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Deformation,fragmentation and acceleration of a controlled fragmentation charge casing

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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

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

Additive manufacturing of 18%nickel maraging steels:Defect,structure and mechanical properties:A review

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journal of Materials Science & Technology 2022年第25期120卷 227-252页

作者： Lulu Guo Lina Zhang j.el andersson Olanrewaju Ojo Department of Mechanical Engineering University of ManitobaWinnipeg R3T 5V6Canada Department of Engineering Science University WestTrollh tan 46186Sweden

This paper reviews the latest research progress in the additive manufacturing(AM)process of 18%nickel maraging steels,which involves laser-based powder bed fusion(L-PBF),laser-based directed energy deposition(L-DED),and wire arc additive manufacturing(WAAM).The emphasis is on the defects,structure,and mechanical properties of the additive manufactured 18%nickel maraging *** first,this article outlines the influences of the processing parameters of AM techniques on the defects formed in the fabricated parts,in terms of the L-PBF and *** macrostructure and microstructure characteristics of as-built and heat-treated 18%nickel maraging steel are then described in ***,the mechanical properties of as-built and heat-treated 18%nickel maraging steel are assessed,such as their tensile,hardness,impact toughness,and fatigue ***,future directions for work on the AM of 18%nickel maraging steel are provided.

关键词： Additive manufacturing 18%Nickel maraging steel Defects Macrostructure Microstructure Mechanical properties

Solid oxide fuel cell interconnect design optimization considering the thermal stresses

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Science Bulletin 2016年第17期61卷 1333-1344页

作者： Min Xu Tingshuai Li Ming Yang Martin andersson School of Energy Science and Engineering University of Electronic Science and Technology of China Department of Energy Sciences Faculty of EngineeringLund University

The mechanical failure of solid oxide fuel cell(SOFC) components may cause cracks with consequences such as gas leakage,structure instability and reduction of cell lifetime.A comprehensive 3D model of the thermal stresses of an anode-supported planar SOFC is presented in this *** main objective of this paper is to get an interconnect optimized design by evaluating the thermal stresses of an anode-supported SOFC for different designs,which would be a new criterion for interconnect *** model incorporates the momentum,mass,heat,ion and electron transport,as well as steady-state *** from methane steam reforming and water-gas shift reaction were considered in our *** results examine the relationship between the interconnect structures and thermal stresses in SOFC at certain mechanical properties.A wider interconnect of the anode side lowers the stress *** simulation results also indicate that thermal stress of coflow design is smaller than that of counterflow,corresponding to the temperature *** study shows that it is possible to design interconnects for an optimum thermal stress performance of the cell.

关键词： Solid oxide fuel cell Thermal stresses Interconnect Optimization Finite element method

Framework for assessing quality of care for inflammatory bowel disease in Sweden

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World journal of Gastroenterology 2012年第10期18卷 1085-1092页

作者： Martin Rejler jrgen Tholstrup Mattias elg Anna Spngéus Boel andersson Gre Department of Medicine Highland Hospital S 57533 Eksj Sweden Division of Quality Management and Technology and HelIX Vinn Excellence Centre Linkping University S 58183 Sweden Department of Medical and Health Sciences Faculty of Health Sciences Linkping University S 58183 Sweden jnkping Academy for Improvement of Health and Welfare The School of Health Sciences Jnkping University Jnkping Academy Box 1026 S 55111 Jnkping Sweden

AIM: To create and apply a framework for quality assessment and improvement in care for inflammatory bowel disease (IBD) patients. METHODS A framework for quality assessment and improvement was created for IBD based on two generally acknowledged quality models. The model of Donabedian (Df) offers a logistical and productive perspective and the Clinical Value Compass (CVC) model adds a management and service perspective. The framework creates a pedagogical tool to understand the balance between the dimensions of clinical care (CVC) and the components of clinical outcome (Df). The merged models create a framework of the care process dimensions as a whole, reflecting important parts of the IBD care delivery system in a local setting. Clinical and organizational quality measures were adopted from clinical experience and the literature and were integrated into the framework. Data were collected at the yearly check-up for 481 IBD patients during 2008. The application of the quality assessment framework was tested and evaluated in a local clinical IBD care setting in jnkping County, Sweden. RESULTS: The main outcome was the presentation of how locally-selected clinical quality measures, integrated into two complementary models to develop a frame-work, could be instrumental in assessing the quality of care delivered to patients with IBD. The selected quality measures of the framework noted less anemia in the population than previously reported, provided information about hospitalization rates and the few surgical procedures reported, and noted good access to the clinic. CONCLUSION: The applied local quality framework was feasible and useful for assessing the quality of care delivered to IBD patients in a local setting.

关键词： Quality measures Inflammatory bowel disease Value compass Donabedian Quality improvement

DHT-and blockchain-based smart identification for video conferencing

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Blockchain(Research and Applications) 2022年第2期3卷 90-101页

作者： Morteza Alizadeh Karl andersson Olov Schelen Department of Computer Science Electrical and Space EngineeringLuleåUniversity of TechnologySE-93187SkellefteåSweden

Video conferencing applications help people communicate via the Internet and provide a significant and consistent basis for virtual ***,integrity,security,identification,and authentication problems are still *** video conference technologies typically rely on cloud systems to provide a stable and secure basis for executing tasks and *** the same time,video conferencing applications are being migrated from centralized to decentralized solutions for better performance without the need for third-party *** article demonstrates a decentralized smart identification scheme for video conferencing applications based on biometric technology,machine learning,and a decentralized hash table combined with blockchain *** store users'information on a distributed hash table and transactional events on the distributed ledger after identifying users by implementing machine learning ***,we leverage distributed ledger technology's immutability and traceability properties and distributed hash table unlimited storage feature to improve the system's storage capacity and immutability by evaluating three possible *** experimental results show that an architecture based on blockchain and distributed hash table has better efficiency but needs a longer time to execute than the two other architectures using a centralized database.

关键词： Video conferencing Blockchain IPFS Decentralized web hosting Machine learning

Deteriorated function of cutaneous microcirculation in chronic congestive heart failure

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journal of Geriatric Cardiology 2011年第2期8卷 82-87页

作者： Marie-Louise Edvinsson Erik Uddman Sven E andersson Department of Emergency Medicine Lund University Hospital SE- 221 85 LUND Sweden

Background Chronic congestive heart failure is a complex condition that leads to dysfunction in the peripheral microcirculation. We have previously shown that vascular reactivity is reduced with increasing age. In this study, we examined a group of very old patients with severe chronic heart failure to test the hypothesis that vascular function is further compromised by a combination of heart failure and aging. Methods Cutaneous forearm blood flow was measured by laser Doppler flowmetry and compared among three groups： Group 1 （n = 20, mean ±SE： 85.5 ±4 years）, heart failure patients with New York Heart Association class Ⅳ （NYHA Ⅳ） and with a NT-proBNP level ≥5000 ng/L; Group 2 （n = 15, mean ±SE： 76.5 ±2 years）, heart failure patients with NYHA II and NT-proBNP ≤2000 ng/L, and Group 3 （n = 10, mean ±SE： 67.6 ±3.0 years）, healthy controls with no clinical signs of heart failure. The vasodilator response to the iontophoretic administration of acetylcholine （ACh）, acting via an endothelial mechanism, and sodium nitroprusside （SNP）, acting via a smooth muscle cell mechanism, were studied. Results All patients with heart failure had significantly reduced vascular reactivity independent of the mode of stimulation （ACh, SNP or heat） when compared to healthy controls. However, the responses did not differ between the two groups of heart failure patients. Conclusions Cutaneous vascular reactivity is reduced in heart failure patients and does not correlate with the severity of the condition or age of patients.

关键词： heart failure cutaneous microcirculation endothelial responses acetylcholine smooth muscle responses

Erratum to： Patterns of coccolithophore pigment change under global acidification conditions based on in-situ observations at BATS site between july 1990-Dec 2008

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Frontiers of Earth Science 2017年第2期11卷 308-309页

作者： jianhai LV Yaoqiu KUANG Hui ZHAO Andreas andersson Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Bermuda Institute of Ocean Sciences Ferry Reach St. Georges GE-01 Bermuda Guangdong Ocean University Zhanjiang 524088 China Marine and Fishery Environment Monitoring Center of Guangzhou Guangzhou 510235 China

Erratum to： Front. Earth Sci. DOI 10.1007/sl1707-015-0503-x The authors requested that an Erratum be published containing a correction to the authors lists, text, acknowledgements.1） Dr. Andreas andersson was unknowingly and incorrectly included as a co-author on this paper. He did not see or contribute to this manuscript before submission and does not endorse the results and findings of this study. Dr. andersson is not a co-author. The paper should be cited as：＂Lv j, Kuang Y, Zhao H （2017）. Patterns of coccolithophore pigment change under global acidification conditions based on in-situ observations at BATS site between july 1990-Dec 2008. Frontiers of Earth Science, 11 （2）： 297-307＂.

关键词： dissolved inorganic carbon BATS MLD coccolithophore pigments the Bermuda

Risk factors and outcomes for patients with pancreatic cancer undergoing surgical exploration without resection due to metastatic disease:A national cohort study

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Hepatobiliary & Pancreatic Diseases International 2022年第3期21卷 279-284页

作者： Emil Sahlstrom Paulina Bereza-Carlson johan Nilsson Bobby Tingstedt Bodil andersson Department of Clinical Sciences Lund SurgeryLund UniversitySweden Department of Surgery Central Hospital KristianstadSweden Department of Translational Medicine Cardiothoracic surgery and bioinformaticsLund UniversitySweden Department of Thoracic and vascular surgery Skane University hospitalLundSweden Department of Surgery Skane University HospitalLundSweden

Background:Unresectable disease is sometimes diagnosed during surgery in patients with pancreatic ductal adenocarcinoma(PDAC).This study aimed to identify preoperative risk factors for metastatic disease diagnosed at surgical exploration and to investigate and compare survival in resected and nonresected ***:Patients were identified from the Swedish National Pancreatic and Periampullary Cancer Registry *** of metastatic disease were evaluated with a multivariable logistic regression model,and survival was evaluated with Kaplan-Meier estimates and log-rank ***:In total,1938 patients with PDAC were scheduled for *** unresectable situation was diagnosed intraoperatively in 399 patients(20.6%),including 234(12.1%)with metastasized *** risk factors for metastasis were involuntary weight loss(OR=1.72;95%CI:1.27-2.33)and elevated carbohydrate antigen 19-9(CA19-9)(35-599 U/m L,OR=1.79,95%CI:1.11-2.89;≥600 U/m L,OR=3.24,95%CI:2.04-5.17).Overall survival was lower among patients with metastasized disease than that among patients with a resectable tumor(Pelevation of CA19-9 are preoperative risk factors for diagnosing metastasized disease during surgical exploration.

关键词： Pancreatic cancer Surgery Metastasized Exploration