Science.gov

Sample records for allegheny mountain tunnel

  1. Bat activity in harvested and intact forest stands in the allegheny mountains

    USGS Publications Warehouse

    Owen, S.F.; Menzel, M.A.; Edwards, J.W.; Ford, W.M.; Menzel, J.M.; Chapman, B.R.; Wood, P.B.; Miller, K.V.

    2004-01-01

    We used Anabat acoustical monitoring devices to examine bat activity in intact canopy forests, complex canopy forests with gaps, forests subjected to diameter-limit harvests, recent deferment harvests, clearcuts and unmanaged forested riparian areas in the Allegheny Mountains of West Virginia in the summer of 1999. We detected eight species of bats, including the endangered Indiana bat (Myotis sodalis). Most bat activity was concentrated in forested riparian areas. Among upland habitats, activity of silver-haired bats (Lasionycteris noctivagans) and hoary bats (Lasiurus cinereus) was higher in open, less cluttered vegetative types such as recent deferment harvests and clearcuts. Our results suggest that bat species in the central Appalachians partially segregate themselves among vegetative conditions based on differences in body morphology and echolocation call characteristics. From the standpoint of conserving bat foraging habitat for the maximum number of species in the central Appalachians, special emphasis should be placed on protecting forested riparian areas.

  2. Tunneling progress on the Yucca Mountain Project

    SciTech Connect

    Hansmire, W.H.; Munzer, R.J.

    1996-06-01

    The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation.

  3. View of Flume Tunnel #3 through Purple Mountain, showing flume ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Flume Tunnel #3 through Purple Mountain, showing flume entering into the tunnel. Looking south - Childs-Irving Hydroelectric Project, Childs System, Flume Tunnel No. 3, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  4. TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Morris, J.P.; Hansmire, W.H. |

    1995-03-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long-term, high-level nuclear waste repository in the United States. The current status of this long-term project from the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF) Tunnel, which is being excavated with a 7.6 m (25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3.0 to 7.6 m (10 to 25 ft). Prior to construction, extensive constructability reviews were an interactive part of the final design. The intent was to establish a constructable design that met the long-term stability requirements for radiological safety of a future repository, while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  5. TBM tunneling on the Yucca Mountain Project: Proceedings

    SciTech Connect

    Williamson, G.E.; Gowring, I.M.

    1995-07-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long term, high level nuclear waste repository in the United States. Status of this long-term project form the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF), which is being excavated with a 7. 6 m(25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3 to 7.6 m(10 to 25 ft). Prior to construction, extensive constructibility reviews were an interactive part of the final design. Intent was to establish a constructible design that met the long-term stability requirements for radiological safety of a future repository while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  6. Tunnel boring machine applications; Yucca Mountain Exploratory Studies Facility

    SciTech Connect

    Bhattacharyya, K.K.; McDonald, R.; Saunders, R.S.

    1992-11-01

    This paper reports that characterization of Yucca Mountain for a potential repository requires construction of an underground Exploratory Studies Facility (ESF). Mechanical excavating methods have been proposed for construction of the ESF as they offer a number of advantages over drilling and blasting at the Yucca Mountain site, including; less ground disturbance and therefore a potential for less adverse effects on the integrity of the site, creation of a more stable excavation cross section requiring less ground support, and an inherently safer and cleaner working environment. The tunnel boring machine (TBM) provides a proven technology for excavating the welded and unwelded Yucca Mountain tuffs. The access ramps and main underground tunnels form the largest part of the ESF underground construction work, and have been designed for excavation by TBM.

  7. Tunneling on the Yucca Mountain Project: Progress and lessons learned

    SciTech Connect

    Hansmire, W.H.; Rogers, D.J.; Wightman, W.D.

    1996-06-01

    The Yucca Mountain Site Characterization Project is the US`s effort to confirm the technical acceptability of Yucca Mountain as a repository for high-level nuclear waste. A key part of the site characterization project is the construction of a 7.8-km-long, 7.6-m-diameter tunnel for in-depth geologic and other scientific investigations. The work is governed in varying degrees by the special requirements for nuclear quality assurance, which imposes uncommon and often stringent limitations on the materials which can be used in construction, the tunneling methods and procedures used, and record-keeping for many activities. This paper presents the current status of what has been learned, how construction has adapted to meet the requirements, and how the requirements were interpreted in a mitigating way to meet the legal obligations, yet build the tunnel as rapidly as possible. With regard to design methodologies and the realities of tunnel construction, ground support with a shielded Tunnel Boring Machine is discussed. Notable lessons learned include the need for broad design analyses for a wide variety of conditions and how construction procedures affect ground support.

  8. A tunnel boring system for the Yucca Mountain Project

    SciTech Connect

    Short, S.N.

    1994-12-31

    Design of the Yucca Mountain Project (YMP) tunnel boring machine (TBM) and backup began in June of 1993, with fabrication, machining and light assembly proceeding through to the end of the year. The original specifications for the project were contained in the request for quote for the YMP TBM and in Construction & Tunneling Services proposal document. As with all complex custom assignments, much of the finer details of the definition of the final scope of delivery was concurrent with the design effort itself. The summation of this effort is described in this paper. The major technical scope of the machine delivery is defined by the parameters listed in TABLE 1. Within the confines of the installed power and design excavation rates, the final product has been tailored to suit the particular needs of the project.

  9. System safety analysis of the Yucca Mountain tunnel boring machine

    SciTech Connect

    Smith, M.G.; Booth, L.; Eisler, L.

    1995-12-01

    The purpose of this analysis was to systematically identify and evaluate hazards related to the tunnel boring machine to be used at Yucca Mountain. This analysis required three steps to complete the risk evaluation: hazard/scenario identification, consequence assessment, and frequency assessment. The result was a `risk evaluation` of the scenarios identified in this analysis in accordance with MIL-STD-882C. The risk assessment in this analysis characterized the accident scenarios associated with the TBM in terms of relative risk and included recommendations for mitigating all identified risks.

  10. Moisture Observations in Sealed Tunnels at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Coleman, N. M.; Winterle, J.; Arlt, H.; Dinwiddie, C.; Fedors, R.

    2002-12-01

    assessments of deep percolation and seepage. The NRC staff believes that long-term empirical observations in sealed tunnels could be an element of a performance confirmation plan for Yucca Mountain.

  11. 77 FR 51512 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Warren, Pennsylvania. The... conducted: Allegheny Resource Advisory Committee members will solicit and consider project proposals...

  12. MISTY ECHO tunnel dynamics experiment data report; Volume 2, Appendices: Yucca Mountain Site Characterization Project

    SciTech Connect

    Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.

    1992-04-01

    Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.

  13. MISTY ECHO Tunnel Dynamics Experiment--Data report: Volume 1; Yucca Mountain Site Characterization Project

    SciTech Connect

    Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.

    1992-04-01

    Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.

  14. Construction monitoring activities in the Yucca Mountain ESF Starter Tunnel

    SciTech Connect

    Pott, J.; Costin, L.S.; Brechtel, C.E

    1993-12-31

    An underground test facility known as the Exploratory Studies Facility (ESF) is planned as part of the characterization of a site for a potential high-level nuclear waste repository at Yucca Mountain, NV. The first part of the ESF that will be constructed is the North Ramp Starter Tunnel (NRST), which will provide a facility for launching the tunnel-boring machine to be used in the construction of the ESF. Geotechnical monitoring activities are planned for the NRST to provide for the collection of data to confirm design concepts and to enhance safety during construction. This paper describes the activities to be conducted and their objectives. The construction monitoring activities are part of a study defined in the In Situ Design Verification Study Plan. The objectives of this study are to (1) monitor and observe the long-term behavior of openings in a range of ground conditions in the repository host rock, and (2) to observe and evaluate the construction of the ESF with respect to implications for repository construction and performance. Initiating geotechnical monitoring activities in the NRST will allow geotechnical data required to confirm adequate design, construction and long term performance to be collected from the very beginning of underground construction. In addition, the planned monitoring is consistent with standard practice for assuring quality and safety during similar rock excavation for civil construction. The geotechnical monitoring activities addressed by this experiment plan are grouped into three tasks: (1) evaluation of mining methods, (2) monitoring of ground support systems and (3) monitoring drift stability. A general description of each of the tasks is presented below.

  15. 76 FR 50993 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Warren, Pennsylvania....

  16. 76 FR 50994 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Clarendon, Pennsylvania....

  17. 76 FR 38109 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Marienville, Pennsylvania....

  18. 76 FR 45227 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF AGRICULTURE Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Clarendon, Pennsylvania....

  19. 76 FR 23275 - Allegheny Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Allegheny Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Allegheny Resource Advisory Committee will meet in Clarendon, Pennsylvania....

  20. Application of quality assurance controls to TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Christensen, J.D.

    1996-06-01

    As part of the Yucca Mountain Project (YMP), a 7.62-meter diameter tunnel is being constructed using a Tunnel Boring Machine (TBM). This tunnel, which may form a portion of a permanent high-level nuclear waste repository, is being constructed under the auspices of a nuclear quality assurance (QA) program. The YMP nuclear QA program applies to items and activities determined to be important to radiological safety, waste isolation, and potential interactions with the environment. The items and activities determined to be important have been assigned a quality assurance classification. This paper focuses on the items (rockbolts, steel sets, and shotcrete) and quality affecting activities involved in providing ground support and excavating the tunnel. Typical activities that have been assigned QA classifications include TBM maintenance, control of water used in the tunnel during construction, and control of diesel emissions in the tunnel. The paper concludes that the key to the successful implementation of nuclear QA requirements for tunneling at Yucca Mountain was the assignment of personnel with the appropriate mix of tunneling and nuclear experience.

  1. 77 FR 21522 - Boundary Establishment for the Allegheny National Wild and Scenic River, Allegheny National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Boundary Establishment for the Allegheny National Wild and Scenic... Act, the USDA Forest Service, Washington Office, is transmitting the final boundary of the Allegheny... phone (814) 728-6239. SUPPLEMENTARY INFORMATION: The Allegheny Wild and Scenic River boundary...

  2. A tunnel runs through it: an inside view of the Tualatin Mountains, Oregon

    USGS Publications Warehouse

    Walsh, Ken; Peterson, Gary L.; Beeson, Marvin H.; Wells, Ray E.; Fleck, Robert J.; Evarts, Russell C.; Duvall, Alison; Blakely, Richard J.; Burns, Scott

    2011-01-01

    The Tualatin Mountains form a northwest-striking ridge about 350 m high that separates Portland, Oregon, from the cities of the Tualatin Valley to the west. Known informally as the Portland Hills, the ridge is a late Cenozoic anticline, bounded by reverse faults that dip toward the anticlinal axis. The anticline is a broad, open fold consisting chiefly of Miocene Columbia River Basalt Group, with remnants of Miocene-Pliocene Troutdale Formation and Pleistocene basalt of the Boring Volcanic Field on the flanks of the anticline. Anticlinal structures similar to the Tualatin Mountains are characteristic of the northern Willamette Valley, where the structures accommodate margin-parallel shortening of the Cascadia fore arc. Global Positioning System (GPS) results indicate that the shortening is due to the northward motion of Oregon at several millimeters per year with respect to stable North America. Some of the uplifts may contain active faults, but the structures are poorly exposed and are overlain by thick Pleistocene loess and Missoula flood deposits. Between 1993 and 1998, construction of the 3-mile-long (4500-m-long) TriMet MAX Light Rail tunnel through the Tualatin Mountains provided an unusual opportunity to investigate the geological structure and history of the Tualatin Mountains. This report is a collaborative effort among the tunnel geologists and the U.S. Geological Survey (USGS) to document the geologic story and quantify late Cenozoic and Quaternary deformation rates of the Tualatin Mountains.

  3. Elevation view of west portal, looking due east. Eastbound train ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation view of west portal, looking due east. Eastbound train entering tunnel. Allegheny tunnel at right; Gallitzin Tunnel (Haer no. PA-516) at left. - Pennsylvania Railroad, Allegheny Tunnel, Beneath Allegheny Mountain, east of Railroad Street, Gallitzin, Cambria County, PA

  4. Apportionment of NMHC tailpipe vs non-tailpipe emissions in the Fort McHenry and Tuscarora mountain tunnels

    NASA Astrophysics Data System (ADS)

    Gertler, Alan W.; Fujita, Eric M.; Pierson, William R.; Wittorff, David N.

    Measurements of on-road emissions of non-methane hydrocarbons (NMHCs) were made in the Fort McHenry Tunnel (Baltimore) and Tuscarora Mountain Tunnel (Pennsylvania) during the summer of 1992. Measurements were made during 11 one-hour periods in the Fort McHenry Tunnel and during 11 one-hour periods in the Tuscarora Mountain Tunnel. The observed light-duty fleets were quite new, with a median model year of approximately 1989. Speciated NMHC values were obtained from analyses of canister and Tenax samples, and light-duty speciated emission factors were calculated for the two tunnels. Fuel samples were collected in the area around the tunnels for use in constructing headspace and liquid fuel profiles for the chemical mass balance (CMB) receptor model. Profiles of tailpipe emissions were obtained from the literature. The CMB was used to apportion tailpipe from non-tailpipe emissions. Non-tailpipe sources were found to constitute approximately 15% of the light-duty NMHC emissions. The Federal automotive emission-rate models, MOBILE4.1 and MOBILE5, underpredicted non-tailpipe emissions, assigning approximately 9% and 6.5%, respectively, to non-tailpipe sources. In terms of total absolute emissions, MOBILE5 predictions were approximately a factor of 2 greater than MOBILE4.1 predictions. Both MOBILE4.1 and MOBILE5 underestimated the NMHC emissions in the Fort McHenry Tunnel and overpredicted the NMHC emissions in the Tuscarora Mountain Tunnel. In all cases, the MOBILE models underestimated the absolute value of the non-tailpipe emissions. The ability of the MOBILE models to account for observed emissions when conditions are more variable than those studies in the Fort McHenry and Tuscarora Mountain tunnels is still an open question.

  5. Natural convection in tunnels at Yucca Mountain and impact on drift seepage

    SciTech Connect

    Halecky, N.; Birkholzer, J.T.; Peterson, P.

    2010-04-15

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock in the drift center to the drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water-induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  6. Consideration from a geological risk in a geological survey of mountain tunnel

    NASA Astrophysics Data System (ADS)

    Hasegawa, Nobusuke; Ohtsu, Hiroyasu

    In mountain tunnel construction project, ground condition expected in a preliminary survey and a real condition cause often large deviations. As the result, the large increase of construction cost occurs after the start of excavation. One of the causes of such deviations is the uncertainty of ground information in a preliminary survey. Then, we have studied on the evaluation technique for the uncertainty of ground information and the risk in tunnel digging cost fluctuation caused by the uncertainty (the following, geological risk). In the past study, we paid our attention to the quantity of deviations with an expected digging cost considering the uncertainty and a real cost. However, in geological risk management, it is important to consider the situation that occurs a significant loss when actualized, too. Therefore, conducting a case study in a tunnel that carried out an addition al survey because a bad ground condition which was not foreseen in a preliminary survey appear ed, we studied the geological risk in the preliminary and the additional survey, and compared with construction cost and geological risk. We expected that the probability that the real cost appeared on the risk curve in the additional survey would be higher than the one in the preliminary survey. However, the probability in the additional survey became lower than the one in the preliminary survey when the ground information was added without evaluating uncertainty of ground information appropriately. As the result, we found that it was important to add geological information which is evaluated appropriately, instead of simply adding geological information.

  7. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    SciTech Connect

    Ray, J.M.; Newsom, J.C.

    1994-12-01

    The Prototype Air-Coring Test was conducted at the Nevada Test Site (NTS) G-Tunnel facility to evaluate standard coring techniques, modified slightly for air circulation, for use in testing at a prospective nuclear waste repository at Yucca Mountain, Nevada. Air-coring technology allows sampling of subsurface lithology with minimal perturbation to ambient characteristic such as that required for exploratory holes near aquifers, environmental applications, and site characterization work. Two horizontal holes were cored, one 50 ft long and the other 150 ft long, in densely welded fractured tuff to simulate the difficult drilling conditions anticipated at Yucca Mountain. Drilling data from seven holes on three other prototype tests in nonwelded tuff were also collected for comparison. The test was used to establish preliminary standards of performance for drilling and dust collection equipment and to assess procedural efficiencies. The Longyear-38 drill achieved 97% recovery for HQ-size core (-2.5 in.), and the Atlas Copco dust collector (DCT-90) captured 1500 lb of fugitive dust in a mine environment with only minor modifications. Average hole production rates were 6-8 ft per 6-h shift in welded tuff and almost 20 ft per shift on deeper holes in nonwelded tuff. Lexan liners were successfully used to encapsulate core samples during the coring process and protect core properties effectively. The Prototype Air-Coring Test demonstrated that horizontal air coring in fractured welded tuff (to at least 150 ft) can be safely accomplished by proper selection, integration, and minor modification of standard drilling equipment, using appropriate procedures and engineering controls. The test also indicated that rig logistics, equipment, and methods need improvement before attempting a large-scale dry drilling program at Yucca Mountain.

  8. A Modeling Study Evaluating the Thermal-Hydrological Conditions In and Near Waste Emplacement Tunnels At Yucca Mountain

    SciTech Connect

    J.T. Birkholzer; N. Halecky; S.W> Webb; P.F. Peterson; G.S. Bodvarsson

    2006-10-11

    In heated tunnels such as those designated for emplacement of radioactive waste at the proposed geologic repository at Yucca Mountain, temperature gradients cause natural convection processes that may significantly influence the moisture conditions in the tunnels and in the surrounding fractured rock. Large-scale convection cells in the heated tunnels would provide an effective mechanism for turbulent mixing and axial transport of vapor generated from evaporation of pore water in the nearby formation. As a result, vapor would be transported from the elevated-temperature sections of the tunnels into cool end sections (where no waste is emplaced), would condense there, and subsequently drain into underlying rock units. To study these processes, we have developed a new simulation method that couples existing tools for simulating thermal-hydrological (TH) conditions in the fractured formation with a module that approximates turbulent natural convection in heated emplacement drifts. The new method simultaneously handles (1) the flow and energy transport processes in the fractured rock, (2) the flow and energy transport processes in the cavity, and (3) the heat and mass exchange at the rock-cavity interface. An application is presented studying the future TH conditions within and near a representative waste emplacement tunnel at Yucca Mountain. Particular focus is on the potential for condensation along the emplacement section, a possible result of heat output differences between individual waste packages.

  9. Mountains

    SciTech Connect

    Fuller, M.

    1989-01-01

    This book covers the following topics: Above the forest: the alpine tundra; Solar energy, water, wind and soil in mountains; Mountain weather; Mountain building and plate tectonics; Mountain walls: forming, changing, and disappearing; Living high: mountain ecosystems; Distribution of mountain plants and animals; On foot in the mountains: how to hike and backpack; Ranges and peaks of the world. Map and guidebook sources, natural history and mountain adventure trips, mountain environmental education centers and programs, and sources of information on trails for the handicapped are included.

  10. YUCCA MOUNTAIN SITE CHARACTERIZATIONS PROJECT TUNNEL BORING MACHINE (TBM) SYSTEM SAFETY ANALYSIS

    SciTech Connect

    N /A

    1997-02-19

    The purpose of this analysis is to systematically identify and evaluate hazards related to the tunnel boring machine (TBM) used in the Exploratory Studies Facility (ESF) at the Yucca Mountain Site Characterization Project. This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. Since the TBM is an ''as built'' system, the M&O is conducting the System Safety Analysis during the construction or assembly phase of the TBM. A largely qualitative approach was used since a radiological System Safety Analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the TBM in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the system/subsystem/component design, (2) add safety features and capabilities to existing designs, and (3) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions. The scope of this analysis is limited to the TBM during normal operations, excluding hazards occurring during assembly and test of the TBM or maintenance of the TBM equipment.

  11. Allegheny County, PA: Mobilizing To Reduce Juvenile Crime.

    ERIC Educational Resources Information Center

    Hsia, Heidi M.

    Juvenile crime and its immediate and long-term economic and human costs have become a national concern. Programs to prevent and reduce delinquency have developed across the country and one such program in Allegheny County, Pennsylvania (which includes Pittsburgh) is described in this bulletin. The Allegheny program exemplifies a large-scale,…

  12. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada

    SciTech Connect

    Spycher, N.F.; Sonnenthal, E.L.; Apps, J.A.

    2002-09-01

    The evolution of fluid chemistry and mineral alteration around a potential waste emplacement tunnel (drift) is evaluated using numerical modeling. The model considers the flow of water, gas, and heat, plus reactions between minerals, CO{sub 2} gas, and aqueous species, and porosity permeability-capillary pressure coupling for a dual permeability (fractures and matrix) medium. Two possible operating temperature modes are investigated: a ''high-temperature'' case with temperatures exceeding the boiling point of water for several hundred years, and a ''low-temperature'' case with temperatures remaining below boiling for the entire life of the repository. In both cases, possible seepage waters are characterized by dilute to moderate salinities and mildly alkaline pH values. These trends in fluid composition and mineral alteration are controlled by various coupled mechanisms. For example, upon heating and boiling, CO{sub 2} exsolution from pore waters raises pH and causes calcite precipitation. In condensation zones, this CO{sub 2} redissolves, resulting in a decrease in pH that causes calcite dissolution and enhances feldspar alteration to clays. Heat also enhances dissolution of wallrock minerals leading to elevated silica concentrations. Amorphous silica precipitates through evaporative concentration caused by boiling in the high-temperature case, but does not precipitate in the low-temperature case. Some alteration of feldspars to clays and zeolites is predicted in the high-temperature case. In both cases, calcite precipitates when percolating waters are heated near the drift. The predicted porosity decrease around drifts in the high-temperature case (several percent of the fracture volume) is larger by at least one order of magnitude than in the low temperature case. Although there are important differences between the two investigated temperature modes in the predicted evolution of fluid compositions and mineral alteration around drifts, these differences are

  13. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada.

    PubMed

    Spycher, N F; Sonnenthal, E L; Apps, J A

    2003-01-01

    The evolution of fluid chemistry and mineral alteration around a potential waste emplacement tunnel (drift) is evaluated using numerical modeling. The model considers the flow of water, gas, and heat, plus reactions between minerals, CO(2) gas, and aqueous species, and porosity-permeability-capillary pressure coupling for a dual permeability (fractures and matrix) medium. Two possible operating temperature modes are investigated: a "high-temperature" case with temperatures exceeding the boiling point of water for several hundred years, and a "low-temperature" case with temperatures remaining below boiling for the entire life of the repository. In both cases, possible seepage waters are characterized by dilute to moderate salinities and mildly alkaline pH values. These trends in fluid composition and mineral alteration are controlled by various coupled mechanisms. For example, upon heating and boiling, CO(2) exsolution from pore waters raises pH and causes calcite precipitation. In condensation zones, this CO(2) redissolves, resulting in a decrease in pH that causes calcite dissolution and enhances feldspar alteration to clays. Heat also enhances dissolution of wall rock minerals leading to elevated silica concentrations. Amorphous silica precipitates through evaporative concentration caused by boiling in the high-temperature case, but does not precipitate in the low-temperature case. Some alteration of feldspars to clays and zeolites is predicted in the high-temperature case. In both cases, calcite precipitates when percolating waters are heated near the drift. The predicted porosity decrease around drifts in the high-temperature case (several percent of the fracture volume) is larger by at least one order of magnitude than in the low temperature case. Although there are important differences between the two investigated temperature modes in the predicted evolution of fluid compositions and mineral alteration around drifts, these differences are largely within to

  14. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Spycher, N. F.; Sonnenthal, E. L.; Apps, J. A.

    2003-05-01

    The evolution of fluid chemistry and mineral alteration around a potential waste emplacement tunnel (drift) is evaluated using numerical modeling. The model considers the flow of water, gas, and heat, plus reactions between minerals, CO 2 gas, and aqueous species, and porosity-permeability-capillary pressure coupling for a dual permeability (fractures and matrix) medium. Two possible operating temperature modes are investigated: a "high-temperature" case with temperatures exceeding the boiling point of water for several hundred years, and a "low-temperature" case with temperatures remaining below boiling for the entire life of the repository. In both cases, possible seepage waters are characterized by dilute to moderate salinities and mildly alkaline pH values. These trends in fluid composition and mineral alteration are controlled by various coupled mechanisms. For example, upon heating and boiling, CO 2 exsolution from pore waters raises pH and causes calcite precipitation. In condensation zones, this CO 2 redissolves, resulting in a decrease in pH that causes calcite dissolution and enhances feldspar alteration to clays. Heat also enhances dissolution of wall rock minerals leading to elevated silica concentrations. Amorphous silica precipitates through evaporative concentration caused by boiling in the high-temperature case, but does not precipitate in the low-temperature case. Some alteration of feldspars to clays and zeolites is predicted in the high-temperature case. In both cases, calcite precipitates when percolating waters are heated near the drift. The predicted porosity decrease around drifts in the high-temperature case (several percent of the fracture volume) is larger by at least one order of magnitude than in the low temperature case. Although there are important differences between the two investigated temperature modes in the predicted evolution of fluid compositions and mineral alteration around drifts, these differences are largely within to the

  15. Preliminary numerical modeling for the G-Tunnel welded tuff mining experiment; Yucca Mountain site characterization project

    SciTech Connect

    Johnson, R.L.; Bauer, S.J.

    1991-09-01

    Yucca Mountain, located in Southern Nevada, is to be considered as a potential site for a nuclear waste repository. Located in Rainier Mesa on the Nevada Test Site, G-Tunnel has been the site of a series of experiments, part of whose purpose is to evaluate measurement techniques for rock mechanics before testing in the Exploratory Shaft. Rainier Mesa is composed of welded and nonwelded tuffs that have thermal and mechanical properties and stress states similar to those of tuffs expected to be encountered at Yucca Mountain. A series of finite element calculations were performed to aid in designing instrumentation for the experiments in G-Tunnel and later to correlate with measured data. In this report are presented the results of the preliminary finite element calculations performed in conjunction with experimental measurements of drift convergence, or closure, and rock mass relaxation zones made before, during, and after completing the welded tuff mining experiment in G-Tunnel. Tape extensometer measurements of drift convergences and measurements determined by multiple point borehole extensometers are compared with corresponding calculated values using linear elastic and jointed rock material models. 9 refs., 25 figs., 7 tabs.

  16. Discrete-fracture modeling of thermal-hydrological processes at Yucca Mountain and the LLNL G-Tunnel heater test

    SciTech Connect

    Nitao, J.J.; Buscheck, T.A.

    1995-11-09

    An in situ heater test was performed at G-Tunnel, Nevada Nuclear Test Site, to investigate the thermal-hydrological response of unsaturated, fractured volcanic tuff under conditions similar to those at Yucca Mountain. The NUFT flow and transport code was used to model the test using discrete-fracture and equivalent-continuum approaches. Nonequilibrium fracture flow and thermal buoyant gas-phase convection were found to be the likely causes for observed lack of condensate imbibition into the matrix. The potential repository at Yucca Mountain was also modeled. Disequilibrium fracture flow is predicted to occur for less than a hundred years after emplacement followed by a period of fracture-matrix equilibrium, during which the equivalent-continuum and discrete-fracture models give almost identical results.

  17. WATER QUALITY IN OPEN FINISHED WATER RESERVOIRS - ALLEGHENY COUNTY, PENNSYLVANIA

    EPA Science Inventory

    The purpose of this investigation was to study water quality changes occurring in open reservoirs in the distribution systems of five water supplies located in Allegheny County, Pennsylvania. Results of chemical, bacteriological, and biological analyses showed deterioration of wa...

  18. 77 FR 66791 - Proposed Flood Elevation Determinations for Allegheny County, PA (All Jurisdictions)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... proposed rulemaking at 76 FR 72661, proposing flood elevation determinations along one or more flooding... Allegheny County, PA (All Jurisdictions) AGENCY: Federal Emergency Management Agency, DHS. ACTION: Proposed... rule concerning proposed flood elevation determinations for Allegheny County, Pennsylvania...

  19. 40 CFR 81.230 - Allegheny Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Allegheny Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.230 Allegheny Intrastate Air Quality Control Region. The Allegheny...

  20. Elevation view of west portal, looking due east. Eastbound train ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation view of west portal, looking due east. Eastbound train entering tunnel. Westbound conrail locomotive emerging from tunnel. Allegheny tunnel at right; Gallitzin Tunnel (Haer no. PA-516) at left. - Pennsylvania Railroad, Allegheny Tunnel, Beneath Allegheny Mountain, east of Railroad Street, Gallitzin, Cambria County, PA

  1. 75 FR 81469 - Safety Zone; Allegheny River, Pittsburgh, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ...-2010-1082 and are available online by going to http://www.regulations.gov , inserting USCG-2010-1082 in.... 2064; Department of Homeland Security Delegation No. 0170.1. 0 2. Add Sec. 165.T08-1082 to read as follows: Sec. 165.T08-1082 Safety Zone; Allegheny River, Pittsburgh, PA. (a) Location. The following...

  2. Allegheny Portage Railroad: Developing Transportation Technology. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Eick, Brian; Wallner, Rick

    1999-01-01

    Presents a lesson that will help students discover the innovative technologies of the Allegheny Portage Railroad that can be used when teaching about early 19th-century expansion and industrialization. Expounds that students' skills in geography and history will be strengthened through map reading, examination of pictures, and analysis of…

  3. Ages and Origins of Calcite and Opal in the Exploratory Studies Facility Tunnel, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Paces, James B.; Neymark, Leonid A.; Marshall, Brian D.; Whelan, Joseph F.; Peterman, Zell E.

    2001-01-01

    Deposits of calcite and opal are present as coatings on open fractures and lithophysal cavities in unsaturated-zone tuffs at Yucca Mountain, Nevada, site of a potential high-level radioactive waste repository. Outermost layers of calcite and opal have radiocarbon ages of 16,000 to 44,000 years before present and thorium-230/uranium ages of 28,000 to more than 500,000 years before present. These ages are young relative to the 13-million-year age of the host rocks. Multiple subsamples from the same outer layer typically show a range of ages with youngest ages from the thinnest subsamples. Initial uranium-234/uranium-238 activity ratios between 1 and 9.5 show a distinct negative correlation with thorium-230/uranium age and are greater than 4 for all but one sample younger than 100,000 years before present. These data, along with micrometer-scale layering and distinctive crystal morphologies, are interpreted to indicate that deposits formed very slowly from water films migrating through open cavities. Exchanges of carbon dioxide and water vapor probably took place between downward-migrating liquids and upward-migrating gases at low rates, resulting in oversaturation of mineral constituents at crystal extremities and more or less continuous deposition of very thin layers. Therefore, subsamples represent mixtures of older and younger layers on a scale finer than sampling techniques can resolve. Slow, long-term rates of deposition (less than about 5 millimeters of mineral per million years) are inferred from subsamples of outermost calcite and opal. These growth rates are similar to those calculated assuming that total coating thicknesses of 10 to 40 millimeters accumulated over 12 million years. Calcite has a wide range of delta carbon-13 values from about -8.2 to 8.5 per mil and delta oxygen-18 values from about 10 to 21 per mil. Systematic microsampling across individual mineral coatings indicates basal (older) calcite tends to have the largest delta carbon-13 values

  4. Elevation view of west portal, looking due east. Eastbound conrail ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation view of west portal, looking due east. Eastbound conrail locomotive approaching tunnel in right foreground. Allegheny tunnel at right; Gallitzin Tunnel (Haer no. PA-516) at left. - Pennsylvania Railroad, Allegheny Tunnel, Beneath Allegheny Mountain, east of Railroad Street, Gallitzin, Cambria County, PA

  5. Calibration of a two-dimensional hydrodynamic model for parts of the Allegheny, Monongahela, and Ohio Rivers, Allegheny County, Pennsylvania

    USGS Publications Warehouse

    Fulton, John W.; Wagner, Chad R.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Allegheny County Sanitary Authority, developed a validated two-dimensional Resource Management Associates2 (RMA2) hydrodynamic model of parts of the Allegheny, Monongahela, and Ohio Rivers (Three Rivers) to help assess the effects of combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) on the rivers. The hydrodynamic model was used to drive a water-quality model of the study area that was capable of simulating the transport and fate of fecal-indicator bacteria and chemical constituents under open-water conditions. The study area includes 14 tributary streams and parts of the Three Rivers where they enter and exit Allegheny County, an area of approximately 730 square miles (mi2). The city of Pittsburgh is near the center of the county, where the Allegheny and Monongahela Rivers join to form the headwaters of the Ohio River. The Three Rivers are regulated by a series of fixed-crest dams, gated dams, and radial (tainter) gates and serve as the receiving waters for tributary streams, CSOs, and SSOs. The RMA2 model was separated into four individual segments on the basis of the U.S. Army Corps of Engineers navigational pools in the study area (Dashields; Emsworth; Allegheny River, Pool 2; and Braddock), which were calibrated individually using measured water-surface slope, velocity, and discharge during high- and low-flow conditions. The model calibration process included the comparison of water-surface elevations at five locations and velocity profiles at more than 80 cross sections in the study area. On the basis of the calibration and validation results that included water-surface elevations and velocities, the model is a representative simulation of the Three Rivers flow patterns for discharges ranging from 4,050 to 47,400 cubic feet per second (ft3/s) on the Allegheny River, 2,550 to 40,000 ft3/s on the Monongahela River, and 10,900 to 99,000 ft3/s on the Ohio River. The Monongahela River was

  6. 76 FR 27892 - Special Local Regulation; Allegheny River, Pittsburgh, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ...The Coast Guard is establishing a temporary special local regulation from the Point State Park (mile marker 0.0) to the River Rescue station (mile marker 0.5) on the Allegheny River, extending 200 feet out from the right descending bank. The special local regulation is being established to safeguard participants of the Venture Outdoors Festival from the hazards of marine traffic. Entry into,......

  7. Allegheny woodrat (Neotoma magister) use of rock drainage channels on reclaimed mines in southern West Virginia

    USGS Publications Warehouse

    Chamblin, H.D.; Wood, P.B.; Edwards, J.W.

    2004-01-01

    Allegheny woodrats (Neotoma magister) currently receive protected status throughout their range due to population declines. Threats associated with habitat fragmentation (e.g., introduced predators, disease, loss of connectivity among subpopulations and habitat loss) may explain why Allegheny woodrats are no longer found in many areas where they existed just 25 y ago. In southern West Virginia, surface coal mining is a major cause of forest fragmentation. Furthermore, mountaintop mining, the prevalent method in the region, results in a loss of rock outcrops and cliffs within forested areas, typical habitat of the Allegheny woodrat To determine the extent that Allegheny woodrats make use of reclaimed mine land, particularly rock drainages built during reclamation, we sampled 24 drainage channels on reclaimed surface mines in southern West Virginia, collected habitat data at each site and used logistic regression to identify habitat variables related to Allegheny woodrat presence. During 187 trap nights, 13 adult, 2 subadult and 8 juvenile Allegheny woodrats were captured at 13 of the 24 sites. Percent of rock as a groundcover and density of stems >15 cm diameter-at-breast-height (DBH) were related to Allegheny woodrat presence and were significantly greater at sites where Allegheny woodrats were present than absent. Sites where Allegheny woodrats were present differed substantially from other described habitats in West Virginia, though they may simulate boulder piles that occur naturally. Our findings suggest the need for additional research to examine the dynamics between Allegheny woodrat populations inhabiting rock outcrops in forests adjacent to mines and populations inhabiting constructed drainage channels on reclaimed mines. However, if Allegheny woodrats can use human-created habitat, our results will be useful to surface mine reclamation and to other mitigation efforts where rocky habitats are lost or disturbed.

  8. 77 FR 71117 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Allegheny County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ...; Allegheny County Incorporation by Reference of Pennsylvania's Control of NO X Emissions From Glass Melting... regulation to control nitrogen oxides (NO X ) emissions from glass melting furnaces to the Allegheny County... Pennsylvania regulations and related definitions for controlling NO X emissions from glass melting...

  9. 77 FR 71140 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Allegheny County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ...; Allegheny County Incorporation by Reference of Pennsylvania's Consumer Products Regulations AGENCY... 2105.88--Consumer Products to Allegheny County Health Department (ACHD) Rules and Regulations, Article... Products) of PADEP's Air Pollution Control Act to reduce emissions of volatile organic compounds (VOC)....

  10. ALLEGHENY FRONT AND HICKORY CREEK ROADLESS AREAS, PENNSYLVANIA.

    USGS Publications Warehouse

    Schweinfurth, Stanley P.; Girol, Vaughn P.

    1984-01-01

    On the basis of a mineral-resource survey the Allegheny Front and Hickory Creek Roadless Areas, Pennsylvania, have a substantiated potential for oil resources, a probable potential for gas resources, and little likelihood for the occurrence of coal and metallic mineral resources. The oil and gas in the Upper Devonian rocks are found in stratigraphic traps, that commonly are not evident from surface indications. The only sure method to determine if the Upper Devonian sandstones contain oil or gas at a specific site is to drill through the sequence and test the more favorable zones.

  11. A reconnaissance geochemical survey of the Allegheny Front and Hickory Creek Roadless Areas, Allegheny National Forest, Warren County, Pennsylvania

    USGS Publications Warehouse

    Hickling, N.L.; Schweinfurth, Stanley P.; Adrian, Betty M.

    1983-01-01

    A reconnaissance geochemical survey of the Allegheny Front and Hickory Creek Roadless Areas, Warren County, Pennsylvania, was made by members of the U.S. Geological Survey (USGS) to test for indistinct or unexposed mineral deposits that might be recognized by geochemical halos. Analyses using semiquantitative emission spectrography and atomic absorption for 32 elements were performed on 21 stream-sediment samples and 31 bedrock samples from the Allegheny Front tract, and on 23 stream-sediment samples and 6 bedrock samples from the Hickory Creek tract. Bedrock samples analyzed are primarily sandstone, siltstone and shale. Neither major chemical anomalies nor obviously anomalous chemical-element concentrations related to mineralized bedrock were indicated in the geochemical survey. Metallic mineral deposits were not identified in the study area during the survey, which is consistent with other studies reported in the literature for the surrounding region. The lithologic units exposed in the roadless areas do not commonly host metallic deposits in the surrounding region, and the probability is low that such deposits occur in the roadless areas.

  12. The Tunnels of Samos

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1995-01-01

    This 'Project Mathematics' series video from CalTech presents the tunnel of Samos, a famous underground aquaduct tunnel located near the capital of Pithagorion (named after the famed Greek mathematician, Pythagoras, who lived there), on one of the Greek islands. This tunnel was constructed around 600 BC by King Samos and was built under a nearby mountain. Through film footage and computer animation, the mathematical principles and concepts of why and how this aquaduct tunnel was built are explained.

  13. 77 FR 66606 - Allegheny Electric Cooperative, Inc. and the Connecticut Bank and Trust Company, National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Allegheny Electric Cooperative, Inc. and the Connecticut Bank and Trust Company, National Association; Notice of Application for Partial Transfer of License, and...

  14. 3. VIEW OF TUNNEL INTAKE, WITH LOG TRASH RACK, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF TUNNEL INTAKE, WITH LOG TRASH RACK, LOOKING SOUTH - High Mountain Dams in Upalco Unit, Farmers Lake Tunnel, Ashley National Forest, 5.7 miles North of Swift Creek Campground, Mountain Home, Duchesne County, UT

  15. 5. VIEW OF TUNNEL OUTLET AND CHANNEL, LOOKING SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF TUNNEL OUTLET AND CHANNEL, LOOKING SOUTH - High Mountain Dams in Upalco Unit, Farmers Lake Tunnel, Ashley National Forest, 5.7 miles North of Swift Creek Campground, Mountain Home, Duchesne County, UT

  16. Coseismic deformation of the Wrights tunnel during the 1906 San Francisco earthquake: A key to understanding 1906 fault slip and 1989 surface ruptures in the southern Santa Cruz Mountains, California

    USGS Publications Warehouse

    Prentice, C.S.; Ponti, D.J.

    1997-01-01

    The Wrights tunnel is an abandoned railroad tunnel that crosses the San Andreas fault in the southern Santa Cruz Mountains in the vicinity of the 1989 Loma Prieta earthquake. The tunnel was damaged and deformed during the 1906 San Francisco earthquake and a plot showing postearthquake measurements made in the tunnel is given by Lawson [1908]. The amount of offset shown on this plot (1.5 m) has been used in several studies as being representative of the amount of fault offset along this segment of the San Andreas fault in 1906. Our historical research shows that different observers reported different amounts of fault offset in the tunnel and that the 1.5 m given on the plot is not a surveyed measurement. In addition, the plot of the tunnel has been interpreted in several previous studies as evidence of a broad (1.5 km) zone of faulting beneath Summit Ridge. Our analysis shows that this plot need not indicate a broad zone of deformation. Our historical research and modeling of the tunnel measurements indicate that faulting was confined to a zone less than 400 m wide and that 60-85% of the coseismic slip occurred across a single fault plane. There is no evidence for offset across a second shear zone beneath Summit Ridge in 1906. This implies that surface fractures reported on Summit Ridge in 1906 were not associated with significant deformation of the tunnel, implying that they were shallow, surficial features. By analogy, the very similar fractures that occurred on Summit Ridge in 1989 were also probably the result of shallow gravitational, rather than deep-seated tectonic, processes. Our modeling also indicates that total coseismic, near-surface slip across the San Andreas fault zone in the Wrights tunnel in 1906 was at least 1.7-1.8 m.

  17. Fecal-Indicator Bacteria in the Allegheny, Monongahela, and Ohio Rivers and Selected Tributaries, Allegheny County, Pennsylvania, 2001-2005

    USGS Publications Warehouse

    Buckwalter, Theodore F.; Zimmerman, Tammy M.; Fulton, John W.

    2006-01-01

    Concentrations of fecal-indicator bacteria were determined in 1,027 water-quality samples collected from July 2001 through August 2005 during dry- (72-hour dry antecedent period) and wet-weather (48-hour dry antecedent period and at least 0.3 inch of rain in a 24-hour period) conditions in the Allegheny, Monongahela, and Ohio Rivers (locally referred to as the Three Rivers) and selected tributaries in Allegheny County. Samples were collected at five sampling sites on the Three Rivers and at eight sites on four tributaries to the Three Rivers having combined sewer overflows. Water samples were analyzed for three fecal-indicator organisms fecal coliform, Escherichia coli (E. coli), and enterococci bacteria. Left-bank and right-bank surface-water samples were collected in addition to a cross-section composite sample at each site. Concentrations of fecal coliform, E. coli, and enterococci were detected in 98.6, 98.5, and 87.7 percent of all samples, respectively. The maximum fecal-indicator bacteria concentrations were collected from Sawmill Run, a tributary to the Ohio River; Sawmill Run at Duquesne Heights had concentrations of fecal coliform, E. coli, and enterococci of 410,000, 510,000, and 180,000 col/100 mL, respectively, following a large storm. The samples collected in the Three Rivers and selected tributaries frequently exceeded established recreational standards and criteria for bacteria. Concentrations of fecal coliform exceeded the Pennsylvania water-quality standard (200 col/100 mL) in approximately 63 percent of the samples. Sample concentrations of E. coli and enterococci exceeded the U.S. Environmental Protection Agency (USEPA) water-quality criteria (235 and 61 col/100 mL, respectively) in about 53 and 47 percent, respectively, of the samples. Fecal-indicator bacteria were most strongly correlated with streamflow, specific conductance, and turbidity. These correlations most frequently were observed in samples collected from tributary sites. Fecal

  18. An epidemiologic study of homicides in Allegheny County, Pennsylvania.

    PubMed

    Costantino, J P; Kuller, L H; Perper, J A; Cypess, R H

    1977-10-01

    Extensive demographic data concerning homicide victims and perpetrators in Allegheny County, 1966-1974, were obtained retrospectively from the records of the County Coroner's Office and Police Department. Analysis revealed that the demographic characteristics describing perpetrators and victims were essentially identical. Rates of homicide peaked in the young adult years of life. The race ratio (B/W) among victims was 18.7 for males and 6.7 for females, while sex ratio (M/F) was 5.4 for blacks and 1.9 for whites. An inverse relationship between the rate of homicide and socioeconomic status was present among both black and white races. The majority of victims were killed by a spouse, relative, or friend (66%), usually in familiar locations, i.e., residence or place of work (60%), and usually during an alteration (68%). Shooting was the method used to perpetrate 61% of the killings, most of which were by means of a handgun. An increasing trend of homicide was noted, particularly for the type perpetrated by shooting. PMID:910799

  19. 4. VIEW FROM MIDDLE ADIT OF WAWONA TUNNEL AT HWY. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW FROM MIDDLE ADIT OF WAWONA TUNNEL AT HWY. 120. TUNNEL #1 IS IN LOWER CENTER OF IMAGE. - Big Oak Flat Road Tunnel No. 1, Through mountain spur on New Big Oak Flat Road, Yosemite Village, Mariposa County, CA

  20. 77 FR 790 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM...) Rules of Practice and Procedures, 18 CFR 385.206, FirstEnergy Solutions Corp., Allegheny Energy...

  1. 76 FR 81923 - Trans-Allegheny Interstate Line Company; Notice of Amendment To Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Trans-Allegheny Interstate Line Company; Notice of Amendment To Petition for Declaratory Order Take notice that on December 20, 2011, Trans-Allegheny Interstate Line Company...

  2. 75 FR 73064 - Lock Hydro Friends Fund XLI; Allegheny 7 Hydro, LLC; Notice of Competing Preliminary Permit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ... Energy Regulatory Commission Lock Hydro Friends Fund XLI; Allegheny 7 Hydro, LLC; Notice of Competing... 19, 2010. On May 18, 2010, Lock Hydro Friends Fund XLI, and Allegheny 7 Hydro, LLC filed applications, pursuant to section 4(f) of the Federal Power Act, proposing to study the feasibility of hydropower at...

  3. Maryland: Mountains to the Sea. A Gallery Class, Grades 4-6.

    ERIC Educational Resources Information Center

    National Aquarium in Baltimore, MD. Dept. of Education.

    The "Maryland: Mountains to the Sea" exhibit (National Aquarium in Baltimore) consists of four exhibits and eight graphics panels. The exhibits are an Allegheny pond and a salt marsh which are both partially open, Assateague beach which includes birds, and the continental shelf. A variety of Maryland pond and ocean fish, crabs, and water birds are…

  4. Transport of radon gas into a tunnel at Yucca Mountain--estimating large-scale fractured tuff hydraulic properties and implications for the operation of the ventilation system.

    PubMed

    Unger, André; Finsterle, Stefan; Bodvarsson, Gudmundur

    2004-06-01

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of 1 x 10(-11) m2 and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level. PMID:15134873

  5. Transport of Radon Gas into a Tunnel at Yucca Mountain-Estimating Large-Scale Fractured Tuff Hydraulic Properties and Implications for the Operation of the Ventilation System

    SciTech Connect

    A. Unger; S. Finsterle; G. Bodvarsson

    2003-06-06

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of l x 10{sup -11} m{sup 2} and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level.

  6. 77 FR 71139 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Allegheny County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... Glass Melting Furnaces AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY... oxides (NO X ) emissions from glass melting furnaces to the Allegheny County Health Department (ACHD... related definitions for controlling NO X emissions from glass melting furnaces. The SIP revision is...

  7. Passing on a Culture: West Virginia Traditional Musical Heritage and the Allegheny Echoes Programme

    ERIC Educational Resources Information Center

    Swain, Leila Ryland

    2010-01-01

    Allegheny Echoes is a summer programme of instruction and performance of music and poetry held in Marlinton, WV. The Bing Brothers learned their traditional music from the Hammons family of Pocahontas County, WV, in an informal setting of friendship and collaboration. The Hammons family was recorded in the 1970s by Alan Jabbour and others; the…

  8. 78 FR 34584 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Allegheny County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ...; Allegheny County Reasonably Available Control Technology Under the 8-Hour Ozone National Ambient Air Quality... Pennsylvania Department of Environmental Protection, Bureau of Air Quality Control, P.O. Box 8468, 400 Market... this document, whenever ``we,'' ``us,'' or ``our'' is used, we mean EPA. On February 26, 2013 (78...

  9. 77 FR 71115 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Allegheny County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ...; Allegheny County Incorporation by Reference of Pennsylvania's Consumer Products Regulations AGENCY... Department of Environmental Protection (PADEP). The SIP revision adds Section 2105.88--Consumer Products from... incorporate by reference 25 Pa. Code sections 130.201-130.471 (Consumer Products) of the PADEP Air...

  10. Allegheny National Forest, CCC Camp ANF1 , The camp’s main ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Allegheny National Forest, CCC Camp ANF-1 , The camp’s main entrance is located at the intersection of Duhring Road (ANF 131) and ANF 124, Pennsylvania, with the interior site road known as Trail Ride Drive., Marienville, Forest County, PA

  11. A Study of Continuing Legal Education of Allegheny County Bar Association Members.

    ERIC Educational Resources Information Center

    Davis, Benjamin George

    Legal education needs and preferences of lawyers in the Allegheny County, Pennsylvania, Bar Association were surveyed, with attention to such factors as motivation and lawyer characteristics. A pretested 40-item questionnaire was sent to all 2,218 members. Findings included the following: (1) felt needs pertained to trial work, real property law,…

  12. Fleas (Siphonaptera) of the Allegheny woodrat (Neotoma magister) in West Virginia with comments on host specificity

    USGS Publications Warehouse

    Castleberry, S.B.; Castleberry, N.L.; Wood, P.B.; Ford, W.M.; Mengak, M.T.

    2003-01-01

    Previous research has indicated fewer host-specific ectoparasites on woodrats of the eastern United States as compared to western woodrat species. The Allegheny woodrat (Neotoma magister) is a species of conservation concern that is associated with rocky habitats in the Appalachian and Interior Highland regions in the eastern United States. We examined Allegheny woodrat flea parasites in the core of the distribution to further elucidate patterns of ectoparasite host specificity in woodrats of the eastern United States. Of 346 fleas collected from 62 Allegheny woodrats, all but 1 were identified as Orchopeas pennsylvanicus. The single exception was a male Epitedia cavernicola, which represents only the second collection of this species from West Virginia. Unlike the eastern woodrat (Neotoma floridana), which hosts a variety of generalist flea parasites, Allegheny woodrats in our study were host to only 2 flea species, both of which are host specific to woodrats. We suggest that flea host specificity may be related to the specific habitat requirements of this species.

  13. 40 CFR 81.230 - Allegheny Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Allegheny Intrastate Air Quality Control Region. 81.230 Section 81.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.230...

  14. 40 CFR 81.230 - Allegheny Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Allegheny Intrastate Air Quality Control Region. 81.230 Section 81.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.230...

  15. 76 FR 6612 - Lock+ Hydro Friends Fund XL; FFP Missouri 4, LLC; Allegheny 4 Hydro, LLC; Three Rivers Hydro, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-07

    ...; Project No. 13782-000] Lock+ Hydro Friends Fund XL; FFP Missouri 4, LLC; Allegheny 4 Hydro, LLC; Three... drawing will serve as the tiebreaker. Based on the drawing, the order of priority is as follows: 1....

  16. 76 FR 4892 - Lock+ Hydro Friends Fund XXXIX, FFP Missouri 3, LLC, Allegheny 3 Hydro, LLC, Three Rivers Hydro...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    ..., Three Rivers Hydro, LLC; Notice Announcing Preliminary Permit Drawing January 20, 2011. On May 18, 2010... Missouri 3, LLC, for Project No. 13749-000, Allegheny 3 Hydro, LLC, for Project No. 13775-000, and...

  17. Mechanical tunnel excavation in welded tuff

    SciTech Connect

    Sperry, P.E.

    1991-12-31

    The Technical Review Board for the US high-level radioactive waste facility at Yucca Mountain has recommended maximum use of {open_quotes}the most modern mechanical excavation techniques...in order to reduce disturbance to the rock walls and to achieve greater economy of time and cost.{close_quotes} Tunnels for the waste repository at Yucca Mountain can be economically constructed with mechanical excavation equipment. This paper presents the results of mechanical excavation of a tunnel in welded tuff, similar to the tuffs of Yucca Mountain. These results are projected to excavation of emplacement drifts in Yucca Mountain using a current state-of-the-art tunnel boring machine (TBM).

  18. Health status indicators for the year 2000: projections for Allegheny County, Pennsylvania.

    PubMed Central

    Carson, C A; Zucconi, S L

    1993-01-01

    A consensus set of health status indicators was released in July 1991 by the Centers for Disease Control and Prevention for use by public health officials at the Federal, State, and local levels in identifying and monitoring issues of public health importance. These health status indicators have been projected for the Year 2000 in Allegheny County, PA, with linear regression analyses of historical data. Indications are that mortality rates for black infants, breast cancer mortality, suicide, lung cancer mortality, incidence of acquired immunodeficiency syndrome, and the number of measles cases likely will not meet the year 2000 targets in Allegheny County. These data will prove useful in monitoring progress towards the year 2000 objectives and provide comparative data for other geographic areas of the United States with similar demographic characteristics. PMID:8265755

  19. Effects of high salinity wastewater discharges on unionid mussels in the Allegheny River, Pennsylvania

    USGS Publications Warehouse

    Kathleen Patnode; Hittle, Elizabeth A.; Robert Anderson; Lora Zimmerman; Fulton, John W.

    2015-01-01

    We examined the effect of high salinity wastewater (brine) from oil and natural gas drilling on freshwater mussels in the Allegheny River, Pennsylvania, during 2012. Mussel cages (N = 5 per site) were deployed at two sites upstream and four sites downstream of a brine treatment facility on the Allegheny River. Each cage contained 20 juvenile northern riffleshell mussels Epioblasma torulosa rangiana). Continuous specific conductance and temperature data were recorded by water quality probes deployed at each site. To measure the amount of mixing throughout the entire study area, specific conductance surveys were completed two times during low-flow conditions along transects from bank to bank that targeted upstream (reference) reaches, a municipal wastewater treatment plant discharge upstream of the brine-facility discharge, the brine facility, and downstream reaches. Specific conductance data indicated that high specific conductance water from the brine facility (4,000–12,000 µS/cm; mean 7,846) compared to the reference reach (103–188 µS/cm; mean 151) is carried along the left descending bank of the river and that dilution of the discharge via mixing does not occur until 0.5 mi (805 m) downstream. Juvenile northern riffleshell mussel survival was severely impaired within the high specific conductance zone (2 and 34% at and downstream of the brine facility, respectively) and at the municipal wastewater treatment plant (21%) compared to background (84%). We surveyed native mussels (family Unionidae) at 10 transects: 3 upstream, 3 within, and 4 downstream of the high specific conductance zone. Unionid mussel abundance and diversity were lower for all transects within and downstream of the high conductivity zone compared to upstream. The results of this study clearly demonstrate in situ toxicity to juvenile northern riffleshell mussels, a federally endangered species, and to the native unionid mussel assemblage located downstream of a brine discharge to the

  20. Lithostratigraphy of Upper Devonian Scherr-Foreknobs and Lockhaven Formations near Allegheny front of central Pennsylvanian

    SciTech Connect

    Warne, A.G.; McGhee, G.R. Jr.

    1986-05-01

    Five well-exposed sections (at Madley, New Baltimore, Altoona, Milesburg, and Lockhaven) of Upper Devonian marine strata were measured and analyzed to refine lithologic and temporal correlations along the Allegheny Front of Pennsylvania. The members of the Scherr and Foreknobs formations (Minnehaha Springs, Mallow, Briery Gap, Blizzard, Pound, and Red Lock) are recognized as far north as Altoona. Farther north at Milesburg and Lockhaven, the lithology of the upper parts of the Lockhaven Formation are markedly different from the contiguous Foreknobs Formation, but the Minnehaha Springs member of the basal Scherr and lower-middle Lockhaven Formations is recognized in all sections studied. The Minnehaha Springs member (a 50 to 100-ft, resistant, medium-gray to red-gray sandy silt unit) is considered to be the result of a brief sea level lowering and is therefore nearly isochronous. The isochronous nature of the Minnehaha Springs member is substantiated by biostratigraphic data; therefore, it is considered the most reliable datum for correlating the sections of this study. The lithologic information of the six measured sections was augmented by 38 wells logs of oil and gas wells of the region. From the combined lithologic data, three generalized lithofacies cross sections were generated. These cross sections clearly indicate that: (1) the strike of the paleoshoreline was nearly parallel with the Allegheny Front; (2) a major delta lobe existed in central Pennsylvania during the Late Devonian; but (3) the size and influence of the delta on depositional environments was not constant through space and time.

  1. Allegheny woodrat (Neotoma magister) captive propagation to promote recovery of declining populations.

    PubMed

    Smyser, Timothy J; Swihart, Robert K

    2014-01-01

    The Allegheny woodrat (Neotoma magister) is endemic to the eastern United States with local distributions restricted to rocky habitats within deciduous forests. Over the last 40 years, woodrats have declined precipitously due to an array of human-mediated pressures. There is growing interest in the captive propagation of woodrats as a tool to promote in situ conservation, but their solitary social structure, territorial behavior, and low fecundity present challenges for the attainment of levels of ex situ reproduction sufficient to support reintroduction programs. In 2009 we established a captive breeding program with 12 wild-caught individuals (4.8) collected from Indiana and Pennsylvania. Restricting breeding to wild-caught individuals, over 26 months we produced 19 litters comprised of 43 pups (26.17), of which 40 (24.16) survived to weaning. In sum, wild-caught individuals readily habituated to the captive environment and the low fecundity of woodrats was offset by high survival rates for both adults and juveniles. Therefore, when managed appropriately, captive Allegheny woodrat populations should be capable of supporting the release of surplus individuals to augment in situ conservation measures. PMID:24391017

  2. 78 FR 12750 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM... sections 206 and 306 of the Federal Power Act, 16 U.S.C. 824(e) and 825(e), FirstEnergy Solutions Corp....

  3. 77 FR 20019 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM... Practice and Procedure, 18 CFR 385.206 and 206(h), FirstEnergy Solutions Corp. (FirstEnergy Solutions)...

  4. 78 FR 58533 - FirstEnergy Generation, LLC, Allegheny Energy Supply Company, LLC, and Green Valley Hydro, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 2280-017, 2343-084, 2459-245, 2516-057, 2517-036, 3494- 091, 3671-086, 2391-046, 2425-052, and 2509-046] FirstEnergy Generation, LLC, Allegheny Energy...

  5. 77 FR 38271 - Voluntary Termination of Foreign-Trade Subzone 33B Verosol USA, Inc. Kennedy Township, Allegheny...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... Subzone 33B at the Verosol USA, Inc., plant in Kennedy Township, Allegheny County, Pennsylvania (Board Order 416, 54 FR 164, 1/4/89); Whereas, the Regional Industrial Development Corporation of Southwestern... Foreign-Trade Zones Board Voluntary Termination of Foreign-Trade Subzone 33B Verosol USA, Inc....

  6. 78 FR 2392 - Allegheny Energy Supply, LLC; Notice of Intent To File License Application, Filing of Pre...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ..., Filing of Pre-Application Document (PAD), Commencement of Pre-Filing Process, and Scoping; Request for Comments on the PAD and Scoping Document, and Identification of Issues and Associated Study Requests a.... Allegheny Energy Supply, LLC, filed with the Commission a Pre- Application Document (PAD; including...

  7. 77 FR 9225 - Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-16

    ... Energy Regulatory Commission Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM States, Inc., et al. v. PJM Interconnection, L.L.C.; Notice of Filing Take notice that on... required by section 18.17.4 of the Amended and Restated Operating Agreement of PJM Interconnection,...

  8. 78 FR 57680 - Bessemer and Lake Erie Railroad Company-Abandonment Exemption-in Allegheny County, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... Surface Transportation Board Bessemer and Lake Erie Railroad Company--Abandonment Exemption-- in Allegheny... line either is pending with the Surface Transportation Board (Board) or with any U.S. District Court or... the Surface Transportation Board, 395 E Street SW., Washington, DC 20423-0001. \\2\\ The Board...

  9. Comparison of Skylab and Landsat Lineaments with Joint Orientations in Northcentral Pennsylvania. [on Allegheny Plateau

    NASA Technical Reports Server (NTRS)

    Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Kowalik, W. S.

    1975-01-01

    The author has identified the following significant results. The histogram peaks of lineaments mapped from Skylab photograph at a scale of 1:517,000 lie subparallel, within 20 deg, to major shale joints and coal cleats on part of the Allegheny Plateau. The Landsat lineament, mapped at 1:989,000 are biased by illumination and scan line directions. While there is an illumination bias in the Skylab photograph, its direction does not coincide with the main transverse lineament trend, thus providing an independent assessment of the illumination direction bias. The coincidence in direction regardless of scale of the linear features suggests a mechanical relationship between joints, fracture traces, and lineaments which is more consistent with a tensional model than a shear model of origin.

  10. Assessment of freshwater mussels in the Allegheny River at Foxburg, Pennsylvania, 1998

    USGS Publications Warehouse

    Anderson, Robert M.

    2000-01-01

    The upper reaches of the Allegheny River are a high-quality resource that supports populations of a number of endangered species. Two endangered species of freshwater mussel, the northern riffleshell, Epioblasma torulosa rangiana, and clubshell, Pleurobema clava, are present in this river reach. Prior to a bridge-replacement project at the Allegheny River at Foxburg, Pa. (river mile 86.2), a mussel survey was conducted to determine if either of the protected endangered species are present and to assess the quality of the mussel bed at this site. Shore and near-shore searches followed by SCUBA diving transects determined that a mussel bed is present at this location. The freshwater-mussel community consists of at least 14 species and includes both endangered species. Substrate type, stream velocity, and channel morphology combined with results from the transect searches documented that the mussel bed is largely limited to the east side of the river. A two-stage sampling design was employed to estimate the overall mussel abundance within the bed. Twelve 4-m2 (square meter) cells were sampled with four 0.25-m2 quadrants per cell. The mean population density within the mussel bed is 8.4 mussel per square meter. The overall mussel population in the survey area is 225,567 individuals (95-percent confidence interval, 135,973 to 374,195). River-bed scour and acid mine drainage appear to limit mussel distribution in the center and left section of the channel. Overall, a healthy and diverse mussel bed exists at this site.

  11. Yucca Mountain Milestone

    SciTech Connect

    Hunt, Rod

    1997-06-09

    The Department of Energy project to determine if the Yucca Mountain site in Nevada is suitable for geologic disposal of high-level nuclear waste reached a major milestone in late April when a 25-foot-diameter tunnel boring machine ``holed through'' completing a five-mile-long, horseshoe-shaped excavation through the mountain. When the cutting-head of the giant machine broke through to daylight at the tunnel's south portal, it ended a 2 1/2-year excavation through the mountain that was completed ahead of schedule and with an outstanding safety record. Video of the event was transmitted live by satellite to Washington, DC, where it was watched by Secretary of Energy Frederico Pena and other high-level DOE officials, signifying the importance of the project's mission to find a repository for high-level nuclear waste and spent nuclear fuel produced by nuclear power plants. This critical undertaking is being performed by DOE's Office of Civilian Radioactive Waste Management (OCRWM). The tunnel is the major feature of the Exploratory Studies Facility (ESF), which serves as an underground laboratory for engineers and scientists to help determine if Yucca Mountain is suitable to serve as a repository for the safe disposal of high-level nuclear waste. Morrison Knudsen's Environmental/Government Group is providing design and construction-management services on the project. The MK team is performing final design for the ESF and viability assessment design for the underground waste repository that will be built only if the site is found suitable for such a mission. In fact, if at anytime during the ESF phase, the site is found unsuitable, the studies will be stopped and the site restored to its natural state.

  12. Christmas Mountains

    Atmospheric Science Data Center

    2013-04-17

    article title:  Christmas Mountains     View Larger Image ... New Brunswick. Located above image center are the Christmas Mountains, a region of old-growth forest nestled in a remote wilderness. Within ...

  13. Determination of locally formed sulfates for Allegheny county`s PM10 state implementation plan

    SciTech Connect

    Weaver, C.J.; Patel, H.L.; Houston, R.M.

    1995-12-31

    In support of a State Implementation Plan for the Liberty Borough/Clairton PM10 nonattainment area, Allegheny County developed a procedure for determining the concentrations of locally formed secondary PM10 that contributes to PM10 concentrations monitored within the nonattainment area. The County defines secondary PM10 concentration as the sum of the concentrations of sulfate, nitrate, and ammonium formed outside the emitting sources. Analysis of monitored data showed that under certain meteorological conditions, substantial secondary PM10 was formed at some locations within the nonattainment area. The days within the modeling year were divided into categories according to the average local wind speed and average mixing height for each day. Secondary PM10 concentrations were predicted for each category. Sulfate typically accounts for at least sixty percent of the secondary PM10. Filter analysis shows that sulfate concentrations are three times those of ammonia. Concentrations of the other cations and metals do not follow the same trend as do sulfate concentrations and are consistently too small to account for the sulfate present. This indicates that the total mass of these species in the nonattainment area is present as a mixture of ammonium sulfates and ammonium nitrates.

  14. Prevalence of Baylisascaris procyonis in habitat associated with Allegheny woodrat (Neotoma magister) populations in Indiana.

    PubMed

    Page, L Kristen; Johnson, Scott A; Swihart, Robert K; Kazacos, Kevin R

    2012-04-01

    Allegheny woodrat (Neotoma magister) populations have been in decline across their range since the late 1970s. Hypotheses proposed to explain these declines include habitat fragmentation and loss, decreased food availability, and increased mortality from infection with Baylisascaris procyonis. We investigated the prevalence of B. procyonis at raccoon (Procyon lotor) latrines in woodrat cliff habitats (n = 18) along the Ohio River in southern Indiana in 1995. We located 275 latrines (mean = 15.3/site; range, 6-34) and found B. procyonis in 13 (4.7%) latrines across all sites. When present at a site, B. procyonis occurred, on average, at 11.1%of latrines (range, 3-36%). Woodrat abundance, determined through a concurrent live-trapping program, was significantly higher (χ(2) = 5.12, df = 1, P = 0.024) at sites where B. procyonis was not found (9.5 ± 2.52) than at sites with B. procyonis (3.7 ± 2.2). Our analyses support the hypothesis that this parasite could contribute to declines in woodrat abundance. Because woodrats cache nonfood items, including raccoon feces, and are highly susceptible to the parasite, they are at increased risk for B. procyonis infection, which could be deleterious, especially to small populations. PMID:22493131

  15. Appalachian Mountains

    Atmospheric Science Data Center

    2014-05-15

    article title:  Appalachian Mountains     View Larger Image Multi-angle views of the Appalachian Mountains, March 6, 2000 . The true-color image at left is a ... from Lake Ontario to northern Georgia, and spanning the Appalachian Mountains. The three images to the right are also in true-color, ...

  16. Massanutten Mountain, Virginia, USA (Anaglyph)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Massanutten Mountain lies in the Shenandoah Valley of northern Virginia. Rock layers in the mountain are folded downward in an overall 'U' shape (called a syncline) which accounts for its peculiar double ridge shape with a highly elongated valley between. The ridges have formed because they are capped with a sandstone layer which is resistant to weathering and erosion. Limestones and shales are less resistant and form the lowlands and valleys. The north and south forks of the Shenandoah River flank Massanutten Mountain and display unusually pronounced meander patterns. Other layered sedimentary rocks form other ridgeline patterns in the Allegheny Mountains, to the upper left. But the igneous and metamorphic (crystalline) rocks of the Blue Ridge Mountains erode into a very different topographic pattern to the southeast. This small area provides an excellent example rock type, geologic structure, and fluvial (stream) processes all influencing landform development.

    This anaglyph was produced by first shading a preliminary elevation model from data acquired by the Shuttle Radar Topography Mission. The stereoscopic effect was then created by generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

    Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C

  17. Water tunnels

    NASA Technical Reports Server (NTRS)

    Bjarke, Lisa J.

    1991-01-01

    Some of the uses of water tunnels are demonstrated through the description of the NASA Ames-Dryden Flow Visualization Facility. It is concluded that water tunnels are capable of providing a quick and inexpensive means of flow visualization and can aid in the understanding of complex fluid mechanics phenomena.

  18. 14. Newfound Gap Road, view from atop tunnel, Tennessee side. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Newfound Gap Road, view from atop tunnel, Tennessee side. - Great Smoky Mountains National Park Roads & Bridges, Newfound Gap Road, Between Gatlinburg, TN & Cherokee, NC, Gatlinburg, Sevier County, TN

  19. Use of experimental translocations of Allegheny woodrat to decipher causal agents of decline.

    PubMed

    Smyser, Timothy J; Johnson, Scott A; Page, L Kristen; Hudson, Cassie M; Rhodes, Olin E

    2013-08-01

    Translocations are an important tool for wildlife conservation, although progress in the field of reintroduction biology has been hindered by the ad hoc and opportunistic nature of many translocations. We used an experimental translocation to elucidate the role of raccoon roundworm (Baylisascaris procyonis) and inbreeding depression in the decline of the Allegheny woodrat (Neotoma magister), an endangered species. We translocated woodrats from genetically diverse populations in the core of the species range to 4 previously occupied sites (reintroductions) and 2 sites supporting genetically depauperate populations (reinforcements) in Indiana (U.S.A.). In 2 reintroduction sites and 1 reinforcement site, we distributed anthelmintic baits to passively deworm raccoons and reduce the risk of woodrat exposure to roundworms. The remaining sites served as controls. We used raccoon latrine surveys and fecal flotation to monitor temporal variability in roundworm prevalence and effect of treatment. We used live trapping and microsatellite genotyping to monitor the demographic and genetic response of translocated populations over the following 54 months. At the conclusion of the study, 4 of 6 translocations were successfully maintaining abundance through local recruitment. The distribution of anthelmintic baits reduced levels of roundworm contamination, but levels of contamination were also low in 2 of 3 control sites. Reintroductions failed at control sites, one of which was due to high roundworm exposure. The other failed control reintroduction was likely attributable to demographic stochasticity and limited reproductive potential following initial mortality within the first 4 months. In both control and treatment reinforcements, increases in both allelic richness and heterozygosity were accompanied by increases in abundance, which is suggestive of genetic rescue. Our results demonstrate that mitigation of roundworm exposure through the distribution of anthelmintic baits can

  20. Tunneling machine

    SciTech Connect

    Snyder, L.L.

    1980-02-19

    A diametrically compact tunneling machine for boring tunnels is disclosed. The machine includes a tubular support frame having a hollow piston mounted therein which is movable from a retracted position in the support frame to an extended position. A drive shaft is rotatably mounted in the hollow piston and carries a cutter head at one end. The hollow piston is restrained against rotational movement relative to the support frame and the drive shaft is constrained against longitudinal movement relative to the hollow piston. A plurality of radially extendible feet project from the support frame to the tunnel wall to grip the tunnel wall during a tunneling operation wherein the hollow piston is driven forwardly so that the cutter head works on the tunnel face. When the hollow piston is fully extended, a plurality of extendible support feet, which are fixed to the rearward and forward ends of the hollow piston, are extended, the radially extendible feet are retracted and the support frame is shifted forwardly by the piston so that a further tunneling operation may be initiated.

  1. Water quality in the Allegheny and Monongahela River basins, Pennsylvania, West Virginia, New York, and Maryland, 1996-98

    USGS Publications Warehouse

    Anderson, Robert M.; Beer, Kevin M.; Buckwalter, Theodore F.; Clark, Mary E.; McAuley, Steven D.; Sams, James I., III; Williams, Donald R.

    2000-01-01

    Major influences and findings for ground water quality, surface water quality, and biology in the Allegheny and Monongahela River basins are described and illustrated. Samples were collected in a variety of media to determine trace elements, sulfate, pesticides, nitrate, volatile organic compounds, organochlorine compounds, and radon-222. This report discusses the influences of several land-use practices, such as coal mining, urbanization, agriculture, and forestry. The report also includes a summary of a regional investigation of water quality and quality invertebrates in the Northern and Central Appalachian coal regions.

  2. Recognition Tunneling

    PubMed Central

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-01-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode (“tethered molecule-pair” configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the “free analyte” configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules. PMID:20522930

  3. Fecal-indicator bacteria in the Allegheny, Monongahela, and Ohio Rivers, near Pittsburgh, Pennsylvania, July-September 2001

    USGS Publications Warehouse

    Fulton, John W.; Buckwalter, Theodore F.

    2004-01-01

    This report presents the results of a study by the Allegheny County Health Department (ACHD) and the U.S. Geological Survey (USGS) to determine the concentrations of fecal-indicator bacteria in the Allegheny, Monongahela, and Ohio Rivers (Three Rivers) in Allegheny County, Pittsburgh, Pa. Water-quality samples and river-discharge measurements were collected from July to September 2001 during dry- (72-hour dry antecedent period), mixed-, and wet-weather (48-hour dry antecedent period and at least 0.3 inch of rain in a 6-hour period) conditions at five sampling sites on the Three Rivers in Allegheny County. Water samples were collected weekly to establish baseline conditions and during successive days after three wet-weather events. Water samples were analyzed for fecal-indicator organisms including fecal-coliform (FC) bacteria, Escherichia coli (E. coli), and enterococci bacteria. Water samples were collected by the USGS and analyzed by the ACHD Laboratory. At each site, left-bank and right-bank surface-water samples were collected in addition to a composite sample (discharge-weighted sample representative of the channel cross section as a whole) at each site. Fecal-indicator bacteria reported in bank and composite samples were used to evaluate the distribution and mixing of bacteria-source streams in receiving waters such as the Three Rivers. Single-event concentrations of enterococci, E. coli, and FC during dry-weather events were greater than State and Federal water-quality standards (WQS) in 11, 28, and 28 percent of the samples, respectively; during mixed-weather events, concentrations of fecal-indicator bacteria were greater than WQS in 28, 37, and 43 percent of the samples, respectively; and during wet-weather events, concentrations of fecal-indicator bacteria were greater than WQS in 56, 71, and 81 percent of samples, respectively. Single-event, wet-weather concentrations exceeded those during dry-weather events for all sites except the Allegheny River at

  4. Vocational Programs for the Mentally Retarded in Allegheny County: A Study of Selected Sheltered Workshops and High School Programs. Final Report.

    ERIC Educational Resources Information Center

    Gordon, Elizabeth; Zamule, Elisabeth

    This report discusses sheltered workshop programming and high school-level vocational training for mentally retarded (MR) individuals in Allegheny County, Pennsylvania. Sheltered workshops conducted by Goodwill Industries and Parc-way Industries were examined to determine client characteristics and the rate of placement in competitive employment.…

  5. The Development of a Strategic Plan To Provide a Multisite Electronic Engineering Technology Program at the Community College of Allegheny County.

    ERIC Educational Resources Information Center

    Cunningham, Pearly

    A project was undertaken to develop a strategic plan to implement a multisite electronic engineering technology (EET) program at Pennsylvania's Community College of Allegheny County. Specifically, the project sought to determine how electronic communication technologies could provide a virtual learning community for the program; appropriate plans…

  6. The Panther Mountain circular structure, a possible buried meteorite crater

    NASA Technical Reports Server (NTRS)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    1992-01-01

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  7. The Panther Mountain circular structure, a possible buried meteorite crater

    NASA Astrophysics Data System (ADS)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  8. Stone Mountain

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This color image taken by the panoramic camera onboard the Mars Exploration Rover Opportunity shows the part of the rock outcrop dubbed Stone Mountain at Meridiani Planum, Mars. Scientists are examining Stone Mountain with the instruments on the rover's instrument deployment device, or 'arm,' in search of clues about the composition of the rock outcrop. [figure removed for brevity, see original site] A Patch of Stone (Figure credit: NASA/JPL/Cornell/USGS)

    The colorless square in this color image of the martian rock formation called Stone Mountain is one portion of the rock being analyzed with tools on the Mars Exploration Rover Opportunity's instrument deployment device, or 'arm.' The square area is approximately 3 centimeters (1.2 inches) across. Stone Mountain is located within the rock outcrop on Meridiani Planum, Mars. The image was taken by the rover's panoramic camera.

  9. Mountain research

    NASA Astrophysics Data System (ADS)

    The newly incorporated International Mountain Society (IMS) will in May begin publication of an interdisciplinary scientific journal, Mountain Research and Development. The quarterly will be copublished with the United National University; additional support will come from UNESCO.A primary objective of IMS is to ‘help solve mountain land-use problems by developing a foundation of scientific and technical knowledge on which to base management decisions,’ according to Jack D. Ives, president of the Boulder-based organization. ‘The Society is strongly committed to the belief that a rational worldwide approach to mountain problems must involve a wide range of disciplines in the natural and human sciences, medicine, architecture, engineering, and technology.’

  10. A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

    2012-05-01

    The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

  11. Detailed gravity mapping of the Panther Mountain circular structure, Catskill Mountains, New York

    SciTech Connect

    Isachsen, Y.W. ); Revetta, F.A. )

    1993-03-01

    The Panther Mountain circular structure is located in the Catskill Mountains near the eastern edge of the Allegheny Plateau where depth through the sedimentary section to basement is about 3200 m. The structure is distinguished from the rest of the Plateau only by its physiography. It is a circular mountain mass, 10 km in diameter, defined by an anomalous annular drainage pattern formed by Esopus Creek and its tributary Woodland Creek. Because of pervasive fluvial cross bedding in the sedimentary pile, the authors were unable to determine whether the structure is slightly domical, sightly basinal, or unwarped. North-south and east-west gravity profiles were next made and modeled to look for a subsurface explanation for the structure. The only computed profiles that matched the measured values were those for a shallowly-buried meteorite crater with its underlying breccia lens, lying beneath the Panther Mountain. Renewed interest in the structure led them to make 125 new gravity measurements, in a study that is continuing. Gravity values are corrected using the International Gravity Formula of 1967 and densities of 2.67 and 2.50 gms/cm[sup 3]. Terrain corrections were computed using an inner radius of .895 km and an outer radius of 166.70 km. The complete Bouguer gravity anomaly was separated into its regional and residual components to obtain a third order residual gravity map for computer modeling. The residual gravity map confirms the earlier detected gravity low and leaves the buried meteorite crater model as a viable model.

  12. Mechanical excavator performance in Yucca Mountain tuffs

    SciTech Connect

    Ozdemir, L.; Hansen, F.D.

    1991-01-01

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests and potentially large-scale laboratory demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs. 3 refs., 2 tabs.

  13. Mechanical excavator performance in Yucca Mountain tuffs

    SciTech Connect

    Ozdemir, L.; Hansen, F.D.

    1991-12-31

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests, and potentially large-scale lab. demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well-quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs.

  14. Tunneling Nanotubes

    PubMed Central

    Lou, Emil; Fujisawa, Sho; Barlas, Afsar; Romin, Yevgeniy; Manova-Todorova, Katia; Moore, Malcolm A.S.; Subramanian, Subbaya

    2012-01-01

    Tunneling nanotubes are actin-based cytoplasmic extensions that function as intercellular channels in a wide variety of cell types.There is a renewed and keen interest in the examination of modes of intercellular communication in cells of all types, especially in the field of cancer biology. Tunneling nanotubes –which in the literature have also been referred to as “membrane nanotubes,” “’intercellular’ or ‘epithelial’ bridges,” or “cytoplasmic extensions” – are under active investigation for their role in facilitating direct intercellular communication. These structures have not, until recently, been scrutinized as a unique and previously unrecognized form of direct cell-to-cell transmission of cellular cargo in the context of human cancer. Our recent study of tunneling nanotubes in human malignant pleural mesothelioma and lung adenocarcinomas demonstrated efficient transfer of cellular contents, including proteins, Golgi vesicles, and mitochondria, between cells derived from several well-established cancer cell lines. Further, we provided effective demonstration that such nanotubes can form between primary malignant cells from human patients. For the first time, we also demonstrated the in vivo relevance of these structures in humans, having effectively imaged nanotubes in intact solid tumors from patients. Here we provide further analysis and discussion on our findings, and offer a prospective ‘road map’ for studying tunneling nanotubes in the context of human cancer. We hope that further understanding of the mechanisms, methods of transfer, and particularly the role of nanotubes in tumor-stromal cross-talk will lead to identification of new selective targets for cancer therapeutics. PMID:23060969

  15. Caucasus Mountains

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Often regarded as the southeastern border of Europe, the Caucasus Mountains can be seen here stretching from the Black Sea (left) to the Caspian Sea (right). The mountain range spans 700 miles (1125 km), crossing the countries of Russian Federation, Georgia, and Azerbaijan from left to right respectively. With a snowline of approximately 11,000 feet and peaks such as Mt. Elbrus, that reach 15,000 feet, much of the snow visible in this image is present year round. Also visible in this image are apparent phytoplankton blooms in the Caspian Sea, marked by blue-green swirls.

  16. Magnificent Mountains

    ERIC Educational Resources Information Center

    Anderson, Heather

    2004-01-01

    One way to increase awareness of endangered national heritage is to teach youth the importance of the land through the study of selected works of art. This article describes a lesson, in which students will study the work of Thomas Moran and create a mountain range collage. A short biography of Thomas Moran is included.

  17. Effects of Coal-Mine Drainage on Stream Water Quality in the Allegheny and Monongahela River Basins-Sulfate Transport and Trends

    USGS Publications Warehouse

    Sams, James I., III; Beer, Kevin M.

    2000-01-01

    In 1980, the Allegheny and Monongahela Rivers transported a sulfate load of 1.2 million and 1.35 million tons, respectively, to the Ohio River at Pittsburgh. The Monongahela River Basin had a sulfate yield of 184 tons per square mile per year compared to 105 tons per square mile per year for the Allegheny River Basin. Within the large Allegheny and Monongahela River Basins, the subbasins with the highest sulfate yields in tons per square mile per year were those of Redstone Creek (580), Blacklick Creek (524), Conemaugh River (292), Buffalo Creek (247), Stonycreek River (239), Two Lick Creek (231), Dunkard Creek (212), and Loyalhanna Creek (196). These basins have been extensively mined. The sulfate yields of Brokenstraw and Conewango Creeks, which are outside the area underlain by coal and thus contain no coal mines, were 25 and 24 tons per square mile per year, respectively. Within the Allegheny and Monongahela River Basins, seven sites showed significant trends in sulfate concentration from 1965 to 1995. Dunkard Creek and Stonycreek River show significant upward trends in sulfate concentration. These trends appear to be related to increases in coal production in the two basins from 1965 to 1995. Blacklick Creek at Josephine and Loyalhanna Creek at Loyalhanna Dam show significant downward trends in sulfate concentration between 1965 and 1995. Blacklick Creek had a 50-percent decrease in sulfate concentration. Coal production in the Blacklick Creek Basin, which reached its peak at almost 4 million tons per year in the 1940's, dropped to less than 1 million tons per year by 1995. In the Loyalhanna Creek Basin, which had a 41-percent decrease in sulfate concentration, coal-production rates dropped steadily from more than 1.5 million tons per year in the 1940's to less than 200,000 tons per year in 1995.

  18. Domino Tunneling.

    PubMed

    Schreiner, Peter R; Wagner, J Philipp; Reisenauer, Hans Peter; Gerbig, Dennis; Ley, David; Sarka, János; Császár, Attila G; Vaughn, Alexander; Allen, Wesley D

    2015-06-24

    Matrix-isolation experiments near 3 K and state-of-the-art quantum chemical computations demonstrate that oxalic acid [1, (COOH)2] exhibits a sequential quantum mechanical tunneling phenomenon not previously observed. Intensities of numerous infrared (IR) bands were used to monitor the temporal evolution of the lowest-energy O-H rotamers (1cTc, 1cTt, 1tTt) of oxalic acid for up to 19 days following near-infrared irradiation of the matrix. The relative energies of these rotamers are 0.0 (1cTc), 2.6 (1cTt), and 4.0 (1tTt) kcal mol(-1). A 1tTt → 1cTt → 1cTc isomerization cascade was observed with half-lives (t1/2) in different matrix sites ranging from 30 to 360 h, even though the sequential barriers of 9.7 and 10.4 kcal mol(-1) are much too high to be surmounted thermally under cryogenic conditions. A general mathematical model was developed for the complex kinetics of a reaction cascade with species in distinct matrix sites. With this model, a precise, global nonlinear least-squares fit was achieved simultaneously on the temporal profiles of nine IR bands of the 1cTc, 1cTt, and 1tTt rotamers. Classes of both fast (t(1/2) = 30-50 h) and slow (t(1/2) > 250 h) matrix sites were revealed, with the decay rate of the former in close agreement with first-principles computations for the conformational tunneling rates of the corresponding isolated molecules. Rigorous kinetic and theoretical analyses thus show that a "domino" tunneling mechanism is at work in these oxalic acid transformations. PMID:26027801

  19. Looking into Tunnel Books.

    ERIC Educational Resources Information Center

    Hinshaw, Craig

    1999-01-01

    Describes how to make tunnel books, which are viewed by looking into a "tunnel" created by accordion-folded expanding sides. Suggests possible themes. Describes how to create a walk-through tunnel book for first grade students. (CMK)

  20. Carpal tunnel release

    MedlinePlus

    Median nerve decompression; Carpal tunnel decompression; Surgery - carpal tunnel ... The median nerve and the tendons that flex (or curl) your fingers go through a passage called the carpal tunnel in ...

  1. Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

    PubMed

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-01

    The presence of bromide in rivers does not affect ecosystems or present a human health risk; however, elevated concentrations of bromide in drinking water sources can lead to difficulty meeting drinking water disinfection byproduct (DBP) regulations. Recent attention has focused on oil and gas wastewater and coal-fired power plant wet flue gas desulfurization (FGD) wastewater bromide discharges. Bromide can be added to coal to enhance mercury removal, and increased use of bromide at some power plants is expected. Evaluation of potential increases in bromide concentrations from bromide addition for mercury control is lacking. The present work utilizes bromide monitoring data in the Allegheny River and a mass-balance approach to elucidate bromide contributions from anthropogenic and natural sources under current and future scenarios. For the Allegheny River, the current bromide is associated approximately 49% with oil- and gas-produced water discharges and 33% with coal-fired power plants operating wet FGD, with 18% derived from natural sources during mean flow conditions in August. Median wet FGD bromide loads could increase 3-fold from 610 to 1900 kg/day if all plants implement bromide addition for mercury control. Median bromide concentrations in the lower Allegheny River in August would rise to 410, 200, and 180 μg/L under low-, mean-, and high-flow conditions, respectively, for the bromide-addition scenario. PMID:27538590

  2. SANDIA MOUNTAIN WILDERNESS, NEW MEXICO.

    USGS Publications Warehouse

    Hedlund, D.C.; Kness, R.F.

    1984-01-01

    Geologic and mineral-resource investigations in the Sandia Mountains in New Mexico indicate that a small part of the area has a probable mineral-resource potential. Most of the mineral occurrences are small barite-fluorite veins that occur along faults on the eastern slope of the range. The barite veins in the Landsend area and in the Tunnel Spring area are classed as having a probable mineral-resource potential. Fluorite veins which occur at the La Luz mine contain silver-bearing galeana and the area near this mine is regarded as having a probable resource potential for silver. No energy resources were identified in this study.

  3. Measurement of atmospheric pollutants associated with oil and natural gas exploration and production activity in Pennsylvania's Allegheny National Forest.

    PubMed

    Pekney, Natalie J; Veloski, Garret; Reeder, Matthew; Tamilia, Joseph; Rupp, Erik; Wetzel, Alan

    2014-09-01

    Oil and natural gas exploration and production (E&P) activities generate emissions from diesel engines, compressor stations, condensate tanks, leaks and venting of natural gas, construction of well pads, and well access roads that can negatively impact air quality on both local and regional scales. A mobile, autonomous air quality monitoring laboratory was constructed to collect measurements of ambient concentrations of pollutants associated with oil and natural gas E&P activities. This air-monitoring laboratory was deployed to the Allegheny National Forest (ANF) in northwestern Pennsylvania for a campaign that resulted in the collection of approximately 7 months of data split between three monitoring locations between July 2010 and June 2011. The three monitoring locations were the Kane Experimental Forest (KEF) area in Elk County, which is downwind of the Sackett oilfield; the Bradford Ranger Station (BRS) in McKean County, which is downwind of a large area of historic oil and gas productivity; and the U.S. Forest Service Hearts Content campground (HC) in Warren County, which is in an area relatively unimpacted by oil and gas development and which therefore yielded background pollutant concentrations in the ANF. Concentrations of criteria pollutants ozone and NO2 did not vary significantly from site to site; averages were below National Ambient Air Quality Standards. Concentrations of volatile organic compounds (VOCs) associated with oil and natural gas (ethane, propane, butane, pentane) were highly correlated. Applying the conditional probability function (CPF) to the ethane data yielded most probable directions of the sources that were coincident with known location of existing wells and activity. Differences between the two impacted and one background site were difficult to discern, suggesting the that the monitoring laboratory was a great enough distance downwind of active areas to allow for sufficient dispersion with background air such that the localized

  4. Carpal tunnel biopsy

    MedlinePlus

    Calandruccio JH. Carpal tunnel syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; 2012: ...

  5. [Mountain sickness].

    PubMed

    Bultas, Jan

    2015-01-01

    Mountaineering brings many health risks, one of which is mountain sickness. Its mildest form - acute mountain sickness - is mainly characterized by subjective symptoms (headache, loss of appetite, insomnia, weakness, nausea and rarely also vomiting). Advanced and life-threatening forms are characterized by tissue edema - cerebral or pulmonary high altitude edema. The common denominator of these acute forms is the low oxygen tension leading to hypoxemia and tissue ischemia. Sum of maladaptive or adaptive processes can modify the clinical picture. Underlying mechanisms of the chronic forms of pulmonary disease are the adaptation processes - pulmonary hypertension and polycythemia leading to heart failure.The only causal therapeutic intervention is to restore adequate oxygen tension, descend to lower altitudes or oxygen therapy. Pharmacotherapy has only a supportive effect. The prophylaxis includes stimulation of the respiratory center by carbonic anhydrase inhibitors (acetazolamide) antiedematous treatment with glucocorticoids (dexamethasone), increase lymphatic drainage of the lungs and brain by β2-agonists (salmeterol) or mitigation of pulmonary hypertension by calcium channel blockers or phosphodiesterase-5 inhibitors (sildenafil or tadalafil). PMID:26750624

  6. Electron tunnel sensor technology

    NASA Technical Reports Server (NTRS)

    Waltman, S. B.; Kaiser, W. J.

    1989-01-01

    The recent development of Scanning Tunneling Microscopy technology allows the application of electron tunneling to position detectors for the first time. The vacuum tunnel junction is one of the most sensitive position detection mechanisms available. It is also compact, simple, and requires little power. A prototype accelerometer based on electron tunneling, and other sensor applications of this promising new technology are described.

  7. 15-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1934-01-01

    Constructing the forms for the foundation of the 15-Foot Spin Tunnel. Charles Zimmerman was given the assignment to design and build a larger spin tunnel that would supplant the 5-foot Vertical Wind Tunnel. Authorization to build the tunnel using funds from the Federal Public Works Administration (PWA) came in June 1933. Construction started in late winter 1934 and the tunnel was operational in April 1935. The initial construction costs were $64,000. The first step was to pour the foundation for the tunnel and the housing which would encase the wind tunnel.

  8. 2. EAGLE MOUNTAIN SWITCHYARD. EAGLE MOUNTAIN PUMP PLANT CAN BE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EAGLE MOUNTAIN SWITCHYARD. EAGLE MOUNTAIN PUMP PLANT CAN BE SEEN THROUGH SWITCHYARD IN BACKGROUND. 165MM LENS. - Eagle Mountain Pump Plant, Ten miles north of Route 10, southeast of Eagle Mountain, Eagle Mountain, Riverside County, CA

  9. Construction monitoring activities in the ESF starter tunnel

    SciTech Connect

    Pott, J.; Carlisle, S.

    1994-05-01

    In situ design verification activities am being conducted in the North Ramp Starter Tunnel of the Yucca Mountain Project Exploratory Studies Facility. These activities include: monitoring the peak particle velocities and evaluating the damage to the rock mass associated with construction blasting, assessing the rock mass quality surrounding the tunnel, monitoring the performance of the installed ground support, and monitoring the stability of the tunnel. In this paper, examples of the data that have been collected and preliminary conclusions from the data are presented.

  10. Inspection of a hydropower tunnel using remotely operated vehicles (ROV): A 5-year case study

    SciTech Connect

    Hosko, M.A.

    1995-12-31

    Since commercial operation in 1988, the 21 MW Raystown Hydroelectric Project, William F. Matson Generating Station in central Pennsylvania, has used several different methods to inspect the condition of the 283-meter (930-foot) long, 3.65-meter (12-foot) diameter, concrete-lined tunnel. These inspections have been required to meet the FERC license conditions and the separate Memorandum of Understanding (MOU) between the U.S. Army Corps of Engineers, Baltimore District and the Licensee, Allegheny Electric Cooperative, Inc., of Harrisburg, PA. Since the tunnel and connected 168-meter (550-foot) long steel penstock are the only water passage to the two-unit generating plant, any intrusive inspection requires an outage, thus the optimal inspection technique minimizes the plant downtime. Inspections have included a lengthy and costly dewatered tunnel walk through, an underwater inspection using commercial divers and hand-held video, and most recently three annual inspections using three different types of Remotely Operated Vehicles (ROV) supplied by vendor services. Each inspection concentrated on the examination of the condition of the tunnel concrete, including radial cracks and condition of construction joints, longitudinal crack propagation, aggregate erosion and concrete patch condition. Use of a computerized database program for mapping will also be discussed as a useful tool. This paper details experience with each of these methods with an emphasis on lessons learned and applications for the hydro industry.

  11. Cryogenic wind tunnels. II

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    The application of the cryogenic concept to various types of tunnels including Ludwieg tube tunnel, Evans clean tunnel, blowdown, induced-flow, and continuous-flow fan-driven tunnels is discussed. Benefits related to construction and operating costs are covered, along with benefits related to new testing capabilities. It is noted that cooling the test gas to very low temperatures increases Reynolds number by more than a factor of seven. From the energy standpoint, ambient-temperature fan-driven closed-return tunnels are considered to be the most efficient type of tunnel, while a large reduction in the required tunnel stagnation pressure can be achieved through cryogenic operation. Operating envelopes for three modes of operation for a cryogenic transonic pressure tunnel with a 2.5 by 2.5 test section are outlined. A computer program for calculating flow parameters and power requirements for wind tunnels with operating temperatures from saturation to above ambient is highlighted.

  12. Cryogenic wind tunnels. III

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    Specific problems pertaining to cryogenic wind tunnels, including LN(2) injection, GN(2) exhaust, thermal insulation, and automatic control are discussed. Thermal and other physical properties of materials employed in these tunnels, properties of cryogenic fluids, storage and transfer of liquid nitrogen, strength and toughness of metals and nonmetals at low temperatures, and material procurement and qualify control are considered. Safety concerns with cryogenic tunnels are covered, and models for cryogenic wind tunnels are presented, along with descriptions of major cryogenic wind-tunnel facilities the United States, Europe, and Japan. Problems common to wind tunnels, such as low Reynolds number, wall and support interference, and flow unsteadiness are outlined.

  13. 4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific Standard Double-Track Tunnel, ca. 1913. Compare to photos in documentation sets for Tunnel 18 (HAER No. CA-197), Tunnel 34 (HAER No. CA-206), and Tunnel 1 (HAER No. CA-207). - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  14. Occurrence and trends in the concentrations of fecal-indicator bacteria and the relation to field water-quality parameters in the Allegheny, Monongahela, and Ohio Rivers and selected tributaries, Allegheny County, Pennsylvania, 2001–09

    USGS Publications Warehouse

    Fulton, John W.; Koerkle, Edward H.; McCoy, Jamie L.; Zarr, Linda F.

    2016-01-01

    A total of 1,742 water samples were collected at 52 main-stem and tributary sites. Quantifiable concentrations of Escherichia coli (E. coli) were reported in 1,667 samples, or 97.0 percent of 1,719 samples; concentrations in 853 samples (49.6 percent) exceeded the U.S. Environmental Protection Agency (EPA) recreational water-quality criterion of 235 colonies per 100 milliliters (col/100 mL). Quantifiable concentrations of fecal coliform (FC) bacteria were reported in 1,693 samples, or 98.8 percent of 1,713 samples; concentrations in 780 samples (45.5 percent) exceeded the Commonwealth of Pennsylvania water contact criterion of 400 col/100 mL. Quantifiable concentrations of enterococci bacteria were reported in 912 samples, or 87.5 percent of 1,042 samples; concentrations in 483 samples (46.4 percent) exceeded the EPA recreational water-quality criterion of 61 col/100 mL. The median percentage of samples in which bacteria concentrations exceeded recreational water-quality standards across all sites with five or more samples was 48 for E. coli, 43 for FC, and 75 for enterococci. E. coli, FC, and enterococci concentrations at main-stem sites had significant positive correlations with streamflow under all weather conditions, with rho values ranging from 0.203 to 0.598. Seasonal Kendall and logistic regression were evaluated to determine whether statistically significant trends were present during the period 2001–09. In general, Seasonal Kendall tests for trends in E. coli and FC bacteria were inconclusive. Results of logistic regression showed no significant trends in dry-weather exceedance of the standards; however, significant decreases in the likelihood that wet-weather E. coli and FC bacteria concentrations will exceed EPA recreational standards were found at the USGS streamgaging station Allegheny River at 9th Street Bridge. Nonparametric correlation analysis, including Spearman’s rho and the paired Prentice-Wilcoxon test, was used to screen for associations

  15. Major SSC tunneling begins

    SciTech Connect

    Not Available

    1993-01-11

    In Texas, work has been completed on the first on the Superconducting Supercollider's major shafts. Now a boring machine has started driving the fifty-four mile elliptical accelerator tunnel. To date, contracts let for the tunnel have come in far below preliminary estimates. Five of the main fourteen foot diameter tunnel contracts have been awarded for a total of 107.4 million dollars, about forty million dollars below estimates. These contracts represent %60 percent of the total tunneling project.

  16. Variable Density Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Variable Density Tunnel in operation. Man at far right is probably Harold J. 'Cannonball' Tuner, longtime safety officer, who started with Curtiss in the teens. This view of the Variable Density Tunnel clearly shows the layout of the Tunnel's surroundings, as well as the plumbing and power needs of the this innovative research tool.

  17. Squeezable electron tunneling junctions

    NASA Astrophysics Data System (ADS)

    Moreland, J.; Alexander, S.; Cox, M.; Sonnenfeld, R.; Hansma, P. K.

    1983-09-01

    We report a versatile new technique for constructing electron tunneling junctions with mechanically-adjusted artificial barriers. I-V curves are presented for tunneling between Ag electrodes with vacuum, gas, liquid or solid in the barrier. An energy gap is apparent in the measured I-V curve when tunneling occurs between superconducting Pb electrodes.

  18. Impacts of Sedimentation from Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds of the Allegheny National Forest of Northwestern Pennsylvania

    SciTech Connect

    Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

    2011-01-01

    Fritz, Kelley'*, Steven Harris', Harry Edenborn2, and James Sams2. 'Clarion University of Pennsylvania, Clarion, PA 16214, 2National Energy Technology Laboratory, U.S. Dept. Energy, Pittsburgh, PA 15236. Impacts a/Sedimentation/rom Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds a/the Allegheny National Forest a/Northwestern Pennsylvania - The Allegheny National Forest (ANF), located in northwestern Pennsy Ivania, is a multiuse forest combining commercial development with recreational and conservation activities. As such, portions of the ANF have been heavily logged and are now the subject of widespread oil and gas development. This rapid increase in oil and gas development has led to concerns about sediment runoff from the dirt and gravel roads associated with development and the potential impact on the aquatic biota of the receiving streams. We examined and compared the benthic macroinvertebrate communities in two adjacent watersheds of similar size and topography in the ANF; the Hedgehog Run watershed has no oil and gas development, while the adjacent Grunder Run watershed has extensive oil and gas development. In Hedgehog and Grunder Run, we collected monthly kicknet samples from riffles and glides at two sites from April to October 2010. At the same intervals, we measured standard water quality parameters, including conductivity and turbidity. Preliminary results have indicated much higher turbidity in Grunder Run, but little difference in the diversity and abundance of benthic macro invertebrates inhabiting the two streams.

  19. The Impact of Commercially Treated Oil and Gas Produced Water Discharges on Bromide Concentrations and Modeled Brominated Trihalomethane Disinfection Byproducts at two Downstream Municipal Drinking Water Plants in the Upper Allegheny River, Pennsylvania, USA

    EPA Science Inventory

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species were observed in finished water at several Western Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in br...

  20. Rocky Mountain spotted fever

    MedlinePlus

    Rocky Mountain spotted fever is a disease caused by a type of bacteria carried by ticks. ... Rocky Mountain spotted fever is caused by the bacteria Rickettsia rickettsii (R. Rickettsii) , which is carried by ticks. The ...

  1. Acute mountain sickness

    MedlinePlus

    High altitude cerebral edema; Altitude anoxia; Altitude sickness; Mountain sickness; High altitude pulmonary edema ... Acute mountain sickness is caused by reduced air pressure and lower oxygen levels at high altitudes. The faster you ...

  2. Rocky Mountain spotted fever

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000654.htm Rocky Mountain spotted fever To use the sharing features on this page, please enable JavaScript. Rocky Mountain spotted fever is a disease caused by a ...

  3. The impact of commercially treated oil and gas produced water discharges on bromide concentrations and modeled brominated trihalomethane disinfection byproducts at two downstream municipal drinking water plants in the upper Allegheny River, Pennsylvania, USA.

    PubMed

    Landis, Matthew S; Kamal, Ali S; Kovalcik, Kasey D; Croghan, Carry; Norris, Gary A; Bergdale, Amy

    2016-01-15

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species was observed in finished water at several Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in bromide (Br(-)) concentrations in the Allegheny River was implicated to be the cause of the elevated water disinfection byproducts. This study focused on quantifying the contribution of Br(-) from a commercial wastewater treatment facility (CWTF) that solely treats wastes from oil and gas producers and discharges into the upper reaches of the Allegheny River, and impacts on two downstream PDWs. In 2012, automated daily integrated samples were collected on the Allegheny River at six sites during three seasonal two-week sampling campaigns to characterize Br(-) concentrations and river dispersion characteristics during periods of high and low river discharges. The CWTF discharges resulted in significant increases in Br(-) compared to upstream baseline values in PDW raw drinking water intakes during periods of low river discharge. During high river discharge, the assimilative dilution capacity of the river resulted in lower absolute halide concentrations, but significant elevations Br(-) concentrations were still observed at the nearest downstream PDW intake over baseline river levels. On days with active CWTF effluent discharge the magnitude of bromide impact increased by 39 ppb (53%) and 7 ppb (22%) for low and high river discharge campaigns, respectively. Despite a declining trend in Allegheny River Br(-) (2009-2014), significant impacts from CWTF and coal-fired power plant discharges to Br(-) concentrations during the low river discharge regime at downstream PDW intakes was observed, resulting in small modeled increases in total THM (3%), and estimated positive shifts (41-47%) to more toxic brominated THM analogs. The lack of available coincident measurements of THM, precursors, and physical parameters

  4. Gas shows during construction of hydraulic tunnels

    SciTech Connect

    Razumov, V.K.; Skiba, S.I.

    1987-10-01

    The authors investigate the occurrence of and the geological factors behind rock bursts during the construction of diversion tunnels of five hydroelectric power plants located in the mountainous regions of the Caucasus. Gas migration and saturation behavior is explained for the various forms of strata and rock found in the region. Carbon dioxide and methane are determined to be the prevalent gases. The influence of the tectonics of the region is assessed. Corollaries to coal mining engineering are drawn. Water influx as a result of rock bursts is briefly discussed.

  5. Dynamic response of tunnels in jointed rocks

    SciTech Connect

    Heuze, F.E.; Shaffer, R.J.; Walton, O.R.; Maddix, D.M.

    1993-09-01

    The current proposed site for an underground nuclear waste repository is at Yucca Mountain, Nevada. The host rock is a jointed tuff. The question is: how will the repository behave under strong earthquake motion. The basic requirement for analysis is an ability to follow the dynamic motion of a multiplicity of discrete particles, i.e., rock blocks separated by joints and faults. The authors describe the application of the discrete element method (DEM) to the dynamic analysis of the response of tunnels in jointed rocks to earthquake loading. In situations where large motions of many blocks and collapse occur, the discontinuum-based DEM approach appears superior to other methods of analysis.

  6. The cryogenic wind tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1976-01-01

    Based on theoretical studies and experience with a low speed cryogenic tunnel and with a 1/3-meter transonic cryogenic tunnel, the cryogenic wind tunnel concept was shown to offer many advantages with respect to the attainment of full scale Reynolds number at reasonable levels of dynamic pressure in a ground based facility. The unique modes of operation available in a pressurized cryogenic tunnel make possible for the first time the separation of Mach number, Reynolds number, and aeroelastic effects. By reducing the drive-power requirements to a level where a conventional fan drive system may be used, the cryogenic concept makes possible a tunnel with high productivity and run times sufficiently long to allow for all types of tests at reduced capital costs and, for equal amounts of testing, reduced total energy consumption in comparison with other tunnel concepts.

  7. Simulator of Road Tunnel

    NASA Astrophysics Data System (ADS)

    Danišovič, Peter; Schlosser, František; Šrámek, Juraj; Rázga, Martin

    2015-05-01

    A Tunnel Traffic & Operation Simulator is a device of the Centre of Transport Research at the University of Žilina. The Simulator allows managing technological equipment of virtual two-tube highway tunnel, which is interconnected with simulation of vehicle traffic in tunnel. Changes of the traffic-operation states and other equipment are reflecting at the simulated traffic, as well as simulations of various emergency events in traffic initiate changes in tunnel detecting and measuring devices. It is thus possible to simulate emergency states, which can be affected by various faults of technology as well as by climatic conditions. The solutions can be found in irreplaceable experiences of Slovak road tunnel operators, changes of trafficoperation states, visualizations of operator technological display screens, technological devices labelling in order to increase operational safety of road tunnels.

  8. Inelastic tunnel diodes

    NASA Technical Reports Server (NTRS)

    Anderson, L. M. (Inventor)

    1984-01-01

    Power is extracted from plasmons, photons, or other guided electromagnetic waves at infrared to midultraviolet frequencies by inelastic tunneling in metal-insulator-semiconductor-metal diodes. Inelastic tunneling produces power by absorbing plasmons to pump electrons to higher potential. Specifically, an electron from a semiconductor layer absorbs a plasmon and simultaneously tunnels across an insulator into metal layer which is at higher potential. The diode voltage determines the fraction of energy extracted from the plasmons; any excess is lost to heat.

  9. Charge Islands Through Tunneling

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  10. The Design of Wind Tunnels and Wind Tunnel Propellers

    NASA Technical Reports Server (NTRS)

    Warner, Edward P; Norton, F H; Hebbert, C M

    1919-01-01

    Report discusses the theory of energy losses in wind tunnels, the application of the Drzewiecki theory of propeller design to wind tunnel propellers, and the efficiency and steadiness of flow in model tunnels of various types.

  11. Atom Tunneling in Chemistry.

    PubMed

    Meisner, Jan; Kästner, Johannes

    2016-04-25

    Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom tunneling can be indirectly detected by temperature-independent rate constants at low temperature or by enhanced kinetic isotope effects. In contrast, the influence of tunneling on the reaction rates can be monitored directly through computational investigations. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes. PMID:26990917

  12. Tunnel closure calculations

    SciTech Connect

    Moran, B.; Attia, A.

    1995-07-01

    When a deeply penetrating munition explodes above the roof of a tunnel, the amount of rubble that falls inside the tunnel is primarily a function of three parameters: first the cube-root scaled distance from the center of the explosive to the roof of the tunnel. Second the material properties of the rock around the tunnel, and in particular the shear strength of that rock, its RQD (Rock Quality Designator), and the extent and orientation of joints. And third the ratio of the tunnel diameter to the standoff distance (distance between the center of explosive and the tunnel roof). The authors have used CALE, a well-established 2-D hydrodynamic computer code, to calculate the amount of rubble that falls inside a tunnel as a function of standoff distance for two different tunnel diameters. In particular they calculated three of the tunnel collapse experiments conducted in an iron ore mine near Kirkeness, Norway in the summer of 1994. The failure model that they used in their calculations combines an equivalent plastic strain criterion with a maximum tensile strength criterion and can be calibrated for different rocks using cratering data as well as laboratory experiments. These calculations are intended to test and improve the understanding of both the Norway Experiments and the ACE (Array of conventional Explosive) phenomenology.

  13. Analysis of labour accidents in tunnel construction and introduction of prevention measures.

    PubMed

    Kikkawa, Naotaka; Itoh, Kazuya; Hori, Tomohito; Toyosawa, Yasuo; Orense, Rolando P

    2015-01-01

    At present, almost all mountain tunnels in Japan are excavated and constructed utilizing the New Austrian Tunneling Method (NATM), which was advocated by Prof. Rabcewicz of Austria in 1964. In Japan, this method has been applied to tunnel construction since around 1978, after which there has been a subsequent decrease in the number of casualties during tunnel construction. However, there is still a relatively high incidence of labour accidents during tunnel construction when compared to incidence rates in the construction industry in general. During tunnel construction, rock fall events at the cutting face are a particularly characteristic of the type of accident that occurs. In this study, we analysed labour accidents that possess the characteristics of a rock fall event at a work site. We also introduced accident prevention measures against rock fall events. PMID:26027707

  14. Analysis of labour accidents in tunnel construction and introduction of prevention measures

    PubMed Central

    KIKKAWA, Naotaka; ITOH, Kazuya; HORI, Tomohito; TOYOSAWA, Yasuo; ORENSE, Rolando P.

    2015-01-01

    At present, almost all mountain tunnels in Japan are excavated and constructed utilizing the New Austrian Tunneling Method (NATM), which was advocated by Prof. Rabcewicz of Austria in 1964. In Japan, this method has been applied to tunnel construction since around 1978, after which there has been a subsequent decrease in the number of casualties during tunnel construction. However, there is still a relatively high incidence of labour accidents during tunnel construction when compared to incidence rates in the construction industry in general. During tunnel construction, rock fall events at the cutting face are a particularly characteristic of the type of accident that occurs. In this study, we analysed labour accidents that possess the characteristics of a rock fall event at a work site. We also introduced accident prevention measures against rock fall events. PMID:26027707

  15. Tunneling Magnetothermopower in Magnetic Tunnel Junction Nanopillars

    NASA Astrophysics Data System (ADS)

    Liebing, N.; Serrano-Guisan, S.; Rott, K.; Reiss, G.; Langer, J.; Ocker, B.; Schumacher, H. W.

    2011-10-01

    We study tunneling magnetothermopower (TMTP) in CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars. Thermal gradients across the junctions are generated by an electric heater line. Thermopower voltages up to a few tens of μV between the top and bottom contact of the nanopillars are measured which scale linearly with the applied heating power and hence the thermal gradient. The thermopower signal varies by up to 10μV upon reversal of the relative magnetic configuration of the two CoFeB layers from parallel to antiparallel. This signal change corresponds to a large spin-dependent Seebeck coefficient of the order of 100μV/K and a large TMTP change of the tunnel junction of up to 90%.

  16. Tunneling magnetothermopower in magnetic tunnel junction nanopillars.

    PubMed

    Liebing, N; Serrano-Guisan, S; Rott, K; Reiss, G; Langer, J; Ocker, B; Schumacher, H W

    2011-10-21

    We study tunneling magnetothermopower (TMTP) in CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars. Thermal gradients across the junctions are generated by an electric heater line. Thermopower voltages up to a few tens of μV between the top and bottom contact of the nanopillars are measured which scale linearly with the applied heating power and hence the thermal gradient. The thermopower signal varies by up to 10  μV upon reversal of the relative magnetic configuration of the two CoFeB layers from parallel to antiparallel. This signal change corresponds to a large spin-dependent Seebeck coefficient of the order of 100  μV/K and a large TMTP change of the tunnel junction of up to 90%. PMID:22107572

  17. Shotcrete in tunnel design

    SciTech Connect

    Golser, J.; Galler, R.; Schubert, P.; Rabensteiner, K.

    1995-12-31

    Shotcrete is an important structural element for tunnel support. Green shotcrete is exposed to compression strain rates and tunnel design requires a realistic material law for shotcrete. A modified rate of flow method simulates shotcrete behavior very well and can be incorporated in Finite Element calculations.

  18. Electron-Tunneling Magnetometer

    NASA Technical Reports Server (NTRS)

    Kaiser, William J.; Kenny, Thomas W.; Waltman, Steven B.

    1993-01-01

    Electron-tunneling magnetometer is conceptual solid-state device operating at room temperature, yet offers sensitivity comparable to state-of-art magnetometers such as flux gates, search coils, and optically pumped magnetometers, with greatly reduced volume, power consumption, electronics requirements, and manufacturing cost. Micromachined from silicon wafer, and uses tunneling displacement transducer to detect magnetic forces on cantilever-supported current loop.

  19. Micromachined Tunneling Accelerometer

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas W.; Waltman, Stephen B.; Kaiser, William J.; Reynolds, Joseph K.

    1993-01-01

    Separation of tunneling electrodes adjusted by varying electrostatic force. Major components of tunneling transducer formed on two silicon chips by microfabrication techniques. Use of electrostatic deflection reduces sensitivity of transducer to thermal drift and simplifies design. Sensitivity suitable for applications in which larger acceleration-sensing instruments required.

  20. Coherent revival of tunneling

    NASA Astrophysics Data System (ADS)

    Hsu, Liang-Yan; Rabitz, Herschel

    2015-07-01

    We introduce a tunneling effect by a driving field, referred to as coherent revival of tunneling (CRT), corresponding to complete tunneling (transmission coefficient =1 ) that is revived from the circumstance of total reflection (transmission coefficient ≈0 ) through application of an appropriate perpendicular high-frequency ac field. To illustrate CRT, we simulate electron transport through fish-bone-like quantum-dot arrays by using single-particle Green's functions along with Floquet theory, and we explore the corresponding current-field amplitude characteristics as well as current-polarization characteristics. In regard to the two characteristics, we show that CRT exhibits entirely different features than coherent destruction of tunneling and photon-assisted tunneling. We also discuss two practical conditions for experimental realization of CRT.

  1. Geohydrologic data and models of Rainier Mesa and their implications to Yucca Mountain

    SciTech Connect

    Wang, J.S.Y.; Cook, N.G.W.; Wollenberg, H.A.; Carnahan, C.L.; Javandel, I.; Tsang, C.F.

    1993-01-01

    The geohydrologic data collected at Rainier Mesa provide the only extensive observations in tunnels presently available on flow and transport in tuff units similar to those of a potential nuclear waste repository at Yucca Mountain. This information can, therefore, be of great value in planning the Exploratory Studies Facility (ESF) testing in underground drifts at Yucca Mountain. In this paper, we compare the geohydrologic characteristics of tuff units of these two sites and summarize the hydrochemical data indicating the presence of nearly meteoric water in Rainier Mesa tunnels. A simple analytic model is used to evaluate the possibility of propagating transient pulses of water along fractures or faults through the Paintbrush nonwelded tuff unit to reach the tunnel beds below. The results suggest that fast flow could occur without significant mixing between meteoric fracture water and matrix pore water. The implications of these findings on planning for the ESF Calico Hills study at Yucca Mountain are discussed.

  2. The aeolian wind tunnel

    NASA Technical Reports Server (NTRS)

    Iversen, J. D.

    1991-01-01

    The aeolian wind tunnel is a special case of a larger subset of the wind tunnel family which is designed to simulate the atmospheric surface layer winds to small scale (a member of this larger subset is usually called an atmospheric boundary layer wind tunnel or environmental wind tunnel). The atmospheric boundary layer wind tunnel is designed to simulate, as closely as possible, the mean velocity and turbulence that occur naturally in the atmospheric boundary layer (defined as the lowest portion of the atmosphere, of the order of 500 m, in which the winds are most greatly affected by surface roughness and topography). The aeolian wind tunnel is used for two purposes: to simulate the physics of the saltation process and to model at small scale the erosional and depositional processes associated with topographic surface features. For purposes of studying aeolian effects on the surface of Mars and Venus as well as on Earth, the aeolian wind tunnel continues to prove to be a useful tool for estimating wind speeds necessary to move small particles on the three planets as well as to determine the effects of topography on the evolution of aeolian features such as wind streaks and dune patterns.

  3. Ultrafast scanning tunneling microscopy

    SciTech Connect

    Botkin, D.A. |

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  4. Carpal Tunnel Syndrome

    MedlinePlus

    ... at the base of your hand. It contains nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the nerve to be compressed. Symptoms usually start gradually. As ...

  5. Tarsal Tunnel Syndrome

    MedlinePlus

    ... and nerves. One of these structures is the posterior tibial nerve, which is the focus of tarsal tunnel ... syndrome is a compression, or squeezing, on the posterior tibial nerve that produces symptoms anywhere along the path ...

  6. Carpal Tunnel Syndrome

    MedlinePlus

    ... through NIH's National Center for Complementary and Alternative Medicine are investigating the effects of acupuncture on pain, loss of median nerve function, and changes in the brain associated with carpal tunnel syndrome. In addition, a ...

  7. Carpal Tunnel Surgery

    MedlinePlus Videos and Cool Tools

    ... is the incriminating structure in carpal tunnel syndrome. As it increases in size, the pressures within the ... you can visualize the movement of the tendons as I move the fingers, the tendons are gliding ...

  8. Carpal tunnel biopsy

    MedlinePlus

    ... syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative ... Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, ...

  9. Inelastic electron tunneling spectroscopy

    NASA Technical Reports Server (NTRS)

    Khanna, S. K.; Lambe, J.

    1983-01-01

    Inelastic electron tunneling spectroscopy is a useful technique for the study of vibrational modes of molecules adsorbed on the surface of oxide layers in a metal-insulator-metal tunnel junction. The technique involves studying the effects of adsorbed molecules on the tunneling spectrum of such junctions. The data give useful information about the structure, bonding, and orientation of adsorbed molecules. One of the major advantages of inelastic electron tunneling spectroscopy is its sensitivity. It is capable of detecting on the order of 10 to the 10th molecules (a fraction of a monolayer) on a 1 sq mm junction. It has been successfully used in studies of catalysis, biology, trace impurity detection, and electronic excitations. Because of its high sensitivity, this technique shows great promise in the area of solid-state electronic chemical sensing.

  10. Carpal tunnel syndrome

    MedlinePlus

    ... also need to make changes in your work duties or home and sports activities. Some of the ... Call for an appointment with your provider if: You have symptoms of carpal tunnel syndrome Your symptoms ...

  11. MARBLE MOUNTAIN WILDERNESS, CALIFORNIA.

    USGS Publications Warehouse

    Donato, Mary M.; Hale, William N.

    1984-01-01

    The Marble Mountain Wilderness is located in the north-central Klamath Mountains of northern California. Geologic, geochemical, geophysical, and mineral investigations indicate that the wilderness has areas of probable and substantiated resource potential for placer gold, for chromite, and for marble. The geologic terrane precludes the occurrence of fossil fuel resources.

  12. Tunnelling in carbonic acid.

    PubMed

    Wagner, J Philipp; Reisenauer, Hans Peter; Hirvonen, Viivi; Wu, Chia-Hua; Tyberg, Joseph L; Allen, Wesley D; Schreiner, Peter R

    2016-06-14

    The cis,trans-conformer of carbonic acid (H2CO3), generated by near-infrared radiation, undergoes an unreported quantum mechanical tunnelling rotamerization with half-lives in cryogenic matrices of 4-20 h, depending on temperature and host material. First-principles quantum chemistry at high levels of theory gives a tunnelling half-life of about 1 h, quite near those measured for the fastest rotamerizations. PMID:27248671

  13. Electron tunnel sensor technology

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Waltman, S. B.; Reynolds, J. K.; Kaiser, W. J.

    1991-01-01

    Researchers designed and constructed a novel electron tunnel sensor which takes advantage of the mechanical properties of micro-machined silicon. For the first time, electrostatic forces are used to control the tunnel electrode separation, thereby avoiding the thermal drift and noise problems associated with piezoelectric actuators. The entire structure is composed of micro-machined silicon single crystals, including a folded cantilever spring and a tip. The application of this sensor to the development of a sensitive accelerometer is described.

  14. The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

    NASA Technical Reports Server (NTRS)

    Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

    2010-01-01

    The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

  15. Mountaineering fatalities on Denali.

    PubMed

    McIntosh, Scott E; Campbell, Aaron D; Dow, Jennifer; Grissom, Colin K

    2008-01-01

    Mount McKinley, or Denali, is the tallest mountain in North America and attracts over 1,000 climbers annually from around the world. Since Denali is located within a national park, the National Park Service (NPS) manages mountaineering activities and attempts to maintain a balance of an adventurous experience while promoting safety. We retrospectively reviewed the fatalities on Denali from 1903 to 2006 to assist the NPS, medical personnel, and mountaineers improve safety and reduce fatalities on the mountain. Historical records and the NPS climber database were reviewed. Demographics, mechanisms, and circumstances surrounding each fatality were examined. Fatality rates and odds ratios for country of origin were calculated. From 1903 through the end of the 2006 climbing season, 96 individuals died on Denali. The fatality rate is declining and is 3.08/1,000 summit attempts. Of the 96 deaths, 92% were male, 51% occurred on the West Buttress route, and 45% were due to injuries sustained from falls. Sixty-one percent occurred on the descent and the largest number of deaths in 1 year occurred in 1992. Climbers from Asia had the highest odds of dying on the mountain. Fatalities were decreased by 53% after a NPS registration system was established in 1995. Although mountaineering remains a high-risk activity, safety on Denali is improving. Certain groups have a significantly higher chance of dying. Registration systems and screening methods provide ways to target at-risk groups and improve safety on high altitude mountains such as Denali. PMID:18331224

  16. Single Electron Tunneling

    SciTech Connect

    Ruggiero, Steven T.

    2005-07-25

    Financial support for this project has led to advances in the science of single-electron phenomena. Our group reported the first observation of the so-called ''Coulomb Staircase'', which was produced by tunneling into ultra-small metal particles. This work showed well-defined tunneling voltage steps of width e/C and height e/RC, demonstrating tunneling quantized on the single-electron level. This work was published in a now well-cited Physical Review Letter. Single-electron physics is now a major sub-field of condensed-matter physics, and fundamental work in the area continues to be conducted by tunneling in ultra-small metal particles. In addition, there are now single-electron transistors that add a controlling gate to modulate the charge on ultra-small photolithographically defined capacitive elements. Single-electron transistors are now at the heart of at least one experimental quantum-computer element, and single-electron transistor pumps may soon be used to define fundamental quantities such as the farad (capacitance) and the ampere (current). Novel computer technology based on single-electron quantum dots is also being developed. In related work, our group played the leading role in the explanation of experimental results observed during the initial phases of tunneling experiments with the high-temperature superconductors. When so-called ''multiple-gap'' tunneling was reported, the phenomenon was correctly identified by our group as single-electron tunneling in small grains in the material. The main focus throughout this project has been to explore single electron phenomena both in traditional tunneling formats of the type metal/insulator/particles/insulator/metal and using scanning tunneling microscopy to probe few-particle systems. This has been done under varying conditions of temperature, applied magnetic field, and with different materials systems. These have included metals, semi-metals, and superconductors. Amongst a number of results, we have

  17. Carpal Tunnel Syndrome

    PubMed Central

    Zimmerman, Gregory R.

    1994-01-01

    Carpal tunnel syndrome is a neuropathy resulting from compression of the median nerve as it passes through a narrow tunnel in the wrist on its way to the hand. The lack of precise objective and clinical tests, along with symptoms that are synonymous with other syndromes in the upper extremity, cause carpal tunnel syndrome to appear to be a rare entity in athletics. However, it should not be ruled out as a possible etiology of upper extremity paralysis in the athlete. More typically, carpal tunnel syndrome is the most common peripheral entrapment neuropathy encountered in industry. Treatment may include rest and/or splinting of the involved wrist, ice application, galvanic stimulation, or iontophoresis to reduce inflammation, and then transition to heat modalities and therapeutic exercises for developing flexibility, strength, and endurance. In addition, an ergonomic assessment should be conducted, resulting in modifications to accommodate the carpal tunnel syndrome patient. ImagesFig 3.Fig 4.Fig 5.Fig 6.Fig 7. PMID:16558255

  18. 20-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1947-01-01

    Construction of a typical model used in the 20-Foot Spin Tunnel. >From 'Characteristics of Nine Research Wind Tunnels of the Langley Aeronautical Laboratory': 'Dynamic models are used for free-spinning tunnel tests. A dynamic model is one for which geometric similarity between model and airplane is extended to obtain geometric similarity of the paths of motion of corresponding points by maintaining constant, in addition to the scale ratio of linear dimensions, three other ratios, that of force, mass, and time. In model testing, however, complete similarity can generally not be duplicated and some compromise is necessary. For free-spinning-model tests in the NACA 20-foot tunnel, the ratio of inertia to frictional or viscous forces (Reynolds number) is not maintained constant, but the ratio of inertia to gravity forces (Froude number) is maintained constant.' 'Models used in the spin tunnel until recently [this report was written in 1957] were made primarily of balsa and reinforced with hardwood. Now, plastic models are being used almost entirely, because they are more durable and when properly constructed are no heavier than balsa models. The models are constructed accurately to scale by pressing plastic material and class cloth into a previously constructed mold. A typical mod is shown in [this picture]. The model is swung as a torsional pendulum and is ballasted to obtain dynamic similarity by placing lead weights in suitable locations within the model wings and fuselage. Corrections are made for the effect of ambient and entrapped air.'

  19. Condensate Mixtures and Tunneling

    SciTech Connect

    Timmermans, E.

    1998-09-14

    The experimental study of condensate mixtures is a particularly exciting application of the recently developed atomic-trap Bose-Einstein condensate (BEC) technology: such multiple condensates represent the first laboratory systems of distinguishable boson superfluid mixtures. In addition, as the authors point out in this paper, the possibility of inter-condensate tunneling greatly enhances the richness of the condensate mixture physics. Not only does tunneling give rise to the oscillating particle currents between condensates of different chemical potentials, such as those studied extensively in the condensed matter Josephson junction experiments, it also affects the near-equilibrium dynamics and stability of the condensate mixtures. In particular, the stabilizing influence of tunneling with respect to spatial separation (phase separation) could be of considerable practical importance to the atomic trap systems. Furthermore, the creation of mixtures of atomic and molecular condensates could introduce a novel type of tunneling process, involving the conversion of a pair of atomic condensate bosons into a single molecular condensate boson. The static description of condensate mixtures with such type of pair tunneling suggests the possibility of observing dilute condensates with the liquid-like property of a self-determined density.

  20. East portal of Tunnel No. 1292, Indigo Tunnel, showing interior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East portal of Tunnel No. 1292, Indigo Tunnel, showing interior timber framing, looking southwest. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  1. West portal of Tunnel No. 1292, Indigo Tunnel at milepost ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West portal of Tunnel No. 1292, Indigo Tunnel at milepost 129.95, largely obscured by overgrowth. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  2. View of entrance tunnel. Tunnel right to Control Center, left ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of entrance tunnel. Tunnel right to Control Center, left to Antenna Silos - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

  3. Magnetic flux tube tunneling

    SciTech Connect

    Dahlburg, R.B.; Antiochos, S.K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of {ital orthogonal} magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can {open_quotes}tunnel{close_quotes} through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch {gt}1, and the Lundquist number must be somewhat large, {ge}2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and {open_quotes}pass{close_quotes} through each other. The implications of these results for solar and space plasmas are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  4. Femtosecond scanning tunneling microscope

    SciTech Connect

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  5. Uncooled tunneling infrared sensor

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas W. (Inventor); Kaiser, William J. (Inventor); Podosek, Judith A. (Inventor); Vote, Erika C. (Inventor); Muller, Richard E. (Inventor); Maker, Paul D. (Inventor)

    1995-01-01

    An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane. The resulting infrared sensor can be miniaturized to pixel dimensions smaller than 100 .mu.m. An alternative embodiment is implemented using a corrugated membrane to permit large deflection without complicated clamping and high deflection voltages. The alternative embodiment also employs a pinhole aperture in a membrane to accommodate environmental temperature variation and a sealed chamber to eliminate environmental contamination of the tunneling electrodes and undesireable accoustic coupling to the sensor.

  6. Magnetic flux tube tunneling

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Antiochos, S. K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of orthogonal magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can ``tunnel'' through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch >>1, and the Lundquist number must be somewhat large, >=2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and ``pass'' through each other. The implications of these results for solar and space plasmas are discussed.

  7. Mountain-Top Science

    ERIC Educational Resources Information Center

    Cussen, John P.

    1976-01-01

    Described is the Talcott Mountain Science Center for Student Involvement, Inc., near Hartford, Connecticut, and the programs in natural science offered at the facility and by center personnel in local schools. (SL)

  8. Acute mountain sickness

    MedlinePlus

    High altitude cerebral edema; Altitude anoxia; Altitude sickness; Mountain sickness; High altitude pulmonary edema ... If you have fluid in your lungs (pulmonary edema), treatment may include: Oxygen A high blood pressure ...

  9. View down tank tunnel (tunnel no. 2) showing pipes and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View down tank tunnel (tunnel no. 2) showing pipes and walkway of metal grating, side tunnel to tank 3 is on the left - U.S. Naval Base, Pearl Harbor, Diesel Purification Plant, North Road near Pierce Street, Pearl City, Honolulu County, HI

  10. Using noble gases to investigate mountain-front recharge

    USGS Publications Warehouse

    Manning, A.H.; Solomon, D.K.

    2003-01-01

    Mountain-front recharge is a major component of recharge to inter-mountain basin-fill aquifers. The two components of mountain-front recharge are (1) subsurface inflow from the mountain block (subsurface inflow), and (2) infiltration from perennial and ephemeral streams near the mountain front (stream seepage). The magnitude of subsurface inflow is of central importance in source protection planning for basin-fill aquifers and in some water rights disputes, yet existing estimates carry large uncertainties. Stable isotope ratios can indicate the magnitude of mountain-front recharge relative to other components, but are generally incapable of distinguishing subsurface inflow from stream seepage. Noble gases provide an effective tool for determining the relative significance of subsurface inflow, specifically. Dissolved noble gas concentrations allow for the determination of recharge temperature, which is correlated with recharge elevation. The nature of this correlation cannot be assumed, however, and must be derived for the study area. The method is applied to the Salt Lake Valley Principal Aquifer in northern Utah to demonstrate its utility. Samples from 16 springs and mine tunnels in the adjacent Wasatch Mountains indicate that recharge temperature decreases with elevation at about the same rate as the mean annual air temperature, but is on average about 2??C cooler. Samples from 27 valley production wells yield recharge elevations ranging from the valley elevation (about 1500 m) to mid-mountain elevation (about 2500 m). Only six of the wells have recharge elevations less than 1800 m. Recharge elevations consistently greater than 2000 m in the southeastern part of the basin indicate that subsurface inflow constitutes most of the total recharge in this area. ?? 2003 Published by Elsevier Science B.V.

  11. YUCCA MOUNTAIN SITE DESCRIPTION

    SciTech Connect

    A.M. Simmons

    2004-04-16

    The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.

  12. High-speed Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Ackeret, J

    1936-01-01

    Wind tunnel construction and design is discussed especially in relation to subsonic and supersonic speeds. Reynolds Numbers and the theory of compressible flows are also taken into consideration in designing new tunnels.

  13. Two-dimensional wind tunnel

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Information on the Japanese National Aerospace Laboratory two dimensional transonic wind tunnel, completed at the end of 1979 is presented. Its construction is discussed in detail, and the wind tunnel structure, operation, test results, and future plans are presented.

  14. Wind tunnel wall interference

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Mineck, Raymond E.; Barnwell, Richard W.; Kemp, William B., Jr.

    1986-01-01

    About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.

  15. Instrumentation in wind tunnels

    NASA Technical Reports Server (NTRS)

    Takashima, K.

    1986-01-01

    Requirements in designing instrumentation systems and measurements of various physical quantities in wind tunnels are surveyed. Emphasis is given to sensors used for measuring pressure, temperature, and angle, and the measurements of air turbulence and boundary layers. Instrumentation in wind tunnels require accuracy, fast response, diversity and operational simplicity. Measurements of force, pressure, attitude angle, free flow, pressure distribution, and temperature are illustrated by a table, and a block diagram. The LDV (laser Doppler velocimeter) method for measuring air turbulence and flow velocity and measurement of skin friction and flow fields using laser holograms are discussed. The future potential of these techniques is studied.

  16. Scanning tunneling microscope nanoetching method

    DOEpatents

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  17. Magnetic Fluxtube Tunneling

    NASA Technical Reports Server (NTRS)

    Dahlburg, Russell B.; Antiochos,, Spiro K.; Norton, D.

    1996-01-01

    We present numerical simulations of the collision and subsequent interaction of two initially orthogonal, twisted, force free field magnetic fluxtubes. The simulations were carried out using a new three dimensional explicit parallelized Fourier collocation algorithm for solving the viscoresistive equations of compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the fluxtubes can 'tunnel' through each other. Two key conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch much greater than 1, and the magnetic Lundquist number must be somewhat large, greater than or equal to 2880. This tunneling behavior has not been seen previously in studies of either vortex tube or magnetic fluxtube interactions. An examination of magnetic field lines shows that tunneling is due to a double reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections and 'pass' through each other. The implications of these results for solar and space plasmas are discussed.

  18. Tunnelling with wormhole creation

    SciTech Connect

    Ansoldi, S.; Tanaka, T.

    2015-03-15

    The description of quantum tunnelling in the presence of gravity shows subtleties in some cases. We discuss wormhole production in the context of the spherically symmetric thin-shell approximation. By presenting a fully consistent treatment based on canonical quantization, we solve a controversy present in the literature.

  19. Dry wind tunnel system

    NASA Technical Reports Server (NTRS)

    Chen, Ping-Chih (Inventor)

    2013-01-01

    This invention is a ground flutter testing system without a wind tunnel, called Dry Wind Tunnel (DWT) System. The DWT system consists of a Ground Vibration Test (GVT) hardware system, a multiple input multiple output (MIMO) force controller software, and a real-time unsteady aerodynamic force generation software, that is developed from an aerodynamic reduced order model (ROM). The ground flutter test using the DWT System operates on a real structural model, therefore no scaled-down structural model, which is required by the conventional wind tunnel flutter test, is involved. Furthermore, the impact of the structural nonlinearities on the aeroelastic stability can be included automatically. Moreover, the aeroservoelastic characteristics of the aircraft can be easily measured by simply including the flight control system in-the-loop. In addition, the unsteady aerodynamics generated computationally is interference-free from the wind tunnel walls. Finally, the DWT System can be conveniently and inexpensively carried out as a post GVT test with the same hardware, only with some possible rearrangement of the shakers and the inclusion of additional sensors.

  20. Wind Tunnel Balances

    NASA Technical Reports Server (NTRS)

    Warner, Edward P; Norton, F H

    1920-01-01

    Report embodies a description of the balance designed and constructed for the use of the National Advisory Committee for Aeronautics at Langley Field, and also deals with the theory of sensitivity of balances and with the errors to which wind tunnel balances of various types are subject.

  1. Carpal tunnel syndrome

    PubMed Central

    2014-01-01

    Introduction Carpal tunnel syndrome is a collection of clinical symptoms and signs caused by compression of the median nerve within the carpal tunnel. However, the severity of symptoms and signs does not often correlate well with the extent of nerve compression. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments, non-drug treatments, and surgical treatments for carpal tunnel syndrome? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 33 studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: carpal tunnel release surgery (open and endoscopic), diuretics, local corticosteroids injection, non-steroidal anti-inflammatory drugs (NSAIDs), therapeutic ultrasound, and wrist splints.

  2. Full Scale Tunnel model

    NASA Technical Reports Server (NTRS)

    1929-01-01

    Interior view of Full-Scale Tunnel (FST) model. (Small human figures have been added for scale.) On June 26, 1929, Elton W. Miller wrote to George W. Lewis proposing the construction of a model of the full-scale tunnel . 'The excellent energy ratio obtained in the new wind tunnel of the California Institute of Technology suggests that before proceeding with our full scale tunnel design, we ought to investigate the effect on energy ratio of such factors as: 1. small included angle for the exit cone; 2. carefully designed return passages of circular section as far as possible, without sudden changes in cross sections; 3. tightness of walls. It is believed that much useful information can be obtained by building a model of about 1/16 scale, that is, having a closed throat of 2 ft. by 4 ft. The outside dimensions would be about 12 ft. by 25 ft. in plan and the height 4 ft. Two propellers will be required about 28 in. in diameter, each to be driven by direct current motor at a maximum speed of 4500 R.P.M. Provision can be made for altering the length of certain portions, particularly the exit cone, and possibly for the application of boundary layer control in order to effect satisfactory air flow.

  3. The Channel Tunnel

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The Channel Tunnel is a 50.5 km-long rail tunnel beneath the English Channel at the Straits of Dover. It connects Dover, Kent in England with Calais, northern France. The undersea section of the tunnel is unsurpassed in length in the world. A proposal for a Channel tunnel was first put forward by a French engineer in 1802. In 1881, a first attempt was made at boring a tunnel from the English side; the work was halted after 800 m. Again in 1922, English workers started boring a tunnel, and advanced 120 m before it too was halted for political reasons. The most recent attempt was begun in 1987, and the tunnel was officially opened in 1994. At completion it was estimated that the project cost around $18 billion. It has been operating at a significant loss since its opening, despite trips by over 7 million passengers per year on the Eurostar train, and over 3 million vehicles per year.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring

  4. TBM performance prediction in Yucca Mountain welded tuff from linear cutter tests

    SciTech Connect

    Gertsch, R.; Ozdemir, L.; Gertsch, L.

    1992-11-01

    This paper discusses performance prediction which were developed for tunnel boring machines operating in welded tuff for the construction of the experimental study facility and the potential nuclear waste repository at Yucca Mountain. The predictions were based on test data obtained from an extensive series of linear cutting tests performed on samples of Topopah String welded tuff from the Yucca Mountain Project site. Using the cutter force, spacing, and penetration data from the experimental program, the thrust, torque, power, and rate of penetration were estimated for a 25 ft diameter tunnel boring machine (TBM) operating in welded tuff. The result show that the Topopah Spring welded tuff (TSw2) can be excavated at relatively high rates of advance with state-of-the-art TBMs. The result also show, however, that the TBM torque and power requirements will be higher than estimated based on rock physical properties and past tunneling experience in rock formations of similar strength.

  5. A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 1

    SciTech Connect

    Jones, robert C; Drollinger, Harold; Bullard, Thomas F; Ashbaugh, Laurence J; Griffin, Wayne R

    2013-06-01

    This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase, Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts. The U16

  6. A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 2

    SciTech Connect

    Jones, Roberrt C; Drollinger, Harold

    2013-06-01

    This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase, Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts. The U16

  7. Low-disturbance wind tunnels

    NASA Technical Reports Server (NTRS)

    Beckwith, I. E.; Applin, Z. T.; Stainback, P. C.; Maestrello, L.

    1986-01-01

    During the past years, there was an extensive program under way at the Langley Research Center to upgrade the flow quality in several of the large wind tunnels. This effort has resulted in significant improvements in flow quality in these tunnels and has also increased the understanding of how and where changes in existing and new wind tunnels are most likely to yield the desired improvements. As part of this ongoing program, flow disturbance levels and spectra were measured in several Langley tunnels before and after modifications were made to reduce acoustic and vorticity fluctuations. A brief description of these disturbance control features is given for the Low-Turbulence Pressure Tunnel, the 4 x 7 Meter Tunnel, and the 8 Foot Transonic Pressure Tunnel. To illustrate typical reductions in disturbance levels obtained in these tunnels, data from hot-wire or acoustic sensors are presented. A concept for a subsonic quiet tunnel designed to study boundary layer stability and transition is also presented. Techniques developed at Langley in recent years to eliminate the high intensity and high-frequency acoustic disturbances present in all previous supersonic wind tunnels are described. In conclusion, the low-disturbance levels present in atmospheric flight can now be simulated in wind tunnels over the speed range from low subsonic through high supersonic.

  8. Andean flat subduction maintained by slab tunneling

    NASA Astrophysics Data System (ADS)

    Schepers, Gerben; van Hinsbergen, Douwe; Kosters, Martha; Boschman, Lydian; McQuarrie, Nadine; Spakman, Wim

    2016-04-01

    In two segments below the Andean mountain belt, the Nazca Plate is currently subducting sub-horizontally below South America over a distance of 200-300 km before the plate bends into the mantle. Such flat slab segments have pronounced effects on orogenesis and magmatism and are widely believed to be caused by the downgoing plate resisting subduction due to its local positive buoyancy. In contrast, here we show that flat slabs primarily result from a local resistance against rollback rather than against subduction. From a kinematic reconstruction of the Andean fold-thrust belt we determine up to ~390 km of shortening since ~50 Ma. During this time the South American Plate moved ~1400 km westward relative to the mantle, thus forcing ~1000 km of trench retreat. Importantly, since the 11-12 Ma onset of flat slab formation, ~1000 km of Nazca Plate subduction occurred, much more than the flat slab lengths, which leads to our main finding that the flat slabs, while being initiated by arrival of buoyant material at the trench, are primarily maintained by locally impeded rollback. We suggest that dynamic support of flat subduction comes from the formation of slab tunnels below segments with the most buoyant material. These tunnels trap mantle material until tearing of the tunnel wall provides an escape route. Fast subduction of this tear is followed by a continuous slab and the process can recur during ongoing rollback of the 7000 km wide Nazca slab at segments with the most buoyant subducting material, explaining the regional and transient character of flat slabs. Our study highlights the importance of studying subduction dynamics in absolute plate motion context.

  9. Introduction to cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.

    1985-01-01

    The background to the evolution of the cryogenic wind tunnel is outlined, with particular reference to the late 60's/early 70's when efforts were begun to re-equip with larger wind tunnels. The problems of providing full scale Reynolds numbers in transonic testing were proving particularly intractible, when the notion of satisfying the needs with the cryogenic tunnel was proposed, and then adopted. The principles and advantages of the cryogenic tunnel are outlined, along with guidance on the coolant needs when this is liquid nitrogen, and with a note on energy recovery. Operational features of the tunnels are introduced with reference to a small low speed tunnel. Finally the outstanding contributions are highlighted of the 0.3-Meter Transonic Cryogenic Tunnel (TCT) at NASA Langley Research Center, and its personnel, to the furtherance of knowledge and confidence in the concept.

  10. Techniques For Mass Production Of Tunneling Electrodes

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas W.; Podosek, Judith A.; Reynolds, Joseph K.; Rockstad, Howard K.; Vote, Erika C.; Kaiser, William J.

    1993-01-01

    Techniques for mass production of tunneling electrodes developed from silicon-micromachining, lithographic patterning, and related microfabrication processes. Tunneling electrodes named because electrons travel between them by quantum-mechanical tunneling; tunneling electrodes integral parts of tunneling transducer/sensors, which act in conjunction with feedback circuitry to stabilize tunneling currents by maintaining electrode separations of order of 10 Angstrom. Essential parts of scanning tunneling microscopes and related instruments, and used as force and position transducers in novel microscopic accelerometers and infrared detectors.

  11. STRAWBERRY MOUNTAIN WILDERNESS, OREGON.

    USGS Publications Warehouse

    Thayer, T.P.; Stotelmeyer, Ronald B.

    1984-01-01

    The Strawberry Mountain Wilderness extends 18 mi along the crest of the Strawberry Range and comprises about 53 sq mi in the Malheur National Forest, Grant County, Oregon. Systematic geologic mapping, geochemical sampling and detailed sampling of prospect workings was done. A demonstrated copper resource in small quartz veins averaging at most 0. 33 percent copper with traces of silver occurs in shear zones in gabbro. Two small areas with substantiated potential for chrome occur near the northern edge of the wilderness. There is little promise for the occurrence of additional mineral or energy resources in the Strawberry Mountain Wilderness.

  12. Mountain Home Well - Photos

    DOE Data Explorer

    Shervais, John

    2012-01-11

    The Snake River Plain (SRP), Idaho, hosts potential geothermal resources due to elevated groundwater temperatures associated with the thermal anomaly Yellowstone-Snake River hotspot. Project HOTSPOT has coordinated international institutions and organizations to understand subsurface stratigraphy and assess geothermal potential. Over 5.9km of core were drilled from three boreholes within the SRP in an attempt to acquire continuous core documenting the volcanic and sedimentary record of the hotspot: (1) Kimama, (2) Kimberly, and (3) Mountain Home. The Mountain Home drill hole is located along the western plain and documents older basalts overlain by sediment. Data submitted by project collaborator Doug Schmitt, University of Alberta

  13. 20-Foot Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1941-01-01

    The large structure on the left of the photograph is the Free-Spinning Wind Tunnel in which dynamic scale models of modern airplanes are tested to determine their spinning characteristics and ability to recover from spins from movement of the control surfaces. From the information obtained in this manner, the spin recovery characteristics of the full-scale airplane may be predicted. The large sphere on the right is 60 feet in diameter and houses the NACA 12-Foot Free-Flight Wind Tunnel in which dynamic scale models of airplanes are flown in actual controlled flight to provide information from which the stability characteristics of the full-scale airplane may be predicted.

  14. Possibility of hyperbolic tunneling

    SciTech Connect

    Lobo, Francisco S. N.; Mimoso, Jose P.

    2010-08-15

    Traversable wormholes are primarily useful as 'gedanken experiments' and as a theoretician's probe of the foundations of general relativity. In this work, we analyze the possibility of having tunnels in a hyperbolic spacetime. We obtain exact solutions of static and pseudo-spherically symmetric spacetime tunnels by adding exotic matter to a vacuum solution referred to as a degenerate solution of class A. The physical properties and characteristics of these intriguing solutions are explored, and through the mathematics of embedding it is shown that particular constraints are placed on the shape function, that differ significantly from the Morris-Thorne wormhole. In particular, it is shown that the energy density is always negative, and the radial pressure is positive, at the throat, contrary to the Morris-Thorne counterpart. Specific solutions are also presented by considering several equations of state, and by imposing restricted choices for the shape function or the redshift function.

  15. Uncooled tunneling infrared sensor

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas W. (Inventor); Kaiser, William J. (Inventor); Podosek, Judith A. (Inventor); Vote, Erika C. (Inventor); Rockstad, Howard K. (Inventor); Reynolds, Joseph K. (Inventor)

    1994-01-01

    An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane which would otherwise change deflection depending upon incident infrared radiation. The resulting infrared sensor will meet or exceed the performance of all other broadband, uncooled, infrared sensors and can be miniaturized to pixel dimensions smaller than 100 .mu.m. The technology is readily implemented as a small-format linear array suitable for commercial and spacecraft applications.

  16. Tunnel boring machine

    SciTech Connect

    Snyder, L. L.

    1985-07-09

    A tunnel boring machine for controlled boring of a curvilinear tunnel including a rotating cutter wheel mounted on the forward end of a thrust cylinder assembly having a central longitudinal axis aligned with the cutter wheel axis of rotation; the thrust cylinder assembly comprising a cylinder barrel and an extendable and retractable thrust arm received therein. An anchoring assembly is pivotally attached to the rear end of the cylinder barrel for anchoring the machine during a cutting stroke and providing a rear end pivot axis during curved cutting strokes. A pair of laterally extending, extendable and retractable arms are fixedly mounted at a forward portion of the cylinder barrel for providing lateral displacement in a laterally curved cutting mode and for anchoring the machine between cutting strokes and during straight line boring. Forward and rear transverse displacement and support assemblies are provided to facilitate cutting in a transversely curved cutting mode and to facilitate machine movement between cutting strokes.

  17. Tunneling in Molecular Magnets

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, Avinash

    This thesis is about the tunneling dynamics of the Fe8 molecule in the presence of an environment. Although a lot of progress has been made experimentally to determine among many things the extremely small tunnel splitting energies of this macromolecule, the question of how the environment affects the molecule has still not been properly understood. It is the purpose of this thesis to put forward a coherent model for the decoherence processes that affect the Fe8 molecule. The decoherence allows us to treat the Fe8 molecules as classical objects and we can write down rate equations that determine the relaxation dynamics of the entire Fe8 solid. The theoretical predictions are in very good agreement with Monte-Carlo simulations of spherical samples. We believe that the model developed can be generalized to different geometries and also improvised to tackle the different experimental protocols that have been undertaken on these macroscopic molecules.

  18. On tunneling across horizons

    NASA Astrophysics Data System (ADS)

    Vanzo, L.

    2011-07-01

    The tunneling method for stationary black holes in the Hamilton-Jacobi variant is reconsidered in the light of some critiques that have been moved against. It is shown that once the tunneling trajectories have been correctly identified the method is free from internal inconsistencies, it is manifestly covariant, it allows for the extension to spinning particles and it can even be used without solving the Hamilton-Jacobi equation. These conclusions borrow support on a simple analytic continuation of the classical action of a pointlike particle, made possible by the unique assumption that it should be analytic in the complexified Schwarzschild or Kerr-Newman space-time. A more general version of the Parikh-Wilczek method will also be proposed along these lines.

  19. Unitary Plan Supersonic Tunnel

    NASA Technical Reports Server (NTRS)

    1953-01-01

    Unitary Plan Supersonic Tunnel: In this aerial photograph of construction in the early 1950s, the return air passages are shown in the rear, center. This area was later covered with walls and a roof so that upon completion of the facility, it was not visible from the exterior. Three air storage spheres and the cooling tower are at the extreme right of the building. The spheres store dry air at 150 pounds per square inch. The cooling tower dissipates heat from coolers that control the test air temperature. One of many research facilities at NASA Langley Research Center in Hampton, Virginia, the Unitary Plan Wind Tunnel is used for experimental investigations at supersonic speeds.

  20. 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of 5-Foot Vertical Wind Tunnel. The 5-Foot Vertical Wind Tunnel was built to study spinning characteristics of aircraft. It was an open throat tunnel capable of a maximum speed of 80 mph. NACA engineer Charles H. Zimmerman designed the tunnel starting in 1928. Construction was completed in December 1929. It was one of two tunnels which replaced the original Atmospheric Wind Tunnel (The other was the 7x10-Foot Wind Tunnel.). In NACA TR 387 (p. 499), Carl Wenzinger and Thomas Harris report that 'the tunnel passages are constructed of 1/8-inch sheet iron, stiffened with angle iron and bolted together at the corners. The over-all dimensions are: Height 31 feet 2 inches; length, 20 feet 3 inches; width, 10 feet 3 inches.' The tunnel was partially constructed in the Langley hanger as indicated by the aircraft in the background. Published in NACA TR 387, 'The Vertical Wind Tunnel of the National Advisory Committee for Aeronautics,' by Carl J. Wenzinger and Thomas A. Harris, 1931.

  1. Tunnel boring machine

    SciTech Connect

    Dillingham, R.G.; Hamburger, H.

    1982-09-14

    A tunneling machine is disclosed which includes a hollow shield, a nonrotatable outer housing mounted in the shield for longitudinal movement, and inner housing rotatably mounted within the outer housing, an excavator including a boom and bucket pivotally mounted on the forward end of the inner housing, and a boom cylinder having a forward portion pivotally engaged with the boom and a rear portion mounted at the rearward portion of the inner housing.

  2. Full Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Installation of Full Scale Tunnel (FST) power plant. Virginia Public Service Company could not supply adequate electricity to run the wind tunnels being built at Langley. (The Propeller Research Tunnel was powered by two submarine diesel engines.) This led to the consideration of a number of different ideas for generating electric power to drive the fan motors in the FST. The main proposition involved two 3000 hp and two 1000 hp diesel engines with directly connected generators. Another, proposition suggested 30 Liberty motors driving 600 hp DC generators in pairs. For a month, engineers at Langley were hopeful they could secure additional diesel engines from decommissioned Navy T-boats but the Navy could not offer a firm commitment regarding the future status of the submarines. By mid-December 1929, Virginia Public Service Company had agreed to supply service to the field at the north end of the King Street Bridge connecting Hampton and Langley Field. Thus, new plans for FST powerplant and motors were made. Smith DeFrance described the motors in NACA TR No. 459: 'The most commonly used power plant for operating a wind tunnel is a direct-current motor and motor-generator set with Ward Leonard control system. For the FST it was found that alternating current slip-ring induction motors, together with satisfactory control equipment, could be purchased for approximately 30 percent less than the direct-current equipment. Two 4000-horsepower slip-ring induction motors with 24 steps of speed between 75 and 300 r.p.m. were therefore installed.'

  3. 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Schematic drawing of 5-Foot Vertical Wind Tunnel. Carl Wenzinger and Thomas Harris describe the tunnel in NACA TR No. 387: 'The tunnel has an open jet, an open test chamber, and a closed return passage. ... The air passes through the test section in a downward direction then enters the exit cone and passes through the first set of guide vanes to a propeller. From here it passes, by way of the return passage, through the successive sets of guide vanes at the corners, then through the honeycomb, and finally through the entrance cone.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet to within 0.5%. The turbulence present in the tunnel has been compared with that of several other tunnels by means of the results of sphere drag tests and was found to average well with the values of those tunnels. Included also in the report are comparisons of results of stable autorotation and of rolling-moment tests obtained both in the vertical tunnel and in the old horizontal 5-foot atmospheric tunnel.' The design of a vertical tunnel having a 5-foot diameter jet was accordingly started by the National Advisory Committee for Aeronautics in 1928. Actual construction of the new tunnel was completed in 1930, and the calibration tests were then made.'

  4. Resonant Tunneling Spin Pump

    NASA Technical Reports Server (NTRS)

    Ting, David Z.

    2007-01-01

    The resonant tunneling spin pump is a proposed semiconductor device that would generate spin-polarized electron currents. The resonant tunneling spin pump would be a purely electrical device in the sense that it would not contain any magnetic material and would not rely on an applied magnetic field. Also, unlike prior sources of spin-polarized electron currents, the proposed device would not depend on a source of circularly polarized light. The proposed semiconductor electron-spin filters would exploit the Rashba effect, which can induce energy splitting in what would otherwise be degenerate quantum states, caused by a spin-orbit interaction in conjunction with a structural-inversion asymmetry in the presence of interfacial electric fields in a semiconductor heterostructure. The magnitude of the energy split is proportional to the electron wave number. Theoretical studies have suggested the possibility of devices in which electron energy states would be split by the Rashba effect and spin-polarized currents would be extracted by resonant quantum-mechanical tunneling.

  5. Smart tunnel: Docking mechanism

    NASA Technical Reports Server (NTRS)

    Schliesing, John A. (Inventor); Edenborough, Kevin L. (Inventor)

    1989-01-01

    A docking mechanism is presented for the docking of a space vehicle to a space station comprising a flexible tunnel frame structure which is deployable from the space station. The tunnel structure comprises a plurality of series connected frame sections, one end section of which is attached to the space station and the other end attached to a docking module of a configuration adapted for docking in the payload bay of the space vehicle. The docking module is provided with trunnions, adapted for latching engagement with latches installed in the vehicle payload bay and with hatch means connectable to a hatch of the crew cabin of the space vehicle. Each frame section comprises a pair of spaced ring members, interconnected by actuator-attenuator devices which are individually controllable by an automatic control means to impart relative movement of one ring member to the other in six degrees of freedom of motion. The control means includes computer logic responsive to sensor signals of range and attitude information, capture latch condition, structural loads, and actuator stroke for generating commands to the onboard flight control system and the individual actuator-attenuators to deploy the tunnel to effect a coupling with the space vehicle and space station after coupling. A tubular fluid-impervious liner, preferably fabric, is disposed through the frame sections of a size sufficient to accommodate the passage of personnel and cargo.

  6. Analysis of shield tunnel

    NASA Astrophysics Data System (ADS)

    Ding, W. Q.; Yue, Z. Q.; Tham, L. G.; Zhu, H. H.; Lee, C. F.; Hashimoto, T.

    2004-01-01

    This paper proposes a two-dimensional finite element model for the analysis of shield tunnels by taking into account the construction process which is divided into four stages. The soil is assumed to behave as an elasto-plastic medium whereas the shield is simulated by beam-joint discontinuous model in which curved beam elements and joint elements are used to model the segments and joints, respectively. As grout is usually injected to fill the gap between the lining and the soil, the property parameters of the grout are chosen in such a way that they can reflect the state of the grout at each stage. Furthermore, the contact condition between the soil and lining will change with the construction stage, and therefore, different stress-releasing coefficients are used to account for the changes. To assess the accuracy that can be attained by the method in solving practical problems, the shield tunnelling in the No. 7 Subway Line Project in Osaka, Japan, is used as a case history for our study. The numerical results are compared with those measured in the field. The results presented in the paper show that the proposed numerical procedure can be used to effectively estimate the deformation, stresses and moments experienced by the surrounding soils and the concrete lining segments. The analysis and method presented in this paper can be considered to be useful for other subway construction projects involving shield tunnelling in soft soils. Copyright

  7. Evaluating tunnel kiln performance

    SciTech Connect

    O`Connor, K.R.; Carty, W.M.; Ninos, N.J.

    1997-08-01

    Process improvements in the production of whitewares provide the potential for substantial savings for manufacturers. A typical whiteware manufacturer incurs an annual defective product loss of {approximately}$20 million when accounting for raw materials, energy, labor and waste disposal. Reduction in defective product loss of 1% could result in a savings in excess of $1 million annually. This study was designed to establish benchmarks for two conventional tunnel kilns used to bisque-fire dinnerware at Buffalo China Inc. (Buffalo, NY). The benchmark was established by assessing the current conditions and variability of the two tunnel kilns as a function of the fracture strength of sample bars that were made from production body. Sample bars were fired in multiple locations in both kilns to assess the conditions and variability of firing within each kiln. Comparison of strength results between the two kilns also was assessed. These comparisons were accomplished through applied statistical analysis, wherein significant statistical variations were identified and isolated for both tunnel kilns. The statistical methods and tools used in this analysis are readily accessible to manufacturers, thus allowing implementation of similar analysis, or benchmarking, in-house.

  8. Tunnelling from black holes and tunnelling into white holes

    NASA Astrophysics Data System (ADS)

    Chatterjee, Bhramar; Ghosh, A.; Mitra, P.

    2008-03-01

    Hawking radiation is nowadays being understood as tunnelling through black hole horizons. Here, the extension of the Hamilton-Jacobi approach to tunnelling for non-rotating and rotating black holes in different non-singular coordinate systems not only confirms this quantum emission from black holes but also reveals the new phenomenon of absorption into white holes by quantum mechanical tunnelling. The rôle of a boundary condition of total absorption or emission is also clarified.

  9. Seismic monitoring of the Yucca Mountain facility

    SciTech Connect

    Garbin, H.D.; Herrington, P.B.; Kromer, R.P.

    1997-08-01

    Questions have arisen regarding the applicability of seismic sensors to detect mining (re-entry) with a tunnel boring machine (TBM). Unlike cut and blast techniques of mining which produce impulsive seismic signals, the TBM produces seismic signals which are of long duration. (There are well established techniques available for detecting and locating the sources of the impulsive signals.) The Yucca Mountain repository offered an opportunity to perform field evaluations of the capabilities of seismic sensors because during much of 1996, mining there was progressing with the use of a TBM. During the mining of the repository`s southern branch, an effort was designed to evaluate whether the TBM could be detected, identified and located using seismic sensors. Three data acquisition stations were established in the Yucca Mountain area to monitor the TBM activity. A ratio of short term average to long term average algorithm was developed for use in signal detection based on the characteristics shown in the time series. For location of the source of detected signals, FK analysis was used on the array data to estimate back azimuths. The back azimuth from the 3 component system was estimated from the horizontal components. Unique features in the timing of the seismic signal were used to identify the source as the TBM.

  10. Yucca Mountain tuffs

    SciTech Connect

    1996-08-01

    This is a compilation of petrographic slides detailing the microstructure and petrographic character of the tuff deposits associated with the Yucca Mountain radioactive waste repository. It describes crystal structures, clay alterations, and mineral associations. The paper contains a description of the petrographic thin-sections but contains no narrative or conclusions of what the slides suggest with regards to the facility.

  11. DOE's Yucca Mountain Studies.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC.

    This booklet is about the disposal of high-level nuclear waste in the United States with a particular focus on Yucca Mountain, Nevada as a repository site. Intended for readers who do not have a technical background, the booklet discusses why scientists and engineers think high-level nuclear waste may be disposed of safely underground. An…

  12. The Strongest Mountain

    ERIC Educational Resources Information Center

    Monnes, Colleen

    2004-01-01

    The article describes an activity for the author's fifth-grade students called "build the strongest mountain." To them, it was not a lesson--it was a challenge. To the author, it was an activity that turned a run-of-the-mill Earth science unit into a terrific opportunity for students to demonstrate their knowledge of erosion and develop…

  13. Mountain-Plains Curriculum.

    ERIC Educational Resources Information Center

    Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

    The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

  14. Collision and mountain building

    NASA Astrophysics Data System (ADS)

    Trifonov, V. G.

    2016-01-01

    The spatial, chronological, and genetic relationships of recent (Late Alpine) collisions to mountain building are considered at three levels of scale: (i) in separate zones of the Arabian-Caucasus segment of the Alpine-Himalayan Orogenic Belt, (ii) throughout the central segment of this belt from the Alps to the Himalalayas, and (iii) in Central Asia and other mountain belts of continents. Three stages of mountain building are distinguished at all three levels. The first stage starts with widespread collision and similar plate interactions from the end of the Eocene to the middle Miocene and is expressed in the formation of uplifts, commonly no higher than the moderately elevated level in regions that concentrate deformations of transverse shortening induced by compression. The second short stage, which embraces the Pliocene-Quaternary and occasionally the end of the Miocene, differs in general, though differentiated in the value and intensification of vertical movements, when the height of mountains increases by 2-3 times. Elevations are spread over certain platform territories and even frameworks of rift zones. This is related not so much to the intensity of compression and shortening as to the compositional transformation of the upper mantle and the lower crust, leading to their decompaction. Comparison with the Hercynian and Caledonian orogenic stages shows that the second phase, predetermined by widespread collision, reflects a more important geodynamic event expressed in a change of the global plate interaction system and its deep-seated sources.

  15. Rocky Mountain Perspectives.

    ERIC Educational Resources Information Center

    Dutkiewicz, Jody Steiner, Ed.

    This publication features articles detailing the state of educational programs in the Rocky Mountain area. The articles address: 1) the impact of physical geography on culture, education, and lifestyle; 2) the education of migrant and/or agricultural workers and their children; 3) educational needs of children in rural areas; 4) outdoor education;…

  16. The Mountaineer Minority

    ERIC Educational Resources Information Center

    Egerton, John; Gaillard, Frye

    1974-01-01

    Discusses the new Appalachian movement, based on the assumption that mountain people are a distinct and maligned cultural minority; the people of Appalachia, white, black and red, have begun to strike back against the dam-builders, strip-miners, and others they say are gouging out the region's mineral resources by the cheapest means possible no…

  17. [Mountaineering and altitude sickness].

    PubMed

    Maggiorini, M

    2001-06-01

    Almost every second trekker or climber develops two to three symptoms of the high altitude illness after a rapid ascent (> 300 m/day) to an altitude above 4000 m. We distinguish two forms of high altitude illness, a cerebral form called acute mountain sickness and a pulmonary form called high altitude pulmonary edema. Essentially, acute mountain sickness is self-limiting and benign. Its symptoms are mild to moderate headache, loss of appetite, nausea, dizziness and insomnia. Nausea rarely progresses to vomiting, but if it does, this may anticipate a progression of the disease into the severe form of acute mountain sickness, called high altitude cerebral edema. Symptoms and signs of high altitude cerebral edema are severe headache, which is not relieved by acetaminophen, loss of movement coordination, ataxia and mental deterioration ending in coma. The mechanisms leading to acute mountain sickness are not very well understood; the loss of cerebral autoregulation and a vasogenic type of cerebral edema are being discussed. High altitude pulmonary edema presents in roughly twenty percent of the cases with mild symptoms of acute mountain sickness or even without any symptoms at all. Symptoms associated with high altitude pulmonary edema are incapacitating fatigue, chest tightness, dyspnoe at the minimal effort that advances to dyspnoe at rest and orthopnoe, and a dry non-productive cough that progresses to cough with pink frothy sputum due to hemoptysis. The hallmark of high altitude pulmonary edema is an exaggerated hypoxic pulmonary vasoconstriction. Successful prophylaxis and treatment of high altitude pulmonary edema using nifedipine, a pulmonary vasodilator, indicates that pulmonary hypertension is crucial for the development of high altitude pulmonary edema. The primary treatment of high altitude illness consists in improving hypoxemia and acclimatization. For prophylaxis a slow ascent at a rate of 300 m/day is recommended, if symptoms persist, acetazolamide at a

  18. Submucosal tunneling techniques: current perspectives

    PubMed Central

    Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

    2014-01-01

    Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments. PMID:24741323

  19. Digital mountains: toward development and environment protection in mountain regions

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaobo

    2007-06-01

    Former studies on mountain system are focused on the department or subject characters, i.e. different department and branches of learning carry out researches only for their individual purposes and with individual characters of the subject of interests. As a whole, their investigation is lacking of comprehensive study in combination with global environment. Ecological environment in mountain regions is vulnerable to the disturbance of human activities. Therefore, it is a key issue to coordinate economic development and environment protection in mountain regions. On the other hand, a lot of work is ongoing on mountain sciences, especially depending on the application of RS and GIS. Moreover, the development of the Digital Earth (DE) provides a clue to re-understand mountains. These are the background of the emergence of the Digital Mountains (DM). One of the purposes of the DM is integrating spatial related data and information about mountains. Moreover, the DM is a viewpoint and methodology of understanding and quantifying mountains holistically. The concept of the DM is that, the spatial and temporal data related to mountain regions are stored and managed in computers; moreover, manipulating, analyzing, modeling, simulating and sharing of the mountain information are implemented by utilizing technologies of RS, GIS, GPS, Geo-informatic Tupu, computer, virtual reality (VR), 3D simulation, massive storage, mutual operation and network communication. The DM aims at advancing mountain sciences and sustainable mountain development. The DM is used to providing information and method for coordinating the mountain regions development and environment protection. The fundamental work of the DM is the design of the scientific architecture. Furthermore, construct and develop massive databases of mountains are the important steps these days.

  20. Unstable semiclassical trajectories in tunneling.

    PubMed

    Levkov, D G; Panin, A G; Sibiryakov, S M

    2007-10-26

    Some tunneling phenomena are described, in the semiclassical approximation, by unstable complex trajectories. We develop a systematic procedure to stabilize the trajectories and to calculate the tunneling probability, including both the suppression exponent and prefactor. We find that the instability of tunneling solutions modifies the power-law dependence of the prefactor on Planck's variant as compared to the case of stable solutions. PMID:17995308

  1. Geochemical study of acid mine drainage of the Big Lick Tunnel area, Williamstown, PA

    SciTech Connect

    Tollin, S. . Dept. of Geosciences)

    1993-03-01

    Acid mine drainage in the anthracite region of Pennsylvania continues to be a significant environmental problem. This study examines the acid mine outflow from the Big Lick Tunnel, north of Williamstown, Dauphin County, Pennsylvania. The tunnel drains abandoned mines on the north side of the Big Lick Mountain. Mining ceased in the area circa 1940, and the tunnel has been in operation since that time. The water, soil and stream bed sediment geochemistry has been studied to determine their changes in chemistry over distance. The pH, TDS and metal concentrations were the primary focus. Metal concentrations were determined using an ICP unit. Data indicates the pH of the outflow to range between 6.7 and 7.3 Fe and Mn concentrations are as high as 9.7 ppb. Extensive metal precipitation ( yellow boy'') occurs within the tunnel and for several hundred meters from the mouth of the tunnel. The combination of near neutral pH and high metal concentration suggest that the drainage is in contact with highly alkaline materials prior to discharge from the tunnel. The geology of the area does not suggest bedrock as the possible source of alkaline material. One hypothesis is that the acidic water is reacting with the concrete tunnel and being neutralized. Data also suggests that the Fe precipitates much quicker than the Mn, resulting in a zonation between Fe-rich and Mn-rich sediments along the length of the drainage.

  2. Experiences from the planning, construction and supporting of a road tunnel subjected to heavy rockbursting

    NASA Astrophysics Data System (ADS)

    Broch, E.; Sørheim, S.

    1984-01-01

    A 5360 m long road tunnel along a fjord with mountains rising steeply up to 1500 meters above sea level has recently been completed in Norway. 3 km of the tunnel was subjected to rockbursting caused by high and anisotropic stresses in the Precambrian gneisses. During the construction it was necessary to install 15 000 rock-bolts. Steelfibre reinforced shotcrete was successfylly applied for the first time to help stabilize the spalling rock. Supporting measures were only needed for the half of the tunnel closest to the fjord. 2600 m3 shotcrete was used. The paper outlines the preinvestigations and the design approach used for tunnels subjected to high and anisotropic stresses, and gives information about the construction and the support works carried out. A tunnel mapping system is described together with a classification of rockbursting activity in tunnels. Stresses in the rock were calculated by the use of finite element models and measured with “doorstopper” cells and the CSIR three-dimensional gauge. Comparisons of calculated and measured stresses are carried out. Rockbursting activity as observed along the tunnel is related to the estimated and observed stresses as well as to the properties of the rocks. Simple classification systems are used to correlate the results. Experiences from the use of the support are given.

  3. View of entrance tunnel outside Portal elevator. Tunnel ahead to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of entrance tunnel outside Portal elevator. Tunnel ahead to Control Center, right to Launchers, left to Antenna Silos - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

  4. View of Water Storage Tank off entrance tunnel. Tunnel at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Water Storage Tank off entrance tunnel. Tunnel at left of image to Launch Silos - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

  5. Carpal tunnel syndrome

    PubMed Central

    Aroori, Somaiah; Spence, Roy AJ

    2008-01-01

    Carpal tunnel syndrome is one of the most common peripheral neuropathies. It affects mainly middle aged women. In the majority of patients the exact cause and pathogenesis of CTS is unclear. Although several occupations have been linked to increased incidence and prevalence of CTS the evidence is not clear. Occupational CTS is uncommon and it is essential to exclude all other causes particularly the intrinsic factors such as obesity before attributing it to occupation. The risk of CTS is high in occupations involving exposure to high pressure, high force, repetitive work, and vibrating tools. The classic symptoms of CTS include nocturnal pain associated with tingling and numbness in the distribution of median nerve in the hand. There are several physical examination tests that will help in the diagnosis of CTS but none of these tests are diagnostic on their own. The gold standard test is nerve conduction studies. However, they are also associated with false positive and false negative results. The diagnosis of CTS should be based on history, physical examination and results of electrophysiological studies. The patient with mild symptoms of CTS can be managed with conservative treatment, particularly local injection of steroids. However, in moderate to severe cases, surgery is the only treatment that provides cure. The basic principle of surgery is to increase the volume of the carpal tunnel by dividing transverse carpal ligament to release the pressure on the median nerve. Apart from early recovery and return to work there is no significant difference in terms of early and late complications and long-term pain relief between endoscopic and open carpal tunnel surgery. PMID:18269111

  6. Full Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of Full Scale Tunnel (FST). In November 1929, Smith DeFrance submitted his recommendations for the general design of the Full Scale Wind Tunnel. The last on his list concerned the division of labor required to build this unusual facility. He believed the job had five parts and described them as follows: 'It is proposed that invitations be sent out for bids on five groups of items. The first would be for one contract on the complete structure; second the same as first, including the erection of the cones but not the fabrication, since this would be more of a shipyard job; third would cover structural steel, cover, sash and doors, but not cones or foundation; fourth, foundations; an fifth, fabrication of cones.' DeFrance's memorandum prompted the NACA to solicit estimates from a large number of companies. Preliminary designs and estimates were prepared and submitted to the Bureau of the Budget and Congress appropriated funds on February 20, 1929. The main construction contract with the J.A. Jones Company of Charlotte, North Carolina was signed one year later on February 12, 1930. It was a peculiar structure as the building's steel framework is visible on the outside of the building. DeFrance described this in NACA TR No. 459: 'The entire equipment is housed in a structure, the outside walls of which serve as the outer walls of the return passages. The over-all length of the tunnel is 434 feet 6 inches, the width 222 feet, and the maximum height 97 feet. The framework is of structural steel....' (pp. 292-293)

  7. Full Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of Full-Scale Tunnel (FST). In November 1929, Smith DeFrance submitted his recommendations for the general design of the Full Scale Wind Tunnel. The last on his list concerned the division of labor required to build this unusual facility. He believed the job had five parts and described them as follows: 'It is proposed that invitations be sent out for bids on five groups of items. The first would be for one contract on the complete structure; second the same as first, including the erection of the cones but not the fabrication, since this would be more of a shipyard job; third would cover structural steel, cover, sash and doors, but not cones or foundation; fourth, foundations; and fifth, fabrication of cones.' DeFrance's memorandum prompted the NACA to solicit estimates from a large number of companies. Preliminary designs and estimates were prepared and submitted to the Bureau of the Budget and Congress appropriated funds on February 20, 1929. The main construction contract with the J.A. Jones Company of Charlotte, North Carolina was signed one year later on February 12, 1930. It was a peculiar structure as the building's steel framework is visible on the outside of the building. DeFrance described this in NACA TR No. 459: 'The entire equipment is housed in a structure, the outside walls of which serve as the outer walls of the return passages. The over-all length of the tunnel is 434 feet 6 inches, the width 222 feet, and the maximum height 97 feet. The framework is of structural steel....' (pp. 292-293).

  8. Electroacupuncture Helped Ease Carpal Tunnel in Study

    MedlinePlus

    ... 159240.html Electroacupuncture Helped Ease Carpal Tunnel in Study But experts say finding is preliminary, didn't ... condition known as carpal tunnel syndrome. In the study, electroacupuncture helped carpal tunnel patients with long-lasting ...

  9. Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Chennault, Jonathan

    2004-01-01

    The Icing Research Tunnel in Building 11 at the NASA Glenn Research Center is committed to researching the effects of in flight icing on aircraft and testing ways to stop the formation of hazardous icing conditions on planes. During this summer, I worked here with Richard DelRosa, the lead engineer for this area. address one of the major concerns of aviation: icing conditions. During the war, many planes crashed (especially supply planes going over the.Himalayas) because ice built up in their wings and clogged the engines. To this day, it remains the largest ice tunnel in the world, with a test section that measures 6 feet high, 9 feet long, and 20 feet wide. It can simulate airspeeds from 50 to 300 miles per hour at temperatures as low as -50 Fahrenheit. Using these capabilities, IRT can simulate actual conditions at high altitudes. The first thing I did was creating a cross reference in Microsoft Excel. It lists commands for the DPU units that control the pressure and temperature variations in the tunnel, as well as the type of command (keyboard, multiplier, divide, etc). The cross reference also contains the algorithm for every command, and which page it is listed in on the control sheet (visual Auto-CAD graphs, which I helped to make). I actually spent most of the time on the computer using Auto-CAD. I drew a diagram of the entire icing tunnel and then drew diagrams of its various parts. Between my mentor and me, we have drawings of every part of it, from the spray bars to the thermocouples, power cabinets, input-output connectors for power systems, and layouts of various other machines. I was also responsible for drawing schematics for the Escort system (which controls the spray bars), the power system, DPUs, and other electrical systems. In my spare time, I am attempting to build and program the "toddler". Toddler is a walking robot that I have to program in PBASIC language. When complete, it should be able to walk on level terrain while avoiding obstacles in

  10. Virtual-detector approach to tunnel ionization and tunneling times

    NASA Astrophysics Data System (ADS)

    Teeny, Nicolas; Keitel, Christoph H.; Bauke, Heiko

    2016-08-01

    Tunneling times in atomic ionization are studied theoretically by a virtual detector approach. A virtual detector is a hypothetical device that allows one to monitor the wave function's density with spatial and temporal resolution during the ionization process. With this theoretical approach, it becomes possible to define unique moments when the electron enters and leaves with highest probability the classically forbidden region from first principles and a tunneling time can be specified unambiguously. It is shown that neither the moment when the electron enters the tunneling barrier nor when it leaves the tunneling barrier coincides with the moment when the external electric field reaches its maximum. Under the tunneling barrier as well as at the exit the electron has a nonzero velocity in the electric field direction. This nonzero exit velocity has to be incorporated when the free motion of the electron is modeled by classical equations of motion.

  11. Vapor-phase transport in the near-drift environment at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Salve, Rohit; Kneafsey, Timothy J.

    2005-01-01

    A key issue regarding the performance of the potential high-level radioactive waste repository at Yucca Mountain, Nevada, is the likelihood of precipitation percolating a vertical distance of ˜300 m through fractured unsaturated rock into drifts containing waste packages. Water enhances waste package corrosion and is required for transport of released radionuclides. To evaluate the propensity for seepage into tunnels at Yucca Mountain, a 5-m-diameter, 2.7-km-long tunnel, commonly referred to as the Cross Drift (CD), was excavated in 1998, branching off from the main Exploratory Studies Facility tunnel. Sections of this tunnel have been isolated from ventilation for extended periods over the last 4 years. We present continuous measurements of relative humidity and temperature and periodic observations of liquid water in the CD over two periods. During this observation duration the terminal section of the drift was partitioned into four sections by bulkheads, and ventilation to these sections was minimized to a few days. We compare these observations to results from analytical and numerical models to investigate processes associated with the movement of water vapor between the tunnel bore and the surrounding fractured rock formation. Observations from this effort indicate that fractures can be primary paths for unsaturated zone vapor flow in the immediate vicinity of emplacement drifts. Observations, measurements, and analysis indicate the need for a model that includes fracture-dominated vapor transport as a significant contributor to total water flow into the drifts.

  12. Vapor-phase transport in the near-drift environment at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Salve, Rohit; Kneafsey, Timothy J.

    2005-01-01

    A key issue regarding the performance of the potential high-level radioactive waste repository at Yucca Mountain, Nevada, is the likelihood of precipitation percolating a vertical distance of ~300 m through fractured unsaturated rock into drifts containing waste packages. Water enhances waste package corrosion and is required for transport of released radionuclides. To evaluate the propensity for seepage into tunnels at Yucca Mountain, a 5-m-diameter, 2.7-km-long tunnel, commonly referred to as the Cross Drift (CD), was excavated in 1998, branching off from the main Exploratory Studies Facility tunnel. Sections of this tunnel have been isolated from ventilation for extended periods over the last 4 years. We present continuous measurements of relative humidity and temperature and periodic observations of liquid water in the CD over two periods. During this observation duration the terminal section of the drift was partitioned into four sections by bulkheads, and ventilation to these sections was minimized to a few days. We compare these observations to results from analytical and numerical models to investigate processes associated with the movement of water vapor between the tunnel bore and the surrounding fractured rock formation. Observations from this effort indicate that fractures can be primary paths for unsaturated zone vapor flow in the immediate vicinity of emplacement drifts. Observations, measurements, and analysis indicate the need for a model that includes fracture-dominated vapor transport as a significant contributor to total water flow into the drifts.

  13. Performance predictions for mechanical excavators in Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    SciTech Connect

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J.

    1992-09-01

    The performances of several mechanical excavators are predicted for use in the tuffs at Yucca Mountain: Tunnel boring machines, the Mobile Miner, a roadheader, a blind shaft borer, a vertical wheel shaft boring machine, raise drills, and V-Moles. Work summarized is comprised of three parts: Initial prediction using existing rock physical property information; Measurement of additional rock physical properties; and Revision of the initial predictions using the enhanced database. The performance predictions are based on theoretical and empirical relationships between rock properties and the forces-experienced by rock cutters and bits during excavation. Machine backup systems and excavation design aspects, such as curves and grades, are considered in determining excavator utilization factors. Instanteous penetration rate, advance rate, and cutter costs are the fundamental performance indicators.

  14. The Langley Wind Tunnel Enterprise

    NASA Technical Reports Server (NTRS)

    Paulson, John W., Jr.; Kumar, Ajay; Kegelman, Jerome T.

    1998-01-01

    After 4 years of existence, the Langley WTE is alive and growing. Significant improvements in the operation of wind tunnels have been demonstrated and substantial further improvements are expected when we are able to truly address and integrate all the processes affecting the wind tunnel testing cycle.

  15. Modeling Indirect Tunneling in Silicon

    NASA Astrophysics Data System (ADS)

    Chen, Edward

    Indirect tunneling in silicon p-n junctions catches people's attention again in recent years. First, the phenomenon induces a serious leakage problem, so called gate-induced drain leakage (GIDL) effect, in modern metal-oxide-semiconductor field-effect transistors (MOSFETs). Second, it is utilized to develop a novel tunneling transistor with the sharp turn-on ability for continuing ITRS roadmap. Although the indirect tunneling is important for the state-of-the-art transistor-technology, the accuracy of the present tunneling models in technology computer-aided design (TCAD) tools is still vague. In the research work, the theory of indirect tunneling in silicon has been thoroughly studied. The phonon-assisted tunneling model has been developed and compared with the existing ones in the Sentaurus-Synopsys, Medici-Synopsys, and Atlas-Silvaco TCAD tools. Beyond these existing models, ours successfully predicts the indirect tunneling current under the different field direction in silicon. In addition, bandgap narrowing in heavily-doped p-n junctions under the reverse-biased condition is also studied during the model development. At the end of the research work, the application to low standby power (LSTP) transistors is demonstrated to show the capability of our tunneling model in the device level.

  16. Two tunnels to inflation

    SciTech Connect

    Aguirre, Anthony; Johnson, Matthew C.

    2006-06-15

    We investigate the formation via tunneling of inflating (false-vacuum) bubbles in a true-vacuum background, and the reverse process. Using effective potentials from the junction condition formalism, all true- and false-vacuum bubble solutions with positive interior and exterior cosmological constant, and arbitrary mass are catalogued. We find that tunneling through the same effective potential appears to describe two distinct processes: one in which the initial and final states are separated by a wormhole (the Farhi-Guth-Guven mechanism), and one in which they are either in the same hubble volume or separated by a cosmological horizon. In the zero-mass limit, the first process corresponds to the creation of an inhomogenous universe from nothing, while the second mechanism is equivalent to the nucleation of true- or false-vacuum Coleman-De Luccia bubbles. We compute the probabilities of both mechanisms in the WKB approximation using semiclassical Hamiltonian methods, and find that--assuming both process are allowed--neither mechanism dominates in all regimes.

  17. Tunneling magnetic force microscopy

    NASA Technical Reports Server (NTRS)

    Burke, Edward R.; Gomez, Romel D.; Adly, Amr A.; Mayergoyz, Isaak D.

    1993-01-01

    We have developed a powerful new tool for studying the magnetic patterns on magnetic recording media. This was accomplished by modifying a conventional scanning tunneling microscope. The fine-wire probe that is used to image surface topography was replaced with a flexible magnetic probe. Images obtained with these probes reveal both the surface topography and the magnetic structure. We have made a thorough theoretical analysis of the interaction between the probe and the magnetic fields emanating from a typical recorded surface. Quantitative data about the constituent magnetic fields can then be obtained. We have employed these techniques in studies of two of the most important issues of magnetic record: data overwrite and maximizing data-density. These studies have shown: (1) overwritten data can be retrieved under certain conditions; and (2) improvements in data-density will require new magnetic materials. In the course of these studies we have developed new techniques to analyze magnetic fields of recorded media. These studies are both theoretical and experimental and combined with the use of our magnetic force scanning tunneling microscope should lead to further breakthroughs in the field of magnetic recording.

  18. Tunnel electroresistance through organic ferroelectrics

    PubMed Central

    Tian, B. B.; Wang, J. L.; Fusil, S.; Liu, Y.; Zhao, X. L.; Sun, S.; Shen, H.; Lin, T.; Sun, J. L.; Duan, C. G.; Bibes, M.; Barthélémy, A.; Dkhil, B.; Garcia, V.; Meng, X. J.; Chu, J. H.

    2016-01-01

    Organic electronics is emerging for large-area applications such as photovoltaic cells, rollable displays or electronic paper. Its future development and integration will require a simple, low-power organic memory, that can be written, erased and readout electrically. Here we demonstrate a non-volatile memory in which the ferroelectric polarisation state of an organic tunnel barrier encodes the stored information and sets the readout tunnel current. We use high-sensitivity piezoresponse force microscopy to show that films as thin as one or two layers of ferroelectric poly(vinylidene fluoride) remain switchable with low voltages. Submicron junctions based on these films display tunnel electroresistance reaching 1,000% at room temperature that is driven by ferroelectric switching and explained by electrostatic effects in a direct tunnelling regime. Our findings provide a path to develop low-cost, large-scale arrays of organic ferroelectric tunnel junctions on silicon or flexible substrates. PMID:27143121

  19. Tunnel electroresistance through organic ferroelectrics.

    PubMed

    Tian, B B; Wang, J L; Fusil, S; Liu, Y; Zhao, X L; Sun, S; Shen, H; Lin, T; Sun, J L; Duan, C G; Bibes, M; Barthélémy, A; Dkhil, B; Garcia, V; Meng, X J; Chu, J H

    2016-01-01

    Organic electronics is emerging for large-area applications such as photovoltaic cells, rollable displays or electronic paper. Its future development and integration will require a simple, low-power organic memory, that can be written, erased and readout electrically. Here we demonstrate a non-volatile memory in which the ferroelectric polarisation state of an organic tunnel barrier encodes the stored information and sets the readout tunnel current. We use high-sensitivity piezoresponse force microscopy to show that films as thin as one or two layers of ferroelectric poly(vinylidene fluoride) remain switchable with low voltages. Submicron junctions based on these films display tunnel electroresistance reaching 1,000% at room temperature that is driven by ferroelectric switching and explained by electrostatic effects in a direct tunnelling regime. Our findings provide a path to develop low-cost, large-scale arrays of organic ferroelectric tunnel junctions on silicon or flexible substrates. PMID:27143121

  20. Tunnel electroresistance through organic ferroelectrics

    NASA Astrophysics Data System (ADS)

    Tian, B. B.; Wang, J. L.; Fusil, S.; Liu, Y.; Zhao, X. L.; Sun, S.; Shen, H.; Lin, T.; Sun, J. L.; Duan, C. G.; Bibes, M.; Barthélémy, A.; Dkhil, B.; Garcia, V.; Meng, X. J.; Chu, J. H.

    2016-05-01

    Organic electronics is emerging for large-area applications such as photovoltaic cells, rollable displays or electronic paper. Its future development and integration will require a simple, low-power organic memory, that can be written, erased and readout electrically. Here we demonstrate a non-volatile memory in which the ferroelectric polarisation state of an organic tunnel barrier encodes the stored information and sets the readout tunnel current. We use high-sensitivity piezoresponse force microscopy to show that films as thin as one or two layers of ferroelectric poly(vinylidene fluoride) remain switchable with low voltages. Submicron junctions based on these films display tunnel electroresistance reaching 1,000% at room temperature that is driven by ferroelectric switching and explained by electrostatic effects in a direct tunnelling regime. Our findings provide a path to develop low-cost, large-scale arrays of organic ferroelectric tunnel junctions on silicon or flexible substrates.

  1. Cost-Effective Cementitious Material Compatible with Yucca Mountain Repository Geochemistry

    SciTech Connect

    Dole, LR

    2004-12-17

    The current plans for the Yucca Mountain (YM) repository project (YMP) use steel structures to stabilize the disposal drifts and connecting tunnels that are collectively over 100 kilometers in length. The potential exist to reduce the underground construction cost by 100s of millions of dollars and improve the repository's performance. These economic and engineering goals can be achieved by using the appropriate cementitious materials to build out these tunnels. This report describes the required properties of YM compatible cements and reviews the literature that proves the efficacy of this approach. This report also describes a comprehensive program to develop and test materials for a suite of underground construction technologies.

  2. Pre-construction geologic section along the cross drift through the potential high-level radioactive waste repository, Yucca Mountain, Nye County, Nevada

    SciTech Connect

    Potter, C.J.; Day, W.C.; Sweetkind, D.S.; Juan, C.S.; Drake, R.M. II

    1998-12-31

    As part of the Site Characterization effort for the US Department of Energy`s Yucca Mountain Project, tunnels excavated by tunnel boring machines provide access to the volume of rock that is under consideration for possible underground storage of high-level nuclear waste beneath Yucca Mountain, Nevada. The Exploratory Studies Facility, a 7.8-km-long, 7.6-m-diameter tunnel, has been excavated, and a 2.8-km-long, 5-m-diameter Cross Drift will be excavated in 1998 as part of the geologic, hydrologic and geotechnical evaluation of the potential repository. The southwest-trending Cross Drift branches off of the north ramp of the horseshoe-shaped Exploratory Studies Facility. This report summarizes an interpretive geologic section that was prepared for the Yucca Mountain Project as a tool for use in the design and construction of the Cross Drift.

  3. Patient-centred mountain medicine.

    PubMed

    Szawarski, Piotr; Hillebrandt, David

    2016-08-01

    Venturing into the mountains, doctors have accompanied expeditions to provide routine care to the teams, undertake research and occasionally take on a rescue role. The role of doctors practicing mountain medicine is evolving. Public health issues involving concepts of health and safety have become necessary with the coming of commercial and youth expeditions. Increasingly individuals with a disability or a medical diagnosis choose to ascend to high altitudes. Doctors become involved in assessment of risk and providing advice for such individuals. The field of mountain medicine is perhaps unique in that acceptance of risk is part of the ethos of climbing and adventure. The pursuit of mountaineering goals may represent the ultimate conquest of a disability. Knowledge of mountain environment is essential in facilitating mountain ascents for those who choose to undertake them, in spite of a disability or medical condition. PMID:27234206

  4. Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Parui, Subir; Ribeiro, Mário; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2016-08-01

    The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al2O3/NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

  5. Tunnelling microscopy of DNA

    NASA Astrophysics Data System (ADS)

    Selci, Stefano; Cricenti, Antonio

    1991-01-01

    Uncoated DNA molecules marked with an activated tris (1-aziridinyl) phosphine oxide (TAPO) solution were deposited on gold substrates and imaged in air with a high resolution Scanning Tunnelling Microscope (STM). The STM operated simultaneously in the constant-current and gap-modulated mode. Highly reproducible STM images have been obtained and interpreted in terms of expected DNA structure. The main periodicity, regularly presented in molecules several hundred Ångstrom long, ranges from 25 Å to 35 Å with an average diameter of 22 Å. Higher resolution images of the minor groove have revealed the phosphate groups along the DNA backbones. Constant-current images of TAPO deposited on gold show a crystalline structure of rows of molecules with a side-by-side spacing of 3 Å.

  6. The virtual wind tunnel

    NASA Technical Reports Server (NTRS)

    Bryson, Steve; Levit, Creon

    1992-01-01

    Consideration is given to the design and implementaion of a virtual environment linked to a graphics workstation for the visualization of complex fluid flows. The user wears a stereo head-tracked display which displays 3D information and an instrumented glove to intuitively position flow-visualization tools. The idea is to create for the user an illusion that he or she is actually in the flow manipulating visualization tools. The user's presence does not disturb the flow so that sensitive flow areas can be easily investigated. The flow is precomputed and can be investigated at any length scale and with control over time. Particular attention is given to the visualization structures and their interfaces in the virtual environment, hardware and software, and the performance of the virtual wind tunnel using flow past a tapered cylinder as an example.

  7. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.; Jefferies, Sharon; Howe, A. Scott; Howard, Robert; Mary, Natalie; Watson, Judith; Lewis, Ruthan

    2016-01-01

    When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

  8. Spin tunneling in conducting oxides

    SciTech Connect

    Bratkovsky, A.

    1998-12-31

    Different tunneling mechanisms in conventional and half-metallic ferromagnetic tunnel junctions are analyzed within the same general method. Direct tunneling is compared with impurity-assisted, surface state assisted, and inelastic contributions to a tunneling magnetoresistance (TMR). Theoretically calculated direct tunneling in iron group systems leads to about a 30% change in resistance, which is close to experimentally observed values. It is shown that the larger observed values of the TMR might be a result of tunneling involving surface polarized states. The authors find that tunneling via resonant defect states in the barrier radically decreases the TMR (down to 4% with Fe-based electrodes), and a resonant tunnel diode structure would give a TMR of about 8%. With regards to inelastic tunneling, magnons and phonons exhibit opposite effects: one-magnon emission generally results in spin mixing and, consequently, reduces the TMR, whereas phonons are shown to enhance the TMR. The inclusion of both magnons and phonons reasonably explains an unusually bias dependence of the TMR. The model presented here is applied qualitatively to half-metallics with 100% spin polarization, where one-magnon processes are suppressed and the change in resistance in the absence of spin-mixing on impurities may be arbitrarily large. Even in the case of imperfect magnetic configurations, the resistance change can be a few 1,000%. Examples of half-metallic systems are CrO{sub 2}/TiO{sub 2} and CrO{sub 2}/RuO{sub 2}, and an account of their peculiar band structures is presented. The implications and relation of these systems to CMR materials, which are nearly half-metallic, are discussed.

  9. Dual-Element Tunneling Accelerometer

    NASA Technical Reports Server (NTRS)

    Kaiser, William J.; Kenny, Thomas W.; Rockstad, Howard K.; Reynolds, Joseph K.

    1994-01-01

    Improved micromachined tunneling accelerometer contains two deflecting transducer elements: One an elastically supported proof mass having relatively low resonant frequency; other cantilever tunneling transducer that tracks displacement of proof mass and has relatively high resonant frequency ({sup a} 10 kHz). Deflection voltage generated by circuit like described in "Wideband Feedback Circuit for Tunneling Sensor" (NPO-18866). Accelerometers of this type suited for underwater acoustic measurements, detecting vibrations associated with malfunctions in vehicles, detecting seismic signals, monitoring and controlling vibrations in structures, and other applications.

  10. Pathophysiology of carpal tunnel syndrome

    PubMed Central

    Aboonq, Moutasem S.

    2015-01-01

    Carpal tunnel syndrome (CTS) is the most common median nerve neuropathy, accounting for 90% of all neuropathies. Carpal tunnel syndrome presents in 3.8% of the general population, with a higher prevalence among women. There are several risk factors associated with CTS, including both medical and non medical factors. The pathophysiologic mechanisms involved in the median nerve compression and traction are thought to be complex, and as yet are not fully understood. The present review aimed to provide an overview of the pathophysiology of median nerve neuropathy in the carpal tunnel, and subsequent development of CTS. PMID:25630774

  11. Resonant torus-assisted tunneling.

    PubMed

    Yi, Chang-Hwan; Yu, Hyeon-Hye; Kim, Chil-Min

    2016-01-01

    We report a new type of dynamical tunneling, which is mediated by a resonant torus, i.e., a nonisolated periodic orbit. To elucidate the phenomenon, we take an open elliptic cavity and show that a pair of resonances localized on two classically disconnected tori tunnel through a resonant torus when they interact with each other. This so-called resonant torus-assisted tunneling is verified by using Husimi functions, corresponding actions, Husimi function distributions, and the standard deviations of the actions. PMID:26871067

  12. Optical Detection of Tunneling Ionization

    SciTech Connect

    Verhoef, Aart J.; Mitrofanov, Alexander V.; Kartashov, Daniil V.; Baltuska, Andrius

    2010-04-23

    We have experimentally detected optical harmonics that are generated due to a tunneling-ionization-induced modulation of the electron density. The optical signature of electron tunneling can be isolated from concomitant optical responses by using a noncollinear pump-probe setup. Whereas previously demonstrated tools for attosecond metrology of gases, plasmas, and surfaces rely on direct detection of charged particles, detection of the background-free time-resolved optical signal, which uniquely originates from electron tunneling, offers an interesting alternative that is especially suited for systems in which free electrons cannot be directly measured.

  13. Wideband Feedback Circuit For Tunneling Sensor

    NASA Technical Reports Server (NTRS)

    Kaiser, William J.; Kenny, Thomas W.; Rockstad, Howard K.; Reynolds, Joseph K.

    1994-01-01

    Improved feedback circuit designed for use in controlling tunneling displacement transducer. Features include stability and nearly flat frequency response up to 50 kHz. Transducer could be that in scanning tunneling microscope, or any of micromachined electromechanical transducers described in "Micromachined Electron-Tunneling Infrared Detectors" (NPO-18413), "Micromachined Tunneling Accelerometer" (NPO-18513), and "Improved Electromechanical Infrared Sensor" (NPO-18560).

  14. Experiments with a Model Water Tunnel

    NASA Technical Reports Server (NTRS)

    Jacobs, Eastman N; Abbott, Ira H

    1930-01-01

    This report describes a model water tunnel built in 1928 by the NACA to investigate the possibility of using water tunnels for aerodynamic investigations at large scales. The model tunnel is similar to an open-throat wind tunnel, but uses water for the working fluid.

  15. Altitude, Acute Mountain Sickness and Headache

    MedlinePlus

    ... Mountain Sickness, and Headache Print Email Altitude, Acute Mountain Sickness, and Headache ACHE Newsletter Sign up for ... entering your e-mail address below. Altitude, Acute Mountain Sickness, and Headache David W. Dodick, MD, FAHS, ...

  16. Environmental and hydrogeological problems in karstic terrains crossed by tunnels: a case study

    NASA Astrophysics Data System (ADS)

    Gisbert, J.; Vallejos, A.; González, A.; Pulido-Bosch, A.

    2009-07-01

    The construction of one of the high-speed railway tunnels between Malaga and Córdoba (South Spain) beneath the Abdalajís mountains occasioned a series of hydrogeological problems with geotechnical and environmental impacts. The double tunnel, 7,300 m in length, runs south to north across several lines of small, calcareous mountains that have a highly complex structure. Beneath the Jurassic limestones lie Triassic clays and evaporites. Overlying the limestones is an essentially marly and limestone-marl Cretaceous series, which culminates with Miocene marls containing some organic matter. These mountains have generated springs that are used for urban water supply and irrigation, as well as drinking fountains in the surrounding villages. The initial water level in the aquifer series varied from 400 to 650 m above sea level. After drilling approximately 2,900 m, and intercepting a fracture zone within the carbonate rocks, a sudden water eruption occurred that reached a peak flow of 800 L/s. After a short while, spring discharges dried up, leading to a public protest. In this paper, we describe the geological and hydrogeological settings, the development of the aquifer as the drilling operation proceeded, the measures adopted and the responses subsequent to completion of the tunnel, including the effect of rainfall on the recovery of water levels. Lastly, a generalized estimate is made of how the system functions, and a forecast is made for recovery of its equilibrium.

  17. Human impacts to mountain streams

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen

    2006-09-01

    Mountain streams are here defined as channel networks within mountainous regions of the world. This definition encompasses tremendous diversity of physical and biological conditions, as well as history of land use. Human effects on mountain streams may result from activities undertaken within the stream channel that directly alter channel geometry, the dynamics of water and sediment movement, contaminants in the stream, or aquatic and riparian communities. Examples include channelization, construction of grade-control structures or check dams, removal of beavers, and placer mining. Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes. An overview of the relative intensity of human impacts to mountain streams is provided by a table summarizing human effects on each of the major mountainous regions with respect to five categories: flow regulation, biotic integrity, water pollution, channel alteration, and land use. This table indicates that very few mountains have streams not at least moderately affected by land use. The least affected mountainous regions are those at very high or very low latitudes, although our scientific ignorance of conditions in low-latitude mountains in particular means that streams in these mountains might be more altered than is widely recognized. Four case studies from northern Sweden (arctic region), Colorado Front Range (semiarid temperate region), Swiss Alps (humid temperate region), and Papua New Guinea (humid tropics) are also used to explore in detail the history and effects on rivers of human activities in mountainous regions. The overview and case studies indicate that mountain streams must be managed with particular attention to upstream/downstream connections, hillslope

  18. Appendix C: A comparative study of small scale remotely sensed data for monitoring clearcutting in hardwood forests. M.S. Thesis; [Allegheny National Forest, Pennsylvania and the Adirondacks, New York

    NASA Technical Reports Server (NTRS)

    Hafker, W. R.

    1980-01-01

    Manual photointerpretation techniques were used to analyze images acquired by high altitude aircraft, the Skylab multispectral and Earth terrain camera (ETC), the LANDSAT multispectral scanner, and the LANDSAT-3 return beam vidicon camera. A color-additive viewer, and digital image analysis were also used on the LANDSAT MSS imagery. The value of each type of remotely sensed data was judged by the ease and accuracy of clearcut identification, and by the amount of detail discernible, especially regarding revegetation. Results of a site study in the Allegheny National Forest, Pennsylvania indicate that high altitude aerial photography, especially color infrared photography acquired during the growing season, is well suited for identifying clearcuts and assessing revegetation. Although photographs acquired with Skylab's ETC also yielded good results, only incomplete inventories of clearcuts could be made using LANDSAT imagery. Results for the Adirondack region of New York State were similar for the aircraft and satellite photography, but even less satisfactory for the LANDSAT imagery.

  19. Preliminary studies of tunnel interface response modeling using test data from underground storage facilities.

    SciTech Connect

    Sobolik, Steven Ronald; Bartel, Lewis Clark

    2010-11-01

    In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock properties such as P-wave and S-wave velocities. The data presented from this report are associated with sites used for the development of underground repositories for the disposal of radioactive waste; these sites have been excavated in volcanic tuff (Yucca Mountain) and granite (HRL in Sweden, URL in Canada). Using the data from Yucca Mountain, a numerical simulation effort was undertaken to evaluate the effects of the damage zone on seismic responses. Calculations were performed using the parallelized version of the time-domain finitedifference seismic wave propagation code developed in the Geophysics Department at Sandia National Laboratories. From these numerical simulations, the damage zone does not have a significant effect upon the tunnel response, either for a purely elastic case or an anelastic case. However, what was discovered is that the largest responses are not true reflections, but rather reradiated Stoneley waves generated as the air/earth interface of the tunnel. Because of this, data processed in the usual way may not

  20. Wind tunnel observations of drifting snow

    NASA Astrophysics Data System (ADS)

    Paterna, Enrico; Crivelli, Philip; Lehning, Michael

    2016-04-01

    Drifting snow has a significant impact on snow redistribution in mountains, prairies as well as on glaciers, ice shelves, and sea ice. In all these environments, the local mass balance is highly influenced by drifting snow. Understanding the dynamic of snow saltation is crucial to the accurate description of the process. We applied digital shadowgraphy in a cold wind tunnel to measure drifting snow over natural snow covers. The acquisition and evaluation of time-resolved shadowgraphy images allowed us to resolve a large part of the saltation layer. The technique has been successfully compared to the measurements obtained from a Snow Particle Counter, considered the most robust technique for snow mass-flux measurements so far. The streamwise snow transport is dominated by large-scale events. The vertical snow transport has a more equal distribution of energy across the scales, similarly to what is observed for the flow turbulence velocities. It is hypothesized that the vertical snow transport is a quantity that reflects the local entrainment of the snow crystals into the saltation layer while the streamwise snow transport results from the streamwise development of the trajectories of the snow particles once entrained, and therefore is rather a non-local quantity.

  1. SP mountain data analysis

    NASA Technical Reports Server (NTRS)

    Rawson, R. F.; Hamilton, R. E.; Liskow, C. L.; Dias, A. R.; Jackson, P. L.

    1981-01-01

    An analysis of synthetic aperture radar data of SP Mountain was undertaken to demonstrate the use of digital image processing techniques to aid in geologic interpretation of SAR data. These data were collected with the ERIM X- and L-band airborne SAR using like- and cross-polarizations. The resulting signal films were used to produce computer compatible tapes, from which four-channel imagery was generated. Slant range-to-ground range and range-azimuth-scale corrections were made in order to facilitate image registration; intensity corrections were also made. Manual interpretation of the imagery showed that L-band represented the geology of the area better than X-band. Several differences between the various images were also noted. Further digital analysis of the corrected data was done for enhancement purposes. This analysis included application of an MSS differencing routine and development of a routine for removal of relief displacement. It was found that accurate registration of the SAR channels is critical to the effectiveness of the differencing routine. Use of the relief displacement algorithm on the SP Mountain data demonstrated the feasibility of the technique.

  2. Flatback airfoil wind tunnel experiment.

    SciTech Connect

    Mayda, Edward A.; van Dam, C.P.; Chao, David D.; Berg, Dale E.

    2008-04-01

    A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

  3. Multisensor system for tunnel inspection

    NASA Astrophysics Data System (ADS)

    Idoux, Maurice

    2005-01-01

    The system is aimed at assisting inspection and monitoring of the degradation of tunnels in order to minimize maintenance and repair time. ATLAS 70 is a complete sensors/software package which enables thorough diagnosis of tunnel wall conditions. The data collected locally are stored on a computer hard disk for subsequent analysis in a remote location via elaborate dedicated software. The sensors and local computer are loaded onto a rail and/or road vehicle of specific design, i.e. with even travelling speed of 2 to 5 km/h. Originally, the system has been developed for the Paris Underground Company and has since been applied to rail and road tunnels, large town sewage systems, clean water underground aqueducts and electric cable tunnels.

  4. Tunneling Plasmonics in Bilayer Graphene.

    PubMed

    Fei, Z; Iwinski, E G; Ni, G X; Zhang, L M; Bao, W; Rodin, A S; Lee, Y; Wagner, M; Liu, M K; Dai, S; Goldflam, M D; Thiemens, M; Keilmann, F; Lau, C N; Castro-Neto, A H; Fogler, M M; Basov, D N

    2015-08-12

    We report experimental signatures of plasmonic effects due to electron tunneling between adjacent graphene layers. At subnanometer separation, such layers can form either a strongly coupled bilayer graphene with a Bernal stacking or a weakly coupled double-layer graphene with a random stacking order. Effects due to interlayer tunneling dominate in the former case but are negligible in the latter. We found through infrared nanoimaging that bilayer graphene supports plasmons with a higher degree of confinement compared to single- and double-layer graphene, a direct consequence of interlayer tunneling. Moreover, we were able to shut off plasmons in bilayer graphene through gating within a wide voltage range. Theoretical modeling indicates that such a plasmon-off region is directly linked to a gapped insulating state of bilayer graphene, yet another implication of interlayer tunneling. Our work uncovers essential plasmonic properties in bilayer graphene and suggests a possibility to achieve novel plasmonic functionalities in graphene few-layers. PMID:26222509

  5. The Unitary Plan Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Wedgworth, Kevin; Woo, Alex C.

    1994-01-01

    The Unitary Plan Facility is the most heavily used wind tunnel in all of NASA. Every major commercial transport and almost every fighter built in the United States over the last 30 years has been tested in this tunnel. Also tested in this tunnel complex were models of the Space Shuttle, as well as the Mercury, Gemini, and Apollo capsules. The wind tunnel represents a unique national asset of vital importance to the nation's defense and its competitive position in the world aerospace market. In 1985, the Unitary Plan Facility was named a National Historic Landmark by the National Park Service because of 'its significant associations with the development of the American Space Program.'

  6. Electron tunneling in proteins program.

    PubMed

    Hagras, Muhammad A; Stuchebrukhov, Alexei A

    2016-06-01

    We developed a unique integrated software package (called Electron Tunneling in Proteins Program or ETP) which provides an environment with different capabilities such as tunneling current calculation, semi-empirical quantum mechanical calculation, and molecular modeling simulation for calculation and analysis of electron transfer reactions in proteins. ETP program is developed as a cross-platform client-server program in which all the different calculations are conducted at the server side while only the client terminal displays the resulting calculation outputs in the different supported representations. ETP program is integrated with a set of well-known computational software packages including Gaussian, BALLVIEW, Dowser, pKip, and APBS. In addition, ETP program supports various visualization methods for the tunneling calculation results that assist in a more comprehensive understanding of the tunneling process. © 2016 Wiley Periodicals, Inc. PMID:26990540

  7. Tunnel construction for a desertron

    SciTech Connect

    Hinterberger, H.; Huson, F.R.

    1983-03-27

    The tunnel in this model of construction is 3-1/2 feet wide by 5 feet high. It is assumed that the tunnel contains a rail system and guidance system for: (1) An enclosed car used for transport of 2 people and some tools. (2) A magnet mover. This robot could pick up a magnet and transport it at about 10 miles per hour. (3) An alignment robot. The alignment robot would intercept E.M. waves (microwaves, lasers) to determine its position in the tunnel. Then workers could come along inside the tunnel hoop and nail it together and to the floor. The trench would then be back-filled with a 1 foot berm on top. A rail system would be installed and a support stand for the magnet.

  8. YUCCA MOUNTAIN PROJECT - A BRIEFING --

    SciTech Connect

    NA

    2003-08-05

    This report has the following articles: Nuclear waste--a long-term national problem; Spent nuclear fuel; High-level radioactive waste; Radioactivity and the environment; Current storage methods; Disposal options; U.S. policy on nuclear waste; The focus on Yucca Mountain; The purpose and scope of the Yucca Mountain Project; The approach for permanently disposing of waste; The scientific studies at Yucca Mountain; The proposed design for a repository at Yucca Mountain; Natural and engineered barriers would work together to isolate waste; Meticulous science and technology to protect people and the environment; Licensing a repository; Transporting waste to a permanent repository; The Environmental Impact Statement for a repository; Current status of the Yucca Mountain Project; and Further information available on the Internet.

  9. Quantum tunneling through graphene nanorings

    NASA Astrophysics Data System (ADS)

    Wu, Zhenhua; Zhang, Z. Z.; Chang, Kai; Peeters, F. M.

    2010-05-01

    We investigate theoretically quantum transport through graphene nanorings in the presence of a perpendicular magnetic field. Our theoretical results demonstrate that the graphene nanorings behave like a resonant tunneling device, contrary to the Aharonov-Bohm oscillations found in conventional semiconductor rings. The resonant tunneling can be tuned by the Fermi energy, the size of the central part of the graphene nanorings and the external magnetic field.

  10. Quantum tunneling through graphene nanorings.

    PubMed

    Wu, Zhenhua; Zhang, Z Z; Chang, Kai; Peeters, F M

    2010-05-01

    We investigate theoretically quantum transport through graphene nanorings in the presence of a perpendicular magnetic field. Our theoretical results demonstrate that the graphene nanorings behave like a resonant tunneling device, contrary to the Aharonov-Bohm oscillations found in conventional semiconductor rings. The resonant tunneling can be tuned by the Fermi energy, the size of the central part of the graphene nanorings and the external magnetic field. PMID:20388970

  11. Guidelines for tunneling in enzymes

    PubMed Central

    Moser, Christopher C.; Ross Anderson, J. L.; Dutton, P. Leslie

    2010-01-01

    Summary Here we extend the engineering descriptions of simple, single-electron-tunneling chains common in oxidoreductases to quantify sequential oxidation-reduction rates of two-or-more electron cofactors and substrates. We identify when nicotinamides may be vulnerable to radical mediated oxidation-reduction and merge electron-tunneling expressions with the chemical rate expressions of Eyring. The work provides guidelines for the construction of new artificial oxidoreductases inspired by Nature but adopting independent design and redox engineering. PMID:20460101

  12. The exploratory studies facility (ESF) at Yucca Mountain - Description and status

    SciTech Connect

    Simecka, W.B.; Replogle, J.M.; Mckenzie, D.G.

    1994-12-31

    The Exploratory Studies Facility (ESF) at Yucca Mountain, Nevada will be a 25 kilometer underground network of inclined ramps, tunnels, and test alcoves. It will serve as an underground laboratory for the execution of a testing program conceived to assess the suitability of Yucca Mountain as a site to host a potential high level nuclear waste repository. This paper contains a description of the ESF, a summary of the major types of tests currently planned, and a report on the current status of the ongoing design and construction activities. The ESF is being designed and constructed in phases. Currently, the Detailed Design, or {open_quotes}Title II Design{close_quotes} is centered on the second of ten major design packages. Construction has begun on excavation of the {open_quotes}starter tunnel{close_quotes} for a Tunnel Boring Machine (TBM) expected to begin operation in late FY 1994. The EFS program will provide information critical to the evaluation of Yucca Mountain as a potential repository site, and will house a suite of state-of-the-art tests designed to gather this information. The ESF is a one of a kind opportunity to examine, in minute detail, all facets of a sites` geology; its thermal, mechanical, and hydrologic properties; and to study the linkages between these properties.

  13. 5-foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1932-01-01

    The researcher is sitting above the exit cone of the 5-foot Vertical Wind Tunnel and is examining the new 6-component spinning balance. This balance was developed between 1930 and 1933. It was an important advance in the technology of rotating or rolling balances. As M.J. Bamber and C.H. Zimmerman wrote in NACA TR 456: 'Data upon the aerodynamic characteristics of a spinning airplane may be obtained in several ways; namely, flight tests with full-scale airplanes, flight tests with balanced models, strip-method analysis of wind-tunnel force and moment tests, and wind-tunnel tests of rotating models.' Further, they note: 'Rolling-balance data have been of limited value because it has not been possible to measure all six force and moment components or to reproduce a true spinning condition. The spinning balance used in this investigation is a 6-component rotating balance from which it is possible to obtain wind-tunnel data for any of a wide range of possible spinning conditions.' Bamber and Zimmerman described the balance as follows: 'The spinning balance consists of a balance head that supports the model and contains the force-measuring units, a horizontal turntable supported by streamline struts in the center of the jet and, outside the tunnel, a direct-current driving motor, a liquid tachometer, an air compressor, a mercury manometer, a pair of indicating lamps, and the necessary controls. The balance head is mounted on the turntable and it may be set to give any radius of spin between 0 and 8 inches.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual

  14. Spin-dependent tunneling effects in magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Gao, Li

    2009-03-01

    It has long been known that current extracted from magnetic electrodes through ultra thin oxide tunnel barriers is spin polarized. This current gives rise to two important properties: tunneling magnetoresistance (TMR) when the tunnel barrier is sandwiched between two thin magnetic electrodes and, spin momentum transfer, which can be used to manipulate the magnetic state of the magnetic electrodes. In the first part of my talk I show how the structure of thin CoFe layers can be made amorphous by simply sandwiching them between two amorphous layers, one of them the tunnel barrier. No glass forming elements are needed. By slightly changing the thickness of these layers or by heating them above their glass transition temperature they become crystalline. Surprisingly, the TMR of the amorphous structure is significantly higher than of its crystalline counterpart. The tunneling anisotropic magnetoresistance, which has complex voltage dependence, is also discussed. In the second part of my talk I discuss the microwave emission spectrum from magnetic tunnel junctions induced by spin torque from spin polarized dc current passed through the device. We show that the spectrum is very sensitive to small variations in device structures, even in those devices which exhibit similarly high TMR (˜120%) and which have similar resistance-area products (˜4-10 φμm^2). We speculate that these variations are due to non-uniform spatial magnetic excitation arising from inhomogeneous current flow through the tunnel barrier. [In collaboration with Xin Jiang, M. Hayashi, Rai Moriya, Brian Hughes, Teya Topuria, Phil Rice, and Stuart S.P. Parkin

  15. Tunnel boring machine

    SciTech Connect

    Turner, J.

    1985-10-22

    A tunnel boring machine including the following elements: a full face rotary cutterhead; a cutterhead support on which the cutterhead is mounted; a gripper system carried by a gripper support frame for reacting thrust, steering, roll correction, and torque forces; a conveyor system for transporting muck from behind the rotary cutterhead to a dump point rearwardly of the machine; primary propel cylinders for advancing the cutterhead which are mounted between the gripper support frame and the cutterhead support, the primary propel cylinders consisting of a series of at least three pairs of double acting hydraulic cylinders arranged annularly in equally spaced apart locations and in a series of V-shaped configurations between the gripper support frame and the cutterhead support, each such pair of primary propel cylinders having an included angle between the cylinders of about 15/sup 0/ and 60/sup 0/ and with a line bisecting the included angle between the cylinders extending generally parallel to the longitudinal centerline of the machine; and a hydraulic control system for controlling the pairs of primary propel cylinders to effect axial forward thrust on the cutterhead by simultaneous actuation of all the primary propel cylinders while transmitting the reaction torque exerted on the cutterhead support by rotation of the cutterhead, steering of the cutterhead support and the cutterhead by selective actuation of only a portion of the primary propel cylinders, and roll corrections of the cutterhead support and the cutterhead by selective actuation of alternate members of the primary propel cylinders.

  16. Majorana tunneling entropy

    NASA Astrophysics Data System (ADS)

    Smirnov, Sergey

    2015-11-01

    In thermodynamics a macroscopic state of a system results from a number of its microscopic states. This number is given by the exponent of the system's entropy exp(S ) . In noninteracting systems with discrete energy spectra, such as large scale quantum dots, S as a function of the temperature has usually a plateau shape with integer values of exp(S ) on these plateaus. Plateaus with noninteger values of exp(S ) are fundamentally forbidden and would be thermodynamically infeasible. Here we investigate the entropy of a noninteracting quantum dot coupled via tunneling to normal metals with continuum spectra as well as to topological superconductors. We show that the entropy may have noninteger plateaus if the topological superconductors support weakly overlapping Majorana bound states. This brings a fundamental change in the thermodynamics of the quantum dot whose specific heat cV acquires low-temperature Majorana peaks which should be absent according to the conventional thermodynamics. We also provide a fundamental thermodynamic understanding of the transport properties, such as the linear conductance. In general our results show that the thermodynamics of systems coupled to Majorana modes represents a fundamental physical interest with diverse applications depending on versatility of possible coupling mechanisms.

  17. Differential Hydrogeological Effects of Draining Tunnels Through the Northern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Vincenzi, Valentina; Gargini, Alessandro; Goldscheider, Nico; Piccinini, Leonardo

    2014-05-01

    Water inflows are a major challenge in tunnelling and particularly difficult to predict in geological settings consisting of heterogeneous sedimentary rock formations with complex tectonic structure. For a high-speed railway line between Bologna and Florence (Italy), a series of seven railway tunnels was drilled through turbiditic formations, ranging from pelitic rocks with thin arenitic layers over sequences including thick-bedded sandstone to calcareous rocks showing chemical dissolution phenomena (karstification). The tunnels were built as draining tunnels and caused significant impacts, such as drying of springs and base-flow losses at mountain streams. A comprehensive hydrological monitoring programme and four multi-tracer test were done, focusing on four sections of the tunnel system. The tracer tests delivered unprecedented data on groundwater flow and transport in turbiditic aquifers and made it possible to better characterize the differential impacts of tunnel drainage along a geological gradient. The impact radius is 200 m in the thin-bedded sequences but reaches 2.3-4.0 km in calcareous and thick-bedded arenitic turbidites. Linear flow velocities, as determined from the peaks of the tracer breakthrough curves, range from 3.6 m/day in the thin-bedded turbidites to 39 m/day in the calcareous rocks (average values from the four test sites). At several places, discrete fault zones were identified as main hydraulic pathways between impacted streams and draining tunnels. This case shows that ignoring the hydrogeological conditions in construction projects can cause terrible damage, and the study presents an approach to better predict hydraulic impacts of draining tunnels in complex sedimentary rock settings.

  18. Scanning Tunneling Optical Resonance Microscopy

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Wilt, Dave; Raffaelle, Ryne; Gennett, Tom; Tin, Padetha; Lau, Janice; Castro, Stephanie; Jenkins, Philip; Scheiman, Dave

    2003-01-01

    Scanning tunneling optical resonance microscopy (STORM) is a method, now undergoing development, for measuring optoelectronic properties of materials and devices on the nanoscale by means of a combination of (1) traditional scanning tunneling microscopy (STM) with (2) tunable laser spectroscopy. In STORM, an STM tip probing a semiconductor is illuminated with modulated light at a wavelength in the visible-to-near-infrared range and the resulting photoenhancement of the tunneling current is measured as a function of the illuminating wavelength. The photoenhancement of tunneling current occurs when the laser photon energy is sufficient to excite charge carriers into the conduction band of the semiconductor. Figure 1 schematically depicts a proposed STORM apparatus. The light for illuminating the semiconductor specimen at the STM would be generated by a ring laser that would be tunable across the wavelength range of interest. The laser beam would be chopped by an achromatic liquid-crystal modulator. A polarization-maintaining optical fiber would couple the light to the tip/sample junction of a commercial STM. An STM can be operated in one of two modes: constant height or constant current. A STORM apparatus would be operated in the constant-current mode, in which the height of the tip relative to the specimen would be varied in order to keep the tunneling current constant. In this mode, a feedback control circuit adjusts the voltage applied to a piezoelectric actuator in the STM that adjusts the height of the STM tip to keep the tunneling current constant. The exponential relationship between the tunneling current and tip-to-sample distance makes it relatively easy to implement this mode of operation. The choice of method by which the photoenhanced portion of the tunneling current would be measured depends on choice of the frequency at which the input illumination would be modulated (chopped). If the frequency of modulation were low enough (typically < 10 Hz) that the

  19. Selenite transport in unsaturated tuff from Yucca Mountain

    SciTech Connect

    Conca, J.L.; Triay, I.R.

    1994-04-01

    Direct measurements of unsaturated selenite retardation coefficients and unsaturated hydraulic conductivity were obtained on two tuff samples from Yucca Mountain using the UFA{trademark} technology. The retardation factor for the selenite species was only 2.5 in both Yucca Mountain vitric member at 62.6% saturation and zeolitized nonwelded tuff from G-tunnel at 52.8% saturation with respect to J-13 well water from the Nevada Test Site contaminated with selenium at 1.31 mg/l (ppm). In batch tests on the same material using 1.2 mg/l (ppm), the average K{sub d} was determined to be 13, giving retardation factors higher than the UFA column breakthrough tests by an order of magnitude. The difference could result from preferential flow paths in the UFA column as might occur in the field or differences in residence times between the two types of test. The unsaturated hydraulic conductivities during the experiments were 2.49 {times} 10{sup {minus}8} cm/s for the Yucca Mountain vitric member and 1.16 {times} 10{sup {minus}8} cm/s for the zeolitized nonwelded tuff.

  20. Geology at Yucca Mountain

    SciTech Connect

    1993-05-01

    Both advocates and critics disagree on the significance and interpretation of critical geological features which bear on the safety and suitability of Yucca Mountain as a site for the construction of a high-level radioactive waste repository. Critics believe that there is sufficient geological evidence to rule the site unsuitable for further investigation. Some advocates claim that there is insufficient data and that investigations are incomplete, while others claim that the site is free of major obstacles. We have expanded our efforts to include both the critical evaluations of existing geological and geochemical data and the collection of field data and samples for the purpose of preparing scientific papers for submittal to journals. Summaries of the critical reviews are presented in this paper.

  1. Iron Mountain Electromagnetic Results

    SciTech Connect

    Gail Heath

    2012-07-01

    Iron Mountain Mine is located seventeen miles northwest of Redding, CA. After the completion of mining in early 1960s, the mine workings have been exposed to environmental elements which have resulted in degradation in water quality in the surrounding water sheds. In 1985, the EPA plugged ore stoops in many of the accessible mine drifts in an attempt to restrict water flow through the mine workings. During this process little data was gathered on the orientation of the stoops and construction of the plugs. During the last 25 years, plugs have begun to deteriorate and allow acidic waters from the upper workings to flow out of the mine. A team from Idaho National Laboratory (INL) performed geophysical surveys on a single mine drift and 3 concrete plugs. The project goal was to evaluate several geophysical methods to determine competence of the concrete plugs and orientation of the stopes.

  2. ESTIMATES OF CLOUD WATER DEPOSITION AT MOUNTAIN DEPOSITION AT MOUNTAIN ACID DEPOSITION PROGRAM SITES IN THE APPALACHIAN MOUNTAINS

    EPA Science Inventory

    Cloud water deposition was estimated at three high elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY, Whitetop Mountain, VA, and Clingrnan's Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). ...

  3. The self streamlining wind tunnel. [wind tunnel walls

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.

    1975-01-01

    A two dimensional test section in a low speed wind tunnel capable of producing flow conditions free from wall interference is presented. Flexible top and bottom walls, and rigid sidewalls from which models were mounted spanning the tunnel are shown. All walls were unperforated, and the flexible walls were positioned by screw jacks. To eliminate wall interference, the wind tunnel itself supplied the information required in the streamlining process, when run with the model present. Measurements taken at the flexible walls were used by the tunnels computer check wall contours. Suitable adjustments based on streamlining criteria were then suggested by the computer. The streamlining criterion adopted when generating infinite flowfield conditions was a matching of static pressures in the test section at a wall with pressures computed for an imaginary inviscid flowfield passing over the outside of the same wall. Aerodynamic data taken on a cylindrical model operating under high blockage conditions are presented to illustrate the operation of the tunnel in its various modes.

  4. Improved multidimensional semiclassical tunneling theory.

    PubMed

    Wagner, Albert F

    2013-12-12

    We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula. PMID:24224758

  5. Interface-modification-enhanced tunnel electroresistance in multiferroic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Mao, H. J.; Miao, P. X.; Cong, J. Z.; Song, C.; Cui, B.; Peng, J. J.; Li, F.; Wang, G. Y.; Zhao, Y. G.; Sun, Y.; Xiao, L. R.; Pan, F.

    2014-08-01

    We report a large tunnel electroresistance (TER) effect up to ˜104% in La0.67Sr0.33MnO3/BaTiO3/Co (LSMO/BTO/Co) multiferroic tunnel junctions (MFTJs), which couples with well-defined tunnel magnetoresistance. The large TER is related to (LaAlO3)0.3(LaSrTaO6)0.7 substrates which guarantee a high-quality LSMO/BTO interface and robust ferroelectricity in BTO. The insert of 0.5 nm-thick Pt between the Co electrode and BTO barrier further enhances the TER value to 105% and improves the endurance of the MFTJs, ascribed to the shortened screening length and reduced oxidation of BTO/Co interface. Their use would advance the process towards practical MFTJs with four resistance states.

  6. 27 CFR 9.80 - York Mountain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false York Mountain. 9.80... Mountain. (a) Name. The name of the viticultural area described in this section is “York Mountain.” (b) Approved map. The approved map for the York Mountain viticultural area is the U.S.G.S. map entitled...

  7. 27 CFR 9.55 - Bell Mountain.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Bell Mountain. 9.55... Mountain. (a) Name. The name of the viticultural area described in this section is “Bell Mountain.” (b) Approved map. The appropriate map for determining the boundaries of the Bell Mountain viticultural area...

  8. 27 CFR 9.167 - Red Mountain

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Red Mountain 9.167 Section... Mountain (a) Name. The name of the viticultural area described in this section is “Red Mountain.” (b) Approved maps. The appropriate map for determining the boundaries of the Red Mountain viticultural area...

  9. 27 CFR 9.55 - Bell Mountain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Bell Mountain. 9.55... Mountain. (a) Name. The name of the viticultural area described in this section is “Bell Mountain.” (b) Approved map. The appropriate map for determining the boundaries of the Bell Mountain viticultural area...

  10. 27 CFR 9.55 - Bell Mountain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Bell Mountain. 9.55... Mountain. (a) Name. The name of the viticultural area described in this section is “Bell Mountain.” (b) Approved map. The appropriate map for determining the boundaries of the Bell Mountain viticultural area...

  11. 27 CFR 9.55 - Bell Mountain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bell Mountain. 9.55... Mountain. (a) Name. The name of the viticultural area described in this section is “Bell Mountain.” (b) Approved map. The appropriate map for determining the boundaries of the Bell Mountain viticultural area...

  12. 27 CFR 9.167 - Red Mountain

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Red Mountain 9.167 Section... Mountain (a) Name. The name of the viticultural area described in this section is “Red Mountain.” (b) Approved maps. The appropriate map for determining the boundaries of the Red Mountain viticultural area...

  13. 27 CFR 9.80 - York Mountain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false York Mountain. 9.80... Mountain. (a) Name. The name of the viticultural area described in this section is “York Mountain.” (b) Approved map. The approved map for the York Mountain viticultural area is the U.S.G.S. map entitled...

  14. 27 CFR 9.167 - Red Mountain

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Red Mountain 9.167 Section... Mountain (a) Name. The name of the viticultural area described in this section is “Red Mountain.” (b) Approved maps. The appropriate map for determining the boundaries of the Red Mountain viticultural area...

  15. 27 CFR 9.80 - York Mountain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false York Mountain. 9.80... Mountain. (a) Name. The name of the viticultural area described in this section is “York Mountain.” (b) Approved map. The approved map for the York Mountain viticultural area is the U.S.G.S. map entitled...

  16. 27 CFR 9.55 - Bell Mountain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Bell Mountain. 9.55... Mountain. (a) Name. The name of the viticultural area described in this section is “Bell Mountain.” (b) Approved map. The appropriate map for determining the boundaries of the Bell Mountain viticultural area...

  17. 27 CFR 9.80 - York Mountain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false York Mountain. 9.80... Mountain. (a) Name. The name of the viticultural area described in this section is “York Mountain.” (b) Approved map. The approved map for the York Mountain viticultural area is the U.S.G.S. map entitled...

  18. 27 CFR 9.167 - Red Mountain

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Red Mountain 9.167 Section... Mountain (a) Name. The name of the viticultural area described in this section is “Red Mountain.” (b) Approved maps. The appropriate map for determining the boundaries of the Red Mountain viticultural area...

  19. 27 CFR 9.167 - Red Mountain

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Red Mountain 9.167 Section... Mountain (a) Name. The name of the viticultural area described in this section is “Red Mountain.” (b) Approved maps. The appropriate map for determining the boundaries of the Red Mountain viticultural area...

  20. 27 CFR 9.80 - York Mountain.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false York Mountain. 9.80... Mountain. (a) Name. The name of the viticultural area described in this section is “York Mountain.” (b) Approved map. The approved map for the York Mountain viticultural area is the U.S.G.S. map entitled...

  1. Conversion of Non-Tunneled to Tunneled Hemodialysis Catheters

    SciTech Connect

    Ha, Thuong G. Van Fimmen, Derek; Han, Laura; Funaki, Brian S.; Santeler, Scott; Lorenz, Jonathan

    2007-04-15

    Purpose. To determine the safety and efficacy of conversion of non-tunneled (temporary) catheters to tunneled catheters in hemodialysis patients. Methods. A retrospective review of 112 consecutive conversions in 111 patients was performed over a period of 4 years. Fourteen patients were lost to follow-up. The remaining 97 patients had clinical follow-up. Temporary catheters were converted to tunneled catheters utilizing the same internal jugular venotomy sites and a modified over-the-wire technique with use of a peel-away sheath . Follow-up clinical data were reviewed. Results. Technical success was achieved in all 112 procedures. None of the 97 patients with follow-up suffered early infection within 30 days. The total number of follow-up catheter days was 13,659 (range 2-790). Cases of confirmed and suspected bacteremia requiring catheter removal occurred at a frequency of 0.10 per 100 catheter days. Suspected catheter infection treated with antibiotics but not requiring catheter intervention occurred at a frequency of 0.04 per 100 catheter days. Frequency of all suspected or confirmed infections was 0.14 per 100 catheter days. Catheter interventions as a result of poor blood flow, inadvertent removal, catheter fracture, or kinking occurred at a rate of 0.18 per 100 catheter days. Life table analysis revealed primary patency rates of 86%, 64%, and 39% at 30 days, 90 days, and 180 days, respectively. Conclusion. Conversion of temporary catheters to tunneled catheters using the pre-existing venotomy sites is safe and has low rates of infection and malfunction. These rates are comparable to previously published rates for tunneled catheters placed de novo and tunneled catheter exchanges.

  2. National Wind Tunnel Complex (NWTC)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Wind Tunnel Complex (NWTC) Final Report summarizes the work carried out by a unique Government/Industry partnership during the period of June 1994 through May 1996. The objective of this partnership was to plan, design, build and activate 'world class' wind tunnel facilities for the development of future-generation commercial and military aircraft. The basis of this effort was a set of performance goals defined by the National Facilities Study (NFS) Task Group on Aeronautical Research and Development Facilities which established two critical measures of improved wind tunnel performance; namely, higher Reynolds number capability and greater productivity. Initial activities focused upon two high-performance tunnels (low-speed and transonic). This effort was later descoped to a single multipurpose tunnel. Beginning in June 1994, the NWTC Project Office defined specific performance requirements, planned site evaluation activities, performed a series of technical/cost trade studies, and completed preliminary engineering to support a proposed conceptual design. Due to budget uncertainties within the Federal government, the NWTC project office was directed to conduct an orderly closure following the Systems Design Review in March 1996. This report provides a top-level status of the project at that time. Additional details of all work performed have been archived and are available for future reference.

  3. Ventilation design for Yucca Mountain Exploratory Studies Facility

    SciTech Connect

    Jurani, R.S.

    1995-12-31

    Yucca Mountain, located in Southern Nevada approximately 160 km northwest of Las Vegas, is currently the site of intensive surface-based and underground investigations. The investigations are required to determine if the site is suitable for long term isolation of the Nation`s high level nuclear waste inventory. A major component of the program is the Exploratory Studies Facility, or ESF. The ESF, when completed, will consist of approximately 25,600 meters of tunnels and drifts. The network of tunnels and drifts will house and support a wide array of testing programs conceived to provide physical information about the site. Information on geologic, geomechanical, and hydrologic data will be used in the repository design if the site is found suitable. Besides a few special requirements, the general ESF ventilation criteria during construction are similar to that of commercial tunneling and mining operations. The minimum air velocity at the Tunnel Boring Machine (TBM) and other active mining faces is 0.51 meter per second (m/s) (100 feet per minute [fpm]). Airways, estimated leakages and ventilation controls are converted into equivalent resistances for input to mine ventilation network computer simulations. VNETPC Version 3.1 computer software is used to generate the ventilation models for optimized system design and component selection. Subsequently, actual performance of the ventilation system will be verified and validated to comply with applicable nuclear regulatory quality assurance requirements. Dust control in the ESF is dependent on effective dust collection, enclosure, and airflow dilution. Minimum use of water, as feasible, is necessary to avoid adding moisture to the potential repository horizon. The limitation of water use for test drilling and TBM operation, and the rigid compliance with applicable federal and state regulations, make the ESF a ventilation design challenge.

  4. Extinction of Harrington's Mountain Goat

    NASA Astrophysics Data System (ADS)

    Mead, Jim I.; Martin, Paul S.; Euler, Robert C.; Long, Austin; Jull, A. J. T.; Toolin, Laurence J.; Donahue, Douglas J.; Linick, T. W.

    1986-02-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 ± 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters.

  5. Extinction of Harrington's mountain goat

    SciTech Connect

    Mead, J.I.; Martin, P.S.; Euler, R.C.; Long, A.; Jull, A.J.T.; Toolin, L.J.; Donahue, D.J.; Linick, T.W.

    1986-02-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 +/- 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters.

  6. Mid-pacific mountains revisited

    NASA Astrophysics Data System (ADS)

    Kroenke, Loren W.; Kellogg, James N.; Nemoto, Kenji

    1985-06-01

    The Mid-Pacific Mountains are guyots whose volcanic pedestals have been constructed on a broad basement plateau, the flanks of which are downfaulted. Edifice construction may have been controlled by an orthogonal system of intersecting faults trending roughly ENE and NNW. Low amplitude gravity anomalies observed over the Mid-Pacific Mountains indicate complete Airy-Heiskanen isostatic compensation, crustal thickening, and eruption on thin elastic lithosphere. Tholeiites of the Mid-Pacific Mountains resemble lavas of Iceland and the Galapagos Islands. The orthogonal fault system, low gravity anomalies, and lava chemistry of the Mid-Pacific Mountains can be explained by eruption on or near a great ENE-trending rift system.

  7. The Dilemma of Mountain Roads

    EPA Science Inventory

    Mountain roads and trails are proliferating throughout developing Southeast Asia with severe but largely unrecognized long-term consequences related to effects of landslides and surface erosion on communities and downstream resources.

  8. Geography and Weather: Mountain Meterology.

    ERIC Educational Resources Information Center

    Mogil, H. Michael; Collins, H. Thomas

    1990-01-01

    Provided are 26 ideas to help children explore the effects of mountains on the weather. Weather conditions in Nepal and Colorado are considered separately. Nine additional sources of information are listed. (CW)

  9. Atlas Mountain Range, Mali, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    ATLAS pallets are backdropped against the Atlas Mountains (31.0N, 1.0W). ATLAS is an acronym for ATmospheric Laboratory for Applications and Science. Taken from a point over Mali, in the western Sahara, the northwest looking view shows dunes in the Iguidi dune sea and colors characteristic of the Saharan side of the Atlas Mountains. The edge of a large sandstorm, that transported sand and dust to Yugoslavia and beyond, can also be seen.

  10. Carpal tunnel syndrome and work.

    PubMed

    Newington, Lisa; Harris, E Clare; Walker-Bone, Karen

    2015-06-01

    Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, and it frequently presents in working-aged adults. Its mild form causes 'nuisance' symptoms including dysaesthesia and nocturnal waking. At its most severe, CTS can significantly impair motor function and weaken pinch grip. This review discusses the anatomy of the carpal tunnel and the clinical presentation of the syndrome as well as the classification and diagnosis of the condition. CTS has a profile of well-established risk factors including individual factors and predisposing co-morbidities, which are briefly discussed. There is a growing body of evidence for an association between CTS and various occupational factors, which is also explored. Management of CTS, conservative and surgical, is described. Finally, the issue of safe return to work post carpal tunnel release surgery and the lack of evidence-based guidelines are discussed. PMID:26612240

  11. Other cryogenic wind tunnel projects

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1989-01-01

    The first cryogenic tunnel was built in 1972. Since then, many cryogenic wind-tunnel projects were started at aeronautical research centers around the world. Some of the more significant of these projects are described which are not covered by other lecturers at this Special Course. Described are cryogenic wind-tunnel projects in five countries: China (Chinese Aeronautical Research and Development Center); England (College of Aeronautics at Cranfield, and Royal Aerospace Establishment-Bedford); Japan (National Aerospace Laboratory, University of Tsukuba, and National Defense Academy); United States (Douglas Aircraft Co., University of Illinois at Urbana-Champaign and NASA Langley); and U.S.S.R. (Central Aero-Hydronamics Institute (TsAGI), Institute of Theoretical and Applied Mechanics (ITAM), and Physical-Mechanical Institute at Kharkov (PMI-K).

  12. Io: Mountains and crustal extension

    NASA Technical Reports Server (NTRS)

    Heath, M. J.

    1985-01-01

    It is argued that there is good reason to conclude that mountains on Io, like those on Earth, are subject to growth and decay. The decay of mountains will be assisted by the ability of SO sub 2 to rot silicate rock and by explosive escape of sub-surface SO sub 2 from aquifers (Haemus Mons is seen to be covered by bright material, presumably fallout from a SO sub 2 rich plume which had been active on the mountain flanks). On the west side of the massif at 10 degrees S, 270 degrees W a rugged surface consists of long ridges running perpendicular to the downslope direction, suggesting tectonic denudation with crustal blocks sliding down the mountain flank. Tectonic denudation may be assisted, as in the case of the Bearpaw Mountains, Montana by overloading mountain flanks with volcanic products. The surfaces of some massifs exhibit a well developed, enigmatic corrugated terrain, consisting of complex ridge systems. Ridges may bifurcate, anastomose to form closed depressions and form concentric loops. Taken together, observations of morphology, heat flux, surface deposits and styles of volcanism may point to the existence of lithosphere domains with distinct compositions and tectonic regimes.

  13. Uplift of the Transantarctic Mountains

    SciTech Connect

    Stump, E.

    1987-09-01

    The Transantarctic Mountains, a major continental range, extend approximately 3,000 kilometers, vary from less than 50 to more than 400 kilometers wide, and have elevations of up to 4,500 meters. Earth scientists have generally defined the stratigraphy of the range and recognize that uplift of the region occurred after the Jurassic period but still know very little about the processes that effected uplift. Unlike other major mountain chains, the Transantarctic Mountains show no evidence of thrusting, folding, regional metamorphism, and andesitic volcanism associated with their uplift. The objectives during austral summer 1987-1988 are to map the uplift geometry of the Transantarctic Mountains using erosion surfaces (pre-Devonian Kukir peneplain) and widespread terrace levels as datum planes and to determine the uplift rates for the mountain range using fission-track dating of apatites. Presently, fission-track dating provides only quantitative data on the initiation time, amount, and rate of uplift. Through research, the authors hopes to extend data from Victoria Land through 1,600 kilometers of the Transantarctic Mountains. This study also has implications for the glacial history of Antarctica, because the uplift occurred during the inception, growth, and subsequent fluctuations of the east and west antarctic ice sheets. It will also add to our understanding of the nature of the East-West Antarctic boundary and to the knowledge of the sedimentation history in the Ross embayment and the basins beneath polar plateau.

  14. Computational multiqubit tunnelling in programmable quantum annealers.

    PubMed

    Boixo, Sergio; Smelyanskiy, Vadim N; Shabani, Alireza; Isakov, Sergei V; Dykman, Mark; Denchev, Vasil S; Amin, Mohammad H; Smirnov, Anatoly Yu; Mohseni, Masoud; Neven, Hartmut

    2016-01-01

    Quantum tunnelling is a phenomenon in which a quantum state traverses energy barriers higher than the energy of the state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational multiqubit tunnelling has not yet been observed, and a theory of co-tunnelling under high- and low-frequency noises is lacking. Here we show that 8-qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational primitive where classical paths are trapped in a false minimum. In support of the design of quantum annealers we develop a nonperturbative theory of open quantum dynamics under realistic noise characteristics. This theory accurately predicts the rate of many-body dissipative quantum tunnelling subject to the polaron effect. Furthermore, we experimentally demonstrate that quantum tunnelling outperforms thermal hopping along classical paths for problems with up to 200 qubits containing the computational primitive. PMID:26739797

  15. Tunnelling in van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Mishchenko, Artem; Novoselov, Kostya; Geim, Andre; Eaves, Laurence; Falko, Vladimir

    When graphene and other conductive two-dimensional (2D) materials are separated by an atomically thin insulating 2D crystal, quantum mechanical tunnelling leads to appreciable current between two 2D conductors due to the overlap of their wavefunctions. These tunnel devices demonstrate interesting physics and potential for applications: such effects as resonant tunnelling, negative differential conductance, light emission and detection have already been demonstrated. In this presentation we will outline the current status and perspectives of tunnelling transistors based on 2D materials assembled into van der Waals heterostructures. Particularly, we will present results on mono- and bilayer graphene tunnelling, tunnelling in 2D crystal-based quantum wells, and tunnelling in superconducting 2D materials. Such effects as momentum and chirality conservation, phonon- and impurity-assisted tunnelling will also be discussed. Finally, we will ponder the implications of discovered effects for practical applications.

  16. Computational multiqubit tunnelling in programmable quantum annealers

    PubMed Central

    Boixo, Sergio; Smelyanskiy, Vadim N.; Shabani, Alireza; Isakov, Sergei V.; Dykman, Mark; Denchev, Vasil S.; Amin, Mohammad H.; Smirnov, Anatoly Yu; Mohseni, Masoud; Neven, Hartmut

    2016-01-01

    Quantum tunnelling is a phenomenon in which a quantum state traverses energy barriers higher than the energy of the state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational multiqubit tunnelling has not yet been observed, and a theory of co-tunnelling under high- and low-frequency noises is lacking. Here we show that 8-qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational primitive where classical paths are trapped in a false minimum. In support of the design of quantum annealers we develop a nonperturbative theory of open quantum dynamics under realistic noise characteristics. This theory accurately predicts the rate of many-body dissipative quantum tunnelling subject to the polaron effect. Furthermore, we experimentally demonstrate that quantum tunnelling outperforms thermal hopping along classical paths for problems with up to 200 qubits containing the computational primitive. PMID:26739797

  17. Molecular series-tunneling junctions.

    PubMed

    Liao, Kung-Ching; Hsu, Liang-Yan; Bowers, Carleen M; Rabitz, Herschel; Whitesides, George M

    2015-05-13

    Charge transport through junctions consisting of insulating molecular units is a quantum phenomenon that cannot be described adequately by classical circuit laws. This paper explores tunneling current densities in self-assembled monolayer (SAM)-based junctions with the structure Ag(TS)/O2C-R1-R2-H//Ga2O3/EGaIn, where Ag(TS) is template-stripped silver and EGaIn is the eutectic alloy of gallium and indium; R1 and R2 refer to two classes of insulating molecular units-(CH2)n and (C6H4)m-that are connected in series and have different tunneling decay constants in the Simmons equation. These junctions can be analyzed as a form of series-tunneling junctions based on the observation that permuting the order of R1 and R2 in the junction does not alter the overall rate of charge transport. By using the Ag/O2C interface, this system decouples the highest occupied molecular orbital (HOMO, which is localized on the carboxylate group) from strong interactions with the R1 and R2 units. The differences in rates of tunneling are thus determined by the electronic structure of the groups R1 and R2; these differences are not influenced by the order of R1 and R2 in the SAM. In an electrical potential model that rationalizes this observation, R1 and R2 contribute independently to the height of the barrier. This model explicitly assumes that contributions to rates of tunneling from the Ag(TS)/O2C and H//Ga2O3 interfaces are constant across the series examined. The current density of these series-tunneling junctions can be described by J(V) = J0(V) exp(-β1d1 - β2d2), where J(V) is the current density (A/cm(2)) at applied voltage V and βi and di are the parameters describing the attenuation of the tunneling current through a rectangular tunneling barrier, with width d and a height related to the attenuation factor β. PMID:25871745

  18. Superresolution via enhanced evanescent tunneling.

    PubMed

    Salandrino, Alessandro; Christodoulides, Demetrios N

    2011-02-15

    We here propose the concept of enhanced evanescent tunneling (EET). Our analysis indicates that by means of a suitable control field, the transmission of evanescent waves across a forbidden gap can be enhanced by several orders of magnitude-well beyond the ordinary frustrated total internal reflection case. We show how such a phenomenon can be used to probe both the amplitude and phase of the evanescent portion of the angular spectrum, thereby allowing target superresolution. In principle EET can be manifested in other areas of physics where wave tunneling is involved. PMID:21326431

  19. Rocky Mountain spotted fever.

    PubMed

    Comer, K M

    1991-01-01

    Rocky Mountain spotted fever is an endemic tickborne disease found throughout the United States and other regions of the world. Exposure may result in a spectrum of disease from subclinical infection to severe or fatal multiorgan collapse. The disease is maintained in nature in Ixodid tick vectors and their hosts. The most important ticks in the United States are Dermacentor variabilis and Dermacentor andersoni. Small mammals are the natural reservoirs in the wild. Dogs become infected when a tick harboring Rickettsia rickettsii feeds on the dog. Dogs do not develop sufficient rickettsemia to act as a reservoir in the transmission of Rickettsia rickettsii. Thus, although dogs act as sentinels to the presence of the disease, they cannot directly transmit infection. Signs in early stages of disease often are nonspecific. The most characteristic laboratory abnormality is thrombocytopenia, but serologic testing is necessary for confirmation of infection. Tetracycline and chloramphenicol are effective antibiotics to treat infection. Treatment should continue for 14 to 21 days to allow host immune defenses to develop and eradicate the organism. Prevention requires avoidance of tick-infested areas and rapid removal of ticks should exposure occur. PMID:2014623

  20. Resonance tunneling spectroscopy of heteropoly compounds

    SciTech Connect

    Dalidchik, F. I. Budanov, B. A.; Kolchenko, N. N.; Balashov, E. M.; Kovalevskii, S. A.

    2012-12-15

    The electron tunneling spectra of phosphomolybdic and phosphomolybdovanadic acids have been measured using a scanning tunneling microscope. A new mechanism of negative differential resistance (NDR) formation in tunneling nanocontacts is established, which is general for all systems featuring the Wannier-Stark localization effect. A two-center inelastic resonance tunneling model is constructed, which allows the values of both electron and vibrational energy parameters to be determined from the measured spectra.

  1. 7 CFR 58.621 - Freezing tunnels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Freezing tunnels. 58.621 Section 58.621 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....621 Freezing tunnels. Freezing tunnels for quick freezing at extremely low temperatures shall...

  2. 49 CFR 177.810 - Vehicular tunnels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vehicular tunnels. 177.810 Section 177.810... Information and Regulations § 177.810 Vehicular tunnels. Except as regards Class 7 (radioactive) materials... through any urban vehicular tunnel used for mass transportation....

  3. 7 CFR 58.621 - Freezing tunnels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Freezing tunnels. 58.621 Section 58.621 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....621 Freezing tunnels. Freezing tunnels for quick freezing at extremely low temperatures shall...

  4. 43 CFR 3832.40 - Tunnel sites.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Tunnel sites. 3832.40 Section 3832.40..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING MINING CLAIMS OR SITES Tunnel Sites § 3832.40 Tunnel sites....

  5. 49 CFR 177.810 - Vehicular tunnels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Vehicular tunnels. 177.810 Section 177.810... Information and Regulations § 177.810 Vehicular tunnels. Except as regards Class 7 (radioactive) materials... through any urban vehicular tunnel used for mass transportation....

  6. Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

    SciTech Connect

    Cleland, A.N.

    1991-04-01

    Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q {approx} 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement.

  7. Natural Barriers of the Geosphere at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Arlt, H.; Kotra, J.; Mohanty, S.; Winterle, J.

    2005-05-01

    Geological repositories designed to isolate high-level radioactive waste need natural and engineered barriers that prevent or slow the release of radioactive elements into the accessible environment to acceptable regulatory limits. Under the U.S. Nuclear Regulatory Commission's (NRC's) regulations, a barrier is any material, structure, or feature that prevents or substantially reduces the rate of movement of water or radionuclides from the repository to the accessible environment. In 1982, Congress passed the Nuclear Waste Policy Act which directed the NRC to include multiple barriers in regulating geologic disposal of high-level radioactive waste. Accordingly, as provided in 10 CFR Part 63, the NRC's regulations for Yucca Mountain require a repository to include multiple barriers to ensure the system is robust and not wholly dependent on any single barrier. Any potential license application to construct a repository at Yucca Mountain must identify the multiple barriers (both natural and engineered), describe the capabilities of each barrier, and provide the technical bases for the capabilities of the barriers. The NRC believes that understanding the capability of the repository's component barriers improves understanding of the overall system. The objective of this paper is to discuss potential natural barriers of the geosphere at Yucca Mountain and describe the NRC regulatory requirements for such barriers. To better understand the natural barriers of the geosphere, it helps to divide the barriers into groups of features and their associated processes. Natural barriers, i.e., barriers not constructed by man, ideally include processes that delay the transport of radionuclides from reaching the accessible environment or limit the amount of water that can seep from a ground surface to the depth of an underground repository. Natural barriers at Yucca Mountain may include: topographic influences on precipitation runoff; soil and plants influences on evaporation and

  8. Spinoff from Wind Tunnel Technology

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Douglas Juanarena, a former NASA Langley instrument design engineer, found a solution to the problem of long, repetitive tunnel runs needed to measure airflow pressures. Electronically scanned pressure (ESP) replaced mechanical systems with electronic sensors. Juanarena licensed the NASA-patented technology and now manufactures ESP modules for research centers, aerospace companies, etc.

  9. [Modified Class II tunnel preparation].

    PubMed

    Rimondini, L; Baroni, C

    1991-05-15

    Tunnel preparations for restoration of Class II carious lesions in primary molars preserve the marginal ridge and minimize sacrifice of healthy tooth substructure. Materials with improved bonding to tooth structure and increase potential for fluoride release allow Class II restorations without "extension for prevention". PMID:1864420

  10. A seamless ubiquitous telehealthcare tunnel.

    PubMed

    Cheng, Po-Hsun; Lin, Bor-Shing; Yu, Chu; Hu, Shun-Hsiang; Chen, Sao-Jie

    2013-08-01

    Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP) is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields. PMID:23917812

  11. Micromachined electron tunneling infrared sensors

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Kaiser, W. J.; Podosek, J. A.; Rockstad, H. K.; Reynolds, J. K.

    1993-01-01

    The development of an improved Golay cell is reported. This new sensor is constructed entirely from micromachined silicon components. A silicon oxynitride (SiO(x)N(y)) membrane is deflected by the thermal expansion of a small volume of trapped gas. To detect the motion of the membrane, an electron tunneling transducer is used. This sensor detects electrons which tunnel through the classically forbidden barrier between a tip and a surface; the electron current is exponentially dependent on the separation between the tip and the surface. The sensitivity of tunneling transducers constructed was typically better than 10(exp -3) A/square root of Hz. Through use of the electron tunneling transducer, the scaling laws which have prevented the miniaturization of the Golay cell are avoided. This detector potentially offers low cost fabrication, compatibility with silicon readout electronics, and operation without cooling. Most importantly, this detector may offer better sensitivity than any other uncooled infrared sensor, with the exception of the original Golay cell.

  12. [Ultrasonography for carpal tunnel syndrome].

    PubMed

    Nakamichi, Kenichi

    2014-03-01

    Ultrasonography in cases of carpal tunnel syndrome is described with respect to the following aspects: (1) imaging technique; (2) image characteristics; (3) detection of pathophysiology; (4) diagnosis of idiopathic cases; (5) screening of local pathologies (space-occupying lesions, tenosynovitis, and bone and joint abnormalities), incomplete release, and anatomic variations; and (6) role in facilitating minimally-invasive surgery. PMID:24607945

  13. Videometric Applications in Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Burner, A. W.; Radeztsky, R. H.; Liu, Tian-Shu

    1997-01-01

    Videometric measurements in wind tunnels can be very challenging due to the limited optical access, model dynamics, optical path variability during testing, large range of temperature and pressure, hostile environment, and the requirements for high productivity and large amounts of data on a daily basis. Other complications for wind tunnel testing include the model support mechanism and stringent surface finish requirements for the models in order to maintain aerodynamic fidelity. For these reasons nontraditional photogrammetric techniques and procedures sometimes must be employed. In this paper several such applications are discussed for wind tunnels which include test conditions with Mach number from low speed to hypersonic, pressures from less than an atmosphere to nearly seven atmospheres, and temperatures from cryogenic to above room temperature. Several of the wind tunnel facilities are continuous flow while one is a short duration blowdown facility. Videometric techniques and calibration procedures developed to measure angle of attack, the change in wing twist and bending induced by aerodynamic load, and the effects of varying model injection rates are described. Some advantages and disadvantages of these techniques are given and comparisons are made with non-optical and more traditional video photogrammetric techniques.

  14. SCALING: Wind Tunnel to Flight

    NASA Astrophysics Data System (ADS)

    Bushnell, Dennis M.

    2006-01-01

    Wind tunnels have wide-ranging functionality, including many applications beyond aeronautics, and historically have been the major source of information for technological aerodynamics/aeronautical applications. There are a myriad of scaling issues/differences from flight to wind tunnel, and their study and impacts are uneven and a function of the particular type of extant flow phenomena. Typically, the most serious discrepancies are associated with flow separation. The tremendous ongoing increases in numerical simulation capability are changing and in many aspects have changed the function of the wind tunnel from a (scaled) "predictor" to a source of computational calibration/validation information with the computation then utilized as the flight prediction/scaling tool. Numerical simulations can increasingly include the influences of the various scaling issues. This wind tunnel role change has been occurring for decades as computational capability improves in all aspects. Additional issues driving this trend are the increasing cost (and time) disparity between physical experiments and computations, and increasingly stringent accuracy requirements.

  15. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.; Mary, Natalie; Howe, A. Scott; Jeffries, Sharon

    2016-01-01

    How Mars surface crews get into their ascent vehicle has profound implications for Mars surface architecture. To meet planetary protection protocols, the architecture has get Intravehicular Activity (IVA)-suited crew into a Mars Ascent Vehicle (MAV) without having to step outside into the Mars environment. Pushing EVA suit don/doff and EVA operations to an element that remains on the surface also helps to minimize MAV cabin volume, which in turn can reduce MAV cabin mass. Because the MAV will require at least seven kilograms of propellant to ascend each kilogram of cabin mass, minimal MAV mass is desired. For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The "Minimum Functional Tunnel" is a conceptual design that performs a single function. Having established this baseline configuration, the next step is to trade design options, evaluate other applications, and explore alternative solutions.

  16. A Seamless Ubiquitous Telehealthcare Tunnel

    PubMed Central

    Cheng, Po-Hsun; Lin, Bor-Shing; Yu, Chu; Hu, Shun-Hsiang; Chen, Sao-Jie

    2013-01-01

    Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP) is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields. PMID:23917812

  17. Scale Model Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Canacci, Victor A.

    1997-01-01

    NASA Lewis Research Center's Icing Research Tunnel (IRT) is the world's largest refrigerated wind tunnel and one of only three icing wind tunnel facilities in the United States. The IRT was constructed in the 1940's and has been operated continually since it was built. In this facility, natural icing conditions are duplicated to test the effects of inflight icing on actual aircraft components as well as on models of airplanes and helicopters. IRT tests have been used successfully to reduce flight test hours for the certification of ice-detection instrumentation and ice protection systems. To ensure that the IRT will remain the world's premier icing facility well into the next century, Lewis is making some renovations and is planning others. These improvements include modernizing the control room, replacing the fan blades with new ones to increase the test section maximum velocity to 430 mph, installing new spray bars to increase the size and uniformity of the artificial icing cloud, and replacing the facility heat exchanger. Most of the improvements will have a first-order effect on the IRT's airflow quality. To help us understand these effects and evaluate potential improvements to the flow characteristics of the IRT, we built a modular 1/10th-scale aerodynamic model of the facility. This closed-loop scale-model pilot tunnel was fabricated onsite in the various shops of Lewis' Fabrication Support Division. The tunnel's rectangular sections are composed of acrylic walls supported by an aluminum angle framework. Its turning vanes are made of tubing machined to the contour of the IRT turning vanes. The fan leg of the tunnel, which transitions from rectangular to circular and back to rectangular cross sections, is fabricated of fiberglass sections. The contraction section of the tunnel is constructed from sheet aluminum. A 12-bladed aluminum fan is coupled to a turbine powered by high-pressure air capable of driving the maximum test section velocity to 550 ft

  18. Aeroelastic instability stoppers for wind tunnel models

    NASA Technical Reports Server (NTRS)

    Doggett, R. V., Jr.; Ricketts, R. H. (Inventor)

    1981-01-01

    A mechanism for diverting the flow in a wind tunnel from the wing of a tested model is described. The wing is mounted on the wall of a tunnel. A diverter plate is pivotally mounted on the tunnel wall ahead of the model. An actuator fixed to the tunnel is pivotably connected to the diverter plate, by plunger. When the model is about to become unstable during the test the actuator moves the diverter plate from the tunnel wall to divert maintaining stable model conditions. The diverter plate is then retracted to enable normal flow.

  19. Tunneling time, what is its meaning?

    NASA Astrophysics Data System (ADS)

    McDonald, C. R.; Orlando, G.; Vampa, G.; Brabec, T.

    2015-03-01

    The tunnel time ionization dynamics for bound systems in laser fields are investigated. Numerical analysis for a step function switch-on of the field allows for the tunnel time to be defined as the time it takes the ground state to develop the under-barrier wavefunction components necessary to achieve the static field ionization rate. A relation between the tunnel time and the Keldysh time is established. The definition of the tunnel time is extended to time varying fields and experimental possibilities for measuring the tunnel time are discussed.

  20. Hydrometeorology of Rocky Mountain floods

    NASA Astrophysics Data System (ADS)

    Jarrett, Robert D.

    Climatology and flood hydrology of the Rocky Mountains were the topics of a workshop held in Lakewood, Colo., October 4-5, 1990. Ninety-one people participated in the workshop, which was organized by Robert Jarrett, U.S. Geological Survey, Denver; John Liou, Federal Emergency Management Agency, Denver; and Doug Laiho, Delta Environmental Consultants, Boulder, representing the American Society of Civil Engineers.The workshop was held to address some of the recognized complexities in the hydrometeorology of floods in the Rocky Mountains. The complexities are caused by the effects of rough mountain terrain on meteorology, snowmelt and rainfall flooding, and limited rainfall and streamflow data. The current theories and methods used to estimate flood flows in the Rocky Mountains, particularly estimation of the probable maximum precipitation (PMP) and the probable maximum flood (PMF), have been questioned by hydrologists and engineers for some time. Purposes of the workshop were to review the current understanding and ongoing research of floods—both frequent and extreme, including the PMF, in the Rocky Mountains; to bring together scientists, engineers, and flood-plain managers in government, industry, consulting firms, and universities; and to provide a mechanism for the exchange of ideas and technology between climatologists, meteorologists, hydrologists, engineers, and managers.

  1. Mountain biking injuries: an update.

    PubMed

    Kronisch, Robert L; Pfeiffer, Ronald P

    2002-01-01

    This article reviews the available literature regarding injuries in off-road bicyclists. Recent progress in injury research has allowed the description of several patterns of injury in this sport. Mountain biking remains popular, particularly among young males, although sales and participation figures have decreased in the last several years. Competition in downhill racing has increased, while cross-country racing has decreased somewhat in popularity. Recreational riders comprise the largest segment of participants, but little is known about the demographics and injury epidemiology of noncompetitive mountain cyclists. Most mountain bikers participating in surveys reported a history of previous injuries, but prospective studies conducted at mountain bike races have found injury rates of <1%. The most common mechanism of injury involves a forward fall over the handlebars, usually while riding downhill, which can result in direct trauma to the head, torso and upper extremities. A variety of factors can be associated with this type of fall, including trail surface irregularities, mechanical failures and loss of control. In mountain bike racing the risk of injury may be higher for women than men. Minor injuries such as abrasions and contusions occur frequently, but are usually of little consequence. Fractures usually involve the torso or upper extremities, and shoulder injuries are common. Head and face injuries are not always prevented by current helmet designs. Fatal injuries are rare but have been reported. Improvements in safety equipment, rider training and racecourse design are suggested injury prevention measures. The authors encourage continued research in this sport. PMID:12076178

  2. Mountaineer`s gas facilities decision support system

    SciTech Connect

    1997-02-01

    Mountaineer Gas Co. of Charleston, W.Va., is justifiably proud of its capacity to combine electronic maps with a full database of information about its facilities and customers, and use that mix to make the decisions required in operating a gas company with better information and more quickly. Determining when a pipeline needs replacement or repair used to take several days at Mountaineer. With the new system in place, the decision can be made in a matter of minutes. The paper describes the system and its development, then discusses adding customer information as the next step.

  3. 2. 'Tunnel No 6 West End, Front Elevation, Sectional Elevation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. 'Tunnel No 6 West End, Front Elevation, Sectional Elevation on Centerline of Portal,' Southern Pacific Standard Single-Track Tunnel, 1910. Tunnel 6, which today would be Tunnel 20, was daylighted and no longer exists. Compare to photos in documentation sets for Tunnel 23 (HAER No. CA-198), Tunnel 24 (HAER No. CA-200), Tunnel 25 (HAER No. CA-201), Tunnel 27 (HAER No. CA-203), Tunnel 28 (HAER No. CA-204), and Tunnel 29 (HAER No. CA-205). - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  4. Remark on massive particle's de Sitter tunneling

    SciTech Connect

    Jiang, Qing-Quan; Chen, De-You; Wen, Dan E-mail: deyouchen@126.com

    2013-11-01

    In the work [J. Y. Zhang and Z. Zhao, Massive particles's black hole tunneling and de Sitter tunneling, Nucl. Phys. B 725 (2005) 173.], the Hawking radiation of the massive particle via tunneling from the de Sitter cosmological horizon has been first described in the tunneling framework. However, the geodesic equation of the massive particle was unnaturally and awkwardly defined there by investigating the relation between the group and phase velocity. In this paper, we start from the Lagrangian analysis on the action to naturally produce the geodesic equation of the tunneling massive particle. Then, based on the new definition for the geodesic equation, we revisit the Hawking radiation of the massive particle via tunneling from the de Sitter cosmological horizon. It is noteworthy that, the highlight of our work is a new and important development of the Parikh-Wilczek's tunneling method, which can make it more physical.

  5. Constructing the Exploratory Studies Facility at Yucca Mountain

    SciTech Connect

    Kalia, H.N.; Replogle, J.M.

    1996-05-01

    Yucca Mountain Site Characterization Office of the US Department of Energy (DOE) is constructing an underground Exploratory Studies Facility (ESF), approximately 160 km (100 miles) northwest of Las Vegas, Nevada. This facility is being used to obtain geological, hydrological, geomechanical, thermomechanical and geochemical information to characterize, Yucca Mountain as a potential site to isolate High-Level Radioactive Waste from the accessible environment. The ESF, when completed, will consist of two ramps from surface (North and South ramp) to the potential repository horizon formations, a drift connecting the two ramps, test alcoves, and above and below ground operational support facilities. The ramps and connecting drift are being mined by a 7.62 m (25 ft) diameter, fully shielded, Tunnel Boring Machine (TBM). This paper describes the current status of the construction of the ESF and test alcoves. At the time of this writing, the following has been accomplished: North Ramp excavation is complete; four test alcoves have been excavated and are in use for scientific experiments; the excavation has reached the potential repository horizon; the drift connecting the two ramps is being excavated, and the excavation of a test alcove for thermal testing is in progress. The mining operations are ahead of schedule, and to date March 26, 1996, the TBM has excavated over 4623 m(15,160 ft.) without any major breakdowns or accidents. The average advance for a three shift (two mining shifts) production day has been 33.46 m (110 ft.). Maximum advance for a week was 218.3 m (716 ft.). An Alpine Miner (AM 75) roadheader is being used to excavate test alcoves. The major ground support system consists of Supper Swellex rock bolts, steel sets as required, Williams rock bolts and channels, and welded wire fabric. Various sections of the tunnel have been instrumented, and the entire excavation has been geologically mapped. To date, the site conditions have been those predicted.

  6. Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions

    NASA Astrophysics Data System (ADS)

    Tao, L. L.; Wang, J.

    2016-06-01

    We report the investigation on the ferroelectricity and tunneling electroresistance (TER) effect in PbTiO3 (PTO)-based ferroelectric tunnel junctions (FTJs) using first-principles calculations. For symmetric FTJs, we have calculated the average polarizations of PTO film and effective screening lengths of different metal electrodes for a number of FTJs, which is useful for experimental research. For asymmetric FTJs, significant asymmetric ferroelectric displacements in PTO film are observed, which is attributed to the intrinsic field generated by the two dissimilar electrodes. Moreover, by performing quantum transport calculations on those asymmetric FTJs, a sizable TER effect is observed. It is found that the asymmetry of ferroelectric displacements in PTO barrier, which is determined by the difference of work functions of the electrodes, controls the observed TER effect. Our results will help unravel the TER mechanism of asymmetric FTJs in most experiments and will be useful for the designing of FTJ-based devices.

  7. 10. SLIGHTLY OBLIQUE VIEW OF EAGLE MOUNTAIN PUMP COMPLEX. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. SLIGHTLY OBLIQUE VIEW OF EAGLE MOUNTAIN PUMP COMPLEX. NOTE AUXILIARY STRUCTURES. - Eagle Mountain Pump Plant, Ten miles north of Route 10, southeast of Eagle Mountain, Eagle Mountain, Riverside County, CA

  8. Timber Mountain Precipitation Monitoring Station

    SciTech Connect

    Lyles, Brad; McCurdy, Greg; Chapman, Jenny; Miller, Julianne

    2012-01-01

    A precipitation monitoring station was placed on the west flank of Timber Mountain during the year 2010. It is located in an isolated highland area near the western border of the Nevada National Security Site (NNSS), south of Pahute Mesa. The cost of the equipment, permitting, and installation was provided by the Environmental Monitoring Systems Initiative (EMSI) project. Data collection, analysis, and maintenance of the station during fiscal year 2011 was funded by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office Environmental Restoration, Soils Activity. The station is located near the western headwaters of Forty Mile Wash on the Nevada Test and Training Range (NTTR). Overland flows from precipitation events that occur in the Timber Mountain high elevation area cross several of the contaminated Soils project CAU (Corrective Action Unit) sites located in the Forty Mile Wash watershed. Rain-on-snow events in the early winter and spring around Timber Mountain have contributed to several significant flow events in Forty Mile Wash. The data from the new precipitation gauge at Timber Mountain will provide important information for determining runoff response to precipitation events in this area of the NNSS. Timber Mountain is also a groundwater recharge area, and estimation of recharge from precipitation was important for the EMSI project in determining groundwater flowpaths and designing effective groundwater monitoring for Yucca Mountain. Recharge estimation additionally provides benefit to the Underground Test Area Sub-project analysis of groundwater flow direction and velocity from nuclear test areas on Pahute Mesa. Additionally, this site provides data that has been used during wild fire events and provided a singular monitoring location of the extreme precipitation events during December 2010 (see data section for more details). This letter report provides a summary of the site location, equipment, and data collected in

  9. TRM performance prediction in Yucca Mountain welded tuff from linear cutter tests

    SciTech Connect

    Gertsch, R.; Ozdemir, L.; Gertsch, L.

    1992-12-31

    Performance predictions were developed for tunnel boring machines operating in welded tuff for the construction of the experimental study facility and the potential nuclear waste repository at Yucca Mountain. The predictions were based on test data obtained from an extensive series of linear cutting tests performed on samples of Topopah Spring welded tuff from the Yucca Mountain Project site. Using the cutter force, spacing, and penetration data from the experimental program, the thrust, torque, power, and rate of penetration were estimated for a 25 ft diameter tunnel boring machine (TBM) operating in welded tuff. Guidelines were developed for the optimal design of the TBM cutterhead to achieve high production rates at the lowest possible excavation costs. The results show that the Topopah Spring welded tuff (TSw2) can be excavated at relatively high rates of advance with state-of-the-art TBMs. The results also show, however, that the TBM torque and power requirements will be higher than estimated based on rock physical properties and past tunneling experience in rock formations of similar strength.

  10. White Mountain Wilderness, New Mexico

    SciTech Connect

    Segerstrom, K.; Stotelmeyer, R.B.

    1984-01-01

    On the basis of a mineral survey made during 1971-1973, the White Mountain Wilderness, which constitutes much of the western and northern White Mountains, New Mexico, is appraised to have six areas of probable mineral potential for base and precious metals. In mineral deposits exist in the wilderness, the potential is for small deposits of base and precious metals in veins and breccia pipes or, more significantly, the possibility for large low-grade disseminated porphyry-type molybdenum deposits. There is little promise for the occurrence of geothermal energy resources in the area.

  11. BLOOD MOUNTAIN ROADLESS AREA, GEORGIA.

    USGS Publications Warehouse

    Koeppen, Robert P.; Armstrong, Michelle K.

    1984-01-01

    A mineral-resource survey of the Blood Mountain Roadless Area, Georgia, indicates that there is little promise for the occurrence of mineral and energy resources. Natural gas may be present at great depth, perhaps 5 mi down and below the overthrust sheets of the Blue Ridge Mountains, but presently available information is not adequate to evaluate the resource potential of this commodity. Further seismic studies and exploratory drilling are needed to evaluate the gas potential of this part of the Eastern Overthrust Belt.

  12. Yearly report, Yucca Mountain project

    SciTech Connect

    Brune, J.N.

    1992-09-30

    We proposed to (1) Develop our data logging and analysis equipment and techniques for analyzing seismic data from the Southern Great Basin Seismic Network (SGBSN), (2) Investigate the SGBSN data for evidence of seismicity patterns, depth distribution patterns, and correlations with geologic features (3) Repair and maintain our three broad band downhole digital seismograph stations at Nelson, nevada, Troy Canyon, Nevada, and Deep Springs, California (4) Install, operate, and log data from a super sensitive microearthquake array at Yucca Mountain (5) Analyze data from micro-earthquakes relative to seismic hazard at Yucca Mountain.

  13. Construction of the exploratory studies facility at Yucca Mountain - North Ramp

    SciTech Connect

    Kalia, H.N.; Repogle, J.M.; McNeely, J.E.

    1995-05-01

    Yucca Mountain Site Characterization Office of the US Department of Energy is constructing an Exploratory Studies Facility, approximately 160 km (100 miles) northwest of Las Vegas, Nevada. This facility will be used to gather geological, hydrological, geomechanical, thermomechanical, and geochemical information to characterize Yucca Mountain as a potential site to isolate High-Level Radioactive Waste from the accessible environment. The Exploratory Studies Facility, when completed shall consist of two ramps from the surface, a connecting drift, underground test areas and below ground operational support facilities. The ramps and connecting drift are being mined by a 7.62 m (25 ft) diameter Tunnel Boring Machine. This machine was fabricated for the Department of Energy by Construction Tunneling Services, Inc; of Kent, Washington. This paper describes the current status of the concentration of the North Ramp at Yucca Mountain. At the time of this writing, the North Ramp had advanced to a distance of about 517 m (1700 ft). With the exception of some minor problems through Bow Ridge fault, the excavation has progressed as expected.

  14. Drift natural convection and seepage at the Yucca Mountain repository

    NASA Astrophysics Data System (ADS)

    Halecky, Nicholaus Eugene

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock, from the hot drift center to the cool drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water- induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  15. Harmonic multiplication using resonant tunneling

    NASA Technical Reports Server (NTRS)

    Sollner, T. C. L. G.; Brown, E. R.; Goodhue, W. D.; Correa, C. A.

    1988-01-01

    This paper demonstrates the use of resonant-tunneling diodes as varistors for harmonic multiplication. It is shown that efficient odd-harmonic conversion is possible and that even harmonics do not appear because of the antisymmetry of the current-voltage (I-V) curve. It is also shown that, with the proper choice of resonant-tunneling structure and pump amplitude, most of the harmonic output power can be confined to a single odd-harmonic frequency. Fifth-harmonic multiplication was demonstrated with an output at 21.75 GHz and a power conversion efficiency of 0.5 percent, and a fifth-harmonic efficiency of 2.7 percent was achieved in a circuit simulation using an improved I-V curve.

  16. Tunneling decay of false kinks

    NASA Astrophysics Data System (ADS)

    Dupuis, Éric; Gobeil, Yan; MacKenzie, Richard; Marleau, Luc; Paranjape, M. B.; Ung, Yvan

    2015-07-01

    We consider the decay of "false kinks," that is, kinks formed in a scalar field theory with a pair of degenerate symmetry-breaking false vacua in 1 +1 dimensions. The true vacuum is symmetric. A second scalar field and a peculiar potential are added in order for the kink to be classically stable. We find an expression for the decay rate of a false kink. As with any tunneling event, the rate is proportional to exp (-SE) where SE is the Euclidean action of the bounce describing the tunneling event. This factor varies wildly depending on the parameters of the model. Of interest is the fact that for certain parameters SE can get arbitrarily small, implying that the kink is only barely stable. Thus, while the false vacuum itself may be very long-lived, the presence of kinks can give rise to rapid vacuum decay.

  17. Wind tunnel flow generation section

    NASA Technical Reports Server (NTRS)

    Sorensen, N. E. (Inventor)

    1974-01-01

    A flow generation section for a wind tunnel test facility is described which provides a uniform flow for the wind tunnel test section over a range of different flow velocities. The throat of the flow generation section includes a pair of opposed boundary walls which are porous to the flowing medium in order to provide an increase of velocity by expansion. A plenum chamber is associated with the exterior side of each of such porous walls to separate the same from ambient pressure. A suction manifold is connected by suction lines with each one of the chambers. Valves are positioned in each of the lines to enable the suction manifold to be independently varied.

  18. Spin tunneling in magnetic molecules

    NASA Astrophysics Data System (ADS)

    Kececioglu, Ersin

    In this thesis, we will focus on spin tunneling in a family of systems called magnetic molecules such as Fe8 and Mn12. This is comparatively new, in relation to other tunneling problems. Many issues are not completely solved and/or understood yet. The magnetic molecule Fe 8 has been observed to have a rich pattern of degeneracies in its magnetic spectrum. We focus on these degeneracies from several points of view. We start with the simplest anisotropy Hamiltonian to describe the Fe 8 molecule and extend our discussion to include higher order anisotropy terms. We give analytical expressions as much as we can, for the degeneracies in the semi-classical limit in both cases. We reintroduce jump instantons to the instanton formalism. Finally, we discuss the effect of the environment on the molecule. Our results, for all different models and techniques, agree well with both experimental and numerical results.

  19. Fermion tunneling from dynamical horizons

    NASA Astrophysics Data System (ADS)

    Di Criscienzo, R.; Vanzo, L.

    2008-06-01

    The instability against emission of fermionic particles by the trapping horizon of an evolving black hole is analyzed and confirmed using the Hamilton-Jacobi tunneling method. This method automatically selects one special expression for the surface gravity of a changing horizon. The results also apply to point masses embedded in an expanding universe. As a bonus of the tunneling method, we gain the insight that the surface gravity still defines a temperature parameter as long as the evolution is sufficiently slow that the black-hole pass through a sequence of quasi-equilibrium states, and that black holes should be semi-classically unstable even in a hypothetical world without bosonic fields.

  20. Single-contact tunneling thermometry

    DOEpatents

    Maksymovych, Petro

    2016-02-23

    A single-contact tunneling thermometry circuit includes a tunnel junction formed between two objects. Junction temperature gradient information is determined based on a mathematical relationship between a target alternating voltage applied across the junction and the junction temperature gradient. Total voltage measured across the junction indicates the magnitude of the target alternating voltage. A thermal gradient is induced across the junction. A reference thermovoltage is measured when zero alternating voltage is applied across the junction. An increasing alternating voltage is applied while measuring a thermovoltage component and a DC rectification voltage component created by the applied alternating voltage. The target alternating voltage is reached when the thermovoltage is nullified or doubled by the DC rectification voltage depending on the sign of the reference thermovoltage. Thermoelectric current and current measurements may be utilized in place of the thermovoltage and voltage measurements. The system may be automated with a feedback loop.

  1. PHYSICAL MODEL FOR RECOGNITION TUNNELING

    PubMed Central

    Krstić, Predrag; Ashcroft, Brian; Lindsay, Stuart

    2015-01-01

    Recognition tunneling (RT) identifies target molecules trapped between tunneling electrodes functionalized with recognition molecules that serve as specific chemical linkages between the metal electrodes and the trapped target molecule. Possible applications include single molecule DNA and protein sequencing. This paper addresses several fundamental aspects of RT by multiscale theory, applying both all-atom and coarse-grained DNA models: (1) We show that the magnitude of the observed currents are consistent with the results of non-equilibrium Green's function calculations carried out on a solvated all-atom model. (2) Brownian fluctuations in hydrogen bond-lengths lead to current spikes that are similar to what is observed experimentally. (3) The frequency characteristics of these fluctuations can be used to identify the trapped molecules with a machine-learning algorithm, giving a theoretical underpinning to this new method of identifying single molecule signals. PMID:25650375

  2. Epidote from the Zard Mountains, Kharan, Balochistan, Pakistan

    USGS Publications Warehouse

    Brownfield, Michael E.; Lowers, Heather; Betterton, William K.

    2013-01-01

    The authors received two unusual crystals of epidote from Rock Currier, Jewel Tunnel Imports, in 2012. The mineral specimens were collected at Zard Mountain (Zard Koh), in the central part of the Ruskoh Mountains (Rusk Koh), west of Kharan, Balochistan, Pakistan (written communication, Rock Currier, 2013). The epidote locality was most likely discovered in 2010. These epidote crystals were unusual in both form and composition. The large crystals were flat tabular and pseudohexagonal in shape which is an uncommon crystal form for a monoclinic mineral (fig. 1). Other specimens from the same locality have been described as pseudo-octahedral in shape. The two crystals range in size from 5.5 to 6.5 centimeters (2.2 to 2.6 inches) and are slightly magnetic. The epidote crystals have a core matrix that resembles a weathered igneous rock. Some micro brown- to reddish-titanite crystals were observed under a binocular microscope on the surface and core areas of the crystals (figs. 2 and 3). Other minerals observed in the core areas include feldspar, biotite, and quartz. The crystals display evidence of cluster-growth with points of attachment to other crystals. The epidotes were most likely collected in pockets of a weathered igneous-skarn deposit.

  3. Model of 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Model of 5-Foot Vertical Wind Tunnel. Carl Wenzinger and Thomas Harris wrote in NACA TR 387: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet to within 0.5 per cent. The turbulence present in the tunnel has been compared with that of several other tunnels by means of the results of sphere drag tests and was found to average well with the values of those tunnels. Included also in the report are comparisons of results of stable autorotation and of rolling-moment tests obtained both in the vertical tunnel and in the old horizontal 5-foot atmospheric tunnel.' The design of a vertical tunnel having a 5-foot diameter jet was accordingly started by the National Advisory Committee for Aeronautics in 1928. Actual construction of the new tunnel was completed in 1930, and the calibration tests were then made.'

  4. Variable density turbulence tunnel facility

    NASA Astrophysics Data System (ADS)

    Bodenschatz, E.; Bewley, G. P.; Nobach, H.; Sinhuber, M.; Xu, H.

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10-4 m2/s and 10-7 m2/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number Rλ ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to Rλ ≈ 8000.

  5. Observing remnants by fermions' tunneling

    SciTech Connect

    Chen, D.Y.; Wu, H.W.; Yang, H. E-mail: iverwu@uestc.edu.cn

    2014-03-01

    The standard Hawking formula predicts the complete evaporation of black holes. In this paper, we introduce effects of quantum gravity into fermions' tunneling from Reissner-Nordstrom and Kerr black holes. The quantum gravity effects slow down the increase of Hawking temperatures. This property naturally leads to a residue mass in black hole evaporation. The corrected temperatures are affected by the quantum numbers of emitted fermions. Meanwhile, the temperature of the Kerr black hole is a function of θ due to the rotation.

  6. 27 CFR 9.94 - Howell Mountain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Howell Mountain. 9.94... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell Mountain.” (b) Approved maps. The appropriate maps for determining the boundaries of the Howell...

  7. 27 CFR 9.102 - Sonoma Mountain.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Sonoma Mountain. 9.102... Sonoma Mountain. (a) Name. The name of the viticultural area described in this section is “Sonoma Mountain.” (b) Approved maps. The approved maps for determining the boundary of the Sonoma...

  8. 27 CFR 9.112 - Arkansas Mountain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Arkansas Mountain. 9.112... Arkansas Mountain. (a) Name. The name of the viticultural area described in this section is “Arkansas Mountain.” (b) Approved maps. The appropriate maps for determining the boundary of the Arkansas...

  9. 27 CFR 9.102 - Sonoma Mountain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Sonoma Mountain. 9.102... Sonoma Mountain. (a) Name. The name of the viticultural area described in this section is “Sonoma Mountain.” (b) Approved maps. The approved maps for determining the boundary of the Sonoma...

  10. 49 CFR 71.8 - Mountain zone.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Mountain zone. 71.8 Section 71.8 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part of the United States that is west of...

  11. 27 CFR 9.94 - Howell Mountain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Howell Mountain. 9.94... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell Mountain.” (b) Approved maps. The appropriate maps for determining the boundaries of the Howell...

  12. 27 CFR 9.94 - Howell Mountain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Howell Mountain. 9.94... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell Mountain.” (b) Approved maps. The appropriate maps for determining the boundaries of the Howell...

  13. 27 CFR 9.112 - Arkansas Mountain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Arkansas Mountain. 9.112... Arkansas Mountain. (a) Name. The name of the viticultural area described in this section is “Arkansas Mountain.” (b) Approved maps. The appropriate maps for determining the boundary of the Arkansas...

  14. 49 CFR 71.8 - Mountain zone.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Mountain zone. 71.8 Section 71.8 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part of the United States that is west of...

  15. 27 CFR 9.94 - Howell Mountain.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Howell Mountain. 9.94... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell Mountain.” (b) Approved maps. The appropriate maps for determining the boundaries of the Howell...

  16. 27 CFR 9.102 - Sonoma Mountain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Sonoma Mountain. 9.102... Sonoma Mountain. (a) Name. The name of the viticultural area described in this section is “Sonoma Mountain.” (b) Approved maps. The approved maps for determining the boundary of the Sonoma...

  17. 27 CFR 9.112 - Arkansas Mountain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Arkansas Mountain. 9.112... Arkansas Mountain. (a) Name. The name of the viticultural area described in this section is “Arkansas Mountain.” (b) Approved maps. The appropriate maps for determining the boundary of the Arkansas...

  18. 27 CFR 9.102 - Sonoma Mountain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Sonoma Mountain. 9.102... Sonoma Mountain. (a) Name. The name of the viticultural area described in this section is “Sonoma Mountain.” (b) Approved maps. The approved maps for determining the boundary of the Sonoma...

  19. 49 CFR 71.8 - Mountain zone.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Mountain zone. 71.8 Section 71.8 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part of the United States that is west of...

  20. 27 CFR 9.112 - Arkansas Mountain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Arkansas Mountain. 9.112... Arkansas Mountain. (a) Name. The name of the viticultural area described in this section is “Arkansas Mountain.” (b) Approved maps. The appropriate maps for determining the boundary of the Arkansas...

  1. 27 CFR 9.94 - Howell Mountain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Howell Mountain. 9.94... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell Mountain.” (b) Approved maps. The appropriate maps for determining the boundaries of the Howell...

  2. 49 CFR 71.8 - Mountain zone.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Mountain zone. 71.8 Section 71.8 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part of the United States that is west of...

  3. 27 CFR 9.102 - Sonoma Mountain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Sonoma Mountain. 9.102... Sonoma Mountain. (a) Name. The name of the viticultural area described in this section is “Sonoma Mountain.” (b) Approved maps. The approved maps for determining the boundary of the Sonoma...

  4. 49 CFR 71.8 - Mountain zone.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Mountain zone. 71.8 Section 71.8 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part of the United States that is west of...

  5. Effects of diesel exhaust on the microbiota within a tuffaceous tunnel system

    SciTech Connect

    Haldeman, D.L.; Lagadinos, T.; Amy, P.S.; Hersman, L.; Meike, A.

    1996-08-01

    The abundance and distribution of microbiota that may be impacted by diesel and diesel exhaust were investigated from three depths into the walls and invert (floor) of U12n tunnel at Rainier Mesa, Nevada Test Site, a potential geological analog of Yucca Mountain. Enumerations included total cell counts, and numbers of aerobic heterotrophic, sulfate-reducing, nitrate-reducing, and diesel-degrading bacteria. Additionally, the disappearance of total petroleum hydrocarbons was determined in microcosms containing subsurface materials that were amended with diesel fuel. Results revealed that microbes capable of utilizing diesel and diesel combustion products were present in the subsurface in both the walls and the invert of the tunnel. The abundance of specific bacterial types in the tunnel invert, a perturbed environment, was greater than that observed in the tunnel wall. Few trends of microbial distribution either into the tunnel wall or the invert were noted with the exception of aerobic heterotrophic abundance which increased with depth into the wall and decreased with depth into the invert. No correlation between microbiota and a specific introduced chemical species have yet been determined. The potential for microbial contamination of the tunnel wall during sampling was determined to be negligible by the use of fluorescently labeled latex spheres (1{mu}m in dia.) as tracers. Results indicate that additional investigations might be needed to examine the microbiota and their possible impacts on the geology and geochemistry of the subsurface, both indigenous microbiota and those microorganisms that will likely be introduced by anthropogenic activity associated with the construction of a high-level waste repository.

  6. Seismic prediction ahead of tunnel constructions

    NASA Astrophysics Data System (ADS)

    Jetschny, S.; Bohlen, T.; Nil, D. D.; Giese, R.

    2007-12-01

    To increase safety and efficiency of tunnel constructions, online seismic exploration ahead of a tunnel can become a valuable tool. Within the \\it OnSite project founded by the BMBF (German Ministry of Education and Research) within \\it GeoTechnologien a new forward looking seismic imaging technique is developed to e.g. determine weak and water bearing zones ahead of the constructions. Our approach is based on the excitation and registration of \\it tunnel surface waves. These waves are excited at the tunnel face behind the cutter head of a tunnel boring machine and travel into drilling direction. Arriving at the front face they generate body waves (mainly S-waves) propagating further ahead. Reflected S-waves are back- converted into tunnel surface waves. For a theoretical description of the conversion process and for finding optimal acquisition geometries it is of importance to study the propagation characteristics of tunnel surface waves. 3D seismic finite difference modeling and analytic solutions of the wave equation in cylindric coordinates revealed that at higher frequencies, i.e. if the tunnel diameter is significantly larger than the wavelength of S-waves, these surface waves can be regarded as Rayleigh-waves circulating the tunnel. For smaller frequencies, i.e. when the S-wavelength approaches the tunnel diameter, the propagation characteristics of these surface waves are then similar to S- waves. Field measurements performed by the GeoForschungsZentrum Potsdam, Germany at the Gotthard Base Tunnel (Switzerland) show both effects, i.e. the propagation of Rayleigh- and body-wave like waves along the tunnel. To enhance our understanding of the excitation and propagation characteristics of tunnel surface waves the transition of Rayleigh to tube-waves waves is investigated both analytically and by numerical simulations.

  7. Tunneling decay of false vortices

    NASA Astrophysics Data System (ADS)

    Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han

    2013-10-01

    We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.

  8. Quiet Supersonic Wind Tunnel Development

    NASA Technical Reports Server (NTRS)

    King, Lyndell S.; Kutler, Paul (Technical Monitor)

    1994-01-01

    The ability to control the extent of laminar flow on swept wings at supersonic speeds may be a critical element in developing the enabling technology for a High Speed Civil Transport (HSCT). Laminar boundary layers are less resistive to forward flight than their turbulent counterparts, thus the farther downstream that transition from laminar to turbulent flow in the wing boundary layer is extended can be of significant economic impact. Due to the complex processes involved experimental studies of boundary layer stability and transition are needed, and these are performed in "quiet" wind tunnels capable of simulating the low-disturbance environment of free flight. At Ames, a wind tunnel has been built to operate at flow conditions which match those of the HSCT laminar flow flight demonstration 'aircraft, the F-16XL, i.e. at a Mach number of 1.6 and a Reynolds number range of 1 to 3 million per foot. This will allow detailed studies of the attachment line and crossflow on the leading edge area of the highly swept wing. Also, use of suction as a means of control of transition due to crossflow and attachment line instabilities can be studied. Topics covered include: test operating conditions required; design requirements to efficiently make use of the existing infrastructure; development of an injector drive system using a small pilot facility; plenum chamber design; use of computational tools for tunnel and model design; and early operational results.

  9. Water jet assisted tunnel boring

    SciTech Connect

    Ozdemir, L.

    1984-06-21

    Mechanical tunnel boring has experienced significant growth over the last two decades. Improved machine design and performance coupled with a better understanding of factors affecting boreability have contributed to a dramatic increase in the number of machine bored tunnels. Today, tunnel boring machines (TBMs) are finding widespread application in various sectors of underground construction industry, both civil and mining. Most of the hard rock formations considered unsuited to mechanical boring only a few years ago are now excavated with TBMs with favorable economics compared to conventional drill and blast methods. Despite the advancements accomplished, TBMs need further improvements in design and operation to exend their capabilities and to reduce excavation costs, particularly in hard, abrasive rocks. The design of TBMs has presently reached a state where no additional major breakthroughs are anticipated in the near future. The cutter material appears to be the major obstacle to achieving further performance improvements. The amount of load which the cutters can sustain with acceptable levels of wear is the limiting factor determining the magnitude of the power that can be placed on a TBM. In fact, most present day TBMs can generate more thrust and torque than the individual cutters are capable of supporting.

  10. The optimum hypersonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Trimmer, L. L.; Cary, A., Jr.; Voisinet, R. L. P.

    1986-01-01

    The capabilities of existing hypersonic wind tunnels in the U.S. are assessed to form a basis for recommendations for a new, costly facility which would provide data for modeling the hypervelocity aerodynamics envisioned for the new generation of aerospace vehicles now undergoing early studies. Attention is given to the regimes, both entry and aerodynamic, which the new vehicles will encounter, and the shortcomings of data generated for the Orbiter before flight are discussed. The features of foreign-gas, impulse, aeroballistic range, arc-heated and combustion-heated facilities are examined, noting that in any hypersonic wind tunnel the flow must be preheated to prevent liquefaction upon expansion in the test channel. The limitations of the existing facilities and the identification of the regimes which must be studied lead to a description of the characteristics of an optimum hypersonic wind tunnel, including the operations and productivity, the instrumentation, the nozzle design and the flow quality. Three different design approaches are described, each costing at least $100 million to achieve workability.

  11. Models for cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Lawing, Pierce L.

    1989-01-01

    Model requirements, types of model construction methods, and research in new ways to build models are discussed. The 0.3-m Transonic Cryogenic Tunnel was in operation for 16 years and many 2-D airfoil pressure models were tested. In addition there were airfoil models dedicated to transition detection techniques and other specialized research. There were also a number of small 3-D models tested. A chronological development in model building technique is described which led to the construction of many successful models. The difficulties of construction are illustrated by discussing several unsuccessful model fabrication attempts. The National Transonic Facility, a newer and much larger tunnel, was used to test a variety of models including a submarine, transport and fighter configurations, and the Shuttle Orbiter. A new method of building pressure models was developed and is described. The method is centered on the concept of bonding together plates with pressure channels etched into the bond planes, which provides high density pressure instrumentation with minimum demand on parent model material. With care in the choice of materials and technique, vacuum brazing can be used to produce strong bonds without blocking pressure channels and with no bonding voids between channels. Using multiple plates, a 5 percent wing with 96 orifices was constructed and tested in a transonic cryogenic wind tunnel. Samples of test data are presented and future applications of the technology are suggested.

  12. Confocal Annular Josephson Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto

    2016-04-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  13. Thermal radiation scanning tunnelling microscopy

    NASA Astrophysics Data System (ADS)

    de Wilde, Yannick; Formanek, Florian; Carminati, Rémi; Gralak, Boris; Lemoine, Paul-Arthur; Joulain, Karl; Mulet, Jean-Philippe; Chen, Yong; Greffet, Jean-Jacques

    2006-12-01

    In standard near-field scanning optical microscopy (NSOM), a subwavelength probe acts as an optical `stethoscope' to map the near field produced at the sample surface by external illumination. This technique has been applied using visible, infrared, terahertz and gigahertz radiation to illuminate the sample, providing a resolution well beyond the diffraction limit. NSOM is well suited to study surface waves such as surface plasmons or surface-phonon polaritons. Using an aperture NSOM with visible laser illumination, a near-field interference pattern around a corral structure has been observed, whose features were similar to the scanning tunnelling microscope image of the electronic waves in a quantum corral. Here we describe an infrared NSOM that operates without any external illumination: it is a near-field analogue of a night-vision camera, making use of the thermal infrared evanescent fields emitted by the surface, and behaves as an optical scanning tunnelling microscope. We therefore term this instrument a `thermal radiation scanning tunnelling microscope' (TRSTM). We show the first TRSTM images of thermally excited surface plasmons, and demonstrate spatial coherence effects in near-field thermal emission.

  14. Confocal Annular Josephson Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  15. Quantum Tunneling Affects Engine Performance.

    PubMed

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here. PMID:26283246

  16. Autonomous Robotic Inspection in Tunnels

    NASA Astrophysics Data System (ADS)

    Protopapadakis, E.; Stentoumis, C.; Doulamis, N.; Doulamis, A.; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-06-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel's lining, for a narrow region close to detected crack is performed; allowing for the deduction of potential deformations. The robotic platform consists of an autonomous mobile vehicle; a crane arm, guided by the computer vision-based crack detector, carrying ultrasound sensors, the stereo cameras and the laser scanner. Visual inspection is based on convolutional neural networks, which support the creation of high-level discriminative features for complex non-linear pattern classification. Then, real-time 3D information is accurately calculated and the crack position and orientation is passed to the robotic platform. The entire system has been evaluated in railway and road tunnels, i.e. in Egnatia Highway and London underground infrastructure.

  17. Porewater pressure control on subglacial soft sediment remobilization and tunnel valley formation: A case study from the Alnif tunnel valley (Morocco)

    NASA Astrophysics Data System (ADS)

    Ravier, Edouard; Buoncristiani, Jean-François; Guiraud, Michel; Menzies, John; Clerc, Sylvain; Goupy, Bastien; Portier, Eric

    2014-05-01

    In the eastern part of the Moroccan Anti-Atlas Mountains, the Alnif area exposes a buried Ordovician glacial tunnel valley (5 km wide, 180 m deep) cut into preglacial marine sediments. The preglacial sedimentary sequence, deposited in a marine environment, is characterized by a typical "layer-cake" configuration of permeable (sand) and impermeable (clays and early-cemented sandstones) layers. At the base of the tunnel valley, a discontinuous and fan-shaped glacial conglomeratic unit 10 to 15 m thick occurs, erosively deposited over preglacial marine sediments. The conglomeratic unit is composed of preglacial intraclasts embedded within a sandy matrix. Both preglacial and glacial sediments display soft-sediment deformation structures related to fluctuating porewater pressure and strain rates, including ball structures, clastic dykes, fluted surfaces, turbate structures, folds and radial extensional normal faults. Kinematics and relative chronology of these deformation structures allow the role of porewater pressure in the process of tunnel valley genesis on soft beds to be understood. The tunnel valley formed through multi-phased episodes of intense hydrofracturing of the preglacial bed due to overpressure development promoted by ice sheet growth over the study area, and configuration of the substratum. Transport of the resulting conglomerate composed of preglacial intraclasts and fluidized sand occurred through subglacial pipes. The brecciated material is deposited in subglacial cavities, forming fans of massive sandy conglomerate infilling the base of the tunnel valley. The conglomeratic unit is partially reworked by meltwater and exhibits intense soft-sediment deformations, due to episodes of ice-bed coupling and decoupling.

  18. Anatomy of a Mountain Range.

    ERIC Educational Resources Information Center

    Chew, Berkeley

    1993-01-01

    Provides written tour of Colorado Rockies along San Juan Skyway in which the geological features and formation of the mountain range is explored. Discusses evidence of geologic forces and products such as plate tectonic movement and the Ancestral Rockies; subduction and the Laramide Orogeny; volcanism and calderas; erosion, faulting, land…

  19. Lone Mountain processing boosts recovery

    SciTech Connect

    Baumgarth, T.; Bethell, P.; Gupta, B.K.

    2005-08-01

    A new deslime column flotation circuit installed at Arch Coal's Lone Mountain preparation plant in St. Charles, Va., USA recovers an additional 20 tph. The article describes how this column technology was selected. It explains the circuit design, start-up and post upgrade distant testing. 4 figs., 4 tabs.

  20. Artifical Mountains: A Synthetic Approach

    ERIC Educational Resources Information Center

    Sipiera, Paul P.; Aumann, John A.

    1974-01-01

    Describes a secondary science unit which uses an urban environment to develop a comparison between naturally formed mountains and man-constructed skyscrapers. The unit is one in a series of fifty laboratory activities designed to stimulate students of earth science by interrelating scientific principles and procedures to a familiar environment.…

  1. Gearing Up for Mountain Biking.

    ERIC Educational Resources Information Center

    Jahnke, Thomas; Hamson, Mike

    1999-01-01

    Examines the gear system of a mountain bike to discover any redundancy in the many gear settings available to the cyclist. Suggests a best strategy for changing up through the gears on a typical 21-gear system and an adjustment to the available gears that would result in a smoother change. (Author/ASK)

  2. The Mountaineer-Malaysia Connection.

    ERIC Educational Resources Information Center

    Young, Jeff

    1997-01-01

    A 26-day summer field course of West Virginia University's (WVU) Recreation and Parks Department took students to Malaysia's mountains and rainforests to observe how Malaysians are managing national parks, problem elephants, and population pressures on parks. The adventure provided powerful learning experiences. Further exchanges between WVU and…

  3. Products of an Artificially Induced Hydrothermal System at Yucca Mountain

    SciTech Connect

    S. Levy

    2000-08-07

    Studies of mineral deposition in the recent geologic past at Yucca Mountain, Nevada, address competing hypotheses of hydrothermal alteration and deposition from percolating groundwater. The secondary minerals being studied are calcite-opal deposits in fractures and lithophysal cavities of ash-flow tuffs exposed in the Exploratory Studies Facility (ESF), a 7.7-km tunnel excavated by the Yucca Mountain Site Characterization Project within Yucca Mountain. An underground field test in the ESF provided information about the minerals deposited by a short-lived artificial hydrothermal system and an opportunity for comparison of test products with the natural secondary minerals. The heating phase lasted nine months, followed by a nine-month cooling period. Natural pore fluids were the only source of water during the thermal test. Condensation and reflux of water driven away from the heater produced fluid flow in certain fractures and intersecting boreholes. The mineralogic products of the thermal test are calcite-gypsum aggregates of less than 4-micrometer crystals and amorphous silica as glassy scale less than 0.2 mm thick and as mounds of tubules with diameters less than 0.7 micrometers. The minute crystal sizes of calcite and gypsum from the field test are very different from the predominantly coarser calcite crystals (up to cm scale) in natural secondary-mineral deposits at the site. The complex micrometer-scale textures of the amorphous silica differ from the simple forms of opal spherules and coatings in the natural deposits, even though some natural spherules are as small as 1 micrometer. These differences suggest that the natural minerals, especially if they were of hydrothermal origin, may have developed coarser or simpler forms during subsequent episodes of dissolution and redeposition. The presence of gypsum among the test products and its absence from the natural secondary-mineral assemblage may indicate a higher degree of evaporation during the test than

  4. Transit time estimation of tunnel inflow in fractured granites

    NASA Astrophysics Data System (ADS)

    Balvín, A.; Hokr, M.; Šanda, M.; Vitvar, T.; Rálek, P.

    2012-04-01

    We study the water flow from surface to a tunnel in the average depth of 100 m to evaluate the water residence times in the fractured rock. Transport of 2H and 18O in groundwater was simulated by use of the lumped parameter approach. The area of interest is located in the Jizera Mountains near the Bedrichov municipality in the northern part of the Czech Republic. Input concentrations of 2H and 18O were measured at Uhlícská experimental catchment in a 5km distance from the tunnel. The output concentrations were measured in the water supply tunnel near Bedcichov. The tunnel is built in compact granite, it is 2600 m long and has a maximal depth of 150 m. The samples were taken from seven different groundwater seepage sites and from the channel collecting all inflow to the tunnel, in 14 days intervals in the period from February 2010 to present. The groundwater discharges were distinguished by their intensity - three dripping ones and four with continual fluxes. The residence times of the inflowing water were estimated with the dispersion model in the FLOWPC simulation program and cover the range of 2010-2011 years. In addition, we have made preliminary tests with "filtering" the infiltrated concentration data, e.g. assumption of larger ratio of winter infiltration, time shift between snowfall and snowmelt and use of soil water sampling instead of precipitation for the input. The best fit was achieved for spring V7 (for deuterium 2H: water residence time T = 23.6 months, apparent dispersion parameter Pd = 0.28 and Nash-Sutcliffe coefficient 80.3 % and for oxygen 18O: T = 30.9 months, Pd = 0.488 and N-S = 80.1 %, both for redistribution of rain), other fits were approximately 50-65 % (spring V6: T = 24.9 months, Pd = 0.26, N-S = 61.77 %; spring V1: T = 28.6 months, Pd = 0.24, N-S = 50.09 %, both for oxygen 18O). The discharge in the shallow part of the tunnel is probably supplied by flow on the soil-bedrock interface, with a quick reaction to precipitation and dry in

  5. RITD – Wind tunnel testing

    NASA Astrophysics Data System (ADS)

    Haukka, Harri; Harri, Ari-Matti; Aleksashkin, Sergei; Koryanov, Valeri; Schmidt, Walter; Heilimo, Jyri; Finchenko, Valeri; Martynov, Maxim; Ponomarenko, Andrey; Kazakovtsev, Victor; Arruego, Ignazio

    2015-04-01

    An atmospheric re-entry and descent and landing system (EDLS) concept based on inflatable hypersonic decelerator techniques is highly promising for the Earth re-entry missions. We developed such EDLS for the Earth re-entry utilizing a concept that was originally developed for Mars. This EU-funded project is called RITD - Re-entry: Inflatable Technology Development - and it was to assess the bene¬fits of this technology when deploying small payloads from low Earth orbits to the surface of the Earth with modest costs. The principal goal was to assess and develope a preliminary EDLS design for the entire relevant range of aerodynamic regimes expected to be encountered in Earth's atmosphere during entry, descent and landing. The RITD entry and descent system utilizes an inflatable hypersonic decelerator. Development of such system requires a combination of wind tunnel tests and numerical simulations. This included wind tunnel tests both in transsonic and subsonic regimes. The principal aim of the wind tunnel tests was the determination of the RITD damping factors in the Earth atmosphere and recalculation of the results for the case of the vehicle descent in the Mars atmosphere. The RITD mock-up model used in the tests was in scale of 1:15 of the real-size vehicle as the dimensions were (midsection) diameter of 74.2 mm and length of 42 mm. For wind tunnel testing purposes the frontal part of the mock-up model body was manufactured by using a PolyJet 3D printing technology based on the light curing of liquid resin. The tail part of the mock-up model body was manufactured of M1 grade copper. The structure of the mock-up model placed th center of gravity in the same position as that of the real-size RITD. The wind tunnel test program included the defining of the damping factor at seven values of Mach numbers 0.85; 0.95; 1.10; 1.20; 1.25; 1.30 and 1.55 with the angle of attack ranging from 0 degree to 40 degrees with the step of 5 degrees. The damping characteristics of

  6. Micromachined Tunneling Displacement Transducers for Physical Sensors

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Kaiser, W. J.; Podosek, J. A.; Rockstad, H. K.; Reynolds, J. K.; Vote, E. C.

    1993-01-01

    We have designed and constructed a series of tunneling sensors which take advantage of the extreme position sensitivity of electron tunneling. In these sensors, a tunneling displacement transducer, based on scanning tunneling microscopy principles, is used to detect the signal-induced motion of a sensor element. Through the use of high-resonant frequency mechanical elements for the transducer, sensors may be constructed which offer wide bandwidth, and are robust and easily operated. Silicon micromachining may be used to fabricate the transducer elements, allowing integration of sensor and control electronics. Examples of tunneling accelerometers and infrared detectors will be discussed. In each case, the use of the tunneling transducer allows miniaturization of the sensor as well as enhancement of the sensor performance.

  7. 1. West portal of Tunnel 26, contextual view to northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. West portal of Tunnel 26, contextual view to northeast from atop Tunnel 25 (HAER CA-201), with Tunnel 27 (HAER CA-203) visible in distance, 210mm lens. View is along new line, with original Central Pacific Transcontinental line crossing over the top above Tunnel 26. - Central Pacific Transcontinental Railroad, Tunnel No. 26, Milepost 133.29, Applegate, Placer County, CA

  8. West portal of Tunnel No. 1292, Indigo Tunnel, milepost 129.95, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West portal of Tunnel No. 1292, Indigo Tunnel, milepost 129.95, looking northeast. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  9. Low-Frequency Electromagnetic Backscattering from Tunnels

    SciTech Connect

    Casey, K; Pao, H

    2007-01-16

    Low-frequency electromagnetic scattering from one or more tunnels in a lossy dielectric half-space is considered. The tunnel radii are assumed small compared to the wavelength of the electromagnetic field in the surrounding medium; a tunnel can thus be modeled as a thin scatterer, described by an equivalent impedance per unit length. We examine the normalized backscattering width for cases in which the air-ground interface is either smooth or rough.

  10. Wind-Tunnel/Flight Correlation, 1981

    NASA Technical Reports Server (NTRS)

    Mckinney, L. W. (Editor); Baals, D. D. (Editor)

    1982-01-01

    Wind-tunnel/flight correlation activities are reviewed to assure maximum effectiveness of the early experimental programs of the National Transonic Facility (NTF). Topics included a status report of the NTF, the role of tunnel-to-tunnel correlation, a review of past flight correlation research and the resulting data base, the correlation potential of future flight vehicles, and an assessment of the role of computational fluid dynamics.

  11. Homoepitaxial graphene tunnel barriers for spin transport

    NASA Astrophysics Data System (ADS)

    Friedman, Adam

    Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions (magnetic field, temperature, etc.) usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. We demonstrate successful tunneling, charge, and spin transport with a fluorinated graphene tunnel barrier on a graphene channel. We show that while spin transport stops short of room temperature, spin polarization efficiency values are the highest of any graphene spin devices. We also demonstrate that hydrogenation of graphene can also be used to create a tunnel barrier. We begin with a four-layer stack of graphene and hydrogenate the top few layers to decouple them from the graphene transport channel beneath. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures and determine spin lifetimes with the non-local Hanle effect to be commensurate with previous studies. The measured spin polarization efficiencies for hydrogenated graphene are higher than most oxide tunnel barriers on graphene, but not as high as with fluorinated graphene tunnel barriers. However, here we show that spin transport persists up to room temperature. Our results for the hydrogenated graphene tunnel barriers are compared with fluorinated tunnel barriers and we discuss the

  12. Tunneling Ionization Time Resolved by Backpropagation

    NASA Astrophysics Data System (ADS)

    Ni, Hongcheng; Saalmann, Ulf; Rost, Jan-Michael

    2016-07-01

    We determine the ionization time in tunneling ionization by an elliptically polarized light pulse relative to its maximum. This is achieved by a full quantum propagation of the electron wave function forward in time, followed by a classical backpropagation to identify tunneling parameters, in particular, the fraction of electrons that has tunneled out. We find that the ionization time is close to zero for single active electrons in helium and in hydrogen if the fraction of tunneled electrons is large. We expect our analysis to be essential to quantify ionization times for correlated electron motion.

  13. Tunneling Ionization Time Resolved by Backpropagation.

    PubMed

    Ni, Hongcheng; Saalmann, Ulf; Rost, Jan-Michael

    2016-07-01

    We determine the ionization time in tunneling ionization by an elliptically polarized light pulse relative to its maximum. This is achieved by a full quantum propagation of the electron wave function forward in time, followed by a classical backpropagation to identify tunneling parameters, in particular, the fraction of electrons that has tunneled out. We find that the ionization time is close to zero for single active electrons in helium and in hydrogen if the fraction of tunneled electrons is large. We expect our analysis to be essential to quantify ionization times for correlated electron motion. PMID:27447504

  14. Electronic tunneling currents at optical frequencies

    NASA Technical Reports Server (NTRS)

    Faris, S. M.; Fan, B.; Gustafson, T. K.

    1975-01-01

    Rectification characteristics of nonsuperconducting metal-barrier-metal junctions as deduced from electronic tunneling theory have been observed experimentally for optical frequency irradiation of the junction.

  15. Palladium electrodes for molecular tunnel junctions.

    PubMed

    Chang, Shuai; Sen, Suman; Zhang, Peiming; Gyarfas, Brett; Ashcroft, Brian; Lefkowitz, Steven; Peng, Hongbo; Lindsay, Stuart

    2012-10-26

    Gold has been the metal of choice for research on molecular tunneling junctions, but it is incompatible with complementary metal-oxide-semiconductor fabrication because it forms deep level traps in silicon. Palladium electrodes do not contaminate silicon, and also give higher tunnel current signals in the molecular tunnel junctions that we have studied. The result is cleaner signals in a recognition-tunneling junction that recognizes the four natural DNA bases as well as 5-methyl cytosine, with no spurious background signals. More than 75% of all the recorded signal peaks indicate the base correctly. PMID:23037952

  16. Reducing Airborne Debris In Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Sleeper, Robert K.

    1993-01-01

    In proposed technique to trap airborne particles during normal wind-tunnel testing, large sections of single-backed adhesive paper or cloth mounted with adhesive side exposed to flow. Adhesive material securely installed on flow vanes, walls, or other surfaces of wind tunnel in manner facilitating replacement. Installed or replaced anytime permissible to enter tunnel. Provides safe, inexpensive, rugged, passive, continuous, and otherwise inert cleansing action suitable for wind tunnel of any size. Also applied to specialized clean-room environments and to air-conditioning systems in general.

  17. Observation of density-induced tunneling.

    PubMed

    Jürgensen, Ole; Meinert, Florian; Mark, Manfred J; Nägerl, Hanns-Christoph; Lühmann, Dirk-Sören

    2014-11-01

    We study the dynamics of bosonic atoms in a tilted one-dimensional optical lattice and report on the first direct observation of density-induced tunneling. We show that the interaction affects the time evolution of the doublon oscillation via density-induced tunneling and pinpoint its density and interaction dependence. The experimental data for different lattice depths are in good agreement with our theoretical model. Furthermore, resonances caused by second-order tunneling processes are studied, where the density-induced tunneling breaks the symmetric behavior for attractive and repulsive interactions predicted by the Hubbard model. PMID:25415904

  18. PUREX Storage Tunnels dangerous waste permit application

    SciTech Connect

    Not Available

    1991-12-01

    The PUREX Storage Tunnels are a mixed waste storage unit consisting of two underground railroad tunnels: Tunnel Number 1 designated 218-E-14 and Tunnel Number 2 designated 218-E-15. The two tunnels are connected by rail to the PUREX Plant and combine to provide storage space for 48 railroad cars (railcars). The PUREX Storage Tunnels provide a long-term storage location for equipment removed from the PUREX Plant. Transfers into the PUREX Storage Tunnels are made on an as-needed basis. Radioactively contaminated equipment is loaded on railcars and remotely transferred by rail into the PUREX Storage Tunnels. Railcars act as both a transport means and a storage platform for equipment placed into the tunnels. This report consists of part A and part B. Part A reports on amounts and locations of the mixed water. Part B permit application consists of the following: Facility Description and General Provisions; Waste Characteristics; Process Information; Groundwater Monitoring; Procedures to Prevent Hazards; Contingency Plan; Personnel Training; Exposure Information Report.

  19. Tunneling ionization time-resolved by backpropagation

    NASA Astrophysics Data System (ADS)

    Ni, Hongcheng; Saalmann, Ulf; Rost, Jan M.; Max-Planck-Institut für Physik komplexer Systeme Team

    2016-05-01

    We determine the ionization time in tunneling ionization by an elliptically polarized light pulse relative to its maximum. This is achieved by a full quantum propagation of the electron wave function forward in time, followed by a classical backpropagation to identify tunneling parameters, in particular the fraction of electrons that has tunneled out. We find, that the ionization time is close to zero for single active electrons in helium and in hydrogen if the fraction of tunneled electrons is large. We expect our analysis to be essential to quantify ionization times for correlated electron motion. This work was supported by Alexander von Humboldt Foundation.

  20. Is carpal tunnel decompression warranted for HNPP?

    PubMed

    Earle, Nicholas; Zochodne, Douglas W

    2013-12-01

    The role of carpal tunnel decompression surgery for patients that have hereditary neuropathy with liability to pressure palsy (HNPP) is currently unknown. Since recovery from carpal tunnel compression is often associated with remyelination or nodal reconstruction rather than axonal regeneration, it is uncertain whether the PMP22 deletion associated with HNPP interrupts myelin or nodal reconstitution. We describe two patients with genetically confirmed HNPP and symptomatic carpal tunnel syndrome that had clinical and electrophysiological improvement after surgical decompression. The findings indicate a capacity for conduction repair in HNPP. They also suggest a need for further investigation and discussion around whether to offer carpal tunnel decompression to symptomatic HNPP patients. PMID:24171697

  1. Sourcebook of locations of geophysical surveys in tunnels and horizontal holes, including results of seismic refraction surveys, Rainier Mesa, Aqueduct Mesa, and Area 16, Nevada Test Site

    USGS Publications Warehouse

    Carroll, R.D.; Kibler, J.E.

    1983-01-01

    Seismic refraction surveys have been obtained sporadically in tunnels in zeolitized tuff at the Nevada Test Site since the late 1950's. Commencing in 1967 and continuing to date (1982), .extensive measurements of shear- and compressional-wave velocities have been made in five tunnel complexes in Rainier and Aqueduct Mesas and in one tunnel complex in Shoshone Mountain. The results of these surveys to 1980 are compiled in this report. In addition, extensive horizontal drilling was initiated in 1967 in connection with geologic exploration in these tunnel complexes for sites for nuclear weapons tests. Seismic and electrical surveys were conducted in the majority of these holes. The type and location of these tunnel and borehole surveys are indexed in this report. Synthesis of the seismic refraction data indicates a mean compressional-wave velocity near the nuclear device point (WP) of 23 tunnel events of 2,430 m/s (7,970 f/s) with a range of 1,846-2,753 m/s (6,060-9,030 f/s). The mean shear-wave velocity of 17 tunnel events is 1,276 m/s (4,190 f/s) with a range of 1,140-1,392 m/s (3,740-4,570 f/s). Experience indicates that these velocity variations are due chiefly to the extent of fracturing and (or) the presence of partially saturated rock in the region of the survey.

  2. Best Practices Case Study: Pine Mountain Builders - Pine Mountain, GA

    SciTech Connect

    2011-09-01

    Case study of Pine Mountain Builders who worked with DOE’s IBACOS team to achieve HERS scores of 59 on 140 homes built around a wetlands in Georgia. The team used taped rigid foam exterior sheathing and spray foam insulation in the walls and on the underside of the attic for a very tight 1.0 to 1.8 ACH 50 building shell.

  3. Multiscale Thermohydrologic Model Supporting the Licence Application for the Yucca Mountain Repository

    SciTech Connect

    T.A> Buscheck; Y. Sun; Y. Hao

    2006-03-28

    The MultiScale ThermoHydrologic Model (MSTHM) predicts thermal-hydrologic (TH) conditions within emplacement tunnels (drifts) and in the adjoining host rock at Yucca Mountain, Nevada, which is the proposed site for a radioactive waste repository in the US. Because these predictions are used in the performance assessment of the Yucca Mountain repository, they must address the influence of variability and uncertainty of the engineered- and natural-system parameters that significantly influence those predictions. Parameter-sensitivity studies show that the MSTHM predictions adequately propagate the influence of parametric variability and uncertainty. Model-validation studies show that the influence of conceptual-model uncertainty on the MSTHM predictions is insignificant compared to that of parametric uncertainty, which is propagated through the MSTHM.

  4. Multiscale Thermohydrologic Model Supporting the License Application for the Yucca Mountain Repository

    SciTech Connect

    Buscheck, T A; Sun, Y; Hao, Y

    2006-01-31

    The MultiScale ThermoHydrologic Model (MSTHM) predicts thermal-hydrologic (TH) conditions within emplacement tunnels (drifts) and in the adjoining host rock at Yucca Mountain, Nevada, which is the proposed site for a radioactive waste repository in the U.S. Because these predictions are used in the performance assessment of the Yucca Mountain repository, they must address the influence of variability and uncertainty of the engineered- and natural-system parameters that significantly influence those predictions. Parameter-sensitivity studies show that the MSTHM predictions adequately propagate the influence of parametric variability and uncertainty. Model-validation studies show that the influence of conceptual-model uncertainty on the MSTHM predictions is insignificant compared to that of parametric uncertainty, which is propagated through the MSTHM.

  5. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of Full-Scale Tunnel (FST). In November 1929, Smith DeFrance submitted his recommendations for the general design of the Full Scale Wind Tunnel. The last on his list concerned the division of labor required to build this unusual facility. He believed the job had five parts and described them as follows: 'It is proposed that invitations be sent out for bids on five groups of items. The first would be for one contract on the complete structure; second the same as first, including the erection of the cones but not the fabrication, since this would be more of a shipyard job; third would cover structural steel, cover, sash and doors, but not cones or foundation; fourth, foundations; an fifth, fabrication of cones.' DeFrance's memorandum prompted the NACA to solicit estimates from a large number of companies. Preliminary designs and estimates were prepared and submitted to the Bureau of the Budget and Congress appropriated funds on February 20, 1929. The main construction contract with the J.A. Jones Company of Charlotte, North Carolina was signed one year later on February 12, 1930. It was a peculiar structure as the building's steel framework is visible on the outside of the building. DeFrance described this in NACA TR No. 459: 'The entire equipment is housed in a structure, the outside walls of which serve as the outer walls of the return passages. The over-all length of the tunnel is 434 feet 6 inches, the width 222 feet, and the maximum height 97 feet. The framework is of structural steel....' (pp. 292-293).

  6. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of Full-Scale Tunnel (FST): 120-Foot Truss hoisting, one and two point suspension. In November 1929, Smith DeFrance submitted his recommendations for the general design of the Full Scale Wind Tunnel. The last on his list concerned the division of labor required to build this unusual facility. He believed the job had five parts and described them as follows: 'It is proposed that invitations be sent out for bids on five groups of items. The first would be for one contract on the complete structure; second the same as first, including the erection of the cones but not the fabrication, since this would be more of a shipyard job; third would cover structural steel, cover, sash and doors, but not cones or foundation; fourth, foundations; and fifth, fabrication of cones.' DeFrance's memorandum prompted the NACA to solicit estimates from a large number of companies. Preliminary designs and estimates were prepared and submitted to the Bureau of the Budget and Congress appropriated funds on February 20, 1929. The main construction contract with the J.A. Jones Company of Charlotte, North Carolina was signed one year later on February 12, 1930. It was a peculiar structure as the building's steel framework is visible on the outside of the building. DeFrance described this in NACA TR No. 459: 'The entire equipment is housed in a structure, the outside walls of which serve as the outer walls of the return passages. The over-all length of the tunnel is 434 feet 6 inches, the width 222 feet, and the maximum height 97 feet. The framework is of structural steel....' (pp. 292-293)

  7. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.

    2016-01-01

    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

  8. Giant electrode effect on tunnelling electroresistance in ferroelectric tunnel junctions.

    PubMed

    Soni, Rohit; Petraru, Adrian; Meuffels, Paul; Vavra, Ondrej; Ziegler, Martin; Kim, Seong Keun; Jeong, Doo Seok; Pertsev, Nikolay A; Kohlstedt, Hermann

    2014-01-01

    Among recently discovered ferroelectricity-related phenomena, the tunnelling electroresistance (TER) effect in ferroelectric tunnel junctions (FTJs) has been attracting rapidly increasing attention owing to the emerging possibilities of non-volatile memory, logic and neuromorphic computing applications of these quantum nanostructures. Despite recent advances in experimental and theoretical studies of FTJs, many questions concerning their electrical behaviour still remain open. In particular, the role of ferroelectric/electrode interfaces and the separation of the ferroelectric-driven TER effect from electrochemical ('redox'-based) resistance-switching effects have to be clarified. Here we report the results of a comprehensive study of epitaxial junctions comprising BaTiO(3) barrier, La(0.7)Sr(0.3)MnO(3) bottom electrode and Au or Cu top electrodes. Our results demonstrate a giant electrode effect on the TER of these asymmetric FTJs. The revealed phenomena are attributed to the microscopic interfacial effect of ferroelectric origin, which is supported by the observation of redox-based resistance switching at much higher voltages. PMID:25399545

  9. Some deep caves in Biokovo Mountain (Croatia)

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Garasic, Davor

    2014-05-01

    The investigation of 3 caves explored more than 1000 meters in depth in the Dinaric karst area in Croatia, has been in progress for a considerable period of time. These are complex speleological features situated in the longest mountain range of the Dinaric karst, i.e. at the Northern Velebit mountain range. In fact, these caves have been studied for over two decades now. The first one is a cave system of Lukina jama (Luke's Cave) - Trojama cave, which has been investigated until the depth of 1421 meters (Jalžić, 2007; Šmida, 1993). Its total length is 3731 meters and a new expedition will soon continue to investigate this pit through speleodiving in siphons. The second greatest cave by depth is Slovačka jama (Slovak Cave), 1320 meters in depth, with cave chanals measuring 5677 meters in total length. The third greatest cave by depth is the Cave system of Velebita, reaching down to 1026 m in depth, with the chanal length of 3176 meters (Bakšić, 2006a; 2006b). However, another 3 speleological sites, which can rightly be added to those deeper than 1000 m, have recently been discovered. These are three caverns that were discovered during construction of the Sveti Ilija Tunnel that passes through Mt. Biokovo, in the Dinaric karst area. These caverns undoubtedly point to the link with the ground surface, while the rock overburden above the tunnel in the zone where the caverns were discovered ranges from 1250 and 1350 meters. Bats from the ground surface were found in the caverns and, according to measurements, they are situated in the depth from 200 and 300 meters below the tunnel level. This would mean that the depth of these newly found caves ranges from 1450 and 1650 m, when observed from the ground surface. There are several hundreds of known caves in Biokovo, and the deepest ones discovered so far are Jama Mokre noge (Wet Feet Cave) 831 m in depth, and Jama Amfora (Amphora Cave) 788 m in depth (Bockovac, 1999; Bakšić & all, 2002; Lacković & all, 2001

  10. 1. West portal of Tunnel 17, contextual view to northeast, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. West portal of Tunnel 17, contextual view to northeast, 135mm lens. The tunnel penetrates the toe of Dorris Hill, which rises to the left. - Southern Pacific Railroad Natron Cutoff, Tunnel No. 17, Milepost 408, Dorris, Siskiyou County, CA

  11. Help Students Tunnel Their Way to Math and Writing Skills.

    ERIC Educational Resources Information Center

    MacMath, Russ

    1987-01-01

    A teacher describes how a cardboard box tunnel was used to capitalize on children's fascination with boxes. The finished tunnel offers opportunities for honing math and writing skills. Layouts for tunnels and related activities are suggested. (MT)

  12. 6. VIEW OF TUNNEL OPENING AT CAMDEN STATION (SOUTH END) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF TUNNEL OPENING AT CAMDEN STATION (SOUTH END) LOOKING OUT FROM A COUPLE OF HUNDRED FEET INSIDE TUNNEL. - Baltimore & Ohio Railroad, Howard Street Tunnel, 1300 Mount Royal Avenue, Baltimore, Independent City, MD

  13. 340. Caltrans, Photographer October 14, 1935 "TUNNEL WEST PORTAL"; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    340. Caltrans, Photographer October 14, 1935 "TUNNEL - WEST PORTAL"; VIEW OF TUNNEL - WEST PORTAL' UNDER CONSTRUCTION SHOWING EXCAVATION OF TUNNEL AFTER POUR. 5-1669 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  14. 1. West portal of Tunnel 22, contextual view to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. West portal of Tunnel 22, contextual view to the northwest, 135mm lens. Tunnel 22 pierces a ridge separating Oakridge from Westfir. - Southern Pacific Railroad Natron Cutoff, Tunnel 22, Milepost 581.85, Oakridge, Lane County, OR

  15. View of Irving Flume Tunnel #1 showing the steel flume ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Irving Flume Tunnel #1 showing the steel flume with trestles leading into concrete tunnel. Looking south - Childs-Irving Hydroelectric Project, Irving System, Flume Tunnel No. 1, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  16. 1. West portal of Tunnel 25, contextual view to northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. West portal of Tunnel 25, contextual view to northeast from Tunnel 24 (HAER CA-200), 135mm lens. - Central Pacific Transcontinental Railroad, Tunnel No. 25, Milepost 133.09, Applegate, Placer County, CA

  17. 4. East portal of Tunnel 25, view to southwest from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. East portal of Tunnel 25, view to southwest from west end of Tunnel 26 (HAER CA-202), 135mm lens. - Central Pacific Transcontinental Railroad, Tunnel No. 25, Milepost 133.09, Applegate, Placer County, CA

  18. NORTHERN END OF VIADUCT WHERE IT ENTERS BATTERY STREET TUNNEL. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTHERN END OF VIADUCT WHERE IT ENTERS BATTERY STREET TUNNEL. LAKE UNION VISIBLE IN BACKGROUND. TUNNEL PROCEEDS IN CUT AND COVER FASHION DIRECTLY BENEATH BATTERY STREET. - Alaskan Way Viaduct and Battery Street Tunnel, Seattle, King County, WA

  19. Simple estimation of minimum unsaturated contaminant travel times at Rainier Mesa and Shoshone Mountain, Nevada Test Site

    NASA Astrophysics Data System (ADS)

    Ebel, B. A.; Nimmo, J. R.

    2008-12-01

    In the unsaturated zone the fastest travel times frequently occur via preferential flow that bypasses the soil/rock matrix. Experimental data provide compelling evidence that minimum solute travel times through preferential paths depend primarily on whether water supply is continuous versus non-continuous in time, with little influence from matrix hydraulic properties. We employ a simple model based on this "source- responsive" paradigm to estimate minimum preferential travel times to the regional water table for nonreactive radionuclides at Rainier Mesa and Shoshone Mountain within the Nevada Test Site. The radionuclides at the site originate from underground nuclear testing within a ~1-km-thick unsaturated zone. Contaminated sources at Rainier Mesa and Shoshone Mountain that are continuously supplied include ponded water in certain tunnels, filled detention basins, and partially-filled boreholes with detonation cavities. Tunnels without ponding and unfilled detonation cavities are considered non-continuous sources supplied by percolation of precipitation. Decades of geological and hydrological characterizations provide the foundation for establishing preferential flow as a viable transport mechanism at Rainier Mesa and Shoshone Mountain Our estimated minimum travel times via preferential flow for Rainier Mesa are one to two months for a continuously-supplied source and tens to hundreds of years for a non-continuous source. Previous studies in the scientific literature conducted isotopic analysis of fracture water collected in tunnels at Rainier Mesa that indicated transit times for 400 m of transport from land surface to tunnel levels of one to 40 years. Four monitoring wells in the carbonate aquifer have not detected radionuclide levels above the drinking water standards at Rainier Mesa. Travel times for both the continuously and non-continuously supplied sources at Shoshone Mountain are twice the Rainier Mesa estimates, resulting from longer transport distances

  20. Davies Critical Point and Tunneling

    NASA Astrophysics Data System (ADS)

    La, Hoseong

    2012-04-01

    From the point of view of tunneling, the physical meaning of the Davies critical point of a second-order phase transition in the black hole thermodynamics is clarified. At the critical point, the nonthermal contribution vanishes so that the black hole radiation is entirely thermal. It separates two phases: one with radiation enhanced by the nonthermal contribution, the other suppressed by the nonthermal contribution. We show this in both charged and rotating black holes. The phase transition is also analyzed in the cases in which emissions of charges and angular momenta are incorporated.

  1. Tunneling without barriers with gravity

    NASA Astrophysics Data System (ADS)

    Kanno, Sugumi; Sasaki, Misao; Soda, Jiro

    2012-04-01

    We consider the vacuum decay of the flat Minkowski space to an anti-de Sitter space. We find a one-parameter family of potentials that allow exact, analytical instanton solutions describing tunneling without barriers in the presence of gravity. In the absence of gravity, such instantons were found by Linde and rediscovered and discussed by Lee and Weinberg more than a quarter of a century ago. The bounce action is also analytically computed. We discuss possible implications of these new instantons to cosmology in the context of the string theory landscape.

  2. Comment on ``Quantum tunneling time''

    NASA Astrophysics Data System (ADS)

    Hahne, G. E.

    2005-02-01

    In this Comment on the paper by Wanget al., Phys. Rev. A692004052108], it is pointed out that (i) a group-theoretical argument advanced in the first part of their derivation is both flawed and not needed in what follows, (ii) they then assert a formula that leads to a physically incorrect phase (as distinguished from group) delay time in the motion of a free particle, and (iii) their subsequent derivation contains a mathematical error, such that the outcome is a new formula for the tunneling time that avoids the second problem, but such that the result is unfounded and is therefore of unknown physical content.

  3. Tunneling spectroscopy of anisotropic superconductors

    SciTech Connect

    Kashiwaya, Satoshi; Koyanagi, Masao; Kajimura, Koji; Tanaka, Yukio

    1996-12-31

    Tunneling spectroscopy of normal-insulator-superconductor junction is investigated theoretically. In anisotropic superconductors, differently from the case of isotropic superconductor, the effective pair potentials felt by quasiparticles depend on the direction of their motion. By taking this effect into account, it is shown that the conductance spectra strongly depend on the crystal orientation. Using Green`s function method, local density of states (LDOS) in superconductor is also calculated. The close relation between conductance spectra and LDOS is presented. The calculation is compared with experimental spectra of high-{Tc} superconductors.

  4. Quantum tunneling beyond semiclassical approximation

    NASA Astrophysics Data System (ADS)

    Banerjee, Rabin; Ranjan Majhi, Bibhas

    2008-06-01

    Hawking radiation as tunneling by Hamilton-Jacobi method beyond semiclassical approximation is analysed. We compute all quantum corrections in the single particle action revealing that these are proportional to the usual semiclassical contribution. We show that a simple choice of the proportionality constants reproduces the one loop back reaction effect in the spacetime, found by conformal field theory methods, which modifies the Hawking temperature of the black hole. Using the law of black hole mechanics we give the corrections to the Bekenstein-Hawking area law following from the modified Hawking temperature. Some examples are explicitly worked out.

  5. Fermion tunneling beyond semiclassical approximation

    NASA Astrophysics Data System (ADS)

    Majhi, Bibhas Ranjan

    2009-02-01

    Applying the Hamilton-Jacobi method beyond the semiclassical approximation prescribed in R. Banerjee and B. R. Majhi, J. High Energy Phys.JHEPFG1029-8479 06 (2008) 09510.1088/1126-6708/2008/06/095 for the scalar particle, Hawking radiation as tunneling of the Dirac particle through an event horizon is analyzed. We show that, as before, all quantum corrections in the single particle action are proportional to the usual semiclassical contribution. We also compute the modifications to the Hawking temperature and Bekenstein-Hawking entropy for the Schwarzschild black hole. Finally, the coefficient of the logarithmic correction to entropy is shown to be related with the trace anomaly.

  6. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1929-01-01

    Modified propeller and spinner in Full-Scale Tunnel (FST) model. On June 26, 1929, Elton W. Miller wrote to George W. Lewis proposing the construction of a model of the full-scale tunnel. 'The excellent energy ratio obtained in the new wind tunnel of the California Institute of Technology suggests that before proceeding with our full scale tunnel design, we ought to investigate the effect on energy ratio of such factors as: 1. small included angle for the exit cone; 2. carefully designed return passages of circular section as far as possible, without sudden changes in cross sections; 3. tightness of walls. It is believed that much useful information can be obtained by building a model of about 1/16 scale, that is, having a closed throat of 2 ft. by 4 ft. The outside dimensions would be about 12 ft. by 25 ft. in plan and the height 4 ft. Two propellers will be required about 28 in. in diameter, each to be driven by direct current motor at a maximum speed of 4500 R.P.M. Provision can be made for altering the length of certain portions, particularly the exit cone, and possibly for the application of boundary layer control in order to effect satisfactory air flow. This model can be constructed in a comparatively short time, using 2 by 4 framing with matched sheathing inside, and where circular sections are desired they can be obtained by nailing sheet metal to wooden ribs, which can be cut on the band saw. It is estimated that three months will be required for the construction and testing of such a model and that the cost will be approximately three thousand dollars, one thousand dollars of which will be for the motors. No suitable location appears to exist in any of our present buildings, and it may be necessary to build it outside and cover it with a roof.' George Lewis responded immediately (June 27) granting the authority to proceed. He urged Langley to expedite construction and to employ extra carpenters if necessary. Funds for the model came from the FST project

  7. Quantum temporal probabilities in tunneling systems

    SciTech Connect

    Anastopoulos, Charis Savvidou, Ntina

    2013-09-15

    We study the temporal aspects of quantum tunneling as manifested in time-of-arrival experiments in which the detected particle tunnels through a potential barrier. In particular, we present a general method for constructing temporal probabilities in tunneling systems that (i) defines ‘classical’ time observables for quantum systems and (ii) applies to relativistic particles interacting through quantum fields. We show that the relevant probabilities are defined in terms of specific correlation functions of the quantum field associated with tunneling particles. We construct a probability distribution with respect to the time of particle detection that contains all information about the temporal aspects of the tunneling process. In specific cases, this probability distribution leads to the definition of a delay time that, for parity-symmetric potentials, reduces to the phase time of Bohm and Wigner. We apply our results to piecewise constant potentials, by deriving the appropriate junction conditions on the points of discontinuity. For the double square potential, in particular, we demonstrate the existence of (at least) two physically relevant time parameters, the delay time and a decay rate that describes the escape of particles trapped in the inter-barrier region. Finally, we propose a resolution to the paradox of apparent superluminal velocities for tunneling particles. We demonstrate that the idea of faster-than-light speeds in tunneling follows from an inadmissible use of classical reasoning in the description of quantum systems. -- Highlights: •Present a general methodology for deriving temporal probabilities in tunneling systems. •Treatment applies to relativistic particles interacting through quantum fields. •Derive a new expression for tunneling time. •Identify new time parameters relevant to tunneling. •Propose a resolution of the superluminality paradox in tunneling.

  8. Stress changes ahead of an advancing tunnel

    USGS Publications Warehouse

    Abel, J.F.; Lee, F.T.

    1973-01-01

    Instrumentation placed ahead of three model tunnels in the laboratory and ahead of a crosscut driven in a metamorphic rock mass detected stress changes several tunnel diameters ahead of the tunnel face. Stress changes were detected 4 diameters ahead of a model tunnel drilled into nearly elastic acrylic, 2??50 diameters ahead of a model tunnel drilled into concrete, and 2 diameters ahead of a model tunnel drilled into Silver Plume Granite. Stress changes were detected 7??50 diameters ahead of a crosscut driven in jointed, closely foliated gneisses and gneissic granites in an experimental mine at Idaho Springs, Colorado. These results contrast markedly with a theoretical elastic estimate of the onset of detectable stress changes at 1 tunnel diameter ahead of the tunnel face. A small compressive stress concentration was detected 2 diameters ahead of the model tunnel in acrylic, 1.25 diameters ahead of the model tunnel in concrete, and 1 diameter ahead of the model tunnel in granite. A similar stress peak was detected about 6 diameters ahead of the crosscut. No such stress peak is predicted from elastic theory. The 3-dimensional in situ stress determined in the field demonstrate that geologic structure controls stress orientations in the metamorphic rock mass. Two of the computed principal stresses are parallel to the foliation and the other principal stress is normal to it. The principal stress orientations vary approximately as the foliation attitude varies. The average horizontal stress components and the average vertical stress component are three times and twice as large, respectively, as those predicted from the overburden load. An understanding of the measured stress field appears to require the application of either tectonic or residual stress components, or both. Laboratory studies indicate the presence of proportionately large residual stresses. Mining may have triggered the release of strain energy, which is controlled by geologic structure. ?? 1973.

  9. Microbial activity at Yucca Mountain

    SciTech Connect

    Horn, J.M.; Meike, A.

    1995-09-25

    The U.S. Department of Energy is engaged in a suitability study for a potential geological repository at Yucca Mountain, Nevada, for the containment and storage of commercially generated spent fuel and defense high-level nuclear waste. There is growing recognition of the role that biotic factors could play in this repository, either directly through microbially induced corrosion (MIC), or indirectly by altering the chemical environment or contributing to the transport of radionuclides. As a first step toward describing and predicting these processes, a workshop was held on April 10-12, 1995, in Lafayette, California. The immediate aims of the workshop were: (1) To identify microbially related processes relevant to the design of a radioactive waste repository under conditions similar to those at Yucca Mountain. (2) To determine parameters that are critical to the evaluation of a disturbed subterranean environment. (3) To define the most effective means of investigating the factors thus identified.

  10. Recompression therapy of mountain sickness.

    PubMed

    Marković, Dubravko; Kovacević, Hasan

    2002-03-01

    This paper describes the treatment of a severe case of acute mountain sickness with a portable hyperbaric chamber. A 37-year old climber was treated for acute high altitude pulmonary oedema, which developed on the North Col of Mount Everest, at an altitude of 7,060 m. The treatment in the portable Gamow bag hyperbaric chamber lasted two hours, with a bag pressure of 103 mm Hg (0.136 kg/cm2 or 2 psig) using ambient air, without the addition of oxygen. With this pressure increase, the hyperbaric chamber lowered the patient's effective ambient altitude from 6,050 to 4,400 m. The treatment was successful and the pulmonary oedema disappeared. Outside the hyperbaric chamber, the patient recovered fully when he reached the altitude of 2,000 m. Portable hyperbaric chamber is recommended for the treatment of severe cases of acute mountain sickness, as well as for risky descent to lower altitudes. PMID:12150075

  11. Anti-Atlas Mountains, Morocco

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Anti-Atlas Mountains of northern Africa and the nearby Atlas mountains were created by the prolonged collision of the African and Eurasian tectonic plates, beginning about 80 million years ago. Massive sandstone and limestone layers have been crumpled and uplifted more than 4,000 meters in the High Atlas and to lower elevations in the Anti-Atlas. Between more continuous major fold structures, such as the Jbel Ouarkziz in the southwestern Anti-Atlas, tighter secondary folds (arrow) have developed. Earlier, the supercontinent of Pangea rifted apart to form precursors to the Mediterranean and the Atlantic Ocean (Beauchamp and others, 1996). In those seas sands, clays, limey sediments, and evaporite layers (gypsum, rock salt) were deposited. Later, during the mountain-building plate collision, the gypsum layers flowed under the pressure and provided a slippery surface on which overlying rigid rocks could glide (Burkhard, 2001). The broad, open style of folds seen in this view is common where evaporites are involved in the deformation. Other examples can be found in the Southern Zagros of Iran and the Sierra Madre Oriental of Mexico. Information Sources: Beauchamp, W., Barazangi, M., Demnati, A., and El Alji, M., 1996, Intracontinental rifting and inversion: Missour Basin and Atlas Mountains, Morocco: Tulsa, American Association of Petroleum Geologists Bulletin, v. 80, No. 9, p. 1459-1482. Burkhard, Martin, 2001, Tectonics of the Anti-Atlas of Morocco -- Thin-skin/thick-skin relationships in an atypical foreland fold belt. University of Neuchatel, Switzerland: http://www-geol.unine.ch/Structural/Antiatlas.html (accessed 1/29/02). STS108-711-25 was taken in December, 2001 by the crew of Space Shuttle mission 108 using a Hasselblad camera with 250-mm lens. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography

  12. Enhancement of tunnel magnetoresistance in magnetic tunnel junction by a superlattice barrier

    SciTech Connect

    Chen, C. H.; Hsueh, W. J.

    2014-01-27

    Tunnel magnetoresistance of magnetic tunnel junction improved by a superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The forbidden band of the superlattice is used to predict the low transmission range in the superlattice barrier. By forbidding electron transport in the anti-parallel configuration, the tunnel magnetoresistance is enhanced in the superlattice junction. The results show that the tunnel magnetoresistance ratio for a superlattice magnetic tunnel junction is greater than that for traditional single or double barrier junctions.

  13. Micrometeorites from the Transantarctic Mountains

    PubMed Central

    Rochette, P.; Folco, L.; Suavet, C.; van Ginneken, M.; Gattacceca, J.; Perchiazzi, N.; Braucher, R.; Harvey, R. P.

    2008-01-01

    We report the discovery of large accumulations of micrometeorites on the Myr-old, glacially eroded granitic summits of several isolated nunataks in the Victoria Land Transantarctic Mountains. The number (>3,500) of large (>400 μm and up to 2 mm in size) melted and unmelted particles is orders of magnitudes greater than other Antarctic collections. Flux estimates, bedrock exposure ages and the presence of ≈0.8-Myr-old microtektites suggest that extraterrestrial dust collection occurred over the last 1 Myr, taking up to 500 kyr to accumulate based on 2 investigated find sites. The size distribution and frequency by type of cosmic spherules in the >200-μm size fraction collected at Frontier Mountain (investigated in detail in this report) are similar to those of the most representative known micrometeorite populations (e.g., South Pole Water Well). This and the identification of unusual types in terms of composition (i.e., chondritic micrometeorites and spherulitic aggregates similar to the ≈480-kyr-old ones recently found in Antarctic ice cores) and size suggest that the Transantarctic Mountain micrometeorites constitute a unique and essentially unbiased collection that greatly extends the micrometeorite inventory and provides material for studies on micrometeorite fluxes over the recent (≈1 Myr) geological past. PMID:19011091

  14. The hydrology of Yucca Mountain

    SciTech Connect

    Flint, A.L.; Flint, L.E.; Bodvarsson, G.S.; Kwicklis, E.M.; Fabryka-Martin, J.M.

    2000-12-04

    Yucca Mountain, located in southern Nevada in the Mojave Desert, is being considered as a geologic repository for high-level radioactive waste. Although the site is arid, previous studies indicate net infiltration rates of 5-10 mm yr(-1) under current climate conditions. Unsaturated flow of water through the mountain generally is vertical and rapid through the fractures of the welded tuffs and slow through the matrix of the nonwelded tuffs. The vitric-zeolitic boundary of the nonwelded tuffs below the potential repository, where it exists, causes perching and substantial lateral flow that eventually flows through faults near the eastern edge of the potential repository and recharges the underlying groundwater system. Fast pathways are located where water flows relatively quickly through the unsaturated zone to the water table. For the bulk of the water a large part of the travel time from land surface to the potential repository horizon (similar to 300 m below land surface) is through the interlayered, low fracture density, nonwelded tuff where flow is predominantly through the matrix. The unsaturated zone at Yucca Mountain is being modeled using a three-dimensional, dual-continuum numerical model to predict the results of measurements and observations in new boreholes and excavations. The interaction between experimentalists and modelers is providing confidence in the conceptual model and the numerical model and is providing researchers with the ability to plan further testing and to evaluate the usefulness or necessity of further data collection.

  15. Tunnel Correction for Compressible Subsonic Flow

    NASA Technical Reports Server (NTRS)

    Baranoff, A. V.

    1947-01-01

    This report presents a treatment of the effects of the tunnel walls on the flow velocity and direction in a compressible medium at subsonic speed by an approximate method. Calculations are given for the rotationally symmetric and two- dimensionl problems of the flow past bodies, as well for the downwash effect in the tunnel with circular cross section.

  16. Object-Based Attention and Cognitive Tunneling

    ERIC Educational Resources Information Center

    Jarmasz, Jerzy; Herdman, Chris M.; Johannsdottir, Kamilla Run

    2005-01-01

    Simulator-based research has shown that pilots cognitively tunnel their attention on head-up displays (HUDs). Cognitive tunneling has been linked to object-based visual attention on the assumption that HUD symbology is perceptually grouped into an object that is perceived and attended separately from the external scene. The present research…

  17. Ac electronic tunneling at optical frequencies

    NASA Technical Reports Server (NTRS)

    Faris, S. M.; Fan, B.; Gustafson, T. K.

    1974-01-01

    Rectification characteristics of non-superconducting metal-barrier-metal junctions deduced from electronic tunneling have been observed experimentally for optical frequency irradiation of the junction. The results provide verification of optical frequency Fermi level modulation and electronic tunneling current modulation.

  18. Tunnelling from non-localised initial states

    NASA Technical Reports Server (NTRS)

    Bowcock, Peter; Gregory, Ruth

    1991-01-01

    An approach for calculating tunneling amplitudes from a nonlocalized initial state is presented. Generalizing the matching conditions and equations of motion to allow for complex momentum permits a description of tunneling in the presence of so-called classical motion. Possible applications of the method are presented.

  19. Prediction of swelling rocks strain in tunneling

    NASA Astrophysics Data System (ADS)

    Parsapour, D.; Fahimifar, A.

    2016-05-01

    Swelling deformations leading to convergence of tunnels may result in significant difficulties during the construction, in particular for long term use of tunnels. By extracting an experimental based explicit analytical solution for formulating swelling strains as a function of time and stress, swelling strains are predicted from the beginning of excavation and during the service life of tunnel. Results obtained from the analytical model show a proper agreement with experimental results. This closed-form solution has been implemented within a numerical program using the finite element method for predicting time-dependent swelling strain around tunnels. Evaluating effects of swelling parameters on time-dependent strains and tunnel shape on swelling behavior around the tunnel according to this analytical solution is considered. The ground-support interaction and consequent swelling effect on the induced forces in tunnel lining is considered too. Effect of delay in lining installation on swelling pressure which acting on the lining and its structural integrity, is also evaluated. A MATLAB code of " SRAP" is prepared and applied to calculate all swelling analysis around tunnels based on analytical solution.

  20. Virtual Processes and Quantum Tunnelling as Fictions

    ERIC Educational Resources Information Center

    Arthur, Richard T. W.

    2012-01-01

    In this paper it is argued that virtual processes are dispensable fictions. The argument proceeds by a comparison with the phenomenon of quantum tunnelling. Building on an analysis of Levy-Leblond and Balibar, it is argued that, although the phenomenon known as quantum tunnelling certainly occurs and is at the basis of many paradigmatic quantum…

  1. Scanning scene tunnel for city traversing.

    PubMed

    Zheng, Jiang Yu; Zhou, Yu; Milli, Panayiotis

    2006-01-01

    This paper proposes a visual representation named scene tunnel for capturing urban scenes along routes and visualizing them on the Internet. We scan scenes with multiple cameras or a fish-eye camera on a moving vehicle, which generates a real scene archive along streets that is more complete than previously proposed route panoramas. Using a translating spherical eye, properly set planes of scanning, and unique parallel-central projection, we explore the image acquisition of the scene tunnel from camera selection and alignment, slit calculation, scene scanning, to image integration. The scene tunnels cover high buildings, ground, and various viewing directions and have uniformed resolutions along the street. The sequentially organized scene tunnel benefits texture mapping onto the urban models. We analyze the shape characteristics in the scene tunnels for designing visualization algorithms. After combining this with a global panorama and forward image caps, the capped scene tunnels can provide continuous views directly for virtual or real navigation in a city. We render scene tunnel dynamically by view warping, fast transmission, and flexible interaction. The compact and continuous scene tunnel facilitates model construction, data streaming, and seamless route traversing on the Internet and mobile devices. PMID:16509375

  2. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Wing and nacelle set-up in Full-Scale Tunnel (FST). The NACA conducted drag tests in 1931 on a P3M-1 nacelle which were presented in a special report to the Navy. Smith DeFrance described this work in the report's introduction: 'Tests were conducted in the full-scale wind tunnel on a five to four geared Pratt and Whitney Wasp engine mounted in a P3M-1 nacelle. In order to simulate the flight conditions the nacelle was assembled on a 15-foot span of wing from the same airplane. The purpose of the tests was to improve the cooling of the engine and to reduce the drag of the nacelle combination. Thermocouples were installed at various points on the cylinders and temperature readings were obtained from these by the power plants division. These results will be reported in a memorandum by that division. The drag results, which are covered by this memorandum, were obtained with the original nacelle condition as received from the Navy with the tail of the nacelle modified, with the nose section of the nacelle modified, with a Curtiss anti-drag ring attached to the engine, with a Type G ring developed by the N.A.C.A., and with a Type D cowling which was also developed by the N.A.C.A.' (p. 1)

  3. Unimpeded Tunneling in Graphene Nanoribbons

    NASA Astrophysics Data System (ADS)

    Iurov, Andrii; Roslyak, Oleksiy; Gumbs, Godfrey; Huang, Danhong

    2010-03-01

    The Klein paradox is unimpeded tunneling of the purely bonded Dirac electron state across arbitrary wide gated region. Its another manifestation is perfect reflection in the graphene stacks. We studied the Klein paradox in zigzag (ZNR) and anti- zigzag (AZNR) graphene nanoribbons. For ZNR (AZNR), the number N of lattice sites across the nanoribbon is even (odd). Since the ZNR and AZNR (configurations are indistinguishable in the Dirac formalism, we supplemented the model with a pseudo-parity operator whose eigenvalues correctly give the dependence on N for the sublattice wavefunctions, in agreement with the tight- binding model. We have shown that the Klein tunneling in zigzag nanoribbons is determined by conservation of the pseudo-parity rather than pseudo-spin which is required in infinite graphene. Chirality is the projection of the pseudo-spin on momentum at different corners of the Brillouin zone. Perfect transmission for head-on incidence is replaced by perfect transmission at the center of the ribbon.

  4. Spin-valley filter and tunnel magnetoresistance in asymmetrical silicene magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Wang, Dali; Huang, Zeyuan; Zhang, Yongyou; Jin, Guojun

    2016-05-01

    The spin and valley transports and tunnel magnetoresistance are studied in a silicene-based asymmetrical magnetic tunnel junction consisting of a ferromagnetic tunnel barrier, sandwiched between a ferromagnetic electrode and a normal electrode. For such an asymmetrical silicene junction, a general formulism is established. The numerical results show that the spin-valley resolved conductances strongly depend on the magnetization orientation of the ferromagnetic tunnel barrier, and the fully spin-valley polarized current can be realized by tuning a perpendicularly applied electric field. We also find that the tunnel magnetoresistance in this case can be effectively modified by the external electric field when the conductance is fully spin-valley polarized. In particular, the exchange field in the ferromagnetic electrode can further substantially enhance the tunnel magnetoresistance of the system. Our work provides a practical method for electric and magnetic manipulation of valley/spin polarization and tunnel magnetoresistance.

  5. Enhancing metal-insulator-insulator-metal tunnel diodes via defect enhanced direct tunneling

    SciTech Connect

    Alimardani, Nasir; Conley, John F.

    2014-08-25

    Metal-insulator-insulator-metal tunnel diodes with dissimilar work function electrodes and nanolaminate Al{sub 2}O{sub 3}-Ta{sub 2}O{sub 5} bilayer tunnel barriers deposited by atomic layer deposition are investigated. This combination of high and low electron affinity insulators, each with different dominant conduction mechanisms (tunneling and Frenkel-Poole emission), results in improved low voltage asymmetry and non-linearity of current versus voltage behavior. These improvements are due to defect enhanced direct tunneling in which electrons transport across the Ta{sub 2}O{sub 5} via defect based conduction before tunneling directly through the Al{sub 2}O{sub 3}, effectively narrowing the tunnel barrier. Conduction through the device is dominated by tunneling, and operation is relatively insensitive to temperature.

  6. Aberrant Radial Artery Causing Carpal Tunnel Syndrome

    PubMed Central

    Kokkalis, Zinon T.; Tolis, Konstantinos E.; Megaloikonomos, Panayiotis D.; Panagopoulos, Georgios N.; Igoumenou, Vasilios G.; Mavrogenis, Andreas F.

    2016-01-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic. PMID:27517078

  7. Aberrant Radial Artery Causing Carpal Tunnel Syndrome.

    PubMed

    Kokkalis, Zinon T; Tolis, Konstantinos E; Megaloikonomos, Panayiotis D; Panagopoulos, Georgios N; Igoumenou, Vasilios G; Mavrogenis, Andreas F

    2016-06-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic. PMID:27517078

  8. Tunneling Anomalous and Spin Hall Effects.

    PubMed

    Matos-Abiague, A; Fabian, J

    2015-07-31

    We predict, theoretically, the existence of the anomalous Hall effect when a tunneling current flows through a tunnel junction in which only one of the electrodes is magnetic. The interfacial spin-orbit coupling present in the barrier region induces a spin-dependent momentum filtering in the directions perpendicular to the tunneling current, resulting in a skew tunneling even in the absence of impurities. This produces an anomalous Hall conductance and spin Hall currents in the nonmagnetic electrode when a bias voltage is applied across the tunneling heterojunction. If the barrier is composed of a noncentrosymmetric material, the anomalous Hall conductance and spin Hall currents become anisotropic with respect to both the magnetization and crystallographic directions, allowing us to separate this interfacial phenomenon from the bulk anomalous and spin Hall contributions. The proposed effect should be useful for proving and quantifying the interfacial spin-orbit fields in metallic and metal-semiconductor systems. PMID:26274432

  9. PUREX Storage Tunnels dangerous waste permit application

    SciTech Connect

    Not Available

    1990-09-01

    The Hanford Site is operated by the US Department of Energy-Richland Operations Office. The PUREX Storage Tunnels are a storage unit located on the Hanford Site. The unit consists of two earth-covered railroad tunnels that are used for storage of process equipment (some containing dangerous waste) removed from the PUREX Plant. Radioactively contaminated equipment is loaded on railroad cars and remotely transferred into the tunnels for long-term storage. Westinghouse Hanford Company is a major contractor to the US Department of Energy-Richland Operations Office and serves as a co-operator of the PUREX Storage Tunnels, the waste management unit addressed by this permit application. This appendix contains Tunnel 1 Construction Specifications, HWS-5638, consisting of 49 pages.

  10. Mountain Weather and Climate, Third Edition

    NASA Astrophysics Data System (ADS)

    Hastenrath, Stefan

    2009-05-01

    For colleagues with diverse interests in the atmosphere, glaciers, radiation, landforms, water resources, vegetation, human implications, and more, Mountain Weather and Climate can be a valuable source of guidance and literature references. The book is organized into seven chapters: 1, Mountains and their climatological study; 2,Geographical controls of mountain meteorological elements; 3, Circulation systems related to orography; 4, Climatic characteristics of mountains; 5, Regional case studies; 6, Mountain bioclimatology; and 7, Changes in mountain climates. These chapters are supported by l78 diagrams and photographs, 47 tables, and some 2000 literature references. The volume has an appendix of units and energy conversion factors and a subject index, but it lacks an author index.

  11. SANTA LUCIA WILDERNESS, AND GARCIA MOUNTAIN, BLACK MOUNTAIN, LA PANZA, MACHESNA MOUNTAIN, LOS MACHOS HILLS, BIG ROCKS, AND STANLEY MOUNTAIN ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Frizzell, Virgil A., Jr.; Kuizon, Lucia

    1984-01-01

    The Santa Lucia Wilderness Area and Garcia Mountain, Black Mountain, La Panza, Machesna Mountain, Los Machos Hills, Big Rocks, and Stanley Mountain Roadless Areas together occupy an area of about 218 sq mi in the Los Padres National Forest, California. On the basis of a mineral-resource evaluation a small area in the Black Mountain Roadless Area has a probable mineral-resource potential for uranium, and a small area in the Stanley Mountain Roadless Area has probable potential for low-grade mercury resources. Although petroleum resources occur in rocks similar to those found in the study area, no potential for petroleum resources was identified in the wilderness or any of the roadless areas. No resource potential for other mineral resources was identified in any of the areas. Detailed geologic mapping and geochemical sampling probably would increase knowledge about distribution and modes of occurrence of uranium and cinnabar in those areas, respectively.

  12. Resonant tunneling dynamics and the related tunneling time

    NASA Astrophysics Data System (ADS)

    Xiao, Zhi; Huang, Hai; Lu, Xiang-Xiang

    2015-01-01

    In close analogy with optical Fabry-Pérot (FP) interferometer, we rederive the transmission and reflection coefficients of tunneling through a rectangular double barrier (RDB). Based on the same analogy, we also get an analytic finesse formula for its filtering capability of matter waves, and with this formula, we reproduce the RDB transmission rate in exactly the same form as that of FP interferometer. Compared with the numerical results obtained from the original finesse definition, we find the formula works well. Next, we turn to the elusive time issue in tunneling, and show that the "generalized Hartman effect" can be regarded as an artifact of the opaque limit βl → ∞. In the thin barrier approximation, phase (or dwell) time does depend on the free inter-barrier distance d asymptotically. Further, the analysis of transmission rate in the neighborhood of resonance shows that, phase (or dwell) time could be a good estimate of the resonance lifetime. The numerical results from the uncertainty principle support this statement. This fact can be viewed as a support to the idea that, phase (or dwell) time is a measure of lifetime of energy stored beneath the barrier. To confirm this result, we shrink RDB to a double Dirac δ-barrier. The landscape of the phase (or dwell) time in k and d axes fits excellently well with the lifetime estimates near the resonance. As a supplementary check, we also apply phase (or dwell) time formula to the rectangular well, where no obstacle exists to the propagation of particle. However, due to the self-interference induced by the common cavity-like structure, phase (or dwell) time calculation leads to a counterintuitive "slowing down" effect, which can be explained appropriately by the lifetime assumptions.

  13. Geographic Information Science and Mountain Geomorphology

    NASA Astrophysics Data System (ADS)

    Scuderi, Louis A.

    Mountain areas are among the most threatened environments worldwide.These sensitive systems suffer from human encroachment, resource extraction, and subsequent environmental degradation. Mountain ecosystems are also extremely sensitive to climate variability with impacts on snow and ice cover, hydrologic response, and sediment yield. From this perspective, mountain environments can be viewed as one of the “canaries in the coal mine” for the entire global environmental system.

  14. 7 x 10-Foot Atmospheric Wind Tunnel (AWT)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Force Test set-up in 7 x 10-Foot Atmospheric Wind Tunnel (AWT). In 1928, the NACA decided to replace its original Atmospheric Wind Tunnel (AWT #1) with two tunnels--the 5-foot vertical tunnel and a 7 by 10 foot rectangular throat tunnel. Both were open-throat, closed-return-passage tunnels and were housed in the same building the first wind tunnel had been located in. While the 5-foot vertical tunnel was to be used mainly for spin tests, the 7x10 was an all-purpose tunnel although the main intent was to study stability and control problems. Construction was completed in the summer of 1930; calibration later that same year. The balance was installed and the tunnel went into operation in early 1931. There was a 6-component balance in this wind tunnel. The balance could support either static or rotation tests.

  15. Precipitation Across India's Ghats Mountains (IMERG)

    NASA Video Gallery

    Animation of precipitation rates across India and surrounding countries. Notice the heavy rains throughout the Ghats Mountain range which resulted in devastating landslides along India's west coast...

  16. Landscape, Mountain Worship and Astronomy in Socaire

    NASA Astrophysics Data System (ADS)

    Moyano, Ricardo

    The spatiotemporal analysis of mountain worship in the indigenous community of Socaire, Atacama, northern Chile, relates to cultural, geographical, climatic, psychological, and astronomical information gathered from ethno archaeological studies. We identify a system of offerings to the mountains that incorporates concepts such as ceque (straight line), mayllku (mountain lord or ancestor), and pacha (space and time). Here, the mountains on the visible horizon (Tumisa, Lausa, Chiliques, Ipira, and Miñiques) feature as the fingers on the left hand (PAH Triad). This structure regulates annual activities and rituals and sets the basis for the Socaireños' worldview raised on a humanized landscape.

  17. G-Tunnel Welded Tuff Mining Experiment instrumentation evaluations; Yucca Mountain Site Characterization Project

    SciTech Connect

    Zimmerman, R.M.; Bellman, R.A. Jr.; Mann, K.L.; Thompson, T.W.

    1992-04-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratory has conducted a mine-by experiment in welded tuff so that information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth-blasting techniques were used. This report describes the results of the evaluations of nine different instrument or measurement systems used in conjunction with these mining activities.

  18. G-tunnel pressurized slot-testing evaluations; Yucca Mountain Site Characterization Project

    SciTech Connect

    Zimmerman, R.M.; Sifre-Soto, C.; Mann, K.L.; Bellman, R.A. Jr.; Luker, S.; Dodds, D.J.

    1992-04-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratories elected to conduct a development program to enhance mechanical-type measurements. The program was focused on pressurized slot testing and featured (1) development of an improved method to cut slots using a chain saw with diamond-tipped cutters, (2) measurements useful for determining in situ stresses normal to slots, (3) measurements applicable for determining the in situ modulus of deformation parallel to a drift surface, and (4) evaluations of pressurized slot strength testing results and methods. This report contains data interpretation and evaluations. Included are recommendations for future efforts. This third report contains the interpretations of the testing with emphasis on the measurement results as they apply to describing rock behavior. In particular, emphases are placed on (1) normal stress determinations using the flatjack cancellation (FC) method, (2) modulus of deformation determinations, and (3) high pressure investigations. Most of the material in the first two reports is not repeated here. Appropriate data are repeated in tabular form.

  19. G-Tunnel pressurized slot-testing preparations; Yucca Mountain Site Characterization Project

    SciTech Connect

    Zimmerman, R.M.; Sifre-Soto, C.; Mann, K.L.; Bellman, R.A. Jr.; Luker, S.; Dodds, D.J.

    1992-04-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National laboratories elected to conduct a development program on pressurized slot testing and featured (1) development of an improved method to cut slots using a chain saw with diamond-tipped cutters, (2) measurements useful for determining in situ stresses normal to slots, (3) measurements applicable for determining the in situ modulus of deformation parallel to a drift surface, and (4) evaluations of the potentials of pressurized slot strength testing. This report describes the preparations leading to the measurements and evaluations.

  20. A Mountain-Scale Thermal Hydrologic Model for Simulating FluidFlow and Heat Transfer in Unsaturated Fractured Rock

    SciTech Connect

    Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson,Gudmundur S.

    2005-05-25

    A multidimensional, mountain-scale, thermal-hydrologic (TH) numerical model is presented for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository in the Yucca Mountain unsaturated zone (UZ), Nevada. The model, consisting of both two-dimensional (2-D) and three-dimensional (3-D) representations of the UZ repository system, is based on the current repository design, drift layout, thermal loading scenario, and estimated current and future climate conditions. This mountain-scale TH model evaluates the coupled TH processes related to mountain-scale UZ flow. It also simulates the impact of radioactive waste heat release on the natural hydrogeological system, including heat-driven processes occurring near and far away from the emplacement tunnels or drifts. The model simulations predict thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. These simulations provide mountain-scale thermally perturbed flow fields for assessing the repository performance under thermal loading conditions.