5,168 research outputs found

    In-Column Electrochemical Detection for Liquid Chromatography

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    This research focuses on the development of whole column detection (WCD) for liquid chromatography (LC). The WCD uses electrochemical techniques for detecting the analytes passing through the separation column. Electrode array for in-column electrochemical detection (ICED) is fabricated along the separation column to enable whole column separation monitoring and allow better understanding on the affinity of particular analyte to the stationary and mobile phases. Numerical models were built to understand the feasibility and differences of electrochemical detection within an unpacked and packed column. From the simulated results, the surface area of the electrode was not hindered by the presence of the particles in flow condition. An electrochemical microfluidic device has been successfully fabricated on PET (polyethylene terephthalate) substrate using the reverse imprinting technique. The photolithographically produced gold metal electrode lines were imprinted into the PET substrate using a blank mould and produced an inlaid electrode array with overall step residue within 40 nm. The semi-cured thermoset polyester channel was irreversibly thermal bonded on the PET substrate. The devices were able to tolerate pressure in excess of 90 bars. The PET column was packed with 5 μm C18 silica beads to perform reverse phase chromatography separation. The array was electrochemically characterised using standard redox probes in both stagnant conditions and under flow. Both numerical modelling and experimental data show improved sensitivity under flow and a limiting current which scaled linearly with cubic root of volume flow rate. Isocratic and gradient mode chromatographic separations of neurotransmitters and metabolites: serotonin, dopamine, adrenaline, 5- HIAA and DOPAC were conducted in the fabricated device. Separation progress was electrochemically detected at multiple locations along the column. Whole column assessment on separation efficiency and column packing efficiency monitoring were conducted using the ICED

    The numerical operator method to the real time dynamics of currents through the nanostructures with different topologies

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    We present the numerical operator method designed for the real time dynamics of currents through nanostructures beyond the linear response regime. We apply this method to the transient and stationary currents through nanostructures with different topologies, e.g., the flakes of square and honeycomb lattices. We find a quasi-stationary stage with a life proportional to the flake size in the transient currents through the square flakes, but this quasi-stationary stage is destroyed in the presence of disorder. However, there is no quasi-stationary stage in the transient currents through the honeycomb flakes, showing that the transient current depends strongly upon the topologies of the nanostructures. We also study the stationary current by taking the limit of the current at long times. We find that the stationary current through a square flake increases smoothly as the voltage bias increasing. In contrast, we find a threshold voltage in the current-voltage curve through a honeycomb flake, indicating a gap at the Fermi energy of a honeycomb flake.Comment: 13 pages, 4 figure

    Digital or Diligent? Web 2.0's challenge to formal schooling

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    This paper explores the tensions that arise for young people as both 'digital kids' and 'diligent students'. It does so by drawing on a study conducted in an elite private school, where the tensions between 'going digital' and 'being diligent' are exacerbated by the high value the school places on academic achievement, and on learning through digital innovation. At the school under study, high levels of intellectual and technological resourcing bring with them an equally high level of expectation to excel in traditional academic tasks and high-stakes assessment. The students, under constant pressure to perform well in standardised tests, need to make decisions about the extent to which they take up school-sanctioned digitally enhanced learning opportunities that do not explicitly address academic performance. The paper examines this conundrum by investigating student preparedness to engage with a new learning innovation – a student-led media centre – in the context of the traditional pedagogical culture that is relatively untouched by such digital innovation. The paper presents an analysis of findings from a survey of 481 students in the school. The survey results were subjected to quantitative regression tree modelling to flesh out how different student learning dispositions, social and technological factors influence the extent to which students engage with a specific digital learning opportunity in the form of the Web 2.0 Student Media Centre (SMC) designed to engage the senior school community in flexible digital-networked learning. What emerges from the study is that peer support, perceived ease of use and usefulness, learning goals and cognitive playfulness are significant predictors of the choices that students make to negotiate the fundamental tensions of being digital and/or diligent. In scrutinising the tensions around a digital or a diligent student identity in this way, the paper contributes new empirical evidence to understanding the problematic relationship between student-led learning using new digital media tools and formal schooling

    Receptiveness Of E-Banking By Malaysian Consumers

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    Evolusi menuju era Internet dan perbankan Internet telah menjadi transformasi paling asas dilalui oleh industri perbankan sehingga kini. Industri perbankan sedang mengalami perubahan yang pesat ekoran perkembangan teknologi maklumat dan komunikasi. Kajian tentang penerimaan perbankan Internet oleh individu amatlah berkurangan. Oleh itu, satu kajian patut dijalankan untuk memahami faktor mempengaruhi keinginan individu dalam penggunaan perbankan Internet. The evolution into the Internet and Internet banking era is set to be the most fundamental transformation that the industry would have ever had to undergo. Malaysia banking industries is undergoing rapid transition due to developments in information technology and telecommunications. There is little research on Internet banking adoption by individuals. Therefore, it is timely to conduct a research to understand individuals' intention to use Internet banking in Malaysia

    E-Commerce Catalogue Application For EON (Edaran Otomobil Nasional)

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    The purpose of this project is to develop a prototype e-commerce catalogue application for EON (Edaran Otomobil Nasional). The EON web page provides online customization and ordering of cars services to customers. The cars available are Proton Waja, Proton Perdana V6, Proton Wira Sedan and Proton Iswara. Other services include on-line booking of time to service cars, information about the cars such as prices, model specifications, pictures of cars etc, links to other homepages such as financial institution, insurance companies and second hand Proton cars dealers. There is also information about the EON sales branches and EON services centers throughout Malaysia. The business module of EON web page consiss of four main funtional modules. They are the view information module, online customization and ordering module, on-line booking module and advertisement module. This project uses the Web Page Development Methodology (WPD) as the development methodology. Finally, this project discusses some flaws, constraints and recommendations for future development

    E-MAIL WRITING PROJECTS IN AN EFL CONTEXT: FROMLINGUISTIC AND ATTITUDINAL PERSPECTIVES

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    A great number of benefits have been claimed in a Computer-Mediated Communication (CMC) context; however, little research has been conducted by the method of discourse analysis. The purpose of this study is to, through discourse analysis, unfold and uncover EFL learners’ underlying feelings about e-mail writing and their writing styles. The participants were thirty-four Applied English-majored college students, writing e-mail to their peers for five times. Based on the data collected from the learners’ e-mail and reflection discourse, the results showed that the majority (88.24%) had positive attitudes towards e-mail writing. Besides positive feelings about this writing project, the learners presented highly active participation in writing e-mail to their peers. Through the e-mail writing project, they not only had more opportunities to use the target language, but also supported each other to deal with academic and personal difficulties. Furthermore, their e-mail writing style had also been analyzed. Through the analysis, it was claimed that EFL learners also used repeated letters, punctuation marks, emoticons, and special features in the e-mail writing. Implications of these findings for future studies are proposed to be of help to those who would like to apply e-mail writing to an EFL context.  Article visualizations

    Surfactants in Enhanced Oil Recovery

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    Petroleum provides the main energy supply to the world. Within the past 30 years, crude oil price has been increasing due to the ever-increasing demand for more energy resources. This has given way to recover more oil from existing resources as primary and secondary recovery can only recover one-third of the Original-Oil-in-Place (OOIP). Enhanced oil recovery (EOR) implies oil recovery beyond the conventional recovery stages of primary or secondary recovery. The title of this report is Surfactants in Enhanced Oil Recovery, the main objective of the project is to evaluate commercially available surfactant products for their potential as wettability modifier and interfacial tension reducer by performing spontaneous imbibition test on cores. Other objectives include literature review on current EOR initiatives and opportunities in Malaysia and design of spontaneous imbibition cell. A total of 8 preliminary screening tests and 6 second stage test has been conducted to screen 6 commercially available surfactants. The experimental work done has proven that certain surfactants can increase the recovery of oil by altering the wettability from water wet to oil. With the addition of alkali, the recovery factor is higher. Recommendations for future work include conducting the experiments at real reservoir temperature for higher accuracy results and using chemical systems with different concentrations of surfactants diluted with different solvent to compare the best system for highest recovery of oil. The first part of the report gives the background studies of the project with a brief overview of Malaysia oil and gas industry and EOR status in Malaysia. First part also includes problem statement and objectives of the project. Second part of the report detailed on the literature review on mechanisms involve in chemical EOR and chemistry of surfactants as a potential wettability modifier and interfacial tension reducer. Third part of the report focus on the experimental work, the experimental procedure, equipments and chemicals used, design of imbibition cell and discussions of the results obtained. The recommendations and conclusions are made in the last part of the report

    ASSESSING REGIONAL CLIMATE AND LOCAL LANDCOVER IMPACTS ON VEGETATION WITH REMOTE SENSING

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    Landcover change alters not only the surface landscape but also regional carbon and water cycling. The objective of this study was to assess the potential impacts of landcover change across the Kansas River Basin (KRB) by comparing local microclimatic impacts and regional scale climate influences. This was done using a 25-year time series of Normalized Difference Vegetation Index (NDVI) and precipitation (PPT) data analyzed using multi-resolution information theory metrics. Results showed both entropy of PPT and NDVI varied along a pronounced PPT gradient. The scalewise relative entropy of NDVI was the most informative at the annual scale, while for PPT the scalewise relative entropy varied temporally and by landcover type. The relative entropy of NDVI and PPT as a function of landcover showed the most information at the 512-day scale for all landcover types, implying different landcover types had the same response across the entire KRB. This implies that land use decisions may dramatically alter the local time scales of responses to global climate change. Additionally, altering land cover (e.g., for biofuel production) may impact ecosystem functioning at local to regional scales and these impacts must be considered for accurately assessing future implications of climate change
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