Temperature-Controlled Clamping and Releasing Mechanism

A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of approx. =180 K and approx. =293 K. The mechanism satisfied a need specific to a program that involved repeated excursions of a spectrometer between a room-temperature atmospheric environment and a cryogenic vacuum testing environment. The mechanism was also to be utilized in the intended application of the spectrometer, in which the spectrometer would be clamped for protection during launch of a spacecraft and released in the cold of outer space to allow it to assume its nominal configuration for scientific observations. The mechanism is passive in the sense that its operation does not depend on a control system and does not require any power other than that incidental to heating and cooling. The clamping and releasing action is effected by bolt-preloaded stacks of shape-memory-alloy (SMA) cylinders. In designing this mechanism, as in designing other, similar SMA mechanisms, it was necessary to account for the complex interplay among thermal expansion, elastic and inelastic deformation under load, and SMA thermomechanical properties

Multiple-Cone Sunshade for a Spaceborne Telescope

A document describes a sunshade assembly for the spaceborne telescope of the Terrestrial Planet Finder Coronagraph mission. During operation, the telescope is aimed at target stars in the semihemisphere away from the Earth's Sun. The observatory rotates about its pointing axis during a single star observation, resulting in relative movement of the Sun. The sunshade assembly protects the telescope against excessive solar-induced thermal distortions for times long enough to complete observations. The assembly includes a cylindrical baffle immediately surrounding the telescope, and a series of coaxial conical shields at half-cone angle increments of between 3 and 6. The black inner surface of the cylindrical baffle suppresses stray light. The outer surface of the cylindrical baffle and all the surfaces of the conical shields except the outermost one are specular and highly reflective in the infrared. The outer surface of the outer shield is a material with low solar absorptance and high infrared emittance, such as silverized Teflon or white paint. This arrangement strongly radiatively couples each shield layer more effectively to cold space than to adjacent shield layers. The result is that the solar-driven temperature gradients in the cylindrical baffle are nearly negated, and only weakly communicated to the highly-infrared-reflective face of the primary telescope mirror

Soa Reference Architecture Blueprint

Service Oriented Architecture (SOA) is a framework for integrating business processes and supporting IT infrastructure as secure, standardized components services that can be reused and combined to address changing business priorities. Services are the building blocks of SOA and new applications can be constructed through consuming these services and orchestrating services within a business process. In SOA, services is map to the business functions that are identified during business process analysis. Upon a successful implementation of SOA, the enterprise gain benefit by reducing development time, utilizing flexibility and responsive application structure, and following dynamic connectivity of application logics between business partners. This paper presents SOA reference architecture blueprint as the building blocks of SOA which is services, service components and flows that together support enterprise business processes and the business goals. Layanan Berorientasi Arsitektur (SOA) merupakan framework untuk mengintegrasikan proses bisnis dan mendukung infrastruktur TI secara aman, layanan komponen standar yang dapat digunakan kembali dan dikombinasikan untuk mengatasi Perubahan prioritas bisnis. Layanan merupakan blok bangunan SOA, di mana aplikasi baru dapat dibangun melalui konsumsi layanan ini dan merancang layanan dalam proses bisnis. Dalam SOA, layanan dipetakan ke fungsi bisnis yang diidentifikasi selama analisis proses bisnis. Setelah keberhasilan implementasi SOA, Perusahaan memperoleh keuntungan diantaranya mengurangi waktu pengembangan, memanfaatkan fleksibilitas dan struktur aplikasi responsif, dan mengikuti konektivitas dinamis dari logika aplikasi antara mitra bisnis. Paper ini menyajikan cetak biru referensi arsitektur SOA sebagai blok bangunan SOA yang merupakan komponen pelayanan jasa, dan arus yang bersama-sama mendukung proses bisnis Perusahaan dan tujuan bisnis

The Ursinus Weekly, April 27, 1959

Annual Spring retreat at Camp Mensch Mill, May 1-3 • Gold Cadillac chosen to be Spring production • Drummond, Haigh pitch Ursinus win against LaSalle • IF marked by picnics, parties and track contest • Students working abroad take funds for return • Vern Morgan stars against Haverford and F&M teams • Modern art in religion topic illustrated by Martin Zipin in talk • Snyder pres. of WSGA; Witmer, Moore head Y • UC baseball team trounces Fords and Engineers • UC Women\u27s Club fetes seniors to annual party • Editorial: Purpose • Professor opinion: Dr. William J. Phillips • Numbers • Becoming a student • Girls teams down opponents 15-2, 8-5 • Swarthmore beats UC 9-0 in tennis • Morgan beats 3 records; Aims for 4th Wednesday • Flora McQueen chosen for moderator of May Day • Mumford talks on Wright\u27s conceithttps://digitalcommons.ursinus.edu/weekly/1384/thumbnail.jp

Jitter studies for the secondary and tertiary mirror systems on the Thirty Meter Telescope

The Secondary Mirror System (M2S) and Tertiary Mirror System (M3S) of the Thirty Meter Telescope (TMT) consist of passively mounted mirrors supported in kinematic cell assemblies that are moved during telescope tracking to counteract effects of changing zenith angle and thermal gradients within the telescope structure. TMT is concerned that the requirements for pointing jitter during Adaptive Optics tracking for the M2 and M3 Systems are very challenging with a risk of requiring complex stabilization systems for compliance. Both systems were researched to determine whether similar un-stabilized hardware exists that can meet the TMT jitter requirements. Tests using representative TMT tracking motions were then performed to measure jitter on similar existing hardware. The results of these hardware tests have been analyzed. Test results, remaining risk assessment and further testing plans are presented

The Application of Pentaprism Scanning Technology on the Manufacturing of M3MP

The PSS (pentaprism scanning system) has advantages of simple structure, needless of reference flat, be able of on-site testing, etc, it plays an important role in large flat reflective mirror’s manufacturing, especially the high accuracy testing of low order aberrations. The PSS system measures directly the slope information of the tested flat surface. Aimed at the unique requirement of M3MP, which is the prototype mirror of the tertiary mirror in TMT (Thirty Meter Telescope) project, this paper analyzed the slope distribution of low order aberrations, power and astigmatism, which is very important in the manufacturing process of M3MP. Then the sample route lines of PSS are reorganized and new data process algorism is implemented. All this work is done to improve PSS’s measure sensitivity of power and astigmatism, for guiding the manufacturing process of M3MP

Hydraulic supports for polishing TMT M3MP

For polishing the ultra-thin TMT M3MP, a polishing support system with 18 hydraulic supports (HS) is introduced. This work focuses on the designing and testing of these HSs. Firstly the design concept of HS system is discussed; then mechanical implementation of the HS structure is carried out, with special consideration of fluid cycling, work pressurization and the weight component. Afterward the piping installation and the de-gas process for the working fluid are implemented. Pressurization and stiffness are well checked before system integration for the single HS unit. Finally the support system is integrated for the polishing process

Edge control in a computer controlled optical surfacing process using a heterocercal tool influence function

Edge effect is regarded as one of the most difficult technical issues in a computer controlled optical surfacing (CCOS) process. Traditional opticians have to even up the consequences of the two following cases. Operating CCOS in a large overhang condition affects the accuracy of material removal, while in a small overhang condition, it achieves a more accurate performance, but leaves a narrow rolled-up edge, which takes time and effort to remove. In order to control the edge residuals in the latter case, we present a new concept of the ‘heterocercal’ tool influence function (TIF). Generated from compound motion equipment, this type of TIF can ‘transfer’ the material removal from the inner place to the edge, meanwhile maintaining the high accuracy and efficiency of CCOS. We call it the ‘heterocercal’ TIF, because of the inspiration from the heterocercal tails of sharks, whose upper lobe provides most of the explosive power. The heterocercal TIF was theoretically analyzed, and physically realized in CCOS facilities. Experimental and simulation results showed good agreement. It enables significant control of the edge effect and convergence of entire surface errors in large tool-to-mirror size-ratio conditions. This improvement will largely help manufacturing efficiency in some extremely large optical system projects, like the tertiary mirror of the Thirty Meter Telescope