University of Khartoum Engineering Journal最新文献_第4页

Laboratory Study of Steel Slag Used for Stabilizing Expansive Soil 钢渣稳定膨胀土的室内研究

University of Khartoum Engineering Journal Pub Date : 2022-10-31 DOI: 10.53332/kuej.v6i2.1002

Magdi M. E. Zumrawi, Alaa Abdel-Aziz Ali Babikir

引用次数: 1

Speed Control of Direct Current Motor via Pole Placement Control 采用极位控制的直流电机转速控制

University of Khartoum Engineering Journal Pub Date : 2022-10-31 DOI: 10.53332/kuej.v7i1.993

Sallah Eldeen M. A. Sharief, Ibrahim M. H. Sanhoury

引用次数: 0

Design and Simulation of Fuzzy Logic Controller for DSTATCOM in Power System 电力系统DSTATCOM模糊控制器的设计与仿真

University of Khartoum Engineering Journal Pub Date : 2022-10-31 DOI: 10.53332/kuej.v6i2.999

Awadalla Taifour Ali, Eisa Bashier M. Eltayeb, Rufidah M. Bakhit

引用次数: 0

Numerical Analysis of Deep Excavation 深基坑数值分析

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v9i2.965

Suliman B. A. Mohamed, Magdi M. E. Zumrawi

引用次数: 1

A Simple Staircase Modulation for A Cascaded H-bridge Multilevel Inverter 级联h桥多电平逆变器的简单阶梯调制

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v9i2.959

Othman Hassan Abdalla, Hesham Norallah, Ahmed Annhwi, Fawaz Fathi

引用次数: 3

Determination of Cooling Load for a Solar Cooled Building in Khartoum Using a Simulation Method 喀土穆某太阳能制冷建筑冷负荷的模拟确定

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v7i2.979

Kamal Nasreldin Abdalla, Elamin Ahmed Osman

{"title":"Determination of Cooling Load for a Solar Cooled Building in Khartoum Using a Simulation Method","authors":"Kamal Nasreldin Abdalla, Elamin Ahmed Osman","doi":"10.53332/kuej.v7i2.979","DOIUrl":"https://doi.org/10.53332/kuej.v7i2.979","url":null,"abstract":"Cooling load calculations are normally carried out assuming steady state conditions. This is a simple but conservative approach that leads to overestimation of the cooling capacity. For more accurate estimation of cooling loads, one has to take into account the thermal capacity of the walls and internal heat sources, which makes the problem more complicated. In this paper, the unsteady state heat transfer formulation has been used to determine the air conditioning cooling load for a building in Khartoum for a hot summer day. An explicit method was used to calculate the nodal temperatures at each time step of the thermal network. A simulation program was developed to calculate the cooling load at each time step. The building is cooled by absorption cooling system comprised mainly of an evacuated tube solar collector, a lithium bromide –water absorption air conditioner, a storage tank fitted with an auxiliary heater. A mathematical model is built to simulate the absorption cooling system for the solar cooled building and the results showed that the absorption system driven by solar energy from the evacuated tubes solar collector is enough to cover the cooling load demand by the building more than ten hours.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77064645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On The Integration and Evaluation of Vertical Control Information and Uncertainties in Leveling Networks Using Least Squares Modeling 基于最小二乘模型的水准网垂直控制信息与不确定性集成与评价

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v7i2.972

Gamal H. Seedahmed

{"title":"On The Integration and Evaluation of Vertical Control Information and Uncertainties in Leveling Networks Using Least Squares Modeling","authors":"Gamal H. Seedahmed","doi":"10.53332/kuej.v7i2.972","DOIUrl":"https://doi.org/10.53332/kuej.v7i2.972","url":null,"abstract":"Proper integration and evaluation of an existing vertical control information with the adjustment of a new leveling network require a stepwise approach that could reveal the hidden aspects of their uncertainties or stochastic properties. The general use of the control information as fixed quantities in the adjustment of the leveling networks is a major flaw. To this end, the fundamental concepts of least squares solutions offer a flexible and a rich framework for proper integration and modeling of control information and their uncertainty for new leveling networks. This paper provides a comprehensive review and analysis of a workflow that can be used to integrate and evaluate the existing control information or benchmarks to a new leveling network. In particular, this paper exploits three different approaches of least squares solutions to integrate and evaluate the stochastic properties of the existing control information and observations that belong to a new network. First, ordinary least squares solution, which constrained by Gauss-Markov model, was exploited to depict the normal practice of leveling networks adjustment in which the control information will be introduced as constant or fixed values. Second, least squares solution with pseudo observations was exploited for proper integration of control information and their stochastic properties. Third, free-network least squares solution was exploited as a mechanism to separate and quantify the stochastic properties of the observations from the ones that will be associated with the control information. Through the use of a numerical example, this paper offers some new perspectives and a detailed analysis that explains the interplay between the different aspects of least squares solutions for the integration and evaluation of vertical control information and their uncertainties with new leveling networks.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73050849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

AN EMPIRICAL APPROACH TO DESIGN A PIFA ANTENNA 一种设计pifa天线的经验方法

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v9i2.961

Sami M. Sharif, Iman D. Abdalla

{"title":"AN EMPIRICAL APPROACH TO DESIGN A PIFA ANTENNA","authors":"Sami M. Sharif, Iman D. Abdalla","doi":"10.53332/kuej.v9i2.961","DOIUrl":"https://doi.org/10.53332/kuej.v9i2.961","url":null,"abstract":"Abstract: A parametric study is performed on a Planar Inverted F Antenna (PIFA) that operates at the frequency of 900 MHz The effect of the variation of the parameters on the bandwidth (BW) is analyzed. The study is performed using the Finite Element Method (FEM) numerical technique and the High Frequency Structural Simulator (HFSS) software.Regression analysis is applied on the data obtained from the simulation to present a mathematical model that estimates the fractional bandwidth FBW. An empirical equation that predicts the FBW of the PIFA is introduced. The equation uses the effective designparameters; substrate material thickness and ground plane dimensions as predictors. A comparison between the results calculated by the equation and the results obtained via simulation is carried out for validation purposes. The results are found to be very close except for the values corresponding to substrate thicknesses above 6mm. Moreover, a second simulator using a different numerical technique is used for further verification.A PIFA that operates at the 900 MHz frequency is fabricated. The results obtained from the physical measurement are compared with the results calculated by the empirical equation and the results obtained from the simulation. Close compatibility is observed.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78403227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of Air Quality in Sudanese Gold Mining Fields 苏丹金矿田空气质量评价

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v9i2.957

Hunaida AbdElbage Abazar Ahmed, Kamal Eldin Eltayeb Yassin

{"title":"Evaluation of Air Quality in Sudanese Gold Mining Fields","authors":"Hunaida AbdElbage Abazar Ahmed, Kamal Eldin Eltayeb Yassin","doi":"10.53332/kuej.v9i2.957","DOIUrl":"https://doi.org/10.53332/kuej.v9i2.957","url":null,"abstract":"This study intended to provide a base line and describe the current air quality in Sudanese Gold mining fields. It covers 21 gold marketing centers in 5 states; namely Northern, River Nile, Gadaref, Red Sea and Kurdofan state. The main objectives of the survey is the detection of any significant concentrations that exceed Occupational Safety and Health norms and specifying the key emission sources, and also identification and assessing of the health hazards and environmental impacts. The tests were carried out by using electronic portable devices to measure the concentrations of pollutants in air. The measured pollutants were: Dust or Particulate Matter (PM), Nitrogen Dioxide (NO2), Volatile Organic Components (VOCs), Sulphur Dioxide (SO2), Ammonia (NH3), Carbon Monoxide (CO) and Ozone (O3). National Ambient Air Quality Standards (NAAQSs) and Sudanese Standards for Ambient Air Pollutants were used for comparison purposes. In addition to that, Air Quality Index (AQI) was applied for the average concentrations of each pollutant. It was found that, all gold marketing centers suffered from very high concentration of PM2.5 and PM10. 90.5% of those centers had higher NO2 concentration than the standards, 37% of it was increased by 200% and 42% of it was increased by 150%. In addition to that, 48% of gold marketing centers had higher SO2 concentration than the standards. On the other hand, concentrations of other pollutants obtained were found within the allowable limits. Finally, it was concluded that all those centers are contaminated with one or more air pollutants. Therefore, it was recommended to improve the environmental conditions by mitigating emissions from point sources. Supervisors have been advised to assume their responsibilities in controlling the use of Personal Protective Equipment (PPE) in addition to the dissemination of safety culture through psychological approach.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78092310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Automatic Extraction of Corner Points from Aerial Images Using Point-Feature Operators and Hough Transform 基于点特征算子和Hough变换的航空图像角点自动提取

University of Khartoum Engineering Journal Pub Date : 2022-10-23 DOI: 10.53332/kuej.v9i2.964

Mohamed Eltahir Idris, Gamal H. Seedahmed

{"title":"Automatic Extraction of Corner Points from Aerial Images Using Point-Feature Operators and Hough Transform","authors":"Mohamed Eltahir Idris, Gamal H. Seedahmed","doi":"10.53332/kuej.v9i2.964","DOIUrl":"https://doi.org/10.53332/kuej.v9i2.964","url":null,"abstract":"Low-level feature extraction such as lines and points (i.e. corners), forms a fundamental step in digital photogrammetry and other fields. They supply the inputs for the photogrammetric orientation procedures; and they serve as an intermediate input for other processes such as object recognition. With the accumulation of knowledge, the research community is in a better position to develop new generations of smart algorithms and solutions that possess a new level of maturity and understanding for the underlying challenges of automation. To this end, this paper presents an innovative approach for corner point extraction that combines the outputs from classical point feature operators with Hough Transform to generate a better hypothesis for a corner point that can be used for applications in urban areas. In particular, extracted point features were used to guide line extraction in a local neighbourhood by Hough Transform. Then the corner points that will be obtained from lines intersection in this local neighbourhood will be compared with their nearby ones that were extracted by point feature operators. Based on passing a set of criteria, the intersection points from lines will replace the point feature as aset of potential corner points. Experimental findings show promising results of the proposed approach that raises the confidence level of the extracted corners and eliminating outliers.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"110 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87677260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0