101 research outputs found
A Study of Aquatic Insects of Logan River, Utah
The author\u27s main purpose is to discover and record what insects are present at different locations in the Logan River during the months of September, 1953, to June, 1954
Dynamic Technique for Optimizing Universal Mobile Telecommunication System Active Set.
Dalam tesis ini, High-Speed Down Load Packet (HSDPA) diselidik dengan menggunakan Nisbah Kehilangan Paket (Packet Loss Ratio) dan Nisbah Penggunaan Paket ( Packet Comsumption), disebabkan perubahan bilangan sel dalam set aktif.
In this thesis, an investigation of High Speed Down Load Packet (HSDPA) is made with packet Loss Ratio and Packet Consumption Ratio, Which is caused by changing the number of cells in the active set
Solution Of Convective Boundary Layer Flows Via Scaling Group Transformation Method
The aim of this thesis is to find similarity solutions for some models in fluid mechanics
using the method of scaling group transformation. In this thesis the steady two-dimensional
incompressible laminar boundary layer on a flat plate as well as wedge flow models both in
porous media and clear media have been studied.
Tujuan tesis ini adalah untuk mencari penyelesaian keserupaan bagi beberapa model
dalam mekanik bendalir menggunakan kaedah penjelmaan kumpulan penskalaan. Dalam tesis
ini aliran lapisan sempadan berlamina dua dimensi tak boleh mampat yang mantap pada plat rata
dan baji di dalam media berliang dan tidak berliang telah dikaji
Anomaly-Based Detection Approach To Detect The Flash Crowd Attack During The Flash Event
The goal of the thesis is to propose an approach that can detect flash crowd attacks that target web servers during flash events. The proposed approach consists of four phases to achieve the goal of the research. The proposed approach is evaluated using three different datasets distributed in three scenarios. The first scenario is aimed to validate the detection accuracy of the proposed approach when a web server is in a normal situation (when there is no threat targeting the server). The second scenario (flash event dataset) is aimed to improve the accuracy of the proposed approach in detecting anomalous behaviour when the server is facing a flash event. The third scenario (flash crowd attack dataset) is aimed to verify and validate the accuracy of the proposed approach in terms of detecting the flash crowd attack that targets the web server during the flash event
Heat transfer analysis for falkner-skan boundary layer flow past a stationary wedge with slips boundary conditions considering temperature-dependent thermal conductivity
We studied the problem of heat transfer for Falkner-Skan boundary layer flow past a stationary wedge with momentum and thermal slip boundary conditions and the temperature dependent thermal conductivity. The governing partial differential equations for the physical situation are converted into a set of ordinary differential equations using scaling group of transformations. These are then numerically solved using the Runge-Kutta-Fehlberg fourth-fifth order numerical method. The momentum slip parameter δ leads to increase in the dimensionless velocity and the rate of heat transfer whilst it decreases the dimensionless temperature and the friction factor. The thermal slip parameter leads to the decrease rate of heat transfer as well as the dimensionless temperature. The dimensionless velocity, rate of heat transfer and the friction factor increase with the Falkner-Skan power law parameter m but the dimensionless fluid temperature decreases with m. The dimensionless fluid temperature and the heat transfer rate decrease as the thermal conductivity parameter A increases. Good agreements are found between the numerical results of the present paper with published results
Microbial Contamination of Date Rutab Collected from the Markets of Al-Hofuf City in Saudi Arabia
The microbial contamination of 60 samples from six date cultivars in the rutab stage purchased from different retail outlets in AL-Hofuf City, Saudi Arabia was studied. All samples were found contaminated with aerobic mesophilic bacteria at loads in the order 102 to 105 cfu/cm2 with some significant differences among varieties that can be attributed to differences in the weather conditions during rutab season. Also all samples, except only one, were contaminated with molds and yeasts at loads in the order 102 to 103 cfu/cm2. Potentially pathogenic Staphylococcus aureus was detected in 57 samples and A. flavus/parasiticus in 13 samples, while coliforms were detected in 39 samples
An Improved Fuzzy Logic Controller Design for PV Inverters Utilizing Differential Search Optimization
This paper presents an adaptive fuzzy logic controller (FLC) design technique for photovoltaic (PV) inverters using differential search algorithm (DSA). This technique avoids the exhaustive traditional trial and error procedure in obtaining membership functions (MFs) used in conventional FLCs. This technique is implemented during the inverter design phase by generating adaptive MFs based on the evaluation results of the objective function formulated by the DSA. In this work, the mean square error (MSE) of the inverter output voltage is used as an objective function. The DSA optimizes the MFs such that the inverter provides the lowest MSE for output voltage and improves the performance of the PV inverter output in terms of amplitude and frequency. The design procedure and accuracy of the optimum FLC are illustrated and investigated using simulations conducted for a 3 kW three-phase inverter in a MATLAB/Simulink environment. Results show that the proposed controller can successfully obtain the desired output when different linear and nonlinear loads are connected to the system. Furthermore, the inverter has reasonably low steady state error and fast response to reference variation
Multi-layer photovoltaic fault detection algorithm
This study proposes a fault detection algorithm based on the analysis of the theoretical curves which describe the behaviour of an existing grid-connected photovoltaic (GCPV) system. For a given set of working conditions, a number of attributes such as voltage ratio (VR) and power ratio (PR) are simulated using virtual instrumentation LabVIEW software. Furthermore, a third-order polynomial function is used to generate two detection limits (high and low limits) for the VR and PR ratios. The high and low detection limits are compared with real-time long-term data measurements from a 1.1 kWp GCPV system installed at the University of Huddersfield, United Kingdom. Furthermore, samples that lie out of the detecting limits are processed by a fuzzy logic classification system which consists of two inputs (VR and PR) and one output membership function. The obtained results show that the fault detection algorithm accurately detects different faults occurring in the PV system. The maximum detection accuracy (DA) of the proposed algorithm before considering the fuzzy logic system is equal to 95.27%; however, the fault DA is increased up to a minimum value of 98.8% after considering the fuzzy logic system
Possible Protective Anticancer effect of Ethanol Fraction of Iraqi Hibiscus Tiliaceus L. Leaves Extract on Diethylnitrosamine-induced Hepatocarcinogenesis in Male Rats
Abstract
Liver cancer with hepatocellular carcinoma a serious clinical illness that progresses quickly and has a bad prognosis because to increased malignancy. Fibrosis is the precursor of liver cancer, which progresses to cirrhosis and carcinoma Diethylnitrosamine (DEN) is a chemical molecule that has been used as a carcinogenic agent to promote cancer in test animals because of its strong carcinogenic potential. Herbal plants have long been used as inexpensive, effective alternatives to pharmaceuticals in various liver-associated complications, since they contain many bioactive compounds useful in liver disorders. Hibiscus tiliaceus L. (Malvaceae) contain various phytochemicals in the plant extracts such as Flavonoids, phenols, alkaloids, Tannins, Saponins, Quinones, Coumarine, Triterpenoids, glycosides and Steroids. Thus, has various health benefits, and have medicinal and therapeutic values, It could be a source of natural antioxidants, antimicrobials, hepatoprotective compounds, and antimutagenic effects.
The study was designed To study the possible protective role of Iraqi Hibiscus tiliaceus L. ethanol leaves extract administered in two different doses on diethylnitrosamine induced liver carcinoma in male Wistar Albino rats. Rats utilized in this study were randomized into 4 groups (six rats per each group); Group I: (Control) Rats were administered oral daily dose of 1ml /kg/day of distilled water for 20 weeks; Group II: rats intraperitoneally injected with 70 mg/kg diethyl nitrosamine once per week for 10 continuous weeks; Group III: Rats were administered 250mg/kg of Iraqi Hibiscus tiliaceus L. ethanol leaves extract as chronic oral administration with food for 5 days per week for 20 weeks and subsequently intraperitoneal dose of diethylnitrosamine (70 mg/kg) once per week for 10 continuous weeks; Groups IV: Rats were administered 500mg/kg of Hibiscus tiliaceus L. ethanol leaves extract as chronic oral administration with food for 5 days per week for 20 weeks with subsequently intraperitoneal dose of diethylnitrosamine (70 mg/kg) once per week for 10 continuous weeks. The finding revealed that Iraqi Hibiscus tiliaceus L. ethanol leaves extract showed significant reduction (P<0.05) in malondialdehyde, alpha fetoprotein (AFP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), total bilirubin (TSB), pro-inflammatory cytokines include transforming growth factor beta (TGFβ), tumor necrosis factor alpha (TNFα) and significant elevation (P<0.05) of anti-oxidant enzyme superoxide dismutase (SOD) in dose dependent manner. In conclusion this study demonstrated that the chemoprotective role of Hibiscus tiliaceus L. ethanol leaves extract might be explained by; lowered levels of hepatic enzymes, pro-inflammatory cytokines, and antioxidant levels, as well as decreased levels of alpha fetoprotein (AFP), the gold standard for detecting hepatocellular carcinoma
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