Developmental research of sustainable technologies to minimise problematic road embankment settlements

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

Pull-Out Resistance of Sand-Geosynthetics Reinforcement

Geosynthetics are widely used in earth retaining structures such as steep slope and earth retaining wall. The stability of the earth retaining structures depends on the interaction between geosynthetics and soil at the reinforced area known as reinforcement mechanism. The reinforcement mechanism of the soil reinforced structure usually difficult to be analysed thoroughly. It is because the preliminary study on the pull-out resistance and durability of the reinforcement material is not taking into account before it has been used to the site location especially in Malaysian practises. Less supervision and the assessment after the installation of the reinforcement materials also contributed to the failure of the soil reinforcement. In this paper, the laboratory model was used to imply the real condition of the soil reinforced structure using pull-out test. A standard pull-out test was carried out by using geotextile and geogrid reinforcing elements embedded into silica sand of size D50=1.357 mm and D50=0.571 mm subjected to normal pressures of 100 kPa, 150 kPa and 200 kPa. Comparative result and analysis showed that the geotextile reinforcement give more resistance rather than geogrid reinforcement under high normal pressure

Impact of localization on Dyson's circular ensemble

A wide variety of complex physical systems described by unitary matrices have been shown numerically to satisfy level statistics predicted by Dyson's circular ensemble. We argue that the impact of localization in such systems is to provide certain restrictions on the eigenvalues. We consider a solvable model which takes into account such restrictions qualitatively and find that within the model a gap is created in the spectrum, and there is a transition from the universal Wigner distribution towards a Poisson distribution with increasing localization.Comment: To be published in J. Phys.

Using of Chroococcus SP. to Treat Polluted Water with Cadmium & Nickel

Chroococcus sp. was exposed to different concentrations 0.3, 0.5, 1, 2, 3, 4, 5, 6 and 7 ppm, from cadmium and nickel. The results revealed that the ability of the alga to remove cadmium and nickel was increased with the increase of the metal concentration which the alga exposed to them and this case does not record before. This may relate to mechanisms of adsorption and removal which not understood perfectly till now according to many researches that concerned with this field of studies. It was noticed that the removal percentage of cadmium reaches to 77.66 & 76% in the two higher concentrations 6 & 7 ppm, which exposed to the alga till the last day (twelve days) from the experiment, but same percentage (77.66 & 76%) was recorded on the eighth day of the experiment to remove nickel and decrease to 12.5 & 28% on the last day of the experiment for the above two concentrations

Quasiperiodic functions theory and the superlattice potentials for a two-dimensional electron gas

We consider Novikov problem of the classification of level curves of quasiperiodic functions on the plane and its connection with the conductivity of two-dimensional electron gas in the presence of both orthogonal magnetic field and the superlattice potentials of special type. We show that the modulation techniques used in the recent papers on the 2D heterostructures permit to obtain the general quasiperiodic potentials for 2D electron gas and consider the asymptotic limit of conductivity when $\tau \to \infty$. Using the theory of quasiperiodic functions we introduce here the topological characteristics of such potentials observable in the conductivity. The corresponding characteristics are the direct analog of the "topological numbers" introduced previously in the conductivity of normal metals.Comment: Revtex, 16 pages, 12 figure

The Bivariate Rogers-Szeg\"{o} Polynomials

We present an operator approach to deriving Mehler's formula and the Rogers formula for the bivariate Rogers-Szeg\"{o} polynomials $h_n(x,y|q)$. The proof of Mehler's formula can be considered as a new approach to the nonsymmetric Poisson kernel formula for the continuous big $q$-Hermite polynomials $H_n(x;a|q)$ due to Askey, Rahman and Suslov. Mehler's formula for $h_n(x,y|q)$ involves a ${}_3\phi_2$ sum and the Rogers formula involves a ${}_2\phi_1$ sum. The proofs of these results are based on parameter augmentation with respect to the $q$-exponential operator and the homogeneous $q$-shift operator in two variables. By extending recent results on the Rogers-Szeg\"{o} polynomials $h_n(x|q)$ due to Hou, Lascoux and Mu, we obtain another Rogers-type formula for $h_n(x,y|q)$. Finally, we give a change of base formula for $H_n(x;a|q)$ which can be used to evaluate some integrals by using the Askey-Wilson integral.Comment: 16 pages, revised version, to appear in J. Phys. A: Math. Theo

A new class of coherent states with Meixner-Pollaczek polynomials for the Gol'dman-Krivchenkov Hamiltonian

A class of generalized coherent states with a new type of the identity resolution are constructed by replacing the labeling parameter zn/n! of the canonical coherent states by Meixner-Pollaczek polynomials with specific parameters. The constructed coherent states belong to the state Hilbert space of the Gol'dman-Krivchenkov Hamiltonian.Comment: 10 pages, Submitte

Enhancement of Landfill Daily Cover in Minimizing the Migration of Heavy Metals in Landfill Leachate by Using Natural Soil, Pressmud Empty Fruit Bunch (EFB) in PulauBurung Landfill

This study emphasizes on the removal of heavy metals in landfill leachate by using natural soil mixed with agricultural wastes. The agricultural wastes used in this study werenatural soil or known as laterite soil, pressmud which is a waste from sugar refinery process and Empty Fruit Bunch (EFB), one of many forms of waste fromoil palm industry. The laterite soil was mixed with these wastes at different percentages of weight ratio namely 50S:40P:10E, 50S:30P:20E, 50S:25P:25E, 50S:10P:40E and 50S:20P:30E. The terms S, P and E each refers to soil, pressmud and empty fruit bunch respectively.Removal efficiency tests were also carried out and the results showed that the mixtures of laterite soil have the ability to remove concentrationsof As2+, Cd2+, Cr2+, Cu2+, Fe2+, Ni2+ and Zn2+between a range of 86% (minimum) and 99% (maximum) compared to removal via soil per se. Ergo, the laterite soil-pressmud-EFB mixtures signify great potential to be made as a daily cover material that minimizes heavy metals migration in landfill leachate, eliminates odor issues and providesadditional protection from further infiltration

Countries experiences: review of district health management in developing and low developing countries

A strong healthcare system is characterized by efficient health service delivery, adequate manpower and resource generation, a sustainable financing system and good governance. District healthcare system is the one closest to the people and its performance in relation to resource allocation impacts directly on the community health status. Over the years, many of the developed nations have learned to prioritize it mainly because it remains the most ideal way of improving population health through activities of general health promotion, disease prevention and provision of basic medical care. In the developing countries, achievement of district health system is not uniform and even among countries with comparable income per capita, wide variations exist. While some have attained a commendable population health status by strengthening their district healthcare systems by redoubling government’s commitment, enhancing resource production, encouraging fairness in healthcare financing and adopting development-oriented health policies, many others are facing healthcare challenges from lack of political will, limited resource allocation and shortage of both manpower and service infrastructure. For these countries, there is an urgent need to transform the district health system so that new and existing health problems can be dealt with decisively and more efficiently. This will require a renewed commitment from the state governments, reprioritizing and readjustment of present health programs, an inter-sectorial collaboration that involves all relevant stakeholders including the communities, and a renewed investment in sustainable health policies that deliver maximum impact at minimal cost