Source rock evaluation of Kharita and Bahariya formations in some wells,North Western Desert,Egypt: Visual palynofacies and organic geochemical approaches

Palynofacies analyses were applied on ninety-one samples from the subsurface Albian – Cenomanian succession represented by Kharita and Bahariya formations, encountered in El-Noor, and South Sallum wells, located in the North Western Desert, Egypt, to visually characterize the content of dispersed organic matter, as well as, organic geochemical characterization to reveal the depositional paleoenvironments and source rock potentiality. The result recognized of five palynofacies associations in the studied interval. The deposition of Kharita Formation took place mainly in a steady and a relatively stable deltaic to marginal environment continued as well in the lower part of Bahariya Formation with minor changes. The marine influence became more common in the upper part of Bahariya Formation showing the exceptional high hydrocarbon potential recorded in the studied interval. This indicates marine transgression by the end of the early Cenomanian (Upper Bahariya) age. Samples from the Kharita Formation contain abundant brown phytoclasts which suggest gas-prone kerogen type III and IV. While Bahariya Formation includes translucent, brown cuticles and woody tracheid phytoclasts pointing to more promising gas-prone kerogen type III. The organic geochemical analysis shows poor to fair gas-prone source rock potential within the study section., Thermally, the color of the spore grains in Kharita and Bahariya formations show that dark yellow to orange, indicates immature besides their general little poor hydrocarbon generation potentiality.     

影响沙漠空气滤清器试验室寿命的因素

沙漠空气滤清器是为长期在恶劣环境下工作的重型卡车、工程机械配套的一种高效率、长寿命滤清器,用以防止各类灰尘进入发动机引起早磨,延长发动机寿命,减少维护时间,降低维护成本。阐述了沙漠空气滤清器的典型结构和工作原理,介绍了试验室寿命的概念和计算方法,分析了影响沙漠空气滤清器试验室寿命的因素,并提出了一些建议。     

阿尔及利亚南部某市供水工程设计

阿尔及利亚南部城市某供水工程输水管道横跨撒哈拉沙漠737 km,经过路线地形复杂。管道流态包含重力流和压力流,同时具有长距离、大流量、高扬程的特点。本文介绍了该供水工程中的管道设计,对输水管线进行了正常状态和过渡状态水力计算,有效地保证了供水系统的安全性及可靠性。     

INORGANIC CHEMICAL COMPOSITION OF AEROSOLS SETTLING IN HAMAD TOWN,BAHRAIN FOLLOWING DUST HAZE STORMS

The inorganic chemical composition of settling particles from 10 dust storms in Hamad Town, Bahrain has been determined. These storms occurred over a 3‐year period. Meteorological conditions during the storms were examined and the storms classified, according to their trajectories, into two types: (a) a low pressure system from the Mediteranean, which traveled east into the Gulf and caused periods of disturbed weather and causing of northwesterly winds; and (b) a low pressure over Pakistan causing dry north‐westerly wind, known locally as Al‐Barah. After this period, the low pressure system declined allowing the formation of south‐easterly winds known as the Kaus. The composition of the dust storms is montonic. The settling particles are relatively enriched in Ca ²⁺, K ⁺ and SO ^2? ₄ derived from local soil, and Cl ^? from the sea.     

沙漠公路固化材料的研究与应用

本文介绍新型NS系列固化材料的特性及其在塔里木沙漠石油公路筑路工程中的应用。经现场筑路证明，以水淬矿渣与多种添加剂为主要成分的NS固化材料能就地固结沙漠沙，使铺筑后的道路具有较小的干燥收缩、温度收缩和较好的抗冻融耐久性，可采用集中搅拌法或路拌法施工。     

Case studies of large-scale PV systems distributed around desert area of the world

To show the huge potential of PV systems, the authors have been studying the feasibility of large-scale PV plants. If a PV module cost is assumed to be 100¥/W, it gives the electricity at a cost of 7.70−13.12 ¥/kWh for a 100 MW plant size located at 6 desert sites around the world, considering the site irradiation,local labor cost, etc. for each site. In spite of the fixed, flat plate, the cost can reach a fairly low level. The station will be composed of 20 sub-units × 10 units of 500 kW optimum size sub-units.     

A new index for mapping lichen-dominated biological soil crusts in desert areas

Tracking the presence, distribution and disappearance of biological soil crusts is important for ecosystem management of desert regions and provides highly valuable information on desertification and climate change studies in arid environments. Based on the analysis of the spectral features of biological soil crusts, we propose a new biological soil crust index (BSCI) for biological soil crusts mapping. Using both a radiative transfer simulation and an analysis of a Landsat Enhanced Thematic Mapper Plus (ETM+) image, we examined the ability of satellite remote sensing to detect and map biological soil crusts. Our simulation indicated that Landsat ETM+ data could be used, after atmospheric correction, to detect biological soil crusts if 33% or more of any pixel was accounted for by biological soil crusts. When the proposed BSCI was applied to the detection of biological soil crusts in the Gurbantonggut Desert, Xingjiang, China, a Kappa coefficient of 0.82 and an overall accuracy of 94.7% were achieved. These experimental results indicate that the new index is applicable to identification of lichen-dominated biological soil crusts, and therefore has good potential for biological soil crust detection and mapping in cool and cold deserts.     

被动式蒸发冷却下向通风降温技术在中庭中应用的思考

被动式直接蒸发冷却下向通风降温技术是一种高效、无污染、低能耗、使用费用低廉的绿色降温技术,被认为是中庭降温的最佳技术,该文用案例分析的方法比较了以色列布劳斯坦沙漠建筑研究中心和美国凤凰城奥康纳联邦法院的中庭设计方法及其技术措施,揭示了利用相同技术为中庭降温而产生截然不同热舒适效果的原因,提出被动式建筑设计原则、适宜的技...     

Performance of solid particles flow thermal storage material made of desert sand

It is a safe and low-cost new heat storage method to realize sensible heat storage at medium and high temperature by using flowing inorganic inert solid particle materials. The cost and performance of granular heat storage medium are very important for this kind of heat storage technology. The yellow sand in southeast of Tenggri Desert in Ningxia is studied. By thermal shock and grinding methods, the tests of thermal shock-resistance and wear resistance were carried out, under laboratory conditions, for the unscreened raw sand and the screened sand samples with three grain sizes (40–60 mesh, 60–80 mesh, and 80–100 mesh). The particle size of the raw sand is 150–300 µm (60–100 meshes) accounts for 60% (wt %) or more and meets the requirement of heat storage material. The density, thermal conductivity, and specific heat of raw sand are higher than those of three kinds of screened sand. Thermal shock and grinding affect the particle size distribution, density, specific heat, and thermal conductivity of the particles. The degree of influence varies with the particle size. The volume ratio heat capacity is used to measure the heat storage performance of the particles. Thermal shock results in a better thermal storage performance of the screened sand than the original sand. After comprehensive analysis of the properties of three kinds of screened sand, it is found that the content of 60–80 mesh-screened sand (31.75%) is the highest in the original sand. After thermal shock and grinding, the screened sand not only has good heat storage performance (average volumetric specific heat capacity 3.232 J· K^?3· K^?1), but also has the smallest change of particle size (breaking rate is less than 24, and agglomeration rate is less than 6), and the thermal shock resistance and wear resistance are outstanding. It is suggested that the screened sand with the particle size range of 200-300µm (60–80 mesh), also the particles with the highest content in the original sand, should be selected as the solid particle flowing heat storage medium.     

Quantitative mapping of arid alluvial fan surfaces using field spectrometer and hyperspectral remote sensing

Mapping and dating of arid and semi-arid alluvial fans are of great importance in many Quaternary studies. Yet the most common mapping method of these features is based on visual, qualitative interpretation of air-photos. In this study we examine the feasibility of mapping arid alluvial surfaces by using airborne hyperspectral reflective remote sensing methodology. This technique was tested on Late Pleistocene to Holocene alluvial fan surfaces located in the hyperarid southern Arava valley, Israel. Results of spectral field measurements showed that the surface reflectance is controlled by two main surficial processes, which are used as relative age criteria: the degree of desert pavement development (gravel coverage %) controls the absorption feature depths, while the rock coating development influences significantly the overall reflectance of the surface, but its effect on the absorption feature depths is limited. We show that as the percent of the surface covered by gravels increases, the absorption feature depth of the common gravels, in this case carbonate at 2.33 μm, increases as well; whereas the absorption features depth of the fine particle in-between the gravels, decrease (hydroxyl and ferric absorption features at 2.21 μm, and 0.87 μm, respectively), as the fines are removed from the surface. Using these correlations we were able to map the surface gravel coverage (%) on the entire alluvial fan, by calculating the gravel coverage (%) in each pixel of the hyperspectral image. The prediction of gravel coverage (%) is with accuracy of ± 15% (e.g. gravel coverage of 50% can be predicted to be 35% to 65%). Using extensive accuracy assessment data, we show that the spectral based mapping maintained high accuracy degree (R² = 0.57 to 0.83). The quantitative methodology developed in this study for mapping alluvial surfaces can be adapted for other surfaces and piedmonts throughout the arid regions of the world.