scholarly journals Determination of Effective Atomic Numbers Using Different Methods for Some Low-Z Materials

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Vishwanath P. Singh ◽  
N. M. Badiger ◽  
Nil Kucuk
Keyword(s):  
Experimental Data ◽  
Bone Marrow ◽  
Pair Production ◽  
Interpolation Method ◽  
Direct Method ◽  
Thyroid Tissue ◽  
Adipose Tissues ◽  
Effective Atomic Numbers ◽  
Good Agreement

In the present work, different methods were used to determine the effective atomic numbers of some low-Z materials, namely, polyethylene (PE), polystyrene (PS), polypropylene (PP), Perspex (PX), polycarbonate (PC), nylon 6-6 (PA-6), plaster of Paris (POP), and TH/L2. These methods are the direct method, the interpolation method, Auto-Zeff software, and single value XMuDat computer program. Some of the results obtained were compared with experimental data wherever possible. It can be concluded from this work that the effective atomic numbers calculated with the direct, the interpolation and Auto-Zeff methods demonstrate a good agreement in Compton scattering and pair production energy regions. A large difference in the effective atomic numbers calculated by the direct and the interpolation methods of low-Z materials was also observed in photoelectric and pair production regions. It was determined that PE, PS, PX, and PA-6 were equivalent to adipose and muscle; POP was equivalent to cortical bone; TH/L2 was equivalent to thyroid tissue; PP was equivalent to yellow bone marrow and adipose tissues; PC was equivalent to spongiosa.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

Processing a Brookfield Rotational Viscometer Measurement Results in the MATLAB

2020 ◽  
Vol 834 ◽  
pp. 82-89
Author(s):  
Evgenii Igorevich Kurkin ◽  
Vladislava Olegovna Chertykovtseva ◽  
Yaroslav Vyacheslavovich Zakhvatkin
Keyword(s):  
Experimental Data ◽  
Carbon Fibers ◽  
Power Law Model ◽  
Rotational Viscometer ◽  
Measurement Results ◽  
Automatic Capture ◽  
Type Power ◽  
Short Carbon ◽  
Good Agreement

The Brookfield_to_MATLAB and ViscosityApproximation codes for processing of experiments results for determination of viscosity on a rotational Brookfield DV3T viscometer is developed in the MATLAB. The codes allow to carry out automatic capture data, to calculate the shear rate for standard spindles RV-1 ... RV-7, to sort the measurement results on temperatures, to combine the experimental data and to determine the coefficients of the Andrade type power-law model. Paper describes experiment results on determination of viscosity of the epoxy binder reinforced by short carbon fibers. The coefficients of the viscosity model are determined by the linear regression coefficients. The obtained determination coefficient shows a good agreement of the model with the experimental data. The results are used for study various contents of a mass fraction of fibers: 0%, 5%, 10%, and 15%.

The use of electron gas modification in the evaluation of the vibration frequencies and the specific heat of lithium

1960 ◽  
Vol 259 (1298) ◽  
pp. 361-369 ◽  
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Electron Gas ◽  
Vibration Frequencies ◽  
Specific Heats ◽  
Air Temperatures ◽  
Set Up ◽  
Good Agreement ◽  
Secular Determinant

A secular determinant for the determination of vibration frequencies of lithium has been set up by Launay’s method which takes the electron gas into account. Theoretical elastic constants have been used in the calculation of the force constants. Frequencies have been calculated for 47 points of the first Brillouin zone which gives the value of 3 x 1000 = 3000 frequencies by symmetry. Specific heats have been calculated by numerical computation in the range 300 to 6°K and show good agreement with the experimental data. The agreement below liquid-air temperatures is surprising in view of the known phase transformation of lithium.

scholarly journals Comparison of Hydraulic Conductivity Values Obtained from Empirical Formulae and Laboratory Experiments

2020 ◽  
Vol 68 (4) ◽  
pp. 669-678
Author(s):  
Mario Hala ◽  
Lubomír Petrula ◽  
Zakaraya Alhasan
Keyword(s):  
Experimental Data ◽  
Hydraulic Conductivity ◽  
Laboratory Experiments ◽  
Internal Erosion ◽  
Variable Porosity ◽  
Groundwater Flow Regime ◽  
Series Of Experiments ◽  
Different Grain Size ◽  
Good Agreement

Hydraulic conductivity determination plays an essential role in the investigation of groundwater flow regime which can then influence many field problems such as pumping capabilities in the area, transport of contaminant or heat and soil internal erosion. Numerous equations based on dimensional analysis or experimental measurements have been published since the end of the 19th century for the determination of hydraulic conductivity. However, not all of these formulae are applicable for every material and all of them bring some uncertainty in the value of hydraulic conductivity. This paper contains a description of experimental research carried out concerning the determination of hydraulic conductivity for four types of sand with different grain size distribution curves and variable porosity. Obtained values of hydraulic conductivity ranged from 1 × 10-4 to 4 × 10-3 according to the sample porosity. The series of experiments consisted of 160 separate tests conducted in order to obtain relevant statistical sets. In this paper, the experimental data are discussed and compared with hydraulic conductivities obtained from 6 empirical formulae recommended in a previous study. The comparison showed that some empirical formulae provide a good agreement with the experimental data (the most precise were formulae published by Terzaghi and by Sauerbrey). However, some formulae showed high deviation from measured data (formula published by Zamarin).

VLE Determination of Carbon Dioxide Loaded Aqueous Alkanolamine Mixtures Using Modified Kent Eisenberg Model

2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Humbul Suleman ◽  
Abdulhalim Shah Maulud ◽  
Zakaria Man
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Model Parameters ◽  
Thermodynamic Models ◽  
Carbon Dioxide Absorption ◽  
Proposed Model ◽  
Wide Range ◽  
Experimental Values ◽  
Good Agreement

AbstractA computationally simple thermodynamic framework has been presented to correlate the vapour-liquid equilibria of carbon dioxide absorption in five representative types of alkanolamine mixtures. The proposed model is an extension of modified Kent Eisenberg model for the carbon dioxide loaded aqueous alkanolamine mixtures. The model parameters are regressed on a large experimental data pool of carbon dioxide solubility in aqueous alkanolamine mixtures. The model is applicable to a wide range of temperature (298–393 K), pressure (0.1–6000 kPa) and alkanolamine concentration (0.3–5 M). The correlated results are compared to the experimental values and found to be in good agreement with the average deviations ranging between 6% and 20%. The model results are comparable to other thermodynamic models.

scholarly journals Theory determination of $$\varvec{\bar{B}\rightarrow D^{(*)}\ell ^-\bar{\nu }}$$ form factors at $$\varvec{\mathcal {O}(1/m_c^2)}$$

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Marzia Bordone ◽  
Martin Jung ◽  
Danny van Dyk
Keyword(s):  
Experimental Data ◽  
Light Cone ◽  
Sum Rules ◽  
Form Factors ◽  
Longitudinal Polarization ◽  
Polarization Fraction ◽  
Theoretical Results ◽  
Good Agreement ◽  
Lepton Flavour

Abstract We carry out an analysis of the full set of ten $$\bar{B}\rightarrow D^{(*)}$$B¯→D(∗) form factors within the framework of the Heavy-Quark Expansion (HQE) to order $$\mathcal {O}\left( \alpha _s,\,1/m_b,\,1/m_c^2\right) $$Oαs,1/mb,1/mc2, both with and without the use of experimental data. This becomes possible due to a recent calculation of these form factors at and beyond the maximal physical recoil using QCD light-cone sum rules, in combination with constraints from lattice QCD, QCD three-point sum rules and unitarity. We find good agreement amongst the various theoretical results, as well as between the theoretical results and the kinematical distributions in $$\bar{B}\rightarrow D^{(*)}\lbrace e^-,\mu ^-\rbrace \bar{\nu }$$B¯→D(∗){e-,μ-}ν¯ measurements. The coefficients entering at the $$1/m_c^2$$1/mc2 level are found to be of $$\mathcal {O}(1)$$O(1), indicating convergence of the HQE. The phenomenological implications of our study include an updated exclusive determination of $$|V_{cb}|$$|Vcb| in the HQE, which is compatible with both the exclusive determination using the BGL parametrization and with the inclusive determination. We also revisit predictions for the lepton-flavour universality ratios $$R_{D^{(*)}}$$RD(∗), the $$\tau $$τ polarization observables $$P_\tau ^{D^{(*)}}$$PτD(∗), and the longitudinal polarization fraction $$F_L$$FL. Posterior samples for the HQE parameters are provided as ancillary files, allowing for their use in subsequent studies.

Prediction of Mechanical Properties of Al-Based FGM Crash Box Fabricated by Heat Treatment Process

2013 ◽  
Vol 465-466 ◽  
pp. 647-651 ◽  
Author(s):  
Saifulnizan Jamian ◽  
Mohammad Rusydi Zainal Abidin
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Temperature Distribution ◽  
Material Properties ◽  
Interpolation Method ◽  
Functionally Graded ◽  
Local Material ◽  
Local Material Properties

In this paper, mechanical properties of Al functionally graded materials (FGMs) crash box fabricated by heat treatment is predicted based on temperature distribution and experimental data. The Al FGM crash box is fabricated by applying different temperature at the both ends of a square hollow Al column for 4 hours. Due to the gradient in heat treatment temperature along the height of the Al column, the microstructure is locally varied so that a certain variation of local material properties is achieved. The determination of material properties at any point along the height of Al FGM crash box experimentally is uneasy. The Lagrange interpolation method is proposed to predict the variation of local material properties at any point along the height of Al FGM crash box for further work such as simulation of impact on the crash box. The determination of mechanical properties is successfully predicted using the available experimental data and the temperature distribution obtained in simulation.

Determination of Minimum Fluidization Velocity for Gas-Solid Beds by Experimental Data and Numerical Simulations

2011 ◽  
Author(s):  
Meire Pereira de Souza Braun ◽  
Geraldo Luiz Palma ◽  
Helio Aparecido Navarro ◽  
Paulo Sergio Varoto
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Particle Diameter ◽  
Minimum Fluidization Velocity ◽  
Ergun Equation ◽  
Fluidization Velocity ◽  
Minimum Fluidization ◽  
Experimental Apparatus ◽  
Good Agreement

The purpose of this work is to predict the minimum fluidization velocity Umf in a gas-solid fluidized bed. The study was carried out with an experimental apparatus for sand particles with diameters between 310μm and 590μm, and density of 2,590kg/m3. The experimental results were compared with numerical simulations developed in MFIX (Multiphase Flow with Interphase eXchange) open source code [1], for three different sizes of particles: 310mum, 450μm and 590μm. A homogeneous mixture with the three kinds of particles was also studied. The influence of the particle diameter was presented and discussed. The Ergun equation was also used to describe the minimum fluidization velocity. The experimental data presented a good agreement with Ergun equation and numerical simulations.

scholarly journals Determination of effective atomic numbers and electron densities from mass attenuation coefficients for some selected complexes containing lanthanides

2017 ◽  
Vol 95 (10) ◽  
pp. 1005-1011 ◽  
Author(s):  
Ferdi Akman ◽  
Mustafa Recep Kaçal ◽  
Feride Akman ◽  
Mustafa Serkan Soylu
Keyword(s):  
Chemical Parameters ◽  
Electron Densities ◽  
Attenuation Coefficients ◽  
Transmission Geometry ◽  
Mass Attenuation Coefficients ◽  
Effective Atomic Numbers ◽  
Theoretical Results ◽  
Good Agreement ◽  
Mass Attenuation

The effective atomic numbers and electron densities for the pure elemental forms of gadolinium (Gd), dysprosium (Dy), erbium (Er), and ytterbium (Yb), and some of their selected complexes, were obtained from the measured total mass attenuation coefficients at 13.92, 17.75, 20.78, 26.34, and 59.54 keV photon energies using a high-resolution Si(Li) detector by adopting transmission geometry. The measured results were compared with two different theoretical results. Within experimental deviations, our data are in good agreement with the theoretical values. The obtained parameters were also interpreted with some selected chemical parameters.

A New Approach to Surface Tension According to the Surface Topographical Features in Laser Cutting Technology

2013 ◽  
Vol 334-335 ◽  
pp. 65-70 ◽  
Author(s):  
Marta Harničárová ◽  
Jan Valíček ◽  
Jana Müllerová ◽  
Milena Kušnerová ◽  
Radovan Grznárik ◽  
...  
Keyword(s):  
Surface Tension ◽  
Laser Cutting ◽  
Direct Method ◽  
Surface Tensions ◽  
New Approach ◽  
Cut Quality ◽  
Different Sources ◽  
Clean Metal ◽  
Good Agreement

Laser - cut quality is mainly characterized by a degree of accuracy in shape, size and also by surface layer conditions after cutting associated with surface roughness. An experimental determination of surface tension (or tensor components) of clean metal surfaces is very difficult and there is no direct method for its measurement. Attention was paid to numerical derivation of surface tensions according to the surface topographical features in laser cutting technology. The surface tensions and temperature dependencies of several metallic materials have been determined and confirmed by data obtained from the literature. It was found to be in very good agreement between our results and data from different sources in the literature.

Sign in / Sign up

Export Citation Format

Share Document