scholarly journals The State of stress in the Sanford Underground Research Facility (SURF) in Lead South Dakota

2016 ◽  
Author(s):  
Moo Y. Lee
2020 ◽  
Vol 50 ◽  
pp. 2060002
Author(s):  
David Woodward

LUX (Large Underground Xenon) was a dark matter experiment, which was housed at the Sanford Underground Research Facility (SURF) in South Dakota until late 2016, and previously set world-leading limits on Weakly Interacting Massive Particles (WIMPs), axions and axion-like particles (ALPs). This proceeding presents an overview of the LUX experiment and discusses the most recent analysis efforts, which are probing various dark matter models and detection techniques. In particular, studies of signals from inelastic scattering processes and of single scintillation photon events have improved the sensitivity of the experiment to low mass WIMPs. Additionally, a model-independent search for modulations in the LUX electron recoil rate is presented, demonstrating the most sensitive annual modulation search to date.


2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
N. Abgrall ◽  
E. Aguayo ◽  
F. T. Avignone ◽  
A. S. Barabash ◽  
F. E. Bertrand ◽  
...  

The MajoranaDemonstratorwill search for the neutrinoless double-beta(ββ0ν)decay of the isotopeGe with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The Demonstratoris being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the Demonstratorand the details of its design.


Author(s):  
Nils Cwiekala ◽  
David A Hills

The state of stress present in an elastic half-plane contact problem, where one or both bodies is subject to remote tension has been investigated, both for conditions of full stick and partial slip. The state of stress present near the contact edges is studied for different loading scenarios in an asymptotic form. This is of practical relevance to the study of contacts experiencing fretting fatigue, and enables the environment in which cracks nucleate to be specified.


Author(s):  
Battista Grosso ◽  
Valentina Dentoni ◽  
Augusto Bortolussi

AbstractUnderground quarrying is rarely adopted for granite extraction due to the difficulties in the implementation of traditional technologies (drilling and explosive). As alternative to drilling and explosive, the combination of diamond wire and water jet seems to be the most promising available technology. The cutting performance achievable with the water jet technology depends on the operative parameters, the material characteristics and the state of stress within the rock massif. To assess the effect of the state of stress on the cutting rate, laboratory tests have been performed with an oscillating water jet machine on granite samples subjected to a static load. The stress distribution in the layer of rock to be removed has been evaluated by numerical simulation with the FLAC code (Fast Lagrangian Analysis of Continua). The correlation between the results of the cutting tests and the numerical models of the rock samples has been inferred. Starting from a conceptual model, which theoretically describes the relationship between the cutting rate and the stress, a step function was defined that indicates the ranges of stress where predefined values of the cutting rate are workable.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 110-111
Author(s):  
David A Clizer ◽  
Paul Cline ◽  
Brent Frederick ◽  
Ryan S Samuel

Abstract Dried distiller grains with solubles (DDGS) is a popular protein source in grow-finish swine diets to replace soybean meal. An experiment was conducted at the South Dakota State University commercial swine research facility to determine the effect of standardized ileal digestible (SID) Trp:Lys ratio in grow-finish swine diets containing 40% DDGS compared to a standard corn-soybean meal diet. A total of 1,170 pigs (38.6 ± 0.2 kg initial BW) were utilized in a 98-d trial (9 pens per treatment). Pens of pigs were randomly allotted to 1 of 4 DDGS dietary treatments providing SID Trp at 15, 18, 21, and 24% of Lys or a corn-soybean meal diet (18%). Diets were isocaloric, with lysine at 100% of the requirement. From d 0 to 82, increasing Trp:Lys ratio in DDGS diets improved (P < 0.01) BW, ADG, and ADFI with no effect on F:G. Pigs fed the corn-soybean meal diet had greater (P < 0.01) BW, ADG, ADFI, and F:G compared to the DDGS diets with the exception of the ADFI of the 24% Trp:Lys treatment. From d 82 to 98, increasing SID Trp:Lys in DDGS diets had no effect on performance. Overall (d 0 to 98), increasing SID Trp:Lys in DDGS diets increased (P < 0.02) final BW and ADG, but pigs failed to perform to the same degree as the corn-soybean meal diet. Increasing SID Trp:Lys in DDGS diets resulted in an increase in hot carcass weight (P < 0.01); however, diets containing DDGS had decreased (P < 0.02) hot carcass weight, dressing percentage, percent lean, and loin depth compared to pigs fed the corn-soybean meal diet. These results indicate that increasing the SID Trp:Lys in diets containing 40% DDGS improved performance in early grow-finish phases with no effect in late finishing, but performance was inferior to standard corn-soybean meal diets.


2016 ◽  
Vol 61 (1) ◽  
pp. 199-216 ◽  
Author(s):  
Marilena Cardu ◽  
Sergio Dipietromaria ◽  
Pierpaolo Oreste

Abstract The aim of this study was to evaluate the state of stress of a „voids-pillar“ structure excavated by means of the sub-level stoping method in an underground limestone quarry near Bergamo (Italy). Both the current structure of the quarry (i.e. the rooms exploited till now) and a possible future scenario were analysed using the (FDM) FLAC 2D code. The quarry has been in operation since 1927; at present, exploitation is carried out underground via the sub-level stoping method. Exploitation involves two levels, with 5 rooms on the upper level and 9 rooms on the lower level. After analysing data obtained from laboratory and in situ tests carried out on rock samples and natural discontinuities, the geomechanical properties of the medium, knowledge of which is essential in order to establish the parameters that must be included in the numerical model, were evaluated. The implementation of three numerical models made it possible to study both the present conditions of quarry exploitation and the evolution of the exploited rooms, as well as a possible expansion involving a third level of rooms. Using the results obtained regarding the stress-strain present in the pillars, a potential change in room geometry was proposed aimed at reducing the stress state inside the pillars, decreasing plasticity and increasing overall quarry safety.


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