The design of a source to simulate the gamma-ray spectrum emitted by a radioisotope thermoelectric generator

A simulated source was designed to duplicate the gamma spectrum of a uniform cylindrical 2200-watt Pu02 radioisotope thermoelectric generator containing 81% Pu-238 and 1.2 ppm Pu-236. Gamma rays from the decay of Pu-238, Am-241, Pu-239, and the 0-18(alpha,n)Ne-21 reaction were catalogued in broad energy groups. Two 46- and one 22-mc Th-228 sources provided simulation at various times in the life of the fuel capsule up to 18 years, which covers the time span of an outer planet mission. Emission from Th-228 represents the overwhelming contribution of the gamma spectrum after the first few years. The sources, in the form of 13-inch rods, were placed in a concentric hole in a cylinder of depleted uranium, which provided shielding equivalent to the self-shielding of the fuel capsule. The thickness of the U-238 cylinder (0.55cm) was determined by Monte Carlo calculations to insure that the spectrum emerging from the simulated source matched that of the fuel capsule

Task constraints of large-sided soccer games : effects of manipulating rewarding rules

The aim of the study was to examine how rewarding rules affects team tactical behaviour, players’ technical, physical and physiological performance in large-sided football games. An elite youth team (age: 14.0±0.2 years) performed 8 vs. 8 large-sided games under three experimental conditions: i) rewarding passing rule (PASS); ii) rewarding compact defending rule (COM); iii) control condition (CNT), using a Latin squared design. Positional data were used to compute effective play-space, team width, length, length-width ratio and approximate entropy, and capture distance covered and average speed displacement. Heart rate values were recorded using short-range radio telemetry. All bouts were filmed, and technical variables based on the TSAP were assessed. Magnitude-based inference and precision estimation was employed. Results showed mainly trivial and small differences between conditions for almost all variables. Received balls (RB) was the single variable that very likely increased with a moderate effect for COM compared to CNT. The small overall effects might indicate that rewarding rules effectiveness depends on i) creating affordances for the desired behaviour instead of trying to directly reward the behaviour; ii) its accordance with team identity; iii) its suitability to players’ skill level iv) combining rules with other coaching tools v) the timescale of exposure

Bibliophilia in Ottoman Aleppo: Muḥammad al-Taqawī and his Medical Library

Recent research has shown that book collecting by private individuals and institutions was a widespread phenomenon in Bilād al-Shām. At least from the Ayyubid period onwards, countless volumes were produced, changed hands in the book market, and lay around in libraries. To this day, Damascus occupies a central position in our knowledge about libraries and book culture in general, while other cities and regions lag behind. In this article, the inventory of an Aleppine book collector is used to take a glimpse at the book culture of Aleppo in the first decades of the seventeenth century. Although most probably not reflecting the sum total of his library, the inventory still allows to ascertain the specific taste of its compiler, an otherwise unknown Aleppine bibliophile. The inventory also provides evidence for the early distribution of Arabic print and pushes the door open for investigating the role of local agents in the early days of attempts by Orientalists to acquire Arabic manuscripts for European libraries

Activities of the RTG Radiation Test Laboratory Progress report, 1 Jul. - 31 Dec. 1969

Safety, gamma ray spectrum, and data analysis of SNAP fuel capsule

Basal lamina formation at the site of spinal cord transection

The pia-glial basal lamina (BL) at the site of spinal cord injury could be an important physical impediment to central nervous system regeneration. We used an epithelial BL-specific immunohistochemical stain to determine the location of the pia-glial BL after spinal cord transection. Small segments of BL were found at the margin of the lesion 5 days after transection. After 10 days, longer and more numerous segments were seen. At 20 days, the entire transected end of the spinal cord was capped by a layer of BL.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50298/1/410080204_ftp.pd

Reactive oxygen species in iridium-based OER catalysts

Tremendous effort has been devoted towards elucidating the fundamental reasons for the higher activity of hydrated amorphous IrIII/IV oxyhydroxides (IrOx) in the oxygen evolution reaction (OER) in comparison with their crystalline counterpart, rutile-type IrO2, by focusing on the metal oxidation state. Here we demonstrate that, through an analogy to photosystem II, the nature of this reactive species is not solely a property of the metal but is intimately tied to the electronic structure of oxygen. We use a combination of synchrotron-based X-ray photoemission and absorption spectroscopies, ab initio calculations, and microcalorimetry to show that holes in the O 2p states in amorphous IrOx give rise to a weakly bound oxygen that is extremely susceptible to nucleophilic attack, reacting stoichiometrically with CO already at room temperature. As such, we expect this species to play the critical role of the electrophilic oxygen involved in O–O bond formation in the electrocatalytic OER on IrOx. We propose that the dynamic nature of the Ir framework in amorphous IrOx imparts the flexibility in Ir oxidation state required for the formation of this active electrophilic oxygen

Application of the ABB ACS550 Frequency Converter in Electrical Drives Laboratory

Labori käigus saab seadistada sagedusmuundurit ABB ACS550 kasutatavale mootorile. Seadistada saab proovida automaatse sisseehitatud seadistamise funktsiooniga ning käsitsi parameetreid sisestades. Pärast automaatset seadistamist saab võrrelda leitud parameetreid mootori nimisildil olevatega. Mootorit on võimalik koormata hooratta ning pöörisvoolupiduriga. Katseid on võimalik sooritada erinevatel koormustel. Koormused on muudetavad piduri kontrollerist, kust saab rakendada ka käivituskõverat. Kasutades vektor- ja skalaarjuhtimist saab katsetada erinevaid käivitus- ja pidurdusvõimalusi. Vektor- ning skalaarjuhtimise erinevused tulevad selgelt katseandmetest välja. Ühendades seadme arvutiga läbi „COM“ pordi on võimalik muunduri juhtimist proovida ka otse arvutist, kasutades selleks tarkvara „Drive window light 2“. Arvutist on muudetavad kõik parameetrid, mida saab muuta juhtpaneelilt. Jooniste vormistamise jaoks saab antud programmist tehtud katse andmed salvestada. Kaugjuhtimise proovimiseks saab muundurile lülitada kaks lukustuvat lülitit ning potentsiomeetri. Lülitite abil on võimalik mootorit käivitada, peatada ning reversseerida. Potentsiomeetriga saab muuta mootori pöörlemiskiirust. Tagasisidet on võimalik saada piduri juhtkontrollerist, läbi piduri võllile kinnitatud anduri. Tagasisidega peab sagedusmuundur suutma taastada kasutaja poolt sisestatud väärtuse koormuse kasvades või langedes.The aim of this paper is to come up with ways in order to use the ABB ACS550 AC drive in the motor controllers laboratory as a part of the motor controllers basics course and give some knowledge about variable frequency drives. Compared to the older device which is currently in use in the laboratory, the ACS550 has more functions. Because of the improved display, it makes using the device easier. The drive can be connected to a computer to get accurate readings of the experiments, which data can be automatically stored. Firstly, the students have to set the drive parameters to the motor they are going to use. This can be done automatically by the drive or manually. Both vector- and scalar control modes can be tested. After which, the differences between the two should become clear. The device can be configured to work in remote mode. Feedback from the brake controller can be used in order to see how feedback works

Ribosoomivalkude vahetus Escherichia coli rakkudes

Ribosoomid viivad läbi valkude sünteesi kõikides elusorganismides. Muutused ribosoomi struktuuris on haruldased ning nende mõjud tema efektiivsusele on tugevad. Valguvahetuse jälgimine in vivo tingimustes on vajalik selleks, et mõista selle rolli eluslooduses. Käesoleva töö raames kirjeldatakse meetodit, mille abil näidatakse ribosoomivalkude vahetust erinevates rakkude kasvufaasides in vivo tingimustes. Töö põhjal järeldatakse, et enamus ribosoomivalke on võimelised vahetuma ribosoomides