Experimental Studies upon the Lethal Doses of X Rays and Radium for Human and other Tumours

1924 ◽  
Vol 29 (289) ◽  
pp. 275-292
Author(s):  
S. Russ
Keyword(s):  
Experimental Studies ◽  
X Rays ◽  
Lethal Doses

scholarly journals A comprehensive Monte Carlo study to design a novel multi-nanoparticle loaded nanocomposites for augmentation of attenuation coefficient in the energy range of diagnostic X-rays

2021 ◽  
Vol 27 (4) ◽  
pp. 279-289
Author(s):  
Elahe Sayyadi ◽  
Asghar Mesbahi ◽  
Reza Eghdam Zamiri ◽  
Farshad Seyyed Nejad
Keyword(s):  
Monte Carlo ◽  
Energy Range ◽  
Radiation Protection ◽  
Experimental Studies ◽  
Rubber Matrix ◽  
Photon Flux ◽  
Monte Carlo Code ◽  
X Rays ◽  
Wide Range ◽  
Shielding Properties

Abstract Introduction: The present study aimed to investigate the radiation protection properties of silicon-based composites doped with nano-sized Bi2O3, PbO, Sm2O3, Gd2O3, WO3, and IrO2 particles. Radiation shielding properties of Sm2O3 and IrO2 nanoparticles were investigated for the first time in the current study. Material and methods: The MCNPX (2.7.0) Monte Carlo code was utilized to calculate the linear attenuation coefficients of single and multi-nano structured composites over the X-ray energy range of 10–140 keV. Homogenous distribution of spherical nanoparticles with a diameter of 100 nm in a silicon rubber matrix was simulated. The narrow beam geometry was used to calculate the photon flux after attenuation by designed nanocomposites. Results: Based on results obtained for single nanoparticle composites, three combinations of different nano-sized fillers Sm2O3+WO3+Bi2O3, Gd2O3+WO3+Bi2O3, and Sm2O3+WO3+PbO were selected, and their shielding properties were estimated. In the energy range of 20-60 keV Sm2O3 and Gd2O3 nanoparticles, in 70-100 keV energy range WO3 and for photons energy higher than 90 keV, PbO and Bi2O3 nanoparticles showed higher attenuation. Despite its higher density, IrO2 had lower attenuation compared to other nanocomposites. The results showed that the nanocomposite containing Sm2O3, WO3, and Bi2O3 nanoparticles provided better shielding among the studied samples. Conclusions: All studied multi-nanoparticle nanocomposites provided optimum shielding properties and almost 8% higher attenuation relative to single nano-based composites over a wide range of photon energy used in diagnostic radiology. Application of these new composites is recommended in radiation protection. Further experimental studies are suggested to validate our findings.

THE IMMEDIATE EFFECTS OF SEVERE LOCAL X IRRADIATION ON THE LIVER OF THE HAMSTER

1952 ◽  
Vol 30 (6) ◽  
pp. 571-577
Author(s):  
Katherine E. Livingstone ◽  
David J. McCallion
Keyword(s):  
Experimental Studies ◽  
Liver Parenchyma ◽  
Liver Cells ◽  
The Body ◽  
Field Size ◽  
Cyclic Variation ◽  
X Rays ◽  
X Irradiation ◽  
Parenchymal Cells ◽  
Cyclic Fluctuation

Opinions regarding the radiosensitivity of the liver, based on clinical and experimental studies, differ widely. No comprehensive study of the immediate effects of severe local X irradiation upon the cytology of the liver parenchyma has been previously undertaken. In the present investigation cytological studies were made upon the livers of hamsters at 4-hr. intervals over a 24-hr. period. It was demonstrated that the amounts of cytoplasmic basophilia, glycogen, and sudanophilic fat show a cyclic variation over the 24-hr. period studied. Adult hamsters were exposed to X rays at the rate of 495 r. per minute with a total dosage of 2000 r. The field size over the liver was 4 cm. by 2 cm. with the rest of the body protected by a lead shield. Following irradiation the animals were sacrificed, two at a time, at 4 hr. intervals over a 24-hr. period. The amounts of basophilic material in the cytoplasm of the parenchymal cells of the liver were considerably decreased at 8 hr. and at 16 hr. after irradiation. At other times the cytoplasmic basophilia of the irradiated liver cells was approximately as dense as that of the control animals. The density of cytoplasmic basophilia showed a cyclic variation approximating that of the controls. The amount of glycogen in the irradiated livers was very much decreased, but still showed a cyclic fluctuation. There was a striking decrease in the amount of sudanophilic fat in the liver cells following irradiation. The results indicate that severe local X irradiation of the liver of the hamster has immediate effects directly upon that organ, resulting in a disturbance of its normal physiological activities.

scholarly journals Haematopoietic role for Patch (Ph) revealed by new W mutant (Wct) in mice

1983 ◽  
Vol 42 (1) ◽  
pp. 29-39 ◽  
Author(s):  
J. F. Loutit ◽  
B. M. Cattanach
Keyword(s):  
Stem Cell ◽  
Red Cells ◽  
Haematopoietic Stem Cell ◽  
Whole Body ◽  
X Rays ◽  
Double Heterozygote ◽  
Chromosome 5 ◽  
Linked Gene ◽  
X Irradiation ◽  
Lethal Doses

SUMMARYA new mutant (Wct) has been identified at the W locus of the mouse. The homozygote is poorly viable. Whereas the heterozygote (Wct / +) is only mildly anaemic like Wυ / +, the double heterozygote Wct + / + Ph is considerably more anaemic than Wυ + / + Ph and it and Wsh + / + Ph have significantly raised leucocyte counts. Wct + / + Ph is also unduly radiosensitive to whole body X-irradiation, 50% dying from haematopoietic failure at a dose of 4·59 ± 0·14 Gy, whereas the median for Wct / + was 6·49 ± 0·28 Gy. Serial blood counts of mice after low- or sub-lethal doses of X-rays revealed significantly more profound depression of counts of both red cells and leucocytes in Wct +, and more notably in Wct + / + Ph, than in + / + or Wsh / + (haematologically normal) iso-dosed mice. We conclude that control of haematopoiesis by chromosome 5 is not confined to the W locus but is shared by the linked gene Ph (and perhaps Rw) and that expression of the change is not limited to the erythron but involves the pluripotent haematopoietic stem cell.

scholarly journals Different modes of runaway electron beams generated in high-pressure gases

2021 ◽  
Vol 2064 (1) ◽  
pp. 012001
Author(s):  
V F Tarasenko ◽  
D A Sorokin ◽  
D V Beloplotov ◽  
M I Lomaev ◽  
E Kh Baksht ◽  
...  
Keyword(s):  
High Pressure ◽  
Runaway Electron ◽  
Experimental Studies ◽  
Beam Current ◽  
Current Amplitude ◽  
X Rays ◽  
X Ray ◽  
Beam Current Amplitude ◽  
The One ◽  
Direction Opposite

Abstract This article presents the results of experimental studies of different modes of a runaway electron beam (RAEB) generation in high-pressure gases as well as X-rays caused by it. In particular, the mode with the greatest beam current amplitude, the one with two current pulses, that with the X-ray pulse duration of 100s ns, the mode in which a RAEB propagates in the direction opposite from an anode, and some others are described. The effect of the cathode design and material on the RAEB current amplitude and duration in atmospheric-pressure air is shown. When analyzing the most common modes, the features of the gap breakdown are used.

scholarly journals Deep Learning Models for Pneumonia Identification and Classification Based on X-Ray Images

2021 ◽  
Vol 38 (3) ◽  
pp. 903-909
Author(s):  
Veeranjaneyulu Naralasetti ◽  
Reshmi Khadherbhi Shaik ◽  
Gayatri Katepalli ◽  
Jyostna Devi Bodapati
Keyword(s):  
Experimental Studies ◽  
Cross Entropy ◽  
X Rays ◽  
Weight Decay ◽  
X Ray ◽  
Proposed Model ◽  
Benchmark Datasets ◽  
Classification Tasks ◽  
Multi Class Classification ◽  
Fully Connected

Diagnosis based on chest X-rays is widely used and approved for the diagnosis of various diseases such as Pneumonia. Manually screening of theses X-ray images technician or radiologist involves expertise and time consuming. Addressing this, we propose an automated approach for the diagnosis of pneumonia by assisting doctors in spotting infected areas in the X-ray images. We propose a deep Convolutional Neural Network (CNN) model for efficiently detecting the presence of pneumonia in the X-ray images. The proposed CNN is designed with 5 convolution blocks followed by 4 fully connected layers. In order to boost the performance of the model, we incorporate batch normalization, dynamic dropout, learning rate decay, L2 regularization weight decay along with Adam optimizer and binary Cross-Entropy loss function while training the model using back propagating algorithm. The proposed model is validated on two publicly accessible benchmark datasets, and the experimental studies conducted on these datasets indicate that the proposed model is efficient. The suggested CNN architecture with specified hyper parameters allows the model to outperform several existing models by achieving accuracy of 97.73% and 91.17% respectively for binary and multi-class classification tasks of pneumonia disease.

scholarly journals Measurements of fast electron beams and soft X-ray emission from plasma-focus experiments

Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Władysław Surała ◽  
Marek J. Sadowski ◽  
Roch Kwiatkowski ◽  
Lech Jakubowski ◽  
Jarosław Żebrowski
Keyword(s):  
Plasma Focus ◽  
Fast Electron ◽  
Hot Spots ◽  
Electron Beams ◽  
Experimental Studies ◽  
Neutron Counter ◽  
X Rays ◽  
Strong Electron ◽  
Time Resolved ◽  
X Ray

Abstract The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF) experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8) measuring channels. For discharges performed with the pure deuterium filling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the first hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds) and appearing in different instants after the current peculiarity (so-called current dip) were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and recorded with nuclear track detectors, were also investigated. Those measurements confirmed a multibeam character of the ion emission. The time-integrated soft X-ray images, which were taken side-on by means of a pinhole camera and sensitive X-ray films, showed the appearance of some filamentary structures and so-called hot spots. The application of small amounts of admixtures of different heavy noble gases, i.e. of argon (4.8% volumetric), krypton (1.6% volumetric), or xenon (0.8% volumetric), decreased intensity of the recorded electron beams, but increased intensity of the soft X-ray emission and showed more distinct and numerous hot spots. The recorded electron spikes have been explained as signals produced by quasi-mono-energetic microbeams emitted from tiny sources (probably plasma diodes), which can be formed near the observed hot spots.

Emergency Medical Services Backboard With a Pressure Dispersion Liner

2009 ◽  
Author(s):  
Matthew R. Henschen ◽  
Adam L. Koesters ◽  
Jonathan Harvey ◽  
Gregory Nemunaitis ◽  
Mehdi Pourazady ◽  
...  
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
X Rays ◽  
Interface Pressure ◽  
Light Pressure ◽  
Average Maximum ◽  
Cord Injury ◽  
Pressure Spike ◽  
Bed Sores ◽  
Trauma Victims

Spinal immobilization is of utmost importance when caring for major trauma victims. Because of the potential for spinal cord injury, trauma victims must be secured to a rigid backboard. Patients are held in position by placing blocks on either side of their head, straps across their forehead, chest, and legs. The goal of using a hard backboard is to reduce the chances of damaging the victim’s neurological functions because of movement of unstable or injured vertebrae. These backboards serve their function of patient immobilization but present another problem for the patient. They have been associated with a skin breakdown condition called decubitus ulcers (bed sores). Bed sores are areas of damaged skin and tissue that develop when sustained pressure causes a restriction of blood circulation to vulnerable parts of the body. Without adequate blood flow, the affected tissue dies. Some patients may be secured to these boards for up to four hours waiting to undergo x-rays. This is more than enough time for ulcers to reach Stage IV which is the deepest and most destructive ulcer. The incidence of pressure ulcers in newly admitted patients has been reported as high as 59% and 50% have been reported at the sacral region [1, 2]. In experimental studies performed on dogs it has been shown that a constant pressure of only 60mmHg for one hour is enough to cause irreversible tissue damage [3]. When the patients are on the backboards it has been shown that there is often a high pressure spike at the sacral prominence where average maximum interface pressure spike of 260mmHg have been noted. When a thin but very heavy gel pad was added to the backboard, the sacral interface pressure was reduced to an average maximum pressure of 188 mmHg [4]. The objective of this project is to develop a backboard with a light pressure dispersion liner to reduce interface pressures on pressure sensitive areas in the supine position.

scholarly journals Theoretical and experimental studies of material radiative properties and their applications to laser and heavy ion inertial fusion

2011 ◽  
Vol 29 (1) ◽  
pp. 69-80 ◽  
Author(s):  
N. Yu. Orlov ◽  
O.B. Denisov ◽  
O.N. Rosmej ◽  
D. Schäfer ◽  
Th. Nisius ◽  
...  
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Radiation Efficiency ◽  
Radiative Properties ◽  
Wall Material ◽  
Inertial Fusion ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
X Ray Absorption

AbstractTheoretical and experimental studies of radiative properties of substances heated by pulsed current devises or lasers and used as X-ray sources have been carried out depending on plasma conditions, and specific spectra of X-ray absorption and radiation for different materials have been calculated. Important features of the theoretical model, known as the ion model of plasma, are discussed. This model can be applied for calculations of the radiative properties of complex materials over a wide range of plasma parameters. For purposes of indirect-driven inertial fusion based on the hohlraum concept, an optimization method is used for the selection of an effective complex hohlraum wall material, which provides high radiation efficiency at laser interaction with the wall. The radiation efficiency of the resulting material is compared with the efficiency of other composite materials that have previously been evaluated theoretically. A similar theoretical study is performed for the optically thin X-pinch plasma produced by exploding wires. Theoretical estimations of radiative efficiency are compared with experimental data that have been obtained from measurements of X-pinch radiation energy yield using two exploding wire materials, NiCr and Alloy 188. It is shown that the theoretical results agree well with the experimental data. A symmetric multilayer X-pinch, where W and Mo wires are used, is as well considered. The theoretical explanation of experimental phenomena is discussed based on the W and Mo radiative spectra. The ion model was as well applied for interpretation of experimental results on opacities of CHO-plasma obtained via indirect heating of low density polymer layers by means of soft X-rays. The new diagnostics method based on the deformation of the of the Carbon absorption K-edge when foam layer is heated to plasma is discussed. The spectral coefficients for X-ray absorption in CHO-plasma are calculated in the photon energy region around the Carbon K-edge for different plasma temperatures and mean foam density. In this case, the Carbon K-edge position on the energy scale can be used for plasma temperature diagnostic.

scholarly journals The Application of X-rays for an Electrodeposition of Composite Coatings with Modified Structures and Properties

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4913
Author(s):  
Natalia Valko ◽  
Wiktoria Evstigneeva ◽  
Victor Anishchik ◽  
Vitalii Bondariev ◽  
Pawel Okal ◽  
...  
Keyword(s):  
Composite Coatings ◽  
Experimental Studies ◽  
Sio2 Nanoparticles ◽  
Electrolytic Cell ◽  
Electrolytic Deposition ◽  
X Rays ◽  
Mass Rate ◽  
Orienting Effect ◽  
Dispersing Ability ◽  
Electroplating Process

Experimental studies of the effect of X-rays on the process of electrolytic deposition of composite coatings are reviewed in this paper. Particular emphasis will be on the applications of X-rays for both the modification of a structure and the mechanical characteristics of galvanic coatings. In particular, this research investigates the Co/SiO2 coatings deposited from aqueous solutions under the effect of X-rays. The results of extensive investigations into the dispersing ability of electrolytes with SiO2 nanoparticles and a mass rate of composite coatings Co/SiO2 indicates that the method of electroplating under the effect of X-rays during the process results in the intensification of diffusion in the electrolyte volume and creates dense, uniform coatings. This research demonstrates that exposure of an electrolytic cell to X-rays during the electroplating process of Co/SiO2 results in an orienting effect on the formation of crystal grains and allows for the creation of dense, morphology uniform coatings with increased hardness and improved adhesion.

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