8,531 research outputs found

    A survey of e-book awareness and usage amongst students in an academic library

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    This paper reports on an online survey of e-book awareness and usage level in a British academic library. The main objectives of this survey were to: (a) assess students' awareness of the availability of e-books in their academic library; (b) measure the level of e-book usage among the students; and (c) identify the reasons why students do or don't use e-books. A self-selected sampling method was employed to generate a sample of students consisting of undergraduate and postgraduate instructional students registered with the University of Strathclyde for academic year 2005/6. An announcement email was posted to the student web portal for a period of three weeks inviting them to participate in the survey. A total of 1372 of responses were returned representing just under 10% response rate. In general, this survey found that e-book awareness was low as was the level of e-book usage amongst the students: 57% of students were not aware of the availability of e-books from the library and 60% of them had not used an e-book. Non-users commented that e-books were not widely advertised or promoted which has most probably contributed to this lack of awareness and non usage. Despite the low levels of e-book awareness and usage, non e-book users indicated their desire to learn more about e-books

    Segmented phase of ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites

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    Segmented thermoset polymeric materials properties mainly classified through its carbonyl hydrogen bonding. The addition of graphite particle loading in polymeric materials tailored the functional characteristic of the composites. Therefore, the carbonyl hydrogen bonding in the hard segments of the synthesized segmented ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites was identified. This composites based green polymer incorporated with varying graphite particles loading were prepared through slip casting method which cure upon UV light. These result in an enhancement of the carbonyl hydrogen bonding which tribute to degree of phase separation (DPS %) in the TPU-G composites ranged from 10-20%, as compared to that in the pure TPU. In addition, the spectroscopy detects the formation of carbonyl hydrogen groups within the TPU-G composites although they are prone to chain scission and undergo photo oxidation subjected to ultraviolet (UV) curing. Upon UV curing, higher graphite weight loading (TPU-G20, TPU-G25 and TPU-G30 composites), shows higher and stable DPS% value, attribute to soft segment- soft segment and hard segment- hard segment establishment. Therefore, the graphite particles dominantly absorb the incident radiation instead of thermoset polyurethane without changing its based

    A Comparison of Real Estate Marketing Systems: Theory and Evidence

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    The objective of this paper is twofold. One is to provide a search-theoretical model of the marketing choice of the seller. The model explains the seemingly contradictory empirical results as to whether a seller raises the price of his house to pass on a portion of the broker's commission to the buyer. The second is to offer empirical evidence on the impact of the MLS on the price. We control for selectivity bias in the data and obtain a surprising result that the decision to use a multiple listing service decreases the sale price of a property.

    Green tea polyphenol-reduced graphene oxide: derivatisation, reduction efficiency, reduction mechanism and cytotoxicity

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    This paper reports on the derivatisation, reduction efficiency, reduction mechanism and cytotoxicity of green tea polyphenol-reduced graphene oxide (GTP-RGO). The reduction of graphene oxide (GO) at 90°C using a weight ratio (WR) of GTP/GO=1 resulted in the production of a stable GTP-RGO dispersion in aqueous media, as indicated by the results of ultravioletvisible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and the measurement of zeta potential and electrophoretic mobility. In addition, the results from UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis indicated the comparable reduction ability of GTP relative to the standard reducing agent, hydrazine (N2H4). The removal mechanism of epoxy group from GO via reduction reaction with GTP was investigated by implementing hybrid functional method of Becke-3-parameters-Lee-Yang-Parr (B3LYP)using Gaussian 09 software. The energy and frequency calculations showed that the GO reduction using GTP was more spontaneous and relatively took place faster than the reduction using N2H4, as evidenced by higher entropy change (ΔS) (0.039 kcal/mol·K) and lower Gibbs free energy (ΔG) barrier (58.880 kcal/mol).The cytotoxicities of GO and GTP-RGO samples were evaluated against human colonic fibroblasts cells (CCD-18Co). The GO sample was determined to be toxic even at low concentration (6.25 μg/mL), while the GTP-RGO sample possesses notably low toxicity at the same concentration. The cell culture experiments revealed that the incorporation of GTP led to a decrease in the toxicity of GTP-RGO samples
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