Barium Fluoride Crystals for Future Hadron Colliders

1994 ◽  
Vol 348 ◽  
Author(s):  
Ren-yuan Zhu ◽  
Da-an Ma ◽  
Harvey Newman
Keyword(s):  
Radiation Resistance ◽  
Production Quality ◽  
Barium Fluoride ◽  
Electromagnetic Calorimeter ◽  
Hadron Colliders ◽  
Excellent Candidate ◽  
Current Production ◽  
Fluoride Crystals ◽  
Optical Bleaching

ABSTRACTThis report summarizes the radiation resistance of the current production BaF2 crystals. An approach to implement optical bleaching in situ is also presented. By using optical bleaching current production quality BaF2 crystals could serve as an excellent candidate to construct a precision electromagnetic calorimeter at future hadron colliders.

scholarly journals Modelling the Heating Process at Transient and Steady State of an In Situ Tape Laying Machine Head

2021 ◽  
Author(s):  
Jhonny Rodrigues ◽  
Paulo Reinier Gonçalves ◽  
Luís Miguel Pina ◽  
Fernando Gomes de Almeida
Keyword(s):  
Temperature Response ◽  
Production Quality ◽  
Heating Process ◽  
Digital Twin ◽  
Finite Differences Method ◽  
Shape Complexity ◽  
Automated Processes ◽  
Alternative Processes ◽  
Time And Energy

As use of composite materials increases, the search for suitable automated processes gains relevance to guarantee production quality by ensuring uniformity of the process, minimizing the amount of generated scrap and reducing time and energy consumption. Limitations on production by traditional means such as hand lay-up, vacuum bagging and in-autoclave methods, tend not to be as efficient when the size and shape complexity of the part being produced increases, motivating the search for alternative processes such as the Automated Tape Laying (ATL). This work aims to describe the process of modelling and simulating a composite ATL with in situ consolidation by characterizing the machine elements, using the finite differences method in conjunction with energy balances, in order to create a digital twin of the process for further control design. The modelling approach implemented is able to follow the process dynamics when changes to the heating element are imposed as well as to predict the composite material temperature response, making it suitable to work as a digital twin of a production process using an ATL machine.

scholarly journals Перенос электрона между разнородными лантаноидами в кристаллах BaF-=SUB=-2-=/SUB=- --- II механизмы переноса

2019 ◽  
Vol 61 (5) ◽  
pp. 888
Author(s):  
Е.А. Раджабов ◽  
В.А. Козловский
Keyword(s):  
Electron Transfer ◽  
Low Temperatures ◽  
Barium Fluoride ◽  
Absorption Bands ◽  
Thermal Electron ◽  
Thermal Transfer ◽  
Trivalent Lanthanide ◽  
Fluoride Crystals ◽  
Divalent Lanthanide ◽  
Thermal Electron Transfer

The processes of electron transfer from a divalent lanthanide acceptor (Eu, Sm, Yb) to a trivalent lanthanide donor (Nd, Sm, Dy, Tm, Yb) and reverse thermal transfer are studied in barium fluoride crystals. Electron phototransfer at room temperatures is accompanied by a counter-movement of the charge-compensating interstitial fluorine. In the process of photobleaching at low temperatures, the divalent lanthanide donor turns out to be near the interstitial fluorine, which causes its 4f-5d absorption bands to shift to the red. The magnitude of the shift increases with decreasing size of the lanthanide in the series (Nd, Sm, Dy, Tm, Yb). Detailed mechanisms of photo and thermal electron transfer between heterogeneous lanthanides in BaF2 crystals are analyzed.

scholarly journals In situ continuous current production from marine floating microbial fuel cells

2018 ◽  
Vol 230 ◽  
pp. 78-85 ◽  
Author(s):  
Giulia Massaglia ◽  
Valentina Margaria ◽  
Adriano Sacco ◽  
Tonia Tommasi ◽  
Simona Pentassuglia ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Continuous Current ◽  
Current Production

scholarly journals Potential for Quantifying Expression of the Geobacteraceae Citrate Synthase Gene To Assess the Activity of Geobacteraceae in the Subsurface and on Current-Harvesting Electrodes

2005 ◽  
Vol 71 (11) ◽  
pp. 6870-6877 ◽  
Author(s):  
Dawn E. Holmes ◽  
Kelly P. Nevin ◽  
Regina A. O'Neil ◽  
Joy E. Ward ◽  
Lorrie A. Adams ◽  
...  
Keyword(s):  
Electron Acceptor ◽  
Citrate Synthase ◽  
Housekeeping Genes ◽  
Geobacter Sulfurreducens ◽  
Contaminated Site ◽  
Reverse Transcription Pcr ◽  
Key Enzyme ◽  
Current Production ◽  
Rates Of Growth

ABSTRACT The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transcription-PCR studies with mRNA extracted from cultures of Geobacter sulfurreducens grown in chemostats with Fe(III) as the electron acceptor or in batch with electrodes as the electron acceptor indicated that transcript levels of the citrate synthase gene, gltA, increased with increased rates of growth/Fe(III) reduction or current production, whereas the expression of the constitutively expressed housekeeping genes recA, rpoD, and proC remained relatively constant. Analysis of mRNA extracted from groundwater collected from a U(VI)-contaminated site undergoing in situ uranium bioremediation revealed a remarkable correspondence between acetate levels in the groundwater and levels of transcripts of gltA. The expression of gltA was also significantly greater in RNA extracted from groundwater beneath a highway runoff recharge pool that was exposed to calcium magnesium acetate in June, when acetate concentrations were high, than in October, when the levels had significantly decreased. It was also possible to detect gltA transcripts on current-harvesting anodes deployed in freshwater sediments. These results suggest that it is possible to monitor the in situ metabolic rate of Geobacteraceae by tracking the expression of the citrate synthase gene.

scholarly journals Radiation Resistance of Biological Reagents for In Situ Life Detection

Astrobiology ◽  
2013 ◽  
Vol 13 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Christopher E. Carr ◽  
Holli Rowedder ◽  
Cyrus Vafadari ◽  
Clarissa S. Lui ◽  
Ethan Cascio ◽  
...  
Keyword(s):  
Radiation Resistance ◽  
Life Detection
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