67 research outputs found

    Holographic Screening Length in a Hot Plasma of Two Sphere

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    We study the screening length of a quark-antiquark pair moving in a hot plasma living in two sphere S2S^2 manifold using AdS/CFT correspondence where the background metric is four dimensional Schwarzschild-AdS black hole. The geodesic solution of the string ends at the boundary is given by a stationary motion in the equatorial plane as such the separation length LL of quark-antiquark pair is parallel to the angular velocity ω\omega. The screening length and the bound energy are computed numerically using Mathematica. We find that the plots are bounded from below by some functions related to the momentum transfer PcP_c of the drag force configuration. We compare the result by computing the screening length in the quark-antiquark reference frame where the gravity dual are "Boost-AdS" and Kerr-AdS black holes. Finding relations of the parameters of both black holes, we argue that the relation between mass parameters MSchM_{Sch} of the Schwarzschild-AdS black hole and MKerrM_{Kerr} of the Kerr-AdS black hole in high temperature is given by MKerr=MSch(1a2l2)3/2M_{Kerr}=M_{Sch}(1-a^2l^2)^{3/2}, where aa is the angular momentum parameter.Comment: Major revision: title changed, adding authors, 13 pages, 8 figures, etc. Accepted for publication in European Physical Journal

    The prediction of moment of inertia of rotating nuclei

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    In this paper the mathematical expression which is given by Bohr for the moment of inertia of even - even nuclei on the basis of the hydrodynamical model is modified. This modification is on the kinetic energy of the surface oscillations including the second and third terms of R- expansion as well as the first term which was already carried out by Bohr. Therefore, this work can be considered the continuation and support of the hydrodynamic model of Bohr. This procedure results in a Bohr formula to be multiplied by a factor which depends on the deformation parameter. Bohr (modified) formula is examined by applying it on axially symmetric even-even nuclei with atomic mass ranged between 150 and 190 as well as to some triaxial symmetry nuclei. The modification of Bohr's formula are discussed including the information on how stable this modification with including second and third terms of R- expansion of Bohr's formula. The results of calculation are compared with the experimental data and the results of Bohr, based earlier. The obtained results are in a good agreement with experimental data by describing almost 0.7 and better than that of the unmodified ones

    Rearward visibility assessment and a proposed performance scoring for ASEAN NCAP

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    Asia has the highest number of registered motorcycles globally and the recent data has shown that motorcycles fatalities has been the major accident and death cases in ASEAN Region. One of the major concerns is the visibility of motorcycles to other vehicles on the road. Thus, in this project, ECE R46 and FMVSS regulations have been referred as the base guidelines to establish a novel test protocols for vehicles rearward visibility assessment. Sixteen cars have been benchmarked and analysed in term of their rear-view mirror (Class I) and external mirror (Class III) performance. Motorcycles visibility to the vehicles’ Class I and Class III mirrors also been assessed by converting the measured data into number of motorcycles based on its width. A proposed performance scoring system for ASEAN NCAP has been developed based on that to address the Motorcycle Safety pillar

    Internet of Things Applications in Precision Agriculture: A Review

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    The goal of this paper is to review the implementation of an Internet of Things (IoT)-based system in the precision agriculture sector. Each year, farmers suffer enormous losses as a result of insect infestations and a lack of equipment to manage the farm effectively. The selected article summarises the recommended systematic equipment and approach for implementing an IoT in smart farming. This review's purpose is to identify and discuss the significant devices, cloud platforms, communication protocols, and data processing methodologies. This review highlights an updated technology for agricultural smart management by revising every area, such as crop field data and application utilization. By customizing their technology spending decisions, agriculture stakeholders can better protect the environment and increase food production in a way that meets future global demand. Last but not least, the contribution of this research is that the use of IoT in the agricultural sector helps to improve sensing and monitoring of production, including farm resource usage, animal behavior, crop growth, and food processing. Also, it provides a better understanding of the individual agricultural circumstances, such as environmental and weather conditions, the growth of weeds, pests, and diseases

    Influence of burrow holes in residual soil slope infiltration

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    Infiltration rate is important factors in the rainfall induced slope failure. The infiltration of water into residual soil was govern by rainfall intensity and also saturated permeability of soil. The existing of burrow holes has proven increases the permeability of the soil with increase in number of burrow holes. Therefore, it is very important to study the effect of burrow holes in residual soil slope and its effect in infiltration rate. The modified constant head permeability was done to study effect of burrow holes in residual soil. Then, the infiltration test was done to study the infiltration rate of residual soil with existing of burrow holes. The result from modified permeability shows that permeability of residual soil increases from 5 x 10-7 m/s to 1.14 x 10-3 m/s for different area of burrow holes. The result from infiltration test proven that when q/ksat greater than 1 the runoff was occurs. Meanwhile, when q/ksat less than 1 infiltration was occurs. The result also indicates that the smaller ratio between of resq/ksat, the faster the infiltration of water into the soil. Ngee Leh, F.L.

    Pairing as an instructional strategy to promote soft skills amongst clinical dental students

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    Training dentists today is challenging as they are expected to provide a wide range of dental care. In the provision of good dental care, soft skills are equally important as clinical skills. Therefore in dental education the development of soft skills are of prime concern. This study sought to identify the development of soft skills when dental students are paired in their clinical training. In this perception study, four open-ended items were used to elicit students’ feedback on the appropriateness of using clinical pairing as an instructional strategy to promote soft skills. The most frequently cited soft skills were teamwork (70%) and communication (25%) skills. However, both negative and positive behaviours were reported. As for critical thinking and problem solving skills, more positive behaviours were reported for abilities such as to explain, analyze, find ideas and alternative solutions, and make decisions. Leadership among peers was not evident as leading without legitimate authority could be a hindrance to its development. If clinical pairing is to be used as an effective instructional strategy to promote soft skills amongst students, clear guidelines need to be developed to prepare students to work in a dental team and the use of appropriate assessment tools can facilitate the development of these soft skills

    Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

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    <p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr<sup>III</sup>(HIDA)(IDA)(H<sub>2</sub>O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO<sub>4</sub><sup>-</sup>] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr<sup>III</sup>(IDA)(Val)(H<sub>2</sub>O)<sub>2</sub>] and [Cr<sup>III</sup>(IDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3 </sub>(1.82 × 10<sup>-3 </sup>s<sup>-1</sup>), is greater than the value of <it>k</it><sub>1 </sub>(1.22 × 10<sup>-3 </sup>s<sup>-1</sup>) for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>at 45.0°C and <it>I </it>= 0.20 mol dm<sup>-3</sup>. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO<sub>4</sub><sup>- </sup>to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3</sub>, is greater than the value of <it>k</it><sub>1 </sub>for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

    Tree height integrated into pantropical forest biomass estimates

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    Copyright © 2012 European Geosciences Union. This is the published version available at http://www.biogeosciences.net/9/3381/2012/bg-9-3381-2012.htmlAboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation

    Coffee and its waste repel gravid Aedes albopictus females and inhibit the development of their embryos

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