Spherical Sector Windows With Restrained Edge for Undersea Applications

A new concept for the mounting of spherical sector windows has been experimentally evaluated under short-term, long-term, and cyclic pressure loadings. The new mounting concept requires that the spherical sector windows be provided with square edges instead of conical edges. The horizontal bearing surface of the square edge carries the axial and the vertical bearing surface the radial thrust of the spherical sector window. Experimental evaluation of the new mounting concept has shown that the spherical windows with square edges are subjected to larger flexure moments than similar windows with conical edges. However, the short-term critical pressures of spherical sector windows with square edges and included angle 75 deg < α < 180 deg were found to be only 10 percent less than those of similar windows with conical edges. For spherical sectors with α < 75 deg the square edge mounting provides significantly higher short-term implosion pressures than conical edge mountings. Based on the short-term critical pressures, strains, stresses, and cyclic fatigue data generated by this study, the spherical shell sector windows with square edge mounting are considered acceptable for service in manned submersibles, habitats, or diving bells.

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Effect of Extended Aging on Asphalt Materials Containing Re-Refined Engine Oil Bottoms

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2632-07 ◽

2017 ◽

Vol 2632 (1) ◽

pp. 60-69 ◽

Cited By ~ 11

Author(s):

David J. Mensching ◽

Adrian Andriescu ◽

Christopher DeCarlo ◽

Xinjun Li ◽

Jack S. Youtcheff

Keyword(s):

Low Temperature ◽

Fatigue Testing ◽

Asphalt Mixture ◽

Field Performance ◽

Cyclic Fatigue ◽

Engine Oil ◽

Short Term ◽

Bending Beam Rheometer ◽

The Difference

The use of re-refined engine oil bottoms (REOBs) in asphalt pavements is a topic of much debate because the aging susceptibility and quantity of the additive in the binder may affect field performance. In this study, four mixtures with varying REOB contents (up to 15%) were long-term oven aged by using a high-temperature, short-duration method (135°C, 24 h) and compared with existing data on mixtures aged with more conventional short-term and long-term oven-aging procedures. The recovered binders underwent Superpave® grading, double-edge notched tension, and extended bending beam rheometer testing, and the binders were subjected to dynamic modulus, cyclic fatigue testing in the asphalt mixture performance tester, and thermal stress restrained specimen testing. Results showed a general insensitivity when short-term oven-aged (135°C, 4 h) materials were compared with long-term oven-aged (85°C, 5 days) materials, whereas the aging process at 135°C over 24 h resulted in substantial changes to the stiffness and relaxation properties across high-, intermediate-, and low-temperature modes. The difference between the stiffness-based and slope-based low-temperature performance grades appears to be an indicator for REOB modification, with the test for physical hardening of the binder being more sensitive than standard bending beam rheometer testing. The details in this paper provide information for the asphalt pavement community to consider as specifications. Standard practices are developed to address REOB modification.

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The CURAT Sonification Game: Gamification for Remote Sonification Evaluation

10.20944/preprints202106.0292.v1 ◽

2021 ◽

Author(s):

Tim Ziemer ◽

Holger Schultheis

Keyword(s):

Sample Size ◽

Experimental Evaluation ◽

Small Sample Size ◽

Large Population ◽

Small Sample ◽

Short Term ◽

Long Period ◽

Future Developments

As sonification is supposed to communicate information to users, experimental evaluation of the subjective appropriateness and effectiveness of the sonification design is often desired and sometimes indispensable. Experiments in the laboratory are typically restricted to short-term usage by a small sample size under unnatural conditions. We introduce the multi-platform CURAT Sonification Game that allows us to evaluate our sonification design by a large population during long-term usage. Gamification is used to motivate users to interact with the sonification regularly and conscientiously over a long period of time. In this paper we present the sonification game and some initial analyses of the gathered data. Furthermore, we hope to reach more volunteers to play the CURAT Sonification Game and help us evaluate and optimize our psychoacoustic sonification design and give us valuable feedback on the game and recommendations for future developments.

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Flanged Acrylic Plastic Hemispherical Shells for Undersea Systems—Part 2: Static and Cyclic Fatigue Life Under Hydrostatic Loading

Journal of Engineering for Industry ◽

10.1115/1.3439417 ◽

1978 ◽

Vol 100 (2) ◽

pp. 249-260

Author(s):

J. D. Stachiw ◽

R. Sletten

Keyword(s):

Fatigue Life ◽

Fatigue Cracks ◽

Cyclic Fatigue ◽

Bearing Surface ◽

Short Term ◽

Ring Groove ◽

Working Pressure ◽

Temperature Range ◽

Acrylic Plastic ◽

Hydrostatic Loading

Over 25 acrylic plastic windows with t/Ri = 0.364 in the shape of hemispherical domes with equatorial flanges have been thermoformed from flat sheets and tested under short term, long term, and cyclic pressure loading at 65–75°F ambient temperature. Two kinds of flanges with O-ring grooves on the bearing surfaces were experimented with: Type 1, a flat lip with a rounded heel and instep, and Type II, a conical lip with a rounded heel. The 14,500 psi short term critical pressure of hemispherical windows with t/Ri = 0.364 was found to be independent of the equatorial flange configuration. Both the static and cyclic fatigue lives of the windows were also found to be independent of equatorial flange configuration. In either case, the maximum acceptable working pressure for 65–75°F temperature range was found to be 1000 psi. Only by elimination of the O-ring groove in the bearing surface of the window flange and the use of a thin neoprene bearing gasket between the arylic flange and the steel is it possible to extend the working pressure to 2000 psi for 65–75°F temperature range. Operating the flanged windows at pressures in excess of the safe working pressures shown above will generate fatigue cracks in the bearing surface of the flange in less than 1000 pressure cycles; at 5000 psi pressure the cyclic fatigue life decreases to less than 100 cycles.

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

Journal of Energy Resources Technology ◽

10.1115/1.3231285 ◽

1986 ◽

Vol 108 (4) ◽

pp. 326-335 ◽

Cited By ~ 1

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).

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Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

Behavioral and Brain Sciences ◽

10.1017/s0140525x15000928 ◽

2016 ◽

Vol 39 ◽

Author(s):

Mary C. Potter

Keyword(s):

Working Memory ◽

Rapid Serial Visual Presentation ◽

Language Comprehension ◽

Short Term Memory ◽

Visual Presentation ◽

Long Term Memory ◽

Short Term ◽

Term Memory ◽

Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159412 ◽

1990 ◽

Vol 48 (3) ◽

pp. 374-375

Author(s):

D.E. Loudy ◽

J. Sprinkle-Cavallo ◽

J.T. Yarrington ◽

F.Y. Thompson ◽

J.P. Gibson

Keyword(s):

Antidepressant Drug ◽

Beagle Dogs ◽

Long Term Effects ◽

Short Term ◽

Platelet Counts ◽

Toxicological Studies ◽

Induced Aggregation ◽

Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

American Journal of Audiology ◽

10.1044/2020_aja-20-00018 ◽

2020 ◽

Vol 29 (4) ◽

pp. 710-727

Author(s):

Beula M. Magimairaj ◽

Naveen K. Nagaraj ◽

Alexander V. Sergeev ◽

Natalie J. Benafield

Keyword(s):

Auditory Processing ◽

Short Term Memory ◽

Group Differences ◽

Long Term Memory ◽

Short Term ◽

Significant Group ◽

Term Memory ◽

Memory And Attention ◽

Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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