Tag Archives: Modeling

Review on Yield Gap Analysis: Modeling of Achievable Yields at Farm Level (Published)

In the present context, ‘model’ is expressed as a computer program that can be repeatedly run several times for computing several designed mathematical or statistical expressions (equations) governing crop growth-environment relations, given appropriate input data. The experiment station yields obtained under a rainfed situation without any nutrient deficiency mostly considered as the potential yields of rainfed crops. Actual yields are obtained by recording crop yields of farmers in the region under investigation and achievable yield is between actual and potential yield. Actual yields are compared with the potential yields to estimate yield gaps of crops for that area and others which have the same agro-ecology. Achievable yield is determined by factors like availability of moisture and nutrients, Precipitation and irrigation as input, Soil profile water holding characteristics, Plant water balance (transpiration, water uptake), Soil water balance (evaporation, infiltration, runoff, flow, drainage) and Nitrogen fertilizer applications as input, Soil nitrogen conditions, Plant nitrogen balance (uptake, fixation, mobilization), Soil nitrogen balance (mineralization, immobilization, nitrification, denitrification). Generally, modeling Achievable yield of farm depend on water and nutrient data of the area and Actual yield is determined by factors like weeds, insect pests, diseases and pollutants.

Keywords: Achievable yield and Farm level, Gap analysis, Modeling

Modeling and Simulation of shroud Ed Wind Turbines to work in Iraqi weather conditions (Published)

Citation: Rajaa Jarallah Abdul Rahman, and  Ahmed Khalid Ibrahim (2022) Modeling and Simulation of shroud Ed Wind Turbines to work in Iraqi weather conditions, European Journal of, Mechanical Engineering Research , Vol. 9, Issue 1, pp.1-11

This study provides an overview of renewable wind energy in Iraq and the possibility of deploying concentrated wind energy technologies to support power generation in agricultural fields. On horizontal wind turbines. The results showed that with the addition of the diffuser, the energy produced shows an increase, and the study also showed that the wind speed in Iraq reaches 8 m per second in the center and south of the country. The study presents wind energy activities in Iraq, and the Iraqi government’s attempts to use wind energy. Renewable energy in general, and wind energy in particular.

Keywords: Ed wind turbines, Iraqi, Modeling, Simulation, Weather, conditions

Impacts of the Use of Distance Education on Learning in Life and Earth Sciences (Published)

Unlike captive aquifers that are relatively protected by their impermeable roof, the Berrechid water table is very vulnerable to pollution from the ground surface. This pollution can be either localized (discharges of domestic and industrial wastewater, solid wastes leached by seepage water, either diffuse (Fertilizer application of soils, treatment of crops with plant protection products). This last mode of contamination presents the danger of being spread over large areas, and therefore of being difficult to control.To model the nitrate transport in the Berrechid aquifer, we used the MT3DMS model coupled with the hydrodynamic model previously created using MODFLOW; this in order to have a decision support tool for optimal management of the region’s groundwater resources.Various simplified water management scenarios are examined, in particular artificial recharge and reduction of pumped water volumes for irrigation. The results show that the halving of current withdrawals would improve the current situation of the Berrechid aquifer by avoiding the appearance of dewatering zones in 2025, with a considerable drop in nitrate concentrations in almost the entire aquifer. This model that we developed could thus be a useful tool for the management and protection of groundwater in the Berrechid aquifer.

Keywords: Berrechid, Groundwater, MODFLOW, MT3DMS, Modeling, Protection

Modeling of CO and PM2.5 Concentration Level in High Traffic Density Areas, Using Regression Model, (Published)

The study modeled air pollutants concentration level in selected high traffic density areas of Port Harcourt, Nigeria. It also investigated the factors that affect the concentration of air pollutants and the effects of vehicular density on the daytime, seasonal and annual patterns. This was with the view to ascertain the pattern of air pollutant concentrations in high traffic density areas of the city. Traffic records were taken at the designated locations by counting the number of vehicles passing through a point for two hours in the morning, afternoon and evening, using a close circuit television (Plate 5.1).  All the parameters were monitored in each location once every month (Monday to Friday) for two years (2016-2017). Data obtained were analyzed using ANOVA and multiple linear regressions, where appropriate. Results obtained revealed that the concentration of CO and PM2.5varied significantly (p < 0.05) between 2016 and 2017. Traffic volume was found to contribute significantly to the concentration of the air pollutants while meteorological factors such as temperature, humidity and wind speed had significant effects on their dispersion. The study concluded that significant relationship exists between the daytime pattern in vehicular volume and air pollutants concentration in the study area. Also, there was an increase in concentration of average air pollutants across the areas monitored between 2016 and 2017. The variation was attributed to increase in vehicular traffic volume. Furthermore, concentration of air pollutants varied at different degrees of temperature, humidity and wind speed. A model was developed to predict the concentration of CO and PM2.5 at various metrological factors and vehicular volume.

Keywords: Air pollutants, Modeling, Traffic, concentration level, vehicular volume

Mathematical Assessment of the Transmission Dynamics of HIV/AIDS with Treatment Effects (Published)

This article examines the transmission dynamics of HIV/AIDS with treatment effects. The total population ( ) was grouped into four compartments namely susceptible individuals at time t   ( ), infected humans at time t ( ), individuals on treatment at time t ( ), and the AIDS carriers at time t  ). A first order deterministic mathematical model for the case is formulated and analyzed to gain insight into the qualitative features of the local stability and disease free equilibrium which enable us to understand the  transmission dynamics of the disease. The numerical simulation of the model was carried out to investigate the sensitivity of some threshold parameters on spread rate of the disease. We also investigated  the impact of early detection of HIV cases and compliant behavior of patients on treatment. Our  results from numerical simulation and early detection of HIV case/ compliant behavior of patients on treatment show that early detection of HIV case and compliant behavior of patients on treatment reduce spread of the disease and minimize rate at which people develop AIDS.

Keywords: HIV/AIDS, Modeling, Transmission dynamics, Treatment., mathematical assessment

MODIFICATION OF EXISTING CULVERTS ON RIVER OMI USING HEC-RAS (Published)

HEC-RAS (Hydrologic Engineering Center’s River Analysis software) is a one-dimensional computer program that models the hydraulics of water flow through natural rivers and other channels [1]. It was used to modify the existing culverts on River Omi which in the past years and of recent has inundated its surroundings. The hydrological data was also measured and used as an input to the model. The model was used over MIKE11, flovial and other hydraulic mathematical model because of its high visual capability and complete output with detailed [2].
The results showed and confirmed that the existing culverts at the considered cross-sections could no longer accommodate the river’s discharge. A box-culvert spanning 7.2m with a rise of 1.8m will be adequate and economical to replace the existing ones. The existing wing wall was sufficient for the modified cross-section.

Keywords: Culverts, Flood, HEC-RAS, Modeling, River Omi

INTEGRATED SOLAR GREEN HOUSE FOR WATER DESALINATION AND PLANTATION IN REMOTE ARID EGYPTIAN COMMUNITIES: MODELING AND ANALYSIS (Published)

Solar desalination is considered as one of the promising renewable energy-powered technology for producing fresh water. The Seawater greenhouse (SWGH) system uses the solar desalination principle and works by saturating the air with moisture vaporizing from saline water inside a greenhouse and later dehumidifying, thus, causing freshwater condensation. The SWGH is a unique concept which combines natural processes, simple construction techniques to provide a low-cost solution to one of the world’s greatest needs-fresh water. It is a method of cultivation that provides desalination, cooling and humidification in an integrated system. Self-sufficiency in water production combined with low internal irrigation requirements mean that the SWGH offers significant water saving by reducing agricultural demand on main and groundwater. Its purpose is to provide a sustainable means of agriculture in arid coastal areas where the scarcity of freshwater and expense of desalination threaten the viability of agriculture.

Keywords: Analysis, Modeling, Solar Energy, arid communities, desalination, plantation

MODELING THE INDICES OF ORGANIZATIONAL AND MARKETING INNOVATIONS ADOPTED BY SMALL SCALE FLOUR AGRO- MARKETING FIRMS ABIA STATE, NIGERIA (Published)

A detailed analysis of the indices of organizational and marketing innovations has been examined in this study. The specific objectives duly analyzed were identification of the features of small scale flour marketing firms; analysis of the profitability and efficiency of the firms using income statement; ascertaining the determinants and indices of organizational, marketing and technological innovations. The technique of data collection was firstly a purposive sampling method to choose Aba and Umuahia Metropolis and small scale flour marketing firms and; secondly a random sampling selection technique was employed in selecting fifty specific firms for the study. The data elicited from sampling of fifty small scale flour marketing firms were analysed via descriptive statistics, income statement, probit and Ordinary Least Square Multiple regression analyses. The report from the results analyses showed that the significant indices of marketing innovation were price strategy, promotion strategy, distribution method, sales method, packaging and production strategies. On the other hand, significant indices of organizational innovation included work arrangement, quality management, motivation, use of promotion, product modification and employee schedule. The organizational innovation was highly significant than marketing innovation of small scale flour marketing firms in contributing towards enhancing the performance of small scale flour marketing firms. Thus, the organizational and marketing innovation indices analyzed in this work remained very significant and highly important tools for profitable marketing activity and in unlocking the marketing potentials of the firms and in encouraging competitive advantage over other firms that were indifferent about the strength of these organizational and marketing innovations. The study indicated that any small scale flour marketing firm that adopted for proper marketing and organizational innovations adapted successfully to emerging marketing challenges. Thus, it is recommended that small scale flour marketing firms should properly engage in organizational innovation involving work arrangement and effective employee work schedule which will contributing efficiently to better firm performance. Further, it is recommended that small scale flour marketing firms should include in their innovation portfolios price strategy, promotion strategy, distribution method, sales method, packaging, motivation, work arrangement, and product modification respectively which have the potentials to sustain the performance of the firms extensively.

Keywords: Determinants, Firm, Flour, Innovations, Marketing, Modeling, Organizational

Modeling Performance Characteristics of a Turbojet Engine (Published)

This work is an approach to analyze the performance of jet engine with an alternative flow control mechanism. The work analyzes the feasibility of a thrust control mechanism by regulating the flow at the engine inlet to increase the engine rpm for the same value. This approach adds value to the design process with the aim of increasing performance levels in the engine operation. The work is focused on performance charactristics of turbojet with reduced inlet pressure to the compressor engine. A real-time turbojet engine integrating aerothermodynamics of engine components, was developed, together with principles of jet propulsion and inter component volume dynamics represented in 1-D non-linear equations. Software program Simulink, a commercially available model based graphical block diagramming tool from MathWorks was used for dynamic modeling of the engine. The result shows that with increase in shaft rpm, pressure and temperature ratio values across the compressor-turbine assembly increases. Performance parameters of the engine are analyzed with the increase in compressor pressure ratio and shaft rpm.

Keywords: Modeling, Propulsive Efficiency, Specific Fuel Consumption, Specific Thrust, Thermal Efficiency, Turbojet