Electrodeposition and characterization of palladium nanostructures on stainless steel and application as hydrogen sensor

Palladium nanostructures have been deposited onto the stainless steel electrode by simple electrochemical deposition method in a buffer solution. The morphology of the synthesized Pd nanoparticles is controllable by deposition potentials because the driving force for various crystal growth mechanisms is merely dependent on applied potentials. The deposited Pd nanoparticles at higher applied potentials showed a cauliflower-like morphology with a nanoscale structure and large surface area. Then, an amperometric hydrogen sensor based on Pd nanoparticles can be constructed. This sensor is based on polymer electrolyte membrane fuel cell (PEMFC) and can be used at the ambient temperature. It is operated in the three-electrode mode that consists of three electrodes (working, counter and reference) and protonated Nafion membrane as proton conducting solid polymer electrolyte (SPE). The steady-state current response is obtained linearly to the concentrations of hydrogen from 50 to 2000 ppm, when a fixed potential of 0.2V is applied to the sensor. Typical factors that influence the performance of the sensor are analyzed and discussed. The simple and inexpensive hydrogen sensor fabricated shows low LOD (10 ppm, based on S/N = 3), wide linear range (50-2000 ppm) and short response time (10-40 s)

Novel positively charged PVDF/SPES membranes surface grafted by hyperbranched polyethyleneimine (HBPEI): Fabrication, characterization, antifouling properties, and performance on the removal of cationic E-coat paint

Surface modification of ultrafiltration membranes has shown a significant potential to reduce fouling and increase flux and lifetime, which are the most important factors in membrane filtration. In this study, the surface-modified membranes were prepared by grafting hyperbranched polyethyleneimine (HBPEI) onto polyvinylidene fluoride (PVDF)-sulfonated polyethersulphone (SPES) blending membranes. Electrostatic interactions between HBPEI and SPES result in a well-attached positive-charged HBPEI grafting layer on the PVDF membrane surface. Surface-modified membranes were examined for the removal of cationic E-coat paint and their performance was measured in terms of total permeation flux, paint rejection, and fouling resistance parameters. In addition, the physicochemical properties and morphology of the membranes were examined by field emission scanning electron microscopy (FESEM), Fourier-transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), and water contact angle (CA). The optimum membrane shows a total permeation flux of 35.5 L per square meter per hour (LMH) and paint rejection of 99.9%. Additionally, the fouling parameter of the optimized membrane shows a flux recovery ratio of 90%. As a result of its considerable properties, such as the high flux and separation performance as well as its antifouling properties, the surface modified membrane is an excellent candidate for the removal of E-coat paint at industrial scale

Prediction Of Lateral Force In An Off-Road Tire As A Function Of Seven Variables Using Response Surface Methodology (RSM)

In this study an in-situ Single Wheel Tester (iSWT) was used to investigate the effect of some of the most important independent variables on the lateral force of a high lug agricultural tire. The variables include some soil parameters and tire characteristics. Response Surface Methodology (RSM) also was used to construct a design of experiment and propose the lateral force model as a function of seven variables (various combination treatments of soil characteristics and tire parameters). A total of 152 experimental tests were conducted to find appropriate model. Reduced form of a quadratic model was selected to predict the tire lateral force (R2 > 0.9). The results show that the side slip angle and moisture content had major and minimal effect on tire lateral force respectively. Increasing the tire normal load, not only increases the maximum value of tire lateral force attainment, it also pushes the peak value of the lateral force to higher slip angles

Adaptive Neuro-Fuzzy Inference System (ANFIS) Applied for Spectrophotometric Determination of Fluoxetine and Sertraline in Pharmaceutical Formulations and Biological Fluid: Determination of fluoxetine and sertraline in pharmaceutical formulations and biological fluid

The UV-spectrophotometric method of analysis was proposed for simultaneous determination of fluoxetine (FLX) and sertraline (SRT). Considering the strong spectral overlap between UV-Vis spectra of these compounds, a previous separation should be carried out in order to determine them by conventional spectrophotometric techniques. Here, full-spectrum multivariate calibrations adaptive neuro-fuzzy inference system (ANFIS) method is developed.Adaptive neuro-fuzzyinference system (ANFIS) is a neuro fuzzy technique where the fusion is made between the neural network and the fuzzy inference system that is a computational method. The experimental calibration matrix was constructed with 30 samples. The concentration ranges considered were 5-120μg.mL−1fluoxetine and 10-120μg.mL−1sertraline .Absorbance data of the calibration standards were taken between 200-300nm with UV-Vis spectrophotometer. The method was applied to accurately and simultaneously determine the content of pharmaceutical in several synthetic mixtures and real samples. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be 101.26% and 100.24%, respectively for determination of FLX and SRT

Resolving Spectra Overlapping Based on Net Analyte Signal for Simultaneous Spectrophotometric Determination of Fluoxetine and Sertraline

The net analyte signal standard addition method was used for simultaneous spectrophotometric determination of sertraline and fluoxetine in pharmaceutical preparations. The method combines the advantages of the standard addition method with the net analyte signal concept to enable the extraction of information about an analyte from the spectra of multi-component mixtures. This method uses full spectrum realization and does not require calibration and prediction steps. Determination requires only a few measurements. The limit of detection for fluoxetine was 0.31 µg ml-1 and for sertraline was 0.20 µg ml-1. The root mean square error for fluoxetine was 0.45 and for sertraline was 0.39

Neonatal isolation provokes hippocampal apoptosis and recognition memory impairment in rats

Neonatal isolation (NI) has detrimental consequences on the hippocampal neurons of rat neonates. It has been reported to enhance neuronal cell death and impair memory behaviors. We conducted this study to assess the effects of NI on hippocampal apoptosis and recognition memory impairment in the hippocampus of rat neonates. One group of male Wistar rat neonates exposed to NI; rat neonates reared with 1-hour neonatal isolation (NI) for eight consecutive days (P2-P9). On the other hand, the control group reared normally. Novel object recognition test (NOR) test used to evaluate the effects of NI on recognition memory impairment. On day 22 (P22), a TUNEL assay was done. NOR demonstrated that rat neonates who experienced NI had long-term memory deficits (P<0.01). TUNEL assay results showed that NI increased the number of TUNEL positive neurons in CA1, CA3, and DG subfields of the hippocampus (P<0.05, P<0.001, and P<0.001). The present results indicated that NI exerted apoptotic effect and induced recognition memory impairment in the rat neonate’s hippocampus

Numerical and analytical study of ultimate capacity of steel plate shear walls with partial plate-column connection (SPSW-PC)

This research endeavor intends to use the numerical and analytical approaches to investigate the ultimate shear capacity of steel plate shear walls with partial plate-column connection (SPSW-PC). This study aims to provide an analytical relationship for estimating the ultimate capacity of SPSW-PC. Using plastic analysis and considering the mechanism of plastic hinge formation, a relation has been obtained for estimating the ultimate capacity of SPSW-PCs. Extensive parametric studies have been carried out using a nonlinear finite element method to examine the accuracy of the obtained analytical relationships. The parametric studies include investigating the influence of infill plate thickness and width-to-height ratio as well as the ratio of the plate-column detachment length of SPSW-PCs. To this end, comprehensive verification studies are initially performed by comparing the numerical predictions with several reported experimental results to demonstrate the numerical method's reliability and accuracy. Comparison is made between the hysteresis curves, failure modes, and base shear capacities predicted numerically or obtained/observed experimentally. The results show a sound compromise between the ultimate capacity of the analytical relationship and numerical models of parametric studies. Although removing the connection between the web-plate and columns can be beneficial by decreasing the overall system demand on the vertical boundary members, based on the results and findings of this research study, such detachment can reduce the stiffness and strength capacities of steel shear walls by about 25%, on average

Burden of Ischemic Heart Disease Attributable to Low Omega-3 Fatty Acids Intake in Iran: Findings from the Global Burden of Disease Study 2010

Background: Dietary risk factors constitute some of the leading risk factors for cardiovascular disease in Iran. The current study reports the burden of ischemic heart disease (IHD) attributable to a low omega-3 fatty acids intake in Iran using the data of the Global Burden of Disease (GBD) Study 2010. Methods: We used data on Iran for the years 1990, 2005, and 2010 derived from the GBD Study conducted by the Institute for Health Metrics and Evaluation (IHME) in 2010. Using the comparative risk assessment, we calculated the proportion of death, years of life lost, years lived with disability, and disability-adjusted life years (DALYs) caused by IHD attributable to a low omega-3 fatty acids intake in the GBD studies from 1990 to 2010. Results: In 1990, a dietary pattern low in seafood omega-3 fatty acids intake was responsible for 423 (95% uncertainty interval [UI], 300 to 559), 3000 (95% UI, 2182 to 3840), and 4743 (95% UI, 3280 to 6047) DALYs per 100000 persons in the age groups of 15 to 49 years, 50 to 69 years, and 70+ years — respectively — in both sexes.  The DALY rates decreased to 250 (95% UI, 172 to 331), 2078 (95% UI, 1446 to 2729), and 3911 (95% UI, 2736 to 5142) in 2010. The death rates per 100000 persons in the mentioned age groups were 9 (95% UI, 6 to 12), 113 (95% UI, 82 to 144), and 366 (95% UI, 255 to 469) in 1990 versus 6 (95% UI, 4 to 7), 76 (95% UI, 53 to 99), and 344 (95% UI, 241 to 453) in 2010. The burden of IHD attributable to diet low in seafood omega-3 was 1.3% (95% UI, 0.97 to 1.7) of the total DALYs in 1990 and 2.0% (95% UI, 1.45 to 2.63) in 2010 for Iran. Conclusion: The findings of the GBD Study 2010 showed a declining trend in the burden of IHD attributable to a low omega-3 fatty acids intake in a period of 20 years. Additional disease burden studies at national and sub-national levels in Iran using more data sources are suggested for public health priorities and planning public health strategies