نتایج جستجو برای: such as soil properties

تعداد نتایج: 6515199  

Journal: :تحقیقات آب و خاک ایران 0
علیرضا راهب دانشگاه تهران احمد حیدری دانشگاه تهران شهلا محمودی دانشگاه تهران

soil genesis and evolution studies are based on well understanding of geochemical processes involved in pedogenic processes and formation of soil. parent materials are main factors controlling soil properties in arid and semiarid regions. in this study, physicochemical and geochemical properties of 6 selected soil profiles developed on basalt rocks along arid (eshtehard), semiarid (qazvin) and ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1389

oxidative addition reactions of 1,4-diiodo-butane and 1,3-diiodo-propane with [ptme2(ph2phen)]; in which ph2phen=4,7-diphenyl-1,10-phenanthroline, were studied in different solvents such as acetone and benzene.oxidative addition reaction of [pt me2(ph2phen)] with i(ch2)4i and i(ch2)3i produced the [pt me2i(ch2)4(ph2phen)i] (1a) and [pt me2i(ch2)3(ph2phen)i] (1b).all the platinum (iv) products w...

Masood Makarchian, Mehdi Zamani Lenjani, Mohammad Hossin Bazyar, Mostafa Ebrahimi,

Geotechnical engineers, in many cases face with low strength or high swelling potential of clayey soils. Stabilization methods are used to improve the mechanical properties of this type of soils. Lime and cement are the most popular materials used in chemical stabilization of clayey soils. If sulphate exists in the stabilized clayey soil with lime, or if soil is exposed to sulphates, problems s...

ژورنال: علوم آب و خاک 2011
مهدی همایی, , وحیدرضا جلالی, ,

Soil bulk density measurements are often required as an input parameter for models that predict soil processes. Nonparametric approaches are being used in various fields to estimate continuous variables. One type of the nonparametric lazy learning algorithms, a k-nearest neighbor (k-NN) algorithm was introduced and tested to estimate soil bulk density from other soil properties, including soil ...

A. Lakhdar, Ch. Abdelly F. Montemurro, T. Ghnaya Y. Ouni

The environmental, social and economical reasons indicate that the conventional agriculture constitute a continuous pressure contributing to the progressive worsening of environmental conditions, especially by an increasing apply high level of inputs. In this matter, the increasing use of saline irrigation water is one of the main factors resulting in salt accumulation in the plant rhizosp...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده ادبیات و علوم انسانی 1393

from its emergence till present time marxist principles has undergone great changes since their promulgation by marx. many theorists and thinkers set at rectifying marxist tenets and introducing those of their own while others advocated its main concepts and attempted at improving them. among marxist philosophers who had an intensive study of marxs ideology, is louis althusser whose reflections...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده ریاضی 1390

the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

Sterilized soils are commonly used for the study of xenobiotic sorption and as an abiotic control in biodegradation experiments. They are also used for the chemical study of nitrogen and carbon cycle processes and the elimination of the biological factors. In this research the effects of different soil sterilization methods such as autoclaving, fumigating and exposure to ultraviolet and microwa...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی برق و کامپیوتر 1391

this thesis is presented 10 ghz voltage controlled ring oscillator for high speed application. the voltage controlled ring oscillator was designed and fabricated in 0.13یm cmos technology. the oscillator is 7-stages ring oscillator with one inverter replaced by nand-gate for shutting down in the ring oscillator during idle mode. tri-state inverter was used to control of 126 bit vector in ri...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم پایه دامغان 1390

the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...

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