Black Hole Mergers and Gravitational Waves: Opening the New Frontier

NASA Technical Reports Server (NTRS)

Centrella, Joan

2012-01-01

The final merger of two black holes produces a powerful burst of gravitational waves, emitting more energy than all the stars in the observable universe combined. Since these mergers take place in the regime of strong dynamical gravity, computing the gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For more than 30 years, scientists tried to simulate these mergers using the methods of numerical relativity. The resulting computer codes were plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. In the past several years, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will highlight these breakthroughs and the resulting 'gold rush' of new results that is revealing the dynamics of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

Joining strength performances of metal skin and CFRP core laminate structures realized by compression-curing process, with supporting experiments

NASA Astrophysics Data System (ADS)

Quagliato, Luca; Jang, Changsoon; Kim, Naksoo

2018-05-01

In the recent years, the trend of lightening vehicles and structures of every kind has become an ever-growing issue, both for university and industrial researchers. As demonstrated in previous authors' works, laminate structures made of metal skin (MS) and carbon fiber reinforced polymer (CFRP) core show high specific bending strength properties while granting considerable weight reduction but, so far, no investigations have been carried out on the hole sensitivity and joinability of these hybrid structures. In the present research work, the hole size sensitivity of MS-CFRP structure has been studied by means of uniaxial tensile test on 160mm (length), 25mm (width), 2.0mm (average thickness) specimens bored with Ø06mm, Ø9mm, and Ø12mm holes. The specimen thickness is composed of two metal skins of 0.4mm thickness each, 8×0.2mm CFRP stacked layers and two thin epoxy-based adhesive layers. The specimens have been manufactured by means of a compression-curing process in which the different materials are stacked and, thanks to die pressure and temperature, the curing process is completed in a relatively short time (15˜20 minutes). The specimens have been tested by means of simple tension test showing that, for the MS-CFRP material, the smaller the hole the smaller the maximum bearable load. Moreover, specimens with the same hole sizes have been bolted together with class 12 resistance bolts and tested by means of tensile test, allowing to determine the maximum transferable load between the two MS-CFRP plates. Aiming to prove the improvement in the specific transferable load, experiments on only-steel specimens with the same weight of the MS-CFRP ones and joined with the same method and bolts have been carried out, allowing to conclude that, for the 9mm hole bolted plates, the proposed material has a specific maximum transferable 27% higher than that of the steel composing their skins.

Optimization test of the 2BSL-320 vegetable seeders with air-suction drum type

NASA Astrophysics Data System (ADS)

Tang, B.; Wang, Y. S.; Ji, S. Z.

2017-07-01

The seeding raising technology of the hole tray assembly line is an important part of modern agriculture. The 2BSL-320 vegetable seeders with air-suction drum type are implements that are used to fill nutritional soil and press a hole in a float tray to sow seeds precisely. It can complete the whole process of putting down the tray, bedding the soil, scraping the soil, pressing a hole, sowing the seeds, compacting the soil, watering and putting away the tray by one time. Based on the introduction of the structure and working principle of the implement’s critical components, in order to improve the seeding efficiency and the seeding accuracy of the seeders, the response surface tests and the group experiments were carried out in this paper. And the MATLAB tool box was used to conduct fitting and optimization analysis of the test results, also the rationality of the optimization results was validated by experiments, which had provided a theoretical basis for the design of operation parameters in the vegetable seeders and had improved the seeding efficiency and quality.

Planckian charged black holes in ultraviolet self-complete quantum gravity

NASA Astrophysics Data System (ADS)

Nicolini, Piero

2018-03-01

We present an analysis of the role of the charge within the self-complete quantum gravity paradigm. By studying the classicalization of generic ultraviolet improved charged black hole solutions around the Planck scale, we showed that the charge introduces important differences with respect to the neutral case. First, there exists a family of black hole parameters fulfilling the particle-black hole condition. Second, there is no extremal particle-black hole solution but quasi extremal charged particle-black holes at the best. We showed that the Hawking emission disrupts the condition of particle-black hole. By analyzing the Schwinger pair production mechanism, the charge is quickly shed and the particle-black hole condition can ultimately be restored in a cooling down phase towards a zero temperature configuration, provided non-classical effects are taken into account.

Application of drilling, coring, and sampling techniques to test holes and wells

USGS Publications Warehouse

Shuter, Eugene; Teasdale, Warren E.

1989-01-01

The purpose of this manual is to provide ground-water hydrologists with a working knowledge of the techniques of test drilling, auger drilling, coring and sampling, and the related drilling and sampling equipment. For the most part, the techniques discussed deal with drilling, sampling, and completion of test holes in unconsolidated sediments because a hydrologist is interested primarily in shallow-aquifer data in this type of lithology. Successful drilling and coring of these materials usually is difficult, and published research information on the subject is not readily available. The authors emphasize in-situ sampling of unconsolidated sediments to obtain virtually undisturbed samples. Particular attention is given to auger drilling and hydraulic-rotary methods of drilling because these are the principal means of test drilling performed by the U.S. Geological Survey during hydrologic studies. Techniques for sampling areas contaminated by solid or liquid waste are discussed. Basic concepts of well development and a detailed discussion of drilling muds, as related to hole conditioning, also are included in the report. The information contained in this manual is intended to help ground-water hydrologists obtain useful subsurface data and samples from their drilling programs.

Drilling and completion of the three CO2SINK boreholes in Europe's pilot CO2 storage and verification project in an onshore saline aquifer

NASA Astrophysics Data System (ADS)

Prevedel, P.,; Wohlgemuth, L.; Legarth, B.; Henninges, J.; Schütt, H.; Schmidt-Hattenberger, C.; Norden, B.; Förster, A.; Hurter, S.

2009-04-01

This paper reports the CO2SINK drilling and permanent monitoring completions, as well as the well testing techniques applied in Europe's first scientific carbon dioxide onshore storage test in a saline aquifer near the town of Ketzin, 40 km east of Berlin/Germany. Three boreholes, one injection and two observation wells have been drilled in 2007 to a total depth of about 800 m. The wells were completed as "smart" wells containing a variety of permanently installed down-hole sensors, which have successfully proven their functionality during over their first injection year and are the key instruments for the continuous monitoring of the CO2 inside the reservoir during the storage phase. Constructing three wells in close proximity of 50 to 100m distance to each other with a dense sensor and monitoring cable population requires detailed planning and employment of high-end project management tools. All wells were cased with stainless final casings equipped with pre-perforated sand filters in the pay-zone and wired on the outside with two fibre-optical, one multi-conductor copper, and a PU-heating cable to the surface. The reservoir casing section is externally coated with a fibre-glass-resin wrap for electrical insulation of the 15 geo-electrical toroid antennas in the open hole section. A staged cementation program was selected in combination with the application of a newly developed swellable rubber packer technology and specialized cementation down-hole tools. This technology was given preference over perforation work inside the final casing at the reservoir face, which would have created unmanageable risks of potential damage of the outside casing cables. Prior to the start of the injection phase, an extensive production and injection well test program as well as well-to-well interference tests were performed in order to determine the optimum CO2 injection regime.

Sulfur hexafluoride (SF6) versus perfluoropropane (C3F8) tamponade and short term face-down position for macular hole repair: a randomized prospective study.

PubMed

Casini, Giamberto; Loiudice, Pasquale; De Cillà, Stefano; Radice, Paolo; Nardi, Marco

2016-01-01

To compare early visual and anatomical outcomes after either sulfur hexafluoride (SF 6 ) or perfluoropropane (C 3 F 8 ) tamponade for macular hole repair. 147 eyes affected by primary full-thickness macular hole underwent pars plana vitrectomy with dye assisted removal of the internal limiting membrane and gas tamponade. Prone position was prescribed for 48 h after surgery. All patients were divided into 3 groups depending on the size of the hole: small (<250 µm), medium (>250-<400 µm) or large (>400 µm). Eyes within the same group randomly received either SF 6 (70 eyes) or C 3 F 8 (77 eyes). A complete ophthalmic evaluation, including best corrected visual acuity and anatomic status of the macular holes, was conducted preoperatively, at 1 week and 1 month after surgery. Macular hole volume was calculated using optical coherence tomography scans. The Wilcoxon Signed Ranks Test, the Mann-Whitney Test, the Spearman's rank-order correlation coefficient and the study of variance for repeated measures were used for statistical analysis. Mean best-corrected visual acuity improved from 0.92 logMAR to 0.28 logMAR (P < 0.001). A reduction of the dimensions of macular holes was observed in all cases, with a total repair of 90 % (63/70 eyes) in the SF 6 group and 91 % in the C 3 F 8 group (70/77 eyes). There was a negative correlation between the initial minor diameter, the volume of the hole and the rate of anatomic success. Short-term anatomical and visual outcomes were similar in eyes treated with either SF 6 or C 3 F 8 , independently of the stage of the macular hole. The initial volume and the minor diameter of the hole may be considered as valid tools for predicting surgical success. Age and gender did not appear to have influenced the prognosis.

Novel, Miniature Multi-Hole Probes and High-Accuracy Calibration Algorithms for their use in Compressible Flowfields

NASA Technical Reports Server (NTRS)

Rediniotis, Othon K.

1999-01-01

Two new calibration algorithms were developed for the calibration of non-nulling multi-hole probes in compressible, subsonic flowfields. The reduction algorithms are robust and able to reduce data from any multi-hole probe inserted into any subsonic flowfield to generate very accurate predictions of the velocity vector, flow direction, total pressure and static pressure. One of the algorithms PROBENET is based on the theory of neural networks, while the other is of a more conventional nature (polynomial approximation technique) and introduces a novel idea of local least-squares fits. Both algorithms have been developed to complete, user-friendly software packages. New technology was developed for the fabrication of miniature multi-hole probes, with probe tip diameters all the way down to 0.035". Several miniature 5- and 7-hole probes, with different probe tip geometries (hemispherical, conical, faceted) and different overall shapes (straight, cobra, elbow probes) were fabricated, calibrated and tested. Emphasis was placed on the development of four stainless-steel conical 7-hole probes, 1/16" in diameter calibrated at NASA Langley for the entire subsonic regime. The developed calibration algorithms were extensively tested with these probes demonstrating excellent prediction capabilities. The probes were used in the "trap wing" wind tunnel tests in the 14'x22' wind tunnel at NASA Langley, providing valuable information on the flowfield over the wing. This report is organized in the following fashion. It consists of a "Technical Achievements" section that summarizes the major achievements, followed by an assembly of journal articles that were produced from this project and ends with two manuals for the two probe calibration algorithms developed.

Making and Testing Hybrid Gravitational Waves from Colliding Black Holes and Neutron Stars

NASA Astrophysics Data System (ADS)

Garcia, Alyssa; Lovelace, Geoffrey; SXS Collaboration

2016-03-01

The Laser Interferometer Gravitational-wave Observatory (LIGO) is a detector that is currently working to observe gravitational waves (GW) from astronomical sources, such as colliding black holes and neutron stars, which are among LIGO's most promising sources. Observing as many waves as possible requires accurate predictions of what the waves look like, which are only possible with numerical simulations. In this poster, I will present results from new simulations of colliding black holes made using the Spectral Einstein Code (SpEC). In particular, I will present results for extending new and existing waveforms and using an open-source library. To construct a waveform that spans the frequency range where LIGO is most sensitive, we combine inexpensive, post-Newtonian approximate waveforms (valid far from merger) and numerical relativity waveforms (valid near the time of merger, when all approximations fail), making a hybrid GW. This work is one part of a new prototype framework for Numerical INJection Analysis with Matter (Matter NINJA). The complete Matter NINJA prototype will test GW search pipelines' abilities to find hybrid waveforms, from simulations containing matter (such as black hole-neutron star binaries), hidden in simulated detector noise.

Black Holes, Hidden Symmetry and Complete Integrability: Brief Review

NASA Astrophysics Data System (ADS)

Frolov, Valeri P.

This chapter contains a brief review of the remarkable properties of higher dimensional rotating black holes with the spherical topology of the horizon. We demonstrate that these properties are connected with and generated by a special geometrical object, the Principal Conformal Killing-Yano tensor (PCKYT). The most general solution, describing such black holes, Kerr-NUT-ADS metric, admits this structure. Moreover a solution of the Einstein Equations with (or without) a cosmological constant which possesses PCKYT is the Kerr-NUT-ADS metric. This object (PCKYT) is responsible for such remarkable properties of higher dimensional rotating black holes as: (i) complete integrability of geodesic equations and (ii) complete separation of variables of the important field equations.

Predicting Binary Black Hole Collisions Using Numerical Methods in Collaboration with LIGO

NASA Astrophysics Data System (ADS)

Afshari, Nousha; Lovelace, Geoffrey

2015-04-01

Detecting astronomical gravitational waves will soon open a new window on the universe. The effects of gravitational waves have already been seen indirectly, but a direct observation of these waves will test Einstein's theory of general relativity under the most extreme conditions. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, will soon begin searching for gravitational waves, and the first direct detections are likely in the next few years. To help LIGO detect as many gravitational waves as possible, a major research effort is underway to accurately predict the expected waves. In this presentation, I will discuss new supercomputer simulations of merging black holes--some of the brightest sources of gravitational waves--that I have completed using the Spectral Einstein Code (http://www.black-holes.org/SpEC.html).

Merging Black Holes, Gravitational Waves, and Numerical Relativity

NASA Technical Reports Server (NTRS)

Centrella, Joan M.

2009-01-01

The final merger of two black holes will emit more energy than all the stars in the observable universe combined. This energy will come in the form of gravitational waves, which are a key prediction of Einstein's general relativity and a new tool for exploring the universe. Observing these mergers with gravitational wave detectors, such as the ground-based LIGO and the space-based LISA, requires knowledge of the radiation waveforms. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes were long plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and w aefo rms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

Geothermal observation wells, Mt. Hood, Oregon. Final report, October 4, 1977-July 9, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Covert, W.F.; Meyer, H.J.

1979-11-01

Exploration drilling operations were conducted which included the deepening of an existing hole, designated as Old Maid Flat No. 1, from 1850 ft (564 m) to 4002 (1220 m) on the western approaches to Mt. Hood and the drilling of three new holes ranging from 940 ft (287 m) to 1340 ft (409 m). The Clear Fork hole, located in Old Maid Flat, was drilled to 1320 ft (402 m). The Zigzag hole was drilled to 940 ft (287 m) at the southwestern base of Mt. Hood in the Zigzag River valley. The remaining hole was drilled on the Timberlinemore » Lodge grounds which is on the south flank of Mt. Hood at an elevation of about 6000 ft (1829 m) above sea level. The deepening project designated as Old Maid Flat No. 1 encountered a maximum bottom hole temperature of about 180/sup 0/F (82/sup 0/C) and is to this date the deepest exploratory hole in the Mt. Hood vicinity. No significant drilling problems were encountered. The Clear Fork and Zigzag River holes were completed without significant problems. The Timberline Lodge hole encountered severe drilling conditions, including unconsolidated formations. Two strings of tools were left in the hole from structural collapse of the hole. The hole was scheduled as a 2000 ft (610 m) test. Drilling did not proceed beyond 1350 ft (412 m) and due to junk it was unobstructed to a depth of 838 ft (255 m). Observation pipe was installed to 735 ft (224 m) due to further disintegration of the hole. The work was prematurely terminated due to weather conditions.« less

A Proposed Borehole Scientific Laboratory in Quay County, New Mexico, USA

NASA Astrophysics Data System (ADS)

Nielson, Dennis; Eckels, Marc; Mast, Peter; Zellman, Mark; Creed, Robert

2017-04-01

Our team has received funding from the US Department of Energy to initiate a Deep Borehole Field Test that will develop a subsurface test site to evaluate the drilling and scientific aspects of deep borehole disposal of nuclear waste in crystalline rock. Phase 1 of the project will focus on Public Outreach and land acquisition whereas Phase 2 will generate a drilling and testing plan and secure regulatory approvals. Phase 3 will complete the Drilling and Testing Plan and Phase 4 will include the drilling and testing. Phase 5 will be devoted to borehole science and experiments with emplacement technology. Although we are specifically considering issues associated with the disposal of waste, this project is a proof of concept, and no waste will be emplaced at our site. In brief, the concept envisions an 8-1/2 inch open-hole completion at a depth of 5000 m in crystalline rock. There will be an extensive program of sample collection (including core) and analysis as well as geophysical logging and borehole testing. Critical issues will be low permeability in the crystalline rock as well as the ability to manage borehole quality. Our team has proposed a site in Quay County, New Mexico that has an 850 meter thick Paleozoic section overlying homogeneous Precambrian granite. A subsequent phase of the project may drill a second hole with a 17-1/2 inch completion located about 200 m from the first. Our long-term plan is that this site will be managed as a deep scientific observatory that also provides a facility for scientific experiments and testing of borehole infrastructure and drilling equipment.

Occult Blood Testing for Early Detection of Colorectal Cancer: Diagnostic Outcomes

PubMed Central

Hislop, T. Gregory; Morrison, Brenda J.; Hoogewerf, Peter E.; Burns, Sheilagh D.; Sizto, Ronald

1987-01-01

Three thousand five hundred and fifty-four asymptomatic persons from 32 family practices returned hemoccult II tests for colorectal cancer; 2.2% of these returned tests were positive. The diagnoses for the 47 persons with positive tests which were done while on meat restriction included six cancers (1.7/1000) and five polyps (1.4/1000); 18 were diagnosed with other known sources, and 18 were undiagnosed. All polyps and four of six cancers were diagnosed by combined barium enema with sigmoidoscopy or by colonoscopy. Five of six cancers were diagnosed at early stages. Meat restriction, the method of returning the test for analysis, the number of holes completed in the test, and the delay time from completing the test to analysis did not influence the likelihood of a positive test. PMID:20469468

Computing black hole partition functions from quasinormal modes

DOE PAGES

Arnold, Peter; Szepietowski, Phillip; Vaman, Diana

2016-07-07

We propose a method of computing one-loop determinants in black hole space-times (with emphasis on asymptotically anti-de Sitter black holes) that may be used for numerics when completely-analytic results are unattainable. The method utilizes the expression for one-loop determinants in terms of quasinormal frequencies determined by Denef, Hartnoll and Sachdev in [1]. A numerical evaluation must face the fact that the sum over the quasinormal modes, indexed by momentum and overtone numbers, is divergent. A necessary ingredient is then a regularization scheme to handle the divergent contributions of individual fixed-momentum sectors to the partition function. To this end, we formulatemore » an effective two-dimensional problem in which a natural refinement of standard heat kernel techniques can be used to account for contributions to the partition function at fixed momentum. We test our method in a concrete case by reproducing the scalar one-loop determinant in the BTZ black hole background. Furthermore, we then discuss the application of such techniques to more complicated spacetimes.« less

Information loss.

PubMed

Unruh, William G; Wald, Robert M

2017-09-01

The complete gravitational collapse of a body in general relativity will result in the formation of a black hole. Although the black hole is classically stable, quantum particle creation processes will result in the emission of Hawking radiation to infinity and corresponding mass loss of the black hole, eventually resulting in the complete evaporation of the black hole. Semiclassical arguments strongly suggest that, in the process of black hole formation and evaporation, a pure quantum state will evolve to a mixed state, i.e. there will be 'information loss'. There has been considerable controversy over this issue for more than 40 years. In this review, we present the arguments in favor of information loss, and analyze some of the counter-arguments and alternative possibilities.

Information loss

NASA Astrophysics Data System (ADS)

Unruh, William G.; Wald, Robert M.

2017-09-01

The complete gravitational collapse of a body in general relativity will result in the formation of a black hole. Although the black hole is classically stable, quantum particle creation processes will result in the emission of Hawking radiation to infinity and corresponding mass loss of the black hole, eventually resulting in the complete evaporation of the black hole. Semiclassical arguments strongly suggest that, in the process of black hole formation and evaporation, a pure quantum state will evolve to a mixed state, i.e. there will be ‘information loss’. There has been considerable controversy over this issue for more than 40 years. In this review, we present the arguments in favor of information loss, and analyze some of the counter-arguments and alternative possibilities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, Leo C.; Yagi, Kent; Yunes, Nicolás, E-mail: leostein@astro.cornell.edu

The gravitational field outside of astrophysical black holes is completely described by their mass and spin frequency, as expressed by the no-hair theorems. These theorems assume vacuum spacetimes, and thus they apply only to black holes and not to stars. Despite this, we analytically find that the gravitational potential of arbitrarily rapid, rigidly rotating stars can still be described completely by only their mass, spin angular momentum, and quadrupole moment. Although these results are obtained in the nonrelativistic limit (to leading order in a weak-field expansion of general relativity, GR), they are also consistent with fully relativistic numerical calculations ofmore » rotating neutron stars. This description of the gravitational potential outside the source in terms of just three quantities is approximately universal (independent of equation of state). Such universality may be used to break degeneracies in pulsar and future gravitational wave observations to extract more physics and test GR in the strong-field regime.« less

Reconnaissance report on geology of Eklutna Lake dam site and conduit route near Anchorage, Alaska

USGS Publications Warehouse

Bateman, A.F.

1947-01-01

C. A foundation exploration program is recommended that includes deepening test pit No. 1 and drill hole No. 2, and drilling 11 new holes. It is suggested that one drill hold near the center of the valley be taken to bedrock to give a complete picture of the fill materials underlying the foundation. 3. Delivery of water from the forebay of the reservoir to the powerhouse eight miles downvalley by means of a conduit is regarded as infeasible because: difficult terrain of the route will require earthwork more extensive than the volume of the dam; the route is subject to land slides, and will require expensive maintenance; it is more or less completely exposed to adverse winter conditions that may engender icing conditions; and it is easily subject to sabotage. It is recommended that the water be taken to the powerhouse through a rock tunnel.

Quantum space and quantum completeness

NASA Astrophysics Data System (ADS)

Jurić, Tajron

2018-05-01

Motivated by the question whether quantum gravity can "smear out" the classical singularity we analyze a certain quantum space and its quantum-mechanical completeness. Classical singularity is understood as a geodesic incompleteness, while quantum completeness requires a unique unitary time evolution for test fields propagating on an underlying background. Here the crucial point is that quantum completeness renders the Hamiltonian (or spatial part of the wave operator) to be essentially self-adjoint in order to generate a unique time evolution. We examine a model of quantum space which consists of a noncommutative BTZ black hole probed by a test scalar field. We show that the quantum gravity (noncommutative) effect is to enlarge the domain of BTZ parameters for which the relevant wave operator is essentially self-adjoint. This means that the corresponding quantum space is quantum complete for a larger range of BTZ parameters rendering the conclusion that in the quantum space one observes the effect of "smearing out" the singularity.

Records of wells and test holes in the Nevada Test Site and vicinity (through December 1966)

USGS Publications Warehouse

Thordarson, William; Young, R.A.; Winograd, I.J.

1967-01-01

Hydrogeologic and construction data obtained from 119 test holes, wells, and emplacement holes at the Nevada Test Site and vicinity (through December 1966) are tabulated. The availability of cuttings, cores, lithologic logs, geophysical logs, formation-water analyses, hydraulic test data, and detailed construction data for each hole, as well as references to published reports for selected holes, are noted.

Tube cutter tool and method of use for coupon removal

DOEpatents

Nachbar, H.D.; Etten, M.P. Jr.; Kurowski, P.A.

1997-05-06

A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place. 4 figs.

Tube cutter tool and method of use for coupon removal

DOEpatents

Nachbar, Henry D.; Etten, Jr., Marvin P.; Kurowski, Paul A.

1997-01-01

A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place.

CONCOMITANT MACULAR HOLE AND CENTRAL SEROUS CHORIORETINOPATHY AFTER BLUNT EYE TRAUMA.

PubMed

Tekin, Kemal; Citirik, Mehmet; Atalay, Muhammed; Teke, Mehmet Yasin

2018-01-01

To report concomitant macular hole and central serous chorioretinopathy after blunt trauma. Case presentation. A 31-year-old man presented with a complaint of a reduction in visual acuity and blurred vision in the right eye after blunt eye trauma. The patient did not have a history of any systemic disorders and drug administration. On ocular examination, best corrected visual acuity was 2/20 in the right eye and 20/20 in the left eye. His intraocular pressures were 14 mmHg right eye and 13 mmHg left eye by applanation tonometry. Dilated fundus examination of the right eye showed macular hole and serous macular detachment, whereas the left eye was completely normal. Optical coherence tomography confirmed the full-thickness macular hole and subretinal fluid in the right eye, and ink-blot leakage pattern was determined in fundus fluorescein angiography. The patient was followed up without systemic therapy. Three months later, the vision was 10/20 in the right eye with completely closed macular hole and complete resolution of subretinal fluid. This is the first case which describes concomitant macular hole and central serous chorioretinopathy after blunt eye trauma. This presentation demonstrates that macular hole and central serous chorioretinopathy can be developed after blunt trauma. Both pathology may result with spontaneous closure of macular hole and spontaneous resolution of subretinal fluid within 3 months.

Constraints on core collapse from the black hole mass function

NASA Astrophysics Data System (ADS)

Kochanek, C. S.

2015-01-01

We model the observed black hole mass function under the assumption that black hole formation is controlled by the compactness of the stellar core at the time of collapse. Low-compactness stars are more likely to explode as supernovae and produce neutron stars, while high-compactness stars are more likely to be failed supernovae that produce black holes with the mass of the helium core of the star. Using three sequences of stellar models and marginalizing over a model for the completeness of the black hole mass function, we find that the compactness ξ2.5 above which 50% of core collapses produce black holes is ξ _{2.5}^{50%}=0.24 (0.15 < ξ _{2.5}^{50%} < 0.37 at 90% confidence). The models also predict that f = 0.18 (0.09 < f < 0.39) of core collapses fail. We tested four other criteria for black hole formation based on ξ2.0 and ξ3.0, the compactnesses at enclosed masses of 2.0 or 3.0 rather than 2.5 M⊙, the mass of the iron core MFe, and the mass inside the oxygen burning shell MO. We found that ξ2.0 works as well as ξ2.5, while ξ3.0, MFe and MO are significantly worse. As expected from the high compactness of 20-25 M⊙ stars, black hole formation in this mass range provides a natural explanation of the red supergiant problem.

Fractographic analysis of 2.0-mm plates with a screw locking system in simulated fractures of the mandibular body.

PubMed

de Medeiros, Raquel Correia; Lauria de Moura, Andrezza; Rodrigues, Danillo Costa; Menezes Mendes, Marcelo Breno; Sawazaki, Renato; Fernandes Moreira, Roger William

2014-06-01

The purpose of the present study was to analyze the fractured plates from 2 brands of 2.0-mm locking fixation systems submitted to axial linear load testing. Four aluminum hemimandibles with linear sectioning to simulate a mandibular body fracture were used as a substrate and fixed with 2 fixation techniques from 2 national brands: Tóride and Traumec. The techniques were as follows: one 4-hole plate, with four 6-mm screws in the tension zone, and one 4-hole plate, with four 10-mm screws in the compression zone; and one 4-hole plate, with four 6-mm holes in the neutral zone. The hemimandibles were submitted to vertical linear load tests using an Instron 4411 mechanical test machine. The system was submitted to the test until complete failure had occurred. Next, a topographic analysis of the surface of the plates was performed using a stereomicroscope and an electronic scanning microscope. The samples were evaluated using different magnifications, and images were obtained. The surface of the fracture analyzed in scanning electron microscopy demonstrated a ductile-type fracture, usually found in the traction test bodies of ductile materials, such as titanium. No evidence of failure was observed in any fracture surface from a change in the structure or composition of the material. The plates were fractured by a ductile rupture mechanism, as expected, suggesting that the manufacturing of the national brand name plates used in the present study has been under adequate quality control, with no structural changes produced by the manufacturing process that could compromise their function. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Esmeralda Energy Company, Final Scientific Technical Report, January 2008. Emigrant Slimhole Drilling Project, DOE GRED III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deymonaz, John; Hulen, Jeffrey B.; Nash, Gregory D.

2008-01-22

The Emigrant Slimhole Drilling Project (ESDP) was a highly successful, phased resource evaluation program designed to evaluate the commercial geothermal potential of the eastern margin of the northern Fish Lake Valley pull-apart basin in west-central Nevada. The program involved three phases: (1) Resource evaluation; (2) Drilling and resource characterization; and (3) Resource testing and assessment. Efforts included detailed geologic mapping; 3-D modeling; compilation of a GIS database; and production of a conceptual geologic model followed by the successful drilling of the 2,938 foot deep 17-31 slimhole (core hole), which encountered commercial geothermal temperatures (327⁰ F) and exhibits an increasing, conductive,more » temperature gradient to total depth; completion of a short injection test; and compilation of a detailed geologic core log and revised geologic cross-sections. Results of the project greatly increased the understanding of the geologic model controlling the Emigrant geothermal resource. Information gained from the 17-31 core hole revealed the existence of commercial temperatures beneath the area in the Silver Peak Core Complex which is composed of formations that exhibit excellent reservoir characteristics. Knowledge gained from the ESDP may lead to the development of a new commercial geothermal field in Nevada. Completion of the 17-31 core hole also demonstrated the cost-effectiveness of deep core drilling as an exploration tool and the unequaled value of core in understanding the geology, mineralogy, evolutional history and structural aspects of a geothermal resource.« less

Standard methods for filled hole tension testing of textile composites

NASA Technical Reports Server (NTRS)

Portanova, M. A.; Masters, J. E.

1995-01-01

The effects of two test specimen geometry parameters, the specimen width and W/D ratio, on filled-hole tensile strength were determined for textile composite materials. Test data generated by Boeing and Lockheed on 2-D and 3-D braids, and 3-D weaves were used to make these evaluations. The investigation indicated that filled-hole tensile-strength showed little sensitivity to either parameter. Test specimen configurations used in open-hole tension tests, such as those suggested by ASTM D5766 - Standard Test Method for Open Hole Tensile Strength of Polymer Matrix Composite Laminates or those proposed by MIL-HDBK-17-lD should provide adequate results for material comparisons studies. Comparisons of the materials' open-hole and filled-hole tensile strengths indicated that the latter were generally lower than the former. The 3-D braids were the exception; their filled-hole strengths were unexpected larger than their open-hole strengths. However, these increases were small compared to the scatter in the data. Thus, filled hole tension may be a critical design consideration for textile composite materials.

Predicting Failure Progression and Failure Loads in Composite Open-Hole Tension Coupons

NASA Technical Reports Server (NTRS)

Arunkumar, Satyanarayana; Przekop, Adam

2010-01-01

Failure types and failure loads in carbon-epoxy [45n/90n/-45n/0n]ms laminate coupons with central circular holes subjected to tensile load are simulated using progressive failure analysis (PFA) methodology. The progressive failure methodology is implemented using VUMAT subroutine within the ABAQUS(TradeMark)/Explicit nonlinear finite element code. The degradation model adopted in the present PFA methodology uses an instantaneous complete stress reduction (COSTR) approach to simulate damage at a material point when failure occurs. In-plane modeling parameters such as element size and shape are held constant in the finite element models, irrespective of laminate thickness and hole size, to predict failure loads and failure progression. Comparison to published test data indicates that this methodology accurately simulates brittle, pull-out and delamination failure types. The sensitivity of the failure progression and the failure load to analytical loading rates and solvers precision is demonstrated.

The Virtual Peg Insertion Test as an assessment of upper limb coordination in ARSACS patients: a pilot study.

PubMed

Gagnon, Cynthia; Lavoie, Caroline; Lessard, Isabelle; Mathieu, Jean; Brais, Bernard; Bouchard, Jean-Pierre; Fluet, Marie-Christine; Gassert, Roger; Lambercy, Olivier

2014-12-15

This paper introduces a novel assessment tool to provide clinicians with quantitative and more objective measures of upper limb coordination in patients suffering from Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS). The Virtual Peg Insertion Test (VPIT) involves manipulating an instrumented handle in order to move nine pegs into nine holes displayed in a virtual environment. The main outcome measures were the number of zero-crossings of the hand acceleration vector, as a measure of movement coordination and the total time required to complete the insertion of the nine pegs, as a measure of overall upper limb performance. 8\\9 patients with ARSACS were able to complete five repetitions with the VPIT. Patients were found to be significantly less coordinated and slower than age-matched healthy subjects (p<0.01). Performance of ARSACS patients was positively correlated with the Nine-Hole Peg Test (r=0.85, p<0.01) and with age (r=0.93, p<0.01), indicative of the degenerative nature of the disease. This study presents preliminary results on the use of a robotics and virtual reality assessment tool with ARSACS patients. Results highlight its potential to assess impaired coordination and monitor its progression over time. Copyright © 2014 Elsevier B.V. All rights reserved.

SSME seal test program: Test results for hole-pattern damper seals

NASA Technical Reports Server (NTRS)

Childs, D. W.

1985-01-01

The results consisting of direct and transverse force coefficients are presented for thirteen, hole-pattern, damper-seal configurations. The designation damper seal refers to a seal which uses a deliberately roughened stator nd smooth rotor, to increase the net damping force developed by a seal. The designation hole-pattern refers to a stator roughness pattern which is developed by a pattern of round holes while are milled into the stator. All seals tested use the same smooth rotor and have the same constant minimum clearance. The seal tests examined the following major design options: (1) hole-area density, i.e., the proportion of stator surface area consumed by holes; and (2) hole depth, particularly the ratio of hole depth to minimum clearance. In addition, limited data were taken to examine the influence of in-line versus staggered hole patterns and flat-bottomed versus spherical-bottomed holes.

Drilling and production aspects of horizontal wells in the Austin Chalk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheikholeslami, B.A.; Scholhman, B.W.; Seidel, F.A.

1991-07-01

This paper discusses testing of horizontal technology for use in the highly fractured Giddings oil field. Three short-and seven medium-radius wells were drilled successfully in the Austin Chalk formation. The paper discusses well plans, bottomhole assemblies, trajectory control, telemetry, mud systems, hydraulics, hole cleaning, casing design, cementing, problems encountered, formation evaluation, completions, and reservoir response.

Basic data from five core holes in the Raft River geothermal area, Cassia County, Idaho

USGS Publications Warehouse

Crosthwaite, E. G.

1976-01-01

meters) were completed in the area (Crosthwaite, 1974), and the Aerojet Nuclear Company, under the auspices of the U.S. Energy Research and Development Administration, was planning some deep drilling 4,000 to 6,000 feet (1,200 to 1,800 meters) (fig. 1). The purpose of the core drilling was to provide information to test geophysical interpretations of the subsurface structure and lithology and to provide hydrologic and geologic data on the shallow part of the geothermal system. Samples of the core were made available to several divisions and branches of the Geological Survey and to people and agencies outside the Survey. This report presents the basic data from the core holes that had been collected to September 1, 1975, and includes lithologic and geophysical well logs, chemical analyses of water (table 1), and laboratory analyses of cores (table 2) that were completed as of the above date. The data were collected by the Idaho District office, Hydrologic Laboratory, Borehole Geophysics Research Project, and Drilling, Sampling, and Testing Section, all of the Water Resources Division, and the Branch of Central Environmental Geology of the Geologic Divison.

Constraining the spin and the deformation parameters from the black hole shadow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsukamoto, Naoki; Li, Zilong; Bambi, Cosimo, E-mail: tsukamoto@fudan.edu.cn, E-mail: zilongli@fudan.edu.cn, E-mail: bambi@fudan.edu.cn

2014-06-01

Within 5–10 years, very-long baseline interferometry (VLBI) facilities will be able to directly image the accretion flow around SgrA*, the super-massive black hole candidate at the center of the Galaxy, and observe the black hole ''shadow''. In 4-dimensional general relativity, the no-hair theorem asserts that uncharged black holes are described by the Kerr solution and are completely specified by their mass M and by their spin parameter a. In this paper, we explore the possibility of distinguishing Kerr and Bardeen black holes from their shadow. In Hioki and Maeda (2009), under the assumption that the background geometry is described bymore » the Kerr solution, the authors proposed an algorithm to estimate the value of a/M by measuring the distortion parameter δ, an observable quantity that characterizes the shape of the shadow. Here, we try to extend their approach. Since the Hioki-Maeda distortion parameter is degenerate with respect to the spin and possible deviations from the Kerr solution, one has to measure another quantity to test the Kerr black hole hypothesis. We study a few possibilities. We find that it is extremely difficult to distinguish Kerr and Bardeen black holes from the sole observation of the shadow, and out of reach for the near future. The combination of the measurement of the shadow with possible accurate radio observations of a pulsar in a compact orbit around SgrA* could be a more promising strategy to verify the Kerr black hole paradigm.« less

SSME seal test program: Test results for smooth, hole-pattern and helically-grooved stators

NASA Technical Reports Server (NTRS)

Childs, Dara W.

1987-01-01

All of the listed seals were tested in a liquid Halon test facility at high Reynolds numbers. In addition, a helically-grooved-stator seal was tested in an air seal facility. An analysis of the test results with comparisons to theoretical predictions supports the following conclusions: (1) For small seals, the Hirs' friction-factor model is more restricted than had been thought; (2) For smooth seals, predictions of stiffness and damping improve markedly as the radical clearance is reduced; (3) Friction-factor data for hole-pattern-seal stators frequently deviates from the Hirs model; (4) Predictions of stiffness and damping coefficients for hole-pattern-stator seals is generally reasonable; (5) Tests for the hole-pattern stators at reduced clearances show no clear optimum for hole-pattern seals with respect to either hole-area ratio or hole depth to minimum clearance ratios; (6) Tests of these hole-pattern stators show no significant advantage in net damping over smooth seals; (7) Tests of helically-grooved seal stators in Halon show reasonable agreement between theory and prediction for leakage and direct stiffness but poor agreement for the net damping coefficient.

Geothermal Exploration of Newberry Volcano, Oregon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waibel, Albert F.; Frone, Zachary S.; Blackwell, David D.

Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315°C (600°F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three yearsmore » have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.« less

Failure mechanisms of uni-ply composite plates with a circular hole under static compressive loading

NASA Technical Reports Server (NTRS)

Khamseh, A. R.; Waas, A. M.

1992-01-01

The objective of the study was to identify and study the failure mechanisms associated with compressive-loaded uniply graphite/epoxy square plates with a central circular hole. It is found that the type of compressive failure depends on the hole size. For large holes with the diameter/width ratio exceeding 0.062, fiber buckling/kinking initiated at the hole is found to be the dominant failure mechanism. In plates with smaller hole sizes, failure initiates away from the hole edge or complete global failure occurs. Critical buckle wavelengths at failure are presented as a function of the normalized hole diameter.

Standard methods for open hole tension testing of textile composites

NASA Technical Reports Server (NTRS)

Portanova, M. A.; Masters, J. E.

1995-01-01

Sizing effects have been investigated by comparing the open hole failure strengths of each of the four different braided architectures as a function of specimen thickness, hole diameter, and the ratio of specimen width to hole diameter. The data used to make these comparisons was primarily generated by Boeing. Direct comparisons of Boeing's results were made with experiments conducted at West Virginia University whenever possible. Indirect comparisons were made with test results for other 2-D braids and 3-D weaves tested by Boeing and Lockheed. In general, failure strength was found to decrease with increasing plate thickness, increase with decreasing hole size, and decreasing with decreasing width to diameter ratio. The interpretation of the sensitive to each of these geometrical parameters was complicated by scatter in the test data. For open hole tension testing of textile composites, the use of standard testing practices employed by industry, such as ASTM D5766 - Standard Test Method for Open Hole Tensile Strength of Polymer Matrix Composite Laminates should provide adequate results for material comparisons studies.

PEGASUS 5: An Automated Pre-Processor for Overset-Grid CFD

NASA Technical Reports Server (NTRS)

Suhs, Norman E.; Rogers, Stuart E.; Dietz, William E.; Kwak, Dochan (Technical Monitor)

2002-01-01

An all new, automated version of the PEGASUS software has been developed and tested. PEGASUS provides the hole-cutting and connectivity information between overlapping grids, and is used as the final part of the grid generation process for overset-grid computational fluid dynamics approaches. The new PEGASUS code (Version 5) has many new features: automated hole cutting; a projection scheme for fixing gaps in overset surfaces; more efficient interpolation search methods using an alternating digital tree; hole-size optimization based on adding additional layers of fringe points; and an automatic restart capability. The new code has also been parallelized using the Message Passing Interface standard. The parallelization performance provides efficient speed-up of the execution time by an order of magnitude, and up to a factor of 30 for very large problems. The results of three example cases are presented: a three-element high-lift airfoil, a generic business jet configuration, and a complete Boeing 777-200 aircraft in a high-lift landing configuration. Comparisons of the computed flow fields for the airfoil and 777 test cases between the old and new versions of the PEGASUS codes show excellent agreement with each other and with experimental results.

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

Accelerated observers and the notion of singular spacetime

NASA Astrophysics Data System (ADS)

Olmo, Gonzalo J.; Rubiera-Garcia, Diego; Sanchez-Puente, Antonio

2018-03-01

Geodesic completeness is typically regarded as a basic criterion to determine whether a given spacetime is regular or singular. However, the principle of general covariance does not privilege any family of observers over the others and, therefore, observers with arbitrary motions should be able to provide a complete physical description of the world. This suggests that in a regular spacetime, all physically acceptable observers should have complete paths. In this work we explore this idea by studying the motion of accelerated observers in spherically symmetric spacetimes and illustrate it by considering two geodesically complete black hole spacetimes recently described in the literature. We show that for bound and locally unbound accelerations, the paths of accelerated test particles are complete, providing further support to the regularity of such spacetimes.

Completion Report for Model Evaluation Well ER-5-5: Corrective Action Unit 98: Frenchman Flat

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Underground Test Area and Boreholes Programs and Operations

2013-01-18

Model Evaluation Well ER-5-5 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of Nevada Environmental Management Operations at the Nevada National Security Site (formerly known as the Nevada Test Site). The well was drilled in July and August 2012 as part of a model evaluation well program in the Frenchman Flat area of Nye County, Nevada. The primary purpose of the well was to provide detailed geologic, hydrogeologic, chemical, and radiological data that can be used to test and build confidence in the applicability of the Frenchman Flat Corrective Action Unitmore » flow and transport models for their intended purpose. In particular, this well was designed to obtain data to evaluate the uncertainty in model forecasts of contaminant migration from the upgradient underground nuclear test MILK SHAKE, conducted in Emplacement Hole U-5k in 1968, which were considered to be uncertain due to the unknown extent of a basalt lava-flow aquifer present in this area. Well ER-5-5 is expected to provide information to refine the Phase II Frenchman Flat hydrostratigraphic framework model, if necessary, as well as to support future groundwater flow and transport modeling. The 31.1-centimeter (cm) diameter hole was drilled to a total depth of 331.3 meters (m). The completion string, set at the depth of 317.2 m, consists of 16.8-cm stainless-steel casing hanging from 19.4-cm carbon-steel casing. The 16.8-cm stainless-steel casing has one slotted interval open to the basalt lava-flow aquifer and limited intervals of the overlying and underlying alluvial aquifer. A piezometer string was also installed in the annulus between the completion string and the borehole wall. The piezometer is composed of 7.3-cm stainless-steel tubing suspended from 6.0-cm carbon-steel tubing. The piezometer string was landed at 319.2 m, to monitor the basalt lava-flow aquifer. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, preliminary water quality measurements, and water-level measurements. The well penetrated 331.3 m of Quaternary–Tertiary alluvium, including an intercalated layer of saturated basalt lava rubble. No well development or hydrologic testing was conducted in this well immediately after completion; however, a preliminary water level was measured in the piezometer string at the depth of 283.4 m on September 25, 2012. No tritium above the minimum detection limit of the field instruments was detected in this hole. Future well development, sampling, and hydrologic testing planned for this well will provide more accurate hydrologic information for this site. The stratigraphy, general lithology, and water level were as expected, though the expected basalt lava-flow aquifer is basalt rubble and not the dense, fractured lava as modeled. The lack of tritium transport is likely due to the difference in hydraulic properties of the basalt lava-flow rubble encountered in the well, compared to those of the fractured aquifer used in the flow and transport models.« less

Preliminary report on the geology, geophysics and hydrology of USBM/AEC Colorado core hole No. 2, Piceance Creek Basin, Rio Blanco County, Colorado

USGS Publications Warehouse

Ege, J.R.; Carroll, R.D.; Welder, F.A.

1967-01-01

Approximately 1,400 feet of continuous core was taken .between 800-2,214 feet in depth from USBM/AEC Colorado core hole No. 2. The drill, site is located in the Piceance Creek basin, Rio Blanco County, Colorado. From ground surface the drill hole penetrated 1,120 feet of the Evacuation Creek Member and 1,094 feet of oil shale in the Parachute Creek Member of the Green River Formation. Oil shale yielding more than 20 gallons per ton occurs between 1,260-2,214 feet in depth. A gas explosion near the bottom of the hole resulted in abandonment of the exploratory hole which was still in oil shale. The top of the nahcolite zone is at 1,693 feet. Below this depth the core contains common to abundant amounts of sodium bicarbonate salt intermixed with oil shale. The core is divided into seven structural zones that reflect changes in joint intensity, core loss and broken core due to natural causes. The zone of poor core recovery is in the Interval between 1,300-1,450 feet. Results of preliminary geophysical log analyses indicate that oil yields determined by Fischer assay compare favorably with yields determined by geophysical log analyses. There is strong evidence that analyses of complete core data from Colorado core holes No. 1 and No. 2 reveal a reliable relationship between geophysical log response and oil yield. The quality of the logs is poor in the rich shale section and the possibility of repeating the logging program should be considered. Observations during drilling, coring, and hydrologic testing of USBM/AEC Colorado core hole No. 2 reveal that the Parachute Creek Member of the Green River Formation is the principal aquifer water in the Parachute Creek Member is under artesian pressure. The upper part of the aquifer has a higher hydrostatic head than, and is hydrologically separated from the lower part of the aquifer. The transmissibility of the aquifer is about 3500 gpd per foot. The maximum water yield of the core hole during testing was about 500 gpm. Chemical analyses of water samples indicate that the content of dissolved solids is low, the principal ions being sodium and bicarbonate. Although the hole was originally cored, to a depth of 2,214 feet, ,the present depth is about 2,100 feet. This report presents a preliminary evaluation of core examination, geophysical log interpretation and hydrological tests from the USBM/AEC Colorado core hole No. 2. The cooperation of the U.S. Bureau of Mines is gratefully acknowledged. The reader is referred to Carroll and others (1967) for comparison of USBM/AEC Col0rado core hole No. 1 with USBM/AEC Colorado core hole No. 2.

Spontaneous closure of traumatic macular hole.

PubMed

Sanjay, Srinivasan; Yeo, Tun Kuan; Au Eong, Kah-Guan

2012-07-01

Macular hole formation is a well-known complication following ocular trauma. Less commonly recognised is the spontaneous closure of such holes. A 27-year-old man presented with a history of blunt trauma to his left eye. Eye evaluation showed conjunctival laceration, diffuse retinal oedema and multiple retinal haemorrhages in that eye. A month later, he developed a full thickness macular hole. Two months later, there was spontaneous complete closure of the full-thickness macular hole in the left eye as confirmed on optical coherence tomography. Spontaneous closure of hole is not uncommon. Observation for a period of up to 12 months is a reasonable management option. Macular hole surgery for traumatic macular holes may be delayed in such cases.

An experimental study of compression failure of fibrous laminated composites in the presence of stress gradients

NASA Technical Reports Server (NTRS)

Waas, A. M.; Knauss, W. G.; Babcock, C. D., Jr.

1990-01-01

Mechanisms of failure in laminates in the presence of a stress raiser were experimentally studied. The damage initiation and propagation throughout the entire load history were examined via real-time holographic interferometry and photomicrography of the hole surface. Multilayered composite flat plates made of T300/BP907 and IM7/8551-7 were tested. It is shown that the failure is initiated as a localized instability in the 0-deg plies at the hole surface approximately at right angles to the loading direction. A series of events is described which culminates in the complete loss of flexural stiffness of each of the delaminated portions, leading to catastrophic failure of the plate.

Capacitively Coupled Resistivity Survey of Selected Irrigation Canals Within the North Platte River Valley, Western Nebraska and Eastern Wyoming, 2004 and 2007-2009

USGS Publications Warehouse

Burton, Bethany L.; Johnson, Michaela R.; Vrabel, Joseph; Imig, Brian H.; Payne, Jason; Tompkins, Ryan E.

2009-01-01

Due to water resources of portions of the North Platte River basin being designated as over-appropriated by the State of Nebraska Department of Natural Resources (DNR), the North Platte Natural Resources District (NPNRD), in cooperation with the DNR, is developing an Integrated Management Plan (IMP) for groundwater and surface water in the NPNRD. As part of the IMP, a three-dimensional numerical finite difference groundwater-flow model is being developed to evaluate the effectiveness of using leakage of water from selected irrigation canal systems to manage groundwater recharge. To determine the relative leakage potential of the upper 8 m of the selected irrigation canals within the North Platte River valley in western Nebraska and eastern Wyoming, the U.S. Geological Survey performed a land-based capacitively coupled (CC) resistivity survey along nearly 630 km of 13 canals and 2 laterals in 2004 and from 2007 to 2009. These 13 canals were selected from the 27 irrigation canals in the North Platte valley due to their location, size, irrigated area, and relation to the active North Platte valley flood plain and related paleochannels and terrace deposits where most of the saturated thickness in the alluvium exists. The resistivity data were then compared to continuous cores at 62 test holes down to a maximum depth of 8 m. Borehole electrical conductivity (EC) measurements at 36 of those test holes were done to correlate resistivity values with grain sizes in order to determine potential vertical leakage along the canals as recharge to the underlying alluvial aquifer. The data acquired in 2004, as well as the 25 test hole cores from 2004, are presented elsewhere. These data were reprocessed using the same updated processing and inversion algorithms used on the 2007 through 2009 datasets, providing a consistent and complete dataset for all collection periods. Thirty-seven test hole cores and borehole electrical conductivity measurements were acquired based on the 2008 data. This report presents comparisons between the CC resistivity data and results from the 37 test holes and includes all binned and inverted CC resistivity datasets from all four years as well as the EC log data for the 37 test holes acquired in 2008 and 2009. The information gained from these data can help State and local water managers and scientists better understand the characteristics of the shallow subsurface underlying the irrigation canals so that the water resources can be managed more effectively.

New Panorama Reveals More Than a Thousand Black Holes

NASA Astrophysics Data System (ADS)

2007-03-01

By casting a wide net, astronomers have captured an image of more than a thousand supermassive black holes. These results give astronomers a snapshot of a crucial period when these monster black holes are growing, and provide insight into the environments in which they occur. The new black hole panorama was made with data from NASA's Chandra X-ray Observatory, the Spitzer Space Telescope and ground-based optical telescopes. The black holes in the image are hundreds of millions to several billion times more massive than the sun and lie in the centers of galaxies. X-ray, IR & Optical Composites of Obscured & Unobscured AGN in Bootes Field X-ray, IR & Optical Composites of Obscured & Unobscured AGN in Bootes Field Material falling into these black holes at high rates generates huge amounts of light that can be detected in different wavelengths. These systems are known as active galactic nuclei, or AGN. "We're trying to get a complete census across the Universe of black holes and their habits," said Ryan Hickox of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. "We used special tactics to hunt down the very biggest black holes." Instead of staring at one relatively small part of the sky for a long time, as with the Chandra Deep Fields -- two of the longest exposures obtained with the observatory -- and other concentrated surveys, this team scanned a much bigger portion with shorter exposures. Since the biggest black holes power the brightest AGN, they can be spotted at vast distances, even with short exposures. Scale Chandra Images to Full Moon Scale Chandra Images to Full Moon "With this approach, we found well over a thousand of these monsters, and have started using them to test our understanding of these powerful objects," said co-investigator Christine Jones, also of the CfA. The new survey raises doubts about a popular current model in which a supermassive black hole is surrounded by a doughnut-shaped region, or torus, of gas. An observer from Earth would have their view blocked by this torus by different amounts, depending on the orientation of the torus. According to this model, astronomers would expect a large sample of black holes to show a range of absorption of the radiation from the nuclei. This absorption should range from completely exposed to completely obscured, with most in-between. Nuclei that are completely obscured are not detectable, but heavily obscured ones are. "Instead of finding a whole range, we found nearly all of the black holes are either naked or covered by a dense veil of gas," said Hickox. "Very few are in between, which makes us question how well we know the environment around these black holes." This study found more than 600 obscured and 700 unobscured AGN, located between about six to 11 billion light years from Earth. They were found using an early application of a new search method. By looking at the infrared colors of objects with Spitzer, AGN can be separated from stars and galaxies. The Chandra and optical observations then verify these objects are AGN. This multi-wavelength method is especially efficient at finding obscured AGN. "These results are very exciting, using two NASA Great Observatories to find and understand the largest sample of obscured supermassive black holes ever found in the distant universe", said co-investigator Daniel Stern, of NASA's Jet Propulsion Laboratory in Pasadena, Calif. The Chandra image is the largest contiguous field ever obtained by the observatory. At 9.3 square degrees, it is over 40 times larger than the full moon seen on the night sky and over 80 times larger than either of the Chandra Deep Fields. This survey, taken in a region of the Bootes constellation, involved 126 separate pointings of 5,000-second Chandra exposures each. The researchers combined this with data obtained from Spitzer, and Kitt Peak's 4-meter Mayall and the MMT 6.5-meter optical telescopes, both located outside Tuscon, Ariz., from the same patch of sky. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Quantum information cannot be completely hidden in correlations: implications for the black-hole information paradox.

PubMed

Braunstein, Samuel L; Pati, Arun K

2007-02-23

Can quantum-information theory shed light on black-hole evaporation? By entangling the in-fallen matter with an external system we show that the black-hole information paradox becomes more severe, even for cosmologically sized black holes. We rule out the possibility that the information about the in-fallen matter might hide in correlations between the Hawking radiation and the internal states of the black hole. As a consequence, either unitarity or Hawking's semiclassical predictions must break down. Any resolution of the black-hole information crisis must elucidate one of these possibilities.

Novel fiber-based technique for inspection of holes in narrow-bore tubes

NASA Astrophysics Data System (ADS)

Bernard, Fabien; Flaherty, Tony; O'Connor, Gerard M.

2009-06-01

Optical tools offer a route to increasing throughput and efficiency in industrial inspection operations, one of the most time-consuming and labour-intensive aspects of modern manufacturing. One prominent example in the medical device industry is inspection of drilled holes, particularly in narrow-bore tubes (precision-flow devices, such as catheters for drug delivery, radio-opaque contrast agents, etc). The products in which these holes feature are increasing in complexity (reduced dimensions, increasing number of drilled features- in some products now reaching into the hundreds). These trends present a number of technical challenges, not least to ensure that holes are completed and that no damage to the part occurs as a result of over-drilling, for example. This paper will present a novel sensor based on back-side illumination of the drilled hole using side-glowing optical fibers to detect, qualify and quantify drilled holes. The concept is based on inserting a laser-coupled side-glowing optical fiber into the lumen of the tube to be drilled, and imaging the light emitted from this fiber through a drilled hole using a vision system mounted external to the tube. The light from the fiber allows rapid determination of hole completion, shape and size, as well as quantity in the case of products with multiple holes. If the fiber is mounted in the tube prior to drilling, the light emitted from the fiber can be used as a real-time hole breakthrough sensor, preventing under or overdrilling of the tube.

Spontaneous closure of traumatic macular hole

PubMed Central

Sanjay, Srinivasan; Yeo, Tun Kuan; Au Eong, Kah-Guan

2012-01-01

Macular hole formation is a well-known complication following ocular trauma. Less commonly recognised is the spontaneous closure of such holes. A 27-year-old man presented with a history of blunt trauma to his left eye. Eye evaluation showed conjunctival laceration, diffuse retinal oedema and multiple retinal haemorrhages in that eye. A month later, he developed a full thickness macular hole. Two months later, there was spontaneous complete closure of the full-thickness macular hole in the left eye as confirmed on optical coherence tomography. Spontaneous closure of hole is not uncommon. Observation for a period of up to 12 months is a reasonable management option. Macular hole surgery for traumatic macular holes may be delayed in such cases. PMID:23961017

Testing quantum gravity through dumb holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pourhassan, Behnam, E-mail: b.pourhassan@du.ac.ir; Faizal, Mir, E-mail: f2mir@uwaterloo.ca; Irving K. Barber School of Arts and Sciences, University of British Columbia - Okanagan, Kelowna, BC V1V 1V7

We propose a method to test the effects of quantum fluctuations on black holes by analyzing the effects of thermal fluctuations on dumb holes, the analogs for black holes. The proposal is based on the Jacobson formalism, where the Einstein field equations are viewed as thermodynamical relations, and so the quantum fluctuations are generated from the thermal fluctuations. It is well known that all approaches to quantum gravity generate logarithmic corrections to the entropy of a black hole and the coefficient of this term varies according to the different approaches to the quantum gravity. It is possible to demonstrate thatmore » such logarithmic terms are also generated from thermal fluctuations in dumb holes. In this paper, we claim that it is possible to experimentally test such corrections for dumb holes, and also obtain the correct coefficient for them. This fact can then be used to predict the effects of quantum fluctuations on realistic black holes, and so it can also be used, in principle, to experimentally test the different approaches to quantum gravity.« less

Geology and paleontology of five cores from Screven and Burke counties, eastern Georgia

USGS Publications Warehouse

Edwards, Lucy E.

2001-01-01

Five deep stratigraphic test holes were drilled from 1991 to 1993 in support of multidisciplinary investigations to determine the stratigraphy of Upper Cretaceous and Tertiary sediments of the coastal plain in east-central Georgia. Cored sediment and geological logs from the Millhaven test hole in Screven County and the Girard and Millers Pond test holes in Burke County are the primary sources of lithologic and paleontologic information from this report. Lithologic and paleontologic information from the Thompson Oak and McBean test holes in Burke County supplements the discussion of stratigraphy and sedimentation in the updip part of the study area near the Millers Pond test hole.

Subchondral chitosan/blood implant-guided bone plate resorption and woven bone repair is coupled to hyaline cartilage regeneration from microdrill holes in aged rabbit knees.

PubMed

Guzmán-Morales, J; Lafantaisie-Favreau, C-H; Chen, G; Hoemann, C D

2014-02-01

Little is known of how to routinely elicit hyaline cartilage repair tissue in middle-aged patients. We tested the hypothesis that in skeletally aged rabbit knees, microdrill holes can be stimulated to remodel the bone plate and induce a more integrated, voluminous and hyaline cartilage repair tissue when treated by subchondral chitosan/blood implants. New Zealand White rabbits (13 or 32 months old, N = 7) received two 1.5 mm diameter, 2 mm depth drill holes in each knee, either left to bleed as surgical controls or press-fit with a 10 kDa (distal hole: 10K) or 40 kDa (proximal hole: 40K) chitosan/blood implant with fluorescent chitosan tracer. Post-operative knee effusion was documented. Repair tissues at day 0 (N = 1) and day 70 post-surgery (N = 6) were analyzed by micro-computed tomography, and by histological scoring and histomorphometry (SafO, Col-2, and Col-1) at day 70. All chitosan implants were completely cleared after 70 days, without increasing transient post-operative knee effusion compared to controls. Proximal control holes had worse osteochondral repair than distal holes. Both implant formulations induced bone remodeling and improved lateral integration of the bone plate at the hole edge. The 40K implant inhibited further bone repair inside 50% of the proximal holes, while the 10K implant specifically induced a "wound bloom" reaction, characterized by decreased bone plate density in a limited zone beyond the initial hole edge, and increased woven bone (WB) plate repair inside the initial hole (P = 0.016), which was accompanied by a more voluminous and hyaline cartilage repair (P < 0.05 vs control defects). In a challenging aged rabbit model, bone marrow-derived hyaline cartilage repair can be promoted by treating acute drill holes with a biodegradable subchondral implant that elicits bone plate resorption followed by anabolic WB repair within a 70-day repair period. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Black hole evaporation in conformal gravity

NASA Astrophysics Data System (ADS)

Bambi, Cosimo; Modesto, Leonardo; Porey, Shiladitya; Rachwał, Lesław

2017-09-01

We study the formation and the evaporation of a spherically symmetric black hole in conformal gravity. From the collapse of a spherically symmetric thin shell of radiation, we find a singularity-free non-rotating black hole. This black hole has the same Hawking temperature as a Schwarzschild black hole with the same mass, and it completely evaporates either in a finite or in an infinite time, depending on the ensemble. We consider the analysis both in the canonical and in the micro-canonical statistical ensembles. Last, we discuss the corresponding Penrose diagram of this physical process.

Black hole evaporation in conformal gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bambi, Cosimo; Rachwał, Lesław; Modesto, Leonardo

We study the formation and the evaporation of a spherically symmetric black hole in conformal gravity. From the collapse of a spherically symmetric thin shell of radiation, we find a singularity-free non-rotating black hole. This black hole has the same Hawking temperature as a Schwarzschild black hole with the same mass, and it completely evaporates either in a finite or in an infinite time, depending on the ensemble. We consider the analysis both in the canonical and in the micro-canonical statistical ensembles. Last, we discuss the corresponding Penrose diagram of this physical process.

Chemical analysis of water samples and geophysical logs from cored test holes drilled in the central Oklahoma Aquifer, Oklahoma

USGS Publications Warehouse

Schlottmann, Jamie L.; Funkhouser, Ron A.

1991-01-01

Chemical analyses of water from eight test holes and geophysical logs for nine test holes drilled in the Central Oklahoma aquifer are presented. The test holes were drilled to investigate local occurrences of potentially toxic, naturally occurring trace substances in ground water. These trace substances include arsenic, chromium, selenium, residual alpha-particle activities, and uranium. Eight of the nine test holes were drilled near wells known to contain large concentrations of one or more of the naturally occurring trace substances. One test hole was drilled in an area known to have only small concentrations of any of the naturally occurring trace substances.Water samples were collected from one to eight individual sandstone layers within each test hole. A total of 28 water samples, including four duplicate samples, were collected. The temperature, pH, specific conductance, alkalinity, and dissolved-oxygen concentrations were measured at the sample site. Laboratory determinations included major ions, nutrients, dissolved organic carbon, and trace elements (aluminum, arsenic, barium, beryllium, boron, cadmium, chromium, hexavalent chromium, cobalt, copper, iron, lead, lithium, manganese, mercury, molybdenum, nickel, selenium, silver, strontium, vanadium and zinc). Radionuclide activities and stable isotope (5 values also were determined, including: gross-alpha-particle activity, gross-beta-particle activity, radium-226, radium-228, radon-222, uranium-234, uranium-235, uranium-238, total uranium, carbon-13/carbon-12, deuterium/hydrogen-1, oxygen-18/oxygen-16, and sulfur-34/sulfur-32. Additional analyses of arsenic and selenium species are presented for selected samples as well as analyses of density and iodine for two samples, tritium for three samples, and carbon-14 for one sample.Geophysical logs for most test holes include caliper, neutron, gamma-gamma, natural-gamma logs, spontaneous potential, long- and short-normal resistivity, and single-point resistance. Logs for test-hole NOTS 7 do not include long- and short-normal resistivity, spontaneous-potential, or single-point resistivity. Logs for test-hole NOTS 7A include only caliper and natural-gamma logs.

Assessment of subjective intraocular forward scattering and quality of vision after posterior chamber phakic intraocular lens with a central hole (Hole ICL) implantation.

PubMed

Iijima, Ayaka; Shimizu, Kimiya; Yamagishi, Mayumi; Kobashi, Hidenaga; Igarashi, Akihito; Kamiya, Kazutaka

2016-12-01

To evaluate the subjective intraocular forward scattering and quality of vision after posterior chamber phakic intraocular lens with a central hole (Hole ICL, STAAR Surgical) implantation. We prospectively examined 29 eyes of 29 consecutive patients (15 men and 14 women; ages, 37.2 ± 8.8 years) undergoing Hole ICL implantation. We assessed the values of the logarithmic straylight value [log (s)] using a straylight meter (C-Quant ™ , Oculus) preoperatively and 3 months postoperatively. The patients completed a questionnaire detailing symptoms on a quantitative grading scale (National Eye Institute Refractive Error Quality of Life Instrument-42; NEI RQL-42) 3 months postoperatively. We compared the preoperative and postoperative values of the log(s) and evaluated the correlation of these values with patient subjective symptoms. The mean log(s) was not significantly changed, from 1.07 ± 0.20 preoperatively, to 1.06 ± 0.17 postoperatively (Wilcoxon signed-rank test, p = 0.641). There was a significant correlation between the preoperative and postoperative log(s) (Spearman's correlation coefficient r = 0.695, p < 0.001). The postoperative log(s) was significantly associated with the scores of glare in the questionnaire (Spearman's correlation coefficient r = -0.575, p = 0.017). According to our experience, Hole ICL implantation does not induce a significant additional change in the subjective intraocular forward scattering. The symptom of glare after Hole ICL implantation was significantly correlated with the postoperative intraocular forward scattering in relation to the preoperative one. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Towards a formalism for mapping the spacetimes of massive compact objects: Bumpy black holes and their orbits

NASA Astrophysics Data System (ADS)

Collins, Nathan A.; Hughes, Scott A.

2004-06-01

Astronomical observations have established that extremely compact, massive objects are common in the Universe. It is generally accepted that these objects are, in all likelihood, black holes. As observational technology has improved, it has become possible to test this hypothesis in ever greater detail. In particular, it is or will be possible to measure the properties of orbits deep in the strong field of a black hole candidate (using x-ray timing or future gravitational-wave measurements) and to test whether they have the characteristics of black hole orbits in general relativity. Past work has shown that, in principle, such measurements can be used to map the spacetime of a massive compact object, testing in particular whether the object’s multipolar structure satisfies the rather strict constraints imposed by the black hole hypothesis. Performing such a test in practice requires that we be able to compare against objects with the “wrong” multipole structure. In this paper, we present tools for constructing the spacetimes of bumpy black holes: objects that are almost black holes, but that have some multipoles with the wrong value. In this first analysis, we focus on objects with no angular momentum. Generalization to bumpy Kerr black holes should be straightforward, albeit labor intensive. Our construction has two particularly desirable properties. First, the spacetimes which we present are good deep into the strong field of the object—we do not use a “large r” expansion (except to make contact with weak field intuition). Second, our spacetimes reduce to the exact black hole spacetimes of general relativity in a natural way, by dialing the “bumpiness” of the black hole to zero. We propose that bumpy black holes can be used as the foundation for a null experiment: if black hole candidates are indeed the black holes of general relativity, their bumpiness should be zero. By comparing the properties of orbits in a bumpy spacetime with those measured from an astrophysical source, observations should be able to test this hypothesis, stringently testing whether they are in fact the black holes of general relativity.

Five-Hole Flow Angle Probe Calibration for the NASA Glenn Icing Research Tunnel

NASA Technical Reports Server (NTRS)

Gonsalez, Jose C.; Arrington, E. Allen

1999-01-01

A spring 1997 test section calibration program is scheduled for the NASA Glenn Research Center Icing Research Tunnel following the installation of new water injecting spray bars. A set of new five-hole flow angle pressure probes was fabricated to properly calibrate the test section for total pressure, static pressure, and flow angle. The probes have nine pressure ports: five total pressure ports on a hemispherical head and four static pressure ports located 14.7 diameters downstream of the head. The probes were calibrated in the NASA Glenn 3.5-in.-diameter free-jet calibration facility. After completing calibration data acquisition for two probes, two data prediction models were evaluated. Prediction errors from a linear discrete model proved to be no worse than those from a full third-order multiple regression model. The linear discrete model only required calibration data acquisition according to an abridged test matrix, thus saving considerable time and financial resources over the multiple regression model that required calibration data acquisition according to a more extensive test matrix. Uncertainties in calibration coefficients and predicted values of flow angle, total pressure, static pressure. Mach number. and velocity were examined. These uncertainties consider the instrumentation that will be available in the Icing Research Tunnel for future test section calibration testing.

Neurodegeneration in newborn rats following propofol and sevoflurane anesthesia.

PubMed

Bercker, Sven; Bert, Bettina; Bittigau, Petra; Felderhoff-Müser, Ursula; Bührer, Christoph; Ikonomidou, Chrysanthy; Weise, Mirjam; Kaisers, Udo X; Kerner, Thoralf

2009-08-01

Propofol and sevoflurane are commonly used drugs in pediatric anesthesia. Exposure of newborn rats to a variety of anesthetics has been shown to induce apoptotic neurodegeneration in the developing brain. Newborn Wistar rats were treated with repeated intraperitoneal injections of propofol or sevoflurane inhalation and compared to controls. Brains were examined histopathologically using the De Olmos cupric silver staining. Additionally, a summation score of the density of apoptotic cells was calculated for every brain. Spatial memory learning was assessed by the Morris Water Maze (MWM) test and the hole board test, performed in 7 weeks old animals who underwent the same anesthetic procedure. Brains of propofol-treated animals showed a significant higher neurodegenerative summation score (24,345) when compared to controls (15,872) and to sevoflurane-treated animals (18,870). Treated animals also demonstrated persistent learning deficits in the hole board test, whereas the MWM test revealed no differences between both groups. Among other substances acting via GABAA agonism and/or NMDA antagonism propofol induced neurodegeneration in newborn rat brains whereas a sevoflurane based anesthesia did not. The significance of these results for clinical anesthesia has not been completely elucidated. Future studies have to focus on the detection of safe anesthetic strategies for the developing brain.

Ground-water data for the Hanna and Carbon basins, south-central Wyoming, through 1980

USGS Publications Warehouse

Daddow, P.B.

1986-01-01

Groundwater resources in the Hanna and Carbon Basins of Wyoming were assessed in a study from 1974 through 1980 because of the development of coal mining in the area. Data collected from 105 wells during that study, including well-completion records, lithologic logs, and water levels, are presented. The data are from stock wells, coal-test holes completed as observation wells by the U.S. Geological Survey. The data are mostly from mined coal-bearing formations: the Tertiary Hanna Formation and the Tertiary and Cretaceous Ferris Formation. Well-completion data and lithologic logs were collected on-site during drilling of the wells or from U.S. Geological Survey files, company records, Wyoming State Engineer well-permit files, and published reports. (USGS)

An Investigation of the IMO Spread of Flame Test Method.

DTIC Science & Technology

1992-03-01

Sensors: Medtherm Model 64-3-20 Radiation Pyrometer: Honeywell, Model 939A4 Minature Radiamatic Pyrometer. Data Acquisition: Hewlett Packard Model 7100B...radiant panel. Circular holes were cut along the dummy specimen center line at 50, 200, 350, 500 and 650 mm to accommodate the Medtherm flux sensor...char line 75 0-250 Complete black char; pieces are exploding and separating from backing; heavy smoke 120 Explosive delamination; no flame 130 300

Site Report for USGS Test Holes Drilled at Cape Charles, Northampton County, Virginia, in 2004

USGS Publications Warehouse

Gohn, Gregory S.; Sanford, Ward E.; Powars, David S.; Horton, J. Wright; Edwards, Lucy E.; Morin, Roger H.; Self-Trail, Jean M.

2007-01-01

The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and June 2004, as part of an investigation of the buried, late Eocene Chesapeake Bay impact structure. The first hole is designated as the USGS-Sustainable Technology Park test hole #1 (USGS-STP1). This test hole was abandoned at a depth of 300 ft; cuttings samples were collected, but no cores or geophysical logs were acquired. The second hole is designated as the USGS-Sustainable Technology Park test hole #2 (USGS-STP2). This test hole was drilled to a depth of 2,699 ft. Cores were collected between depths of 1,401.7 ft and 1,420.7 ft and between 2,440.0 ft and 2,699.0 ft. Cuttings samples were collected from the uncored intervals below 280-ft depth. Interim sets of geophysical logs were acquired during the drilling operation, and one final set was acquired at the end of drilling. Two wells were installed in the USGS-STP2 test hole. The deep well (designated 62G-24) was screened between 2,260 ft and 2,280 ft, and the shallow well (designated 62G-25) was screened between 1,360 ft and 1,380 ft. Ground-water salinities stabilized at 40 parts per thousand for the deep well and 20 parts per thousand for the shallow well. The geologic section encountered in the test holes consists of three main units: (1) Eocene, Oligocene, Miocene, Pliocene, and Pleistocene sands and clays are present between land surface and a depth of 1,163 ft; (2) sediment-clast breccias of the impact structure are present between depths of 1,163 ft and 2,150 ft; and (3) crystalline-clast breccias and cataclastic gneiss of the impact structure are present between depths of 2,150 ft and 2,699 ft.

Microleakage of different sealing materials in access holes of internal connection implant systems.

PubMed

Park, Sung-Do; Lee, Yoon; Kim, Yu-Lee; Yu, Sang-Hui; Bae, Ji-Myung; Cho, Hye-Won

2012-09-01

Current implant systems cannot completely prevent microleakage from the access holes of screw-retained implant prostheses, which may constitute risks to the clinical success of the implants. The purpose of this study was to evaluate the levels of microleakage through the access holes of screw-retained implant prostheses sealed with different materials. An implant with an internal hexagonal configuration was connected to a temporary abutment with an acrylic resin crown. The apical 6.5 mm of the access hole was filled with 1 of the following materials: cotton pellet, silicone sealing material, vinyl polysiloxane, or gutta-percha. The remaining coronal 3 mm was sealed with composite resin. Cyclic loading with 21 N at 1 Hz was applied 16,000 times to the specimens in 0.5% basic fuchsin solution according to the long axis of the tooth. Basic fuchsin dye which penetrated into the internal wall of the abutment through the access hole was dissolved with methyl alcohol. Then the absorbance was measured by a spectrophotometer at 540 nm to evaluate the degree of microleakage. The results were statistically analyzed with 1-way ANOVA and the Tukey HSD test. From greatest to least, the levels of microleakage were in the following order: cotton pellet, silicone sealing material, vinyl polysiloxane, and gutta-percha. The microleakage associated with gutta-percha was not significantly different from that of vinyl polysiloxane. When sealing the access holes of screw-retained implant prostheses, gutta-percha or vinyl polysiloxane would help reduce microleakage. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

The Hole-Count Test Revisited: Effects of Test Specimen Thickness

NASA Technical Reports Server (NTRS)

Lyman, C. E.; Ackland, D. W.; Williams, D. B.; Goldstein, J. I.

1989-01-01

For historical reasons the hole count, an important performance test for the Analytical Electron Microscope (AEM), is somewhat arbitrary yielding different numbers for different investigators. This was not a problem a decade ago when AEM specimens were often bathed with large fluxes of stray electrons and hard x rays. At that time the presence or absence of a thick Pt second condenser (C2) aperture could be detected by a simple comparison of the x-ray spectrum taken 'somewhere in the hole' with a spectrum collected on a 'typical thickness' of Mo or Ag foil. A high hole count of about 10-20% indicated that the electron column needed modifications; whereas a hole count of 1-2% was accepted for most AEM work. The absolute level of the hole count is a function of test specimen atomic number, overall specimen shape, and thin-foil thickness. In order that equivalent results may be obtained for any AEM in any laboratory in the world, this test must become standardized. The hole-count test we seek must be as simpl and as nonsubjective as the graphite 0.344nm lattice-line-resolution test. This lattice-resolution test spurred manufacturers to improve the image resolution of the TEM significantly in the 1970s and led to the even more stringent resolution tests of today. A similar phenomenon for AEM instruments would be welcome. The hole-count test can also indicate whether the spurious x-ray signal is generated by high-energy continuum x rays (bremsstrahlung) generated in the electron column (high K-line to L-line ratio) or uncollimated electrons passing through or around the C2 aperture (low K/L ratio).

Results of Hydraulic Tests in Miocene Tuffaceous Rocks at the C-Hole Complex, 1995 to 1997, Yucca Mountain, Nye County, Nevada

USGS Publications Warehouse

Geldon, Arthur L.; Umari, Amjad M.A.; Fahy, Michael F.; Earle, John D.; Gemmell, James M.; Darnell, Jon

2002-01-01

Four hydraulic tests were conducted by the U.S. Geological Survey at the C-hole complex at Yucca Mountain, Nevada, between May 1995 and November 1997. These tests were conducted as part of ongoing investigations to determine the hydrologic and geologic suitability of Yucca Mountain as a potential site for permanent underground storage of high-level nuclear waste. The C-hole complex consists of three 900-meter-deep boreholes that are 30.4 to 76.6 meters apart. The C-holes are completed in fractured, variably welded tuffaceous rocks of Miocene age. Six hydrogeologic intervals occur within the saturated zone in these boreholes - the Calico Hills, Prow Pass, Upper Bullfrog, Lower Bullfrog, Upper Tram, and Lower Tram intervals. The Lower Bullfrog and Upper Tram intervals contributed about 90 percent of the flow during hydraulic tests. The four hydraulic tests conducted from 1995 to 1997 lasted 4 to 553 days. Discharge from the pumping well, UE-25 c #3, ranged from 8.49 to 22.5 liters per second in different tests. Two to seven observation wells, 30 to 3,526 meters from the pumping well, were used in different tests. Observation wells included UE-25 c #1, UE-25 c #2, UE-25 ONC-1, USW H-4, UE-25 WT #14, and UE-25 WT #3 in the tuffaceous rocks and UE-25 p #1 in Paleozoic carbonate rocks. In all hydraulic tests, drawdown in the pumping well was rapid and large (2.9-11 meters). Attributable mostly to frictional head loss and borehole-skin effects, this drawdown could not be used to analyze hydraulic properties. Drawdown and recovery in intervals of UE-25 c #1 and UE-25 c #2 and in other observation wells typically was less than 51 centimeters. These data were analyzed. Hydrogeologic intervals in the C-holes have layered heterogeneity related to faults and fracture zones. Transmissivity, hydraulic conductivity, and storativity generally increase downhole. Transmissivity ranges from 4 to 1,600 meters squared per day; hydraulic conductivity ranges from 0.1 to 50 meters per day; and storativity ranges from 0.00002 to 0.002. Transmissivity in the Miocene tuffaceous rocks decreases from 2,600 to 700 meters squared per day northwesterly across the 21-square-kilometer area affected by hydraulic tests at the C-hole complex. The average transmissivity of the tuffaceous rocks in this area, as determined from plots of drawdown in most or all observation wells as functions of time or distance from the pumping well, is 2,100 to 2,600 meters squared per day. Average storativity determined from these plot ranges is 0.0005 to 0.002. Hydraulic conductivity ranges from less than 2 to more than 10 meters per day; it is largest where prominent northerly trending faults are closely spaced or intersected by northwesterly trending faults. During hydraulic tests, the Miocene tuffaceous rocks functioned as a single aquifer. Drawdown occurred in all monitored intervals of the C-holes and other observation wells, regardless of the hydrogeologic interval being pumped. This hydraulic connection across geologic and lithostratigraphic contacts is believed to result from interconnected faults, fractures, and intervals with large matrix permeability. Samples of UE-25 c #3 water, analyzed from 1995 to 1997, seem to indicate that changes in the quality of the water pumped from that well are probably due solely to lateral variations in water quality within the tuffaceous rocks.

Spacetime completeness of non-singular black holes in conformal gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bambi, Cosimo; Rachwał, Lesław; Modesto, Leonardo, E-mail: bambi@fudan.edu.cn, E-mail: lmodesto@sustc.edu.cn, E-mail: grzerach@gmail.com

We explicitly prove that the Weyl conformal symmetry solves the black hole singularity problem, otherwise unavoidable in a generally covariant local or non-local gravitational theory. Moreover, we yield explicit examples of local and non-local theories enjoying Weyl and diffeomorphism symmetry (in short co-covariant theories). Following the seminal paper by Narlikar and Kembhavi, we provide an explicit construction of singularity-free spherically symmetric and axi-symmetric exact solutions for black hole spacetimes conformally equivalent to the Schwarzschild or the Kerr spacetime. We first check the absence of divergences in the Kretschmann invariant for the rescaled metrics. Afterwords, we show that the new typesmore » of black holes are geodesically complete and linked by a Newman-Janis transformation just as in standard general relativity (based on Einstein-Hilbert action). Furthermore, we argue that no massive or massless particles can reach the former Schwarzschild singularity or touch the former Kerr ring singularity in a finite amount of their proper time or of their affine parameter. Finally, we discuss the Raychaudhuri equation in a co-covariant theory and we show that the expansion parameter for congruences of both types of geodesics (for massless and massive particles) never reaches minus infinity. Actually, the null geodesics become parallel at the r =0 point in the Schwarzschild spacetime (the origin) and the focusing of geodesics is avoided. The arguments of regularity of curvature invariants, geodesic completeness, and finiteness of geodesics' expansion parameter ensure us that we are dealing with singularity-free and geodesically-complete black hole spacetimes.« less

A Tortuous Process of Surgical Treatment for a Large Calcified Chronic Subdural Hematoma.

PubMed

Li, Huan; Mao, Xiang; Tao, Xiao-Gang; Li, Jing-Sheng; Liu, Bai-Yun; Wu, Zhen

2017-12-01

Calcified chronic subdural hematoma (CCSDH) is a rare disease for which no standard approach to treatment has been established. Reports covering both burr hole trepanation and craniotomy for CCSDH are rare. Furthermore, infection of CCSDH after the burr hole trepanation has not been reported in the literature. A 61-year-old man presented with left frontotemporoparietal CCSDH demonstrated on computed tomography (CT) scan. The patient underwent 2 separate burr hole trepanations with intraoperative irrigation and postoperative drainage. These procedures led to infection of the CCSDH. The patient eventually underwent an open craniotomy to provide complete removal of the hematoma. Owing to the complex contents of a CCSDH, burr hole trepanation cannot adequately drain the hematoma or relieve the mass effect. Craniotomy is a much more reliable approach for achieving complete resection of a CCSDH. Copyright © 2017 Elsevier Inc. All rights reserved.

Innermost stable circular orbit of spinning particle in charged spinning black hole background

NASA Astrophysics Data System (ADS)

Zhang, Yu-Peng; Wei, Shao-Wen; Guo, Wen-Di; Sui, Tao-Tao; Liu, Yu-Xiao

2018-04-01

In this paper we investigate the innermost stable circular orbit (ISCO) (spin-aligned or anti-aligned orbit) for a classical spinning test particle with the pole-dipole approximation in the background of Kerr-Newman black hole in the equatorial plane. It is shown that the orbit of the spinning particle is related to the spin of the test particle. The motion of the spinning test particle will be superluminal if its spin is too large. We give an additional condition by considering the superluminal constraint for the ISCO in the black hole backgrounds. We obtain numerically the relations between the ISCO and the properties of the black holes and the test particle. It is found that the radius of the ISCO for a spinning test particle is smaller than that of a nonspinning test particle in the black hole backgrounds.

The Fossil Record of Black Hole Seeds, with Spatially Resolved Spectroscopy

NASA Astrophysics Data System (ADS)

Trump, Jonathan R.; CANDELS, 3D-HST

2016-01-01

I will present the first robust measurement of black hole occupation over a wide range of host galaxy mass (8

Feasibility and application of single-hole video-assisted thoracoscope in pulmonary peripheral tumors.

PubMed

Wang, Xin; Wang, Lei; Zhang, Hao; Li, Ke; Gong, Xiangnan

2016-12-01

The feasibility and clinical application of single-hole video-assisted thoracoscope in pulmonary peripheral tumors was examined. From March, 2011 to March, 2015, we retrospectively analyzed the clinical data obtained from 32 patients with pulmonary peripheral tumor that received single-hole thoracoscopic surgery. We completed the surgery via a 1.5-cm incision on the seventh or eighth rib in midaxillary line as the observation hole, and a 4.0-5.0-cm incision in the lateral margin of pectoralis major in the fourth or fifth rib in midaxillary line as the operation hole. All the patients had completed the tumor-reductive surgery under single-hole thoracoscope successfully. None required second operation hole or needed a transfer to thoracotomy. Operation time was 40-100 min with an average of 65.78±15.87 min. Intraoperative blood loss was 20-100 ml, with an average of 47.19±26.91 ml. Post-operative chest drainage time was 3-6 days, with an average of 4.22±0.87 days. Hospitalization time after operation was 5-7 days, with an average hospitalization time of 5.97±0.82 days. No patient received a second surgery for pulmonary leak or bleeding and no patient had any complication. All the cases recovered without any problem. In conclusion, for patients with pulmonary peripheral tumor, single-hole video-assisted thoracoscope could further reduce their surgical trauma. The operation was safe and feasible and worthy of wide application.

Study of the influence of hole quality on composite materials

NASA Technical Reports Server (NTRS)

Pengra, J. J.

1980-01-01

The influence of hole quality on the structural behavior of composite materials was investigated. From an industry survey it was determined that the most frequent imperfections encountered during hole fabrication are chipout, delamination, and oversize conditions. These hole flaw types were generated in critical areas of static, compression, and fatigue specimens fabricated from T300/5208 graphite/epoxy system. The specimens were tested in static and cyclic pin bearing modes in addition to compression loading. Results of these tests are presented and discussed. The hole chipout defect reduced the static and cyclic endurance characteristics. Oversize holes also lowered the cyclic pin bearing endurance, but had no influence of the static pin bearing characteristics. Delamination had no insignificant influence on the static tension and cyclic pin bearing characteristics. Compression tests demonstrated a deleterious effect for chipout of delamination defects. Hole quality requirements proposed are discussed.

Self-cleaning effect in high quality percussion ablating of cooling hole by picosecond ultra-short pulse laser

NASA Astrophysics Data System (ADS)

Zhao, Wanqin; Yu, Zhishui

2018-06-01

Comparing with the trepanning technology, cooling hole could be processed based on the percussion drilling with higher processing efficiency. However, it is widely believed that the ablating precision of hole is lower for percussion drilling than for trepanning, wherein, the melting spatter materials around the hole surface and the recast layer inside the hole are the two main issues for reducing the ablating precision of hole, especially for the recast layer, it can't be eliminated completely even through the trepanning technology. In this paper, the self-cleaning effect which is a particular property just for percussion ablating of holes has been presented in detail. In addition, the reasons inducing the self-cleaning effect have been discussed. At last, based on the self-cleaning effect of percussion drilling, high quality cooling hole without the melting spatter materials around the hole surface and recast layer inside the hole could be ablated in nickel-based superalloy by picosecond ultra-short pulse laser.

Extraordinary light transmission through opaque thin metal film with subwavelength holes blocked by metal disks.

PubMed

Li, Wen-Di; Hu, Jonathan; Chou, Stephen Y

2011-10-10

We observed that when subwavelength-sized holes in an optically opaque metal film are completely covered by opaque metal disks larger than the holes, the light transmission through the holes is not reduced, but rather enhanced. Particularly we report (i) the observation of light transmission through the holes blocked by the metal disks up to 70% larger than the unblocked holes; (ii) the observation of tuning the light transmission by varying the coupling strength between the blocking disks and the hole array, or by changing the size of the disks and holes; (iii) the observation and simulation that the metal disk blocker can improve light coupling from free space to a subwavelength hole; and (iv) the simulation that shows the light transmission through subwavelength holes can be enhanced, even though the gap between the disk and the metal film is partially connected with a metal. We believe these finding should have broad and significant impacts and applications to optical systems in many fields.

Experimental study on deep hole drilling of 17-4PH material

NASA Astrophysics Data System (ADS)

Uzhanfeng, LI; Uquantai, LI

2018-02-01

This paper uses 17-4PH material as the research object, according to the material characteristics of 17-4PH, designed and carried out deep hole drilling test. The purpose of the experiment is to study and discuss the three major problems of tool wear, chip shape and axial deviation of the hole in the process of deep hole drilling of 17-4PH materials. Through the deep hole drilling test of 17-4PH material, the variation of the chip shape and the deflection of the hole axis was obtained under different wear conditions.

A Hydrostratigraphic Framework Model and Alternatives for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Clark, Lincoln and Nye Counties, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bechtel Nevada

2005-09-01

A new, revised three-dimensional (3-D) hydrostratigraphic framework model for Frenchman Flat was completed in 2004. The area of interest includes Frenchman Flat, a former nuclear testing area at the Nevada Test Site, and proximal areas. Internal and external reviews of an earlier (Phase I) Frenchman Flat model recommended additional data collection to address uncertainties. Subsequently, additional data were collected for this Phase II initiative, including five new drill holes and a 3-D seismic survey.

Effect of verification cores on tip capacity of drilled shafts.

DOT National Transportation Integrated Search

2009-02-01

This research addressed two key issues: : 1) Will verification cores holes fill during concrete backfilling? If so, what are the mechanical properties of the : filling material? In dry conditions, verification core holes always completely fill with c...

A microscopic description of black hole evaporation via holography

DOE PAGES

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

2016-07-19

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

A microscopic description of black hole evaporation via holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

Insight into the microscopic structure of an AdS black hole from a thermodynamical phase transition.

PubMed

Wei, Shao-Wen; Liu, Yu-Xiao

2015-09-11

Comparing with an ordinary thermodynamic system, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole system crosses the small-large black hole coexistence curve, while when the system passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole.

How Complete is Mid-Infrared Selection of Active Galactic Nuclei?

NASA Astrophysics Data System (ADS)

Grae Short, Miona; Diamond-Stanic, Aleks

2015-01-01

Essentially every galaxy hosts a supermassive black hole, and roughly 10% of those black holes are currently growing as active galactic nuclei (AGNs). Given the compelling evidence that galaxies and black holes co-evolve, there is strong motivation to study how black holes assemble their mass through cosmic time. However, this is challenging because a large fraction of black hole growth is enshrouded by gas and dust. Deep and wide surveys at X-ray and infrared wavelengths offer a powerful way to study the obscured AGN population, but an important caveat is that X-ray surveys are not complete for the most highly absorbed sources and infrared surveys are not able to distinguish low-luminosity AGNs from normal galaxies. To help address these outstanding issues and to analyze the completeness of mid-infrared AGN selection, we use Spitzer and WISE photometry to study the mid-infrared colors of a complete sample of local AGNs. The sample is drawn from the revised Shapley-Ames galaxy catalog and includes every galaxy in the sky brighter than B=13 that is known to host Seyfert activity. This sample is unique in its sensitivity to low-luminosity and highly obscured sources. Our main result is that most of these known AGNs would be classified as normal galaxies on the basis of their mid-infrared colors, implying that analogs to local Seyfert galaxies would not be identified as AGNs in existing surveys. We find that this a strong function of AGN luminosity, and we also present trends as a function of AGN obscuration, galaxy luminosity, and stellar mass. These results provide important insights into the AGN population that is missing from our census of black hole growth in the distant universe. This work was supported by the National Science Foundation's REU program through NSF Award AST-1004881. We also acknowledge support from The Grainger Foundation and from gifts made to the Department of Astronomy at UW-Madison.

Black hole ringdown echoes and howls

NASA Astrophysics Data System (ADS)

Nakano, Hiroyuki; Sago, Norichika; Tagoshi, Hideyuki; Tanaka, Takahiro

2017-07-01

Recently the possibility of detecting echoes of ringdown gravitational waves from binary black hole mergers was shown. The presence of echoes is expected if the black hole is surrounded by a mirror that reflects gravitational waves near the horizon. Here, we present slightly more sophisticated templates motivated by a waveform which is obtained by solving the linear perturbation equation around a Kerr black hole with a complete reflecting boundary condition in the stationary traveling wave approximation. We estimate that the proposed template can bring about a 10% improvement in the signal-to-noise ratio.

Chiral Majorana interference as a source of quantum entanglement

NASA Astrophysics Data System (ADS)

Chirolli, Luca; Baltanás, José Pablo; Frustaglia, Diego

2018-04-01

Two-particle Hanbury Brown-Twiss interferometry with chiral Majorana modes produces maximally entangled electron-hole pairs. We promote the electron-hole quantum number to an interferometric degree of freedom and complete the set of linear tools for single- and two-particle interferometry by introducing a key phase gate that, combined with a Mach-Zehnder, allows full electron-hole rotations. By considering entanglement witnesses built on current cross-correlation measurements, we find that the possibility of independent local-channel rotations in the electron-hole subspace leads to a significant boost of the entanglement detection power.

BATSE imaging survey of the Galactic plane

NASA Technical Reports Server (NTRS)

Grindlay, J. E.; Barret, D.; Bloser, P. F.; Zhang, S. N.; Robinson, C.; Harmon, B. A.

1997-01-01

The burst and transient source experiment (BATSE) onboard the Compton Gamma Ray Observatory (CGRO) provides all sky monitoring capability, occultation analysis and occultation imaging which enables new and fainter sources to be searched for in relatively crowded fields. The occultation imaging technique is used in combination with an automated BATSE image scanner, allowing an analysis of large data sets of occultation images for detections of candidate sources and for the construction of source catalogs and data bases. This automated image scanner system is being tested on archival data in order to optimize the search and detection thresholds. The image search system, its calibration results and preliminary survey results on archival data are reported on. The aim of the survey is to identify a complete sample of black hole candidates in the galaxy and constrain the number of black hole systems and neutron star systems.

Selected Hydrogeologic Data for the High Plains Aquifer in Southwestern Laramie County, Wyoming, 1931-2006

USGS Publications Warehouse

Hallberg, Laura L.; Mason, Jon P.

2007-01-01

The U.S. Geological Survey, in cooperation with the Wyoming State Engineer's Office, created a hydrogeologic database for southwestern Laramie County, Wyoming. The database contains records from 166 wells and test holes drilled during 1931-2006. Several types of information, including well construction; well or test hole locations; lithologic logs; gamma, neutron, spontaneous-potential, and single-point resistivity logs; water levels; and transmissivities and storativities estimated from aquifer tests, are available in the database. Most wells and test holes in the database have records containing information about construction, location, and lithology; 77 wells and test holes have geophysical logs; 70 wells have tabulated water-level data; and 60 wells have records of aquifer-test results.

Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic Conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

USGS Publications Warehouse

Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

2010-01-01

Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative to volcanic-rock units is exemplified by the large difference in their estimated maximum hydraulic conductivity; 4,000 and 400 feet per day, respectively. Simulated minimum estimates of hydraulic conductivity are inexact and represent the lower detection limit of the method. Minimum thicknesses of lithologic intervals also were defined for comparing AnalyzeHOLE results to hydraulic properties in regional ground-water flow models.

Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairbank, Brian D.; Smith, Nicole

The Crump Geyser Exploration and Drilling Project – High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling ran from January 29, 2010 to September 30, 2013. During Phase 1 of the project, collection of all geophysical surveys was completed as outlined in the Statement of Project Objectives. In addition, a 5000-foot full sized exploration well was drilled by Ormat, and preexisting drilling data was discovered for multiple temperature gradient wells within the project area. Three dimensional modeling and interpretation of results from the geophysical surveys and drilling data gave confidence to move to the project into Phase 2more » drilling. Geological and geophysical survey interpretations combined with existing downhole temperature data provided an ideal target for the first slim-hole drilled as the first task in Phase 2. Slim-hole 35-34 was drilled in September 2011 and tested temperature, lithology, and permeability along the primary range-bounding fault zone near its intersection with buried northwest-trending faults that have been identified using geophysical methods. Following analysis of the results of the first slim-hole 35-34, the second slim hole was not drilled and subsequent project tasks, including flowing differential self-potential (FDSP) surveys that were designed to detail the affect of production and injection on water flow in the shallow aquifer, were not completed. NGP sold the Crump project to Ormat in August 2014, afterwards, there was insufficient time and interest from Ormat available to complete the project objectives. NGP was unable to continue managing the award for a project they did not own due to liability issues and Novation of the award was not a viable option due to federal award timelines. NGP submitted a request to mutually terminate the award on February 18, 2015. The results of all of the technical surveys and drilling are included in this report. Fault interpretations from surface geology, aeromag, seismic, and gravity data sets are in good agreement, illustrating two or more major range-bounding faults and buried northwest trending faults. The intersections of these fault systems provide the primary targets for drilling.« less

A classical instability of Reissner-Nordstrom solutions and the fate of magnetically charged black holes

NASA Technical Reports Server (NTRS)

Lee, Kimyeong; Nair, V. P.; Weinberg, Erick J.

1991-01-01

Working in the context of spontaneously broken gauge theories, we show that the magnetically charged Reissner-Nordstrom solution develops a classical instability if the horizon is sufficiently small. This instability has significant implications for the evolution of a magnetically charged black hole. In particular, it leads to the possibility that such a hole could evaporate completely, leaving in its place a nonsingular magnetic monopole.

Remarks on non-singular black holes

NASA Astrophysics Data System (ADS)

Frolov, Valeri P.

2018-01-01

We briefly discuss non-singular black hole models, with the main focus on the properties of non-singular evaporating black holes. Such black holes possess an apparent horizon, however the event horizon may be absent. In such a case, the information from the black hole interior may reach the external observer after the complete evaporation of the black hole. This model might be used for the resolution of the information loss puzzle. However, as we demonstrate, in a general case the quantum radiation emitted from the black hole interior, calculated in the given black hole background, is very large. This outburst of the radiation is exponentially large for models with the redshift function α = 1. We show that it can be suppressed by including a non-trivial redshift function. However, even this suppression is not enough to guarantee self-consistency of the model. This problem is a manifestation of a general problem, known as the "mass inflation". We briefly comment on possible ways to overcome this problem in the models of non-singular evaporating black holes.

The region interior to the event horizon of the regular Hayward black hole

NASA Astrophysics Data System (ADS)

Perez-Roman, Ivan; Bretón, Nora

2018-06-01

The Painlevé-Gullstrand coordinates allow us to explore the interior of the regular Hayward black hole. The behavior of an infalling particle in traversing the Hayward black hole is compared with the one inside the Schwarzschild and Reissner-Nordstrom singular black holes. When approaching the origin the test particle trajectories present differences depending if the center is regular or singular. The velocities of the infalling test particle into the modified Hayward black hole are analyzed as well. As compared with the normal Hayward, in the modified Hayward black hole the particle moves faster and the surface gravity is smaller.

Spectroscopy of Kerr Black Holes with Earth- and Space-Based Interferometers.

PubMed

Berti, Emanuele; Sesana, Alberto; Barausse, Enrico; Cardoso, Vitor; Belczynski, Krzysztof

2016-09-02

We estimate the potential of present and future interferometric gravitational-wave detectors to test the Kerr nature of black holes through "gravitational spectroscopy," i.e., the measurement of multiple quasinormal mode frequencies from the remnant of a black hole merger. Using population synthesis models of the formation and evolution of stellar-mass black hole binaries, we find that Voyager-class interferometers will be necessary to perform these tests. Gravitational spectroscopy in the local Universe may become routine with the Einstein Telescope, but a 40-km facility like Cosmic Explorer is necessary to go beyond z∼3. In contrast, detectors like eLISA (evolved Laser Interferometer Space Antenna) should carry out a few-or even hundreds-of these tests every year, depending on uncertainties in massive black hole formation models. Many space-based spectroscopical measurements will occur at high redshift, testing the strong gravity dynamics of Kerr black holes in domains where cosmological corrections to general relativity (if they occur in nature) must be significant.

Orbit classification in an equal-mass non-spinning binary black hole pseudo-Newtonian system

NASA Astrophysics Data System (ADS)

Zotos, Euaggelos E.; Dubeibe, Fredy L.; González, Guillermo A.

2018-07-01

The dynamics of a test particle in a non-spinning binary black hole system of equal masses is numerically investigated. The binary system is modelled in the context of the pseudo-Newtonian circular restricted three-body problem, such that the primaries are separated by a fixed distance and move in a circular orbit around each other. In particular, the Paczyński-Wiita potential is used for describing the gravitational field of the two non-Newtonian primaries. The orbital properties of the test particle are determined through the classification of the initial conditions of the orbits, using several values of the Jacobi constant, in the Hill's regions of possible motion. The initial conditions are classified into three main categories: (i) bounded, (ii) escaping, and (iii) displaying close encounters. Using the smaller alignment index chaos indicator, we further classify bounded orbits into regular, sticky, or chaotic. To gain a complete view of the dynamics of the system, we define grids of initial conditions on different types of two-dimensional planes. The orbital structure of the configuration plane, along with the corresponding distributions of the escape and collision/close encounter times, allow us to observe the transition from the classical Newtonian to the pseudo-Newtonian regime. Our numerical results reveal a strong dependence of the properties of the considered basins with the Jacobi constant as well as with the Schwarzschild radius of the black holes.

The Effect of Hole Quality on the Fatigue Life of 2024-T3 Aluminum Alloy Sheet

NASA Technical Reports Server (NTRS)

Everett, Richard A., Jr.

2004-01-01

This paper presents the results of a study whose main objective was to determine which type of fabrication process would least affect the fatigue life of an open-hole structural detail. Since the open-hole detail is often the fundamental building block for determining the stress concentration of built-up structural parts, it is important to understand any factor that can affect the fatigue life of an open hole. A test program of constant-amplitude fatigue tests was conducted on five different sets of test specimens each made using a different hole fabrication process. Three of the sets used different mechanical drilling procedures while a fourth and fifth set were mechanically drilled and then chemically polished. Two sets of specimens were also tested under spectrum loading to aid in understanding the effects of residual compressive stresses on fatigue life. Three conclusions were made from this study. One, the residual compressive stresses caused by the hole-drilling process increased the fatigue life by two to three times over specimens that were chemically polished after the holes were drilled. Second, the chemical polishing process does not appear to adversely affect the fatigue life. Third, the chemical polishing process will produce a stress-state adjacent to the hole that has insignificant machining residual stresses.

Optimization of Elastically Tailored Tow-Placed Plates with Holes

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Tatting, Brian F.; Guerdal, Zafer

2003-01-01

Elastic stiffness tailoring of laminated composite panels by allowing the fibers to curve within the plane of the laminate is a design concept that has been demonstrated to be both beneficial and practical. The objective of the present paper is to demonstrate the effectiveness of stiffness tailoring through the use of curvilinear fibers to reduce stress concentrations around the hole and improve the load carrying capability of panels. Preliminary panel designs that are to be manufactured and tested were determined through design studies for flat plates without holes under axial compression using an optimization program. These candidate designs were then analyzed with finite element models that accurately reflect the test conditions and geometries in order to decide upon the final designs for manufacture and testing. An advanced tow-placement machine is used to manufacture the test panels with varying fiber orientation angles. A total of six large panels measuring three feet by six feet, each of which is used to produce four specimens with or without holes, are fabricated. The panels were machined into specimens with holes and tested at NASA Langley Research Center. Buckling response and failure of panels without holes and with two different hole dimensions are presented. Buckling and failure loads of tow-steered specimens are significantly greater than the buckling and failure loads of traditional straight-fiber specimens.

The Rates of Type I X-ray Bursts from Transients Observed with RXTE: Evidence for Black Hole Event Horizons

NASA Astrophysics Data System (ADS)

Remillard, R. A.; Lin, D.; Cooper, R. L.; Narayan, R.

2005-12-01

We measure the rates of type I X-ray bursts from a likely complete sample of 37 non-pulsing Galactic X-ray transients observed with the RXTE ASM during 1996-2004. Our strategy is to test the prevailing paradigms for these sources, which are well-categorized in the literature as either neutron-star systems or black hole candidates. Burst rates are measured as a function of the bolometric luminosity, and the results are compared with burst models for neutron stars and for heavy compact objects with a solid surface. We use augmented versions of the models developed by Narayan & Heyl (2002; 2003). For a given mass, we consider a range of conditions in both the radius and the temperature at the boundary below the accretion layer. We find 135 type I bursts in 3.7 Ms of PCA light curves for the neutron-star group, and the burst rate function is generally consistent with the model predictions for bursts from accreting neutron stars. On the other hand, none of the (20) bursts candidates passed spectral criteria for type I bursts in 6.5 Ms of PCA light curves for black-hole binaries and candidates. The burst function upper limits are inconsistent with the predictions of the burst model for heavy compact objects with a solid surface. The consistency probability is found to be below 10-7 for dynamical black-hole binaries, falling to below 10-13 for the additional exposures of black-hole candidates. These results provide indirect evidence that black holes do have event horizons. This research was supported, in part, by NASA science programs.

Space Oddities: The Search For Ephemeral Coronal Holes

NASA Astrophysics Data System (ADS)

O'Connor, Rachel E.; Pesnell, W. Dean; Kirk, Michael S.; Karna, Nishu

2016-10-01

Ephemeral coronal holes are short-lived, volatile counterparts to equatorial coronal holes. Very little is known about their characteristics and behavior aside from their definition: open, unipolar magnetic field lines resulting in darkened regions of the corona. The first exemplar of this phenomenon was observed by NASA's Solar Dynamics Observatory (SDO) on October 26, 2010, which spurred our search for other occurrences in order to understand the frequency and evolution of these phenomena. To accomplish this, we visually evaluated SDO 211 Å images on a 12-hour cadence between June 2010 and June 2016. Each compact and isolated dim region we encountered was flagged as a potential ephemeral coronal hole for further analysis. This preliminary effort resulted in 149 candidate holes. For further analysis of their characteristics, we applied a strict definition criterion of an ephemeral coronal hole. This criterion was a set of four factors that were created in order to ensure events being observed were isolated, individual events- the candidates had to be dark relative to the surrounding material, not influenced by a nearby eruption, not obviously connected to other coronal hole structures, and their lifetime had to occur completely within the disk crossing. This criterion was designed so that events could be completely analyzed, from beginning to end, to better understand the origins. Application of this criterion eliminated all candidates but 5 of the original 149. True ephemeral coronal holes are rare occurrences, appearing only five times in six years. Future research in this area is needed to both locate additional events and study the underlying driving forces behind these rare phenomena.

Testing for Controlled Rapid Pressurization

DOE Data Explorer

Steven Knudsen

2014-09-03

Borehole W1 is a NQ core hole drilled at our test site in Socorro. The rock is rhyolite. Borehole W1 which was used to test gas-gas explosive mixtures is 55 feet deep with casing (pinkish in the drawing) set to 35 feet. The model is a representation of the borehole and the holes we cored around the central borehole after the test. The brown colored core holes showed dye when we filled W1 with water and slightly pressurized it. This indicates there was some path between W1 and the colored core hole. The core holes are shown to their TD in the drawing. The green plane is a fracture plane which we believe is the result of the explosions of the gas mixture in W1. Data resource is a 2D .pdf Solid Works Drawing of borehole w-1

Sleeve Expansion of Bolt Holes in Railroad Rail : Volume II, Process Parameters and Procedures

DOT National Transportation Integrated Search

1980-02-01

The bolt-hole cold-expansion process has been applied to railroad rail in laboratory tests and has demonstrated a potential for the reduction of rail-bolt-hole-failure incidence. Limited field tests also have been conducted and are currently under lo...

Aspects of noncommutative (1+1)-dimensional black holes

NASA Astrophysics Data System (ADS)

Mureika, Jonas R.; Nicolini, Piero

2011-08-01

We present a comprehensive analysis of the spacetime structure and thermodynamics of (1+1)-dimensional black holes in a noncommutative framework. It is shown that a wider variety of solutions are possible than the commutative case considered previously in the literature. As expected, the introduction of a minimal length θ cures singularity pathologies that plague the standard two-dimensional general relativistic case, where the latter solution is recovered at large length scales. Depending on the choice of input parameters (black hole mass M, cosmological constant Λ, etc.), black hole solutions with zero, up to six, horizons are possible. The associated thermodynamics allows for the either complete evaporation, or the production of black hole remnants.

A classical instability of Reissner-Nordstrom solutions and the fate of magnetically charged black holes

NASA Technical Reports Server (NTRS)

Lee, Kimyeong; Nair, V. P.; Weinberg, Erick J.

1992-01-01

Working in the context of spontaneously broken gauge theories, it is shown that the magnetically charged Reissner-Nordstrom solution develops a classical instability if the horizon is sufficiently small. This instability has significant implications for the evolution of a magnetically charged black hole. In particular, it leads to the possibility that such a hole could evaporate completely, leaving in its place a nonsingular magnetic monopole.

RoboSimian Cuts Hole in Wall

NASA Image and Video Library

2015-06-09

Using a cordless power drill, RoboSimian cuts a hole into a panel of drywall to complete one of the tasks in the DARPA Robotics Challenge Finals in Pomona, California. This image was taken on June 6, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19326

Directly comparing gravitational wave data to numerical relativity simulations: systematics

NASA Astrophysics Data System (ADS)

Lange, Jacob; O'Shaughnessy, Richard; Healy, James; Lousto, Carlos; Zlochower, Yosef; Shoemaker, Deirdre; Lovelace, Geoffrey; Pankow, Christopher; Brady, Patrick; Scheel, Mark; Pfeiffer, Harald; Ossokine, Serguei

2017-01-01

We compare synthetic data directly to complete numerical relativity simulations of binary black holes. In doing so, we circumvent ad-hoc approximations introduced in semi-analytical models previously used in gravitational wave parameter estimation and compare the data against the most accurate waveforms including higher modes. In this talk, we focus on the synthetic studies that test potential sources of systematic errors. We also run ``end-to-end'' studies of intrinsically different synthetic sources to show we can recover parameters for different systems.

Selected Ground-Water Data for Yucca Mountain Region, Southern Nevada and Eastern California, Through December 1998

DTIC Science & Technology

2001-01-01

data; X, un ll-completion report, or Fenix & Scisson, Inc., or Raytheon Services Nevada hole-history data; J, Johnston (19 rs (1988); T, Thordarson ...associated with weapons-testing hydrology programs ( Thordarson and others, 1967; Johnston, 1968) or Yucca Mountain site-characterization studies...MV-1, AD-4a, AD-5, AD-6, AD-8, and AM-4. Thordarson and others (1967) describe the contributing unit at site RV-1. Dudley and Larson (1976

Black hole event horizons — Teleology and predictivity

NASA Astrophysics Data System (ADS)

Bhattacharya, Swastik; Shankaranarayanan, S.

2017-11-01

General Relativity predicts the existence of black holes. Access to the complete spacetime manifold is required to describe the black hole. This feature necessitates that black hole dynamics is specified by future or teleological boundary condition. Here, we demonstrate that the statistical mechanical description of black holes, the raison d’être behind the existence of black hole thermodynamics, requires teleological boundary condition. Within the fluid-gravity paradigm — Einstein’s equations when projected on spacetime horizons resemble Navier-Stokes equation of a fluid — we show that the specific heat and the coefficient of bulk viscosity of the horizon fluid are negative only if the teleological boundary condition is taken into account. We argue that in a quantum theory of gravity, the future boundary condition plays a crucial role. We briefly discuss the possible implications of this at late stages of black hole evaporation.

Testing General Relativity with the Reflection Spectrum of the Supermassive Black Hole in 1H0707-495.

PubMed

Cao, Zheng; Nampalliwar, Sourabh; Bambi, Cosimo; Dauser, Thomas; García, Javier A

2018-02-02

Recently, we have extended the x-ray reflection model relxill to test the spacetime metric in the strong gravitational field of astrophysical black holes. In the present Letter, we employ this extended model to analyze XMM-Newton, NuSTAR, and Swift data of the supermassive black hole in 1H0707-495 and test deviations from a Kerr metric parametrized by the Johannsen deformation parameter α_{13}. Our results are consistent with the hypothesis that the spacetime metric around the black hole in 1H0707-495 is described by the Kerr solution.

Universally stable black holes

NASA Astrophysics Data System (ADS)

Bueno, Pablo; Cano, Pablo A.

We argue that, when certain higher-curvature corrections are added to the four-dimensional Einstein-Hilbert action, black holes become stable below certain mass. We show this to be the case for an infinite family of ghost-free theories involving terms of arbitrarily high order in curvature. The thermodynamic behavior of the new black holes is universal for arbitrary values of the couplings, with the only exception of the Schwarzschild solution itself, which is recovered when all the couplings are set to zero. For this class of theories, the issue of non-unitary evolution is inexistent, as black holes never evaporate completely.

Quantum efficiency investigations of type-II InAs/GaSb midwave infrared superlattice photodetectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giard, E., E-mail: edouard.giard@onera.fr; Ribet-Mohamed, I.; Jaeck, J.

2014-07-28

We present in this paper a comparison between different type-II InAs/GaSb superlattice (T2SL) photodiodes and focal plane array (FPA) in the mid-wavelength infrared domain to understand which phenomenon drives the performances of the T2SL structure in terms of quantum efficiency (QE). Our measurements on test photodiodes suggest low minority carrier diffusion length in the “InAs-rich” design, which penalizes carriers' collection in this structure for low bias voltage and front side illumination. This analysis is completed by a comparison of the experimental data with a fully analytic model, which allows to infer a hole diffusion length shorter than 100 nm. In addition,more » measurements on a FPA with backside illumination are finally presented. Results show an average QE in the 3–4.7 μm window equal to 42% for U{sub bias} = −0.1 V, 77 K operating temperature and no anti-reflection coating. These measurements, completed by modulation transfer function and noise measurements, reveal that the InAs-rich design, despite a low hole diffusion length, is promising for high performance infrared imaging applications.« less

Strain measurements in composite bolted-joint specimens

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Lightfoot, M. C.; Perry, J. C.

1979-01-01

Strain data from a series of bolted joint tests is presented. Double lap, double hole, double lap, single hole, and open hole tensile specimens were tested and the strain gage locations, load strain responses, and load axial displacement responses are presented. The open hole specimens were gaged to determine strain concentration factors. The double lap, double hole specimens were gaged to determine the uniformity of the strain in the joint and the amount of load transferred past the first bolt. The measurements indicated roughly half the load passed the first bolt to be reacted by the second bolt.

Neogene and Quaternary geology of a stratigraphic test hole on Horn Island, Mississippi Sound

USGS Publications Warehouse

Gohn, Gregory S.; Brewster-Wingard, G. Lynn; Cronin, Thomas M.; Edwards, Lucy E.; Gibson, Thomas G.; Rubin, Meyer; Willard, Debra A.

1996-01-01

During April and May, 1991, the U.S. Geological Survey (USGS) drilled a 510-ft-deep, continuously cored, stratigraphic test hole on Horn Island, Mississippi Sound, as part of a field study of the Neogene and Quaternary geology of the Mississippi coastal area. The USGS drilled two new holes at the Horn Island site. The first hole was continuously cored to a depth of 510 ft; coring stopped at this depth due to mechanical problems. To facilitate geophysical logging, an unsampled second hole was drilled to a depth of 519 ft at the same location.

Weatherford Inclined Wellbore Construction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulte, R.

The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed construction of an inclined wellbore with seven (7) inch, twenty-three (23) pound casing at a total depth of 1296 feet. The inclined wellbore is near vertical to 180 feet with a build angle of approximately 4.5 degrees per hundred feet thereafter. The inclined wellbore was utilized for further proprietary testing after construction and validation. The wellbore is available to other companies requiring a cased hole environment with known deviation out to fifty degrees (50) from vertical. The wellbore may also be used by RMOTC for further deepening into the fracturedmore » shales of the Steele and Niobrara formation.« less

Is the Gravitational-Wave Ringdown a Probe of the Event Horizon?

PubMed

Cardoso, Vitor; Franzin, Edgardo; Pani, Paolo

2016-04-29

It is commonly believed that the ringdown signal from a binary coalescence provides a conclusive proof for the formation of an event horizon after the merger. This expectation is based on the assumption that the ringdown waveform at intermediate times is dominated by the quasinormal modes of the final object. We point out that this assumption should be taken with great care, and that very compact objects with a light ring will display a similar ringdown stage, even when their quasinormal-mode spectrum is completely different from that of a black hole. In other words, universal ringdown waveforms indicate the presence of light rings, rather than of horizons. Only precision observations of the late-time ringdown signal, where the differences in the quasinormal-mode spectrum eventually show up, can be used to rule out exotic alternatives to black holes and to test quantum effects at the horizon scale.

Spectroscopy of Kerr black holes with Earth- and space-based interferometers

NASA Astrophysics Data System (ADS)

Berti, Emanuele; Sesana, Alberto; Barausse, Enrico; Cardoso, Vitor; Belczynski, Krzysztof

2017-01-01

We estimate the potential of present and future interferometric gravitational-wave detectors to test the Kerr nature of black holes through ``gravitational spectroscopy,'' i.e. the measurement of multiple quasinormal mode frequencies from the remnant of a black hole merger. Using population synthesis models of the formation and evolution of stellar-mass black hole binaries, we find that Voyager-class interferometers will be necessary to perform these tests. Gravitational spectroscopy in the local Universe may become routine with the Einstein Telescope, but a 40-km facility like Cosmic Explorer is necessary to go beyond z 3 . In contrast, eLISA-like detectors should carry out a few - or even hundreds - of these tests every year, depending on uncertainties in massive black hole formation models. Many space-based spectroscopical measurements will occur at high redshift, testing the strong gravity dynamics of Kerr black holes in domains where cosmological corrections to general relativity (if they occur in nature) must be significant. NSF CAREER Grant No. PHY-1055103, NSF Grant No. PHY-1607130, FCT contract IF/00797/2014/CP1214/CT0012.

Logarithmic corrections to entropy of magnetically charged AdS4 black holes

NASA Astrophysics Data System (ADS)

Jeon, Imtak; Lal, Shailesh

2017-11-01

Logarithmic terms are quantum corrections to black hole entropy determined completely from classical data, thus providing a strong check for candidate theories of quantum gravity purely from physics in the infrared. We compute these terms in the entropy associated to the horizon of a magnetically charged extremal black hole in AdS4×S7 using the quantum entropy function and discuss the possibility of matching against recently derived microscopic expressions.

The Extreme Spin of the Black Hole Cygnus X-1

NASA Technical Reports Server (NTRS)

Gou, Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

2011-01-01

Remarkably, an astronomical black hole is completely described by the two numbers that specify its mass and its spin. Knowledge of spin is crucial for understanding how, for example, black holes produce relativistic jets. Recently, it has become possible to measure the spins of black holes by focusing on the very inner region of an accreting disk of hot gas orbiting the black hole. According to General Relativity (GR), this disk is truncated at an inner radius 1 that depends only on the mass and spin of the black hole. We measure the radius of the inner edge of this disk by fitting its continuum X-ray spectrum to a fully relativistic model. Using our measurement of this radius, we deduce that the spin of Cygnus X-1 exceeds 97% of the maximum value allowed by GR.

LISA Pathfinder

NASA Technical Reports Server (NTRS)

Stebbins, Robin

2008-01-01

USA Pathfinder is a space mission dedicated to demonstrating technology for the Laser Interferometer Space Antenna (LISA). LISA is a joint ESA/NASA mission to detect low-frequency gravitational waves on the 0.0001 to 0.1 Hz frequency band. LISA is expected to observe 100's of merging massive black hole binaries out z-15, tens of thousands of close compact binary systems in the Milky Way, merging intermediate-mass black hole binaries, tens of stellar-mass black holes falling into supermassive black holes in galactic centers, and possibly other exotic sources. Several critical LISA technologies have not been demonstrated at the requisite level of performance. In spaceflight, and some fight hardware cannot be tested in a 1-g environment. Hence, the LISA Pathfinder mission is being implemented to demonstrate these critical LISA technologies in a relevant flight environment. LISA Pathfinder mimics one arm of the LISA constellation by shrinking the 5-million-kilometer armlength down to a few tens of centimeters. The experimental concept is to measure the relative separation between two test masses nominally following their own geodesics, and thereby determine the relative residual acceleration between them near 1 mHz, about a decade above the lowest frequency required by LISA. To implement such a concept, disturbances on the test masses must be kept very small by many design features, but chiefly by "drag-free" flight. A drag-free spacecraft follows a free-falling test mass which it encloses, but has no mechanical connection to. The spacecraft senses it's orientation and separation with respect to the proof mass, and its propulsion system is commanded to keep the spacecraft centered about the test mass. Thus, the spacecraft shields the test mass from most external influences, and minimizes the effect of force gradients arising from the spacecraft, and acting on the test mass. LISA Pathfinder will compare the geodesic of one test mass against that of the other. Only a metrology system based on interferometry can achieve the displacement sensitivity. Interferometers monitor the separation of both test masses with a sensitivity comparable to that required by LISA, and using the same technologies. LISA Pathfinder is scheduled to be launched in the first half of 1020 to a Lissajous orbit around the first Sun-Earth Lagrange point, L1. In addition to a complete European technology package (the LISA Technology Package, or LTP), LISA Pathfinder will also carry thrusters and software, known as ST-7, a part of NASA's New Millennium Program.

Petrology of deep drill hole, Kilauea Volcano

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grose, L.T.; Keller, G.V.

1976-12-01

The first deep drill hole (1262 m TD) at the summit of an active volcano (1102 m elev) was drilled in 1973 at Kilauea volcano, Hawaii with support from NSF and USGS. The hole is located within southern margin of Kilauea caldera in northern part of a 15 km/sup 2/ triangular block bounded by east rift zone, Koae fault zone, and southwest rift zone-a summit area relatively free of faults, rifts, and extrusions. Nearest eruptions are from fissures 1.2 km away which are active in 1974 and which do not trend toward the drill hole. Core recovery totals 47 mmore » from 29 core runs at rather evenly spaced intervals to total depth. Megascopic, thin-section, and X-ray examination reveals: (1) Recovered core is essentially vesicular, intergranular, nonporphyritic to porphyritic olivine basalt with minor olivine diabase, picrite diabase, and basalt, (2) Hyaloclastite and pillow basalt are absent, (3) Below water table (614 m elev) with increasing depth, vesicularity decreases, and density, crystallinity, competence, vesicle fill, and alteration irregularly increase, (4) Alteration first occurs at water table where calcite and silica partially fill vesticles and olivine is partially serpentinized, (5) At about 570 m elev massive serpentinization of olivine and deposition of montmorillonite-nontronite occur; at about 210 m elev truscottite and tobermorite occur in vesicles; at about 35 m elev mordenite occurs in vesicles, (6) Bottom-hole cores have complete filling of vesicles with silica, minor silica replacement, and complete alteration of olivine, and (7) Plagioclase is unaltered. Chemical analyses of bottom-hole cores are similar to those of modern summit lavas. Alteration and low porosity in bottom-hole cores plus abrupt temperature increase suggest the drill hole penetrated a self-sealed ''cap rock'' to a hydrothermal convection cell and possibly a magma body.« less

Probabilistic and Other Neural Nets in Multi-Hole Probe Calibration and Flow Angularity Pattern Recognition

NASA Technical Reports Server (NTRS)

Baskaran, Subbiah; Ramachandran, Narayanan; Noever, David

1998-01-01

The use of probabilistic (PNN) and multilayer feed forward (MLFNN) neural networks are investigated for calibration of multi-hole pressure probes and the prediction of associated flow angularity patterns in test flow fields. Both types of networks are studied in detail for their calibration and prediction characteristics. The current formalism can be applied to any multi-hole probe, however the test results for the most commonly used five-hole Cone and Prism probe types alone are reported in this article.

Innovative design of composite structures: Design, manufacturing, and testing of plates utilizing curvilinear fiber trajectories

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Rust, R. J.; Waters, W. A., Jr.

1994-01-01

As a means of improving structural design, the concept of fabricating flat plates containing holes by incorporating curvilinear fiber trajectories to transmit loads around the hole is studied. In the present discussion this concept is viewed from a structural level, where access holes, windows, doors, and other openings are of significant size. This is opposed to holes sized for mechanical fasteners. Instead of cutting the important load-bearing fibers at the hole edge, as a conventional straightline design does, the curvilinear design preserves the load-bearing fibers by orienting them in smooth trajectories around the holes, their loading not ending abruptly at the hole edge. Though the concept of curvilinear fiber trajectories has been studied before, attempts to manufacture and test such plates have been limited. This report describes a cooperative effort between Cincinnati Milacron Inc., NASA Langley Research Center, and Virginia Polytechnic Institute and State University to design, manufacture, and test plates using the curvilinear fiber trajectory concept. The paper discusses details of the plate design, details of the manufacturing, and a summary of results from testing the plates with inplane compressive buckling loads and tensile loads. Comparisons between the curvilinear and conventional straightline fiber designs based on measurements and observation are made. Failure modes, failure loads, strains, deflections, and other key responses are compared.

TEST-HOLE CONSTRUCTION FOR A NEUTRONIC REACTOR

DOEpatents

Ohlinger, L.A.; Seitz, F.; Young, G.J.

1959-02-17

Test-hole construction is described for a reactor which provides safe and ready access to the neutron flux region for specimen materials which are to be irradiated therein. An elongated tubular thimble adapted to be inserted in the access hole through the wall of the reactor is constructed of aluminum and is provided with a plurality of holes parallel to the axis of the thimble for conveying the test specimens into position for irradiation, and a conduit for the circulation of coolant. A laminated shield formed of alternate layers of steel and pressed wood fiber is disposed lengthwise of the thimble near the outer end thereof.

Deconvolving instrumental and intrinsic broadening in core-shell x-ray spectroscopies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fister, T. T.; Seidler, G. T.; Rehr, J. J.

2007-05-01

Intrinsic and experimental mechanisms frequently lead to broadening of spectral features in core-shell spectroscopies. For example, intrinsic broadening occurs in x-ray absorption spectroscopy (XAS) measurements of heavy elements where the core-hole lifetime is very short. On the other hand, nonresonant x-ray Raman scattering (XRS) and other energy loss measurements are more limited by instrumental resolution. Here, we demonstrate that the Richardson-Lucy (RL) iterative algorithm provides a robust method for deconvolving instrumental and intrinsic resolutions from typical XAS and XRS data. For the K-edge XAS of Ag, we find nearly complete removal of {approx}9.3 eV full width at half maximum broadeningmore » from the combined effects of the short core-hole lifetime and instrumental resolution. We are also able to remove nearly all instrumental broadening in an XRS measurement of diamond, with the resulting improved spectrum comparing favorably with prior soft x-ray XAS measurements. We present a practical methodology for implementing the RL algorithm in these problems, emphasizing the importance of testing for stability of the deconvolution process against noise amplification, perturbations in the initial spectra, and uncertainties in the core-hole lifetime.« less

Device for measuring hole elongation in a bolted joint

NASA Technical Reports Server (NTRS)

Wichorek, Gregory R. (Inventor)

1987-01-01

A device to determine the operable failure mode of mechanically fastened lightweight composite joints by measuring the hole elongation of a bolted joint is disclosed. The double-lap joint test apparatus comprises a stud, a test specimen having a hole, two load transfer plates, and linear displacement measuring instruments. The test specimen is sandwiched between the two load transfer plates and clamped together with the stud. Spacer washers are placed between the test specimen and each load transfer plate to provide a known, controllable area for the determination of clamping forces around the hole of the specimen attributable to bolt torque. The spacer washers also provide a gap for the mounting of reference angles on each side of the test specimen. Under tensile loading, elongation of the hole of the test specimen causes the stud to move away from the reference angles. This displacement is measured by the voltage output of two linear displacement measuring instruments that are attached to the stud and remain in contact with the reference angles throughout the tensile loading. The present invention obviates previous problems in obtaining specimen deformation measurements by monitoring the reference angles to the test specimen and the linear displacement measuring instruments to the stud.

Riveting in metal airplane construction. Part III : strength of riveted joints in duralumin (continued)

NASA Technical Reports Server (NTRS)

Pleines, Wilhelm

1930-01-01

This report includes strength of riveted joints in duralumin, descriptions of test procedure and results of tests. Tabulated data includes: curshing strength by failure for various conditions, shearing strength of hole edge zone in direction of tearing, tearing strengths of plates weakened by rivet holes, and enlargement of holes at beginning of break.

HORIZONTAL BEAM HOLE NO. 3. PLUG AND RADIATION DOOR HAVE ...

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

HORIZONTAL BEAM HOLE NO. 3. PLUG AND RADIATION DOOR HAVE BEEN REMOVED. EXPERIMENTAL APPARATUS WAS INSERTED INTO THE HOLE. NOTE VALVE CUBICLES NEAR FLOOR ON EACH SIDE OF HB-3. INL NEGATIVE NO. 3471. Unknown Photographer, 10/12/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Absorption of a particle by a rotating black hole: The potential barrier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heller, Leon

For a test particle approaching a rapidly rotating black hole we find a range of values of the particle’s energy and angular momentum, on the order of 1% or more of the corresponding values of the hole, such that three conditions are satisfied. The particle can reach the horizon. After absorption the new hole still has a horizon. The area of the new hole is less than the area of the original one, in apparent violation of a theorem of Hawking. As a result, we offer support for the claim that the test particle approximation is the cause of themore » violation.« less

Absorption of a particle by a rotating black hole: The potential barrier

DOE PAGES

Heller, Leon

2016-09-02

For a test particle approaching a rapidly rotating black hole we find a range of values of the particle’s energy and angular momentum, on the order of 1% or more of the corresponding values of the hole, such that three conditions are satisfied. The particle can reach the horizon. After absorption the new hole still has a horizon. The area of the new hole is less than the area of the original one, in apparent violation of a theorem of Hawking. As a result, we offer support for the claim that the test particle approximation is the cause of themore » violation.« less

Hydrostratigraphic interpretation of test-hole and borehole geophysical data, Kimball, Cheyenne, and Deuel Counties, Nebraska, 2011-12

USGS Publications Warehouse

Hobza, Christopher M.; Sibray, Steven S.

2014-01-01

Recently (2004) adopted legislation in Nebraska requires a sustainable balance between long-term supplies and uses of surface-water and groundwater and requires Natural Resources Districts to understand the effect of groundwater use on surface-water systems when developing a groundwater-management plan. The South Platte Natural Resources District (SPNRD) is located in the southern Nebraska Panhandle and overlies the nationally important High Plains aquifer. Declines in water levels have been documented, and more stringent regulations have been enacted to ensure the supply of ground-water will be sufficient to meet the needs of future generations. Because an improved understanding of the hydrogeologic characteristics of this aquifer system is needed to ensure sustainability of groundwater withdrawals, the U.S. Geological Survey, in cooperation with the SPNRD, Conservation and Survey Division of the University of Nebraska-Lincoln, and the Nebraska Environmental Trust, began a hydrogeologic study of the SPNRD to describe the lithology and thickness of the High Plains aquifer. This report documents these characteristics at 29 new test holes, 28 of which were drilled to the base of the High Plains aquifer. Herein the High Plains aquifer is considered to include all hydrologically connected units of Tertiary and Quaternary age. The depth to the base of aquifer was interpreted to range from 37 to 610 feet in 28 of the 29 test holes. At some locations, particularly northern Kimball County, the base-of-aquifer surface was difficult to interpret from drill cutting samples and borehole geophysical logs. The depth to the base of aquifer determined for test holes drilled for this report was compared with the base-of-aquifer surface interpreted by previous researchers. In general, there were greater differences between the base-of-aquifer elevation reported herein and those in previous studies for areas north of Lodgepole Creek compared to areas south of Lodgepole Creek. The largest difference was at test hole 5-SP-11, where an Ogallala-filled paleovalley prevously had been interpreted based on relatively sparse test-hole data west of 5-SP-11. The base of aquifer near test hole 5-SP-11 reported herein is approximately 230 ft higher in elevation than previously interpreted. Among other test holes that are likely to have been drilled in Ogallala-filled paleovalleys, the greatest difference in the interpreted base of aquifer was for test hole 7-CC-11, northeast of Potter, Nebraska, where the base of aquifer is 180 feet deeper than previously interpreted. Interpretation of test-hole and borehole geophysical data for 29 additional test holes will improve resource managers’ understanding of the hydrogeologic characteristics, including aquifer thickness. Aquifer thickness, which is related to total water in storage, is not well quantified in the north and south tablelands. The additional hydrostratigraphic interpretations provided in this report will improve the hydrogeologic framework used in current (2014) and future groundwater models, which are the basis for many water-management decisions.

Factors governing hole expansion ratio of steel sheets with smooth sheared edge

NASA Astrophysics Data System (ADS)

Yoon, Jae Ik; Jung, Jaimyun; Lee, Hak Hyeon; Kim, Gyo-Sung; Kim, Hyoung Seop

2016-11-01

Stretch-flangeability measured using hole expansion test (HET) represents the ability of a material to form into a complex shaped component. Despite its importance in automotive applications of advanced high strength steels, stretch-flangeability is a less known sheet metal forming property. In this paper, we investigate the factors governing hole expansion ratio (HER) by means of tensile test and HET. We correlate a wide range of tensile properties with HERs of steel sheet specimens because the stress state in the hole edge region during the HET is almost the same as that of the uniaxial tensile test. In order to evaluate an intrinsic HER of steel sheet specimens, the initial hole of the HET specimen is produced using a milling process after punching, which can remove accumulated shearing damage and micro-void in the hole edge region that is present when using the standard HER evaluation method. It was found that the intrinsic HER of steel sheet specimens was proportional to the strain rate sensitivity exponent and post uniform elongation.

Method for Estimating Thread Strength Reduction of Damaged Parent Holes with Inserts

NASA Technical Reports Server (NTRS)

Johnson, David L.; Stratton, Troy C.

2005-01-01

During normal assembly and disassembly of bolted-joint components, thread damage and/or deformation may occur. If threads are overloaded, thread damage/deformation can also be anticipated. Typical inspection techniques (e.g. using GO-NO GO gages) may not provide adequate visibility of the extent of thread damage. More detailed inspection techniques have provided actual pitch-diameter profiles of damaged-hardware holes. A method to predict the reduction in thread shear-out capacity of damaged threaded holes has been developed. This method was based on testing and analytical modeling. Test samples were machined to simulate damaged holes in the hardware of interest. Test samples containing pristine parent-holes were also manufactured from the same bar-stock material to provide baseline results for comparison purposes. After the particular parent-hole thread profile was machined into each sample a helical insert was installed into the threaded hole. These samples were tested in a specially designed fixture to determine the maximum load required to shear out the parent threads. It was determined from the pristine-hole samples that, for the specific material tested, each individual thread could resist an average load of 3980 pounds. The shear-out loads of the holes having modified pitch diameters were compared to the ultimate loads of the specimens with pristine holes. An equivalent number of missing helical coil threads was then determined based on the ratio of shear-out loads for each thread configuration. These data were compared with the results from a finite element model (FEM). The model gave insights into the ability of the thread loads to redistribute for both pristine and simulated damage configurations. In this case, it was determined that the overall potential reduction in thread load-carrying capability in the hardware of interest was equal to having up to three fewer threads in the hole that bolt threads could engage. One- half of this potential reduction was due to local pitch-diameter variations and the other half was due to overall pitch-diameter enlargement beyond Class 2 fit. This result was important in that the thread shear capacity for this particular hardware design was the limiting structural capability. The details of the method development, including the supporting testing, data reduction and analytical model results comparison will be discussed hereafter.

General nonextremal rotating charged Gödel black holes in minimal five-dimensional gauged supergravity.

PubMed

Wu, Shuang-Qing

2008-03-28

I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds.

Computation of Discrete Slanted Hole Film Cooling Flow Using the Navier-Stokes Equations.

DTIC Science & Technology

1982-07-01

7 -121 796 COMPUTATION OF DISCRETE SLANTED HOLE FILM COOLING FLOW i/ i USING THE NAVIER- ..(U) CIENTIFIC RESEARCH ASSOCIATES INC GLASTONBURY CT H...V U U6-IMSA P/ & .OS,-TR. 82-1004 Report R82-910002-4 / COMPUTATION OF DISCRETE SLAMED HOLE FILM COOLING FLOW ( USING THE XAVIER-STOKES EQUATIONS H...CL SIT %GE (f.en Dae Entere)04 REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM REPORT NUMBER 2. GOVT ACCESSION NO] S. RECIPIENT’S CATALOG NUMBERAO

Black hole state counting in loop quantum gravity: a number-theoretical approach.

PubMed

Agulló, Iván; Barbero G, J Fernando; Díaz-Polo, Jacobo; Fernández-Borja, Enrique; Villaseñor, Eduardo J S

2008-05-30

We give an efficient method, combining number-theoretic and combinatorial ideas, to exactly compute black hole entropy in the framework of loop quantum gravity. Along the way we provide a complete characterization of the relevant sector of the spectrum of the area operator, including degeneracies, and explicitly determine the number of solutions to the projection constraint. We use a computer implementation of the proposed algorithm to confirm and extend previous results on the detailed structure of the black hole degeneracy spectrum.

Area-angular-momentum inequality for axisymmetric black holes.

PubMed

Dain, Sergio; Reiris, Martin

2011-07-29

We prove the local inequality A≥8π|J|, where A and J are the area and angular momentum of any axially symmetric closed stable minimal surface in an axially symmetric maximal initial data. From this theorem it is proved that the inequality is satisfied for any surface on complete asymptotically flat maximal axisymmetric data. In particular it holds for marginal or event horizons of black holes. Hence, we prove the validity of this inequality for all dynamical (not necessarily near equilibrium) axially symmetric black holes.

Deployment and evaluation of a dual-sensor autofocusing method for on-machine measurement of patterns of small holes on freeform surfaces.

PubMed

Chen, Xiaomei; Longstaff, Andrew; Fletcher, Simon; Myers, Alan

2014-04-01

This paper presents and evaluates an active dual-sensor autofocusing system that combines an optical vision sensor and a tactile probe for autofocusing on arrays of small holes on freeform surfaces. The system has been tested on a two-axis test rig and then integrated onto a three-axis computer numerical control (CNC) milling machine, where the aim is to rapidly and controllably measure the hole position errors while the part is still on the machine. The principle of operation is for the tactile probe to locate the nominal positions of holes, and the optical vision sensor follows to focus and capture the images of the holes. The images are then processed to provide hole position measurement. In this paper, the autofocusing deviations are analyzed. First, the deviations caused by the geometric errors of the axes on which the dual-sensor unit is deployed are estimated to be 11 μm when deployed on a test rig and 7 μm on the CNC machine tool. Subsequently, the autofocusing deviations caused by the interaction of the tactile probe, surface, and small hole are mathematically analyzed and evaluated. The deviations are a result of the tactile probe radius, the curvatures at the positions where small holes are drilled on the freeform surface, and the effect of the position error of the hole on focusing. An example case study is provided for the measurement of a pattern of small holes on an elliptical cylinder on the two machines. The absolute sum of the autofocusing deviations is 118 μm on the test rig and 144 μm on the machine tool. This is much less than the 500 μm depth of field of the optical microscope. Therefore, the method is capable of capturing a group of clear images of the small holes on this workpiece for either implementation.

Extreme gravity tests with gravitational waves from compact binary coalescences: (II) ringdown

NASA Astrophysics Data System (ADS)

Berti, Emanuele; Yagi, Kent; Yang, Huan; Yunes, Nicolás

2018-05-01

The LIGO/Virgo detections of binary black hole mergers marked a watershed moment in astronomy, ushering in the era of precision tests of Kerr dynamics. We review theoretical and experimental challenges that must be overcome to carry out black hole spectroscopy with present and future gravitational wave detectors. Among other topics, we discuss quasinormal mode excitation in binary mergers, astrophysical event rates, tests of black hole dynamics in modified theories of gravity, parameterized "post-Kerr" ringdown tests, exotic compact objects, and proposed data analysis methods to improve spectroscopic tests of Kerr dynamics by stacking multiple events.

Modeling cross-hole slug tests in an unconfined aquifer

DOE PAGES

Malama, Bwalya; Kuhlman, Kristopher L.; Brauchler, Ralf; ...

2016-06-28

Cross-hole slug test date are analyzed with an extended version of a recently published unconfined aquifer model accounting for waterable effects using the linearized kinematic condition. The use of cross-hole slug test data to characterize aquifer heterogeneity and source/observation well oscillation parameters is evaluated. The data were collected in a series of multi-well and multi-level pneumatic slug tests conducted at a site in Widen, Switzerland. Furthermore, the tests involved source and observation well pairs separated by distances of up to 4 m, and instrumented with pressure transducers to monitor aquifer response in discrete intervals.

Multipole moments of bumpy black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vigeland, Sarah J.

General relativity predicts the existence of black holes, compact objects whose spacetimes depend only on their mass, spin, and charge in vacuum (the 'no-hair' theorem). As various observations probe deeper into the strong fields of black hole candidates, it is becoming possible to test this prediction. Previous work suggested that such tests can be performed by measuring whether the multipolar structure of black hole candidates has the form that general relativity demands, and introduced a family of 'bumpy black hole' spacetimes to be used for making these measurements. These spacetimes have generalized multipoles, where the deviation from the Kerr metricmore » depends on the spacetime's 'bumpiness'. In this paper, we show how to compute the Geroch-Hansen moments of a bumpy black hole, demonstrating that there is a clean mapping between the deviations used in the bumpy black hole formalism and the Geroch-Hansen moments. We also extend our previous results to define bumpy black holes whose current moments, analogous to magnetic moments of electrodynamics, deviate from the canonical Kerr value.« less

Testing general relativity using gravitational wave signals from the inspiral, merger and ringdown of binary black holes

NASA Astrophysics Data System (ADS)

Ghosh, Abhirup; Johnson-McDaniel, Nathan K.; Ghosh, Archisman; Kant Mishra, Chandra; Ajith, Parameswaran; Del Pozzo, Walter; Berry, Christopher P. L.; Nielsen, Alex B.; London, Lionel

2018-01-01

Advanced LIGO’s recent observations of gravitational waves (GWs) from merging binary black holes have opened up a unique laboratory to test general relativity (GR) in the highly relativistic regime. One of the tests used to establish the consistency of the first LIGO event with a binary black hole merger predicted by GR was the inspiral-merger-ringdown consistency test. This involves inferring the mass and spin of the remnant black hole from the inspiral (low-frequency) part of the observed signal and checking for the consistency of the inferred parameters with the same estimated from the post-inspiral (high-frequency) part of the signal. Based on the observed rate of binary black hole mergers, we expect the advanced GW observatories to observe hundreds of binary black hole mergers every year when operating at their design sensitivities, most of them with modest signal to noise ratios (SNRs). Anticipating such observations, this paper shows how constraints from a large number of events with modest SNRs can be combined to produce strong constraints on deviations from GR. Using kludge modified GR waveforms, we demonstrate how this test could identify certain types of deviations from GR if such deviations are present in the signal waveforms. We also study the robustness of this test against reasonable variations of a variety of different analysis parameters.

Orbit classification in an equal-mass non-spinning binary black hole pseudo-Newtonian system

NASA Astrophysics Data System (ADS)

Zotos, Euaggelos E.; Dubeibe, F. L.; González, Guillermo A.

2018-04-01

The dynamics of a test particle in a non-spinning binary black hole system of equal masses is numerically investigated. The binary system is modeled in the context of the pseudo-Newtonian circular restricted three-body problem, such that the primaries are separated by a fixed distance and move in a circular orbit around each other. In particular, the Paczyński-Wiita potential is used for describing the gravitational field of the two non-Newtonian primaries. The orbital properties of the test particle are determined through the classification of the initial conditions of the orbits, using several values of the Jacobi constant, in the Hill's regions of possible motion. The initial conditions are classified into three main categories: (i) bounded, (ii) escaping and (iii) displaying close encounters. Using the smaller alignment index (SALI) chaos indicator, we further classify bounded orbits into regular, sticky or chaotic. To gain a complete view of the dynamics of the system, we define grids of initial conditions on different types of two-dimensional planes. The orbital structure of the configuration plane, along with the corresponding distributions of the escape and collision/close encounter times, allow us to observe the transition from the classical Newtonian to the pseudo-Newtonian regime. Our numerical results reveal a strong dependence of the properties of the considered basins with the Jacobi constant as well as with the Schwarzschild radius of the black holes.

Aeroelastic Studies of a Rectangular Wing with a Hole: Correlation of Theory and Experiment

NASA Technical Reports Server (NTRS)

Conyers, Howard J.; Dowell, Earl H.; Hall, Kenneth C.

2010-01-01

Two rectangular wing models with a hole have been designed and tested in the Duke University wind tunnel to better understand the effects of damage. A rectangular hole is used to simulate damage. The wing with a hole is modeled structurally as a thin elastic plate using the finite element method. The unsteady aerodynamics of the plate-like wing with a hole is modeled using the doublet lattice method. The aeroelastic equations of motion are derived using Lagrange's equation. The flutter boundary is found using the V-g method. The hole's location effects the wing's mass, stiffness, aerodynamics and therefore the aeroelastic behavior. Linear theoretical models were shown to be capable of predicting the critical flutter velocity and frequency as verified by wind tunnel tests.

Anomalies and Hawking fluxes from the black holes of topologically massive gravity

NASA Astrophysics Data System (ADS)

Porfyriadis, Achilleas P.

2009-05-01

The anomaly cancelation method proposed by Wilczek et al. is applied to the black holes of topologically massive gravity (TMG) and topologically massive gravito-electrodynamics (TMGE). Thus the Hawking temperature and fluxes of the ACL and ACGL black holes are found. The Hawking temperatures obtained agree with the surface gravity formula. Both black holes are rotating and this gives rise to appropriate terms in the effective U (1) gauge field of the reduced (1 + 1)-dimensional theory. It is found that the terms in this U (1) gauge field correspond exactly to the correct angular velocities on the horizon of both black holes as well as the correct electrostatic potential of the ACGL black hole. So the results for the Hawking fluxes derived here from the anomaly cancelation method, are in complete agreement with the ones obtained from integrating the Planck distribution.

Charge loss (or the lack thereof) for AdS black holes

NASA Astrophysics Data System (ADS)

Ong, Yen Chin; Chen, Pisin

2014-06-01

The evolution of evaporating charged black holes is complicated to model in general, but is nevertheless important since the hints to the Information Loss Paradox and its recent firewall incarnation may lie in understanding more generic geometries than that of Schwarzschild spacetime. Fortunately, for sufficiently large asymptotically flat Reissner-Nordström black holes, the evaporation process can be modeled via a system of coupled linear ordinary differential equations, with charge loss rate governed by Schwinger pair-production process. The same model can be generalized to study the evaporation of AdS Reissner-Nordström black holes with flat horizon. It was recently found that such black holes always evolve towards extremality since charge loss is inefficient. This property is completely opposite to the asymptotically flat case in which the black hole eventually loses its charges and tends towards Schwarzschild limit. We clarify the underlying reason for this different behavior.

The joint fit of the BHMF and ERDF for the BAT AGN Sample

NASA Astrophysics Data System (ADS)

Weigel, Anna K.; Koss, Michael; Ricci, Claudio; Trakhtenbrot, Benny; Oh, Kyuseok; Schawinski, Kevin; Lamperti, Isabella

2018-01-01

A natural product of an AGN survey is the AGN luminosity function. This statistical measure describes the distribution of directly measurable AGN luminosities. Intrinsically, the shape of the luminosity function depends on the distribution of black hole masses and Eddington ratios. To constrain these fundamental AGN properties, the luminosity function thus has to be disentangled into the black hole mass and Eddington ratio distribution function. The BASS survey is unique as it allows such a joint fit for a large number of local AGN, is unbiased in terms of obscuration in the X-rays and provides black hole masses for type-1 and type-2 AGN. The black hole mass function at z ~ 0 represents an essential baseline for simulations and black hole growth models. The normalization of the Eddington ratio distribution function directly constrains the AGN fraction. Together, the BASS AGN luminosity, black hole mass and Eddington ratio distribution functions thus provide a complete picture of the local black hole population.

Binary Black Hole Mergers, Gravitational Waves, and LISA

NASA Technical Reports Server (NTRS)

Centrella, Joan; Baker, J.; Boggs, W.; Kelly, B.; McWilliams, S.; vanMeter, J.

2008-01-01

The final merger of comparable mass binary black holes is expected to be the strongest source of gravitational waves for LISA. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. We will present the results of new simulations of black hole mergers with unequal masses and spins, focusing on the gravitational waves emitted and the accompanying astrophysical "kicks." The magnitude of these kicks has bearing on the production and growth of supermassive black holes during the epoch of structure formation, and on the retention of black holes in stellar clusters.

Water-level data from wells and test holes through 1991 and potentiometric contours as of 1991 for Yucca Flat, Nevada Test Site, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hale, G.S.; Trudeau, D.A.; Savard, C.S.

The underground nuclear testing program of the US Department of Energy (USDOE) takes place at the Nevada Test Site (NTS), about 65 mi north-west of Las Vegas, Nevada. Underground nuclear tests at Yucca Flat, one of the USDOE test areas at NTS, have affected hydrologic conditions, including groundwater levels. The purpose of this map report, prepared in cooperation with USDOE, is to present selected water-level data collected from wells and test holes through December 1991, and to show potentiometric contours representing 1991 water-table conditions in the Yucca Flat area. The more generic term, potentiometric contours, is used herein rather thanmore » ``water-table contours`` because the hydrologic units contributing water to wells and test holes may not accurately represent the water table. The water table is that surface in an unconfined water body at which the pressure is atmospheric. It is defined by the altitude at which non- perched ground water is first found in wells and test holes. Perched ground water is defined as unconfined ground water separated from an underlying body of ground water by an unsaturated zone. This map report updates information on water levels in some wells and test holes and the resulting water-table contours in rocks of Cenozoic and Paleozoic age shown by Doty and Thordarson for 1980 conditions.« less

Effectiveness of combined macular buckle under direct vision and vitrectomy with ILM peeling in refractory macular hole retinal detachment with extreme high axial myopia: a 24-month comparative study

PubMed Central

Ma, Jin; Li, Honghui; Ding, Xiaohu; Tanumiharjo, Silvia; Lu, Lin

2017-01-01

Purpose To evaluate the efficacy of a combined macular buckle under direct vision and 23-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in refractory macular hole retinal detachment (MHRD) with extreme high axial myopia. Design Prospective, randomised controlled study. Participants The study included 98 eyes of 98 patients of MHRD with extreme high axial (>30 mm) myopia. Intervention Patients were randomly assigned to undergo PPV with ILM peeling (group 1, n=52) or PPV with ILM peeling combined with macular buckle under direct vision (group 2, n=46). Main outcome measures Complete ocular examination included best-corrected visual acuity (BCVA) (LogMAR), applanation tonometry, optical biometry, slit-lamp biomicroscopy, colour fundus photography, ultrasound examination and optical coherence tomography at baseline and every follow-up visit. Results Initial retinal reattachment rate was significantly higher in group 2 than in group 1 at 12-month postoperatively (χ2 test, p=0.020). Macular hole closure rate in group 2 was significantly higher than that in group 1 at 3, 12, 18 and 24 months postoperatively (Fisher's exact test, p<0.05). In initial retinal reattachment cases, the mean BCVA decreased significantly in group 2 than in group 1 at 3 months postoperatively (Wilcoxon matched pairs signed rank test, p=0.036), and had increased significantly in group 2 than in group 1 since 6 months postoperatively (Wilcoxon matched pairs signed rank test, p<0.05). Mean axial lengths in group 2 were significantly shorter than that of group 1 at each follow-up time point (Wilcoxon matched pairs signed rank test, p<0.05). Conclusions Combined macular buckle under direct vision and PPV with ILM peeling is more effective in treatment of MHRD with extreme high axial (>30 mm) myopia. PMID:28292775

Black holes, hidden symmetries, and complete integrability

NASA Astrophysics Data System (ADS)

Frolov, Valeri P.; Krtouš, Pavel; Kubizňák, David

2017-11-01

The study of higher-dimensional black holes is a subject which has recently attracted vast interest. Perhaps one of the most surprising discoveries is a realization that the properties of higher-dimensional black holes with the spherical horizon topology and described by the Kerr-NUT-(A)dS metrics are very similar to the properties of the well known four-dimensional Kerr metric. This remarkable result stems from the existence of a single object called the principal tensor. In our review we discuss explicit and hidden symmetries of higher-dimensional Kerr-NUT-(A)dS black hole spacetimes. We start with discussion of the Killing and Killing-Yano objects representing explicit and hidden symmetries. We demonstrate that the principal tensor can be used as a "seed object" which generates all these symmetries. It determines the form of the geometry, as well as guarantees its remarkable properties, such as special algebraic type of the spacetime, complete integrability of geodesic motion, and separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations. The review also contains a discussion of different applications of the developed formalism and its possible generalizations.

Black holes, hidden symmetries, and complete integrability.

PubMed

Frolov, Valeri P; Krtouš, Pavel; Kubizňák, David

2017-01-01

The study of higher-dimensional black holes is a subject which has recently attracted vast interest. Perhaps one of the most surprising discoveries is a realization that the properties of higher-dimensional black holes with the spherical horizon topology and described by the Kerr-NUT-(A)dS metrics are very similar to the properties of the well known four-dimensional Kerr metric. This remarkable result stems from the existence of a single object called the principal tensor. In our review we discuss explicit and hidden symmetries of higher-dimensional Kerr-NUT-(A)dS black hole spacetimes. We start with discussion of the Killing and Killing-Yano objects representing explicit and hidden symmetries. We demonstrate that the principal tensor can be used as a "seed object" which generates all these symmetries. It determines the form of the geometry, as well as guarantees its remarkable properties, such as special algebraic type of the spacetime, complete integrability of geodesic motion, and separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations. The review also contains a discussion of different applications of the developed formalism and its possible generalizations.

BPS-like bound and thermodynamics of the charged BTZ black hole

NASA Astrophysics Data System (ADS)

Cadoni, Mariano; Monni, Cristina

2009-07-01

The charged Bañados-Teitelboim-Zanelli (BTZ) black hole is plagued by several pathologies: (a) Divergent boundary terms are present in the action; hence, we have a divergent black-hole mass. (b) Once a finite, renormalized, mass M is defined, black-hole states exist for arbitrarily negative values of M. (c) There is no upper bound on the charge Q. We show that these pathological features are an artifact of the renormalization procedure. They can be completely removed by using an alternative renormalization scheme leading to a different definition M0 of the black-hole mass, which is the total energy inside the horizon. The new mass satisfies a BPS-like bound M0≥(π)/(2)Q2, and the heat capacity of the hole is positive. We also discuss the black-hole thermodynamics that arises when M0 is interpreted as the internal energy of the system. We show, using three independent approaches (black-hole thermodynamics, Einstein equations, and Euclidean action formulation), that M0 satisfies the first law if a term describing the mechanical work done by the electrostatic pressure is introduced.

Cross-hole fracture connectivity assessed using hydraulic responses during liner installations in crystalline bedrock boreholes

NASA Astrophysics Data System (ADS)

Persaud, Elisha; Levison, Jana; Pehme, Peeter; Novakowski, Kentner; Parker, Beth

2018-01-01

In order to continually improve the current understanding of flow and transport in crystalline bedrock environments, developing and improving fracture system characterization techniques is an important area of study. The presented research examines the installation of flexible, impermeable FLUTe™ liners as a means for assessing cross-hole fracture connectivity. FLUTe™ liners are used to generate a new style of hydraulic pulse, with pressure response monitored in a nearby network of open boreholes drilled in gneissic rock of the Canadian Shield in eastern Ontario, Canada. Borehole liners were installed in six existing 10-15 cm diameter boreholes located 10-35 m apart and drilled to depths ranging between 25-45 m. Liner installation tests were completed consecutively with the number of observation wells available for each test ranging between one and six. The collected pressure response data have been analyzed to identify significant groundwater flow paths between source and observation boreholes as well as to estimate inter-well transmissivity and storativity using a conventional type-curve analysis. While the applied solution relies on a number of general assumptions, it has been found that reasonable comparison can be made to previously completed pulse interference and pumping tests. Results of this research indicate areas where method refinement is necessary, but, nonetheless, highlight the potential for use in crystalline bedrock environments. This method may provide value to future site characterization efforts given that it is complementary to, and can be used in conjunction with, other currently employed borehole liner applications, such as the removal of cross-connection at contaminated sites and the assessment of discrete fracture distributions when boreholes are sealed, recreating natural hydraulic gradient conditions.

Development of nondestructive testing techniques for plated-through holes in multilayer printed circuit boards

NASA Technical Reports Server (NTRS)

Anthony, P. L.; Mcmurtrey, J. E.

1971-01-01

The development of a nondestructive test with the capability to interrogate plated-through holes as small as 0.51 millimeters inside diameter is discussed. The system can detect defects such as holes, voids, cracks, and thin spots that reduce the current carrying capability of plates-through interconnects by 20 percent or more. Efforts were directed toward the design and fabrication of magnetic circuitry mutual coupling probes and to evaluate the effectiveness of these devices for detecting in multilayer board plated-through holes.

Northern part, Ten Mile and Taunton River basins

USGS Publications Warehouse

Williams, John R.; Willey, Richard E.

1967-01-01

This report is one of two prepared by the Geological Survey for the Water Resources Commission. The principal purpose of this report is to make available the basic data on which the other, a map showing availability of ground water, is based. This basic-data report also can be used by engineers, planners, and others interested in or responsible for water-resources planning to determine the materials to be encountered (tables 3 and 4) and the yields which may be obtained from wells and test holes (tables 1 and 2) in the stratified sand and gravel that are the principal source of ground water and in bedrock. Partial and complete chemical analyses (tables 7 and 8) of these test holes and of some privately-owned wells provide information on the general quality of the water for domestic and other uses. A tabulation of existing municipal supplies, their capacity, production (table 5), and chemical quality of the water (table 6) may be used for regional planning purposes. Water-level measurements (figure 1) can be used to determine the annual fluctuations of the water table in certain types of materials. Seismic work (table 9) in the Canoe River valley, Norton, and test drilling with a power augur (tables 2 and 4) were done for the Geological Survey as  part of the investigation.

DEVELOPMENT OF NEW DRILLING FLUIDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

David B. Burnett

2003-08-01

The goal of the project has been to develop new types of drill-in fluids (DIFs) and completion fluids (CFs) for use in natural gas reservoirs. Phase 1 of the project was a 24-month study to develop the concept of advanced type of fluids usable in well completions. Phase 1 tested this concept and created a kinetic mathematical model to accurately track the fluid's behavior under downhole conditions. Phase 2 includes tests of the new materials and practices. Work includes the preparation of new materials and the deployment of the new fluids and new practices to the field. The project addressesmore » the special problem of formation damage issues related to the use of CFs and DIFs in open hole horizontal well completions. The concept of a ''removable filtercake'' has, as its basis, a mechanism to initiate or trigger the removal process. Our approach to developing such a mechanism is to identify the components of the filtercake and measure the change in the characteristics of these components when certain cleanup (filtercake removal) techniques are employed.« less

σ-Hole and π-Hole Synthon Mimicry in Third-Generation Crystal Engineering: Design of Elastic Crystals.

PubMed

Saha, Subhankar; Desiraju, Gautam R

2017-04-06

Designing elastic crystals is a difficult task and is of relevance in potential applications from materials to biology. Here, multi-step crystal engineering based on σ-hole and π-hole synthon mimicry is performed to obtain binary organic molecular crystals with a high degree of flexibility. A structural model is proposed based only on σ-hole-oriented type-II halogen bonds with their characteristic orthogonal geometry. These σ-hole contacts are then partly replaced by chemically and geometrically similar π-hole synthons to obtain new crystals in the second step. In the final step, all the σ-hole interactions are replaced with π-hole interactions and elastic crystals of non-halogenated compounds are obtained. All the crystals obtained according to our protocols are found to be elastic. When crystals that do not conform to the desired structure type appeared, they were found to be brittle. This underlines the role of orthogonal-type interactions, whether they are of the σ-hole or π-hole type, in achieving elasticity. This is the first report in which π-hole interactions are used for property engineering. This example may illustrate a new generation of crystal engineering in which a particular property is associated more with topological rather than chemical attributes, although the significance of the latter cannot be completely excluded. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design of a Pneumatic Tool for Manual Drilling Operations in Confined Spaces

NASA Astrophysics Data System (ADS)

Janicki, Benjamin

This master's thesis describes the design process and testing results for a pneumatically actuated, manually-operated tool for confined space drilling operations. The purpose of this device is to back-drill pilot holes inside a commercial airplane wing. It is lightweight, and a "locator pin" enables the operator to align the drill over a pilot hole. A suction pad stabilizes the system, and an air motor and flexible drive shaft power the drill. Two testing procedures were performed to determine the practicality of this prototype. The first was the "offset drill test", which qualified the exit hole position error due to an initial position error relative to the original pilot hole. The results displayed a linear relationship, and it was determined that position errors of less than .060" would prevent the need for rework, with errors of up to .030" considered acceptable. For the second test, a series of holes were drilled with the pneumatic tool and analyzed for position error, diameter range, and cycle time. The position errors and hole diameter range were within the allowed tolerances. The average cycle time was 45 seconds, 73 percent of which was for drilling the hole, and 27 percent of which was for positioning the device. Recommended improvements are discussed in the conclusion, and include a more durable flexible drive shaft, a damper for drill feed control, and a more stable locator pin.

Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boccard, Mathieu; Holman, Zachary C.

Amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide beingmore » shown to surpass amorphous silicon for temperatures above 300 °C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.« less

Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boccard, Mathieu; Holman, Zachary C.

With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphousmore » silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.« less

Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

DOE PAGES

Boccard, Mathieu; Holman, Zachary C.

2015-08-14

With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphousmore » silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.« less

Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site

NASA Astrophysics Data System (ADS)

Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa

2017-04-01

Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and petrophysical tests and analyses. The interpretation of the geophysical logging data and borehole oriented images, and core data allowed us to define the stratigraphy, structures and petrophysical properties in the subsurface. Quaternary sediments overlie unconformably weathered, deformed and partially metamorphosed Paleozoic rocks. A gap of the Tertiary rocks at the drillsite was detected. Structures at intensely fractured and faulted sections were measured and have yielded valuable data to understand the subsurface geology, hydrology and geological evolution in that area. Logging, borehole imaging and monitoring carried out in the scientific boreholes Almera-1 and Almera-2 has allowed also to identify three preferential groundwater flow paths in the subsurface. Geophysical logging data combined with groundwater monitoring allowed us to identify three zones of high permeability in the subsurface. Logging data combined with core analysis were used to characterize the aquifers lithology and their respective petrophysical properties. We also analyzed the aquifer dynamics and potential relationships between the variations in groundwater levels and the rainfalls by comparing the groundwater monitoring results and the rainfall. A seismic survey was carried out to outline the geological structures beyond Almera-1 borehole, a vertical reverse pseudo-3D (2.5D) seismic tomography experiment. The results allowed us to define the geological structure beyond the borehole wall and also a correlation between the different geological units in the borehole and their geometry and spatial geophysical and seismic image.

Late Closure of a Stage III Idiopathic Macular Hole after Pars Plana Vitrectomy.

PubMed

Afrashi, Filiz; Öztaş, Zafer; Nalçacı, Serhad

2015-12-01

A 57-year-old female presented to our hospital with decreased vision in her right eye. Detailed ocular examination was performed, and a macular hole was detected in the right eye. The presence of a full-thickness stage III macular hole was confirmed with optical coherence tomography (OCT) imaging. Pars plana vitrectomy followed by long-acting gas tamponade (C3F8) was performed as treatment. One month after surgery, clinical examination revealed a persistent macular hole, confirmed by an OCT scan. Although the patient was scheduled for reoperation, the surgery was postponed due to personal reasons of the patient. Surprisingly, after five months, a closure pattern with accompanying epiretinal membrane was observed in the macular hole area. The closure of the macular hole was completed without any further intervention 8 months post-surgery. In cases of unclosed macular hole after the first surgery, if a second surgery cannot be performed, follow-up with OCT recommended due to the possibility of spontaneous closure. However, spontaneous closure of a persistent macular hole following PPV is rare, so early diagnosis and surgical repair of unclosed macular holes must remain the primary goal.

Estimating when the Antarctic Ozone Hole will Recover

NASA Technical Reports Server (NTRS)

Newman, Paul A.; Nash, Eric R.; Douglass, Anne R.; Nielsen, J. Eric; Pawson, Steven; Stolarski, Richard S.

2007-01-01

The Antarctic ozone hole develops each year and culminates by early spring (late September - early October). The severity of the hole has been assessed from satellites using the minimum total ozone value from the October monthly mean (depth of the hole) and by calculating the average area coverage during this September-October period. Profile information shows that ozone is completely destroyed in the 14-2 1 km layer by early October. Ozone is mainly destroyed by halogen (chlorine and bromine) catalytic cycles, and these losses are modulated by temperature variations. Because atmospheric halogen levels are responding to international a'greements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. Using projections of halogen levels combined with age-of-air estimates, we find that the ozone hole is recovering at an extremely slow rate and that large ozone holes will regularly recur over the next 2 decades. We estimate that the ozone hole will begin to show first signs of size decrease in about 2023, and the hole will fully recover to pre-1980 levels in approximately 2070. Estimates of the ozone hole's recovery from models reveal important differences that will be discussed.

Estimating When the Antarctic Ozone Hole Will Recover

NASA Technical Reports Server (NTRS)

Newman, Paul A.; Nash, Eric R.; Douglass, Anne R.; Nielsen, J. Eric; Pawson, Steven; Stolarski, Richard S.

2007-01-01

The Antarctic ozone hole develops each year and culminates by early spring (late September - early October). The severity of the hole has been assessed from satellites using the minimum total ozone value from the October monthly mean (depth of the hole) and by calculating the average area coverage during this September-October period. Profile information shows that ozone is completely destroyed in the 14-21 km layer by early October. Ozone is mainly destroyed by halogen (chlorine and bromine) catalytic cycles, and these losses are modulated by temperature variations. Because atmospheric halogen levels are responding to international agreements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. Using projections of halogen levels combined with age-of-air estimates, we find that the ozone hole is recovering at an extremely slow rate and that large ozone holes will regularly recur over the next 2 decades. We estimate that the ozone hole will begin to show first signs of size decrease in about 2023, and the hole will fully recover to pre-1980 levels in approximately 2070. Estimates of the ozone hole's recovery from models reveal important differences that will be discussed.

The Final Merger of Massive Black Holes: Recoils, Gravitational Waves, and Electromagnetic Signatures

NASA Technical Reports Server (NTRS)

Centrella, Joan M.

2010-01-01

The final merger of two massive black holes produces a powerful burst of gravitational radiation, emitting more energy than all the stars in the observable universe combined. The resulting gravitational waveforms will be easily detectable by the space-based LISA out to redshifts z greater than 10, revealing the masses and spins of the black holes to high precision. If the merging black holes have unequal masses, or asymmetric spins, the final black hole that forms can recoil with a velocity exceeding 1000 km/s. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new results that are revealing the dynamics and waveforms of binary black hole mergers, recoil velocities, and the possibility of accompanying electromagnetic outbursts.

Notched Strength Allowables and Inplane Shear Strength of AS4/VRM-34 Textile Laminates

NASA Technical Reports Server (NTRS)

Grenoble, Ray W.; Johnston, William M.

2013-01-01

Notched and unnotched strength allowables were developed for a textile composite to provide input data to analytical structural models based on the Pultruded Rod Stiffened Efficient Unitized Structure (PRSEUS) concept. Filled-hole tensile strength, filled-hole compressive strength, and inplane shear strength along stitch lines have been measured. The material system evaluated in this study is based on warp-knitted preforms of AS4 carbon fibers and VRM-34 epoxy resin, which have been processed via resin infusion and oven curing. All specimens were tested in as-fabricated (dry) condition. Filled-hole strengths were evaluated with and without through-thickness stitching. The effects of scaling on filled-hole tensile strength were evaluated by testing specimens in two widths, but with identical width / hole-diameter ratios. Inplane shear specimens were stitched in two configurations, and two specimen thicknesses were tested for each stitch configuration.

TESTING THE NO-HAIR THEOREM WITH OBSERVATIONS IN THE ELECTROMAGNETIC SPECTRUM. II. BLACK HOLE IMAGES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johannsen, Tim; Psaltis, Dimitrios, E-mail: timj@physics.arizona.ed, E-mail: dpsaltis@email.arizona.ed

2010-07-20

According to the no-hair theorem, all astrophysical black holes are fully described by their masses and spins. This theorem can be tested observationally by measuring (at least) three different multipole moments of the spacetimes of black holes. In this paper, we analyze images of black holes within a framework that allows us to calculate observables in the electromagnetic spectrum as a function of the mass, spin, and, independently, the quadrupole moment of a black hole. We show that a deviation of the quadrupole moment from the expected Kerr value leads to images of black holes that are either prolate ormore » oblate depending on the sign and magnitude of the deviation. In addition, there is a ring-like structure around the black hole shadow with a diameter of {approx}10 black hole masses that is substantially brighter than the image of the underlying accretion flow and that is independent of the astrophysical details of accretion flow models. We show that the shape of this ring depends directly on the mass, spin, and quadrupole moment of the black hole and can be used for an independent measurement of all three parameters. In particular, we demonstrate that this ring is highly circular for a Kerr black hole with a spin a {approx}< 0.9 M, independent of the observer's inclination, but becomes elliptical and asymmetric if the no-hair theorem is violated. Near-future very long baseline interferometric observations of Sgr A* will image this ring and may allow for an observational test of the no-hair theorem.« less

Self-completeness and the generalized uncertainty principle

NASA Astrophysics Data System (ADS)

Isi, Maximiliano; Mureika, Jonas; Nicolini, Piero

2014-03-01

The generalized uncertainty principle discloses a self-complete characteristic of gravity, namely the possibility of masking any curvature singularity behind an event horizon as a result of matter compression at the Planck scale. In this paper we extend the above reasoning in order to overcome some current limitations to the framework, including the absence of a consistent metric describing such Planck-scale black holes. We implement a minimum-size black hole in terms of the extremal configuration of a neutral non-rotating metric, which we derived by mimicking the effects of the generalized uncertainty principle via a short scale modified version of Einstein gravity. In such a way, we find a self- consistent scenario that reconciles the self-complete character of gravity and the generalized uncertainty principle.

Self-completeness and the generalized uncertainty principle

NASA Astrophysics Data System (ADS)

Isi, Maximiliano; Mureika, Jonas; Nicolini, Piero

2013-11-01

The generalized uncertainty principle discloses a self-complete characteristic of gravity, namely the possibility of masking any curvature singularity behind an event horizon as a result of matter compression at the Planck scale. In this paper we extend the above reasoning in order to overcome some current limitations to the framework, including the absence of a consistent metric describing such Planck-scale black holes. We implement a minimum-size black hole in terms of the extremal configuration of a neutral non-rotating metric, which we derived by mimicking the effects of the generalized uncertainty principle via a short scale modified version of Einstein gravity. In such a way, we find a self-consistent scenario that reconciles the self-complete character of gravity and the generalized uncertainty principle.

Hydrostratigraphic interpretation of test-hole and surface geophysical data, Elkhorn and Loup River Basins, Nebraska, 2008 to 2011

USGS Publications Warehouse

Hobza, Christopher M.; Bedrosian, Paul A.; Bloss, Benjamin R.

2012-01-01

The Elkhorn-Loup Model (ELM) was begun in 2006 to understand the effect of various groundwater-management scenarios on surface-water resources. During phase one of the ELM study, a lack of subsurface geological information was identified as a data gap. Test holes drilled to the base of the aquifer in the ELM study area are spaced as much as 25 miles apart, especially in areas of the western Sand Hills. Given the variable character of the hydrostratigraphic units that compose the High Plains aquifer system, substantial variation in aquifer thickness and characteristics can exist between test holes. To improve the hydrogeologic understanding of the ELM study area, the U.S. Geological Survey, in cooperation with the Nebraska Department of Natural Resources, multiple Natural Resources Districts participating in the ELM study, and the University of Nebraska-Lincoln Conservation and Survey Division, described the subsurface lithology at six test holes drilled in 2010 and concurrently collected borehole geophysical data to identify the base of the High Plains aquifer system. A total of 124 time-domain electromagnetic (TDEM) soundings of resistivity were collected at and between selected test-hole locations during 2008-11 as a quick, non-invasive means of identifying the base of the High Plains aquifer system. Test-hole drilling and geophysical logging indicated the base-of-aquifer elevation was less variable in the central ELM area than in previously reported results from the western part of the ELM study area, where deeper paleochannels were eroded into the Brule Formation. In total, more than 435 test holes were examined and compared with the modeled-TDEM soundings. Even where present, individual stratigraphic units could not always be identified in modeled-TDEM sounding results if sufficient resistivity contrast was not evident; however, in general, the base of aquifer [top of the aquifer confining unit (ACU)] is one of the best-resolved results from the TDEM-based models, and estimates of the base-of-aquifer elevation are in good accordance with those from existing test-hole data. Differences between ACU elevations based on modeled-TDEM and test-hole data ranged from 2 to 113 feet (0.6 to 34 meters). The modeled resistivity results reflect the eastward thinning of Miocene-age and older stratigraphic units, and generally allowed confident identification of the accompanying change in the stratigraphic unit forming the ACU. The differences in elevation of the top of the Ogallala, estimated on the basis of the modeled-TDEM resistivity, and the test-hole data ranged from 11 to 251 feet (3.4 to 77 meters), with two-thirds of model results being within 60 feet of the test-hole contact elevation. The modeled-TDEM soundings also provided information regarding the distribution of Plio-Pleistocene gravel deposits, which had an average thickness of 100 feet (30 meters) in the study area; however, in many cases the contact between the Plio-Pleistocene deposits and the overlying Quaternary deposits cannot be reliably distinguished using TDEM soundings alone because of insufficient thickness or resistivity contrast.

Testing the fidelity of laminations as a proxy for oxygen concentration in the Bering Sea over millennial to orbital timescales

NASA Astrophysics Data System (ADS)

Black, A. E.; Baranow, N.; Amdur, S.; Cook, M. S.

2017-12-01

Ocean circulation and biological productivity play an important role in the climate system through their contribution to global heat transport and air-sea exchange of CO­2. Oceanic oxygen concentration provides insight to ocean circulation and biological productivity. Sediment laminations provide a valuable proxy for local oceanic oxygen concentration. Many sediment cores from the Pacific Ocean are laminated from the last deglaciation, but previous studies have not provided an in-depth examination of laminations over many glacial and interglacial (G/IG) cycles. Typically, studies to date that consider bioturbation as a proxy for oxygen concentration have only considered one sediment core from a site, leaving ambiguity as to whether laminations faithfully record local oxygen levels. With sediment cores from three different holes (A, C, D) on the northern Bering Slope from IODP site U1345 (1008m), we investigate how faithfully laminations record oxygen concentration. We assign a bioturbation index from 1 to 4 for 1-cm intervals for the cores from each of the three holes and align the holes based on physical properties data. We find that the bioturbation is relatively consistent (within one bioturbation unit) between holes, suggesting that laminations may be a faithful, if not perfect, proxy for local oxygen concentration. After examining laminations from a complete hole, representing over 500,000 years, there seems to be no consistent pattern of laminations during the past five glacial cycles, suggesting there is no consistent pattern to oxygen concentration during glacial periods in the northern Bering Slope. Thus, hypotheses on ocean circulation and productivity in the northern Bering Sea from the last deglaciation may not apply to previous G/IG cycles.

Development of a thermally-assisted piercing (TAP) process for introducing holes into thermoplastic composites

NASA Astrophysics Data System (ADS)

Brown, Nicholas W. A.

Composite parts can be manufactured to near-net shape with minimum wastage of material; however, there is almost always a need for further machining. The most common post-manufacture machining operations for composite materials are to create holes for assembly. This thesis presents and discusses a thermally-assisted piercing process that can be used as a technique for introducing holes into thermoplastic composites. The thermally-assisted piercing process heats up, and locally melts, thermoplastic composites to allow material to be displaced around a hole, rather than cutting them out from the structure. This investigation was concerned with how the variation of piercing process parameters (such as the size of the heated area, the temperature of the laminate prior to piercing and the geometry of the piercing spike) changed the material microstructure within carbon fibre/Polyetheretherketone (PEEK) laminates. The variation of process parameters was found to significantly affect the formation of resin rich regions, voids and the fibre volume fraction in the material surrounding the hole. Mechanical testing (using open-hole tension, open-hole compression, plain-pin bearing and bolted bearing tests) showed that the microstructural features created during piercing were having significant influence over the resulting mechanical performance of specimens. By optimising the process parameters strength improvements of up to 11% and 21% were found for pierced specimens when compared with drilled specimens for open-hole tension and compression loading, respectively. For plain-pin and bolted bearing tests, maximum strengths of 77% and 85%, respectively, were achieved when compared with drilled holes. Improvements in first failure force (by 10%) and the stress at 4% hole elongation (by 18%), however, were measured for the bolted bearing tests when compared to drilled specimens. The overall performance of pierced specimens in an industrially relevant application ultimately depends on the properties required for that specific scenario. The results within this thesis show that the piercing technique could be used as a direct replacement to drilling depending on this application.

The AIROPA software package: milestones for testing general relativity in the strong gravity regime with AO

NASA Astrophysics Data System (ADS)

Witzel, Gunther; Lu, Jessica R.; Ghez, Andrea M.; Martinez, Gregory D.; Fitzgerald, Michael P.; Britton, Matthew; Sitarski, Breann N.; Do, Tuan; Campbell, Randall D.; Service, Maxwell; Matthews, Keith; Morris, Mark R.; Becklin, E. E.; Wizinowich, Peter L.; Ragland, Sam; Doppmann, Greg; Neyman, Chris; Lyke, James; Kassis, Marc; Rizzi, Luca; Lilley, Scott; Rampy, Rachel

2016-07-01

General relativity can be tested in the strong gravity regime by monitoring stars orbiting the supermassive black hole at the Galactic Center with adaptive optics. However, the limiting source of uncertainty is the spatial PSF variability due to atmospheric anisoplanatism and instrumental aberrations. The Galactic Center Group at UCLA has completed a project developing algorithms to predict PSF variability for Keck AO images. We have created a new software package (AIROPA), based on modified versions of StarFinder and Arroyo, that takes atmospheric turbulence profiles, instrumental aberration maps, and images as inputs and delivers improved photometry and astrometry on crowded fields. This software package will be made publicly available soon.

Pneumatic testing in 45-degree-inclined boreholes in ash-flow tuff near Superior, Arizona

USGS Publications Warehouse

LeCain, G.D.

1995-01-01

Matrix permeability values determined by single-hole pneumatic testing in nonfractured ash-flow tuff ranged from 5.1 to 20.3 * 1046 m2 (meters squared), depending on the gas-injection rate and analysis method used. Results from the single-hole tests showed several significant correlations between permeability and injection rate and between permeability and test order. Fracture permeability values determined by cross-hole pneumatic testing in fractured ash-flow tuff ranged from 0.81 to 3.49 * 1044 m2, depending on injection rate and analysis method used. Results from the cross-hole tests monitor intervals showed no significant correlation between permeability and injection rate; however, results from the injection interval showed a significant correlation between injection rate and permeability. Porosity estimates from the 'cross-hole testing range from 0.8 to 2.0 percent. The maximum temperature change associated with the pneumatic testing was 1.2'(2 measured in the injection interval during cross-hole testing. The maximum temperature change in the guard and monitor intervals was O.Ip C. The maximum error introduced into the permeability values due to temperature fluctuations is approximately 4 percent. Data from temperature monitoring in the borehole indicated a positive correlation between the temperature decrease in the injection interval during recovery testing and the gas-injection rate. The thermocouple psychrometers indicated that water vapor was condensing in the boreholes during testing. The psychrometers in the guard and monitor intervals detected the drier injected gas as an increase in the dry bulb reading. The relative humidity in the test intervals was always higher than the upper measurement limit of the psychrometers. Although the installation of the packer system may have altered the water balance of the borehole, the gas-injection testing resulted in minimal or no changes in the borehole relative humidity.

Deformational injection rate measuring method

NASA Astrophysics Data System (ADS)

Marčič, Milan

2002-09-01

After completing the diesel engine endurance testing, we detected various traces of thermal load on the walls of combustion chambers located in the engine pistons. The engines were fitted with ω combustion chambers. The thermal load of different intensity levels occurred where the spray of fuel, fuel vapor, and air interacted with the combustion chamber wall. The uneven thermal load distribution of the combustion chamber wall results from varying injection rates in each injection nozzle hole. The most widely applied controlling methods so far for injection rate measurement, such as the Zeuch and Bosch concepts, allow measurement of only the total injection rate in multihole nozzles, without providing any indication whatsoever of the injection rate differences in individual injection nozzle holes. The new deformational measuring method described in the article allows the injection rate to be measured in each hole of the multihole nozzle. The results of the measurements using this method showed that the differences occurred in injection rates of individual injection nozzle holes. These differences may be the cause of various thermal loads on the combustion chamber walls. The criterion for injection rate is the deformation of the membrane due to an increase in the fuel quantity in the measuring space and due to the pressure waves resulting from the fuel being injected into the measuring space. The membrane deformation is measured using strain gauges, glued to the membrane and forming the Wheatstone's bridge. We devoted special attention to the temperature compensation of the Wheatstone's bridge and the membrane, heated up during the measurements.

43 CFR 3253.11 - Must I notify BLM when I have completed my exploration operations?

Code of Federal Regulations, 2011 CFR

2011-10-01

... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) GEOTHERMAL...) Complete any geophysical exploration operations; (b) Complete the drilling of temperature gradient well(s... gradient well; and (d) Plug shot holes and reclaim all exploration sites. ...

A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

NASA Astrophysics Data System (ADS)

Rakow, Alexi Schroder

Fatigue cracks initiating at fastener hole locations in metallic components are among the most common form of airframe damage. The fastener hole site has been surveyed as the second leading initiation site for fatigue related accidents of fixed wing aircraft. Current methods for inspecting airframes for these cracks are manual, whereby inspectors rely on non-destructive inspection equipment or hand-held probes to scan over areas of a structure. Use of this equipment often demands disassembly of the vehicle to search appropriate hole locations for cracks, which elevates the complexity and cost of these maintenance inspections. Improved reliability, safety, and reduced cost of such maintenance can be realized by the permanent integration of sensors with a structure to detect this damage. Such an integrated system of sensors would form a structural health monitoring (SHM) system. In this study, an Additive, Interleaved, Multi-layer Electromagnetic (AIME) sensor was developed and integrated with the shank of a fastener to form a SHM Fastener, a new SHM technology targeted at detection of fastener hole cracks. The major advantages of the SHM Fastener are its installation, which does not require joint layer disassembly, its capability to detect inner layer cracks, and its capability to operate in a continuous autonomous mode. Two methods for fabricating the proposed SHM Fastener were studied. The first option consisted of a thin flexible printed circuit film that was bonded around a thin metallic sleeve placed around the fastener shank. The second option consisted of coating sensor materials directly to the shank of a part in an effort to increase the durability of the sensor under severe loading conditions. Both analytical and numerical models were developed to characterize the capability of the sensors and provide a design tool for the sensor layout. A diagnostic technique for crack growth monitoring was developed to complete the SHM system, which consists of the sensor, data acquisition hardware, algorithm, and diagnostic display. The AIME sensor design, SHM Fastener, and complete SHM system are presented along with experimental results from a series of single-layer and bolted double lap joint aluminum laboratory specimens to validate the capability of these sensors to monitor metallic joints for fastener hole cracks. Fatigue cracks were successfully tracked to over 0.7 inches from the fastener hole in these tests. Sensor output obtained from single-layer fatigue specimens was compared with analytical predictions for fatigue crack growth versus cycle number showing a good correlation in trend between sensor output and predicted crack size.

Biomechanical Testing of a 3-Hole versus a 4-Hole Sliding Hip Screw in the presence of a Retrograde Intramedullary Nail for Ipsilateral Intertrochanteric and Femur Shaft Fractures.

PubMed

Olsen, Michael; Goshulak, Peter; Crookshank, Meghan C; Moktar, Joel; Brazda, Ignace J; Schemitsch, Emil H; Zdero, Radovan

2018-04-03

The goal of this study was to compare a 3-hole vs. a 4-hole sliding hip screw (SHS) in the presence of a retrograde intramedullary (RIM) nail for fixing intertrochanteric and comminuted midshaft femur fractures. Mechanical tests were performed on 10 matched pairs of human cadaveric femurs that were osteotomized and then fixed using a 3-hole SHS vs. the traditional "gold standard" 4-hole SHS in the presence of a RIM nail. Data showed no differences between the 3-hole SHS with RIM nail vs. 4-hole SHS with RIM nail for stiffness (281 +/- 127 vs. 260 +/- 118 N/mm, p=0.76), clinical failure at 10 mm of hip displacement (2014 +/- 363 vs. 2134 +/- 614 N, p=0.52), or ultimate mechanical failure (3476 +/- 776 vs. 3669 +/- 755 N, p=0.12). For this fracture pattern, a 3-hole SHS with RIM nail may be a suitable surgical alternative to the traditional "gold standard" method, since it provides the same biomechanical properties while potentially reducing surgical time, blood loss, and hardware used. Level III biomechanical study.

The current ability to test theories of gravity with black hole shadows

NASA Astrophysics Data System (ADS)

Mizuno, Yosuke; Younsi, Ziri; Fromm, Christian M.; Porth, Oliver; De Laurentis, Mariafelicia; Olivares, Hector; Falcke, Heino; Kramer, Michael; Rezzolla, Luciano

2018-04-01

Our Galactic Centre, Sagittarius A*, is believed to harbour a supermassive black hole, as suggested by observations tracking individual orbiting stars1,2. Upcoming submillimetre very-long baseline interferometry images of Sagittarius A* carried out by the Event Horizon Telescope collaboration (EHTC)3,4 are expected to provide critical evidence for the existence of this supermassive black hole5,6. We assess our present ability to use EHTC images to determine whether they correspond to a Kerr black hole as predicted by Einstein's theory of general relativity or to a black hole in alternative theories of gravity. To this end, we perform general-relativistic magnetohydrodynamical simulations and use general-relativistic radiative-transfer calculations to generate synthetic shadow images of a magnetized accretion flow onto a Kerr black hole. In addition, we perform these simulations and calculations for a dilaton black hole, which we take as a representative solution of an alternative theory of gravity. Adopting the very-long baseline interferometry configuration from the 2017 EHTC campaign, we find that it could be extremely difficult to distinguish between black holes from different theories of gravity, thus highlighting that great caution is needed when interpreting black hole images as tests of general relativity.

Burr hole drainage for complicated spontaneous intracranial hypotension syndrome.

PubMed

Liu, Yu-Fang; Lin, Hung-Lin; Cho, Der-Yang; Chen, Chun-Chung; Lo, Yu-Chien; Chiou, Shang-Ming

2008-09-01

Spontaneous intracranial hypotension is a potentially severe condition that is caused by continuous cerebrospinal fluid leakage. Clinically, most patients have a benign course and the condition remits after conservative management. We report two consecutive patients who presented with acute expansion of subdural collection and disturbed consciousness. Both patients recovered completely after undergoing burr hole drainage.

Scattering of Dirac waves off Kerr black holes

NASA Astrophysics Data System (ADS)

Chakrabarti, Sandip K.; Mukhopadhyay, Banibrata

2000-10-01

Chandrasekhar separated the Dirac equation for spinning and massive particles in Kerr geometry into radial and angular parts. Here we solve the complete wave equation and find out how the Dirac wave scatters off Kerr black holes. The eigenfunctions, eigenvalues and reflection and transmission co-efficients are computed. We compare the solutions with several parameters to show how a spinning black hole recognizes the mass and energy of incoming waves. Very close to the horizon the solutions become independent of the particle parameters, indicating the universality of the behaviour.

Alignment Tool For Inertia Welding

NASA Technical Reports Server (NTRS)

Snyder, Gary L.

1991-01-01

Compact, easy-to-use tool aligns drive bar of inertia welder over hole in stub. Ensures drive bar concentric to hole within 0.002 in. (0.051 mm.). Holds two batteries and light bulb. Electrical circuit completed, providing current to bulb when pin in contact with post. When pin centered in post hole, it does not touch post, and lamp turns off. Built for use in making repair welds on liquid-oxygen-injector posts in Space Shuttle main engine. Version having suitably modified dimensions used to facilitate alignment in other forests of post.

Probing Black Holes With Gravitational Radiation

NASA Astrophysics Data System (ADS)

Cornish, Neil J.

2006-09-01

Gravitational radiation can provide unique insights into the dynamics and evolution of black holes. Gravitational waveforms encode detailed information about the spacetime geometry, much as the sounds made by a musical instrument reflect the geometry of the instrument. The LISA gravitational wave observatory will be able to record black holes colliding out to the edge of the visible Universe, with an expected event rate of tens to thousands per year. LISA has unmatched capabilities for studying the role of black holes in galactic evolution, in particular, by studying the mergers of seed black holes at very high redshift, z > 5. Merger events at lower redshift will be detected at extremely high signal-to-noise, allowing for precision tests of the black hole paradigm. Below z=1 LISA will be able to record stellar remnants falling into supermassive black holes. These extreme mass ratio inspiral events will yield insights into the dynamics of galactic cusps, and the brighter events will provide incredibly precise tests of strong field, dynamical gravity.

Wake Measurement Downstream of a Hybrid Wing Body Model with Blown Flaps

NASA Technical Reports Server (NTRS)

Lin, John C.; Jones, Gregory S.; Allan, Brian G.; Westra, Bryan W.; Collins, Scott W.; Zeune, Cale H.

2010-01-01

Flow-field measurements were obtained in the wake of a full-span Hybrid Wing Body model with internally blown flaps. The test was performed at the NASA Langley 14 x 22 Foot Subsonic Tunnel at low speeds. Off-body measurements were obtained with a 7-hole probe rake survey system. Three model configurations were investigated. At 0deg angle of attack the surveys were completed with 0deg and 60deg flap deflections. At 10deg angle of attack the wake surveys were completed with a slat and a 60deg flap deflection. The 7-hole probe results further quantified two known swirling regions (downstream of the outboard flap edge and the inboard/outboard flap juncture) for the 60deg flap cases with blowing. Flowfield results and the general trends are very similar for the two blowing cases at nozzle pressure ratios of 1.37 and 1.56. High downwash velocities correlated with the enhanced lift for the 60deg flap cases with blowing. Jet-induced effects are the largest at the most inboard station for all (three) velocity components due in part to the larger inboard slot height. The experimental data are being used to improve computational tools for high-lift wings with integrated powered-lift technologies.

The merger of small and large black holes

NASA Astrophysics Data System (ADS)

Mösta, P.; Andersson, L.; Metzger, J.; Szilágyi, B.; Winicour, J.

2015-12-01

We present simulations of binary black-hole mergers in which, after the common outer horizon has formed, the marginally outer trapped surfaces (MOTSs) corresponding to the individual black holes continue to approach and eventually penetrate each other. This has very interesting consequences according to recent results in the theory of MOTSs. Uniqueness and stability theorems imply that two MOTSs which touch with a common outer normal must be identical. This suggests a possible dramatic consequence of the collision between a small and large black hole. If the penetration were to continue to completion, then the two MOTSs would have to coalesce, by some combination of the small one growing and the big one shrinking. Here we explore the relationship between theory and numerical simulations, in which a small black hole has halfway penetrated a large one.

Fading Hawking radiation

NASA Astrophysics Data System (ADS)

Sakalli, Izzet; Halilsoy, Mustafa; Pasaoglu, Hale

2012-07-01

In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek's tunneling formalism amalgamated with quantum corrections to all orders in ħ is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to "no information loss".

WIPP Intermediate Scale Borehole Test. A pretest analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Argueello, J.G.

A three-dimensional finite element structural analysis of the Intermediate Scale Borehole Test at the WIPP has been performed. The analysis provides insight into how a relatively new excavation in a creeping medium responds when introduced into an existing pillar which has been undergoing stress redistribution for 5.7 years. The stress field of the volume of material in the immediate vicinity of the borehole changes significantly when the hole is drilled. Closure of the hole is predicted to be larger in the vertical direction than in the horizontal direction, leading to an ovaling of the hole. The relatively high stresses nearmore » the hole persist even at the end of the simulation, 2 years after the hole is drilled.« less

Destroying charged black holes in higher dimensions with test particles

NASA Astrophysics Data System (ADS)

Wu, Bin; Liu, Weiyang; Tang, Hao; Yue, Rui-Hong

2017-07-01

A possible way to destroy the Tangherlini Reissner-Nordström black hole is discussed in the spirit of Wald’s gedanken experiment. By neglecting radiation and self force effects, the absorbing condition and destruction condition of the test point particle which is capable of destroying the black hole are obtained. We find that it is impossible to challenge the weak cosmic censorship for an initially extremal black hole in all dimensions. Instead, it is shown that the near extremal black hole will turn into a naked singularity in this particular process, in which case the allowed range of the particle’s energy is very narrow. The result indicates that the self-force effects may well change the outcome of the calculation.

Borehole flowmeter logging for the accurate design and analysis of tracer tests.

PubMed

Basiricò, Stefano; Crosta, Giovanni B; Frattini, Paolo; Villa, Alberto; Godio, Alberto

2015-04-01

Tracer tests often give ambiguous interpretations that may be due to the erroneous location of sampling points and/or the lack of flow rate measurements through the sampler. To obtain more reliable tracer test results, we propose a methodology that optimizes the design and analysis of tracer tests in a cross borehole mode by using vertical borehole flow rate measurements. Experiments using this approach, herein defined as the Bh-flow tracer test, have been performed by implementing three sequential steps: (1) single-hole flowmeter test, (2) cross-hole flowmeter test, and (3) tracer test. At the experimental site, core logging, pumping tests, and static water-level measurements were previously carried out to determine stratigraphy, fracture characteristics, and bulk hydraulic conductivity. Single-hole flowmeter testing makes it possible to detect the presence of vertical flows as well as inflow and outflow zones, whereas cross-hole flowmeter testing detects the presence of connections along sets of flow conduits or discontinuities intercepted by boreholes. Finally, the specific pathways and rates of groundwater flow through selected flowpaths are determined by tracer testing. We conclude that the combined use of single and cross-borehole flowmeter tests is fundamental to the formulation of the tracer test strategy and interpretation of the tracer test results. © 2014, National Ground Water Association.

Hydrogeologic monitoring at the Faultless site, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thordarson, W.

The Faultless event was the detonation of an intermediate-yield nuclear device on January 19, 1968, at a depth of 975 meters below the surface of Hot Creek Valley, Nevada. This report presents details of the hydrogeology and radiochemical monitoring, primarily for the reentry hole UC-1-P-2SR; data from test holes HTH-1, HTH-2, UCE-18, instrument holes UC-1-I-1 and UC-1-I-2, and the abandoned reentry hole UC-1-P-1S are included. The reentry hole UC-1-P-2SR was drilled to a total depth of 1097 meters. The hole penetrated valley-fill sediments above the Tubble Chimney, as well as valley-fill and Tertiary tuffaceous sediments within the rubble chimney andmore » rubble-filled cavity. Monitoring of the water level in the reentry hole indicated that, from 1970-1974, the water level was approximately 694.9 meters in depth below land surface. From 1974 to the present (1983), the water level rose slowly to a depth of 335.1 meters below land surface as the rubble chimney became filled with water. In 1976, the water-level in test hole HTH-1 returned to a depth 6.7 meters above the pre-event water level, and the water level in test hole HTH-2 returned to a depth 2.7 meters above the pre-event water level. Ground water sampled from reentry hole UC-1-P-2SR is a predominantly sodium bicarbonate type containing some sulfate and minor chloride, similar to water from test hole HTH-1. Tritium concentrations fluctuated from a maximum value of 9.2 x 10/sup 8/ picocuries per liter in 1976, decreasing to 10/sup 5/ picocuries per liter in 1977, followed by a gradual increase to values of 10/sup 7/ picocuries per liter from 1980 to 1982. After 1971, gross-beta concentration ranged between 1.2 and 130 picocuries per liter, but generally was less than 10 picocuries per liter. Gross-alpha concentration generally was less than 10 micrograms per liter from 1975 to 1982. 15 refs., 11 figs., 13 tabs.« less

Graphical viewer for displaying locations and logs of selected wells and test holes in Putnam County, New York

USGS Publications Warehouse

Wolcott, Stephen W.

2005-01-01

Aquifers (water bearing geologic units) are the primary source of drinking water in most of Putnam County, N.Y. The principal sources of data used to define the geometry and hydraulic characteristics of aquifers are the logs of wells and test holes within the county. This report explains how to use a graphical viewer, available on the World Wide Web (http://ny.water.usgs.gov/pubs/of/of051198), to locate selected wells and test holes in Putnam County and display their logs.

Selected data for wells and test holes used in structure-contour maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills area, South Dakota

USGS Publications Warehouse

Carter, J.M.

1999-01-01

This report presents selected data on wells and test holes that were used in the construction of structure-contour maps of selected formations that contain major aquifers in the Black Hills area of western South Dakota. Altitudes of the top of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation are presented for the wells and test holes presented in this report.

Microbial communities and their potential for degradation of dissolved organic carbon in cryoconite hole environments of Himalaya and Antarctica.

PubMed

Sanyal, Aritri; Antony, Runa; Samui, Gautami; Thamban, Meloth

2018-03-01

Cryoconite holes (cylindrical melt-holes on the glacier surface) are important hydrological and biological systems within glacial environments that support diverse microbial communities and biogeochemical processes. This study describes retrievable heterotrophic microbes in cryoconite hole water from three geographically distinct sites in Antarctica, and a Himalayan glacier, along with their potential to degrade organic compounds found in these environments. Microcosm experiments (22 days) show that 13-60% of the dissolved organic carbon in the water within cryoconite holes is bio-available to resident microbes. Biodegradation tests of organic compounds such as lactate, acetate, formate, propionate and oxalate that are present in cryoconite hole water show that microbes have good potential to metabolize the compounds tested. Substrate utilization tests on Biolog Ecoplate show that microbial communities in the Himalayan samples are able to oxidize a diverse array of organic substrates including carbohydrates, carboxylic acids, amino acids, amines/amides and polymers, while Antarctic communities generally utilized complex polymers. In addition, as determined by the extracellular enzyme activities, majority of the microbes (82%, total of 355) isolated in this study (Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Basidiomycota) had ability to degrade a variety of compounds such as proteins, lipids, carbohydrates, cellulose and lignin that are documented to be present within cryoconite holes. Thus, microbial communities have good potential to metabolize organic compounds found in the cryoconite hole environment, thereby influencing the water chemistry in these holes. Moreover, microbes exported downstream during melting and flushing of cryoconite holes may participate in carbon cycling processes in recipient ecosystems. Copyright © 2018 Elsevier GmbH. All rights reserved.

49 CFR 230.72 - Testing main reservoirs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... drilled over its entire surface with telltale holes that are 3/16 of an inch in diameter. The holes shall...)) Where: D = Extreme depth of telltale holes in inches but in no case less than one-sixteenth inch; P...; and R = inside radius of the reservoir in inches. (2) One row of holes shall be drilled lengthwise of...

Testing various modes of installation for permanent broadband stations in open field environment

NASA Astrophysics Data System (ADS)

Vergne, Jérôme; Charade, Olivier; Arnold, Benoît; Louis-Xavier, Thierry

2014-05-01

In the framework of the RESIF (Réseau Sismologique et géodésique Français) project, we plan to install more than one hundred new permanent broadband stations in metropolitan France within the next 6 years. Whenever possible, the sensors will be installed in natural or artificial underground cavities that provide a stable thermal environment. However such places do not exist everywhere and we expect that about half the future stations will have to be set up in open fields. For such sites, we are thus looking for a standard model of hosting infrastructure for the sensors that would be easily replicated and would provide good noise level performances at long periods. Since early 2013, we have been operating a prototype station at Clévilliers, a small location in the sedimentary Beauce plain, where we test three kinds of buried seismic vaults and a down-hole installation. The cylindrical seismic vaults are 3m deep and 1m wide and only differ by the type of coupling between the casing and the concrete slab where we installed insulated Trillium T120PA seismometers. The down-hole installation consists in a 3m deep well hosting a Trillium Posthole seismometer. For reference, another sensor has been installed in a ~50cm deep hole, similarly to the way we test every new potential site. Here we compare the noise level in each infrastructure at different frequencies. We observe quite similar performances for the vertical component recorded in the different wells. Conversely, the noise levels on the horizontal components at periods greater than 10s vary by more than 20dB depending on the installation condition. The best results are obtained in the completely decoupled vault and for the down-hole setting, both showing performances comparable to some of our permanent stations installed in tunnels. The amplitude of the horizontal noise also appears to be highly correlated to wind speed recorded on site, even at long periods. The variable response of each vault to such external forcing can partly explain the variations of the seismic noise levels.

Three-dimensional hole transport in nickel oxide by alloying with MgO or ZnO

NASA Astrophysics Data System (ADS)

Alidoust, Nima; Carter, Emily A.

2015-11-01

It has been shown previously that the movement of a hole in nickel oxide is confined to two dimensions, along a single ferromagnetic plane. Such confinement may hamper hole transport when NiO is used as a p-type transparent conductor in various solar energy conversion technologies. Here, we use the small polaron model, along with unrestricted Hartree-Fock and complete active space self-consistent field calculations to show that forming substitutional MxNi1-xO alloys with M = Mg or Zn reduces the barrier for movement of a hole away from the ferromagnetic plane to which it is confined. Such reduction occurs for hole transfer alongside one or two M ions that have been substituted for Ni ions. Furthermore, the Mg and Zn ions do not trap holes on O sites in their vicinity, and NiO's transparency is preserved upon forming the alloys. Thus, forming MxNi1-xO alloys with M = Mg or Zn may enhance NiO's potential as a p-type transparent conducting oxide, by disrupting the two-dimensional confinement of holes in pure NiO.

Study of the location of testing area in residual stress measurement by Moiré interferometry combined with hole-drilling method

NASA Astrophysics Data System (ADS)

Qin, Le; Xie, HuiMin; Zhu, RongHua; Wu, Dan; Che, ZhiGang; Zou, ShiKun

2014-04-01

This paper investigates the effect of the location of testing area in residual stress measurement by Moiré interferometry combined with hole-drilling method. The selection of the location of the testing area is analyzed from theory and experiment. In the theoretical study, the factors which affect the surface released radial strain ɛ r were analyzed on the basis of the formulae of the hole-drilling method, and the relations between those factors and ɛ r were established. By combining Moiré interferometry with the hole-drilling method, the residual stress of interference-fit specimen was measured to verify the theoretical analysis. According to the analysis results, the testing area for minimizing the error of strain measurement is determined. Moreover, if the orientation of the maximum principal stress is known, the value of strain will be measured with higher precision by the Moiré interferometry method.

Shining Light on Quantum Gravity with Pulsar-Black hole Binaries

NASA Astrophysics Data System (ADS)

Estes, John; Kavic, Michael; Lippert, Matthew; Simonetti, John H.

2017-03-01

Pulsars are some of the most accurate clocks found in nature, while black holes offer a unique arena for the study of quantum gravity. As such, pulsar-black hole (PSR-BH) binaries provide ideal astrophysical systems for detecting the effects of quantum gravity. With the success of aLIGO and the advent of instruments like SKA and eLISA, the prospects for the discovery of such PSR-BH binaries are very promising. We argue that PSR-BH binaries can serve as ready-made testing grounds for proposed resolutions to the black hole information paradox. We propose using timing signals from a pulsar beam passing through the region near a black hole event horizon as a probe of quantum gravitational effects. In particular, we demonstrate that fluctuations of the geometry outside a black hole lead to an increase in the measured root mean square deviation of the arrival times of pulsar pulses traveling near the horizon. This allows for a clear observational test of the nonviolent nonlocality proposal for black hole information escape. For a series of pulses traversing the near-horizon region, this model predicts an rms in pulse arrival times of ˜ 30 μ {{s}} for a 3{M}⊙ black hole, ˜ 0.3 {ms} for a 30{M}⊙ black hole, and ˜ 40 {{s}} for Sgr A*. The current precision of pulse time-of-arrival measurements is sufficient to discern these rms fluctuations. This work is intended to motivate observational searches for PSR-BH systems as a means of testing models of quantum gravity.

Modeling Film-Coolant Flow Characteristics at the Exit of Shower-Head Holes

NASA Technical Reports Server (NTRS)

Garg, Vijay K.; Gaugler, R. E. (Technical Monitor)

2000-01-01

The coolant flow characteristics at the hole exits of a film-cooled blade are derived from an earlier analysis where the hole pipes and coolant plenum were also discretized. The blade chosen is the VKI rotor with three staggered rows of shower-head holes. The present analysis applies these flow characteristics at the shower-head hole exits. A multi-block three-dimensional Navier-Stokes code with Wilcox's k-omega model is used to compute the heat transfer coefficient on the film-cooled turbine blade. A reasonably good comparison with the experimental data as well as with the more complete earlier analysis where the hole pipes and coolant plenum were also gridded is obtained. If the 1/7th power law is assumed for the coolant flow characteristics at the hole exits, considerable differences in the heat transfer coefficient on the blade surface, specially in the leading-edge region, are observed even though the span-averaged values of h (heat transfer coefficient based on T(sub o)-T(sub w)) match well with the experimental data. This calls for span-resolved experimental data near film-cooling holes on a blade for better validation of the code.

The physics of black hole x ray novae

NASA Technical Reports Server (NTRS)

Wheeler, J. C.; Kim, S.-W.; Moscoso, M. D.; Mineshige, S.

1994-01-01

X-ray transients that are established or plausible black hole candidates have been discovered at a rate of about one per year in the galaxy for the last five years. There are now well over a dozen black hole candidates, most being in the category of X-ray novae with low-mass companions. There may be hundreds of such transient systems in the galaxy yet to be discovered. Classic black hole candidates like Cygnus X-1 with massive companions are in the minority, and their census in the galaxy and magellanic clouds is likely to be complete. The black hole X-ray novae (BHXN) do not represent only the most common environment in which to discover black holes. Their time dependence gives a major new probe with which to study the physics of accretion into black holes. The BHXN show both a soft X-ray flux from an optically thick disk and a hard power law tail that is reminiscent of AGN spectra. The result may be new insight into the classical systems like Cyg X-1 and LMC X-1 that show similar power law tails, but also to accretion into supermassive black holes and AGN.

Site-Control of InAs/GaAs Quantum Dots with Indium-Assisted Deoxidation

PubMed Central

Hussain, Sajid; Pozzato, Alessandro; Tormen, Massimo; Zannier, Valentina; Biasiol, Giorgio

2016-01-01

Site-controlled epitaxial growth of InAs quantum dots on GaAs substrates patterned with periodic nanohole arrays relies on the deterministic nucleation of dots into the holes. In the ideal situation, each hole should be occupied exactly by one single dot, with no nucleation onto planar areas. However, the single-dot occupancy per hole is often made difficult by the fact that lithographically-defined holes are generally much larger than the dots, thus providing several nucleation sites per hole. In addition, deposition of a thin GaAs buffer before the dots tends to further widen the holes in the [110] direction. We have explored a method of native surface oxide removal by using indium beams, which effectively prevents hole elongation along [110] and greatly helps single-dot occupancy per hole. Furthermore, as compared to Ga-assisted deoxidation, In-assisted deoxidation is efficient in completely removing surface contaminants, and any excess In can be easily re-desorbed thermally, thus leaving a clean, smooth GaAs surface. Low temperature photoluminescence showed that inhomogeneous broadening is substantially reduced for QDs grown on In-deoxidized patterns, with respect to planar self-assembled dots. PMID:28773333

Preliminary Results from Downhole Osmotic Samplers in a Gas Tracer Injection Experiment in the Upper Oceanic Crust on the Eastern Flank of the Juan de Fuca Ridge.

NASA Astrophysics Data System (ADS)

de Jong, M. T.; Clark, J. F.; Neira, N. M.; Fisher, A. T.; Wheat, C. G.

2015-12-01

We present results from a gas tracer injection experiment in the ocean crust on the eastern flank of the Juan de Fuca Ridge, in an area of hydrothermal circulation. Sulfur hexafluoride (SF6) tracer was injected in Hole 1362B in 2010, during IODP Expedition 327. Fluid samples were subsequently collected from a borehole observatory (CORK) installed in this hole and similar CORKs in three additional holes (1026B, 1362A, and 1301A), located 300 to 500 m away. This array of holes is located on 3.5 My old seafloor, as an array oriented subparallel to the Endeavor Segment of Juan de Fuca Ridge. Borehole fluid samples were collected in copper coils using osmotic pumps. In addition to pumps at seafloor wellheads, downhole sampling pumps were installed in the perforated casing in the upper ocean crust. These downhole samplers were intended to produce a high-resolution continuous record of tracer concentrations, including records from the first year after tracer injection in Holes 1362A and 1362B. In contrast, wellhead samplers were not installed on these CORKs holes until 2011, and wellhead records from all CORKs have a record gap of up to one year, because of a delayed expedition in 2012. The downhole samples were recovered with the submersible Alvin in August 2014. SF6 concentrations in downhole samples recovered in 2014 are generally consistent with data obtained from wellhead samples. Of particular interest are the results from Hole 1362B, where a seafloor valve was opened and closed during various recovery expeditions. High resolution tracer curves produced from the 1362B downhole samples confirm that these operations produced an SF6 breakthrough curve corresponding to a classic push-pull test used to evaluate contaminant field locations in terrestrial setting. Complete analyses of downhole samples from these CORKs are expected to produce high-resolution breakthrough curves that will allow more precise analysis and modeling of hydrothermal flow in the study area.

Quantification of the Upper Extremity Motor Functions of Stroke Patients Using a Smart Nine-Hole Peg Tester

PubMed Central

Marik, Anikó Rita; Fazekas, Gábor

2018-01-01

This paper introduces a smart nine-hole peg tester (s-9HPT), which comprises a standard nine-hole peg test pegboard, but with light-emitting diodes (LEDs) next to each hole. The s-9HPT still supports the traditional nine-hole peg test operating mode, in which the order of the peg placement and removal can be freely chosen. Considering this, the s-9HPT was used in lab research to analyze the traditional procedure and possible new procedures. As this analysis required subjects with similar levels of dexterity, measurement data from 16 healthy subjects (seven females, nine males, 25–80 years old) were used. We consequently found that illuminating the LEDs in various patterns facilitated guided tests of diverse complexity levels. Next, to demonstrate the clinical application of the s-9HPT, the improvement in the hand dexterity of 12 hospitalized stroke patients (45–80 years old, six females and six males) was monitored during their rehabilitation. Here, we used traditional and guided tests validated by healthy subjects. Consequently, improvements were found to be patient specific. At the beginning of rehabilitation, traditional tests suitably indicate improvements, while guided tests are beneficial following improvements in motor functions. Further, the guided tests motivated certain patients, meaning the rehabilitation was more effective for these individuals. PMID:29850001

Signatures of a staggered-flux phase in the t-J model with two holes on a 32-site lattice

NASA Astrophysics Data System (ADS)

Leung, P. W.

2000-09-01

We study the relevance of the staggered-flux phase in the t-J model using a system with two holes on a 32-site lattice with periodic boundary conditions. We find a staggered-flux pattern in the current-current correlation in the lowest energy d-wave state where there is mutual attraction between the holes. This staggered correlation decays faster with distance when the hole binding becomes stronger. This is in complete agreement with a recent study by Ivanov, Lee, and Wen [Phys. Rev. Lett. 84, 3958 (2000)] based on the SU(2) theory, and strongly suggests that the staggered-flux phase is a key ingredient in the t-J model. We further show that this staggered-flux pattern does not exist in a state where the holes repel each other. Correlations of the chirality operator S1.(S2×S3) show that the staggered pattern of the chirality is closely tied to the holes.

Black Hole Event Horizons and Advection-Dominated Accretion

NASA Technical Reports Server (NTRS)

McClintock, Jeffrey; Mushotzky, Richard F. (Technical Monitor)

2002-01-01

The work supported in part by this grant is part of a larger program on the detection of black hole event horizons, which is also partially supported by NASA grant GO0-1105A. This work has been carried out primarily in collaboration with Dr. M. Garcia and Prof. R. Narayan at the Harvard-Smithsonian Center for Astrophysics and with D. Barret and J. Hameury at Centre d'Etude Spoliate des Rayonnements, France. Our purpose is to confirm the existence of black-hole event horizons by comparing accreting black holes to secreting neutron stars in quiescent X-ray novae. Such a comparison is feasible because black holes and neutron stars are both present in similar environments in X-ray novae. Our second purpose is to assess the nature of accretion flows onto black holes at very low mass transfer rates. Observations of some XMM targets are still pending, whereas most of the Chandra observations have been completed. We anticipate further publications on this work in the future.

Resonant photoluminescence studies of carrier localisation in c-plane InGaN/GaN quantum well structures

NASA Astrophysics Data System (ADS)

Blenkhorn, W. E.; Schulz, S.; Tanner, D. S. P.; Oliver, R. A.; Kappers, M. J.; Humphreys, C. J.; Dawson, P.

2018-05-01

In this paper we report on changes in the form of the low temperature (12 K) photoluminescence spectra of an InGaN/GaN quantum well structure as a function of excitation photon energy. As the photon energy is progressively reduced we observe at a critical energy a change in the form of the spectra from one which is determined by the occupation of the complete distribution of hole localisation centres to one which is determined by the resonant excitation of specific localisation sites. This change is governed by an effective mobility edge whereby the photo-excited holes remain localised at their initial energy and are prevented from scattering to other localisation sites. This assignment is confirmed by the results of atomistic tight binding calculations which show that the wave function overlap of the lowest lying localised holes with other hole states is low compared with the overlap of higher lying hole states with other higher lying hole states.

The Final Merger of Massive Black Holes: Recoils, Gravitational Waves, and Electromagnetic Signatures

NASA Astrophysics Data System (ADS)

Centrella, Joan

2010-03-01

The final merger of two massive black holes produces a powerful burst of gravitational radiation, emitting more energy than all the stars in the observable universe combined. The resulting gravitational waveforms will be easily detectable by the space-based LISA out to redshifts z > 10, revealing the masses and spins of the black holes to high precision. If the merging black holes have unequal masses, or asymmetric spins, the final black hole that forms can recoil with a velocity exceeding 1000 km/s. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new results that are revealing the dynamics and waveforms of binary black hole mergers, recoil velocities, and the possibility of accompanying electromagnetic outbursts. This research is supported in part by NASA grant 06-BEFS06-19 to Goddard Space Flight Center.

LIGO and the opening of a unique observational window on the universe.

PubMed

Kalogera, Vassiliki; Lazzarini, Albert

2017-03-21

A unique window on the universe opened on September 14, 2015, with direct detection of gravitational waves by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors. This event culminated a half-century effort around the globe to develop terrestrial detectors of adequate sensitivity to achieve this goal. It also happened appropriately only a few months before the centennial of Einstein's final paper introducing the general theory of relativity. This detection provided the surprising discovery of a coalescing pair of "heavy" black holes (more massive than [Formula: see text] M[Formula: see text]) leading to the formation of a spinning [Formula: see text]62 solar mass black hole. One more binary black-hole detection and a significant candidate event demonstrated that a population of such merging binaries is formed in nature with a broad mass spectrum. This unique observational sample has already provided concrete measurements on the coalescence rates and has allowed us to test the theory of general relativity in the strong-field regime. As this nascent field of gravitational-wave astrophysics is emerging we are looking forward to the detection of binary mergers involving neutron stars and their electromagnetic counterparts, as well as continuous-wave sources, supernovae, a stochastic confusion background of compact-object mergers, known sources detected in unexpected ways, and completely unknown sources.

LIGO and the opening of a unique observational window on the universe

PubMed Central

Kalogera, Vassiliki; Lazzarini, Albert

2017-01-01

A unique window on the universe opened on September 14, 2015, with direct detection of gravitational waves by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors. This event culminated a half-century effort around the globe to develop terrestrial detectors of adequate sensitivity to achieve this goal. It also happened appropriately only a few months before the centennial of Einstein’s final paper introducing the general theory of relativity. This detection provided the surprising discovery of a coalescing pair of “heavy” black holes (more massive than ≃25 M๏) leading to the formation of a spinning ≃62 solar mass black hole. One more binary black-hole detection and a significant candidate event demonstrated that a population of such merging binaries is formed in nature with a broad mass spectrum. This unique observational sample has already provided concrete measurements on the coalescence rates and has allowed us to test the theory of general relativity in the strong-field regime. As this nascent field of gravitational-wave astrophysics is emerging we are looking forward to the detection of binary mergers involving neutron stars and their electromagnetic counterparts, as well as continuous-wave sources, supernovae, a stochastic confusion background of compact-object mergers, known sources detected in unexpected ways, and completely unknown sources. PMID:28283663

Cosmic censorship of rotating Anti-de Sitter black hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gwak, Bogeun; Lee, Bum-Hoon, E-mail: rasenis@sogang.ac.kr, E-mail: bhl@sogang.ac.kr

2016-02-01

We test the validity of cosmic censorship in the rotating anti-de Sitter black hole. For this purpose, we investigate whether the extremal black hole can be overspun by the particle absorption. The particle absorption will change the mass and angular momentum of the black hole, which is analyzed using the Hamilton-Jacobi equations consistent with the laws of thermodynamics. We have found that the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.

Holes in the ocean: Filling voids in bathymetric lidar data

NASA Astrophysics Data System (ADS)

Coleman, John B.; Yao, Xiaobai; Jordan, Thomas R.; Madden, Marguertie

2011-04-01

The mapping of coral reefs may be efficiently accomplished by the use of airborne laser bathymetry. However, there are often data holes within the bathymetry data which must be filled in order to produce a complete representation of the coral habitat. This study presents a method to fill these data holes through data merging and interpolation. The method first merges ancillary digital sounding data with airborne laser bathymetry data in order to populate data points in all areas but particularly those of data holes. What follows is to generate an elevation surface by spatial interpolation based on the merged data points obtained in the first step. We conduct a case study of the Dry Tortugas National Park in Florida and produced an enhanced digital elevation model in the ocean with this method. Four interpolation techniques, including Kriging, natural neighbor, spline, and inverse distance weighted, are implemented and evaluated on their ability to accurately and realistically represent the shallow-water bathymetry of the study area. The natural neighbor technique is found to be the most effective. Finally, this enhanced digital elevation model is used in conjunction with Ikonos imagery to produce a complete, three-dimensional visualization of the study area.

Development of a Split Bitter-type Magnet System for Dusty Plasma Experiments

NASA Astrophysics Data System (ADS)

Bates, Evan; Romero-Talamas, Carlos A.; Birmingham, William J.; Rivera, William F.

2014-10-01

A 10 Tesla Bitter-type magnetic system is under development at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County (UMBC). We present here an optimization technique that uses differential evolution to minimize the omhic heating produced by the coils, while constraining the magnetic field in the experimental volume. The code gives us the optimal dimensions for the coil system including: coil length, turn thickness, disks radii, resistance, and total current required for a constant magnetic field. Finite element parametric optimization is then used to establish the optimal design for water cooling holes. Placement of the cooling holes will also take into consideration the magnetic forces acting on the copper alloy disks to ensure the material strength is not compromised during operation. The proposed power and cooling water delivery subsystems for the coils are also presented. Upon completion and testing of the magnet system, planned experiments include the propagation of magnetized waves in dusty plasma crystals under various boundary conditions, and viscosity in rotational shear flow, among others.

Filling the gap of existing MWA-VCS archival data

NASA Astrophysics Data System (ADS)

Xue, M.; Bhat, R.; Tremblay, S.; Ord, S.; Sobey, C.; Kirsten, F.

2017-01-01

Since July 2014, around 110 hours of high time resolution voltage data observed by MWA Voltage Capture System (VCS; Tremblay et al. 2015) have been archived on tapes in the Pawsey Supercomputing Centre. Except some short duration test data and calibration data, the total amount of the observation data which have a duration longer than 400 s is 84 hours. These data cover a significant portion of a lot of the Southern sky and could be used for many science purposes including radio pulsars census and fast radio bursts (FRBs) searching. But there are still some 'holes' in the sky that we do not have VCS archival data for yet. We are proposing a set of MWA-VCS drift scan observations of 3 hours to fill some of these 'holes' and help provide a more complete MWA-VCS data set. We will also census known (cataloged) pulsars in these areas. These observations would be performed between 170-200 MHz. This project will form part of the PhD program of Mengyao Xue.

Fluid-inclusion evidence for previous higher temperatures in the SUNEDCO 58-28 drill hole near Breitenbush hot springs, Oregon

USGS Publications Warehouse

Bargar, Keith E.; ,

1993-01-01

The SUNEDCO 58-28 geothermal exploration drill hole was completed in 1981 to a depth of 2, 457 m near Breitenbush Hot Springs in the Western Cascade Mountains of northern Oregon. One hundred thirteen liquid-rich fluid inclusions (mostly secondary) were analyzed from drill cuttings samples of hydrothermal quartz, calcite, and anhydrite, as well as primary quartz phenocrysts. Except for one hydrothermal quartz specimen, minimum homogenization temperature (Th) measurements of fluid inclusions plot very close to the present measured temperatures for the drill hole. Fluid-inclusion data from near the bottom of the drill hole suggest that these rocks were altered by water of significantly greater salinity than Breitenbush Hot Springs water.

Geohydrologic data from test hole USW UZ-7, Yucca Mountain area, Nye County, Nevada

USGS Publications Warehouse

Kume, Jack; Hammermeister, D.P.

1990-01-01

This report contains a description of the methods used in drilling and coring of the test-hole USW UZ-7, a description of the methods used in collecting, handling, and testing of test-hole samples; Lithologic information from the test hole; and water-content, water-potential, bulk-density, grain-density, porosity, and tritium data for the test hole. Test-hole USW UZ-7 was drilled and cored to a total depth of 62.94 m. The drilling was done using air as a drilling fluid to minimize disturbance to the water content of cores, drill-bit cuttings, and borehole wall-rock. Beginning at the land surface, the unsaturated-zone rock that was penetrated consisted of alluvium; welded and partially to nonwelded ash-flow tuff; bedded and reworked ash-fall tuff; nonwelded ash-flow tuff; and welded ash-flow tuff. Values of gravimetric water content and water potential of alluvium were intermediate between the extreme values in welded and nonwelded units of tuff. Gravimetric water content was largest in bedded and nonwelded ash-fall tuffs and was smallest in welded ash-flow tuff. Values of water potential were more negative in densely welded ash-flow tuffs and were less negative in bedded and nonwelded ash-fall tuffs. Bulk density was largest in densely welded ash-flow tuffs and smallest in nonwelded and bedded ash-fall tuffs. Grain density was uniform but was slightly larger in nonwelded and bedded ash-fall tuffs than in welded ash-flow tuffs. Porosity trends were opposite to bulk-density trends. Tritium content in alluvium was smallest near the alluvium-bedrock contact, markedly increased in the middle of the deposit, and decreased in the near-surface zone of the deposit. (Author 's abstract)

Effect of Impact Damage and Open Hole on Compressive Strength of Hybrid Composite Laminates

NASA Technical Reports Server (NTRS)

Hiel, Clement; Brinson, H. F.

1993-01-01

Impact damage tolerance is a frequently listed design requirement for composites hardware. The effect of impact damage and open hole size on laminate compressive strength was studied on sandwich beam specimens which combine CFRP-GFRP hybrid skins and a syntactic foam core. Three test specimen configurations have been investigated for this study. The first two were sandwich beams which were loaded in pure bending (by four point flexure). One series had a skin damaged by impact, and the second series had a circular hole machined through one of the skins. The reduction of compressive strength with increasing damage (hole) size was compared. Additionally a third series of uniaxially loaded open hole compression coupons were tested to generate baseline data for comparison with both series of sandwich beams.

Effects of a Knee Brace With a Patellar Hole Versus Without a Patellar Hole in Patients With Knee Osteoarthritis: A Double-Blind, Randomized Controlled Trial.

PubMed

Added, Marco Aurélio Nemitalla; Added, Caroline; Kasawara, Karina Tamy; Rotta, Viviane Perez; de Freitas, Diego Galace

2017-01-01

The objective of this study was to observe the immediate effect of a knee brace with a patellar hole versus without a patellar hole on pain perception in patients with knee osteoarthritis. To accomplish this, a double-blind, randomized controlled trial enrolled 108 patients divided into two groups (knee brace with a patellar hole or without a patellar hole). Patients were evaluated by the Visual Analogue Scale (VAS) in order to measure their pain sensation, the Timed Up and Go (TUG) test was used to evaluate their ability to walk, and the 8-m walking test (8MWT) was used to estimate their walking speed. Both groups presented significant reduction in pain perception, higher function of the lower extremities, and greater mobility while wearing a knee brace. However, the patients who wore a knee brace without a patellar hole presented more favorable results than those who wore a knee brace with a patellar hole: a 1.6-point reduction was found versus 1.1 points in the VAS, the patients presented 0.7 s less time versus 0.4 s in the TUG, and the speed was reduced by 1.4 s versus 0.8 s in the 8MWT. Therefore, the knee brace without a patellar hole presented more favorable results when compared with the knee brace with a patellar hole.

1393 Ring Bus at JPL: Description and Status

NASA Technical Reports Server (NTRS)

Wysocky, Terry R.

2007-01-01

Completed Ring Bus IC V&V Phase - Ring Bus Test Plan Completed for SIM Project - Applicable to Other Projects Implemented a Avionics Bus Based upon the IEEE 1393 Standard - Excellent Starting Point for a General Purpose High-Speed Spacecraft Bus - Designed to Meet SIM Requirements for - Real-time deterministic, distributed systems. - Control system requirements - Fault detection and recovery Other JPL Projects Considering Implementation F'light Software Ring Bus Driver Module Began in 2006, Continues Participating in Standard Revision. Search for Earth-like planets orbiting nearby stars and measure the masses and orbits of the planets it finds. Survey 2000 nearby stars for planetary systems to learn whether our Solar System is unusual, or typical. Make a new catalog of star position 100 times more accurate than current measurements. Learn how our galaxy formed and will evolve by studying the dynamics of its stars. Critically test models of exactly how stars shine, including exotic objects like black holes, neutron stars and white dwarfs.

Sizes of Black Holes Throughout the Universe

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2018-05-01

What is the distribution of sizes of black holes in our universe? Can black holes of any mass exist, or are there gaps in their possible sizes? The shape of this black-hole mass function has been debated for decades and the dawn of gravitational-wave astronomy has only spurred further questions.Mind the GapsThe starting point for the black-hole mass function lies in the initial mass function (IMF) for stellar black holes the beginning size distribution of black holes after they are born from stars. Instead of allowing for the formation of stellar black holes of any mass, theoretical models propose two gaps in the black-hole IMF:An upper mass gap at 50130 solar masses, due to the fact that stellar progenitors of black holes in this mass range are destroyed by pair-instability supernovae.A lower mass gap below 5 solar masses, which is argued to arise naturally from the mechanics of supernova explosions.Missing black-hole (BH) formation channels due to the existence of the lower gap (LG) and the upper gap (UG) in the initial mass function. a) The number of BHs at all scales are lowered because no BH can merge with BHs in the LG to form a larger BH. b) The missing channel responsible for the break at 10 solar masses, resulting from the LG. c) The missing channel responsible for the break at 60 solar masses, due to the interaction between the LG and the UG. [Christian et al. 2018]We can estimate the IMF for black holes by scaling a typical IMF for stars and then adding in these theorized gaps. But is this initial distribution of black-hole masses the same as the distribution that we observe in the universe today?The Influence of MergersBased on recent events, the answer appears to be no! Since the first detections of gravitational waves in September 2015, we now know that black holes can merge to form bigger black holes. An initial distribution of black-hole masses must therefore evolve over time, as mergers cause the depletion of low-mass black holes and an increase in higher-mass black holes.A team of scientists led by Pierre Christian, an Einstein Fellow at Harvard University, has now looked into characterizing this shift. In particular, Christian and collaborators explore how black-hole mergers in the centers of dense star clustersultimately shape the black-hole mass function of the universe.Black Holes TodayChristian and collaborators use analytical models of coagulation mergers of particles to form larger particles to estimate the impact of mergers in star clusters on resulting black-hole sizes. They find that, over an evolution of 10 billion years, mergers can appreciably fill in the upper mass gap of the black-hole IMF.An example of the black-hole mass function that can result from evolving the initial mass function complete with gaps over time. Two breaks appear as a result of the initial gaps: one at 10 (LB) and one at 60 solar masses (UB). [Christian et al. 2018]The lower mass gap, on the other hand, leaves observable signatures in the final black-hole mass function: a break at 10 solar masses (since black holes below this mass cant be created by mergers) and one at 60 solar masses (caused by the interaction of the upper and lower gaps). As we build up black-hole statistics in the future (thanks, gravitational-wave detectors!), searching for these breaks will help us to test our models.Lastly, the authors find that their models can only be consistent with observations if ejection is efficient black holes must be regularly ousted from star clusters through interactions with other bodies or as a result of kicks when they merge. This idea is consistent with many recent studies supporting a large population of free-floating stellar-mass black holes.CitationPierre Christian et al 2018 ApJL 858 L8. doi:10.3847/2041-8213/aabf88

Standard Methods for Bolt-Bearing Testing of Textile Composites

NASA Technical Reports Server (NTRS)

Portanova, M. A.; Masters, J. E.

1995-01-01

The response of three 2-D braided materials to bolt bearing loading was evaluated using data generated by Boeing Defense and Space Group in Philadelphia, PA. Three test methods, stabilized single shear, unstabilized single shear, and double shear, were compared. In general, these textile composites were found to be sensitive to bolt bearing test methods. The stabilized single shear method yielded higher strengths than the unstabilized single shear method in all cases. The double shear test method always produced the highest strengths but these results may be somewhat misleading. It is therefore recommended that standard material comparisons be made using the stabilized single shear test method. The effects of two geometric parameters, W/D and e/D, were also studied. An evaluation of the effect of the specimen width (W) to hole diameter (D) ratio concluded that bolt bearing responses were consistent with open hole tension results. A W/D ratio of 6 or greater should be maintained. The proximity of the hole to the specimen edge significantly affected strength. In all cases, strength was improved by increasing the ratio of the distance from the hole center to the specimen edge (e) to the hole diameter (D) above 2. An e/D ratio of 3 or greater is recommended.

Test-particle dynamics in general spherically symmetric black hole spacetimes

NASA Astrophysics Data System (ADS)

De Laurentis, Mariafelicia; Younsi, Ziri; Porth, Oliver; Mizuno, Yosuke; Rezzolla, Luciano

2018-05-01

To date, the most precise tests of general relativity have been achieved through pulsar timing, albeit in the weak-field regime. Since pulsars are some of the most precise and stable "clocks" in the Universe, present observational efforts are focused on detecting pulsars in the vicinity of supermassive black holes (most notably in the Galactic Centre), enabling pulsar timing to be used as an extremely precise probe of strong-field gravity. In this paper, a mathematical framework to describe test-particle dynamics in general black-hole spacetimes is presented and subsequently used to study a binary system comprising a pulsar orbiting a black hole. In particular, taking into account the parameterization of a general spherically symmetric black-hole metric, general analytic expressions for both the advance of the periastron and for the orbital period of a massive test particle are derived. Furthermore, these expressions are applied to four representative cases of solutions arising in both general relativity and in alternative theories of gravity. Finally, this framework is applied to the Galactic center S -stars and four distinct pulsar toy models. It is shown that by adopting a fully general-relativistic description of test-particle motion which is independent of any particular theory of gravity, observations of pulsars can help impose better constraints on alternative theories of gravity than is presently possible.

MTR CAISSONS WERE DRILLED INTO BEDROCK. IN CENTER OF VIEW, ...

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

MTR CAISSONS WERE DRILLED INTO BEDROCK. IN CENTER OF VIEW, CONCRETE FLOWS FROM TRUCK INTO DRUM, WHICH IS LOWERED INTO CAISSON AND RELEASED AT BOTTOM OF HOLE. BEYOND, TRUCK-MOUNTED DRILLING RIG DRILLS HOLE FOR ANOTHER CAISSON NEAR EDGE OF EXCAVATION. MATERIAL REMOVED FROM HOLE IS CARRIED BY CONVEYOR TO WAITING TRUCK. INL NEGATIVE NO. 307. Unknown Photographer, 6/1950. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Hole expansion test of third generation steels

NASA Astrophysics Data System (ADS)

Agirre, Julen; Mendiguren, Joseba; Galdos, Lander; de Argandoña, Eneko Sáenz

2017-10-01

The trend towards the implementation of new materials in the chassis of the automobiles is considerably making more complex the manufacturing of the components that built it up. In this scenario materials with higher strengths and lower formabilities are daily faced by tool makers and component producers what reduces the process windows and makes the forming processes to be in the limits of the materials. One of the concerns that tool makers must face during the definition of the tools is the expansion ratios that the holes in the sheet may reach before producing a breakage due to the stretching of the material (also known as edge cracks). For the characterization of such limits, a standard test, the hole expansion test, can be applied so that the limits of the material are known. At the present study, hole expansion tests of a third generation steel, Fortiform1050 with a thickness of 1.2 millimeters have been carried out and compared them to a mild steel, DX54D with a thickness of 0.6 millimeters. A comparison for each material in terms of technology used to punch the hole, mechanical punching vs laser cutting has also been conducted. In addition, the measurement technique (online measurement vs offline measurement) followed in the Hole Expansion Ratio (HER) identification has also been analyzed. Finally, differences between both materials and techniques are presented.

Effects of bolt-hole contact on bearing-bypass damage-onset strength

NASA Technical Reports Server (NTRS)

Crews, John H., Jr.; Naik, Rajiv A.

1991-01-01

A combined experimental and analytical study was conducted to investigate the effects of bolt-hole contact on the bearing bypass strength of a graphite-epoxy laminate. Tests were conducted on specimens consisting of 16-ply quasi-isotropic T300/5208 laminates with a centrally located hole. Bearing loads were applied through a clearance-fit steel bolt. Damage onset strength and damage mode were determined for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each measured damage-onset strength. For the tension bearing-bypass cases tested, the bolt contact half-angle was approximately 60 degrees at damage onset. For compression, the contact angle was 20 degrees as the bypass load increased. A corresponding decrease in the bearing damage onset strength was attributed to the decrease in contact angle which made the bearing loads more severe. Hole boundary stresses were also computed by superimposing stresses for separate bearing and bypass loading. Stresses at the specimen net section were accurately approximated by the superposition procedure. However, the peak bearing stresses had large errors because the bolt contact angles were not represented correctly. For compression, peak bearing stress errors of nearly 50 percent were calculated.

Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors

NASA Astrophysics Data System (ADS)

Shoemaker, Deirdre; Jani, Karan; London, Lionel; Pekowsky, Larne

Gravitational waves deliver information in exquisite detail about astrophysical phenomena, among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling binary black hole sources of gravitational radiation requires solving the Einstein equations of General Relativity using powerful computer hardware and sophisticated numerical algorithms. This proceeding presents where we are in understanding ground-based gravitational waves resulting from the merger of black holes and the implications of these sources for the advent of gravitational-wave astronomy.

Searches for Kaluza-Klein graviton excitations and microscopic black holes with the aid of the CMS detector at the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savina, M. V., E-mail: savina@cern.ch

2015-06-15

A survey of the results of the Compact Muon Solenoid (CMS) experiment that concern searches for massive Kaluza-Klein graviton excitations and microscopic black holes, quantum black holes, and string balls within models of low-energy multidimensional gravity is presented on behalf of the CMS Collaboration. The analysis in question is performed on the basis of a complete sample of data accumulated for proton-proton collisions at the c.m. energies of 7 and 8 TeV at the Large Hadron Collider (LHC) over the period spanning 2010 and 2012.

Slicing the vacuum: New accelerating mirror solutions of the dynamical Casimir effect

NASA Astrophysics Data System (ADS)

Good, Michael R. R.; Linder, Eric V.

2017-12-01

Radiation from accelerating mirrors in a Minkowski spacetime provides insights into the nature of horizons, black holes, and entanglement entropy. We introduce new, simple, symmetric and analytic moving mirror solutions and study their particle, energy, and entropy production. This includes an asymptotically static case with finite emission that is the black hole analog of complete evaporation. The total energy, total entropy, total particles, and spectrum are the same on both sides of the mirror. We also study its asymptotically inertial, drifting analog (which gives a black hole remnant) to explore differences in finite and infinite production.

A General Relativistic Null Hypothesis Test with Event Horizon Telescope Observations of the Black Hole Shadow in Sgr A*

NASA Astrophysics Data System (ADS)

Psaltis, Dimitrios; Özel, Feryal; Chan, Chi-Kwan; Marrone, Daniel P.

2015-12-01

The half opening angle of a Kerr black hole shadow is always equal to (5 ± 0.2)GM/Dc2, where M is the mass of the black hole and D is its distance from the Earth. Therefore, measuring the size of a shadow and verifying whether it is within this 4% range constitutes a null hypothesis test of general relativity. We show that the black hole in the center of the Milky Way, Sgr A*, is the optimal target for performing this test with upcoming observations using the Event Horizon Telescope (EHT). We use the results of optical/IR monitoring of stellar orbits to show that the mass-to-distance ratio for Sgr A* is already known to an accuracy of ∼4%. We investigate our prior knowledge of the properties of the scattering screen between Sgr A* and the Earth, the effects of which will need to be corrected for in order for the black hole shadow to appear sharp against the background emission. Finally, we explore an edge detection scheme for interferometric data and a pattern matching algorithm based on the Hough/Radon transform and demonstrate that the shadow of the black hole at 1.3 mm can be localized, in principle, to within ∼9%. All these results suggest that our prior knowledge of the properties of the black hole, of scattering broadening, and of the accretion flow can only limit this general relativistic null hypothesis test with EHT observations of Sgr A* to ≲10%.

Data for ground-water test hole near Zamora, Central Valley Aquifer Project, California

USGS Publications Warehouse

French, J.J.; Page, R.W.; Bertoldi, G.L.

1982-01-01

Preliminary data are presented for the first of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 SE 1/4 sec. 34, T. 12 N. , R. 1 E., Yolo County, California, about 3 miles northeast of the town of Zamora. Drilled to a depth of 2,500 feet below land surface, the hole is cased to a depth of 190 feet and equipped with three piezometer tubes to depths of 947, 1,401, and 2,125 feet. A 5-foot well screen is at the bottom of each piezometer. Eighteen cores and 68 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, diatom identification, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Grainex Mar-M 247 Turbine Disk Life Study for NASA's High Temperature High Speed Turbine Seal Test Facility

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.

2015-01-01

An experimental and analytical fatigue life study was performed on the Grainex Mar-M 247 disk used in NASA s Turbine Seal Test Facility. To preclude fatigue cracks from growing to critical size in the NASA disk bolt holes due to cyclic loading at severe test conditions, a retirement-for-cause methodology was adopted to detect and monitor cracks within the bolt holes using eddy-current inspection. For the NASA disk material that was tested, the fatigue strain-life to crack initiation at a total strain of 0.5 percent, a minimum to maximum strain ratio of 0, and a bolt hole temperature of 649 C was calculated to be 665 cycles using -99.95 percent prediction intervals. The fatigue crack propagation life was calculated to be 367 cycles after implementing a safety factor of 2 on life. Thus, the NASA disk bolt hole total life or retirement life was determined to be 1032 cycles at a crack depth of 0.501 mm. An initial NASA disk bolt hole inspection at 665 cycles is suggested with 50 cycle inspection intervals thereafter to monitor fatigue crack growth.

A GIS-based atmospheric dispersion model for pollutants emitted by complex source areas.

PubMed

Teggi, Sergio; Costanzini, Sofia; Ghermandi, Grazia; Malagoli, Carlotta; Vinceti, Marco

2018-01-01

Gaussian dispersion models are widely used to simulate the concentrations and deposition fluxes of pollutants emitted by source areas. Very often, the calculation time limits the number of sources and receptors and the geometry of the sources must be simple and without holes. This paper presents CAREA, a new GIS-based Gaussian model for complex source areas. CAREA was coded in the Python language, and is largely based on a simplified formulation of the very popular and recognized AERMOD model. The model allows users to define in a GIS environment thousands of gridded or scattered receptors and thousands of complex sources with hundreds of vertices and holes. CAREA computes ground level, or near ground level, concentrations and dry deposition fluxes of pollutants. The input/output and the runs of the model can be completely managed in GIS environment (e.g. inside a GIS project). The paper presents the CAREA formulation and its applications to very complex test cases. The tests shows that the processing time are satisfactory and that the definition of sources and receptors and the output retrieval are quite easy in a GIS environment. CAREA and AERMOD are compared using simple and reproducible test cases. The comparison shows that CAREA satisfactorily reproduces AERMOD simulations and is considerably faster than AERMOD. Copyright © 2017 Elsevier B.V. All rights reserved.

KSC-08pd0784

NASA Image and Video Library

2008-03-21

CAPE CANAVERAL, Fla. --- In the Astrotech payload processing facility, NASA's Gamma-Ray Large Area Space Telescope, or GLAST, completes the test of the deployment mechanism on its solar arrays. The telescope will launch aboard a Delta II rocket May 16 from Launch Pad 17-B on Cape Canaveral Air Force Station. A powerful space observatory, the GLAST will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts. Photo credit: NASA/Jim Grossmann

WIPP (Waste Isolation Pilot Plant) intermediate scale borehole test: A pretest analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Argueello, J.G.

A three-dimensional finite element structural analysis of the Intermediate Scale Borehole Test at the Waste Isolation Pilot Plant (WIPP) has been performed. The analysis provides insight into how a relatively new excavation in a creeping medium responds when introduced into an existing pillar which has been undergoing stress redistribution for 5.7 years. The stress field of the volume of material in the immediate vicinity of the borehole changes significantly when the hole is drilled. Closure of the hole is predicted to be larger in the vertical direction than in the horizontal direction, leading to an ovaling of the hole. Themore » relatively high stresses near the hole persist even at the end of the simulation, 2 years after the hole is drilled. 12 ref., 10 figs.« less

Sparger system for MMH-helium vents

NASA Technical Reports Server (NTRS)

Rakow, A.

1983-01-01

Based on a calculated vent flow rate and MMH concentration, a TI-59 program was run to determine total sparger hole area for a given sparger inlet pressure. Hole diameter is determined from a mass transfer analysis in the holding tank to achieve complete capture of MMH. In addition, based on oxidation kinetics and vapor pressure data, MMh atmospheric concentrations are determined 2 ft above the holding tank.

The influence of surface modification on sound absorption coefficient of albizzia wood absorber

NASA Astrophysics Data System (ADS)

Diharjo, Kuncoro; Prabowo, Anditya E.; Jamasri, Suharty, Neng Sri

2017-01-01

The purpose of this research is to investigate the influence of surface modification to sound absorption on absorber based albizia wood and kenaf fiber. The absorber was produced using the albizia wood as main materials, and the kenaf fiber was used as acoustic fill. The albizia wood used for producing the absorber was cut in the transverse direction so that its surface had good porosity. The size of specimens had 100 mm in diameter and 40 mm in thickness. The configuration of resonator cavities was 30 mm in diameter and 20 mm in depth, and each resonator was completed with a neck hole of the resonator. The types of surface modification were the addition of screen printing ink, fabric (with and without neck hole), and vinyl-wallpaper (with and without neck hole). According to ISO 10534-2, the absorber specimens were tested using two microphones impedance tube with random noise source to get the curve of noise absorption coefficient (NAC) for each specimen. The result shows that both unmodified absorber and absorber modified with screen printing ink have the similar characteristic of NAC and they are feasible to be used as an absorber in conversation rooms. The addition of fabric and vinyl-wallpaper as cover on the absorber surface give the positive effect of the air gap, and it increases the NAC in low frequency (100-400 Hz). However, the covers decrease the NAC in high frequency (400-1,400 Hz). The holes on the fabric and wallpaper covers give the improvement of NAC.

Perventricular double-device closure of wide-spaced multi-hole perimembranous ventricular septal defect.

PubMed

Liang, Fei; Hongxin, Li; Zhang, Hai-Zhou; Wenbin, Guo; Zou, Cheng-Wei; Farhaj, Zeeshan

2017-04-17

Device closure of a wide-spaced multi-hole PmVSD is difficult to succeed in percutaneous approach. This study is to evaluate the feasibility, safety and efficacy of perventricular device closure of wide-spaced multi-hole PmVSD using a double-device implanting technique. Sixteen patients with wide-spaced multi-hole PmVSD underwent perventricular closure with two devices through an inferior median sternotomy approach under transesophageal echocardiographic guidance. The largest hole and its adjacent small holes were occluded with an optimal-sized device. The far-away residual hole was occluded with the other device using a probe-assisted delivery system. All patients were followed up for a period of 1 to 4 years to determine the residual shunt, atrioventricular block and the adjacent valvular function. The number of the holes of the PmVSD was 2 to 4. The maximum distance between the holes was 5.0 to 10.0 mm (median, 6.4 mm). The diameter of the largest hole was 2.5 to 7.0 mm (median, 3.6 mm). The success rate of double-device closure was 100%. Immediate residual shunts were found in 6 patients (38%), and incomplete right bundle branch block at discharge occurred in 3 cases (19%). Both complications decreased to 6% at 1-year follow-up. Neither of them had a severe device-related complication. Perventricular closure of a wide-spaced multi-hole PmVSD using a double-device implanting technique is feasible, safe, and efficacious. In multi-hole PmVSDs with the distance between the holes of more than 5 mm, double-device implantation may achieve a complete occlusion.

Instrumentation used for hydraulic testing of potential water-bearing formations at the Waste Isolation Pilot Plant site in southeastern New Mexico

USGS Publications Warehouse

Basler, J.A.

1983-01-01

Requirements for testing hydrologic test wells at the proposed Waste Isolation Pilot Plant near Carlsbad, New Mexico, necessitated the use of inflatable formation packers and pressure transducers. Observations during drilling and initial development indicated small formation yields which would require considerable test times by conventional open-casing methods. A pressure-monitoring system was assembled for performance evaluation utilizing commercially available components. Formation pressures were monitored with a down-hole strain-gage transducer. An inflatable packer equipped with a 1/4-inch-diameter steel tube extending through the inflation element permitted sensing formation pressures in isolated test zones. Surface components of the monitoring system provided AC transducer excitation, signal conditioning for recording directly in engineering units, and both analog and digital recording. Continuous surface monitoring of formation pressures provided a means of determining test status and projecting completion times during any phase of testing. Maximum portability was afforded by battery operation with all surface components mounted in a small self-contained trailer. (USGS)

Fracture Strength of Single-Crystal Silicon Carbide Microspecimens at Room and Elevated Temperature

NASA Technical Reports Server (NTRS)

Nemeth, Noel N.; Sharpe, William N., Jr.; Beheim, Glenn M.; Evans, Laura J.; Jadaan, Osama M.

2007-01-01

Three shapes of tensile specimens were tested--curved with a very low stress concentration factor and straight with either a circular hole or an elliptical hole. The nominal thickness was 125 micron with a net section 100 micron wide; the overall length of these microspecimens was 3.1 mm. They were fabricated by an improved version of deep reactive ion etching, which produced specimens with smooth sidewalls and cross-sections having a slightly trapezoidal shape that was exaggerated inside the holes. The novel test setup used a vertical load train extending into a resistance furnace. The specimens had wedge-shaped ends which fit into ceramic grips. The fixed grip was mounted on a ceramic post, and the movable grip was connected to a load cell and actuator outside the furnace with a ceramic-encased nichrome wire. The same arrangement was used for tests at 24 and at 1000 C. The strengths of the curved specimens for two batches of material (made with slightly different processes) were 0.66+/-0.12 GPa and 0.45+/-0.20 GPa respectively at 24 C with identical values at 1000 C. The fracture strengths of the circular-hole and elliptical-hole specimens (computed from the stress concentration factors and measured loads at failure) were approximately 1.2 GPa with slight decreases at the higher temperature. Fractographic examinations showed failures initiating on the surface--primarily at corners. Weibull predictions of fracture strengths for the hole specimens based on the properties of the curved specimens were reasonably effective for the circular holes, but not for the elliptical holes.

The study of Equatorial coronal hole during maximum phase of Solar Cycle 21, 22, 23 and 24

NASA Astrophysics Data System (ADS)

Karna, Mahendra; Karna, Nishu

2017-08-01

The 11-year Solar Cycle (SC) is characterized by the periodic change in the solar activity like sunspot numbers, coronal holes, active regions, eruptions such as flares and coronal mass ejections. We study the relationship between equatorial coronal holes (ECH) and the active regions (AR) as coronal whole positions and sizes change with the solar cycle. We made a detailed study of equatorial coronal hole for four solar maximum: Solar Cycle 21 (1979,1980,1981 and 1982), Solar Cycle 22 (1989, 1990, 1991 and 1992), Solar Cycle 23 (1999, 2000, 2001 and 2002) and Solar Cycle 24 (2012, 2013, 2014 and 2015). We used publically available NOAA solar coronal hole data for cycle 21 and 22. We measured the ECH region using the EIT and AIA synoptic map for cycle 23 and 24. We noted that in two complete 22-year cycle of solar activity, the equatorial coronal hole numbers in SC 22 is greater than SC 21 and similarly, SC 24 equatorial coronal hole numbers are greater than SC 23. Moreover, we also compared the position of AR and ECH during SC 23 and 24. We used daily Solar Region Summary (SRS) data from SWPC/NOAA website. Our goal is to examine the correlation between equatorial holes, active regions, and flares.

The secondary maxima in black hole X-ray nova light curves - Clues toward a complete picture

NASA Technical Reports Server (NTRS)

Chen, Wan; Livio, Mario; Gehrels, Neil

1993-01-01

We study the secondary maxima observed commonly in the X-ray/optical light curves of black hole X-ray novae and show that they can play an important role in our understanding of the X-ray nova phenomenon. We discuss the observational characteristics of the secondary maxima and possible mechanisms to produce them. We propose a complete scenario for black hole X-ray nova events. The main outburst is caused by a disk instability. The second maximum is caused by X-ray evaporation of the matter near the inner Lagrangian (L1) region when the disk becomes optically thin. The third maximum (or the final minioutburst) is due to a mass transfer instability caused by hard X-ray heating of the subphotospheric layers of the secondary during the outburst. We predict that the newly discovered X-ray nova GRO J0422 + 32 may develop a final minioutburst in early 1993 and that its binary orbital period is less than 7 hr.

On the catalysis of the electroweak vacuum decay by black holes at high temperature

NASA Astrophysics Data System (ADS)

Canko, D.; Gialamas, I.; Jelic-Cizmek, G.; Riotto, A.; Tetradis, N.

2018-04-01

We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum at high temperature. We base our analysis on the assumption that, at temperatures much higher than the Hawking temperature, the main effect of the black hole is to distort the Higgs configuration dominating the transition to the new vacuum. We estimate the barrier for the transition by the ADM mass of this configuration, computed through the temperature-corrected Higgs potential. We find that the exponential suppression of the nucleation rate can be reduced significantly, or even eliminated completely, in the black-hole background if the Standard Model Higgs is coupled to gravity through the renormalizable term ξ R h^2.

Measurements of the stress supported by the crush zone in open hole composite laminates loaded in compression

NASA Technical Reports Server (NTRS)

Guynn, E. Gail; Bradley, Walter L.

1989-01-01

Measurements of the stress supported by the crush zone in open hole specimens loaded in compression were carried out on two composite laminates, AS4/PEEK and IM6/HST-7, containing circular holes of three different diameters. Compression tests were conducted in a specially designed high-axial-alignment material test system machine. Results indicated that the local stress supported in the crush zone is much less than the stress required to initiate the crush, providing the reason for the finding of Guynn et al. (1987) that the Dugdale model does not accurately predict the load-damage size relationship of open hole composite specimens loaded in compression.

Searching for Black Holes

NASA Technical Reports Server (NTRS)

Garcia, M.

1998-01-01

Our UV/VIS work concentrates on black hole X-ray nova. These objects consist of two stars in close orbit, one of which we believe is a black hole - our goal is to SHOW that one is a black hole. In order to reach this goal we carry out observations in the Optical, UV, IR and X-ray bands, and compare the observations to theoretical models. In the past year, our UV/VIS grant has provided partial support (mainly travel funds and page charges) for work we have done on X-ray nova containing black holes and neutron stars. We have been very successful in obtaining telescope time to support our project - we have completed approximately a dozen separate observing runs averaging 3 days each, using the MMT (5M), Lick 3M, KPNO 2.1M, CTIO 4M, CTIO 1.5M, and the SAO/WO 1.2M telescopes. These observations have allowed the identification of one new black hole (Nova Oph 1977), and allowed the mass of another to be measured (GS2000+25). Perhaps our most exciting new result is the evidence we have gathered for the existence of 'event horizons' in black hole X-ray nova.

30 CFR 282.22 - Delineation Plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CONTINENTAL SHELF FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR Obligations and Responsibilities of Lessees... operation in the environment which will be encountered. (e) Maps showing the proposed locations of test drill holes, the anticipated depth of penetration of test drill holes, the locations where surficial...

A massive binary black-hole system in OJ 287 and a test of general relativity.

PubMed

Valtonen, M J; Lehto, H J; Nilsson, K; Heidt, J; Takalo, L O; Sillanpää, A; Villforth, C; Kidger, M; Poyner, G; Pursimo, T; Zola, S; Wu, J-H; Zhou, X; Sadakane, K; Drozdz, M; Koziel, D; Marchev, D; Ogloza, W; Porowski, C; Siwak, M; Stachowski, G; Winiarski, M; Hentunen, V-P; Nissinen, M; Liakos, A; Dogru, S

2008-04-17

Tests of Einstein's general theory of relativity have mostly been carried out in weak gravitational fields where the space-time curvature effects are first-order deviations from Newton's theory. Binary pulsars provide a means of probing the strong gravitational field around a neutron star, but strong-field effects may be best tested in systems containing black holes. Here we report such a test in a close binary system of two candidate black holes in the quasar OJ 287. This quasar shows quasi-periodic optical outbursts at 12-year intervals, with two outburst peaks per interval. The latest outburst occurred in September 2007, within a day of the time predicted by the binary black-hole model and general relativity. The observations confirm the binary nature of the system and also provide evidence for the loss of orbital energy in agreement (within 10 per cent) with the emission of gravitational waves from the system. In the absence of gravitational wave emission the outburst would have happened 20 days later.

Experimental investigation of the effects of compound angle holes on film cooling effectiveness and heat transfer performance using a transient liquid crystal thermometry technique

NASA Astrophysics Data System (ADS)

Seager, David J.; Liburdy, James A.

1997-11-01

To further understand the effect of both compound angle holes and hole shaping on film cooling, detailed heat transfer measurements were obtained using hue based thermochromic liquid crystal method. The data were analyzed to measure both the full surface adiabatic effectiveness and heat transfer coefficient. The compound angles that were evaluated consist of holes that were aligned 0 degrees, 45 degrees, 60 degrees and 90 degrees to the main cross flow direction. Hole shaping variations from the traditional cylindrical shaped hole include forward diffused and laterally diffused hole geometries. Geometric parameters that were selected were the length to diameter ratio of 3.0, and the inclination angle 35 degrees. A density ratio of 1.55 was obtained for all teste. For each set of conditions the blowing ratio was varied to be 0.88, 1.25, and 1.88. Adiabatic effectiveness was obtained using a steady state test, while an active heating surface was used to determine the heat transfer coefficient using a transient method. The experimental method provides a unique method of analyzing a three-temperature heat transfer problem by providing detailed surface transport properties. Based on these results for the different hole geometries at each blowing ratio conclusions are drawn relative to the effects of compound angle holes on the overall film cooling performance.

Sleeve expansion of bolt holes in railroad rail. volume III - field experiment results

DOT National Transportation Integrated Search

1998-02-01

The bolt-hole cold-expansion process has been demonstrated by laboratory tests to significantly affect the initiation and propagation of fatigue cracks from rail bolt holes such that a reduction of the incidence of rail-bolt-holde failure in cold-exp...

Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer withdrawals on the Upper Floridan aquifer at Barbour Pointe Community, Chatham County, Georgia, 2013

USGS Publications Warehouse

Gonthier, Gerard; Clarke, John S.

2016-06-02

Two test wells were completed at the Barbour Pointe community in western Chatham County, near Savannah, Georgia, in 2013 to investigate the potential of using the Lower Floridan aquifer as a source of municipal water supply. One well was completed in the Lower Floridan aquifer at a depth of 1,080 feet (ft) below land surface; the other well was completed in the Upper Floridan aquifer at a depth of 440 ft below land surface. At the Barbour Pointe test site, the U.S. Geological Survey completed electromagnetic (EM) flowmeter surveys, collected and analyzed water samples from discrete depths, and completed a 72-hour aquifer test of the Floridan aquifer system withdrawing from the Lower Floridan aquifer.Based on drill cuttings, geophysical logs, and borehole EM flowmeter surveys collected at the Barbour Pointe test site, the Upper Floridan aquifer extends 369 to 567 ft below land surface, the middle semiconfining unit, separating the two aquifers, extends 567 to 714 ft below land surface, and the Lower Floridan aquifer extends 714 to 1,056 ft below land surface.A borehole EM flowmeter survey indicates that the Upper Floridan and Lower Floridan aquifers each contain four water-bearing zones. The EM flowmeter logs of the test hole open to the entire Floridan aquifer system indicated that the Upper Floridan aquifer contributed 91 percent of the total flow rate of 1,000 gallons per minute; the Lower Floridan aquifer contributed about 8 percent. Based on the transmissivity of the middle semiconfining unit and the Floridan aquifer system, the middle semiconfining unit probably contributed on the order of 1 percent of the total flow.Hydraulic properties of the Upper Floridan and Lower Floridan aquifers were estimated based on results of the EM flowmeter survey and a 72-hour aquifer test completed in Lower Floridan aquifer well 36Q398. The EM flowmeter data were analyzed using an AnalyzeHOLE-generated model to simulate upward borehole flow and determine the transmissivity of water-bearing zones. Aquifer-test data were analyzed with a two-dimensional, axisymmetric, radial, transient, groundwater-flow model using MODFLOW–2005. The flowmeter-survey and aquifer-test simulations provided an estimated transmissivity of about 60,000 square feet per day for the Upper Floridan aquifer and about 5,000 square feet per day for the Lower Floridan aquifer.Water in discrete-depth samples collected from the Upper Floridan aquifer, middle semiconfining unit, and Lower Floridan aquifer during the EM flowmeter survey in August 2013 was low in dissolved solids. Tested constituents were in concentrations within established U.S. Environmental Protection Agency drinking water-quality criteria. Concentrations of measured constituents in water samples from Lower Floridan aquifer well 36Q398 collected at the end of the 72-hour aquifer test in November 2013 were generally higher than in the discrete-depth samples collected during EM flowmeter testing in August 2013 but remained within established drinking water-quality criteria.Water-level data for the aquifer test were filtered for external influences such as barometric pressure, earth-tide effects, and long-term trends to enable detection of small (less than 1 ft) water-level responses to aquifer-test withdrawal. During the 72-hour aquifer test, the Lower Floridan aquifer was pumped at a rate of 750 gallons per minute resulting in a drawdown response of 35.5 ft in the pumped well; 1.6 ft in the Lower Floridan aquifer observation well located about 6,000 ft west of the pumped well; and responses of 0.7, 0.6, and 0.4 ft in the Upper Floridan aquifer observation wells located about 36 ft, 6,000 ft, and 6,800 ft from the pumped well, respectively

The evolution of kicked stellar-mass black holes in star cluster environments

NASA Astrophysics Data System (ADS)

Webb, Jeremy J.; Leigh, Nathan W. C.; Singh, Abhishek; Ford, K. E. Saavik; McKernan, Barry; Bellovary, Jillian

2018-03-01

We consider how dynamical friction acts on black holes that receive a velocity kick while located at the centre of a gravitational potential, analogous to a star cluster, due to either a natal kick or the anisotropic emission of gravitational waves during a black hole-black hole merger. Our investigation specifically focuses on how well various Chandrasekhar-based dynamical friction models can predict the orbital decay of kicked black holes with mbh ≲ 100 M⊙ due to an inhomogeneous background stellar field. In general, the orbital evolution of a kicked black hole follows that of a damped oscillator where two-body encounters and dynamical friction serve as sources of damping. However, we find models for approximating the effects of dynamical friction do not accurately predict the amount of energy lost by the black hole if the initial kick velocity vk is greater than the stellar velocity dispersion σ. For all kick velocities, we also find that two-body encounters with nearby stars can cause the energy evolution of a kicked BH to stray significantly from standard dynamical friction theory as encounters can sometimes lead to an energy gain. For larger kick velocities, we find the orbital decay of a black hole departs from classical theory completely as the black hole's orbital amplitude decays linearly with time as opposed to exponentially. Therefore, we have developed a linear decay formalism, which scales linearly with black hole mass and v_k/σ in order to account for the variations in the local gravitational potential.

Study of pharmacological activities of methanol extract of Jatropha gossypifolia fruits.

PubMed

Apu, Apurba Sarker; Hossain, Faruq; Rizwan, Farhana; Bhuyan, Shakhawat Hossan; Matin, Maima; Jamaluddin, A T M

2012-12-01

The present study was carried out to investigate the possible in vivo analgesic, neuropharmacological and anti-diarrheal activities of the methanol extract of Jatropha gossypifolia fruits. The analgesic activity was measured by acetic acid induced writhing inhibition test. The neuropharmacological activities were evaluated by hole cross, hole-board, and elevated plus-maze (EPM) tests and the anti-diarrheal activity was assessed by castor oil induced diarrhea inhibition method. The extract showed highly significant (P < 0.001) analgesic activity with % inhibitions of writhing response at doses 200 and 400 mg/kg body weight were 77.86% and 71.25%, respectively. The extract at both doses showed significant (P < 0.05) sedative effect in-hole cross test. In-hole board test, the extract showed highly significant (P < 0.001) anxiolytic activity at lower dose whereas this activity was observed at higher dose in EPM test. The extract also showed highly significant (P < 0.001) anti-diarrheal activity. The findings of the study clearly indicate the presence of significant analgesic, neuropharmacological and anti-diarrheal properties of the plant, which demands further investigation including, compound isolation.

Bolted joints in graphite-epoxy composites

NASA Technical Reports Server (NTRS)

Hart-Smith, L. J.

1976-01-01

All-graphite/epoxy laminates and hybrid graphite-glass/epoxy laminates were tested. The tests encompassed a range of geometries for each laminate pattern to cover the three basic failure modes - net section tension failure through the bolt hole, bearing and shearout. Static tensile and compressive loads were applied. A constant bolt diameter of 6.35 mm (0.25 in.) was used in the tests. The interaction of stress concentrations associated with multi-row bolted joints was investigated by testing single- and double-row bolted joints and open-hole specimens in tension. For tension loading, linear interaction was found to exist between the bearing stress reacted at a given bolt hole and the remaining tension stress running by that hole to be reacted elsewhere. The interaction under compressive loading was found to be non-linear. Comparative tests were run using single-lap bolted joints and double-lap joints with pin connection. Both of these joint types exhibited lower strengths than were demonstrated by the corresponding double-lap joints. The analysis methods developed here for single bolt joints are shown to be capable of predicting the behavior of multi-row joints.

Effectiveness of combined macular buckle under direct vision and vitrectomy with ILM peeling in refractory macular hole retinal detachment with extreme high axial myopia: a 24-month comparative study.

PubMed

Ma, Jin; Li, Honghui; Ding, Xiaohu; Tanumiharjo, Silvia; Lu, Lin

2017-10-01

To evaluate the efficacy of a combined macular buckle under direct vision and 23-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in refractory macular hole retinal detachment (MHRD) with extreme high axial myopia. Prospective, randomised controlled study. The study included 98 eyes of 98 patients of MHRD with extreme high axial (>30 mm) myopia. Patients were randomly assigned to undergo PPV with ILM peeling (group 1, n=52) or PPV with ILM peeling combined with macular buckle under direct vision (group 2, n=46). Complete ocular examination included best-corrected visual acuity (BCVA) (LogMAR), applanation tonometry, optical biometry, slit-lamp biomicroscopy, colour fundus photography, ultrasound examination and optical coherence tomography at baseline and every follow-up visit. Initial retinal reattachment rate was significantly higher in group 2 than in group 1 at 12-month postoperatively (χ 2 test, p=0.020). Macular hole closure rate in group 2 was significantly higher than that in group 1 at 3, 12, 18 and 24 months postoperatively (Fisher's exact test, p<0.05). In initial retinal reattachment cases, the mean BCVA decreased significantly in group 2 than in group 1 at 3 months postoperatively (Wilcoxon matched pairs signed rank test, p=0.036), and had increased significantly in group 2 than in group 1 since 6 months postoperatively (Wilcoxon matched pairs signed rank test, p<0.05). Mean axial lengths in group 2 were significantly shorter than that of group 1 at each follow-up time point (Wilcoxon matched pairs signed rank test, p<0.05). Combined macular buckle under direct vision and PPV with ILM peeling is more effective in treatment of MHRD with extreme high axial (>30 mm) myopia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

High-Time-Resolution Study of Magnetic Holes in the Solar Wind

NASA Technical Reports Server (NTRS)

Lazarus, Alan; Kasper, Justin; Stevens, Michael

2003-01-01

The objectives of this investigation are to determine the internal plasma structure of kinetic-scale and larger scale magnetic holes, and to determine their stability, their source mechanism(s), and their spatial extent. It is also of importance to determine the relationship between kinetic-scale holes and long-duration holes. As smaller and smaller magnetic depressions are investigated in order to make this a complete study, a robust criterion is necessary for distinguishing magnetic holes from random or unresolvable fluctuations in the interplanetary magnetic field. In order to resolve this ambiguity, we obtained from the MFI experiments magnetic field measurements from the WIND spacecraft at a time resolution of 46 to 184 ms over certain periods. We have also devised a measure of certainty for magnetic hole detections. The certainty factor, q, is defined as the difference between the mean magnetic field in the hole and the local magnetic field, in units of the local standard deviation of the field strength. For fullest generality, it is necessary to calculate this q over the range of available scales of interest, from 60 ms up to 300 s. This technique establishes a two dimensional matrix of relative probabilities that a hole of some duration (d) might exist in the data set at a given time (t). In identifying q-peaks in time and duration, we also come upon a natural method for distinguishing holes with internal structure from multiple holes in close proximity or holes nested inside of others. If two q-peaks are more than a half-width apart, they are simply said to be separate events.

Selective-area catalyst-free MBE growth of GaN nanowires using a patterned oxide layer.

PubMed

Schumann, T; Gotschke, T; Limbach, F; Stoica, T; Calarco, R

2011-03-04

GaN nanowires (NWs) were grown selectively in holes of a patterned silicon oxide mask, by rf-plasma-assisted molecular beam epitaxy (PAMBE), without any metal catalyst. The oxide was deposited on a thin AlN buffer layer previously grown on a Si(111) substrate. Regular arrays of holes in the oxide layer were obtained using standard e-beam lithography. The selectivity of growth has been studied varying the substrate temperature, gallium beam equivalent pressure and patterning layout. Adjusting the growth parameters, GaN NWs can be selectively grown in the holes of the patterned oxide with complete suppression of the parasitic growth in between the holes. The occupation probability of a hole with a single or multiple NWs depends strongly on its diameter. The selectively grown GaN NWs have one common crystallographic orientation with respect to the Si(111) substrate via the AlN buffer layer, as proven by x-ray diffraction (XRD) measurements. Based on the experimental data, we present a schematic model of the GaN NW formation in which a GaN pedestal is initially grown in the hole.

Black hole based quantum computing in labs and in the sky

NASA Astrophysics Data System (ADS)

Dvali, Gia; Panchenko, Mischa

2016-08-01

Analyzing some well established facts, we give a model-independent parameterization of black hole quantum computing in terms of a set of macro and micro quantities and their relations. These include the relations between the extraordinarily-small energy gap of black hole qubits and important time-scales of information-processing, such as, scrambling time and Page's time. We then show, confirming and extending previous results, that other systems of nature with identical quantum informatics features are attractive Bose-Einstein systems at the critical point of quantum phase transition. Here we establish a complete isomorphy between the quantum computational properties of these two systems. In particular, we show that the quantum hair of a critical condensate is strikingly similar to the quantum hair of a black hole. Irrespectively whether one takes the similarity between the two systems as a remarkable coincidence or as a sign of a deeper underlying connection, the following is evident. Black holes are not unique in their way of quantum information processing and we can manufacture black hole based quantum computers in labs by taking advantage of quantum criticality.

A Global Spectral Study of Stellar-Mass Black Holes with Unprecedented Sensitivity

NASA Astrophysics Data System (ADS)

Garci, Javier

There are two well established populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, many millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with masses in the range millions to billions of solar masses, which reside in the nucleus of most galaxies. Supermassive black holes play a leading role in shaping galaxies and are central to cosmology. However, they are hard to study because they are dim and they scarcely vary on a human timescale. Luckily, their variability and full range of behavior can be very effectively studied by observing their stellar-mass cousins, which display in miniature the full repertoire of a black hole over the course of a single year. The archive of data collected by NASA's Rossi X-ray Timing Explorer (RXTE) during its 16 year mission is of first importance for the study of stellar-mass black holes. While our ultimate goal is a complete spectral analysis of all the stellar-mass black hole data in the RXTE archive, the goal of this proposal is the global study of six of these black holes. The two key methodologies we bring to the study are: (1) Our recently developed calibration tool that increases the sensitivity of RXTE's detector by up to an order of magnitude; and (2) the leading X-ray spectral "reflection" models that are arguably the most effective means currently available for probing the effects of strong gravity near the event horizon of a black hole. For each of the six black holes, we will fit our models to all the archived spectral data and determine several key parameters describing the black hole and the 10-million-degree gas that surrounds it. Of special interest will be our measurement of the spin (or rate of rotation) of each black hole, which can be as high as tens of thousands of RPM. Profoundly, all the properties of an astronomical black hole are completely defined by specifying its spin and its mass. The main goal of this project is a global spectroscopic studies of six bright black holes using our reflection models and new calibration tools. These synoptic studies will provide a panoramic view of black hole behavior and advance the measurement of black hole spin. The relevance of our proposed study to this NASA Research Announcement is clear because our work represents a vital use of NASA's High Energy Astrophysics Science Archive Research Center (HEASARC); conversely, it is the HEASARC that makes our work possible. In addition, our work naturally responds to the following words in the NRA: ``...the development of tools for mining the vast reservoir of information locked within [the HEASARC]...is also eligible for funding under the Astrophysics Data Analysis Program.'' Specifically we will provide new data analysis tools to the community for the study of data collected by a wide range of past, current and future X-ray missions (e.g., RXTE, Chandra, XMM-Newton, NuSTAR, Swift, NICER). Finally, we are responsive to Objective 1.6 in NASA's Strategic Plan for 2014 that calls for ``exploring the extreme conditions of the universe'' and the continuing aspiration to ``probe the origin and destiny of the universe, including the first moments of the Big Bang and the nature of black holes...''. The proposed program will be carried out over the course of three years.

Notch strength of composites

NASA Technical Reports Server (NTRS)

Whitney, J. M.

1983-01-01

The notch strength of composites is discussed. The point stress and average stress criteria relate the notched strength of a laminate to the average strength of a relatively long tensile coupon. Tests of notched specimens in which microstrain gages have been placed at or near the edges of the holes have measured strains much larger that those measured in an unnotched tensile coupon. Orthotropic stress concentration analyses of failed notched laminates have also indicated that failure occurred at strains much larger than those experienced on tensile coupons with normal gage lengths. This suggests that the high strains at the edge of a hole can be related to the very short length of fiber subjected to these strains. Lockheed has attempted to correlate a series of tests of several laminates with holes ranging from 0.19 to 0.50 in. Although the average stress criterion correlated well with test results for hole sizes equal to or greater than 0.50 in., it over-estimated the laminate strength in the range of hole sizes from 0.19 to 0.38 in. It thus appears that a theory is needed that is based on the mechanics of failure and is more generally applicable to the range of hole sizes and the varieties of laminates found in aircraft construction.

A GENERAL RELATIVISTIC NULL HYPOTHESIS TEST WITH EVENT HORIZON TELESCOPE OBSERVATIONS OF THE BLACK HOLE SHADOW IN Sgr A*

DOE Office of Scientific and Technical Information (OSTI.GOV)

Psaltis, Dimitrios; Özel, Feryal; Chan, Chi-Kwan

2015-12-01

The half opening angle of a Kerr black hole shadow is always equal to (5 ± 0.2)GM/Dc{sup 2}, where M is the mass of the black hole and D is its distance from the Earth. Therefore, measuring the size of a shadow and verifying whether it is within this 4% range constitutes a null hypothesis test of general relativity. We show that the black hole in the center of the Milky Way, Sgr A*, is the optimal target for performing this test with upcoming observations using the Event Horizon Telescope (EHT). We use the results of optical/IR monitoring of stellar orbits to showmore » that the mass-to-distance ratio for Sgr A* is already known to an accuracy of ∼4%. We investigate our prior knowledge of the properties of the scattering screen between Sgr A* and the Earth, the effects of which will need to be corrected for in order for the black hole shadow to appear sharp against the background emission. Finally, we explore an edge detection scheme for interferometric data and a pattern matching algorithm based on the Hough/Radon transform and demonstrate that the shadow of the black hole at 1.3 mm can be localized, in principle, to within ∼9%. All these results suggest that our prior knowledge of the properties of the black hole, of scattering broadening, and of the accretion flow can only limit this general relativistic null hypothesis test with EHT observations of Sgr A* to ≲10%.« less

Analysis of single-hole and cross-hole tracer tests conducted at the Nye County early warning drilling program well complex, Nye County, Nevada

USGS Publications Warehouse

Umari, A.; Earle, J.D.; Fahy, M.F.

2006-01-01

As part of the effort to understand the flow and transport characteristics downgradient from the proposed high-level radioactive waste geologic repository at Yucca Mountain, Nevada, single- and cross-hole tracer tests were conducted from December 2004 through October 2005 in boreholes at the Nye County 22 well complex. The results were analyzed for transport properties using both numerical and analytical solutions of the governing advection dispersion equation. Preliminary results indicate effective flow porosity values ranging from 1.0 ?? 10-2 for an individual flow path to 2.0 ?? 10 -1 for composite flow paths, longitudinal dispersivity ranging from 0.3 to 3 m, and a transverse horizontal dispersivity of 0.03 m. Individual flow paths identified from the cross-hole testing indicate some solute diffusion into the stagnant portion of the alluvial aquifer.

Listvenite formation from peridotite: Insights from Oman Drilling Project hole BT1B and preliminary reaction path model approach.

NASA Astrophysics Data System (ADS)

de Obeso, J. C.; Kelemen, P. B.; Manning, C. E.; Michibayashi, K.; Harris, M.

2017-12-01

Oman Drilling Project hole BT1B drilled 300 meters through the basal thrust of the Samail ophiolite. The first 200 meters of this hole are dominated by listvenites (completely carbonated peridotites) and serpentinites. Below 200 meters the hole is mainly composed of metasediments and metavolcanics. This core provides a unique record of interaction between (a) mantle peridotite in the leading edge of the mantle wedge and (b) hydrous, CO2 rich fluids derived from subducting lithologies similar to those in the metamorphic sole. We used EQ3/6 to simulate a reaction path in which hydrous fluid in equilibrium with qtz + calcite + feldspar + chlorite or smectite reacts with initially fresh peridotite at 100°C (the estimated temperature of alteration, Falk & Kelemen GCA 2015) and 5 kb. Water was first equilibrated with minerals observed during core description in the metamorphic sole at 100°C and 5kb. This fluid is then reacted with olivine enstatite and diopside (Mg#90) approximating the average composition of residual mantle peridotite (harzburgite) in Oman. Secondary minerals resulting from complete reaction are then reacted again with the initial fluid in an iterative process, up to water/rock > 1000. Water/rock close to 1 results in complete serpentinization of the peridotite, with chrysotile, brucite and magnetite as the only minerals. Water/rock >10 produces carbonates, chlorite and talc. Further increasing water/rock to > 100 produces assemblages dominated by carbonates and quartz with minor muscovite, similar to listvenites of hole BT1B that contain qtz + carbonates + Fe-oxyhydroxides + relict spinel ± chromian muscovite and fuchsite. The results of this preliminary model are consistent with the complex veining history of core from BT1B, with carbonate/iron oxide veins in both listvenites and serpentinites interpreted to be the earliest record of peridotite carbonation after initial serpentinization.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 sevenmore » 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.« less

EFFECT OF PILOT HOLE TAPPING ON PULLOUT STRENGTH AND INSERTION TORQUE OF DUAL CORE PEDICLE SCREWS.

PubMed

Rosa, Rodrigo César; Silva, Patrícia; Falcai, Maurício José; Shimano, Antônio Carlos; Defino, Helton Luiz Aparecido

2010-01-01

To evaluate the influence of pilot hole tapping on pullout resistance and insertion torque of pedicle screws with a conical core. Mechanical tests using a universal testing machine were performed on pedicle screws with a conical core that were inserted into pedicles in the fifth lumbar vertebra of calves. The insertion torque was measured using a torque meter with a capacity of 10 Nm, which was considered to be the highest torque value. The pilot holes were prepared using a probe of external diameter 3.8 mm and tapping of the same dimensions and thread characteristics as the screw. Decreased insertion torque and pullout resistance were observed in the group with prior tapping of the pilot hole. Pilot hole tapping reduced the insertion torque and pullout resistance of pedicle screws with a conical core that had been inserted into the pedicle of the fifth lumbar vertebra of calves.

Final 2014 Remedial Action Report Project Chariot, Cape Thompson, Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

2015-03-01

This report was prepared to document remedial action (RA) work performed at the former Project Chariot site located near Cape Thompson, Alaska during 2014. The work was managed by the U.S. Army Corps of Engineers (USACE) Alaska District for the U.S. Department of Energy (DOE) Office of Legacy Management (LM). Due to the short field season and the tight barge schedule, all field work was conducted at the site July 6 through September 12, 2014. Excavation activities occurred between July 16 and August 26, 2014. A temporary field camp was constructed at the site prior to excavation activities to accommodatemore » the workers at the remote, uninhabited location. A total of 785.6 tons of petroleum, oil, and lubricants (POL)-contaminated soil was excavated from four former drill sites associated with test holes installed circa 1960. Diesel was used in the drilling process during test hole installations and resulted in impacts to surface and subsurface soils at four of the five sites (no contamination was identified at Test Hole Able). Historic information is not definitive as to the usage for Test Hole X-1; it may have actually been a dump site and not a drill site. In addition to the contaminated soil, the steel test hole casings were decommissioned and associated debris was removed as part of the remedial effort.« less

Influence of the hole geometry on the flow distribution in ventricular catheters for hydrocephalus.

PubMed

Giménez, Ángel; Galarza, Marcelo; Pellicer, Olga; Valero, José; Amigó, José M

2016-07-15

Hydrocephalus is a medical condition consisting of an abnormal accumulation of cerebrospinal fluid within the brain. A catheter is inserted in one of the brain ventricles and then connected to an external valve to drain the excess of cerebrospinal fluid. The main drawback of this technique is that, over time, the ventricular catheter ends up getting blocked by the cells and macromolecules present in the cerebrospinal fluid. A crucial factor influencing this obstruction is a non-uniform flow pattern through the catheter, since it facilitates adhesion of suspended particles to the walls. In this paper we focus on the effects that tilted holes as well as conical holes have on the flow distribution and shear stress. We have carried out 3D computational simulations to study the effect of the hole geometry on the cerebrospinal fluid flow through ventricular catheters. All the simulations were done with the OpenFOAM® toolbox. In particular, three different groups of models were investigated by varying (i) the tilt angles of the holes, (ii) the inner and outer diameters of the holes, and (iii) the distances between the so-called hole segments. The replacement of cylindrical holes by conical holes was found to have a strong influence on the flow distribution and to lower slightly the shear stress. Tilted holes did not involve flow distribution changes when the hole segments are sufficiently separated, but the mean shear stress was certainly reduced. The authors present new results about the behavior of the fluid flow through ventricular catheters. These results complete earlier work on this topic by adding the influence of the hole geometry. The overall objective pursued by this research is to provide guidelines to improve existing commercially available ventricular catheters.

No static bubbling spacetimes in higher dimensional Einstein–Maxwell theory

NASA Astrophysics Data System (ADS)

Kunduri, Hari K.; Lucietti, James

2018-03-01

We prove that any asymptotically flat static spacetime in higher dimensional Einstein–Maxwell theory must have no magnetic field. This implies that there are no static soliton spacetimes and completes the classification of static non-extremal black holes in this theory. In particular, these results establish that there are no asymptotically flat static spacetimes with non-trivial topology, with or without a black hole, in Einstein–Maxwell theory.

Instabilities orginating from suction holes used for Laminar Flow Control (LFC)

NASA Technical Reports Server (NTRS)

Watmuff, Jonathan H.

1994-01-01

A small-scale wind tunnel previously used for turbulent boundary layer studies has been modified for experiments in laminar flow control. The facility incorporates suction through interchangeable porous test surfaces which are used to stabilize the boundary layer and delay transition to turbulent flow. The thin porous test surfaces are supported by a baffled plenum chamber box which also acts to gather the flow through the surface into tubes which are routed to a high pressure fan. An elliptic leading edge is attached to the assembly to establish a new layer on the test plate. A slot is used to remove the test section flow below the leading edge. The test section was lengthened and fitted with a new ceiling. Substantial modifications were also made to the 3D probe traverse. Detailed studies have been made using isolated holes to explore the underlying instability mechanisms. The suction is perturbed harmonically and data are averaged on the basis of the phase of the disturbance. Conditions corresponding to strong suction and without suction have been studied. In both cases, 3D contour surfaces in the vicinity of the hole show highly three-dimensional T-S waves that fan out away from the hole with streamwise distance. With suction, the perturbations on the centerline are much stronger and decay less rapidly, while the far field is similar to the case without suction. Downstream the contour surfaces of the bow-shaped TS waves develop spanwise irregularities which eventually form into clumps. The contours remain smooth when suction is not applied. Even without suction, the harmonic point source is challenging for CFD; e.g. DNS has been used for streamwise growth. With suction, grid resources are consumed by the hole and this makes DNS even more expensive. Limited DNS results so far indicate that the vortices which emanate from suction holes appear to be stable. The spanwise clumping observed in the experiment is evidence of a secondary instability that could be associated with suction vortices. A typical porous surface for LFC consists of 0.002 inch diameter holes with 0.020 inch grid spacing L, which is too small to resolve disturbances. A 20:1 scale porous test surface has been machined for improved spatial resolution while the L/d is still representative of flight conditions. Designers of porous surfaces use Goldsmith's criterion to minimize crossstream interaction. However nothing is known about the streamwise interactions. Results using two holes, aligned but displaced in the streamwise direction, indicate that partial TS wave cancellation is possible, depending on the hole spacing and disturbance frequency. Using DNS for streamwise interaction studies will be prohibitively expensive if linear superposition cannot be used for the multiple holes.

Drilling the near cortex with elongated figure-of-8 holes to reduce the stiffness of a locking compression plate construct.

PubMed

Chen, Jerry Yongqiang; Zhou, Zhihong; Ang, Benjamin Fu Hong; Yew, Andy Khye Soon; Chou, Siaw Meng; Chia, Shi-Lu; Koh, Joyce Suang Bee; Howe, Tet Sen

2015-12-01

To compare the stiffness of locking compression plate (LCP) constructs with or without drilling the near cortex with elongated figure-of-8 holes. 24 synthetic bones were sawn to create a 10-mm gap and were fixed with a 9-hole 4.5-mm narrow LCP. In 12 bones, the near cortex of the adjacent holes to the LCP holes was drilled to create elongated figure-of-8 holes before screw insertion. The stiffness of LCP constructs under axial loading or 4-point bending was assessed by (1) dynamic quasi-physiological testing for fatigue strength, (2) quasi-static testing for stiffness, and (3) testing for absolute strength to failure. None of the 24 constructs had subcatastrophic or catastrophic failure after 10 000 cycles of fatigue loading (p=1.000). The axial stiffness reduced by 16% from 613±62 to 517±44 N/mm (p=0.012) in the case group, whereas the bending stiffness was 16±1 Nm2 in both groups (p=1.000). The maximum axial load to catastrophic failure was 1596±84 N for the control group and 1627±48 N for the case group (p=0.486), whereas the maximum bending moment to catastrophic failure was 79±12 and 80±10 Nm, respectively (p=0.919). Drilling the near cortex with elongated figure-of-8 holes reduces the axial stiffness of the LCP construct, without compromising its bending stiffness or strength.

Black hole and cosmos with multiple horizons and multiple singularities in vector-tensor theories

NASA Astrophysics Data System (ADS)

Gao, Changjun; Lu, Youjun; Yu, Shuang; Shen, You-Gen

2018-05-01

A stationary and spherically symmetric black hole (e.g., Reissner-Nordström black hole or Kerr-Newman black hole) has, at most, one singularity and two horizons. One horizon is the outer event horizon and the other is the inner Cauchy horizon. Can we construct static and spherically symmetric black hole solutions with N horizons and M singularities? The de Sitter cosmos has only one apparent horizon. Can we construct cosmos solutions with N horizons? In this article, we present the static and spherically symmetric black hole and cosmos solutions with N horizons and M singularities in the vector-tensor theories. Following these motivations, we also construct the black hole solutions with a firewall. The deviation of these black hole solutions from the usual ones can be potentially tested by future measurements of gravitational waves or the black hole continuum spectrum.

The relationship between walking, manual dexterity, cognition and activity/participation in persons with multiple sclerosis.

PubMed

Kierkegaard, Marie; Einarsson, Ulrika; Gottberg, Kristina; von Koch, Lena; Holmqvist, Lotta Widén

2012-05-01

Multiple sclerosis has a vast impact on health, but the relationship between walking, manual dexterity, cognition and activity/participation is unclear. The specific aims were to explore the discriminative ability of measures of walking, manual dexterity and cognition, and to identify cut-off values in these measures, for prediction of independence in personal and instrumental activities of daily living (ADL) and activity/participation in social and lifestyle activities. Data from 164 persons with multiple sclerosis were collected during home visits with the following measures: the 2 × 5 m walk test, the Nine-hole Peg Test, the Symbol Digit Modalities Test, the Katz Personal and Instrumental ADL Indexes, and the Frenchay Activities Index (measuring frequency in social and lifestyle activities). The 2 × 5 m walk test and the Nine-hole Peg Test had high and better discriminative and predictive ability than the Symbol Digit Modalities Test. Cut-off values were identified. The accuracy of predictions was increased above all by combining the 2 × 5 m walk test and the Nine-hole Peg Test. The proposed cut-off values in the 2 × 5 m walk test and the Nine-hole Peg Test may be used as indicators of functioning and to identify persons risking activity limitations and participation restrictions. However, further studies are needed to confirm the usefulness in clinical practice.

Research on the EDM Technology for Micro-holes at Complex Spatial Locations

NASA Astrophysics Data System (ADS)

Y Liu, J.; Guo, J. M.; Sun, D. J.; Cai, Y. H.; Ding, L. T.; Jiang, H.

2017-12-01

For the demands on machining micro-holes at complex spatial location, several key technical problems are conquered such as micro-Electron Discharge Machining (micro-EDM) power supply system’s development, the host structure’s design and machining process technical. Through developing low-voltage power supply circuit, high-voltage circuit, micro and precision machining circuit and clearance detection system, the narrow pulse and high frequency six-axis EDM machining power supply system is developed to meet the demands on micro-hole discharging machining. With the method of combining the CAD structure design, CAE simulation analysis, modal test, ODS (Operational Deflection Shapes) test and theoretical analysis, the host construction and key axes of the machine tool are optimized to meet the position demands of the micro-holes. Through developing the special deionized water filtration system to make sure that the machining process is stable enough. To verify the machining equipment and processing technical developed in this paper through developing the micro-hole’s processing flow and test on the real machine tool. As shown in the final test results: the efficient micro-EDM machining pulse power supply system, machine tool host system, deionized filtration system and processing method developed in this paper meet the demands on machining micro-holes at complex spatial locations.

29 CFR Appendix E to Subpart L of... - Test Methods for Protective Clothing

Code of Federal Regulations, 2011 CFR

2011-07-01

... penetration. One block shall have a hole drilled to hold an 8D common nail firmly at an angle of 98°. The second block shall have a maximum 1/2-inch (1.3 cm) diameter hole drilled through it so that the hole... 11 irons thick, and a new 8D nail, shall be placed as follows: the 8D nail in the hole, the sample of...

Effect of drilled holes on the bending strength of large dimension Douglas-fir lumber

Treesearch

R.H. Falk; D. DeVisser; G.R. Plume; K.J. Fridley

2003-01-01

In this study, experimental bending tests were performed on nominal 4-by 8-inch (actual 89-mm by 191-mm)lumber members to determine how a notch and holes drilled in the wide face affect edge wise bending strength. Holes were drilled at the midspan in three locations relative to the edge. The results appear to justify an allowable hole one-half the allowable knot size...

29 CFR Appendix E to Subpart L of... - Test Methods for Protective Clothing

Code of Federal Regulations, 2013 CFR

2013-07-01

... penetration. One block shall have a hole drilled to hold an 8D common nail firmly at an angle of 98°. The second block shall have a maximum 1/2-inch (1.3 cm) diameter hole drilled through it so that the hole... 11 irons thick, and a new 8D nail, shall be placed as follows: the 8D nail in the hole, the sample of...

Experimental Study on Environment Friendly Tap Hole Clay for Blast Furnace

NASA Astrophysics Data System (ADS)

Siva kumar, R.; Mohammed, Raffi; Srinivasa Rao, K.

2018-03-01

Blast furnace (BF) is the best possible route of iron production available. Blast furnace is a high pressure vessel where iron ore is melted and liquid iron is produced. The liquid iron is tapped through the hole in Blast Furnace called tap hole. The tapped liquid metal flowing through the tap hole is plugged using a clay called tap hole clay. Tap hole clay (THC) is a unshaped refractory used to plug the tap hole. The tap hole clay extruded through the tap hole using a gun. The tap hole clay is designed to expand and plug the tap hole. The tap hole filled with clay is drilled using drill bit and the hole made through the tap hole to tap the liquid metal accumulated inside the furnace. The number of plugging and drilling varies depending on the volume of the furnace. The tap hole clay need to have certain properties to avoid problems during plugging and drilling. In the present paper tap hole clay properties in industrial use was tested and studied. The problems were identified related to tap hole clay manufacturing. Experiments were conducted in lab scale to solve the identified problems. The present composition was modified with experimental results. The properties of the modified tap hole clay were found suitable and useful for blast furnace operation with lab scale experimental results.

A SMALL-ANGLE DRILL-HOLE WHIPSTOCK

DOEpatents

Nielsen, D.E.; Olsen, J.L.; Bennett, W.P.

1963-01-29

A small angle whipstock is described for accurately correcting or deviating a drill hole by a very small angle. The whipstock is primarily utilized when drilling extremely accurate, line-of-slight test holes as required for diagnostic studies related to underground nuclear test shots. The invention is constructed of a length of cylindrical pipe or casing, with a whipstock seating spike extending from the lower end. A wedge-shaped segment is secured to the outer circumference of the upper end of the cylinder at a position diametrically opposite the circumferential position of the spike. Pin means are provided for affixing the whipstock to a directional drill bit and stem to alloy orienting and setting the whipstock properly in the drill hole. (AEC)

Macular Hole Development After Vitrectomy for Floaters: A Case Report.

PubMed

Appeltans, Andrea; Mura, Marco; Bamonte, Giulio

2017-12-01

The purpose of this report is to describe a case of macular hole development after vitrectomy for floaters with induction of posterior vitreous detachment. A 44-year-old otherwise healthy man presented with visually debilitating floaters in his right eye; these had been present for more than 2 years. Preoperative examination was unremarkable in both eyes, apart from some degree of vitreous degeneration in the right eye. Preoperative visual acuity was 20/20 bilaterally. A 25-gauge transconjunctival sutureless pars plana complete vitrectomy with induction of posterior vitreous detachment was performed in the right eye. Upon examination 1 month after surgery, a small full-thickness macular hole was detected in the right eye. Visual acuity was diminished to 20/80. The macular hole was closed after a second vitrectomy with internal limiting membrane peeling and gas tamponade. Macular hole development should be listed as a possible complication of vitrectomy for visually debilitating floaters when a posterior vitreous detachment is induced during surgery.

Meissner effect for axially symmetric charged black holes

NASA Astrophysics Data System (ADS)

Gürlebeck, Norman; Scholtz, Martin

2018-04-01

In our previous work [N. Gürlebeck and M. Scholtz, Phys. Rev. D 95, 064010 (2017), 10.1103/PhysRevD.95.064010], we have shown that electric and magnetic fields are expelled from the horizons of extremal, stationary and axially symmetric uncharged black holes; this is called the Meissner effect for black holes. Here, we generalize this result in several directions. First, we allow that the black hole carries charge, which requires a generalization of the definition of the Meissner effect. Next, we introduce the notion of almost isolated horizons, which is weaker than the usual notion of isolated horizons, since the geometry of the former is not necessarily completely time independent. Moreover, we allow the horizon to be pierced by strings, thereby violating the usual assumption on the spherical topology made in the definition of the weakly isolated horizon. Finally, we spell out in detail all assumptions entering the proof and show that the Meissner effect is an inherent property of black holes even in full nonlinear theory.

A unitary model of the black hole evaporation

NASA Astrophysics Data System (ADS)

Feng, Yu-Lei; Chen, Yi-Xin

2014-12-01

A unitary effective field model of the black hole evaporation is proposed to satisfy almost the four postulates of the black hole complementarity (BHC). In this model, we enlarge a black hole-scalar field system by adding an extra radiation detector that couples with the scalar field. After performing a partial trace over the scalar field space, we obtain an effective entanglement between the black hole and the detector (or radiation in it). As the whole system evolves, the S-matrix formula can be constructed formally step by step. Without local quantum measurements, the paradoxes of the information loss and AMPS's firewall can be resolved. However, the information can be lost due to quantum decoherence, as long as some local measurement has been performed on the detector to acquire the information of the radiation in it. But unlike Hawking's completely thermal spectrum, some residual correlations can be found in the radiations. All these considerations can be simplified in a qubit model that provides a modified quantum teleportation to transfer the information via an EPR pairs.

Gravitational Waves from Black Hole Mergers

NASA Technical Reports Server (NTRS)

Centrella, Joan

2007-01-01

The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GEO600, as well as the space-based interferometer LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, data analysis, and astrophysics.

Evaporation of large black holes in AdS: coupling to the evaporon

NASA Astrophysics Data System (ADS)

Rocha, Jorge V.

2008-08-01

Large black holes in an asymptotically AdS spacetime have a dual description in terms of approximately thermal states in the boundary CFT. The reflecting boundary conditions of AdS prevent such black holes from evaporating completely. On the other hand, the formulation of the information paradox becomes more stringent when a black hole is allowed to evaporate. In order to address the information loss problem from the AdS/CFT perspective we then need the boundary to become partially absorptive. We present a simple model that produces the necessary changes on the boundary by coupling a bulk scalar field to the evaporon, an external field propagating in one extra spatial dimension. The interaction is localized at the boundary of AdS and leads to partial transmission into the additional space. The transmission coefficient is computed in the planar limit and perturbatively in the coupling constant. Evaporation of the large black hole corresponds to cooling down the CFT by transferring energy to an external sector.

Flip-flopping binary black holes.

PubMed

Lousto, Carlos O; Healy, James

2015-04-10

We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

Nimbus-7 TOMS Antarctic ozone atlas: August through November, 1989

NASA Technical Reports Server (NTRS)

Krueger, Arlin J.; Penn, Lanning M.; Larko, David E.; Doiron, Scott D.; Guimaraes, Patricia T.

1990-01-01

Because of the great environmental significance of ozone and to support continuing research at the Antarctic and other Southern Hemisphere stations, the development of the 1989 ozone hole was monitored using data from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) instrument, produced in near-real-time. This Atlas provides a complete set of daily polar orthographic projections of the TOMS total ozone measurements over the Southern Hemisphere for the period August 1 through November 30, 1989. The 1989 ozone hole developed in a manner similar to that of 1987, reaching a comparable depth in early October. This was in sharp contrast to the much weaker hole of 1988. The 1989 ozone hole remained at polar latitudes as it filled in November, in contrast to other recent years when the hole drifted to mid-latitudes before disappearing. Daily ozone values above selected Southern Hemisphere stations are presented, along with comparisons of the 1989 ozone distribution to that of other years.

Binary Black Holes, Gravitational Waves, and Numerical Relativity

NASA Technical Reports Server (NTRS)

Centrella, John

2007-01-01

The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GE0600, as well as the space-based interferometer LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, data analysis, and astrophysics.

Binary Black Holes: Mergers, Dynamics, and Waveforms

NASA Astrophysics Data System (ADS)

Centrella, Joan

2007-04-01

The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GEO600, as well as the space-based interferometer LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, data analysis, and astrophysics.

Test methods for textile composites

NASA Technical Reports Server (NTRS)

Minguet, Pierre J.; Fedro, Mark J.; Gunther, Christian K.

1994-01-01

Various test methods commonly used for measuring properties of tape laminate composites were evaluated to determine their suitability for the testing of textile composites. Three different types of textile composites were utilized in this investigation: two-dimensional (2-D) triaxial braids, stitched uniweave fabric, and three-dimensional (3-D) interlock woven fabric. Four 2-D braid architectures, five stitched laminates, and six 3-D woven architectures were tested. All preforms used AS4 fibers and were resin-transfer-molded with Shell RSL-1895 epoxy resin. Ten categories of material properties were investigated: tension, open-hole tension, compression, open-hole compression, in-plane shear, filled-hole tension, bolt bearing, interlaminar tension, interlaminar shear, and interlaminar fracture toughness. Different test methods and specimen sizes were considered for each category of test. Strength and stiffness properties obtained with each of these methods are documented in this report for all the material systems mentioned above.

Characterizing the stretch-flangeability of hot rolled multiphase steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pathak, N.; Butcher, C.; Worswick, M.

2013-12-16

Hole expansion tests are commonly used to characterize the edge stretching limit of a material. Traditionally, a conical punch is used to expand a punched hole until a through-thickness crack appears. However, many automotive stretch flanging operations involve in-plane edge stretching that is best captured with a flat punch. In this paper, hole expansion tests were carried out on two different hot-rolled multiphase steels using both flat and conical punches. The fracture mechanisms for both punch types were investigated using scanning electron microscopy (SEM)

Numerical relativity waveform surrogate model for generically precessing binary black hole mergers

NASA Astrophysics Data System (ADS)

Blackman, Jonathan; Field, Scott E.; Scheel, Mark A.; Galley, Chad R.; Ott, Christian D.; Boyle, Michael; Kidder, Lawrence E.; Pfeiffer, Harald P.; Szilágyi, Béla

2017-07-01

A generic, noneccentric binary black hole (BBH) system emits gravitational waves (GWs) that are completely described by seven intrinsic parameters: the black hole spin vectors and the ratio of their masses. Simulating a BBH coalescence by solving Einstein's equations numerically is computationally expensive, requiring days to months of computing resources for a single set of parameter values. Since theoretical predictions of the GWs are often needed for many different source parameters, a fast and accurate model is essential. We present the first surrogate model for GWs from the coalescence of BBHs including all seven dimensions of the intrinsic noneccentric parameter space. The surrogate model, which we call NRSur7dq2, is built from the results of 744 numerical relativity simulations. NRSur7dq2 covers spin magnitudes up to 0.8 and mass ratios up to 2, includes all ℓ≤4 modes, begins about 20 orbits before merger, and can be evaluated in ˜50 ms . We find the largest NRSur7dq2 errors to be comparable to the largest errors in the numerical relativity simulations, and more than an order of magnitude smaller than the errors of other waveform models. Our model, and more broadly the methods developed here, will enable studies that were not previously possible when using highly accurate waveforms, such as parameter inference and tests of general relativity with GW observations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Townsend, M., Prothro, L. B., Obi, C.

A test bed for a series of chemical explosives tests known as Source Physics Experiments (SPE) was constructed in granitic rock of the Climax stock, in northern Yucca Flat at the Nevada National Security Site in 2010-2011. These tests are sponsored by the U.S. Department of Energy, National Nuclear Security Administration's National Center for Nuclear Security. The test series is designed to study the generation and propagation of seismic waves, and will provide data that will improve the predictive capability of calculational models for detecting and characterizing underground explosions. Abundant geologic data are available for the area, primarily as amore » result of studies performed in conjunction with the three underground nuclear tests conducted in the Climax granite in the 1960s and a few later studies of various types. The SPE test bed was constructed at an elevation of approximately 1,524 meters (m), and consists of a 91.4-centimeter (cm) diameter source hole at its center, surrounded by two rings of three 20.3-cm diameter instrument holes. The inner ring of holes is positioned 10 m away from the source hole, and the outer ring of holes is positioned 20 m from the source hole. An initial 160-m deep core hole was drilled at the location of the source hole that provided information on the geology of the site and rock samples for later laboratory testing. A suite of geophysical logs was run in the core hole and all six instruments holes to obtain matrix and fracture properties. Detailed information on the character and density of fractures encountered was obtained from the borehole image logs run in the holes. A total of 2,488 fractures were identified in the seven boreholes, and these were ranked into six categories (0 through 5) on the basis of their degree of openness and continuity. The analysis presented here considered only the higher-ranked fractures (ranks 2 through 5), of which there were 1,215 (approximately 49 percent of all fractures identified from borehole image logs). The fractures were grouped into sets based on their orientation. The most ubiquitous fracture set (50 percent of all higher-ranked fractures) is a group of low-angle fractures (dips 0 to 30 degrees). Fractures with dips of 60 to 90 degrees account for 38 percent of high-ranked fractures, and the remaining 12 percent are fractures with moderate dips (30 to 60 degrees). The higher-angle fractures are further subdivided into three sets based on their dip direction: fractures of Set 1 dip to the north-northeast, fractures of Set 2 dip to the south-southwest, and Set 3 consists of high-angle fractures that dip to the southeast and strike northeast. The low-angle fractures (Set 4) dip eastward. Fracture frequency does not appear to change substantially with depth. True fracture spacing averages 0.9 to 1.2 m for high-angle Sets 1, 2, and 3, and 0.6 m for Set 4. Two significant faults were observed in the core, centered at the depths of 25.3 and 32.3 m. The upper of these two faults dips 80 degrees to the north-northeast and, thus, is related to the Set-1 fractures. The lower fault dips 79 degrees to the south-southwest and is related to SPE Set-2 fractures. Neither fault has an identifiable surface trace. Groundwater was encountered in all holes drilled on the SPE test bed, and the fluid level averaged about 15.2 to 18.3 m below ground surface. An informal study of variations in the fluid level in the holes conducted during various phases of construction of the test bed concluded that groundwater flow through the fractured granitic rocks is not uniform, and appears to be controlled by variations in the orientation and degree of interconnectedness of the fractures. It may also be possible that an aplite dike or quartz vein may be present in the test bed, which could act as a barrier to groundwater flow and, thus, could account for anisotropy seen in the groundwater recovery measurements.« less

Method of making organic light emitting devices

DOEpatents

Shiang, Joseph John [Niskayuna, NY; Janora, Kevin Henry [Schenectady, NY; Parthasarathy, Gautam [Saratoga Springs, NY; Cella, James Anthony [Clifton Park, NY; Chichak, Kelly Scott [Clifton Park, NY

2011-03-22

The present invention provides a method for the preparation of organic light-emitting devices comprising a bilayer structure made by forming a first film layer comprising an electroactive material and an INP precursor material, and exposing the first film layer to a radiation source under an inert atmosphere to generate an interpenetrating network polymer composition comprising the electroactive material. At least one additional layer is disposed on the reacted first film layer to complete the bilayer structure. The bilayer structure is comprised within an organic light-emitting device comprising standard features such as electrodes and optionally one or more additional layers serving as a bipolar emission layer, a hole injection layer, an electron injection layer, an electron transport layer, a hole transport layer, exciton-hole transporting layer, exciton-electron transporting layer, a hole transporting emission layer, or an electron transporting emission layer.

Search for gravitational waves from binary black hole inspiral, merger, and ringdown

NASA Astrophysics Data System (ADS)

Abadie, J.; Abbott, B. P.; Abbott, R.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Antonucci, F.; Arain, M. A.; Araya, M. C.; Aronsson, M.; Aso, Y.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Babak, S.; Baker, P.; Ballardin, G.; Ballinger, T.; Ballmer, S.; Barker, D.; Barnum, S.; Barone, F.; Barr, B.; Barriga, P.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Bauchrowitz, J.; Bauer, Th. S.; Behnke, B.; Beker, M. G.; Belletoile, A.; Benacquista, M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birindelli, S.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Boccara, C.; Bock, O.; Bodiya, T. P.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Boyle, M.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Breyer, J.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Budzyński, R.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet-Castell, J.; Burmeister, O.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cain, J.; Calloni, E.; Camp, J. B.; Campagna, E.; Campsie, P.; Cannizzo, J.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chaibi, O.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chassande-Mottin, E.; Chelkowski, S.; Chen, Y.; Chincarini, A.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Clark, D.; Clark, J.; Clayton, J. H.; Cleva, F.; Coccia, E.; Colacino, C. N.; Colas, J.; Colla, A.; Colombini, M.; Conte, R.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coulon, J.-P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Culter, R. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; D'Antonio, S.; Danzmann, K.; Das, K.; Dattilo, V.; Daudert, B.; Davier, M.; Davies, G.; Davis, A.; Daw, E. J.; Day, R.; Dayanga, T.; Derosa, R.; Debra, D.; Debreczeni, G.; Degallaix, J.; Del Prete, M.; Dergachev, V.; de Rosa, R.; Desalvo, R.; Devanka, P.; Dhurandhar, S.; di Fiore, L.; di Lieto, A.; di Palma, I.; di Paolo Emilio, M.; di Virgilio, A.; Díaz, M.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Dorsher, S.; Douglas, E. S. D.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Dueck, J.; Dumas, J.-C.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Ely, G.; Engel, R.; Etzel, T.; Evans, M.; Evans, T.; Fafone, V.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Flaminio, R.; Flanigan, M.; Flasch, K.; Foley, S.; Forrest, C.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Galimberti, M.; Gammaitoni, L.; Garofoli, J. A.; Garufi, F.; Gáspár, M. E.; Gemme, G.; Genin, E.; Gennai, A.; Gholami, I.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Greverie, C.; Grosso, R.; Grote, H.; Grunewald, S.; Guidi, G. M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hall, P.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Hayler, T.; Heefner, J.; Heitmann, H.; Hello, P.; Heng, I. S.; Heptonstall, A. W.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hodge, K. A.; Holt, K.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hoyland, D.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Jaranowski, P.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kanner, J. B.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, H.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Kowalska, I.; Kozak, D.; Krause, T.; Kringel, V.; Krishnamurthy, S.; Krishnan, B.; Królak, A.; Kuehn, G.; Kullman, J.; Kumar, R.; Kwee, P.; Landry, M.; Lang, M.; Lantz, B.; Lastzka, N.; Lazzarini, A.; Leaci, P.; Leong, J.; Leonor, I.; Leroy, N.; Letendre, N.; Li, J.; Li, T. G. F.; Liguori, N.; Lin, H.; Lindquist, P. E.; Lockerbie, N. A.; Lodhia, D.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lu, P.; Luan, J.; Lubiński, M.; Lucianetti, A.; Lück, H.; Lundgren, A. D.; Machenschalk, B.; Macinnis, M.; Mageswaran, M.; Mailand, K.; Majorana, E.; Mak, C.; Maksimovic, I.; Man, N.; Mandel, I.; Mandic, V.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Masserot, A.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIvor, G.; McKechan, D. J. A.; Meadors, G.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Menéndez, D. F.; Mercer, R. A.; Merill, L.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Michel, C.; Milano, L.; Miller, J.; Minenkov, Y.; Mino, Y.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Mohan, M.; Mohanty, S. D.; Mohapatra, S. R. P.; Moraru, D.; Moreau, J.; Moreno, G.; Morgado, N.; Morgia, A.; Morioka, T.; Mors, K.; Mosca, S.; Moscatelli, V.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murray, P. G.; Nash, T.; Nawrodt, R.; Nelson, J.; Neri, I.; Newton, G.; Nishizawa, A.; Nocera, F.; Nolting, D.; Ochsner, E.; O'Dell, J.; Ogin, G. H.; Oldenburg, R. G.; O'Reilly, B.; O'Shaughnessy, R.; Osthelder, C.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Pagliaroli, G.; Palladino, L.; Palomba, C.; Pan, Y.; Pankow, C.; Paoletti, F.; Papa, M. A.; Pardi, S.; Pareja, M.; Parisi, M.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patel, P.; Pathak, D.; Pedraza, M.; Pekowsky, L.; Penn, S.; Peralta, C.; Perreca, A.; Persichetti, G.; Pichot, M.; Pickenpack, M.; Piergiovanni, F.; Pietka, M.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Poggiani, R.; Postiglione, F.; Prato, M.; Predoi, V.; Price, L. R.; Prijatelj, M.; Principe, M.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Quetschke, V.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radke, T.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Rankins, B.; Rapagnani, P.; Raymond, V.; Re, V.; Reed, C. M.; Reed, T.; Regimbau, T.; Reid, S.; Reitze, D. H.; Ricci, F.; Riesen, R.; Riles, K.; Roberts, P.; Robertson, N. A.; Robinet, F.; Robinson, C.; Robinson, E. L.; Rocchi, A.; Roddy, S.; Rolland, L.; Rollins, J.; Romano, J. D.; Romano, R.; Romie, J. H.; Rosińska, D.; Röver, C.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sakata, S.; Sakosky, M.; Salemi, F.; Sammut, L.; Sancho de La Jordana, L.; Sandberg, V.; Sannibale, V.; Santamaría, L.; Santostasi, G.; Saraf, S.; Sassolas, B.; Sathyaprakash, B. S.; Sato, S.; Satterthwaite, M.; Saulson, P. R.; Savage, R.; Schilling, R.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sergeev, A.; Shaddock, D. A.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Singer, A.; Sintes, A. M.; Skelton, G.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Somiya, K.; Sorazu, B.; Speirits, F. C.; Sperandio, L.; Stein, A. J.; Stein, L. C.; Steinlechner, S.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A. S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Szokoly, G. P.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Toncelli, A.; Tonelli, M.; Torre, O.; Torres, C.; Torrie, C. I.; Tournefier, E.; Travasso, F.; Traylor, G.; Trias, M.; Tseng, K.; Turner, L.; Ugolini, D.; Urbanek, K.; Vahlbruch, H.; Vaishnav, B.; Vajente, G.; Vallisneri, M.; van den Brand, J. F. J.; van den Broeck, C.; van der Putten, S.; van der Sluys, M. V.; van Veggel, A. A.; Vass, S.; Vasuth, M.; Vaulin, R.; Vavoulidis, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Veltkamp, C.; Verkindt, D.; Vetrano, F.; Viceré, A.; Villar, A. E.; Vinet, J.-Y.; Vocca, H.; Vorvick, C.; Vyachanin, S. P.; Waldman, S. J.; Wallace, L.; Wanner, A.; Ward, R. L.; Was, M.; Wei, P.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, L.; Willke, B.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Yakushin, I.; Yamamoto, H.; Yamamoto, K.; Yeaton-Massey, D.; Yoshida, S.; Yu, P.; Yvert, M.; Zanolin, M.; Zhang, L.; Zhang, Z.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

2011-06-01

We present the first modeled search for gravitational waves using the complete binary black-hole gravitational waveform from inspiral through the merger and ringdown for binaries with negligible component spin. We searched approximately 2 years of LIGO data, taken between November 2005 and September 2007, for systems with component masses of 1-99M⊙ and total masses of 25-100M⊙. We did not detect any plausible gravitational-wave signals but we do place upper limits on the merger rate of binary black holes as a function of the component masses in this range. We constrain the rate of mergers for 19M⊙≤m1, m2≤28M⊙ binary black-hole systems with negligible spin to be no more than 2.0Mpc-3Myr-1 at 90% confidence.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, B.

A specially designed wire line retrievable continuous coring system cored its initial project wells to total depth in hard rock formations in less than half the time that would have been required by conventional coring rigs. The hybrid wire line coring systems have since been used on other wells in similar lithologies, with a total of 38,000 m (124,640 ft) of hole cored and with penetration rates averaging 2.27 m/hr (7.45 ft/hr). This paper reports that Parker Drilling Co. designed the hybrid rigs and has recently been contracted to wire line core several holes for oil and gas exploration inmore » the Congo. The first core hole has been completed to 1,490 m, and total depth was reached in 21 days. The rig is now being mobilized to a second hole in the Congo.« less

Liners and Low Luminosity AGN in the ROSAT Database

NASA Technical Reports Server (NTRS)

Elvis, Martin; West, Donald K. (Technical Monitor)

2003-01-01

This program has led to a series of papers being written and published in the Astrophysical Journal. Together these papers try to explain major parts of the LINER and low luminosity AGN puzzle. One paper ('Accretion Disk Instabilities, Cold Dark Matter Models, and Their Role in Quasar Evolution', Hatziminaoglou E., Siemiginowska A., & Elvis M., 2001, ApJ, 547, 90) describes an analytical model for the evolution of the quasar luminosity function. By combining the Press-Schechter formalism for the masses of initial structures with the luminosity distribution for a population of single mass black holes given by an unstable accretion disk an almost complete end-to-end physics-based model of quasar evolution is produced. In this model black holes spend 75% of their time in a low accretion state (at L(Edd)). This low state population of black holes is likely to be observed as the LINER and low luminosity AGNs in the local universe. Another paper ('Broad Emission Line Regions in AGN: the Link with the Accretion Power', Nicastro F., 2000, ApJ Letters, 530, L65) gives a physical basis for why low state black holes appear as LINERS. By linking the Lightman-Eardley instability in an accretion disk to the ori.gin of a wind that contains the broad emission line cloud material this model explains the large widths seen in these lines as being the Keplerian velocity of the disk at the instability radius. For LINERS the key is that below an accretion rate of 10(exp -3)M(sub Edd)the Lightman-Eardley instability falls within the innermost stable orbit of the disk, and so leaves the entire disk stable. No wind occurs, and so no broad emission lines are seen. Most LINERS are likely to be black holes in this low state. Tests of this model are being considered.

49 CFR 230.41 - Flexible staybolts with caps.

Code of Federal Regulations, 2012 CFR

2012-10-01

... staybolts that have telltale holes between 3/16 inch and 7/32 inch in diameter, and which extend the entire... or other suitable method, that the telltale holes are open their entire length. Any leakage from these telltale holes during the hydrostatic test indicates that the bolt is broken and must be replaced...

25 CFR 214.13 - Diligence; annual expenditures; mining records.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ores by drilling within 1 year test holes aggregating 2,000 feet unless a sufficient ore body is... of the drill holes, to justify the expenditure, the sinking of a shaft to the ore body, and the... leased premises accurate records of the drilling, redrilling, or deepening of all holes showing the...

30 CFR 77.1501 - Auger mining; inspections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be recorded as provided in paragraph (a) of this section. (c) When an auger hole penetrates an... the collar of the hole by a qualified person using devices approved by the Secretary to determine if... combustion engines shall not be operated in the vicinity of any auger hole in which tests for methane or...

49 CFR 230.41 - Flexible staybolts with caps.

Code of Federal Regulations, 2013 CFR

2013-10-01

... staybolts that have telltale holes between 3/16 inch and 7/32 inch in diameter, and which extend the entire... or other suitable method, that the telltale holes are open their entire length. Any leakage from these telltale holes during the hydrostatic test indicates that the bolt is broken and must be replaced...

25 CFR 214.13 - Diligence; annual expenditures; mining records.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ores by drilling within 1 year test holes aggregating 2,000 feet unless a sufficient ore body is... of the drill holes, to justify the expenditure, the sinking of a shaft to the ore body, and the... leased premises accurate records of the drilling, redrilling, or deepening of all holes showing the...

49 CFR 230.41 - Flexible staybolts with caps.

Code of Federal Regulations, 2011 CFR

2011-10-01

... staybolts that have telltale holes between 3/16 inch and 7/32 inch in diameter, and which extend the entire... or other suitable method, that the telltale holes are open their entire length. Any leakage from these telltale holes during the hydrostatic test indicates that the bolt is broken and must be replaced...

49 CFR 230.41 - Flexible staybolts with caps.

Code of Federal Regulations, 2014 CFR

2014-10-01

... staybolts that have telltale holes between 3/16 inch and 7/32 inch in diameter, and which extend the entire... or other suitable method, that the telltale holes are open their entire length. Any leakage from these telltale holes during the hydrostatic test indicates that the bolt is broken and must be replaced...

Critically Loaded Hole Technology Pilot Collaborative Test Programme.

DTIC Science & Technology

1980-11-01

270 rpm Spindle Speed - 1450 rpm Feed Rate - Manual Feed Rate - Manual Cutting Fluid - Dry Cutting Fluid - Dry Tool Type - Cordia S-18 Tool Type... Cordia S-18 TABLE XI MANUFACTURING DETAILS FOR HIGH AND LOW QUALITY HOLES SELECTED BY THE UNITED KINGDOM HIGH QUALITY LOW QUALITY Pilot Hole: - 1/8 inch

40 CFR 280.21 - Upgrading of existing UST systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sound and free of corrosion holes prior to installing the cathodic protection system; or (ii) The tank... for corrosion holes by conducting two (2) tightness tests that meet the requirements of § 280.43(c... operation of the cathodic protection system; or (iv) The tank is assessed for corrosion holes by a method...

40 CFR 280.21 - Upgrading of existing UST systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sound and free of corrosion holes prior to installing the cathodic protection system; or (ii) The tank... for corrosion holes by conducting two (2) tightness tests that meet the requirements of § 280.43(c... operation of the cathodic protection system; or (iv) The tank is assessed for corrosion holes by a method...

Coal test drilling for the DE-NA-Zin Bisti Area, San Juan County, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, R.W.; Jentgen, R.W.

1980-01-01

From October 1978 to June 1979, the US Geological Survey (USGS) drilled 51 test holes, and cored 9 holes, in the vicinity of the Bisti Trading Post in the southwestern part of the San Juan Basin, San Juan County, New Mexico. The drilling was done in response to expressions of interest received by the Bureau of Land Management concerning coal leasing and, in some places, badlands preservation. The object of the drilling was to determine the depth, thickness, extent, and quality of the coal in the Upper Cretaceous Fruitland Formation in northwest New Mexico. The holes were geophysically logged immediatelymore » after drilling. Resistivity spontaneous-potential, and natural gamma logs were run in all of the holes. A high-resolution density log was also run in all holes drilled before January 13, when a logging unit from the USGS in Albuquerque was available. After January 13, the holes were logged by a USGS unit from Casper, Wyoming that lacked density logging capabilities. At nine locations a second hole was drilled, about 20 ft from the first hole, down to selected coal-bearing intervals and the coal beds were cored. A detailed description of each of the cores is given on the page(s) following the logs for each hole. From these coal cores, 32 intervals were selected and submitted to the Department of Energy in Pittsburgh, Pennsylvania, for analysis.« less

Axial Fatigue Tests at Zero Mean Stress of 24S-T and 75S-T Aluminum-alloy Strips with a Central Circular Hole

NASA Technical Reports Server (NTRS)

Brueggeman, W C; Mayer, M JR

1948-01-01

Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section dropped sharply as the ration D/W was increased from zero to about 0.25. The plain specimens showed quite a pronounced decrease in fatigue strength with increasing width. The holed specimens showed only slight and rather inconclusive evidence of this size effect. The fatigue stress-concentration factor was higher for 75S-T than for 24S-T alloy. Evidence was found that a very small hole would not cause any reduction in fatigue strength.

Annual National Test and Evaluation Conference (27th) Held in Tampa, Florida on March 14-17, 2011

DTIC Science & Technology

2011-03-17

Based Test & Evaluation PETALLINGFRAGMENTATION RADIAL FRACTUREBRITTLE FRACTURE DUCTILE HOLE GROWTH PLUGGING THREAT VELOCITY MATERIAL MATERIAL V50 TYPE...Less Complex Less Costly Testing More Complex More Costly PETALLINGFRAGMENTATION RADIAL FRACTUREBRITTLE FRACTURE DUCTILE HOLE GROWTH PLUGGING...Reversible injuries; medical attention required 3 Serious Fracture of skull, penetration < 2 cm Reversible injuries; hospitalization required 4 Severe

Strength evaluation test of pressureless-sintered silicon nitride at room temperature

NASA Technical Reports Server (NTRS)

Matsusue, K.; Takahara, K.; Hashimoto, R.

1984-01-01

In order to study strength characteristics at room temperature and the strength evaluating method of ceramic materials, the following tests were conducted on pressureless sintered silicon nitride specimens: bending tests, the three tensile tests of rectangular plates, holed plates, and notched plates, and spin tests of centrally holed disks. The relationship between the mean strength of specimens and the effective volume of specimens are examined using Weibull's theory. The effect of surface grinding on the strength of specimens is discussed.

The Black Hole Mass-Bulge Luminosity Relationship for Reverberation-Mapped AGNs in the Near-IR

NASA Astrophysics Data System (ADS)

Nicholas, Emily; Bentz, M. C.

2014-01-01

We present preliminary results for a near-IR M-L scaling relationship for active galaxies in the reverberation sample. We are particularly interested in the effect of host-galaxy morphology on the M-L scaling relationship. In order to study evolution over cosmic time we must employ scaling relations, which are calibrated to the direct methods of black hole mass measurement and rely on correlations between host galaxy properties and black hole masses. However, it remains uncertain which scaling relation most reliably predicts black hole masses based on host galaxy observables. Recent studies of the M- relationship have uncovered a possible offset in the relationship due to the presence of a pseudobulge or bar in the host galaxy. This offset would adversely affect one's ability to use the M-relationship as a way to estimate black hole masses efficiently because it would require the detailed morphology of the galaxy to be known a priori. Preliminary results based on optical HST data suggest that the M-L relation for active galaxies with reverberation-based black hole masses is not plagued by the same offsets. However, due to dust and on-going star formation, the optical data yield an M-L relationship with a slightly higher scatter than the M- relation. We have carried out near-IR imaging with the WIYN High-Resolution Infrared Camera (WHIRC) on the WIYN telescope to minimize the effects of dust and star formation in order to test whether the M-L relationship is a more accurate predictor of black hole masses and a potentially more fundamental relationship. The imaging campaign has been completed, and we are currently in the process of carefully modeling the galaxy surface brightness features so that we can accurately remove the contribution from the point spread function of the active nucleus. We present our preliminary results here, and we expect that the final results will prove to be quite useful in conjunction with future large imaging surveys, such as LSST, which have no dedicated spectroscopic component. Our team is also in the process of improving distance measurements to these galaxies, which could potentially help to decrease the scatter in bulge luminosity measurements for the reverberation sample.

Summary and interpretation of dye-tracer tests to investigate the hydraulic connection of fractures at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Kentucky

USGS Publications Warehouse

Taylor, Charles J.

1994-01-01

Dye-tracer tests were done during 1985-92 to investigate the hydraulic connection between fractures in Pennsylvanian coal-bearing strata at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Ky. Fluorescent dye was injected into a core hole penetrating near-surface and mining-induced fractures near the crest of the ridge. The rate and direction of migration of dye in the subsurface were determined by measuring the relative concentration of dye in water samples collected from piezometers completed in conductive fracture zones and fractured coal beds at various stratigraphic horizons within the ridge. Dye-concentration data and water-level measurements for each piezometer were plotted as curves on dye-recovery hydrographs. The dye-recovery hydrographs were used to evaluate trends in the fluctuation of dye concentrations and hydraulic heads in order to identify geologic and hydrologic factors affecting the subsurface transport of dye. The principal factors affecting the transport of dye in the subsurface hydrologic system were determined to be (1) the distribution, interconnection, and hydraulic properties of fractures; (2) hydraulic-head conditions in the near-fracture zone at the time of dye injection; and (3) subsequent short- and long-term fluctuations in recharge to the hydrologic system. In most of the dye-tracer tests, dye-recovery hydrographs are characterized by complex, multipeaked dye-concentration curves that are indicative of a splitting of dye flow as ground water moved through fractures. Intermittent dye pulses (distinct upward spikes in dye concentration) mark the arrivals of dye-labeled water to piezometers by way of discrete fracture-controlled flow paths that vary in length, complexity, and hydraulic conductivity. Dye injections made during relatively high- or increasinghead conditions resulted in rapid transport of dye (within several days or weeks) from near-surf ace fractures to piezometers. Injections made during relatively low- or decreasing-head conditions resulted in dye being trapped in hydraulically dead zones in water-depleted fractures. Residual dye was remobilized from storage and transported (over periods ranging from several months to about 2 years) by increased recharge to the hydrologic system. Subsequent fluctuations in hydraulic gradients, resulting from increases or decreases in recharge to the hydrologic system, acted to speed or slow the transport of dye along the fracture-controlled flow paths. The dye-tracer tests also demonstrated that mining-related disturbances significantly altered the natural fracture-controlled flow paths of the hydrologic system over time. An abandoned underground mine and subsidence-related surface cracks extend to within 250 ft of the principal dye-injection core hole. Results from two of the dye-tracer tests at the site indicate that the annular seal in the core hole was breached by subsurface propagation of the mining-induced fractures. This propagation of fractures resulted in hydraulic short-circuiting between the dye-injection zone in the core hole and two lower piezometer zones, and a partial disruption of the hydraulic connection between the injection core hole and downgradient piezometers on the ridge crest and valley wall. In addition, injected dye was detected in piezometers monitoring a flooded part of the abandoned underground mine. Dye was apparently transported into the mine through a hydraulic connection between the injection core hole and subsidence-related fractures.

The implementation of the integrated design process in the hole-plan system

NASA Astrophysics Data System (ADS)

Ruy, Won-Sun; Ko, Dae-Eun; Yang, Young-Soon

2012-12-01

All current shipyards are using the customized CAD/CAM programs in order to improve the design quality and increase the design efficiency. Even though the data structures for ship design and construction are almost completed, the implementation related to the ship design processes are still in progress so that it has been the main causes of the bottleneck and delay during the middle of design process. In this study, we thought that the hole-plan system would be a good example which is remained to be improved. The people of outfitting division who don't have direct authority to edit the structural panels, should request the hull design division to install the holes for the outfitting equipment. For acceptance, they should calculate the hole position, determine the hole type, and find the intersected contour of panel. After consideration of the hull people, the requested holes are manually installed on the hull structure. As the above, many processes are needed such as communication and discussion between the divisions, drawings for hole-plan, and the consideration for the structural or production compatibility. However this iterative process takes a lot of working time and requires mental pressure to the related people and cross-division conflict. This paper will handle the hole-plan system in detail to automate the series of process and minimize the human efforts and time-consumption.

KSC-99pc0172

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), the overhead crane lifts Chandra X-ray Observatory completely out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

A Novel Approach to Turbulence Stimulation for Ship-Model Testing

DTIC Science & Technology

2010-05-11

surface. These holes were either part of the manufacturing of the plate or unused holes drilled for probes. To fill these holes, an epoxy -based...mixture was used, which was applied over a hole and the surrounding surfaces. Once the epoxy had cured, the model was wet sanded with several different...Suboff model is a generic submarine form developed by using two separate parabolic formulae for the bow and stern sections (Stettler, 2009). The 2-D

Apparatus for advancing a wellbore using high power laser energy

DOEpatents

Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

2014-09-02

Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

Novel Acoustic Scattering Processes for Target Discrimination

DTIC Science & Technology

2014-12-31

Woods Hole Oceanographic Institution. WORK COMPLETED During FY10, in addition to La Follett’s thesis [6] a publication appeared based primarily on...function of tilt angle is very similar to the case in which the cylinder is hung adjacent to a flat floating platform of closed-cell extruded ...departed during FY10 who are currently employed at NSWC-PCD and remain involved in related research. Dr. Baik [5] is currently a postdoc at Woods Hole

Conformally flat black hole initial data with one cylindrical end

NASA Astrophysics Data System (ADS)

Gabach Clément, María E.

2010-06-01

We give a complete analytical proof of the existence and uniqueness of extreme-like black hole initial data for Einstein equations, which possess a cylindrical end, analogous to extreme Kerr, extreme Reissner-Nördstrom and extreme Bowen-York's initial data. This extends and refines a previous result (Dain and Clement 2009 Class. Quantum Grav. 26 035020) to a general case of conformally flat, maximal initial data with angular momentum, linear momentum and matter.

Automated Detection and Closing of Holes in Aerial Point Clouds Using AN Uas

NASA Astrophysics Data System (ADS)

Fiolka, T.; Rouatbi, F.; Bender, D.

2017-08-01

3D terrain models are an important instrument in areas like geology, agriculture and reconnaissance. Using an automated UAS with a line-based LiDAR can create terrain models fast and easily even from large areas. But the resulting point cloud may contain holes and therefore be incomplete. This might happen due to occlusions, a missed flight route due to wind or simply as a result of changes in the ground height which would alter the swath of the LiDAR system. This paper proposes a method to detect holes in 3D point clouds generated during the flight and adjust the course in order to close them. First, a grid-based search for holes in the horizontal ground plane is performed. Then a check for vertical holes mainly created by buildings walls is done. Due to occlusions and steep LiDAR angles, closing the vertical gaps may be difficult or even impossible. Therefore, the current approach deals with holes in the ground plane and only marks the vertical holes in such a way that the operator can decide on further actions regarding them. The aim is to efficiently create point clouds which can be used for the generation of complete 3D terrain models.

Study of pharmacological activities of methanol extract of Jatropha gossypifolia fruits

PubMed Central

Apu, Apurba Sarker; Hossain, Faruq; Rizwan, Farhana; Bhuyan, Shakhawat Hossan; Matin, Maima; Jamaluddin, A.T.M

2012-01-01

Objective: The present study was carried out to investigate the possible in vivo analgesic, neuropharmacological and anti-diarrheal activities of the methanol extract of Jatropha gossypifolia fruits. Materials and Methods: The analgesic activity was measured by acetic acid induced writhing inhibition test. The neuropharmacological activities were evaluated by hole cross, hole-board, and elevated plus-maze (EPM) tests and the anti-diarrheal activity was assessed by castor oil induced diarrhea inhibition method. Findings: The extract showed highly significant (P < 0.001) analgesic activity with % inhibitions of writhing response at doses 200 and 400 mg/kg body weight were 77.86% and 71.25%, respectively. The extract at both doses showed significant (P < 0.05) sedative effect in-hole cross test. In-hole board test, the extract showed highly significant (P < 0.001) anxiolytic activity at lower dose whereas this activity was observed at higher dose in EPM test. The extract also showed highly significant (P < 0.001) anti-diarrheal activity. Conclusion: The findings of the study clearly indicate the presence of significant analgesic, neuropharmacological and anti-diarrheal properties of the plant, which demands further investigation including, compound isolation. PMID:24808665

Testing the Binary Black Hole Nature of a Compact Binary Coalescence

NASA Astrophysics Data System (ADS)

Krishnendu, N. V.; Arun, K. G.; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

A QUANTITATIVE TEST OF THE NO-HAIR THEOREM WITH Sgr A* USING STARS, PULSARS, AND THE EVENT HORIZON TELESCOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Psaltis, Dimitrios; Wex, Norbert; Kramer, Michael

The black hole in the center of the Milky Way, Sgr A*, has the largest mass-to-distance ratio among all known black holes in the universe. This property makes Sgr A* the optimal target for testing the gravitational no-hair theorem. In the near future, major developments in instrumentation will provide the tools for high-precision studies of its spacetime via observations of relativistic effects in stellar orbits, in the timing of pulsars, and in horizon-scale images of its accretion flow. We explore here the prospect of measuring the properties of the black hole spacetime using all of these three types of observations.more » We show that the correlated uncertainties in the measurements of the black hole spin and quadrupole moment using the orbits of stars and pulsars are nearly orthogonal to those obtained from measuring the shape and size of the shadow the black hole casts on the surrounding emission. Combining these three types of observations will therefore allow us to assess and quantify systematic biases and uncertainties in each measurement and lead to a highly accurate, quantitative test of the gravitational no-hair theorem.« less

Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

PubMed

Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

Electromagnetic perturbations of black holes in general relativity coupled to nonlinear electrodynamics

NASA Astrophysics Data System (ADS)

Toshmatov, Bobir; Stuchlík, Zdeněk; Schee, Jan; Ahmedov, Bobomurat

2018-04-01

The electromagnetic (EM) perturbations of the black hole solutions in general relativity coupled to nonlinear electrodynamics (NED) are studied for both electrically and magnetically charged black holes, assuming that the EM perturbations do not alter the spacetime geometry. It is shown that the effective potentials of the electrically and magnetically charged black holes related to test perturbative NED EM fields are related to the effective metric governing the photon motion, contrary to the effective potential of the linear electrodynamic (Maxwell) field that is related to the spacetime metric. Consequently, corresponding quasinormal (QN) frequencies differ as well. As a special case, we study new family of the NED black hole solutions which tend in the weak field limit to the Maxwell field, giving the Reissner-Nordström (RN) black hole solution. We compare the NED Maxwellian black hole QN spectra with the RN black hole QN spectra.

Thermal stress measurement in continuous welded rails using the hole-drilling method

NASA Astrophysics Data System (ADS)

Zhu, Xuan; Lanza di Scalea, Francesco; Fateh, Mahmood

2016-04-01

The absence of expansion joints in Continuous Welded Rail (CWR) has created the need for the railroad industry to determine the in-situ level of thermal stresses so as to prevent train accidents caused by rail buckling in hot weather and by rail breakage in cold weather. The development of non-destructive or semi-destructive methods for determining the level of thermal stresses in rails is today a high research priority. This study explores the known hole-drilling method as a possible solution to this problem. A new set of calibration coefficients to compute the relieved stress field with the finer hole depth increments was determined by a 3D Finite Element Analysis that modeled the entire hole geometry, including the mechanics of the hole bottom and walls. To compensate the residual stress components, a linear relationship was experimentally established between the longitudinal and the vertical residual stresses of two common sizes of rails, the 136RE and the 141RE, with statistical significance. This result was then utilized to isolate the longitudinal thermal stress component in hole-drilling tests conducted on the 136RE and 141RE thermally-loaded rails at the Large-scale CWR Test-bed of UCSD's Powell Research Laboratories. The results from the Test-bed showed that the hole-drilling procedure, with the appropriate residual stress compensation, can indeed estimate the in-situ thermal stresses to achieve a +/-5°F accuracy of Neutral Temperature determination with a 90% statistical confidence, which is the desired industry gold standard.

Preparation and properties of evaporated CdTe films compared with single crystal CdTe. Progress report No. 3, May 1-July 31, 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bube, R.H.

1981-01-01

Preparation of the hot-wall vacuum deposition system nears completion and the first trial evaporation should take place in mid October. A UTI 100C Mass Analyzer with a 1 to 300 AMU capability has been ordered for the system. Preliminary tests indicate good temperature tracking between the furnace core and the CdTe source itself. Homojunction cells prepared by HWVE deposition of n-CdTe on p-CdTe substrates in October 1980 show no significant change in dark or light properties after open-circuit storage for the next 9 months. CdTe single crystal boules have been grown with P, As and Cs impurity. For P impuritymore » it appears from our data that the segregation coefficient is close to unity, that the value of hole density is controlled by the P and not by some unknown background acceptor, and that growth with excess Cd gives slightly higher values of hole density than growth with excess Te. CdTe:As crystals appear similar to CdTe:P crystals.« less

Evaluation of four biodegradable, injectable bone cements in an experimental drill hole model in sheep.

PubMed

von Rechenberg, Brigitte; Génot, Oliver R; Nuss, Katja; Galuppo, Larry; Fulmer, Mark; Jacobson, Evan; Kronen, Peter; Zlinszky, Kati; Auer, Jörg A

2013-09-01

Four cement applications were tested in this investigation. Two dicalcium phosphate dihydrate (DCPD-brushite) hydraulic cements, an apatite hydraulic fiber loaded cement, and a calcium sulfate cement (Plaster of Paris) were implanted in epiphyseal and metaphyseal cylindrical bone defects in sheep. The in vivo study was performed to assess the biocompatibility and bone remodeling of four cement formulations. After time periods of 2, 4, and 6 months, the cement samples were clinically and histologically evaluated. Histomorphometrically, the amount of new bone formation, fibrous tissue, and bone marrow and the area of remaining cement were measured. In all specimens, no signs of inflammation were detectable either macroscopically or microscopically. Cements differed mainly in their resorption time. Calcium sulfate was already completely resorbed at 2 months and showed a variable amount of new bone formation and/or fibrous tissue in the original drill hole over all time periods. The two DCPD cements in contrast were degraded to a large amount at 6 months, whereas the apatite was almost unchanged over all time periods. Copyright © 2013. Published by Elsevier B.V.

Sgr A* and general relativity

NASA Astrophysics Data System (ADS)

Johannsen, Tim

2016-06-01

General relativity has been widely tested in weak gravitational fields but still stands largely untested in the strong-field regime. According to the no-hair theorem, black holes in general relativity depend only on their masses and spins and are described by the Kerr metric. Mass and spin are the first two multipole moments of the Kerr spacetime and completely determine all higher-order moments. The no-hair theorem and, hence, general relativity can be tested by measuring potential deviations from the Kerr metric affecting such higher-order moments. Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, is a prime target for precision tests of general relativity with several experiments across the electromagnetic spectrum. First, near-infrared (NIR) monitoring of stars orbiting around Sgr A* with current and new instruments is expected to resolve their orbital precessions. Second, timing observations of radio pulsars near the Galactic center may detect characteristic residuals induced by the spin and quadrupole moment of Sgr A*. Third, the event horizon telescope, a global network of mm and sub-mm telescopes, aims to study Sgr A* on horizon scales and to image the silhouette of its shadow cast against the surrounding accretion flow using very-long baseline interferometric (VLBI) techniques. Both NIR and VLBI observations may also detect quasiperiodic variability of the emission from the accretion flow of Sgr A*. In this review, I discuss our current understanding of the spacetime of Sgr A* and the prospects of NIR, timing, and VLBI observations to test its Kerr nature in the near future.

49 CFR 229.31 - Main reservoir tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... chief mechanical officer may be drilled over its entire surface with telltale holes that are three-sixteenths of an inch in diameter. The holes shall be spaced not more than 12 inches apart, measured both... formula— D = (.6PR/S-0.6P) Where: D = extreme depth of telltale holes in inches but in no case less than...

16 CFR § 1511.3 - Guard or shield requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... those of Figure 1(a) by such a force shall fail the test in this part. (b) Ventilation holes. The pacifier guard or shield shall contain at least two holes symmetrically located and each being at least 0.20 inches (5 millimeters) in minor dimension. The edge of any hole shall be no closer than 0.20...

16 CFR 1511.3 - Guard or shield requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... those of Figure 1(a) by such a force shall fail the test in this part. (b) Ventilation holes. The pacifier guard or shield shall contain at least two holes symmetrically located and each being at least 0.20 inches (5 millimeters) in minor dimension. The edge of any hole shall be no closer than 0.20...

40 CFR 60.113b - Testing and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

...), prior to filling the storage vessel with VOL. If there are holes, tears, or other openings in the..., or the seal is detached, or there are holes or tears in the seal fabric, the owner or operator shall... has defects, the primary seal has holes, tears, or other openings in the seal or the seal fabric, or...

Thermodynamic phase transition in the rainbow Schwarzschild black hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gim, Yongwan; Kim, Wontae, E-mail: yongwan89@sogang.ac.kr, E-mail: wtkim@sogang.ac.kr

2014-10-01

We study the thermodynamic phase transition in the rainbow Schwarzschild black hole where the metric depends on the energy of the test particle. Identifying the black hole temperature with the energy from the modified dispersion relation, we obtain the modified entropy and thermodynamic energy along with the modified local temperature in the cavity to provide well defined black hole states. It is found that apart from the conventional critical temperature related to Hawking-Page phase transition there appears an additional critical temperature which is of relevance to the existence of a locally stable tiny black hole; however, the off-shell free energymore » tells us that this black hole should eventually tunnel into the stable large black hole. Finally, we discuss the reason why the temperature near the horizon is finite in the rainbow black hole by employing the running gravitational coupling constant, whereas it is divergent near the horizon in the ordinary Schwarzschild black hole.« less

Efficient Creation of Overset Grid Hole Boundaries and Effects of Their Locations on Aerodynamic Loads

NASA Technical Reports Server (NTRS)

Chan, William Machado; Pandya, Shishir Ashok; Rogers, Stuart E.

2013-01-01

Recent developments on the automation of the X-rays approach to hole-cutting in over- set grids is further improved. A fast method to compute an auxiliary wall-distance function used in providing a rst estimate of the hole boundary location is introduced. Subsequent iterations lead to automatically-created hole boundaries with a spatially-variable o set from the minimum hole. For each hole boundary location, an averaged cell attribute measure over all fringe points is used to quantify the compatibility between the fringe points and their respective donor cells. The sensitivity of aerodynamic loads to di erent hole boundary locations and cell attribute compatibilities is investigated using four test cases: an isolated re-entry capsule, a two-rocket con guration, the AIAA 4th Drag Prediction Workshop Common Research Model (CRM), and the D8 \\Double Bubble" subsonic aircraft. When best practices in hole boundary treatment are followed, only small variations in integrated loads and convergence rates are observed for different hole boundary locations.

Cortical Motor Circuits after Piano Training in Adulthood: Neurophysiologic Evidence.

PubMed

Houdayer, Elise; Cursi, Marco; Nuara, Arturo; Zanini, Sonia; Gatti, Roberto; Comi, Giancarlo; Leocani, Letizia

2016-01-01

The neuronal mechanisms involved in brain plasticity after skilled motor learning are not completely understood. We aimed to study the short-term effects of keyboard training in music-naive subjects on the motor/premotor cortex activity and interhemispheric interactions, using electroencephalography and transcranial magnetic stimulation (TMS). Twelve subjects (experimental group) underwent, before and after a two week-piano training: (1) hand-motor function tests: Jamar, grip and nine-hole peg tests; (2) electroencephalography, evaluating the mu rhythm task-related desynchronization (TRD) during keyboard performance; and (3) TMS, targeting bilateral abductor pollicis brevis (APB) and abductor digiti minimi (ADM), to obtain duration and area of ipsilateral silent period (ISP) during simultaneous tonic contraction of APB and ADM. Data were compared with 13 controls who underwent twice these measurements, in a two-week interval, without undergoing piano training. Every subject in the experimental group improved keyboard performance and left-hand nine-hole peg test scores. Pre-training, ISP durations were asymmetrical, left being longer than right. Post-training, right ISPAPB increased, leading to symmetrical ISPAPB. Mu TRD during motor performance became more focal and had a lesser amplitude than in pre-training, due to decreased activity over ventral premotor cortices. No such changes were evidenced in controls. We demonstrated that a 10-day piano-training was associated with balanced interhemispheric interactions both at rest and during motor activation. Piano training, in a short timeframe, may reshape local and inter-hemispheric motor cortical circuits.

Increase in the light collection from a scintillation strip with a hole for the WLS fiber using filling materials of various types

NASA Astrophysics Data System (ADS)

Artikov, A. M.; Baranov, V. Yu.; Budagov, J. A.; Glagolev, V. V.; Davydov, Yu. I.; Kolomoets, V. I.; Simonenko, A. V.; Tereschenko, V. V.; Kharzheev, Yu. N.; Chokheli, D.; Shalyugin, A. N.

2017-01-01

The light collection of extruded scintillation strip samples with the help of WLS fibers placed in a longitudinal hole inside of the plates has been measured. The holes are filled with various liquid fillers. Measurements are performed under irradiation by cosmic muons. A method for pumping a liquid filler with a viscosity of more than 10 Pa s into the strip hole with a WLS fiber inside is devised and successfully tested.

Femoral Iatrogenic Subtrochanteric Fatigue Fracture Risk is not Increased by Placing Drill Holes Below the Level of the Lesser Trochanter.

PubMed

Tsai, Andrew G; Ashworth, Timothy J; Marcus, Randall; Akkus, Ozan

2017-01-01

Iatrogenic subtrochanteric fractures of the femur can occur postoperatively following placement of screws in the lateral femoral cortex. Drilling holes below the lesser trochanter is generally avoided to prevent fatigue failure; however, there is little biomechanical evidence to support this recommendation. We hypothesized that hole placement below the level of the lesser trochanter will not accelerate fatigue failure compared to holes at the level of the lesser trochanter. Twelve matched-pairs of male fresh-frozen cadaveric femurs were used for biomechanical testing. A single screw hole was drilled through the lateral femoral cortex either at the level of the lesser trochanter (proximal-hole group) or below the lesser trochanter (distal-hole group). Each femur was cycled to failure using a physiologically-relevant loading model. Paired t-test was used to evaluate for a difference in cycles to failure between groups. There was no statistical difference in cycles to failure between the groups with the hole drilled at or below the lesser trochanter. The traditional recommendation to avoid drilling holes below the level of the lesser trochanter is based mainly on experience and case reports in the literature. The results of this study indicate that placing holes below the level of the lesser trochanter, in and of itself, may not pose any additional risk of fracture. Other important factors need to be considered, such as tapering of the lateral femoral cortex. There are often situations where the patient's anatomy and facture pattern is more conducive to placing a screw distal to the lesser trochanter. This study may allow surgeons greater flexibility in placing screws more distally in the lateral femoral cortex by demonstrating the safety of doing so, at least in the population studied.

Supermassive Black Hole Binaries in High Performance Massively Parallel Direct N-body Simulations on Large GPU Clusters

NASA Astrophysics Data System (ADS)

Spurzem, R.; Berczik, P.; Zhong, S.; Nitadori, K.; Hamada, T.; Berentzen, I.; Veles, A.

2012-07-01

Astrophysical Computer Simulations of Dense Star Clusters in Galactic Nuclei with Supermassive Black Holes are presented using new cost-efficient supercomputers in China accelerated by graphical processing cards (GPU). We use large high-accuracy direct N-body simulations with Hermite scheme and block-time steps, parallelised across a large number of nodes on the large scale and across many GPU thread processors on each node on the small scale. A sustained performance of more than 350 Tflop/s for a science run on using simultaneously 1600 Fermi C2050 GPUs is reached; a detailed performance model is presented and studies for the largest GPU clusters in China with up to Petaflop/s performance and 7000 Fermi GPU cards. In our case study we look at two supermassive black holes with equal and unequal masses embedded in a dense stellar cluster in a galactic nucleus. The hardening processes due to interactions between black holes and stars, effects of rotation in the stellar system and relativistic forces between the black holes are simultaneously taken into account. The simulation stops at the complete relativistic merger of the black holes.

Evidence of Electron-Hole Imbalance in WTe2 from High-Resolution Angle-Resolved Photoemission Spectroscopy

NASA Astrophysics Data System (ADS)

Wang, Chen-Lu; Zhang, Yan; Huang, Jian-Wei; Liu, Guo-Dong; Liang, Ai-Ji; Zhang, Yu-Xiao; Shen, Bing; Liu, Jing; Hu, Cheng; Ding, Ying; Liu, De-Fa; Hu, Yong; He, Shao-Long; Zhao, Lin; Yu, Li; Hu, Jin; Wei, Jiang; Mao, Zhi-Qiang; Shi, You-Guo; Jia, Xiao-Wen; Zhang, Feng-Feng; Zhang, Shen-Jin; Yang, Feng; Wang, Zhi-Min; Peng, Qin-Jun; Xu, Zu-Yan; Chen, Chuang-Tian; Zhou, Xing-Jiang

2017-08-01

WTe2 has attracted a great deal of attention because it exhibits extremely large and nonsaturating magnetoresistance. The underlying origin of such a giant magnetoresistance is still under debate. Utilizing laser-based angle-resolved photoemission spectroscopy with high energy and momentum resolutions, we reveal the complete electronic structure of WTe2. This makes it possible to determine accurately the electron and hole concentrations and their temperature dependence. We find that, with increasing the temperature, the overall electron concentration increases while the total hole concentration decreases. It indicates that the electron-hole compensation, if it exists, can only occur in a narrow temperature range, and in most of the temperature range there is an electron-hole imbalance. Our results are not consistent with the perfect electron-hole compensation picture that is commonly considered to be the cause of the unusual magnetoresistance in WTe2. We identified a flat band near the Brillouin zone center that is close to the Fermi level and exhibits a pronounced temperature dependence. Such a flat band can play an important role in dictating the transport properties of WTe2. Our results provide new insight on understanding the origin of the unusual magnetoresistance in WTe2.

Propagation of flexural waves in inhomogeneous plates exhibiting hysteretic nonlinearity: Nonlinear acoustic black holes.

PubMed

Gusev, Vitalyi E; Ni, Chenyin; Lomonosov, Alexey; Shen, Zhonghua

2015-08-01

Theory accounting for the influence of hysteretic nonlinearity of micro-inhomogeneous material on flexural wave in the plates of continuously varying thickness is developed. For the wedges with thickness increasing as a power law of distance from its edge strong modifications of the wave dynamics with propagation distance are predicted. It is found that nonlinear absorption progressively disappearing with diminishing wave amplitude leads to complete attenuation of acoustic waves in most of the wedges exhibiting black hole phenomenon. It is also demonstrated that black holes exist beyond the geometrical acoustic approximation. Applications include nondestructive evaluation of micro-inhomogeneous materials and vibrations damping. Copyright © 2015 Elsevier B.V. All rights reserved.

Low resistivity ZnO-GO electron transport layer based CH{sub 3}NH{sub 3}PbI{sub 3} solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Muhammad Imran, E-mail: imranrahbar@scme.nust.edu.pk, E-mail: amirhabib@scme.nust.edu.pk; Hussain, Zakir; Mujahid, Mohammad

Perovskite based solar cells have demonstrated impressive performances. Controlled environment synthesis and expensive hole transport material impede their potential commercialization. We report ambient air synthesis of hole transport layer free devices using ZnO-GO as electron selective contacts. Solar cells fabricated with hole transport layer free architecture under ambient air conditions with ZnO as electron selective contact achieved an efficiency of 3.02%. We have demonstrated that by incorporating GO in ZnO matrix, low resistivity electron selective contacts, critical to improve the performance, can be achieved. We could achieve max efficiency of 4.52% with our completed devices for ZnO: GO composite. Impedancemore » spectroscopy confirmed the decrease in series resistance and an increase in recombination resistance with inclusion of GO in ZnO matrix. Effect of temperature on completed devices was investigated by recording impedance spectra at 40 and 60 {sup o}C, providing indirect evidence of the performance of solar cells at elevated temperatures.« less

Sky Localization of Complete Inspiral-Merger-Ringdown Signals for Nonspinning Black Hole Binaries with LISA

NASA Technical Reports Server (NTRS)

McWilliams, Sean T.; Lang, Ryan N.; Baker, John G.; Thorpe, James Ira

2011-01-01

We investigate the capability of LISA to measure the sky position of equal-mass, nonspinning black hole binaries, including for the first time the entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the complete three-channel LISA response. For an ensemble of systems near the peak of LISA's sensitivity band, with total rest mass of 2 x l0(exp 6) Stellar Mass at a redshift of z = 1 with random orientations and sky positions, we find median sky localization errors of approximately approx. 3 arcminutes. This is comparable to the field of view of powerful electromagnetic telescopes, such as the James Webb Space Telescope, that could be used to search for electromagnetic signals associated with merging black holes. We investigate the way in which parameter errors decrease with measurement time, focusing specifically on the additional information provided during the merger-ringdown segment of the signal. We find that this information improves all parameter estimates directly, rather than through diminishing correlations with any subset of well-determined parameters.

Design and Manufacture of Elastically Tailored Tow Placed Plates

NASA Technical Reports Server (NTRS)

Tatting, Brain F.; Guerdal, Zafer; Jegley, Dawn (Technical Monitor)

2002-01-01

Elastic stiffness tailoring of laminated composite panels by allowing the fibers to curve within the plane of the laminate is a relatively novel design concept that has been demonstrated to be both beneficial and practical. In particular, for structures with highly non-uniform stress states, such as the case of a flat panel with a central hole subjected to in-plane loading, the concept is likely to provide substantial improvements in load carrying capability. The objective of the present study is to determine the effectiveness of stiffness tailoring through the use of curvilinear fibers to reduce stress concentrations around the hole and improve the load carrying capability of panels with holes. In this study software was created that translates standard finite element models with traditional laminate definitions into ones that possess stacking sequences with curvilinear fiber paths that are directly manufacturable using an advanced tow placement machine. Preliminary designs for the manufacturing and testing phase were determined through rudimentary design studies for flat plates without holes under axial compression. These candidate designs were then analyzed using finite element models that accurately reflect the test conditions and geometries in order to select final designs for testing. A total of six large panels, measuring three feet by six feet, each of which are used to produce four specimens with or without holes, were fabricated and delivered to NASA for machining and testing.

Data for ground-water test hole near Butte City, Central Valley aquifer project, California

USGS Publications Warehouse

French, James J.; Page, R.W.; Bertoldi, G.L.

1983-01-01

This report provides preliminary data for the third of seven test holes drilled as part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 32, T. 19 N., R. 1 W., Glenn County, California, about one-half mile south of the town of Butte City. Drilled to a depth of 1,432 feet below land surface, the hole is cased to a depth of 82 feet and equipped with three piezometer tubes to depths of 592 feet, 968 feet, and 1,330 feet. A 5-foot well screen is at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer , and the well bore is filled between the plugs with sediment. Nine cores and 49 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, and chemical quality of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Data for ground-water test hole near Nicolaus, Central Valley aquifer project, California

USGS Publications Warehouse

French, James J.; Page, R.W.; Bertoldi, Gilbert L.

1983-01-01

Preliminary data are provided for the third of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 2, T.12N., R.3E., Sutter County, California, about 1 1/2 miles northwest of the town of Nicolaus. Drilled to a depth of 1,150 feet below land surface, the hole is cased to a depth of 100 feet and equipped with three piezometer tubes to depths of 311, 711, and 1,071 feet. A 5-foot well screen is set in sand at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer, and the well bore is filled between the plugs with sediment. Thirty-one cores and 34 sidewall cores were recovered. Laboratory tests were made for minerology, consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis of the three tapped zones and measured for water level. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Pulsation of black holes

NASA Astrophysics Data System (ADS)

Gao, Changjun; Lu, Youjun; Shen, You-Gen; Faraoni, Valerio

2018-01-01

The Hawking-Penrose singularity theorem states that a singularity forms inside a black hole in general relativity. To remove this singularity one must resort to a more fundamental theory. Using a corrected dynamical equation arising in loop quantum cosmology and braneworld models, we study the gravitational collapse of a perfect fluid sphere with a rather general equation of state. In the frame of an observer comoving with this fluid, the sphere pulsates between a maximum and a minimum size, avoiding the singularity. The exterior geometry is also constructed. There are usually an outer and an inner apparent horizon, resembling the Reissner-Nordström situation. For a distant observer the horizon crossing occurs in an infinite time and the pulsations of the black hole quantum "beating heart" are completely unobservable. However, it may be observable if the black hole is not spherical symmetric and radiates gravitational wave due to the quadrupole moment, if any.

Hawking radiation via anomaly cancellation for the black holes of five-dimensional minimal gauged supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porfyriadis, Achilleas P.

2009-04-15

The anomaly cancellation method proposed by Wilczek et al. is applied to the general charged rotating black holes in five-dimensional minimal gauged supergravity. Thus Hawking temperature and fluxes are found. The Hawking temperature obtained agrees with the surface gravity formula. The black holes have charge and two unequal angular momenta, and these give rise to appropriate terms in the effective U(1) gauge field of the reduced (1+1)-dimensional theory. In particular, it is found that the terms in this U(1) gauge field correspond exactly to the correct electrostatic potential and the two angular velocities on the horizon of the black holes,more » and so the results for the Hawking fluxes derived here from the anomaly cancellation method are in complete agreement with the ones obtained from integrating the Planck distribution.« less

On the on-shell: the action of AdS4 black holes

NASA Astrophysics Data System (ADS)

Halmagyi, Nick; Lal, Shailesh

2018-03-01

We compute the on-shell action of static, BPS black holes in AdS4 from N=2 gauged supergravity coupled to vector multiplets and show that for a certain class it is equal to minus the entropy of the black hole. Holographic renormalization is used to demonstrate that with Neumann boundary conditions on the scalar fields, the divergent and finite contributions from the asymptotic boundary vanish. The entropy arises from the extrinsic curvature on Σ g × S 1 evaluated at the horizon, where Σ g may have any genus g ≥ 0. This provides a clarification of the equivalence between the partition function of the twisted ABJM theory on Σ g × S 1 and the entropy of the dual black hole solutions. It also demonstrates that the complete entropy resides on the AdS2 × Σ g horizon geometry, implying the absence of hair for these gravity solutions.

Early Student Support for Process Studies of Surface Freshwater Dispersal

DTIC Science & Technology

2016-06-24

Hole Oceanographic Institution REPORT NUMBER Department of Physical Oceanography - MS #29 FINAL Woods Hole, MA 02543 9. SPONSORING/MONITORING AGENCY...s proJect supports .e researc m p ysrcal oceanography of a Ph.D. student m the MIT/WHO! Jomt Program. The prOJect beoefited from, and... oceanography and has presented his work at meetings and conferences. He is working on manuscripts for publication and expects to complete his Ph.D. in 20 18

Drilling cost-cutting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capuano, L.E. Jr.

This presentation by Louis E. Capuano, Jr., President, ThermaSource, Inc., discusses cost-cutting in the drilling phase of geothermal energy exploration and production. All aspects of a geothermal project including the drilling must be streamlined to make it viable and commercial. If production could be maximized from each well, there would be a reduction in drilling costs. This could be achieved in several ways, including big hole and multi-hole completion, directional drilling, better knowledge of the resource and where to penetrate, etc.

Fracture Testing of Integral Stiffened Structure

NASA Technical Reports Server (NTRS)

Newman, John A.; Smith, Stephen W.; Piascik, Robert S.; Dawicke, David S.; Johnston, William M.; Willard, Scott A.

2008-01-01

Laboratory testing was conducted to evaluate safety concerns for integrally-stiffened tanks that were found to have developed cracks during pressurization testing. Cracks occurred at fastener holes where additional stiffeners were attached to the integrally-stiffened tank structure. Tests were conducted to obtain material properties and to reproduce the crack morphologies that were observed in service to help determine if the tanks are safe for operation. Reproducing the cracking modes observed during pressurization testing required a complex loading state involving both a tensile load in the integrally-stiffened structure and a pin-load at a fastener hole.

Characteristics of a 30-cm thruster operated with small hole accelerator grid ion optics

NASA Technical Reports Server (NTRS)

Vahrenkamp, R. P.

1976-01-01

Small hole accelerator grid ion optical systems have been tested as a possible means of improving 30-cm ion thruster performance. The effects of small hole grids on the critical aspects of thruster operation including discharge chamber performance, doubly-charged ion concentration, effluent beam characteristics, and plasma properties have been evaluated. In general, small hole accelerator grids are beneficial in improving thruster performance while maintaining low double ion ratios. However, extremely small accelerator aperture diameters tend to degrade beam divergence characteristics. A quantitative discussion of these advantages and disadvantages of small hole accelerator grids, as well as resulting variations in thruster operation characteristics, is presented.

Particle accelerators inside spinning black holes.

PubMed

Lake, Kayll

2010-05-28

On the basis of the Kerr metric as a model for a spinning black hole accreting test particles from rest at infinity, I show that the center-of-mass energy for a pair of colliding particles is generically divergent at the inner horizon. This shows not only that classical black holes are internally unstable, but also that Planck-scale physics is a characteristic feature within black holes at scales much larger that the Planck length. The novel feature of the divergence discussed here is that the phenomenon is present only for black holes with rotation, and in this sense it is distinct from the well-known Cauchy horizon instability.

Black holes and beyond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathur, Samir D., E-mail: mathur.16@osu.edu

The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome 'remnants'. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in themore » bound state. The interior of the black hole gets completely altered to a 'fuzzball' structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates together with ideas about entangled states leads to a natural set of conjectures on many long-standing questions in gravity: the significance of Rindler and de Sitter entropies, the notion of black hole complementarity, and the fate of an observer falling into a black hole. - Highlights: Black-Right-Pointing-Pointer The information paradox is a serious problem. Black-Right-Pointing-Pointer To solve it we need to find 'hair' on black holes. Black-Right-Pointing-Pointer In string theory we find 'hair' by the fuzzball construction. Black-Right-Pointing-Pointer Fuzzballs help to resolve many other issues in gravity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johannsen, Tim; Psaltis, Dimitrios, E-mail: timj@physics.arizona.ed, E-mail: dpsaltis@email.arizona.ed

According to the no-hair theorem, an astrophysical black hole is uniquely described by only two quantities, the mass and the spin. In this series of papers, we investigate a framework for testing the no-hair theorem with observations of black holes in the electromagnetic spectrum. We formulate our approach in terms of a parametric spacetime which contains a quadrupole moment that is independent of both mass and spin. If the no-hair theorem is correct, then any deviation of the black hole quadrupole moment from its Kerr value has to be zero. We analyze in detail the properties of this quasi-Kerr spacetimemore » that are critical to interpreting observations of black holes and demonstrate their dependence on the spin and quadrupole moment. In particular, we show that the location of the innermost stable circular orbit and the gravitational lensing experienced by photons are affected significantly at even modest deviations of the quadrupole moment from the value predicted by the no-hair theorem. We argue that observations of black hole images, of relativistically broadened iron lines, as well as of thermal X-ray spectra from accreting black holes will lead in the near future to an experimental test of the no-hair theorem.« less

Holographic entanglement entropies for Schwarzschild and Reisner-Nordström black holes in asymptotically Minkowski spacetimes

NASA Astrophysics Data System (ADS)

Sun, Yuan; Zhao, Liu

2017-04-01

Holographic entanglement entropies (HEE) associated with four-dimensional Schwarzschild and Reisner-Nordström (RN) black holes in asymptotically Minkowski spacetimes are investigated. Unlike the cases of asymptotically AdS spacetimes for which the boundaries are always taken at (timelike) conformal infinities, we take the boundaries at either large but finite radial coordinates (far boundary) or very close to the black hole event horizons (near horizon boundary). The reason for such choices is that such boundaries are similar to the conformal infinity of AdS spacetime in that they are all timelike, so that there may be some hope to define dual systems with ordinary time evolution on such boundaries. Our results indicate that, in the case of far boundaries, the leading-order contribution to HEEs comes from the background Minkowski spacetime; however, the next-to-leading-order contribution which arises from the presence of the black holes is always proportional to the black hole mass, which constitutes a version of the first law of HEE for asymptotically flat spacetimes, and the higher-order contributions are always negligibly small. In the case of near horizon boundaries, the leading-order contribution to HEE is always proportional to the area of the black hole event horizon, and the case of extremal RN black holes is distinguished from the cases of nonextremal black holes in that the minimal surface defining HEE is completely immersed inside the boundary up to the second order in the perturbative expansion.

Black hole formation in a contracting universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quintin, Jerome; Brandenberger, Robert H., E-mail: jquintin@physics.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca

We study the evolution of cosmological perturbations in a contracting universe. We aim to determine under which conditions density perturbations grow to form large inhomogeneities and collapse into black holes. Our method consists in solving the cosmological perturbation equations in complete generality for a hydrodynamical fluid. We then describe the evolution of the fluctuations over the different length scales of interest and as a function of the equation of state for the fluid, and we explore two different types of initial conditions: quantum vacuum and thermal fluctuations. We also derive a general requirement for black hole collapse on sub-Hubble scales,more » and we use the Press-Schechter formalism to describe the black hole formation probability. For a fluid with a small sound speed (e.g., dust), we find that both quantum and thermal initial fluctuations grow in a contracting universe, and the largest inhomogeneities that first collapse into black holes are of Hubble size and the collapse occurs well before reaching the Planck scale. For a radiation-dominated fluid, we find that no black hole can form before reaching the Planck scale. In the context of matter bounce cosmology, it thus appears that only models in which a radiation-dominated era begins early in the cosmological evolution are robust against the formation of black holes. Yet, the formation of black holes might be an interesting feature for other models. We comment on a number of possible alternative early universe scenarios that could take advantage of this feature.« less

A 15.65-solar-mass black hole in an eclipsing binary in the nearby spiral galaxy M 33.

PubMed

Orosz, Jerome A; McClintock, Jeffrey E; Narayan, Ramesh; Bailyn, Charles D; Hartman, Joel D; Macri, Lucas; Liu, Jiefeng; Pietsch, Wolfgang; Remillard, Ronald A; Shporer, Avi; Mazeh, Tsevi

2007-10-18

Stellar-mass black holes are found in X-ray-emitting binary systems, where their mass can be determined from the dynamics of their companion stars. Models of stellar evolution have difficulty producing black holes in close binaries with masses more than ten times that of the Sun (>10; ref. 4), which is consistent with the fact that the most massive stellar black holes known so far all have masses within one standard deviation of 10. Here we report a mass of (15.65 +/- 1.45) for the black hole in the recently discovered system M 33 X-7, which is located in the nearby galaxy Messier 33 (M 33) and is the only known black hole that is in an eclipsing binary. To produce such a massive black hole, the progenitor star must have retained much of its outer envelope until after helium fusion in the core was completed. On the other hand, in order for the black hole to be in its present 3.45-day orbit about its (70.0 +/- 6.9) companion, there must have been a 'common envelope' phase of evolution in which a significant amount of mass was lost from the system. We find that the common envelope phase could not have occurred in M 33 X-7 unless the amount of mass lost from the progenitor during its evolution was an order of magnitude less than what is usually assumed in evolutionary models of massive stars.

Numerical Researches on Dynamical Systems with Relativistic Spin

NASA Astrophysics Data System (ADS)

Han, W. B.

2010-04-01

It is well known that spinning compact binaries are one of the most important research objects in the universe. Especially, EMRIs (extreme mass ratio inspirals) involving stellar compact objects which orbit massive black holes, are considered to be primary sources of gravitational radiation (GW) which could be detected by the space-based interferometer LISA. GW signals from EMRIs can be used to test general relativity, measure the masses and spins of central black holes and study essential physics near horizons. Compared with the situation without spin, the complexity of extreme objects, most of which rotate very fast, is much higher. So the dynamics of EMRI systems are numerically and analytically studied. We focus on how the spin effects on the dynamics of these systems and the produced GW radiations. Firstly, an ideal model of spinning test particles around Kerr black hole is considered. For equatorial orbits, we present the correct expression of effective potential and analyze the stability of circular orbits. Especially, the gravitational binding energy and frame-dragging effect of extreme Kerr black hole are much bigger than those without spin. For general orbits, spin can monotonically enlarge orbital inclination and destroy the symmetry of orbits about equatorial plane. It is the most important that extreme spin can produce orbital chaos. By carefully investigating the relations between chaos and orbital parameters, we point out that chaos usually appears for orbits with small pericenter, big eccentricity and orbital inclination. It is emphasized that Poincaré section method is invalid to detect the chaos of spinning particles, and the way of systems toward chaos is the period-doubling bifurcation. Furthermore, we study how spins effect on GW radiations from spinning test particles orbiting Kerr black holes. It is found that spins can increase orbit eccentricity and then make h+ component be detected more easily. But for h× component, because spins change orbital inclination in a complicated way, it is more difficult to build GW signal templates. Secondly, based on the scalar gravity theory, a numerical relativistic model of EMRIs is constructed to consider the self-gravity and radiation reaction of low-mass objects. Finally, we develop a new method with multiple steps for Hamilton systems to meet the needs of numerical researches. This method can effectively maintain each conserved quantity of the separable Hamilton system. In addition, for constrained system with a few first integrals, we present a new numerical stabilization method named as adjustment-stabilization method, which can maintain all known conserved quantities in a given dynamical system and greatly improve the numerical accuracy. Our new method is the most complete stabilization method up to now.

Self-Advancing Step-Tap Drills

NASA Technical Reports Server (NTRS)

Pettit, Donald R.; Camarda, Charles J.; Penner, Ronald K.; Franklin, Larry D.

2007-01-01

Self-advancing tool bits that are hybrids of drills and stepped taps make it possible to form threaded holes wider than about 1/2 in. (about 13 mm) without applying any more axial force than is necessary for forming narrower pilot holes. These self-advancing stepped-tap drills were invented for use by space-suited astronauts performing repairs on reinforced carbon/carbon space-shuttle leading edges during space walks, in which the ability to apply axial drilling forces is severely limited. Self-advancing stepped-tap drills could also be used on Earth for making wide holes without applying large axial forces. A self-advancing stepped-tap drill (see figure) includes several sections having progressively larger diameters, typically in increments between 0.030 and 0.060 in. (between about 0.8 and about 1.5 mm). The tip section, which is the narrowest, is a pilot drill bit that typically has a diameter between 1/8 and 3/16 in. (between about 3.2 and about 4.8 mm). The length of the pilot-drill section is chosen, according to the thickness of the object to be drilled and tapped, so that the pilot hole is completed before engagement of the first tap section. Provided that the cutting-edge geometry of the drill bit is optimized for the material to be drilled, only a relatively small axial force [typically of the order of a few pounds (of the order of 10 newtons)] must be applied during drilling of the pilot hole. Once the first tap section engages the pilot hole, it is no longer necessary for the drill operator to apply axial force: the thread engagement between the tap and the workpiece provides the axial force to advance the tool bit. Like the pilot-drill section, each tap section must be long enough to complete its hole before engagement of the next, slightly wider tap section. The precise values of the increments in diameter, the thread pitch, the rake angle of the tap cutting edge, and other geometric parameters of the tap sections must be chosen, in consideration of the workpiece material and thickness, to prevent stripping of threads during the drilling/tapping operation. A stop-lip or shoulder at the shank end of the widest tap section prevents further passage of the tool bit through the hole.

The formation of stellar black holes

NASA Astrophysics Data System (ADS)

Mirabel, Félix

2017-08-01

It is believed that stellar black holes (BHs) can be formed in two different ways: Either a massive star collapses directly into a BH without a supernova (SN) explosion, or an explosion occurs in a proto-neutron star, but the energy is too low to completely unbind the stellar envelope, and a large fraction of it falls back onto the short-lived neutron star (NS), leading to the delayed formation of a BH. Theoretical models set progenitor masses for BH formation by implosion, namely, by complete or almost complete collapse, but observational evidences have been elusive. Here are reviewed the observational insights on BHs formed by implosion without large natal kicks from: (1) the kinematics in three dimensions of space of five Galactic BH X-ray binaries (BH-XRBs), (2) the diversity of optical and infrared observations of massive stars that collapse in the dark, with no luminous SN explosions, possibly leading to the formation of BHs, and (3) the sources of gravitational waves (GWs) produced by mergers of stellar BHs so far detected with LIGO. Multiple indications of BH formation without ejection of a significant amount of matter and with no natal kicks obtained from these different areas of observational astrophysics, and the recent observational confirmation of the expected dependence of BH formation on metallicity and redshift, are qualitatively consistent with the high merger rates of binary black holes (BBHs) inferred from the first detections with LIGO.

Sputter-deposited WO x and MoO x for hole selective contacts

DOE PAGES

Bivour, Martin; Zähringer, Florian; Ndione, Paul F.; ...

2017-09-21

Here, reactive sputter deposited tungsten and molybdenum oxide (WO x, MoO x) thin films are tested for their ability to form a hole selective contact for Si wafer based solar cells. A characterization approach based on analyzing the band bending induced in the c-Si absorber and the external and implied open-circuit voltage of test structures was used. It is shown that the oxygen partial pressure allows to tailor the selectivity to some extent and that a direct correlation between induced band bending and hole selectivity exists. Although the selectivity of the sputtered films is inferior to the reference films depositedmore » by thermal evaporation, these results demonstrate a good starting point for further optimizations of sputtered WO x and MoO x towards higher work functions to improve the hole selectivity.« less

Towards experimentally testing the paradox of black hole information loss

NASA Astrophysics Data System (ADS)

Zhang, Baocheng; Cai, Qing-yu; Zhan, Ming-sheng; You, Li

2013-02-01

Information about the collapsed matter in a black hole will be lost if Hawking radiations are truly thermal. Recent studies discover that information can be transmitted from a black hole by Hawking radiations, due to their spectrum deviating from exact thermality when backreaction is considered. In this paper, we focus on the spectroscopic features of Hawking radiation from a Schwarzschild black hole, contrasting the differences between the nonthermal and thermal spectra. Of great interest, we find that the energy covariances of Hawking radiations for the thermal spectrum are exactly zero, while the energy covariances are nontrivial for the nonthermal spectrum. Consequently, the nonthermal spectrum can be distinguished from the thermal one by counting the energy covariances of successive emissions, which provides an avenue towards experimentally testing the long-standing “information loss paradox.”

Sputter-deposited WO x and MoO x for hole selective contacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bivour, Martin; Zähringer, Florian; Ndione, Paul F.

Here, reactive sputter deposited tungsten and molybdenum oxide (WO x, MoO x) thin films are tested for their ability to form a hole selective contact for Si wafer based solar cells. A characterization approach based on analyzing the band bending induced in the c-Si absorber and the external and implied open-circuit voltage of test structures was used. It is shown that the oxygen partial pressure allows to tailor the selectivity to some extent and that a direct correlation between induced band bending and hole selectivity exists. Although the selectivity of the sputtered films is inferior to the reference films depositedmore » by thermal evaporation, these results demonstrate a good starting point for further optimizations of sputtered WO x and MoO x towards higher work functions to improve the hole selectivity.« less

Data for four geologic test holes in the Sacramento Valley, California

USGS Publications Warehouse

Berkstresser, C.F.; French, J.J.; Schaal, M.E.

1985-01-01

The report provides geological and geophysical data for four of seven test holes drilled as a part of the Central Valley Aquifer Project, which is part of the Regional Aquifer Systems Analysis. The holes were drilled with a rotary well drilling machine to depths of 900 feet in the southwestern part of the Sacramento Valley in Solano and Yolo Counties. Geologic data for each well include lithology, texture, color, character of the contact, sorting, rounding, and cementation, determined from cuttings, cores, and sidewall covers. Fifty cores, 3 feet long, were obtained from each hole, and from eight to fourteen sidewall cores were collected. Geophysical data include a dual-induction log, spherically focused log (SFL), compensated neutron-formation density log, gamma-ray log, and a caliper log. These data are presented in four tables and on four plates. (USGS)

Black hole spectroscopy: Systematic errors and ringdown energy estimates

NASA Astrophysics Data System (ADS)

Baibhav, Vishal; Berti, Emanuele; Cardoso, Vitor; Khanna, Gaurav

2018-02-01

The relaxation of a distorted black hole to its final state provides important tests of general relativity within the reach of current and upcoming gravitational wave facilities. In black hole perturbation theory, this phase consists of a simple linear superposition of exponentially damped sinusoids (the quasinormal modes) and of a power-law tail. How many quasinormal modes are necessary to describe waveforms with a prescribed precision? What error do we incur by only including quasinormal modes, and not tails? What other systematic effects are present in current state-of-the-art numerical waveforms? These issues, which are basic to testing fundamental physics with distorted black holes, have hardly been addressed in the literature. We use numerical relativity waveforms and accurate evolutions within black hole perturbation theory to provide some answers. We show that (i) a determination of the fundamental l =m =2 quasinormal frequencies and damping times to within 1% or better requires the inclusion of at least the first overtone, and preferably of the first two or three overtones; (ii) a determination of the black hole mass and spin with precision better than 1% requires the inclusion of at least two quasinormal modes for any given angular harmonic mode (ℓ , m ). We also improve on previous estimates and fits for the ringdown energy radiated in the various multipoles. These results are important to quantify theoretical (as opposed to instrumental) limits in parameter estimation accuracy and tests of general relativity allowed by ringdown measurements with high signal-to-noise ratio gravitational wave detectors.

A Hamiltonian approach for the Thermodynamics of AdS black holes

NASA Astrophysics Data System (ADS)

Baldiotti, M. C.; Fresneda, R.; Molina, C.

2017-07-01

In this work we study the Thermodynamics of D-dimensional Schwarzschild-anti de Sitter (SAdS) black holes. The minimal Thermodynamics of the SAdS spacetime is briefly discussed, highlighting some of its strong points and shortcomings. The minimal SAdS Thermodynamics is extended within a Hamiltonian approach, by means of the introduction of an additional degree of freedom. We demonstrate that the cosmological constant can be introduced in the thermodynamic description of the SAdS black hole with a canonical transformation of the Schwarzschild problem, closely related to the introduction of an anti-de Sitter thermodynamic volume. The treatment presented is consistent, in the sense that it is compatible with the introduction of new thermodynamic potentials, and respects the laws of black hole Thermodynamics. By demanding homogeneity of the thermodynamic variables, we are able to construct a new equation of state that completely characterizes the Thermodynamics of SAdS black holes. The treatment naturally generates phenomenological constants that can be associated with different boundary conditions in underlying microscopic theories. A whole new set of phenomena can be expected from the proposed generalization of SAdS Thermodynamics.

Development of a mouse test for repetitive, restricted behaviors: relevance to autism.

PubMed

Moy, Sheryl S; Nadler, Jessica J; Poe, Michele D; Nonneman, Randal J; Young, Nancy B; Koller, Beverly H; Crawley, Jacqueline N; Duncan, Gary E; Bodfish, James W

2008-03-17

Repetitive behavior, a core symptom of autism, encompasses stereotyped responses, restricted interests, and resistance to change. These studies investigated whether different components of the repetitive behavior domain could be modeled in the exploratory hole-board task in mice. Four inbred mouse strains, C57BL/6J, BALB/cByJ, BTBR T+tf/J, and FVB/NJ, and mice with reduced expression of Grin1, leading to NMDA receptor hypofunction (NR1neo/neo mice), were tested for exploration and preference for olfactory stimuli in an activity chamber with a 16-hole floor-board. Reduced exploration and high preference for holes located in the corners of the chamber were observed in BALB/cByJ and BTBR T+tf/J mice. All inbred strains had initial high preference for a familiar olfactory stimulus (clean cage bedding). BTBR T+tf/J was the only strain that did not demonstrate a shift in hole preference towards an appetitive olfactory stimulus (cereal or a chocolate chip), following home cage exposure to the food. The NR1neo/neo mice showed lower hole selectivity and aberrant olfactory stimulus preference, in comparison to wildtype controls. The results indicate that NR1neo/neo mice have repetitive nose poke responses that are less modified by environmental contingencies than responses in wildtype mice. 25-30% of NMDA receptor hypomorphic mice also show self-injurious responses. Findings from the olfactory studies suggest that resistance to change and restricted interests might be modeled in mice by a failure to alter patterns of hole preference following familiarization with an appetitive stimulus, and by high preference persistently demonstrated for one particular olfactory stimulus. Further work is required to determine the characteristics of optimal mouse social stimuli in the olfactory hole-board test.

Collisions Around a Black Hole Mean Mealtime

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-08-01

When a normally dormant supermassive black hole burps out a brief flare, its assumed that a star was torn apart and fell into the black hole. But a new study suggests that some of these flares might have a slightly different cause.Not a Disruption?Artists impression of a tidal disruption event, in which a star has been pulled apart and its gas feeds the supermassive black hole. [NASA/JPL-Caltech]When a star swings a little too close by a supermassive black hole, the black holes gravity can pull the star apart, completely disrupting it. The resulting gas can then accrete onto the black hole, feeding it and causing it to flare. The predicted frequency of these tidal disruption events and their expected light curves dont perfectly match all our observations of flaring black holes, however.This discrepancy has led two scientists from the Columbia Astrophysics Laboratory, Brian Metzger and Nicholas Stone, to wonder if we can explain flares from supermassive black holes in another way. Could a differentevent masquerade as a tidal disruption?Evolution of a stars semimajor axis (top panel) and radius (bottom panel) as a function of time since Roche-lobe overflow began onto a million-solar-mass black hole. Curves show stars of different masses. [Metzger Stone 2017]Inspirals and OutspiralsIn the dense nuclear star cluster surrounding a supermassive black hole, various interactions can send stars on new paths that take them close to the black hole. In many of these interactions, the stars will end up on plunging orbits, often resulting in tidal disruption. But sometimes stars can approach the black hole on tightly bound orbits with lower eccentricities.A main-sequence star on such a path, in what is known as an extreme mass ratio inspiral (EMRI), slowly approaches the black hole over a period of millions of years, eventually overflowing its Roche lobe and losing mass. Theradius of the star inflates, driving more mass loss and halting the stars inward progress. The star then reverses course and migrates outward again as a brown dwarf.Metzger and Stone demonstrate that the timescale for this process is shorter than the time delay expected between successive EMRIs. The likelihood is high, they show, that two consecutive EMRIs would collide while one is inspiraling and the other is outspiraling.Results of a CollisionSchematic diagram (not to scale) showing how two circular EMRI orbits can intersect as the main-sequence star migrates inward (blue) and the brown dwarf very slowly migrates outward (red). [Metzger Stone 2017]Because both stars are deep in the black holes gravitational well, they collide with enormous relative velocities ( 10% the speed of light!). If this collision is head-on, one or both stars will be completely destroyed. The resulting gas then accretes onto the black hole, producing a flare very similar to a classical tidal disruption event.If the stars instead meet on a grazing collision, Metzger and Stone show that this liberates gas from at least one of the stars. The gas forms an accretion disk around the black hole, causing a transient flare similar to some of the harder-to-explain flares weve observed that dont quite fit our models for tidal disruption events.In this latter scenario, the stars survive to encounter each other again, decades to millennia later. These grazing collisions between the pair can continue to produce quasi-periodic flares for thousands of years or longer.Metzger and Stone argue that EMRI collisions have the potential to explain some of the flares from supermassive black holes that we had previously attributed to tidal disruption events. More detailed modeling will allow us to explore this idea further in the future.CitationBrian D. Metzger and Nicholas C. Stone 2017 ApJ 844 75. doi:10.3847/1538-4357/aa7a16

2011 Release of the Evaluated Nuclear Data Library (ENDL2011.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, D. A.; Beck, B.; Descalles, M. A.

LLNL’s Computational Nuclear Physics Group and Nuclear Theory and Modeling Group have collaborated to produce the last of three major releases of LLNL’s evaluated nuclear database, ENDL2011. ENDL2011 is designed to support LLNL’s current and future nuclear data needs by providing the best nuclear data available to our programmatic customers. This library contains many new evaluations for radiochemical diagnostics, structural materials, and thermonuclear reactions. We have made an effort to eliminate all holes in reaction networks, allowing in-line isotopic creation and depletion calculations. We have striven to keep ENDL2011 at the leading edge of nuclear data library development by reviewingmore » and incorporating new evaluations as they are made available to the nuclear data community. Finally, this release is our most highly tested release as we have strengthened our already rigorous testing regime by adding tests against IPPE Activation Ratio Measurements, many more new critical assemblies and a more complete set of classified testing (to be detailed separately).« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johannsen, Tim; Psaltis, Dimitrios, E-mail: timj@physics.arizona.edu, E-mail: dpsaltis@email.arizona.edu

According to the no-hair theorem, astrophysical black holes are uniquely described by their masses and spins. An observational test of the no-hair theorem can be performed by measuring at least three different multipole moments of the spacetime of a black hole and verifying whether their values are consistent with the unique combinations of the Kerr solution. In this paper, we study quasi-periodic variability observed in the emission from black holes across the electromagnetic spectrum as a test of the no-hair theorem. We derive expressions for the Keplerian and epicyclic frequencies in a quasi-Kerr spacetime, in which the quadrupole moment ismore » a free parameter in addition to mass and spin. We show that, for moderate spins, the Keplerian frequency is practically independent of small deviations of the quadrupole moment from the Kerr value, while the epicyclic frequencies exhibit significant variations. We apply this framework to quasi-periodic oscillations (QPOs) in black hole X-ray binaries in two different scenarios. In the case that a pair of QPOs can be identified as the fundamental g- and c-modes in the accretion disk, we show that the no-hair theorem can be tested in conjunction with an independent mass measurement. If pairs of oscillations are identified with non-parametric resonance of dynamical frequencies in the accretion disk, then testing the no-hair theorem also requires an independent measurement of the black hole spin. In addition, we argue that VLBI observations of Sgr A* may test the no-hair theorem through a combination of imaging observations and the detection of quasi-periodic variability.« less

Test holes drilled in support of ground-water investigations, Project Gnome, Eddy County, New Mexico

USGS Publications Warehouse

Cooper, J.B.

1962-01-01

Project Gnome is a proposed underground nuclear shot to be detonated within a massive salt bed in Eddy County, N. Mex. Potable and neat potable ground water is present in rocks above the salt and is being studied in relation to this nuclear event. This report presents details of two test holes which were drilled to determine ground-water conditions in the near vicinity of the shot point. A well-defined aquifer is present at the site of USGS test hole 1, about 1,000 feet south of the access shaft to the underground shot point. Water with 75 feet of artesian pressure head is contained in the Culebra dolomite member of the Rustler formation. The dolomite aquifer is 32 feet thick and its top lies at a depth of 517 feet below land surface. The aquifer yielded 100 gpm (gallons per minute) with a drawdown of 40 feet during a pumping period of 24 hours. Water was not found in rocks above or below the Culebra dolomite. At the site of USGS test hole 2, about 2 miles southwest of the access shaft no distinctive aquifer exists. About one-half gpm was yielded to the well from the rocks between the Culebra dolomite and the top of the salt. Water could not be detected in the Culebra dolomite or overlying rocks. The report contains drawdown and recovery curves of yield tests, drilling-time charts, and electric logs. The data are given in tables; they include summaries of hole construction, sample description logs, water measurements, drilling-time logs, and water analyses.

Advances in Distance-Based Hole Cuts on Overset Grids

NASA Technical Reports Server (NTRS)

Chan, William M.; Pandya, Shishir A.

2015-01-01

An automatic and efficient method to determine appropriate hole cuts based on distances to the wall and donor stencil maps for overset grids is presented. A new robust procedure is developed to create a closed surface triangulation representation of each geometric component for accurate determination of the minimum hole. Hole boundaries are then displaced away from the tight grid-spacing regions near solid walls to allow grid overlap to occur away from the walls where cell sizes from neighboring grids are more comparable. The placement of hole boundaries is efficiently determined using a mid-distance rule and Cartesian maps of potential valid donor stencils with minimal user input. Application of this procedure typically results in a spatially-variable offset of the hole boundaries from the minimum hole with only a small number of orphan points remaining. Test cases on complex configurations are presented to demonstrate the new scheme.

Thermal stability of black holes with arbitrary hairs

NASA Astrophysics Data System (ADS)

Sinha, Aloke Kumar

2018-02-01

We have derived the criteria for thermal stability of charged rotating black holes, for horizon areas that are large relative to the Planck area (in these dimensions). In this paper, we generalized it for black holes with arbitrary hairs. The derivation uses results of loop quantum gravity and equilibrium statistical mechanics of the grand canonical ensemble and there is no explicit use of classical spacetime geometry at all in this analysis. The assumption is that the mass of the black hole is a function of its horizon area and all the hairs. Our stability criteria are then tested in detail against some specific black holes, whose metrics provide us with explicit relations for the dependence of the mass on the area and other hairs of the black holes. This enables us to predict which of these black holes are expected to be thermally unstable under Hawking radiation.

CPT-hole closure

USGS Publications Warehouse

Noce, T.E.; Holzer, T.L.

2003-01-01

The long-term stability of deep holes 1.75 inches. (4.4 cm) in diameter by 98.4 feet (30 m) created by cone penetration testing (CPT) was monitored at a site in California underlain by Holocene and Pleistocene age alluvial fan deposits. Portions of the holes remained open both below and above the 28.6-foot (8.7 m)-deep water table for approximately three years, when the experiment was terminated. Hole closure appears to be a very slow process that may take decades in the stiff soils studied here. Other experience suggests holes in softer soils may also remain open. Thus, despite their small diameter, CPT holes may remain open for years and provide paths for rapid migration of contaminants. The observations confirm the need to grout holes created by CPT soundings as well as other direct-push techniques in areas where protection of shallow ground water is important.

Advances in Domain Connectivity for Overset Grids Using the X-Rays Approach

NASA Technical Reports Server (NTRS)

Chan, William M.; Kim, Noah; Pandya, Shishir A.

2012-01-01

Advances in automation and robustness of the X-rays approach to domain connectivity for overset grids are presented. Given the surface definition for each component that makes up a complex configuration, the determination of hole points with appropriate hole boundaries is automatically and efficiently performed. Improvements made to the original X-rays approach for identifying the minimum hole include an automated closure scheme for hole-cutters with open boundaries, automatic determination of grid points to be considered for blanking by each hole-cutter, and an adaptive X-ray map to economically handle components in close proximity. Furthermore, an automated spatially varying offset of the hole boundary from the minimum hole is achieved using a dual wall-distance function and an orphan point removal iteration process. Results using the new scheme are presented for a number of static and relative motion test cases on a variety of aerospace applications.

Non-equilibrium condensation process in holographic superconductor with nonlinear electrodynamics

NASA Astrophysics Data System (ADS)

Liu, Yunqi; Gong, Yungui; Wang, Bin

2016-02-01

We study the non-equilibrium condensation process in a holographic superconductor with nonlinear corrections to the U (1) gauge field. We start with an asymptotic Anti-de-Sitter (AdS) black hole against a complex scalar perturbation at the initial time, and solve the dynamics of the gravitational systems in the bulk. When the black hole temperature T is smaller than a critical value T c , the scalar perturbation grows exponentially till saturation, the final state of spacetime approaches to a hairy black hole. In the bulk theory, we find the clue of the influence of nonlinear corrections in the gauge filed on the process of the scalar field condensation. We show that the bulk dynamics in the non-equilibrium process is completely consistent with the observations on the boundary order parameter. Furthermore we examine the time evolution of horizons in the bulk non-equilibrium transformation process from the bald AdS black hole to the AdS hairy hole. Both the evolution of apparent and event horizons show that the original AdS black hole configuration requires more time to finish the transformation to become a hairy black hole if there is nonlinear correction to the electromagnetic field. We generalize our non-equilibrium discussions to the holographic entanglement entropy and find that the holographic entanglement entropy can give us further understanding of the influence of the nonlinearity in the gauge field on the scalar condensation.

Multicentered black holes with a negative cosmological constant

NASA Astrophysics Data System (ADS)

Chimento, Samuele; Klemm, Dietmar

2014-01-01

We present a recipe that allows us to construct multicentered black holes embedded in an arbitrary Friedmann-Lemaître-Robertson-Walker (FLRW) universe. These solutions are completely determined by a function satisfying the conformal Laplace equation on the spatial slices E3, S3, or H3. Since anti-de Sitter (AdS) space can be written in FLRW coordinates, this includes as a special case multicentered black holes in AdS, in the sense that, far away from the black holes, the energy density and the pressure approach the values given by a negative cosmological constant. We study in some detail the physical properties of the single-centered asymptotically AdS case, which does not coincide with the usual Reissner-Nordström-AdS black hole, but is highly dynamical. In particular, we determine the curvature singularities and trapping horizons of this solution, compute the surface gravity of the trapping horizons, and show that the generalized first law of black hole dynamics proposed by Hayward holds in this case. It turns out that the spurious big bang/big crunch singularities that appear when one writes AdS in FLRW form become real in the presence of these dynamical black holes. This implies that actually only one point of the usual conformal boundary of AdS survives in the solutions that we construct. Finally, a generalization to arbitrary dimension is also presented.

Measuring the stellar luminosity function and spatial density profile of the inner 0.5 pc of the Milky Way nuclear star cluster

NASA Astrophysics Data System (ADS)

Do, Tuan; Ghez, Andrea; Lu, Jessica R.; Morris, Mark R.; Yelda, Sylvana; Martinez, Gregory D.; Peter, Annika H. G.; Wright, Shelley; Bullock, James; Kaplinghat, Manoj; Matthews, K.

2012-07-01

We report on measurements of the luminosity function of early (young) and late-type (old) stars in the central 0.5 pc of the Milky Way nuclear star cluster as well as the density profiles of both components. The young (~ 6 Myr) and old stars (> 1 Gyr) in this region provide different physical probes of the environment around a supermassive black hole; the luminosity function of the young stars offers us a way to measure the initial mass function from star formation in an extreme environment, while the density profile of the old stars offers us a probe of the dynamical interaction of a star cluster with a massive black hole. The two stellar populations are separated through a near-infrared spectroscopic survey using the integral-field spectrograph OSIRIS on Keck II behind the laser guide star adaptive optics system. This spectroscopic survey is able to separate early-type (young) and late-type (old) stars with a completeness of 50% at K' = 15.5. We describe our method of completeness correction using a combination of star planting simulations and Bayesian inference. The completeness corrected luminosity function of the early-type stars contains significantly more young stars at faint magnitudes compared to previous surveys with similar depth. In addition, by using proper motion and radial velocity measurements along with anisotropic spherical Jeans modeling of the cluster, it is possible to measure the spatial density profile of the old stars, which has been difficult to constrain with number counts alone. The most probable model shows that the spatial density profile, n(r) propto r-γ, to be shallow with γ = 0.4 ± 0.2, which is much flatter than the dynamically relaxed case of γ = 3/2 to 7/4, but does rule out a 'hole' in the distribution of old stars. We show, for the first time, that the spatial density profile, the black hole mass, and velocity anisotropy can be fit simultaneously to obtain a black hole mass that is consistent with that derived from individual orbits of stars at distances < 1000 AU from the Galactic center.

Effectiveness of commercial video gaming on fine motor control in chronic stroke within community-level rehabilitation.

PubMed

Paquin, Kate; Ali, Suzanne; Carr, Kelly; Crawley, Jamie; McGowan, Cheri; Horton, Sean

2015-01-01

The purpose of this study was to investigate the effectiveness of commercial gaming as an intervention for fine motor recovery in chronic stroke. Ten chronic phase post-stroke participants (mean time since CVA = 39 mos; mean age = 72 yrs) completed a 16-session program using the Nintendo Wii for 15 min two times per week with their more affected hand (10 right handed). Functional recovery (Jebsen Hand Function Test (JHFT), Box and Block Test (BBT), Nine Hole Peg Test (NHPT)), and quality of life (QOL; Stroke Impact Scale (SIS)) were measured at baseline (pre-testing), after 8 sessions (mid-testing) and after 16 sessions (post-testing). Significant improvements were found with the JHFT, BBT and NHPT from pre-testing to post-testing (p = 0.03, p = 0.03, p = 0.01, respectively). As well, there was an increase in perceived QOL from pre-testing to post-testing, as determined by the SIS (p = 0.009). Commercial gaming may be a viable resource for those with chronic stroke. Future research should examine the feasibility of this as a rehabilitation tool for this population. Stroke survivors often live with lasting effects from their injury, however, those with chronic stroke generally receive little to no rehabilitation due to a perceived motor recovery plateau. Virtual reality in the form of commercial gaming is a novel and motivating way for clients to complete rehabilitation. The Nintendo Wii may be a feasible device to improve both functional ability and perceived quality of life in chronic stroke survivors.

Hybrid Parallel-Slant Hole Collimators for SPECT Imaging

NASA Astrophysics Data System (ADS)

Bai, Chuanyong; Shao, Ling; Ye, Jinghan; Durbin, M.; Petrillo, M.

2004-06-01

We propose a new collimator geometry, the hybrid parallel-slant (HPS) hole geometry, to improve sensitivity for SPECT imaging with large field of view (LFOV) gamma cameras. A HPS collimator has one segment with parallel holes and one or more segments with slant holes. The collimator can be mounted on a conventional SPECT LFOV system that uses parallel-beam collimators, and no additional detector or collimator motion is required for data acquisition. The parallel segment of the collimator allows for the acquisition of a complete data set of the organs-of-interest and the slant segments provide additional data. In this work, simulation studies of an MCAT phantom were performed with a HPS collimator with one slant segment. The slant direction points from patient head to patient feet with a slant angle of 30/spl deg/. We simulated 64 projection views over 180/spl deg/ with the modeling of nonuniform attenuation effect, and then reconstructed images using an MLEM algorithm that incorporated the hybrid geometry. It was shown that sensitivity to the cardiac region of the phantom was increased by approximately 50% when using the HPS collimator compared with a parallel-hole collimator. No visible artifacts were observed in the myocardium and the signal-to-noise ratio (SNR) of the myocardium walls was improved. Compared with collimators with other geometries, using a HPS collimator has the following advantages: (a) significant sensitivity increase; (b) a complete data set obtained from the parallel segment that allows for artifact-free image reconstruction; and (c) no additional collimator or detector motion. This work demonstrates the potential value of hybrid geometry in collimator design for LFOV SPECT imaging.

Development and verification of global/local analysis techniques for laminated composites

NASA Technical Reports Server (NTRS)

Thompson, Danniella Muheim; Griffin, O. Hayden, Jr.

1991-01-01

A two-dimensional to three-dimensional global/local finite element approach was developed, verified, and applied to a laminated composite plate of finite width and length containing a central circular hole. The resulting stress fields for axial compression loads were examined for several symmetric stacking sequences and hole sizes. Verification was based on comparison of the displacements and the stress fields with those accepted trends from previous free edge investigations and a complete three-dimensional finite element solution of the plate. The laminates in the compression study included symmetric cross-ply, angle-ply and quasi-isotropic stacking sequences. The entire plate was selected as the global model and analyzed with two-dimensional finite elements. Displacements along a region identified as the global/local interface were applied in a kinematically consistent fashion to independent three-dimensional local models. Local areas of interest in the plate included a portion of the straight free edge near the hole, and the immediate area around the hole. Interlaminar stress results obtained from the global/local analyses compares well with previously reported trends, and some new conclusions about interlaminar stress fields in plates with different laminate orientations and hole sizes are presented for compressive loading. The effectiveness of the global/local procedure in reducing the computational effort required to solve these problems is clearly demonstrated through examination of the computer time required to formulate and solve the linear, static system of equations which result for the global and local analyses to those required for a complete three-dimensional formulation for a cross-ply laminate. Specific processors used during the analyses are described in general terms. The application of this global/local technique is not limited software system, and was developed and described in as general a manner as possible.

ETR, TRA642. ON BASEMENT FLOOR. REACTOR VESSEL WILL BE PLACED ...

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

ETR, TRA-642. ON BASEMENT FLOOR. REACTOR VESSEL WILL BE PLACED WITHIN THE INNER METAL FORM. WHEN CONCRETE IS POURED OUTSIDE THIS FORM, CONDUIT HOLES WILL BE PRESERVE SPACE THROUGH HOLES. INL NEGATIVE NO. 56-1507. Jack L. Anderson, Photographer, 5/8/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Iron K α line of Kerr black holes with Proca hair

NASA Astrophysics Data System (ADS)

Zhou, Menglei; Bambi, Cosimo; Herdeiro, Carlos A. R.; Radu, Eugen

2017-05-01

We continue our study on the capabilities of present and future x-ray missions to test the nature of astrophysical black hole candidates via x-ray reflection spectroscopy and distinguish Kerr black holes from other solutions of 4-dimensional Einstein's gravity in the presence of a matter field. Here we investigate the case of Kerr black holes with Proca hair [1]. The analysis of a sample of these configurations suggests that even extremely hairy black holes can mimic the iron line profile of the standard Kerr black holes, and, at least for the configurations of our study, we find that current x-ray missions cannot distinguish these objects from Kerr black holes. This contrasts with our previous findings for the case of Kerr black holes with scalar (rather than Proca) hair [2], even though such comparison may be biased by the limited sample. Future x-ray missions can detect the presence of Proca hair, but a theoretical knowledge of the expected intensity profile (currently missing) can be crucial to obtain strong constraints.

Use of calophyllum inophyllum biofuel blended with diesel in DI diesel engine modified with nozzle holes and its size

NASA Astrophysics Data System (ADS)

Vairamuthu, G.; Sundarapandian, S.; Thangagiri, B.

2016-05-01

Improved thermal efficiency, reduction in fuel consumption and pollutant emissions from biodiesel fueled diesel engines are important issues in engine research. To achieve these, fast and perfect air-biodiesel mixing are the most important requirements. The mixing quality of biodiesel spray with air can be improved by better design of the injection system. The diesel engine tests were conducted on a 4-stroke tangentially vertical single cylinder (TV1) kirloskar 1500 rpm water cooled direct injection diesel engine with eddy current dynamometer. In this work, by varying different nozzles having spray holes of 3 (base, Ø = 0.280 mm), 4 (modified, Ø = 0.220 mm) and 5 (modified, Ø = 0.240 mm) holes, with standard static injection timing of 23° bTDC and nozzle opening pressure (NOP) of 250 bar maintained as constant throughout the experiment under steady state at full load condition of the engine. The effect of varying different nozzle configuration (number of holes), on the combustion, performance and exhaust emissions, using a blend of calophyllum inophyllum methyl ester by volume in diesel were evaluated. The test results showed that improvement in terms of brake thermal efficiency and specific fuel consumption for 4 holes and 5 holes nozzle operated at NOP 250 bar. Substantial improvements in the reduction of emissions levels were also observed for 5 holes nozzle operated at NOP 250 bar.

Compression failure mechanisms of uni-ply composite plates with a circular cutout

NASA Technical Reports Server (NTRS)

Khamseh, A. R.; Waas, A. M.

1992-01-01

The effect of circular-hole size on the failure mode of uniply graphite-epoxy composite plates is investigated experimentally and analytically for uniaxial compressive loading. The test specimens are sandwiched between polyetherimide plastic for nondestructive evaluations of the uniply failure mechanisms associated with a range of hole sizes. Finite-element modeling based on classical lamination theory is conducted for the corresponding materials and geometries to reproduce the experimental results analytically. The type of compressive failure is found to be a function of hole size, with fiber buckling/kinking at the hole being the dominant failure mechanism for hole diam/plate width ratios exceeding 0.062. The results of the finite-element analysis supported the experimental data for these failure mechanisms and for those corresponding to smaller hole sizes.

Astrophysical flows near [Formula: see text] gravity black holes.

PubMed

Ahmed, Ayyesha K; Azreg-Aïnou, Mustapha; Bahamonde, Sebastian; Capozziello, Salvatore; Jamil, Mubasher

In this paper, we study the accretion process for fluids flowing near a black hole in the context of f ( T ) teleparallel gravity. Specifically, by performing a dynamical analysis by a Hamiltonian system, we are able to find the sonic points. After that, we consider different isothermal test fluids in order to study the accretion process when they are falling onto the black hole. We find that these flows can be classified according to the equation of state and the black hole features. Results are compared in f ( T ) and f ( R ) gravity.

Comparison of Open-Hole Compression Strength and Compression After Impact Strength on Carbon Fiber/Epoxy Laminates for the Ares I Composite Interstage

NASA Technical Reports Server (NTRS)

Hodge, Andrew J.; Nettles, Alan T.; Jackson, Justin R.

2011-01-01

Notched (open hole) composite laminates were tested in compression. The effect on strength of various sizes of through holes was examined. Results were compared to the average stress criterion model. Additionally, laminated sandwich structures were damaged from low-velocity impact with various impact energy levels and different impactor geometries. The compression strength relative to damage size was compared to the notched compression result strength. Open-hole compression strength was found to provide a reasonable bound on compression after impact.

Portable punch and die jig

DOEpatents

Lewandowski, Edward F.; Anderson, Petrus A.

1978-01-01

A portable punch and die jig includes a U-shaped jig of predetermined width having a slot of predetermined width in the base thereof extending completely across the width of the jig adapted to fit over the walls of rectangular tubes and a punch and die assembly disposed in a hole extending through the base of the jig communicating with the slot in the base of the jig for punching a hole in the walls of the rectangular tubes at precisely determined locations.

The Effect of Radiation "Memory" in Alkali-Halide Crystals

NASA Astrophysics Data System (ADS)

Korovkin, M. V.; Sal'nikov, V. N.

2017-01-01

The exposure of the alkali-halide crystals to ionizing radiation leads to the destruction of their structure, the emergence of radiation defects, and the formation of the electron and hole color centers. Destruction of the color centers upon heating is accompanied by the crystal bleaching, luminescence, and radio-frequency electromagnetic emission (REME). After complete thermal bleaching of the crystal, radiation defects are not completely annealed, as the electrons and holes released from the color centers by heating leave charged and locally uncompensated defects. Clusters of these "pre centers" lead to electric microheterogeneity of the crystal, the formation of a quasi-electret state, and the emergence of micro-discharges accompanied by radio emission. The generation of REME associated with residual defectiveness, is a manifestation of the effect of radiation "memory" in dielectrics.

Quantum dynamics of a two-state system induced by a chirped zero-area pulse

NASA Astrophysics Data System (ADS)

Lee, Han-gyeol; Song, Yunheung; Kim, Hyosub; Jo, Hanlae; Ahn, Jaewook

2016-02-01

It is well known that area pulses make Rabi oscillation and chirped pulses in the adiabatic interaction regime induce complete population inversion of a two-state system. Here we show that chirped zero-area pulses could engineer an interplay between the adiabatic evolution and Rabi-like rotations. In a proof-of-principle experiment utilizing spectral chirping of femtosecond laser pulses with a resonant spectral hole, we demonstrate that the chirped zero-area pulses could induce, for example, complete population inversion and return of the cold rubidium atom two-state system. Experimental result agrees well with the theoretically considered overall dynamics, which could be approximately modeled to a Ramsey-like three-pulse interaction, where the x and z rotations are driven by the hole and the main pulse, respectively.

The Chandra Deep Wide-Field Survey: Completing the new generation of Chandra extragalactic surveys

NASA Astrophysics Data System (ADS)

Hickox, Ryan

2016-09-01

Chandra X-ray surveys have revolutionized our view of the growth of black holes across cosmic time. Recently, fundamental questions have emerged about the connection of AGN to their host large scale structures that clearly demand a wide, deep survey over a large area, comparable to the recent extensive Chandra surveys in smaller fields. We propose the Chandra Deep Wide-Field Survey (CDWFS) covering the central 6 sq. deg in the Bootes field, totaling 1.025 Ms (building on 550 ks from the HRC GTO program). CDWFS will efficiently probe a large cosmic volume, allowing us to carry out accurate new investigations of the connections between black holes and their large-scale structures, and will complete the next generation surveys that comprise a key part of Chandra's legacy.

The Chandra X-ray Observatory removed from its container in the Vertical Processing Facility

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), the overhead crane lifts Chandra X-ray Observatory completely out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

Effect of an external magnetic field on particle acceleration by a rotating black hole surrounded with quintessential energy

NASA Astrophysics Data System (ADS)

Shaymatov, Sanjar; Ahmedov, Bobomurat; Stuchlík, Zdeněk; Abdujabbarov, Ahmadjon

We investigate particle motion and collisions in the vicinity of rotating black holes immersed in combined cosmological quintessential scalar field and external magnetic field. The quintessential dark-energy field governing the spacetime structure is characterized by the quintessential state parameter ωq ∈ (‑1; ‑1/3) characterizing its equation of state, and the quintessential field-intensity parameter c determining the static radius where the black hole attraction is just balanced by the quintessential repulsion. The magnetic field is assumed to be test field that is uniform close to the static radius, where the spacetime is nearly flat, being characterized by strength B there. Deformations of the test magnetic field in vicinity of the black hole, caused by the Ricci non-flat spacetime structure are determined. General expression of the center-of-mass energy of the colliding charged or uncharged particles near the black hole is given and discussed in several special cases. In the case of nonrotating black holes, we discuss collisions of two particles freely falling from vicinity of the static radius, or one such a particle colliding with charged particle revolving at the innermost stable circular orbit. In the case of rotating black holes, we discuss briefly particles falling in the equatorial plane and colliding in close vicinity of the black hole horizon, concentrating attention to the interplay of the effects of the quintessential field and the external magnetic field. We demonstrate that the ultra-high center-of-mass energy can be obtained for black holes placed in an external magnetic field for an infinitesimally small quintessential field-intensity parameter c; the center-of-mass energy decreases if the quintessential field-intensity parameter c increases.

Burner rig study of variables involved in hole plugging of air cooled turbine engine vanes

NASA Technical Reports Server (NTRS)

Deadmore, D. L.; Lowell, C. E.

1983-01-01

The effects of combustion gas composition, flame temperatures, and cooling air mass flow on the plugging of film cooling holes by a Ca-Fe-P-containing deposit were investigated. The testing was performed on film-cooled vanes exposed to the combustion gases of an atmospheric Mach 0.3 burner rig. The extent of plugging was determined by measurement of the open hole area at the conclusion of the tests as well as continuous monitoring of some of the tests using stop-action photography. In general, as the P content increased, plugging rates also increased. The plugging was reduced by increasing flame temperature and cooling air mass flow rates. At times up to approximately 2 hours little plugging was observed. This apparent incubation period was followed by rapid plugging, reaching in several hours a maximum closure whose value depended on the conditions of the test.

PIA22224

NASA Image and Video Library

2018-02-28

NASA's Curiosity Mars rover used a new drill method to produce a hole on Feb. 26, 2018, in a target named Lake Orcadie. The hole marks the first operation of the rover's drill since a motor problem began acting up more than a year ago. An early test produced a hole about a half-inch (1-centimeter) deep at Lake Orcadie --- not enough for a full scientific sample, but enough to validate that the new method works mechanically. This was just the first in what will be a series of tests to determine how well the new drill method can collect samples. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22224

A new adhesive technique for internal fixation in midfacial surgery

PubMed Central

Endres, Kira; Marx, Rudolf; Tinschert, Joachim; Wirtz, Dieter Christian; Stoll, Christian; Riediger, Dieter; Smeets, Ralf

2008-01-01

Background The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could offer a viable alternative for fixing the plates without screws. In order to achieve the adhesive bonding of bone cement to cortical bone in the viscerocranium, an amphiphilic bone bonding agent was created, analogous to the dentin bonding agents currently on the market. Methods The adhesive bonding strengths were measured using tension tests. For this, metal plates with 2.0 mm diameter screw holes were cemented with PMMA bone cement to cortical bovine bone samples from the femur diaphysis. The bone was conditioned with an amphiphilic bone bonding agent prior to cementing. The samples were stored for 1 to 42 days at 37 degrees C, either moist or completely submerged in an isotonic NaCl-solution, and then subjected to the tension tests. Results Without the bone bonding agent, the bonding strength was close to zero (0.2 MPa). Primary stability with bone bonding agent is considered to be at ca. 8 MPa. Moist storage over 42 days resulted in decreased adhesion forces of ca. 6 MPa. Wet storage resulted in relatively constant bonding strengths of ca. 8 MPa. Conclusion A new amphiphilic bone bonding agent was developed, which builds an optimizied interlayer between the hydrophilic bone surface and the hydrophobic PMMA bone cement and thus leads to adhesive bonding between them. Our in vitro investigations demonstrated the adhesive bonding of PMMA bone cement to cortical bone, which was also stable against hydrolysis. The newly developed adhesive fixing technique could be applied clinically when the fixation of osteosynthesis plates with screws is impossible. With the detected adhesion forces of ca. 6 to 8 MPa, it is assumed that the adhesive fixation system is able to secure bone fragments from the non-load bearing midfacial regions in their orthotopic positions until fracture consolidation is complete. PMID:18489785

The anti-de Sitter Gott universe: a rotating BTZ wormhole

NASA Astrophysics Data System (ADS)

Holst, Sören; Matschull, Hans-Jürgen

1999-10-01

Recently, it has been shown that a (2 + 1)-dimensional black hole can be created by the collapse of two colliding massless particles in an otherwise empty anti-de Sitter space. Here we generalize this construction to the case of a non-zero impact parameter. The resulting spacetime, which may be regarded as a Gott universe in an anti-de Sitter background, contains closed timelike curves. By treating these as singular we are able to interpret our solution as a rotating black hole, hence providing a link between the Gott universe and the BTZ black hole. When analysing the spacetime we see how the full causal structure of the interior can be almost completely inferred just from considerations of the conformal boundary.

A flexible method for residual stress measurement of spray coated layers by laser made hole drilling and SLM based beam steering

NASA Astrophysics Data System (ADS)

Osten, W.; Pedrini, G.; Weidmann, P.; Gadow, R.

2015-08-01

A minimum invasive but high resolution method for residual stress analysis of ceramic coatings made by thermal spraycoating using a pulsed laser for flexible hole drilling is described. The residual stresses are retrieved by applying the measured surface data for a model-based reconstruction procedure. While the 3D deformations and the profile of the machined area are measured with digital holography, the residual stresses are calculated by FE analysis. To improve the sensitivity of the method, a SLM is applied to control the distribution and the shape of the holes. The paper presents the complete measurement and reconstruction procedure and discusses the advantages and challenges of the new technology.

Critical cell wall hole size for lysis in Gram-positive bacteria

NASA Astrophysics Data System (ADS)

Mitchell, Gabriel; Wiesenfeld, Kurt; Nelson, Daniel; Weitz, Joshua

2013-03-01

Gram-positive bacteria transport molecules necessary for their survival through holes in their cell wall. The holes in cell walls need to be large enough to let critical nutrients pass through. However, the cell wall must also function to prevent the bacteria's membrane from protruding through a large hole into the environment and lysing the cell. As such, we hypothesize that there exists a range of cell wall hole sizes that allow for molecule transport but prevent membrane protrusion. Here we develop and analyze a biophysical theory of the response of a Gram-positive cell's membrane to the formation of a hole in the cell wall. We predict a critical hole size in the range 15-24nm beyond which lysis occurs. To test our theory, we measured hole sizes in Streptococcus pyogenes cells undergoing enzymatic lysis via transmission electron microscopy. The measured hole sizes are in strong agreement with our theoretical prediction. Together, the theory and experiments provide a means to quantify the mechanisms of death of Gram-positive cells via enzymatically mediated lysis and provides insight into the range of cell wall hole sizes compatible with bacterial homeostasis.

Vacuum decay container/closure integrity testing technology. Part 2. Comparison to dye ingress tests.

PubMed

Wolf, Heinz; Stauffer, Tony; Chen, Shu-Chen Y; Lee, Yoojin; Forster, Ronald; Ludzinski, Miron; Kamat, Madhav; Mulhall, Brian; Guazzo, Dana Morton

2009-01-01

Part 1 of this series demonstrated that a container closure integrity test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method using a VeriPac 325/LV vacuum decay leak tester by Packaging Technologies & Inspection, LLC (PTI) is capable of detecting leaks > or = 5.0 microm (nominal diameter) in rigid, nonporous package systems, such as prefilled glass syringes. The current study compared USP, Ph.Eur. and ISO dye ingress integrity test methods to PTI's vacuum decay technology for the detection of these same 5-, 10-, and 15-microm laser-drilled hole defects in 1-mL glass prefilled syringes. The study was performed at three test sites using several inspectors and a variety of inspection conditions. No standard dye ingress method was found to reliably identify all holed syringes. Modifications to these standard dye tests' challenge conditions increased the potential for dye ingress, and adjustments to the visual inspection environment improved dye ingress detection. However, the risk of false positive test results with dye ingress tests remained. In contrast, the nondestructive vacuum decay leak test method reliably identified syringes with holes > or = 5.0 microm.

Probability of detection for bolt hole eddy current in extracted from service aircraft wing structures

NASA Astrophysics Data System (ADS)

Underhill, P. R.; Uemura, C.; Krause, T. W.

2018-04-01

Fatigue cracks are prone to develop around fasteners found in multi-layer aluminum structures on aging aircraft. Bolt hole eddy current (BHEC) is used for detection of cracks from within bolt holes after fastener removal. In support of qualification towards a target a90/95 (detect 90% of cracks of depth a, 95% of the time) of 0.76 mm (0.030"), a preliminary probability of detection (POD) study was performed to identify those parameters whose variation may keep a bolt hole inspection from attaining its goal. Parameters that were examined included variability in lift-off due to probe type, out-of-round holes, holes with diameters too large to permit surface-contact of the probe and mechanical damage to the holes, including burrs. The study examined the POD for BHEC of corner cracks in unfinished fastener holes extracted from service material. 68 EDM notches were introduced into two specimens of a horizontal stabilizer from a CC-130 Hercules aircraft. The fastener holes were inspected in the unfinished state, simulating potential inspection conditions, by 7 certified inspectors using a manual BHEC setup with an impedance plane display and also with one inspection conducted utilizing a BHEC automated C-Scan apparatus. While the standard detection limit of 1.27 mm (0.050") was achieved, given the a90/95 of 0.97 mm (0.039"), the target 0.76 mm (0.030") was not achieved. The work highlighted a number of areas where there was insufficient information to complete the qualification. Consequently, a number of recommendations were made. These included; development of a specification for minimum probe requirements; criteria for condition of the hole to be inspected, including out-of-roundness and presence of corrosion pits; statement of range of hole sizes; inspection frequency and data display for analysis.

Binary Black Hole Mergers, Gravitational Waves, and LISA

NASA Astrophysics Data System (ADS)

Centrella, Joan; Baker, J.; Boggs, W.; Kelly, B.; McWilliams, S.; van Meter, J.

2007-12-01

The final merger of comparable mass binary black holes is expected to be the strongest source of gravitational waves for LISA. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. We will present the results of new simulations of black hole mergers with unequal masses and spins, focusing on the gravitational waves emitted and the accompanying astrophysical "kicks.” The magnitude of these kicks has bearing on the production and growth of supermassive blackholes during the epoch of structure formation, and on the retention of black holes in stellar clusters. This work was supported by NASA grant 06-BEFS06-19, and the simulations were carried out using Project Columbia at the NASA Advanced Supercomputing Division (Ames Research Center) and at the NASA Center for Computational Sciences (Goddard Space Flight Center).

Experimental Heat Transfer and Bulk Air Temperature Measurements for a Multipass Internal Cooling Model with Ribs and Bleed

NASA Technical Reports Server (NTRS)

Thurman, Douglas; Poinsatte, Philip

2001-01-01

An experimental study was made to obtain heat transfer and air temperature data for a simple three-leg serpentine test section that simulates a turbine blade internal cooling passage with trip strips and bleed holes. The objectives were to investigate the interaction of ribs and various bleed conditions on internal cooling and to gain a better understanding of bulk air temperature in an internal passage. Steady-state heat transfer measurements were obtained using a transient technique with thermochromic liquid crystals. Trip strips were attached to one wall of the test section and were located either between or near the bleed holes. The bleed holes, used for film cooling, were metered to simulate the effect of external pressure on the turbine blade. Heat transfer enhancement was found to be greater for ribs near bleed holes compared to ribs between holes, and both configurations were affected slightly by bleed rates upstream. Air temperature measurements were taken at discrete locations along one leg of the model. Average bulk air temperatures were found to remain fairly constant along one leg of the model.

Experimental Heat Transfer and Bulk Air Temperature Measurements for a Multipass Internal Cooling Model with Ribs and Bleed

NASA Technical Reports Server (NTRS)

Thurman, Douglas; Poinsatte, Philip

2000-01-01

An experimental study was made to obtain heat transfer and air temperature data for a simple 3-leg serpentine test section that simulates a turbine blade internal cooling passage with trip strips and bleed holes. The objectives were to investigate the interaction of ribs and various bleed conditions on internal cooling and to gain a better understanding of bulk air temperature in an internal passage. Steady state heat transfer measurements were obtained using a transient technique with thermochromic liquid crystals. Trip strips were attached to one wall of the test section and were located either between or near the bleed holes. The bleed holes, used for film cooling, were metered to simulate the effect of external pressure on the turbine blade. Heat transfer enhancement was found to be greater for ribs near bleed holes compared to ribs between holes, and both configurations were affected slightly by bleed rates upstream. Air temperature measurements were taken at discreet locations along one leg of the model. Average bulk air temperatures were found to remain fairly constant along one leg of the model.

Testing general relativity's no-hair theorem with x-ray observations of black holes

NASA Astrophysics Data System (ADS)

Hoormann, Janie K.; Beheshtipour, Banafsheh; Krawczynski, Henric

2016-02-01

Despite its success in the weak gravity regime, general relativity (GR) has yet to be verified in the regime of strong gravity. In this paper, we present the results of detailed ray-tracing simulations aiming at clarifying if the combined information from x-ray spectroscopy, timing, and polarization observations of stellar mass and supermassive black holes can be used to test GR's no-hair theorem. The latter states that stationary astrophysical black holes are described by the Kerr family of metrics, with the black hole mass and spin being the only free parameters. We use four "non-Kerr metrics," some phenomenological in nature and others motivated by alternative theories of gravity, and study the observational signatures of deviations from the Kerr metric. Particular attention is given to the case when all the metrics are set to give the same innermost stable circular orbit in quasi-Boyer-Lindquist coordinates. We give a detailed discussion of similarities and differences of the observational signatures predicted for black holes in the Kerr metric and the non-Kerr metrics. We emphasize that even though some regions of the parameter space are nearly degenerate even when combining the information from all observational channels, x-ray observations of very rapidly spinning black holes can be used to exclude large regions of the parameter space of the alternative metrics. Although it proves difficult to distinguish between the Kerr and non-Kerr metrics for some portions of the parameter space, the observations of very rapidly spinning black holes like Cyg X-1 can be used to rule out large regions for several black hole metrics.

Hole-pin joining structure with fiber-round-hole distribution of lobster cuticle and biomimetic study.

PubMed

Chen, Bin; Fan, Jinghong; Gou, Jihua; Lin, Shiyun

2014-12-01

Observations of the cuticle of the Boston Spiny Lobster using scanning electron microscope (SEM) show that it is a natural biocomposite consisting of chitin fibers and sclerotic-protein matrix with hierarchical and helicoidal structure. The SEM images also indicate that there is a hole-pin joining structure in the cuticle. In this joining structure, the chitin fibers in the neighborhood of the joining holes continuously round the holes to form a fiber-round-hole distribution. The maximum pullout force of the fibers in the fiber-round-hole distribution, which is closely related to the fracture toughness of the cuticle, is investigated and compared with that of the fibers in non-fiber-round-hole distribution based on their representative models. It is revealed that the maximum pullout force of the fibers in the fiber-round-hole distribution is significantly larger than that of the fibers in the non-fiber-round-hole distribution, and that a larger diameter of the hole results in a larger difference in the maximum pullout forces of the fibers between the two kinds of the fiber distributions. Inspired by the fiber-round-hole distribution found in the cuticle, composite specimens with the fiber-round-hole distribution were fabricated with a special mold and process to mirror the fiber-round-hole distribution. The fracture toughness of the biomimetic composite specimens is tested and compared with that of the conventional composite specimens with the non-fiber-round-hole distribution. It is demonstrated that the fracture toughness of the biomimetic composite specimens with the fiber-round-hole distribution is significantly larger than that of the conventional composite specimens with the non-fiber-round-hole distribution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Can test fields destroy the event horizon in the Kerr–Taub–NUT spacetime?

NASA Astrophysics Data System (ADS)

Düztaş, Koray

2018-02-01

In this work we investigate if the interaction of the Kerr–Taub–NUT spacetime with test scalar and neutrino fields can lead to the destruction of the event horizon. It turns out that both extremal and nearly extremal black holes can be destroyed by scalar and neutrino fields if the initial angular momentum of the spacetime is sufficiently large relative to its mass and NUT charge. This is the first example in which a classical field satisfying the null energy condition can actually destroy an extremal black hole. For scalar fields, the modes that can lead to the destruction of the horizon are restricted to a narrow range due to superradiance. Since superradiance does not occur for neutrino fields, the destruction of the horizon by neutrino fields is generic, and it cannot be fixed by backreaction effects. We also show that the extremal black holes that can be destroyed by scalar fields correspond to naked singularities in the Kerr limit, in accord with the previous results which imply that extremal Kerr black holes cannot be destroyed by scalar test fields.

Materials investigation and tests for the development of space compatible electrical connectors

NASA Technical Reports Server (NTRS)

Pomeroy, C.; Mccabe, T.

1971-01-01

A molding study of compounds based on copolymers of highly fluorinated olefins and of flame retardant silicone is reported. Both single cavity and four cavity molds having size 22 and 24 holes with three webs in each hole were used. Also covered are dielectric strength, arc resistance, Bashore rebound, and maintenance aging tests on the various materials that have been successfully molded.

Multichannel Analysis of Surface Waves and Down-Hole Tests in the Archeological "Palatine Hill" Area (Rome, Italy): Evaluation and Influence of 2D Effects on the Shear Wave Velocity

NASA Astrophysics Data System (ADS)

Di Fiore, V.; Cavuoto, G.; Tarallo, D.; Punzo, M.; Evangelista, L.

2016-05-01

A joint analysis of down-hole (DH) and multichannel analysis of surface waves (MASW) measurements offers a complete evaluation of shear wave velocity profiles, especially for sites where a strong lateral variability is expected, such as archeological sites. In this complex stratigraphic setting, the high "subsoil anisotropy" (i.e., sharp lithological changes due to the presence of anthropogenic backfill deposits and/or buried man-made structures) implies a different role for DH and MASW tests. This paper discusses some results of a broad experimental program conducted on the Palatine Hill, one of the most ancient areas of the city of Rome (Italy). The experiments were part of a project on seismic microzoning and consisted of 20 MASW and 11 DH tests. The main objective of this study was to examine the difficulties related to the interpretation of the DH and MASW tests and the reliability limits inherent in the application of the noninvasive method in complex stratigraphic settings. As is well known, DH tests provide good determinations of shear wave velocities (Vs) for different lithologies and man-made materials, whereas MASW tests provide average values for the subsoil volume investigated. The data obtained from each method with blind tests were compared and were correlated to site-specific subsurface conditions, including lateral variability. Differences between punctual (DH) and global (MASW) Vs measurements are discussed, quantifying the errors by synthetic comparison and by site response analyses. This study demonstrates that, for archeological sites, VS profiles obtained from the DH and MASW methods differ by more than 15 %. However, the local site effect showed comparable results in terms of natural frequencies, whereas the resolution of the inverted shear wave velocity was influenced by the fundamental mode of propagation.

Elasto-Plastic 3D Finite Element Contact Analysis of a Hole Containing a Circular Insert in a Fatigue Test Coupon

DTIC Science & Technology

2015-08-01

primarily concerned with the results of a three-dimensional elasto– plastic finite element contact analysis of a typical aluminium fatigue test coupon...determine the nonlinear three-dimensional elasto–plastic contact stress distributions around a circular hole in an aluminium plate that is fitted...Australian Air Force (RAAF) airframes. An aluminium -alloy fatigue test coupon (see Figure 1) has been designed and applied in support of the validation of

James Webb Space Telescope Out of Chamber “A” on This Week @NASA – December 1, 2017

NASA Image and Video Library

2017-12-01

Our James Webb Space Telescope is now out of the historic Chamber A vacuum facility at our Johnson Space Center in Houston, after completing cryogenic testing designed to ensure the telescope works well in the cold, airless environment of space. Set to launch in 2019, Webb will study every phase in the history of our Universe, starting with the first luminous glows following the Big Bang. Also, NASA’s Next Mars Rover Mission, New Space Station Crew Trains for Launch, Update for Next SpaceX Launch to Space Station, Giant Black Hole Pair Photobombs Andromeda Galaxy, and Historic Apollo Mission Control Center Will Be Restored!

Quiet eye training facilitates competitive putting performance in elite golfers.

PubMed

Vine, Samuel J; Moore, Lee J; Wilson, Mark R

2011-01-01

The aim of this study was to examine the effectiveness of a brief quiet eye (QE) training intervention aimed at optimizing visuomotor control and putting performance of elite golfers under pressure, and in real competition. Twenty-two elite golfers (mean handicap 2.7) recorded putting statistics over 10 rounds of competitive golf before attending training individually. Having been randomly assigned to either a QE training or Control group, participants were fitted with an Applied Science Laboratories Mobile Eye tracker and performed 20 baseline (pre-test) putts from 10 ft. Training consisted of video feedback of their gaze behavior while they completed 20 putts; however the QE-trained group received additional instructions related to maintaining a longer QE period. Participants then recorded their putting statistics over a further 10 competitive rounds and re-visited the laboratory for retention and pressure tests of their visuomotor control and putting performance. Overall, the results were supportive of the efficacy of the QE training intervention. QE duration predicted 43% of the variance in putting performance, underlying its critical role in the visuomotor control of putting. The QE-trained group maintained their optimal QE under pressure conditions, whereas the Control group experienced reductions in QE when anxious, with subsequent effects on performance. Although their performance was similar in the pre-test, the QE-trained group holed more putts and left the ball closer to the hole on missed putts than their Control group counterparts in the pressure test. Importantly, these advantages transferred to the golf course, where QE-trained golfers made 1.9 fewer putts per round, compared to pre-training, whereas the Control group showed no change in their putting statistics. These results reveal that QE training, incorporated into a pre-shot routine, is an effective intervention to help golfers maintain control when anxious.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sibbett, B.S.; Nielson, D.L.; Adams, M.C.

This technical report on the Phase II geothermal exploration of Ascension Island documents the data collected during thermal gradient drilling and the subsequent thermal and fluid chemical investigations. It also documents the completion of the Phase II exploration strategy which was proposed at the end of the Phase I--Preliminary Examination of Ascension Island. The thermal gradient drilling resulted in seven holes which range from 206 to 1750 ft (53-533 m) deep, with a cumulative footage of 6563 ft (2000 m). The drilling procedure and the problems encountered during the drilling have been explained in detail to provide information valuable formore » any subsequent drilling program on the island. In addition, the subsurface geology encountered in the holes has been documented and, where possible, correlated with other holes or the geology mapped on the surface of the island. Temperatures measured in the holes reach a maximum of 130 F (54.4 C) at 1285 ft (391.7 m) in hole GH-6. When the temperatures of all holes are plotted against elevation, the holes can be classed into three distinct groups, those which have no thermal manifestations, those with definite geothermal affinities, and one hole which is intermediate between the other two. From consideration of this information, it is clear that the highest geothermal potential on the island is in the Donkey Flat area extending beneath Middleton Ridge, and in the Cricket Valley area. Because of the greater drilling depths and the remote nature of the Cricket Valley area, it is recommended that future exploration concentrate in the area around Middleton Ridge.« less

The close environments of accreting massive black holes are shaped by radiative feedback.

PubMed

Ricci, Claudio; Trakhtenbrot, Benny; Koss, Michael J; Ueda, Yoshihiro; Schawinski, Kevin; Oh, Kyuseok; Lamperti, Isabella; Mushotzky, Richard; Treister, Ezequiel; Ho, Luis C; Weigel, Anna; Bauer, Franz E; Paltani, Stephane; Fabian, Andrew C; Xie, Yanxia; Gehrels, Neil

2017-09-27

The majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies across the electromagnetic spectrum. The origin of this trend may be driven by the increase in the inner radius of the obscuring material with incident luminosity, which arises from the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism that regulates obscuration unclear. Here we report a systematic multi-wavelength survey of hard-X-ray-selected black holes that reveals that radiative feedback on dusty gas is the main physical mechanism that regulates the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas is located within a few to tens of parsecs of the accreting supermassive black hole (within the sphere of influence of the black hole), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate.

Internal Limiting Membrane Flap Techniques for the Repair of Large Macular Holes: a Short-Term Follow-up of Anatomical and Functional Outcomes.

PubMed

Guber, J; Lang, C; Valmaggia, C

2017-04-01

Background To evaluate the technique of inverted internal limiting membrane (ILM) flaps for the management of large macular holes and autologous ILM free flaps for non-closing macular holes. Patients and methods All macular holes were treated with pars plana vitrectomy and dual blue assisted ILM flap technique. The inverted ILM flap was created as a primary procedure for large macular holes (diameter > 400 µm). On the other hand, the free ILM flap technique was used as a secondary procedure for non-closing macular holes after failed initial standard procedure. SD-OCT images were taken to assess the anatomical outcome of surgery, while best corrected visual acuity (BCVA) was used to evaluate the functional outcome during a 2-month follow-up. Results All patients underwent successful planned manipulation of the ILM flap. In seven patients/eyes, an inverted ILM flap was created, in three patients/eyes a free ILM flap translocation was performed. All patients achieved complete anatomical closure. Partial microstructural reconstruction, demonstrated on SD-OCT as restoration of the external limiting membrane and the ellipsoid zone, was observed in some cases as early as one month after surgery. Functionally, in comparison to baseline, most of the patients showed improvements in BCVA of 1 to 2 lines at the first postoperative follow-up visit. Conclusions Inverted ILM flaps for large macular holes and free flaps for non-closing macular holes appear to be a safe and effective approach, with favourable short-term anatomical and functional results. Georg Thieme Verlag KG Stuttgart · New York.

The close environments of accreting massive black holes are shaped by radiative feedback

NASA Astrophysics Data System (ADS)

Ricci, Claudio; Trakhtenbrot, Benny; Koss, Michael J.; Ueda, Yoshihiro; Schawinski, Kevin; Oh, Kyuseok; Lamperti, Isabella; Mushotzky, Richard; Treister, Ezequiel; Ho, Luis C.; Weigel, Anna; Bauer, Franz E.; Paltani, Stephane; Fabian, Andrew C.; Xie, Yanxia; Gehrels, Neil

2017-09-01

The majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies across the electromagnetic spectrum. The origin of this trend may be driven by the increase in the inner radius of the obscuring material with incident luminosity, which arises from the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism that regulates obscuration unclear. Here we report a systematic multi-wavelength survey of hard-X-ray-selected black holes that reveals that radiative feedback on dusty gas is the main physical mechanism that regulates the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas is located within a few to tens of parsecs of the accreting supermassive black hole (within the sphere of influence of the black hole), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate.

A computational fluid dynamics simulation framework for ventricular catheter design optimization.

PubMed

Weisenberg, Sofy H; TerMaath, Stephanie C; Barbier, Charlotte N; Hill, Judith C; Killeffer, James A

2017-11-10

OBJECTIVE Cerebrospinal fluid (CSF) shunts are the primary treatment for patients suffering from hydrocephalus. While proven effective in symptom relief, these shunt systems are plagued by high failure rates and often require repeated revision surgeries to replace malfunctioning components. One of the leading causes of CSF shunt failure is obstruction of the ventricular catheter by aggregations of cells, proteins, blood clots, or fronds of choroid plexus that occlude the catheter's small inlet holes or even the full internal catheter lumen. Such obstructions can disrupt CSF diversion out of the ventricular system or impede it entirely. Previous studies have suggested that altering the catheter's fluid dynamics may help to reduce the likelihood of complete ventricular catheter failure caused by obstruction. However, systematic correlation between a ventricular catheter's design parameters and its performance, specifically its likelihood to become occluded, still remains unknown. Therefore, an automated, open-source computational fluid dynamics (CFD) simulation framework was developed for use in the medical community to determine optimized ventricular catheter designs and to rapidly explore parameter influence for a given flow objective. METHODS The computational framework was developed by coupling a 3D CFD solver and an iterative optimization algorithm and was implemented in a high-performance computing environment. The capabilities of the framework were demonstrated by computing an optimized ventricular catheter design that provides uniform flow rates through the catheter's inlet holes, a common design objective in the literature. The baseline computational model was validated using 3D nuclear imaging to provide flow velocities at the inlet holes and through the catheter. RESULTS The optimized catheter design achieved through use of the automated simulation framework improved significantly on previous attempts to reach a uniform inlet flow rate distribution using the standard catheter hole configuration as a baseline. While the standard ventricular catheter design featuring uniform inlet hole diameters and hole spacing has a standard deviation of 14.27% for the inlet flow rates, the optimized design has a standard deviation of 0.30%. CONCLUSIONS This customizable framework, paired with high-performance computing, provides a rapid method of design testing to solve complex flow problems. While a relatively simplified ventricular catheter model was used to demonstrate the framework, the computational approach is applicable to any baseline catheter model, and it is easily adapted to optimize catheters for the unique needs of different patients as well as for other fluid-based medical devices.

San Andreas fault zone drilling project: scientific objectives and technological challenges

USGS Publications Warehouse

Hickman, S.H.; Younker, L.W.; Zoback, M.D.

1995-01-01

We are leading a new international initiative to conduct scientific drilling within the San Andreas fault zone at depths of up to 10 km. This project is motivated by the need to understand the physical and chemical processes operating within the fault zone and to answer fundamental questions about earthquake generation along major plate-boundary faults. Through a comprehensive program of coring, fluid sampling, downhole measurements, laboratory experimentation, and long-term monitoring, we hope to obtain critical information on the structure, composition, mechanical behavior and physical state of the San Andreas fault system at depths comparable to the nucleation zones of great earthquakes. The drilling, sampling and observational requirements needed to ensure the success of this project are stringent. These include: 1) drilling stable vertical holes to depths of about 9 km in fractured rock at temperatures of up to 300°C; 2) continuous coring and completion of inclined holes branched off these vertical boreholes to intersect the fault at depths of 3, 6, and 9 km; 3) conducting sophisticated borehole geophysical measurements and fluid/rock sampling at high temperatures and pressures; and 4) instrumenting some or all of these inclined core holes for continuous monitoring of earthquake activity, fluid pressure, deformation and other parameters for periods of up to several decades. For all of these tasks, because of the overpressured clay-rich formations anticipated within the fault zone at depth, we expect to encounter difficult drilling, coring and hole-completion conditions in the region of greatest scientific interest.

Understanding the build-up of supermassive black holes and galaxies

NASA Astrophysics Data System (ADS)

Carrera, Francisco; Ueda, Yoshihiro; Georgakakis, Antonis

2016-07-01

One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionisedmaterial that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe. The excellent survey capabilities of Athena/WFI (effective area, angular resolution, field of view) will allow to measure the incidence of feedback in the shape of warm absorbers and Ultra Fast Outflows among the general population of AGN, as well as to complete the census of black hole growth by detecting and characterising significant samples of the most heavily obscured (including Compton thick) AGN, to redshifts z~3-4. The outstanding spectral throughput and resolution of Athena/X-IFU will permit measuring the energetics of those outflows to assess their influence on their host galaxies. The demographics of the heavily obscured and outflowing populations relative to their hosts are fundamental for understanding how major black hole growth events relate to the build-up of galaxies.

Quantum criticality and black holes.

PubMed

Sachdev, Subir; Müller, Markus

2009-04-22

Many condensed matter experiments explore the finite temperature dynamics of systems near quantum critical points. Often, there are no well-defined quasiparticle excitations, and so quantum kinetic equations do not describe the transport properties completely. The theory shows that the transport coefficients are not proportional to a mean free scattering time (as is the case in the Boltzmann theory of quasiparticles), but are completely determined by the absolute temperature and by equilibrium thermodynamic observables. Recently, explicit solutions of this quantum critical dynamics have become possible via the anti-de Sitter/conformal field theory duality discovered in string theory. This shows that the quantum critical theory provides a holographic description of the quantum theory of black holes in a negatively curved anti-de Sitter space, and relates its transport coefficients to properties of the Hawking radiation from the black hole. We review how insights from this connection have led to new results for experimental systems: (i) the vicinity of the superfluid-insulator transition in the presence of an applied magnetic field, and its possible application to measurements of the Nernst effect in the cuprates, (ii) the magnetohydrodynamics of the plasma of Dirac electrons in graphene and the prediction of a hydrodynamic cyclotron resonance.

Experimental assessment of film cooling performance of short cylindrical holes on a flat surface

NASA Astrophysics Data System (ADS)

Singh, Kuldeep; Premachandran, B.; Ravi, M. R.

2016-12-01

The present study is an experimental investigation of film-cooling over a flat surface from the short cylindrical holes. The film cooling holes used in the combustion chamber and the afterburner liner of an aero engine has length-to-diameter (L/D) typically in the range 1-2, while the cooling holes used in turbine blades has L/D > 3. Based on the classification given in the literature, cooling holes with L/D ≤ 3 are named as short holes and cooling holes with L/D > 3 are named as long holes. Short film cooling holes cause jetting of the secondary fluid whereas the secondary fluid emerging from long holes has characteristics similar to fully developed turbulent flow in pipe. In order to understand the difference in the film cooling performance of long and short cooling holes, experimental study is carried out for five values of L/D in the range 1-5, five injection angles, α = 15°-90° and five mainstream Reynolds number 1.25 × 105-6.25 × 105 and two blowing ratios, M = 0.5-1.0. The surface temperature of the test plate is monitored using infrared thermography. The results obtained from the present study showed that the film-cooling effectiveness is higher for the longest holes (L/D = 5) investigated in the present work in comparison to that for the shorter holes. Short holes are found to give better effectiveness at the lowest investigated injection angle i.e. α = 15° in the near cooling hole region, whereas film cooling effectiveness obtained at injection angle, α = 45° is found to be better than other injection angles for longest investigated holes, i.e. L/D = 5.

DOE/NV/25946--1586 Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

NASA Astrophysics Data System (ADS)

Townsend, M.; Huckins-Gang, H.; Prothro, L.; Reed, D.

2012-12-01

The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE N1) test was conducted in May 2011, using 0.1 ton of explosives at the depth of 54.9 m in the U 15n source hole. SPE N2 was conducted in October 2011, using 1.0 ton of explosives at the depth of 45.7 m in the same source hole. The SPE N3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE N2, and at the same depth as SPE N2, within the damage zone created by the SPE N2 explosion to investigate damage effects on seismic wave propagation. Following the SPE N2 shot and prior to the SPE N3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE N2 shot point location to obtain information necessary to characterize the damage zone. The desire was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE N2 core hole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories for measurement of physical and mechanical properties. A video was also run in the source hole after it was cleaned out. A significant natural fault zone was encountered in the angle core hole between 5.7 and 7.5 m from the shot point. However, several of the fractures observed in the core hole are interpreted as having been caused by the explosion. The fractures are characterized by a "fresh," mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets; they are common starting at about 5.4 m from the shot point. Within about 3.3 m of the shot point to the end of the recovered core at 1.6 m from the shot point, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

Rotating black hole solutions in relativistic analogue gravity

NASA Astrophysics Data System (ADS)

Giacomelli, Luca; Liberati, Stefano

2017-09-01

Simulation and experimental realization of acoustic black holes in analogue gravity systems have lead to a novel understanding of relevant phenomena such as Hawking radiation or superradiance. We explore here the possibility of using relativistic systems for simulating rotating black hole solutions and possibly get an acoustic analogue of a Kerr black hole. In doing so, we demonstrate a precise relation between nonrelativistic and relativistic solutions and provide a new class of vortex solutions for relativistic systems. Such solutions might be used in the future as a test bed in numerical simulations as well as concrete experiments.

Gravitational polarizability of black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damour, Thibault; Lecian, Orchidea Maria; APC, UMR 7164 du CNRS, Universite Paris 7, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13

The gravitational polarizability properties of black holes are compared and contrasted with their electromagnetic polarizability properties. The 'shape' or 'height' multipolar Love numbers h{sub l} of a black hole are defined and computed. They are then compared to their electromagnetic analogs h{sub l}{sup EM}. The Love numbers h{sub l} give the height of the lth multipolar 'tidal bulge' raised on the horizon of a black hole by faraway masses. We also discuss the shape of the tidal bulge raised by a test-mass m, in the limit where m gets very close to the horizon.

A Test of Black-Hole Disk Truncation: Thermal Disk Emission in the Bright Hard State

NASA Astrophysics Data System (ADS)

Steiner, James

2017-09-01

The assumption that a black hole's accretion disk extends inwards to the ISCO is on firm footing for soft spectral states, but has been challenged for hard spectral states where it is often argued that the accretion flow is truncated far from the horizon. This is of critical importance because black-hole spin is measured on the basis of this assumption. The direct detection (or absence) of thermal disk emission associated with a disk extending to the ISCO is the smoking-gun test to rule truncation in or out for the bright hard state. Using a self-consistent spectral model on data taken in the bright hard state while taking advantage of the complementary coverage and capabilities of Chandra and NuSTAR, we will achieve a definitive test of the truncation paradigm.

Dynamic fisheye grids for binary black hole simulations

NASA Astrophysics Data System (ADS)

Zilhão, Miguel; Noble, Scott C.

2014-03-01

We present a new warped gridding scheme adapted to simulating gas dynamics in binary black hole spacetimes. The grid concentrates grid points in the vicinity of each black hole to resolve the smaller scale structures there, and rarefies grid points away from each black hole to keep the overall problem size at a practical level. In this respect, our system can be thought of as a ‘double’ version of the fisheye coordinate system, used before in numerical relativity codes for evolving binary black holes. The gridding scheme is constructed as a mapping between a uniform coordinate system—in which the equations of motion are solved—to the distorted system representing the spatial locations of our grid points. Since we are motivated to eventually use this system for circumbinary disc calculations, we demonstrate how the distorted system can be constructed to asymptote to the typical spherical polar coordinate system, amenable to efficiently simulating orbiting gas flows about central objects with little numerical diffusion. We discuss its implementation in the Harm3d code, tailored to evolve the magnetohydrodynamics equations in curved spacetimes. We evaluate the performance of the system’s implementation in Harm3d with a series of tests, such as the advected magnetic field loop test, magnetized Bondi accretion, and evolutions of hydrodynamic discs about a single black hole and about a binary black hole. Like we have done with Harm3d, this gridding scheme can be implemented in other unigrid codes as a (possibly) simpler alternative to adaptive mesh refinement.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broderick, Avery E.; Johannsen, Tim; Loeb, Abraham

The advent of the Event Horizon Telescope (EHT), a millimeter-wave very long baseline interferometric array, has enabled spatially resolved studies of the subhorizon-scale structure for a handful of supermassive black holes. Among these, the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), presents the largest angular cross section. Thus far, these studies have focused on measurements of the black hole spin and the validation of low-luminosity accretion models. However, a critical input in the analysis of EHT data is the structure of the black hole spacetime, and thus these observations provide the novel opportunitymore » to test the applicability of the Kerr metric to astrophysical black holes. Here we present the first simulated images of a radiatively inefficient accretion flow (RIAF) around Sgr A* employing a quasi-Kerr metric that contains an independent quadrupole moment in addition to the mass and spin that fully characterize a black hole in general relativity. We show that these images can be significantly different from the images of an RIAF around a Kerr black hole with the same spin and demonstrate the feasibility of testing the no-hair theorem by constraining the quadrupolar deviation from the Kerr metric with existing EHT data. Equally important, we find that the disk inclination and spin orientation angles are robust to the inclusion of additional parameters, providing confidence in previous estimations assuming the Kerr metric based on EHT observations. However, at present, the limits on potential modifications of the Kerr metric remain weak.« less

Ion extraction from a plasma

NASA Technical Reports Server (NTRS)

Aston, G.; Wilbur, P. J.

1981-01-01

The physical processes governing ion extraction from a plasma have been examined experimentally. The screen hole plasma sheath (the transition region wherein significant ion acceleration and complete electron retardation occurs) has been defined by equipotential plots for a variety of ion accelerator system geometries and operating conditions. It was found that the screen hole plasma sheath extends over a large distance, and influences ion and electron trajectories at least 15 Debye lengths within the discharge chamber. The electron density variation within the screen hole plasma sheath satisfied a Maxwell-Boltzmann density distribution at an effective electron temperature dependent on the discharge plasma primary-to-Maxwellian electron density ratio. Plasma ion flow up to and through the sheath was predominantly one-dimensional, and the ions entered the sheath region with a modified Bohm velocity. Low values of the screen grid thickness to screen hole diameter ratio were found to give good ion focusing and high extracted ion currents because of the effect of screen webbing on ion focusing.

Soft Hair on Black Holes

NASA Astrophysics Data System (ADS)

Hawking, Stephen W.; Perry, Malcolm J.; Strominger, Andrew

2016-06-01

It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

Simulating Gravitational Wave Emission from Massive Black Hole Binaries

NASA Technical Reports Server (NTRS)

Centrella, Joan

2008-01-01

The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. In the past few years, this situation has changed dramatically, with a series of amazing breakthroughs. This talk will focus on the recent advances that are revealing these waveforms. highlighting their astrophysical consequences and the dramatic new potential for discovery that arises when merging black holes will be observed using gravitational waves.

Towngas Lantau link beach approach, Hong Kong and China Gas Co. Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Callnon, D.P.; Bertolucci, L.

1997-07-01

Horizontal directional drilling (HDD) laid dual, 12-in. OD, natural gas pipelines beneath a critical sea wall on Lantau island, Hong Kong New Territories. This was part of a 30-mile gas pipeline crossing under the South China Sea associated with the Towngas Lantau construction project for Hong Kong`s new Chep Lap Kok International Airport. During a twenty-one day project, Cherrington Corp. drilled and forward-reamed two, 20-in., 1,294-ft. holes to pull back the twin pipelines. The project was completed during typhoon weather, strong currents and logistical problems associated with operation in a remote uninhabited area. The successful installation of the twin gasmore » lines was the result of proper hole design, high-quality surveying techniques and innovative directional drilling methods. Each hole exited approximately 90-ft. from the pre-installed product pipe in the sea floor trench. A 20-in. reamer with bull-nose and rear stabilizer was used to open both holes from 9 to 20-inches.« less

Soft Hair on Black Holes.

PubMed

Hawking, Stephen W; Perry, Malcolm J; Strominger, Andrew

2016-06-10

It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocha, P; Da Silva, M F A; Wang, Anzhong

2008-11-15

Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent stable gravastars, and in some cases they represent 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in some other cases they collapse until themore » formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both stable gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.« less

Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes.

PubMed

Petermann, Jana S; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W; Gossner, Martin M

2016-01-01

Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and functioning. We furthermore conclude that artificial tree-hole analogues represent a useful experimental alternative to test effects of changes in forest management on natural communities.

Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes

PubMed Central

Petermann, Jana S.; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W.; Gossner, Martin M.

2016-01-01

Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and functioning. We furthermore conclude that artificial tree-hole analogues represent a useful experimental alternative to test effects of changes in forest management on natural communities. PMID:27187741

Temporary camps at drill hole U19aq on Pahute Mesa, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pippin, L.C.; Reno, R.L.; Henton, G.H.

1992-01-01

The US Department of Energy, Nevada Field Office, has proposed a nuclear test at drill hole U19aq (902100N/585000E, Nevada Coordinate System, Central Zone) on Pahute Mesa, Nevada Test Site, Nevada. In compliance with Section 106 of the National Historic Preservation Act, the DOE/NV had the Quatenary Sciences Center, Desert Research Institute, identify and evaluate the potential effects of this activity on cultural resources. To determine the nature of cultural resources in the area, DRI conducted a Class III intensive archaeological survey of an approximately 1-km[sup 2] area around the drill hole. That survey, conducted in June 1985, located and recordedmore » 20 archaeological sites. Two of those sites, interpreted as temporary camps of ancient hunters and gatherers, covered an extensive portion of the area proposed for nuclear testing. Half the sites were small concentrations of artifacts or isolated artifacts and were collected at the time of their discovery and 10 sites were left in place. Those sites were in danger of being adversely affected by the land-disturbing activities proposed at the drill hole. In August and September 1985, DRI conducted limited test excavations (15 test units) at those sites to further evaluate their scientific significance and to provide information that could be used in designing a plan for data recovery.« less

Temporary camps at drill hole U19aq on Pahute Mesa, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pippin, L.C.; Reno, R.L.; Henton, G.H.

1992-12-31

The US Department of Energy, Nevada Field Office, has proposed a nuclear test at drill hole U19aq (902100N/585000E, Nevada Coordinate System, Central Zone) on Pahute Mesa, Nevada Test Site, Nevada. In compliance with Section 106 of the National Historic Preservation Act, the DOE/NV had the Quatenary Sciences Center, Desert Research Institute, identify and evaluate the potential effects of this activity on cultural resources. To determine the nature of cultural resources in the area, DRI conducted a Class III intensive archaeological survey of an approximately 1-km{sup 2} area around the drill hole. That survey, conducted in June 1985, located and recordedmore » 20 archaeological sites. Two of those sites, interpreted as temporary camps of ancient hunters and gatherers, covered an extensive portion of the area proposed for nuclear testing. Half the sites were small concentrations of artifacts or isolated artifacts and were collected at the time of their discovery and 10 sites were left in place. Those sites were in danger of being adversely affected by the land-disturbing activities proposed at the drill hole. In August and September 1985, DRI conducted limited test excavations (15 test units) at those sites to further evaluate their scientific significance and to provide information that could be used in designing a plan for data recovery.« less

Tidal Forces in Dyonic Reissner-Nördstrom Black Hole

NASA Astrophysics Data System (ADS)

Sharif, M.; Kousar, Lubna

2018-03-01

This paper investigates the tidal as well as magnetic charge effects produced in dyonic Reissner-Nordström black hole. We evaluate Newtonian radial acceleration using radial geodesics for freely falling test particles. We establish system of equations governing radial and angular tidal forces using geodesic deviation equation and discuss their solutions for bodies falling freely towards this black hole. The radial tidal force turns out to be compressing outside the event horizon whereas the angular tidal force changes sign between event and Cauchy horizons unlike Schwarzschild black hole. The radial geodesic component starts decreasing in dyonic Reissner-Nordström black hole unlike Schwarzschild case. We conclude that magnetic charge strongly affects the radial as well as angular components of tidal force.

Nonlinear inversion of borehole-radar tomography data to reconstruct velocity and attenuation distribution in earth materials

USGS Publications Warehouse

Zhou, C.; Liu, L.; Lane, J.W.

2001-01-01

A nonlinear tomographic inversion method that uses first-arrival travel-time and amplitude-spectra information from cross-hole radar measurements was developed to simultaneously reconstruct electromagnetic velocity and attenuation distribution in earth materials. Inversion methods were developed to analyze single cross-hole tomography surveys and differential tomography surveys. Assuming the earth behaves as a linear system, the inversion methods do not require estimation of source radiation pattern, receiver coupling, or geometrical spreading. The data analysis and tomographic inversion algorithm were applied to synthetic test data and to cross-hole radar field data provided by the US Geological Survey (USGS). The cross-hole radar field data were acquired at the USGS fractured-rock field research site at Mirror Lake near Thornton, New Hampshire, before and after injection of a saline tracer, to monitor the transport of electrically conductive fluids in the image plane. Results from the synthetic data test demonstrate the algorithm computational efficiency and indicate that the method robustly can reconstruct electromagnetic (EM) wave velocity and attenuation distribution in earth materials. The field test results outline zones of velocity and attenuation anomalies consistent with the finding of previous investigators; however, the tomograms appear to be quite smooth. Further work is needed to effectively find the optimal smoothness criterion in applying the Tikhonov regularization in the nonlinear inversion algorithms for cross-hole radar tomography. ?? 2001 Elsevier Science B.V. All rights reserved.

A comparative study of irrigation versus no irrigation during burr hole craniostomy to treat chronic subdural hematoma.

PubMed

Wang, Qiang-Ping; Yuan, Ye; Guan, Jun-Wen; Jiang, Xiao-Bing

2017-09-11

Burr hole craniostomy is a widely used method for the evacuation of CSDH. However it is not clear whether the irrigation during operation improves the prognosis or gives rise to additional complications instead. This retrospective cohort study was conducted to determine this issue. Patients attending two medical centers in China who underwent burr hole drainage with irrigation (BHDI) or burr hole drainage without irrigation (BHD) for unilateral CSDH during January 2013 to December 2016 were included in this study. The patients' clinical information and follow-up data were retrospectively reviewed, and the radiologic findings were processed using the 3D Slicer software. The differences in outcomes were identified using t-test, chi-square test, or Fisher's exact test. A total of 151 patients comprising 63 patients in the BHD group and 88 patients in the BHDI group were included. Patients in the BHDI group had a higher volume of pneumocrania on the first postoperative day than that of patients in the BHD group (p < 0.05). No significant differences were observed between the two approaches in rates of rebleeding, recurrence and other complications (p > 0.05). Irrigation had no improvement in the long-term curative effect on CSDH, but it increased the risk of short-term complication in terms of pneumocrania. Therefore, this study suggests that irrigation is not an obligatory procedure during burr hole drainage.

Georgia tech catalog of gravitational waveforms

NASA Astrophysics Data System (ADS)

Jani, Karan; Healy, James; Clark, James A.; London, Lionel; Laguna, Pablo; Shoemaker, Deirdre

2016-10-01

This paper introduces a catalog of gravitational waveforms from the bank of simulations by the numerical relativity effort at Georgia Tech. Currently, the catalog consists of 452 distinct waveforms from more than 600 binary black hole simulations: 128 of the waveforms are from binaries with black hole spins aligned with the orbital angular momentum, and 324 are from precessing binary black hole systems. The waveforms from binaries with non-spinning black holes have mass-ratios q = m 1/m 2 ≤ 15, and those with precessing, spinning black holes have q ≤ 8. The waveforms expand a moderate number of orbits in the late inspiral, the burst during coalescence, and the ring-down of the final black hole. Examples of waveforms in the catalog matched against the widely used approximate models are presented. In addition, predictions of the mass and spin of the final black hole by phenomenological fits are tested against the results from the simulation bank. The role of the catalog in interpreting the GW150914 event and future massive binary black-hole search in LIGO is discussed. The Georgia Tech catalog is publicly available at einstein.gatech.edu/catalog.

Autologous neurosensory retinal free patch transplantation for persistent full-thickness macular hole.

PubMed

De Giacinto, Chiara; D'Aloisio, Rossella; Cirigliano, Gabriella; Pastore, Marco Rocco; Tognetto, Daniele

2018-03-27

To evaluate anatomical and functional outcomes after autologous neurosensory retinal free patch (ANRFP) transplantation for persistent idiopathic full-thickness macular hole (iFTMH). A 65-year-old woman with persistent macular hole in her right eye after previous 27-gauge pars plana vitrectomy with internal limiting membrane peeling and long-acting gas tamponade underwent ANRFP transplantation. Before surgery, best corrected visual acuity in her right eye was 20/800. Optical coherence tomography (OCT) showed a 715-micron-diameter FTMH. To treat the persistent FTMH, a small autologous neurosensory retinal patch was transplanted and placed inside the macular hole under perfluorocarbon liquids (PFCL). PFCL-air exchange was performed, and long-acting gas tamponade was carried out. Clinical features of the macular area, visual acuity (VA), fundus autofluorescence, microperimetry and OCT were recorded during the 10-month follow-up. The macular hole appeared successfully closed with retinal patch stable and well plugged into the hole during the whole follow-up. VA improved to 20/100 and microperimetry revealed an increase in mean retinal sensitivity from 14.7 dB at 1 month to 15.6 dB at 10 months postoperatively. OCT showed a well-distinguishable retinal patch into the hole 1 month after surgery and a completely integrated retinal patch between the retinal layers 10 months postoperatively. No intra- and postoperative complications were noticed. ANRFP transplantation may represent an innovative technique for persistent iFTMH treatment.

Vacuum birefringence and the x-ray polarization from black-hole accretion disks

NASA Astrophysics Data System (ADS)

Caiazzo, Ilaria; Heyl, Jeremy

2018-04-01

In the next decade, x-ray polarimetry will open a new window on the high-energy Universe, as several missions that include an x-ray polarimeter are currently under development. Observations of the polarization of x rays coming from the accretion disks of stellar-mass and supermassive black holes are among the new polarimeters' major objectives. In this paper, we show that these observations can be affected by the quantum electrodynamic (QED) effect of vacuum birefringence: after an x-ray photon is emitted from the accretion disk, its polarization changes as the photon travels through the accretion disk's magnetosphere, as a result of the vacuum becoming birefringent in the presence of a magnetic field. We show that this effect can be important for black holes in the energy band of the upcoming polarimeters and has to be taken into account in a complete model of the x-ray polarization that we expect to detect from black-hole accretion disks, both for stellar mass and for supermassive black holes. We find that, for a chaotic magnetic field in the disk, QED can significantly decrease the linear polarization fraction of edge-on photons, depending on the spin of the hole and on the strength of the magnetic field. This effect can provide, for the first time, a direct way to probe the magnetic field strength close to the innermost stable orbit of black-hole accretion disks and to study the role of magnetic fields in astrophysical accretion in general.

Black hole remnants and the information loss paradox

NASA Astrophysics Data System (ADS)

Chen, P.; Ong, Y. C.; Yeom, D.-h.

2015-11-01

Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a "remnant" has remained unpopular and is often dismissed due to some "undesired properties" of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of the information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that the singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate the information loss paradox and the firewall controversy. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

Non-Contact EDDY Current Hole Eccentricity and Diameter Measurement

NASA Technical Reports Server (NTRS)

Chern, E. James

1998-01-01

Precision holes are among the most critical features of a mechanical component. Deviations from permissible tolerances can impede operation and result in unexpected failure. We have developed an automated non-contact eddy current hole diameter and eccentricity measuring system. The operating principle is based on the eddy current lift-off effect, which is the coil impedance as a function of the distance between the coil and the test object. An absolute eddy current probe rotates in the hole. The impedance of each angular position is acquired and input to the computer for integration and analysis. The eccentricity of the hole is the profile of the impedance as a function of angular position as compared to a straight line, an ideal hole. The diameter of the hole is the sum of the diameter of the probe and twice the distance-calibrated impedance. An eddy current image is generated by integrating angular scans for a plurality of depths between the top and bottom to display the eccentricity profile. This system can also detect and image defects in the hole. The method for non-contact eddy current hole diameter and eccentricity measurement has been granted a patent by the U.S. Patent and Trademark Office.

Multi-objective optimization of hole characteristics during pulsed Nd:YAG laser microdrilling of gamma-titanium aluminide alloy sheet

NASA Astrophysics Data System (ADS)

Biswas, R.; Kuar, A. S.; Mitra, S.

2014-09-01

Nd:YAG laser microdrilled holes on gamma-titanium aluminide, a newly developed alloy having wide applications in turbine blades, engine valves, cases, metal cutting tools, missile components, nuclear fuel and biomedical engineering, are important from the dimensional accuracy and quality of hole point of view. Keeping this in mind, a central composite design (CCD) based on response surface methodology (RSM) is employed for multi-objective optimization of pulsed Nd:YAG laser microdrilling operation on gamma-titanium aluminide alloy sheet to achieve optimum hole characteristics within existing resources. The three characteristics such as hole diameter at entry, hole diameter at exit and hole taper have been considered for simultaneous optimization. The individual optimization of all three responses has also been carried out. The input parameters considered are lamp current, pulse frequency, assist air pressure and thickness of the job. The responses at predicted optimum parameter level are in good agreement with the results of confirmation experiments conducted for verification tests.

Effect of Boundary-Layer Bleed Hole Inclination Angle and Scaling on Flow Coefficient Behavior

NASA Technical Reports Server (NTRS)

Eichorn, Michael B.; Barnhart, Paul J.; Davis, David O.; Vyas, Manan A.; Slater, John W.

2013-01-01

Phase II data results of the Fundamental Inlet Bleed Experiments study at NASA Glenn Research Center are presented which include flow coefficient behavior for 21 bleed hole configurations. The bleed configurations are all round holes with hole diameters ranging from 0.795 to 6.35 mm, hole inclination angles from 20deg to 90deg, and thickness-to-diameter ratios from 0.25 to 2.0. All configurations were tested at a unit Reynolds number of 2.46 10(exp 7)/m and at discrete local Mach numbers of 1.33, 1.62, 1.98, 2.46, and 2.92. Interactions between the design parameters of hole diameter, hole inclination angle, and thickness-to-diameter as well as the interactions between the flow parameters of pressure ratio and Mach number upon the flow coefficient are examined, and a preliminary statistical model is proposed. An existing correlation is also examined with respect to this data.

Fabrication of PDMS through-holes using the MIMIC method and the surface treatment by atmospheric-pressure CH4/He RF plasma

NASA Astrophysics Data System (ADS)

Choi, Jongchan; Lee, Kyeong-Hwan; Yang, Sung

2011-09-01

This note presents a simple fabrication process for patterning micro through-holes in a PDMS layer by a combination of the micromolding in capillaries (MIMIC) method and the surface treatment by atmospheric-pressure CH4/He RF plasma. The fabrication process is confirmed by forming micro through-holes with various shapes including circle, C-shape, open microfluidic channel and hemisphere. All micro through-holes of various shapes in a wide range of diameters and heights are well fabricated by the proposed method. Also, a 3D micromixer containing a PDMS micro through-hole layer formed by the proposed method is built and its performance is tested as another practical demonstration of the proposed fabrication method. Therefore, we believe that the proposed fabrication process will build a PDMS micro through-hole layer in a simple and easy way and will contribute to developing highly efficient multi-layered microfluidic systems, which may require PDMS micro through-hole layers.

An exact solution for a rotating black hole in modified gravity

NASA Astrophysics Data System (ADS)

Filippini, Francesco; Tasinato, Gianmassimo

2018-01-01

Exact solutions describing rotating black holes can offer important tests for alternative theories of gravity, motivated by the dark energy and dark matter problems. We present an analytic rotating black hole solution for a class of vector-tensor theories of modified gravity, valid for arbitrary values of the rotation parameter. The new configuration is characterised by parametrically large deviations from the Kerr-Newman geometry, controlled by non-minimal couplings between vectors and gravity. It has an oblate horizon in Boyer-Lindquist coordinates, and it can rotate more rapidly and have a larger ergosphere than black holes in General Relativity (GR) with the same asymptotic properties. We analytically investigate the features of the innermost stable circular orbits for massive objects on the equatorial plane, and show that stable orbits lie further away from the black hole horizon with respect to rotating black holes in GR. We also comment on possible applications of our findings for the extraction of rotational energy from the black hole.

Evaluation of Sedative and Hypnotic Activity of Ethanolic Extract of Scoparia dulcis Linn.

PubMed Central

Moniruzzaman, Md.; Atikur Rahman, Md.; Ferdous, Afia

2015-01-01

Scoparia dulcis Linn. (SD) is a perennial herb that has been well studied for its antioxidant, anti-inflammatory, antidiabetic, and hepatoprotective effects. However, scientific information on SD regarding the neuropharmacological effect is limited. This study evaluated the sedative and hypnotic effect of the ethanolic extract of whole plants of Scoparia dulcis (EESD). For this purpose, the whole plants of S. dulcis were extracted with ethanol following maceration process and tested for the presence of phytochemical constituents. The sedative and hypnotic activity were then investigated using hole cross, open field, hole-board, rota-rod, and thiopental sodium-induced sleeping time determination tests in mice at the doses of 50, 100, and 200 mg/kg of EESD. Diazepam at the dose of 1 mg/kg was used as a reference drug in all the experiments. We found that EESD produced a significant dose-dependent inhibition of locomotor activity of mice both in hole cross and open field tests (P < 0.05). Besides, it also decreased rota-rod performances and the number of head dips in hole-board test. Furthermore, EESD significantly decreased the induction time to sleep and prolonged the duration of sleeping, induced by thiopental sodium. Taken together, our study suggests that EESD may possess sedative principles with potent hypnotic properties. PMID:25861372

Evaluation of Sedative and Hypnotic Activity of Ethanolic Extract of Scoparia dulcis Linn.

PubMed

Moniruzzaman, Md; Atikur Rahman, Md; Ferdous, Afia

2015-01-01

Scoparia dulcis Linn. (SD) is a perennial herb that has been well studied for its antioxidant, anti-inflammatory, antidiabetic, and hepatoprotective effects. However, scientific information on SD regarding the neuropharmacological effect is limited. This study evaluated the sedative and hypnotic effect of the ethanolic extract of whole plants of Scoparia dulcis (EESD). For this purpose, the whole plants of S. dulcis were extracted with ethanol following maceration process and tested for the presence of phytochemical constituents. The sedative and hypnotic activity were then investigated using hole cross, open field, hole-board, rota-rod, and thiopental sodium-induced sleeping time determination tests in mice at the doses of 50, 100, and 200 mg/kg of EESD. Diazepam at the dose of 1 mg/kg was used as a reference drug in all the experiments. We found that EESD produced a significant dose-dependent inhibition of locomotor activity of mice both in hole cross and open field tests (P < 0.05). Besides, it also decreased rota-rod performances and the number of head dips in hole-board test. Furthermore, EESD significantly decreased the induction time to sleep and prolonged the duration of sleeping, induced by thiopental sodium. Taken together, our study suggests that EESD may possess sedative principles with potent hypnotic properties.

TESTING THE BLACK HOLE NO-HAIR THEOREM WITH OJ287

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valtonen, M. J.; Mikkola, S.; Lehto, H. J.

2011-11-20

We examine the ability to test the black hole no-hair theorem at the 10% level in this decade using the binary black hole in OJ287. In the test we constrain the value of the dimensionless parameter q that relates the scaled quadrupole moment and spin of the primary black hole: q{sub 2} = -q {chi}{sup 2}. At the present we can say that q = 1 {+-} 0.3 (1{sigma}), in agreement with general relativity and the no-hair theorems. We demonstrate that this result can be improved if more observational data are found in historical plate archives for the 1959 andmore » 1971 outbursts. We also show that the predicted 2015 and 2019 outbursts will be crucial in improving the accuracy of the test. Space-based photometry is required in 2019 July due the proximity of OJ287 to the Sun at the time of the outburst. The best situation would be to carry out the photometry far from the Earth, from quite a different vantage point, in order to avoid the influence of the nearby Sun. We have considered in particular the STEREO space mission, which would be ideal if it has a continuation in 2019, or the Long Range Reconnaissance Imager on board the New Horizons mission to Pluto.« less

Effect of Film-Hole Shape on Turbine Blade Film Cooling Performance

NASA Technical Reports Server (NTRS)

Han, J. C.; Teng, S.

2000-01-01

The detailed heat transfer coefficient and film cooling effectiveness distributions as well as tile detailed coolant jet temperature profiles on the suction side of a gas turbine blade A,ere measured using a transient liquid crystal image method and a traversing cold wire and a traversing thermocouple probe, respectively. The blade has only one row of film holes near the gill hole portion on the suction side of the blade. The hole geometries studied include standard cylindrical holes and holes with diffuser shaped exit portion (i.e. fanshaped holes and laidback fanshaped holes). Tests were performed on a five-blade linear cascade in a low-speed wind tunnel. The mainstream Reynolds number based on cascade exit velocity was 5.3 x 10(exp 5). Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. The wake Strouhal number was kept at 0 or 0.1. Coolant blowing ratio was varied from 0.4 to 1.2. Results show that both expanded holes have significantly improved thermal protection over the surface downstream of the ejection location, particularly at high blowing ratios. However, the expanded hole injections induce earlier boundary layer transition to turbulence and enhance heat transfer coefficients at the latter part of the blade suction surface. In general, the unsteady wake tends to reduce film cooling effectiveness.

A simple test of choice stepping reaction time for assessing fall risk in people with multiple sclerosis.

PubMed

Tijsma, Mylou; Vister, Eva; Hoang, Phu; Lord, Stephen R

2017-03-01

Purpose To determine (a) the discriminant validity for established fall risk factors and (b) the predictive validity for falls of a simple test of choice stepping reaction time (CSRT) in people with multiple sclerosis (MS). Method People with MS (n = 210, 21-74y) performed the CSRT, sensorimotor, balance and neuropsychological tests in a single session. They were then followed up for falls using monthly fall diaries for 6 months. Results The CSRT test had excellent discriminant validity with respect to established fall risk factors. Frequent fallers (≥3 falls) performed significantly worse in the CSRT test than non-frequent fallers (0-2 falls). With the odds of suffering frequent falls increasing 69% with each SD increase in CSRT (OR = 1.69, 95% CI: 1.27-2.26, p = <0.001). In regression analysis, CSRT was best explained by sway, time to complete the 9-Hole Peg test, knee extension strength of the weaker leg, proprioception and the time to complete the Trails B test (multiple R 2   =   0.449, p < 0.001). Conclusions A simple low tech CSRT test has excellent discriminative and predictive validity in relation to falls in people with MS. This test may prove useful in documenting longitudinal changes in fall risk in relation to MS disease progression and effects of interventions. Implications for rehabilitation Good choice stepping reaction time (CSRT) is required for maintaining balance. A simple low-tech CSRT test has excellent discriminative and predictive validity in relation to falls in people with MS. This test may prove useful documenting longitudinal changes in fall risk in relation to MS disease progression and effects of interventions.

30 CFR 14.22 - Test for flame resistance of conveyor belts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the front of the rails and 1 ± 1/8 inch (2.5 ± 0.3 cm) from the outer lengthwise edge of each rail; (3... holes approximately 9/32 inch (0.7 cm) in diameter along both edges of the belt sample, starting at the first rail hole within 2 inches (5.1 cm) from the front edge of the sample. Make the next hole 5 ± 1/4...

Integrability of spinning particle motion in higher-dimensional rotating black hole spacetimes.

PubMed

Kubizňák, David; Cariglia, Marco

2012-02-03

We study the motion of a classical spinning particle (with spin degrees of freedom described by a vector of Grassmann variables) in higher-dimensional general rotating black hole spacetimes with a cosmological constant. In all dimensions n we exhibit n bosonic functionally independent integrals of spinning particle motion, corresponding to explicit and hidden symmetries generated from the principal conformal Killing-Yano tensor. Moreover, we demonstrate that in 4-, 5-, 6-, and 7-dimensional black hole spacetimes such integrals are in involution, proving the bosonic part of the motion integrable. We conjecture that the same conclusion remains valid in all higher dimensions. Our result generalizes the result of Page et al. [Phys. Rev. Lett. 98, 061102 (2007)] on complete integrability of geodesic motion in these spacetimes.

Mold bolt and means for achieving close tolerances between bolts and bolt holes

NASA Technical Reports Server (NTRS)

Johnston, David L. (Inventor); Bryant, Phillip G. (Inventor)

1993-01-01

In the space shuttle, a cargo bay storage rack was required which was to be manufactured from a metal-plastic composite and bolted to a cargo structure. Following completion, utilization of the rack was disallowed due to tolerances, that is, the size differences between the outside bolt diameter and the inside hole diameter. In addition to the space shuttle problem there are other close tolerance requirements for bolts. Such environments often benefit from close tolerance bolting. Frequently such fabrication is not cost effective. Consequently there is a need for means of achieving close tolerances between bolts and bolt holes. Such means are provided. After compressing the elements together a strong rigid plastic, ceramic, or ceramic plastic fluid is forced into a channel extending through the bolt.

Can massive primordial black holes be produced in mild waterfall hybrid inflation?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawasaki, Masahiro; Tada, Yuichiro, E-mail: kawasaki@icrr.u-tokyo.ac.jp, E-mail: yuichiro.tada@ipmu.jp

We studied the possibility whether the massive primordial black holes (PBHs) surviving today can be produced in hybrid inflation. Though it is of great interest since such PBHs can be the candidate for dark matter or seeds of the supermassive black holes in galaxies, there have not been quantitatively complete works yet because of the non-perturbative behavior around the critical point of hybrid inflation. Therefore, combining the stochastic and δ N formalism, we numerically calculated the curvature perturbations in a non-perturbative way and found, without any specific assumption of the types of hybrid inflation, PBHs are rather overproduced when themore » waterfall phase of hybrid inflation continues so long that the PBH scale is well enlarged and the corresponding PBH mass becomes sizable enough.« less

The 1988 Antarctic ozone monitoring Nimbus-7 TOMS data atlas

NASA Technical Reports Server (NTRS)

Krueger, Arlin J.; Penn, Lanning M.; Larko, David E.; Doiron, Scott D.; Guimaraes, Patricia T.

1989-01-01

Because of the great environmental significance of ozone and to support continuing research at McMurdo, Syowa, and other Southern Hemisphere stations, the development of the 1988 ozone hole was monitored using data from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) instrument, produced in near-real-time. This Atlas provides a complete set of daily polar orthographic projections of the TOMS total ozone measurements over the Southern Hemisphere for the period August 1 through November 17, 1988. Although total ozone in mini-holes briefly dropped below 150 DU in late August, the main ozone hole is seen to be much less pronounced than in 1987. Minimum values, observed in late September and early October 1988, were seldom less than 175 DU. Compared with the same period in 1987, when a pronounced ozone hole whose minimum value of 109 Dobson Units (DU) was the lowest total ozone ever observed, the 1988 ozone hole is displaced from the South Pole, opposing a persistent maximum with values consistently above 500 DU. Daily ozone values above selected Southern Hemisphere stations are presented, along with comparisons of the 1988 ozone distribution to that of other years.

Horizontal natural gas storage caverns and methods for producing same

DOEpatents

Russo, Anthony

1995-01-01

The invention provides caverns and methods for producing caverns in bedded salt deposits for the storage of materials that are not solvents for salt. The contemplated salt deposits are of the bedded, non-domed variety, more particularly salt found in layered formations that are sufficiently thick to enable the production of commercially usefully sized caverns completely encompassed by walls of salt of the formation. In a preferred method, a first bore hole is drilled into the salt formation and a cavity for receiving insolubles is leached from the salt formation. Thereafter, at a predetermined distance away from the first bore hole, a second bore hole is drilled towards the salt formation. As this drill approaches the salt, the drill assumes a slant approach and enters the salt and drills through it in a horizontal direction until it intersects the cavity for receiving insolubles. This produces a substantially horizontal conduit from which solvent is controlledly supplied to the surrounding salt formation, leaching the salt and producing a concentrated brine which is removed through the first bore hole. Insolubles are collected in the cavity for receiving insolubles. By controlledly supplying solvent, a horizontal cavern is produced with two bore holes extending therefrom.

Tracing Supermassive Black Hole Growth with Offset and Dual AGN

NASA Astrophysics Data System (ADS)

Comerford, Julia

The growth of supermassive black holes is tied to the evolution of their host galaxies, but we are still missing a fundamental understanding of how and when supermassive black holes build up their mass. Black hole mass growth can be traced when the black holes are powered as active galactic nuclei (AGN), and AGN activity can be triggered by the stochastic accretion of gas or by gas inflows driven by galaxy mergers. Galaxy merger simulations make a series of predictions about the AGN that are triggered by mergers: (1) major mergers preferentially trigger higher-luminosity AGN, (2) minor mergers more often trigger AGN activity in one supermassive black hole while major mergers more often trigger AGN activity in both black holes in a merger, and (3) black hole mass growth peaks when the black holes approach the center (<10 kpc separations) of the merger-remnant galaxy. Observational tests of these predictions from theory have been limited by the difficulty in defining a clean observational sample of AGN in galaxy mergers and the observational challenge of spatially resolving two AGN with small (<10kpc) separations. Here we present offset and dual AGN as a new observational tool that can be used to address how and when supermassive black hole mass growth occurs. A merger of two galaxies brings two supermassive black holes together, and the two black holes exist at kpc-scale separations for 100 Myr before ultimately merging. While the black holes are at kpc-scale separations, they are known as dual AGN when both of them are fueled as AGN and offset AGN when only one is fueled as an AGN. Since offset and dual AGN only occur in galaxy mergers, by their very definition, they provide a clean observational sample of black hole mass growth in galaxy mergers. The small, kpc-scale separations of offset and dual AGN also enable an observational test of black hole fueling near the centers of merger-remnant galaxies. The full potential of offset and dual AGN for such studies of black hole mass growth has not yet been realized, due to the small number of such systems known. To date, only 13 confirmed offset and dual AGN are known. Here we propose a new observational approach to identifying offset and dual AGN, which will increase the known number from 13 to 100. This technique depends on multiwavelength archival data from HST, Spitzer, XMM-Newton, and Chandra, and it selects offset/dual AGN candidates as active galaxies (identified by Spitzer, XMMNewton, and Chandra detections) that exhibit two stellar bulges in their HST images. Our follow-up longslit spectroscopy will then confirm whether the two nuclei in fact correspond to offset AGN or dual AGN. The catalog of 100 offset and dual AGN that we build with this approach will enable offset and dual AGN to be used, for the first time, for statistical studies of black hole mass growth. We will use the catalog to test theoretical predictions about (1) whether major mergers preferentially fuel higher-luminosity AGN, (2) whether offset AGN are preferentially triggered by minor mergers and dual AGN preferentially triggered by major mergers, and (3) at what black hole separations the mass growth of black holes peaks. The primary emphasis of this project is the analysis of multiwavelength archival data from several NASA space missions, which is aligned with the goals of the Astrophysics Data Analysis Program. This project will advance offset and dual AGN as a new tool for statistical studies of galaxy evolution, and the results of our study will promote the NASA Cosmic Origins program in one of its objectives, which is to understand how galaxies evolve.

Thermal stability of charged rotating quantum black holes

NASA Astrophysics Data System (ADS)

Sinha, Aloke Kumar; Majumdar, Parthasarathi

2017-12-01

Criteria for thermal stability of charged rotating black holes of any dimension are derived for horizon areas that are large relative to the Planck area (in these dimensions). The derivation is based on generic assumptions of quantum geometry, supported by some results of loop quantum gravity, and equilibrium statistical mechanics of the Grand Canonical ensemble. There is no explicit use of classical spacetime geometry in this analysis. The only assumption is that the mass of the black hole is a function of its horizon area, charge and angular momentum. Our stability criteria are then tested in detail against specific classical black holes in spacetime dimensions 4 and 5, whose metrics provide us with explicit relations for the dependence of the mass on the charge and angular momentum of the black holes. This enables us to predict which of these black holes are expected to be thermally unstable under Hawking radiation.

Can we track holes?

PubMed Central

Horowitz, Todd S.; Kuzmova, Yoana

2011-01-01

The evidence is mixed as to whether the visual system treats objects and holes differently. We used a multiple object tracking task to test the hypothesis that figural objects are easier to track than holes. Observers tracked four of eight items (holes or objects). We used an adaptive algorithm to estimate the speed allowing 75% tracking accuracy. In Experiments 1–5, the distinction between holes and figures was accomplished by pictorial cues, while red-cyan anaglyphs were used to provide the illusion of depth in Experiment 6. We variously used Gaussian pixel noise, photographic scenes, or synthetic textures as backgrounds. Tracking was more difficult when a complex background was visible, as opposed to a blank background. Tracking was easier when disks carried fixed, unique markings. When these factors were controlled for, tracking holes was no more difficult than tracking figures, suggesting that they are equivalent stimuli for tracking purposes. PMID:21334361

Accurate Semilocal Density Functional for Condensed-Matter Physics and Quantum Chemistry.

PubMed

Tao, Jianmin; Mo, Yuxiang

2016-08-12

Most density functionals have been developed by imposing the known exact constraints on the exchange-correlation energy, or by a fit to a set of properties of selected systems, or by both. However, accurate modeling of the conventional exchange hole presents a great challenge, due to the delocalization of the hole. Making use of the property that the hole can be made localized under a general coordinate transformation, here we derive an exchange hole from the density matrix expansion, while the correlation part is obtained by imposing the low-density limit constraint. From the hole, a semilocal exchange-correlation functional is calculated. Our comprehensive test shows that this functional can achieve remarkable accuracy for diverse properties of molecules, solids, and solid surfaces, substantially improving upon the nonempirical functionals proposed in recent years. Accurate semilocal functionals based on their associated holes are physically appealing and practically useful for developing nonlocal functionals.

Gravitational waves from extreme mass ratio inspirals around bumpy black holes

NASA Astrophysics Data System (ADS)

Moore, Christopher J.; Chua, Alvin J. K.; Gair, Jonathan R.

2017-10-01

The space based interferometer LISA will be capable of detecting the gravitational waves emitted by stellar mass black holes or neutron stars slowly inspiralling into the supermassive black holes found in the centre of most galaxies. The gravitational wave signal from such an extreme mass ratio inspiral (EMRI) event will provide a unique opportunity to test whether the spacetime metric around the central black hole is well described by the Kerr solution. In this paper a variant of the well studied ‘analytic kludge’ model for EMRIs around Kerr black holes is extended to a family of parametrically deformed bumpy black holes which preserve the basic symmetries of the Kerr metric. The new EMRI model is then used to quantify the constraints that LISA observations of EMRIs may be able to place on the deviations, or bumps, on the Kerr metric.

Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

PubMed Central

Martinell, Jordi; Kowalewski, Michał; Domènech, Rosa

2012-01-01

We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid polychaetes are preyed upon by drilling predators and may provide a viable source of data on biotic interactions in the fossil record. PMID:22496828

Pitch Angles Of Artificially Redshifted Galaxies

NASA Astrophysics Data System (ADS)

Shields, Douglas W.; Davis, B.; Johns, L.; Berrier, J. C.; Kennefick, D.; Kennefick, J.; Seigar, M.

2012-05-01

We present the pitch angles of several galaxies that have been artificially redshifted using Barden et al’s FERENGI software. The (central black hole mass)-(spiral arm pitch angle) relation has been used on a statistically complete sample of local galaxies to determine the black hole mass function of local spiral galaxies. We now measure the pitch angles at increasing redshifts by operating on the images pixel-by-pixel. The results will be compared to the pitch angle function as measured in the GOODS field. This research was funded in part by NASA / EPScOR.

Experimental study of flow due to an isolated suction hole and a partially plugged suction slot

NASA Technical Reports Server (NTRS)

Goglia, G. L.; Wilkinson, S. P.

1980-01-01

Details for construction of a model of a partially plugged, laminar flow control, suction slot and an isolated hole are presented. The experimental wind tunnel facility and instrumentation is described. Preliminary boundary layer velocity profiles (without suction model) are presented and shown to be in good agreement with the Blasius laminar profile. Recommendations for the completion of the study are made. An experimental program for study of transition on a rotating disk is described along with preliminary disturbance amplification rate data.

Schwarzschild Solution: A Historical Perspective

NASA Astrophysics Data System (ADS)

Bartusiak, Marcia

2016-03-01

While eighteenth-century Newtonians had imagined a precursor to the black hole, the modern version has its roots in the first full solution to Einstein's equations of general relativity, derived by the German astronomer Karl Schwarzschild on a World War I battlefront just weeks after Einstein introduced his completed theory in November 1915. This talk will demonstrate how Schwarzschild's solution is linked to the black hole and how it took more than half a century for the physics community to accept that such a bizarre celestial object could exist in the universe.

Vacuum decay container closure integrity leak test method development and validation for a lyophilized product-package system.

PubMed

Patel, Jayshree; Mulhall, Brian; Wolf, Heinz; Klohr, Steven; Guazzo, Dana Morton

2011-01-01

A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated for container-closure integrity verification of a lyophilized product in a parenteral vial package system. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity check, and for testing product stored on stability in lieu of sterility tests. Method development and optimization challenge studies incorporated artificially defective packages representing a range of glass vial wall and sealing surface defects, as well as various elastomeric stopper defects. Method validation required 3 days of random-order replicate testing of a test sample population of negative-control, no-defect packages and positive-control, with-defect packages. Positive-control packages were prepared using vials each with a single hole laser-drilled through the glass vial wall. Hole creation and hole size certification was performed by Lenox Laser. Validation study results successfully demonstrated the vacuum decay leak test method's ability to accurately and reliably detect those packages with laser-drilled holes greater than or equal to approximately 5 μm in nominal diameter. All development and validation studies were performed at Whitehouse Analytical Laboratories in Whitehouse, NJ, under the direction of consultant Dana Guazzo of RxPax, LLC, using a VeriPac 455 Micro Leak Test System by Packaging Technologies & Inspection (Tuckahoe, NY). Bristol Myers Squibb (New Brunswick, NJ) fully subsidized all work. A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated to detect defects in stoppered vial packages containing lyophilized product for injection. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity check, and for testing product stored on stability in lieu of sterility tests. Test method validation study results proved the method capable of detecting holes laser-drilled through the glass vial wall greater than or equal to 5 μm in nominal diameter. Total test time is less than 1 min per package. All method development and validation studies were performed at Whitehouse Analytical Laboratories in Whitehouse, NJ, under the direction of consultant Dana Guazzo of RxPax, LLC, using a VeriPac 455 Micro Leak Test System by Packaging Technologies & Inspection (Tuckahoe, NY). Bristol Myers Squibb (New Brunswick, NJ) fully subsidized all work.

Auto Indexer Auto-Indexer for Percussive Hammers: Vane Motor Dynamometer Testing

DOE Data Explorer

Su, Jiann

2012-01-01

Objectives Options associated with geothermal drilling operations are generally limited by factors such as formation temperature and rock strength. The objective of the research is to expand the "tool box" available to the geothermal driller by furthering the development of a high-temperature drilling motor that can be used in directional drilling applications for drilling high temperature geothermal formations. The motor is specifically designed to operate in conjunction with a pneumatic down-the-hole-hammer. It provides a more compact design compared to traditional drilling motors such as PDMs (positive displacement motors). The packaging can help to enhance directional drilling capabilities. It uses no elastomeric components, which enables it to operate in higher temperatures ( >250 °F). Current work on the motor has shown that is a capable of operating under pneumatic power with a down-the-hole-hammer. Further development work will include continued testing and refining motor components and evaluating motor capabilities. Targets/Milestones Complete testing current motor - 12/31/2010 Make final material and design decisions - 01/31/2011 Build and test final prototype - 04/31/2011 Final demonstration - 07/31/2011 Impacts The development of the motor will help to achieve program technical objectives by improving well construction capabilities. This includes enabling high-temperature drilling as well as enhancing directional drilling. A key component in the auto indexer is the drive motor. It is an air-driven vane motor that converts the energy stored in the compressed air to mechanical energy. The motor is attached to hammer-like components which impart an impulsive load onto the drive shaft. The impulsive force on the drive shaft in turn creates an indexing action. A controlled test was performed to characterize the performance of the the vane motor for a given pressure. The Sandia dynamometer test station was used to determine the performance of the motor for a given input pressure.

Coalescence of two spinning black holes: An effective one-body approach

NASA Astrophysics Data System (ADS)

Damour, Thibault

2001-12-01

We generalize to the case of spinning black holes a recently introduced ``effective one-body'' approach to the general relativistic dynamics of binary systems. We show how to approximately map the conservative part of the third post-Newtonian (3PN) dynamics of two spinning black holes of masses m1, m2 and spins S1, S2 onto the dynamics of a non-spinning particle of mass μ≡m1m2/(m1+m2) in a certain effective metric geffμν(xλM,ν,a) which can be viewed either as a spin deformation [with the deformation parameter a≡Seff/M] of the recently constructed 3PN effective metric geffμν(xλM,ν), or as a ν deformation [with the comparable-mass deformation parameter ν≡m1m2/(m1+m2)2] of a Kerr metric of mass M≡m1+m2 and (effective) spin Seff≡[1+3m2/(4m1)]S1+[1+3m1/(4m2)]S2. The combination of the effective one-body approach, and of a Padé definition of the crucial effective radial functions, is shown to define a dynamics with much improved post-Newtonian convergence properties, even for black hole separations of the order of 6 GM/c2. The complete (conservative) phase-space evolution equations of binary spinning black hole systems are written down and their exact and approximate first integrals are discussed. This leads to the approximate existence of a two-parameter family of ``spherical orbits'' (with constant radius), and of a corresponding one-parameter family of ``last stable spherical orbits'' (LSSO). These orbits are of special interest for forthcoming LIGO-VIRGO-GEO gravitational wave observations. The binding energy and total angular momentum of LSSO's are studied in some detail. It is argued that for most (but not all) of the parameter space of two spinning holes the approximate (leading-order) effective one-body approach introduced here gives a reliable analytical tool for describing the dynamics of the last orbits before coalescence. This tool predicts, in a quantitative way, how certain spin orientations increase the binding energy of the LSSO. This leads to a detection bias, in LIGO-VIRGO-GEO observations, favoring spinning black hole systems, and makes it urgent to complete the conservative effective one-body dynamics given here by adding (resummed) radiation reaction effects, and by constructing gravitational waveform templates that include spin effects. Finally, our approach predicts that the spin of the final hole formed by the coalescence of two arbitrarily spinning holes never approaches extremality.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, Ben; Moore, Joe; Segall, Marylin

The Tularosa-Hueco basin in south-central New Mexico has long been known as an extensional area of high heat flow. Much of the basin is within the Fort Bliss military reservation, which is an exceptionally high value customer for power independent of the regional electric grid and for direct use energy in building climate control. A series of slim holes drilled in the 1990s established the existence of a thermal anomaly but not its practical value. This study began in 2009 with a demonstration of new exploration drilling technology. The subsequent phases reported here delivered a useful well, comparative exploration datamore » sets and encouragement for further development. A production-size well, RMI56-5, was sited after extensive study of archival and newly collected data in 2010-2011. Most of 2012 was taken up with getting state and Federal authorities to agree on a lead agency for permitting purposes, getting a drilling permit and redesigning the drilling program to suit available equipment. In 2013 we drilled, logged and tested a 924 m well on the McGregor Range at Fort Bliss using a reverse circulation rig. Rig tests demonstrated commercial permeability and the well has a 7-inch slotted liner for use either in production or injection. An August 2013 survey of the completed well showed a temperature of 90 C with no reversal, the highest such temperature in the vicinity. The well’s proximity to demand suggests a potentially valuable resource for direct use heat and emergency power generation. The drilling produced cuttings of excellent size and quality. These were subjected to traditional analyses (thin sections, XRD) and to the QEMScan™ for comparison. QEMScan™ technology includes algorithms for determining such properties of rocks as density, mineralogy, heavy/light atoms, and porosity to be compared with direct measurements of the cuttings. In addition to a complete cuttings set, conventional and resistivity image logs were obtained in the open hole before the well was cased.« less

T1 Recovery Is Predominantly Found in Black Holes and Is Associated with Clinical Improvement in Patients with Multiple Sclerosis.

PubMed

Thaler, C; Faizy, T D; Sedlacik, J; Holst, B; Stürner, K; Heesen, C; Stellmann, J-P; Fiehler, J; Siemonsen, S

2017-02-01

Quantitative MR imaging parameters help to evaluate disease progression in multiple sclerosis and increase correlation with clinical disability. We therefore hypothesized that T1 values might be a marker for ongoing tissue damage or even remyelination and may help increase clinical correlation. MR imaging was performed in 17 patients with relapsing-remitting MS at baseline and after 12 months of starting immunotherapy with dimethyl fumarate. On baseline images, lesion segmentation was performed for normal-appearing white matter, T2 hyperintense (FLAIR lesions), T1 hypointense (black holes), and contrast-enhancing lesions, and T1 relaxation times were obtained at baseline and after 12 months. Changes in clinical status were assessed by using the Expanded Disability Status Scale and Symbol Digit Modalities Test at both dates (Expanded Disability Status Scale-difference/Symbol Digit Modalities Test-diff). The highest T1 relaxation time at baseline was measured in black holes (1460.2 ± 209.46 ms) followed by FLAIR lesions (1400.38 ± 189.1 ms), pure FLAIR lesions (1327.5 ± 210.04 ms), contrast-enhancing lesions (1205.59 ± 199.95 ms), and normal-appearing white matter (851.34 ± 30.61 ms). After 12 months, T1 values had decreased significantly in black holes (1369.4 ± 267.81 ms), contrast-enhancing lesions (1079.57 ± 183.36 ms) (both P < .001), and normal-appearing white matter (841.98 ± 36.1 ms, P = .006). With the Jonckheere-Terpstra Test, better clinical scores were associated with decreasing T1 relaxation times in black holes ( P < .05). T1 relaxation time is a useful quantitative MR imaging technique, which helps detect changes in MS lesions with time. We assume that these changes are associated with the degree of myelination within the lesions themselves and are pronounced in black holes. Additionally, decreasing T1 values in black holes were associated with clinical improvement. © 2017 by American Journal of Neuroradiology.

KSC-2012-2017

NASA Image and Video Library

2012-04-10

VANDENBERG AIR FORCE BASE, Calif. – The Pegasus payload fairing has been opened to reveal NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, in Orbital Sciences’ hangar on Vandenberg Air Force Base in California. Access to the spacecraft is needed for compatibility testing to verify communication with a tracking station in Hawaii. With the change in the launch timeframe to June, this station will be needed to support launch. After processing of Orbital’s Pegasus XL rocket and the spacecraft are complete, they will be flown on Orbital's L-1011 carrier aircraft from Vandenberg to the Ronald Reagan Ballistic Missile Defense Test Site on the Pacific Ocean’s Kwajalein Atoll for launch. The high-energy X-ray telescope will conduct a census of black holes, map radioactive material in young supernovae remnants, and study the origins of cosmic rays and the extreme physics around collapsed stars. For more information, visit http://www.nasa.gov/nustar. Photo credit: NASA/Randy Beaudoin, VAFB

Labyrinth and cerebral-spinal fluid pressure changes in guinea pigs and monkeys during simulated zero G

NASA Technical Reports Server (NTRS)

Parker, D. E.

1977-01-01

This study was undertaken to explore the hypothesis that shifts of body fluids from the legs and torso toward the head contribute to the motion sickness experienced by astronauts and cosmonauts. The shifts in body fluids observed during zero-G exposure were simulated by elevating guinea pigs' and monkeys' torsos and hindquarters. Cerebral-spinal fluid pressure was recorded from a transducer located in a brain ventricle; labyrinth fluid pressure was recorded from a pipette cemented in a hole in a semicircular canal. An anticipated divergence in cerebral-spinal fluid pressure and labyrinth fluid pressure during torso elevation was not observed. The results of this study do not support a fluid shift mechanism of zero-G-induced motion sickness. However, a more complete test of the fluid shift mechanism would be obtained if endolymph and perilymph pressure changes were determined separately; we have been unable to perform this test to date.

16 CFR 1511.3 - Guard or shield requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... seconds. Any pacifier which can be completely drawn through an opening with dimensions no greater than....20 inches (5 millimeters) in minor dimension. The edge of any hole shall be no closer than 0.20...

16 CFR 1511.3 - Guard or shield requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... seconds. Any pacifier which can be completely drawn through an opening with dimensions no greater than....20 inches (5 millimeters) in minor dimension. The edge of any hole shall be no closer than 0.20...

16 CFR 1511.3 - Guard or shield requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... seconds. Any pacifier which can be completely drawn through an opening with dimensions no greater than....20 inches (5 millimeters) in minor dimension. The edge of any hole shall be no closer than 0.20...

Development and evaluation of needle trap device geometry and packing methods for automated and manual analysis.

PubMed

Warren, Jamie M; Pawliszyn, Janusz

2011-12-16

For air/headspace analysis, needle trap devices (NTDs) are applicable for sampling a wide range of volatiles such as benzene, alkanes, and semi-volatile particulate bound compounds such as pyrene. This paper describes a new NTD that is simpler to produce and improves performance relative to previous NTD designs. A NTD utilizing a side-hole needle used a modified tip, which removed the need to use epoxy glue to hold sorbent particles inside the NTD. This design also improved the seal between the NTD and narrow neck liner of the GC injector; therefore, improving the desorption efficiency. A new packing method has been developed and evaluated using solvent to pack the device, and is compared to NTDs prepared using the previous vacuum aspiration method. The slurry packing method reduced preparation time and improved reproducibility between NTDs. To evaluate the NTDs, automated headspace extraction was completed using benzene, toluene, ethylbenzene, p-xylene (BTEX), anthracene, and pyrene (PAH). NTD geometries evaluated include: blunt tip with side-hole needle, tapered tip with side-hole needle, slider tip with side-hole, dome tapered tip with side-hole and blunt with no side-hole needle (expanded desorptive flow). Results demonstrate that the tapered and slider tip NTDs performed with improved desorption efficiency. Copyright © 2011 Elsevier B.V. All rights reserved.

Using Simulations of Black Holes to Study General Relativity and the Properties of Inner Accretion Flow

NASA Astrophysics Data System (ADS)

Hoormann, Janie Katherine

2016-06-01

While Albert Einstein's theory of General Relativity (GR) has been tested extensively in our solar system, it is just beginning to be tested in the strong gravitational fields that surround black holes. As a way to study the behavior of gravity in these extreme environments, I have used and added to a ray-tracing code that simulates the X-ray emission from the accretion disks surrounding black holes. In particular, the observational channels which can be simulated include the thermal and reflected spectra, polarization, and reverberation signatures. These calculations can be performed assuming GR as well as four alternative spacetimes. These results can be used to see if it is possible to determine if observations can test the No-Hair theorem of GR which states that stationary, astrophysical black holes are only described by their mass and spin. Although it proves difficult to distinguish between theories of gravity, it is possible to exclude a large portion of the possible deviations from GR using observations of rapidly spinning stellar mass black holes such as Cygnus X-1. The ray-tracing simulations can furthermore be used to study the inner regions of black hole accretion flows. I examined the dependence of X-ray reverberation observations on the ionization of the disk photosphere. My results show that X-ray reverberation and X-ray polarization provides a powerful tool to constrain the geometry of accretion disks which are too small to be imaged directly. The second part of my thesis describes the work on the balloon-borne X-Calibur hard X-ray polarimetry mission and on the space-borne PolSTAR polarimeter concept.

Roughans Point, Revere, Massachusetts Coastal Flood Protection Study. Volume I. Main Report.

DTIC Science & Technology

1982-12-01

1982 conducted bT, Rusty Iwanowicz , Massachusetts Division of Marine Fisheries, concluded that the shoreline area that would be impacted by the... Iwanowicz , DMF, and Charles Freeman of my staff. In this survey, five test holes were dug seaward of the area of project impact in areas which Mr... Iwanowicz felt would indicate the productivity of the clam flat. Two holes revealed no shellfish, and the best hole produced two razor clams, two