289 research outputs found

    Contingent Valuation Method: Valuing Cultural Heritage

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    Cultural heritage is not easy to be valued in a market because it is a very unique product which gives a community (ies), nation(s) an identity and a sense of belonging. Debate on the valuation of cultural heritage surrounds despite growing attention by economists and policy makers. The attention on the estimation of economic values for cultural goods and services has been great by economics throughout the past two decades (Choi, et al., 2009; Kaminski, McLoughlin, & Sodagar, 2007; Navrud & Ready, 2002, Noonan, 2003; Venkatachalam, 2004). The two stated preference methods which are commonly used in valuing non-use goods; i.e. contingent valuation method and choice modelling. Each of these two valuation method has its own strengths and weaknesses and may even complement each other depending on the parameters of the study. However, according to Kaminski et al., 2007; Noonan, 2003, the usage of choice modelling to estimate cultural values has been limited due to the growing usage of contingent valuation. Therefore, this paper will discuss contingent valuation method in valuing amenities and aim to contribute the knowledge on contingent valuation method for nonmarket goods. (Abstract by author

    Rayleigh-Benard Convection in Large-Aspect-Ratio Domains

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    The coarsening and wavenumber selection of striped states growing from random initial conditions are studied in a non-relaxational, spatially extended, and far-from-equilibrium system by performing large-scale numerical simulations of Rayleigh-B\'{e}nard convection in a large-aspect-ratio cylindrical domain with experimentally realistic boundaries. We find evidence that various measures of the coarsening dynamics scale in time with different power-law exponents, indicating that multiple length scales are required in describing the time dependent pattern evolution. The translational correlation length scales with time as t0.12t^{0.12}, the orientational correlation length scales as t0.54t^{0.54}, and the density of defects scale as t0.45t^{-0.45}. The final pattern evolves toward the wavenumber where isolated dislocations become motionless, suggesting a possible wavenumber selection mechanism for large-aspect-ratio convection.Comment: 5 pages, 6 figure

    Thermal Conductivity and Viscosity Of Al2o3 Nanofluids for Different Based Ratio of Water and Ethylene Glycol Mixture

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    In the thermal engineering applications, suspension of nanoparticles in conventional fluid has positive potential in enhancing the convective heat transfer performance. The evaluation of thermo-physical properties is essential to investigate the forced convection heat transfer of nanofluids. Hence, the present study reports the analysis on thermal conductivity and dynamic viscosity for Al2O3 nanoparticle dispersed in a different volume ratio of water (W) and ethylene glycol (EG) mixture. The Al2O3 nanofluids are formulated using the two-step method for three different base mixtures with volume ratio of 40:60, 50:50 and 60:40 (W:EG). The measurement of thermal conductivity and viscosity were performed using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV-III Rheometer; respectively for temperature from 30 to 70 °C and volume concentration of 0.2–1.0%. The average thermal conductivity enhancement of Al2O3 nanofluids in the three base ratios varied from 2.6 to 12.8%. The nanofluids have better enhancement as the percentage of ethylene glycol increases. Meanwhile, the average dynamic viscosity enhanced up to 50% for 60:40 (W:EG). The enhancement of viscosity for nanofluids decreased with the increment percentage of ethylene glycol. The properties enhancement of the Al2O3 nanofluids is significantly influenced by the concentration, temperature, and based ratio

    Therapeutic efficacy of intravenously administered transferrin-conjugated dendriplexes on prostate carcinomas

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    Aim: Improved treatments for prostate cancer are critically needed in order to overcome metastasis and lethal recurrence. Intravenously administered gene therapy would be an attractive anticancer treatment strategy; however, the lack of suitable carrier systems able to selectively deliver therapeutic genes to tumors has so far limited this investigation. Given that transferrin receptors are overexpressed on prostate cancer cells, the purpose of this study is to determine whether transferrin-conjugated dendriplexes encoding TNF-α, TNF-related apoptosis-inducing ligand and IL-12 would suppress the growth of prostate cancer cell lines in vitro and in vivo. Materials & methods: Transferrin-conjugated dendriplexes encoding TNF-α, TNF-related apoptosis-inducing ligand and IL-12 were intravenously administered to mice bearing subcutaneous PC-3 and DU145 tumors. Results: The administration of the transferrin-conjugated generation 3 diaminobutyric polypropylenimine dendriplex encoding TNF-α resulted in tumor suppression for 60% of PC-3 and 50% of DU145 prostate tumors. Conclusion: These dendriplexes hold great potential as a novel approach for prostate cancer therapy

    A review of concurrency control technique in distributed database

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    Concurrency is a process where multiple simultaneous transactions of data in database system perform. Due to this condition, the concurrency control method can help and avoid the data inconsistencies when the system is accessed by the user. This paper elaborately discusses the distributed database in the aspect of concurrency control techniques. This research reviews three algorithms; DSL, VGA, and SBA in terms of the waiting time, validation, performance, delay and also the number of message exchange. SBA shows the best performance among others. Meanwhile, a comparison between FBS and S2PL be done in order to measure the time of response in high and low-security level. In Addition, the fairness level of the system also been measured. It is shown that FBS shows an improving of time and positive result when dealing with a high-security level performance of the transaction. FBS also improved in terms of fairness at the different level of security

    Deep to shallow-marine sedimentology and impact of volcanism within the Middle Triassic Palaeo-Tethyan Semantan Basin, Singapore

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    The Middle Triassic Pulau Ayer Chawan Formation is a predominantly deep-marine, occasionally shallow-marine sedimentary succession, deposited in the Singapore sector of the Palaeo-Tethyan Semantan Basin. The formation provides an important record of the dynamic interplay between a siliciclastic sedimentary system and the products of an adjacent active volcanic arc. It is characterised by six sub-environments, including: deep-marine turbidite fan, deep-marine background sedimentation, subaqueous debris cone, shallow-marine, volcanically-sourced turbidite fan, and hyaloclastite mound or ridge. Turbidite fan deposits preserve the input of both siliciclastic and volcaniclastic sediments from the shelf, transported into the deep-marine environment by a suite of subaqueous sediment gravity flow processes, including: turbidity currents; mixed flow types (hybrid event beds); concentrated and hyper concentrated sediment gravity flows, and debris flows. Thick heterolithic successions of debrites were likely sourced through regular collapse of an unstable shelf. The presence of hybrid event beds, encountered within the deep-marine turbidite fans, supports a slope that was out-of-grade, and may have been actively retreating towards the hinterland. Together, these factors suggest regional-scale uplift of the eastern margins of the Semantan Basin during Triassic times, most likely facilitated through volcanic activity in the adjacent Palaeo-Tethys Sukhothai Arc. Evidence for contemporaneous, arc-related magmatism includes ubiquitous volcaniclastic sedimentary rocks within formation, including pyroclastic density current deposits and perhaps more-strikingly through the hyaloclastites of the Nanyang Member. The hyaloclastites formed through quenching of magmas delivered into the deep-marine setting from a series of sub-sea vents or mounds

    Antiviral activity of silymarin against chikungunya virus

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    Citation: Lani, R., Hassandarvish, P., Chiam, C. W., Moghaddam, E., Chu, J. J. H., Rausalu, K., . . . Zandi, K. (2015). Antiviral activity of silymarin against chikungunya virus. Scientific Reports, 5, 10. doi:10.1038/srep11421The mosquito-borne chikungunya virus (CHIKV) causes chikungunya fever, with clinical presentations such as severe back and small joint pain, and debilitating arthritis associated with crippling pains that persist for weeks and even years. Although there are several studies to evaluate the efficacy of drugs against CHIKV, the treatment for chikungunya fever is mainly symptom-based and no effective licensed vaccine or antiviral are available. Here, we investigated the antiviral activity of three types of flavonoids against CHIKV in vitro replication. Three compounds: silymarin, quercetin and kaempferol were evaluated for their in vitro antiviral activities against CHIKV using a CHIKV replicon cell line and clinical isolate of CHIKV of Central/East African genotype. A cytopathic effect inhibition assay was used to determine their activities on CHIKV viral replication and quantitative reverse transcription PCR was used to calculate virus yield. Antiviral activity of effective compound was further investigated by evaluation of CHIKV protein expression using western blotting for CHIKV nsP1, nsP3, and E2E1 proteins. Briefly, silymarin exhibited significant antiviral activity against CHIKV, reducing both CHIKV replication efficiency and down-regulating production of viral proteins involved in replication. This study may have important consequence for broaden the chance of getting the effective antiviral for CHIKV infection

    Paleozoic to Cenozoic sedimentary bedrock geology and lithostratigraphy of Singapore

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    A new lithostratigraphical framework for Singapore is proposed, based on the analysis of c. 20,000 m of core recovered from 121 c. 205 m deep boreholes and augmented with 218 field localities from across Singapore. The new framework describes a succession dating from the Carboniferous to the Quaternary. New U-Pb detrital zircon dates and fossil analysis were used to constrain the ages of key sedimentary units. The oldest known sedimentary rocks in Singapore are found to be the deformed Carboniferous (Mississippian) Sajahat Formation. These are succeeded by the newly erected, Middle and Upper Triassic, marine to continental Jurong Group and Sentosa Group successions that accumulated in the southern part of the Semantan Basin. The Jurong Group comprises four formations: the Tuas Formation, the Pulau Ayer Chawan Formation, the Pandan Formation and the Boon Lay Formation. The Sentosa Group contains two formations: the Tanjong Rimau Formation and the Fort Siloso Formation. In Singapore, the depositional record during this time is related to late Permian to Triassic arc magmatism in the southern part of the forearc basin to the Sukhothai Arc. The Jurong and Sentosa groups were deformed and weakly metamorphosed during the final stages of the Late Triassic to Early Jurassic orogenic event, deformation that led to the formation of the syn-orogenic conglomerates of the Buona Vista Formation. Following this, two distinct Lower Cretaceous sedimentary successions overstepped the Jurong and Sentosa group strata, including the Kusu Formation and the Bukit Batok Formation, both deposited in the southern part of the Tembeling Basin. A series of Neogene to Quaternary formations overly the Mesozoic and Palaeozoic stratigraphy, including the Fort Canning Formation, Bedok Formation and the Kallang Group

    Mean flow and spiral defect chaos in Rayleigh-Benard convection

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    We describe a numerical procedure to construct a modified velocity field that does not have any mean flow. Using this procedure, we present two results. Firstly, we show that, in the absence of mean flow, spiral defect chaos collapses to a stationary pattern comprising textures of stripes with angular bends. The quenched patterns are characterized by mean wavenumbers that approach those uniquely selected by focus-type singularities, which, in the absence of mean flow, lie at the zig-zag instability boundary. The quenched patterns also have larger correlation lengths and are comprised of rolls with less curvature. Secondly, we describe how mean flow can contribute to the commonly observed phenomenon of rolls terminating perpendicularly into lateral walls. We show that, in the absence of mean flow, rolls begin to terminate into lateral walls at an oblique angle. This obliqueness increases with Rayleigh number.Comment: 14 pages, 19 figure
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