335 research outputs found

    Simulation of granular soil behaviour using the bullet physics library

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    A physics engine is computer software which provides a simulation of certain physical systems, such as rigid body dynamics, soft body dynamics and fluid dynamics. Physics engines were firstly developed for using in animation and gaming industry ; nevertheless, due to fast calculation speed they are attracting more and more attetion from researchers of the engineering fields. Since physics engines are capable of performing fast calculations on multibody rigid dynamic systems, soil particles can be modeled as distinct rigid bodies. However, up to date, it is not clear to what extent they perform accurately in modeling soil behaviour from a geotechnical viewpoint. To investigate this, examples of pluviation and vibration-induced desification were simulated using the physics engine called Bullet physics library. In order to create soil samples, first, randomly shaped polyhedrons, representing gravels, were generated using the Voronoi tessellation approach. Then, particles were pluviated through a funnel into a cylinder. Once the soil particles settled in a static state, the cylinder was subjected to horizontal sinusoidal vibration for a period of 20 seconds. The same procedure for sample perparation was performed in the laboratory. The results of pluviation and vibration tests weere recorded and compared to those of simulations. A good agreement has been found between the results of simulations and laboratory tests. The findings in this study reinforce the idea that physics engines can be employed as a geotechnical engineering simulation tool

    Corporate Social Responsibility in Islamic and Conventional View: A Theoretical Approach

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    This article is a literature study on CSR in conventional and Islamic banks, which is the result of research in the field of strategic management. CSR is not a foreign subject for the organization, it is not only related to the law but more than that it is part of the company’s ethics in operation. Islamic banking and conventional banking is inseparable from morals and ethics whose activities relate to the public. CSR has become important for Islamic and conventional banking, but in reality, these two banks differ both in philosophy and in operation. Islamic banking is more emphasis on social orientation without neglecting profit, a banking system that is run based on sharia law to prosper society and reach Falah. While conventional banks are more profit-oriented, CSR in conventional banking emphasizes improving financial performance. Theoretically, CSR in Western concepts can be applied in Islamic organizations, but the content remains different.     Keywords: CSR, Islamic Banking, Conventional banking, Syaria

    Analisis Pemahaman Mahasiswa Tingkat II Terhadap Penggunaan Ungkapan Ndesu Atau Noda

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    The aim of this research is to know how good is the comprehension of second semester students of Japanese Language Study Program FKIP University of Riau in using Ndesu expression. In this research, the writer use descriptive method with quantitative approach. Object of this research is second semester students of academic year 2014/2015 Japanese Education Study Program FKIP University of Riau that consists of 39 students, but only 22 students are ready to join in collecting the data. The writer use questionnaire and test as the data collecting technique in this research. Questionnaire given to the students contains students' prior knowledge about ndesu expression, and test that given to the students contains questions about ndesu expression. The result of the questionnaire and the test are manually calculated to know the result of the questionnaire and the test.The result of this research is respondents understand with the function of ndesu expression in asking the reason and mentioning the reason, and respondents not understand with the function of the ndesu expression in asking the explanation and (ć…ˆè§Šă‚Œă€‚ć‰çœźă)sakibure maeoki

    A review of gelatin: properties, sources, process, applications, and commercialisation

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    This review begins with a discussion of the general properties of gelatin and its sources, particularly in the food and health industries, and then briefly address the status quo of gelatin in today’s market. Apart from the basic chemical compounds and gelatin types, this paper also discussed the commercialisation of gelatin. This study also highlights the production of conventional gelatin and its current method of processing, i.e. enzymatic hydrolysis. In addition, the variety of raw materials of collagen is outlined and briefly broached the plant hydrocolloids which have been labeled as ’veggie-gelatin’. With regard to the potential and market stability of gelatin, its recent studies are summarised in this paper. Accordingly, this paper focuses on assessing the general utilities of the various sources of collagen as gelatin derivatives. At that basis, the aim of this review is to provide an insight into gelatin in current applications, market value and progress in gelatin extraction

    Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. I. The Complex Behavior of the M8.5 Dwarf TVLM513-46546

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    [Abridged] We present the first simultaneous radio, X-ray, ultraviolet, and optical spectroscopic observations of the M8.5 dwarf TVLM513-46546, with a duration of 9 hours. These observations are part of a program to study the origin of magnetic activity in ultracool dwarfs, and its impact on chromospheric and coronal emission. Here we detect steady quiescent radio emission superposed with multiple short-duration, highly polarized flares; there is no evidence for periodic bursts previously reported for this object, indicating their transient nature. We also detect soft X-ray emission, with L_X/L_bol~10^-4.9, the faintest to date for any object later than M5, and a possible weak X-ray flare. TVLM513-46546 continues the trend of severe violation of the radio/X-ray correlation in ultracool dwarfs, by nearly 4 orders of magnitude. From the optical spectroscopy we find that the Balmer line luminosity exceeds the X-ray luminosity by a factor of a few, suggesting that, unlike in early M dwarfs, chromospheric heating may not be due to coronal X-ray emission. More importantly, we detect a sinusoidal H-alpha light curve with a period of 2 hr, matching the rotation period of TVLM513-46546. This is the first known example of such Balmer line behavior, which points to a co-rotating chromospheric hot spot or an extended magnetic structure, with a covering fraction of about 50%. This feature may be transitory based on the apparent decline in light curve peak during the four observed maxima. From the radio data we infer a large scale steady magnetic field of ~100 G, in good agreement with the value required for confinement of the X-ray emitting plasma. The radio flares, on the other hand, are produced in a component of the field with a strength of ~3 kG and a likely multi-polar configuration.Comment: 13 pages, 4 figure

    Use of a Combination of MRSS-ANP for Making an Innovative Landfill Siting Decision Model

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    Landfill siting is a complex, multicriteria decision-making problem that needs an extensive evaluation of environmental, social, land use, and operational criteria. Integration of a median ranked sample set (MRSS) and an analytic network process (ANP) has been implemented to rank the associated criteria and select a suitable landfill site. It minimizes the uncertainty and the subjectivity of human judgments. Four groups of experts with different backgrounds participated in this study, and each group contained four experts. The respondent preferences were ranked in a 4-by-4 matrix to obtain the judgment sets for the MRSS. These sets were subsequently analyzed using ANP to obtain the priorities in the landfill siting criteria. The results show that land topology and distance from surface water are the most influential factors, with priorities of 0.18 and 0.17, respectively. The proposed integrated model may become a promising tool for the environmental planners and decision makers

    Sensitivity Analysis of Average Inventory Level (AIL) at a Specialized Hospital

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    . Hospital inventory management play a very significant role in hospital's performance. Too much inventory wiil lead to excessive inventory cost but too low inventory might result in dissatisfactions of patiens and lack of performance of physicians or doctors. Economic order Quantity (EOQ) is an inventory control method that can help hospital to minimize total inventort cost. However, managers might find difficulties in deterimining the right amount of ordering and holding cost which are needed in calculating EOQ. This research is a case study from a class “A” specialized hospital. Inventory data of pharmaceutical items are calculated to measure the sensitivity of changes in ordering and holding cost to average inventory level which will lead to understock or overstock. Different ordering cost and holding cost will lead to different proportion of overstock and understock but will not give a significant differences. This research recommend EOQ model to be used in hospital inventory management inspite of the difficulty and hesitation of hospitals to estimate ordering and holding cost

    Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. II. Mixed Trends in VB10 and LSR1835+32 and the Possible Role of Rotation

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    [Abridged] As part of our on-going investigation of magnetic activity in ultracool dwarfs we present simultaneous radio, X-ray, UV, and optical observations of LSR1835+32 (M8.5), and simultaneous X-ray and UV observations of VB10 (M8), both with a duration of about 9 hours. LSR1835+32 exhibits persistent radio emission and H-alpha variability on timescales of ~0.5-2 hr. The detected UV flux is consistent with photospheric emission, and no X-ray emission is detected to a deep limit of L_X/L_bol<10^-5.7. The H-alpha and radio emission are temporally uncorrelated, and the ratio of radio to X-ray luminosity exceeds the correlation seen in F-M6 stars by >2x10^4. Similarly, L_Halpha/L_X>10 is at least 30 times larger than in early M dwarfs, and eliminates coronal emission as the source of chromospheric heating. The lack of radio variability during four rotations of LSR1835+32 requires a uniform stellar-scale field of ~10 G, and indicates that the H-alpha variability is dominated by much smaller scales, <10% of the chromospheric volume. VB10, on the other hand, shows correlated flaring and quiescent X-ray and UV emission, similar to the behavior of early M dwarfs. Delayed and densely-sampled optical spectra exhibit a similar range of variability amplitudes and timescales to those seen in the X-rays and UV, with L_Halpha/L_X~1. Along with our previous observations of the M8.5 dwarf TVLM513-46546 we conclude that late M dwarfs exhibit a mix of activity patterns, which points to a transition in the structure and heating of the outer atmosphere by large-scale magnetic fields. We find that rotation may play a role in generating the fields as evidenced by a tentative correlation between radio activity and rotation velocity. The X-ray emission, however, shows evidence for super-saturation at vsini>25 km/s.Comment: Submitted to Ap

    Einstein's "Zur Elektrodynamik..." (1905) Revisited, with Some Consequences

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    Einstein, in his "Zur Elektrodynamik bewegter Korper", gave a physical (operational) meaning to "time" of a remote event in describing "motion" by introducing the concept of "synchronous stationary clocks located at different places". But with regard to "place" in describing motion, he assumed without analysis the concept of a system of co-ordinates. In the present paper, we propose a way of giving physical (operational) meaning to the concepts of "place" and "co-ordinate system", and show how the observer can define both the place and time of a remote event. Following Einstein, we consider another system "in uniform motion of translation relatively to the former". Without assuming "the properties of homogeneity which we attribute to space and time", we show that the definitions of space and time in the two systems are linearly related. We deduce some novel consequences of our approach regarding faster-than-light observers and particles, "one-way" and "two-way" velocities of light, symmetry, the "group property" of inertial reference frames, length contraction and time dilatation, and the "twin paradox". Finally, we point out a flaw in Einstein's argument in the "Electrodynamical Part" of his paper and show that the Lorentz force formula and Einstein's formula for transformation of field quantities are mutually consistent. We show that for faster-than-light bodies, a simple modification of Planck's formula for mass suffices. (Except for the reference to Planck's formula, we restrict ourselves to Physics of 1905.)Comment: 55 pages, 4 figures, accepted for publication in "Foundations of Physics

    Stormwater characterisation and modelling for Sungai Air Hitam in Selangor, Malaysia using model for urban stormwater improvement conceptualisation (music)

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    The aim of this study is to evaluate the current water quality status of one of the urban rivers in Malaysia, called Sungai Air Hitam. The river's water supply is not only unsuitable for the inhabitants but also hazardous to the aquatic species that depend on it. In order to simulate the water quality formulation of the river, the Model for Urban Stormwater Improvement Conceptualization (MUSIC) was used. The effects of various best management practices (BMPs) components have been examined to improve the river's water quality. This study also investigated different scenarios of the expected future changes in the land cover and the quality of the river. As the proportion of impervious surfaces increases, the urban hydrology cycle can be significantly altered, resulting in an increase in volumes and peak flows, and a decrease in storage, infiltration, and interception. The MUSIC results have shown significant reductions in biochemical oxygen demand (BOD), total suspended solids (TSS), total phosphorus (TP), and total nitrogen (TN) after introducing BMPs. It was also noticed that the prediction of pollutants falls within the acceptable range set by the Urban Stormwater Management Manual for Malaysia (MSMA) 2nd edition. For the land cover, it was found that the total reduction of BOD, TSS, TP, and TN for existing land use is 92.5 %, 94.5 %, 90.7 % and 91.9 %. Meanwhile, the total reduction in future land use is 81.6 % for BOD, 86.2 % for TSS, 80.9 % for TP and 80.8 % for TN. From the simulation results, it was observed that the application of BMPs has successfully reduced the observed mean BOD concentration from 92.38 mg/L (Class V) to 6.93 mg/L (Class IV) of the national water quality standards, NWQS, water quality index. As a result, the water quality index of the overall catchment has improved from Class IV to Class III (WQ1, WQ3, and WQ4) and from Class V to IV (WQ2) with the application of the BMPs. This assessment aims to raise awareness within the Sungai Air Hitam community regarding the importance of preserving river cleanliness and understanding the long-term environmental impact of water quality. These findings underscore the importance of an integrated system in managing urban water systems, which can offer valuable insight to the decision-makers
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