نتایج جستجو برای: mass density

تعداد نتایج: 849091  

Journal: :Applied Physics Letters 2010

جامی‌الاحمدی, نرگس, عباسی, شهرام, قنبری, جمشید,

In this paper,the effect of troidal magnetic field is studied in standard self-gravitating thin disks with β priscription. By applying the magnetic field, we expect to see different behaviors compared to a non-magnetic field case.The study reveals self-similar solutions for radial infall velocity, rotation velocity, surface density and mass accretion rate. Our results also show that by increasi...

ژورنال: آبخیزداری ایران 2022

The aim of this study was to evaluate the impact of forest on erosion and runoff variables and compare it with rangeland and agricultural in part of Mereg watershed located in Kermanshah province. At first, three forest mass were identified and divided into three density categories (low, medium and Many), then Soil and hydrological parameters were measured in each forest density area and also i...

Journal: :physical chemistry research 0
seyed ahmad razavizadeh department of chemistry, payame noor university, p. o. box: 19395-3697, iran setareh sheikh department of chemistry, shiraz branch, islamic azad university zeinab nassaj gerowgi department of chemistry, payame noor university

density, viscosity and refractive index of pure, binary and ternary mixtures of diethanolamine (dea) and methyl diethanolamine (mdea) with water have been measured at different temperatures from 288.15 k to 323.15 k at atmospheric pressure. also, this study presents the effects of mixture composition and temperature upon these thermo- physical properties. to measure the density and refractive i...

ژورنال: سنجش و ایمنی پرتو 2020

In this research, water equivalent ratios (WER) at helium ion beam energy ranging 25-250 MeV/u for four potential plastic dosimetric materials: polycarbonate (PC), polypropylene (PP), polymethyl methacrylate (PMMA), and paraffin have been calculated using MCNPX Monte Carlo code. Among studied materials, PC and PP with 0.979 and 1.177 show minimum and maximum differences with water respectively....

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده علوم 1393

in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...

Journal: :مهندسی بیوسیستم ایران 0
مهدی کرامت جهرمی شاهین رفیعی علی جعفری سیدسعید محتسبی رضا میراشه

as a first step towards mechanization related to any product, including date fruit, it is necessary to have comprehensive information about the product. physical and mechanical properties are needed for the design of post harvest machinery and equipment. the objective of this study was to determine and compare some physical properties such as dimension, mass and volume, particulate density, pit...

Journal: :caspian journal of environmental sciences 2010
a. najafi

the effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope ( 20%.) the results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slope...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2001
R Rajesh S N Majumdar

We reexamine a simple lattice model of aggregation in which masses diffuse and coalesce upon contact with rate 1 and every nonzero mass chips off a single unit of mass and adds it to a randomly chosen neighbor with rate w. The dynamics conserves the average mass density rho and in the stationary state the system undergoes a nonequilibrium phase transition in the (rho-w) plane across a critical ...

Journal: :Physical review letters 2001
J Weller A Albrecht

We investigate the potential of a future supernova data set, as might be obtained by the proposed SNAP satellite, to discriminate among different "dark energy" theories that describe an accelerating Universe. We find that many such models can be distinguished with a fit to the effective pressure-to-density ratio w of this energy. More models can be distinguished when the effective slope dw/dz o...

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