Subcooled flow boiling heat transfer of ethanol aqueous solutions in vertical annulus space

The subcooled flow boiling heat-transfer characteristics of water and ethanol solutions in a vertical annulus have been investigated up to heat flux 132kW/m2. The variations in the effects of heat flux and fluid velocity, and concentration of ethanol on the observed heat-transfer coefficients over a range of ethanol concentrations implied an enhanced contribution of nucleate boiling heat transfer in flow boiling, where both forced convection and nucleate boiling heat transfer occurred. Increasing the ethanol concentration led to a significant deterioration in the observed heat-transfer coefficient because of a mixture effect, that resulted in a local rise in the saturation temperature of ethanol/water solution at the vapor-liquid interface. The reduction in the heat-transfer coefficient with increasing ethanol concentration is also attributed to changes in the fluid properties (for example, viscosity and heat capacity) of tested solutions with different ethanol content. The experimental data were compared with some well-established existing correlations. Results of comparisons indicate existing correlations are unable to obtain the acceptable values. Therefore a modified correlation based on Gnielinski correlation has been proposed that predicts the heat transfer coefficient for ethanol/water solution with uncertainty about 8% that is the least in comparison to other well-known existing correlations

Nucleate pool boiling heat transfer of binary nano mixtures under atmospheric pressure around a smooth horizontal cylinder

Influence of Al2O3 nanoparticles on nucleate pool boiling heat transfer of diluted binary water-glycerol mixtures has been experimentally measured up to heat flux 91 kW/m2 at diluted volume fractions of 1% to 5% of glycerol into pure water at volumetric concentrations 0.5%, 1% and 1.5% of Al2O3 nanoparticles. Obtained results indicate that presence of nanoparticles into the mixtures result in increasing the pool boiling heat transfer coefficient values and also result in decreasing the wall superheat temperature of surface. Increased values of heat transfer are increased with increasing the volume fractions of Al2O3 too. Generally, it is concurred that Al2O3 nanoparticles typically enhance the pool boiling heat transfer coefficient of binary water-glycerol mixture in comparison with absence of nanoparticles circumstances, up to 25% at 1.5% Al2O3. Additionally, new simple semi - mathematical model has been proposed for a rough estimating of enhanced values with uncertainty about 8%

Simulation study of a pulsed DBD with an electrode containing charge injector parts

By using a multispecies fluid model, the tunability and controllability of plasma parameters such as distributions of electron density, electron energy, ion density, and electric field in a microdielectric barrier discharge (DBD) with a charge injector electrode and driven by negatively polarized nanosecond pulsed voltage superimposed on a positive DC bias voltage are investigated. To this end, the effects of changing features of pulsed voltage like pulse rise time (10–20 ns), pulse peak width (10–15 ns), and pulse fall time (20–30 ns) on characteristics of argon plasma formed inside the reactor are studied. The results show that with the increase in pulse width and pulse rise time, the density of electron and ion increases, while fall time change does not significantly affect the plasma parameters. Generally, the results of this study explicitly prove the possibility of controlling plasma formed inside DBD reactors driven by negative pulse voltage combined with a positive DC voltage, which is very important in waste gas conversion applications

Clinical efficacy and mechanistic evaluation of aflibercept for proliferative diabetic retinopathy (acronym CLARITY): a multicentre phase IIb randomised active-controlled clinical trial

Introduction Proliferative diabetic retinopathy (PDR) is the main cause of severe visual loss in people with diabetes mellitus. The standard treatment for this condition is panretinal photocoagulation (PRP). This laser treatment is inherently destructive, with predictable adverse effects on visual function, and a safer alternative is required. Intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors can induce short-term regression of retinal neovascularisation. The aim of this randomised controlled trial is to determine the efficacy, safety and cost-effectiveness of intravitreal aflibercept, an inhibitor of VEGF-A, VEGF-B and placental growth factor (PLGF), in PDR, and to investigate the impact on local oxygenation. Methods and analysis This is a phase IIb randomised controlled single-masked multicentre clinical trial to determine the impact of repeated intravitreal aflibercept injections in the treatment and prevention of PDR. 220 participants with treatment-naïve or treated but active retinal neovascularisation in at least one eye will be randomly allocated 1:1 to intravitreal aflibercept injections or PRP for a period of 52�weeks. The primary outcome is the change in best-corrected visual acuity in the study eye at 52�weeks. Secondary outcomes include changes from baseline in other visual functions, anatomical changes and cost-effectiveness. Ocular and non-ocular adverse events will also be reported over 52�weeks. Ethics and dissemination The study has been approved by the National Research Ethics Service (NRES) committee with respect to scientific content and compliance with applicable research and human subjects� regulations. Findings will be reported through scientific publications and research conferences. The results of this study will provide clinical evidence for the feasibility, efficacy safety and cost-effectiveness of intravitreal aflibercept for PDR

Evaluation of labor indices in prolonged pregnancy in Shabihkhani Hospital, Kashan 2003

Background: Prolonged pregnancy influences different aspects of maternal and neonatal health. Although it is accepted that drug intervention is necessary before labor in prolonged pregnancy but there is debate about the termination time of the pregnancy. Considering the importance and prevalence of this entity we studied the labor indices in the hospitalized women with prolonged pregnancy in Kashan, in 1382-1383.Material and Methods: This descriptive study carried out on 450 women with gestational age of more than 40 weeks (based on their LMP or sonography before 30 weeks) admitted for termination of pregnancy by induction. They had no medical or obstetrical problem. Labor indices including dilatation and effacement at the time of admission, number of inductions, duration of hospitalization, dystocia and type of delivery, as well as mother�s age, history of prolonged pregnancy, and number of parturitions were recorded and then on the base of gestational age categorized in 4 following groups: 40w to 41w and 3days, 40w and 4days to 41w, 41w and 1days to 41w and 3days and 41w, 4days or more.Results: Data showed that 131 women (29.1) have terminated in 40 to 40w and 3days of gestation and 130 women (28.9) in 40w and 4days to 41w, 150 women (33.3) in 41w and 1days to 41w and 3days and only 39 women (8.7) after 41w and 3 day 12 (2.7) of which were more than 42 weeks. There wasn't significant difference between women in dilatation and effacement on admission, dystocia and type of delivery but there was significant difference in the number of induction and duration of hospitalization. Termination of pregnancy in lower gestational age causes increased number of inductions and duration of hospitalization. The most frequent reason for cesarean section was lack of response to drug interventions and induction in lower gestational age. Conclusion: We recommend no intervention for termination of delayed pregnancy up to 41.5 weeks in women without problem

Stage at diagnosis and delay in seeking medical care among women with breast cancer, Delhi, India

Background: Patients with cancer often delay seeking medical advice in developing countries. It can adversely influence the outcome of disease. Objectives: The present study was performed to determine the stage at diagnosis and delay in seeking medical care among women with breast cancer in Delhi, India. Patients and Methods: This was a cross-sectional study based on a census (case series) approach to reach all women (172) diagnosed with primary breast cancer �detected in surgery Out Patient Department (OPD) from January 2007 to December 2009� at Lok Nayak Hospital, Delhi, India. Patients were interviewed using a self-structure questionnaire. Seeking behavior variables were awareness of problem, first consultation, followed physician's advice, detection of problem, system of medicine and gap between knowing the problem and consultation (patient delay). Statistical Analysis was performed using the Microsoft SPSS-pc version 14.0 statistical program. The analytic methods were used (mean, standard deviation, X2, Fisher's Exact Test, K-S, Kruskal-Wallis) for variables. All statistical tests were performed at a significance level of 5 (P &lt; 0.05). Results: the mean age of women was 46.99 years. 38.4 of women were � 40 years. 61 of women were in stage IV of cancer at the time of diagnosis. The mean duration of gap between knowing the problem and consulting a physician (patients delay) was 10.90 months. There was no significant association between stage of cancer and consultation gap. A significant association was found between the stage of breast cancer and income; women with lower income had a higher stage of breast cancer (P < 005). Conclusions: A significant association was found between ages of women with their delays in consultation. Delay is still prevalent amongst women with breast cancer. It seems necessary to design educating programs for women in both clinical and community settings, about breast cancer and early detection practices. © 2014, Iranian Red Crescent Medical Journal

Evaluation of the prevalence of Chlamydia Trachomatis and its associated factors in patients with pelvic inflammatory disorders in Shabihkhani Hospital in Kashan in 2000

History and Objectives: Considering the incidence of Chlamydia trachomatis and its known complications and costly diagnostic methods needing especial facilities, this study was carried out to determine its prevalence among patients with pelvic inflammatory disorders. Materials and Methods: The descriptive strategy of this study was conducted on 323 cases. After a diagnosis of PID on the basis of medical history and clinical examination, samples were collected from endocervix by a swab and tested by fluorescent antibody direct method. In addition, information on age, multiparous status, contraceptive method and so on was collected through arranging interview. At last, the prevalence was calculated for the society. Results: A total of 323 women with PID were studied in whom only 33 cases (10.2) showed chlamydial infection. There was an inverse relationship between prevalence and the factors increased age, age of intercourse engagement, number of intercourse/week and knowledge level. There was also a lower rate of prevalence when using condom and/or contraceptive pill and coitus interruptus increased the incidence rate. In addition, patients with PID showed a higher rate of dysmenorrhea and dyspareunia and there was no significant relationship between infection and uterine bleeding and/or dysuira. Patients with cervical hypertrophy showed a higher rate of PID. Conclusion: prevalence of Chlamydia trachomatis is not high in PID. Nonetheless, because of its complications, it is necessary to conduct studies on its causative factors and to lower its incidence