Evaluation of Radio-Photoluminescence Spectra of Copper-Doped Phosphate Glass Dosimeter Irradiated with Ionized Particles

2016 ◽  
Vol 698 ◽  
pp. 163-170 ◽  
Author(s):  
Raj Kumar Parajuli ◽  
Wataru Kada ◽  
Shunsuke Kawabata ◽  
Yoshinori Matsubara ◽  
Kenta Miura ◽  
...  
Keyword(s):  
Background Radiation ◽  
Luminescence Center ◽  
Copper Ion ◽  
Irradiation Effect ◽  
X Rays ◽  
Particle Detection ◽  
Luminescent Center ◽  
Proton Beam Irradiation ◽  
Glass Dosimeter ◽  
Two Peaks

A radio-photoluminescence (RPL) dosimeter with a copper-ion luminescent center was fabricated to evaluate its response in ionized particle detection. A focused proton microbeam with varying energies up to 3 MeV and heavy ions of 490 MeV osmium (Os) were employed along with X-rays to evaluate its performance in micrometer-scale radiation monitoring. The response to ionized particles was evaluated under focused proton beam irradiation where the peak wavelength differed from that obtained under X-ray irradiation. Two peaks were observed under Os irradiation where the secondary-generated particles and photons have a significant effect on the dosimeter. The results suggest that the fabricated RPL dosimeter with copper luminescence center could be used to estimate the irradiation effect of primary ionized particles separately from the effects of secondary particles, photons, and environmental background radiation.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

scholarly journals Radiophobia: 7 Reasons Why Radiography Used in Spine and Posture Rehabilitation Should Not Be Feared or Avoided

Dose-Response ◽  
2018 ◽  
Vol 16 (2) ◽  
pp. 155932581878144 ◽  
Author(s):  
Paul A. Oakley ◽  
Deed E. Harrison
Keyword(s):  
Low Dose ◽  
Background Radiation ◽  
Threshold Model ◽  
Radiation Risk ◽  
Biomechanical Analysis ◽  
Cellular Damage ◽  
Imaging Method ◽  
X Rays ◽  
Low Dose Radiation ◽  
Dose Radiation

Evidence-based contemporary spinal rehabilitation often requires radiography. Use of radiography (X-rays or computed tomography scans) should not be feared, avoided, or have their exposures lessened to decrease patient dose possibly jeopardizing image quality. This is because all fears of radiation exposures from medical diagnostic imaging are based on complete fabrication of health risks based on an outdated, invalid linear model that has simply been propagated for decades. We present 7 main arguments for continued use of radiography for routine use in spinal rehabilitation: (1) the linear no-threshold model for radiation risk estimates is invalid for low-dose exposures; (2) low-dose radiation enhances health via the body’s adaptive response mechanisms (ie, radiation hormesis); (3) an X-ray with low-dose radiation only induces 1 one-millionth the amount of cellular damage as compared to breathing air for a day; (4) radiography is below inescapable natural annual background radiation levels; (5) radiophobia stems from unwarranted fears and false beliefs; (6) radiography use leads to better patient outcomes; (7) the risk to benefit ratio is always beneficial for routine radiography. Radiography is a safe imaging method for routine use in patient assessment, screening, diagnosis, and biomechanical analysis and for monitoring treatment progress in daily clinical practice.

scholarly journals The ultraviolet background (intergalactic gas, the Galaxy, and subcosmic rays)

1970 ◽  
Vol 36 ◽  
pp. 341-348
Author(s):  
V. G. Kurt ◽  
R. A. Sunyaev
Keyword(s):  
Interstellar Medium ◽  
Background Radiation ◽  
Neutral Hydrogen ◽  
Exchange Interactions ◽  
List Type ◽  
X Rays ◽  
Intergalactic Gas ◽  
Hydrogen Atoms ◽  
Uv Spectrum ◽  
The Galaxy

(1)Observations. – A survey is made of observations of the background radiation at UV wavelengths from above the atmosphere. Sources of the background radiation and ways of determining the extragalactic component of the background are discussed. Future observations are also discussed.(2)Cosmology. – Limits to the properties of the intergalactic gas follow from observations of the UV background. The problem of detecting galaxies at early stages in their evolution is considered.(3)The Galaxy. – Observations and theoretical estimates are given for the integrated brightness of the Galaxy at UV wavelengths beyond the Lyman-α line. Also discussed are the nature of the Lyman-α emission from the Milky Way and the principal ways of constructing the luminosity function of stars in the Galaxy from observations of the integrated UV spectrum.(4)Subcosmic Rays in the Interstellar Medium. – Fast neutral excited hydrogen atoms can be formed from charge-exchange interactions between subcosmic-ray protons and neutral interstellar gas. Upper limits are given to the energy density of subcosmic rays having E ~ 100 keV.(5)Limits on the Background Radiation in the range <912 Å. – The distribution of neutral hydrogen in the peripheries of galaxies allows limits to be obtained for the flux of metagalactic ionising radiation. The heating and ionisation of the interstellar medium by X-rays is considered.

scholarly journals Patient understanding of radiation risk from medical computed tomography - A comparison of Hispanic vs. Non-Hispanic Emergency Department populations

2015 ◽  
Author(s):  
Afton McNierney-Moore ◽  
Cynthia Smith ◽  
Jose H. Guardiola ◽  
K Tom Xu ◽  
Peter Richman
Keyword(s):  
Background Radiation ◽  
Radiation Risk ◽  
Good Knowledge ◽  
Independent Effect ◽  
X Rays ◽  
Multivariate Logistic Regression ◽  
Lifetime Cancer Risk ◽  
Convenience Sample ◽  
Medical Testing ◽  
Hispanic Patients

Background: Cultural differences and language barriers may adversely impact patients with respect to understanding the risks/benefits of medical testing. Objective: We hypothesized that there would be no difference in Hispanic vs. non-Hispanic patients’ knowledge of radiation risk that results from CT of the abdomen/pelvis (CTAP). Methods: We enrolled a convenience sample of adults at an inner-city ED. Patients provided written answers to rate agreement on a 10-point scale for two correct statements comparing radiation exposure equality between: CTAP and 5 years of background radiation (question 1); CTAP and 200 chest x-rays (question 3). Patients also rated their agreement that multiple CT scans increase the lifetime cancer risk (question 2). Scores of > 8 were considered good knowledge. Multivariate logistic regression analyses were performed to estimate the independent effect of the Hispanic variable. Results: 600 patients in the study group; 63% Hispanic, mean age 39.2 +/- 13.9 years. Hispanics and non-Hispanics whites were similar with respect to good knowledge-level answers to question 1 (17.3 vs 15.1%; OR=1.2; 95 % CI=0.74- 2.0), question 2 (31.2 vs. 39.3%; OR=0.76; 95% CI=0.54 - 1.1), and question 3 (15.2 vs. 16.5%; OR =1.1; 95% CI= 0.66 - 1.8). Compared to patients who earned < $20,000, patients with income > $40,000 were more likely to answer question 2 with good knowledge (OR =1.96; 95% CI=1.2 – 3.1). Conclusion: The study group’s overall knowledge of radiation risk was poor, but we did not find significant differences between Hispanic vs. non-Hispanic patients.

Ferromagnetic-Like Behavior of Pt Nanoparticles

2012 ◽  
Vol 190 ◽  
pp. 443-446 ◽  
Author(s):  
S. D. Antipov ◽  
G. E. Gorunov ◽  
N. S. Perov ◽  
M. N. Pivkina ◽  
E. E. Said-Galiyev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Size Distribution ◽  
Chemical Method ◽  
Chemical Deposition ◽  
Pt Nanoparticles ◽  
X Rays ◽  
Temperature Range ◽  
Highly Dispersed ◽  
Two Peaks

The magnetic properties of small 4d, 5d metal nanoparticles of Pd, Pt (clusters) are attracting a great attention because these materials in bulk are paramagnetic. In this work we report the ferromagnetic-like behavior of the small Pt nanoparticles prepared by chemical method. Highly dispersed Pt clusters have been synthesized on the surfaces of a porous spherical γ-Al2O3 particles. The process of the chemical deposition of metalorganic fluid with employment of the supercritical fluid was used. The samples of the Pt/γ-Al2O3 nanoparticles have been prepared in INEOS RAS. The nanoparticles size distribution was determined by small-angle X-rays scattering (SAXS). It was found that the Pt clusters have a bimodal particle size distribution with two peaks: R1max=20 Å and R2max=40 Å. The magnetic properties of the clusters have been investigated, using VSM magnetometer, in magnetic field up to ±3 kOe and at a temperature range from 80 to 400 K. It was observed that Pt/γ-Al2O3 nanoparticles show the ferromagnetic-like behavior in whole specified temperature range, the value of coercivity decreases gradually from 130 Oe to 80 Oe. The origin of ferromagnetic-like behavior of the Pt/γ-Al2O3 nanoparticles is discussed.

Background Radiation: Detection, Measurement and Hazards

2017 ◽  
pp. 119-122
Author(s):  
Rajan Paudel Chhetri
Keyword(s):  
Background Radiation ◽  
Radiation Detection ◽  
Significant Risk ◽  
Alpha Particles ◽  
X Rays ◽  
Human Beings ◽  
Radiation Level ◽  
Beta Particles ◽  
Agriculture Industry ◽  
Ionizing Radiations

Radiation is a form of energy. It is of two types: non-ionizing and ionizing. Among them, ionizing radiations have hazardous health effects upon human beings. Different types of cancers may arise from the overexposure to ionizing radiations like alpha- particles, beta-particles, gamma- rays, x-rays etc. Further, ionizing radiations have very important utilities in case of paper handling and use. Radiations can be used for various beneficial purposes like medical imaging, radiation therapy, improvement of quality of agriculture, industry etc. The overall radiation from various sources on a specific location on earth's surface refers to the background radiation level of that zone. Exposure to background radiation is an inescapable feature of the environment. A portable GM counter was used to quantify the total radiation level at different places. The finding of this shows a variation of radiation level. Comparatively large values of radiation counts at high altitude and low values at river side. There is no any abnormal value of radiation counts for all sample places. So, there is, generally, no significant risk of public exposure to the background radiation for sample places.The Himalayan Physics Vol. 6 & 7, 2017 (119-122)

Investigation of Elemental Analysis of Water Samples by Radioalpha Induced X-Ray Emission Spectroscopy*

1974 ◽  
Vol 18 ◽  
pp. 333-342
Author(s):  
R. Hight ◽  
C. C. Foster
Keyword(s):  
Water Samples ◽  
Background Radiation ◽  
Trace Element Analysis ◽  
Alpha Particles ◽  
Particle Accelerators ◽  
X Rays ◽  
Element Analysis ◽  
Worst Case ◽  
Helium Atmosphere ◽  
X Ray

AbstractAlpha particles and protons from charged particle accelerators and photons from both x-ray tubes and radioactive sources have been shown to be useful for the excitation of characteristic x-rays for multi-element energy dispersive trace analysis of environmental samples to the few ppm range. We have investigated the use of 4.5 MeV alpha particles from a thin window Po-210 source of 5 mCi effective strength to directly excite x-rays from trace elements in 1 cc water samples evaporated on 1.75 mg/cm2 thick mylar backings in a helium atmosphere in a lucite enclosure. Minimum detectable amounts (MDA's) were established for 19 elements (22 ≤ Z ≤ 82) using K-, L- and M- radiation and 50 minute counting times. The smallest MDA determined was 0.11 μg for vanadium. Other representative MDA's, in μg, are Fe-0.54, Mo-0.31 and Pb-0.43. MDA's lower by an average factor of about 10 over an eight month source life would result from the use of 1 Ci of Po-210 for 50 minutes per sample. Thinner sample backings and improved source encapsulation will reduce background radiation and further improve sensitivity. Comparison of our MDA's (5 mCi-Po-210) with those of Blasius et al., who used radiophoton sources and 40,000 sec. counting times to determine trace metal pollutants in water samples, shows radioalpha excitation to have comparable sensitivity in the worst case, arsenic and better, by more than two orders of magnitude, sensitivity in the best case, vanadium.Radioalpha induced x-ray trace element analysis offers the same advantages of portability, ease of operation, low maintenance and cost, and "in house" availability as radiophoton induced analysis. Because of the availability of more intense sources (up to 10 Ci), the fact that the detected radiation (x-rays) differs from the excitation radiation (a-particles) and that K, L, and M x-ray emission cross-sections depend essentially only on the emitted x-ray energy, lower MDA's are obtainable for many elements in thin samples for comparable counting times, as well.

scholarly journals X-Ray Hesitancy: Patients’ Radiophobic Concerns Over Medical X-rays

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582095954 ◽  
Author(s):  
Paul A. Oakley ◽  
Deed E. Harrison
Keyword(s):  
Low Dose ◽  
Background Radiation ◽  
X Rays ◽  
Adaptive Responses ◽  
Low Dose Radiation ◽  
X Ray ◽  
X Ray Imaging ◽  
The Family ◽  
Diagnostic Radiation ◽  
Dose Radiation

All too often the family physician, orthopedic surgeon, dentist or chiropractor is met with radiophobic concerns about X-ray imaging in the clinical setting. These concerns, however, are unwarranted fears based on common but ill-informed and perpetuated ideology versus current understanding of the effects of low-dose radiation exposures. Themes of X-ray hesitancy come in 3 forms: 1. All radiation exposures are harmful (i.e. carcinogenic); 2. Radiation exposures are cumulative; 3. Children are more susceptible to radiation. Herein we address these concerns and find that low-dose radiation activates the body’s adaptive responses and leads to reduced cancers. Low-dose radiation is not cumulative as long as enough time (e.g. 24 hrs) passes prior to a repeated exposure, and any damage is repaired, removed, or eliminated. Children have more active immune systems; the literature shows children are no more affected than adults by radiation exposures. Medical X-rays present a small, insignificant addition to background radiation exposure that is not likely to cause harm. Doctors and patients alike should be better informed of the lack of risks from diagnostic radiation and the decision to image should rely on the best evidence, unique needs of the patient, and the expertise of the physician—not radiophobia.

scholarly journals The Radiation Transfer of Soft X-rays

1997 ◽  
Vol 166 ◽  
pp. 337-340 ◽  
Author(s):  
Jürgen Kerp ◽  
Jochen Pietz
Keyword(s):  
Power Law ◽  
Intensity Distribution ◽  
Galactic Halo ◽  
Background Radiation ◽  
Plasma Temperature ◽  
Intensity Variation ◽  
Background Intensity ◽  
X Rays ◽  
Energy Bands ◽  
X Ray

AbstractWe discuss the link between the halo plasma temperature and the power-law spectral index of the extragalactic background radiation. This link is of strong influence for the derivation of the Galactic halo intensity distribution. In principal, we can distinguish between two combinations of Galactic halo plasma temperature and power-law slope. The first combination consists of a halo plasma of Thalo = 106 K and an E−2 approximation of the extragalactic background radiation. The second combination is Thalo = 106.2 K and an E−1.5. Both combinations are in agreement with recent observational results, thus it is not feasible to discriminate between both models on the basis of X-ray data available. But, the soft X-ray background intensity distribution in the ¼ keV and ¾ keV ROSAT energy bands differs significantly. The Thalo = 106 K and an E−2 allows a patchy ¼ keV intensity distribution while the Thalo = 106.2 K and an E−1.5 predicts a much smoother intensity variation since the hotter halo plasma accounts for a significant fraction of the ¾ keV background radiation.

scholarly journals Patient understanding of radiation risk from medical computed tomography - A comparison of Hispanic vs. Non-Hispanic Emergency Department populations

2015 ◽  
Author(s):  
Afton McNierney-Moore ◽  
Cynthia Smith ◽  
Jose H. Guardiola ◽  
K Tom Xu ◽  
Peter Richman
Keyword(s):  
Background Radiation ◽  
Radiation Risk ◽  
Good Knowledge ◽  
Independent Effect ◽  
X Rays ◽  
Multivariate Logistic Regression ◽  
Lifetime Cancer Risk ◽  
Convenience Sample ◽  
Medical Testing ◽  
Hispanic Patients

Background: Cultural differences and language barriers may adversely impact patients with respect to understanding the risks/benefits of medical testing. Objective: We hypothesized that there would be no difference in Hispanic vs. non-Hispanic patients’ knowledge of radiation risk that results from CT of the abdomen/pelvis (CTAP). Methods: We enrolled a convenience sample of adults at an inner-city ED. Patients provided written answers to rate agreement on a 10-point scale for two correct statements comparing radiation exposure equality between: CTAP and 5 years of background radiation (question 1); CTAP and 200 chest x-rays (question 3). Patients also rated their agreement that multiple CT scans increase the lifetime cancer risk (question 2). Scores of > 8 were considered good knowledge. Multivariate logistic regression analyses were performed to estimate the independent effect of the Hispanic variable. Results: 600 patients in the study group; 63% Hispanic, mean age 39.2 +/- 13.9 years. Hispanics and non-Hispanics whites were similar with respect to good knowledge-level answers to question 1 (17.3 vs 15.1%; OR=1.2; 95 % CI=0.74- 2.0), question 2 (31.2 vs. 39.3%; OR=0.76; 95% CI=0.54 - 1.1), and question 3 (15.2 vs. 16.5%; OR =1.1; 95% CI= 0.66 - 1.8). Compared to patients who earned < $20,000, patients with income > $40,000 were more likely to answer question 2 with good knowledge (OR =1.96; 95% CI=1.2 – 3.1). Conclusion: The study group’s overall knowledge of radiation risk was poor, but we did not find significant differences between Hispanic vs. non-Hispanic patients.

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