Estimation of the Maximum Annual Loads Modeling for Kingdom of Bahrain

The present paper proposes the impact of the air temperature on electricity demand as expected. It is clear that the annual maximum load is recorded versus the years starting by the year 2009 up to 2012. At present, the graph fitting technique is applied with some mathematical and computational tools based on the actual values of the years 2009 up to 2012 considering the lower values, the higher values and the average values of the annual maximum loads for Kingdom of Bahrain. For the three scenarios, the models are obtained by curve fitting technique. As well, the model of actual loads is obtained finally which has mostly the closest values obtained.     

Analytical solution for two-phase flow between two rotating cylinders filled with power law liquid and a micro layer of gas

This paper deals with the effects that a thin gas layer exerts on the hydrodynamic aspects of power law liquid in a radial Couette flow between two cylinders. Analytical solution is made to determine the velocity profile in the two-phase flow system occupied by the power law liquid and the micro layer of a gas. It is shown that the thin (micro) gas layer contributes in reducing torque to set the fluid in motion in most cases. However, by considering generalized power law liquids, this paper limits the credibility for the positive role of the gas layer on reducing the torque for lubrication. For instance, when n < 0.5 (n is the behavior index of the liquid), slight increment in the torque (about 6%) is reported. Finally, energy gradient method is used for stability analysis. It is shown that the stability nature may be changed based on behavior index of the liquid.     

Inline monitoring the effect of chemical inhibitor on the calcium carbonate precipitation and agglomeration

The formation of mineral scale particularly calcium carbonate is a problem for industries ranging from oil and gas to desalination plants. Various techniques have been studied to prevent the formation of scale. The use of chemical inhibitors to prevent calcium carbonate agglomeration is widely studied. The present study attempts to show that the inline monitoring technique is a useful tool for laboratory experimental investigation of agglomeration phenomenon. This method is successful in providing the induction time of starting agglomeration. It was shown that the presence of inhibitor delays the agglomeration and affects the deposition of calcium carbonate.In addition the method is found useful in determining the minimum inhibitor concentration and also to screen various types of inhibitors for the selection. The influence of an inhibitor is studied on scaling solution of various calcium ion concentrations. Finally, the result of inline technique was validated by comparing with the conventional one called offline technique. The SEM images reveal that the mechanism of inhibition might be the surface adsorption or distortion of inhibitor molecules on the growing calcium carbonate crystals.     

Development of novel potentiometric sensors for determination of tartrazine dye concentration in foodstuff products

Tartrazine dye Na₃TZ in foodstuff products was determined by a new modified carbon paste electrode, encoded sensor A, and a coated silver wire electrode, encoded sensor B, based on tartrazine TZ- cetryltrimethyl ammoniumbromide CTAB as a chemical modifier TZ-CTA. The electrodes exhibit the following characteristics listed respectively: a Nernstian slope of 17.9 ± 0.5 and 19.4 ± 0.2 mV/decade for tartrazine ion over a wide concentration range from 4.3 × 10⁻⁷ to 1.0 × 10⁻² and 1.1 × 10⁻⁷ to 1.0 × 10⁻² M. The lower detection limits: 3.2 × 10⁻⁷ and 5.5 × 10⁻⁸ M. Short response time (5–8 s) over the pH range 3.8–7.7 and 4.2–8.1. The proposed sensors display significantly high selectivity for TZ ion over a wide variety of sugars, some anions, common organic, inorganic compounds and additives. The developed electrodes were applied to the potentiometric determination of tartrazine ion in different kinds of foodstuffs: solid jelly (strawberry and custard) powder samples and soft drink (orange) samples with satisfactory results.     

Effect of Thermal Aging on the Optical Properties of ABS Plastics

Poly(acrylonitrile/butadiene/styrene) (ABS) is a two-phase material consisting of elastomer particles in a glassy polymer matric of styrene and acrylonitrile (SAN) [1]. The photooxidation of ABS was the subject of several studies [2, 3]. It was suggested that several processes will take place during photooxidation. These changes include the formation of hydroperoxide [4], chain breakage of the polystyrene, and the oxidation of the polymer as it was monitored by IR spectroscopy [4–6]. Also photooxidation affect the polybutadiene in ABS and oxidizes it, which results in the formation of hydroperoxide. There are no data available on the thermal degradation of ABS. In a previous study the thermal aging of recycled high-impact polystyrene was studied using UV-vis spectroscopy [7]. It was found that this method provided very useful information about the degradation of several industrial polymers [8–12]. In this paper thermal degradation of ABS is investigated by UV-vis and IR spectroscopy.     

Heat transfer in a conical cylinder with porous medium

In this paper, numerical study of heat transfer in a conical annular cylinder fixed with saturated porous medium is presented. The heat transfer is assumed to take place by natural convection and radiation. The inner surface of conical cylinder is maintained at uniform wall temperature. The governing partial differential equations are non-dimensionalised using suitable non-dimensional parameters and then solved by using finite element method. The porous medium is divided using triangular elements with uneven element size. A computer software is used to solve the coupled momentum and energy equations in an iterative manner. The results are discussed for various values of geometric and physical parameters of porous medium with emphasis on cone angle of the cylinder. It is seen that the cone angle plays a vital role in heat transfer from the hot surface to porous medium.     

Sulfonated Beet Pulp as Solid Catalyst in One-Step Esterification of Industrial Palm Fatty Acid Distillate

In this research a new heterogeneous catalyst has been prepared for biodiesel production. The catalyst was prepared by sulfonating industrial sugar waste. Unlike homogeneous catalysts, which require further purification and separation from the biodiesel production reaction media, this inexpensive synthetic catalyst does not need to go through an additional separation process. This advantage consequently minimizes the total application costs. The catalyst was prepared by partially carbonizing sugar beet pulp at 400 °C. The carbonization product was then sulfonated with concentrated H₂SO₄ vapor in order to produce a solid catalyst. The prepared catalyst was used in the esterification reaction between palm fatty acid distillate (PFAD) and methanol. The effects of the temperature, methanol/PFAD ratio, reaction time and catalyst dosage on the efficiency of the production were individually investigated. The optimum biodiesel production occurred at 85 °C, a reaction time of 300 min, catalyst dosage of 3 g and methanol/PFAD ratio of 5:1 (mol/mol), lowering the acid value from 198 to 13.1 (mg KOH/g oil) or the equivalent, with a fatty acid methyl ester yield of around 92 %. The results suggest that the synthesized inexpensive catalyst is useful for biodiesel production from PFAD.     

Risk Assessment in Construction

This study is concerned with the assessment of risk for major construction activities. Risk has been defined as a measure of the probability, the severity, and the exposure of all hazards of an activity. A risk assessor model (RAM) was developed and computerized to determine the risk associated with a particular activity and the justification factor for a proposed remedy. Knowing the value of risk would help contractors identify the high risk of major construction activities and would enable them to allocate safety precautions in a more efficient manner.     

Microwave-assisted urea-modified sorghum biomass for Cr (III) elimination from aqueous solutions

The present study concentrated on the use of an agro-waste biodegradable sorghum biomass in its simple and modified forms for the binding of Cr (III) ions. A relatively new method of modification was adopted using urea under microwave irradiation. FTIR analysis showed the presence of oxygen and nitrogen bearing functional groups in unmodified (UMS) and modified (MS) sorghum biomass. The appearance of new bands and shifts in the peaks confirmed the modification. The influence of different process parameters such as the adsorbent dose, solution pH, contact time, agitation speed and initial metal ion concentration was studied thoroughly to evaluate optimum conditions for adsorption. Maximum adsorption for Cr (III) ions occurred at pH 5.0–6.0 using UMS and MS. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models in a non-linear fashion were used to explain the phenomenon. Maximum adsorption capacity was 7.03 and 16.36 mg of Cr (III) per gram of UMS and MS, respectively. Adsorption mechanism was explored by pseudo-first- and pseudo-second-order kinetic models, and it was found that the process followed pseudo-second-order kinetics. Thermodynamic study indicated the process favorability. The study concluded that urea modification under microwave irradiation produces a non-toxic and more effective adsorbent for Cr (III) remediation by inducing new nitrogen bearing functional groups to sorghum biomass.