• Title/Summary/Keyword: River Nile

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The Influence of Optical Porosity of Tree Windbreaks on Windward Wind Speed, Erosive Force and Sand Deposition

  • Dafa-Alla, M.D.;Al-Amin, Nawal K.N.
    • Journal of Forest and Environmental Science
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    • v.32 no.2
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    • pp.212-218
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    • 2016
  • The research was conducted windward of an irrigated Acacia amplicips Maslin windbreak established to protect As Salam Cement Plant from winds and moving sands. Two belts with approximate optical porosities of 50% and 20% were studied in River Nile State, Sudan. The research aimed at assessing the efficiency of the two belts in wind speed reduction and sand deposition. Research methods included: (i) estimation of optical porosity, (ii) measurements of windward wind speeds at a control and at distances of 0.5 h (h stands for windbreak height), 1 h and 2 h at two vertical levels of 0.25 h and 0.5 h, (iii) estimation of relative wind speeds at the three positions (distance and height) at windward and (iv) estimation of wind erosive forces and prediction of zones of sand deposition. Results show that while the two belts reduced windward wind speeds at the two levels for the three distances, belt II was more effective. Nearest sand deposition occurred at 2 h and 1h windward of belt II and belt I, respectively, at level 0.25 h. At level 0.5 h, sand was deposited only at 2 h windward of belt II and no sand deposition occurred windward of belt I. The study concludes that less porous windbreaks are more effective in reducing wind speed and in depositing sand in windward direction at a distance of not less than twice the belt height.

Isolation and Characterization of Antibiotic and Heavy Metal-Resistant Pseudomonas aeruginosa from Different Polluted Waters in Sohag District, Egypt

  • Soltan, El-Sayed.M.
    • Journal of Microbiology and Biotechnology
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    • v.11 no.1
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    • pp.50-55
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    • 2001
  • Different polluted water samples were collected from a wastewater treatment plant, agricultural drainage canals, the River Nile, and irrigation canals. The samples were examined for the enumeration of Pseudomonas aeruginosa in the Sohag area, Egypt over a period of one year. A total of 240 isolates were collected and tested for their resistance to 12 common antibiotics and 6 heavy metals. The isolates were found to be less resistant to norfloxacin(1.7%), ofloxacin(4.6%), amikacin(9.6%), tobramycin (10.4), carbenicillin (15.4), and gentamycin (41.3%), yet more sensitive to rifampicin (75%), kanamycin (89.6%), ampicillin (90.8%), chloramphenicol (91.7%), streptomycin (92.9%), and tetracyclin(96.3%). In contrast, 7.1%, 12.9%, 25.4%, and 53.7% of the isolates were resistant to lead, cadmium, mercury, and zinc, respectively. None of the isolates had developed a resistance to silver or molybdenum. The high frequency of metal-antibiotic double resistance existed between lead and amikacin (56.5%), cadmium and ofloxacin (72.7%), zinc and norfloxacin (100%), and mercury and carbenicillin (94.6%). The high occurrence of antibiotic-resistant bacteria in natural water could be related to the widespread use of antibiotics, with possible public health hazard.

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The population characteristics of Nile tilapia (Oreochromis niloticus) in Dalseo Stream, South Korea (달서천에 서식하는 나일틸라피아(Oreochromis niloticus) 개체군 특성)

  • Wang, Ju Hyoun;Choi, Jun Kil;Lee, Hwang Goo
    • Korean Journal of Environmental Biology
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    • v.38 no.1
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    • pp.127-136
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    • 2020
  • This study was conducted to investigate the population characteristics of Nile tilapia (Oreochromis niloticus) in the Daegu Metropolitan City thermal effluent stream (Dalseo Stream) from January to November 2019. The collected fish were identified as 4,247 individuals of 20 species from a total of eight families. The dominant species was O. niloticus with 1,306 individuals and a high relative abundance (30.75%). The water temperature of Dalseo Stream was maintained above 10℃ throughout the year, which means that O. niloticus could inhabit it even in winter. The length-weight analysis showed a regression coefficient b of 3.1496, and a condition factor (k) of 0.0025 with a positive slope. Comparing the water temperature of Dalseo Stream and the total length of O. niloticus per investigation period, the 0-age individuals appeared May 29 when the water temperature was maintained above 22℃. In conclusion, the thermal effluent of Dalseo Stream allowed O. niloticus to survive in winter and maintain stable growth conditions and life cycles. The results of this study will inform ecological information on O. niloticus, which suggests that river management efforts should consider the management of O. niloticus populations for the conservation of fish species diversity.

A Fast Bayesian Detection of Change Points Long-Memory Processes (장기억 과정에서 빠른 베이지안 변화점검출)

  • Kim, Joo-Won;Cho, Sin-Sup;Yeo, In-Kwon
    • The Korean Journal of Applied Statistics
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    • v.22 no.4
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    • pp.735-744
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    • 2009
  • In this paper, we introduce a fast approach for Bayesian detection of change points in long-memory processes. Since a heavy computation is needed to evaluate the likelihood function of long-memory processes, a method for simplifying the computational process is required to efficiently implement a Bayesian inference. Instead of estimating the parameter, we consider selecting a element from the set of possible parameters obtained by categorizing the parameter space. This approach simplifies the detection algorithm and reduces the computational time to detect change points. Since the parameter space is (0, 0.5), there is no big difference between the result of parameter estimation and selection under a proper fractionation of the parameter space. The analysis of Nile river data showed the validation of the proposed method.

A Study on the Characteristics of the Designs on Coptic Textiles of Ancient Egypt

  • Han, Jung-Im
    • Journal of Fashion Business
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    • v.15 no.3
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    • pp.112-124
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    • 2011
  • Textile and clothing in Ancient Egypt have carried long history and tradition. Especially, Egyptian textile culture, created mostly by the Copt, has the originality of weaving technology and the artistic beauty of the weaving motifs, making the textiles comparable to modern textiles. The purpose of this study is to research on the characteristics of Coptic textile designs of ancient Egypt and the tunic, a basic garment made of Coptic textiles, and offer materials for the development of the textiles and designs with artistic values which can be shared in the modern era, not just for the research of the relics of the past. Therefore, this study will follow the historical background of Coptic textiles and the process of the development, and look into the distinct features under the categories of material, colors and motifs. In addition, the tunic and its weaving technology will be explained and this will help understand the originality of Coptic textiles. The scope of this study is limited to the period of the 3rd to 12th centuries when the Egyptian weaving technologies advanced dramatically and many of the ancient Egyptian textiles discovered from the grave goods dates back, the research methode of the tunic as well as books published at home and abroad, research paper and photograph works. The textiles had developed along the Egyptian history which was influenced by different cultures such as Greek, Roman, pagan, Christian, and later, Islamic. For the textiles, they used a variety of pictorial motifs including Greek goddesses, pastoral scenes related to the Nile River and animals, human figures, geometrical figures and Christian icons. They are symbolic, natural, and mythological characters, and this explains that the world views and religions of the weavers influenced the development of specific motifs. Coptic textiles was used to make a tunic, a simple straight-sided gown without sleeves worn by men and women and was woven in a combination of linen plain weave and woolen tapestry weave for a tunic. Not only the excellence of the weaving technologies and the beauty of the colors used in the textiles, but also the diversity of the textures through weaving, embroidery, and knotting are detected in Coptic textiles.

Identification of Green Alga Chlorella vulgaris Isolated from Freshwater and Improvement Biodiesel Productivity via UV Irradiation

  • Gomaa, Mohamed A.;Refaat, Mohamed H.;Salim, Tamer M.;El-Sayed, Abo El-Khair B.;Bekhit, Makhlouf M.
    • Microbiology and Biotechnology Letters
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    • v.47 no.3
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    • pp.381-389
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    • 2019
  • Chlorella vulgaris was isolated from the Nile River, Qalubia Governorate, Egypt, for possible use in biodiesel production. BG-II nutrient growth media was used for isolation and laboratory growth. Identification was performed via 18S rRNA gene amplification, followed by sequencing. The alga was exposed to UV-C (254 nm) for 15, 30, and 45 s to improve dry weight accumulation and to increase the oil production. Daily measurements of dry weight ($g{\cdot}l^{-1}$) were performed; oil content and volumetric lipid productivity were also determined. UV-C exposure led to an increase in the volumetric lipid productivity by 27, 27.3, and $32.4mg{\cdot}l^{-1}{\cdot}d^{-1}$ with 15, 30, and 45 s, respectively, as compared with the control, which resulted in $18mg{\cdot}l^{-1}{\cdot}d^{-1}$. Of the examined mutants, the one with the highest productivity was re-irradiated by UV-C (254 nm) for 15, 30, 45, and 60 s. For 15 s of exposure time, the oil content increased to 34%, while it was 31% at 30 s; further, it decreased to 22% at 45 and 60 s exposures. The fatty acid methyl ester profile was 82.22% in the first mutant at 45 s, compared with the wild strain that contained a total of 66.01% of FAs. Furthermore, the highest levels of polyunsaturated fatty acid methyl ester were observed in the mutant exposed for 45 s, and it reached 11.41%, which reduced the cetane number to 71.3.