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Enhancing Precision in Radiotherapy Delivery: Validating Monte Carlo Simulation Models for 6 MV Elekta Synergy Agility LInAC Photon Beam Using Two Models of the GAMOS Code

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World journal of nuclear Science and Technology 2024年第2期14卷 146-163页

作者： nogaye ndiaye Oumar ndiaye Papa Macoumba Faye Kodjo joël Fabrice n’Guessan Djicknack Dione Khady Sy Moussa Hamady Sy Jean Paul Latyr Faye Alassane Traoré Ababacar Sadikhe ndao Institute of Applied nuclear Technology University Cheikh Anta Diop Dakar Senegal International Cancer Center of Dakar Dakar Senegal Department of Physics Faculty of Sciences and Technology University Cheikh Anta Diop Dakar Senegal

The most crucial requirement in radiation therapy treatment planning is a fast and accurate treatment planning system that minimizes damage to healthy tissues surrounding cancer cells. The use of Monte Carlo toolkits has become indispensable for research aimed at precisely determining the dose in radiotherapy. Among the numerous algorithms developed in recent years, the GAMOS code, which utilizes the Geant4 toolkit for Monte Carlo simula-tions, incorporates various electromagnetic physics models and multiple scattering models for simulating particle interactions with matter. This makes it a valuable tool for dose calculations in medical applications and throughout the patient’s volume. The aim of this present work aims to vali-date the GAMOS code for the simulation of a 6 MV photon-beam output from the Elekta Synergy Agility linear accelerator. The simulation involves mod-eling the major components of the accelerator head and the interactions of the radiation beam with a homogeneous water phantom and particle information was collected following the modeling of the phase space. This space was po-sitioned under the X and Y jaws, utilizing three electromagnetic physics mod-els of the GAMOS code: Standard, Penelope, and Low-Energy, along with three multiple scattering models: Goudsmit-Saunderson, Urban, and Wentzel-VI. The obtained phase space file was used as a particle source to simulate dose distributions (depth-dose and dose profile) for field sizes of 5 × 5 cm2 and 10 × 10 cm2 at depths of 10 cm and 20 cm in a water phantom, with a source-surface distance (SSD) of 90 cm from the target. We compared the three electromagnetic physics models and the three multiple scattering mod-els of the GAMOS code to experimental results. Validation of our results was performed using the gamma index, with an acceptability criterion of 3% for the dose difference (DD) and 3 mm for the distance-to-agreement (DTA). We achieved agreements of 94% and 96%, respective

关键词： GAMOS Monte Carlo LInAC Radiotherapy Dose Distribution Phase Space Gamma Index 6 MV Photon Beam

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Size-dependent activity of Fe-n-doped mesoporous carbon nanoparticles towards oxygen reduction reaction

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Green Carbon 2024年第2期2卷 221-230页

作者： Yilun Zhao Zhengbin Tian Wenquan Wang Xiaohui Deng jo-Chi Tseng Guanghui Wang Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Shandong Energy Institute Qingdao 266101China Qingdao new Energy Shandong Laboratory Qingdao 266101China University of Chinese Academy of Sciences Beijing 100049China Japan Synchrotron Radiation Research Institute Hyogo 679-5198Japan

The rational design of Fe–n–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction reaction(ORR).In this study,an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles(ranging from 130 nm to 60 nm and 35 nm,respectively)that feature spiral mesopores on their surface(SMCs).next,atomically dispersed Fe–nx sites are fabricated on the size-tunable SMCs(Fe1/SMC-x,where x represents the SMC size)and the size-dependent activity toward ORR is *** is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs,where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V *** in KOH electrolyte,indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–nx *** addition,when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries(ZABs),it delivers a higher open-circuit voltage(1.514 V),a greater power density(223 mW cm^(−2)),and a larger specific capacity/energy than Pt/C-based *** results further highlight the potential of Fe1/SMC60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.

关键词： Soft-templating approach Size-dependent activity Fe-n-C catalyst Oxygen reduction reaction Zinc-air battery

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Low-Cost and Biodegradable Thermoelectric Devices Based on van der Waals Semiconductors on Paper Substrates

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Energy & Environmental Materials 2024年第1期7卷 201-206页

作者： Gulsum Ersu Carmen Munuera Federico J.Mompean Daniel Vaquero jorge Quereda joão Elias F.S.Rodrigues jose A.Alonso Eduardo Flores jose R.Ares Isabel J.Ferrer Abdullah M.Al-Enizi Ayman nafady Sruthi Kuriakose joshua O.Island Andres Castellanos-Gomez Materials Science Factory Instituto de Ciencia de Materiales de Madrid(ICMM-CSIC)Madrid E-28049Spain nanotechnology Group USAL-NanolabUnivesidad de SalamancaSalamanca Junta de Castilla y León 37007Spain GISC Departamento de Física de MaterialesUniversidad Complutense de MadridMadrid E-28040Spain Departamento de Física Aplicada Centro de Investigación y Estudios AvanzadosMérida 97310Mexico MIRE Group Departamento de Física de MaterialesUniversidad Autónoma de MadridMadrid E-28049Spain Instituto nicolás Cabrera Universidad Autónoma de MadridMadrid E-28049Spain Department of Chemistry College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Department of Physics and Astronomy University of Nevada Las VegasLas Vegas NV 89154USA

We present a method to fabricate handcrafted thermoelectric devices on standard office paper *** devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(n-type semiconductors),deposited by simply rubbing powder of these materials against *** thermoelectric properties of these semiconducting films revealed maximum Seebeck coefficients of(+1.32±0.27)mV K^(-1)and(-0.82±0.15)mV K^(-1)for WS_(2)and TiS_(3),***,Peltier elements were fabricated by interconnecting the P-and n-type films with graphite electrodes.A thermopower value up to 6.11 mV K^(-1)was obtained when the Peltier element were constructed with three *** findings of this work show proof-of-concept devices to illustrate the potential application of semiconducting van der Waals materials in future thermoelectric power generation as well as temperature sensing for low-cost disposable electronic devices.

关键词： paper-based electronics Seebeck effect semiconductors thermoelectrics van der Waals materials

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Visible-light-activated n-doped CQDs/g-C3n4/Bi2WO6 nanocomposites with different component arrangements for the promoted degradation of hazardous vapors

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journal of Materials Science & Technology 2020年第5期40卷 168-175页

作者： Mi Gyeong Kim Wan-Kuen jo Department of Environmental Engineering Kyungpook National University 80 University RoadBukguDaegu702-701Republic of Korea

To investigate whether the arrangement of componentsin multi-composite photocatalysts may affect their photocatalytic properties,due to different charge-transfer routes,two ternary-nanocomposite photocatalysts with different component arrangements,comprising n-doped carbon quantum dots(nCQDs),g-C3n4(Cn),and Bi2WO6(BWO)(hereafter referred to as nCQDs/Cn/BWO),were developed,and the photocatalytic degradation of model hazardous vapors under visible-light illumination was *** I nCQDs/Cn/BWO,which was developed by the combination of nCQDs/BWO and Cn,exhibited photocatalytic ability superior to that of type II nCQDs/Cn/BWO,which was developed by the combination of Cn/BWO and nCQDs;the superior photocatalytic ability corresponded to the dual properties of nCQDs:charge mediation and upconversion ***,the photocatalytic ability of nCQDs/Cn/BWO was greater than those of the reference catalysts;in addition,this photocatalyst exhibited outstanding photochemical ***,the effects of Cn/(BWO+Cn)weight ratio of the Cn/BWO dual nanocomposites and the nCQDs/(BWO+Cn+nCQDs)weight percentage of nCQDs/Cn/BWO ternary nanocomposites on the pollutant removal efficiency were *** plausible mechanisms over the two nCQDs/Cn/BWO photocatalysts for the degradation of hazardous vapors were *** component arrangement approach proposed herein afforded a technique toward the perceptive development of novel multi-component heterostructures for the photocatalytic degradation of hazardous vapors.

关键词： Component arrangement Charge-transfer route nCQDs dual role Charge mediator Upconversion photoluminescence

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Structural metamaterials with negative mechanical/thermomechanical indices: A review

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Progress in natural Science:Materials International 2021年第6期31卷 801-808页

作者： jo?o O.Cardoso jo?o Paulo Borges Alexandre Velhinho CEnIMAT/i3n Departamento de Ciência dos Materiais Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa

Structural metamaterials presenting negative values of one or more mechanical and thermomechanical indices–namely the Poisson's ratio, the linear compressibility, and the coefficient of thermal expansion – are the promising candidates to the applications in many fields, ranging from precision mechanics to biomedical devices or energy absorption. Although scattered mentions may be found in the literature since the late eighties of 20th century, the systematic research efforts concerning these materials became effective much later. The present work is to review the main scientific contributions to the topic in the last five years. This paper first deals with those metamaterials showing a single negative index, and then proceeds to analyze the much less frequent instances of coupled negative indices, with emphasis on the so-called anepectic case, which exhibits an unusual thermomechanical response.

关键词： Mechanical and thermomechanical metamaterials Auxetic Anepectic negative Poisson's ratio negative thermal expansion negative linear compressibility

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Arlenea delicata *** ***.,a new ephedroid plant from the Early Cretaceous Crato Formation,Araripe Basin,northeast Brazil

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Plant Diversity 2024年第3期46卷 362-371页

作者： Alita Maria neves Ribeiro Yong Yang Antonio Alamo Feitosa Saraiva Renan Alfredo Machado Bantim joao Tavares Calixto Junior Flaviana jorge de Lima Programa de Pos-Graduaçao em Diversidade Biologica e Recursos naturais Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil Co-Innovation Center for Sustainable Forestry in Southern China College of Biology and the Environment159 Longpan RoadNanjing Forestry UniversityNanjing210037China Laboratorio de Paleontologia Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil Laboratorio de Estudos da Flora Regional Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil Gondwanan Plants Lab Universidade Federal de PernambucoCentro Academico de VitoriaRua Do Alto Reservatorio S/nBela Vista55608-680Vitoria de Santo AntaoPernambucoBrazil Programa de Pos-Graduaçao em Geociencias(PPGEOC) Universidade Federal de Pernambuco(UFPE)Rua Av.da ArquiteturaS/n°CEP-50740-550Cidade UniversitariaRecifePernambucoBrazil

Ephedroid macrofossils have been widely documented in Cretaceous deposits,including numerous from the Lower Cretaceous Yixian Formation of nE ***,few ephedroid macrofossils have been reported from South ***,we describe a new plant of the family Ephedraceae,Arlenea delicata *** ***.,from the Lower Cretaceous Crato Formation of the Araripe Basin,northeast Brazil,based on the vegetative and reproductive *** has the typical morphological characteristics of ephedroid plants,including fertile reproductive branches,opposite phyllotaxy,terminal female cones,a sympodial branching system,longitudinally striated internodes,and swollen *** new finding is unusual in having inner chlamydosperms subtended by two pairs of bracts,reproductive units connected to branches through swollen receptacles and a smooth seed *** new ephedroid taxon from the Crato Formation increases our understanding of plant diversity of this group during the Early ***,the general morphology(fleshy bracts and enlarged receptacles)of this new fossil discovery indicates that seeds of this plant may have been dispersed by animals such as pterosaurs(mainly the Tapejaridae)and birds(Enantiornithes and Ornituromorpha).If true,this would explain the cosmopolitan distribution of Ephedraceae in the Lower Cretaceous.

关键词： Early Cretaceous Gnetophytes Arlenea delicata Ephedrales Crato Formation

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Disseminated cutaneous leishmaniasis due to Leishmania(Leishmania) amazonensis in human immunodeficiency virus(HIV)-infected patients: A report of two cases

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Asian Pacific journal of Tropical Medicine 2021年第6期14卷 281-284页

作者： Camila F Araújo Iara B n Oliveira Murilo B Silveira Fátima Ribeiro-Dias Hospital de Doenças Tropicais Doutor Anuar Auad GoiâniaGoiásBrazil Laboratório de Imunidade natural(LIn) Instituto de Patologia Tropical e Saúde PúblicaUniversidade Federal de GoiásGoiâniaGoiásBrazil

Rationale: Co-infection of human immunodeficiency virus(HIV) and Leishmania spp. has impact on clinical and therapeutic outcomes of leishmaniases. Most studies do not present the identification of Leishmania species causing American tegumentary leishmaniasis in co-infections. In the Americas, Leishmania(L.) Viannia(V.) braziliensis and L.(V.) guyanensis have been identified. Patient concerns: In this study, two cases of American tegumentary leishmaniasis in patients infected with HIV are described. Patients presented several lesions with rapid dissemination and mucosal involvement. Diagnosis: Disseminated cutaneous leishmaniasis caused by L. amazonensis was identified by molecular test. Interventions: The patients were treated with conventional therapies for HIV infection and American tegumentary leishmaniasis. Outcomes: In co-infection, the clinical manifestations are atypical and the treatment response can be impaired. Lessons: These cases show that HIV infection impacts L. amazonensis infection and point to the relevance of identifying Leishmania species, which can lead to a better patient management.

关键词： Leishmania amazonensis HIV Disseminated cutaneous leishmaniasis Case report

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An AUTOMATED REFEREnCE POInT-LIKE APPROACH FOR MULTicRITERIA SHORTEST PATH PROBLEMS

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journal of Systems Science and Systems Engineering 2006年第3期15卷 314-329页

作者： joo C. n.CLíMACO josé M.F.CRAVEIRInHA Marta M.B.PASCOAL Faculdade de Economia da Universidade de Coimbra Avenida Dias da Silva 165 3004-512 CoimbraPortugal.Instituto de Engenharia de Sistemas e Computadores-CoimbraRua Antero de Quental 199 3000-033 Coimbra Portugal Instituto de Engenharia de Sistemas e Computadores-Coimbra Rua Antero de Quental 199 3000-033 Coimbra Portugal.Departamento de Engenharia Electrotécnica e ComputadoresPolo II da Universidade de Coimbra Pinhal de Marrocos3030-290 CoimbraPortugal Instituto de Engenharia de Sistemas e Computadores-Coimbra Rua Antero de Quental 1993000-033 CoimbraPortugal.Departamento de MatemáticaPolo I da Universidade de CoimbraApartado 30083001-454 CoimbraPortugal

In this paper we introduce a method of analysis for the automated ordenng and selection or solutions of a multicriteria shortest path model. The method is based on a reference point approach, where the paths in a specific priority region are ranked by non-decreasing order of a Chebyshev metric. In order to list paths according with this objective function a labelling algorithm is proposed. The developed method is applied in a video-traffic routing context. Computational results are presented and analysed, for randomly generated networks of significant dimension.

关键词： Routing automated decision multicriteria reference point

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jo.nt member angle limits of composite beams and CFT square columns

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journal of Central South University 2013年第1期20卷 199-206页

作者： LEE Seung-jo LEE Kang-Guk Department of Architecture Chosun College of Science & Technology Research Center for Urban Affair Kyungil University

This work aims to understand the relationship between the member angle limit and the energy ratio for 24 test samples of composite beams and CFT square steel tube columns. This work also compares the formula applicability for member angle limit with the previous test result to provide the basic data for the design of composite beam-CFT column. The evaluation of the member angle limit was performed with concrete compressive strength (fC =22.16 MPa, 30.49 MPa), breadth-to-thickness ratio (B/t=25.0, 33.3, 43.5), and axial capacity ratio (n/n0=0, 0.3, 0.4, 0.5) as the main variables of the test samples. For the relationship between the member angle limit (Ru) and the energy ratio (ES/EC ), the test result shows that the energy ratio becomes lower as the axial capacity ratio and the breadth-to-thickness ratio increase. The energy ratio is lower for the Type B test sample compared with that of Types A and C. For the formula suggested by SATO, the test samples are distributed evenly for comparison between test values and the member angle limit; however, other formulas indicate a deviation. Specifically, for the comparison between R u,cal and R u (Test), Maeda's formula shows severe deviation.

关键词： square steel tube axial capacity ratio member angle limit breadth-to-thickness ratio

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Influence of Microstructures on Polarization Resistance and Hydrogen-Induced Cracking of a Micro-Alloyed Steel Submitted to Different Cooling Rates

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journal of Iron and Steel Research International 2011年第S1期18卷 168-172页

作者： González M R Martins de Araújo D S Goldenstein H Alonso-Falleiros n Departamento de Engenharia Metalúrgica e de Materiais EscolaPolitécnicaUniversidade de Sao Paulo-SP-Brasil

The effect of different microstructures on the polarization resistance (Rp) and the hydrogen-induced cracking (Hic) of a micro-alloyed steel austenitized and submitted to different cooling rates was *** 19.1 x 6 x 2 mm,containing the whole thickness of the plate were extracted from a 20 mm plate and heat treated on a quenching dilatometer,were submitted to Rp and Hic corrosion *** Rp and Hic tests followed as close as possible ASTM G59 and nACE standard TM0284-2003,in this case,modified only with regard to the size of the *** samples transformed from austenite by a slow cooling (cooling rate of 0.5℃.s-1) showed higher susceptibility to hydrogen-induced cracking,with large cracks in the middle of the sample propagating along segregation bands,corresponding to the centerline of the plate *** cooling rates of 10℃.s-1,only small cracks were found in the matrix and micro cracks nucleated at non-metallic *** higher cooling rates (40℃.s-1) very few small cracks were detected,linked to non-metallic *** result suggests that structures formed by polygonal structures and segregation bands (were eutectoid microconstituents predominate) have higher susceptibility to *** predominantly formed by acicular ferrite make it difficult to propagate the cracks among non-oriented and interlaced acicular ferrite *** segregation bands containing eutectoid products also help inhibit cracking and crack propagation;segregation bands can function as pipelines for hydrogen diffusion and offer a path of stress concentration for the propagation of cracks,frequently associated to non-metallic *** resistance essays performed on the steel in theas received condition,prior to any heat treatment,showed larger differences between the regions of the plate,with a considerably lower Rp in the *** austenitization heat treatments followed by cooling rates of 0.5 e 10℃.s-1 made more uniform the

关键词： hydrogen induced cracking polarization resistance micro-alloyed steel control cooling

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