Conical Acrylic Windows Under Long-Term Hydrostatic Pressure of 10,000 psi

1972 ◽  
Vol 94 (4) ◽  
pp. 1053-1059 ◽  
Author(s):  
J. D. Stachiw
Keyword(s):  
Hydrostatic Pressure ◽  
Deep Ocean ◽  
Diameter Ratio ◽  
Conical Cavity ◽  
Ambient Temperatures ◽  
Hydrostatic Loading ◽  
Pressure Application ◽  
Sustained Loading ◽  
General Service

Over 150 conical frustum acrylic plastic windows were subjected to 10,000 psi hydrostatic loading of up to 1000-hr duration in deep ocean simulators maintained at 65–75 deg F ambient temperature. Axial displacements of the windows under hydrostatic loading through the conical cavity in the flange were recorded and plotted as a function of time, thickness to minor diameter ratio (t/D), and included conical angle α. Data indicate that only windows with α ≥ 90 deg and t/D ≥ 0.75 are satisfactory for sustained long-term hydrostatic loading of 1000-hr duration at 10,000 psi in ambient temperatures ≤80 deg F. For general service, which includes also cyclic pressurizations to 10,000 psi, an included angle α ≥ 90 deg and t/D ratio of ≥ 1.0 are recommended. The axial displacement of windows recommended for 10,000 psi service is approximately 0.04D after 1000 hr of sustained loading. Approximately 75 percent of this displacement takes place during the first hour of pressure application.

Conical Acrylic Windows Under Long-Term Hydrostatic Pressure of 5000 psi

1972 ◽  
Vol 94 (3) ◽  
pp. 843-848
Author(s):  
J. D. Stachiw
Keyword(s):  
Hydrostatic Pressure ◽  
Diameter Ratio ◽  
Axial Displacement ◽  
Included Angle ◽  
Temperature Range ◽  
Hydrostatic Loading ◽  
General Service

Conical acrylic windows with included angle 30 deg ≤ α ≤ 150 deg and thickness to minor diameter ratio of 0.375 ≤ t/D ≤ 1.00 have been subjected to 5,000 psi sustained hydrostatic loading of 1,000 hr duration in 65–75 deg F temperature range while the axial displacement of the windows through the flange has been monitored. The magnitude of axial displacement was found to be a function of α, t/D, temperature and duration of loading. Only windows with t/D ratios ≥1.000, 0.625, 0.500, 0.500, and 0.500 for 30, 60, 90, 120, and 150 deg conical angles, respectively, were found to be free of cracks. It is recommended that only windows with included angle α ≥ 60 deg be utilized for general service (long-term and cyclic) under 5,000 psi maximum hydrostatic pressure. The corresponding t/D ratios recommended for general service are 0.750 for α = 60 deg, and 0.625 for α ≥ 90 deg.

Conical Acrylic Windows Under Long Term Hydrostatic Pressure of 20,000 Psi

1970 ◽  
Vol 92 (1) ◽  
pp. 237-256
Author(s):  
J. D. Stachiw
Keyword(s):  
Hydrostatic Pressure ◽  
Room Temperature ◽  
Cone Angle ◽  
Diameter Ratio ◽  
Model Scale ◽  
Hydrostatic Loading ◽  
Pressure Application ◽  
Temperature Test

Conical acrylic windows with cone angles 30 deg ≤ α ≤ 150 deg have been subjected to sustained hydrostatic pressure of 20,000 psi for up to 1,000 hr duration. The thickness to minor diameter ratio (t/D) of the more than 200 windows varied from 0.750 to 2.000. Model scale windows served as the bulk of test specimens, and the majority of the tests were conducted at room temperature. Test findings indicate that only windows with t/D > 1 and cone angle α ≥ 60 deg will not fail in less than 1,000 hr of sustained hydrostatic loading although considerable cracking will take place. For optically acceptable service of 1000 hr duration under 20,000 psi hydrostatic pressure, the windows must have t/D ≥ 2 and a cone angle α ≥ 90 deg. The axial displacements of such windows after 1000 hr of hydrostatic loading at 20,000 psi, are approximately 0.1 times their minor diameter, with approximately 50 percent of this displacement taking place during the first hour of pressure application.

A Deep-Ocean Mass Spectrometer to Monitor Hydrocarbon Seeps and Pipelines

2005 ◽  
Author(s):  
Gary M. McMurtry ◽  
John C. Wiltshire ◽  
Arnaud Bossuyt
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Mass Spectrometer ◽  
Deep Ocean ◽  
Rechargeable Batteries ◽  
Vacuum System ◽  
Power Cable ◽  
Electron Multiplier ◽  
Trace Contaminant

New developments in instrumentation for ocean environmental engineering are allowing unprecedented levels of trace contaminant measurement in the deep ocean. With funding from the U.S. National Science Foundation (NSF), our engineering design team constructed a new mass spectrometer-based in situ analysis system for work in the deep ocean environment over prolonged deployment periods. Our design goals were a depth capability of up to 4,000 m water depth (400 bars hydrostatic pressure) and autonomous operation for periods of up to six months to a year, depending upon the type of external battery system used or other deployment circumstances, e.g., availability of a power cable or fuel cell power source. We chose a membrane introduction mass spectrometry (MIMS) sampling approach, which allows for dissolved gases and volatile organics introduction into the mass spectrometer vacuum system. The MIMS approach and the hydrophobic, silicon-coated membrane chosen both draw upon our previous experience with this technology in the deep ocean. The membrane has been tested to 400 bars in a series of long-term hydrostatic pressure tests, which extend the 200-bar working depth rating of this membrane by a factor of 2. Long-term deployment capability of the moderately powered, approximately 100 W system, was accomplished by power management of the embedded computer system and custom electronics with Windows-based and custom software now fully-developed and bench tested. The entire system fits within a 6.5-inch outside diameter pressure housing that is approximately five feet long. It consists of a 1 to 200 amu range quadrupole mass spectrometer equipped with Faraday and electron multiplier detectors, compact turbo-molecular and backing diaphragm vacuum pumps, internal rechargeable batteries, and internal waste vacuum chamber. Sample routing past the MIMS is accomplished by computer-controlled solenoid valves. We designed the pressure housings of both 6AL4V and type 2 titanium alloys that are rated to working depths of >4,000 m and are essentially corrosion proof over long-term deployments. We designed and integrated a fail-safe valving system for both rapid response to high-pressure MIMS failure and a pressure-switch circuit and high-pressure solenoid valve to detect and protect against slow leaks of the MIMS. To route sample waters to the MIMS-based instrument, we also designed and built a rugged plastic plenum that couples to the face of the sampler head, the latter of which consists of the MIMS inlet and a full-ocean rated thermister temperature probe with an operational range from −5 to 50°C. These instrumentation innovations will be described in the paper.

Implosion Tests of Aluminium Alloy Tubes Under External Hydrostatic Pressure

2018 ◽  
Author(s):  
Teguh Muttaqie ◽  
Jung-Min Sohn ◽  
Sang-Rai Cho ◽  
Sang-Hyun Park ◽  
Gulgi Choi ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Aluminium Alloy ◽  
Pressure Pulse ◽  
Deep Ocean ◽  
External Hydrostatic Pressure ◽  
Nitrogen Gas ◽  
Pressure Drops ◽  
Hydrostatic Loading ◽  
Quantitative Validation ◽  
Alloy 6061

This paper reports the implosion tests of aluminium alloy 6061-T6 tube models under external hydrostatic pressure. The investigations took an emphasis on how to replicate the deep-ocean pressure environment of the implosion phenomenon on a laboratory scale. The parameters which affected the implosion pressure pulse were also observed. Two kinds of implosion tests were conducted, namely, dynamic implosion test and quasi-static implosion test. The pressure drops in the post ultimate regime was negligible in the dynamic implosion test which performed using compressed nitrogen gas. The pressure and strain histories of the both implosion tests were compared and analysed. In addition, non-linear FE analyses for quantitative validation and comparison of the imploded tubes were conducted. The numerical quantities including the initial ovality, thickness unevenness, and air backed fluid cavity parameters are investigated to propose more realistic imploded tubes induced by the external hydrostatic loading.

scholarly journals Influence of the Environment on the Reliability of Security Magnetic Contacts

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 401
Author(s):  
Martin Boros ◽  
Andrej Velas ◽  
Viktor Soltes ◽  
Jacek Dworzecki
Keyword(s):  
Global Warming ◽  
Extreme Conditions ◽  
Alarm System ◽  
Test Device ◽  
Reaction Distance ◽  
Ambient Temperatures ◽  
Thermal Chamber

Magnetic contacts are one of the basic components of an alarm system, providing access to buildings, especially windows and doors. From long-term reliability tests, it can be concluded that magnetic contacts show sufficient reliability. Due to global warming, we can measure high as well as low ambient temperatures in the vicinity of magnetic contacts, which can directly affect their reliability. As part of partial tests, research into the reliability of magnetic contacts, we created a test device with which their reaction distance was examined under extreme conditions simulated in a thermal chamber. The results of the practical tests have yielded surprising results.

scholarly journals Synthesis of Ambient Cured GGBFS Based Alkali Activated Binder Using a Sole Alkaline Activator: A Feasibility Study

2021 ◽  
Vol 11 (13) ◽  
pp. 5887
Author(s):  
Thandiwe Sithole ◽  
Nelson Tsotetsi ◽  
Tebogo Mashifana
Keyword(s):  
Silicate Solution ◽  
Environmental Footprint ◽  
Ambient Temperatures ◽  
Granulated Blast Furnace Slag ◽  
Naoh Solution ◽  
Alkaline Activator ◽  
Porous Morphology ◽  
Furnace Slag ◽  
Alkali Activated

Utilisation of industrial waste-based material to develop a novel binding material as an alternative to Ordinary Portland Cement (OPC) has attracted growing attention recently to reduce or eliminate the environmental footprint associated with OPC. This paper presents an experimental study on the synthesis and evaluation of alkali activated Ground granulated blast furnace slag (GGBFS) composite using a NaOH solution as an alkaline activator without addition of silicate solution. Different NaOH concentrations were used to produce varied GGBFS based alkali activated composites that were evaluated for Uncofined Compressive Strength (UCS), durability, leachability, and microstructural performance. Alkali activated GGBFS composite prepared with 15 M NaOH solution at 15% L/S ratio achieved a UCS of 61.43 MPa cured for 90 days at ambient temperatures. The microstructural results revealed the formation of zeolites, with dense and non-porous morphology. Alkali activated GGBFS based composites can be synthesized using a sole alkaline activator with potential to reduce CO2 emission. The metal leaching tests revealed that there are no potential environmental pollution threats posed by the synthesized alkali activated GGBFS composites for long-term use.

Influence of hypothalamic and ambient temperatures on sleep in kangaroo rats

1979 ◽  
Vol 237 (1) ◽  
pp. R80-R88 ◽  
Author(s):  
S. Sakaguchi ◽  
S. F. Glotzbach ◽  
H. C. Heller
Keyword(s):  
Slow Wave Sleep ◽  
Total Sleep Time ◽  
Paradoxical Sleep ◽  
Sleep Time ◽  
Peripheral Stimulus ◽  
Kangaroo Rats ◽  
Hypothalamic Temperature ◽  
Ambient Temperatures ◽  
Thermoregulatory System

Unanesthetized, unrestrained kangaroo rats (Dipodomys) were studied to examine the changes in the frequency and duration of sleep states caused by long-term manipulations of hypothalamic temperature (Thy) at a thermoneutral (30 degrees C) and a low (20 degrees C) ambient temperature (Ta). A cold stimulus present in either the hypothalamus or the skin decreased both the total sleep time (TST) and the ratio of paradoxical sleep (PS) to TST. At a low Ta, TST, but not the PS-to-TST ratio, was increased by raising Thy, indicating that a cold peripheral stimulus could differentially inhibit PS. At a thermoneutral Ta, cooling Thy decreased both TST and the PS/TST. Changes in the amount of PS were due largely to changes in the frequency, but not the duration, of individual episodes of PS, suggesting that the transition to PS is partially dependent on the thermoregulatory conditions existing during slow-wave sleep (SWS). These results are consistent with the recent findings that the thermoregulatory system is functional during SWS but is inhibited or inactivated during PS.

scholarly journals Impact of long-term storage at ambient temperatures on the total quality and stability of high-pressure processed tomato juice

2015 ◽  
Vol 32 ◽  
pp. 1-8 ◽  
Author(s):  
K.G.L.R. Jayathunge ◽  
Irene R. Grant ◽  
Mark Linton ◽  
Margaret F. Patterson ◽  
Anastasios Koidis
Keyword(s):  
High Pressure ◽  
Tomato Juice ◽  
Total Quality ◽  
Ambient Temperatures ◽  
Long Term Storage ◽  
Term Storage

Behaviour of concrete-encased CFST stub columns subjected to long-term sustained loading

2018 ◽  
Vol 151 ◽  
pp. 58-69 ◽  
Author(s):  
Dan-Yang Ma ◽  
Lin-Hai Han ◽  
Wei Li ◽  
Chao Hou ◽  
Ting-Min Mu
Keyword(s):  
Sustained Loading ◽  
Stub Columns
Sign in / Sign up

Export Citation Format

Share Document