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Full-Text Articles in Engineering

A Neural Network Approach To Predict The Performance Of Recycled Concrete Used In Permeable Reactive Barriers For The Treatment Of Acidic Groundwater, B Guruprasad, Buddhima Indraratna, Long Nghiem, G Regmi Dec 2012

A Neural Network Approach To Predict The Performance Of Recycled Concrete Used In Permeable Reactive Barriers For The Treatment Of Acidic Groundwater, B Guruprasad, Buddhima Indraratna, Long Nghiem, G Regmi

Long D Nghiem

This study developed a neural network model for examining the performance of recycled concrete for the treatment of acidic groundwater. Concentrations of Al, Fe and Ca and alkalinity of the effluent were selected as the output parameters to simulate the performance of recycled concrete for neutralizing acidic groundwater. The input variables were the number of pore volumes, pH, oxidation reduction potential and the average hydraulic conductivity. Of the 658 experimental datasets available, 409 datasets were used for training, 184 datasets were used for validation, and the remaining datasets were used for cross-validation. The reported results indicate that the neural model …


Treatment Of Acidic Groundwater In Acid Sulfate Soil Terrain Using Recycled Concrete: Column Experiments, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, A. Golab, B Guru Prasad Dec 2012

Treatment Of Acidic Groundwater In Acid Sulfate Soil Terrain Using Recycled Concrete: Column Experiments, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, A. Golab, B Guru Prasad

Long D Nghiem

Acidic groundwater generated from pyrite oxidation in acid sulfate (AS) soil is a major geoenvironmental problem in Australia. This study aims to evaluate recycled concrete as a reactive material in permeable reactive barriers (PRBs) for the remediation of acidic groundwater in low-lying AS soil floodplains. Laboratory experiments were systematically conducted to investigate the acid neutralization behavior of recycled concrete and its potential to remove dissolved Al and Fe. The results confirmed that recycled concrete could effectively treat acidic groundwater from an AS soil terrain, resulting in near neutral effluent over a long period with complete removal of Al and Fe. …


Armouring By Precipitates And The Associated Reduction In Hydraulic Conductivity Of Recycled Concrete Aggregates Used In A Novel Prb For The Treatment Of Acidic Groundwater, Punyama Pathirage, Buddhima Indraratna, Long Duc Nghiem, Laura Banasiak, Gyanendra Regmi Dec 2012

Armouring By Precipitates And The Associated Reduction In Hydraulic Conductivity Of Recycled Concrete Aggregates Used In A Novel Prb For The Treatment Of Acidic Groundwater, Punyama Pathirage, Buddhima Indraratna, Long Duc Nghiem, Laura Banasiak, Gyanendra Regmi

Long D Nghiem

Acidic groundwater generated from acid sulphate soil (ASS) is a major geo-environmental problem in Australia. A permeable reactive barrier (PRB) with recycled concrete aggregates as the reactive material has received considerable attention as an innovative, cost effective technology for passive treatment of acidic groundwater in ASS terrain. Laboratory column experiments conducted at the University of Wollongong investigated the acid neutralisation behaviour of recycled concrete and its potential to remove dissolved aluminium (Al) and iron (Fe). The recycled concrete effectively treated the acidic groundwater, resulting in near-neutral effluent pH and complete removal of Al and Fe. However, armouring of the concrete …


Static Flexural Behaviour Of Fly Ash-Based Geopolymer Composite Beam: An Alternative Railway Sleeper, Wahid Ferdous Jul 2012

Static Flexural Behaviour Of Fly Ash-Based Geopolymer Composite Beam: An Alternative Railway Sleeper, Wahid Ferdous

Wahid Ferdous

These days, the most commonly used materials for railway sleepers are timber, concrete and steel. High maintenance cost, installation issues, deterioration of materials, and environmental considerations are among the factors that prompt research and industry to seek a different and more efficient system. This research was undertaken with the aim of developing a material for sleepers which may overcome some of these problems. Through a comprehensive survey of the literature, it was decided to propose and investigate a sleeper system composed of fly ash-based geopolymer concrete and pultruded FRP profile composites. Although the engineering properties of fly ash-based geopolymer concrete …


Highly Linear, Wide-Dynamic-Range Multiple-Input Translinear Element Networks, Kofi Odame, Eric Mcdonald, Bradley Minch Jul 2012

Highly Linear, Wide-Dynamic-Range Multiple-Input Translinear Element Networks, Kofi Odame, Eric Mcdonald, Bradley Minch

Bradley Minch

In this paper, we propose a modification to the class of circuits known as multiple input translinear element (MITE) networks. Our proposed modification leads to a MITE network that is free from certain nonidealities encountered in previous implementations. Further, the new MITE network described here readily accommodates the use of bipolar junction transistors in the input and output stages, thus implying a significantly wider dynamic range than we can achieve using subthreshold MOSFETs.


Treatment Of Acidic Groundwater In Acid Sulfate Soil Terrain Using Recycled Concrete: Column Experiments, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, A. Golab, B Guru Prasad Dec 2011

Treatment Of Acidic Groundwater In Acid Sulfate Soil Terrain Using Recycled Concrete: Column Experiments, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, A. Golab, B Guru Prasad

Buddhima Indraratna

Acidic groundwater generated from pyrite oxidation in acid sulfate (AS) soil is a major geoenvironmental problem in Australia. This study aims to evaluate recycled concrete as a reactive material in permeable reactive barriers (PRBs) for the remediation of acidic groundwater in low-lying AS soil floodplains. Laboratory experiments were systematically conducted to investigate the acid neutralization behavior of recycled concrete and its potential to remove dissolved Al and Fe. The results confirmed that recycled concrete could effectively treat acidic groundwater from an AS soil terrain, resulting in near neutral effluent over a long period with complete removal of Al and Fe. …


Evaluating Waste Concrete For The Treatment Of Acid Sulphate Soil Groundwater From Coastal Floodplains, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, Laura Banasiak Dec 2011

Evaluating Waste Concrete For The Treatment Of Acid Sulphate Soil Groundwater From Coastal Floodplains, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, Laura Banasiak

Buddhima Indraratna

The treatment of acidic groundwater generated from acid sulphate soil (ASS) terrain is a challenging environmental issue in coastal floodplains of Australia. In this study, a laboratory column experiment was conducted to assess the performance of waste concrete for treating the acidic groundwater leachate from ASS terrain of the Shoalhaven region of NSW. The groundwater was highly acidic (pH of 2.5–3.5) and contained elevated concentrations of iron (10–90 mg/L) and aluminium (30–45 mg/L). Passage of the acidic groundwater through the column filled with waste concrete resulted in a significant improvement in water quality. Reduction in the concentration of iron and …


Strength Properties Of Hybrid Nylon-Steel And Polypropylene-Steel Fibre-Reinforced High Strength Concrete At Low Volume Fraction, Hilmi Mahmud Jan 2011

Strength Properties Of Hybrid Nylon-Steel And Polypropylene-Steel Fibre-Reinforced High Strength Concrete At Low Volume Fraction, Hilmi Mahmud

Hilmi Mahmud

The strength properties of hybrid nylon-steel fibre-reinforced concrete were investigated in comparison to that of polypropylene-steel fibre-reinforced concrete, at the same volume fraction (0.5%). The content of the high performance macro structure steel fibres is at 0.4% volume fraction, and the content of micro nylon and polypropylene-fibres is at 0.1% volume fraction. The experimental results show that the compressive strength and splitting tensile strengths and modulus of rupture (MOR) properties of the nylon-steel fibre concrete improved by 3.2, 8.3 and 10.2%, respectively, over those of the polypropylene-steel fibre concrete. On the impact resistance, the first-crack and failure strengths, and the …


A New Method Of Producing High Strength Oil Palm Shell Lightweight Concrete, Zamin Jumaat Dec 2010

A New Method Of Producing High Strength Oil Palm Shell Lightweight Concrete, Zamin Jumaat

Zamin Jumaat

This paper presents a new method to produce high strength lightweight aggregate concrete (HSLWAC) using an agricultural solid waste, namely oil palm shell (OPS). This method is based on crushing large old OPS. Crushed OPS are hard and have a strong physical bond with hydrated cement paste. The 28 and 56 days compressive strength achieved in this study were about 53 and 56 MPa, respectively. Furthermore, it was observed that it was possible to produce grade 30 OPS concrete without the addition of any cementitious materials. Compared to previous studies, significantly lower cement content was used to produce this grade …


An Innovative Concrete Practice Performance Measurement Towards Environmental Improvement In Malaysia, Hilmi Mahmud Jan 2010

An Innovative Concrete Practice Performance Measurement Towards Environmental Improvement In Malaysia, Hilmi Mahmud

Hilmi Mahmud

The environmental impact from the concrete construction industry is quite alarming. The industry is embarking into improving the concrete performance and exploring into alternative materials to reduce such impact. An area which is lacking is improvement in the quality of concrete practice itself. By having good concrete practice, a good quality concrete can be achieved. This paper proposed a performance measurement of concrete practice and applies the measurement to assess the quality of concrete practice for a concrete structure project in Malaysia. © 2010 IEEE.


Design Considerations For The Construction And Operation Of Flour Milling Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater Jun 2007

Design Considerations For The Construction And Operation Of Flour Milling Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater

Kurt A. Rosentrater

Flour milling facilities have been the cornerstone of agricultural processing for centuries. Like most agri-industrial production facilities, flour milling facilities have a number of unique design requirements. Design information, to date, has been limited. In an effort to summarize state of the art design procedures for flour milling facilities constructed in the United States, an overview of accepted standards and procedures has been assembled and discussed. With this paper engineers should become more familiar with specific design considerations for flour milling production facilities and develop appropriate references to expand their knowledge base. Educators may find this paper useful too.


Characterization Of Cement And Concrete Exposed To Laser Radiation At 10.6 Um, María Del Rosario Moreno-Virgen, Juan José Soto-Bernal, Claudio Frausto-Reyes, Adrian Bonilla-Petriciolet Jan 2006

Characterization Of Cement And Concrete Exposed To Laser Radiation At 10.6 Um, María Del Rosario Moreno-Virgen, Juan José Soto-Bernal, Claudio Frausto-Reyes, Adrian Bonilla-Petriciolet

Adrian Bonilla-Petriciolet

In this paper, we report preliminary results of molecular structural changes in cement and concrete caused by laser radiation at 10.6 um. One of those structural changes is the generation of glazes. At low laser powers, the glazes are small and lined up while at high powers, the glazes are bigger and randomly distributed. In the not exposed to laser radiation concrete, the Raman spectrum presents weak peaks at 200 cm-1, 550 cm-1, 700 cm-1, 750 cm-1 and 1 150 cm-1. However, these peaks are amplified by laser exposure and other peaks appear at 800 cm-1 and 1 050 cm-1. …


Design Considerations For The Construction And Operation Of Malting Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater Jul 2005

Design Considerations For The Construction And Operation Of Malting Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater

Kurt A. Rosentrater

Malt production facilities are the producers of ingredients for our baking, beverage, and specialty food industries. To date, information about the unique design requirements of these facilities has been limited. In an effort to summarize state of the art design procedures for malting facilities constructed in North America, an overview of accepted standards and procedures has been assembled. With this paper engineers should become more familiar with specific design considerations for malting plants and develop appropriate references to expand their knowledge base. Educators may find this paper useful too.


Design Considerations For The Construction And Operation Of Feed Milling Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater Aug 2004

Design Considerations For The Construction And Operation Of Feed Milling Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater

Kurt A. Rosentrater

Feed mills represent an important segment of our food production system, supplying the nutritional need for animals in our meat supply system. Agri-industrial facilities such as feed mills have a number of unique design requirements that are relatively unknown. The purpose of this paper is to summarize state of the art design procedures for feed milling facilities constructed in North America. To this end, in Part I of this series, planning, life safety, and structural design criteria for these facilities are examined and relevant theory is presented. Additional resources are cited for further study of concepts. This paper should be …


Design Considerations For The Construction And Operation Of Grain Elevator Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater Aug 2004

Design Considerations For The Construction And Operation Of Grain Elevator Facilities. Part I: Planning, Structural, And Life Safety Considerations, Gregory D. Williams, Kurt A. Rosentrater

Kurt A. Rosentrater

Grain elevators represent a major link our food production system. To date, information about the unique design requirements of these facilities has been limited. In an effort to summarize state of the art design procedures for grain elevator facilities constructed in North America, an overview of accepted standards and procedures has been assembled. With this paper engineers should become more familiar with specific design considerations for grain handling facilities and develop appropriate references to expand their knowledge base. Educators may find this paper useful too.