Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011最新文献_第10页

Probing of order parameters in magnetoelectric multiferroics by neutron diffraction 用中子衍射探测磁电多铁体的有序参数

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966891

K. Krezhov

{"title":"Probing of order parameters in magnetoelectric multiferroics by neutron diffraction","authors":"K. Krezhov","doi":"10.1109/RAST.2011.5966891","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966891","url":null,"abstract":"Neutron scattering methods are indispensable in studying structure-property relationships. Determination of spin arrangements in magnetically ordered materials makes neutron diffraction among the major tools in the research on multiferroics because to understand why a given compound displays or does not display the expected properties calls for detailed information on microscopic level. We describe the efforts to identify new candidate magnetoelectric materials based primarily on considerations of symmetry and the knowledge of the magnetic structure. We found that substitution of half manganese with iron introduces a low level of disorder between the two transition metal positions in the RFeMnO<inf>5</inf> (R=Tb,Yb) structure. The lack of evidence for a crystallographic phase transition to a polar space group rules out expectations of a spontaneous electric polarization. In addition, the observed collinear magnetic structure with k = 0 does not permit a spin polarization.. Therefore, by contrast to well known multiferroics RMn<inf>2</inf>O<inf>5</inf> (R=Tb,Yb), YbMnFeO<inf>5</inf> and TbMnFeO<inf>5</inf> is not expected to be multiferroic compounds. Other examples in this article include nanosize powder material from the mixed oxide system YFe<inf>x</inf>Cr<inf>1−x</inf>O<inf>3</inf> and Y-type hexaferrite multiferroic Ba<inf>2</inf>Mg<inf>2</inf>Fe<inf>12</inf>O<inf>22</inf> as well as antiferromagnetic La<inf>0.5</inf>Pb<inf>0.5</inf>FeO<inf>3</inf>.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117010445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new way of interplanetary transport 一种新的星际运输方式

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966923

A. Oláh

引用次数: 1

TURKSAT-3USAT: A 3U communication CubeSat with passive magnetic stabilization TURKSAT-3USAT:具有无源磁稳定的3U通信立方体卫星

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966949

A. Aslan, A. Sofyali, E. Umit, C. Tola, I. Oz, S. Gulgonul

引用次数: 8

Simulation Model Development Environment using 3 Dimensional Model-Based Approach 基于三维模型方法的仿真模型开发环境

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966877

Hoon-Hee Lee, Cheol-hea Koo, Ki-Lyuk Yong, M. Irvine

引用次数: 0

Spacecraft operator training from simulation to application 航天器操作员从模拟到应用的培训

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966888

O. Kalden, Christian D. Bodemann

引用次数: 0

Towards DMC microsatellites use in forest fire remote sensing: Case of Alsat-1 product-based false alarm rate assessment 面向DMC微卫星在森林火灾遥感中的应用:基于Alsat-1产品的虚警率评估案例

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966814

Mustapha Rebhi, A. Belghoraf

引用次数: 0

A cost-effective Software Development and Validation environment and approach for LEON based satellite & payload subsystems 为基于LEON的卫星和有效载荷子系统提供一种具有成本效益的软件开发和验证环境和方法

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966889

F. Cordero, Jose Mendes, B. Kuppusamy, Thomas Dathe, M. Irvine, Andy Williams

引用次数: 9

Constant thrust glideslope guidance algorithm for rendezvous in multi-body realm 多体空间交会的恒推力滑梯制导算法

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966831

Yijun Lian, Luhua Liu, Y. Meng, G. Tang, Ke-jun Chen

{"title":"Constant thrust glideslope guidance algorithm for rendezvous in multi-body realm","authors":"Yijun Lian, Luhua Liu, Y. Meng, G. Tang, Ke-jun Chen","doi":"10.1109/RAST.2011.5966831","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966831","url":null,"abstract":"A guidance algorithm for spacecraft approaching a target vehicle in a quasi-halo orbit in the real earth-moon system is presented. The algorithm is based on the numerical solution of the time-variant linearized relative dynamics of RTBP in inertial coordinates. The whole trajectory is divided into several segments. The multi-impulse glideslope idea, traditionally used in the near-earth rendezvous, is employed to obtain estimated velocity increment (delta-v) at the joint of two legs. The instantaneous delta-v, as a matter of fact, can not be implemented by any real engine because the thrust magnitude is always finite. Here, the obtained delta-v is translated into thrust duration in the context of a constant thrust magnitude, which is the most simple and robust type in real applications. Ignition and cutoff delays of the thruster are modeled. Current relative state is used to calculate the next delta-v and then flows to the following segment after thrusting in the delta-v direction for the transcribed time period. A thrusting arc is usually followed by a coast arc. The last segment is retuned by being further subdivided into another group of legs using updated control parameters, in order to counteract the strong nonlinearity in multi-body realm. The whole process ends after the last delta-v is dealt with. Simulation environment is established by using DE405 ephemeris, taking into account gravities of the earth, moon, sun, and all other planets. Monte Carlo analysis is conducted by considering the navigation error and the thrust direction error. Results show that the proposed guidance algorithm can effectively maintain control over the flight time with rather satisfactory final position and velocity accuracy.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116272254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Trajectory prediction tools for conceptual design of orbital and suborbital launch vehicles 轨道和亚轨道运载火箭概念设计的轨迹预测工具

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966926

I. Akbulut, A. Cilli, B. Seçkin

{"title":"Trajectory prediction tools for conceptual design of orbital and suborbital launch vehicles","authors":"I. Akbulut, A. Cilli, B. Seçkin","doi":"10.1109/RAST.2011.5966926","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966926","url":null,"abstract":"The need for three degrees of freedom (3DOF) trajectory calculation arises due to two key requirements: First, a precise 3DOF trajectory prediction is an important subroutine of a comprehensive conceptual design tool for launch vehicles, as the main purpose of such a tool is to design a vehicle that is capable of transporting a payload to the desired orbit as realistic as possible. Secondly, it is extremely important to determine the drop zones of separated stages or fairing of the launch vehicle with high accuracy regarding safety and reuse issues. Besides, it may be crucial to determine the landing position of payload in a suborbital launch. For early phases of the conceptual design process, 3DOF trajectory prediction is recommended practice for a satisfactory design analysis. This paper aims to present two different 3DOF trajectory prediction tools, developed simultaneously for both multistage suborbital and orbital launchers, called Sonda-M and Sonda-S. Trajectory predictions are carried out for REXUS-5 sounding rocket of Eurolaunch and predicted results are compared with campaign report accessed from open literature for further evaluation of developed tools.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122594304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multidisciplinary design optimization of an expendable launch vehicle 一次性运载火箭多学科设计优化

Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011 Pub Date : 2011-06-09 DOI: 10.1109/RAST.2011.5966932

Majid Hosseini, A. Toloie, M. Nosratollahi, A. Adami

引用次数: 5