Safety design practices in residential buildings in Saudi Arabia

A survey of current safety practices in the design of residential buildings in Saudi Arabia identified deficiencies in governance and design procedures. A systematic safety compliance checklist was developed to address these deficiencies incorporating existing local safety instructions and international safety codes and standards. Checklist use is intended to ensure compliance with minimal safety requirements in the design of residential buildings.     

Window flow control in computer communication networks

Computer communication networks are basically resource sharing systems and are used for an efficient exchange of information among remote users. Performance (throughput, delay and power) of a computer network depends upon the intensity of data and/or information traffic. If a network's traffic is allowed to increase beyond certain limits, its performance rapidly degrades. In order to keep data traffic under control, some restrictions are applied at various levels of computer communication networks. These restrictions are usually referred to as flow control techniques.

This paper deals with window (also called end-to-end or entry-to-exit) flow control in computer communication networks. In this method, a source node is allowed to have only a limited number of unacknowledged messages, usually termed as “window size”, at a time. Flow control, in this paper, is discussed in the context of three computer communication switching techniques: packet switching, virtual cut-through switching and quasi cut-through switching. The analysis of window flow control is based upon simulation of a typical store-and-forward computer network. Several simulation results are presented to illustrate the effects of window flow control on various computer communication switching techniques.     

Minimum cost route for a highway in heterogeneous terrain

This paper shows that the minimum cost route should satisfy the Snell's law of light refraction and this can be done by successive iteration, in either a forward or backward direction. The number of iterations required for full convergence depends on the geometry of the problem and the cost ratio between each of the two neighbouring cost regions.     

Heavy metal ion removal by amidoximated bagasse

Amidoximated bagasse (Am‐B) was prepared by treating sugarcane bagasse fibers with acrylonitrile in the presence of sodium hydroxide followed by aqueous hydroxyl amine. Adsorption of some heavy metal ions, namely, Cu(II), Hg(II), Ni(II), Cr(III), and Pb(II) on the prepared Am‐B at different metal ion concentration, intervals, and temperatures was studied. Also, the selectivity of the prepared Am‐B toward adsorption of the aforementioned metal ions in an equimolar mixture was studied. The effect of regeneration of Am‐B using ethylenediamine tetraacetic acid disodium salt (EDTA), up to five times, on its adsorption capacity of the aforementioned metal ions was investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 666–670, 2003     

A rheology study of high‐energy radiolysis of a semicrystalline ethylene‐propylene copolymer containing DOP mobilizer

The radiolysis of a poly(ethylene‐co‐propylene), Elpro grade P 750 J, marketed by Thai Polypropylene Co. Ltd. for the manufacture of medical goods, was investigated at ambient temperature and melt rheology measured. The roles of calcium stearate, blended with the Elpro as a processing aid, and dioctyl phthalate (DOP), added in various amounts as a radical scavenger, were assessed. Following radiolysis, G′ and the viscosity of the polymer melts at 453 K both decreased with increasing radiation dose, even when the mobilizer was present. The results indicated that although the DOP did scavenge radicals, it did not protect the polymer from net chain scission in a low‐dose regimen. The value of (G_S ? 4G_X) was approximately 0.6–0.7. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3437–3441, 2006     

Influence of top‐section design and draft‐tube height on the performance of airlift bioreactors containing water‐in‐oil microemulsion

The mixing and mass transfer characteristics of draft‐tube airlift bioreactors (DTAB) for a water‐in‐kerosene microemulsion, as a cold model of petroleum biodesulfurization, were studied. Incomplete gas disengagement at the top‐section of the DTAB and hence high gas recirculation were obtained with the microemulsion system for all the top‐section configurations employed in the present study especially at the high airflow rates. The ratio (S) of the volumes of the riser and the downcomer to the top‐section together with the gas disengagement abilities of the gas separator were both found to affect the mixing performance of the DTAB employed for the microemulsion system. Increase in the draft‐tube height resulted in significant increase in the mixing time (t_m) and a slight increase in the overall volumetric oxygen transfer coefficient (k_La). Increase in the diameter of the top‐section and the height of the liquid above the draft‐tube led to a decrease in k_La, the latter effect being less prominent. New correlations were developed that predicted the mixing time and oxygen transfer coefficients obtained in the present work with reasonable accuracy. Copyright © 2004 Society of Chemical Industry     

Isothermal crystallization and spherulite nucleation in blends of polypropylene with metallocene‐prepared polyethylene

The isothermal crystallization behavior and morphology of a polypropylene (PP)‐based copolymer, a metallocene‐prepared linear low‐density polyethylene (M‐LLDPE) and their three 10/90, 30/70 and 50/50 M‐LLDPE/PP blends have been investigated. The PP and M‐LLDPE contained 5 ethylene and 3.3 mol% hexene‐1 as a comonomer, respectively. Isothermal crystallization studies revealed a different temperature‐dependence on crystallization for M‐LLDPE, PP and their blends and the crystallization half‐life for the M‐LLDPE was higher than either PP or the blends at a certain temperature. The PP‐rich blends also showed a quite similar crystallization rate to that of PP. Investigations on the variation of spherulite growth rate of PP in the blends at different temperatures revealed no significant change and was quite independent of the amount of M‐LLDPE being employed. The morphology studies revealed that the nucleation densities of the PP spherulites decreased by introducing M‐LLDPE into PP and the M‐LLDPE remained as discrete droplets dispersed throughout the PP spherulites. The results obtained were consistent with no miscibility between the two components. Copyright © 2005 Society of Chemical Industry     

Velocity-image model for online signature verification.

In general, online signature capturing devices provide outputs in the form of shape and velocity signals. In the past, strokes have been extracted while tracking velocity signal minimas. However, the resulting strokes are larger and complicated in shape and thus make the subsequent job of generating a discriminative template difficult. We propose a new stroke-based algorithm that splits velocity signal into various bands. Based on these bands, strokes are extracted which are smaller and more simpler in nature. Training of our proposed system revealed that low- and high-velocity bands of the signal are unstable, whereas the medium-velocity band can be used for discrimination purposes. Euclidean distances of strokes extracted on the basis of medium velocity band are used for verification purpose. The experiments conducted show improvement in discriminative capability of the proposed stroke-based system.     

Firm Performance and Information Technology Utilization in the Construction Industry

This paper, which is written to both researchers and practitioners, examines the impact of information technology (IT) on construction firm performance. Based on data collected from 74 construction firms, regression analysis is used to test the relationship between performance and IT. Analysis provides empirical evidence that IT is positively associated with firm performance, schedule performance, and cost performance. Firm performance is a composite score of several metrics of performance: schedule performance, cost performance, customer satisfaction, safety performance, and profit. The regression analysis shows that for every 1?unit increase in IT utilization, there is an increase of about 2, 5, and 3% in firm performance, schedule performance, and cost performance, respectively. No relationship is found between IT use and customer satisfaction, safety performance, and profitability.