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Deformation,fragmentation and acceleration of a controlled fragmentation charge casing

Defence Technology（防务技术） 2019年第5期15卷 786-795页

作者： Andreas Helte olof andersson Patrik Lundberg FOI Defence and SecuritySystems and Technology

Two different finite element software,LS-DYNA and Impetus,have been evaluated to test their ability to predict the deformation,fragmentation and acceleration of a controlled fragmentation charge *** general-purpose program LS-DYNA was used with a multi-material ALE formulation and a masspreserving erosion criterion coupled to a Johnson-Cook fracture *** the Impetus simulations,a third order Lagrangian element formulation was used for the casing and a node-splitting element erosion treatment coupled to a Cockcroft-Latham failure criterion was used to describe casing *** high-explosive gases were described by a discrete particle *** order to acquire data to validate our computational tools and constitutive models,a series of experiments have been performed using a laboratory charge with an internal grooved *** the test series,the charge geometry was fixed except that the groove depth were varied from very shallow to very deep resulting in different deformation patterns,fracture modes and terminal *** diagnostic tools captured the different stages of the expansion and fragmentation of the casing.A high-speed framing camera depicted the deformation pattern before fragmentation and was used to determine the moment when the casing *** different complementary techniques were used to follow the acceleration of the fragments;a Photon Doppler velocimetry to determine the initial acceleration of the casing,double exposed radiographs to estimate the fragment velocity after break-up and a high-speed video to determine the terminal velocity of the fragment after leaving the *** addition,the fragments were soft recovered in a set of sawdust pit tests and their final shape and weight were measured.A SEM was used to characterise the fracture surfaces and to determine the modus of fracture(tensile or shear failure).Comparisons to experiments show that both software can predict the change in deformation behaviour

关键词： Controlled fragmentation Fracture mechanics LS-DYNA Impetus

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Influence of confining prestress on the transition from interface defeat topenetration in ceramic targets

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Defence Technology（防务技术） 2016年第3期12卷 263-271页

作者： Patrik LUNDBERG RenéRENSTROM olof andersson FOI Swedish Defence Research AgencySE-164 90 StockholmSweden

Replica scaled impact experiments with unconfined ceramic targets have shown that the transition velocity,i.e.,the impact velocity at which interface defeat ceases and ceramic penetration occurs,decreased as the length scale increased.A possible explanation of how this scale effect is related to the formation of a cone crack in the ceramic has been presented by the authors in an earlier ***,the influence of confinement and prestress on cone cracking and transition velocity is *** hypothesis is that prestress will suppress the formation and growth of the cone crack by lowering the driving stress.A set of impact experiments has been performed in which the transition velocity for four different levels of prestress has been *** transition velocities as a function of the level of confining prestress is compared to an analytical model for the influence of prestress on the formation and extension of the cone crack in the ceramic *** experiments and model indicate that prestress has a strong influence on the transition from interface defeat to penetration,although the model underestimates the influence of prestress.

关键词： Impact Ceramic Armour Interface defeat Dwell Confinement Prestress

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UTES （Underground Thermal Energy Storage）---Applications and Market Development in Sweden

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Journal of Energy and Power Engineering 2013年第4期7卷 669-678页

作者： olof andersson Jonas Ekkestubbe Anna Ekdahl Sweco Environment Malmo SE-201 22 Sweden

The market for shallow geothermal solutions has been continuously growing in Sweden and is recognized as a cost effective and environmental sound way for space heating. In later years, UTES （underground thermal energy storage） systems have become fTequently installed for combined heating and cooling of commercial and institutional buildings. After 20 years, operational experiences of these systems are proved to be energy efficient, technically safe and profitable. In this paper, the current statistics of UTES applications are given as well as market trends and technical development. The goal is to encourage designers and installers in other counties to use this promising technology.

关键词： Shallow geothermal energy storage ground source heat pumps underground thermal energy storage.

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Psychological and physiological impacts of a fast-track diagnostic workup for men with suspected prostate cancer:Preliminary report from a randomized clinical trial

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Cancer Communications 2020年第5期40卷 239-242页

作者： Jianwei Zhu Ruoqing Chen Sabina Davidsson Jessica Carlsson Anna Messing-Eriksson Jonna Fridfeldt Ove Andrén Sven-olof andersson Unnur Valdimarsdóttir Fang Fang Katja Fall Department of Orthopedic Surgery West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan 610000P.R.China Department of Medical Epidemiology and Biostatistics Karolinska InstitutetStockholm 17177Sweden Clinical Epidemiology and Biostatistics School of Medical SciencesÖrebro UniversityÖrebro 70185Sweden Department of Urology Faculty of Medicine and HealthÖrebro UniversityÖrebro 70185Sweden Department of Epidemiology Harvard T.H.Chan School of Public HealthBostonMassachusetts 02115SA Institute of Environmental Medicine Karolinska InstitutetStockholm 17177Sweden

Dear Editor,The increasing number of men who undergo workup for suspected prostate cancer are subject to severe emotional stress[1].Stress levels seem to be elevated as soon as a suspicion of cancer is raised and the waiting time before a final diagnosis may be equally stressful as the post-diagnostic period[1,2].We recently demonstrated a marked increase in risk for different psychiatric disorders during the six months before prostate cancer diagnosis,highlighting the potential impact of emotional stress experienced while waiting for the diagnosis[3].

关键词： diagnosis elevated emotional

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WARA-PS:a research arena for public safety demonstrations and autonomous collaborative rescue robotics experimentation

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Autonomous Intelligent Systems 2021年第1期1卷 104-134页

作者： Olov andersson Patrick Doherty Mårten Lager Jens-olof Lindh Linnea Persson Elin A.Topp Jesper Tordenlid Bo Wahlberg Department of Computer and Information Science Linköping UniversityLinköpingSweden Saab Kockums MalmöSweden Division of Decision and Control Systems School of Electrical Engineering and Computer ScienceKTH Royal Institute of TechnologyStockholmSweden Department of Computer Science Lund UniversityLundSweden Saab Combitech AB LinköpingSweden Division of Automatic Control Department of Electrical EngineeringLinköping UniversityLinköpingSweden

A research arena(WARA-PS)for sensing,data fusion,user interaction,planning and control of collaborative autonomous aerial and surface vehicles in public safety applications is *** objective is to demonstrate scientific discoveries and to generate new directions for future research on autonomous systems for societal *** enabler is a computational infrastructure with a core system architecture for industrial and academic *** includes a control and command system together with a framework for planning and executing tasks for unmanned surface vehicles and aerial *** motivating application for the demonstration is marine search and rescue operations.A state-of-art delegation framework for the mission planning together with three specific applications is also *** first one concerns model predictive control for cooperative rendezvous of autonomous unmanned aerial and surface *** second project is about learning to make safe real-time decisions under uncertainty for autonomous vehicles,and the third one is on robust terrain-aided navigation through sensor fusion and virtual reality tele-operation to support a GPS-free positioning system in marine *** research results have been experimentally evaluated and demonstrated to industry and public sector audiences at a marine test *** would be most difficult to do experiments on this large scale without the WARA-PS research ***,these demonstrator activities have resulted in effective research dissemination with high public visibility,business impact and new research collaborations between academia and industry.

关键词： Autonomous systems Intelligent system architectures Research demonstration arena Autonomous drones Autonomous marine vessels Public safety and security Collaborative robotics

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Two-Dimensional GaAs/AlGaAs Multiple Quantum Well Spatial Light Modulators

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光学学报 2003年第S1期23卷 339-340页

作者： StéphaneJunique DanielAgren BertrandNoharet LindaHglund olofberg ErikPetrini JanY.andersson Hedda Malm Jan Borglind Smilja Becanovic Optical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenOptical Engineering Department Acreo AB Electrum 236 164 40 Kista SwedenQWIP Technology Department Acreo AB Electrum 236 164 40 Kista SwedenQWIP Technology Department Acreo AB Electrum 236 164 40 Kista SwedenQWIP Technology Department Acreo AB Electrum 236 164 40 Kista Sweden

Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication proce... 详细信息

关键词： GaAs on as for of by be SLM Two-Dimensional GaAs/AlGaAs Multiple Quantum Well Spatial Light Modulators

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Detection of Stiff Nodules Embedded in Soft Tissue Phantoms,Mimicking Cancer Tumours,Using a Tactile Resonance Sensor

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Journal of Biomedical Science and Engineering 2014年第4期7卷 181-193页

作者： Anders P.Astrand Ville Jalkanen Britt M.andersson olof A.Lindahl Department of Applied Physics and Electronics Umea UniversityUmeaSweden Centre for Biomedical Engineering and Physics Umea UniversityUmeaSweden Industrial Doctoral School Umea UniversityUmeaSweden Department of Radiation Sciences Biomedical EngineeringUmea UniversityUmeaSweden Department of Engineering Sciences and Mathematics Lulea University of TechnologyLuleaSweden

Background: Prostate cancer (PCa) is the most common form of cancer among males in Europe and in the USA and the most common curative treatment is removal of the prostate, i.e. prostatectomy. After the removal, the prostate is histopathologically analysed. One area of interest is to examine the perifery of the prostate, as tumours on and near the surface can indicate that the PCa has spread to other parts of the body. There are no current methods to examine the surface of the prostate at the time of surgery. Tactile resonance sensors can be used for detecting areas of different stiffness in soft tissue. Human prostate tissue affected by cancer is usually stiffer than healthy tissue, and for this purpose, a tactile resonance sensor was developed. The aim of this study was to investigate the depth at which embedded stiffer volumes could be detected, using soft tissue phantoms. Methods: With the tactile resonance sensor used in this study, the shift of the resonance frequency and the force at contact with tissue can be measured, and combined into a tissue stiffness parameter. The detection sensitivity of the sensor at impression depths, 0.4 and 0.8 mm, was measured for detection of inserted nodules of stiff silicone in softer silicone and in chicken muscle tissue, mimicking prostate tissue with cancer tumours. Results: Measurements on the silicone samples detected the hidden stiffer object at a depth of 1 - 4 mm with a difference in the stiffness parameter of 80 - 900 mN/kHz (p < 0.028, n = 48). At the depth 5 - 6 mm the difference was smaller but still significant < 30 mN/kHz (p < 0.05, n = 24). For the measurements on chicken muscle, the detectable depth was 4 mm (p < 0.05, n = 24). Conclusion: This model study suggests that, with only a small impression depth of ≤1 mm, the resonance sensor system described here can detect stiffness variations located at least 4 mm in silicone and chicken muscle, mimicking tumours in prostate tissue.

关键词： Tissue Stiffness Resonance Sensor Prostate Cancer Piezoelectric Depth Sensitivity Tactile Sensor

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