45 research outputs found
Characterization of greater middle eastern genetic variation for enhanced disease gene discovery
The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics
Degradation mechanism in zinc sulphide/manganese electroluminescent displays
SIGLEAvailable from British Library Document Supply Centre- DSC:D88195 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Fuel cells, an alternative to standard sources of energy
Three E's are the national energy policy drivers of any country of the world, Energy security, Economic growth and Environmental protection. A fuel cell is an energy conversion device that produces electricity by electrochemically combining fuel (hydrogen) and oxidant (oxygen from the air) gases through electrodes and across an ion conducting electrolyte. The principal characteristic of a fuel cell is its ability to convert chemical energy directly into electrical energy giving much higher conversion efficiencies than any conventional thermo-mechanical system thus extracting more electricity from the same amount of fuel, operate without combustion so they are virtually pollution free and have quieter operation since there are no moving parts. The emission of fuel cells running on hydrogen derived from a renewable source will be nothing but water vapour. Fuel cells are presently under development for a variety of power generation applications in response to the critical need for a cleaner energy technology. This paper reviews the existing or emerging fuel cells technologies, their design and operation, their limitations and their benefits in connection with energy, environment and sustainable development relationship. Few potential applications of fuel cell will be discussed.
Assessing the wind energy potential projects in Algeria
A research program is under way in the SONELGAZ R&D Office with the aim of studying the potential of wind energy in Algeria. This paper presents an analysis of recently collected hourly wind data over a period of almost 5 years between 2002 and 2006, from four selected sites as well as preliminary evaluation of the wind energy potential. The results showed that Tindouf and Dély Brahim sites have higher wind energy potential with annual wind speed average of 5.8 and 5.7 m/s respectively at height of 17 m above ground level (AGL). The two sites are candidates for remote area wind energy applications. The Ouled Fayet and Marsa Ben M'hidi sites wind speed data indicated that the two sites have lower annual wind speed averages between 3.9-4.7 m/s at 17 m AGL. That makes the two sites candidates for installation of windmills to provide water for drinking and small scale irrigation purposes Brief description of the equipment, is also performed. Finally the aim of this work is only a preliminary study in order to assess wind energy analysis in Algeria and give useful insights to engineers and experts dealing with wind energy.Algeria Parameter Weibull Projects WAsP Wind energy
Wind power resource in the south-western region of Algeria
In this study, we present a statistical analysis of wind speeds at Tindouf in Algeria using Risoe National Laboratory's Wind Atlas Analysis and Application Program (WAsP). It requires information related to the sheltering obstacles, surface roughness changes and terrain height variations in order to calculate their effects on the wind. Wind data, consisting of hourly wind speed records over a 5-year period, 2002-2006, were obtained from SONELGAZ R&D Office; the average wind speed at a height of 17 m above ground level was found to range from 7.19 to 7.95 m/s. The Weibull distributions parameters (c and k) were found to vary between 8.0 and 8.9 m/s and 2.54-3.23, respectively, with average power density ranging from 318 to 458 W/m2. The dominant wind directions and the frequency distributions were also determined.Tindouf WAsP Weibull parameters Wind power resource
NEW INSIGHT IN THE DERIVATION OF AMPLIFICATION FACTOR BY TAKING INTO ACCOUNT SOIL PARAMETERS
International audienceIt is currently admitted that the amplification factor (AF) is one of the best tools to describe site effects. AF depends on soil parameters that are derived from the geometrical and mechanical soil properties of the soil profile. Thus, it is important to identify which soil parameters shape the form of the AF. The aim of this paper is to measure the effects of various site parameters on the variation of AF. As the problem is highly complex, a tool using the GRNN (Generalized Regression Neural Network) to understand which soil parameters have been developed. For a particular soil profile it has been found that values of AF derived from GRNN approach are closer to that of 1D linear viscoelastic seismic analysis particularly if the number of parameters increases. Based on this result a sensitivity analysis has been conducted to identify which parameters give good AF. For the practical case where we have to introduce only two parameters, it has been observed that the couple [resonance frequency (f 0) , time-averaged shear-wave velocity in the top 30 m (Vs30)] is the most interesting