Results 1 - 10 of 30
Results 1 - 10 of 30. Search took: 0.017 seconds
|Sort by: date | relevance|
[en] This paper discusses the issue of energy and mineral resources and the effect of appropriate strategic partnerships necessary for its development. The energy related minerals of interest are coal, tar-sand (bitumen), uranium and barytes/bentonite. The strategic development of the minerals and the impact on the Nigeria economy over the years are reviewed. Present status of these minerals show that harnessing them could have serious environmental consequences previously neglected. However, control of emissions for example from coal-fired power status add to the financial cost of the coal-fired power
[en] Factor and cluster analyses as well as the Pearson correlation coefficient have been applied to geochemical data obtained from phosphorite and phosphatic rocks of Duwi Formation exposed at the Red Sea coast, Nile Valley and Western Desert. Sixty-six samples from a total of 71 collected samples were analysed for SiO2, TiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, P2O5, Sr, U and Pb by XRF and their mineral constituents were determined by the use of XRD techniques. In addition, the natural radioactivity of the phosphatic samples due to their uranium, thorium and potassium contents was measured by gamma-spectrometry.The uranium content in the phosphate rocks with P2O5>15% (average of 106.6 ppm) is higher than in rocks with P2O5<15% (average of 35.5 ppm). Uranium distribution is essentially controlled by the variations of P2O5 and CaO, whereas it is not related to changes in SiO2, TiO2, Al2O3, Fe2O3, MgO, Na2O and K2O concentrations.Factor analysis and the Pearson correlation coefficient revealed that uranium behaves geochemically in different ways in the phosphatic sediments and phosphorites in the Red Sea, Nile Valley and Western Desert. In the Red Sea and Western Desert phosphorites, uranium occurs mainly in oxidized U6+ state where it seems to be fixed by the phosphate ion, forming secondary uranium phosphate minerals such as phosphuranylite.In the Nile Valley phosphorites, ionic substitution of Ca2+ by U4+ is the main controlling factor in the concentration of uranium in phosphate rocks. Moreover, fixation of U6+ by phosphate ion and adsorption of uranium on phosphate minerals play subordinate roles
[en] Objective was to study the value of immunohistochemical staining of thyroid transcription factor-1 TTF-1, cytokeratin 7 CK7 and cytokeratin 20 CK20 in the differentiation between primary and secondary pulmonary carcinomas. Forty-three cases of lung carcinoma, 14 squamous cell carcinoma, 12 adenocarcinoma, 8 small cell carcinoma, 3 mesothelioma and 6 metastatic tumors, were collected from the files of Pathology Department, King Abdul-Aziz University Hospital, Jeddah, Saudi Arabia between 2004 and 2006. All cases were stained immunohistochemically following Avidin biotin method using monoclonal antibodies to TTF-1, CK7 and CK20. Immunohistochemical staining of 43 cases of lung carcinoma revealed nuclear immunoreactivity for TTF-1 in all primary adenocarcinoma and small cell carcinoma, while cases of squamous cell carcinoma were negative. Mesotheliomas were negative to TTF-1, CK7 and CK20. Metastatic tumors except for one case metastatic from the thyroid gland were negative to TTF-1. Cytokeratin 7 was positively expressed in primary tumors of lung, as well as metastatic tumors from the thyroid and breast. Cytokeratin 20 was negative in all primary lung tumors, while positive in metastatic carcinomas from the colon. Thyroid transcription factor-1 is a sensitive marker for diagnosis of primary pulmonary adenocarcinoma, and differentiation between poorly differentiated squamous cell carcinoma and small cell carcinoma and adenocarcinoma. Cytokeratin 20 could be marker for metastatic tumors from the colon to the lung since it was negative in all primary lung tumors. (author)
[en] In this paper, we investigated the propagation of shear wave under the influences of the magnetic field, gravitational field, rotation and initially stressed in anisotropic non-homogeneous incompressible elastic medium. It is well known in the literature that the earth medium is not at all initial stress free and homogeneous throughout, but it is initially stressed and non-homogeneous. The frequency equation that determines the velocity of the shear waves has been obtained. Keeping these things in mind, we have discussed the frequency equation in an initially stressed, non-homogeneous medium with gravity field, magnetic field, and rotation. It has been observed that the inhomogeneity parameter, gravity field, magnetic field, and the initial stress play an important role in the propagation of S-waves propagation. The numerical values on the dimensionless phase velocities are calculated and presented graphically to illustrate the dependences upon gravity field, initial stress, magnetic field, anisotropy and rotation comparatively. The results indicate that the effects of gravity field, initial stress, magnetic field, anisotropy, and rotation are very pronounced.
[en] A good knowledge of medfly population dynamics is necessary to control it. Population dynamics are being studied by means of the Jackson trap with trimedlure attractant (male, sex-pheromone). Weekly sampling of wild medfly populations was started in June at Aabde and in August at Sour and Jbeil. Trap surveys of medfly density will be carried for at least one year before sterile males releases are started against a long-established infestation. Since populations can vary with season and in different parts of an infested area. Knowledge of this variation is needede to determine when releases should start, because they should begin, just after or during a population decline. Field evaluation will include, ecological data on medfly population distribution number, host preference, and medfly overwintering. Surveys of medfly adults and larvae, host species, and phenology, temperature and medfly history, all will be used to guide the control program, specifically the sterile fly releases. 3 tabs. 17 annex
[en] In multi-data center computing, data to be processed is not always local to the computation. This is a major challenge especially for data-intensive Cloud computing applications, since large amount of data would need to be either moved the local sites (staging) or accessed remotely over the network (remote I/O). Cloud application developers generally chose between staging and remote I/O intuitively without making any scientific comparison specific to their application data access patterns since there is no generic model available that they can use. In this paper, we propose a generic model for the Cloud application developers which would help them to choose the most appropriate data access mechanism for their specific application workloads. We define the parameters that potentially affect the end-to-end performance of the multi-data center Cloud applications which need to access large datasets over the network. To test and validate our models, we implemented a series of synthetic benchmark applications to simulate the most common data access patterns encountered in Cloud applications. We show that our model provides promising results in different settings with different parameters, such as network bandwidth, server and client capabilities, and data access ratio
[en] A drug contains antioxidants (vitamins and selenium) were studied in minimising the effects of gamma radiation on lipids oxidation in human body. White rats irradiated with 4 gray doses were used. Analysis after 1, 10, 30 days of irradiation were carried out and the results shows that total lipids content, total phospholipids, and total high density protein lipids cholesterol were decreased in blood serum and liver. Total cholesterol content, low density protein lipids cholesterol, and aldehyde produces by the lipids oxidation were increased in the blood serum and liver. Glutathione contents and the activities of antioxidant enzymes were decreased in blood serum and liver. When the irradiated drug, contains antioxidants, taken by the rats, the previous results become better and about the natural rate and this lead to a recommendation to use it for the radiation workers and cancer patients with radiation treatment
[en] Electric power is often produced in locations far from the point of utilization which creates a challenge in stabilizing power grids, particularly since electricity cannot be stored. The production of decentralized electricity by renewable energy sources offers a greater security of supply while protecting the environment. Wind power holds the greatest promise in terms of environmental protection, competitiveness and possible applications. It is known that wind energy production is not always in phase with power needs because of the uncertainty of wind. For that reason, energy storage is the key for the widespread integration of wind energy into the power grids. This paper proposed various energy storage methods that can be used in combination with decentralized wind energy production where an imbalance exists between electricity production and consumption. Energy storage can play an essential role in bringing value to wind energy, particularly if electricity is to be delivered during peak hours. Various types of energy storage are already in use or are being developed. This paper identified the main characteristics of various electricity storage techniques and their applications. They include stationary or embarked storage for long or short term applications. A comparison of characteristics made it possible to determine which types of electricity storage are best suited for wind energy. These include gravity energy; thermal energy; compressed air energy; coupled storage with natural gas; coupled storage with liquefied gas; hydrogen storage for fuel cells; chemical energy storage; storage in REDOX batteries; storage by superconductive inductance; storage in supercondensers; and, storage as kinetic energy. 21 refs., 21 figs
[en] To compare the epidemiologic, clinical and pathologic characteristics of symptomatic and incidental renal cell carcinoma (RCC)in Jordan.Results were compared with published Western figure. Records of 119 patients with renal tumors diagnosed during the period January1992 to December 2001at Jordan University of Science and Technology, Irbid, Jordan were reviewed. Age,gender, radiologic and biologic workup, treatment,features of tumor were reviewed. The mean patient age was 54 and the male to female ratio was 3.4:1. 26% of tumors were discoverd accidentlly.The incidental detction group had significantly small size of tumor.,lower stage and lower histological grading.In symptomatic group woman have significantly lower mean size of tumor than men. A radical nephrectomy was performed in 92% of the cases, and in 8% of the cases, conservative mangement was adopted. The present study showed that the incidence rate of RCC in Jordan is less than Western countries. Significant number of RCC were detected incidently with lower pathological stage and grade. Subsequently these clinically and histologically less aggressive lesions lead to better survival. These data efforts should be directed to the devlopment of screening protocol to detect these lesions early. (author)
[en] As part of a programme on ‘access to clean cooking alternatives in rural India’, induction stoves were introduced in nearly 4000 rural households in Himachal Pradesh, one of the few highly electrified states in India. Analysis of primary usage information from 1000 rural households revealed that electricity majorly replaced Liquid Petroleum Gas (LPG), generally used as a secondary cooking fuel, but did not influence a similar shift from traditional mud stoves as the primary cooking technology. Likewise, the shift from firewood to electricity as a primary cooking fuel was observed in only 5% of the households studied. Country level analysis indicates that rural households falling in lower monthly per capita expenditure (MPCE) classes have lesser access to electricity and clean cooking options than those falling in higher MPCE classes. Again, only three states in India with high levels of rural household electrification report consumption statuses more than 82 kWh per month (the estimated mean for electricity consumption by induction stoves). Overall, the results of the study indicate that induction stoves will have limited potential in reducing the consumption of firewood and LPG if included in energy access programmes, that too only in regions where high levels of electrification exist. - Highlights: • Primary survey of induction stove users was conducted in 1000 rural households. • In 84% households, electricity replaced LPG as the secondary cooking fuel. • In only 5% households, electricity replaced firewood as the primary cooking fuel. • Electricity as a cooking fuel for rural India still needs massive investments. • Currently, induction stoves are only able to reduce consumption of firewood and LPG.