scholarly journals Effect And Application of Ionization Radiation (X-Ray) In Living organism

2013 ◽  
Vol 3 ◽  
pp. 89-92 ◽  
Author(s):  
Suraj Raj Adhikari
Keyword(s):  
Biological Effects ◽  
Living Organism ◽  
Modern Medicine ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
Ionization Radiation ◽  
Science Application ◽  
Living Tissues ◽  
Ionizing Radiations

X-ray is electromagnetic radiation of extremely short wavelength and high frequency. X-rays show wave as well as particle-like properties. X-ray is used in wide range of application such as industry, medicine and science application. It is essential tool in modern medicine. It can result in both beneficial and dangerous biological effects. These ionizing radiations penetrate the living tissues and can destroy living cells, chromosomal aberrations and carcinogenic effect.The Himalayan PhysicsVol. 3, No. 3, July 2012Page: 89-92

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A18 ◽  
Author(s):  
C. H. A. Logan ◽  
B. J. Maughan ◽  
M. N. Bremer ◽  
P. Giles ◽  
M. Birkinshaw ◽  
...  
Keyword(s):  
Angular Resolution ◽  
False Positive Rate ◽  
High Sensitivity ◽  
Point Sources ◽  
Selection Function ◽  
X Rays ◽  
Cluster Emission ◽  
X Ray ◽  
Wide Range ◽  
Function Modelling

Context. The XMM-XXL survey has used observations from the XMM-Newton observatory to detect clusters of galaxies over a wide range in mass and redshift. The moderate PSF (FWHM ~ 6″ on-axis) of XMM-Newton means that point sources within or projected onto a cluster may not be separated from the cluster emission, leading to enhanced luminosities and affecting the selection function of the cluster survey. Aims. We present the results of short Chandra observations of 21 galaxy clusters and cluster candidates at redshifts z > 1 detected in the XMM-XXL survey in X-rays or selected in the optical and infra-red. Methods. With the superior angular resolution of Chandra, we investigate whether there are any point sources within the cluster region that were not detected by the XMM-XXL analysis pipeline, and whether any point sources were misclassified as distant clusters. Results. Of the 14 X-ray selected clusters, 9 are free from significant point source contamination, either having no previously unresolved sources detected by Chandra or with less than about 10% of the reported XXL cluster flux being resolved into point sources. Of the other five sources, one is significantly contaminated by previously unresolved AGN, and four appear to be AGN misclassified as clusters. All but one of these cases are in the subset of less secure X-ray selected cluster detections and the false positive rate is consistent with that expected from the XXL selection function modelling. We also considered a further seven optically selected cluster candidates associated with faint XXL sources that were not classed as clusters. Of these, three were shown to be AGN by Chandra, one is a cluster whose XXL survey flux was highly contaminated by unresolved AGN, while three appear to be uncontaminated clusters. By decontaminating and vetting these distant clusters, we provide a pure sample of clusters at redshift z > 1 for deeper follow-up observations, and demonstrate the utility of using Chandra snapshots to test for AGN in surveys with high sensitivity but poor angular resolution.

A multi-length-scale USAXS/SAXS facility: 10–50 keV small-angle X-ray scattering instrument

2013 ◽  
Vol 46 (5) ◽  
pp. 1508-1512 ◽  
Author(s):  
Byron Freelon ◽  
Kamlesh Suthar ◽  
Jan Ilavsky
Keyword(s):  
Small Angle ◽  
Soft Matter ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
And Performance ◽  
New Facility ◽  
Ray Scattering

Coupling small-angle X-ray scattering (SAXS) and ultra-small-angle X-ray scattering (USAXS) provides a powerful system of techniques for determining the structural organization of nanostructured materials that exhibit a wide range of characteristic length scales. A new facility that combines high-energy (HE) SAXS and USAXS has been developed at the Advanced Photon Source (APS). The application of X-rays across a range of energies, from 10 to 50 keV, offers opportunities to probe structural behavior at the nano- and microscale. An X-ray setup that can characterize both soft matter or hard matter and high-Zsamples in the solid or solution forms is described. Recent upgrades to the Sector 15ID beamline allow an extension of the X-ray energy range and improved beam intensity. The function and performance of the dedicated USAXS/HE-SAXS ChemMatCARS-APS facility is described.

scholarly journals Stellar Winds in Massive X-ray Binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 355-358
Author(s):  
Peter Kretschmar ◽  
Silvia Martínez-Núñez ◽  
Enrico Bozzo ◽  
Lidia M. Oskinova ◽  
Joachim Puls ◽  
...  
Keyword(s):  
Compact Object ◽  
High Mass ◽  
Stellar Winds ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Wide Range ◽  
Strong Winds ◽  
The One ◽  
X Ray Binaries

AbstractStrong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the varying properties of the emitted X-rays; but on the other side the accretor’s gravity and ionizing radiation can strongly influence the wind flow. Based on a collaborative effort of astronomers both from the stellar wind and the X-ray community, this presentation attempts to review our current state of knowledge and indicate avenues for future progress.

scholarly journals A comparison of the radiosensitisation ability of 22 different element metal oxide nanoparticles using clinical megavoltage X-rays

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexandra Guerreiro ◽  
Nicholas Chatterton ◽  
Eleanor M. Crabb ◽  
Jon P. Golding
Keyword(s):  
Dna Damage ◽  
Metal Oxide ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Rays ◽  
X Ray ◽  
Wide Range

Abstract Background A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions. Results Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage. Conclusions Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success.

Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

1997 ◽  
Vol 3 (S2) ◽  
pp. 851-852
Author(s):  
H. Ade
Keyword(s):  
Fine Structure ◽  
Compositional Analysis ◽  
High Sensitivity ◽  
Linear Dichroism ◽  
X Rays ◽  
X Ray ◽  
Absorption Fine ◽  
Nexafs Spectroscopy ◽  
Wide Range ◽  
X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

scholarly journals X-ray studies of the structure of hair, wool, and related fibres.- I. General

1931 ◽  
Vol 230 (681-693) ◽  
pp. 75-101 ◽  
Keyword(s):  
Physical Properties ◽  
Crystalline Structure ◽  
Human Hair ◽  
X Rays ◽  
Present Communication ◽  
Cellulose Fibres ◽  
X Ray ◽  
Usual Manner ◽  
Wide Range ◽  
Muscle Nerve

It is now some ten years since it was first realised that, in common with natural and artificial cellulose fibres, animal fibres with a protein basis are in many cases sufficiently crystalline to yield a pronounced interference figure when examined with monochromatic X-rays. Such “ X-ray fibre diagrams ” were reported in 1921 by HERZOG and JANCKE* for muscle, nerve, sinew, and hair, and in 1924 similar photographs from human hair were obtained by one of the present writers. From an X-ray examination of wool it was concluded by THREADGOLD that “ there is no evidence for assuming the wool fibres and yarns examined to have a crystalline structure,” but in 1927 EWLES and SPEAKMAN had already obtained wool interference figures precisely similar to those previously obtained from hair. The two last-named authors endeavoured to interpret their results in the light of certain physical properties, but it has since become clear that the problem of hair structure is sufficiently complex to necessitate an X-ray study of a wide range of materials under as great a variety of conditions as possible. The present communication is an account of the preliminary results of such an investigation. Over a hundred X-ray photographs have been taken, using copper K-radiation filtered of the MATHS FORMULA line by nickel foil about 1/100 mm. thick. The “ slit” was a rectangular aperture, 4 cm. x 0.5mm., the scattered rays from which were screened off in the usual manner by a secondary slit.

Protection and Monitoring of Ionizing Radiation - Nuclear Medicine

2009 ◽  
Author(s):  
Sajjad Akbar ◽  
M. Shahid Khalil ◽  
Shahzad Ahmad
Keyword(s):  
Nuclear Medicine ◽  
Ionizing Radiation ◽  
Private Sector ◽  
Radiological Protection ◽  
X Rays ◽  
Public And Private ◽  
Military Hospitals ◽  
Ionization Radiation ◽  
Public And Private Sector ◽  
Ionizing Radiations

The advancement in technology has resulted into development of Telethrapy and X-ray machine which has high potential hazards of ionizing radiation to user and patient exposed. Ionizing radiations are referred as gamma rays photons. X-rays can cause conjunctivitis and sterility. Ionization radiation is hazard both in radiotherapy and nuclear medicine department. The energy of this radiation is around 10eV, higher the energy of radiation greater is hazard because of penetration into tissues the basic protection rule is either move way from source of radiation or put absorber in between. These equipments are tools of diagnostics, therefore international commission on radiological protection (ICRP) ha recommended that exposure to radiation be kept minimum. Designing of teletherapy facilities play important role in protection and monitoring of radiations. The author has analyzed the protective measures and monitoring of radiations in various hospitals in public and private sector in Rawalpindi / Islamabad Pakistan. It has been observed that only in military hospitals strict protective and monitoring measurers are taken against radiations but in other public and private sector hospitals such measure are compromised due to lack of proper awareness. Pakistan nuclear regulatory authority (PNRA) is taking measures for ensuring protective and monitoring measurer against radiations and arousing awareness to all concerns.

The influence of X-rays on the stability of selected properties of polyethylene

2018 ◽  
Vol 23 (1) ◽  
pp. 3-11
Author(s):  
Anna Wiśniewska ◽  
Gabriela Chwalik ◽  
Sylwia Łagan
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Living Organism ◽  
Degradation Process ◽  
Material Surface ◽  
Control Group ◽  
X Rays ◽  
X Ray ◽  
The Stability

The evaluation of a degradation process of polyethylene (PE) in in vitro conditions under the influence of X-rays (X) and an in-cubation in two solutions simulating the environment of a living organism (SBF – simulated body fluid) was carried out. A dose corresponding to 10 standard X-ray pictures of the skeletal system as well as Ringer's and saline solutions at 40°C were used in the study. The paper presents the results of the influence of the 12-month studies on the selected surface properties of the material: surface wettability and abrasiveness. The value of surface free energy (SFE) was determined on the basis of the wetting angle measurements. The conductivity of the incubation fluids was also analyzed. The obtained results indicate that the adopted dose of X-ray radiation has no significant effect on the wettability of the surface of polyethylene. The nature of the surface layer of polyethylene did not change as a result of the 12-month incubation and remained hydrophilic. For the samples incubated in both immersion fluids, a decrease in surface free energy (SFE) was observed. For both the irradiated material and the control group, no significant changes in the mass of the samples and the conductivity of the incubation fluids were found, which indicates the stability of polyethylene. However, the abrasion value increased by approximately 26%. With the passage of the incubation time, a decrease in the value of this parameter was observed for the polyethylene subjected to radiation. No significant changes were found for the control group.

Position of exit X-rays from rotated-inclined double-crystal monochromators

1998 ◽  
Vol 5 (3) ◽  
pp. 679-681 ◽  
Author(s):  
Yasuharu Kashihara ◽  
Hiroshi Yamazaki ◽  
Kenji Tamasaku ◽  
Tetsuya Ishikawa
Keyword(s):  
Heat Load ◽  
Diffraction Theory ◽  
Third Generation ◽  
X Rays ◽  
Double Crystal ◽  
Undulator Radiation ◽  
X Ray ◽  
Double Crystal Monochromator ◽  
Asymmetric Reflection ◽  
Wide Range

The rotated-inclined double-crystal monochromator (RIDCM) has been adopted to reduce the heat load from third-generation undulator radiation. The position of the exit X-rays from RIDCM has been calculated as a function of X-ray energy on the basis of diffraction theory including refraction effects. The results show that the positions of the exit X-rays vary over a wide range due to asymmetric reflection. Methods of fixing the exit position in RIDCM are also discussed.

scholarly journals STUDIES ON THE MECHANISM OF ACTION OF IONIZING RADIATIONS

1952 ◽  
Vol 35 (6) ◽  
pp. 865-871 ◽  
Author(s):  
E. S. Guzman Barron ◽  
S. Louise Seki
Keyword(s):  
Cell Division ◽  
Sperm Cells ◽  
X Rays ◽  
Thiol Compounds ◽  
X Ray ◽  
Arbacia Punctulata ◽  
Inhibiting Effect ◽  
Small Doses ◽  
X Irradiation ◽  
Ionizing Radiations

On x-irradiation of the eggs and sperm of Arbacia punctulata there was inhibition of respiration with relatively large doses, whereas there was an increase with small doses. The dose required to produce an increase of respiration depended on the degree of sensitivity of the cell to the effect of ionizing radiation. Sperm cells were more sensitive; then came fertilized eggs; unfertilized eggs were the least sensitive. The inhibiting effect of x-rays on cell division was observed even on irradiation with x-ray doses which produced an increase of respiration. These results are compared to similar effects produced by thiol reagents and are attributed to oxidation of the thiol compounds in the cell.

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