scholarly journals II. Energy of Röntgen and becquerel rays, and the energy required to produce an ion in gases

1901 ◽  
Vol 196 (274-286) ◽  
pp. 25-59 ◽  
Keyword(s):  
X Rays ◽  
Heating Effect ◽  
Ionic Charge ◽  
Special Investigation ◽  
Primary Object ◽  
Complete Absorption ◽  
Pass Through ◽  
Active Substances ◽  
Ionic Energy

The primary object of the investigations described in this paper was the determination of the amount of energy required to produce a gaseous ion when Röntgen rays pass through a gas, and to deduce from it the energy of the radiation emitted per second by uranium, thorium, and other radio-active substances. In order to determine the “ionic energy” (as it will be termed for brevity), it has been necessary to make a special investigation to measure accurately the heating effect of X rays when the rays are absorbed in metals, and also the absorption of the rays in gases. The method employed to determine the ionic energy was briefly as follows :—The total energy of the rays emitted per second was determined by measuring the heating effect of a known proportion of the rays when absorbed in a metal. The total number of ions produced by complete absorption of the rays in the gas was deduced from measurements on the current produced by the ionization of a known volume of the gas and of the absorption of the rays in the gas, assuming the value of the ionic charge recently determined by J. J. Thomson.

scholarly journals Energy of Röntgen and Becquerel rays and the energy required to produce an ion in gases

1901 ◽  
Vol 67 (435-441) ◽  
pp. 245-250 ◽  
Keyword(s):  
The Other ◽  
X Rays ◽  
Heating Effect ◽  
Primary Object ◽  
Pass Through ◽  
Active Substances ◽  
Ionic Energy

The primary object of the investigations described in the paper was the determination of the energy required to produce a gaseous ion when X rays pass through a gas, and to deduce from the result the amount of energy radiated out into the gas by uranium, thorium, and the other radio-active substances. In order to determine this “ionic energy” it has been necessary to accurately measure the heating effect of X rays and the absorption Röntgen radiation in passing through a gas.

The Muon as a Tool for Scanning the Interior of the Human Body

1969 ◽  
Vol 08 (04) ◽  
pp. 311-319 ◽  
Author(s):  
H. Daniel
Keyword(s):  
Chemical Analysis ◽  
Human Body ◽  
Three Dimensional ◽  
Simultaneous Recording ◽  
The Body ◽  
X Rays ◽  
Medium Energy ◽  
Pass Through ◽  
Dimensional Picture

SummaryA completely new technique for scanning the interior of the human body is proposed which is based on the following principle: muons from an accelerator pass through two spark chambers and are stopped in the body. The decay electrons leave the body and pass also two spark chambers. The trajectory co-ordinates read out from the spark chambers allow the determination of the point of decay with high precision. The truly three-dimensional picture obtained in this way is truly three-dimensionally displayed on a screen. Several modifications of the basic method are described, the most important ones being the simultaneous recording of the muonic X-rays (equivalent to a chemical analysis) or of the muon precession. The necessary dose is low. The most serious disadvantage is the need of a medium-energy accelerator. Quantitative figures on resolution, efficiency, and dose are given.

Problems in Thin-Film X-ray Quantification

1990 ◽  
Vol 48 (2) ◽  
pp. 458-459
Author(s):  
J N Chapman ◽  
W A P Nicholson
Keyword(s):  
Thin Film ◽  
Specimen Thickness ◽  
X Rays ◽  
Characteristic Peak ◽  
Local Composition ◽  
X Ray ◽  
Measured Ratio ◽  
Path Lengths ◽  
Composition Changes

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.

scholarly journals Determination of the Vertical Dimension and the Position of the Occlusal Plane in a Removable Prosthesis Using Cephalometric Analysis and Golden Proportion

2021 ◽  
Vol 11 (15) ◽  
pp. 6948
Author(s):  
Gabriele Cervino ◽  
Sergio Sambataro ◽  
Chiara Stumpo ◽  
Salvatore Bocchieri ◽  
Fausto Murabito ◽  
...  
Keyword(s):  
Vertical Dimension ◽  
Occlusal Plane ◽  
X Rays ◽  
Common Procedure ◽  
Lower Incisor ◽  
Golden Proportion ◽  
The Face ◽  
Removable Prosthesis ◽  
Edentulous Patients

The aim of this study is to demonstrate the use and the effectiveness of cephalometry and golden proportions analysis of the face in planning prosthetic treatments in totally edentulous patients. In order to apply this method, latero-lateral and posterior-anterior X-rays must be performed in addition to the common procedure. Two main concerns for totally edentulous patients are the establishment of the vertical dimension and the new position of the occlusal plane. The divine proportion analysis was carried out by the use of a golden divider. The prosthetic protocol was divided into three steps and a case was selected for better understanding. Referring to the golden relations, if the distance from the chin to the wing of the nose is 1.0, the distance from the nose to eye is 0.618. This proportion is useful and effective in determining the correct prosthetic vertical dimension. The incisal margin of the lower incisor must be positioned between Point A (A) and protuberance menti (Pm) according to the gold ratio 0.618 of the total height A-Pm. Posteriorly the occlusal plane must be placed 2 mm below the divine occlusal plane (traced from the incisal margin of lower incisors to Xi point). A prosthesis made in accordance with cephalometric parameters and divine proportions of the face helps to improve the patient’s aesthetics, function and social personality.

scholarly journals Determination of the Efficiency of Production of X-Rays

1918 ◽  
Vol 14 (54) ◽  
pp. 33-33
Author(s):  
P. T. Weeks
Keyword(s):  
X Rays

scholarly journals Electronic Excitations and Radiation Damage in Macromolecular Crystallography

Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 273 ◽  
Author(s):  
José Brandão-Neto ◽  
Leonardo Bernasconi
Keyword(s):  
Chemical Information ◽  
X Rays ◽  
Electronic Excitations ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Successful Approach ◽  
Structural Research

Macromolecular crystallography at cryogenic temperatures has so far provided the majority of the experimental evidence that underpins the determination of the atomic structures of proteins and other biomolecular assemblies by means of single crystal X-ray diffraction experiments. One of the core limitations of the current methods is that crystal samples degrade as they are subject to X-rays, and two broad groups of effects are observed: global and specific damage. While the currently successful approach is to operate outside the range where global damage is observed, specific damage is not well understood and may lead to poor interpretation of the chemistry and biology of the system under study. In this work, we present a phenomenological model in which specific damage is understood as the result of a single process, the steady excitation of crystal electrons caused by X-ray absorption, which acts as a trigger for the bulk effects that manifest themselves in the form of global damage and obscure the interpretation of chemical information from XFEL and synchrotron structural research.

Hemodynamic control using models of electroacoustic signals of an oxygenated neuron

2021 ◽  
Vol 21 (3) ◽  
pp. 50-54
Author(s):  
B.G. Tsugkiev ◽  
◽  
L.Ch. Gagieva ◽  
T.V. Tsugkieva ◽  
M.M. Chegaev ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Nutritional Value ◽  
Growing Season ◽  
Comparative Assessment ◽  
Biologically Active ◽  
Onobrychis Viciifolia ◽  
Iron Copper ◽  
Calcium Phosphorus ◽  
Active Substances

The paper presents a comparative assessment of the nutritional value depending on the phenological phase of Onobrychis viciifolia Scop., as well as the determination of the regularity of the accumulation of biologically active substances and heavy metals in the herb of the species. The yield of green mass of plants was determined. From each hectare of sowing, 9,7 centners of protein can be obtained; the yield of fiber is 13 centners, BEV is 22,9 centners, fat is 1,6 centners, ash is 4 centners and carotene is 13.0 kg. Depending on the growing season, the chemical composition in the grass of Onobrychis viciifolia changes. The content of calcium, phosphorus increases, and the presence of iron, copper, cobalt, zinc, manganese and molybdenum and amino acids decreases.

scholarly journals Determination of Q-convex sets by X-rays

2005 ◽  
Vol 332 (1-3) ◽  
pp. 19-45 ◽  
Author(s):  
Alain Daurat
Keyword(s):  
Convex Sets ◽  
X Rays
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