نتایج جستجو برای: natural attenuation

تعداد نتایج: 528625  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate t...

Journal: :Industrial and Domestic Waste Management 2022

Rapid population growth resulting in industrial proliferation and urbanization has led to the rapid increase pollution of environment. Paint industries urban areas mostly channel their wastewater into streams on land, which results receiving This study aims determine impact effluent discharges from paint soils’ physicochemical properties clean-up polluted soil through monitored natural attenuat...

Background: In this study, a method for linear attenuation coefficient calculation was introduced.Methods: Linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. The calculation was done for Cerrobend as a common radiotherapy modifier and Mercury.Results: The values...

Journal: :journal of biomedical physics and engineering 0
f seif arak university of medical sciences m j tahmasebi-birgani ahvaz jundishapur university of medical sciences m r bayatiani arak university of medical sciences

background: in this study, a method for linear attenuation coefficient calculation was introduced. methods: linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. the calculation was done for cerrobend as a common radiotherapy modifier and mercury. results: the valu...

Journal: :iranian journal of medical physics 0
shahla ahmadi m.sc. in nuclear engineering, faculty of engineering, science and research branch, islamic azad university, tehran, iran hossein rajabi associate professor, medical physics dept., faculty of medicine, tarbiat modares university, tehran, iran farshid babapoor assistant professor, nuclear engineering dept., faculty of engineering, science and research branch, islamic azad university, tehran, iran faraz kalantari ph.d. student, medical physics dept., faculty of medicine, tarbiat modares university, research institute for nuclear medicine, tehran university of medical sciences,tehran, iran

introduction: the main goal of spect imaging is to determine activity distribution inside the organs of the body. however, due to photon attenuation, it is almost impossible to do a quantitative study. in this paper, we suggest a mathematical relationship between activity distribution and its corresponding projections using a transfer matrix. monte carlo simulation was used to find a precise tr...

Journal: :civil engineering infrastructures journal 0
hasan ghasemzadeh assistant professor, k.n. toosi university of technology, civil engineering faculty, tehran, iran amir ali abounouri msc graduate, k.n. toosi university of technology, civil engineering faculty, tehran, iran

stress waves contain useful information about the properties of porous materials; they can be recovered through different non-destructive testing methods such as crosswell, vertical seismic profile, borehole logging as well as sonic tests. in all these methods, it is crucial to assess the effects of frequency on wave attributes including velocity and intrinsic attenuation. the dependency of per...

Journal: :iranian journal of nuclear medicine 2011
faezeh vedaei alireza kamali asl faraz kalantari mojtaba ansari mohammad reza ay

introduction: photon attenuation in tissues is the primary physical degrading factor limiting both visual qualitative interpretation and quantitative analysis capabilities of reconstructed single photon emission computed tomography (spect) images. the aim of present study was to investigate the effect of attenuation correction on the detection of activation foci following statistical analysis w...

Journal: :Water 2021

Natural attenuation (NA) processes represent a valuable option in groundwater remediation. At heavily 1,2-dichloroethane (1,2-DCA) contaminated site, Compound-Specific Isotope Analysis (CSIA) combination with Biological Molecular Tools (BMTs) were implemented as rigorous characterization approach to evaluate the occurrence of Attenuation proximity source area. By use microcosm experiments, pote...

Journal: :iranian journal of basic medical sciences 0
shabnam oloomi department of medical physics, mashhad university of medical science, mashhad, iran hadi noori eskandari department of applied mathematics, school of mathematical sciences, ferdowsi university of mashhad, mashhad, iran seyed rasoul zakavi nuclear medicine research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran peter knoll department of nuclear medicine wilhelminenspital vienna, austria faraz kalantari research center for nuclear medicine, tehran university of medical sciences, tehran, iran mohsen hajizadeh saffar department of medical physics, mashhad university of medical science, mashhad, iran

objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید