4,969 research outputs found

    Analytic Solution for the Ground State Energy of the Extensive Many-Body Problem

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    A closed form expression for the ground state energy density of the general extensive many-body problem is given in terms of the Lanczos tri-diagonal form of the Hamiltonian. Given the general expressions of the diagonal and off-diagonal elements of the Hamiltonian Lanczos matrix, αn(N)\alpha_n(N) and βn(N)\beta_n(N), asymptotic forms α(z)\alpha(z) and β(z)\beta(z) can be defined in terms of a new parameter zn/Nz\equiv n/N (nn is the Lanczos iteration and NN is the size of the system). By application of theorems on the zeros of orthogonal polynomials we find the ground-state energy density in the bulk limit to be given in general by E0=inf[α(z)2β(z)]{\cal E}_0 = {\rm inf}\,\left[\alpha(z) - 2\,\beta(z)\right].Comment: 10 pages REVTex3.0, 3 PS figure

    Cassavabase, an advantage for IITA cassava breeding program

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    Developmental research of sustainable technologies to minimise problematic road embankment settlements

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    Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined

    Spectral properties of operators using tridiagonalisation

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    A general scheme for tridiagonalising differential, difference or q-difference operators using orthogonal polynomials is described. From the tridiagonal form the spectral decomposition can be described in terms of the orthogonality measure of generally different orthogonal polynomials. Three examples are worked out: (1) related to Jacobi and Wilson polynomials for a second order differential operator, (2) related to little q-Jacobi polynomials and Askey-Wilson polynomials for a bounded second order q-difference operator, (3) related to little q-Jacobi polynomials for an unbounded second order q-difference operator. In case (1) a link with the Jacobi function transform is established, for which we give a q-analogue using example (2).Comment: 14 pages, corrections, to appear in Analysis and Application

    Numerical Modelling of Slope Stability and Transient Seepage Analysis: Jalan Puncak Borneo Road Case Study

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    A slope failure event in 2015 at KM 6+500 of Jalan Puncak Borneo in Padawan, Kuching was modelled using Seep/w and Slope/w software of commercial geotechnical programme GEOSTUDIO. The failure was occurred after a prolonged three days of heavy rain. The state road which connected the villagers from Puncak Borneo was cut off and caused traffic congestion.  In this study, the slope stability was evaluated based on finite element and limit equilibrium method by considering the transient seepage analysis due to rainfall infiltration.  The slope failure was modelled based on ground investigation report and published data to replicate the field condition.  A hyetograph was plotted using daily rainfall data and cumulative rainfall depth was determined to obtain the total rainfall during the wet monsoon. As a result of numerical analyses, the factor of safety was observed to fluctuate with time of infiltration. Based on this case study, the factor of safety or FOS reduced with time and a perched water table also has been observed developed just below the pavement.  However, the factor of safety calculated from Slope/w could not replicate the actual failure.  Nevertheless, it can be observed that factor of safety had decreased with respect to infiltration in the analyses.  The steady state condition provided FOS 1.33 and had reduced to 1.27 after 110 days of rainfall event.  Thus, the analyses of this current study have illustrated that the transient analysis is essential to model the seepage behaviour and infiltration event that caused slope failure along Sarawak’s roads

    Numerical Modelling of Slope Stability and Transient Seepage Analysis: Jalan Puncak Borneo Road Case Study

    Get PDF
    A slope failure event in 2015 at KM 6+500 of Jalan Puncak Borneo in Padawan, Kuching was modelled using Seep/w and Slope/w software of commercial geotechnical programme GEOSTUDIO. The failure was occurred after a prolonged three days of heavy rain. The state road which connected the villagers from Puncak Borneo was cut off and caused traffic congestion.  In this study, the slope stability was evaluated based on finite element and limit equilibrium method by considering the transient seepage analysis due to rainfall infiltration.  The slope failure was modelled based on ground investigation report and published data to replicate the field condition.  A hyetograph was plotted using daily rainfall data and cumulative rainfall depth was determined to obtain the total rainfall during the wet monsoon. As a result of numerical analyses, the factor of safety was observed to fluctuate with time of infiltration. Based on this case study, the factor of safety or FOS reduced with time and a perched water table also has been observed developed just below the pavement.  However, the factor of safety calculated from Slope/w could not replicate the actual failure.  Nevertheless, it can be observed that factor of safety had decreased with respect to infiltration in the analyses.  The steady state condition provided FOS 1.33 and had reduced to 1.27 after 110 days of rainfall event.  Thus, the analyses of this current study have illustrated that the transient analysis is essential to model the seepage behaviour and infiltration event that caused slope failure along Sarawak’s roads

    Kajian Awal Penentuan Daerah Prospek Panas Bumi di Gunung Bur Ni Telong Berdasarkan Analisis Data DEM SRTM dan Citra Landsat 8

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    Research for a preliminary study of Bur Ni Telong, geothermal area, Bener Meriah district using remote sensing techniques has been done. The aims of the research were to determine the morphological condition based on the fault and fracture (FFD) map from the interpreted digital elevation model (DEM) shuttle radar topography mission (SRTM) and to know the vegetation density and surface temperature distribution using Landsat 8 image. The DEM SRTM data were analyzed using the lineament pattern which related to faults and fractures. The vegetation density was calculated using normalized difference vegetation index (NDVI) transformation. The estimated surface temperature was used to locate temperature anomaly. Referring to the geographical map, the dense class area include Silih Nara-Ketol-Peulimbang to Peudada, Juli to Sawang, and Bandar area. The fault and fracture dominantly have directions in East-West and Northwest-Southeast. While based on NDVI map we conclude that the area is covered by dense vegetation, dominated by intermediate to dense of vegetation. The LST map shows the location of maximum surface temperature values are in agreement with residential areas and uncovered areas, as in the areas of Simpang Tiga Redelong and Takengon. Some geothermal manifestations are located in sparse to intermediate vegetation areas with high temperature

    Raman spectroscopy of human teeth using integrated optical spectrometers

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    We have designed an arrayed-waveguide grating in silicon oxynitride technology for the detection of Raman signals from tooth enamel in the spectral region between 890 nm and 912 nm. The detected signals for both parallel and cross polarizations are used to distinguish between healthy and carious regions on the tooth surface of extracted human teeth. Our experimental results are in very good agreement with those achieved using conventional Raman spectrometers. Our results represent a step toward the realization of compact, hand-held, integrated spectrometers

    A finite oscillator model related to sl(2|1)

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    We investigate a new model for the finite one-dimensional quantum oscillator based upon the Lie superalgebra sl(2|1). In this setting, it is natural to present the position and momentum operators of the oscillator as odd elements of the Lie superalgebra. The model involves a parameter p (0<p<1) and an integer representation label j. In the (2j+1)-dimensional representations W_j of sl(2|1), the Hamiltonian has the usual equidistant spectrum. The spectrum of the position operator is discrete and turns out to be of the form ±k\pm\sqrt{k}, where k=0,1,...,j. We construct the discrete position wave functions, which are given in terms of certain Krawtchouk polynomials. These wave functions have appealing properties, as can already be seen from their plots. The model is sufficiently simple, in the sense that the corresponding discrete Fourier transform (relating position wave functions to momentum wave functions) can be constructed explicitly

    Factors Influencing Turnover Intention in a Malaysian Manufacturing Company

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    Turnover intention is defined as a process of employee to leave the current job or his willingness to separate from the organization. Truthfully, the talent of one employee cannot be inherited or be same by others new employee, thus, the need to retain the employee talents are crucial for employers and organizations to face the challenges in today’s intense global competition. Employee turnover has become most important issues to most organizations, hence, this issue still need a special attention since it can affect organizational performance. However, in retaining employees, organization cannot escape from exposing their workforce to higher level of work stress in order to achieve high demands and targets. Thus, the main objective of this paper is to examine the relationship between job stress, work engagement, job satisfaction and organizational commitment and employee turnover intention among manufacturing employees in Malaysia. A total of 170 employees were surveyed through a self-administered questionnaire. Statistical Package for Social Science (SPSS) version 20 was employed to perform data analysis of the study. Descriptive, Correlations and Regressions Analyses were performed and the findings revealed that there is significant relationship between work engagement, job satisfaction and organizational commitment and turnover intention. While no significant relationship was found between job stress and turnover intention. &nbsp; &nbsp; Keywords: turnover intention, job stress, work engagement, job satisfaction and organizational commitment
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