Shape Memory Polymer Composite Booms with Applications in Reel-Type Solar Arrays

Solar arrays are the primary energy source for spacecraft.Although traditional rigid solar arrays improve power supply,the quality increases proportionally.Hence,it is difficult to satisfy the requirements of high-power and low-cost space applications.In this study,a shape-memory polymer composite(SMPC)boom was designed,fabricated,and characterized for flexible reel-type solar arrays.The SMPC boom was fabricated from a smart material,a shape-memory polymer composite,whose mechanical properties were tested.Additionally,a mathematical model of the bending stiffness of the SMPC boom was developed,and the bending and buckling behaviors of the boom were further analyzed using the ABAQUS software.An SMPC boom was fabricated to demonstrate its shape memory characteristics,and the driving force of the booms with varying geometric parameters was investigated.We also designed and manufactured a reel-type solar array based on an SMPC boom and verified its self-deployment capability.The results indicated that the SMPC boom can be used as a deployable unit to roll out flexible solar arrays.

2008,Sporting Show Booms at the Right Time

The year of 2008 is the year of Olympic.The city of Beijing,being the host city for the game,implicates numerous potential business opportunities significantly,especially for the sporting goods industry. In china,due to the abundant labor resources,market potentials and favorable policies,the sporting goods industry has developed markedly:within more than 50 years,it

BORDER TRADE BOOMS IN TIBET——An Interview With Director Benba

Benba,38,is Director ofthe BorderTrade Bureau of the TibetAutonomous Region.Born andbrought up in Xigaze,he talkedabout booming border trade in Tibet duringmy recent interview.

Construction Booms in Lhasa

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Deployment Characteristics of Braid Coated Bi-Convex Tape and Bi-SMA Convex Tape Booms for Deployable Membrane Structures

The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON （braid coated bi-convex tape） boom and the SMA-BCON （braid coated bi-shape memory alloy convex tape） boom. Both booms are developed for the deployable membrane structures such as solar sails, thin membrane solar array panels, deorbit mechanisms for small satellites and reflectors of space solar power satellite, etc. BCON booms can store around polygonal or cylindrical center hub, and the booms can deploy by the stepwise manner by releasing a constraint mechanism which pins the boons into two or three points for the total length. SMA-BCON booms are mainly developed for a square center body systems, and SMA is adapted on the bent po^nts of the booms where stored around each edge of the center hub. Through the deployment experiments of both booms, the stepwise deployment behavior and its tendency are obtained. The design concept of BCON boom and SMA-BCON hnnm i~ demonstrated through this study.

Boom Box 3爆炸机独立激发新模式应用开发与测试

随着国内外节点仪的应用,采用全节点仪采集的项目越来越多,有线地震仪的井炮激发方式已经不能完全适用于全节点采集系统,因此,针对全节点采集项目,以“去有线采集系统和无线电台通讯网络”为核心思路,开发出基于Boom Box 3爆炸机的独立激发新模式。本文通过对独立激发新模式的研发思路、放炮操作流程、炮后信息下载以及测试等各方面进行了详细介绍,最后,对基于Boom Box 3爆炸机独立激发新模式的优点进行了分析。

Boom Box3爆炸机独立激发模式简介及应用

Boom Box3爆炸机独立激发模式是一种全新理念的井炮高效采集模式,它基于GPS进行授时定位,基于WiFi-HTML技术进行参数设置和炮后信息处理,基于“时间槽”隔离技术进行自主激发,在复杂地形施工条件下,能够有效提高地震采集效率。本文介绍了Boom Box3爆炸机,对Boom Box3独立激发模式的原理、特点进行了分析,通过Boom Box3独立激发模式测试、应用实例及效果分析,认为该技术有助于提高南方山地和黄土塬地区全节点采集项目的施工效率,降低施工成本。

ARCADE 2 Spatial Roar, What Theory of Relation Reveals

The theory of Relation provides an explanation for the Arcade 2 excess. It assumes that the isotropic radio emission measured by the Arcade 2 Collaboration, which is 5 - 6 times brighter than the expected contributions from known extra-galactic sources, is the residue of an immense primitive energy of ordinary matter released by a relativistic bang almost 100 million years after the big bang, which gave the mass-energy the missing gravity to activate contraction. This relativistic bang, via a Lorentz energy transformation, would have released enormous energy held to be the source of the powerful radio noise detected by the NASA researchers. This transformation would have simultaneously triggered the formation of the first stars from dense gas and the reionization of less dense neutral gas. This departs from the idea that continuous reionization began after the formation of the first stars. We emphasize the importance of primordial magnetic fields, which would have generated significant density fluctuations during recombination and acted as a direct seed for cosmic structures. The first stars and galaxies were bathed in strong magnetic fields that gave rise to the radio microwave din (boom) discovered by Arcade 2. These intense magnetic fields alter the trajectory of charged particles zooming near the speed of light, triggering the space roar and emitting radiation that forms a synchrotron radio background. The theory of Relation offers an alternative to the Lambda-CDM cosmological model, which has become the standard model of the big bang, which leads straight to the vacuum catastrophe.

Upgrade and Renovation of Steel Billet Scalein front of High-speed Wire Furnace

This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit,and analyzes and summarizes the problems existing in the original weighing device for steel billets in production and use.Based on on-site installation conditions,design a new weighing method,match a large range weighing sensor,upgrade the automation control of the weighing device,and remotely transmit the billet weighing data to the MES system of the group.The automatic,stable,reliable,and accurate measurement of steel billet raw materials has been achieved,providing important guarantees for the accurate measurement of production line billet and product yield.

Excess Liquidity,Housing Price Booms and Policy Challenges in China

Incorporating asymmetric cost and benefit of supplying excess liquidity into an otherwise standard time inconsistency model this paper offers an explanation of the excess liquidity and housing price booms recently experienced in China. We find that the central bank＇s incentive to stimulate eeonomie growth with excess liquidity fuels real estate prices and accelerates inflation bias. Therefore, the central bank should free itself from the pressure to achieve an economic growth rate higher than the potential level and assign an appropriate weight to the real estate price fluctuations in the central bank＇s objective function, so that the central bank ＂s policy of stimulating economic growth with excess liquidity can be constrained.

Solar sail attitude control using shape variation of booms

Active attitude control of solar sails is required to control the direction of the force generated by Solar Radiation Pressure(SRP). It is desirable to control the attitude through propellantfree means. This paper proposes a new method for attitude control of solar sails: A boom consisting of "smart" structural material can be deformed by the piezoelectric actuator, and Solar Radiation Pressure torque will be generated due to shape variation of sail membrane caused by boom deformation. The method has the advantages of simple structure, small disturbance and small additional load, and is not limited by the size of the solar sail. The case of rendezvous with the Asteroid 2000SG344 is used to verify the attitude control around the pitch and yaw axes.

Model Design and Development of a Telescopic Palm Fruit Harvester

This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine system development, the material for each component of the machine system was first selected, the boom length, maximum boom angle, force and stroke length of each hydraulic cylinder, the hydraulic pump pressure, base weight, permissible weight of the cutting system and power required were then calculated in the design analysis. Furthermore, from the calculated parameters, the model of the system was created using SolidWorks engineering software, the model was developed and tested. The result shows that the cutting time of the system for one bunch of palm fruit was longer when compared to conventional systems. It was concluded that though the machine is maintenance friendly and portable, further improvements in its design are necessary so as to develop a system that will give desirable economic output at a shorter time.

Influence of Section Size of Telescopic Boom on Stability

The telescopic boom is the main bearing force component of the crane.The rationality of the design will directly affect the performance of the machine and safety.The telescopic boom is a typical thin-walled plate and shell structure.Its main form of damage is the occurrence of buckling,resulting in decreased carrying capacity,or even a security incident.In order to meet the lifting weight and height,to ensure the stability of the telescopic boom has become a major problem of the designer.There are many factors that affect the critical load of the telescopic boom,including support method,inertia moment,length and material.When the support mode,material and length are determined,the maximum factor affecting the buckling critical load is the inertia moment.In this paper,the influence of the section size on the buckling critical load of the telescopic boom is analyzed by using the inertia moment of section method ande finite element method.And the sensitivity analysis is carried out on this basis.The results of the analysis can provide designers with design reference basis.Then a reasonable cross-sectional size can be used to improve the buckling resistance capacity of the telescopic boom.

Boom Box Ⅲ黑屏故障原因及解决方法

Boom BoxⅢ是具有自主激发功能的新一代爆炸机,在激发完成后可自动记录GPS激发时间、坐标位置及井口时间等关键激发信息。这些信息被自动记录到内部CF存储卡上,可以被重复下载供节点仪器切分数据使用,或作为炮点的质控数据。但在实际使用中,Boom BoxⅢ经常发生不明原因的黑屏故障,造成炮点激发信息丢失,不得不重新打井、补炮,给项目生产造成额外的工作量。本文基于实验结果重点分析了故障发生的原因,并和厂家合作找到了解决办法,通过优化爆炸机内部结构,加装元器件,解决了爆炸机黑屏现象。