Discharge Coefficient of a C-Type Piano Key Side Weir at 30° and 120° Sections of a Curved Channel

A piano key side weir (PKSW) is a non-linear weir that discharge exceeds linear weirs by increasing the length in width. PKSW can be used in side weirs with space limitation. As side weirs are extensively used in flood control, water level control in rivers, and water supply channels, it is necessary to use PKSW as side weirs. This research discusses the discharge coefficient of a PKSW by assessing a C-type PKSW at 30° and 120° sections of a channel with a longitudinal curve. Dimensional analysis was used for identifying the parameters effective in the discharge coefficient. The effects of these parameters are examined by analysing the effective parameters. Finally, an empirical relationship has been proposed for determining the discharge coefficient based on the dimensionless parameters for calculating the discharge coefficient with the correlation coefficient of 0.88 and the mean error of 0.091. The influence of the parameter on the PKSW is more than that of the remaining parameters: With an increase in the value of this parameter, considering decreases in the length of the deviation and a lack of submerged inlet keys, the coefficient of discharge increases

The effects of aerobic exercise on cognitive performance and sleep quality haemodialysis patients

BackgroundCognitive impairment and sleep disturbance are very common in chronic kidney disease (CKD) and are strongly associated with increased mortality among the patients. Even though, exercise is considered to be a quantifiable activity that improves cognition in animals and humans, but few studies have examined the efficacy of exercise on cognitive function and sleep quality in CKD.AimsThis study was performed to evaluate the effects of aerobic exercise during haemodialysis on the cognitive performance and sleep quality.MethodsIn this clinical trial study, 38 patients with an average age of 47 years under haemodialysis were divided into control (N=11) and experimental (N=27) groups. Patients in experimental group were participated in a 24 weeks training progressive exercise that performed during the first two hours of their haemodialysis on a stationary bicycle, three times a week, for 75 minutes each time. Cognitive performance using Mini-Mental State Examination, Symbol Digit Test and Trail Making Test–B and sleep quality with PSQI questioner were assessed before, 12 weeks and 24 weeks after training program. Statistical analysis was performed using SPSS 18, Mann-Whitney U and repeated measure analysis.ResultsAfter the exercise, there was a significant increase in the Trail Making Test–B and sleep quality during the first 12 weeks and a significant improvement after 24 weeks in Mini-Mental State Examination and Symbol Digit Test in exercise group (P < 0.05).ConclusionIt seems that aerobic exercises has a significant impact on cognitive performance and sleep quality in haemodialysis patients and can be used as part of the treatment for haemodialysis patients but further research is warranted to clarify the involved mechanisms

Analysis of Cantilever Triple-Layer Piezoelectric Harvester (CTLPH): Non-Resonance Applications

In this research, a design guideline for a kinetic energy converter using a cantilever tri-ple-layer piezoelectric harvester (CTLPH) for low-frequency applications is presented. By combin-ing the constitutive and internal energy equations, the analytical equations for harvested voltage and power were developed. It was also found that frequency of motion, applied tip force, piezoe-lectric coefficients, geometrical dimensions, and mechanical properties of layers play significant roles in the performance of the harvester. Having characterised the voltage regulator module, LTC3588, the dependency of output voltage on both the storage and output capacitors of the LTC3588 was investigated. An experimental measurement using the optical method was carried out to determine the applied tip force. Furthermore, the performance of the CTLPH in low frequencies (< 3.3 Hz) for various resistive loads was investigated. It was found that both excitation frequency and external resistance load are effective on the maximum generated power. The developed CTLPH shows the optimum power of 17.3

Prognostic factors in birth time: A Survival Analysis

The waiting time between children births are called tempo. This phenomenon plays a crucial role in the child and mother health. The purpose of the present study is determination of factors which influence this variable of interest. A significance level of 5% and power of 80% considered to calculate the required sample size for this cross sectional study. The sample size of 124 women determined using PASS software (ver. 11.0.4). These women randomly selected of married women between 15-45 years old with at least two children, living in Irin village. We consider the waiting time between the first and the second birth in women randomly sampled from Irin village of Tehran province of Iran.The selected mothers had 364 children at the time of study. The average and standard error for the number of children were 2.940 and 1.102 respectively. 59% of the children were girl and the rest were boy.Tempo variable as an index estimated using Toki method. The lowest tempo is for 5th to 6th births (28.5) and highest is for 6th to 7th (60). Cox regression model was used to determine the significant explanatory factors.Birth of child was considered as an event and time between the first and the second event was considered as outcome in this model.According to the fitted Cox regression model, only maternal education and father’s occupation were statistically significant at 5% on time to second birth

Water repellent effect and dimension stability of beech wood impregnated with nano-zinc oxide

The objective of this study was to quantify the influence of zinc oxide nanoparticles (nano-ZnO) on the water repellency and dimensional stability of beech wood. Beech wood blocks were treated with a nano-ZnO solution at four treatment levels (0, 10,000, 20,000, and 40,000 ppm) using a modified dip method. Also, a thermal treatment was performed at 60 and 120°C. After conditioning the samples, water absorption, volumetric swelling, water repellency effectiveness, and anti-shrink/anti-swell efficiency were determined within 24 h of soaking time. The results indicated that the nano-ZnO used for wood modification greatly improved dimensional stability and reduced the hygroscopicity of the wood. In addition, the Fourier-transform infrared spectroscopy (FTIR) analysis suggested a strong interaction between the nano-ZnO and the chemical components of wood. The heat treatment effectively improved the effects of nano-ZnO

Incidence and Risk Factors of Neural Tube Defects in Kashan, Central Iran

How to Cite This Article: Talebian A, Soltani B, Sehat M, Zahedi A, Noorian A, Talebian M. Incidence and Risk Factors of Neural Tube Defects in Kashan, Central Iran. Iran J Child Neurol. Summer 2015;9(3):50-56.AbstractObjectiveNeural tube defects (NTDs) are the most common congenital defects of centralnervous system due to neural tube closure deficit during the third and fourthweeks of gestational age. Our study was performed to detect the incidence andrisk factors of NTDs in Kashan, center of Iran.Material &amp; MethodsThis case-control study was done on all pregnancies with NTD affectedneonates (n=91) and 209 pregnancies with normal neonates from February2007 to December 2012 in three hospitals in Kashan, center of Iran. Annual andthe mean incidence of NTDs were calculated. Risk factors including neonatalgender, maternal age, gravidity, maternal abortion history, maternal gestationaldiabetes (GDM), folic acid use, familial marriage, maternal body mass index(BMI), birth season and family history of NTDs were evaluated by interviewwith mothers. Univariate and multivariate logistic regression were used toanalyze the risk factors.ResultsThe mean incidence of NTDs was 2.33 per 1000 births. The multivariate analysisindicated that maternal history of abortion (OR: 4.9, CI: 1.9-12.8), and maternal obesity (OR: 5.4, CI: 1.3-21.8) were significantly associated with NTDs.ConclusionMaternal history of abortion and BMI were the major risk factors of NTDs

The Effect of Premedication by Remifentanil and Magnesium Sulfate in Hemodynamic Responses to Tracheal Intubation in Cesarean Section Delivery: 1 A Randomized Double-Blinded Controlled Study

Background: The preventing effects of remifentanil and magnesium sulfate on hemodynamic responses to&nbsp;tracheal intubation were evaluated in a double-blinded controlled trial on pregnant women undergoing cesarean&nbsp;section delivery.Methods: A total of 54 American Society of Anesthesiologists Class I-II women candidate for cesarean section&nbsp;delivery were randomly assigned to one of three groups (n = 18) to receive one of the following premedication:&nbsp;Intravenous (IV) remifentanil 0.75 µg/kg, IV magnesium sulfate 30 mg/kg, or IV normal saline 10 cc as&nbsp;placebo. All hemodynamic profiles were recorded immediately before and after intubation, and 2, 3, 5 minutes&nbsp;after tracheal intubation.Results: Heart rate and systolic and diastolic blood pressures were significantly lower in the remifentanil group&nbsp;than in other groups both before and immediately after intubation. The trend of the changes in homodynamic&nbsp;responses within 5 minutes following intubation in the magnesium sulfate and placebo group was similar, but&nbsp;this trend in the remifentanil group was significant difference. In the same time, 1st&nbsp;and 5th&nbsp;minute Apgar scores&nbsp;were slightly lower in the remifentanil group than others. The measured parameters of umbilical cord blood pH&nbsp;and PO&nbsp;had no significant differences between the groups.Conclusions: Remifentanil can attenuate hemodynamic response to tracheal intubation more effectively than&nbsp;magnesium sulfate, and thus it can be considered safe for a pregnant candidate for cesarean section