Search results for "block"
showing 10 items of 1177 documents
Structural modelling and mechanical tests supporting the design of the ATHENA X-IFU thermal filters and WFI optical blocking filter
2018
Copyright 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. ATHENA is a Large high energy astrophysics space mission selected by ESA in the Cosmic Vision 2015-2025 Science Program. It will be equipped with two interchangeable focal plane detectors: the X-Ray Integral Field Unit (X-IFU) and the Wide Field Imager (WFI). Both detectors require x-ray transparent filters to fully exploit their sensitivity. In order to maximize the X-ray tra…
Memory effects in single-electron nanostructures
2001
We investigate the memory function at room temperature in devices based on quantum dots. By Low Pressure Chemical Vapour Deposition (LPCVD) we deposited Si dots embedded in SiO2. On these devices flat band voltage shifts were well detected at low write voltages for write times of the order of milliseconds, and furthermore, a plateau in the flat band voltage shift, maybe consequence of Coulomb blockdale, was observed.
Short Form of Spanish Version of the WISC–IV for Intelligence Assessment in Elementary School Children
2014
In educational settings, quick assessments of intelligence are often required to screen children with potential special needs. The WISC–IV is administered individually and takes between one and two hours to complete. Given its widespread use in Spain, a short-form of the Spanish version is likely to be of use to professionals. The goal of this research was to develop a short form of the WISC–IV that can be performed in approximately half an hour. Data obtained in 100 elementary school children were analyzed following the criteria of Resnick and Entin (1971). The results showed that the most accurate estimation of intelligence was achieved with a combination of the Vocabulary, Block Design,…
Baseline design of the thermal blocking filters for the X-IFU detector on board ATHENA
2014
ATHENA is an advanced X-ray observatory designed by a large European consortium to address the science theme "Hot and Energetic Universe" recently selected by ESA for L2 – the second Large-class mission within the Cosmic Vision science program (launch scheduled in 2028). One of the key instruments of the mission is the X-ray Integral Field Unit (X-IFU), an array of Transition Edge Sensor (TES) micro-calorimeters with high energy resolution (2.5 eV @ 6 keV) in the energy range 0.2÷12 keV, operating at the focal plane of a large effective area high angular resolution (5" HEW) grazing incidence X-ray telescope. The X-IFU operates at temperatures below 100 mK and thus requires a sophisticated c…
Industry Emergence between Technology and Zeitgeist
2021
Abstract This chapter examines the dynamics of industry emergence using the case of the blockchain and crypto (BC) industry. The BC industry is a rapidly developing field that has—in less than a decade—transformed from initially being a volunteer project of a small group of cypherpunks to a global industry with a plethora of actors involving vivid entrepreneurial and corporate activity. Importantly, the review of the extant literature and evidence reveals that ideological driving forces, which have been neglected in prior industry emergence research, constitute a major catalyst of this rapid industry development. In this vein, the chapter shows that the ideological notion of ‘decentralizati…
Blockchain for power systems:Current trends and future applications
2020
Abstract Today, the blockchain is synonymous of technological innovation, being recognized among the 10 top strategy technologies in 2018 by the consulting company Gartner, it is more and more adopted in different sectors. However, the initial enthusiasm around this technology is going beyond the peak of inflated expectations, towards more stable applications in money transactions, cryptocurrencies and Digital Commodity Exchanges. Essentially, misguided efforts, the overuse of blockchain, and the Bitcoin's price drop have been the main reasons for this decay in expectations. Nevertheless, the exploitation of the blockchain technology in the power systems area appears largely underexplored, …
Using Blockchain in Digitalizing Enterprise Legacy Systems: An Experience Report
2021
Blockchain technology and distributed ledger technology (DLT) offer a secure, distributed, and tamper-proof way to store and exchange information. However, apart from standard cryptocurrency-based networks, innovations and process improvements based on the blockchain technology have mostly remained on the conceptualizing stage and have not yet reached mass adoption. There is a high demand for practical experiences from developing blockchain and DLT based systems in various domains outside FinTech. This work seeks to contribute to this gap by presenting real-world experiences from developing a proof of concept for automatizing conditional payments in social benefits and healthcare domains. W…
Crystal structure of SrMn2(Si2O7)(OH)2 H2O, a new mineral of the lawsonite type
1992
Crystal with the composition SrMn 2 [Si 2 O 7 ](OH) 2 .H 2 O were found in a sugilite, serandite-pectolite rich sample from the Wessels Mine, Kalahari, South Africa. The crystal structure of the nex compound with space group Cmcm, a = 6.255(1), b = 9.034(2), c = 13.397(2) A, Z = 4 was determined from X-ray single-crystal data (R = 0.048). The structure is of the lawsonite type where Al is completely replaced by Mn 3+ and Ca by Sr. [Mn 3+ O 6 ] octahedra forming edge-sharing chains parallel to a exhibit a Jahn-Teller distortion with four short and two long Mn 3+ -O distances. Sr is in eight-fold coordination and H 2 O is disordered on a split position. Together with orientite, macfallite, ru…
Influence of diamagnetic impurity on mid‐IR absorption in antiferromagnetic insulator NiO
2005
-1 was studied in polycrystalline Ni c Mg 1-c O solid solutions with c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60. The composition and temperature dependences of the absorption suggest that the band has magnetic origin re- lated to simultaneous excitation of two-magnons at the Brillouin-zone boundary and one phonon. -1 in polycrystalline NicMg1-cO solid solutions. Polycrystalline solid solutions NicMg1-cO (c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60) were prepared using ceramic technology from the appropriate amounts of aqueous solutions of Mg(NO3)2·6H2O and Ni(NO3)2·6H2O salts, which were mixed and slowly evaporated. The remaining dry 'flakes' were heated up to 500-600 oC to…
<title>Origin of visible photoluminescence in NiO and Ni<formula><inf><roman>c</roman></inf></formula>Mg<…
2003
A study of the visible photoluminescence in single-crystal NiO and NicMg1-cO (c = 0.99, 0.98 and 0.95) solid solutions is presented for the first time. Two wide luminescence bands, peaked at approximately 12000 cm-1 and approximately 18500 cm-1, were observed. The dependence of their intensity and position on the excitation energy, temperature, and composition were investigated. We attribute the origin of two photoluminescence bands to the impurity- or defect perturbed Ni2+ excitons.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.