Salim Obeid, Kamal Nasreldin Abdalla, Yousef Al Horr
There is a need to control air temperature and humidity in humid regions, especially when fresh air is demanded. This study investigates the performance of a hybrid liquid desiccant (LD) air-conditioning system with a direct expansion (DX) evaporative cooler. Temperature, relative humidity, and power consumption were measured and reported using a wireless data-logging system at the air conditioning unit's key locations. The results showed that the hybrid unit reached a 34 % saving in the cooling load. In addition, the air hybrid liquid desiccant air-conditioning system with the direct expansion evaporative cooler saved about 32% in power consumption, compared to an uncooled desiccant air conditioning system that saved 23%.
{"title":"Hybrid liquid desiccant air-conditioning system with a direct expansion evaporative cooler","authors":"Salim Obeid, Kamal Nasreldin Abdalla, Yousef Al Horr","doi":"10.53332/kuej.v11i2.860","DOIUrl":"https://doi.org/10.53332/kuej.v11i2.860","url":null,"abstract":"There is a need to control air temperature and humidity in humid regions, especially when fresh air is demanded. This study investigates the performance of a hybrid liquid desiccant (LD) air-conditioning system with a direct expansion (DX) evaporative cooler. Temperature, relative humidity, and power consumption were measured and reported using a wireless data-logging system at the air conditioning unit's key locations. The results showed that the hybrid unit reached a 34 % saving in the cooling load. In addition, the air hybrid liquid desiccant air-conditioning system with the direct expansion evaporative cooler saved about 32% in power consumption, compared to an uncooled desiccant air conditioning system that saved 23%.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90808433","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}
E. Sharf, Qabas O.H. Khaleefa, Bouran A.H. Mohammed
This paper aims to study scouring and the recommended countermeasures for Al Manshiya Bridge, which is located in the Blue Nile in Khartoum city. The bridge was constructed in the year 2006, but in 2015; the east embankment approach of the bridge was exposed to scour causing failure of the approach deck slab. The paper follows the general procedure outlined by the Federal Highway Administration (FHWA) for stream stability, evaluating scour at bridges and countermeasures in order to have hydraulically safe bridge. Geomorphic and hydraulic factors affect the stream were studied; a scour analysis was made using Hydrologic Engineering Center - River Analysis System (HEC-RAS) software. To account for long-term, contraction, and local scour potential for the Peak flow event, HEC RAS model was used to construct quasi- unsteady sediment model. In order to protect the bridge, countermeasures for the bridge east abutment and channel adjacent to the bridge are studied, riprap around abutment and spur dikes were considered as the most suitable countermeasures.
{"title":"Evaluation: Screening, Analysis, and Countermeasures for Bridge Scour for AL-Manshia Bridge","authors":"E. Sharf, Qabas O.H. Khaleefa, Bouran A.H. Mohammed","doi":"10.53332/kuej.v11i2.701","DOIUrl":"https://doi.org/10.53332/kuej.v11i2.701","url":null,"abstract":"This paper aims to study scouring and the recommended countermeasures for Al Manshiya Bridge, which is located in the Blue Nile in Khartoum city. The bridge was constructed in the year 2006, but in 2015; the east embankment approach of the bridge was exposed to scour causing failure of the approach deck slab. The paper follows the general procedure outlined by the Federal Highway Administration (FHWA) for stream stability, evaluating scour at bridges and countermeasures in order to have hydraulically safe bridge. Geomorphic and hydraulic factors affect the stream were studied; a scour analysis was made using Hydrologic Engineering Center - River Analysis System (HEC-RAS) software. To account for long-term, contraction, and local scour potential for the Peak flow event, HEC RAS model was used to construct quasi- unsteady sediment model. In order to protect the bridge, countermeasures for the bridge east abutment and channel adjacent to the bridge are studied, riprap around abutment and spur dikes were considered as the most suitable countermeasures.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81882980","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}
Heavy metal is one of the major environmental and ecological problems in this world. The presence of heavy metals in water andwastewater causes toxic effects to the living beings and the environment. Compared to other heavy metals (such as Cr6+, Pb2+, Zn2+ etc.,) the presence of chromium in industrial effluents has become a major problem worldwide as hexavalent chromium is highly toxic to animals due to its ability to generate reactive oxygen species in cells. The excess amount of chromium affects the lungs and lead to respiratory disorders in the human beings. It also contaminates the soil and groundwater. Due to a large number of industries that generate hexavalent chromium in its effluents such as tanneries and electroplating industries, the chromium contamination in the wastewater and aqueous solutions exceeds the tolerance limits. Many remediation processes for removal of hexavalent chromium have been researched and reviewed extensively. Many methods are used to remove the chromium from the aqueous solutions and industrial effluents. This paper reviewed different remediation methods namely: the using of natural absorbent; the conventional chemical reduction method; the bio-absorbent method, nano-technology application; and other remediation methods. For each method, information about major parameters affecting theefficiency of removal of hexavalent chromium (Cr6+) from industrial effluent are stated. Brief discussion is included relating the different methods, in addition to some future aspects for the remediation process.
{"title":"Chromium (VI) Removal Methods from Effluents – A Review Article","authors":"N. Bashir","doi":"10.53332/kuej.v11i2.700","DOIUrl":"https://doi.org/10.53332/kuej.v11i2.700","url":null,"abstract":"Heavy metal is one of the major environmental and ecological problems in this world. The presence of heavy metals in water andwastewater causes toxic effects to the living beings and the environment. Compared to other heavy metals (such as Cr6+, Pb2+, Zn2+ etc.,) the presence of chromium in industrial effluents has become a major problem worldwide as hexavalent chromium is highly toxic to animals due to its ability to generate reactive oxygen species in cells. The excess amount of chromium affects the lungs and lead to respiratory disorders in the human beings. It also contaminates the soil and groundwater. Due to a large number of industries that generate hexavalent chromium in its effluents such as tanneries and electroplating industries, the chromium contamination in the wastewater and aqueous solutions exceeds the tolerance limits. Many remediation processes for removal of hexavalent chromium have been researched and reviewed extensively. Many methods are used to remove the chromium from the aqueous solutions and industrial effluents. This paper reviewed different remediation methods namely: the using of natural absorbent; the conventional chemical reduction method; the bio-absorbent method, nano-technology application; and other remediation methods. For each method, information about major parameters affecting theefficiency of removal of hexavalent chromium (Cr6+) from industrial effluent are stated. Brief discussion is included relating the different methods, in addition to some future aspects for the remediation process.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74015567","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}
Mortada. M. Abdulwahab, A. Suliman, Babiker M. Ahmed, Mohammed B. Elareefi, Ez Alarab E. Abd Elrahman, Ebraheem A. Arbab
In the traditional systems, detection of the faults in the electric lines is more difficult. Detection of faults takes time more than repairing time. In most cases faults or problems in power transmission lines occur due to environmental disturbance. Advanced monitoring system of overhead transmission lines assists in saving human lives and helps in maintenance planning. Tension and loosening are examples of problems that result in the absence of high quality monitoring system. The objective of this paper is to do continuous monitoring of the atmospheric conditions and the sag status in the power transmission lines. The design consist of a group of sensors (distance sensor, wind speed sensor, pressure sensor and deviation sensor), which are used to monitor the atmospheric conditions, and send the records to main controller. The controllers transmit these measured values through Wi-Fi to the web page and display them in the channel graph. The recorded resulting data can be shown in a digital form at any time by selecting any point in the graph. The system is built up by using internet of things (IoT) monitoring technique and global positioning system (GPS) technology to provide the location and guarantee wide range of covering area of the smart grid. The experimental results include the date, time and value and is shown in graphical form to help the manager to analyze the system faults easily. The obtained results were reliable and correct. The results satisfied the goals of the paper and reveal that the use of IoT monitoring system of the transmission lines enhanced the quality of the service.
{"title":"Monitoring System for Overhead Power Transmission Lines in Smart Grid System Using Internet of Things","authors":"Mortada. M. Abdulwahab, A. Suliman, Babiker M. Ahmed, Mohammed B. Elareefi, Ez Alarab E. Abd Elrahman, Ebraheem A. Arbab","doi":"10.53332/kuej.v11i2.703","DOIUrl":"https://doi.org/10.53332/kuej.v11i2.703","url":null,"abstract":"In the traditional systems, detection of the faults in the electric lines is more difficult. Detection of faults takes time more than repairing time. In most cases faults or problems in power transmission lines occur due to environmental disturbance. Advanced monitoring system of overhead transmission lines assists in saving human lives and helps in maintenance planning. Tension and loosening are examples of problems that result in the absence of high quality monitoring system. The objective of this paper is to do continuous monitoring of the atmospheric conditions and the sag status in the power transmission lines. The design consist of a group of sensors (distance sensor, wind speed sensor, pressure sensor and deviation sensor), which are used to monitor the atmospheric conditions, and send the records to main controller. The controllers transmit these measured values through Wi-Fi to the web page and display them in the channel graph. The recorded resulting data can be shown in a digital form at any time by selecting any point in the graph. The system is built up by using internet of things (IoT) monitoring technique and global positioning system (GPS) technology to provide the location and guarantee wide range of covering area of the smart grid. The experimental results include the date, time and value and is shown in graphical form to help the manager to analyze the system faults easily. The obtained results were reliable and correct. The results satisfied the goals of the paper and reveal that the use of IoT monitoring system of the transmission lines enhanced the quality of the service.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87782947","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}
Abdallah Tagalser Mohammed, A. Mustafa, Ashraf A. Osman
The Multiple Channel per Carrier (MCPC) is considered an efficient alternative when used in Ground Station (GS) TV channel stations as it accommodate multiple channel on a limited frequency range. The MCPC technique has been widely used worldwide due to its efficiency. The MCPC technique offers exemplary performance over the traditionally Single channel Per Carrier (SCPC) when considering system accuracy, time, and cost. In this study, the MCPC static mode technique has been investigated using MATLAB tool to simulate a four TV CH system. The GS transmitter and receiver components referenced to four explicit points representing the number of channels carried by the satellite. These components have been constructed and observed using Spectrum Analyzer.
{"title":"Design and Simulation of Ground Station (GS) Television Channel (TV CH) Group","authors":"Abdallah Tagalser Mohammed, A. Mustafa, Ashraf A. Osman","doi":"10.53332/kuej.v11i2.702","DOIUrl":"https://doi.org/10.53332/kuej.v11i2.702","url":null,"abstract":"The Multiple Channel per Carrier (MCPC) is considered an efficient alternative when used in Ground Station (GS) TV channel stations as it accommodate multiple channel on a limited frequency range. The MCPC technique has been widely used worldwide due to its efficiency. The MCPC technique offers exemplary performance over the traditionally Single channel Per Carrier (SCPC) when considering system accuracy, time, and cost. In this study, the MCPC static mode technique has been investigated using MATLAB tool to simulate a four TV CH system. The GS transmitter and receiver components referenced to four explicit points representing the number of channels carried by the satellite. These components have been constructed and observed using Spectrum Analyzer.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83307923","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}
The Zone and Energy Aware protocol based on the Ad hoc On demand Distance Vector (AODV) protocol (ZEA-AODV) provides a superior performance compared to the classic AODV protocol when number of nodes is less than 70 [1]. ZEA-AODV protocol is using location and energy information to reduce energy consumption and routing overhead. It is a combination of the two proposed protocols, Zone-aware AODV (Z-AODV) protocol and Energy-Balanced AODV (EB-AODV) protocol. In [1], we assumed that each host knows its current location precisely. In this paper, Global Positioning System (GPS) error is considered, therefore, the standard GPS error is modelled by generating two samples for movement of a terminal by simulation. One of the movements is as a simulation of the actual movement, and the other one as a simulation of the error. Then both movements are provided to the terminal. This GPS error modelling is considered in the case of ZEA-AODV protocol to investigate the effect of such error on its performance. Using the simulation, it is found that, although the overall performance of ZEA-AODV protocol is degraded when GPS error is considered, but energy conservation is noticeably still better than that of normal AODV protocol.
{"title":"Modelling and Analysis of GPS Error Effect on the Zone and Energy Aware-AODV (ZEA-AODV) Protocol","authors":"Enas Abdalla Elhaj, M. A. H. Abbas","doi":"10.53332/kuej.v11i1.149","DOIUrl":"https://doi.org/10.53332/kuej.v11i1.149","url":null,"abstract":"The Zone and Energy Aware protocol based on the Ad hoc On demand Distance Vector (AODV) protocol (ZEA-AODV) provides a superior performance compared to the classic AODV protocol when number of nodes is less than 70 [1]. ZEA-AODV protocol is using location and energy information to reduce energy consumption and routing overhead. It is a combination of the two proposed protocols, Zone-aware AODV (Z-AODV) protocol and Energy-Balanced AODV (EB-AODV) protocol. In [1], we assumed that each host knows its current location precisely. In this paper, Global Positioning System (GPS) error is considered, therefore, the standard GPS error is modelled by generating two samples for movement of a terminal by simulation. One of the movements is as a simulation of the actual movement, and the other one as a simulation of the error. Then both movements are provided to the terminal. This GPS error modelling is considered in the case of ZEA-AODV protocol to investigate the effect of such error on its performance. Using the simulation, it is found that, although the overall performance of ZEA-AODV protocol is degraded when GPS error is considered, but energy conservation is noticeably still better than that of normal AODV protocol.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73027064","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}
Mortada. M. Abdulwahab, Sahar Abd Elgader Babiker Zedan
Early detection of ionized radiation using intelligent technology will minimize the number of casualties when radiation disasters occur. The objective of this paper is to design sensors network using Raspberry pi technology able to detect any leakage of radiation. The design used the internet of things (IoT) to provide easy and safe monitoring in everywhere. This design calculates the radiation quantity in real time and provides both sound and LED alerts. Geiger-Mueller (GM) counter was used for sensing the ionizing radiation such as gamma rays. An application web was designed to ensure the facility of monitoring radiation everywhere. A daily report of radiation amount over the day can be obtained easily. Each radiation power level was represented by a set of LEDs with different colours. The structures contain sub-nodes, main node and raspberry pi node. XBEE used to connect between sub-nodes and the main node then Ethernet module is used to connect the main node to raspberry pi unit.
{"title":"Real Time Design of Wireless Sensor Network for Monitoring ionized Radiation using Raspberry Pi","authors":"Mortada. M. Abdulwahab, Sahar Abd Elgader Babiker Zedan","doi":"10.53332/kuej.v11i1.146","DOIUrl":"https://doi.org/10.53332/kuej.v11i1.146","url":null,"abstract":"Early detection of ionized radiation using intelligent technology will minimize the number of casualties when radiation disasters occur. The objective of this paper is to design sensors network using Raspberry pi technology able to detect any leakage of radiation. The design used the internet of things (IoT) to provide easy and safe monitoring in everywhere. This design calculates the radiation quantity in real time and provides both sound and LED alerts. Geiger-Mueller (GM) counter was used for sensing the ionizing radiation such as gamma rays. An application web was designed to ensure the facility of monitoring radiation everywhere. A daily report of radiation amount over the day can be obtained easily. Each radiation power level was represented by a set of LEDs with different colours. The structures contain sub-nodes, main node and raspberry pi node. XBEE used to connect between sub-nodes and the main node then Ethernet module is used to connect the main node to raspberry pi unit.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"472 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84764761","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}
This paper presents and discusses the experience gained through the application of base grouting technique applied for improving the capacity of large diameter bored piles foundation system for two heavily loaded bridge structures. Many large diameter bored piles were installed in Sinnar bridges project, Sudan and base treated by cement grout pumped at high pressures to preload the soil beneath their tips. The post construction operation was conveniently implemented for 106 bored piles of 1.5 to 2.0m diameter and 42 to 50m long utilizing equipments that are not sophisticated or expensive. The successful application of base grouting provided valuable insight into the technique’s merits over the currently practiced construction techniques such that the pile’s base capacity component is realized within service displacement limits. The study results indicate that base grouting can substantially improve the ultimate capacities by 2.15 to 2.62 times the values usually estimated for ungrouted bored piles of the same dimensions installed in similar soil conditions. From a foundation design viewpoint, safety factors much lower than those often used for ungrouted bored piles can be adopted for grouted piles of the same dimensions installed at a given site. Otherwise, the dimensions of grouted piles can be reduced whilst providing equivalent capacities as those of ungrouted piles with larger sizes. This will lead to a cost effective foundation design, improve the construction methodology and eventually enhance the overall performance of bored piles foundation when used in future projects.
{"title":"IMPROVING THE CAPACITY OF BORED PILES BY BASE GROUTING CASE STUDY; SINNAR BRIDGES PROJECT IN SUDAN","authors":"A. K. M. Zein","doi":"10.53332/kuej.v11i1.152","DOIUrl":"https://doi.org/10.53332/kuej.v11i1.152","url":null,"abstract":"This paper presents and discusses the experience gained through the application of base grouting technique applied for improving the capacity of large diameter bored piles foundation system for two heavily loaded bridge structures. Many large diameter bored piles were installed in Sinnar bridges project, Sudan and base treated by cement grout pumped at high pressures to preload the soil beneath their tips. The post construction operation was conveniently implemented for 106 bored piles of 1.5 to 2.0m diameter and 42 to 50m long utilizing equipments that are not sophisticated or expensive. The successful application of base grouting provided valuable insight into the technique’s merits over the currently practiced construction techniques such that the pile’s base capacity component is realized within service displacement limits. The study results indicate that base grouting can substantially improve the ultimate capacities by 2.15 to 2.62 times the values usually estimated for ungrouted bored piles of the same dimensions installed in similar soil conditions. From a foundation design viewpoint, safety factors much lower than those often used for ungrouted bored piles can be adopted for grouted piles of the same dimensions installed at a given site. Otherwise, the dimensions of grouted piles can be reduced whilst providing equivalent capacities as those of ungrouted piles with larger sizes. This will lead to a cost effective foundation design, improve the construction methodology and eventually enhance the overall performance of bored piles foundation when used in future projects.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75496264","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}
Mohaid Abbas, Khalid Awad, Alfatih Dirar, M. E. Abdalla, Abdelshakour A. Elkareem
Poly aluminum chloride (PAC) has many applications such as water treatment, separation of slurry in industrial processes. The basic raw material for PAC production is aluminum oxide ore such as Kaolin, Bauxite, Mica and Silliminite. In this study Kaolin was used and investigated carefully. Kaolin is abundant in the Sudan. The chemical composition is ,CaO, MgO, , L.O.I. For the production of liquid PAC, Kaolin was activated by calcination process to produce intermediate product (alumina,). Then the alumina extracted from calcined Kaolin was leached with hydrochloric acid to produce aluminum chloride. Finally base is added to aluminum chloride to produce PAC. The effects of the various parameters of production process (calcination temperature, acid concentration, residence time, ratio Kaolin-acid W/W) were investigated and the optimum conditions were found. The results showed that the optimum calcination temperature for the samples used, is 1000˚C with 3 hour residence time with alumina extract of 28.76 ppm .The optimum leaching conditions were determined and found at: Kaolin grain size, 200 meshes, Temperature, 90 ˚C, Residence Time 30 min, Acid concentration of 8N (HCL), which yielded 59.89 ppm of alum extract.
{"title":"Production of Poly Aluminum Chloride (PAC) from Local Material (Kaolin)","authors":"Mohaid Abbas, Khalid Awad, Alfatih Dirar, M. E. Abdalla, Abdelshakour A. Elkareem","doi":"10.53332/kuej.v11i1.150","DOIUrl":"https://doi.org/10.53332/kuej.v11i1.150","url":null,"abstract":"Poly aluminum chloride (PAC) has many applications such as water treatment, separation of slurry in industrial processes. The basic raw material for PAC production is aluminum oxide ore such as Kaolin, Bauxite, Mica and Silliminite. In this study Kaolin was used and investigated carefully. Kaolin is abundant in the Sudan. The chemical composition is ,CaO, MgO, , L.O.I. For the production of liquid PAC, Kaolin was activated by calcination process to produce intermediate product (alumina,). Then the alumina extracted from calcined Kaolin was leached with hydrochloric acid to produce aluminum chloride. Finally base is added to aluminum chloride to produce PAC. The effects of the various parameters of production process (calcination temperature, acid concentration, residence time, ratio Kaolin-acid W/W) were investigated and the optimum conditions were found. The results showed that the optimum calcination temperature for the samples used, is 1000˚C with 3 hour residence time with alumina extract of 28.76 ppm .The optimum leaching conditions were determined and found at: Kaolin grain size, 200 meshes, Temperature, 90 ˚C, Residence Time 30 min, Acid concentration of 8N (HCL), which yielded 59.89 ppm of alum extract.","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"426 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83561822","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}
This paper presents an experimental evaluation of transmission length in hollow core slabs against 18 suggested equations in some codes of practice in addition to some equations from the previous literature. The experimental transmission length was predicted at 95% average mean strain (95% AMS) by measuring changes in strain after wire cutting on the near concrete face using both electric strain gauge and demountable mechanical strain gauges (DEMEC). The ratio between the measured transmission length and the value predicted using codes of practice equations varied from 1.0 to 1.26. On the other hand, the variation was 0.59 to 1.97 for the equations from the previous literature. The experimental results also confirmed the previous findings of non-linear prestress transfer over the transmission zone
{"title":"Experimental evaluation of transmission length equations for pre-tensioned hollow core slabs","authors":"A. Abdelatif, Mujtaba M. Shanan","doi":"10.53332/kuej.v11i1.147","DOIUrl":"https://doi.org/10.53332/kuej.v11i1.147","url":null,"abstract":"This paper presents an experimental evaluation of transmission length in hollow core slabs against 18 suggested equations in some codes of practice in addition to some equations from the previous literature. The experimental transmission length was predicted at 95% average mean strain (95% AMS) by measuring changes in strain after wire cutting on the near concrete face using both electric strain gauge and demountable mechanical strain gauges (DEMEC). The ratio between the measured transmission length and the value predicted using codes of practice equations varied from 1.0 to 1.26. On the other hand, the variation was 0.59 to 1.97 for the equations from the previous literature. The experimental results also confirmed the previous findings of non-linear prestress transfer over the transmission zone","PeriodicalId":23461,"journal":{"name":"University of Khartoum Engineering Journal","volume":"654 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79013183","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}
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