176 research outputs found

    Morphological and Biochemical Adaptive Changes Associated With A Short-period Starvation of Adult Male Japanese Quail (Coturnix japonica)

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    Objective: The morphological and biochemical impact of a short-period of starvation on Japanese quail was investigated. Materials and Methods: Ten adult male Japanese quail were divided into two groups; control fed and starved. The control-fed group was offered food and water ad libitum and the starved group was subjected to a short-period of food deprivation. After 2.5 days, the serum was obtained and different parameters including the total protein, AST, ALT, triglyceride, HDL, LDL, creatinine and urea were assessed. Gastrointestinal tract, stomach and liver were excised and their masses were estimated. Paraffin and resin embedded sections from the proventriculus, gizzard, liver, duodenum, kidney and pancreas were examined with a light microscopy. Results: Significant decreases in the masses of body, gastrointestinal tract, stomach and liver of the starved group were recorded. The liver and duodenum were the most affected organs. The liver showed depletion of glycogen, vacuolation, hyperemia and cellular infiltrations. Duodenal villi showed degenerative changes in lamina epithelialis and cellular infiltrations in the lamina propria. Biochemical analysis revealed a decreased level of total protein, AST and ALT, increased cholesterol, triglycerides and LDL and unchanged HDL, urea and creatinine by starvation. Conclusion: The current study described in details the effect of short time starvation on quail organs. Time-point adaptive responses of male quail to starvation and refeeding will be investigated in future studies

    Evidence based medical use of aloe vera extracts, short review of literature

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    The use of aloe vera is being promoted for a large variety of conditions. The aim of this review was to summarize all available research papers on aloe vera preparations with a view to providing evidence for or against its clinical effectiveness. Independent literature searches were conducted in PubMed. All studies of controlled clinical trials, observational studies and case series were included. There were no restrictions on the language of publication. All studies were read by all authors and data were extracted in a standardized, pre-defined manner. Even though there are some promising results, clinical effectiveness of oral or topical aloe vera is not sufficiently defined at present

    The new distribution (Topp Leone Marshall Olkin-Weibull) properties with an application

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    The few standard probability distributions available are insufficient for modelling naturally occurring events. Most especially, normal distribution is not ideal for modelling asymmetrical data. Generalizing a new distribution is an important area in probability theory. It is known that we can improve the performance of the distributions by adding a new parameters. So, in this paper, we introduce Topp Leone Marshall Olkin-Weibull distribution as new method with four parameters based on recently proposed family (Topp Leone Marshall-Olkin of distributions). Accordingly, mathematical properties such as quantile function, moments generating functions, entropy, and order statistics have been investigated. The estimation of four parameters by maximum likelihood method was implemented. Application for real data based on the proposed method can be employed to show the best fitting as compared with the other models

    Compressed Measurements Based Spectrum Sensing for Wideband Cognitive Radio Systems

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    Spectrum sensing is the most important component in the cognitive radio (CR) technology. Spectrum sensing has considerable technical challenges, especially in wideband systems where higher sampling rates are required which increases the complexity and the power consumption of the hardware circuits. Compressive sensing (CS) is successfully deployed to solve this problem. Although CS solves the higher sampling rate problem, it does not reduce complexity to a large extent. Spectrum sensing via CS technique is performed in three steps: sensing compressed measurements, reconstructing the Nyquist rate signal, and performing spectrum sensing on the reconstructed signal. Compressed detectors perform spectrum sensing from the compressed measurements skipping the reconstruction step which is the most complex step in CS. In this paper, we propose a novel compressed detector using energy detection technique on compressed measurements sensed by the discrete cosine transform (DCT) matrix. The proposed algorithm not only reduces the computational complexity but also provides a better performance than the traditional energy detector and the traditional compressed detector in terms of the receiver operating characteristics. We also derive closed form expressions for the false alarm and detection probabilities. Numerical results show that the analytical expressions coincide with the exact probabilities obtained from simulations

    Performance Evaluation of Path Loss in Mobile Channel for Karada district in Baghdad City

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    In this work Hata, Lee, Walfisch-Ikegami and Free Space Loss models have been compared with practical path loss based on series of measurements in Karada district in Baghdad for GSM900 downlink band. Hata model showed the closest path loss predictions with mean square error = 10.8 dB, but these results are far from good prediction results and need enhancement. Hata model was optimized using Least Squares method based on measured received signal power. The optimized Hata model showed much better results from the original Hata with mean square error = 6.96 dB. The simulation and calculations were implemented using MATLAB R2009b. The measurements were done using Field Test Display (FTD) with a compatible hand phone to measure signal strength. A Ground Positioning System (GPS) was used to measure the distance from transmitter

    Properties of High Strength Concrete Containing StonePowder as Natural Pozzolanic Materials

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    Currently high-strength concrete is increasingly used in modern concrete technology and particularly in the construction of high rise buildings. This study has been conducted to investigate the properties of high-strength concrete that was produced by using stone powder (SP) as an alternative of proportion on cement after being processed , since its main oxides are similar to those of cement. The aim of the research is to study the effect of (10,15,20,25)% stone powder as replacement of cement, used in concrete mix which it has a mixing proportion of (1:2:1.8;w/c=0.26), and it is shown their effect on some of mechanical properties(compressive strength, splitting tensile strength, and flexural strength). The test results showed clear improvement in some mechanical properties of concrete by using 20% (SP). The increment where its ratio (34, 41, 34.4)% for each compressive strength, splitting tensile strength, and flexural strength compared with reference mixture for the same duration respectively

    Performance investigation of stand-alone induction generator based on STATCOM for wind power application

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    Self-Excited induction generators (SEIG) display a low voltage and frequency regulation due to variable applied load and input rotation speed. Current work presents a simulation and performance analysis of a three-phase wind-driven, SEIG connect to a three-phase load. In addition, an investigation of the dynamic operation of the induction generator from starting steady state until no-load operation. It is assumed that the input mechanical power is constant where the rotor of the SEIG rotates at a constant speed. The value of the excitation capacitance which is necessary to the operation of the induction generator also computed to ensure a smooth and self-excitation starting. The output voltage of the generator is adjusted by varying the reactive power injected by STATCOM. A 3-phase IGBT voltage source inverter with a fuel cell input supply is connected as STATCOM which is used to compensate for the reduction in the supply voltage and its frequency due to variation occurred in the applied loads. This work includes introducing a neuro-fuzzyy logic controller to enhance the performance of the SEIG by regulation the generated voltage and frequency The dynamic model of SEIG with STATCOM and loads are implemented using MATLAB/SIMULIN

    Sponge media drying using a swirling fluidized bed dryer

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    Surface preparation today has seen the introduction of sponge media as an alternative product against the traditionally used abrasive materials. Being soft and elastic, the sponge media reduces air borne emission significantly during surface preparation with capability to be re-used. However the environmental conditions limit the sponge media usage whereby wet surroundings prohibit the re-use of the sponge without being dried properly. This study proposes the swirling fluidized bed dryer as a novel drying technique for sponge media. Batch experiments were conducted to study the bed’s hydrodynamics followed by drying studies for three bed loadings of 0.5 kg, 0.75 kg and 1.0 kg at three drying temperatures of 80°C, 90°C and 100°C. It was found that, minimum fluidization velocities for the wet sponge particles were found to be 1.342, 1.361 and 1.382 m/s with minimum swirling velocities of 1.400, 1.469 and 1.526 m/s. Drying times were recorded between 6 to 16 minutes depending on bed loading and drying temperature. Smaller bed weights exhibits faster drying with constant-rate drying period while higher drying temperature and larger bed load resulted in falling-rate drying period. Thin layer modelling for the falling-rate region indicates that Verma et. al model provides the best fit for the present experimental data with coefficient of determination, R2 = 0.98773, root mean square error, RMSE = 0.05048, residuals = 0.3442 and reduced chi-square, χ2 = 0.00254. The effective diffusivity, Deff, for 0.5 kg bed load was found to be 3.454 x 10-9 m2/s and 1.751 x 10-9 m2/s for 0.75 kg bed load. In conclusion, SFBD was found to be a viable and efficient method in drying of sponge media for various industrial applications particularly surface preparation
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