An-Najah National University

About: An-Najah National University is a education organization based out in Nablus, Palestinian Territory. It is known for research contribution in the topics: Population & Adsorption. The organization has 1857 authors who have published 2607 publications receiving 68226 citations. The organization is also known as: An Najah National University.

Life cycle cost analysis for determining optimal insulation thickness in Palestinian buildings

Abstract: This research performs an optimization of insulation thickness in buildings external walls based on a Life Cycle Costing (LCC) approach. Buildings sector consumes 43% of total Palestinian energy. Although building insulation is a low investment with guaranteed benefits alternative, it is still elective in Palestine. Eight governorates were considered in the analysis. The analysis takes into consideration typical external walls construction, insulation types, weather data, energy prices, heating and cooling equipment conversion efficiencies, and market financial parameters. Two types of insulation were studied which are polystyrene (denoted by I1) and polyurethane (denoted by I2). For energy type, electricity is assumed for summer cooling and LPG fuel for winter heating. Optimal insulation thicknesses were calculated assuming different Degree Days (DD) base temperatures Tb. Results show that insulation type and DD have the highest significant effect on optimal insulation thickness. Polystyrene (I1) and Polyurethane (I2) investment costs are 83 and 171.43 $/m3, respectively. Despite that, same optimum financial benefits can be achieved using (I2) at half thickness compared to (I1). For all cases, optimal thickness varied between 0.4 and 9 cm. At Tb equals to 18 °C, annual savings varied between 4 and 8 $/m2/year. Simple Payback Period (SPBP) analysis values varied between 0.9 and 1.6 years. This research is the first to analyze effects of buildings insulation on annual heating and cooling loads in Palestine. The authors believe that it should motivate decision makers to develop a Palestinian building code that considers building insulation a mandatory item. Fortunately, this research proved that it is financially attractive.

Estimating Optimum Timing for Preventive Maintenance Treatment to Mitigate Pavement Roughness

Abstract: The evaluation of pavement preservation interventions is the most important component of a pavement management system. A rational methodology is needed to evaluate pavement preservation alternatives to maximize project- and network-level benefits. A lack of adequate guidance on the timing of preventive maintenance treatments was the main motivation for this study. On the basis of different evaluation criteria, several mathematical models to estimate optimum timing (OT) of various maintenance treatments were developed. On the basis of long-term benefits, the Area2T model was found to be a rational and practical tool to estimate OT for various maintenance treatments by adjusting the model's parameters. The sensitivity and practical use of the models are demonstrated in the paper. Although the modeling approach uses the existing understanding, the model can be used to estimate OT of a fix on the basis of the pretreatment pavement performance, jump in pavement condition just after treatment, and expected rate...

Eigensolution techniques, their applications and Fisherʼs information entropy of the Tietz-Wei diatomic molecular model

Abstract: In this study, the approximate analytical solutions of Schrodinger, Klein–Gordon and Dirac equations under the Tietz–Wei (TW) diatomic molecular potential are represented by using an approximation for the centrifugal term. We have applied three types of eigensolution techniques: the functional analysis approach, supersymmetry quantum mechanics and the asymptotic iteration method to solve the Klein–Gordon, Dirac and Schrodinger equations, respectively. The energy eigenvalues and the corresponding eigenfunctions for these three wave equations are obtained, and some numerical results and figures are reported. It has been shown that these techniques yielded exactly the same results. some expectation values of the TW diatomic molecular potential within the framework of the Hellmann–Feynman theorem have been presented. The probability distributions that characterize the quantum mechanical states of TW diatomic molecular potential are analyzed by means of complementary information measures of a probability distribution called Fisherʼs information entropy. This distribution has been described in terms of Jacobi polynomials, whose characteristics are controlled by quantum numbers.