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41.
Nitrogen use per unit area in Egyptian agriculture is over 300 kg ha–1. An annual average increase of about 2% till year 2000 was estimated. Fertilizers use is characterised by excessive N application, moderate P use and neglection of K and micronutrients. Consequently, nutrient imbalance occurs in crop plants. Subsidising N fertilizers resulted in their misuse and increasing losses. Efficiency of N use in different areas and crops is low. High nitrate concentrations were detected in drainage as well as ground water. Subsidy was removed and fertilizers handling was left to the free market in 1992/93, which resulted in drastic price increases. It could be demonstrated for many years and in farmers fields that yields can be considerably increased (20%) through balanced fertilizers use based on soil testing and plant analysis and adjusted according to the prevailing farming system, leading to more return and less N-use. Use of micronutrients foliar fertilizers leads to increase in root growth and higher uptake of macronutrients. Use of relatively high rates of fertilizers is still a must, however it should be optimised to obtain the highest possible efficiency. Making crop and location specific fertilizer recommendations available to farmers helps in increasing high quality yields, which results in high economic benefits, keeping agricultural production sustainable and decreasing pollution.  相似文献   
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Effect of provenance of organic matter evaluated through the distribution of occurrence of triterpanes and steranes in surface sediments from coastal stations located in the Gulf of Suez Gulf. The samples have been studied in four coastal stations located in the Gulf of Suez namely: Al–Nasr Oil Company (NPC), West outlet of SOPC, Inlete of SOPC, and El-Sukhna of Loloha Beach. Saturated hydrocarbons were analyzed by gas chromatography–mass spectrometry, to assessing of organic content and maturity level of the sediments. The results showed that the hydrocarbons are originated mainly from predominance of petrogenic and biogenic hydrocarbons with high maturity level.  相似文献   
44.
The drought in Ethiopian Highlands, source of the Nile flood, has been in the news off and on since the early 1970s, to such an extent that it can be inquired if the Nile basin users are exposed to a drought risk increasing in time. Based on a methodology developed by the author and previously used for flood risk assessment, this article aims to study the progressive modification of the likelihood of occurrence of a certain drought event in the Nile River, based on the annual record available at the Aswan station, Egypt. The record is thoroughly studied to detect possible trends and seasonalities. It is then divided into subsamples, on which frequency analyses were performed using the linear moments (L-moments) method. L-moments perform well with short records and are less sensitive to extremes. The 10-, 25-, 50- and 100-year droughts are estimated based on every subsample, then the temporal evolutions of these estimates are investigated. The results show a cyclic pattern of the drought risk, confirming the previously suggested non-stationarity of the flow series as one of the possible interpretation of the Hurst phenomenon.  相似文献   
45.
Several models of multi-criteria decision-making (MCDM) have identified the optimal alternative electrical energy sources to supply certain load in an isolated region in Al-Minya City, Egypt. The load demand consists of water pumping system with a water desalination unit. Various options containing three different power sources: only DG, PV-B system, and hybrid PV-DG-B, two different sizes of reverse osmosis (RO) units; RO-250 and RO-500, two strategies of energy management; load following (LF) and cycle charging (CC), and two sizes of DG; 5 and 10 kW were taken into account. Eight attributes, including operating cost, renewable fraction, initial cost, the cost of energy, excess energy, unmet load, breakeven grid extension distance, and the amount of CO2, were used during the evaluation process. To estimate these parameters, HOMER® software was employed to perform both the simulation and optimization process. Four different weight estimation methods were considered; no priority of criteria, based on a pairwise comparisons matrix of the criteria, CRITIC-method, and entropy-based method. The main findings (output results) confirmed that the optimal option for the case study was hybrid PV-DG-B with the following specification: 5 kW DG, RO-500, and load following control strategy. Under this condition, the annual operating cost and initial costs were $ 5546 and $ 161022, respectively, whereas the cost of energy was 0.077 $/kWh. The excess energy and unmet loads were 40998 and 2371 kWh, respectively. The breakeven grid extension distance and the amount of CO2 were 3.31 km and 5171 kg per year, respectively. Compared with DG only, the amount of CO2 has been sharply reduced by 113939 kg per year.  相似文献   
46.
本文从埃及的标准化机构、标准管理体制、参与国际标准化活动等方面介绍了埃及标准化发展现状,着重介绍了埃及标准的概况,并提供了检索查询埃及标准的方法。  相似文献   
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The construction industry is heavily affected by the troubles arising out of construction disputes, especially when it comes to large-scale projects, as a direct result of the inherent complexity of such projects. This paper seeks the most suitable dispute-resolution mechanism for large-scale construction projects in Egypt, which is a developing country in the Middle East with an emerging reformed economical policy, a population in excess of 70 million people, and an increasing need for infrastructure and industrial development. This dispute-resolution mechanism was attained through a multistep methodology that (1) started with the study of the Arbitration process in relation to an Egyptian construction project with an initial contract price of 85 million; (2) continued with interviews of five senior experts in the field of construction disputes in Egypt about their views pertaining to the most efficient dispute-resolution methodology for Egyptian megaprojects; (3) developed a tailored questionnaire to assess the perceptions of 35 professionals toward the issue of construction disputes and dispute resolution mechanisms, including DRB; (5) concluded by carrying out a what-if scenario for the arbitration case of the large-scale construction project using DRB instead of arbitration. On basis of the analysis of the methodology, the authors concluded that despite the wide range of current dispute-resolution methodologies, the employment of DRBs in accordance with a set of 13 regulatory guidelines should mitigate the negative effects of disputes in Egyptian large-scale construction projects. Accordingly, this paper is both timely and valuable for all owners, contractors, and professionals who are acquainted with Egyptian megaprojects.  相似文献   
49.
Although dietary intake studies have been carried out extensively in most developed countries, to evaluate the health risks of PCDD/Fs and DL-PCBs, no data of this kind exists for Egypt. In this study, concentrations of PCDD/Fs and DL-PCBs were measured using HRGC/HRMS in the most contributing foodstuffs (dairy products, fish/seafood, and meat) randomly collected from Ismailia city, Egypt. The dietary intake of PCDD/Fs and DL-PCBs were subsequently determined, and compared with the most recent studies. To provide a primary estimation of the whole TEQ intake in Egypt if all the main food categories included, an estimation of the dietary intake (based on EU data) for some important and non-measured groups (cereals, vegetables/fruits, eggs and milk) was carried out. The calculated dietary intake based on the WHO assumption of 60 kg bw ranged from 3.69 to 4.0 pg WHO-TEQ/kg bw/day for PCDD/Fs and from, 6.04 to 6.68 pg WHO-TEQ/kg bw/day, if DL-PCBs were included. PCBs intake contributed about 40% of the total TEQ intake. Dairy products (mainly cheese) were the main contributor to the intake of PCDD/Fs (89%), while fish/seafood and meat have more or less the same percent share (5.4%). The dairy products contamination was the reason for our elevated dietary intake, as the content of PCDD/Fs and DL-PCBs is several times higher than in all the developed countries. The total intake (PCDD/Fs+DL-PCBs) due to consumption of dairy products, fish/seafood and meat, is close to that reported in EU countries at the beginning of 1980s, but much higher than all those mentioned in all the recent reports, and higher than the maximum WHO TDI of 4 pg TEQ/kg bw/day. A recalculation of the dietary intake to include not only our measured data but also the data for the non-measured groups, yielded a total intake in the range of 4.06-6.38 pg TEQ/kg bw/day for PCDD/Fs and a range of 6.59-9.98 pg TEQ/kg bw/day for total including PCBs. Results show that cereals and vegetables/fruits contribute significantly to PCDD/Fs TEQ intake in Egypt and play a more important role than fish/seafood and meat. This is the case even though the intake for cereals and vegetables/fruits based on EU data.  相似文献   
50.
张晶 《世界电信》2000,13(1):32-34
从1982年起,埃及电信业开始了一系列的五年计划,旨在集中力量发展埃及的电信网络和业务。国外各大电信设备制造商如阿尔卡特、朗讯科技、爱立信、西门子等活跃在埃及的电信设备市场,协助埃扩展其电信基础设施。目前埃及共有3家大的电信运营公司:埃及电信、埃及移动电话业务公司(ECMS)和国际移动电话集团Misrfone。  相似文献   
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