High-resolution Si Research Articles

ELEMENTAL CONCENTRATION OF PACKAGED MEALS (BAKED AND EXTRUDED GOODS MADE USING COMPOSITE CEREAL-PULSE FLOUR) PROCURED AT DEBRE TABOR MARKETPLACES IN ETHIOPIA

The elemental analysis of packed food items which is collected in Debre Tabor markets, Ethiopia namely Pasta, Macaroni, cookies, biscuit, wheat bread, white teff injera, Red teff injera, barley so, barleycorn and maiz bread samples were carried out using EDX spectrometer. An X-ray beam was used to excite each sample and spectra were recorded with a high-resolution Si(Li) detector. The data analysis was carried out by software. Trace elements P, K, Na, Cl, Mg, Ca, Fe, Al and Zn were estimated, and elemental concentrations were determined. To get the exact results of the present study the analysis repeats three times.

Development of Tincal based polypropylene polymeric materials for radiation shielding applications: Experimental, theoretical, and Monte Carlo investigations

Samples of new polymeric material based on polypropylene doped with various Tincal concentrations have been developed. The prepared samples are coded PT1, PT2, PT3, and PT4. The structural characteristics of the produced polymeric materials were investigated using X-ray diffraction (XRD) and Raman Spectroscopy. The obtained materials' shielding capacity was studied in terms of mass attenuation coefficient and half-value layer. The mass attenuation coefficient was experimentally estimated using a high-resolution Si (Li) detector and a multichannel analyzer with multiple variable sources, and the findings were then compared with the Phy-X/PSD and MCNP algorithms. The existence of two bands at 2.770–2.830 cm−1 and 1.405–1.455 cm−1 in the Raman spectra can be attributed to CH2 vibration modes. Due to the increased density of the sample, Tincal enhancement with greater ratios has a beneficial influence on linear attenuation coefficient (LAC) values. This led the samples to be sorted in the following order: PT1<PT2<PT3<PT4 in terms of LAC. The greatest half value layer (HVL) values for PT1 were found to be between 0.876 and 41.24 cm. Furthermore, the PT4 values were the lowest, ranging from 0.491 to 32.291 cm at 0.015 and 15 MeV, respectively. The obtained results introduced the PT4 sample as the best shield against gamma rays among all prepared samples.

Adsorption characteristics of silver atoms and silver ions on silica surface in silver nanoparticle hydrosol system

Previous studies have demonstrated that silver ions (Ag+) can be released from silver nanoparticles (AgNPs) to produce a system of silver atoms (Ag0) and Ag+ in equilibrium, which may affect the environment through adsorption on sediment. Here, the adsorption behaviour of Ag0 and Ag+ in a AgNP hydrosol system on a silica surface was systematically investigated using experimental evaluation and first-principles calculations based on density functional theory. The adsorption environment and performance were first analysed by batch and fixed-bed experiments, which indicated that less adsorption occurred between silica and silver. Subsequent energy calculations and structural optimisation revealed that both Ag0 and Ag+ were more likely to be chemisorbed on the silica surface through covalent (AgO) bonds. The average adsorption energies of SiO2/Ag+ and SiO2/Ag0 were −5.445 and −3.61 eV, respectively. In addition, Ag0 lost an average of 0.86 electrons to the O4–silica bond. By contrast, only a few electrons, which bonded with O1, were transferred from silica to Ag+. Analyses of the density of states and crystal orbital Hamilton population revealed that O and Ag were hybridised with the 2p–4d orbitals after adsorption. In addition, the peak shifts in the high-resolution Ag 3d, O 1s and Si 2p X-ray photoelectron spectra after adsorption revealed changes in the chemical state. The presence of AgO bonds was confirmed by the surface-enhanced Raman scattering spectrum. Silica was selected as the main component of sediment in this study, and it is hoped that this work will motivate a simulation of the migration and transformation of silver by sediment in the water environment.

Measurement of Total Electronic Cross-Section, Total Atomic Cross-Section, Effective Atomic Numbers, Effective Electron Densities and Kerma for Some Br Compounds

The aim of this study is to calculate the experimental and theoretical the mass attenuation coefficient some Br compounds by using transmission method. Also using these values were determined the total electronic section, total atomic section, effective atomic number, effective electron density and Kerma. We performed the calculations of these values in attenuation by using direct excitation experimental geometry. The total attenuation cross sections of some halogene Br compounds were measured in a narrow beam good geometry using a high resolution Si(Li) detector in the energy with γ photons at 59.543 keV from Am-241 annular source. Theoretical mass attenuation coefficient values were computed from the XCOM data programme, based on mixture rule method. This study provide new insight into the literature since the values of effective atomic number, electron density and Kerma for some Br compounds have not been determined before. According to the results shown in mass attenuation coefficient, Zeff and Neff of Br compounds are closely associated with chemical structure. This research were undertaken to explore how Bromine compounds is gamma ray shielding material.

Non-thermal liquid-to-solid Si conversion induced by electron beam irradiation

A liquid precursor for the semiconductor, Si, called liquid Si (liq-Si), was synthesized. Although liq-Si is converted to semiconducting Si by heating at 400 °C, herein, we demonstrate liquid-to-solid Si conversion without heating using liquid-phase electron beam-induced deposition. This technique realizes the direct deposition of semiconducting Si by irradiating liq-Si with an electron beam. Specifically, at electron beam (diameter, ∼50 nm) irradiation, a Si deposit with a diameter of approximately 240 nm was obtained. It is expected that the application of this developed method will enable the production of high-resolution Si nanostructures and grant access to previously inaccessible devices.

Effect of voltages on [formula omitted] linear attenuation coefficients for some semiconductors

In this work, the change according to the different voltages (0, 5, 10, 15, 20 and, 25 V) of γ−ray linear attenuation coefficients for GaSe, GaSe:Cd, GaSe:Sn, GaTe, GaTe:Cd, Ga0.9In0.1Se, GaTe0.4Se0.6, and GaTe0.8Se0.2 semiconductors have been measured by using an extremely narrow collimated-beam transmission method in the energy 59.54 keV. Gamma-rays of 241Am were detected by using a high-resolution Si(Li) detector and, energy dispersive X-ray fluorescence spectrometer (EDXRFS). GaSe, GaSe:Cd, GaSe:Sn, GaTe, GaTe:Cd, Ga0.9In0.1Se, GaTe0.4Se0.6, and GaTe0.8Se0.2 semiconductors were grown by the Bridgman-Stockbarger method. There are no cracks or voids on the surface of ingots. Samples were cleaved along the cleavage planes (001). The freshly cleaved crystals have mirror-like surfaces even before using mechanical treatment. Results are presented and discussed in this study.

Qualitative elemental analysis of selected potential anti-asthmatic medicinal plant taxa using EDXRF technique

Qualitative elemental analysis was determined in various parts of potential anti-asthmatic medicinal plants using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer. X-ray beam was used to excite each sample and spectra were recorded with a high resolution Si(Li) detector. The data analysis was carried out by the nEXT software. Trace elements P, S, Cl, K, Ca, Mn, Fe, Cu, Zn, Se, Br, Rb and Sr were estimated and elemental concentrations were determined. The results of the present study compared with standard reference material NIST1515 apple leaves for accuracy. The elements K, Ca, Cl, S and P are major constituents and besides Cu, Zn, Fe, Mn, Se, Br, Rb and Sr were present at low level. The presence of Cu, Zn, Mn and Se in medicinal plants plays a vital role on management and control of asthma disease.

Measurement of Mass Attenuation Coefficients for Some Potassium Compounds

In this study, the mass attenuation coefficients of some potassium compounds (KH 2 PO 4 , KNO 3 , K 2 S 2 O 8 , KOH, K 2 HPO 4 , K 2 SO 4 , KCl, KIO 3, and KI) have been measured by using Energy Dispersive X-ray Fluorescence Spectrometer (EDXRFS) and a high-resolution Si(Li) detector. Obtained experimental mass attenuation coefficients have been compared with WinXCom and FFAST theoretical values.

Chemical effect on K shell X-ray fluorescence parameters for some Mn and Ni compounds

Kα, Kβ and total K X-ray fluorescence cross-sections, K shell fluorescence yields, Kβ/KαX-ray intensity ratios, K to L shell vacancy transfer probabilities and Auger electrons emission ratios of some selected Mn and Ni compounds have been investigated. The measurements were carried out by using Am-241 radioactive source and high-resolution Si(Li) detector. The measured results were compared with other experimental values and theoretical calculations. Our values are in good concordance with calculated theoretical and other experimental values.

Investigation of some radiation interaction parameters for bacteria isolated from the soil in the low energy region

The purpose of this work, investigation of radiation attenuation characteristics, such as mass attenuation coefficient (μ/ρ), molar extinction coefficient (ε), effective atomic number (Zeff), and electron density (NE), of isolated bacteria from soil samples taken from Diyarbakır in Turkey. The experiments were performed using a narrow beam geometry with the help of the a high-resolution Si(Li) detector and three different radioactive sources at 15 different photon energies. The ε, Zeff, and NE values for some bacteria isolated from soil, such as Bacillus megaterium, Bacillus simplex, Bacillus subtilis, and commercially purchased Geobacillus stearothermophilus bacterium, were obtained from the measured μ/ρ results in the energy range from 13.94 to 88.04 keV. The experimental values were checked with two different theoretical results and good agreement was observed among them. The results show that Bacillus simplex bacterium has the highest values of μ/ρ and Zeff and Bacillus subtilis bacterium has the biggest values of ε and NE among the present bacteria.

Determination of some selected absorption parameters for Cd, La and Ce elements

The total atomic attenuation cross-section values in the energy region from 14.932 to 57.142 keV were determined to obtain completely experimental values of the K shell absorption edge energies for Cd, La and Ce elements. The photoelectric cross-sections in the aforementioned energy range, K shell photoelectric cross-sections at the K edge, K shell absorption jump ratios, K shell absorption jump factors and K shell oscillator strength values were obtained with the help of the total atomic attenuation cross-sections. The measurements were performed using the secondary excitation geometry including a high resolution Si(Li) detector. 59.54 keV photon energy emitted from the Am-241 annular radioactive source was used as the primary source. The K shell characteristic X-ray energies of the some selected elements between Y and Er were used as the secondary source. The obtained experimental results were checked with the theoretical and other available experimental results, and it was observed that there is a good agreement between them.

Performance of quartz- and sapphire-based double-crystal high-resolution (∼10 meV) RIXS monochromators under varying power loads.

In the context of a novel, high-resolution resonant inelastic X-ray scattering spectrometer, a flat-crystal-based quartz analyzer system has recently been demonstrated to provide an unprecedented intrinsic-energy resolution of 3.9 meV at the Ir L3 absorption edge (11.215 keV) [Kim et al. (2018) Sci. Rep. 8, 1958]. However, the overall instrument resolution was limited to 9.7 meV because of an 8.9 meV incident band pass, generated by the available high-resolution four-bounce Si(844) monochromator. In order to better match the potent resolving power of the novel analyzer with the energy band pass of the incident beam, a quartz(309)-based double-bounce, high-resolution monochromator was designed and implemented, expected to yield an overall instrument resolution of 6.0 meV. The choice of lower-symmetry quartz is very attractive because of its wealth of suitable near-backscattering reflections. However, it was found that during room-temperature operation typical levels of incident power, barely affecting the Si monochromator, caused substantial thermal distortions in the first crystal of the quartz monochromator, rendering it practically unusable. Finite-element analyses and heat-flow analyses corroborate this finding. As a high-flux, lower resolution (15.8 meV) alternative, a two-bounce sapphire(078) version was also tested and found to be less affected than quartz, but notably more than silicon.

Alloying effect on K shell X-ray fluorescence cross-sections and yields in Ti-Ni based shape memory alloys

K shell X-ray fluorescence cross-sections (σKα, σKβ and σK), and K shell fluorescence yields (ωK) of Ti, Ni both in pure metals and in different alloy compositions (TixNi1-x; x = 0.3, 0.4, 0.5, 0.6, 0.7) were measured by using energy dispersive X-ray fluorescence (EDXRF) technique. The samples were excited by 22.69 keV X-rays from a 10 mCi Cd-109 radioactive point source and K X rays emitted by samples were counted by a high resolution Si(Li) solid-state detector coupled to a 4 K multichannel analyzer (MCA). The alloying effects on the X-ray fluorescence (XRF) parameters of Ti-Ni shape memory alloys (SMAs) were investigated. It is clearly observed that alloying effect causes to change in K shell XRF parameter values in Ti-Ni based SMAs for different compositions of x. Also, the present investigation makes it possible to perform reliable interpretation of experimental σKα, σKβ and ωK values for Ti and Ni in SMAs and can also provide quantitative information about the changes of K shell X-ray fluorescence cross sections and fluorescence yields of these metals with alloy composition.

Investigation of alloying effects on XRF parameters of 3d transition metals in Permendur49, Kovar and Ti50Co50 alloys

The alloying effects on X-ray fluorescence (XRF) parameters such as K shell fluorescence cross-sections (σKα, σKβ and σK), K shell average fluorescence yields (ωK) and K to L shell vacancy transfer probabilities (ηKL) of V, Ti, Fe, Co and Ni 3d transition metals in Permendur49 (Fe49Co49V2), Kovar (Fe54Ni29Co17) and Ti50Co50 alloys have been carried out by X-ray fluorescence studies. K X-ray intensity ratios of these 3d transition metals in both pure form and present alloys have been measured following excitation by 22.69 keV X-rays from a 10 mCi 109Cd radioactive point source. The characteristic K-X-ray spectra from samples were detected by a high-resolution Si(Li) solid-state detector. The investigated fluorescence parameters of present 3d transition elements in alloys indicate significant differences with respect to the pure metals. Consequently, the observed change of the investigated fluorescence parameters can be attributed to the delocalization and charge transfer phenomena between the 3d elements in alloys.

Measurements of K X-ray fluorescence cross-sections, fluorescence yields, level widths and radiative vacancy transition probabilities for the elements Zr, Mo, Cd, Er at 59.54 keV

K shell X ray fluorescence cross sections, fluorescence yields, level widths and radiative vacancy transition probabilities were investigated for the elements Zr, Mo, Cd, Er. The measurements were performed using photons of 59.54 keV emitted from an Am-241 (about 100 mCi) point source and a high resolution Si(Li) detector. The experimental results were compared with theoretical calculations and the other results obtained from literature.

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

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.

High resolution K X-ray spectra of selected silicates induced by MeV proton and carbon micro-beams

Abstract Recently we developed a high resolution wavelength dispersive X-ray spectrometer based on the flat diffraction crystals for use with focused ion beams and used it to study chemical effects in ion beam induced Si K X-ray spectra of silicon and its selected binary compounds. In this work we extended the study to selected silicates. We measured high resolution Si Kα and Kβ X-ray spectra of three silicates: feldspar, kyanite and tourmaline. The spectra have been measured with 2 MeV protons (Kα and Kβ regions) and 20 MeV carbon ions (only Kα region). The results obtained for peak relative intensities were analysed and compared with the related relative intensities obtained from Si, SiC and SiO2.

Photon-Induced L-Shell X-Ray Production Cross Sections for Lanthanides at 59.54 keV

The Ll, Lα and Lβ X-ray production cross sections for Pr, Nd, Sm, Eu, Gd and Tb elements were determined using a reflection geometry. The excitation was performed with a 241Am radioactive annular source and the L X-rays emitted from targets were counted with a high-resolution Si (Li) detector. The experimental values were compared with other available experimental results and theoretical data. An agreement is observed between the measured and other experimental results or theoretical data.

Comparative trace elemental analysis of cancerous and non-cancerous tissues of rectal cancer patients using PIXE

Particle Induced X-ray Emission (PIXE), an accelerator based analytical technique has been employed in this work for the analysis of trace elements in the cancerous and non-cancerous tissues of rectal cancer patients. A beam of 3MeV protons generated from 3MV Pelletron accelerator at the Ion Beam Laboratory of Institute of Physics, Bhubaneswar, India was used as projectile to excite the atoms present in the tissues samples. PIXE technique, with its capability to detect simultaneously several elements present at very low concentrations, offers an excellent tool for trace element analysis. The characteristic X-rays emitted by the samples were recorded by a high resolution Si (Li) detector. On the basis of the PIXE spectrum obtained for each sample, the elements Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, and Br were identified and their relative concentrations were estimated in the cancerous and non-cancerous tissues of rectum. The levels of Mn, Fe, Co, Cu, Zn, and As were higher (p<0.005) while the levels of Ca, Cr and Ni were lower (p<0.005) in the cancer tissues relative to the normal tissues. The alterations in the levels of the trace elements observed in the present work are discussed in this paper with respect to their potential role in the initiation, promotion and inhibition of cancer of the rectum.

Experimental values of K to Li sub-shell, K to L, and K to M shell vacancy transfer probabilities for some rare earth elements

The K to Li (i=2,3), K to L, and K to M shell vacancy transfer probabilities for La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er were determined at 59.54keV using a reflection geometry. The measurements were performed using an 241Am annular radioactive source and a high resolution Si(Li) detector. The experimental results were compared with the theoretical values of Hartree-Slater and Hartree-Fock theories, semi-empirical and other available experimental results in the literature. Reasonable agreement is observed between the measured and theoretical results.