The Containment of Disk Burst Fragments by Cylindrical Shells

1974 ◽  
Vol 96 (2) ◽  
pp. 114-123 ◽  
Author(s):  
A. C. Hagg ◽  
G. O. Sankey
Keyword(s):  
Kinetic Energy ◽  
Test Results ◽  
Process Stage ◽  
Inelastic Impact ◽  
Impact Area ◽  
Stage Process ◽  
Local Impact ◽  
Energy Dissipated ◽  
Stage 1 ◽  
Steel Cylindrical Shell

Tests and analysis show that containment of missile-like steel disk fragments by a steel cylindrical shell is a sequential two-stage process. Stage 1 involves inelastic impact and transfer of momentum to include an effective target mass. For nonperforation, the energy dissipated in plastic compression and shear strain at the local impact area must be sufficient to accommodate the loss in kinetic energy of the system. With nonperforation, the process enters stage 2, which involves dissipation of energy in plastic tension strain over extended volumes of shell material. For containment, the energy dissipated in plastic strain in stage 2 must accommodate the residual kinetic energy of the system. Criteria for nonperforation and containment are given which are in satisfactory agreement with test results.

scholarly journals From high friction zone to frontal collapse: dynamics of an ongoing tidewater glacier surge, Negribreen, Svalbard

2020 ◽  
Vol 66 (259) ◽  
pp. 742-754
Author(s):  
Odin Næss Haga ◽  
Robert McNabb ◽  
Christopher Nuth ◽  
Bas Altena ◽  
Thomas Schellenberger ◽  
...  
Keyword(s):  
Tidewater Glaciers ◽  
Process Stage ◽  
Quiescent Phase ◽  
Glacier System ◽  
Digital Elevation ◽  
Stage 4 ◽  
Tidewater Glacier ◽  
Stage Process ◽  
Triggering Mechanisms ◽  
Stage 1

AbstractNegribreen, a tidewater glacier located in central eastern Svalbard, began actively surging after it experienced an initial collapse in summer 2016. The surge resulted in horizontal surface velocities of more than 25 m d−1, making it one of the fastest-flowing glaciers in the archipelago. The last surge of Negribreen likely occurred in the 1930s, but due to a long quiescent phase, investigations of this glacier have been limited. As Negribreen is part of the Negribreen Glacier System, one of the largest glacier systems in Svalbard, investigating its current surge event provides important information on surge behaviour among tidewater glaciers within the region. Here, we demonstrate the surge development and discuss triggering mechanisms using time series of digital elevation models (1969–2018), surface velocities (1995–2018), crevasse patterns and glacier extents from various data sources. We find that the active surge results from a four-stage process. Stage 1 (quiescent phase) involves a long-term, gradual geometry change due to high subglacial friction towards the terminus. These changes allow the onset of Stage 2, an accelerating frontal destabilization, which ultimately results in the collapse (Stage 3) and active surge (Stage 4).

scholarly journals A scoping review protocol to map the evidence on the use of action research methodology by healthcare professionals and in healthcare team settings

2021 ◽  
Vol 4 ◽  
pp. 68
Author(s):  
Kinley Roberts ◽  
Mary Casey ◽  
David Coghlan ◽  
Catherine Cornall ◽  
Clare Hudson ◽  
...  
Keyword(s):  
Action Research ◽  
Scoping Review ◽  
Healthcare Professionals ◽  
Scientific Journal ◽  
Social Situation ◽  
Healthcare Team ◽  
Transformative Change ◽  
Eligibility Criteria ◽  
Process Stage ◽  
Stage 1

Background: Action research (AR) starts with an existing practical situation with which there is a concern or potential for improvement. It seeks transformative change through the simultaneous process of doing research and undertaking actions, both of which are linked together by a critical reflective process. It simultaneously allows one to systematically investigate a given social situation while promoting democratic change and collaborative participation. AR approaches have been used for many years in business management and education. More recently, AR has become an increasingly popular method of inquiry in healthcare, particularly in nursing, to investigate professional practice while simultaneously; introducing innovations; planning and undertaking action; and evaluating new ideas. The overall goal is to augment collaboration whilst improving the patient experience and outcomes. Methods: The Arksey and O'Malley methodology framework will be used to guide this scoping review process: stage 1 will identify the research questions; the eligibility criteria and search strategy will be defined in stage 2; studies will then be selected in stage 3; data will be extracted and charted from these included studies in stage 4; stage 5 involves aggregating and summarising these results along with criteria relevant for health professionals and policy-makers. An optional consultation (stage 6) exercise may potentially be included. Conclusion: This scoping review will comprehensively map the evidence on the use of AR methodology by healthcare professionals and in healthcare team settings. It is predicted that the findings will inform researchers in carrying out future AR and highlight gaps in the literature. An article reporting the results of the completed scoping review will be submitted for publication to a scientific journal and presented at relevant national and international conferences.

Numerical Simulation of the Kinetic Energy Projectile Oblique Penetration into the Concrete

2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Test Results ◽  
Destruction Process ◽  
3D Finite Element ◽  
Finite Element Software ◽  
Simulation Results ◽  
Target Characteristics

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

scholarly journals Immunocytochemical Labeling of Rhabdomeric Proteins inDrosophilaPhotoreceptor Cells Is Compromised by a Light-dependent Technical Artifact

2019 ◽  
Vol 67 (10) ◽  
pp. 745-757 ◽  
Author(s):  
Krystina Schopf ◽  
Thomas K. Smylla ◽  
Armin Huber
Keyword(s):  
Structural Changes ◽  
Protein Transport ◽  
Light Exposure ◽  
Protein Localization ◽  
Photoreceptor Cells ◽  
Antibody Staining ◽  
Technical Artifact ◽  
Stage Process ◽  
Stage 1 ◽  
Antibody Labeling

Drosophila photoreceptor cells are employed as a model system for studying membrane protein transport. Phototransduction proteins like rhodopsin and the light-activated TRPL ion channel are transported within the photoreceptor cell, and they change their subcellular distribution in a light-dependent way. Investigating the transport mechanisms for rhodopsin and ion channels requires accurate histochemical methods for protein localization. By using immunocytochemistry the light-triggered translocation of TRPL has been described as a two-stage process. In stage 1, TRPL accumulates at the rhabdomere base and the adjacent stalk membrane a few minutes after onset of illumination and is internalized in stage 2 by endocytosis after prolonged light exposure. Here, we show that a commonly observed crescent shaped antibody labeling pattern suggesting a fast translocation of rhodopsin, TRP, and TRPL to the rhabdomere base is a light-dependent antibody staining artifact. This artifact is most probably caused by the profound structural changes in the microvillar membranes of rhabdomeres that result from activation of the signaling cascade. By using alternative labeling methods, either eGFP-tags or the self-labeling SNAP-tag, we show that light activation of TRPL transport indeed results in fast changes of the TRPL distribution in the rhabdomere but not in the way described previously.

Design, Analysis and Test of Multi-Stage Crashworthiness Energy Absorbing Device for Railway Vehicles

2019 ◽  
Author(s):  
Haifeng Hong ◽  
Hongtao Liu ◽  
Ziwen Fang ◽  
Kefei Wang ◽  
Jianran Wang ◽  
...  
Keyword(s):  
Railway Vehicle ◽  
Test Results ◽  
Railway Vehicles ◽  
Multi Stage ◽  
Element Simulation ◽  
Sufficient Energy ◽  
Stage 4 ◽  
Third Stage ◽  
Energy Absorbing ◽  
Stage 1

Abstract An anti-collision and energy absorbing device is generally placed at the front end of railway vehicles to provide controlled collapse and sufficient energy absorbing capacity. In the conventional way, the energy absorbing device is usually designed as an integrated part of the carbody that can’t be easily replaced nor maintained after crash. To increase the maintainability and energy absorbing capacity of the energy absorbing device, a Multi-stage Crashworthiness Energy Absorbing Device has been developed, in which the first-stage and the second-stage energy absorbing units can be replaced or repaired under the collision that is not severe enough to initiate the third-stage energy absorbing unit. The Crashworthiness Energy Management (CEM) has four stages: coupler energy absorbing components (stage 1), honeycomb in the sliding center anti-climber (stage 2), metal peeling tubes mounted at the back of the fixed anti-climber (stage 3) and the structural components in the cab area (stage 4). By comparing the simulation results and test results, it is concluded that the finite element simulation model can provide dependable and accurate prediction for collision behaviors. Based on the design, simulation and test data, a safe, reliable and maintainable Multi-stage Crashworthiness Energy Absorbing Device has been verified and validated, which can provide valuable reference for researchers and engineers in the crashworthiness and railway vehicle industry.

scholarly journals Exploring the potential role of community engagement in evaluating clinical and translational science grant proposals

2018 ◽  
Vol 2 (3) ◽  
pp. 139-146 ◽  
Author(s):  
Jeffrey W. Treem ◽  
Margaret Schneider ◽  
Robynn L. Zender ◽  
Dara H. Sorkin
Keyword(s):  
Community Engagement ◽  
Potential Role ◽  
Review Process ◽  
Translational Science ◽  
Community Members ◽  
Grant Proposals ◽  
Stage Process ◽  
Stage 1 ◽  
The University

IntroductionThis study explored the effects of integrating community members into the evaluation of clinical and translational science grants.MethodsThe University of California, Irvine Institute for Clinical and Translational Sciences (ICTS) engaged 21 community reviewers alongside scientific reviewers in a 2-stage process of evaluating research proposals. In Stage 1 reviewers scored proposals, and during Stage 2 two study sections convened: one a mix of community reviewers and scientific reviewers, and one only engaging scientific reviewers. In total, 4 studies were discussed by both study sections.ResultsComparisons of reviews revealed little difference between ratings of community reviewers and those of scientific reviewers, and that community reviewers largely refrained from critiquing scientific or technical aspects of proposals.ConclusionsThe findings suggest that involving community reviewers early in the grant cycle, and exposing them to the entirety of the review process, can bolster community engagement without compromising the rigor of grant evaluations.

scholarly journals Application of Heavy Fuel Test Results to Gas Turbine Operation

1982 ◽  
Author(s):  
R. S. Rose ◽  
A. Caruvana ◽  
A. Cohn ◽  
H. Von Doering
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Ash Deposition ◽  
Test Results ◽  
General Electric ◽  
Demonstration Program ◽  
On Line ◽  
Actual Field ◽  
Ash Removal ◽  
Stage 1

The results of ash deposition tests with simulated residual oil are presented. Both air-cooled and water-cooled nozzles were tested over a range of firing temperature, fuel contaminant levels, and metal surface temperatures. Extensive ash cleaning tests were also completed under full, steady-state operating conditions. Various online ash removal techniques were tested including small nutshells, large nutshells, coke particles, and water droplets. The results of these tests were applied to a General Electric gas turbine to predict actual field operation at turbine inlet temperatures up to 2300°F (1260°C). Use of on-line ash removal and optimum water washing intervals are shown to significantly improve the economics of gas turbine operation on heavy fuels. The improvements in heavy fuel operation were larger with a water-cooled stage 1 nozzle than with an air-cooled nozzle. This work was jointly sponsored by the Electric Power Research Institute and General Electric under the Advanced Cooling, Full-Scale Engine Demonstration Program.

scholarly journals Оптические и структурные свойства наноструктур Ag и c-Si, формирующихся в процессе металл-стимулированного химического травления кремния

2019 ◽  
Vol 53 (4) ◽  
pp. 576
Author(s):  
Ю.А. Жарова ◽  
В.А. Толмачев ◽  
С.И. Павлов
Keyword(s):  
Optical Model ◽  
Single Crystal Silicon ◽  
Silicon Nanostructures ◽  
Crystal Silicon ◽  
Fitting Procedures ◽  
Stage Process ◽  
Three Stages ◽  
Metal Assisted Chemical Etching ◽  
Si Nanostructures ◽  
Stage 1

AbstractThis study consisting of two parts is concerned with the features of the three-stage process of the metal-assisted chemical etching (MACE) of silicon. This process is used to fabricate silicon nanostructures. In the first part of this work, a layer of self-assembled Ag nanoparticles chemically deposited from a solution on the surface of single-crystal silicon (c-Si) (MACE stage 1) was studied, and the second part includes of investigation of Si nanostructures formed in stages 2 and 3. By means of spectroscopic ellipsometry (in the range of wavelengths λ = 250–900 nm), the pseudodielectric functions of the nanostructures were determined and compared for all the three stages of the MACE process. In addition, for the Si nanostructures, the parameters of layers (the thickness and void fraction) were calculated in the context of the multilayer optical model, with the use of Bruggeman’s effective-medium approximation and fitting procedures.

scholarly journals Energy Dissipated in Fatigue and Creep Conditions

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4724
Author(s):  
Stanisław Mroziński ◽  
Zbigniew Lis ◽  
Halina Egner
Keyword(s):  
Fatigue Life ◽  
Constant Load ◽  
Test Results ◽  
Fatigue Load ◽  
P91 Steel ◽  
Fatigue Process ◽  
Energy Dissipated ◽  
Load Conditions

The paper presents the results of tests performed on samples made of P91 steel under combined variable and constant load conditions, at temperature T = 600 °C. The analysis of the test results was carried out with the use of the energetic description of the fatigue process. It was shown that the order of occurrence of the fatigue load and creep in the load program influences the fatigue life and the value of the energy cumulated in the sample until fracture.

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