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Ballistic design and testing of a composite armour reinforced by CNTs suitable for armoured vehicles

defence Technology（防务技术） 2024年第2期32卷 173-195页

作者： Evangelos Ch.Tsirogiannis Evangelos Daskalakis Mohamed H.Hassan Abdalla M.Omar Paulo Bartolo EODH SA Research and Development DepartmentLakkoma Chalkidikis63080Greece School of Mechanical Aerospace and Civil EngineeringUniversity of ManchesterManchesterM139PLUK Singapore Centre for 3D Printing School of Mechanical and Aerospace EngineeringNanyang Technological University639798Singapore

This paper is investigating the use of composite armour reinforced by nanomaterials, for the protection of light armoured(LAV) and medium armoured military vehicles(MAV), and the interaction between the composite materials and high-performance ballistic projectiles. Four armour materials, consisted of front hybrid fibre reinforced polymer cover layer, ceramic strike-face, fibre reinforced polymer intermediate layer and the metal matrix composite reinforced backplate, were manufactured and assembled by adhesive technology. The proposed laminated protection system is suitable for armoured ground vehicles;however, it could be used as armour on ground, air and naval platforms. The design of the protection system, including material selection and thickness, was elaborated depending on the performance requirements of Level 4 + STANAG 4569 military standard(projectile 14.5 mm × 114 mm API B32) and especially on a design philosophy which is analysed with the specifications. The backplate of this new composite is a hybrid material of Metal Matrix Composite(MMC) reinforced with carbon nanotubes(CNTs), manufactured with the use of powder metallurgy technique. The composite backplate material was morphologically, mechanically and chemically analysed. Results show that all plates are presenting high mechanical properties and ballistic characteristics, compared to commonly used armour plates. Real military ballistic tests according to AEP-STANAG 4569 were carried out for the total composite armour systems. After the ballistic tests, AA2024-CNT3 showed the best protection results, compared with the other plates(AA2024-CNT1 and AA2024-CNT2), with the projectile being unable to fully penetrate the composite plate.

关键词： Passive armour protection Protective armour Ballistic performance Hybrid composites Vehicle protection

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Effect of heavy load carriage on cardiorespiratory responses with varying gradients and modes of carriage

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Military Medical research 2019年第1期6卷 53-59页

作者： Subhojit Chatterjee Tirthankar Chatterjee Debojyoti Bhattacharyya Suranjana Sen Madhusudan Pal defence Institute of Physiology and Allied Sciences Defence Research & Development Organisation Ministry of Defence

Background: The present study was undertaken to determine the effect of different uphill and downhill gradients on cardiorespiratory and metabolic responses of soldiers while carrying heavy military loads in two different ***: Eight physically fit male soldiers with a mean age 32.0±2.0 years, a mean height of 169.5±4.9 cm, and a mean weight of 63.8±8.4 kg volunteered for this study. Each volunteer completed treadmill walking trials at a speed of 3.5 km/h while carrying no external load, 31.4 kg load in a distributed mode(existing load carriage ensembles) and compact mode(new back pack) over 5 different downhill and uphill gradients(–5%, –10%, 0%, 5%, 10%) for 6 min at each gradient. During the walking trials, heart rate(HR), oxygen uptake(VO_2), respiratory frequency(RF) and energy expenditure(EE) were determined by the process of breath-by-breath gas analysis using a K4 b2 system. The average of the last 2 min data from each 6 min walking trial for each individual was subjected to statistical ***: All parameters(HR, VO_2, RF, and EE) gradually increased with the change in gradient from downhill to level to uphill. The distributed mode showed higher values compared to compact mode for all gradients, e.g., for VO_2, there was a 10.7, 7.4, 5.1, 28.2 and 18.7% increase in the distributed mode across the 5 different ***: It can be concluded from the present study that the compact mode of load carriage is more beneficial than the distributed mode in terms of cardiorespiratory responses while walking on downhill and uphill surfaces with a 31.4 kg load.

关键词： Heavy load carriage Cardio respiratory responses Gradients Soldiers

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Design of a Biomedical Device to Reduce Anxiety Experienced by Patients Diagnosed with Parkinson’s Disease

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Journal of Biomedical Science and Engineering 2024年第3期17卷 57-71页

作者： Madhini Vigneswaran Anjali Menon research Department MEDIC Foundation Vancouver Canada

Parkinson’s disease (PD) is a neurodegenerative disease that occurs due to loss of nerve cells that produce dopamine in the brain, affecting approximately 4 million people worldwide. PD patients often feel an increase in anxiety levels daily. While there are medications/exercises to help relieve anxiety, there are limited methods to reduce anxiety without the help of a caretaker. As a result, MEDIC Foundation, a non-profit organization in British Columbia, canada, is designing an automated system that consists of a wristband and an application which uses vi-bration therapy to help reduce anxiety of PD patients. Literature reviews were conducted to document the project’s needs. Phase I of the project focused on de-veloping a prototype for the application and phase II on developing the wrist-band. The team developed prototypes of a wristband that automatically applies vibration near the median nerve as the heart rate variability (HRV) deviates away from the normal threshold of the user, and an application that displays real-time heart rate variability signals as well as provides for relaxation. The development of the prototype is still in early progress. By creating this automated system, we aim to provide a solution to senior PD patients to relieve anxiety independently. .

关键词： Vibration Therapy Healthcare Application Parkinson’s Disease Anxiety Wristband Heart Rate Variability

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Flash X-ray radiography technique to study the high velocity impact of soft projectile on E-glass/epoxy composite material

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defence Technology（防务技术） 2019年第2期15卷 216-226页

作者： B.Venkata Ramudu C.Jayarami Reddy V.Madhu Armour Design and development Division Defence Metallurgical Research Laboratory

In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, recovery of the bulging, reverse bulging and its recovery. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.

关键词： Flash X-ray radiography E-Glass/epoxy composite Ballistic impact Numerical simulation

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Quantitative prediction model for the depth limit of oil accumulation in the deep carbonate rocks:A case study of Lower Ordovician in Tazhong area of Tarim Basin

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Petroleum Science 2024年第1期21卷 115-124页

作者： Wen-Yang Wang Xiong-Qi Pang Ya-Ping Wang Zhang-Xin Chen Fu-Jie Jiang Ying Chen State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China research Institute of Exploration and development PetroChina Southwest Oil&Gas Field CompanyChengdu610041SichuanChina Chemical and Petroleum Engineering Schulich School of EngineeringUniversity of CalgaryCalgaryT2N 1N4Canada

With continuous hydrocarbon exploration extending to deeper basins,the deepest industrial oil accumulation was discovered below 8,200 m,revealing a new exploration ***,the extent to which oil exploration can be extended,and the prediction of the depth limit of oil accumulation(DLOA),are issues that have attracted significant attention in petroleum *** it is difficult to characterize the evolution of the physical properties of the marine carbonate reservoir with burial depth,and the deepest drilling still cannot reach the ***,the DLOA cannot be predicted by directly establishing the relationship between the ratio of drilling to the dry layer and the *** this study,by establishing the relationships between the porosity and the depth and dry layer ratio of the carbonate reservoir,the relationships between the depth and dry layer ratio were obtained *** depth corresponding to a dry layer ratio of 100%is the *** on this,a quantitative prediction model for the DLOA was finally *** results indicate that the porosity of the carbonate reservoir,Lower Ordovician in Tazhong area of Tarim Basin,tends to decrease with burial depth,and manifests as an overall low porosity reservoir in deep *** critical porosity of the DLOA was 1.8%,which is the critical geological condition corresponding to a 100%dry layer ratio encountered in the *** depth of the DLOA was 9,000 *** study provides a new method for DLOA prediction that is beneficial for a deeper understanding of oil accumulation,and is of great importance for scientific guidance on deep oil drilling.

关键词： Deep layer Tarim Basin Hydrocarbon accumulation Depth limit of oil accumulation Prediction model

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Parametric study of single confined fragment launch explosive device

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defence Technology（防务技术） 2019年第2期15卷 179-185页

作者： Pankaj K.Choudha A.Kumaraswamy Kusumkant D.Dhote Armament research & development Establishment (DRDO) defence Institute of Advanced Technology

In this article, parametric study of single confined fragment launch device was carried out. The configuration proposed was further studied to derive the empirical relationship for effect of fragment size,charge size, confinement thickness on fragment velocity. The simulations were carried out using ANSYSAUTODYNE explicit solver. Fragment velocities were estimated as a function of different parametric combinations of explosive quantities, charge length to diameter ratio, fragment height to diameter ratio,confinement thickness, fragment material and fragment mass. The data was further converted to charge to metal ratio under fragment and confinement. It was observed that, increase in confinement thickness,charge quantity and decrease in fragment height increases the fragment velocity. It is also noted that,charge to metal mass ratio under fragment significantly affects the fragment velocity. At the end, an empirical relationship for fragment velocity interms of all these parameters was established. Using these relations, two velocities 1831.92 m/s and 2523.9 m/s required for NATO STANAG 4496 IM test were estimated. The design parameters for these velocities are presented. Also, the results estimated using the empirical relationship has been compared with published experimental data. Error in the predicted velocities is within the acceptable range. The empirical relationship proposed will be useful for finalization of design of the fragment launch device.

关键词： Confinement Fragment size Empirical relationship Fragment velocity Insensitive munition test Fragment launching device

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Risk factors for long COVID in children and adolescents:a systematic review and meta-analysis

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World Journal of Pediatrics 2024年第2期20卷 133-142页

作者： Daniel G.Rayner Elaine Wang Cloris Su Om D.Patel Stephanie Aleluya Alessandra Giglia Evelyn Zhu Maha Siddique Department of Health research Methods Evidenceand ImpactFaculty of Health SciencesMcMaster University1280 Main St WHamiltonONL8S 4K1Canada Faculty of Health Sciences McMaster University1280 Main St WHamiltonON L8S 4K1Canada Faculty of Science McMaster University1280 Main St WHamiltonONL8S 4K1Canada

Background The long-term sequelae of COVID-19 in children and adolescents remain poorly understood and *** systematic review and meta-analysis sought to summarize the risk factors for long COVID in the pediatric *** We searched six databases from January 2020 to May 2023 for observational studies reporting on risk factors for long COVID or persistent symptoms those were present 12 or more weeks post-infection using multivariable regression *** registries,reference lists of included studies,and preprint servers were hand-searched for relevant ***-effects meta-analyses were conducted to pool odds ratios for each risk *** study risk of bias was rated using QUIPS,and the GRADE framework was used to assess the certainty of evidence for each unique *** Sixteen observational studies(N=46,262)were included,and 19 risk factors were amenable to *** moderate certainty in the evidence,age(per 2-year increase),allergic rhinitis,obesity,previous respiratory diseases,hospitalization,severe acute COVID-19,and symptomatic acute COVID-19 are probably associated with an increased risk of long *** sex,asthma,comorbidity,and heart diseases may be associated with an increased risk of long COVID,and Asian and Black races may be associated with a decreased risk of long *** did not observe any credible subgroup effects for any risk *** The current body of literature presents several compelling risk factors for the development of long COVID in the pediatric *** research is necessary to elucidate the pathophysiology of long COVID.

关键词： COVID-19 Long COVID Post-acute COVID-19 syndrome Pediatrics Risk factors

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Emerging role of galectin 3 in neuroinflammation and neurodegeneration

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Neural Regeneration research 2024年第9期19卷 2004-2009页

作者： Brian M.Lozinski Khanh Ta Yifei Dong Department of Clinical Neuroscience University of CalgaryCalgaryABCanada Deparment of Biochemistry Microbiology&ImmunologyUniversity of SaskatchewanSaskatoonSKCanada

Neuroinflammation and neurodegeneration are key processes that mediate the development and progression of neurological ***,the mechanisms modulating these processes in different diseases remain incompletely *** in single cell based multi-omic analyses have helped to identify distinct molecular signatures such as Lgals3 that is associated with neuroinflammation and neurodegeneration in the central nervous system(CNS).Lgals3 encodes galectin-3(Gal3),aβ-galactoside and glycan binding glycoprotein that is frequently upregulated by reactive microglia/macrophages in the CNS during various neurological *** Gal3 has previously been associated with non-CNS inflammatory and fibrotic diseases,recent studies highlight Gal3 as a prominent regulator of inflammation and neuroaxonal damage in the CNS during diseases such as multiple sclerosis,Alzheimer’s disease,and Parkinson’s *** this review,we summarize the pleiotropic functions of Gal3 and discuss evidence that demonstrates its detrimental role in neuroinflammation and neurodegeneration during different neurological *** also consider the challenges of translating preclinical observations into targeting Gal3 in the human CNS.

关键词： Alzheimer’s disease Galectin 3 microglia multiple sclerosis neurodegeneration neuroinflammation Parkinson’s disease therapeutics

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Andrographolide inhibits chikungunya virus infection by up-regulating host innate immune pathways

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Asian Pacific Journal of Tropical Medicine 2018年第3期11卷 214-221页

作者： Swati Gupta Kamla Prasad Mishra Paban Kumar Dash Manmohan Parida Lilly Ganju Shashi Bala Singh defence Institute of Physiology & Allied Sciences defence research and development Establishment

Objective: To investigate the therapeutic efficacy of andrographolide, a plant derived compound, against chikungunya virus(CHIKV) infection. Methods: Using flow cytometry and immunoblotting assay, in vitro viral protein expression was studied in THP-1 cells line. In Balb/c mouse neonates, viral RNA copy number was determined by real time PCR. Results:The results showed reduced CHIKV protein expression on andrographolide treatment in CHIKV-infected human peripheral blood mononuclear cells, Vero cells and THP-I cell *** vivo, andrographolide treatment to CHIKV-infected neonates reduced viral RNA copy number. Further. andrographolide also increased cytotoxic T lymphocytes both in vitro and in vivo. Andrographolide also activated host innate immune pathways, viz., protein kinase *** eukaryotic initiation factor 2 α, retinoic acid inducible gene-Ⅰ and interferon regulatory factor 3/7, thereby increasing IFN-a secretion. CHIKV-induced nuclear factor κlight chain enhancer of activated B cells and tumor necrosis factor-a was also reduced on andrographolide treatment. Conclusion: Andrographolide inhibits CHIKV by suppressing viral protein expression and up-regulating host innate immunity and hence could be an effective therapeutic agent against CHIKV infection.

关键词： Chikungunya virus Andrographolide Interferon α Protein kinase R Retinoic acid inducible gene-I Tumor necrosis factor α

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Dispersion sensitivity analysis&consistency im provement of APFSDS

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defence Technology（防务技术） 2017年第4期13卷 316-322页

作者： Sangeeta Sharma Panda L.K. Gite A. Anandaraj R.S. Deodhar D.K. Joshi K.M. Rajan Armament research development Establishment (ARDE) Defence Research Development Organization Ministry of Defence Government of India Pashan Pune Maharashtra 411 021 India

The purpose of this study is to investigate and quantify some possible sources of dispersion of 120 mm APFSDS tank ammunition both experimentally and *** paper aims to point out the most influential source during In-Bore Balloting Motion phase as well as in External Ballistics phase of the ammunition and quantifies its effect on *** obtained from flight trials is critically analysed and parameters affecting dispersion such as initial yaw/pitch rates,yaw/pitch dampening,plane start angle,launch spin,clearance,centre of gravity shift,dynamic imbalance angle,cross wind,*** observed and,later on,studied in detail by extensive External Ballistics Monte Carlo(EBMC)simulation and Six Degree of Freedom(6-DOF)trajectory *** Bore Balloting Motion simulation shows that reduction in residual spin by about 5%results in drastic56%reduction in first maximum yaw.A correlation between first maximum yaw and residual spin is *** of data analysis are used in design modification for existing *** of designs are evaluated numerically before freezing five designs for further *** designs are critically assessed in terms of their comparative performance during In-bore travel&external ballistics *** are validated by free flight trials for the finalised design.

关键词： APFSDS Dispersion Consistency Accuracy Yaw rate Spin Muzzle jump factor In-bore dynamics Monte Carlo simulation

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