2 research outputs found

    The recent expansion of an avian invasive species (the Cattle Egret Ardea ibis) in Algeria

    Get PDF
    This study identifies new information on the recent distribution of an invasive bird species, the Cattle Egret Ardea ibis, in Algeria. Breeding and wintering distributions as well as breeding numbers were obtained from large-scale surveys in 1999 and 2007, and from historical data. Between 1999 and 2007, the total number of colonies found increased from 51 to 87, and most were located in the northern part of the country. The breeding distribution area, confined to the coastal areas in the 1970s, has shifted further south, and reached the northern part of the Sahara since the 2000s. Most colonies were established during the period 1980-1995. The oldest colonies were generally larger than the recent ones. The number of colonies increased by 83% between 1999 and 2007 in the 12 administrative units (wilayas) surveyed. The number of breeding pairs increased from 7765 in 1999 to 28544 in 2007, corresponding to an annual population growth rate of 17.7%. The changes in distribution and population dynamics since the 1970s and the potential factors affecting these changes are discussed

    A Versatile Solar and Electric Water Distiller

    Get PDF
    Abstract— The present paper discusses the feasibility and the features of a newly designed portable water desalinator/distiller. The goal is to design a small unit for desalinating or distilling brackish or soiled water. The proposed desalinator/distiller is a hybrid system that uses two sources of energy, namely: solar and electrical. It relies on solar energy when being used at locations where electricity is expensive or inaccessible. On the other hand, it uses electric energy when sunshine is unavailable for considerable periods of time, such as under rainy or cloudy skies, or during winter seasons when the sun radiation is weak or not enough to evaporate water.    This innovative project is aimed to benefit communities in rural villages, long journey travelers in deserts and arid mountains, people living alongside polluted rivers and lakes, and people living in refugees’ camps.  It can also benefit people with hard water supplies.   The paper investigates and discusses the proposed hybrid desalinator/distiller (HDD). The work presented is based entirely on the work carried out by final year electrical engineering students, during their capstone design project. The project work, presented, is a manifestation of the students learning during previous semesters. It puts into practice the application of thermal and heat transfer principles, that the student learned in earlier courses.   Index Terms—Desalination,desalinator,distiller,solar still,solar energy
    corecore