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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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Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHPA

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Journal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.martínez-montoya R.g.Sanchez-Alvarado D.Y.medina-Velazquez m.L.Carrera-Jota P.garnica-chávez A.de J.morales-Ramirez Higher School of chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

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Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

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chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev Kasim F.magomedov Svetlana ch.gagieva Dmitry A.Kurmaev Yulia V.Nelyubina Evgenii K.golubev maria D.Evseeva Viktor g.Vasil'ev galina g.Nikiforova mikhail I.Buzin Vyacheslav S.Bogdanov Boris m.Bulychev Department of chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(mmAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(m_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHmWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/mg co-catalyst Ultra-high molecular weight polyethylene

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Experimental evaluation of a“U”type earth-to-air heat exchanger planned for narrow installation space in warm climatic conditions

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Energy and Built Environment 2024年第5期5卷 772-786页

作者： Ricardo molina-Rodea Jorge Alejandro Wong-Loya Hugo Pocasangre-chávez Jennifer Reyna-guillén Institute of Renewable Energies National Autonomous University of MexicoTemixcoMorelosMexico

The thermal performance of a“U”type earth-to-air heat exchanger is presented in this experimental *** device has a serial-connected vertical *** wells where tubes were installed have a depth of fewer than 3 m and are separated every 1.5 m,using an installation area of *** experimentation was carried out in march in morelos,mexico when the environmental temperature reaches 35℃ during the *** performance of the device was measured and compared to the requirements of an office for cooling purposes within a university campus to reproduce the space restrictions found in urbanized *** using a small land surface,it is feasible for urbanized *** air temperature inside the“U”type earth-to-air heat exchanger,the surrounding soil temperature,the airspeed,and the power consumed by the fan were *** air temperature and the fan’s power consumption data were obtained by modifying the airspeed in four constant values,from 1.3 m/s to 6.6 m/*** show that the device evaluated in this work has adequate thermal performance for cooling purposes compared to the requirements of an office.A decrease in air temperature was recorded in a range of 5.1℃ to 9.4℃.Over 70%of the total temperature difference was reached in the first well,where the average soil thermal disturbance at 5 cm was 2.8℃.The device achieved a maximum COP of 12.8 and a maximum effectiveness of 88.4%.With these results,it is concluded that the system is suitable for cooling purposes in areas with space *** work is novel since the dimensions available for installation in urbanized areas are considered and compared with the thermal requirements of an *** addition to the fact that there are no published works with vertical heat exchangers connected in series.

关键词： Low temperature geothermal energy Thermal performance Vertical heat exchangers Space restrictions in urbanized areas geothermal direct uses

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Swift XRT Analysis of Type II-P Supernova SN 2008ij

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International Journal of Astronomy and Astrophysics 2024年第3期14卷 220-229页

作者： sh. m. shehata Ahmed m. Fouad R. m. Samir A. A. shaker National Research Institute of Astronomy and geophysics (NRIAg) Helwan Egypt

This study investigates the X-ray properties and evolution of Type II supernovae (SNe II) observed by Swift, examining variations among supernovae and exploring their X-ray characteristics over time. We present the first X-ray study of the Type IIp supernova SN 2008ij using data from the Swift X-ray mission. This investigation focuses on its spectral properties, identifying an X-ray flux of 1.20 (+0.11, −0.10) × 10−13 erg/cm2/s and a plasma temperature of 4.76 (+1.22, −0.83) keV. Our study marks an advancement in understanding SN 2008ij, providing crucial results into its X-ray emission characteristics. These results lay the groundwork for future studies of Type IIp supernovae, offering a foundation for exploring their evolutionary and physical processes.

关键词： X-Ray Core Collapse Supernova Swift (XRT) Observations

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Boron-containing compounds as labels,drugs,and theranostic agents for diabetes and its complications

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World Journal of Diabetes 2024年第6期15卷 1060-1069页

作者： marvin A Soriano-Ursúa R Ivan Cordova-chávez Eunice D Farfan-garcía george Kabalka Department of Physiology Escuela Superior de MedicinaInstituto Politécnico NacionalCiudad de México 11340Mexico Department of Physiology Instituto Politécnico NacionalMexico City 11340Mexico Department of Biochemistry Instituto Politécnico NacionalMexico City 11340Mexico Department of chemistry The University of TennesseeKnoxvilleTN 37996United States

Diabetes is a disease with a high global *** strategies have failed to limit the advancement and impact of the *** early diagnosis and treatment will require the development of new *** this sense,boroncontaining compounds have been reported as agents with the ability to reduce glycemia and *** have also been used for labeling and measuring carbohydrates and other molecules linked to the initial stages of diabetes and its *** addition,certain boron compounds bind to molecules related to diabetes development and their biological activity in the regulation of elevated ***,it should be noted that some boron compounds appear to exert beneficial effects on diabetes complications such as accelerating wound healing while ameliorating pain in diabetic patients.

关键词： Boron Carbohydrates metabolism Diabetes Boronodipyrromethene

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Academic Stress Assessment Using Virtual Reality as an Educational Tool in Spine Surgery

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Open Journal of modern Neurosurgery 2024年第2期14卷 114-123页

作者： Diana chávez Lizárraga Jesús Alberto Pérez Contreras Fernando Alvarado gómez Evelyn Quintero medina Emmanuel Cantú chávez Iván Ulises Sámano López Ana Sofía Peña Blesa Department of Neurosurgery ángeles Pedregal Ciudad de México México Department of Traumatology and Orthopedics Hospital Santa Fe Bogotá Colombia

Introduction: The evaluation of academic stress in medical students and residents is a topic of significant interest, given the considerable challenges they face during their learning process with traditional teaching methods. The use of technologies like virtual reality presents an opportunity to enhance their skills through simulations and training. The main objective of this study is to qualitatively assess the stress levels experienced by medical students and residents by integrating virtual reality into their current learning methods, aiming to improve their ability to manage stressors in their practice. material and methods: A questionnaire was conducted with 12 medical students and 12 Traumatology and orthopedics residents. The purpose of the questionnaire was to evaluate the levels of academic stress using the SISCO inventory. The stress levels were calculated by transforming average values into percentages, and the following criteria were assigned: 0 to 33% for mild Stress, 34 to 66% for moderate Stress, and 67 to 100% for Deep Stress. Then, a virtual reality class focused on spine surgery was provided. Both medical students and residents were trained using the Non Nocere sharpSurgeon software platform and Oculus Quest 2 virtual reality glasses. At the end of the session, a second questionnaire related to the practice with virtual reality was conducted with the same evaluation criteria and a comparative analysis was carried out. Results: 12 undergraduate students from Hospital Angeles mexico, CDmX and 12 traumatology and orthopedics residents at Hospital Santa Fe, Bogota were evaluated. The students in CDmX reported an average qualitative stress of 28.50% during habitual practices, which decreased to an average of 14.67% after virtual reality practice. Residents in Bogotá experienced an average qualitative stress of 30.50% with their current learning methods but this reduced to an average of 13.92% after using virtual reality. These findings indicate that t

关键词： Virtual Reality Academic Stress Learning Strategies Spine Surgery Training

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magnetic resonance imaging-guided focused ultrasound thalamotomy launch with remote telemedicine international proctorship

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chronic Diseases and Translational medicine 2024年第1期10卷 40-50页

作者： Igor V.Buzaev Rezida m.galimova Dinara I.Nabiullina Sergey N.Illarioshkin Naufal sh.Zagidullin shamil m.Safin Department of Surgery Bashkir State Medical UniversityUfaRussia Intelligent Neurosurgery Clinic Ltd.International Medical Center V.S.Buzaev memorialUfaRussia Directorate Research Center of NeurologyVolokolamskoye ShosseMoscowRussia

Background: COVID-19 limitations have hindered the implementation of new technologies by preventing proctors from coming to the *** share our first experience of magnetic resonance imaging(mRI)-guided focused ultrasound(mRgFUS)treatment with an international remote online proctorship,and develop and evaluate the methodology of remote mRgFUS ***: This single-center,nonrandomized controlled prospective study included 94 patients:27 with essential tremor(ET)and 67 with tremor-dominant Parkinson's disease(PD).The coming of proctors was impossible,so we arranged for the remote participation of proctors from the United Kingdom,Spain,and Israel.A total of 38 patients(40.4%)received telemedicine-proctored treatment(proctor group)and 56 received their treatment independently(solo group).We used the Clinical Rating Scale for Tremor(CRST)for ET patients and the Unified Parkinson's Disease Rating Scale(UPDRS)Part III for PD ***: In patients with ET,success rates were 81.8%(proctor group)and 100%(solo group)(p=0.22).CRST reduction on the treated side was 71.43%[65.83%;80.56%](proctor group)versus 60.87%[53.99;79.58](solo group)(p=0.19).None of the patients showed worsening of tremors within 1 *** patients with PD,the success rates were 92.6%(proctor group)and 100%(solo group)(p=0.08).The UPDRS Part III improvement was 30.1%(proctor group)versus 39.9%(solo group)(p=0.003).The 1-year recurrence rate was 40%(proctor group)and 17.5%(solo group)(p=0.04).No complications were observed at 6 ***: We developed a feasible and safe methodology for telemedicine remote online-proctored mRgFUS *** significant difference was observed between the solo and developed remote proctor protocols in terms of complication rate,effect,and long-term results;however,UPDRS Part III improvement was better in the PD solo *** study demonstrated that the mRgFUS international proctorship can be performed successfully remotely.

关键词： essential tremor mRgFUS Parkinson's disease proctor telemedicine

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Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： S.m.Yakout A.m.Youssef Inorganic chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： Semiconductor TiO_(2) Rare earths Congo red methylene blue Solar spectrum Photodegradation

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Standardizing mI-TLIF, a Proposal for a Reproducible Technique

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Open Journal of modern Neurosurgery 2024年第2期14卷 91-103页

作者： Iván Ulises Sámano López Jesús Alberto Pérez Contreras Emmanuel Cantú chávez Diana chávez Lizárraga Ana Sofía Peña Blesa Thania Karina gutiérrez Anchondo Á ngeles Pedregal Ciudad de México México

Background: minimally invasive transforaminal lumbar interbody fusion (mI TLIF) is a widely known and performed technique, however its versatility among different physicians continues to hinder its replication and results. Therefore, this study aimed to provide a step-by-step surgical guide to perform a safe mI-TLIF, based on the results obtained in patients operated on by a single surgeon over a period of 12 years. Patients and methods: A retrospective, single center, longitudinal, and observational cohort study was conducted with 931 patients who underwent mI TLIF by a single surgeon between 2010 and 2022 using the technique described on this paper, each with a minimum follow-up of 12 months. Criteria included Schizas classification, listhesis according to meyerding classification, number of levels treated, cage size, and complications (screw repositioning or cerebrospinal fluid leak). Patient clinical outcomes were assessed using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) for pre- and postoperative radicular pain. Thin slice CT scans were used to assess the progression of the fusion using the Bridwell classification. In the statistical analysis, percentages, median, and interquartile range (IQR) were calculated. Results: Nine hundred and thirty one patients underwent mI TLIF using the technique described, eight hundred and eighty (94.5%) had a single level treated and fifty one (5.5%) had a 2 level procedure (982 levels), an 8mm cage was placed on five hundred and seventeenlevels (52.7%), six hundred and sixty three levels(67.6%) achieved grade I fusion, two hundred and sixty six levels (27.1%) achieved grade II fusion, 52 levels (5.3) achieved grade III fusion and one level (0.1) achieved a grade IV fusion or non-union. Revision surgery was performed on 3 patients (0.3%) for screw repositioning, cerebrospinal fluid leak was present on 2 patients during surgery and treated before closure. VAS scores and ODI were improved at 12 months postop (V

关键词： mITLIF Lumbar Interbody Fusion Technique Pain Relief and Disability

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