Pressure-Resistant Plane Disk Viewports From Allyl Diglycol Carbonate Plastic for Hyperbaric Chambers

1986 ◽  
Vol 108 (4) ◽  
pp. 326-335 ◽  
Author(s):  
J. D. Stachiw ◽  
M. A. Stachiw
Keyword(s):  
Organic Solvents ◽  
Pressure Vessels ◽  
Short Term ◽  
Loss Of Life ◽  
X Ray ◽  
Cyclic Pressure ◽  
Acrylic Plastic ◽  
Plane Disk ◽  
Design Pressure

Acrylic plastic viewports have been used for over 40 yr in pressure vessels for human occupancy without any catastrophic failure resulting in a loss of life. However, there are special applications, such as for example in hyperbaric chambers for medical purposes, where the susceptibility of flexure stressed acrylic plastic to surface crazing and cracking in the presence of common organic solvents contained in antibacterial sprays is a distinct disadvantage. To solve this problem, a search has been initiated for transparent plastics that are not attacked by organic solvents and can be cast economically in thick sections. Allyl diglycol carbonate plastic appears not only to satisfy the foregoing requirement, but also to provide better resistance to abrasion, pitting, and X-ray or gamma irradiation than acrylic plastic. Short-term, long-term, and cyclic pressure testing has been conducted on over one hundred allyl diglycol carbonate plane disk viewports with t/D0 ratio in the 0.06 to 0.4 range and temperature in the 4°C to + 52°C (+40F to 125°F) range. It appears that plane disks cast from allyl diglycol carbonate plastic can perform safely as pressure-resistant viewports in pressure vessels for human occupancy. It is recommended that for such an application their design temperature be limited to under 52°C (125°F), and that their design pressure at 52°C (125°F) design temperature not exceed 4 percent of their (STCP) short-term critical pressure at 24°C (75°F).

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

scholarly journals Enhancing Short-Term Plasticity by Inserting a Thin TiO2 Layer in WOx-Based Resistive Switching Memory

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 908 ◽  
Author(s):  
Hyojong Cho ◽  
Sungjun Kim
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Short Term Memory ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
X Ray ◽  
Short Term Plasticity ◽  
Good Retention

In this work, we emulate biological synaptic properties such as long-term plasticity (LTP) and short-term plasticity (STP) in an artificial synaptic device with a TiN/TiO2/WOx/Pt structure. The graded WOx layer with oxygen vacancies is confirmed via X-ray photoelectron spectroscopy (XPS) analysis. The control TiN/WOx/Pt device shows filamentary switching with abrupt set and gradual reset processes in DC sweep mode. The TiN/WOx/Pt device is vulnerable to set stuck because of negative set behavior, as verified by both DC sweep and pulse modes. The TiN/WOx/Pt device has good retention and can mimic long-term memory (LTM), including potentiation and depression, given repeated pulses. On the other hand, TiN/TiO2/WOx/Pt devices show non-filamentary type switching that is suitable for fine conductance modulation. Potentiation and depression are demonstrated in the TiN/TiO2 (2 nm)/WOx/Pt device with moderate conductance decay by application of identical repeated pulses. Short-term memory (STM) is demonstrated by varying the interval time of pulse inputs for the TiN/TiO2 (6 nm)/WOx/Pt device with a quick decay in conductance.

scholarly journals Physics of Relativistic Jets on Sub-Milliarcsecond Scales

1984 ◽  
Vol 110 ◽  
pp. 207-214
Author(s):  
Martin J. Rees
Keyword(s):  
Energy Production ◽  
Galactic Nuclei ◽  
Primary Energy ◽  
Relativistic Jets ◽  
Short Term ◽  
X Ray ◽  
Long Term Stability ◽  
Extended Sources ◽  
Vlbi Data

The observed superluminal components have (deprojected) lengths of ~ 1020 cm, and imply relativistic bulk motions on these scales. There are, however, persuasive reasons for attributing the primary energy production to scales 1014–1015 cm. Moreover, the initial bifurcation and collimation must also be imposed on these small scales if the long-term stability of the jet axis in extended sources is due to the gyroscopic effect of a spinning black hole (Rees 1978). The issues I shall address in this talk are: how the jet gets from ~ 1015cm to ~ 1019 cm; and what VLBI data can tell us about the properties of galactic nuclei on scales below ~ 1019 cm — scales where optical and X-ray studies provide some evidence, but where there is no short-term hope of achieving spatial resolution.

Simulation of Hydrogen Distribution due to In-Vessel Severe Accident in WWER-1000 NPP Containment: A Comparison of CONTAIN and MELCOR Codes Results

2018 ◽  
Author(s):  
Omid Noorikalkhoran ◽  
Massimiliano Gei
Keyword(s):  
Severe Accident ◽  
Second Step ◽  
Hydrogen Distribution ◽  
Short Term ◽  
Long Time ◽  
Design Basis Accident ◽  
Safety Features ◽  
Design Pressure ◽  
Good Agreement

During a severe accident or Beyond Design Basis Accident (BDBA), the reaction of water with zirconium alloy as fuel clad, radiolysis of water, molten corium-concrete interaction (MCCI) and post-accident corrosion can generate a source of hydrogen. In the present work, hydrogen distribution due to in-vessel reaction (between zircaloy and steam) has been simulated inside a WWER-1000 reactor containment. In the first step, the thermal hydraulic parameters of containment have been simulated for a DECL (Double Ended Cold Leg) accident (DBA phase) in both short and long time and the effects of spray as Engineering Safety Features (ESFs) on mitigating the parameters have been studied. In the second step, it has been assumed that the accident developed into an in-vessel core melting accident. While in pre-phase of core melting (severe accident phase), hydrogen will be produced as a result of zircaloy and steam reaction (BDBA phase), the hydrogen distribution has been simulated for 23 cells inside the reactor containment by using CONTAIN 2.0 (Best estimate code) and MELCOR 1.8.6 codes. Finally, the results have been compared to FSAR results. As it can be seen from the comparisons, both CONTAIN and MELCOR codes can predict the results in good agreement with FSAR (ANGAR code) results. CONTAIN shows peak pressure around 0.36 MPa in short-term and this amount is about 0.38 and 0.4 MPa for MELCOR and ANGAR (FSAR) results respectively. All these values are under design pressure that is around 0.46 MPa. Cell 20 has the maximum mole fraction of hydrogen in long-term about 9.5% while the maximum amount of hydrogen takes place in cell 22. The differences between the results of codes are because of different equations, Models, Numerical methods and assumptions that have been considered by the codes. The simulated Hydrogen Distribution Map (HDM) can be used for upgrading the location of HCAV systems and Hydrogen Mitigator features (like the recombiners and ignitors) inside the containment to reduce the risk of hydrogen explosion.

Polycarbonate Plastic Inserts for Spherical Acrylic Plastic Shells Under Hydrostatic Loading

1981 ◽  
Vol 103 (1) ◽  
pp. 90-98 ◽  
Author(s):  
J. D. Stachiw ◽  
R. B. Dolan ◽  
D. L. Clayton
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Structural Parameters ◽  
Cyclic Fatigue ◽  
Pressure Vessels ◽  
Plastic Shell ◽  
Acrylic Plastic ◽  
Hydrostatic Loading ◽  
Spherical Pressure

An acrylic plastic spherical pressure hull incorporating polycarbonate inserts for mounting of penetrators has been built and pressure tested. The transparent hull will serve as one atmosphere cockpit in Johnson-Sea-Link #3 submersible for 2500 ft. service. Tests have been conducted with model scale polycarbonate inserts in acrylic plastic spherical pressure hulls and windows to evaluate the structural integrity and cyclic fatigue life of polycarbonate plastic inserts and acrylic shells in which they are mounted under repeated hydrostatic pressurizations. Test results indicate that the short term, long term and cyclic fatigue life of a polycarbonate insert, serving as a bulkhead for electric or hydraulic penetrators in spherical acrylic plastic pressure hulls or windows, exceeds that of the acrylic plastic shell in which it is mounted. Structural parameters of polycarbonate inserts are discussed and design criteria formulated for their utilization in manned submersibles and pressure vessels for human occupancy. Particular emphasis is placed on selection of material, seal configuration, and retainment design.

scholarly journals XMM-Newton observations of eleven intermediate polars and possible candidates

2020 ◽  
Vol 639 ◽  
pp. A17
Author(s):  
H. Worpel ◽  
A. D. Schwope ◽  
I. Traulsen ◽  
K. Mukai ◽  
S. Ok
Keyword(s):  
Optical Data ◽  
Plasma Emission ◽  
Short Term ◽  
X Ray ◽  
Hot Plasma ◽  
Intermediate Polars ◽  
Orbital Periods ◽  
Firm Evidence ◽  
Short Term Variability

Aims. We aim to identify new intermediate polars (IPs) in XMM-Newton observations from a list of promising candidates. By selecting targets not previously known to be X-ray bright, we aim to uncover evidence for an X-ray underluminous IP subpopulation. Methods. We performed period searches on the XMM-Newton X-ray and optical data of our targets to seek both the spin and orbital periods, which differ in IPs. We also investigated the X-ray spectra to find the hot plasma emission shown by these objects. With archival Swift data we coarsely investigated the long-term X-ray variability, and with archival optical data from a variety of catalogues, we compared the optical to X-ray luminosity to identify X-ray faint objects. This paper presents the first XMM-Newton observation of the prototype IP, DQ Her. Results. We find firm evidence for HZ Pup, V349 Aqr, and IGR J18151-1052 being IPs, with likely white dwarf spin periods of 1552, 390, and 390 s, respectively. The former two have luminosities typical of IPs, and the latter is strongly absorbed and with unknown distance. GI Mon and V1084 Her are apparently non-magnetic CVs with interesting short-term variability unrelated to WD spin. V533 Her is probably a magnetic CV and remains a good IP candidate, while V1039 Cen is possibly a polar. The remaining candidates were too faint to allow for any firm conclusions.

Civil commitment for opioid misuse: do short-term benefits outweigh long-term harms?

2021 ◽  
pp. medethics-2020-107160
Author(s):  
John C Messinger ◽  
Daniel J Ikeda ◽  
Ameet Sarpatwari
Keyword(s):  
Civil Commitment ◽  
Opioid Use Disorder ◽  
Opioid Use ◽  
Short Term ◽  
Community Based ◽  
Loss Of Life ◽  
Severe Withdrawal ◽  
The Usa ◽  
Overdose Deaths

In response to a sharp rise in opioid-involved overdose deaths in the USA, states have deployed increasingly aggressive strategies to limit the loss of life, including civil commitment—the forcible detention of individuals whose opioid use presents a clear and convincing danger to themselves or others. While civil commitment often succeeds in providing short-term protection from overdose, emerging evidence suggests that it may be associated with long-term harms, including heightened risk of severe withdrawal, relapse and opioid-involved mortality. To better assess and mitigate these harms, states should collect more robust data on long-term health outcomes, decriminalise proceedings and stays, provide access to medications for opioid use disorder and strengthen post-release coordination of community-based treatment.

Manufacture and Use of Setting up Samples

1994 ◽  
Vol 38 ◽  
pp. 337-351
Author(s):  
Frank R. Feret
Keyword(s):  
Quantum Efficiency ◽  
Ambient Pressure ◽  
Fluorescence Analysis ◽  
Short Term ◽  
X Ray ◽  
Intensity Decrease ◽  
Electronic Circuitry ◽  
Tube Output ◽  
Short And Long Term

Abstract In X-ray fluorescence analysis, the specific secondary radiation intensities of the elements are generated and measured by a spectrometer. Usually, the measured intensities are corrected for instrument drift first, then converted into element concentrations. In routine analysis, the intensity is always affected by the instability of the instrument. Instrumental instability consists of two components: short and long term drift Short-term instability is caused by fluctuations in the ambient laboratory conditions and the instrument's components. Long-term drift is caused by aging of the instrument's components (mainly X-ray tube, crystals, detectors, electronic circuitry) and results in a gradual intensity decrease. For example, the X-ray tube output decreases due to pitting of the target and sublimation of metal on the inside of the window. The quantum efficiency of detectors gradually decreases due to drift in potential supply and changes in ambient pressure and temperature.

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