Permeable reactive barrier for groundwater remediation

This article aims to provide an overview of the upcoming technology of permeable reactive barriers for groundwater remediation. A comprehensive list of references and web-links are also provided for further in-depth understanding. A brief discussion on the Australian perspective on this emerging technology is also included.     

Computer-based spelling remediation for dyslexic children

Abstract The SelfSpell programs provide a multi-media environment for dyslexic children which uses synthesised speech to augment the written text. In earlier research we established that by encouraging users to enter a rule to help them remember how to spell each word, SelfSpell was very effective in improving spelling ability. The evaluation study reported here confirmed the efficacy of the rule-based approach using a group of 11-year-old dyslexic children with severe impairments in spelling. Of particular theoretical significance, however, was the finding that use of a mastery learning technique for learning spellings was just as effective as the rule-based approach. These findings are interpreted in the light of Frith's influential framework for the development of reading and spelling ability. It is suggested that the multimedia presentation approach may provide a uniquely effective method for helping dyslexic children to acquire the 'alphabetic' stage of linguistic processing.     

Environmental assessment of an uncontrolled sanitary landfill,Pocos de Caldas,Brazil

There are more than 20,000 uncontrolled sanitary landfill areas in Brazil. The paper reports an integrated study undertaken to develop an environmental assessment of the uncontrolled sanitary landfill area of the city of Po?os de Caldas, State of Minas Gerais, Brazil. A number of remedial alternatives were evaluated. The USGS modular 3D finite difference groundwater flow model (Modflow) and Modular 3D Finite Difference Mass Transport Model (MT3D) software were used to simulate groundwater flow and contaminant transport modelling, as well as to predict changes due to the proposed remediation measures. The remedial alternatives considered for normal conditions from 20 to 40 year periods were waste removal, vertical cut-off barriers, extraction wells and top capping. The results indicated that extraction wells and waste removal are the best alternatives because they significantly reduce both the extension and levels of the contamination plume even after 5 years. The extraction well proved a less expensive remedial alternative than waste removal.      

A comparative study of trends of nitrate,chloride and phosphate concentration levels in selected urban rivers

Concerns for the river environment in Malaysia are highlighted. There had been occurrences of inadequate supply for water in big cities and unexpected floods over the last few years. This paper discussed and compared the results of efforts to clean-up Gombak River which passes through several industrial areas and the City of Kuala Lumpur and Penchala River which passes through the industrial areas and the neighboring City of Petaling Jaya. The trends in the levels of nitrates, chlorides and phosphates present in the rivers were analyzed. Over the period of thirteen years from 1997 to 2009, results of efforts which included public participation, engineering and river works and strict statutory regulations by government had shown success in improving the river water quality. Continued efforts from stakeholders must be harnessed to enhance the health of the Gombak River and the Penchala River.     

Hybridizing food cultures in computer-mediated environments: Creativity and improvisation in Greek food blogs

This paper focuses on the ways in which food blogs influence the evolution of food cultures in computer-mediated environments. Food blogs provide a unique setting in which to study individual creativity and improvisation, as they make everyday food practices visible, pubic and transmittable. This paper proposes a cultural framework of human–computer interaction (HCI) and applies it to the context of food blogging. It stresses the effects of remediation on hybridisation of disciplines, roles and practices, which in turn lead to individual creative practices in the form of bricolage. Three case studies of Greek food blogs abroad are analysed to illustrate the proposed framework and to develop research implications for human–food interaction (HFI).     

改进的预应力锚索模拟方法及数值验证

通过考虑预应力锚索锚固体的抗弯能力,改善数值模拟中预应力锚索的加同效果,以改变大型边坡锚索群加固效果被严重低估的现状,数值试验结果表明,在下一步开挖前,考虑抗弯能力的锚索与不考虑抗弯能力的锚索模型的作用效果完全一致,在下一步开挖后,两种锚索的作用效果出现明显差异,考虑抗弯效果的锚索单元对边坡塑性区、最小主应力的降低及边坡位移的约束效果更加明显。     

Treatment of Groundwater Contaminated with 1,4-Dioxane,Tetrahydrofuran, and Chlorinated Volatile Organic Compounds Using Advanced Oxidation Processes

Ozonation and four types of advanced oxidation processes, including O₃/H₂O₂, O₃/UV, O₃/H₂O₂/UV, and UV/H₂O₂, were evaluated for the treatment of contaminated groundwater at a Superfund site in Simpsonville, South Carolina using bench-scale, batch ozone and UV apparatuses. Although the contaminants of concern were 1,4-dioxane, 1,1-dichloroethene, and trichloroethene, several other chlorinated organics as well as tetrahydrofuran were found in the groundwater samples. The O₃/H₂O₂ treatment with O₃ and H₂O₂ doses of 6 and 1.5 mg/L, respectively, and the UV/H₂O₂ treatment with UV and H₂O₂ doses of 1,000 mJ/cm and 20 mg/L, respectively, were sufficient to degrade 200 µg/L of 1,4-dioxane, 110 µg/L of 1,1-dichloroethene, and 10 µg/L of trichloroethene below their performance standards of 10, 7, and 4 µg/L, respectively. Due to a high bromide concentration (0.35 mg/L) in the groundwater sample, bromate formation was found to be significant in ozone-based treatment, including O₃/H₂O₂.     

岩土工程勘察阶段的污染地基土调查

2009年修订版<岩土工程勘察规范>所做的最大修订,即为对污染地基土调查部分的修订.新修订给出了污染地基土调查的一般指导原则.污染地基土的环境调查涉及多学科的综合应用,一般岩土工程勘察单位还不具备进行污染地基土调查及对调查结果评价的能力,也不具备进行修复治理方案设计和实施的能力.本文结合实际污染地基土的调查、评价及治理...     

Mechanics of Oil Sands Slurry Flow in a Flexible Pipeline System

Slurry transportation is an economic haulage system in oil sands and coal-mining operations characterized by long haulage distances and rugged terrain. In such conditions, the ton-km-hr limits are exceeded creating extreme tire wear and high maintenance costs. Steep haul grades and rugged terrain also cause mechanical wear and tear, which decrease haulage equipment economic life. Hydraulic transportation is a proven and viable technology for slurry transportation in such conditions. Currently, stationary pipeline transportation is being used in transporting minerals in many mines. There is an increasing demand to create slurrified minerals at the mining faces to be transported to the processing plant. However, stationary pipelines are not capable for dealing with the rapidly changing configuration of the mining faces. In this paper, the authors develop the ground articulating pipeline (GAP) technology to address this problem. The GAP system consists of pipelines connected together with flexible joints in each pipe section, which allows deflection to avoid torsional stresses from the adjoining frames. This flexible arrangement accommodates the horizontal and vertical displacements of the mobile system as it follows the hydraulic shovels in the excavation process. The mechanics of the GAP system, as well as the production–economic function, are formulated and simulated over an extended period using data and information from Syncrude’s North Mine. The results show that the GAP system is technically and economically viable for productivity between 6,300 and 6,500 tons per hour. The simulated head loss for the GAP system is 15.66 m per 400 m, which compares with 20 m per 400 m for the existing stationary system at Syncrude. The pressure gradient-radius curves are asymptotic to the pipe boundaries, which indicates steep axial pressure gradient in these areas.