Digital Commons Network^™

Virtual Teams And E-Entrepreneurship, Nader Ale Ebrahim

Nader Ale Ebrahim

The advent of the virtual teams has facilitated the emergence and formation of new companies within the Net Economy which called e-Entrepreneurship. The terms of e-Entrepreneurship and virtual teams still are new in the scholarly papers. Therefore, this introductory presentation focuses on different aspects of virtual teams and e-entrepreneurship.

Correct Spectral Conversion Between Surface‐Enhanced Raman And Plasmon Resonance Scattering From Nanoparticle Dimers For Single‐Molecule Detection, Kyuwan Lee

Kyuwan Lee

Simultaneous measurement of surface-enhanced Raman scattering (SERS) and localized surface plasmon resonance (LSPR) in nanoparticle dimers presents outstanding opportunities in molecular identification and in the elucidation of physical properties, such as the size, distance, and deformation of target species. SERS–LSPR instrumentation exists and has been used under limited conditions, but the extraction of SERS and LSPR readouts from a single measurement is still a challenge. Herein, the extraction of LSPR spectra from SERS signals is reported and a tool for measuring the interparticle distance from Raman enhancement data by the standardization of the SERS signal is proposed. The SERS nanoruler …

Bridge Design For Earthquake Fault Crossings: Synthesis Of Design Issues And Strategies, Rakesh K. Goel, Bing Qu, Osmar Rodriguez, Jennifer Tures

Rakesh K. Goel

As shown by the bridge damages observed from recent earthquakes, the bridges crossing earthquake faults can be more vulnerable compared with those lying on one side of the earthquake faults. Avoiding building bridges across earthquake fault zones might be the best design strategy; however, it is not always possible to do so in regions of high seismicity such as California. While rigorous nonlinear response history analysis (RHA) using the spatially-varying ground motions generated based on site-specific seismological studies can be conducted for bridges crossing fault ruptures; such a design and analysis process is too onerous, making it less practical for …

26 - تحليل تأثيرگذاري ميزان مقاومت حرارتي جداره و جهت جداره هاي نورگذر بر اندازه بهينه پنجره در اقليم تهران, Mona Khatami, Maria Kord-Jamshidi, Behrouz Mohamad Kari, Alireza Zolfaghari

Dr Alireza Zolfaghari

No abstract provided.

Ict For Poverty Alleviation In Pacific Island Nations: Study Of Icts4d In Fiji, Deogratias Harorimana, Opeti Rokotuinivono, Emali Sewale, Fane Salaiwai, Marica Naulu, Evangelin Roy

Dr Deogratias Harorimana

ICT for Poverty Alleviation in Pacific Island Nations: Study of ICTs4D in Fiji There has been a vague and little knowledge on the role or potential of Information and Communications Technologies (ICTs) in relation to addressing poverty in Fiji. This may be probably due to the newness of the technology in the South Pacific Region as a whole but also probably due to the fact that only 9.7% of the current Fiji 931,000 populations are internet users (ITC Figures 2011). This paper reports on finding how ICTs is contributing towards poverty alleviation in Fiji. On the basis of reviewed best …

25 - تحليل تأثيرات استفاده از عايقهاي تغيير فاز دهنده بر ميزان مصرف سالانه انرژي ساختمان در اقليم تهران, Alireza Zolfaghari, Mohamad Solhi, Mohamad Fathian, Hamed Moslehi, Mohamad Rahim-Pour, Mehran Sa'adati-Nasab

Dr Alireza Zolfaghari

No abstract provided.

Us Patent 8,338,976: Magnetically­-Levitated Wind Turbine, Sanza Kazadi

Sanza Kazadi

Short Term Wind Power Forecasting Using Autoregressive Integrated Moving Average Modeling, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Wind energy is one of the most promising electricity generating sources as a clean and free alternate compared with the conventional power plants and due to the volatility feature in the wind speeds it will reflect some problems in power systems reliability particularly if the system is deeply penetrated by wind farms. Therefore, Wind power forecasting issue became and is still an important scope that will help in economic dispatch (ED), unit commitment (UC) purposes to get more reliable and economic systems. This paper introduces short term wind power forecasting model, based on autoregressive integrated moving average (ARIMA) which will …

Analysis Of N-Nitrosamines In Water By Isotope Dilution Gas Chromatography-Electron Ionisation Tandem Mass Spectrometry, James A. Mcdonald, Nick B. Harden, Long Nghiem, Stuart J. Khan

Long D Nghiem

A method has been developed for the determination of eight N-nitrosamines in drinking water and treated municipal effluent. The method uses solid phase extraction (SPE), gas chromatography (GC) and analysis by tandem mass spectrometry (MS-MS) with electron ionization (EI). The target compounds are N-nitrosodimethylamine (NDMA), N-nitrosomethyethylamine (NMEA), N-nitrosodiethylamine NDEA), N-nitrosodipropylamine (NDPA), N-nitrosodi-n-butylamine (NDBuA), N-nitrosodiphenylamine (NDPhA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip), N-nitrosomorpholine (NMorph). The use of direct isotope analogues for isotope dilution analysis of all analytes ensures accurate quantification, accounting for analytical variabilities that may occur during sample processing, extraction and instrumental analysis. Method detection levels (MDLs) were determined to describe analyte …

Effects Of Membrane Fouling And Scaling On Boron Rejection By Nanofiltration And Reverse Osmosis Membranes, Kha Tu, Allan Chivas, Long Nghiem

Long D Nghiem

The effects of membrane fouling on the performance of nanofiltration and reverse osmosis membranes with respect to boron rejection and permeate flux were investigated in this study. A nanofiltration (NF270) membrane and a reverse osmosis (BW30) membrane were used in this investigation. Four typical membrane fouling conditions were simulated under controlled laboratory conditions in a cross-flow membrane system using four model foulants including humic acid, sodium alginate, colloidal silica and CaSO4. Amongst these model foulants, humic acid was found to increase boron rejection whereas the other foulants led to a decrease in boron rejection. Properties of foulants were found to …

Solar-Powered Compaction Garbage Bins In Public Areas: A Preliminary Economic And Environmental Evaluation, Poppy Coleman, Long Nghiem

Long D Nghiem

An excel-based model was developed to evaluate economic and environmental benefits of the solar-powered compaction garbage bins in public areas in Australia. Input data were collected from Brisbane and Wollongong City councils, and Sydney Olympic Park. The results demonstrate that solar-powered compaction garbage bins would provide environmental benefits in all scenarios. However, results of the economic analysis of the three studied areas varied significantly. The unique situation of Sydney Olympic Park made implementation in that facility particularly appealing. A lower monthly rental cost is needed for the implementation of this novel waste management practice.

Removal Of Micropollutants By Membrane Bioreactor Under Temperature Variation, Faisal I. Hai, Karin Tessmer, Luong N. Nguyen, Jinguo Kang, William E. Price, Long Nghiem

Long D Nghiem

The effects of controlled temperature variation in the range of 10–45 °C were assessed in a lab-scale MBR that treated synthetic municipal wastewater spiked with selected micropollutants. The effects were evaluated with respect to total organic carbon (TOC) and total nitrogen (TN) removal, micropollutant removal, sludge growth, level of soluble microbial products (SMPs) in the mixed liquor and membrane fouling. Overall, the temperature shifts caused high variation in the TOC and TN levels in the reactor supernatant, however that in membrane-permeate was relatively more stable, substantiating the robustness of the MBR process. Results regarding the removal of micropollutants at ambient …

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

Long D Nghiem

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 …

Long-Term Performance Of A Permeable Reactive Barrier In Acid Sulphate Soil Terrain, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem

Long D Nghiem

Deep drainage technique utilised for flood mitigation in low-land coastal areas of Australia during the late 1960s has resulted in the generation of sulphuric acid in soil by the oxidation of pyritic materials. Further degradation of the subsurface environment with widespread contamination of the underlying soil and groundwater presents a major and challenging environmental issue in acid sulphate soil (ASS) terrains. Although several ASS remediation techniques recently implemented in the floodplain of Southeast Australia including operation of gates, tidal buffering and lime injections could significantly control the pyrite oxidation, they could not improve the long-term water quality. More recently, permeable …

Geo-Environmental Approaches For The Remediation Of Acid Sulphate Soil In Low-Lying Floodplains, Buddhima Indraratna, Gyanendra Regmi, Long Nghiem, Alexandra N. Golab

Long D Nghiem

Acidity generated from the oxidation of pyrite and other sulphidic compounds that exist at shallow depths in acid sulphate soils (ASS) presents a challenging environmental problem in coastal Australia. The generated acidic groundwater can adversely impact coastal ecosystems, aquaculture and agriculture. Groundwater manipulation using weirs and modified floodgates in creeks and flood mitigation drains in ASS-affected farmland, which has been practiced for over a decade for preventing pyrite oxidation, is not effective in low-lying floodplains due to the high risk of flooding. In this paper, the authors present an overview of their experience in coastal Australia, a critical evaluation of …

Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem

Long D Nghiem

The removal of trace organics by a membrane bioreactor–granular activated carbon (MBR–GAC) integrated system were investigated. The results confirmed that MBR treatment can be effective for the removal of hydrophobic (logD > 3.2) and readily biodegradable trace organics. The data also highlighted the limitation of MBR in removing hydrophilic and persistent compounds (e.g. carbamazepine, diclofenac, and fenoprop) and that GAC could complement MBR very well as a post-treatment process. The MBR– GAC system showed high removal of all selected trace organics including those that are hydrophilic and persistent to biological degradation at up to 406 bed volumes (BV). However, over an …

Effects Of Membrane Fouling On N-Nitrosamine Rejection By Nanofiltration And Reverse Osmosis Membranes, Takahiro Fujioka, Stuart J. Khan, James A. Mcdonald, Rita K. Henderson, Yvan Poussade, Jorg E. Drewes, Long Nghiem

Long D Nghiem

The impact of fouling on N-nitrosamine rejection by nanofiltration (NF) and reverse osmosis (RO) membranes was investigated in this study. Membrane fouling was simulated using tertiary treated effluent and several model fouling solutions (that contained sodium alginate, bovine serum albumin, humic acid or colloidal silica) to elucidate the changes in rejection behaviour of N-nitrosamines. In general, the rejection of N-nitrosamines increased when the membranes were fouled by tertiary effluent. The rejection of small molecular weight N-nitrosamines was most affected by membrane fouling. In particular, the rejection of N-nitrosodimethylamine (NDMA) by the ESPA2 membrane increased from 34 to 73% after membrane …

Extraction And Transport Of Metal Ions And Small Organic Com#163s Using Polymer Inclusion Membranes (Pims), Long Nghiem, Patrick Mornane, Ian Potter, Jilska Perera, Robert Cattral, Spas Kolev

Long D Nghiem

The stability of polymer inclusion membranes (PIMs) relative to other liquid membranes is amongst the major reasons for the recent rejuvenation of interest in carrier-mediated transport for selective separation and recovery of metal ions as well as numerous organic solutes. This is reflected by an increasing number of PIM investigations reported in the literature over the last two decades. Given the outstanding performance of PIMs compared to other types of liquid membranes particularly in terms of membrane lifetime, it has been predicted that practical industrial applications of PIMs will be realized in the near future. This review provides a comprehensive …

Comparison Of The Removal Of Hydrophobic Trace Organic Contaminants By Forward Osmosis And Reverse Osmosis, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech

Long D Nghiem

We compared the rejection behaviours of three hydrophobic trace organic contaminants, bisphenol A, triclosan and diclofenac, in forward osmosis (FO) and reverse osmosis (RO). Using erythritol, xylose and glucose as inert reference organic solutes and the membrane pore transport model, the mean effective pore size of a commercial cellulose-based FO membrane was estimated to be 0.74 nm. When NaCl was used as the draw solute, at the same water permeate flux of 5.4 L/m2 h (or 1.5 mm/s), the adsorption of all three compounds to the membrane in the FO mode was consistently lower than that in the RO mode. …

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Long D Nghiem

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …

Pesticide Removal By A Mixed Culture Of Bacteria And White-Rot Fungi, Faisal I. Hai, Oska Modin, Kazuo Yamamoto, Kensuke Fukushi, Fumiyuki Nakajiam, Long Nghiem

Long D Nghiem

Combining activated sludge cultures with microbes harboring specific degradation pathways could constitute a relevant process for the removal of toxic and recalcitrant organic substances from wastewater. Enhanced removal of three widely used recalcitrant pesticides from their liquid mixture was demonstrated by implementing a non-acclimated mixed culture of bacteria and white-rot fungus. During an incubation period of 14 days, the mixed fungus–bacteria culture achieved 47, 98, and 62% removal of aldicarb, atrazine and alachlor from the liquid phase, respectively. This compared favorably to batches containing only non-acclimated fungus or previously published removal rates with nonacclimated bacterial cultures. Biosorption along with biodegradation …

Removal Of Carbamazepine And Sulfamethoxazole By Mbr Under Anoxic And Aerobic Conditions, Faisal I. Hai, Xueqing Li, William E. Price, Long Nghiem

Long D Nghiem

This study reveals for the first time that near-anoxic conditions (dissolved oxygen, DO - 0.5 mg/L) can be a favorable operating regime for the removal of the persistent micropollutant carbamazepine by MBR treatment. The removal efficiencies of carbamazepine and sulfamethoxazole by an MBR were systematically examined and compared under near-anoxic (DO'" 0.5 mg/L) and aerobic (DO> 2 mg/L) conditions. Preliminary batch tests confirmed that sulfamethoxazole is amenable to both aerobic and anoxic biotransformation. However, carbamazepine-a known persistent compound-showed degradation only under an anoxic environment. In good agreement with the batch tests, during near-anoxic operation, under a high loading of 750 …

Membrane Fouling In The Nanofiltration Of Landfill Leachate And Its Impact On Trace Contaminant Removal, Dirk Vogel, Bernd Bilitewski, Long Nghiem

Long D Nghiem

Landfilling is the most common municipal solid waste disposal method in Australia. During the decomposition of the deposited waste, leachate is generated mainly due to the seepage of stormwater through the landfill body.

Treatment Of Saline Aqueous Solutions Using Direct Contact Membrane Distillation, Long Nghiem, Florian Hildinger, Faisal I. Hai, Tzahi Cath

Long D Nghiem

The treatment of highly saline aqueous solutions using direct contact membrane distillation (DCMD) was evaluated in this study. Experiments were conducted using a flat sheet polytetrafluoroethylene membrane with nominal pore size of 0.22 µm. Seawater, reverse osmosis (RO) concentrate collected from a wastewater reclamation plant, and a synthetic solution containing 2,000 mg/L of CaSO4 were selected as the representative saline solutions. A gradual decline in permeate flux was observed at the beginning of the experiments when the seawater and RO concentrate solutions were treated using the DCMD process, most likely due to initial organic fouling and scaling. In contrast, when …

N-Nitrosamine Removal By Reverse Osmosis For Indirect Potable Water Reuse – A Critical Review Based On Observations From Laboratory, Pilot And Full-Scale Studies, Takahiro Fujioka, Stuart J. Khan, Yvan Poussade, Jorg E. Drewes, Long D. Nghiem

Long D Nghiem

N-nitrosodimethylamine (NDMA) and several other N-nitrosamines have been identified as probable human carcinogens. Here, we review key aspects related to the occurrence and removal of N-nitrosamines by reverse osmosis (RO) membranes in the context of indirect potable water reuse. A comprehensive analysis of the existing data reveals significant variations in the rejection of NDMA by RO membranes reported in the literature, ranging from negligible up to 86%. This review article provides some insight into the reasons for such variations by examining the available data on the effects of operating conditions on NDMA rejection. Amongst several operating parameters investigated so far …

Effects Of Operating Conditions On The Removal Of Trace Organic Contaminants By A Loose Nanofiltration Membrane, Long Nghiem, Stuart Khan

Long D Nghiem

In recent years, there has been considerable research effort focusing on the removal of specific individual contaminants at trace level concentrations instead of the traditional surrogate, and often ill-defined, water quality indicators. The need for this more precise water quality characterisation has been driven by stricter environmental regulations and legislation, and the increasing need to utilise non-traditional water resources including reclaimed municipal wastewaters. Amongst several advanced technologies used for high quality water treatment, removal of trace contaminants by nanofiltration membranes has been investigated to a considerable extent. However, it is known that such membrane filtration processes tend not to operate …

Performance Of A Prb For The Remediation Of Acidic Groundwater In Acid Sulfate Soil Terrain, Buddhima Indraratna, Gyanendra Regmi, Long Nghiem, A. Golab

Long D Nghiem

Contaminated groundwater resulting from pyrite oxidation of acid sulfate soils (ASSs) is a major environmental problem in coastal Australia. A column test was carried out for an extended period with recycled concrete to study the efficiency of the reactive materials for neutralizing acidic groundwater. Results show that the actual acid neutralization capacity of the recycled concrete could decrease to less than 50% of the theoretical value due to armoring effects. Nevertheless, the performance is good as a spot treatment in ASS Terrain using a near-zero cost waste product. Based on the test results and site characterization, a permeable reactive barrier …

Critical Risk Points Of Nanofiltration And Reverse Osmosis Processes In Water Recycling Applications, Long Nghiem, Andrea Schaefer

Long D Nghiem

NF/RO membrane filtration processes have been recognized as an important technology to facilitate water recycling. Those processes are well-proven technologies, which can be used to remove a wide range of contaminants including trace contaminants that are of particular concern in water recycling. However, risk implications in association with brine or concentrate and membrane cleaning wastewater disposal have to date not been adequately understood. This study examines the adsorption and release process of several endocrine-disrupting chemicals (EDCs) during NF/RO filtration processes. Results reported here indicate that the membrane can serve as a large reservoir for EDCs and their release may be …

Membrane Bioreactor Technology For Decentralised Wastewater Treatment, Nichanan Tadkaew, Long Nghiem, Muttucumaru Sivakumar

Long D Nghiem

Driven by stricter environmental regulations and legalisation on wastewater discharge and shrinking fresh water resources, water treatment has become an area of significant concern while at the same time there is a growing interest in utilising non-traditional water resources by means of water reclamation and water recycling.

Strategies To Enhance The Removal Of The Persistent Pharmaceutically Active Compound Carbamazepine By Membrane Bioreactors, Xueqing Li, Faisal I. Hai, Nichanan Tadkaew, Sara Gilbertson, Long Nghiem

Long D Nghiem

Carbamazepine, which is an anti-epileptic drug, is ubiquitously present in municipal wastewater. Owing to its recalcitrant chemical structure, carbamazepine is not significantly removed during conventional biological treatment or even by membrane bioreactor (MBR). With the ultimate aim of providing insights into the strategies to enhance carbamazepine removal, the effect of key operational parameters, namely, loading rate (2–750 μg/L• d), pH (5–9), mixed liquor suspended solids (MLSS) concentration (1–15 g/L) and dissolved oxygen (DO) (