Le monde de la pratique

UK consultant architect George Atkinson reviews current developments in the application of quality assurance principles to construction and describes the potential benefits, simplification of regulating procedures and better arrangements for post‐construction liability.     

Measurement and assessment of ultraviolet radiation in Riyadh,Saudi Arabia

Measurements of ultraviolet solar radiation (UV radiation) of wavelengths 0.295–0.385?μm were recorded from a huge data set collected every 10 minutes for a long period of time (over 60 months) in Riyadh, Saudi Arabia (Lat. 24°6′?N Long. 46°7′?E). The daily and monthly average percent ratio of UV to global irradiance was discussed. Findings indicate that maximum UV radiation occurs in July (16.6?Wm^?2) and the minimum values occur in December (8.3?Wm^?2). The measured UV intensity in Riyadh was compared with those measured in different regional cities; Bahrain, Kuwait, Dhahran, Makkah (Al-Mukkaramah) and Cairo. The results of comparison were discussed and attributed to different causes. It shows that the data of Riyadh are in good agreement with those of Dhahran and Cairo.     

Monitoring Trace Metals in Some Cultured Freshwater Fish Species in Saudi Arabia

Three species of freshwater fishes, Oreochromis niloticus, Clarias lazera and Cyprinus carpio, were collected in marketing size from some fish farms in Al-Kharj region, Riyadh area, Saudi Arabia and examined throughout the year 2012 for the following trace metals contents： chromium （Cr）, lead （Pb）, cobalt （Co）, nickel （Ni）, copper （Cu）, zinc （Zn）, iron （Fe） and cadmium （Cd）. The results showed no detection of Cd in all examined species, however, the mean values of other tested metals were within the standard permissible levels except for Pb which showed higher mean levels ranged from 2.05 ± 0.65 mg/kg to 5.30 ± 0.60 mg/kg in O. niloticus, 0.15 ± 0.13 mg/kg to 6.40 ± 0.10 mg/kg in C. lazera and 1.7 ± 0.20 mg/kg in C. carpio compared to the maximum permissible limits recorded by Saudi Arabia Standards Organization （SASO） for fish and shellfish. Consequently, from the public health point of view, efficient routine examination of cultured fishes to control trace metals during culture processes and before marketing is recommended.     

Molecular Identification of Spoilage Fungi Isolated from Fruit and Vegetables and Their Control with Chitosan

This study investigated fungal spoilage of fruits and vegetables in Saudi Arabia. Activities of cell wall degrading enzymes in fungal isolates were measured. We evaluated the fungicidal activities of chitosan against spoilage fungi. Thirty-three fungal species belonged to 21 fungal genera were collected during this study. ITS sequencing results showed that Alternaria tenuissima, Fusarium chlamydosporum, Penicillium sumatrens, Rhizopus stolonifera, and Trichoderma harzianum were the most common species. The diversity of cell wall degrading enzyme produced by the spoilage fungi revealed that xylanase was the most widely distributed enzyme in fungi followed by amylase and cellulase. Some strains of Macrophomina phaseolina, Trichoderma harzianum, Trichoderma asperellum, Aspergillus niger and Alternaria consortialis showed the highest enzymes activities among tested fungi. Four different concentrations of chitosan (20, 30, 50, and 100 mg/L) were investigated against 22 fungal species. All investigated concentrations of chitosan showed highly significant reduction in the average of radial growth of all tested fungi.     

从沙特阿美石油公司标准看沙特油管和套管生产检验技术要求

2007年我国出口的油井管已达到146．1万t。国外市场已成为我国油井管产品最重要的市场之一。沙特阿拉伯王国是全球最大的产油同，也是全球最大的油井管消费国之一，其石油工业所需的油井管主要从其他国家进口。根据沙特阿美石油公司（SaudiAramco）的油管和套管标准，介绍了沙特市场对油管和套管的生产检验技术要求，提出了我国油管和套管加工工艺技术需要改进的地方。     

Urban and Architectural Sustainability in the Gulf

What is the impact of rapid urbanisation on sustainable development, such as that experienced by cities in the Gulf? Robert Cooke , an Associate Sustainability Consultant at Buro Happold, based in Dubai, seeks to answer this question. He asks what the real contribution might be of the implementation of recent sustainable policies and urban projects, and what more needs to be done to improve the Gulf's ecological footprint and the water-energy nexus.     

Evaluation of engineering properties of scoria in central Harrat Rahat, Saudi Arabia

 Although black scoria deposits occur extensively in western Saudi Arabia, there has been little work undertaken on its engineering characteristics as a light-weight aggregate which can be used in concrete for structural, masonry and insulating purposes. In an attempt to remedy this, central Harrat Rahat was selected for an engineering evaluation of scoria deposits in the vicinity of major cities where it may provide an easily accessible resource for natural aggregate. The petrography of the scoria and the deleterious material content were found to be acceptable by ASTM standards, but grading analyses indicated it would need to be processed before use. The other physical properties of the scoria such as bulk density, specific gravity and absorption indicated that samples from Jabal Halat Ash Shaykh quarry gave acceptable results. The porosity of the scoria is relatively high and some of the pore spaces are not interconnected. The material is pozzolanically active and can be also used as an additive to Portland cement. Received: 16 April 1999 · Accepted: 25 March 2000     

PERMEABILITY ANISOTROPY DISTRIBUTIONS IN AN UPPER JURASSIC CARBONATE RESERVOIR, EASTERN SAUDI ARABIA

Most classical reservoir engineering concepts are based on homogeneous reservoirs despite the fact that homogeneous reservoirs are the exception rather than the rule. This is especially true of carbonate reservoirs in the Middle East which are known to be highly heterogeneous. The realistic petrophysical characterization of these kinds of reservoirs is not an easy task and must include the study of directional variations of permeability. Such variation can be incorporated into engineering calculations as the square root of the ratio of horizontal to vertical permeability, a parameter known as the anisotropy ratio.
This paper addresses the distribution of anisotropy ratio values in an Upper Jurassic carbonate reservoir in the Eastern Province of Saudi Arabia. Based on whole core data from a number of vertical wells, statistical distributions of horizontal and vertical permeability measurements as well as anisotropy ratios were determined. The distributions of both permeability measurements and anisotropy ratios have similar patterns characterized by considerable positive skewness. The coefficients of variation for these distributions are relatively high, indicating their very heterogeneous nature.
Comparison of plots of anisotropy ratios against depth for the wells and the corresponding core permeability values indicate that reservoir intervals with lower vertical permeability yield consistently higher ratios with considerable fluctuations. These intervals are represented by lower porosity mud-rich and/or mud-rich/granular facies. Granular facies, on the other hand, yielded considerably lower ratios without significant fluctuations.     

Need for thermal-storage air-conditioning in Saudi Arabia

In Saudi Arabia, the growth of demand for electrical energy in the rapidly expanding towns, cities and industries, far exceeds the growth of the power being made available. Recently the Saudi Consolidated Electric Companies (SCECO) are facing a shortage of electricity during the summer period mainly due to the high consumption of electricity in the air conditioning sector. The incorporation of thermal energy storage (TES) technologies with a conventional air conditioning system is found to be an appropriate solution for energy-demand management. In this paper an introductory overview of thermal storage air conditioning is presented, comparing phase change (e.g. ice) and sensible heat (e.g. chilled water) storage technologies. The pros and cons of each are evaluated. The suitability of TES technology for the Saudi HVAC (heating, ventilating and air conditioning) industry is explored with the benefits to the owner such as: reduced energy consumption; less operation and maintenance costs; and downsizing of the chiller plant and system for new facility; alternative to new chiller installation to cater for increased cooling load; and stored water as a fire protection source. Furthermore, an economic study has been presented to illustrate the feasibility of TES based air conditioning in Saudi Arabia.     

Public owners' satisfaction with consultancy practices in Saudi Arabia

Between 1970 and 1985 the public expenditure on three development plans in Saudi Arabia amounted to 1940 billion Saudi Riyals. This paper addresses the professional relationship between the public owners and the local architectural and engineering practices which has been measured in the form of overall satisfaction under a five-point scale ranging from excellent to poor, a second aspect identified satisfaction related to the design service and finally, a measure of satisfaction was gained from owners' response to their professional relationship with the practices.