نتایج جستجو برای: hydraulic system was assessed then

تعداد نتایج: 5904866  

2017
Fanhui Zeng Xiaozhao Cheng Jianchun Guo Liang Tao Zhangxin Chen

The selection of appropriate wells for hydraulic fracturing is one of the most important decisions faced by oilfield engineers. It has significant implications for the future development of an oilfield in terms of its productivity and economics. In this study, we developed a fuzzy model for well selection that combines the major objective criteria with the subjective judgments of decision maker...

Journal: :Computers and Electronics in Agriculture 2016
J. B. W. Roeber Santosh K. Pitla M. F. Kocher Joe D. Luck Roger M. Hoy

Tractor hydraulic power is used on a wide range of agricultural implements; however, the availability of operational hydraulic data at points other than full engine throttle position is limited. Operators could utilize this hydraulic data to maximize field efficiency and minimize machinery costs when determining suitable machinery for field operations. A field usable hydraulic test apparatus ca...

In this study a modified entropy-based measure is presented for evaluating the serviceability level of water distribution networks in which the hydraulic uncertainties (flow rates in pipes) as well as the uncertainties due to mechanical parameters (failure probabilities of links) are considered simultaneously. In the proposed entropy calculation method, the connectivity order of the network dem...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده روانشناسی و علوم تربیتی 1389

چکیده : تحقیق حاضر به منظور مقایسه دو روش تدریس انتزاعی و تدریس در متن بر یادگیری دستور زبان ایتالیاییِ زبان آموزان ترم 1 مدرسه ایتالیایی تهران در تابستان 89 صورت گرفت. روش تحقیق آزمایشی بوده و پژوهش بر 30 نفر از زبان آموزان مدرسه ایتالیایی تهران که بصورت تصادفی به 2 گروه جایگزین شدند صورت گرفت. ابزار تحقیق آزمون 30 سوالی تستی از بانک سوالات استاندارد شده بود که به تصادف انتخاب شده بودند.روشهای...

Journal: :Advances in transdisciplinary engineering 2022

This paper studies the electro-hydraulic proportional position control system of a hydraulic rock drilling jumbo. First all, composition is introduced and transfer function components established, mathematical model whole finally obtained through calculation simplification. Then, PID fuzzy strategy were designed by MATLAB software, was built in simulink. Finally, results indicate that controlle...

2017
Elisabet Martínez-Sancho Isabel Dorado-Liñán Uwe G. Hacke Hannes Seidel Annette Menzel

Many temperate European tree species have their southernmost distribution limits in the Mediterranean Basin. The projected climatic conditions, particularly an increase in dryness, might induce an altitudinal and latitudinal retreat at their southernmost distribution limit. Therefore, characterizing the morphological and physiological variability of temperate tree species under dry conditions i...

Journal: :Tree physiology 2008
Sabine Rosner Andrea Klein Ulrich Müller Bo Karlsson

We tested the effects of growth characteristics and basic density on hydraulic and mechanical properties of mature Norway spruce (Picea abies (L.) Karst.) wood from six 24-year-old clones, grown on two sites in southern Sweden differing in water availability. Hydraulic parameters assessed were specific hydraulic conductivity at full saturation (ks100) and vulnerability to cavitation (Psi50), me...

2002
Liu Rong Wang Xuanyin Tao Guoliang Ding Fan

In this paper, the hydraulic servo position control system with generalization pulse code modulation (GPCM) control is studied. The flow rate of the GPCM control system is controlled by a series of N solenoid on-off valves which are calibrated having different flow, and are activated by N bits binary pulse codes. In traditional PCM control, the flow rates of valves are arranged increasing accor...

جلیلوند, حمید, حسینی, سید عطاءاله, لطفعلیان, مجید, پارساخو, آیدین,

Forest roads must be constructed according to technical standards and guidelines which have been published by the scientific and operational organizations. Recently, hydraulic excavators have been used beside the bulldozer for excavating the forest roads. Thus, it is necessary that their ability in construct of standard cross sections be compared. This study was conducted in Lattalar forest whi...

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