Film Fabrication Technologies at NREL

The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers

Reduction of trapped ion anomalous heating by in situ surface plasma cleaning

Anomalous motional heating is a major obstacle to scalable quantum information processing with trapped ions. While the source of this heating is not yet understood, several previous studies suggest that surface contaminants may be largely responsible. We demonstrate an improvement by a factor of four in the room-temperature heating rate of a niobium surface electrode trap by in situ plasma cleaning of the trap surface. This surface treatment was performed with a simple homebuilt coil assembly and commercially-available matching network and is considerably gentler than other treatments, such as ion milling or laser cleaning, that have previously been shown to improve ion heating rates. We do not see an improvement in the heating rate when the trap is operated at cryogenic temperatures, pointing to a role of thermally-activated surface contaminants in motional heating whose activity may freeze out at low temperatures.Comment: 5 pages, 4 figure

Lithostratigraphy and petrography of the Upper Cambrian Maynardville Formation within the Copper Creek fault belt of East Tennessee.

Ever since the Maynardville Formation was first defined by c. R. L. Oder in 1934, it has been the subjeot of considerable controversy. While its age (Croixan) has never been seriously questioned, it has yet to be established definitely whether the Maynardville should be included within the alternating shales and carbonates of the subjacent Conasauga Group or within the overlying Knox Group, consisting almost entirely of limestone and dolomite. The purpose of this investigation was to subdivide the Maynardville Formation within the Copper Ridge strike belt into a laterally traceable vertical succession of parastratigraphic units. A parastratigraphic unit is defined by Krumbein and Sloss (1963, page 333) as a grouping of strata, identified by objective lithologic criteria, but lacking in-either mappability or lithologic homogeneity and constancy. Parastratigraphic units are lithostratigraphic units which are not formally named as formations, members, groups, etc. The effect of dividing the Maynardville Formation into parastratigraphio units is to delineate a grouping of subparallel bands traceable along strike, without proposing formal names for the lithostratigraphic divisions

Concentrated Photovoltaics

70 σ.Στόχος της παρούσας διπλωματικής είναι η βιβλιογραφική ανασκόπηση της τεχνολογίας των συγκεντρωτικών φωτοβολταϊκών (CPV) και στη συνέχεια η μελέτη του ρόλου που μπορούν να παίξουν στην παραγωγή πράσινης, φθηνής ηλεκτρικής ενέργειας σε μεγάλη κλίμακα. Αρχικά, γίνεται μία σύντομη ιστορική αναδρομή στην ιστορία της φωτοβολταϊκής τεχνολογίας, και στη συνέχεια παρουσιάζεται αναλυτικά η τεχνολογία των συγκεντρωτικών φωτοβολταϊκών δίνοντας έμφαση στις διαφορές τους με τα συμβατικά κύτταρα πυριτίου. Έπειτα, παρουσιάζονται οι πιο σημαντικές κατασκευαστικές διαδικασίες (LPE και MOCVD) καθώς και επίκαιρα ζητήματα που αφορούν τις διαδικασίες αυτές. Ειδικό βάρος δίνεται στις τρέχουσες και μελλοντικές δυνατότητες εμπορικής ανάπτυξης των CPV: Παρουσιάζονται σενάρια μελλοντικής υλοποίησης της τεχνολογίας των CPV, καθώς και το τι έχει γίνει μέχρι σήμερα. Αναδεικνύεται ειδικά ο ρόλος των πολυσυνδετικών ηλιακών κελιών(multi-junction solar cells) σαν καταλύτης στη παραγωγή ηλεκτρικής ενέργειας που μπορεί να ανταγωνιστεί ευθέως τις συμβατικές πηγές (άνθρακας, υγραέριο, πυρηνικά καύσιμα). Στο τέλος, αναφέρονται συνοπτικά εφαρμογές μεγάλης κλίμακας. ΘεόδωροςThis diploma thesis is a bibliographical review about Concentrated Photovoltaics (CPV) and the major role they could play in generating solar power on an industrial-size scale. So far, there hasn't been any greek bibliography concerning concentrated photovoltaics and this thesis aims to close that gap. Initially, a small introduction about photovoltaics in general is made, and consenquently CPV technology is explained in detail. Special emphasis is given on its differences with conventional silicon cells. Afterwards, the most important and promising manufactoring processes and techniques are presented(such as LPE and MOCVD) and current challenges and difficulties concerning those techniques are pointed out. Its current and future economic prospects are laid down, especially in comparison to conventional solar cells. Also, we explain in detail why multijunction solar cell technology is an enabler for low cost power generation using concentrated photovoltaic systems. Finally, several current, large scale applications are presented.Θεόδωρος Μ. Μπέλλο

In The Sweet Bye And Bye

https://digitalcommons.library.umaine.edu/mmb-vp/6035/thumbnail.jp

I\u27m Going to Climb The Blue Ridge Mountains : Back to You

https://digitalcommons.library.umaine.edu/mmb-vp/4771/thumbnail.jp