APPLICATION OF HOMOTOPY PERTURBATION METHOD TO THE MATHEMATICAL MODELLING OF TEMPERATURE RISE DURING MICROWAVE HYPERTHERMIA

We study a one dimensional non-linear model of multi-layered human skin exposed to microwave heating during cancer therapy. The model is analyzed using homotopy perturbation method and the fact that there are variations in specific heat, thermal conductivity and blood perfusion from one individual to another were considered. The purpose of this study was to investigate the effect of variable blood perfusion, microwave heating and thermal conductivity on the temperature field during microwave hyperthermia. By varying the parameters, we were able to determine maximum rise of temperature as an individual undergoes cancer therapy. The results were presented in graphs and it was discovered that the temperature of the tumor increases with increase in the microwave heating index while the blood perfusion remain constant.

All optical half subtractor based on threshold switching and beams interference mechanisms

In this paper, ultra-fast, compact and high contrast ratio all optical half subtractor based on photonic crystal designed and simulated. The proposed design will be constructed using both threshold switching and interference of beams mechanisms. The proposed structure is composed of six waveguides and a nonlinear ring resonator. The simulation results show that the contrast ratio for D and B ports were obtained about 18.80 and 15.05 dB, respectively. Also the maximum rise, fall and steady-state times and total footprint for suggested all optical half subtractor are 0.5, 0.25, 1.5 ps and 234 μm2, respectively.

Experimental Investigation on Effects Accumulator Initial Pressure, Pump Displacement and Vehicle Speed on Regeneration Efficiency of the Hydraulic Regenerative Braking System

Recently researchers are focus on evaluation of hydraulic regenerative braking systems for improving fuel economy and reducing pollutant emissions. Present work is oriented to study effects of variation in vehicle speed at braking, accumulator initial pressure and pump displacement on regeneration efficiency of hydraulic regenerative braking system (HRBS) on the school van conveyance in Vadodara city. The results show that the HRBS regeneration efficiency improves between 1.7 to 10% with reduction in initial pressure from 110 to 90bar. Increase in pump displacement from 16 LPM to 23 LPM results in rise in regeneration efficiency of the HRBS between2.6 to 16.7%. While increasing initial speed at braking from 20 to 35 KMPH, regeneration efficiency of the HRBS system rises by 48%. This is the maximum rise in regeneration efficiency while varying the initial braking speed.

On the Feasibility of Surface-Film Lubricated Cold Rolling Without Liquid-Phase Cooling

This tech brief presents some basic theory and calculations to help assess the feasibility of surface-film lubricated dry skin pass of metal strips to enhance surface finish after cold-rolling operations. Results are presented of the required rate of heat removal from the rolling apparatus and the maximum rise of roll surface temperature for steel and aluminum strips under various parametric conditions of practical interest. The theory and the calculation tool may be used to perform analyses with other material, geometry, and operating parameters and to assist the design and development of surface-film lubricated dry skin-pass processes.

Assessment of the Performance for a Hybrid PV / Solar Chimney

In this study, we assessed the performance of a new design of the solar chimney by merging the collector through integrated solar panel by using a solar cell as a glass roof. Assessment of the performance of this new design is the main purpose of this study. Experimental work conducted at Kirkuk (35.46 oN, 44.39 oE) northern Iraq. The experiments conducted during the summer season. A hybrid solar chimney consisting of a solar panel cover replaces the glass cover in the conventional solar chimney. Different instruments used to measure temperature, air velocity, electric current and voltage of solar panel. An experimental model was built to anticipate the performance of a hybrid chimney.It has been shown, that there is an increase in the temperature of the PV panel from the beginning of the day with increased of the incident solar radiation values. It is observed that the angle (45) is the best angle for the energy production. Also, it is noted that (45-panel angle) gives the highest efficiency to this system of the three angles that have been measured (30°, 35°, 45°). The results showed the efficiency of the PV/ solar chimney ranges from 8 % to 13 %. The maximum rise of the air temperature in the solar collector it is found to be 2–3 oC on a typical day.

Hovering Control of Quadrotor Based on Fuzzy Logic

Quadrotor is one of rotary wing UAV types which is able to perform a hover position. In order to take off, landing, and hover, it needs controllers. Conventional controllers have been widely applied in quadrotor, yet they have drawbacks namely overshoot. This paper presents attitude and altitude control algorithm in order to obtain a response as quadrotor hovered optimally within minimum overshoot, rise time, and settling time. The algorithm used is Fuzzy Logic Controller (FLC) algorithm with Mamdani method. By using the algorithm, the quadrotor is able to hover with minimum overshoot and maximum rise time. The advantage of the algorithm is that it does not require linearization model of the quadrotor.

POTENTIAL OF TURMERIC EXTRACT AND ITS FRACTIONS TO CONTROL PEACH FRUIT FLY (DIPTERA: TEPHRITIDAE)

ABSTRACT Potential of turmeric extract and its chemical fractions were evaluated to control the infestation of Bactrocera zonata peach fruit fly in a mortality-based bioassay. The turmeric extract (TE) was taken on Soxhelt's extraction apparatus and chemically fractioned by thin layer followed by column chromatography into 6 fractions (F1 ...F6). Fifty pairs of the flies were fed in cages with 250 and 500 ppm TE and its fractions separately for 20 days along with flies fed on untreated diet to serve as control. The toxicity of TE and each of its fractions was evaluated by calculating percent mortality of fly population after every 5th day in 4 consecutive intervals. Mortality of fly population was observed to be positively correlated with increasing concentrations of TE and its fractions in diet. The mortality of flies fed at 250 and 500 ppm TE was significantly higher at 44.17 and 66.33% compared to 28.88% in control. Percent mortality was much higher in case of flies fed with fractions F1, F3 and F6 i.e. 72.22, 50.00 and 48.76 respectively. Maximum rise of mortality was observed at the end of 3rd interval; in case of flies fed at 500 ppm TE, 52.45 percent mortality was observed at the end of 3rd interval; highest mortality was caused by fraction F1, 51.39% in case of flies fed at 250 ppm and 70.37% in case of those fed at 500 ppm.

Key Parameters Simulation and Design of Natural Gas Engine Based on Diesel

In the paper, the natural gas engine (NGE)model based on AVL BOOST software is built and simulated. The simulation value and experiment value coincide, showing that the NGE model is correct and reasonable. On this basis, the model has been used to analyze the effect of the key parameters, such as compression ratio, ignition advance angle, valve timing, supercharging ratio on the engine power, maximum combustion pressure, exhaust temperature, the maximum rise rate of pressure. Combined with the relevant theories of engine, the value ranges of the key parameters can be designed. The research achievement is valuable in the development and optimization matching of the NGE.

Negatively buoyant projectiles – from weak fountains to heavy vortices

An experimental investigation to establish the maximum rise height zm attained by a finite volume of fluid forced impulsively vertically upwards against its buoyancy into quiescent surroundings of uniform density is described. In the absence of a density contrast, the release propagates as a vortex ring and the vertical trajectory is limited by viscous effects. On increasing the source density of the release, gravitational effects limit the trajectory and a maximum rise height zm is reached. For these negatively buoyant releases, the dependence of zm on the length L of the column of ejected fluid, nozzle diameter D (= 2r0), dispensing time and source reduced gravity is determined by injecting saline solution into a fresh-water environment. For 3.4 ≲ L/D ≲ 9.0, zm/r0 is shown to scale on the source parameter η = Fr(L/D), a product of the source Froude number Fr and the aspect ratio L/D for the finite-volume release. Our results show that the morphology of the cap that develops above the source and the vortical motion induced within are sensitively dependent on the source conditions. Moreover, three rise-height regimes are identified: ‘weak-fountain-transition’, ‘vorticity-development’ and ‘forced-release’ regimes, each with a distinct morphology and dependence of dimensionless rise height on η.

Endothermic and exothermic chemically reacting plumes

We develop a model for a turbulent plume in an unbounded ambient that takes into account a general exothermic or endothermic chemical reaction. These reactions can have an important effect on the plume dynamics since the entrainment rate, which scales with the vertical velocity, will be a function of the heat release or absorption. Specifically, we examine a second-order non-reversible reaction, where one species is present in the plume from a pure source and the other is in the environment. For uniform ambient density and species fields the reaction has an important effect on the deviation from pure plume behaviour as defined by the source parameter Γ. In the case of an exothermic reaction the density difference between the plume and the reference density increases and the plume is ‘lazy’, whereas for an endothermic reaction this difference decreases and the plume is more jet-like. Furthermore, for chemical and density-stratified environments, the reaction will have an important effect on the buoyancy flux because the entrainment rate will not necessarily decrease with distance from the source, as in traditional models. As a result, the maximum rise height of the plume for exothermic reactions may actually decrease with reaction rate if this occurs in a region of high ambient density. In addition, we investigate non-Boussinesq effects, which are important when the heat of reaction is large enough.