Sustainable and environmentally sound solid waste management has been the target of developed countries over the last decade. Nevertheless, developing countries such as Kuwait are still struggling to achieve this goal. The major method of solid waste disposal prevailing in Kuwait is open dumping in abandoned sand quarries. A detailed laboratory testing program was carried out to determine the characteristics of the waste material in an operating landfill at Al-Sulaybiyah, Kuwait. Samples were taken from ten boreholes in the East-West direction of the landfill Laboratory work included determination of 30 chemical parameters such as BOD, COD, nitrogen, heavy metals, etc. The results indicated that the samples were mostly decomposed solid waste as measured by organics (BOD, COD) and nutrients. However, the low BOD/COD ratios showed that the organic matter in the landfill was not easily biodegradable and thus will decompose slowly. Water content and salinity were also high reflecting the possible intrusion (infiltration) of subsurface water into the solid waste layer. The concentration of metals in samples was found to be generally high with concentration increasing with depth especially for Fe, Ca, Co, Mg, V, K, Na and Ba. Heavy metals like Mo, Zn, Cd, Cr, Cu, Pb, Ni, Be, Al, Hg and Sr were also present in considerable quantities in the tested solid waste samples. It is recommended that a suitable system at Al-Sulaybiyah landfill be established that will help to control the release of harmful gases and leachate into the environment.
High frequency electromagnetic radiation is increasingly becoming a source of public concern, as more researchers are linking it to health problems, Many have conducted field surveys to determine existing field levels. This paper presents a measurement survey of radiation levels in the state of Kuwait. A simultaneous measurement of several sources in the critical range of the spectrum is conducted using a selective radiation meter, with a probe capable of measuring the critical range of 75MHz to 3 GHz. We aim to find. the sum due to all sources in the measured range. We also aim to find the highest source at each location, and the contribution of each source, to the total sum. Measurement results of electromagnetic radiation at several areas in Kuwait indicate that the mobile network may not always be the main cause or highest source of radiation. At some locations frequencies other than GSM, especially F.M. may yield higher radiation levels. Additionally other sources, although not the highest, are highly contributing to the total amount of radiation. For each trip to a location the contribution of sources per band and a total sum of levels are found, in percentage of the ICNIRP limit. Results indicate that GSM and FM are the predominant sources. The radiation due to GSM is found to reach a maximum of 78% and a minimum of 17% of the total radiation, while radiation due to FM is found to reach a maximum of 83% and a minimum of 10% of the total radiation.
An interactive software platform, developed at Tikrit University to provide students with a useful training tool for understanding microprocessor arithmetic operations, is presented. The platform design concept is based on the TechCode step-by-step program for problem solving, aimed at testing the understanding of key components presented in the known MUSAID Module. The platform, which was developed under the framework of the eLearning project, is intended to complement rather than replace traditional computer architecture tutorial courses. Its main objective is to design a graphical user interface that provides the end user with maximum control over the presenting process while expecting minimal effort from the presenter programmer: Students feedback has shown promising and encouraging results.
Analysis of bacterial fatty acids as their methyl esters (FAMEs) has been extensively used for rapid diagnosis of anaerobic infections, bacterial classification and taxonomy. This makes bacterial FAMEs and especially hydroxy FAMEs analyses of primary importance for clinical and taxonomical interests. However, selection of the appropriate column and other chromatographic parameters makes it an intricate issue for the simultaneous separation of various classes of compounds. For the resolution of these complex mixtures, we have compared four bonded capillary columns OV1, HP-INNOwax, DB5, and VF5-ms of the same length, internal diameter and coated film thickness. Experimental conditions such as gas flow rate and oven temperature programming were optimized to achieve the best resolution on these columns. The standard FAMEs used in this study contained 6 hydroxy fatty acids, two geometric isomers, two positional isomers in branch chain, a cyclopropane and short and long chain components. We have found that OV1 capillary column of low polarity could give best separation of all classes of bacterial FAMEs present in a mixture. Identification of the FAMEs was carried out from their mass spectral fragmentation.
This paper reports a study of magnetic field intensity in the plunger of tubular linear reluctance motors (TLRMs) with open type magnetic circuits. In this paper, magnetic field intensity is described with regard to the eddy current effect in the iron core of tubular linear reluctance motors. In addition, magnetic field intensity is calculated in the motor operating frequency. The proposed method is able to calculate magnetic field intensity in any radius of the plunger. Electromagnetic finite-element analysis is used for motor simulation and magnetic field intensity calculation when the plunger is completely inside the coil. Simulation results of magnetic field intensity calculation using 3-D FEM with the coil current excitation is compared to theoretical results. The comparison yields a good agreement.
Fly ash has established itself as a potential construction material. It is used as partial replacement for cement and aggregate in cement-based materials. It is now being increasingly used in the design of normal-strength, high-strength and high-performance concretes. Because of this, it has become very important to study the behaviour of concrete containing large volumes of fly ash at elevated temperatures. There has been little research published in this area. Therefore, in this work, high-volume fly ash (HVFA) concrete mixtures were made by replacing 30, 40, and 50% cement with Class F fly ash. Concrete specimens were made and were cured for 28 and 56 days. Then, cylindrical specimens were subjected to elevated temperatures of 80, 100, and 120 degrees C. Tests were performed for measuring the residual compressive strength, splitting tensile strength, and the modulus of elasticity of HVFA concretes. Test results indicated that in comparison with the control mixture, compressive strength, splitting tensile strength and modulus of elasticity of concrete mixtures decreased with an increase in temperature.
Measurements of voltage flicker levels and its frequency is of a great concern to the utility in order to prevent unacceptable voltage fluctuation in the supplying system. A new state space model for voltage flickering is proposed in this paper. In addition, it introduces a new digital approach for estimating voltage flicker and its frequency in an electric arc furnace facilities using discrete least absolute value filtering algorithm. The algorithm is first tested using simulated data. Different factors that affect the estimation process, such as sampling rate and data window size are studied. A practical case study for a steel manufacturing plant is then presented. The practical system is simulated using MATLAB package by constructing a Simulink model that mimics the behavior of this plant. The digitized samples of the voltage waveform obtained via the simulation are fed to the algorithm to predict the flicker distortion caused by arc furnaces used in the plant. Results are reported and discussed to prove the validity of the proposed algorithm in accurately estimating the voltage flickers caused by electric arc furnace.
In this article we derive a generalization of Bernoulli learning model. We study the generalized Bernoulli learning model based on the probability of success p(i) = i(P)/n(P),where n and p are positive integers, which gives the two previous results given by Abdulnasser & Khidr (1981) and Rashad (1998) as special cases, where p = 1 and p = 2, respectively. The limiting distribution of the model is given. A Maple program is written and executed to find the probabilities of the model.
Low power factors have significant detrimental effects on power networks, particularly at the distribution level. They increase network losses, adversely affect voltage profiles, and are a cause of overheating machines and equipment. Various mechanisms have been employed to improve low power factors, including technical solutions, regulations, and financial penalties and incentives. In this paper, a multiplier-based approach for low power factor penalties using payback periods optimized with genetic algorithms is proposed and designed, and a general algorithm derived for utility applications. Inherent to the proposed method are the financial and technical concerns of both electricity utility and customer. A general equation for the multiplier-based approach is derived from simulation results in order to avoid complex optimization algorithms. Using sensitivity analysis to eliminate the wide difference in adopted power factor regulations around the world, the study highlights factors that have to be considered when designing penalties for low power factors.
Hidden Markov models (HMMs) are applied to many problems of computational Molecular Biology. In a predictive task, the HMM is endowed with a decoding algorithm in order to assign the most probable path of states, and in turn the class labeling, to an unknown sequence. In this paper, we have introduced a new decoding algorithm called (Log odd-Viterbi (LV)) for gene finding, which combines the log odd of posterior probability and Viterbi algorithms, to avoid the drawbacks of using only Viterbi}, or Posterior algorithms, and also to avoid under flow problem. LV is a two step process: In the first step, the log odd of posterior probability is computed at each state using posterior decoding algorithm and then the best allowed path through the model is evaluated by Viterbi algorithm. Our simulation results show that our proposed LV has better performance than other existing algorithms in the computational biological problems such as predicting coding regions in prokaryotic DNA sequences.
This paper presents an attempt to use a Differential Evolution algorithm to solve the NP-complete course scheduling problem. The course scheduling problem involves assigning courses, faculty members, and rooms to timeslots, subject to preset constraints. Categorizing the constraints as hard and soft, the goal of this type of problem is satisfying hard constraints and minimizing the violation of the soft constraints. The methods currently used in many educational institutes depend on a manual process that is performed by one or more persons who are experienced in course scheduling. These methods are most likely to be "greedy" in their approach, so they resolve a portion, but not all, of the problem's constraints. Such methods generally require several hours or weeks of negotiation and bargaining to resolve one or more constraints. With the objective of investigating the efficiency of our Differential Evolution based algorithm, a case study is taken from the Computer Engineering (CPE) Department at the College of Engineering and Petroleum in Kuwait University (KU). A wide set of practical constraints are taken into consideration. Moreover, the desired solution is compared to both ad-hoc manual optimization and to some other well-known approaches from the literature. The results show that the proposed method can not only dramatically reduce the execution time, but also improve the quality of the solutions.
An experimental study was undertaken to investigate the influence of shredded carpet wastes in the form of small strips/fibers for improving the dynamic characteristics of a sandy soil. Consolidated undrained cyclic triaxial tests were conducted on saturated specimens with different fiber contents, fiber aspect ratios, confining pressures, and loading cycles. The improving effects of the fiber reinforcement only emerge at higher pressures of 400 and 700 kPa, with the latter showing more pronounced improvement. A hyperbolic function is utilized to describe the nonlinear stress-strain relationship under cyclic loading. The model can fairly well capture the behavior, particularly at lower confining pressures.
In this paper, the approximate solution of avian-human influenza epidemic model is obtained by a reliable algorithm based on an adaptation of the standard variational iteration method (VIM), which is called the multi-stage variational iteration method (MVIM). A comparison between MVIM and the Runge-Kutta method (RK-method) reveals that the proposed technique is a promising tool to solve the considered problem.
Interconnected power systems typically encounter low frequency oscillations during their operations. These oscillations are characterized by groups of coherent generators swinging against each other. When such undesired phenomenon is presented in a power system, it limits the amount of power transfer on the tie-lines among different regions containing the groups of coherent generators. This paper presents a new technique for analyzing the poorly damped low frequency oscillations in power system dynamic swings. The proposed algorithm is based on a meta-heuristic technique that has been getting added attention, i.e., Pattern Search Optimization. The method employs a digital set of measurements for power system dynamic swings to perform the analysis process digitally. The goal is to estimate the amount of damping in the swing curve as well as the oscillation frequency. The problem is formulated and presented as a dynamic estimation problem. The proposed technique is used to perform the estimation process by minimizing the total error associated with the estimated parameters. The algorithm is tested using different cases, including practical data for an existing power system. Results are evaluated and compared with other competing methods to show the potential of the proposed method.
Based on the thin-shell theory and using the computational transfer matrix approach and the Romberg integration method, the free vibration and elastic buckling behaviors of a cylindrical shell with a four lobed cross section of circumferential variable thickness subjected to axially compressive loads is presented. Modal displacements of the shell can be described by trigonometric functions and Fourier's approach is used to separate the variables. The governing equations of the shell are formulated in terms of eight first-order differential equations in the circumferential coordinate, and by using the transfer matrix of the shell, these equations are written in a matrix differential equation. The transfer matrix is derived from the differential equations of the cylindrical shells by introducing the trigonometric functions in the longitudinal direction and applying a numerical integration in the circumferential direction. The natural frequencies and critical loads beside the mode shapes are calculated numerically in terms of the transfer matrix elements for the symmetric and antisymmetric vibration-modes. The influences of the thickness variation of cross-section and radius variation at lobed corners of the shell on the natural frequencies, mode shapes and critical loads are illustrated.
In this study, the joint distributions of order statistics from innid variables from a truncated distribution is expressed in terms of the specialized identities. Then, some results connecting distributions of order statistics from innid variables from a truncated distribution to that of order statistics from iid variables from a truncated distribution are given.
Harsh environmental conditions of drought and high temperature are characteristic features of the long dry season of the arid desert in southern Saudi Arabia. The leafless stem succulent Caralluma acutangula (Decne.) N.E.Br. (Apocynaceae) possesses structural and functional adaptations necessary for survival in its natural habitat. Morphological adaptations include thick epicuticular wax, thick cuticle, low stomatal frequency and lobed stem that gives the plant a low surface : volume ratio. As the plant water status decreased during the dry season, depth of stem lobes increased resulting in increased turbulent air flow and decreased stem temperature. Anatomical adaptations allow for a hydrenchyma-chlorenchyma water movement that helps the hydrenchyma to serve as a water reservoir for maintaining the chlorenchyma water status and preserving photosynthetic machinery. Functional adaptations include constitutive crassulacean acid metabolism (CAM) and a shift to CAM-idling under protracted water stress. Photo-protective strategies included accumulating anthocyanin pigment during the wet season and shifting towards non-radiative dissipation of excess energy during the dry season as indicated by increased non-photochemical chlorophyll fluorescence quenching, denoting increased heat energy dissipative mechanisms during the dry season.
Axisymmetric sudden-expansion geometry of a co-flowing methane-air diffusion flame is considered here in order to investigate the effect of inlet fuel turbulence intensity on the NOx formation and temperature fields using k-epsilon turbulence and beta-PDF combustion models. Both thermal and prompt mechanisms are utilized to predict NO formation in the combustor. The predicted velocity fields and temperature distribution illustrate acceptable agreement to published experimental and numerical data. The obtained results show that increasing fuel turbulence intensity results in decreasing NO formation in the flame zone.
In this paper, we prove unique common fixed-point theorems for six mappings (two set-valued and four single-valued mappings) without assuming compatibility and continuity of any mapping on noncomplete 2-metric spaces. To prove these theorems, we introduce a noncompatible condition, that is, weak commutativity of type (Kh) in a 2-metric space. We show that completeness of the whole space is not necessary for the existence and uniqueness of common fixed point. Also, we prove common fixed point theorems for two self mappings and two sequences set-valued mappings by the same weaker conditions. Our results improve, extend and generalize the corresponding results given by many authors.
This paper shows the results of a study comparing the structural designs of hot-mix asphalt pavements in Kuwait. The pavement design suggested by the locally-developed Kuwait Pavement Design Manual and that by the AASHTO 93 Flexible Pavement Design Guide are compared against typical pavement thicknesses actually used in Kuwait. Four sections of main arterial roads, in Kuwait were studied. Their functional classes as well as other functional classes of roads in Kuwait are briefly described. Traffic volumes on the considered roadway sections were obtained from a traffic volume and speed study. Traffic loads were determined using FHWA's typical ESALs-per-vehicle values, since no information on traffic loads is readily available in Kuwait. Using these values showed that the actual existing thickness of pavements of some major roads in Kuwait are less than the required thickness suggested by the AASHTO 93 Guide with as much as 42%. Moreover, truck weights are not monitored and weight limits are not enforced in the country yet. This adds to the problem of traffic loads carried by major routes which are expected to be the major cause of the frequently occurring pavement distresses and failures. The paper concludes with remarks that must be considered to improve the practice of pavement design and control of traffic loads in Kuwait.
