scholarly journals The conversion of diamond into coke in high vacuum by cathode rays

1908 ◽  
Vol 80 (537) ◽  
pp. 184-185 ◽  
Keyword(s):  
Spectrum Analysis ◽  
High Vacuum ◽  
Alternating Current ◽  
Ground Glass ◽  
Optical Pyrometer ◽  
Vacuum Tube ◽  
Before And After ◽  
Discharge Tubes ◽  
Residual Gas ◽  
Glass Stopper

The objects of the experiment were three-fold: firstly, to ascertain whether a diamond could be entirely converted into coke or graphite by heating in a vacuum by cathode rays; secondly, in the event of this being found practicable, to make a determination by Féry’s optical pyrometer of the temperature at which the conversion takes place; thirdly, to endeavour to ascertain if, during the conversion, any gas was emitted or absorbed by the carbon. The vacuum tube employed is shown in the illustration, where A and B are the two aluminium electrodes, C the diamond and D an air-tight ground-glass stopper joint, through which the diamonds were introduced. Alternating current was employed, each of A and B acting as cathode and anode in turn, while their concave curvature was such as to accurately focus the cathode rays on to the diamond. The latter was supported on a plate of iridium, which, in turn, rested in a platinum cup, this arrangement being designed to prevent any stray cathode rays which might miss the diamond from striking the glass walls of the tube and melting the latter. During the experiment the tube was connected to two mercury pumps of the Toepler type, and in connection with the tube there were also attached two spectrum analysis discharge tubes for the purpose of collecting and examining some of the residual gas in the tube, both before and after the conversion of the diamond into coke.

Optical Properties of Nano-Structure Tungsten-Doped Vanadium Oxide

2012 ◽  
Author(s):  
W. B. Cai ◽  
F. Wang ◽  
Y. P. Miao ◽  
J. Wei ◽  
K. L. Zhang
Keyword(s):  
Optical Properties ◽  
Transition Temperature ◽  
Oxide Film ◽  
Vanadium Oxide ◽  
High Vacuum ◽  
Infrared Transmission ◽  
Dc Magnetron Sputtering ◽  
Nano Structure ◽  
Before And After ◽  
Deposited Film

Tungsten-doped vanadium oxide has been proved to decrease the transition temperature, which enables vanadium oxide film to be more promising. Besides, the nano-structure can improve the properties of the film when compared with the as-deposited film. In this letter, a nano-structure tungsten-doped vanadium oxide film is proposed. Tungsten-doped vanadium oxide film was deposited on the Si (400) substrate by DC magnetron sputtering. The doping level was controlled by adjusting the sputtering time. Then the as-deposited film was annealed to form a nano-structure film at the temperature of 500 °C for 1 h in high vacuum. The morphology and crystalline structure of such films were characterized by AFM and XRD, respectively. Optical properties of the films were tested by FTIR, mainly comparing the infrared transmission before and after annealing.

Exoelectron emission from unexcited metallic glasses Fe78B13Si9 during heat treatment

1992 ◽  
Vol 7 (6) ◽  
pp. 1396-1399 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Tadayoshi Kubozoe ◽  
Yoshikazu Nakamura
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Exoelectron Emission ◽  
Radiation Chemical ◽  
Temperature Range ◽  
High Vacuum Condition ◽  
Before And After ◽  
Ultra High Vacuum Condition

Exoelectron emission from the surface of unexcited metallic glasses Fe78B13Si9 during heat treatment has been studied under ultra high vacuum condition. In the first heating cycle, exoelectrons are emitted from the as-cast ribbon in the temperature range from approximately 423 K to 773 K (150 °C to 500 °C), although the surface of the specimen is not excited by ionizing radiation, chemical processes, or mechanical treatments prior to measurements. In the second and subsequent heating cycles, however, there is no anomalous emission observed in the same temperature range. In order to elucidate the mechanism of emission, the surface of the specimen is observed by the atomic force microscope (AFM) before and after measurements. In the AFM image, many crystallites in the amorphous matrix can be found in the surface of the heated specimen. These experimental results show that exoelectrons are emitted in the same temperature range as the early stages of crystallization on the surface of metallic glasses. We hypothesize that the two effects are correlated.

scholarly journals Laser power meters as an X-ray power diagnostic for LCLS-II

2018 ◽  
Vol 25 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Philip Heimann ◽  
Stefan Moeller ◽  
Sergio Carbajo ◽  
Sanghoon Song ◽  
Georgi Dakovski ◽  
...  
Keyword(s):  
Free Electron Laser ◽  
Laser Power ◽  
High Vacuum ◽  
Average Power ◽  
Gas Analysis ◽  
Ultra High Vacuum ◽  
Beam Path ◽  
X Ray ◽  
High Repetition ◽  
Residual Gas

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. A number of characteristics in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.

The Study of Dynamic Response to Acute Hemorrhage by Pulse Spectrum Analysis

2006 ◽  
Vol 34 (03) ◽  
pp. 449-460 ◽  
Author(s):  
Yu Hsin Chang ◽  
Chia I Tsai ◽  
Jaung Geng Lin ◽  
Yue Der Lin ◽  
Tsai Chung Li ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Spectrum Analysis ◽  
Pulse Spectrum ◽  
Acute Hemorrhage ◽  
Arterial Blood ◽  
Percentage Difference ◽  
Before And After

Traditional Chinese Medicine (TCM) holds that Blood and Qi are fundamental substances in the human body for sustaining normal vital activity. The theory of Qi, Blood and Zang-Fu contribute the most important theoretical basis of human physiology in TCM. An animal model using conscious rats was employed in this study to further comprehend how organisms survive during acute hemorrhage by maintaining the functionalities of Qi and Blood through dynamically regulating visceral physiological conditions. Pulse waves of arterial blood pressure before and after the hemorrhage were taken in parallel to pulse spectrum analysis. Percentage differences of mean arterial blood pressure and harmonics were recorded in subsequent 5-minute intervals following the hemorrhage. Data were analyzed using a one-way analysis of variance (ANOVA) with Duncan's test for pairwise comparisons. Results showed that, within 30 minutes following the onset of acute hemorrhage,the reduction of mean arterial blood pressure was improved from 62% to 20%. Throughout the process, changes to the pulse spectrum appeared to result in a new balance over time. The percentage differences of the second and third harmonics, which were related to kidney and spleen, both increased significantly than baseline and towards another steady state. Apart from the steady state resulting from the previous stage, the percentage difference of the 4th harmonic decreased significantly to another steady state. The observed change could be attributed to the induction of functional Qi, and is a result of Qi-Blood balancing activity that organisms hold to survive against acute bleeding.

Residual gas analysers and their use in high vacuum systems

Vacuum ◽  
1987 ◽  
Vol 37 (3-4) ◽  
pp. 335-338 ◽  
Author(s):  
F.M. Mao ◽  
J.M. Yang ◽  
W.E. Austin ◽  
J.H. Heck
Keyword(s):  
High Vacuum ◽  
Residual Gas ◽  
Vacuum Systems

A New Technology of Hardening Porous Materials of Titan Powders

2007 ◽  
Vol 534-536 ◽  
pp. 613-616
Author(s):  
K.E. Belyavin ◽  
D.V. Minko ◽  
N.V. Reshnetikov
Keyword(s):  
Porous Materials ◽  
Electric Discharge ◽  
New Technology ◽  
Alternating Current ◽  
Maximum Strength ◽  
Structure And Properties ◽  
Optimum Range ◽  
Technological Regimes ◽  
Before And After ◽  
Powder Particles

A technology of hardening porous materials of titan powders has been elaborated. The technology is based on passing alternating current with duration of ~10-1…101 s through porous (35…40%) blanks made by method of Sintering by Electric Discharge (SED) by passing a pulse of current with duration of ~10-5…10-3 s. The influence of technological regimes of porous blanks treatment on their structure and properties is investigated. Geometry and dimension of contact necks between powder particles of obtained samples are evaluated. Variations of porosity and strengths as well as microstructure of porous samples materials before and after treatment are investigated. Optimum range of treatment technological regimes is determined within which porosity of 30…35% with maximum strength values.

Measurement of partial pressures in extremely high vacuum region using a modified residual gas analyzer

1999 ◽  
Vol 70 (3) ◽  
pp. 1880-1884 ◽  
Author(s):  
Shu Watanabe ◽  
Hitoshi Oyama ◽  
Shigeki Kato ◽  
Masakazu Aono
Keyword(s):  
High Vacuum ◽  
Gas Analyzer ◽  
Vacuum Region ◽  
Partial Pressures ◽  
Residual Gas

High-flux neutron irradiation of boron trioxide analyzed with Raman and FTIR spectroscopy

2020 ◽  
Vol 34 (18) ◽  
pp. 2050160
Author(s):  
Matlab N. Mirzayev
Keyword(s):  
Raman Spectrum ◽  
Ftir Spectroscopy ◽  
Functional Groups ◽  
Neutron Irradiation ◽  
Spectrum Analysis ◽  
Boron Oxide ◽  
Fast Neutrons ◽  
Raman Analysis ◽  
Before And After ◽  
Flux Formula

Boron oxide nanopowder is widely used in the production of special glasses and nuclear technology. This paper reports on the optical properties and investigates the formation of new bonds on the structure of nanoboron oxide. In this work, high purity boron oxide samples were irradiated using a energy upto 1 MeV fast neutrons with fluences in the range of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and the neutron flux [Formula: see text] at the room-temperature. Optical properts were determined using Raman spectrum analysis and spectroscopy Fourier transform infrared (FTIR) spectroscopy. FTIR and Raman spectrum analysis were used to explain the chemical bonds and functional groups of nanoboron oxide samples before and after neutron irradiation. When the irradation fluence on [Formula: see text] was increased upto [Formula: see text] it resulted in the formation of a new functional groups [Formula: see text]. From the Raman analysis, the [Formula: see text] was observed to start amorphization after neutron irradiation.

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