نتایج جستجو برای: reduces maintenance costs and operation of irrigation systems
تعداد نتایج: 24146196 فیلتر نتایج به سال:
one of the consequences of poor management and operation of irrigation systems, poor water delivery and distribution channels and divisions and consequently improper distribution of water level downstream. the study of simulation and performance evaluation software using hydrodynamic sobek varamin irrigation is done. in order to evaluate the network performance and compare the results of simula...
the management of machine replacement (specifically tractors) is one of the most critical factors for performing field operations on time. therefore, tractor repair and maintenance costs must be accurately predicted. this research was carried out to evaluate the use of the regression technique in predicting tractor repair and maintenance costs. the study was conducted using empirical data on 60...
Infiltration is the most crucial process affecting surface irrigation uniformity and efficiency as it is the mechanism that transfers and distributes water from the surface to the soil profile. As a direct method of infiltration measurement, the volume balance method requires time, accuracy and high costs. Moreover, before the land preparation and at the research phase the use of this method is...
Recent studies have shown poor performance of irrigation systems, which indicates the requirement for special attention to performance improvement. The first step for improving the performance of irrigation systems is evaluation of the present situation. Performance evaluation methodologies presented so far are either qualitative such as DA (Diagnostic Analysis), RA (Rapid Appraisal) and FA (Fr...
Recent studies have shown poor performance of irrigation systems, which indicates the requirement for special attention to performance improvement. The first step for improving the performance of irrigation systems is evaluation of the present situation. Performance evaluation methodologies presented so far are either qualitative such as DA (Diagnostic Analysis), RA (Rapid Appraisal) and FA (Fr...
Borage (Borago officinalis L.) is a valuable medicinal plant and its production to meet the needs of the pharmaceutical industry has a high value. The objectives of this work were to evaluate water quality and different fertilizer systems on some physiological and biochemical characteristics of borage. The experiment was conducted as a split-plot arrangement based on compelet block design with ...
Despite concern over poorly maintained irrigation systems and insufficient investment in operations and maintenance (O&M) for irrigation systems in most developing couqtries, there is little agreement about how much money is required. A review of 18 Asian Development Bank (ADB) appraisal reports for irrigation projects in Asia, covering the period 1969-78, revealed O&M estimates ranging from US...
High-power diesel-based or grid-connected irrigation systems are being replaced by battery-free, high-power stand-alone Photovoltaic Irrigation Systems (PVIS) that reduce energy costs up to 80% and for which no experimental performance data available. The operation of PVIS is affected various factors, some unrelated the quality PV system itself, generate losses affect their performance: vary wi...
abstract abstract of thesis (includes summary, goals, execution methods, and results) story “al-obnosat al-bayza” is one of the short stories from “hanna mineh” collection. this story is a selection of lives of some humans during a voyage together, each of them is a symbol of human nature (love, mind, kindness) and examine social, cultural, and political aspects of governing system, and it...
در این پایان نامه به بررسی روش های آشکارسازی در سیستم های mc-cdma می پردازیم. با توجه به ماهیت آشکارسازی در این سیستم ها، تکنیک های آشکارسازی را می توان به دو دسته ی اصلی تقسیم نمود: آشکارسازی سیگنال ارسالی یک کاربر مطلوب بدون در نظر گرفتن اطلاعاتی در مورد سایر کاربران تداخل کننده که از آن ها به عنوان آشکارساز های تک کاربره یاد می شود و همچنین آشکارسازی سیگنال ارسالی همه ی کاربران فعال موجود در...
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