208 research outputs found

    Sodium alginate microspheres for extending drug release: formulation and in vitro evaluation

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    In the present study, spherical microspheres of theophylline (TP) using sodium alginate as the hydrophilic carrier were prepared to prolong the release. The shape, surface and size characteristics were determined by scanning electron microscopy. The microspheres were found to be discreet and spherical in shape and had a smoother surface. The mean diameter of seven alginate microspheres formulations were between 7.6 ± 0.52 and 22.35 ±0.31 μm. It was observed that mean particle size of the microspheres increased with an increase in the concentration of polymer. The entrapment efficiency was found to be in the range of 70–93%. Optimized alginate microspheres were found to possess good sphericity, size and adequate entrapment efficiency. The in vitro release studies were carried out in pH progression media (pH 1.2, 2.5, 4.5, 7 and 7.4 solutions). Results indicated that percent drug release decreased with an increased alginate concentration. TP-loaded Alginate microspheres showed extended in vitro drug release thus use of microspheres potentially offers sustained release profile along with improved delivery of TP.Keywords: Extended drug delivery; Sodium alginate; Microspheres; Bronchial asthm

    Optimisation of Diffusion Welding Parametersin Al-Cu Bimetal for Shaped Charge Application

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    Optimum process parameters (temperature, pressure, and time) for diffusion welding of aluminium and copper have been achieved with better shear strength for application in shaped charges using the Taguchi method. The study involved characterising the type and thickness of intermetallic compounds formed at the faying surfaces using optical microscopy, scanning electron microscopy and electron probe micro analyser, lap shear strength assessment, microhardness, and X-ray diffraction. It is confirmed that intermetallic compounds of type Al4Cu (σ), Al2Cu (θ), and AlCu (η1) with traces of Al2Cu3 (δ) and AlCu4 (α2) were formed at the interface. The optimum shear strength of 42.2 N was achieved with diffusion welding at temperature 510oC, pressure 0.5 MPa and time 5400 s. By diffusion welding at these conditions, the shape charge cones fabricated and explosively filled such shaped charges paved, an increase of 0.42 times in the penetration of target with diffusion welded copper-aluminium shape charge cones compared with that from conventional monolithic copper sheet

    Anti-inflammatory and analgesic activity of different fractions of Boswellia serrata

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    The study was designed to investigate the anti-inflammatory and analgesic effect of different fractions of Boswellia serrata. The effect of different fractions of Boswellia serrata were studied using carrageenan induced paw edema, acetic acid induced writhing response, formalin induced pain, hot plate and tail flick method for studying anti-inflammatory and analgesic activity, respectively. The different fractions of B. serrata, essential oil (10 ml/kg), gum (100 mg/kg, resin (100 mg/kg) oleo-resin (100 mg/kg) and oleo-gum-resin (100 mg/kg) significantly reduces carrageenan induced inflammation in rats and shows analgesic activity, as determined by acetic acid induced writhing response, formalin induced pain, hot plate and tail flick method. The different fractions of B. serrata showed prompt anti-inflammatory and analgesic activity due to the inhibition of 5-lipoxygenase enzyme.Keywords: Analgesic; Boswellia serrata; Inflammation; 5- lipoxygenase; Burseraceae

    Correlation Coefficients and Adaptive Threshold-Based Dissolve Detection in High-Quality Videos

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    Rapid enhancements in Multimedia tools and features day per day have made entertainment amazing and the quality visual effects have attracted every individual to watch these days\u27 videos. The fast-changing scenes, light effects, and undistinguishable blending of diverse frames have created challenges for researchers in detecting gradual transitions. The proposed work concentrates to detect gradual transitions in videos using correlation coefficients obtained using color histograms and an adaptive thresholding mechanism. Other gradual transitions including fade out, fade in, and cuts are eliminated successfully, and dissolves are then detected from the acquired video frames. The characteristics of the normalized correlation coefficient are studied carefully and dissolve are extracted simply with low computational and time complexity. The confusion between fade in/out and dissolves is discriminated against using the adaptive threshold and the absence of spikes is not part of the case of dissolves. The experimental results obtained over 14 videos involving lightning effects and rapid object motions from Indian film songs accurately detected 22 out of 25 gradual transitions while falsely detecting one transition. The performance of the proposed scheme over four benchmark videos of the TRECVID 2001 dataset obtained 91.6, 94.33, and 92.03 values for precision, recall, and F-measure respectively

    Land-use, transport and vehicle technology futures: An air pollution assessment of policy combinations for the Cambridge Sub-Region of the UK

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    This paper reports on an investigation of the impact on air-quality of combinations of urban form development scenarios and vehicle fleet technology changes. The scenarios combine policies affecting urban land-use plans within the Cambridge Sub-Region of the UK, alongside technological changes within the projected vehicle fleet. Broadly, the scenarios consist of the ‘Trend’ for urban form policy and vehicle technology and the urban form policy options of ‘Planned expansion’, ‘Market-led development’ and ‘Urban compaction’, each combined with form-appropriate technological scenarios addressing the uptake of current, and future, technologies in the vehicle fleet. The framework developed for environmental assessment is described, from land-use transport interaction, through traffic assignment and emissions modelling, through to dispersion calculations. The urban form-vehicle technology combinations have been assessed in terms of overall vehicle kilometres travelled (VKT), greenhouse gas (CO2) emissions, and local air quality (NOx, NO2, PM, HC). Results are presented for 2021 and show that overall network emissions change from −13% (Compaction) to +8% (Market-led) relative to the Trend, but effects on emissions in individual districts (NOx) may much greater, −40% to +50%. Annual mean concentrations of NO2 at the street level may vary by −7 to 8 μg/m3. The use of electric vehicles in the ‘Urban compaction’ scenario aids mitigation of air quality issues in the city centre. The results are discussed with respect to the feasibility of scenario implementation, current approaches to planning, and trends in vehicle technology. Limitations of the modelling framework are also identified, and future developments outlined

    Four-year assessment of ambient particulate matter and trace gases in the Delhi-NCR region of India

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    A key challenge in controlling Delhi’s air quality is a lack of clear understanding of the impacts of emissions from the surrounding National Capital Region (NCR). Our objectives are to understand the limitations of publicly available data, its utility to determine pollution sources across Delhi-NCR and establish seasonal profiles of chemically active trace gases. We obtained the spatiotemporal characteristics of daily-averaged particulate matter (PM10 and PM2.5) and trace gases (NOX, O3, SO2, and CO) within a network of 12 air quality monitoring stations located over 2000 km2 across Delhi-NCR from January 2014 to December 2017. The highest concentrations of pollutants, except O3, were found at Anand Vihar compared with lowest at Panchkula. A high homogeneity in PM2.5 was observed among Delhi sites as opposed to a high spatial divergence between Delhi and NCR sites. The bivariate polar plots and k-means clustering showed that PM2.5 and PM10 concentrations are dominated by local sources for all monitoring sites across Delhi-NCR. A consequence of the dominance of local source contributions to measured concentrations, except to one site remote from Delhi, is that it is not possible to evaluate the influence of regional pollution transport upon PM concentrations measured at sites within Delhi and the NCR from concentration measurements alone

    Performance Evaluation of UK ADMS-Urban Model and AERMOD Model to Predict the PM10 Concentration for Different Scenarios at Urban Roads in Chennai, India and Newcastle City, UK

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    The pollutants and its effects on human health are now a major issue around the world. The impact of traffic and the resulting vehicle emissions has come to the forefront. Particulate matter is one among six criteria pollutants and air pollution related to particulate matter is now becoming a serious problem in developing as well as developed countries. One of the main sources is from the vehicles and the resuspension caused by the vehicular movement. Source apportionment studies of Chennai (Clean Air Asia: Air quality profile 2010 edition) showed that from the residential monitoring stations levels of particulate matter in Chennai lies in the range of 51–70 µg/m3. According to DoT of the total road emissions in UK, about 80 is generated from particulate matter which is due to road traffic even though there are no factors like resuspension in this country. In UK, 103 areas have been declared as local air quality management areas (LAQMA), while in India, 72 cities have been identified as non-attainment area with respect to various air pollutants. Chennai, India and Newcastle City, UK which are the cities under study are the one among them facing severe air pollution problems. The main objective of the paper is application and evaluation of UK ADMS-Urban and AERMOD model for the prediction of particulate matter (PM10) concentrations at urban roadways in Chennai and in Newcastle. The model evaluation has been carried out using traffic data of 2009, meteorological data provided by Laga Systems, Hyderabad for both the cities and the real-time monitored data of the year 2009. The results of the study identified the trends in pollutant patterns and its variation with the different parameters of meteorological data. The statistical descriptors, namely index of agreement (IA), fractional bias (FB), normalized mean square error (NMSE), geometric mean bias (MG) and geometric mean variance (VG) were used to understand the performance of the model. Results indicated that both the models have been able to predict the pollutant concentration with reasonable accuracy. The IA values for ADMS and AERMOD are found to be 0.39 and 0.37, and 0.48 and 0.44, respectively, for Chennai and Newcastle City

    Short-term effects of air pollution on daily asthma-related emergency department visits in an industrial city

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    BACKGROUND: Epidemiological studies from Europe and North America have provided evidence that exposure to air pollution can aggravate symptoms in asthmatic patients. METHODS: Daily number of AEDv, air pollution levels (PM10, PM2.5, SO2, NO2 and CO) and meteorological variables was obtained from Jubail Industrial City, Saudi Arabia, for the period of 2007-11. Data were analyzed using a time-series approach. Relative risks (RRs) were estimated using Poisson regression. RESULTS: The associations between AEDv and PM10, PM2.5, SO2 and NO2 remained positive and statistically significant after mutual adjustment in the multi-pollutant model.The RR of AEDv increased by 5.4, 4.4, 3.4 and 2.2% per an inter-quartile range increase in SO2 (2.0 ppb), PM2.5 (36 μg/m3), NO2 (7.6 ppb) and PM10 (140 μg/m3), respectively. No significant associations between AEDv and CO were found. CONCLUSIONS: Current levels of ambient air pollution are associated with AEDv in this industrial setting in the Middle East. Greater awareness of environmental health protection and the implementation of effective measures to improve the quality of air in such settings would be beneficial to public health
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