26 resultados para Saudi-Arabia
em CentAUR: Central Archive University of Reading - UK
Resumo:
An initial study of the ichnofabrics of the Upper Jurassic (Kimmeridgian) Jubaila Formation of Saudi Arabia shows that the ichnofabrics are closely matched to the relatively well-described ichnofabrics of the contemporary Fulmar Formation of the UK Continental Shelf (North Sea), in respect of the lower shoreface/offshore transition facies to offshore facies. The ichnology and ichnofabrics of the Lower Jubaila Formation show that deposition took place on an open-marine platform on the Arabian craton subject to periodic storm activity, but under a persisting equilibrium between sediment accumulation and subsidence. This is consistent with the moderately deep-marine foraminiferal assemblages and the presence of calcareous nannofossils. Cyclicity is absent, though storm beds may be grouped, in contrast with the genetic sequences present in the rift and halokinetic scenario of the North Sea. In contrast with the siliciclastic setting hardgrotinds (with Gastrochaenolites), more common firmground omission surfaces, and micritic mudstones with Chondrites and Zoophycos are notable features of the carbonate facies. In siliciclastic successions (parasequences) the latter ichnotaxa are generally regarded as having been deposited in rather deeper water, but in the carbonate Jubaila Formation are interpreted as being associated with local areas of lower turbulence. Likewise, the hardgrounds and firmgrounds, which have not been traced laterally, are tentatively regarded to be of local significance.
Resumo:
The building sector is one of the highest consumers of energy in the world. This has led to high dependency on using fossil fuel to supply energy without due consideration to its environmental impact. Saudi Arabia has been through rapid development accompanied by population growth, which in turn has increased the demand for construction. However, this fast development has been met without considering sustainable building design. General design practices rely on using international design approaches and features without considering the local climate and aspects of traditional passive design. This is by constructing buildings with a large amount of glass fully exposed to solar radiation. The aim of this paper is to investigate the development of sustainability in passive design and vernacular architecture. Furthermore, it compares them with current building in Saudi Arabia in terms of making the most of the climate. Moreover, it will explore the most sustainable renewable energy that can be used to reduce the environmental impact on modern building in Saudi Arabia. This will be carried out using case studies demonstrating the performance of vernacular design in Saudi Arabia and thus its benefits in terms of environmental, economic and social sustainability. It argues that the adoption of a hybrid approach can improve the energy efficiency as well as reduce the carbon footprint of buildings. This is by combining passive design, learning from the vernacular architecture and implementing innovative sustainable technologies.
Resumo:
This paper analyses changes in corporate social responsibility (CSR) reporting practices among Saudi listed companies in the past three years. Using content analysis methodology of annual reports, a sample of 174 annual reports representing 58 Saudi listed companies from different sectors were analysed to investigate the extent of the level of CSR disclosure in the years 2010 to 2012. Our paper focuses on trends of CSR information in the four categories: Environment; Employee; Community and Customer. In developing countries, the CSR disclosure studies are limited and in the case of Saudi Arabia. Overall a significant increase in CSR reporting was observed over that period despite the fact that private-sector companies are still in the early stages of awareness as far as integrating CSR activities into their corporate policies and strategies is concerned.
Resumo:
Present climate in the Nafud desert of northern Saudi Arabia is hyper-arid and moisture brought by north-westerly winds scarcely reaches the region. The existence of abundant palaeolake sediments provides evidence for a considerably wetter climate in the past. However, the existing chronological framework of these deposits is solely based on radiocarbon dating of questionable reliability, due to potential post-depositional contamination with younger 14C. By using luminescence dating, we show that the lake deposits were not formed between 40 and 20 ka as suggested previously, but approximately ca 410 ka, 320 ka, 200 ka, 125 ka, and 100 ka ago. All of these humid phases are in good agreement with those recorded in lake sediments and speleothems from southern Arabia. Surprisingly, no Holocene lake deposits were identified. Geological characteristics of the deposits and diatom analysis suggest that a single, perennial lake covered the entire south-western Nafud ca 320 ka ago. In contrast, lakes of the 200 ka, 125 ka, and 100 ka humid intervals were smaller and restricted to interdune depressions of a pre-existing dune relief. The concurrent occurrence of humid phases in the Nafud, southern Arabia and the eastern Mediterranean suggests that moisture in northern Arabia originated either from the Mediterranean due to more frequent frontal depression systems or from stronger Indian monsoon circulation, respectively. However, based on previously published climate model simulations and palaecolimate evidence from central Arabia and the Negev desert, we argue that humid climate conditions in the Nafud were probably caused by a stronger African monsoon and a distinct change in zonal atmospheric circulation.
Resumo:
This chapter discusses how international assignment was used as tool to expand knowledge within the organisation using the example of the Kingdom of Saudi Arabia, we focus in particularly on the case of repatriation and problems with subsequent staff turnover, among repatriates in Saudi Arabia’s private sector. Before doing so, the chapter provides a background to the Saudi labour market and the impact of Saudization policies that aimed to reduce relying on foreign labour. Following this, the chapter discusses the Saudi government attempt create a national knowledgeable labour force through international assignment. Finally, using the example of an organisation in Saudi Arabia, this chapter illustrates the possible role of Wasta - a prevalent form of nepotism that permeates organizational life in Saudi Arabia - in repatriates managers turnover intention. Our focus is on unravelling the impact of Wasta on HRM practices with a particular focus on the management of the repatriation process of Saudi employees upon their completion of international assignments.
Resumo:
School reform is a major concern in many countries that seek to improve their educational systems and enhance their performances. In consequence, many global schemes, theories, studies, attempts, and programmes have been introduced to promote education in recent years. Saudi Arabia is one of these countries that implemented educational change by introducing many initiatives. The Tatweer Programme is one of these initiatives and is considered as a major recent reform. The main purpose of this study is to investigate this reform in depth by examining the perceptions and experiences of the Tatweer leaders and teachers to find out which extent they have been enabled to be innovative, and to examine the types of leadership and decision-making that have been undertaken by such schools. This study adopted a qualitative case study that employed interviews, focus groups and documentary analysis. The design of the study has been divided into two phases; the first phase was the feasibility study and the second phase was the main study. The research sample of the feasibility study was head teachers, educational experts and Tatweer Unit’s members. The sample of the main study was three Tatweer schools, Tatweer Unit members and one official of Tatweer Project in Riyadh. The findings of this study identified the level of autonomy in managing the school; the Tatweer schools’ system is semi-autonomous when it comes to the internal management, but it lacks autonomy when it comes to staff appointment, student assessment, and curriculum development. In addition, the managerial work has been distributed through teams and members; the Excellence Team plays a critical role in school effectiveness leading an efficient change. Moreover, Professional Learning Communities have been used to enhance the work within Tatweer schools. Finally the findings show that there have been major shifts in the Tatweer schools’ system; the shifting from centralisation to semi-decentralisation; from the culture of the individual to the culture of community; from the traditional school to one focused on self-evaluation and planning; from management to leadership; and from an isolated school being open to society. These shifts have impacted positively on the attitudes of students, parents and staff.
Resumo:
Although foraminifera have been found living in inland saline lakes isolated from the sea, this phenomenon has rarely been recognized in the fossil record. This study documents the occurrence of benthic foraminifera in Holocene lake sediments located nearly 500 km inland from the Red Sea, in the Al-Mundafan region of southern Saudi Arabia. The lake formed during a regional pluvial period, 10,500–6000 yr BP. The presence of foraminifera and brackish charophytes in the studied section represent an interval when the lake was slightly brackish due to high evaporation. The studied sediments yielded a bispecific benthic foraminiferal fauna comprised of Helenina anderseni and Trichohyalus aguayoi, as well as the brackish charophyte genus Lamprothamnium. The benthic foraminifera are species characteristic of mangrove swamps, salt marshes, and lagoons, which are environments currently widespread along the Red Sea coasts. Because the Al Mundafan area was never connected to the sea during the Quaternary, wading birds must have been the vector that transported the foraminifera to the paleolake.
Resumo:
Three gypsiferous-calcareous soils from the Al-Hassa Oasis in Saudi Arabia were examined to determine the conditions under which dissolution of gypsum could be hindered by the formation of coatings of calcite during leaching. Batch extraction with water of a sandy clay loam, a sandy clay and a sandy loam containing 40, 26 and 5% gypsum and 14, 12 and 13% calcite respectively was followed by chemical analysis of the extracts, SEM examination and XRD and EDX microprobe analysis. Extraction in closed centrifuge tubes for I h or 5 h showed that initially gypsum dissolved to give solutions near to equilibrium but then in the sandy clay loam, between one quarter and one third of the gypsum could not dissolve. In the sandy clay about one fifth of the gypsum could not dissolve with none remaining in the sandy loam. All the extracts were close to equilibrium with calcite. SEM and EDX examination showed that coatings of calcite had formed on the gypsum particles. The sandy clay loam was also extracted using an open system in which either air or air +1% CO2 was bubbled through the suspensions for 1 h with stirring. The gypsum dissolved more rapidly and all of the gypsum dissolved. Thus, where the rate of dissolution of gypsum was rapid, calcite did not manage to cover the gypsum surfaces probably because the surface was being continuously removed. Slower leaching conditions in the field are likely to be conducive to the formation of coatings and less dissolution of gypsum. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
A deep-tier, bow-form burrow with a long apertural neck, and several different types of infill is described from Upper Jurassic shelfal carbonates of Saudi Arabia, Miocene pelagic packstones and wackestones of Malta, and Lower Cretaceous shoreface sands and mudrocks of southern England. The two most commonly observed types of infill are a coarse-grained infill, referred to as Glyphichnus-mode (formed by sediment entering the burrow following breakage of the apertural neck), and a laminated, muddy infill, referred to as Cylindrichnus-mode, which is considered to represent passive, drought filling through a complete burrow. The type of infill and aspects of preservation show that these burrows can be used to assess the style of sedimentation, particularly steady aggradation versus periodic erosion. At present the bow-form burrow is not assigned to a specific ichnotaxon.
Resumo:
The aim of this study was to examine the mechanisms by which gypsum increases the sorption of fertilizer-P in soils of and and semi-arid regions. Either gypsum or soil (Usher from the UK; pH 7.8, 7% organic matter, 21% CaCO3: Yasouj from Iran; pH 8.2, 1.4% OM, 18% CaCO3: Ghanimeh from Saudi Arabia; pH 7.8, 1% OM, 26% CaCO3, 13% gypsum) was shaken for 24 It with KH2PO4 solutions in 10 mM CaCl2. With gypsum, grinding increased sorption by a factor of about 3, and increase in pH from 5.6 to 7.5 greatly increased sorption. Scanning electron micrographs (SEM) and EDX quantitative analysis showed that small crystals of gypsum disappeared and roughly spherical particles of dicalcium phosphate (DCPD) were formed. Analysis of equilibrium Solutions showed, using GEOCHEM, that octa-calcium phosphate (OCP) coated the DCPD. For the soils, sorption was in the order Ghanimeh > Yasouj > Usher. Removal of gypsum from Ghanimeh reduced sorption, with precipitated gypsum having a greater effect than gypsum mixed physically with the soil. Addition to Usher had no effect. SEM and EDX could not be used in the soil matrix, but solubility analysis again showed that solutions were close to equilibrium with OCP. Usher was unresponsive to added gypsum, presumably because of its small sorption capacity and high organic matter content. In Ghanimeh and Yasouj soils, gypsum increased sorption by being a source of readily available Ca2+ (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
A numerical mesoscale model is used to make a high-resolution simulation of the marine boundary layer in the Persian Gulf, during conditions of offshore flow from Saudi Arabia. A marine internal boundary layer (MIBL) and a sea-breeze circulation (SBC) are found to co-exist. The sea breeze develops in the mid-afternoon, at which time its front is displaced several tens of kilometres offshore. Between the coast and the sea-breeze system, the MIBL that occurs is consistent with a picture described in the existing literature. However, the MIBL is perturbed by the SBC, the boundary layer deepening significantly seaward of the sea-breeze front. Our analysis suggests that this strong, localized deepening is not a direct consequence of frontal uplift, but rather that the immediate cause is the retardation of the prevailing, low-level offshore wind by the SBC. The simulated boundary-layer development can be accounted for by using a simple 1D Lagrangian model of growth driven by the surface heat flux. This model is obtained as a straightforward modification of an established MIBL analytic growth model.