerospace and civil engineers. A magnet is attached to the beam and a stationary coil is used to generate electrical power. A finite element model for the device was achieved by formulating a set of ordinary differential equations that integrate the mechanical model of the beam with the aero-elastic flutter of the square section at the tip and the electromagnetic effect of the energy harvesting coil, and they were numerically solved. Wind tunnel experiment runs were carried out for a system with a 30 cm beam and a 30 cm long 5cm wide cross section for wind speeds of 2.4 to 3.2 m/s and electric loads of 40© to 4M©. The numerical predictions were found to compare favorably with the experimental results in terms of the induced voltage, frequency, and power output

Effect of Sildenafil Citrate on Success Rate of Ovulation Induction by Clomiphene Citrate

Background: Disorders of ovulation are common causes of infertility, and polycystic ovary syndrome (PCOS) is by far the most frequent condition. Objetive: The aim of this work was to evaluate the effect of adding vaginal sildenafil citrate to clomophine citrate used as ovarian stimulant drug on both endometrial thickness and pregnancy rate in patient with polycystic ovary syndrome (PCO). Patients and Methods: This prospective Comparative study included a total of 58 patients with primary and secondary infertility aged between18 years to 35 years, attending at Outpatient Clinics, Obstetrics and Gynecology Department, Zagazig University Hospitals. Patients were divided into two equal groups; each were 29. 1st Group was given clomiphene, and 2nd group was given Clomophine citrate and Sildenafil. A transvaginal Scan for imaging the uterus and adnexa for any pathology and measuring the basic endometrial thickness was also done on Day 3. Results: This study shows that there was an increase in endometrial thickness in sildenafil group (13.4±1.814 mm) comparable with clomiphene citrate group only (8.52±2.081 mm) (P=0.01). The result was statistically significant with increase threshold regard for implantation with statistically significant in group B (P=0.018). Conclusions: It could be concluded that addition of sildenafil citrate to clomiphene citrate therapy for induction of ovulation in patients with PCOS resulted in significant increase of endometrial thickness and non-significant increase of pregnancy Rates

Craniofacial And Dental Arches Characteristics In Transfusion Dependent Thalassaemia Patients

Penyakit talasemia merupakan penyakit yang biasa di Asia Tenggara. Namun maklumat berkaitan dengan deformasi kraniofasial dan lengkungan gigi serta kerencatan dalam proses pematangan tulang, amatlah terhad. Tujuan kajian ini adalah untuk menentukan prevalen kecacatan kraniofasial pesakit talasemia transfusi dependen (TDT) dan hubungan antara kecacatan ini dengan data klinikal. Kajian ini juga adalah untuk membandingkan ukuran sepalometrik, lengkungan gigi dan kematangan tulang vertebra servikal di kalangan pesakit talasemia transfusidependen dengan kumpulan biasa kawalan. Thalassaemia diseases are common in Southeast Asia. However, information about craniofacial and dental arches deformity as well as retardation of skeletal maturation are deficient in this area. The aims of this study were to determine the prevalence of craniofacial deformity (CFD) in transfusion-dependent thalassaemia (TDT) patients and the association between this deformity and clinical data. It was also to compare cephalometric measurements, dental arches features and cervical vertebral maturation of TDT with a normal control group

Some personality determinants of the effects of participation : a further investigation / 246

Includes bibliographical references (p. 16-17)

Knowledge, Attitudes, and Practice towards Occupational Health and Safety among Nursing Students in Gaza Strip, Palestine

Health and safety in the workplace are critical components in healthcare institutions. Unsafe working conditions are among the causes of poor  quality of care and burnout. This study aims to assess the knowledge, attitudes, and practice of occupational health and safety among nursing  students at Al-Israa University. Methods: In this cross-sectional study, a structured online questionnaire was distributed from March to May 2021. Of the 350 eligible students, 219  students answered the questionnaire (Response rate=62.6). Data were analyzed using the statistical software IBM-SPSS version 22. Descriptive  statistic, Independent- samples T-Test, and ANOVA tests were used. Results: The majority of participants were female (81.7%) and studying in a diploma program. 21% of nursing students have experienced a needle  stick injury. The mean scores for knowledge, attitudes, and practice were (M±SD:78.2% ±12.9, M±SD:80.6% ±7.1, and M±SD:81.2% ±7.6) respectively.  In terms of knowledge, attitudes, and practice the mean scores were statistically significant between nursing students who attended a safety  precautions course and those who didn not (P-value <.05). In terms of attitudes, the mean scores were statistically significant between diploma and  bachelor students (P-value =.026).In terms of practice, the means scores were statistically significant between males and females (P-value =.017),  nursing students who had experience with needle sticks and those who didn’t (P-value =.015). Conclusion: The authors recommend that clinical  training departments and universities continue to offer occupational health and safety courses and training for health science students. Since the  training had a positive impact on the students' practices.&nbsp

Improving high-altitude UV–Vis resistance of PBO braided tendons of NASA’s super pressure balloons

Super pressure balloons (SPBs) are used by the National Aeronautics and Space Administration (NASA) for ultra-long duration ballooning (ULDB) missions which carry various scientific explorations to support space and earth sciences research activities. The resistance to photo-degradation of load-bearing braided tendons of SPBs is critical to the success of ULDB missions. Recognizing the critical need to improve UV and visible light (UV–Vis) protective performance of p-phenylene-2, 6-benzobisoxazole (PBO) braids, North Carolina State University and NASA’s Balloon Program collaborated to investigate the effectiveness of sheath extrusion method in improving the UV–Vis resistance of tendons. This study included two PBO tendon types – 48,000 (48k) denier tendons and 72,000 (72k) denier tendons. Using a sheath extrusion method, the tendons were covered with UV protective sheath of low-density polyethylene containing two types of UV inhibitors – TiO2 rutile nanoparticles and PolyOne PE White CC®. Bare and sheathed tendons were subjected to artificial UVB exposure in the lab as well as to both high altitude and ground exposure during flight missions conducted by NASA. Protection against radiation exposure was evaluated by determining the loss of tensile strength after exposure. UV–Vis protection of tendons improved with an increase in sheath thickness as well as UV inhibitor content in the sheath. The results also showed that 72k denier braids had higher resistance against UV degradation compared to 48k denier braids. In-flight exposure results confirmed the comparative UV protective performance of tendons exposed to accelerated artificial UVB exposure in lab. 72k denier tendon covered with sheath containing 10% PE White CC® (sheath thickness of 0.37 mm) experienced the lowest strength loss among all tendon samples to high-altitude exposure during flight missions. The study has also utilized UV–Vis transmittance of the sheath covering the braids as a method of evaluating the performance of the protective sheaths