• Energy Research
• Closed Access close
• IN close
• SA close
• BE close
• CM close

Uric acid was evaluated for its potential to protect the gastric mucosa against the injuries caused by 80% ethanol, 0.6 m-HCl and 0.2 M-NaOH in rats. Uric acid at doses of 50, 100 or 300 mg/kg body weight provided dose-dependent protection against the ulcerogenic effects of all three agents. Other effects caused by ethanol only were studied. Serum uric acid concentrations were statistically significantly increased by both uric acid and ethanol treatments. Treatments of rats by gavage with 1 ml 80% ethanol was found to cause depletion of stomach-wall mucus, to lower the concentrations of protein, nucleic acids and non-protein sulphydryl groups in the stomach wall, and to cause histopathological lesions, including necrosis, erosions, congestion and haemorrhage, of the stomach wall. Treatment with uric acid, at doses of 50, 100 or 300 mg/kg body weight, by gavage, provided some measure of protection against all of these effects, and the protection was generally dose dependent. The protective effects of uric acid against damage to the gastric-wall mucosa may be mediated through its effects on mucus production and non-protein sulphydryl concentrations, and/or its free-radical scavenging properties.

Abstract An experimental study is conducted to investigate the melting and solidification processes of paraffin wax as a phase change material (PCM) in horizontal double pipe heat latent heat storage unit. The present work on phase change process includes study of temperature variations along the axial distances in PCM, determination of heat transfer coefficient as well as the heat flow rate. A series of experiments was conducted to investigate the effect of increasing the inlet temperature and the mass flow rate of the heat transfer fluid (HTF) both on the charging and discharging processes of the PCM. The experimental results show that the PCM melts and solidifies congruently, and the melting front moves from the left to right side of the PCM container whereas the solidification front moves from right to the left along the axial distances in the PCM container. The results indicate that natural convection dominates the melting process in the liquid phase due to buoyancy effects. On the other hand, the solidification process is dominated by conduction. The flow rate and inlet temperature of the HTF in the experiment range has a significant effect on the phase change processes. The results also indicate that the heat transfer coefficient between the HTF and the PCM was affected by the Reynolds number more during the melting process than during the solidification process. Heat flow rate during the melting and solidification process increased by 25% and 11%, respectively, in the case of increase or decrease by 2 °C of the inlet HTF temperature. The results of this study show that by increasing the inlet water temperature from 70 °C to 74 °C, total melting time can be decreased by 31%.

Abstract In the present work, the generation of hydrogen rich synthetic gas from fluidized bed steam gasification of rice husk has been studied. An equilibrium model based on equilibrium constant and material balance has been developed to predict the gas compositions. The equilibrium gas compositions are compared with the experimental data of the present group as well as of available literature. The energy and exergy analysis of the process have been carried out by varying steam to biomass ratio (ψ) within the range between 0.1–1.5 and gasification temperature from 600 °C to 900 °C. It is observed that both the energy and exergy efficiencies are maximum at the CBP (carbon boundary point) though the hydrogen production increases beyond the CBP. The HHV (higher heating value) and the external energy input both continuously increase with ψ. However, the hydrogen production initially increases with increase in temperature up to 800 °C and then becomes nearly asymptotic. The HHV decreases rapidly with increase in temperature and energy input increases. Therefore, gasification in lower temperature region is observed to be economical in terms of a trade off between external energy input and HHV of the product gas.

The dynamic nature of coral reefs offers a rare opportunity to examine the response of ecosystems to disruption due to climate change. In 1998, the Great Barrier Reef experienced widespread coral bleaching and mortality. As a result, cryptobenthic fish assemblages underwent a dramatic phase-shift. Thirteen years, and up to 96 fish generations later, the cryptobenthic fish assemblage has not returned to its pre-bleach configuration. This is despite coral abundances returning to, or exceeding, pre-bleach values. The post-bleach fish assemblage exhibits no evidence of recovery. If these short-lived fish species are a model for their longer-lived counterparts, they suggest that (1) the full effects of the 1998 bleaching event on long-lived fish populations have yet to be seen, (2) it may take decades, or more, before recovery or regeneration of these long-lived species will begin, and (3) fish assemblages may not recover to their previous composition despite the return of corals.

Enhanced Artificial Bee Colony Optimization (EABCO) algorithm is presented in the paper for economic power dispatch of both thermal plants and hydro power units (fixed head) together. Different constraints considered in this paper are transmission losses, ramp rate limits of thermal generators. Two different cases are taken and the numerical results obtained are studied to test the effectiveness of this suggested technique. The results of the recommended technique are analized with the results already acquired from existing algorithms like differential evolution and evolutionary programming. This comparison draws the conclusion that the EABCO can provide better results and solution than the existing methods in terms of minimum time of computation and low fuel cost.

Edges of the image play an important role in the field of digital image processing and computer vision. The edges reduce the amount of data, extract useful information from the image and preserve significant structural properties of an input image. Further, these edges can be used for object and facial expression detection. In this paper, we will propose new intuitionistic fuzzy divergence and entropy measures with its proof of validity for intuitionistic fuzzy sets. A new and significant technique has been developed for edge detection. To check the robustness of the proposed method, obtained results are compared with Canny, Sobel and Chaira methods. Finally, mean square error (MSE) and peak signal-to-noise ratio (PSNR) have been calculated and PSNR values of proposed method are always equal or greater than the PSNR values of existing methods. The detected edges of the various sample images are found to be true, smooth and sharpen.

A special version of the NOAA HYSPLIT_4 model has been developed and used to estimate the atmospheric fate and transport of mercury in a North American modeling domain. Spatial and chemical interpolation procedures were used to expand the modeling results and provide estimates of the contribution of each source in a 1996 anthropogenic US/Canadian emissions inventory to atmospheric mercury deposition to the Great Lakes. While there are uncertainties in the emissions inventories and ambient data suitable for model evaluation are scarce, model results were found to be reasonably consistent with wet deposition measurements in the Great Lakes region and with independent measurement-based estimates of deposition to Lake Michigan. Sources up to 2000 km from the Great Lakes contributed significant amounts of mercury through atmospheric transport and deposition. While there were significant contributions from incineration and metallurgical sources, coal combustion was generally found to be the largest contributor to atmospheric mercury deposition to the Great Lakes.

Abstract In this paper, a string level fault detection and diagnosis technique for photovoltaic ( P V ) systems based on k-nearest neighbors ( k N N ) rule is proposed. It detects and classifies open circuit faults, line-line ( L - L ) faults, partial shading with and with-out bypass diode faults and partial shading with inverted bypass diode faults in real time. A detailed modeling of the PV systems based on experimental data is presented that only requires available data from the manufacturer’s datasheet reported under standard test conditions ( S T C ) and normal operating cell temperature ( N O C T ) . This model considers the temperature dependent variables such as junction thermal voltage V t , diode quality factor ( A ) and series resistance ( R s ) . Simulations of the developed model have been carried out using Matlab/Simulink. A PV analyzer (Solar I-V) of HT instruments is used to measure the I ( V ) characteristics of PV module. The developed model precisely traces the I ( V ) characteristics of PV systems at different irradiance and temperature levels. The simulation results indicate that the error between the measured data and developed model is less than the models available in the literature. The absolute error is confined in the range 0.61 to 6.5%. Finally, the data generated from proposed model and experimental setup are used to validate and test the performance of the proposed fault detection and classification F D C technique. It is observed from the results that the average of fault classification gives a high accuracy of 98.70%.