K-shell X-ray intensity ratios and vacancy transfer probabilities of Pt, Au, and Pb by a simple method

2014 ◽  
Vol 119 (3) ◽  
pp. 392-397 ◽  
Author(s):  
L. F. M. Anand ◽  
S. B. Gudennavar ◽  
S. G. Bubbly ◽  
B. R. Kerur
Keyword(s):  
X Ray ◽  
2014 ◽  
Vol 92 (11) ◽  
pp. 1301-1304 ◽  
Author(s):  
Linu George ◽  
S.B. Gudennavar ◽  
Daisy Joseph ◽  
S.G. Bubbly

The K shell X-ray photons of Fe, Ag, and Te following the electron capture decay of Co57, Cd109, and I125, respectively, were detected using Si(Li) detector coupled to PC-based 8k multichannel analyzer employing a simple method suggested earlier by our group. The calculated K shell X-ray intensity ratios and vacancy transfer probabilities for these elements are compared with the theoretical values predicted by Scofield and with others’ experimental values obtained via photoionization. It is found that the Κβ to Κα X-ray intensity ratio of Fe is lower by 4.0%, while that of Ag and Te are greater by 7.9% and 19.1%, respectively, from the theoretical values. These deviations may be attributed to the exchange interactions occurring between the 3p–3d shell electrons as well as the recoil effect of the nucleus due to neutrino emission.


Author(s):  
E. A. Kenik ◽  
J. Bentley

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.


2010 ◽  
Vol 19 (01) ◽  
pp. 36-39 ◽  
Author(s):  
P. Chládek ◽  
V. Havlas ◽  
T. Trc

SummaryThe treatment of femoral head necrosis of adults is still rather problematic. Conservative treatment has been reported relatively unsuccessful and surgical treatment does not show convincing results either. The most effective seems to be a surgical treatment in early stages of the disease, however, the diagnosis still remains relatively complicated. For the late stages (2B and above) the most effective treatment option is represented by core decompression and vascular grafting. However, drilling and plombage (especially when using press-fit technique) seems to be successful, although not excellent. The authors describe their own method of drilling and plombage of the necrotic zone of the femoral head in 41 patients with X-ray detected necrotic changes of the femoral head. The pain measured by VAS was seen to decrease after surgery in all patients significantly. The Jacobs score was also observed to have increased (from fair to good outcome). We have not observed any large femoral head collapse after surgery, moreover, in some cases an improvement of the round shape of the femoral head was seen. It is important to mention that in all cases femoral heads with existing necrotic changes (flattening or collapse) were treated. Although the clinical improvement after surgery was not significantly high, the method we describe is a safe and simple method of diminishing pain in attempt to prepare the femoral head for further treatment in a future, without significant restriction of the indication due to necrosis (osteochondroplasty, resurfacing, THR).


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3554
Author(s):  
Melissa M. Suckey ◽  
Donald W. Benza ◽  
John D. DesJardins ◽  
Jeffrey N. Anker

We describe a method to measure micron to millimeter displacement through tissue using an upconversion spectral ruler. Measuring stiffness (displacement under load) in muscles, bones, ligaments, and tendons is important for studying and monitoring healing of injuries. Optical displacement measurements are useful because they are sensitive and noninvasive. Optical measurements through tissue must use spectral rather than imaging approaches because optical scattering in the tissue blurs the image with a point spread function typically around the depth of the tissue. Additionally, the optical measurement should have low background and minimal intensity dependence. Previously, we demonstrated a spectral encoder using either X-ray luminescence or fluorescence, but the X-ray luminescence required an expensive X-ray source and used ionizing radiation, while the fluorescence sensor suffered from interference from autofluorescence. Here, we used upconversion, which can be provided with a simple fiber-coupled spectrometer with essentially autofluorescence-free signals. The upconversion phosphors provide a low background signal, and the use of closely spaced spectral peaks minimizes spectral distortion from the tissue. The small displacement noise level (precision) through tissue was 2 µm when using a microscope-coupled spectrometer to collect light. We also showed proof of principle for measuring strain on a tendon mimic. The approach provides a simple method to study biomechanics using implantable sensors.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
M. Kooti ◽  
A. Naghdi Sedeh

A new and simple method was applied for the synthesis of ZnO nanoparticles with an average size of 20 nm. In this microwave-assisted combustion method, glycine as a fuel and zinc nitrate as precursor were used. The final product was obtained very fast with high yield and purity. The synthesized nanoscale ZnO was characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FT-IR). The size and morphology of the ZnO nanoparticles have been determined by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. This is a simple and fast method for the preparation of ZnO nanoparticles with no need for expensive materials or complicated treatments.


2014 ◽  
Vol 92 (11) ◽  
pp. 1489-1493 ◽  
Author(s):  
P.V. Sreevidya ◽  
S.B. Gudennavar ◽  
Daisy Joseph ◽  
S.G. Bubbly

K shell X-rays of barium and thallium following internal conversion decay in Cs137 and Hg203, respectively, were detected using a Si(Li) X-ray detector coupled to PC-based 8k multichannel analyser employing the method suggested earlier by our group. The K shell X-ray intensity ratios and vacancy transfer probabilities for thallium and barium were calculated. The obtained results are compared with theoretical, semiempirical, and others’ experimental results obtained via photoionization as well as decay processes. The effects of beta decay and internal conversion on X-ray emission probabilities are discussed.


2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.


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