Imaging of near-surface heterogeneities by scattered elastic waves

We have developed an elastic reverse time migration (RTM) approach for imaging near-surface heterogeneities, such as karst features, using scattered waves (e.g., body to P-, S-, and surface waves). Knowledge of location and strength of the scatterers helps in seismic imaging, survey planning, and geotechnical site characterization. To model seismic wave propagation for RTM, we use an elastic staggered-grid finite-difference scheme. The scattered body-to-surface waves provide optimal illumination and wavenumber coverage of the near surface as they travel horizontally along the free surface. We tested the elastic RTM approach on synthetic data simulated using a finite-difference solver and found it to be robust.Saudi AramcoERL Founding Member ConsortiumKuwait Foundation for the Advancement of SciencesKuwait-MIT Center for Natural Resources and the Environmen

The Effects of Buildability Factors on Rebar Fixing Labour Productivity of Beamless Slabs

 Buildability is an important factor affecting labour productivity. Nevertheless, a thorough search of the literature revealed a dearth of research into its effects on in situ reinforced concrete construction, especially at the activity levels. Since rebar fixing is an integral trade of this type of construction material, and beamless slabs are amongst the major encountered activities on construction sites, the objective of this research is to explore the buildability factors affecting its rebar fixing efficiency. To achieve this objective, a large volume of fixing productivity data was collected and analysed using the categorical interaction - regression method. As a result, the main and interaction effects of rebar diameter; reinforcement quantity; slab geometry; and reinforcement layer location are determined. The findings show a significant influence of these factors on the fixing operation, which can be used to provide designers and construction managers with feedback on how well the design of this activity considers the requirements of buildability, and the tangible consequences of designers‟ decisions on labour productivit

Performance evaluation of coaxial horizontal axis hydrokinetic turbines system

Hydrokinetic energy technologies are emerging as a viable solution for renewable power generation. Unlike conventional hydropower turbines, hydrokinetic turbines are environmentally friendly; they operate at zero-head, and do not need dams to preserve the water. Unfortunately, they have a low efficiency which makes their design a challenging task. This work was focused on the hydrodynamic performance of horizontal axis hydrokinetic turbines (HAHkTs) under different turbine arrangements and flow conditions. It was undertaken in an effort to improve the efficiency of small HAHkTs that harness a river\u27s kinetic energy. Four sets of experiments were performed in a water tunnel to investigate small-scale constant cross-section HAHkT models with various configurations. The first set of experiments provided insight into the operating characteristics of a 3-blade single turbine by varying its pitch angle (θ), tip speed ratio (TSR), flow speed (U∞), and applied load. A multi-turbine system of both two and three 3- blade rotors (mounted coaxially to the same shaft) was tested in the second set of experiments. The purpose was to decrease the turbine system solidity while increasing the blade number. Here, the number of and the distance between rotors as well as the rotors relative installation angle were investigated. A long duct reducer was used to shroud single turbine and multi- turbine system in the third set of experiments. The particle image velocimetry (PIV) technique was used in the final set of experiments to examine the flow patterns at different axial locations downstream from two different turbine configurations. The effect of the flow speed on the wake characteristics was also examined in this experiment --Abstract, page iii

Analysing the Impact of the World Trade Organisation (WTO) on the Sustainability of Competitiveness of the Petrochemical Industry in Saudi Arabia

Saudi Arabia undertook measures to liberalize its economy in order to be a part of the WTO, which were carried out in a gradual manner long before the country was accepted as a member of the organization. The reform measures are still being implemented and the economy opening up to foreign investors. The WTO accession has enhanced the optimism of the investors towards the benefits that are expected to be achieved from this membership. The stock market has already responded to these changes through a positive signal and a higher level of foreign direct investment (FDI) is expected in the coming years. This flow of investment will provide an opportunity for diversification of the oil rich economy of Saudi Arabia. Saudi Arabia has been gradually growing into a centre for production of petrochemicals in the world. Owing to the competitive and none fluctuating price of natural gas, investments in olefins and derivatives have increased, which also bring high returns. The aim of this research, hence, is to analyse the impact of Saudi Arabia’s accession to the WTO on the petrochemical industry, and to analyse whether the competitiveness of the industry is sustainable under these new circumstances. In doing so, this study also analysis the strengths, weaknesses, opportunities and threats of the industry with the objective of identifying the competitive advantage of Saudi Arabian petrochemical industry by utilizing Porter’s model. The study also provides a discussion on the possible steps that the government might take towards establishing an economy conducive to foreign investment, competition for the growth of the petrochemicals industry. In responding to the aims and objectives of the study, both the qualitative and quantitative approaches were used. The qualitative analysis includes an analysis of expert opinions collected through elite interviews using semi-structured questionnaires. All these are structured to obtain the opinions of 20 participants regarding the trends and developments of the petrochemical industry and the related policies undertaken by the government. The quantitative analysis includes collecting secondary data for exports and imports of products of the industry along with relevant secondary data analysis of some of the leading petrochemical companies. The results of the analyses at various levels demonstrate that the petrochemicals industry has the potential to contribute to the gross output, diversification of the economy and the sources of earnings, and hence reducing the dependency on oil as the only source of income. In addition, the analysis shows that the industry has potential for the creation of jobs, new openings for investments in businesses, opening up the domestic markets towards certain new products and at the same time bringing down the reliance on imports. Furthermore, the qualitative analysis shows that government has already taken steps towards promotion and encouragement of FDI inflow in the industry but several other measures related to infrastructure and security factors need to be adopted. The nation already enjoys competitive advantages and benefits of location advantages apart from the cost advantage in oil extraction and petrochemicals production. Accession of Saudi Arabia to the WTO as a member country has opened the economy to the outside competition and the petrochemical industry was supposed to be getting the gains from trade and open economy. The global investors have demonstrated their optimism about investment in Saudi Arabia. The existing opportunities in the petrochemical sector will receive a boost apart from diversification of the oil-based economy. The country is gradually becoming a booming centre of petrochemical industry and the growth is exponential. Technological barriers are gradually broken and the industry is moving towards sustainable development. Owing to the competitive pricing of the natural gas sector and cheap availability of feedstock have made it a lucrative place for investment in petrochemical production. However, it will take some more years to realize the full benefit of the accession to the WTO as complementary sectors are also being developed. The membership has however opened the strengths as well as the weaknesses of Saudi’s petrochemical industry to the entire world. Thus, the membership brings on greater transparency, enabling easier and faster assessment and remedies

The introduction of Islamic finance in Libya: Capturing the opportunities for SMEs development / Abdulaziz M. Abdulsaleh.

In most countries, especially the developing ones, SMEs have a dynamic role as engines through which the growth objectives can be accomplished. This is very true in the case of Libya where the economy has been over-reliant on oil and gas as well as inefficient public sector. Unfortunately, SMEs in Libya are not playing their expected role as access to finance remains to be a formidable challenge. While banks remain the major external financier, if not the only one, many studies found that Libyans in general avoid dealing with conventional banks mainly due to religious beliefs. However, the recent introduction of Islamic banking and finance in the country could be a game changer. As such, this paper attempts to assess the opportunities for SMEs development in Libya following the recent introduction of Islamic finance. The study is exploratory; therefore the relevant literature is sourced and reviewed. The review shows that there is a strong demand for Islamic finance products from Libyan businesses including SMEs. Coupled with a strong enabling environment in which political stability and regulatory clarity are maintained Islamic finance is viable and has the ability to significantly contribute to the development of SMEs sector

Management characteristics and organisation context in Saudi Arabia

The purpose of this research was to compare the characteristics of both Western and Saudi senior management in Saudi Arabian business organisations. The author investigated management characteristics, and the differences between Saudi and Western managers in their styles and management practices. In addition, he investigated the underlying causes of ineffective management and ineffective organisational context and systems in Saudi Arabia. Some sources have claimed that Saudi managers are ineffective in their management styles. Yet no effort was made by these sources to compare Saudi and non-Saudi managers. In addition, no study has been made to compare non-government and government business corporations. Also, little has been said elsewhere regarding the social and organisational environments and their effects/impacts on both management and corporations. The present study has attempted to do this. Difficulties in developing management and organisation have arisen because of Saudi Arabia's rapid development from a traditional society towards industrialisation and modernisation. Field research was conducted in several cities of Saudi Arabia from June 1989 to August 1991. Methods of eliciting data included questionnaires and interviews. Data-processing was done by Loughborough University of Technology computer centre. The author found that most Saudi managers lack effective skills and relevant knowledge. They were autocratic, exhibiting an authoritarian style for their personal interests, yet demonstrating people-concern for keeping subordinates happy. By contrast Western managers were high short term task-oriented, with low people-concern, but were strongly influenced by the Saudi Arabian environment. Recommendations for change or improvement may be topics worthy for further study

A Review: Impact of Static and Impact Load on the Mechanical Properties of Plastic Concrete

This review search seeks to know how the replacement effect on concrete is by replacing aggregate (coarse or fine) with plastic granules. Plastic does not dissolve in the climate and provides an early warning for collapses when mixed with concrete to give it more flexibility, making it more crucial to resist tensile stresses, increasing its strength, and seeking to make it more durable. The use of plastic is expanding day by day because of the rapid population increase and their constant demand. Every day, this causes a considerable amount of rubbish, which is harmful and causes pollution and plastic materials to take hundreds of years to dissolve. Solid waste management is currently a difficulty in any country, and the large-scale depletion of resources is causing environmental issues. For the concrete business, an alternative or alternative product must be produced. Plastic waste is the most challenging problem in solid waste management globally. In many countries, concrete has been one of the most excellent solutions for construction materials. It has hastened the pollution of the environment. It would be worthwhile to use plastic waste in concrete to solve the dual problems of a lack of raw materials and the safe disposal of plastic trash. This research aims to see if waste plastic can be used as a fine aggregate in concrete