We have proposed a pocket formula for mass attenuation coefficient(μ/ρ), mass energy absorption coefficient(μ_(en)/ρ), and effective atomic number(Z_(eff)) in different tissues of human organs. We have also assign...We have proposed a pocket formula for mass attenuation coefficient(μ/ρ), mass energy absorption coefficient(μ_(en)/ρ), and effective atomic number(Z_(eff)) in different tissues of human organs. We have also assigned a new chemical formula for all studied tissues based on their composition. We have introduced a new parameter called effective composition index(C_(eff)). Based on this, we have introduced a new method to compute the effective atomic number. The evaluated photon interaction parameters are graphically represented. The evaluated average, maximum,minimum, and standard deviations of effective atomic number are tabulated. The proposed formula produces a mass attenuation coefficient, mass energy absorption coefficient, and effective atomic number from their展开更多
Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,...Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,half and tenth value layers,mean free path,effective atomic and electronic cross sections,effective atomic number,and effective electron density of fifteen essential amino acids have been determined for 133Ba,137Cs,and 60Co gamma-ray sources.The MCNP-4C code and the XCOM program have been used to calculate these parameters.The results have been compared to the available experimental and theoretical data.The theoretical results agreed with the experimental data,with RD values of ≤±7%.In the energy region of 81-1332.5 keV,it was found that the μm,σa,and revalues of the amino acids decreased as the photon energy increased,and the increasing density of amino acids had no steady effect on these quantities.Additionally,results demonstrated that the HVL,TVL,and MFP values increased with the increase in photon energy.The μm,σa,and Zeff values of aspartic acid were the highest among those of all amino acids,and they were the lowest for isoleucine.The Zeff value of each sample containing H,C,N,and O atoms was nearly constant in the studied energy region.The Neffvalues of the studied amino acids varied in the range of 3.14×10^23-3.44×10^23 electron/g.Furthermore,the Neffvalues were approximately independent of the amino acid type in this energy region.展开更多
The objective of the present study is to calculate photon shielding parameters for seven polyethylene-based neutron shielding materials. The parameters include the effective atomic number(Z_(eff)), the effective elect...The objective of the present study is to calculate photon shielding parameters for seven polyethylene-based neutron shielding materials. The parameters include the effective atomic number(Z_(eff)), the effective electron density(N_(eff)) for photon interaction and photon energy absorption,and gamma-ray kerma coefficient(kc). The calculations of Z_(eff)are presented as a single-valued and are energy dependent. While Z_(eff)values were calculated via simplistic powerlaw method, the energy-dependent Z_(eff)for photon interaction(Z_(PI-eff)) and photon energy absorption(Z_(PEA-eff)) are obtained via the direct method for energy ranges of 1 keV–100 GeV and 1 keV–20 Me V, respectively. The kccoefficients are calculated by summing the contributions of the major partial photon interactions for energy range of 1 keV–100 MeV. In most cases, data are presented relative to pure polyethylene to allow direct comparison over a range of energy. The results show that combination of polyethylene with other elements such as lithium and aluminum leads to neutron shielding material with more ability to absorb neutron and crays. Also, the kerma coefficient first increases with Z of the additive element at low photon energies and then converges with pure polyethylene at energies greater than 100 keV.展开更多
Mass attenuation coefficient(μ_m) for polyethylene glycol(PEG) of different molecular weights was determined by using NaI(Tl) scintillator and Win Xcom mixture rule at gamma energies of 59.5, 302.9, 356.0, 661.7, 117...Mass attenuation coefficient(μ_m) for polyethylene glycol(PEG) of different molecular weights was determined by using NaI(Tl) scintillator and Win Xcom mixture rule at gamma energies of 59.5, 302.9, 356.0, 661.7, 1173.2 and 1332.5 keV. The total atomic, molecular and electronic cross sections, half-value layer, effective atomic and electron numbers, mass energy-absorption coefficients and kerma relative to air are calculated. The energy and compositional dependence of μ_m values, and the related radiation absorption parameters, are evaluated and discussed. The experimental results agree well with the theoretical ones, within an uncertainty of 1% in the effective atomic number for all PEG samples at the designated energies.展开更多
Cobalt-free alloy of constituent’s “0.045%C-12.73%Ni-6.53%Cr-3.2%Mo-0.02%Ti-0.01%V” has been prepared by electro slag remelting technique. Mass attenuation coefficient, half value layer and effective atomic number ...Cobalt-free alloy of constituent’s “0.045%C-12.73%Ni-6.53%Cr-3.2%Mo-0.02%Ti-0.01%V” has been prepared by electro slag remelting technique. Mass attenuation coefficient, half value layer and effective atomic number have been determined for the prepared sample at photon energies 235 - 2700 keV. The results are compared with the corresponding theoretical calculations based on XCOM program and a fair agreement is obtained.展开更多
The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectr...The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.展开更多
Mass attenuation coefficients, effective atomic numbers, effective electron densities and Kerma relative to air for adipose, muscle and bone tissues have been investigated in the photon energy region from 20 keV up to...Mass attenuation coefficients, effective atomic numbers, effective electron densities and Kerma relative to air for adipose, muscle and bone tissues have been investigated in the photon energy region from 20 keV up to 50 MeV with Geant4 simulation package and theoretical calculations. Based on Geant4 results of the mass attenuation coefficients, the effective atomic numbers for the tissue models have been calculated. The calculation results have been compared with the values of the Auto-Zeff program and with other studies available in the literature. Moreover, Kerma of studied tissues relative to air has been determined and found to be dependent on the absorption edges of the tissue constituent elements.展开更多
In this work, linear and mass attenuation coefficients, half and tenth-value layers, effective atomic number and electron density of different types of concretes were determined at 316.51, 468.07, 511, 662, 1173 and 1...In this work, linear and mass attenuation coefficients, half and tenth-value layers, effective atomic number and electron density of different types of concretes were determined at 316.51, 468.07, 511, 662, 1173 and 1332 keV using MCNP-4C code and Win XCom programs. The MCNP-4C and Win XCom results agreed well with each other, with differences of \±1.9%. The results agreed with available experimental data, too, with differences of \±6%.The MCNP-4C results showed better agreement with the experimental data than the Win XCom results. Also, it was found that the effective electron density of studied concretes varies in the range of(2.83–3.2) 9 10^(23)electron/g.展开更多
The accuracy of the knowledge of mass transfer parameters （effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient） in the case of frying food, is essential and important for designin...The accuracy of the knowledge of mass transfer parameters （effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient） in the case of frying food, is essential and important for designing, modeling and process optimization. This study is undertaken to develop an approach for determining mass transfer parameters during frying of spherical rice cracker in sunflower oil at 150, 170 and 190 ℃. These parameters were evaluated from the plots of dimensionless concentration ratios against time of frying. Effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient ranged between 1.24×10^-8 to 2.36×10^-8 m^2/s, 1.96 to 2.34 and 5.51×10^-6 to 9.70×10^-6 m/s, respectively. Effective moisture diffusivity and mass transfer coefficient were found to increase with an increasing frying temperature, whereas mass transfer Biot number decreased. An Arrhenius-type relationship was found between effective diffusivity coefficient and frying temperature.展开更多
In this study,we aimed to determine the radiation parameters of some potential bioactive compounds.1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heati...In this study,we aimed to determine the radiation parameters of some potential bioactive compounds.1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method.Aryl part was changed as phenyl(C6H5),4-methylphenyl(4-CH3C6H4),4-fluorophenyl(4-FC6H4),4-nitrophenyl(4-NO2C6H4),4-chlorophenyl(4-ClC6H4),4-bromophenyl(4-BrC6H4),and 2-thienyl(C4H3S-2-yl).Mass attenuation coefficient(μm),effective atomic number(Zeff)and effective electron density(Nel)of compounds were determined experimentally and theoretically for at 8.040,8.910,13.40,14.96,17.48,19.61,22.16,24.94,32.19,36.38,44.48,50.38and 59.54keV photon energies by using an HPGe detector with a resolution of 182eV at 5.9keV.Radiation parameters of these compounds which can be anti-cancer drug candidate were given in the tables.The results show that phenyl ring behave like thiophene ring in terms of radiation absorption.It is thought that the results of study may drive allow the development of drug candidate new compounds in medical oncology.展开更多
Using steel slag and two types of (soft and hard) iron slags, ten samples were prepared. Different gamma radiation interaction parameters were computed theoretically and measured experimentally at different energies: ...Using steel slag and two types of (soft and hard) iron slags, ten samples were prepared. Different gamma radiation interaction parameters were computed theoretically and measured experimentally at different energies: 60 keV, 136 keV, 662 keV, 1173 keV and 1332 keV in low and medium energy range using narrow transmission geometry. It has been observed that shielding effectiveness of a sample is inversely proportional to Half Value Layer (HVL). The obtained results were compared with Pure Flyash and it was observed that slag is better aggregate than flyash in shielding radiation as well as in construction applications. The results have been presented in the form of tables and graphs with more useful conclusions.展开更多
文摘We have proposed a pocket formula for mass attenuation coefficient(μ/ρ), mass energy absorption coefficient(μ_(en)/ρ), and effective atomic number(Z_(eff)) in different tissues of human organs. We have also assigned a new chemical formula for all studied tissues based on their composition. We have introduced a new parameter called effective composition index(C_(eff)). Based on this, we have introduced a new method to compute the effective atomic number. The evaluated photon interaction parameters are graphically represented. The evaluated average, maximum,minimum, and standard deviations of effective atomic number are tabulated. The proposed formula produces a mass attenuation coefficient, mass energy absorption coefficient, and effective atomic number from their
文摘Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,half and tenth value layers,mean free path,effective atomic and electronic cross sections,effective atomic number,and effective electron density of fifteen essential amino acids have been determined for 133Ba,137Cs,and 60Co gamma-ray sources.The MCNP-4C code and the XCOM program have been used to calculate these parameters.The results have been compared to the available experimental and theoretical data.The theoretical results agreed with the experimental data,with RD values of ≤±7%.In the energy region of 81-1332.5 keV,it was found that the μm,σa,and revalues of the amino acids decreased as the photon energy increased,and the increasing density of amino acids had no steady effect on these quantities.Additionally,results demonstrated that the HVL,TVL,and MFP values increased with the increase in photon energy.The μm,σa,and Zeff values of aspartic acid were the highest among those of all amino acids,and they were the lowest for isoleucine.The Zeff value of each sample containing H,C,N,and O atoms was nearly constant in the studied energy region.The Neffvalues of the studied amino acids varied in the range of 3.14×10^23-3.44×10^23 electron/g.Furthermore,the Neffvalues were approximately independent of the amino acid type in this energy region.
文摘The objective of the present study is to calculate photon shielding parameters for seven polyethylene-based neutron shielding materials. The parameters include the effective atomic number(Z_(eff)), the effective electron density(N_(eff)) for photon interaction and photon energy absorption,and gamma-ray kerma coefficient(kc). The calculations of Z_(eff)are presented as a single-valued and are energy dependent. While Z_(eff)values were calculated via simplistic powerlaw method, the energy-dependent Z_(eff)for photon interaction(Z_(PI-eff)) and photon energy absorption(Z_(PEA-eff)) are obtained via the direct method for energy ranges of 1 keV–100 GeV and 1 keV–20 Me V, respectively. The kccoefficients are calculated by summing the contributions of the major partial photon interactions for energy range of 1 keV–100 MeV. In most cases, data are presented relative to pure polyethylene to allow direct comparison over a range of energy. The results show that combination of polyethylene with other elements such as lithium and aluminum leads to neutron shielding material with more ability to absorb neutron and crays. Also, the kerma coefficient first increases with Z of the additive element at low photon energies and then converges with pure polyethylene at energies greater than 100 keV.
基金Deanship of Scientific Research at Al Imam Mohammad Ibn Saud Islamic University for the grant and financial assistance to accomplish this work
文摘Mass attenuation coefficient(μ_m) for polyethylene glycol(PEG) of different molecular weights was determined by using NaI(Tl) scintillator and Win Xcom mixture rule at gamma energies of 59.5, 302.9, 356.0, 661.7, 1173.2 and 1332.5 keV. The total atomic, molecular and electronic cross sections, half-value layer, effective atomic and electron numbers, mass energy-absorption coefficients and kerma relative to air are calculated. The energy and compositional dependence of μ_m values, and the related radiation absorption parameters, are evaluated and discussed. The experimental results agree well with the theoretical ones, within an uncertainty of 1% in the effective atomic number for all PEG samples at the designated energies.
文摘Cobalt-free alloy of constituent’s “0.045%C-12.73%Ni-6.53%Cr-3.2%Mo-0.02%Ti-0.01%V” has been prepared by electro slag remelting technique. Mass attenuation coefficient, half value layer and effective atomic number have been determined for the prepared sample at photon energies 235 - 2700 keV. The results are compared with the corresponding theoretical calculations based on XCOM program and a fair agreement is obtained.
基金supported by the National Key R&D Project of China(No.2017YFC0602100)the National Natural Science Foundation of China(No.41774147)Sichuan Science and Technology Support Program(No.2015GZ0272)
文摘The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.
文摘Mass attenuation coefficients, effective atomic numbers, effective electron densities and Kerma relative to air for adipose, muscle and bone tissues have been investigated in the photon energy region from 20 keV up to 50 MeV with Geant4 simulation package and theoretical calculations. Based on Geant4 results of the mass attenuation coefficients, the effective atomic numbers for the tissue models have been calculated. The calculation results have been compared with the values of the Auto-Zeff program and with other studies available in the literature. Moreover, Kerma of studied tissues relative to air has been determined and found to be dependent on the absorption edges of the tissue constituent elements.
文摘In this work, linear and mass attenuation coefficients, half and tenth-value layers, effective atomic number and electron density of different types of concretes were determined at 316.51, 468.07, 511, 662, 1173 and 1332 keV using MCNP-4C code and Win XCom programs. The MCNP-4C and Win XCom results agreed well with each other, with differences of \±1.9%. The results agreed with available experimental data, too, with differences of \±6%.The MCNP-4C results showed better agreement with the experimental data than the Win XCom results. Also, it was found that the effective electron density of studied concretes varies in the range of(2.83–3.2) 9 10^(23)electron/g.
文摘The accuracy of the knowledge of mass transfer parameters （effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient） in the case of frying food, is essential and important for designing, modeling and process optimization. This study is undertaken to develop an approach for determining mass transfer parameters during frying of spherical rice cracker in sunflower oil at 150, 170 and 190 ℃. These parameters were evaluated from the plots of dimensionless concentration ratios against time of frying. Effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient ranged between 1.24×10^-8 to 2.36×10^-8 m^2/s, 1.96 to 2.34 and 5.51×10^-6 to 9.70×10^-6 m/s, respectively. Effective moisture diffusivity and mass transfer coefficient were found to increase with an increasing frying temperature, whereas mass transfer Biot number decreased. An Arrhenius-type relationship was found between effective diffusivity coefficient and frying temperature.
文摘In this study,we aimed to determine the radiation parameters of some potential bioactive compounds.1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method.Aryl part was changed as phenyl(C6H5),4-methylphenyl(4-CH3C6H4),4-fluorophenyl(4-FC6H4),4-nitrophenyl(4-NO2C6H4),4-chlorophenyl(4-ClC6H4),4-bromophenyl(4-BrC6H4),and 2-thienyl(C4H3S-2-yl).Mass attenuation coefficient(μm),effective atomic number(Zeff)and effective electron density(Nel)of compounds were determined experimentally and theoretically for at 8.040,8.910,13.40,14.96,17.48,19.61,22.16,24.94,32.19,36.38,44.48,50.38and 59.54keV photon energies by using an HPGe detector with a resolution of 182eV at 5.9keV.Radiation parameters of these compounds which can be anti-cancer drug candidate were given in the tables.The results show that phenyl ring behave like thiophene ring in terms of radiation absorption.It is thought that the results of study may drive allow the development of drug candidate new compounds in medical oncology.
文摘Using steel slag and two types of (soft and hard) iron slags, ten samples were prepared. Different gamma radiation interaction parameters were computed theoretically and measured experimentally at different energies: 60 keV, 136 keV, 662 keV, 1173 keV and 1332 keV in low and medium energy range using narrow transmission geometry. It has been observed that shielding effectiveness of a sample is inversely proportional to Half Value Layer (HVL). The obtained results were compared with Pure Flyash and it was observed that slag is better aggregate than flyash in shielding radiation as well as in construction applications. The results have been presented in the form of tables and graphs with more useful conclusions.
