WorldWideScience

Sample records for single shaft disk

  1. Forging Long Shafts On Disks

    Science.gov (United States)

    Tilghman, Chris; Askey, William; Hopkins, Steven

    1989-01-01

    Isothermal-forging apparatus produces long shafts integral with disks. Equipment based on modification of conventional isothermal-forging equipment, required stroke cut by more than half. Enables forging of shafts as long as 48 in. (122 cm) on typical modified conventional forging press, otherwise limited to making shafts no longer than 18 in. (46cm). Removable punch, in which forged material cools after plastic deformation, essential novel feature of forging apparatus. Technology used to improve such products as components of gas turbines and turbopumps and of other shaft/disk parts for powerplants, drive trains, or static structures.

  2. Shaft/shaft-seal interface characteristics of a multiple disk centrifugal blood pump.

    Science.gov (United States)

    Manning, K B; Miller, G E

    1999-06-01

    A multiple disk centrifugal pump (MDCP) is under investigation as a potential left ventricular assist device. As is the case with most shaft driven pumps, leakage problems around the shaft/shaft seal interface are of major interest. If leakage were to occur during or after implantation, potential events such as blood loss, clotting, blood damage, and/or infections might result in adverse effects for the patient. Because these effects could be quite disastrous, potential shaft and shaft seal materials have been investigated to determine the most appropriate course to limit these effects. Teflon and nylon shaft seals were analyzed as potential candidates along with a stainless steel shaft and a Melonite coated shaft. The materials and shafts were evaluated under various time durations (15, 30, 45, and 60 min), motor speeds (800, 1,000, 1,200, and 1,400 rpm), and outer diameters (1/2 and 3/4 inches). The motor speed and geometrical configurations were typical for the MDCP under normal physiologic conditions. An air and water study was conducted to analyze the inner diameter wear, the inner temperature values, and the outer temperature values. Statistical comparisons were computed for the shaft seal materials, the shafts, and the outer diameters along with the inner and outer temperatures. The conclusions made from the results indicate that both the tested shaft seal materials and shaft materials are not ideal candidates to be used for the MDCP. Teflon experienced a significant amount of wear in air and water studies. Nylon did experience little wear, but heat generation was an evident problem. A water study on nylon was not conducted because of its molecular structure.

  3. Shaft flexibility effects on aeroelastic stability of a rotating bladed disk

    Science.gov (United States)

    Khader, Naim; Loewy, Robert

    1989-01-01

    A comprehensive study of Coriolis forces and shaft flexibility effects on the structural dynamics and aeroelastic stability of a rotating bladed-disk assembly attached to a cantilever, massless, flexible shaft is presented. Analyses were performed for an actual bladed-disk assembly, used as the first stage in the fan of the 'E3' engine. In the structural model, both in-plane and out-of-plane elastic deformation of the bladed-disk assembly were considered relative to their hub, in addition to rigid disk translations and rotations introduced by shaft flexibility. Besides structural coupling between blades (through the flexible disk), additional coupling is introduced through quasisteady aerodynamic loads. Rotational effects are accounted for throughout the work, and some mode shapes for the whole structure are presented at a selected rpm.

  4. Analysis of stress and strain in a rotating disk mounted on a rigid shaft

    Directory of Open Access Journals (Sweden)

    Alexandrova Nelli N.

    2006-01-01

    Full Text Available The plane state of stress in an elastic-perfectly plastic isotropic rotating annular disk mounted on a rigid shaft is studied. The analysis of stresses, strains and displacements within the disk of constant thickness and density is based on the Mises yield criterion and its associated flow rule. It is observed that the plastic deformation is localized in the vicinity of the inner radius of the disk, and the disk of a sufficiently large outer radius never becomes fully plastic. The semi-analytical method of stress-strain analysis developed is illustrated by some numerical examples. .

  5. Wet-steam erosion of steam turbine disks and shafts

    International Nuclear Information System (INIS)

    Averkina, N. V.; Zheleznyak, I. V.; Kachuriner, Yu. Ya.; Nosovitskii, I. A.; Orlik, V. G.; Shishkin, V. I.

    2011-01-01

    A study of wet-steam erosion of the disks and the rotor bosses or housings of turbines in thermal and nuclear power plants shows that the rate of wear does not depend on the diagrammed degree of moisture, but is determined by moisture condensing on the surfaces of the diaphragms and steam inlet components. Renovating the diaphragm seals as an assembly with condensate removal provides a manifold reduction in the erosion.

  6. A Two-Disk Extended Jeffcott Rotor Model Distinguishing a Shaft Crack from Other Rotating Asymmetries

    Directory of Open Access Journals (Sweden)

    Xi Wu

    2008-01-01

    Full Text Available A mathematical model of a cracked rotor and an asymmetric rotor with two disks representing a turbine and a generator is utilized to study the vibrations due to imbalance and side load. Nonlinearities typically related with a “breathing” crack are included using a Mayes steering function. Numerical simulations demonstrate how the variations of rotor parameters affect the vibration response and the effect of coupling between torsional and lateral modes. Bode, spectrum, and orbit plots are used to show the differences between the vibration signatures associated with cracked shafts versus asymmetric shafts. Results show how nonlinear lateral-torsional coupling shifts the resonance peaks in the torsional vibration response for cracked shafts and asymmetric rotors. The resonance peaks shift depending on the ratio of the lateral-to-torsional natural frequencies with the peak responses occurring at noninteger values of the lateral natural frequency. When the general nonlinear models used in this study are constrained to reduce to linear torsional vibration, the peak responses occur at commonly reported integer ratios. Full spectrum analyses of the X and Y vibrations reveal distinct vibration characteristics of both cracked and asymmetric rotors including reverse vibration components. Critical speeds and vibration orders predicted using the models presented herein include and extend diagnostic indicators commonly reported.

  7. Free Vibration Analysis of a Spinning Flexible DISK-SPINDLE System Supported by Ball Bearing and Flexible Shaft Using the Finite Element Method and Substructure Synthesis

    Science.gov (United States)

    JANG, G. H.; LEE, S. H.; JUNG, M. S.

    2002-03-01

    Free vibration of a spinning flexible disk-spindle system supported by ball bearing and flexible shaft is analyzed by using Hamilton's principle, FEM and substructure synthesis. The spinning disk is described by using the Kirchhoff plate theory and von Karman non-linear strain. The rotating spindle and stationary shaft are modelled by Rayleigh beam and Euler beam respectively. Using Hamilton's principle and including the rigid body translation and tilting motion, partial differential equations of motion of the spinning flexible disk and spindle are derived consistently to satisfy the geometric compatibility in the internal boundary between substructures. FEM is used to discretize the derived governing equations, and substructure synthesis is introduced to assemble each component of the disk-spindle-bearing-shaft system. The developed method is applied to the spindle system of a computer hard disk drive with three disks, and modal testing is performed to verify the simulation results. The simulation result agrees very well with the experimental one. This research investigates critical design parameters in an HDD spindle system, i.e., the non-linearity of a spinning disk and the flexibility and boundary condition of a stationary shaft, to predict the free vibration characteristics accurately. The proposed method may be effectively applied to predict the vibration characteristics of a spinning flexible disk-spindle system supported by ball bearing and flexible shaft in the various forms of computer storage device, i.e., FDD, CD, HDD and DVD.

  8. Condition monitoring of shaft of single-phase induction motor using optical sensor

    Science.gov (United States)

    Fulzele, Asmita G.; Arajpure, V. G.; Holay, P. P.; Patil, N. M.

    2012-05-01

    Transmission type of optical technique is developed to sense the condition of rotating shafts from a distance. A parallel laser beam is passed tangential over the surface of rotating shaft of a single phase induction motor and its flickering shadow is received on a photo sensor. Variations in sensor voltage output are observed on a digital storage oscilloscope. It is demonstrated that this signal carries information about shaft defects like miss alignment, play and impacts in bearings along with surface deformities. Mathematical model of signals corresponding to these shaft defects is developed. During the development and testing of the sensor, effects of reflections are investigated, sensing phenomenon is simulated, frequency response of the sensor is obtained and its performance is compared with conventional accelerometer.

  9. Disk

    NARCIS (Netherlands)

    P.A. Boncz (Peter); L. Liu (Lei); M. Tamer Özsu

    2008-01-01

    htmlabstractIn disk storage, data is recorded on planar, round and rotating surfaces (disks, discs, or platters). A disk drive is a peripheral device of a computer system, connected by some communication medium to a disk controller. The disk controller is a chip, typically connected to the CPU of

  10. Performance of a single nutating disk engine in the 2 to 500 kW power range

    International Nuclear Information System (INIS)

    Korakianitis, T.; Boruta, M.; Jerovsek, J.; Meitner, P.L.

    2009-01-01

    A new type of internal combustion engine with distinct advantages over conventional piston-engines and gas turbines in small power ranges is presented. The engine has analogies with piston engine operation, but like gas turbines it has dedicated spaces and devices for compression, burning and expansion. The engine operates on a modified limited-pressure thermodynamic cycle. The core of the engine is a nutating non-rotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. In the single-disk configuration a portion of the surface area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The external combustion chamber enables the engine to operate on a variable compression ratio cycle. Variations in cycle temperature ratio and compression ratio during normal operation enable the engine to effectively become a variable-cycle engine, allowing significant flexibility for optimizing efficiency or power output. The thermal efficiency is similar to that of medium sized diesel engines. For the same engine volume and weight this engine produces approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The computed sea-level engine performance at design and off-design conditions in the 2 to 500 kW power range is presented.

  11. Ball-joint versus single monolateral external fixators for definitive treatment of tibial shaft fractures.

    Science.gov (United States)

    Beltsios, Michail; Mavrogenis, Andreas F; Savvidou, Olga D; Karamanis, Eirineos; Kokkalis, Zinon T; Papagelopoulos, Panayiotis J

    2014-07-01

    To compare modular monolateral external fixators with single monolateral external fixators for the treatment of open and complex tibial shaft fractures, to determine the optimal construct for fracture union. A total of 223 tibial shaft fractures in 212 patients were treated with a monolateral external fixator from 2005 to 2011; 112 fractures were treated with a modular external fixator with ball-joints (group A), and 111 fractures were treated with a single external fixator without ball-joints (group B). The mean follow-up was 2.9 years. We retrospectively evaluated the operative time for fracture reduction with the external fixator, pain and range of motion of the knee and ankle joints, time to union, rate of malunion, reoperations and revisions of the external fixators, and complications. The time for fracture reduction was statistically higher in group B; the rate of union was statistically higher in group B; the rate of nonunion was statistically higher in group A; the mean time to union was statistically higher in group A; the rate of reoperations was statistically higher in group A; and the rate of revision of the external fixator was statistically higher in group A. Pain, range of motion of the knee and ankle joints, rates of delayed union, malunion and complications were similar. Although modular external fixators are associated with faster intraoperative fracture reduction with the external fixator, single external fixators are associated with significantly better rates of union and reoperations; the rates of delayed union, malunion and complications are similar.

  12. Torsion of a growing shaft

    Directory of Open Access Journals (Sweden)

    Alexander V. Manzhirov

    2017-12-01

    Full Text Available The torsion of a shaft by rigid disks is considered. The shaft has the form of circular cylinder. Two rigid disks are attached to its end faces. The process of continuous growth of such shaft under the influence of twisting torques applied to the disks is studied. Dual series equations which reflect the mathematical content of the problem at the different stages of the growing process are derived and solved. Results of the numerical analysis and singularities of the qualitative mechanical behaviour of the fundamental characteristics are discussed.

  13. Aggressive discectomy for single level lumbar disk herniation

    Directory of Open Access Journals (Sweden)

    Md. Kamrul Ahsan

    2017-09-01

    Full Text Available Aggressive open lumbar discectomy is the most commonly performed surgical procedure for patients with persistent low back and leg pain. In this retrospective study,  1,380 patients were evaluated for long-term results of aggressive discectomy for the single level lumbar disk herniation. Demographic data, surgical data, complications and reherniation rate were collected and clinical outcomes were assessed using visual analogue score (VAS, Oswestry disability index (ODI and modified Mcnab criteria. The mean follow-up period was 28.8 months. According to the modified Mcnab criteria, the long-term results were excellent in 640 cases, good in 445 cases, fair in 255 cases, and poor in 40 cases. The mean VAS scores for back and radicular pains and ODI at the end of 2 years were 1.1 ± 1.0, 1.5 ± 0.5 and 6.6 ± 3.1% respectively. The complications were foot drop (n=7, dural tear (n=14, superficial wound infection (n=17, discitis (n=37 and reherniation (n=64. The dural tear and superficial wound infections resolved after treatment but 28 discitis patients were treated by conservatively and the remaining 9 underwent surgery. Among reherniation patients, 58 underwent revision discectomy and 4 underwent transforaminal lumbar interbody fusion and stabilization. Aggressive discectomy is an effective treatment of lumbar disk herniation and maintains a lower incidence of reherniation but leads to a collapse of disc height and in long run gives rise to intervertebral instability and accelerates spondylosis.

  14. Shaft adjuster

    Science.gov (United States)

    Harry, Herbert H.

    1989-01-01

    Apparatus and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus.

  15. Shaft Boring Machine: A method of mechanized vertical shaft excavation

    International Nuclear Information System (INIS)

    Goodell, T.M.

    1991-01-01

    The Shaft Boring Machine (SBM) is a vertical application of proven rock boring technology. The machine applies a rotating cutter wheel with disk cutters for shaft excavation. The wheel is thrust against the rock by hydraulic cylinders and slews about the shaft bottom as it rotates. Cuttings are removed by a clam shell device similar to conventional shaft mucking and the muck is hoisted by buckets. The entire machine moves down (and up) the shaft through the use of a system of grippers thrust against the shaft wall. These grippers and their associated cylinders also provide the means to maintain verticality and stability of the machine. The machine applies the same principles as tunnel boring machines but in a vertical mode. Other shaft construction activities such as rock bolting, utility installation and shaft concrete lining can be accomplished concurrent with shaft boring. The method is comparable in cost to conventional sinking to a depth of about 460 meters (1500 feet) beyond which the SBM has a clear host advantage. The SBM has a greater advantage in productivity in that it can excavate significantly faster than drill and blast methods

  16. A new solid-phase extraction disk based on a sheet of single-walled carbon nanotubes.

    Science.gov (United States)

    Niu, Hong Yun; Cai, Ya Qi; Shi, Ya Li; Wei, Fu Sheng; Liu, Jie Min; Jiang, Gui Bin

    2008-11-01

    A new kind of solid-phase extraction disk based on a sheet of single-walled carbon nanotubes (SWCNTs) is developed in this study. The properties of such disks are tested, and different disks showed satisfactory reproducibility. One liter of aqueous solution can pass through the disk within 10-100 min while still allowing good recoveries. Two disks (DD-disk) can be stacked to enrich phthalate esters, bisphenol A (BPA), 4-n-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and chlorophenols from various volumes of solution. The results show that SWCNT disks have high extraction ability for all analytes. The SWCNT disk can extract polar chlorophenols more efficiently than a C(18) disk from water solution. Unlike the activated carbon disk, analytes adsorbed by the new disks can be eluted completely with 8-15 mL of methanol or acetonitrile. Finally, the DD-disk system is used to pretreat 1000-mL real-world water samples spiked with BPA, 4-OP and 4-NP. Detection limits of 7, 25, and 38 ng L(-1) for BPA, 4-OP, and 4-NP, respectively, were achieved under optimized conditions. The advantages of this new disk include its strong adsorption ability, its high flow rate and its easy preparation.

  17. Nanopatterning of magnetic disks by single-step Ar+ Ion projection

    NARCIS (Netherlands)

    Dietzel, A.H.; Berger, R.; Loeschner, H.; Platzgummer, E.; Stengl, G.; Bruenger, W.H.; Letzkus, F.

    2003-01-01

    Large-area Ar+ projection has been used to generate planar magnetic nanostructures on a 1¿-format hard disk in a single step (see Figure). The recording pattern was transferred to a Co/Pt multilayer without resist processes or any other contact to the delicate media surface. It is conceivable that

  18. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    International Nuclear Information System (INIS)

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H.; Cleyrat, C.; Lidke, D. S.; Wilson, B. S.

    2015-01-01

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments

  19. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H., E-mail: jwerner@lanl.gov [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, New Mexico 87545 (United States); Cleyrat, C.; Lidke, D. S.; Wilson, B. S. [Department of Pathology and Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2015-12-15

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

  20. Laser shaft alignment measurement model

    Science.gov (United States)

    Mo, Chang-tao; Chen, Changzheng; Hou, Xiang-lin; Zhang, Guoyu

    2007-12-01

    Laser beam's track which is on photosensitive surface of the a receiver will be closed curve, when driving shaft and the driven shaft rotate with same angular velocity and rotation direction. The coordinate of arbitrary point which is on the curve is decided by the relative position of two shafts. Basing on the viewpoint, a mathematic model of laser alignment is set up. By using a data acquisition system and a data processing model of laser alignment meter with single laser beam and a detector, and basing on the installation parameter of computer, the state parameter between two shafts can be obtained by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated. This will instruct us to move the apparatus to align the shafts.

  1. Four Weeks in a Single-Leg Weight-Bearing Hip Spica Cast is Sufficient Treatment for Isolated Femoral Shaft Fractures in Children Aged 1 to 3 Years.

    Science.gov (United States)

    Jaafar, Sami; Sobh, Ali; Legakis, Julie E; Thomas, Ronald; Buhler, Kelsey; Jones, Eric T

    2016-01-01

    Hip spica casting regimens for the treatment of femoral shaft fractures in a pediatric population aged 1 to 3 years vary. Patient charts were reviewed to determine if there are any clinical differences between 3 and 4 weeks in an ambulatory single-leg hip spica (SLHS) cast versus 6 to 8 weeks in a standard double-leg, non-weight-bearing hip spica cast. The medical records of 109 patients with femoral shaft fractures treated with a hip spica casting from January 1, 2008 to December 31, 2011 were examined. After exclusions, 94 patients were eligible for inclusion in the study. Patient records were assessed, noting age, weight, type of cast, time in cast, and complications. All casts were applied by senior pediatric orthopaedic surgeons at a single institution. Two groups were evaluated: 59 patients in the SLHS group and 35 in the double-leg hip spica group. The 2 groups were demographically similar with an average age of 2 years, 70.2% of patients were male, 45.7% were black, and 35.1% were white. The average time to cast removal was 4.1 weeks for the single-leg group and 5.3 weeks for the double-leg group (Pshaft fractures in patients less than 4 years old can be treated in a weight-bearing SLHS casts for approximately 4 weeks with fewer alignment and skin complications. Level III-clinical retrospective comparative study.

  2. High-Precision Displacement Sensing of Monolithic Piezoelectric Disk Resonators Using a Single-Electron Transistor

    Science.gov (United States)

    Li, J.; Santos, J. T.; Sillanpää, M. A.

    2018-02-01

    A single-electron transistor (SET) can be used as an extremely sensitive charge detector. Mechanical displacements can be converted into charge, and hence, SETs can become sensitive detectors of mechanical oscillations. For studying small-energy oscillations, an important approach to realize the mechanical resonators is to use piezoelectric materials. Besides coupling to traditional electric circuitry, the strain-generated piezoelectric charge allows for measuring ultrasmall oscillations via SET detection. Here, we explore the usage of SETs to detect the shear-mode oscillations of a 6-mm-diameter quartz disk resonator with a resonance frequency around 9 MHz. We measure the mechanical oscillations using either a conventional DC SET, or use the SET as a homodyne or heterodyne mixer, or finally, as a radio-frequency single-electron transistor (RF-SET). The RF-SET readout is shown to be the most sensitive method, allowing us to measure mechanical displacement amplitudes below 10^{-13} m. We conclude that a detection based on a SET offers a potential to reach the sensitivity at the quantum limit of the mechanical vibrations.

  3. Singly-resonant sum frequency generation of visible light in a semiconductor disk laser

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Schlosser, P.J.; Hastie, J.E.

    2009-01-01

    In this paper a generic approach for visible light generation is presented. It is based on sum frequency generation between a semiconductor disk laser and a solid-state laser, where the frequency mixing is achieved within the cavity of the semiconductor disk laser using a singlepass of the solid......-state laser light. This exploits the good beam quality and high intra-cavity power present in the semiconductor disk laser to achieve high conversion efficiency. Combining sum frequency mixing and semiconductor disk lasers in this manner allows in principle for generation of any wavelength within the visible...

  4. Radiation pressure in galactic disks: stability, turbulence, and winds in the single-scattering limit

    Science.gov (United States)

    Wibking, Benjamin D.; Thompson, Todd A.; Krumholz, Mark R.

    2018-04-01

    The radiation force on dust grains may be dynamically important in driving turbulence and outflows in rapidly star-forming galaxies. Recent studies focus on the highly optically-thick limit relevant to the densest ultra-luminous galaxies and super star clusters, where reprocessed infrared photons provide the dominant source of electromagnetic momentum. However, even among starburst galaxies, the great majority instead lie in the so-called "single-scattering" limit, where the system is optically-thick to the incident starlight, but optically-thin to the re-radiated infrared. In this paper we present a stability analysis and multidimensional radiation-hydrodynamic simulations exploring the stability and dynamics of isothermal dusty gas columns in this regime. We describe our algorithm for full angle-dependent radiation transport based on the discontinuous Galerkin finite element method. For a range of near-Eddington fluxes, we show that the medium is unstable, producing convective-like motions in a turbulent atmosphere with a scale height significantly inflated compared to the gas pressure scale height and mass-weighted turbulent energy densities of ˜0.01 - 0.1 of the midplane radiation energy density, corresponding to mass-weighted velocity dispersions of Mach number ˜0.5 - 2. Extrapolation of our results to optical depths of 103 implies maximum turbulent Mach numbers of ˜20. Comparing our results to galaxy-averaged observations, and subject to the approximations of our calculations, we find that radiation pressure does not contribute significantly to the effective supersonic pressure support in star-forming disks, which in general are substantially sub-Eddington. We further examine the time-averaged vertical density profiles in dynamical equilibrium and comment on implications for radiation-pressure-driven galactic winds.

  5. Circumferential shaft seal

    Science.gov (United States)

    Ludwig, L. P. (Inventor)

    1981-01-01

    A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band is disclosed. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

  6. Rotary shaft seal

    International Nuclear Information System (INIS)

    Langebrake, C.O.

    1984-01-01

    The invention is a novel rotary shaft seal assembly which provides positive-contact sealing when the shaft is not rotated and which operates with its sealing surfaces separated by a film of compressed ambient gas whose width is independent of the speed of shaft rotation. In a preferred embodiment, the assembly includes a disc affixed to the shaft for rotation therewith. Axially movable, non-rotatable plates respectively supported by sealing bellows are positioned on either side of the disc to be in sealing engagement therewith. Each plate carries piezoelectric transducer elements which are electrically energized at startup to produce films of compressed ambient gas between the confronting surfaces of the plates and the disc. Following shutdown of the shaft, the transducer elements are de-energized. A control circuit responds to incipient rubbing between the plate and either disc by altering the electrical input to the transducer elements to eliminate rubbing

  7. Improved circumferential shaft seal

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N.

    1974-01-01

    Comparative tests of modified and unmodified carbon ring seals showed that addition of helical grooves to conventional segmented carbon ring seals reduced leakage significantly. Modified seal was insensitive to shaft runout and to flooding by lubricant.

  8. Chemical Safety Alert: Shaft Blow-Out Hazard of Check and Butterfly Valves

    Science.gov (United States)

    Certain types of check and butterfly valves can undergo shaft-disk separation and fail catastrophically, even when operated within their design limits of pressure and temperature, causing toxic/flammable gas releases, fires, and vapor cloud explosions.

  9. Recent quality of ultra large rotor shafts

    International Nuclear Information System (INIS)

    Suzuki, Akira; Kinoshita, Shushi; Morita, Kikuo; Kikuchi, Hideo; Takada, Masayoshi

    1983-01-01

    Large size and high quality are required for rotor shafts accompanying recent trend of thermal and nuclear power generation toward large capacity. As for the low pressure rotor shafts for large capacity turbines, the disks and a shaft tend to be made into one body instead of conventional shrink fit construction, because of the experience of rotor accidents and the improvement of reliability. Therefore the ingots required become more and more large, and excellent production techniques are required for steel making, forging and heat treatment. Kobe Steel Ltd. have made about 20 large generator shafts from 420 t and 500 t ingots, and confirmed their stable high quality. Also a one-body low pressure rotor of 2600 mm diameter was made for trial, and its quality was examined. It was confirmed that the effect of forging and heat treatment was given sufficiently, and the production techniques for super-large one-body rotors were established. In steel making, vacuum degassing was applied twice to decrease hydrogen content, and VV restriction forging and pre-stage treatment were carried out. The properties of large rotors are reported. (Kako, I.)

  10. Shaft siting decision

    International Nuclear Information System (INIS)

    1987-08-01

    This study identifies and establishes relative guidelines to be used for siting of repository shafts. Weights were determined for the significant factors that impact the selection of shaft locations for a nuclear waste repository in salt. The study identified a total of 45 factors. A panel of experienced mining people utilized the Kepner-Tregoe (K-T) Decision Analysis Process to perform a structured evaluation of each significant shaft siting factor. The evaluation determined that 22 of the factors were absolute constraints and that the other 23 factors were desirable characteristics. The group established the relative weights for each of the 23 desirable characteristics by using a paired comparison method. 8 refs., 2 figs., 5 tabs

  11. High pressure shaft seal

    International Nuclear Information System (INIS)

    Martinson, A.R.; Rogers, V.D.

    1980-01-01

    In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

  12. Femoral shaft fractures

    International Nuclear Information System (INIS)

    Bender, C.E.; Campbell, D.C. II

    1985-01-01

    The femur is the longest, largest, and strongest bone in the body. Because of its length, width, and role as primary weight-bearing bone, it must tolerate the extremes of axial loading and angulatory stresses. Massive musculature envelopes the femur. This masculature provides abundant blood supply to the bone, which also allows great potential for healing. Thus, the most significant problem relating to femoral shaft fractures is not healing, but restoration of bone length and alignment so that the femoral shaft will tolerate the functional stresses demanded of it

  13. Extension of the Consolidation 3 shaft

    Energy Technology Data Exchange (ETDEWEB)

    Bohnenkamp, G [Gesteins- und Tiefbau G.m.b.H., Recklinghausen (Germany, F.R.)

    1978-02-01

    The conversion of a mine shaft into a central winning shaft is described, in particular planning principles, problems to be solved, preliminary work, timber drawing, extension work, shaft deepening, and the installation of shaft internals.

  14. Experience in sealing water bearing strata during deep shaft sinking

    Science.gov (United States)

    Kipko, E. Ja.; Polozov, Ju. A.; Lagunov, V. A.; Lushnikova, O. Ju.

    1984-12-01

    The paper deals with major concepts of grouting through holes drilled from the surface. The results of grouting through a single borehole at the location of two 1090 m deep shafts in Donbass are presented.

  15. FRACTURE SHAFT HUMERUS: INTERLOCKING

    Directory of Open Access Journals (Sweden)

    Deepak Kaladagi

    2014-12-01

    Full Text Available BACKGROUND: The incidence of humeral fracture has significantly increased during the present years due to the population growth and road traffic, domestic, industrial, automobile accidents & disasters like tsunami, earthquakes, head-on collisions, polytrauma etc. In order to achieve a stable fixation followed by early mobilization, numerous surgical implants have been devised. PURPOSE: The purpose of this study is to analyze the results of intramedullary fixation of proximal 2/3rd humeral shaft fractures using an unreamed interlocking intramedullary nail. INTRODUCTION: In 40 skeletally matured patients with fracture shaft of humerus admitted in our hospital, we used unreamed antegrade interlocking nails. MATERIAL: We carried out a prospective analysis of 40 patients randomly selected between 2001 to 2014 who were operated at JNMC Belgaum, MMC Mysore & Navodaya Medical College, Raichur. All cases were either RTAs, Domestic, Industrial, automobile accidents & also other modes of injury. METHOD: Routine investigations with pre-anaesthetic check-up & good quality X-rays of both sides of humerus was taken. Time of surgery ranged from 5-10 days from the time of admission. Only upper 1/3rd & middle 1/3rd humeral shaft fractures were included in the study. In all the cases antegrade locked unreamed humeral nails were inserted under C-arm. Patient was placed in supine position & the shoulder was kept elevated by placing a sandbag under the scapula. In all patients incision taken from tip of acromion to 3cm over deltoid longitudinally. Postoperatively sling applied with wrist & shoulder movements started after 24 hours. All the patients ranged between the age of 21-50 years. RESULTS: Total 40 patients were operated. Maximum fracture site were in the middle third- 76%, 14% upper 1/3rd. All 40 patients achieved union. The average time of union was 8-10 weeks. All patients regained full range of movements except in few cases, where there was shoulder

  16. Stagger angle dependence of inertial and elastic coupling in bladed disks

    Science.gov (United States)

    Crawley, E. F.; Mokadam, D. R.

    1984-01-01

    Conditions which necessitate the inclusion of disk and shaft flexibility in the analysis of blade response in rotating blade-disk-shaft systems are derived in terms of nondimensional parameters. A simple semianalytical Rayleigh-Ritz model is derived in which the disk possesses all six rigid body degrees of freedom, which are elastically constrained by the shaft. Inertial coupling by the rigid body motion of the disk on a flexible shaft and out-of-plane elastic coupling due to disk flexure are included. Frequency ratios and mass ratios, which depend on the stagger angle, are determined for three typical rotors: a first stage high-pressure core compressor, a high bypass ratio fan, and an advanced turboprop. The stagger angle controls the degree of coupling in the blade-disk system. In the blade-disk-shaft system, the stagger angle determines whether blade-disk motion couples principally to the out-of-plane or in-plane motion of the disk on the shaft. The Ritz analysis shows excellent agreement with experimental results.

  17. Electromagnetic shaft seal

    International Nuclear Information System (INIS)

    Takahashi, Kenji.

    1994-01-01

    As an electromagnetic shaft seal, there are disposed outwarding electromagnetic induction devices having generating power directing to an electroconductive fluid as an object of sealing, and inwarding electromagnetic induction device added coaxially. There are disposed elongate rectangular looped first coils having a predetermined inner diameter, second coils having the same shape and shifted by a predetermined pitch relative to the first coil and third coil having the same shape and shifted by a predetermined pitch relative to the second coil respectively each at a predetermined inner diameter of clearance to the outwarding electromagnetic induction devices and the inwarding electromagnetic induction device. If the inwarding electromagnetic induction device and the outwarding electromagnetic induction device are operated, they are stopped at a point that the generating power of the former is equal with the sum of the generating power of the latter and a differential pressure. When three-phase AC is charged to the first coil, the second coil and the third coil successively, a force is generated in the advancing direction of the magnetic field in the electroconductive fluid by the similar effect to that of a linear motor, and the seal is maintained at high reliability. Moreover, the limit for the rotational angle of the shaft is not caused. (N.H.)

  18. Shaft seal assembly and method

    Science.gov (United States)

    Keba, John E. (Inventor)

    2007-01-01

    A pressure-actuated shaft seal assembly and associated method for controlling the flow of fluid adjacent a rotatable shaft are provided. The seal assembly includes one or more seal members that can be adjusted between open and closed positions, for example, according to the rotational speed of the shaft. For example, the seal member can be configured to be adjusted according to a radial pressure differential in a fluid that varies with the rotational speed of the shaft. In addition, in the closed position, each seal member can contact a rotatable member connected to the shaft to form a seal with the rotatable member and prevent fluid from flowing through the assembly. Thus, the seal can be closed at low speeds of operation and opened at high speeds of operation, thereby reducing the heat and wear in the seal assembly while maintaining a sufficient seal during all speeds of operation.

  19. RELAP/FRAP-T6 analysis of seized and sheared shaft accidents

    International Nuclear Information System (INIS)

    Bollinger, J.S.; Ito, T.; Peeler, G.B.

    1984-01-01

    Argonne National Laboratory (ANL) performed audit calculations of a Reactor Coolant Pump (RCP) seized/sheared shaft transient for the Westinghouse Seabrook Plant using RELAP5/MOD 1.5 (Cycle 32) and FRAP-T6. The objective was to determine the effect of time of loss of offsite power and other single component failures on the peak clad temperature. The RCP shaft seizure event was modeled in RELAP5 by using the pump model shaft stop option. In modeling the sheared shaft failure, the faulted pump was replaced with a branch component having no flow losses. In general, the RELAP5-predicted system response for the seized shaft transient was very comparable to the results presented in the Seabrook FSAR, although the Reactor Coolant System (RCS) pressure response was somewhat different. The RELAP5 sheared-shaft analysis results were very similar to those for the seized shaft

  20. Vibration of rotating-shaft design spindles with flexible bases

    Science.gov (United States)

    Tseng, Chaw-Wu

    The purpose of this study is to demonstrate an accurate mathematical model predicting forced vibration of rotating-shaft HDD spindle motors with flexible stationary parts. The mathematical model consists of three parts: a rotating part, a stationary part, and bearings. The rotating part includes a flexible hub, a flexible shaft press-fit into the hub, and N elastic disks mounted on the hub. The stationary part can include motor bracket (stator), base casting, and top cover. The bearings under consideration can be ball bearings or hydrodynamic bearings (HDB). The rotating disks are modelled through the classical plate theory. The rotating part (except the disks) and the stationary part are modelled through finite element analyses (FEA). With mode shapes and natural frequencies obtained from FEA, the kinetic and potential energies of the rotating and stationary parts are formulated and discretized to compensate for the gyroscopic effects from rotation. Finally, use of Lagrange equation results in the equations of motion. To verify the mathematical model, frequency response functions are measured experimentally for an HDB spindle carrying two identical disks at motor and drive levels. Experimental measurements agree very well with theoretical predictions not only in resonance frequency but also in resonance amplitude.

  1. TIBIAL SHAFT FRACTURES.

    Science.gov (United States)

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2011-01-01

    The long-bone fractures occur most frequently in the tibial shaft. Adequate treatment of such fractures avoids consolidation failure, skewed consolidation and reoperation. To classify these fractures, the AO/OTA classification method is still used, but it is worthwhile getting to know the Ellis classification method, which also includes assessment of soft-tissue injuries. There is often an association with compartmental syndrome, and early diagnosis can be achieved through evaluating clinical parameters and constant clinical monitoring. Once the diagnosis has been made, fasciotomy should be performed. It is always difficult to assess consolidation, but the RUST method may help in this. Radiography is assessed in two projections, and points are scored for the presence of the fracture line and a visible bone callus. Today, the dogma of six hours for cleaning the exposed fracture is under discussion. It is considered that an early start to intravenous antibiotic therapy and the lesion severity are very important. The question of early or late closure of the lesion in an exposed fracture has gone through several phases: sometimes early closure has been indicated and sometimes late closure. Currently, whenever possible, early closure of the lesion is recommended, since this diminishes the risk of infection. Milling of the canal when the intramedullary nail is introduced is still a controversial subject. Despite strong personal positions in favor of milling, studies have shown that there may be some advantage in relation to closed fractures, but not in exposed fractures.

  2. Large shaft development test plan

    International Nuclear Information System (INIS)

    Krug, A.D.

    1984-03-01

    This test plan proposes the conduct of shaft liner tests as part of the large shaft development test proposed for the Hanford Site in support of the repository development program. The objectives of these tests are to develop techniques for measuring liner alignment (straightness), both construction assembly alignment and downhole cumulative alignment, and to assess the alignment information as a real time feedback to aid the installation procedure. The test plan is based upon installing a 16 foot ID shaft liner into a 20 foot diameter shaft to a depth of 1000 feet. This test plan is considered to be preliminary in that it was prepared as input for the decision to determine if development testing is required in this area. Should the decision be made to proceed with development testing, this test plan shall be updated and revised. 6 refs., 2 figs

  3. Shaft and tunnel sealing considerations

    International Nuclear Information System (INIS)

    Kelsall, P.C.; Shukla, D.K.

    1980-01-01

    Much of the emphasis of previous repository sealing research has been placed on plugging small diameter boreholes. It is increasingly evident that equal emphasis should now be given to shafts and tunnels which constitute more significant pathways between a repository and the biosphere. The paper discusses differences in requirements for sealing shafts and tunnels as compared with boreholes and the implications for seal design. Consideration is given to a design approach for shaft and tunnel seals based on a multiple component design concept, taking into account the requirements for retrievability of the waste. A work plan is developed for the future studies required to advance shaft and tunnel sealing technology to a level comparable with the existing technology for borehole sealing

  4. Achievement report for fiscal 1989. Research and development of ceramic gas turbine (Regenerative single-shaft axial-flow turbine for cogeneration); 1989 nendo ceramic gas turbine no kenkyu kaihatsu seika hokokusho. Cogeneration yo saisei ichijikushiki jikuryu turbine

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-05-01

    With an objective to research and develop a 300-kW class regenerative single-shaft axial-flow turbine having inlet temperature of 1,350 degrees C and thermal efficiency of 42% or higher, activities were performed in the following three fields: 1) heat resistant ceramic members, 2) elementary technologies, and 3) studies on design, prototype fabrication, and operation. In Item 1, a mass production technology was discussed on stator blades and heat transfer pipes for a heat exchanger as the component manufacturing technology, and injection molding conditions were studied and mechanical strength measurement was performed on rotor blades of a separate type axial-flow turbine. In addition, a molding condition producing no cracks was discovered in an integrated type axial-flow turbine whose embedded section has a tapered shape, and the mass production technology was discussed. With regard to the bonding technology, preliminary discussions were given on bonding agents under a prerequisite that a bonding agent shall be used. In Item 2, detailed discussions were launched on the turbine, combustor, heat exchanger, and compressor, including shape decision on the turbine, for example, by using aerodynamic analysis, In Item 3, the basic design was performed following the conceptual design, and a metallic turbine was designed. (NEDO)

  5. ALMA continuum observations of the protoplanetary disk AS 209. Evidence of multiple gaps opened by a single planet

    Science.gov (United States)

    Fedele, D.; Tazzari, M.; Booth, R.; Testi, L.; Clarke, C. J.; Pascucci, I.; Kospal, A.; Semenov, D.; Bruderer, S.; Henning, Th.; Teague, R.

    2018-02-01

    This paper presents new high angular resolution ALMA 1.3 mm dust continuum observations of the protoplanetary system AS 209 in the Ophiuchus star forming region. The dust continuum emission is characterized by a main central core and two prominent rings at r = 75 au and r = 130 au intervaled by two gaps at r = 62 au and r = 103 au. The two gaps have different widths and depths, with the inner one being narrower and shallower. We determined the surface density of the millimeter dust grains using the 3D radiative transfer disk code DALI. According to our fiducial model the inner gap is partially filled with millimeter grains while the outer gap is largely devoid of dust. The inferred surface density is compared to 3D hydrodynamical simulations (FARGO-3D) of planet-disk interaction. The outer dust gap is consistent with the presence of a giant planet (Mplanet 0.7 MSaturn); the planet is responsible for the gap opening and for the pile-up of dust at the outer edge of the planet orbit. The simulations also show that the same planet could be the origin of the inner gap at r = 62 au. The relative position of the two dust gaps is close to the 2:1 resonance and we have investigated the possibility of a second planet inside the inner gap. The resulting surface density (including location, width and depth of the two dust gaps) are in agreement with the observations. The properties of the inner gap pose a strong constraint to the mass of the inner planet (Mplanet disk viscosity (α < 10‑4). Given the young age of the system (0.5-1 Myr), this result implies that the formation of giant planets occurs on a timescale of ≲1 Myr. The reduced image (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A24

  6. Humeral Shaft Fracture: Intramedullary Nailing.

    Science.gov (United States)

    Konda, Sanjit R; Saleh, Hesham; Fisher, Nina; Egol, Kenneth A

    2017-08-01

    This video demonstrates the technique of intramedullary nailing for a humeral shaft fracture. The patient is a 30-year-old man who sustained a gunshot wound to his right arm. The patient was indicated for humeral nailing given the comminuted nature of the diaphysis and to allow for minimal skin incisions. Other relative indications include soft-tissue compromise about the arm precluding a large surgical exposure. This video presents a case of a comminuted humeral shaft fracture treated with an intramedullary nail. Anatomic reduction and stable fixation was obtained with this technique. This case demonstrates a soft-tissue sparing technique of humeral shaft fixation using a humeral intramedullary nail. The technique is easy to perform and has significant benefits in minimizing surgical exposure, decreasing operative time, and decreasing blood loss. In the correct clinical setting, humeral nailing provides an expeditious form of fixation that restores length, alignment, and rotation of the fracture humeral diaphysis.

  7. Exploratory shaft liner corrosion estimate

    International Nuclear Information System (INIS)

    Duncan, D.R.

    1985-10-01

    An estimate of expected corrosion degradation during the 100-year design life of the Exploratory Shaft (ES) is presented. The basis for the estimate is a brief literature survey of corrosion data, in addition to data taken by the Basalt Waste Isolation Project. The scope of the study is expected corrosion environment of the ES, the corrosion modes of general corrosion, pitting and crevice corrosion, dissimilar metal corrosion, and environmentally assisted cracking. The expected internal and external environment of the shaft liner is described in detail and estimated effects of each corrosion mode are given. The maximum amount of general corrosion degradation was estimated to be 70 mils at the exterior and 48 mils at the interior, at the shaft bottom. Corrosion at welds or mechanical joints could be significant, dependent on design. After a final determination of corrosion allowance has been established by the project it will be added to the design criteria. 10 refs., 6 figs., 5 tabs

  8. An exploratory shaft facility in SALT: Draft shaft study plan

    International Nuclear Information System (INIS)

    1987-03-01

    This draft Shaft Study Plan describes a program of testing and monitoring in the Exploratory Shafts of a candidate high-level nuclear waste repository site in Deaf Smith County, Texas. The purpose of the programs to assist with site characterization in support of a determination of site suitability for development as a repository design and performance assessment evaluations. The program includes a variety of geological, geophysical, geomechanical, thermomechanical, and geohydrological testing and monitoring. The program is presented as a series of separate studies concerned with geological, geomechanical, and geohydrological site characterization, and with evaluating the mechanical and hydrological response of the site to construction of the shafts. The various studies, and associated test or monitoring methods are shown. The procedure used in developing the test program has been to initially identify the information necessary to satisfy (1) federal, state, and local requirements, and (2) repository program requirements. These information requirements have then been assessed to determine which requirements can be addressed wholly or in significant part by monitoring and testing from within the shafts. Test methods have been identified to address specific information requirements. 67 refs., 39 figs., 31 tabs

  9. Ultrasonic testing of installed low-pressure turbine shafts

    International Nuclear Information System (INIS)

    Hildmann, I.; Voelker, J.; Ewald, J.

    1987-01-01

    Transverse defects in the admission area of double-flow LP turbine shafts with shrink-on wheel disks can be detected during the onset of crack growth by means of a newly developed test concept with slightly oblique longitudinal US wave incidence, and crack size estimates can be made. For process development and system adjustment a large reference specimen with circular and circular segment-type test reflectors was used. The results of comparative measurements with different types of devices and probes of different transducer size, test frequency and pulse length are presented, and the choice of the technical testing details is substantiated. (orig./DG) [de

  10. Dual-Alloy Disks are Formed by Powder Metallurgy

    Science.gov (United States)

    Harf, F. H.; Miner, R. V.; Kortovich, C. S.; Marder, J. M.

    1982-01-01

    High-performance disks have widely varying properties from hub to rim. Dual property disk is fabricated using two nickel-base alloys, AF-115 for rim and Rene 95 for hub. Dual-alloy fabrication may find applications in automobiles, earth-moving equipment, and energy conversion systems as well as aircraft powerplants. There is potential for such applications as shafts, gears, and blades.

  11. Control rod drive shaft latch

    International Nuclear Information System (INIS)

    Thorp, A.G. II.

    1976-01-01

    A latch mechanism is operated by differential pressure on a piston to engage the drive shaft for a control rod in a nuclear reactor, thereby preventing the control rod from being ejected from the reactor in case of failure of the control rod drive mechanism housing which is subjected to the internal pressure in the reactor vessel. 6 claims, 4 drawing figures

  12. Geotechnical instrumentation for repository shafts

    International Nuclear Information System (INIS)

    Lentell, R.L.; Byrne, J.

    1993-01-01

    The US Congress passed the Nuclear Waste Policy Act in 1980, which required that three distinctly different geologic media be investigated as potential candidate sites for the permanent disposal of high-level nuclear waste. The three media that were selected for study were basalt (WA), salt (TX, LA, MS, UT), and tuff (NV). Preliminary Exploratory Shaft Facilities (ESF) designs were prepared for seven candidate salt sites, including bedded and domal salt environments. A bedded-salt site was selected in Deaf Smith County, TX for detailed site characterization studies and ESF Final Design. Although Congress terminated the Salt Repository Program in 1988, Final Design for the Deaf Smith ESF was completed, and much of the design rationale can be applied to subsequent deep repository shafts. This paper presents the rationale for the geotechnical instrumentation that was designed for construction and operational performance monitoring of the deep shafts of the in-situ test facility. The instrumentation design described herein can be used as a general framework in designing subsequent instrumentation programs for future high-level nuclear waste repository shafts

  13. Update of 1972 status report on deep shaft studies

    International Nuclear Information System (INIS)

    1976-09-01

    The following aspects of shaft sinking are considered: the effects of geology, factors affecting shaft size, the conventional shaft sinking techniques and the newer mechanized methods, several representative or difficult shafts, and certain long-term problems and solutions

  14. 30 CFR 57.19106 - Shaft sets.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft sets. 57.19106 Section 57.19106 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....19106 Shaft sets. Shaft sets shall be kept in good repair and clean of hazardous material. ...

  15. 30 CFR 56.19106 - Shaft sets.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft sets. 56.19106 Section 56.19106 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Shaft sets. Shaft sets shall be kept in good repair and clean of hazardous material. ...

  16. Pre-cementation of deep shaft

    Science.gov (United States)

    Heinz, W. F.

    1988-12-01

    Pre-cementation or pre-grouting of deep shafts in South Africa is an established technique to improve safety and reduce water ingress during shaft sinking. The recent completion of several pre-cementation projects for shafts deeper than 1000m has once again highlighted the effectiveness of pre-grouting of shafts utilizing deep slimline boreholes and incorporating wireline technique for drilling and conventional deep borehole grouting techniques for pre-cementation. Pre-cementation of deep shaft will: (i) Increase the safety of shaft sinking operation (ii) Minimize water and gas inflow during shaft sinking (iii) Minimize the time lost due to additional grouting operations during sinking of the shaft and hence minimize costly delays and standing time of shaft sinking crews and equipment. (iv) Provide detailed information of the geology of the proposed shaft site. Informations on anomalies, dykes, faults as well as reef (gold bearing conglomerates) intersections can be obtained from the evaluation of cores of the pre-cementation boreholes. (v) Provide improved rock strength for excavations in the immediate vicinity of the shaft area. The paper describes pre-cementation techniques recently applied successfully from surface and some conclusions drawn for further considerations.

  17. Mine-shaft conveyance monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Beus, M.J.; Ruff, T.M.; Iverson, S.; McCoy, W.G. [National Institute for Occupational Safety and Health, Spokane, WA (USA). Spokane Research Laboratory

    2000-10-01

    Monitoring conveyance position and wire rope load directly from the skip or cage top offers several significant safety and production advantages. The Spokane Research Laboratory (SRL) of the National Institute for Occupational Safety and Health (NIOSH) developed a shaft conveyance monitoring system (SCMS). This system consists of position and guide-displacement sensors, a maintenance-free battery power supply and a new sensor, which is mounted on the wire rope with a Crosby Clip, to measure hoist-rope tension. A radio data link transmits sensor output to the hoist room. A state-of-the-art automated hoisting test facility was also constructed to test the concept in a controlled laboratory setting. Field tests are now underway at the SRL hoisting research facility and in deep mine shafts in northern Idaho. 4 refs., 5 figs.

  18. In-plane inertial coupling in tuned and severely mistuned bladed disks

    Science.gov (United States)

    Crawley, E. F.

    1982-01-01

    A model has been developed and verified for blade-disk-shaft coupling in rotors due to the in-plane rigid body modes of the disk. An analytic model has been developed which couples the in-plane rigid body modes of the disk on an elastic shaft with the blade bending modes. Bench resonance test were carried out on the M.I.T. Compressor Rotor, typical of research rotors with flexible blades and a thick rigid disk. When the rotor was carefully tuned, the structural coupling of the blades by the disks was confined to zero and one nodal diameter modes, whose modal frequencies were greater than the blade cantilever frequency. In the case of the tuned rotor, and in two cases where severe mistuning was intentionally introduced, agreement between the predicted and observed natural frequencies is excellent. The analytic model was then extended to include the effects of constant angular rotation of the disk.

  19. Large shaft development test plan

    International Nuclear Information System (INIS)

    Krug, A.D.

    1984-03-01

    This test plan proposes the conduct of a large shaft development test at the Hanford site in support of the repository development program. The purpose and objective of the test plan is to obtain the information necessary to establish feasibility and to predict the performance of the drilling system used to drill large diameter shafts. The test plan is based upon drilling a 20 ft diameter shaft to a depth of 1,000 feet. The test plan specifies series of tests to evaluate the performance of the downhole assembly, the performance of the rig, and the ability of the system to cope with geologic hazards. The quality of the hole produced will also be determined. This test plan is considered to be preliminary in that it was prepared as input for the decision to determine if development testing is required in this area. Should the decision be made to proceed with development testing, this test plan shall be updated and revised. 6 refs., 2 figs., 3 tabs

  20. Influence of the shaft rotation on the stability of magnetic fluid shaft seal characteristics

    Science.gov (United States)

    Krakov, M. S.; Nikiforov, I. V.

    2008-12-01

    Distribution of the magnetic particles concentration in a magnetic fluid shaft seal is studied numerically for a rotating shaft. It is revealed that the shaft rotation causes not only an azimuthal flow of the magnetic fluid, but a meridional flow as well. This meridional flow prevents the growth of magnetic particle concentration in the gap of the magnetic fluid shaft seal. As a result, the burst pressure of the magnetic fluid shaft seal for the rotating shaft is stable and does not change with time. Figs 6, Refs 7.

  1. Shaft placement in a bedded salt repository

    International Nuclear Information System (INIS)

    Klasi, M.L.

    1982-10-01

    Preferred shaft pillar sizes and shaft locations were determined with respect to the induced thermal stresses in a generic bedded salt repository at a depth of 610 m with a gross thermal loading of 14.8 W/m 2 . The model assumes isotropic material properties, plane strain and linear elastic behavior. Various shaft locations were analyzed over a 25 year period. The thermal results show that for this time span, the stratigraphy is unimportant except for the region immediately adjacent to the repository. The thermomechanical results show that for the given repository depth of 610 m, a minimum central shaft pillar radius of 244 m is required to equal the material strength in the barrier pillar. An assumed constant stress and constant temperature distribution creep model of the central shaft region adjacent to the repository conservatively overestimates a creep closure of 310 mm in a 6.1 m diameter centrally-located shaft

  2. The SSC access shafts calculational study

    International Nuclear Information System (INIS)

    Baishev, I.S.; Mokhov, N.V.; Toohig, T.E.

    1991-06-01

    The SSC generic shaft requirements and access spacing are considered elsewhere. The shafts connecting the ground surface with the underground accelerator tunnel deliver to the surface some portion of the radiation created in the tunnel. The radiation safety problem of access shafts consists of two major questions: Does the dose equivalent at the ground surface exceed permissible limits? If it exceeds those limits, what additional shielding measures are required? A few works deal with this problem for high energy machines. This work is an attempt to answer these questions for the basic types of shafts specific to the SSC magnet delivery, utility and personnel shafts using full-scale Monte-Carlo calculations of the entire process from hadronic cascades in the lattice elements to particles scattered in the tunnel, niches, alcoves, shafts and surface bunkers and buildings. 9 refs., 16 figs., 1 tab

  3. Shaft MisalignmentDetectionusing Stator Current Monitoring

    OpenAIRE

    Alok Kumar Verma, Somnath Sarangi and M.H. Kolekar

    2013-01-01

    This paper inspects the misaligned of shaft by usingdiagnostic medium such as current and vibration.Misalignments in machines can cause decrease inefficiency and in the long-run it may cause failurebecause of unnecessary vibration, stress on motor,bearings and short-circuiting in stator and rotorwindings.In this study, authors investigate the onsetof instability on a shaft mounted on journal bearings.Shaft displacement and stator current samples duringmachine run up under misaligned condition...

  4. Storage shaft definitive closure plug and method

    International Nuclear Information System (INIS)

    Dardaine, M.

    1992-01-01

    A definitive closure plug system for radioactive waste storage at any deepness, is presented. The inherent weight of the closure materials is used to set in the plug: these materials display an inclined sliding surface in such a way that when the closure material rests on a stable surface of the shaft storage materials, the relative sliding of the different materials tends to spread them towards the shaft internal wall so as to completely occlude the shaft

  5. Full Dynamic Reactions in the Basic Shaft Bearings of Big Band Saw Machines

    Science.gov (United States)

    Marinov, Boycho

    2013-03-01

    The band saws machines are a certain class woodworking machines for longitudinal or transversal cutting as well as for curvilinear wood cutting. These machines saw the wood through a band-saw blade and two feeding wheels. These wheels usually are very large and they are produced with inaccuracies. The centre of mass of the disc is displaced from the axis of rotation of the distance e (eccentricity) and the axis of the disk makes an angle with the axis of rotation. In this paper, the dy- namic reactions in the bearings of the basic shaft, which drives the band saw machines, are analyzed. These reactions are caused by the external loading and the kinematics and the mass characteristics of the rotating disk. The expressions for the full dynamic reactions are obtained. These expressions allow the parameters of the machines to be chosen in such a way that the loading in the shaft and the bearings to be minimal.

  6. Direct shaft torque measurements in a transient turbine facility

    International Nuclear Information System (INIS)

    Beard, Paul F; Povey, Thomas

    2011-01-01

    This paper describes the development and implementation of a shaft torque measurement system for the Oxford Turbine Research Facility (formerly the Turbine Test Facility (TTF) at QinetiQ, Farnborough), or OTRF. As part of the recent EU TATEF II programme, the facility was upgraded to allow turbine efficiency measurements to be performed. A shaft torque measurement system was developed as part of this upgrade. The system is unique in that, to the authors' knowledge, it provided the first direct measurement of shaft torque in a transient turbine facility although the system has wider applicability to rotating test facilities in which power measurement is a requirement. The adopted approach removes the requirement to quantify bearing friction, which can be difficult to accurately calibrate under representative operating conditions. The OTRF is a short duration (approximately 0.4 s run time) isentropic light-piston facility capable of matching all of the non-dimensional parameters important for aerodynamic and heat studies, namely Mach number, Reynolds number, non-dimensional speed, stage pressure ratio and gas-to-wall temperature ratio. The single-stage MT1 turbine used for this study is a highly loaded unshrouded design, and as such is relevant to modern military, or future civil aero-engine design. Shaft torque was measured directly using a custom-built strain gauge-based torque measurement system in the rotating frame of reference. This paper describes the development of this measurement system. The system was calibrated, including the effects of temperature, to a traceable primary standard using a purpose-built facility. The bias and precision uncertainties of the measured torque were ±0.117% and ±0.183%, respectively. To accurately determine the shaft torque developed by a turbine in the OTRF, small corrections due to inertial torque (associated with changes in the rotational speed) and aerodynamic drag (windage) are required. The methods for performing these

  7. Spiral groove seal. [for hydraulic rotating shaft

    Science.gov (United States)

    Ludwig, L. P. (Inventor)

    1973-01-01

    Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove pattern produces a pumping action toward the fluid when the shaft rotates which prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear.

  8. Spiral groove seal. [for rotating shaft

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N. (Inventor)

    1974-01-01

    Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove produces a pumping action toward the fluid when the shaft rotates. This prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear. Provision is made for placing these spiral grooves in communication with the fluid to accelerate the generation of the hydraulic lifting force.

  9. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

    1998-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  10. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

    1999-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  11. 10 MB disk platter from CDC 7638

    CERN Multimedia

    1974-01-01

    This magnetic disk was one of three which interfaced with various Control Data machines. This single platter came from a Control Data 7638 Disk Storage Subsystem and could contain up to 10MB - about the size of a few MP4's on your iPod.

  12. Using combined system of shaft guides for buckets during shaft deepening

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.; Ivenskii, N.S.; Alekhin, P.I.

    1981-06-01

    This paper discusses a system of shaft guides used in the Krasnopol'evsk underground coal mine. The existing skip shaft 514 m deep is deepened to a depth of 700 m. Shaft design is adapted to a system of two pairs of skips, however, only one pair of skips is in operation and the other has been removed. The free space can be used to remove rock material from shaft bottom. It is noted that a system of buckets moving along elastic shaft guides made of rope or along rigid shaft guides can be used. Both solutions have numerous advantages. If rope guides are used time consuming installation of shaft guides is unnecessary in the zone close to the bottom. If rigid guides are used capacity of the bucket can be significantly increased. A system which combines advantages of both solutions is used: in the lower part of the shaft being deepened, buckets are guided by rope, and in the upper zone in which rigid shaft guides have been installed the bucket moves along rigid guides and rope guides simultaneously. Design of the element guiding the bucket is shown in two diagrams. It is noted that using the combined system of shaft guides increases capacity of the hoisting system by 1.5 times.

  13. Exploratory Shaft Facility design basis study report

    International Nuclear Information System (INIS)

    Langstaff, A.L.

    1987-01-01

    The Design Basis Study is a scoping/sizing study that evaluated the items concerning the Exploratory Shaft Facility Design including design basis values for water and methane inflow; flexibility of the design to support potential changes in program direction; cost and schedule impacts that could result if the design were changed to comply with gassy mine regulations; and cost, schedule, advantages and disadvantages of a larger second shaft. Recommendations are proposed concerning water and methane inflow values, facility layout, second shaft size, ventilation, and gassy mine requirements. 75 refs., 3 figs., 7 tabs

  14. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  15. ESF [Exploratory Shaft Facility] flexibility analysis

    International Nuclear Information System (INIS)

    Brusenback, R.W.

    1987-03-01

    This report directs that uncertainty allowances be included within the ESF facilities. The recommendations herein developed are intended as input to Title II Design criteria. Flexibility is measured first by lineal ft of drift, and then by hoisting rate and capacity of supporting utilities and services. A defined probability of need shows an extra 10,000 ft of drift for the first level of flexibility responding to testing and operations, and over 60,000 ft of drift for the second level of flexibility which recognizes possible need for perimeter drifting to investigate geologic stratigraphy. Observing there will be time constraints, a single shaft muck hoisting rate up to 170 to 250 tons per hour is recommended. The potential hoisting rate recommended for flexibility should be satisfied by a hoist approximately equivalent to, or conveniently upgraded from those being considered for sinking and construction, or 1000 horsepower. The cost of flexibility is limited to engineering planning and design (mostly conceptual) which makes later expansion achievable, and to selected items for initial construction where later upgrading would be impractical, impossible, or very costly. The cost is fixed to the level of flexibility and does not vary with excavated footage. The incremental margin is only a small fraction of the additional footage made available. Flexibility presents a strategy and not a position of design or technology. Examples used in this report are intended to be illustrative only, and not to lead design or cost estimates. 7 tabs

  16. Shaft Seal Compensates for Cold Flow

    Science.gov (United States)

    Myers, W. N.; Hein, L. A.

    1985-01-01

    Seal components easy to install. Ring seal for rotating or reciprocating shafts spring-loaded to compensate for slow yielding (cold flow) of sealing material. New seal relatively easy to install because components preassembled, then installed in one piece.

  17. Documentation and verification of the SHAFT code

    International Nuclear Information System (INIS)

    St John, C.M.

    1991-12-01

    The SHAFT code incorporates equations to compute stresses in a shaft liner when the rock through which a shaft passes is subject to known three-dimensional states of stress or strain. The deformation modes considered are hoop deformation, axial deformation, and shear on a plane normal to the shaft axis. Interaction between the liner and the soil and rock is considered, and it is assumed that the liner is in place before loading is applied. This code is intended to be used interactively but creates a permanent record complete with necessary quality assurance information. The code has been carefully verified for the case of generalized plane strain, in which an arbitrary axial strain can be defined. It may also be used for plane stress analysis. Output is given in the form of stresses at selected sample points in the linear and the rock and a simple graphical representation of the distribution of stress through the liner. 12 figs., 13 tabs

  18. Reliability assessment of underground shaft closure

    International Nuclear Information System (INIS)

    Fossum, A.F.; Munson, D.E.

    1994-01-01

    The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties

  19. Failure analysis and shock protection of external hard disk drive ...

    African Journals Online (AJOL)

    Technology for processing and storage of data in portable external storage hard disks has increasingly improved over the years. Currently, terabytes of data can be stored in one portable external storage hard disk drive. Storing such amount of data on a single disk on itself is a risk. Several instances of data lost by big ...

  20. FIXTURING DEVICE FOR DRILLING A STRAIGHT SHAFT

    Directory of Open Access Journals (Sweden)

    SUSAC, Florin

    2017-05-01

    Full Text Available The paper presents a fixturing device used for machining by drilling a straight shaft. The shaft was manufactured on EMCO CONCEPT TURN 55 CNC. The blank used was a bar with circular cross-section. The orientation and fixing scheme of the part and the orientation elements for fixturing device are presented as they were drawn in Autodesk Inventor and AutoCAD software.

  1. Incidence and epidemiology of tibial shaft fractures.

    Science.gov (United States)

    Larsen, Peter; Elsoe, Rasmus; Hansen, Sandra Hope; Graven-Nielsen, Thomas; Laessoe, Uffe; Rasmussen, Sten

    2015-04-01

    The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Retrospective reviews of clinical and radiological records. A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010. The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have the highest frequency between the age of 30 and 40. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. The majority of tibial shaft fractures occur during walking, indoor activity and sports. The distribution among genders shows that males present a higher frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Achievement report for fiscal 1998. Research and development of ceramic gas turbine (Regenerative single-shaft ceramic gas turbine for cogeneration); 1998 nendo ceramic gas turbine no kenkyu kaihatsu seika hokokusho. Cogeneration yo saiseishiki ichijiku ceramic gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    Efforts are exerted to develop a 300kW-class ceramic gas turbine with a turbine inlet temperature of 1350 degrees C and thermal efficiency of 42% or higher. The soundness in strength of the ceramic rotor blades and their fastening structure is confirmed. Rotor blade cushion thickness is found to decrease in start-and-stop repetitions in the initial period, but not thereafter. The exhaust diffuser and exhaust path shape are studied and improved for an increase in output, which improves turbine efficiency by 1.7%. Under the operating conditions of 1350 degrees C and full load, NOx emissions and combustion efficiency prove to be 5.6ppm and 99.9%. Even in the case using a large-diameter liner with its combustion efficiency under light load improved, the ultimate target value is achieved. Studies are further conducted on centrifugal stage loss reduction towards the ultimate goal set for the compressor. The diffuser shape is improved and the shroud clearance is reduced, and insulation efficiency of 81.1% is attained at the designing stage. In a test run of a pilot ceramic gas turbine in which temperature finally arrives at 1350 degrees C, engine thermal efficiency of 35% and shaft output of 282kW are achieved. (NEDO)

  3. Disk Storage Server

    CERN Multimedia

    This model was a disk storage server used in the Data Centre up until 2012. Each tray contains a hard disk drive (see the 5TB hard disk drive on the main disk display section - this actually fits into one of the trays). There are 16 trays in all per server. There are hundreds of these servers mounted on racks in the Data Centre, as can be seen.

  4. Viscoelastic Characterization of Long-Eared Owl Flight Feather Shaft and the Damping Ability Analysis

    Directory of Open Access Journals (Sweden)

    Jia-li Gao

    2014-01-01

    Full Text Available Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082 and golden eagle (1.087 ± 0.074. It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.

  5. Understanding Floppy Disks.

    Science.gov (United States)

    Valentine, Pamela

    1980-01-01

    The author describes the floppy disk with an analogy to the phonograph record, and discusses the advantages, disadvantages, and capabilities of hard-sectored and soft-sectored floppy disks. She concludes that, at present, the floppy disk will continue to be the primary choice of personal computer manufacturers and their customers. (KC)

  6. System design for shaft safety and productivity

    Energy Technology Data Exchange (ETDEWEB)

    Owen, D.; Parsons, R.; Ward, R.

    1988-03-01

    The aim of this paper is to describe the process of designing a system to improve safety and productivity in shafts. The objectives and constraints for the design were set out in official reports following a shaft accident at Markham Colliery in 1973. The problems to be solved were: to enable the shaftsmen to transfer the existing statutory code of signals efficiently from, or on top of, a conveyance anywhere in the shaft to the winding engineman and banksman at the surface: to detect the existence of slack rope or to detect that conditions have arisen that slack rope could be created and transmit this information to where action can be taken; and to allow conversations between winding engineman, banksman and shaftsman making allowances for the high level of acoustic noise in shafts. The approach adopted for slack rope monitoring was to monitor the tension in the cage suspension gear, thus measuring a first order effect. The three problems have a common element: information must be transferred through the shaft. This particular problem was solved with guided radio, using the winding rope as the transmission medium. The radio signal is coupled into the winding rope by means of fixed toroid encircling it at the cage and fixed magnetic antennas at the surface. The design of a digital transmission system for signalling and tension data is discussed. The 'top down' modular approach used in the design enabled full advantage to be taken of the opportunities for building a more reliable, safer and flexible system presented by technologies new to the shaft environment. The resultant system, the Safecom Shaft Signalling Communication and Winder Safety Monitoring System type S100, is in regular use at over 20 installations. 3 refs., 4 figs., 1 tab.

  7. Designing vertical mine shafts under conditions of increasing shaft depth with rock hoisting to the operating mining level

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.

    1983-05-01

    A system for shaft excavation in deep coal mines with mining depth exceeding 1,000 m is discussed. During mine sinking rocks are removed to the ground surface. When depth of a deep mine shaft is increased rocks are removed to the operating mining level, causing lower investment costs than the system with rock hoisting to the ground surface. The Yuzhgiproshakht design firm carries out investigations on the optimum methods for increasing shaft depth in coal mines. Coal mines with the following coal output are included in evaluations: 0.9, 1.2, 1.5, and 1.8 Mt/year. Mine shaft depth of 600, 800, 1000, 1200, 1400 and 1600 m is analyzed. Shaft depth is increased by 100, 200, 300 or 400 m. Shaft sinking rate ranges from 10 to 70 m/month. Effects of rock hoisting from the shaft bottom on the hoisting scheme in a mine shaft are analyzed. Position of hoisting bucket in relation to cages or skips moving in a shaft is investigated. Investigation results are given in 5 schemes. Analyses show that use of a shaft sinking system with rock hoisting to the ground surface during shaft excavation and with rock hoisting to the operating mining level during shaft depth increasing is economical when a shaft with skips is from 7 to 8 m in diameter or when a cage shaft is 6 m, 7 m or 8 m in diameter. Use of standardized shaft excavation systems is recommended. (In Russian)

  8. Development of a set of equations for incorporating disk flexibility effects in rotordynamical analyses

    Science.gov (United States)

    Flowers, George T.; Ryan, Stephen G.

    1991-01-01

    Rotordynamical equations that account for disk flexibility are developed. These equations employ free-free rotor modes to model the rotor system. Only transverse vibrations of the disks are considered, with the shaft/disk system considered to be torsionally rigid. Second order elastic foreshortening effects that couple with the rotor speed to produce first order terms in the equations of motion are included. The approach developed in this study is readily adaptable for usage in many of the codes that are current used in rotordynamical simulations. The equations are similar to those used in standard rigid disk analyses but with additional terms that include the effects of disk flexibility. An example case is presented to demonstrate the use of the equations and to show the influence of disk flexibility on the rotordynamical behavior of a sample system.

  9. HNC IN PROTOPLANETARY DISKS

    International Nuclear Information System (INIS)

    Graninger, Dawn; Öberg, Karin I.; Qi, Chunhua; Kastner, Joel

    2015-01-01

    The distributions and abundances of small organics in protoplanetary disks are potentially powerful probes of disk physics and chemistry. HNC is a common probe of dense interstellar regions and the target of this study. We use the Submillimeter Array (SMA) to observe HNC 3–2 toward the protoplanetary disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296. HNC is detected toward both disks, constituting the first spatially resolved observations of HNC in disks. We also present SMA observations of HCN 3–2 and IRAM 30 m observations of HCN and HNC 1–0 toward HD 163296. The disk-averaged HNC/HCN emission ratio is 0.1–0.2 toward both disks. Toward TW Hya, the HNC emission is confined to a ring. The varying HNC abundance in the TW Hya disk demonstrates that HNC chemistry is strongly linked to the disk physical structure. In particular, the inner rim of the HNC ring can be explained by efficient destruction of HNC at elevated temperatures, similar to what is observed in the ISM. However, to realize the full potential of HNC as a disk tracer requires a combination of high SNR spatially resolved observations of HNC and HCN and disk-specific HNC chemical modeling

  10. HNC IN PROTOPLANETARY DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Graninger, Dawn; Öberg, Karin I.; Qi, Chunhua [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kastner, Joel, E-mail: dgraninger@cfa.harvard.edu [Center for Imaging Science, School of Physics and Astronomy, and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2015-07-01

    The distributions and abundances of small organics in protoplanetary disks are potentially powerful probes of disk physics and chemistry. HNC is a common probe of dense interstellar regions and the target of this study. We use the Submillimeter Array (SMA) to observe HNC 3–2 toward the protoplanetary disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296. HNC is detected toward both disks, constituting the first spatially resolved observations of HNC in disks. We also present SMA observations of HCN 3–2 and IRAM 30 m observations of HCN and HNC 1–0 toward HD 163296. The disk-averaged HNC/HCN emission ratio is 0.1–0.2 toward both disks. Toward TW Hya, the HNC emission is confined to a ring. The varying HNC abundance in the TW Hya disk demonstrates that HNC chemistry is strongly linked to the disk physical structure. In particular, the inner rim of the HNC ring can be explained by efficient destruction of HNC at elevated temperatures, similar to what is observed in the ISM. However, to realize the full potential of HNC as a disk tracer requires a combination of high SNR spatially resolved observations of HNC and HCN and disk-specific HNC chemical modeling.

  11. Magnetically Induced Disk Winds and Transport in the HL Tau Disk

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yasuhiro; Flock, Mario; Turner, Neal J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Okuzumi, Satoshi, E-mail: yasuhiro@caltech.edu [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan)

    2017-08-10

    The mechanism of angular momentum transport in protoplanetary disks is fundamental to understanding the distributions of gas and dust in the disks. The unprecedented ALMA observations taken toward HL Tau at high spatial resolution and subsequent radiative transfer modeling reveal that a high degree of dust settling is currently achieved in the outer part of the HL Tau disk. Previous observations, however, suggest a high disk accretion rate onto the central star. This configuration is not necessarily intuitive in the framework of the conventional viscous disk model, since efficient accretion generally requires a high level of turbulence, which can suppress dust settling considerably. We develop a simplified, semi-analytical disk model to examine under what condition these two properties can be realized in a single model. Recent, non-ideal MHD simulations are utilized to realistically model the angular momentum transport both radially via MHD turbulence and vertically via magnetically induced disk winds. We find that the HL Tau disk configuration can be reproduced well when disk winds are properly taken into account. While the resulting disk properties are likely consistent with other observational results, such an ideal situation can be established only if the plasma β at the disk midplane is β {sub 0} ≃ 2 × 10{sup 4} under the assumption of steady accretion. Equivalently, the vertical magnetic flux at 100 au is about 0.2 mG. More detailed modeling is needed to fully identify the origin of the disk accretion and quantitatively examine plausible mechanisms behind the observed gap structures in the HL Tau disk.

  12. Magnetically Induced Disk Winds and Transport in the HL Tau Disk

    International Nuclear Information System (INIS)

    Hasegawa, Yasuhiro; Flock, Mario; Turner, Neal J.; Okuzumi, Satoshi

    2017-01-01

    The mechanism of angular momentum transport in protoplanetary disks is fundamental to understanding the distributions of gas and dust in the disks. The unprecedented ALMA observations taken toward HL Tau at high spatial resolution and subsequent radiative transfer modeling reveal that a high degree of dust settling is currently achieved in the outer part of the HL Tau disk. Previous observations, however, suggest a high disk accretion rate onto the central star. This configuration is not necessarily intuitive in the framework of the conventional viscous disk model, since efficient accretion generally requires a high level of turbulence, which can suppress dust settling considerably. We develop a simplified, semi-analytical disk model to examine under what condition these two properties can be realized in a single model. Recent, non-ideal MHD simulations are utilized to realistically model the angular momentum transport both radially via MHD turbulence and vertically via magnetically induced disk winds. We find that the HL Tau disk configuration can be reproduced well when disk winds are properly taken into account. While the resulting disk properties are likely consistent with other observational results, such an ideal situation can be established only if the plasma β at the disk midplane is β 0 ≃ 2 × 10 4 under the assumption of steady accretion. Equivalently, the vertical magnetic flux at 100 au is about 0.2 mG. More detailed modeling is needed to fully identify the origin of the disk accretion and quantitatively examine plausible mechanisms behind the observed gap structures in the HL Tau disk.

  13. A PRIMER ON UNIFYING DEBRIS DISK MORPHOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)

    2016-08-20

    A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

  14. A PRIMER ON UNIFYING DEBRIS DISK MORPHOLOGIES

    International Nuclear Information System (INIS)

    Lee, Eve J.; Chiang, Eugene

    2016-01-01

    A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

  15. A Primer on Unifying Debris Disk Morphologies

    Science.gov (United States)

    Lee, Eve J.; Chiang, Eugene

    2016-08-01

    A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

  16. Shaft siting decision report: Final report

    International Nuclear Information System (INIS)

    1985-11-01

    The purpose of this study is to identify and establish relative guidelines to be used for siting of repository shafts. Weights were determined for the significant factors which impact the selection of shaft locations for a nuclear waste repository in salt. The study identified a total of 45 factors. A panel of experienced mining people utilized the Kepner-Tregoe (K-T) Decision Analysis Process to perform a structured evaluation of each significant shaft siting factor. The evaluation determined that 22 of the factors were absolute constraints and that the other 23 factors were desirable characteristics. The group established the relative weights for each of the 23 desirable characteristics by using a paired comparison method. 49 refs., 2 figs., 5 tabs

  17. Waste and dust utilisation in shaft furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Senk, D.; Babich, A.; Gudenau, H.W. [Rhein Westfal TH Aachen, Aachen (Germany)

    2005-07-01

    Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

  18. Ipsilateral humeral neck and shaft fractures

    Directory of Open Access Journals (Sweden)

    Zhu Bin

    2017-01-01

    Full Text Available Background/Aim. Fractures of the proximal humerus or shaft are common, however, ipsilateral neck and shaft humerus fracture is a rare phenomenon. This combination injury is challenging for orthopaedic surgeons because of its complex treatment options at present. The purpose of this study was to review a series of ipsilateral humeral neck and shaft fractures to study the fracture pattern, complications and treatment outcomes of each treatment options used. Methods. A total of six patients (four female and two male with the average age of 42.8 years (range: 36–49 years was collected and reviewed retrospectively. Two of them were treated with double plates and four with antegrade intramedullary nail. According to the Neer’s classification, all proximal fractures were two-part surgical neck fractures. All humeral shaft fractures were located at the middle of one third. Five fractures were simple transverse (A3, one fragmented wedge fracture (B3. One patient had associated radial nerve palsy. Results. All surgical neck fractures except one united uneventfully in the average time span of 8.7 weeks. Four humeral shaft fractures healed in near anatomic alignment. The remaining two patients had the nonunion with no radiological signs of fracture healing. The average University of California, Los Angeles End-Results (UCLA score was 23.1. On the contrary, the average American Shoulder and Elbow Surgeon's (ASES score was 73.3. The patients treated with antegrade intramedullary nails presented 70.5 points. The ASES scores were 79 in the double plates group. Conclusions. Ipsilateral humeral shaft and neck fracture is extremely rare. Both antegrade intramedullar nailing and double plates result in healing of fractures. However the risk of complication is lower in the double plating group.

  19. Construction of blind shafts with the PVS 3500 planetary full shaft drilling machine

    International Nuclear Information System (INIS)

    Glogowski, P.; Kolditz, H.

    1992-01-01

    The PVS 3500 planetary full shaft drilling machine has proved as a prototype in the construction of two blind shafts. The drilling rate of 8 m/shift or 25.6 m 3 /MS is outstanding for the initial use of this drilling machine. Blind shafts were cut from the solid by a dry drilling method for the first time. It opens up the possibility of making available storage boreholes for larger quantities of radioactive waste with low activity and for toxic waste materials. (orig.)

  20. Exploring Disks Around Planets

    Science.gov (United States)

    Kohler, Susanna

    2017-07-01

    Giant planets are thought to form in circumstellar disks surrounding young stars, but material may also accrete into a smaller disk around the planet. Weve never detected one of these circumplanetary disks before but thanks to new simulations, we now have a better idea of what to look for.Image from previous work simulating a Jupiter-mass planet forming inside a circumstellar disk. The planet has its own circumplanetary disk of accreted material. [Frdric Masset]Elusive DisksIn the formation of giant planets, we think the final phase consists of accretion onto the planet from a disk that surrounds it. This circumplanetary disk is important to understand, since it both regulates the late gas accretion and forms the birthplace of future satellites of the planet.Weve yet to detect a circumplanetary disk thus far, because the resolution needed to spot one has been out of reach. Now, however, were entering an era where the disk and its kinematics may be observable with high-powered telescopes (like the Atacama Large Millimeter Array).To prepare for such observations, we need models that predict the basic characteristics of these disks like the mass, temperature, and kinematic properties. Now a researcher at the ETH Zrich Institute for Astronomy in Switzerland, Judit Szulgyi, has worked toward this goal.Simulating CoolingSzulgyi performs a series of 3D global radiative hydrodynamic simulations of 1, 3, 5, and 10 Jupiter-mass (MJ) giant planets and their surrounding circumplanetary disks, embedded within the larger circumstellar disk around the central star.Density (left column), temperature (center), and normalized angular momentum (right) for a 1 MJ planet over temperatures cooling from 10,000 K (top) to 1,000 K (bottom). At high temperatures, a spherical circumplanetary envelope surrounds the planet, but as the planet cools, the envelope transitions around 64,000 K to a flattened disk. [Szulgyi 2017]This work explores the effects of different planet temperatures and

  1. Capillary condensation between disks in two dimensions

    OpenAIRE

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial capillary fluctuations play a dominant role. A simple approximative analytical expression of the interfacial free energy is developed and is validated numerically. The capillary condensation is characteri...

  2. Latest advances in high brightness disk lasers

    Science.gov (United States)

    Kuhn, Vincent; Gottwald, Tina; Stolzenburg, Christian; Schad, Sven-Silvius; Killi, Alexander; Ryba, Tracey

    2015-02-01

    In the last decade diode pumped solid state lasers have become an important tool for many industrial materials processing applications. They combine ease of operation with efficiency, robustness and low cost. This paper will give insight in latest progress in disk laser technology ranging from kW-class CW-Lasers over frequency converted lasers to ultra-short pulsed lasers. The disk laser enables high beam quality at high average power and at high peak power at the same time. The power from a single disk was scaled from 1 kW around the year 2000 up to more than 10 kW nowadays. Recently was demonstrated more than 4 kW of average power from a single disk close to fundamental mode beam quality (M²=1.38). Coupling of multiple disks in a common resonator results in even higher power. As an example we show 20 kW extracted from two disks of a common resonator. The disk also reduces optical nonlinearities making it ideally suited for short and ultrashort pulsed lasers. In a joint project between TRUMPF and IFSW Stuttgart more than 1.3 kW of average power at ps pulse duration and exceptionally good beam quality was recently demonstrated. The extremely low saturated gain makes the disk laser ideal for internal frequency conversion. We show >1 kW average power and >6 kW peak power in multi ms pulsed regime from an internally frequency doubled disk laser emitting at 515 nm (green). Also external frequency conversion can be done efficiently with ns pulses. >500 W of average UV power was demonstrated.

  3. Incidence and epidemiology of tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Elsøe, Rasmus; Hansen, Sandra Hope

    2015-01-01

    Introduction: The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large....... The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have...... frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. Conclusion: This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type...

  4. Exploratory shaft conceptual design report: Permian Basin

    International Nuclear Information System (INIS)

    1983-07-01

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Permian Basin locatd in the western part of Texas. Conceptualized designs for other possible locations (Paradox Basin in Utah and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  5. Exploratory shaft conceptual design report: Paradox Basin

    International Nuclear Information System (INIS)

    1983-07-01

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Paradox Basin located in the southeastern part of Utah. Conceptualized designs for other possible locations (Permian Basin in Texas and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  6. Three-dimensional measurement of femoral neck anteversion and neck shaft angle.

    Science.gov (United States)

    Sangeux, Morgan; Pascoe, Jessica; Graham, H Kerr; Ramanauskas, Fiona; Cain, Tim

    2015-01-01

    We present a three-dimensional measurement technique for femoral neck anteversion and neck shaft angles which do not require alignment of the femoral and scanner axes. Two assessors performed the measurements on 11 patients (22 femurs). Repeatability between assessors was 2.7 degrees for femoral neck anteversion and 4.8 degrees for neck shaft angle. Measurements compared with an alternative single slice method were different by 2 degrees (3 degrees) in average. The method was repeatable and appropriate for clinical practice.

  7. Connect-disconnect coupling for preadjusted rigid shafts

    Science.gov (United States)

    Bajkowski, F. W.; Holmberg, A.

    1969-01-01

    Coupling device enables a rigid shaft to be connected to or disconnected from a fixed base without disturbing the point of adjustment of the shaft in a socket or causing the shaft to rotate. The coupling consists of an externally threaded, internally slotted boss extending from the fixed base.

  8. 30 CFR 77.1911 - Ventilation of slopes and shafts.

    Science.gov (United States)

    2010-07-01

    ... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All slopes and... connected to the slope or shaft opening with fireproof air ducts; (3) Designed to permit the reversal of the...

  9. Procedure for determining the optimum rate of increasing shaft depth

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.

    1983-03-01

    Presented is an economic analysis of increasing shaft depth during mine modernization. Investigations carried out by the Yuzhgiproshakht Institute are analyzed. The investigations are aimed at determining the optimum shaft sinking rate (the rate which reduces investment to the minimum). The following factors are considered: coal output of a mine (0.9, 1.2, 1.5 and 1.8 Mt/year), depth at which the new mining level is situated (600, 800, 1200, 1400 and 1600 m), four schemes of increasing depth of 2 central shafts (rock hoisting to ground surface, rock hoisting to the existing level, rock haulage to the developed level, rock haulage to the level being developed using a large diameter borehole drilled from the new level to the shaft bottom and enlarged from shaft bottom to the new level), shaft sinking rate (10, 20, 30, 40, 50 and 60 m/month), range of increasing shaft depth (the difference between depth of the shaft before and after increasing its depth by 100, 200, 300 and 400 m). Comparative evaluations show that the optimum shaft sinking rate depends on the scheme for rock hoisting (one of 4 analyzed), range of increasing shaft depth and gas content in coal seams. The optimum shaft sinking rate ranges from 20 to 40 m/month in coal mines with low methane content and from 20 to 30 m/month in gassy coal mines. The planned coal output of a mine does not influence the optimum shaft sinking rate.

  10. OPTIMIZATION OF PLY STACKING SEQUENCE OF COMPOSITE DRIVE SHAFT USING PARTICLE SWARM ALGORITHM

    Directory of Open Access Journals (Sweden)

    CHANNAKESHAVA K. R.

    2011-06-01

    Full Text Available In this paper an attempt has been made to optimize ply stacking sequence of single piece E-Glass/Epoxy and Boron /Epoxy composite drive shafts using Particle swarm algorithm (PSA. PSA is a population based evolutionary stochastic optimization technique which is a resent heuristic search method, where mechanics are inspired by swarming or collaborative behavior of biological population. PSA programme is developed to optimize the ply stacking sequence with an objective of weight minimization by considering design constraints as torque transmission capacity, fundamental natural frequency, lateral vibration and torsional buckling strength having number of laminates, ply thickness and stacking sequence as design variables. The weight savings of the E-Glass/epoxy and Boron /Epoxy shaft from PAS were 51% and 85 % of the steel shaft respectively. The optimum results of PSA obtained are compared with results of genetic algorithm (GA results and found that PSA yields better results than GA.

  11. Stability analysis of internally damped rotating composite shafts using a finite element formulation

    Science.gov (United States)

    Ben Arab, Safa; Rodrigues, José Dias; Bouaziz, Slim; Haddar, Mohamed

    2018-04-01

    This paper deals with the stability analysis of internally damped rotating composite shafts. An Euler-Bernoulli shaft finite element formulation based on Equivalent Single Layer Theory (ESLT), including the hysteretic internal damping of composite material and transverse shear effects, is introduced and then used to evaluate the influence of various parameters: stacking sequences, fiber orientations and bearing properties on natural frequencies, critical speeds, and instability thresholds. The obtained results are compared with those available in the literature using different theories. The agreement in the obtained results show that the developed Euler-Bernoulli finite element based on ESLT including hysteretic internal damping and shear transverse effects can be effectively used for the stability analysis of internally damped rotating composite shafts. Furthermore, the results revealed that rotor stability is sensitive to the laminate parameters and to the properties of the bearings.

  12. Preparation of thin actinide metal disks using a multiple disk casting technique

    International Nuclear Information System (INIS)

    Conner, W.V.

    1975-01-01

    A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting, This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (Auth.)

  13. Preparation of thin actinide metal disks using a multiple disk casting technique

    International Nuclear Information System (INIS)

    Conner, W.V.

    1976-01-01

    A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting. This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (author)

  14. Magnetohydrodynamics of accretion disks

    International Nuclear Information System (INIS)

    Torkelsson, U.

    1994-04-01

    The thesis consists of an introduction and summary, and five research papers. The introduction and summary provides the background in accretion disk physics and magnetohydrodynamics. The research papers describe numerical studies of magnetohydrodynamical processes in accretion disks. Paper 1 is a one-dimensional study of the effect of magnetic buoyancy on a flux tube in an accretion disk. The stabilizing influence of an accretion disk corona on the flux tube is demonstrated. Paper 2-4 present numerical simulations of mean-field dynamos in accretion disks. Paper 11 verifies the correctness of the numerical code by comparing linear models to previous work by other groups. The results are also extended to somewhat modified disk models. A transition from an oscillatory mode of negative parity for thick disks to a steady mode of even parity for thin disks is found. Preliminary results for nonlinear dynamos at very high dynamo numbers are also presented. Paper 3 describes the bifurcation behaviour of the nonlinear dynamos. For positive dynamo numbers it is found that the initial steady solution is replaced by an oscillatory solution of odd parity. For negative dynamo numbers the solution becomes chaotic at sufficiently high dynamo numbers. Paper 4 continues the studies of nonlinear dynamos, and it is demonstrated that a chaotic solution appears even for positive dynamo numbers, but that it returns to a steady solution of mixed parity at very high dynamo numbers. Paper 5 describes a first attempt at simulating the small-scale turbulence of an accretion disk in three dimensions. There is only find cases of decaying turbulence, but this is rather due to limitations of the simulations than that turbulence is really absent in accretion disks

  15. Combined-cycle power plant. 500 MW on a single shaft. Active stability improvement of the compressor - methods of analysis. Final report; GuD-Kraftwerk, 500 MW auf einer Welle. Aktive Stabilitaetsverbesserung am Verdichter - Analyseverfahren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stoff, H.; Methling, F.O.

    2002-07-01

    Various analysis techniques are tested as possible stall and surge avoidance monitoring systems on high-speed axial compressors. Measurements were taken in a 4-stage transonic compressor with igv in the region of stable operation as well as approaching and crossing the surge line with fully developed rotating stall. The measurements contain the static wall pressure in front of each blade row. Artificial neural networks, Fourier techniques and cepstral analysis are investigated. The different methods are checked on a single sensor signal to reduce the instrumentational effort. Using the cepstral analysis a characteristic parameter is calculated which is valid in all investigated regions of operation of the compressor. This characteristic parameter is based on the blade passing frequency, i.e. in the terms of cepstral analysis it is the intensity of the fundamental component as well as the intensities of all its higher harmonics which are covered by the sensor signal. (orig.)

  16. Concepts for backfilling and sealing of shafts

    International Nuclear Information System (INIS)

    Pierau, B.

    1990-01-01

    The disposal site is situated at a depth of 1000 to 1200 meters. It is covered by very thick cretatious mudstone layers forming the main barrier against the spread of radioactively contaminated water into the biosphere. Because of the excavation works and the resulting stress redistributions, the material surrounding the shafts is probably broken up, which leads to increased permeability in comparison with the intact rock. It is planned to backfill the shafts with an insoluble mineral mixture including a fine fraction necessary to achieve the sealing required. The joints and cracks in the brocken-up surrounding material are believed to be sealed by themselves due to swelling of the mudstone. Some strata of the mudstone contain more than 20% of smektite, a swelling clay mineral. Those regions, where the broken-up zone cannot be considered sure to self-seal due to swelling, are planned to be sealed by pressure grouting using clay suspension. (orig./HP) [de

  17. Exploratory shaft facility preliminary designs - Permian Basin

    International Nuclear Information System (INIS)

    1983-09-01

    The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables

  18. Work on a transfer tunnel access shaft

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Civil engineers work on one of the access shafts from the SPS to the LHC transfer tunnel, which will allow components and equipment to be lowered directly so that minimal transport is required. The transfer tunnel will take a proton beam from the SPS pre-accelerator and inject it into the clockwise circulating ring in the LHC where the beam will be accelerated to a final energy of 7 TeV.

  19. Modeling collisions in circumstellar debris disks

    Science.gov (United States)

    Nesvold, Erika

    2015-10-01

    resonances near the chaotic zone. I investigate the effects of the initial eccentricity distribution of the disk particles and find a negligible effect on the gap size at Jovian planet masses, since collisions tend to erase memory of the initial particle eccentricity distributions. I also find that the presence of Trojan analogs is a potentially powerful diagnostic of planets in the mass range ˜1--10MJup. I apply my model to place new upper limits on planets around Fomalhaut, HR 4796 A, HD 202628, HD 181327, and beta Pictoris. Finally, to show how SMACK can be used to analyze a single debris disk in detail, I present a new model of the beta Pictoris disk and planet system that, for the first time, combines simulations of the colliding planetesimals and the dynamics of the dust grains, allowing me to model features and asymmetries in both submillimeter and scattered light images of the disk. I combine a 100,000 superparticle SMACK simulation with N-body integrations of the dust produced by the simulated collisions. I find that secular perturbations of the planet's measured inclination and eccentricity can explain the observed warp and planetesimal ring, while collisions between planetesimals shape the disk by eroding close-in material. The complex 3D structure of the disk due to the perturbations from the planet creates an azimuthally asymmetric spatial distribution of collisions, which could contribute to the observed azimuthal clump of CO gas seen with ALMA. My simulations of the small dust grains produced by collisions demonstrate that the "birth ring" approximation for beta Pictoris fails to account for the ˜54% of dust mass produced outside of the planetesimal ring. I also reproduce the gross morphology of high-resolution scattered light images of the disk, including the two-disk "x"-pattern seen in scattered light, which has not been replicated by previous dust dynamics models.

  20. Disk Defect Data

    Data.gov (United States)

    National Aeronautics and Space Administration — How Data Was Acquired: The data presented is from a physical simulator that simulated engine disks. Sample Rates and Parameter Description: All parameters are...

  1. Dynamics of dense particle disks

    International Nuclear Information System (INIS)

    Araki, S.; Tremaine, S.; Toronto Univ., Canada)

    1986-01-01

    The present investigation of mechanical equilibrium and collisional transport processes in dense, differentially rotating particle disks is based on the Enskog (1922) theory of dense, hard sphere gases, with the single exception that the spheres are inelastic. The viscous instability suggested as a source of Saturn B ring structure does not arise in the models presented, although the ring may be subject to a phase transition analogous to the liquid-solid transition observed in molecular dynamics simulations of elastic hard spheres. In such a case, the ring would alternately exhibit zero-shear, or solid, and high shear, or liquid, zones. 29 references

  2. Empirical Temperature Measurement in Protoplanetary Disks

    Science.gov (United States)

    Weaver, Erik; Isella, Andrea; Boehler, Yann

    2018-02-01

    The accurate measurement of temperature in protoplanetary disks is critical to understanding many key features of disk evolution and planet formation, from disk chemistry and dynamics, to planetesimal formation. This paper explores the techniques available to determine temperatures from observations of single, optically thick molecular emission lines. Specific attention is given to issues such as the inclusion of optically thin emission, problems resulting from continuum subtraction, and complications of real observations. Effort is also made to detail the exact nature and morphology of the region emitting a given line. To properly study and quantify these effects, this paper considers a range of disk models, from simple pedagogical models to very detailed models including full radiative transfer. Finally, we show how the use of the wrong methods can lead to potentially severe misinterpretations of data, leading to incorrect measurements of disk temperature profiles. We show that the best way to estimate the temperature of emitting gas is to analyze the line peak emission map without subtracting continuum emission. Continuum subtraction, which is commonly applied to observations of line emission, systematically leads to underestimation of the gas temperature. We further show that once observational effects such as beam dilution and noise are accounted for, the line brightness temperature derived from the peak emission is reliably within 10%–15% of the physical temperature of the emitting region, assuming optically thick emission. The methodology described in this paper will be applied in future works to constrain the temperature, and related physical quantities, in protoplanetary disks observed with ALMA.

  3. Verbatim Floppy Disk

    CERN Multimedia

    1976-01-01

    Introduced under the name "Verbatim", Latin for "literally", these disks that sized more than 5¼ inches have become almost universal on dedicated word processing systems and personal computers. This format was replaced more slowly by the 3½-inch format, introduced for the first time in 1982. Compared to today, these large format disks stored very little data. In reality, they could only contain a few pages of text.

  4. Multimegawatt disk generator system for space applications

    International Nuclear Information System (INIS)

    Solbes, A.; Iwata, H.

    1988-01-01

    The conceptual design of a 100 megawatt - 500 seconds disk MHD generator system suitable as a burst power source for a space based neutral particle beam (NPB) is presented. The system features two disk generators operated in the magnetic field produced by a single circular superconducting magnet. Gelled reactants are used as the energy source. The oxidizer gel includes the alkali seed. The high heat flux areas of the power train are water cooled. Heat is rejected to a hydrogen stream which is also used for cooling of the exit section. The hydrogen is also used to mitigate the effects of the exhaust products of combustion on the platform. The two disk channels are operated in parallel. A dc to dc converter consolidates the channel's output into a single 100 kilovolt dc output

  5. Mass distributions in disk galaxies

    NARCIS (Netherlands)

    Martinsson, Thomas; Verheijen, Marc; Bershady, Matthew; Westfall, Kyle; Andersen, David; Swaters, Rob

    We present results on luminous and dark matter mass distributions in disk galaxies from the DiskMass Survey. As expected for normal disk galaxies, stars dominate the baryonic mass budget in the inner region of the disk; however, at about four optical scale lengths (hR ) the atomic gas starts to

  6. Dusty disks around young stars

    NARCIS (Netherlands)

    Verhoeff, A.

    2009-01-01

    Stars are formed through the collapse of giant molecular clouds. During this contraction the matter spins up and naturally forms a circumstellar disk. Once accretion comes to a halt, these disks are relatively stable. Some disks are known to last up to 10 Myrs. Most disks however, dissipate on

  7. A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

    Science.gov (United States)

    Hua, Wei; Miao, Lizhen; Zhang, Haibo; Huang, Jinquan

    2015-12-01

    A closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

  8. 2TB hard disk drive

    CERN Multimedia

    This particular object was used up until 2012 in the Data Centre. It slots into one of the Disk Server trays. Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes (link is external). They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks (link is external)." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

  9. THE ROLE OF MULTIPLICITY IN DISK EVOLUTION AND PLANET FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Adam L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI 96822 (United States); Ireland, Michael J. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Hillenbrand, Lynne A. [California Institute of Technology, Department of Astrophysics, MC 249-17, Pasadena, CA 91125 (United States); Martinache, Frantz [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States)

    2012-01-20

    The past decade has seen a revolution in our understanding of protoplanetary disk evolution and planet formation in single-star systems. However, the majority of solar-type stars form in binary systems, so the impact of binary companions on protoplanetary disks is an important element in our understanding of planet formation. We have compiled a combined multiplicity/disk census of Taurus-Auriga, plus a restricted sample of close binaries in other regions, in order to explore the role of multiplicity in disk evolution. Our results imply that the tidal influence of a close ({approx}<40 AU) binary companion significantly hastens the process of protoplanetary disk dispersal, as {approx}2/3 of all close binaries promptly disperse their disks within {approx}<1 Myr after formation. However, prompt disk dispersal only occurs for a small fraction of wide binaries and single stars, with {approx}80%-90% retaining their disks for at least {approx}2-3 Myr (but rarely for more than {approx}5 Myr). Our new constraints on the disk clearing timescale have significant implications for giant planet formation; most single stars have 3-5 Myr within which to form giant planets, whereas most close binary systems would have to form giant planets within {approx}<1 Myr. If core accretion is the primary mode for giant planet formation, then gas giants in close binaries should be rare. Conversely, since almost all single stars have a similar period of time within which to form gas giants, their relative rarity in radial velocity (RV) surveys indicates either that the giant planet formation timescale is very well matched to the disk dispersal timescale or that features beyond the disk lifetime set the likelihood of giant planet formation.

  10. Debris Disks: Probing Planet Formation

    OpenAIRE

    Wyatt, Mark C.

    2018-01-01

    Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on circumstellar disk evolution and the outcome of planet formation. The debris disk population can be explained by the steady collisional erosion of planetesimal belts; population models constrain where (10-100au) and in what quantity (>1Mearth) planetesimals (>10km i...

  11. Fast, Capacious Disk Memory Device

    Science.gov (United States)

    Muller, Ronald M.

    1990-01-01

    Device for recording digital data on, and playing back data from, memory disks has high recording or playback rate and utilizes available recording area more fully. Two disks, each with own reading/writing head, used to record data at same time. Head on disk A operates on one of tracks numbered from outside in; head on disk B operates on track of same number in sequence from inside out. Underlying concept of device applicable to magnetic or optical disks.

  12. Source to Accretion Disk Tilt

    OpenAIRE

    Montgomery, M. M.; Martin, E. L.

    2010-01-01

    Many different system types retrogradely precess, and retrograde precession could be from a tidal torque by the secondary on a misaligned accretion disk. However, a source to cause and maintain disk tilt is unknown. In this work, we show that accretion disks can tilt due to a force called lift. Lift results from differing gas stream supersonic speeds over and under an accretion disk. Because lift acts at the disk's center of pressure, a torque is applied around a rotation axis passing through...

  13. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    OpenAIRE

    Luo Jun; Wang Zhiqian; Shen Chengwu; Wen Zhuoman; Liu Shaojin; Cai Sheng; Li Jianrong

    2015-01-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendic...

  14. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.

    2014-09-01

    Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

  15. Grouting of nuclear waste vault shafts

    International Nuclear Information System (INIS)

    Gyenge, M.

    1980-01-01

    A nuclear waste vault must be designed and built to ensure adequate isolation of the nuclear wastes from human contact. Consequently, after a vault has been fully loaded it must be adequately sealed off to prevent radionuclide migration which may be provided by circulating ground water. Of particular concern in vault sealing are the physical and chemical properties of the sealing materials its long-term durability and stability and the techniques used for its emplacement. Present grouting technology and grout material are reviewed in terms of the particular needs of shaft grouting. Areas requiring research and development are indicated

  16. FOMALHAUT'S DEBRIS DISK AND PLANET: CONSTRAINING THE MASS OF FOMALHAUT B FROM DISK MORPHOLOGY

    International Nuclear Information System (INIS)

    Chiang, E.; Kalas, P.; Graham, J. R.; Kite, E.; Clampin, M.

    2009-01-01

    Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M pl J , an orbital semimajor axis a pl > 101.5 AU, and an orbital eccentricity e pl = 0.11-0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a ∼ 133 AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e ∼ 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of ∼ 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to ∼ 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties may be large. If the apsidal misalignment proves real, our calculated upper mass limit of 3M J still holds. If the orbits are aligned, our model predicts M pl = 0.5M J , a pl = 115 AU, and e pl = 0

  17. Residual torsional properties of composite shafts subjected to impact loadings

    International Nuclear Information System (INIS)

    Sevkat, Ercan; Tumer, Hikmet

    2013-01-01

    Highlights: • Impact loading reduces the torsional strength of composite shaft. • Impact energy level determines the severity of torsional strength reduction. • Hybrid composite shafts can be manufactured by mixing two types of filament. • Maximum torque capacity of shafts can be estimated using finite element method. - Abstract: This paper presents an experimental and numerical study to investigate residual torsional properties of composite shafts subjected to impact loadings. E-glass/epoxy, carbon/epoxy and E-glass–carbon/epoxy hybrid composite shafts were manufactured by filament winding method. Composite shafts were impacted at 5, 10, 20 and 40 J energy levels. Force–time and energy–time histories of impact tests were recorded. One composite shaft with no impact, and four composite shafts with impact damage, five in total, were tested under torsion. Torque-twisting angle relations for each test were obtained. Reduction at maximum torque and maximum twisting angle induced by impact loadings were calculated. While 5 J impact did not cause significant reduction at maximum torque and maximum twisting angle, remaining impact loadings caused 34–67% reduction at maximum torque, and 30–61% reduction at maximum twisting angle. Reductions increased with increasing energy levels and varied depending on the material of composite shafts. The 3-D finite element (FE) software, Abaqus, incorporated with an elastic orthotropic model, was then used to simulate the torsion tests. Good agreement between experimental and numerical results was achieved

  18. Increasing shaft depth with rock hoisting to the surface. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.

    1982-06-01

    Schemes of shaft construction with increasing shaft depth depend on: shaft depth, shaft diameter, types of hoisting systems, schemes of shaft reinforcement. Investigations carried out in underground coal mines in the USSR show that waste rock haulage to the surface by an independent hoisting system is most economical. Installation of this system depends on the existing hoisting scheme. When one of the operating cages or skips can be removed without a negative influence on mine operation the system of rock waste hoisting is used. The hoisting bucket used for rock removal from the shaft bottom moves in the shaft section from which one of the cages or skips has been removed. Examples of using this scheme in Donbass, Kuzbass and other coal basins are given. Economic aspects of waste material hoisting to the surface are analyzed. The system is economical when the remaining hoisting system can accept additional loads after removal of a cage or skip from the shaft. Investigations show that use of a bucket with a capacity from 2.5 to 3.0 m/sup 3/ for waste rock removal from the shaft being modernized and deepened is most economical.

  19. PLANETESIMAL DISK MICROLENSING

    International Nuclear Information System (INIS)

    Heng, Kevin; Keeton, Charles R.

    2009-01-01

    Motivated by debris disk studies, we investigate the gravitational microlensing of background starlight by a planetesimal disk around a foreground star. We use dynamical survival models to construct a plausible example of a planetesimal disk and study its microlensing properties using established ideas of microlensing by small bodies. When a solar-type source star passes behind a planetesimal disk, the microlensing light curve may exhibit short-term, low-amplitude residuals caused by planetesimals several orders of magnitude below Earth mass. The minimum planetesimal mass probed depends on the photometric sensitivity and the size of the source star, and is lower when the planetesimal lens is located closer to us. Planetesimal lenses may be found more nearby than stellar lenses because the steepness of the planetesimal mass distribution changes how the microlensing signal depends on the lens/source distance ratio. Microlensing searches for planetesimals require essentially continuous monitoring programs that are already feasible and can potentially set constraints on models of debris disks, the progeny of the supposed extrasolar analogues of Kuiper Belts.

  20. Contact Problem of Disk on Shaft Fixed by Induction Shrink Fit

    Czech Academy of Sciences Publication Activity Database

    Ulrych, B.; Kotlan, V.; Doležel, Ivo

    2012-01-01

    Roč. 88, 12B (2012), s. 32-34 ISSN 0033-2097 Institutional research plan: CEZ:AV0Z20760514 Keywords : induction shrink fit * contact problem * transfer of torque Subject RIV: BA - General Mathematics Impact factor: 0.244, year: 2011

  1. Capillary condensation between disks in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial...... capillary fluctuations play a dominant role. A simple approximative analytical expression of the interfacial free energy is developed and is validated numerically. The capillary condensation is characterized by the analysis of the coverage of the condensed phase, its stability, and asymptotic behaviors...

  2. Premixed direct injection disk

    Science.gov (United States)

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; Zuo, Baifang; Uhm, Jong Ho

    2013-04-23

    A fuel/air mixing disk for use in a fuel/air mixing combustor assembly is provided. The disk includes a first face, a second face, and at least one fuel plenum disposed therebetween. A plurality of fuel/air mixing tubes extend through the pre-mixing disk, each mixing tube including an outer tube wall extending axially along a tube axis and in fluid communication with the at least one fuel plenum. At least a portion of the plurality of fuel/air mixing tubes further includes at least one fuel injection hole have a fuel injection hole diameter extending through said outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.

  3. Herniated lumbar intervertebral disk

    International Nuclear Information System (INIS)

    Hochhauser, L.; Cacayorin, E.D.; Karcnik, T.J.; McGowan, D.P.; Clark, K.G.; Storrs, D.; Kieffer, S.A.

    1988-01-01

    From a series of 25 patients with low-back pain and sciatica who subsequently underwent surgical exploration, 24 lumbar herniated disks and one asymmetrically bulging disk were correctly diagnosed with use of a 0.5-T MR imaging unit. The radiologic findings on saggital images included a polypoid protrusion beyond the posterior margin of the vertebral bodies more clearly displayed with T1-weighted than with T-2 weighted sequences and a focal extension into the extradural space on axial views. In most, the signal intensity of HNP was isointense to the disk of origin. The study suggests that MR imaging is currently capable of accurately predicting an HNP. The diagnosis is based primarily on morphologic characteristics rather than signal intensity alterations

  4. Relativistic, accreting disks

    International Nuclear Information System (INIS)

    Abramowicz, M.A; Jaroszynski, M.; Sikora, M.

    1978-01-01

    An analytic theory of the hydrodynamical structure of accreting disks (without self-gravitation but with pressure) orbiting around and axially symmetric, stationary, compact body (e.g. black hole) is presented. The inner edge of the marginally stable accreting disk (i.e. disk with constant angular momentum density) has a sharp cusp located on the equatorial plane between rsub(ms) and rsub(mb). The existence of the cusp is also typical for any angular momentum distribution. The physical importance of the cusp follows from the close analogy with the case of a close binary system (L 1 Lagrange point on the Roche lobe). The existence of the cusp is thus a crucial phenomenon in such problems as boundary condition for the viscous stresses, accretion rate etc. (orig.) [de

  5. Relativistic, accreting disks

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, M A; Jaroszynski, M; Sikora, M [Polska Akademia Nauk, Warsaw

    1978-02-01

    An analytic theory of the hydrodynamical structure of accreting disks (without self-gravitation but with pressure) orbiting around an axially symmetric, stationary, compact body (e.g. black hole) is presented. The inner edge of the marginally stable accreting disk (i.e. disk with constant angular momentum density) has a sharp cusp located on the equatorial plane between r/sub ms/ and r/sub mb/. The existence of the cusp is also typical for any angular momentum distribution. The physical importance of the cusp follows from the close analogy with the case of a close binary system (L/sub 1/ Lagrange point on the Roche lobe). The existence of the cusp is thus a crucial phenomenon in such problems as boundary condition for the viscous stresses, accretion rate, etc.

  6. Chemistry in protoplanetary disks

    Science.gov (United States)

    Semenov, D. A.

    2012-01-01

    In this lecture I discuss recent progress in the understanding of the chemical evolution of protoplanetary disks that resemble our Solar system during the first ten million years. At the verge of planet formation, strong variations of temperature, density, and radiation intensities in these disks lead to a layered chemical structure. In hot, dilute and heavily irradiated atmosphere only simple radicals, atoms, and atomic ions can survive, formed and destroyed by gas-phase processes. Beneath the atmosphere a partly UV-shielded, warm molecular layer is located, where high-energy radiation drives rich chemistry, both in the gas phase and on dust surfaces. In a cold, dense, dark disk midplane many molecules are frozen out, forming thick icy mantles where surface chemistry is active and where complex (organic) species are synthesized.

  7. Removable control rod drive shaft guide

    International Nuclear Information System (INIS)

    Ales, M.W.; Brown, S.K.; Dixon, L.D.

    1988-01-01

    A removable control rod drive shaft guide is described for a control rod ''guide'' structure card, comprising: a. a substantially annular shaped main body portion having a central axial bore for receiving a control rod drive shaft and an upper exterior groove for receiving removal tooling; b. the main body portion having a reduced outer diameter at its lower section; c. a shoulder portion integral with the main body portion for supporting the main body portion on the guide structure card; d. the shoulder portion having a substantially radial bore and the reduced outer diameter lower section having a slot in alignment with the radial bore; e. a locking arm ''pivotaly'' mounted in the radial bore which protrudes into the slot and is movable between a first normal locking position for engaging the guide structure card and a second release position; f. a spring received within a second axial bore in the main body portion and biased against the locking arm for urging and locking arm into the first normal locking position; and g. a release tab at one end of the locking arm for moving the locking arm into the second release position

  8. Visualization of the flow in a cylindrical container with a rotating disk

    Science.gov (United States)

    Imahoko, Ryoki; Kurakata, Hiroki; Sakakibara, Jun

    2017-11-01

    We studied a behavior of the flow in a cylindrical container with a rotating disk. The apparatus consists of a fixed cylindrical container of the inner diameter of 140 mm and height H, and a coaxial rotating disc with a diameter of 140 mm connected with a cylindrical shaft driven by an electrical motor. The radial gap between rotating disk and side wall is very slight distance. The height H is variable up to 100 mm. The velocity distribution in the container was measured by means of particle image velocimetry (PIV). The results of this experiments will be discussed at the conference.

  9. Circumstellar and circumplanetary disks

    Science.gov (United States)

    Chiang, Eugene

    2000-11-01

    This thesis studies disks in three astrophysical contexts: (1)protoplanetary disks; (2)the Edgeworth-Kuiper Belt; and (3)planetary rings. We derive hydrostatic, radiative equilibrium models of passive protoplanetary disks surrounding T Tauri and Herbig Ae/Be stars. Each disk is encased by an optically thin layer of superheated dust grains. This layer is responsible for up to ~70% of the disk luminosity at wavelengths between ~5 and 60 μm. The heated disk flares and absorbs more stellar radiation at a given stellocentric distance than a flat disk would. Spectral energy distributions are computed and found to compare favorably with the observed flattish infrared excesses of several young stellar objects. Spectral features from dust grains in the superheated layer appear in emission if the disk is viewed nearly face-on. We present the results of a pencil-beam survey of the Kuiper Belt using the Keck 10-m telescope. Two new objects are discovered. Data from all surveys are pooled to construct the luminosity function from mR = 20 to 27. The cumulative number of objects per square degree, Σ(surface area but the largest bodies contain most of the mass. To order-of-magnitude, 0.2 M⊕ and 1 × 1010 comet progenitors lie between 30 and 50 AU. The classical Kuiper Belt appears truncated at a distance of 50 AU. We propose that rigid precession of narrow eccentric planetary rings surrounding Uranus and Saturn is maintained by a balance of forces due to ring self- gravity, planetary oblateness, and interparticle collisions. Collisional impulses play an especially dramatic role near ring edges. Pressure-induced accelerations are maximal near edges because there (1)velocity dispersions are enhanced by resonant satellite perturbations, and (2)the surface density declines steeply. Remarkably, collisional forces felt by material in the last ~100 m of a ~10 km wide ring can increase equilibrium masses up to a factor of ~100. New ring surface densities are derived which accord with

  10. Seeded inert gas driven disk generator

    International Nuclear Information System (INIS)

    Joshi, N.K.; Venkatramani, N.; Rohatgi, V.K.

    1987-01-01

    This report outlines the present status of work being carried out in closed cycle MHD and disk generators. It gives the basic principles and discusses a proposal for setting up an experimental facility to study nonequilibrium plasmas using an inert gas driven disk generator. Disk geometry is a near ideal geometry for plasma studies since it has single or few pair electrodes combined with near perfect insulating walls. The proposed outlay of facility with components and subsystem is given. The facility may also be used to study the concept of fully ionized seed and to develop advanced diagnostic techniques. The absic equation describing the working parameters of such a system is also given in the Appendix. (author). 57 refs

  11. Fractures of the shafts of the tibia and fibula

    International Nuclear Information System (INIS)

    Bender, C.E.; Campbell, D.C.

    1985-01-01

    Fractures of the shafts of the tibia and fibula are the most common long bone fractures. This chapter discusses tibial and fibular shaft fractures. Treatment of tibial and fibular fractures is similar and, therefore, reference is primarily made to the tibia. Diagnostic techniques are also evaluated

  12. Boundary integral method for torsion of composite shafts

    International Nuclear Information System (INIS)

    Chou, S.I.; Mohr, J.A.

    1987-01-01

    The Saint-Venant torsion problem for homogeneous shafts with simply or multiply-connected regions has received a great deal of attention in the past. However, because of the mathematical difficulties inherent in the problem, very few problems of torsion of shafts with composite cross sections have been solved analytically. Muskhelishvili (1963) studied the torsion problem for shafts with cross sections having several solid inclusions surrounded by an elastic material. The problem of a circular shaft reinforced by a non-concentric round inclusion, a rectangular shaft composed of two rectangular parts made of different materials were solved. In this paper, a boundary integral equation method, which can be used to solve problems more complex than those considered by Katsikadelis et. al., is developed. Square shaft with two dissimilar rectangular parts, square shaft with a square inclusion are solved and the results compared with those given in the reference cited above. Finally, a square shaft composed of two rectangular parts with circular inclusion is solved. (orig./GL)

  13. Percutaneous Kirschner wire (K-wire) fixation for humerus shaft ...

    African Journals Online (AJOL)

    Background: Fractures of the humeral shaft are uncommon, representing less than 10 percent of all fractures in children. Humeral shaft fractures in children can be treated by immobilisation alone. A small number of fractures are unable to be reduced adequately or maintained in adequate alignment, and these should be ...

  14. New endoscope shaft for endoscopic transsphenoidal pituitary surgery.

    NARCIS (Netherlands)

    Lindert, E.J. van; Grotenhuis, J.A.

    2005-01-01

    OBJECTIVE: To describe a new endoscope shaft developed for suction-aspiration during endoscopic transsphenoidal pituitary surgery. METHODS: A custom-made shaft for a Wolf endoscope (Richard Wolf GmbH, Knittlingen, Germany) was developed with a height of 10 mm and a width of 5 mm, allowing an

  15. Proceedings of the conference on shaft drilling technology

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This book contains the following topics, Market analysis, World-wide operations, Innovative drilling and boring, Raise boring, Shaft lining and fittings, Entry considerations for the Yucca Mountain exploratory shaft facility for potential Radioactive Waste Disposal, Drilling rigs in the coal industry

  16. 46 CFR 171.100 - Shaft tunnels and stern tubes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Shaft tunnels and stern tubes. 171.100 Section 171.100... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.100 Shaft tunnels and... passengers on an international voyage. (b) The watertight seal in the bulkhead between the stern tube space...

  17. A coupled mechanical/hydrologic model for WIPP shaft seals

    International Nuclear Information System (INIS)

    Ehgartner, B.

    1991-06-01

    Effective sealing of the Waste Isolation Pilot Plant (WIPP) shafts will be required to isolate defense-generated transuranic wastes from the accessible environment. Shafts penetrate water-bearing hard rock formations before entering a massive creeping-salt formation (Salado) where the WIPP is located. Short and long-term seals are planned for the shafts. Short-term seals, a composite of concrete and bentonite, will primarily be located in the hard rock formations separating the water-bearing zones from the Salado Formation. These seals will limit water flow to the underlying long-term seals in the Salado. The long-term seals will consist of lengthly segments of initially unsaturated crushed salt. Creep closure of the shaft will consolidate unsaturated crushed salt, thereby reducing its permeability. However, water passing through the upper short-term seals and brine inherent to the salt host rock itself will eventually saturate the crushed salt and consolidation could be inhibited. Before saturating, portions of the crushed salt in the shafts are expected to consolidate to a permeability equivalent to the salt host rock, thereby effectively isolating the waste from the overlying water-bearing formations. A phenomenological model is developed for the coupled mechanical/hydrologic behavior of sealed WIPP shafts. The model couples creep closure of the shaft, crushed salt consolidation, and the associated reduction in permeability with Darcy's law for saturated fluid flow to predict the overall permeability of the shaft seal system with time. 17 refs., 6 figs., 1 tab

  18. Hair Shaft Abnormality in Children: a Narrative Review

    Directory of Open Access Journals (Sweden)

    Ghasem Rahmatpour Rokni

    2017-08-01

    Full Text Available Background Hair is an ectodermal structure, and its formation is regulated by master genes important in embryology. Hair shaft consists of three major regions: the medulla, cortex and cuticle. Hair shaft abnormality will divide structural hair abnormalities into two broad categories - those associated with increased hair fragility and those not associated with increased hair fragility. We conducted a review study to assess hair shaft abnormality in children. Materials and Methods We conducted a review of all papers published on hair shaft abnormalities. A literature search was performed using PubMed, Scopus and Google Scholar on papers publish from 1990 to 2016. The search terms were: hair shaft abnormality, Hair loss, Hair fragility. All abstracts and full text English-language articles were studied. Results While common developmental and structural features are shared in hair follicles and hair shafts. Anomalies of the hair shaft are separated into those with and those without increased hair fragility. Conclusion Although hair has no vital function, it may serve as an indicator for human health. Clinical and morphological hair abnormalities can be clues to specific complex disorders. Hair shaft abnormalities can be inherited or acquired, can reflect a local problem or a systemic disease.

  19. Exploratory Shaft Seismic Design Basis Working Group report

    International Nuclear Information System (INIS)

    Subramanian, C.V.; King, J.L.; Perkins, D.M.; Mudd, R.W.; Richardson, A.M.; Calovini, J.C.; Van Eeckhout, E.; Emerson, D.O.

    1990-08-01

    This report was prepared for the Yucca Mountain Project (YMP), which is managed by the US Department of Energy. The participants in the YMP are investigating the suitability of a site at Yucca Mountain, Nevada, for construction of a repository for high-level radioactive waste. An exploratory shaft facility (ESF) will be constructed to permit site characterization. The major components of the ESF are two shafts that will be used to provide access to the underground test areas for men, utilities, and ventilation. If a repository is constructed at the site, the exploratory shafts will be converted for use as intake ventilation shafts. In the context of both underground nuclear explosions (conducted at the nearby Nevada Test Site) and earthquakes, the report contains discussions of faulting potential at the site, control motions at depth, material properties of the different rock layers relevant to seismic design, the strain tensor for each of the waveforms along the shaft liners, and the method for combining the different strain components along the shaft liners. The report also describes analytic methods, assumptions used to ensure conservatism, and uncertainties in the data. The analyses show that none of the shafts' structures, systems, or components are important to public radiological safety; therefore, the shafts need only be designed to ensure worker safety, and the report recommends seismic design parameters appropriate for this purpose. 31 refs., 5 figs., 6 tabs

  20. Performance of meta power rotor shaft torque meter

    DEFF Research Database (Denmark)

    Schmidt Paulsen, U.

    2002-01-01

    The present report describes the novel experimental facility in detecting shaft torque in the transmission system (main rotor shaft, exit stage of gearbox) of a wind turbine, the results and the perspectives in using this concept. The measurements arecompared with measurements, based on existing ...

  1. Waste and dust utilisation in shaft furnaces

    Directory of Open Access Journals (Sweden)

    Senk, D.

    2005-12-01

    Full Text Available Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilized e.g. in agglomeration processes (sintering, pelletizing or briquetting and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverized coal (PC has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

    Los residuos y polvos de filtro provenientes de la industria siderúrgica, de la obtención de metales no ferrosos y de otras industrias, pueden ser utilizados, por ejemplo, en procesos de aglomeración como sintetizado, peletizado o briqueteado. En su caso, estos pueden ser inyectados en los hornos de cuba. Este artículo se enfoca a la inyección de estos materiales en los hornos de cuba. El comportamiento de la combustión y reducción de los polvos ricos en hierro y carbono y también lodos que contienen plomo, zinc y compuestos alcalinos y otros residuos con o sin carbón pulverizado (CP fue examinado, cuando se inyectaron en hornos de cuba. Los siguientes hornos de cuba fueron examinados: Horno alto, cubilote, OxiCup y horno de cuba Imperial Smelting. Las investigaciones se llevaron a cabo a escala de laboratorio e industrial. Algunos residuos y polvos bajo ciertas condiciones, no sólo pueden ser reciclados, sino también mejoran la eficiencia de combustión en las toberas, la operación y productividad del horno.

  2. Modeling Protoplanetary Disks

    Science.gov (United States)

    Holman, Megan; Tubbs, Drake; Keller, L. D.

    2018-01-01

    Using spectra models with known parameters and comparing them to spectra gathered from real systems is often the only ways to find out what is going on in those real systems. This project uses the modeling programs of RADMC-3D to generate model spectra for systems containing protoplanetary disks. The parameters can be changed to simulate protoplanetary disks in different stages of planet formation, with different sized gaps in different areas of the disks, as well as protoplanetary disks that contain different types of dust. We are working on producing a grid of models that all have different variations in the parameters in order to generate a miniature database to use for comparisons to gathered spectra. The spectra produced from these simulations will be compared to spectra that have been gathered from systems in the Small Magellanic cloud in order to find out the contents and stage of development of that system. This allows us to see if and how planets are forming in the Small Magellanic cloud, a region which has much less metallicity than our own galaxy. The data we gather from comparisons between the model spectra and the spectra of systems in the Small Magellanic Cloud can then be applied to how planets may have formed in the early universe.

  3. The Disk Mass Project

    NARCIS (Netherlands)

    Verheijen, Marc A. W.; Bershady, Matthew A.; Swaters, Rob A.; Andersen, David R.; Westfall, Kyle B.; de Jong, Roelof Sybe

    2007-01-01

    Little is known about the content and distribution of dark matter in spiral galaxies. To break the degeneracy in galaxy rotation curve decompositions, which allows a wide range of dark matter halo density profiles, an independent measure of the mass surface density of stellar disks is needed. Here,

  4. Ipsilateral femoral neck and shaft fractures: An overlooked association

    International Nuclear Information System (INIS)

    Daffner, R.H.; Riemer, B.L.; Butterfield, S.L.

    1991-01-01

    A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG)

  5. Ipsilateral femoral neck and shaft fractures: An overlooked association

    Energy Technology Data Exchange (ETDEWEB)

    Daffner, R.H. (Dept. of Diagnostic Radiology, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA)); Riemer, B.L.; Butterfield, S.L. (Dept. of Orthopedic Surgery, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA))

    1991-05-01

    A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG).

  6. Exploratory Shaft Facility quality assurance impact evaluation

    International Nuclear Information System (INIS)

    1987-08-01

    This report addresses the impact of the quality assurance practices used for the Exploratory Shaft Facility (ESF) design, and construction in licensing as part of the repository. Acceptance criteria used for evaluating the suitability of ESF QA practices are based on documents that had not been invoked for repository design or construction activities at the time of this evaluation. This report identifies the QA practices necessary for ESF design and construction licensability. A review and evaluation of QA practices for ESF design and construction resulted in the following conclusions. QA practices were found to be acceptable with a few exceptions. QA practices for construction activities were found to be insufficiently documented in implementing procedures to allow a full and effective evaluation for licensing purposes. Recommendations are provided for mitigating impacts to ensure compatibility of the QA practices with those considered necessary for repository licensing. 8 refs., 3 tabs

  7. Tibial shaft fractures in football players

    Directory of Open Access Journals (Sweden)

    Daisley Susan

    2007-06-01

    Full Text Available Abstract Background Football is officially the most popular sport in the world. In the UK, 10% of the adult population play football at least once a year. Despite this, there are few papers in the literature on tibial diaphyseal fractures in this sporting group. In addition, conflicting views on the nature of this injury exist. The purpose of this paper is to compare our experience of tibial shaft football fractures with the little available literature and identify any similarities and differences. Methods and Results A retrospective study of all tibial football fractures that presented to a teaching hospital was undertaken over a 5 year period from 1997 to 2001. There were 244 tibial fractures treated. 24 (9.8% of these were football related. All patients were male with a mean age of 23 years (range 15 to 29 and shin guards were worn in 95.8% of cases. 11/24 (45.8% were treated conservatively, 11/24 (45.8% by Grosse Kemp intramedullary nail and 2/24 (8.3% with plating. A difference in union times was noted, conservative 19 weeks compared to operative group 23.9 weeks (p Conclusion Our series compared similarly with the few reports available in the literature. However, a striking finding noted by the authors was a drop in the incidence of tibial shaft football fractures. It is likely that this is a reflection of recent compulsory FIFA regulations on shinguards as well as improvements in the design over the past decade since its introduction.

  8. Global Sensitivity Analysis of High Speed Shaft Subsystem of a Wind Turbine Drive Train

    Directory of Open Access Journals (Sweden)

    Saeed Asadi

    2018-01-01

    Full Text Available The wind turbine dynamics are complex and critical area of study for the wind industry. Quantification of the effective factors to wind turbine performance is valuable for making improvements to both power performance and turbine health. In this paper, the global sensitivity analysis of validated mathematical model for high speed shaft drive train test rig has been developed in order to evaluate the contribution of systems input parameters to the specified objective functions. The drive train in this study consists of a 3-phase induction motor, flexible shafts, shafts’ coupling, bearing housing, and disk with an eccentric mass. The governing equations were derived by using the Lagrangian formalism and were solved numerically by Newmark method. The variance based global sensitivity indices are introduced to evaluate the contribution of input structural parameters correlated to the objective functions. The conclusion from the current research provides informative beneficial data in terms of design and optimization of a drive train setup and also can provide better understanding of wind turbine drive train system dynamics with respect to different structural parameters, ultimately designing more efficient drive trains. Finally, the proposed global sensitivity analysis (GSA methodology demonstrates the detectability of faults in different components.

  9. Identifying Likely Disk-hosting M dwarfs with Disk Detective

    Science.gov (United States)

    Silverberg, Steven; Wisniewski, John; Kuchner, Marc J.; Disk Detective Collaboration

    2018-01-01

    M dwarfs are critical targets for exoplanet searches. Debris disks often provide key information as to the formation and evolution of planetary systems around higher-mass stars, alongside the planet themselves. However, less than 300 M dwarf debris disks are known, despite M dwarfs making up 70% of the local neighborhood. The Disk Detective citizen science project has identified over 6000 new potential disk host stars from the AllWISE catalog over the past three years. Here, we present preliminary results of our search for new disk-hosting M dwarfs in the survey. Based on near-infrared color cuts and fitting stellar models to photometry, we have identified over 500 potential new M dwarf disk hosts, nearly doubling the known number of such systems. In this talk, we present our methodology, and outline our ongoing work to confirm systems as M dwarf disks.

  10. Deformation and Life Analysis of Composite Flywheel Disk and Multi-disk Systems

    Science.gov (United States)

    Arnold, S. M.; Saleeb, A. F.; AlZoubi, N. R.

    2001-01-01

    In this study an attempt is made to put into perspective the problem of a rotating disk, be it a single disk or a number of concentric disks forming a unit. An analytical model capable of performing an elastic stress analysis for single/multiple, annular/solid, anisotropic/isotropic disk systems, subjected to both pressure surface tractions, body forces (in the form of temperature-changes and rotation fields) and interfacial misfits is derived and discussed. Results of an extensive parametric study are presented to clearly define the key design variables and their associated influence. In general the important parameters were identified as misfit, mean radius, thickness, material property and/or load gradation, and speed; all of which must be simultaneously optimized to achieve the "best" and most reliable design. Also, the important issue of defining proper performance/merit indices (based on the specific stored energy), in the presence of multiaxiality and material anisotropy is addressed. These merit indices are then utilized to discuss the difference between flywheels made from PMC and TMC materials with either an annular or solid geometry. Finally two major aspects of failure analysis, that is the static and cyclic limit (burst) speeds are addressed. In the case of static limit loads, upper, lower, and out-of-plane bounds for disks with constant thickness are presented for both the case of internal pressure loading (as one would see in a hydroburst test) and pure rotation (as in the case of a free spinning disk). The results (interaction diagrams) are displayed graphically in designer friendly format. For the case of fatigue, a representative fatigue/life master curve is illustrated in which the normalized limit speed versus number of applied cycles is given for a cladded TMC disk application.

  11. SHABERTH - ANALYSIS OF A SHAFT BEARING SYSTEM (CRAY VERSION)

    Science.gov (United States)

    Coe, H. H.

    1994-01-01

    The SHABERTH computer program was developed to predict operating characteristics of bearings in a multibearing load support system. Lubricated and non-lubricated bearings can be modeled. SHABERTH calculates the loads, torques, temperatures, and fatigue life for ball and/or roller bearings on a single shaft. The program also allows for an analysis of the system reaction to the termination of lubricant supply to the bearings and other lubricated mechanical elements. SHABERTH has proven to be a valuable tool in the design and analysis of shaft bearing systems. The SHABERTH program is structured with four nested calculation schemes. The thermal scheme performs steady state and transient temperature calculations which predict system temperatures for a given operating state. The bearing dimensional equilibrium scheme uses the bearing temperatures, predicted by the temperature mapping subprograms, and the rolling element raceway load distribution, predicted by the bearing subprogram, to calculate bearing diametral clearance for a given operating state. The shaft-bearing system load equilibrium scheme calculates bearing inner ring positions relative to the respective outer rings such that the external loading applied to the shaft is brought into equilibrium by the rolling element loads which develop at each bearing inner ring for a given operating state. The bearing rolling element and cage load equilibrium scheme calculates the rolling element and cage equilibrium positions and rotational speeds based on the relative inner-outer ring positions, inertia effects, and friction conditions. The ball bearing subprograms in the current SHABERTH program have several model enhancements over similar programs. These enhancements include an elastohydrodynamic (EHD) film thickness model that accounts for thermal heating in the contact area and lubricant film starvation; a new model for traction combined with an asperity load sharing model; a model for the hydrodynamic rolling and

  12. ALMA Survey of Lupus Protoplanetary Disks. II. Gas Disk Radii

    Science.gov (United States)

    Ansdell, M.; Williams, J. P.; Trapman, L.; van Terwisga, S. E.; Facchini, S.; Manara, C. F.; van der Marel, N.; Miotello, A.; Tazzari, M.; Hogerheijde, M.; Guidi, G.; Testi, L.; van Dishoeck, E. F.

    2018-05-01

    We present Atacama Large Millimeter/Sub-Millimeter Array (ALMA) Band 6 observations of a complete sample of protoplanetary disks in the young (∼1–3 Myr) Lupus star-forming region, covering the 1.33 mm continuum and the 12CO, 13CO, and C18O J = 2–1 lines. The spatial resolution is ∼0.″25 with a medium 3σ continuum sensitivity of 0.30 mJy, corresponding to M dust ∼ 0.2 M ⊕. We apply Keplerian masking to enhance the signal-to-noise ratios of our 12CO zero-moment maps, enabling measurements of gas disk radii for 22 Lupus disks; we find that gas disks are universally larger than millimeter dust disks by a factor of two on average, likely due to a combination of the optically thick gas emission and the growth and inward drift of the dust. Using the gas disk radii, we calculate the dimensionless viscosity parameter, α visc, finding a broad distribution and no correlations with other disk or stellar parameters, suggesting that viscous processes have not yet established quasi-steady states in Lupus disks. By combining our 1.33 mm continuum fluxes with our previous 890 μm continuum observations, we also calculate the millimeter spectral index, α mm, for 70 Lupus disks; we find an anticorrelation between α mm and millimeter flux for low-mass disks (M dust ≲ 5), followed by a flattening as disks approach α mm ≈ 2, which could indicate faster grain growth in higher-mass disks, but may also reflect their larger optically thick components. In sum, this work demonstrates the continuous stream of new insights into disk evolution and planet formation that can be gleaned from unbiased ALMA disk surveys.

  13. KINEMATICS AND DYNAMICS OF BALLS WHILE BEING POLISHED BETWEEN MISALIGNED DISKS IN DRIVEN SEPARATOR

    Directory of Open Access Journals (Sweden)

    K. G. Schetnikovich

    2007-01-01

    Full Text Available The paper contains description of tool design which is used for rough polishing of balls made of brittle materials. This tool consists of top disk, which is fi-eely set on pouring bearing of the separator shaft, and a bottom disk with elastic coating. Theoretical investigations of ball kinematics have permitted to determine an angular velocity of the balls in the machining zone, value and direction oi slipping speed with respect to the tool.it has been determined that even change of the position of bail rotation instantaneous axis relative to the separator is reached at equality of angular velocities of the bottom disk and the separator. When the top disk is freely set slipping speed is equal for all the balls of the machined lot. When the top disk is stationary slipping speed is significantly increasing however its value becomes variable and depends on ball distance to separator rotation axis.The presented equations of ball dynamics in the machining zone have made it possible to detennine a cohesive force with the bottom disk, frictional forces against the top disk and separator. Recommendations on selection of machining modes at initial and final stages of ball polishing are given in the paper.

  14. An assumed mode method and finite element method investigation of the coupled vibration in a flexible-disk rotor system with lacing wires

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shui-Ting; Huang, Hong-Wu [Hunan University, Changsha (China); Chiu, Yi-Jui; Yu, Guo-Fei [Xiamen University of Technology, Xiamen (China); Yang, Chia-Hao [Taipei Chengshih University of Science and Technology, Taipei (China); Jian, Sheng-Rui [I-Shou University, Kaohsiung (China)

    2017-02-15

    The Assumed mode method (AMM) and Finite element method (FEM) were used. Their results were compared to investigate the coupled shaft-torsion, disk-transverse, and blade-bending vibrations in a flexible-disk rotor system. The blades were grouped with a spring. The flexible-disk rotor system was divided into three modes of coupled vibrations: Shaft-disk-blade, disk-blade, and blade-blade. Two new modes of coupled vibrations were introduced, namely, lacing wires-blade and lacing wires-disk-blade. The patterns of change of the natural frequencies and mode shapes of the system were discussed. The results showed the following: first, mode shapes and natural frequencies varied, and the results of the AMM and FEM differed; second, numerical calculation results showed three influencing factors on natural frequencies, namely, the lacing wire constant, the lacing wire location, and the flexible disk; lastly, the flexible disk could affect the stability of the system as reflected in the effect of the rotational speed.

  15. Experimental Investigation of A Twin Shaft Micro Gas-Turbine System

    International Nuclear Information System (INIS)

    Sadig, Hussain; Sulaiman, Shaharin Anwar; Ibrahim, Idris

    2013-01-01

    Due to the fast depletion of fossil fuels and its negative impact on the environment, more attention has been concentrated to find new resources, policies and technologies, which meet the global needs with regard to fuel sustainability and emissions. In this paper, as a step to study the effect of burning low calorific value fuels on gas-turbine performance; a 50 kW slightly pressurized non-premixed tubular combustor along with turbocharger based twin shaft micro gas-turbine was designed and fabricated. A series of tests were conducted to characterize the system using LPG fuel. The tests include the analysis of the temperature profile, pressure and combustor efficiency as well as air fuel ratio and speed of the second turbine. The tests showed a stable operation with acceptable efficiency, air fuel ratio, and temperature gradient for the single and twin shaft turbines.

  16. The effect of texture on the shaft surface on the sealing performance of radial lip seals

    Science.gov (United States)

    Guo, Fei; Jia, XiaoHong; Gao, Zhi; Wang, YuMing

    2014-07-01

    On the basis of elastohydrodynamic model, the present study numerically analyzes the effect of various microdimple texture shapes, namely, circular, square, oriented isosceles triangular, on the pumping rate and the friction torque of radial lip seals, and determines the microdimple texture shape that can produce positive pumping rate. The area ratio, depth and shape dimension of a single texture are the most important geometric parameters which influence the tribological performance. According to the selected texture shape, parameter analysis is conducted to determine the optimal combination for the above three parameters. Simultaneously, the simulated performances of radial lip seal with texture on the shaft surface are compared with those of the conventional lip seal without any texture on the shaft surface.

  17. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    Science.gov (United States)

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

    2015-10-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  18. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    Directory of Open Access Journals (Sweden)

    Luo Jun

    2015-10-01

    Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  19. DC Control Effort Minimized for Magnetic-Bearing-Supported Shaft

    Science.gov (United States)

    Brown, Gerald V.

    2001-01-01

    A magnetic-bearing-supported shaft may have a number of concentricity and alignment problems. One of these involves the relationship of the position sensors, the centerline of the backup bearings, and the magnetic center of the magnetic bearings. For magnetic bearings with permanent magnet biasing, the average control current for a given control axis that is not bearing the shaft weight will be minimized if the shaft is centered, on average over a revolution, at the magnetic center of the bearings. That position may not yield zero sensor output or center the shaft in the backup bearing clearance. The desired shaft position that gives zero average current can be achieved if a simple additional term is added to the control law. Suppose that the instantaneous control currents from each bearing are available from measurements and can be input into the control computer. If each control current is integrated with a very small rate of accumulation and the result is added to the control output, the shaft will gradually move to a position where the control current averages to zero over many revolutions. This will occur regardless of any offsets of the position sensor inputs. At that position, the average control effort is minimized in comparison to other possible locations of the shaft. Nonlinearities of the magnetic bearing are minimized at that location as well.

  20. Dynamic analysis of cross shaft type universal joint with clearance

    International Nuclear Information System (INIS)

    Lu, Jian Wei; Wang, Gong Cheng; Chen, Hao; Vakakis, Alexander F.; Bergman, Lawrence A.

    2013-01-01

    Cross shaft type universal joint is widely used in ground vehicles to transfer torque between two intersecting axes, and its transmission feature can make a great contribution to NVH performance of the vehicle. We looked at the assembling clearance at cross shaft neck, and presented a dynamic model of cross shaft type universal joint with clearance at cross shaft neck. Two-state model is applied to describe the contact force between the cross shaft and driving joint fork based on Hertz theorem, and lumped mass method is applied to build up the dynamic model of the universal joint. Based on this model, numerical analysis is carried out to discuss the transmission feature of the universal joint with clearance at cross shaft neck, and the influence of clearance on the dynamic behavior of the system is evaluated with numerical results based on time history, power spectrum, and phase portrait. The method and conclusions presented are helpful to improvement of the transmission feature of cross shaft type universal joint.

  1. Brown dwarf disks with ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, L.; Isella, A. [Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Testi, L.; De Gregorio-Monsalvo, I. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Natta, A. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Scholz, A., E-mail: lricci@astro.caltech.edu [School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2014-08-10

    We present Atacama Large Millimeter/submillimeter Array continuum and spectral line data at 0.89 mm and 3.2 mm for three disks surrounding young brown dwarfs and very low mass stars in the Taurus star forming region. Dust thermal emission is detected and spatially resolved for all the three disks, while CO(J = 3-2) emission is seen in two disks. We analyze the continuum visibilities and constrain the disks' physical structure in dust. The results of our analysis show that the disks are relatively large; the smallest one has an outer radius of about 70 AU. The inferred disk radii, radial profiles of the dust surface density, and disk to central object mass ratios lie within the ranges found for disks around more massive young stars. We derive from our observations the wavelength dependence of the millimeter dust opacity. In all the three disks, data are consistent with the presence of grains with at least millimeter sizes, as also found for disks around young stars, and confirm that the early stages of the solid growth toward planetesimals occur also around very low-mass objects. We discuss the implications of our findings on models of solids evolution in protoplanetary disks, the main mechanisms proposed for the formation of brown dwarfs and very low-mass stars, as well as the potential of finding rocky and giant planets around very low-mass objects.

  2. Vibration of imperfect rotating disk

    Directory of Open Access Journals (Sweden)

    Půst L.

    2011-12-01

    Full Text Available This study is concerned with the theoretical and numerical calculations of the flexural vibrations of a bladed disk. The main focus of this study is to elaborate the basic background for diagnostic and identification methods for ascertaining the main properties of the real structure or an experimental model of turbine disks. The reduction of undesirable vibrations of blades is proposed by using damping heads, which on the experimental model of turbine disk are applied only on a limited number of blades. This partial setting of damping heads introduces imperfection in mass, stiffness and damping distribution on the periphery and leads to more complicated dynamic properties than those of a perfect disk. Calculation of FEM model and analytic—numerical solution of disk behaviour in the limited (two modes frequency range shows the splitting of resonance with an increasing speed of disk rotation. The spectrum of resonance is twice denser than that of a perfect disk.

  3. Evolution of magnetic disk subsystems

    Science.gov (United States)

    Kaneko, Satoru

    1994-06-01

    The higher recording density of magnetic disk realized today has brought larger storage capacity per unit and smaller form factors. If the required access performance per MB is constant, the performance of large subsystems has to be several times better. This article describes mainly the technology for improving the performance of the magnetic disk subsystems and the prospects of their future evolution. Also considered are 'crosscall pathing' which makes the data transfer channel more effective, 'disk cache' which improves performance coupling with solid state memory technology, and 'RAID' which improves the availability and integrity of disk subsystems by organizing multiple disk drives in a subsystem. As a result, it is concluded that since the performance of the subsystem is dominated by that of the disk cache, maximation of the performance of the disk cache subsystems is very important.

  4. Herniated disk disease

    International Nuclear Information System (INIS)

    Ross, J.S.; Masaryk, T.J.; Modic, M.T.; Bohlman, H.; Wilber, G.; Carter, J.

    1988-01-01

    Thirty patients with symptoms of disk herniation and no previous surgery were examined with Gd-DTPA-enhanced MR imaging. Studies obtained before and after administration of Gd-DTPA included the following sequences: sagittal and axial spin echo (SE) 500/17 (repetition time, msec/echo time, msec), sagittal SE 2,000/60, sagittal FLASH 200/13/60. Studies were interpreted separately for presence of extradural disease (EDD) characterized by morphology, mass effect, and enhancement. Post Gd-DTPA diagnoses were: normal, n = 1; herniation, n = 28; neoplasm, n = 1. Tissue diagnosis was obtained in 13. The Gd-DTPA examination correctly changed the diagnosis in one case, provided increased confidence in the diagnosis in four, and was equivalent to the precontrast study in eight. Increased conspicuity of EDD with Gd-DTPA was related to the enhancement of epidural space analogous to IV CT and enhancement of scar surrounding disk herniation. Histologically, this scar was identical to that seen in postoperative spines, Gd-DTPA appears to be a useful adjunct in cervical and thoracic degenerative disk disease

  5. Construction features of the exploratory shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    Adair, G.W.; Fiore, J.N.

    1984-01-01

    The Exploratory Shaft (ES) at Yucca Mountain is planned to be constructed during 1985 and 1986 as part of the detailed site characterization for one of three sites which may be selected as candidates for location of a high-level radioactive waste repository. Conventional mining methods will be used for the shaft sinking phase of the ES project. The ES will be comprised of surface support facilities, a 1480-ft-deep circular shaft lined with concrete to a finished inside diameter of 12 ft, lateral excavations and test installations extending up to 200 ft from the shaft, and long lateral borings extending up to 2300 ft from the shaft. The estimated time for sinking the shaft to a total depth of about 1480 ft and completing the lateral excavations and borings is about two years. The major underground development planned for the primary test level at a depth of 1200 ft consists of the equivalent of 1150 ft of 15- by 15-ft drift. The total volume of rock to be removed from the shaft proper and the lateral excavations totals about 1/2 million cubic feet. Construction equipment for the shaft and underground excavation phases consists of conventional mine hoisting equipment, shot hole and rock bolt drilling jumbos, mucking machines, and hauling machines. The desire to maintain relatively uniform and even walls in selected shaft and drift intervals will require that controlled blasting techniques be employed. Certain lateral boring operations associated with tests to be conducted in the underground development may pose some unusual problems or require specialized equipment. One of the operations is boring and lining a 30-in.-diam by 600-ft-long horizontal hole with a boring machine being developed under the direction of Sandia National Laboratories. Another special operation is coring long lateral holes (500 to 2000 ft) with minimum use of liquid circulating fluids. 8 figures

  6. Construction features of the Exploratory Shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    Adair, G.W.; Fiore, J.N.

    1984-01-01

    The Exploratory Shaft (ES) at Yucca Mountain is planned to be constructed during 1985 and 1986 as part of the detailed site characterization for one of three sites which may be selected as candidates for location of a high-level radioactive waste repository. Conventional mining methods will be used for the shaft sinking phase of the ES project. The ES will be comprised of surface support facilities, a 1,480-foot-deep circular shaft lined with concrete to a finished inside diameter of 12 feet, lateral excavations and test installations extending up to 200 feet from the shaft, and long lateral borings extending up to 2,300 feet from the shaft. The estimated time for sinking the shaft to a total depth of about 1,480 feet and completing the lateral excavations and borings is about two years. The major underground development planned for the primary test level at a depth of 1,200 feet consists of the equivalent of 1,150 feet of 15- by 15-foot drift. The total volume of rock to be removed from the shaft proper and the lateral excavations totals about 1/2 million cubic feet. Construction equipment for the shaft and underground excavation phases consists of conventional mine hoisting equipment, shot hole and rock bolt drilling jumbos, mucking machines, and hauling machines. The desire to maintain relatively uniform and even walls in selected shaft and drift intervals will require that controlled blasting techniques be employed. Such techniques generally classified as ''smooth blasting'' are commonly used for excavation in the construction industry

  7. Mechanical coupling for a rotor shaft assembly of dissimilar materials

    Science.gov (United States)

    Shi, Jun [Glastonbury, CT; Bombara, David [New Hartford, CT; Green, Kevin E [Broad Brook, CT; Bird, Connic [Rocky Hill, CT; Holowczak, John [South Windsor, CT

    2009-05-05

    A mechanical coupling for coupling a ceramic disc member to a metallic shaft includes a first wedge clamp and a second wedge clamp. A fastener engages a threaded end of a tie-bolt to sandwich the ceramic disc between the wedge clamps. An axial spring is positioned between the fastener and the second wedge clamp to apply an axial preload along the longitudinal axis. Another coupling utilizes a rotor shaft end of a metallic rotor shaft as one wedge clamp. Still another coupling includes a solid ceramic rotor disc with a multiple of tie-bolts radially displaced from the longitudinal axis to exert the preload on the solid ceramic rotor disc.

  8. Application of hydraulically assembled shaft coupling hubs to large agitators

    International Nuclear Information System (INIS)

    Murray, W.E.; Anderson, T.D.; Bethmann, H.K.

    1991-01-01

    This paper describes the basis for and implementation of hydraulically assembled shaft coupling hubs for large tank-mounted agitators. This modification to the original design was intended to minimize maintenance personnel exposure to ionizing radiation and also provide for disassembly capability without damage to shafts or hubs. In addition to realizing these objectives, test confirmed that the modified couplings reduced agitator shaft end runouts approximately 65%, thereby reducing bearing loads and increasing service life, a significant enhancement for a nuclear facility. 5 refs

  9. WIPP air-intake shaft disturbed-rock zone study

    International Nuclear Information System (INIS)

    Dale, T.; Hurtado, L.D.

    1996-01-01

    The disturbed-rock zone surrounding the air-intake shaft at the Waste Isolation Pilot Plant (WIPP) site was investigated to determine the extent and the permeability of the disturbed-rock zone as a function of radial distance from the 6.1 m diameter shaft, at different elevations within the Salado. Gas- and brine-permeability tests were performed in the bedded halite of the Salado formation at two levels within the air-intake shaft. The gas- and brine-permeability test results demonstrated that the radial distance to an undisturbed formation permeability of 1 x 10 -21 m 2 was less than 3.0 m

  10. Proposed design procedure for transmission shafting under fatigue loading

    Science.gov (United States)

    Loewenthal, S. H.

    1978-01-01

    The B106 American National Standards Committee is currently preparing a new standard for the design of transmission shafting. A design procedure, proposed for use in the new standard, for computing the diameter of rotating solid steel shafts under combined cyclic bending and steady torsion is presented. The formula is based on an elliptical variation of endurance strength with torque exhibited by combined stress fatigue data. Fatigue factors are cited to correct specimen bending endurance strength data for use in the shaft formula. A design example illustrates how the method is to be applied.

  11. Device for selectively securing an object to a shaft

    International Nuclear Information System (INIS)

    Calizano, F.; Chauvel, M.

    1984-01-01

    A magnetic tape reel is secured to a reel drive motor shaft by a device including a hub secured to the shaft, a plurality of shoes, and actuating means for thrusting the shoes against the reel and for releasing them from contact with the reel. The securing device includes a cam mounted on the shaft in combination with a locking device including the cam periphery. The locking device thrusts the shoes against the object and is operated by rotation of the motor. The cam is immobilized in rotation while the shoes are locked

  12. ANALYTICAL EVALUATION OF CRACK PROPAGATION FOR BULB HYDRAULIC TURBINES SHAFTS

    Directory of Open Access Journals (Sweden)

    Mircea O. POPOVICU

    2011-05-01

    Full Text Available The Hydroelectric Power Plants uses the regenerating energy of rivers. The hydraulic Bulb turbines running with low heads are excellent alternative energy sources. The shafts of these units present themselves as massive pieces, with cylindrical shape, manufactured from low-alloyed steels. The paper analyses the fatigue cracks occurring at some turbines in the neighbourhood of the connection zone between the shaft and the turbine runner flange. To obtain the tension state in this zone ANSIS and AFGROW computing programs were used. The number of running hours until the piercing of the shaft wall is established as a useful result.

  13. Reactor coolant pump shaft seal stability during station blackout

    International Nuclear Information System (INIS)

    Rhodes, D.B.; Hill, R.C.; Wensel, R.G.

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries

  14. Design and Delivery of HMT Half-Shaft Prototype

    Science.gov (United States)

    2012-11-01

    spindle welded to the outer joint output is ease of Design  and Delivery of HMT Half‐ Shaft  Prototype    24    assembly. Flange 1 contains threaded... spindle , and splined shafts . Also, the spindle of the production design is splined to match the splines of the hub internals. 2.2. Analysis The...inner-joint (Figure 33). Design  and Delivery of HMT Half‐ Shaft  Prototype    27      Figure 33: FBD of Flange/ Spindle Applying Newton’s Laws to the

  15. Reactor coolant pump shaft seal stability during station blackout

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, D B; Hill, R C; Wensel, R G

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

  16. Gear-shaft linkage, especially for nuclear reactor coolant pumps

    International Nuclear Information System (INIS)

    Delaunois, T.; Lefevre, R.

    1990-01-01

    The pump comprises: - inlet and outlet channels for the pumped fluid - a rotating shaft - a gear wheel mounted on the shaft by an axial locking nut which can support the axial hydraulic force - a thermal barrier above the gear wheel. A hydrostatic bearing fitted to the exterior surround of the gear wheel, the gear shaft linkage is made by at least a centering and locating device having a cylindrical span and an axial stop and another independent device which can take up the torque [fr

  17. Coupled vibration study of the blade of the flexible wind wheel with the low-speed shafting

    International Nuclear Information System (INIS)

    Su, L Y; Zhao, R Z; Liu, H; Meng, Z R

    2013-01-01

    Movement and deformation of flexible wind wheel has a profound effect on dynamics of the low-speed shafting in Megawatt wind turbine. The paper is based on the power production1.2 MW wind turbine, vibration characteristics of elastic wind wheel with the low-speed shafting were studied. In order to obtain the finite element model, the author created a physical model of this coupled system and used the minimum energy principle to simplify the model. While its single blade simplified as cantilever. Using modal superposition method for solving the coupled system model. Structural mechanics equations were used to solve the simple blade finite element model. Analyzing the natural frequency of the coupled system and the stress diagram, the results indicate that in the coupling system, low frequency vibration occurs in the low-speed shaft bearing, while the high-frequency vibration happens on wind turbine blades. In the low-frequency vibration process, blades vibration and low-speed shaft vibration there is a strong correlation. Contrast inherent frequency of the wind wheel with natural frequency of a single blade, the results show that the frequency of the wind wheel slightly less than it in the single blade

  18. Torsional vibrations of shafts of mechanical systems

    Science.gov (United States)

    Gulevsky, V. A.; Belyaev, A. N.; Trishina, T. V.

    2018-03-01

    The aim of the research is to compare the calculated dependencies for determining the equivalent rigidity of a mechanical system and to come to an agreement on the methods of compiling dynamic models for systems with elastic reducer couplings in applied and classical oscillation theories. As a result of the analysis, it was revealed that most of the damage in the mechanisms and their details is due to the appearance of oscillations due to the dynamic impact of various factors: shock and alternating loads, unbalanced parts of machines, etc. Therefore, the designer at the design stage, and the engineer in the process of operation should provide the possibility of regulating the oscillatory processes both in details and machines by means of creating rational designs, as well as the use of special devices such as vibration dampers, various vibrators with optimal characteristics. A method is proposed for deriving a formula for determining the equivalent stiffness of a double-mass oscillating system of a multistage reducer with elastic reducer links without taking into account the internal losses and inertia of its elements, which gives a result completely coinciding with the result obtained by the classical theory of small mechanical oscillations and allows eliminating formulas for reducing the moments of inertia of the flywheel masses and the stiffness of the shafts.

  19. Warm modified Chaplygin gas shaft inflation

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Abdul; Ilyas, Amara; Rani, Shamaila [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan)

    2017-02-15

    In this paper, we examine the possible realization of a new inflation family called ''shaft inflation'' by assuming the modified Chaplygin gas model and a tachyon scalar field. We also consider the special form of the dissipative coefficient Γ = a{sub 0}(T{sup 3})/(φ{sup 2}) and calculate the various inflationary parameters in the scenario of strong and weak dissipative regimes. In order to examine the behavior of inflationary parameters, the n{sub s}-φ, n{sub s}-r, and n{sub s}-α{sub s} planes (where n{sub s}, α{sub s}, r, and φ represent the spectral index, its running, tensor-to-scalar ratio, and scalar field, respectively) are being developed, which lead to the constraints r < 0.11, n{sub s} = 0.96 ± 0.025, and α{sub s} = -0.019 ± 0.025. It is quite interesting that these results of the inflationary parameters are compatible with BICEP2, WMAP (7+9) and recent Planck data. (orig.)

  20. Computing Temperatures in Optically Thick Protoplanetary Disks

    Science.gov (United States)

    Capuder, Lawrence F.. Jr.

    2011-01-01

    We worked with a Monte Carlo radiative transfer code to simulate the transfer of energy through protoplanetary disks, where planet formation occurs. The code tracks photons from the star into the disk, through scattering, absorption and re-emission, until they escape to infinity. High optical depths in the disk interior dominate the computation time because it takes the photon packet many interactions to get out of the region. High optical depths also receive few photons and therefore do not have well-estimated temperatures. We applied a modified random walk (MRW) approximation for treating high optical depths and to speed up the Monte Carlo calculations. The MRW is implemented by calculating the average number of interactions the photon packet will undergo in diffusing within a single cell of the spatial grid and then updating the packet position, packet frequencies, and local radiation absorption rate appropriately. The MRW approximation was then tested for accuracy and speed compared to the original code. We determined that MRW provides accurate answers to Monte Carlo Radiative transfer simulations. The speed gained from using MRW is shown to be proportional to the disk mass.

  1. A case for Redundant Arrays of Inexpensive Disks (RAID)

    Science.gov (United States)

    Patterson, David A.; Gibson, Garth; Katz, Randy H.

    1988-01-01

    Increasing performance of CPUs and memories will be squandered if not matched by a similar performance increase in I/O. While the capacity of Single Large Expensive Disks (SLED) has grown rapidly, the performance improvement of SLED has been modest. Redundant Arrays of Inexpensive Disks (RAID), based on the magnetic disk technology developed for personal computers, offers an attractive alternative to SLED, promising improvements of an order of magnitude in performance, reliability, power consumption, and scalability. This paper introduces five levels of RAIDs, giving their relative cost/performance, and compares RAID to an IBM 3380 and a Fujitsu Super Eagle.

  2. Drilled Shaft Foundations for Noise Barrier Walls and Slope Stabilization

    Science.gov (United States)

    2002-12-01

    This research project is focused on two primary objectives. The first objective relates to the development of a methodology for using the SPT (Standard Penetration Test) results to design the laterally loaded drilled shafts. The second objective aims...

  3. Grinding Method and Error Analysis of Eccentric Shaft Parts

    Science.gov (United States)

    Wang, Zhiming; Han, Qiushi; Li, Qiguang; Peng, Baoying; Li, Weihua

    2017-12-01

    RV reducer and various mechanical transmission parts are widely used in eccentric shaft parts, The demand of precision grinding technology for eccentric shaft parts now, In this paper, the model of X-C linkage relation of eccentric shaft grinding is studied; By inversion method, the contour curve of the wheel envelope is deduced, and the distance from the center of eccentric circle is constant. The simulation software of eccentric shaft grinding is developed, the correctness of the model is proved, the influence of the X-axis feed error, the C-axis feed error and the wheel radius error on the grinding process is analyzed, and the corresponding error calculation model is proposed. The simulation analysis is carried out to provide the basis for the contour error compensation.

  4. Effectiveness of plate augmentation for femoral shaft nonunion after nailing

    Directory of Open Access Journals (Sweden)

    Chin-Jung Lin

    2012-08-01

    Conclusion: Plate augmentation with retention of the nail with autologous bone grafting may be an effective and reliable alternative in treating nonunion of the femoral shaft fracture after open reduction and internal fixation with intramedullary nail.

  5. Nonsynchronous vibrations observed in a supercritical power transmission shaft

    Science.gov (United States)

    Darlow, M. S.; Zorzi, E. S.

    1979-01-01

    A flexible shaft is prone to a number of vibration phenomena which occur at frequencies other than synchronous with rotational speed. Nonsynchronous vibrations from several sources were observed while running a test rig designed to simulate the operation of a supercritical power transmission shaft. The test rig was run first with very light external damping and then with a higher level of external damping, for comparison. As a result, the effect of external damping on the nonsynchronous vibrations of the test rig was observed. All of these nonsynchronous vibrations were of significant amplitude. Their presence in the vibrations spectra for a supercritical power transmission shaft at various speeds in the operating range indicates that very careful attention to all of the vibration spectra should be made in any supercritical power transmission shafting. This paper presents a review of the analysis performed and a comparison with experimental data. A thorough discussion of the observed nonsynchronous whirl is also provided.

  6. Shaft Crack Identification Based on Vibration and AE Signals

    Directory of Open Access Journals (Sweden)

    Wenxiu Lu

    2011-01-01

    Full Text Available The shaft crack is one of the main serious malfunctions that often occur in rotating machinery. However, it is difficult to locate the crack and determine the depth of the crack. In this paper, the acoustic emission (AE signal and vibration response are used to diagnose the crack. The wavelet transform is applied to AE signal to decompose into a series of time-domain signals, each of which covers a specific octave frequency band. Then an improved union method based on threshold and cross-correlation method is applied to detect the location of the shaft crack. The finite element method is used to build the model of the cracked rotor, and the crack depth is identified by comparing the vibration response of experiment and simulation. The experimental results show that the AE signal is effective and convenient to locate the shaft crack, and the vibration signal is feasible to determine the depth of shaft crack.

  7. The detection of wind turbine shaft misalignment using temperature monitoring

    OpenAIRE

    Tonks, Oliver; Wang, Qing

    2016-01-01

    Temperature is a parameter increasingly monitored in wind turbine systems. This paper details a potential temperature monitoring technique for use on shaft couplings. Such condition monitoring methods aid fault detection in other areas of wind turbines. However, application to shaft couplings has not previously been widely researched. A novel temperature measurement technique is outlined, using an infra-red thermometer which can be applied to online condition monitoring. The method was va...

  8. A shaft seal system for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Hansen, F.D.; Ahrens, E.H.; Dennis, A.W.; Hurtado, L.D.; Knowles, M.K.; Tillerson, J.R.; Thompson, T.W.; Galbraith, D.

    1996-01-01

    As part of the demonstration of compliance with federal regulations, a shaft seal system has been designed for the Waste Isolation Pilot Plant. The system completely fills the 650 m shafts with components consisting of the common engineering materials, each of which possesses low permeability, longevity, and can be constructed using available technology. Design investigations couple rock mechanics and fluid flow analysis and tests of these materials within the natural geological setting, and demonstrate the effectiveness of the design

  9. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  10. Audit: Automated Disk Investigation Toolkit

    Directory of Open Access Journals (Sweden)

    Umit Karabiyik

    2014-09-01

    Full Text Available Software tools designed for disk analysis play a critical role today in forensics investigations. However, these digital forensics tools are often difficult to use, usually task specific, and generally require professionally trained users with IT backgrounds. The relevant tools are also often open source requiring additional technical knowledge and proper configuration. This makes it difficult for investigators without some computer science background to easily conduct the needed disk analysis. In this paper, we present AUDIT, a novel automated disk investigation toolkit that supports investigations conducted by non-expert (in IT and disk technology and expert investigators. Our proof of concept design and implementation of AUDIT intelligently integrates open source tools and guides non-IT professionals while requiring minimal technical knowledge about the disk structures and file systems of the target disk image.

  11. Design capability of CANDU heat transport pump shafts against cracking

    International Nuclear Information System (INIS)

    Kumar, A.N.; Sheikh, Z.B.; Padgett, A.

    1993-01-01

    During 1986 three different Light Water Reactors (LWR's) in the U.S. reported either a cracked or fractured shaft on one or more of their reactor coolant (RC) pumps. The RC pumps for all these stations were supplied by Byron Jackson (BJ) Pump Company. A majority of CANDU heat transport (HT) pumps (equivalent of RC pumps) are supplied by BJ Pump Company and are similar in design to RC pumps. Hence the failure of these RC pumps in the U.S. utilities caused concern regarding the relevance of these failures to the BJ supplied CANDU HT pumps (HTP). This paper presents the results of AECL assessment to establish the capability of the HT pump shaft against cracking. Two methods were used for assessment: (a) detailed comparative design review of the HTP and RCP shafts; (b) semi-empirical analysis of the HTP shafts. The results of the AECL assessment showed significant differences in detailed design, materials, assembly and fits of various components and the control of operating parameters between the HT and RC pumps. It was concluded that because of these differences the failures similar to RC pump shafts are not likely to appear in HT pump shafts. This conclusion is further reinforced by about 140,000 hours of operating history of the longest running HT pump of comparable size to RC Pumps, without failures

  12. Shaft Siting and Configuration for Flexible Operating Mode

    International Nuclear Information System (INIS)

    Robert Boutin

    2001-01-01

    The purpose of this document as stated in the ''Technical Work Plan for Subsurface Design Section FY 01 Work Activities'' (CRWMS M and O 2001a, pg. 14) is to review and evaluate the most current concepts for shaft siting and configuration. The locations of the shaft sites will be evaluated in reference to the overall subsurface ventilation layout shown in Figure 1. The scope will include discussions on pad size requirements, shaft construction components such as collars, shaft stations, sumps, ground support and linings, head frames, fan ducting and facility equipping. In addition to these, shaft excavation methodologies and integration with the overall subsurface construction schedule will be described. The Technical Work Plan (TWP), (CRWMS M and O 2001a), for this document has been prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering and Regulatory Compliance Activities''. This document will be prepared in accordance with AP-3.10Q, ''Analysis and Models''. This document contributes to Site Recommendation (SR). The intended use of this document is to provide an analysis for shaft siting and configuration criteria for subsequent construction. This document identifies preliminary design concepts that should not be used for procurement, fabrication, or construction

  13. Salt Repository Project shaft design guide: Revision 0

    International Nuclear Information System (INIS)

    1987-12-01

    The Salt Repository Project (SRP) Shaft Design Guide (SDG) and the accompanying SRP Input to Seismic Design define the basic approach for developing appropriate shaft designs for a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. The SDG is based on current mining industry standards and practices enhanced to meet the special needs of an underground nuclear waste repository. It provides a common approach for design of both the exploratory and repository shafts. The SDG defines shaft lining and material concepts and presents methods for calculating the loads and displacements that will be imposed on lining structures. It also presents the methodology and formulae for sizing lining components. The SDG directs the shaft designer to sources of geoscience and seismic design data for the Deaf Smith County, Texas repository site. In addition, the SDG describes methods for confirming shaft lining design by means of computer analysis, and it discusses performance monitoring needs that must be considered in the design. 113 refs., 18 figs., 14 tabs

  14. Long-term brine migration through an engineered shaft seal system

    International Nuclear Information System (INIS)

    Fryar, D.G.; Beach, J.A.; Kelley, V.A.; Knowles, M.K.

    1997-01-01

    The shaft seal system for the Waste Isolation Pilot Plant (WIPP) must provide a barrier to the migration of fluids within the shafts to prevent the release of contaminants to the accessible environment. To investigate the performance of the shaft seal system, a set of fluid flow performance models was developed based upon the physical characteristics of the WIPP shaft seal system and the surrounding geologic media. This paper describes the results of a numerical model used to investigate the long-term potential for brine migration through the shaft seal system. Modeling results demonstrate that the WIPP shaft seal system will effectively limit brine migration within the repository shafts

  15. Dust evolution in protoplanetary disks

    OpenAIRE

    Gonzalez , Jean-François; Fouchet , Laure; T. Maddison , Sarah; Laibe , Guillaume

    2007-01-01

    6 pages, 5 figures, to appear in the Proceedings of IAU Symp. 249: Exoplanets: Detection, Formation and Dynamics (Suzhou, China); International audience; We investigate the behaviour of dust in protoplanetary disks under the action of gas drag using our 3D, two-fluid (gas+dust) SPH code. We present the evolution of the dust spatial distribution in global simulations of planetless disks as well as of disks containing an already formed planet. The resulting dust structures vary strongly with pa...

  16. Fallback disks & magnetars: prospects & possibilities

    Science.gov (United States)

    Alpar, M. A.

    Some bound matter in the form of a fallback disk may be an initial parameter of isolated neutron stars at birth which along with the initial rotation rate and dipole and higher multipole magnetic moments determines the evolution of neutron stars and the categories into which they fall This talk reviews the strengths and difficulties of fallback disk models in explaining properties of isolated neutron stars of different categories Evidence for and observational limits on fallback disks will also be discussed

  17. IBM 3390 Hard Disk Platter

    CERN Multimedia

    1991-01-01

    The 3390 disks rotated faster than those in the previous model 3380. Faster disk rotation reduced rotational delay (ie. the time required for the correct area of the disk surface to move to the point where data could be read or written). In the 3390's initial models, the average rotational delay was reduced to 7.1 milliseconds from 8.3 milliseconds for the 3380 family.

  18. STELLAR MASS DEPENDENT DISK DISPERSAL

    International Nuclear Information System (INIS)

    Kennedy, Grant M.; Kenyon, Scott J.

    2009-01-01

    We use published optical spectral and infrared (IR) excess data from nine young clusters and associations to study the stellar mass dependent dispersal of circumstellar disks. All clusters older than ∼3 Myr show a decrease in disk fraction with increasing stellar mass for solar to higher mass stars. This result is significant at about the 1σ level in each cluster. For the complete set of clusters we reject the null hypothesis-that solar and intermediate-mass stars lose their disks at the same rate-with 95%-99.9% confidence. To interpret this behavior, we investigate the impact of grain growth, binary companions, and photoevaporation on the evolution of disk signatures. Changes in grain growth timescales at fixed disk temperature may explain why early-type stars with IR excesses appear to evolve faster than their later-type counterparts. Little evidence that binary companions affect disk evolution suggests that photoevaporation is the more likely mechanism for disk dispersal. A simple photoevaporation model provides a good fit to the observed disk fractions for solar and intermediate-mass stars. Although the current mass-dependent disk dispersal signal is not strong, larger and more complete samples of clusters with ages of 3-5 Myr can improve the significance and provide better tests of theoretical models. In addition, the orbits of extra-solar planets can constrain models of disk dispersal and migration. We suggest that the signature of stellar mass dependent disk dispersal due to photoevaporation may be present in the orbits of observed extra-solar planets. Planets orbiting hosts more massive than ∼1.6 M sun may have larger orbits because the disks in which they formed were dispersed before they could migrate.

  19. A comparison of locked versus nonlocked Enders rods for length unstable pediatric femoral shaft fractures.

    Science.gov (United States)

    Ellis, Henry Bone; Ho, Christine A; Podeszwa, David A; Wilson, Philip L

    2011-12-01

    Stainless steel flexible Enders rods have been used for intramedullary fixation of pediatric femur fractures with good success. Despite intraoperative anatomic alignment, length unstable femur fractures can present postoperatively with fracture shortening. The purpose of this study was to review all length unstable pediatric femoral shaft fractures in which Enders rods were used and compare those that were locked to those that were not locked. A retrospective clinical and radiographic review of all patients at a single institution undergoing flexible intramedullary fixation for length unstable femoral shaft fractures from 2001 to 2008. A length unstable fracture was defined as either a comminuted fracture or a spiral fracture longer than twice the diameter of the femoral shaft. A total of 107 length unstable femoral shaft fractures fixed with Enders rods were identified, of which 37 cases (35%) had both Enders rods "locked" through the eyelet in the distal femur with a 2.7 mm fully threaded cortical screw. Patient demographics, clinical course, complications, fracture characteristics, and radiographic outcomes were compared for the locked and nonlocked groups. There were no statistical differences between the groups in demographic data, operative variables, fracture pattern, fracture location, time to union, femoral alignment, or major complications. Shortening of the femur and nail migration measured at 1 to 6 weeks postoperatively was significantly greater for the nonlocked cases. The medial and lateral locked Enders rods moved 1.3 and 1.9 mm, respectively, and the unlocked Enders each moved 12.1 mm (P < 0.05). At final follow-up there were significantly more (P < 0.05) clinical complaints in nonlocked group, including limp, clinical shortening, and painful palpable rods. Locking Enders rods for length unstable pediatric fractures is an excellent option to prevent shortening and resulted in no additional complications, added surgical time, or increased blood loss

  20. On Shaft Data Acquisition System (OSDAS)

    Science.gov (United States)

    Pedings, Marc; DeHart, Shawn; Formby, Jason; Naumann, Charles

    2012-01-01

    On Shaft Data Acquisition System (OSDAS) is a rugged, compact, multiple-channel data acquisition computer system that is designed to record data from instrumentation while operating under extreme rotational centrifugal or gravitational acceleration forces. This system, which was developed for the Heritage Fuel Air Turbine Test (HFATT) program, addresses the problem of recording multiple channels of high-sample-rate data on most any rotating test article by mounting the entire acquisition computer onboard with the turbine test article. With the limited availability of slip ring wires for power and communication, OSDAS utilizes its own resources to provide independent power and amplification for each instrument. Since OSDAS utilizes standard PC technology as well as shared code interfaces with the next-generation, real-time health monitoring system (SPARTAA Scalable Parallel Architecture for Real Time Analysis and Acquisition), this system could be expanded beyond its current capabilities, such as providing advanced health monitoring capabilities for the test article. High-conductor-count slip rings are expensive to purchase and maintain, yet only provide a limited number of conductors for routing instrumentation off the article and to a stationary data acquisition system. In addition to being limited to a small number of instruments, slip rings are prone to wear quickly, and introduce noise and other undesirable characteristics to the signal data. This led to the development of a system capable of recording high-density instrumentation, at high sample rates, on the test article itself, all while under extreme rotational stress. OSDAS is a fully functional PC-based system with 48 channels of 24-bit, high-sample-rate input channels, phase synchronized, with an onboard storage capacity of over 1/2-terabyte of solid-state storage. This recording system takes a novel approach to the problem of recording multiple channels of instrumentation, integrated with the test

  1. Tibia shaft fractures: costly burden of nonunions

    Directory of Open Access Journals (Sweden)

    Antonova Evgeniya

    2013-01-01

    Full Text Available Abstract Background Tibia shaft fractures (TSF are common for men and women and cause substantial morbidity, healthcare use, and costs. The impact of nonunions on healthcare use and costs is poorly described. Our goal was to investigate patient characteristics and healthcare use and costs associated with TSF in patients with and without nonunion. Methods We retrospectively analyzed medical claims in large U.S. managed care claims databases (Thomson Reuters MarketScan®, 16 million lives. We studied patients ≥ 18 years old with a TSF diagnosis (ICD-9 codes: 823.20, 823.22, 823.30, 823.32 in 2006 with continuous pharmaceutical and medical benefit enrollment 1 year prior and 2 years post-fracture. Nonunion was defined by ICD-9 code 733.82 (after the TSF date. Results Among the 853 patients with TSF, 99 (12% had nonunion. Patients with nonunion had more comorbidities (30 vs. 21, pre-fracture and were more likely to have their TSF open (87% vs. 70% than those without nonunion. Patients with nonunion were more likely to have additional fractures during the 2-year follow-up (of lower limb [88.9% vs. 69.5%, P  Conclusions Nonunions in TSF’s are associated with substantial healthcare resource use, common use of strong opioids, and high per-patient costs. Open fractures are associated with higher likelihood of nonunion than closed ones. Effective screening of nonunion risk may decrease this morbidity and subsequent healthcare resource use and costs.

  2. Mechanised drivage of roads, slopes and shafts

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    The variety of methods of work and the individual nature of statistics available from members makes a comparison of operational activity in this field very difficult. There is considerable variation between members drivage requirements on a ton per metre driven basis. This is primarily dictated by the natural conditions and the consequent methods of work adopted. The cost contribution to coal production from the drivage or heading activity appears to lie between 10 and 30 percent where the method is mainly longwall, and approximately 70 percent where it is mainly roof and pillar. There is therefore an opportunity for significant overall cost reduction if the drivage process itself can be made more efficient and, beyond the activity itself, it appears likely that there should be scope for increasing the tons per metre driven. On the basis of a postulated average roadway life of 5 to 6 years, the subsequent cost of maintenance may add a significant long term burden particularly in deep and highly stressed strata. The R and D work aimed at improved roadway siting, strata consolidation and provision of roof support systems which do not require repair is thus likely to have a basic effect on production costs. Data on shaft construction is limited; but this activity must have major importance to members anticipating increase in production or transfer of production sites; and the likely criteria for operational effectiveness seem likely to be speed of construction rather than purely initial construction cost. There is a relative scarcity of specific mention of debris disposal systems. On the tons/metre data quoted it would however appear that debris disposal from drivages requires some 20 percent or more of colliery haulage demand and must be a significant factor in colliery economics.

  3. [Disk calcifications in children].

    Science.gov (United States)

    Schmit, P; Fauré, C; Denarnaud, L

    1985-05-01

    It is not unusual for intervertebral disk calcifications to be detected in pediatric practice, the 150 or so cases reported in the literature probably representing only a small proportion of lesions actually diagnosed. Case reports of 33 children with intervertebral disk calcifications were analyzed. In the majority of these patients (31 of 33) a diagnosis of "idiopathic" calcifications had been made, the cervical localization of the lesions being related to repeated ORL infections and/or trauma. A pre-existing pathologic factor was found in two cases (one child with juvenile rheumatoid arthritis treated by corticoids and one child with Williams and Van Beuren's syndrome). An uncomplicated course was noted in 31 cases, the symptomatology (pain, spinal stiffness and febricula) improving after several days. Complications developed in two cases: one child had very disabling dysphagia due to an anteriorly protruding cervical herniated disc and surgery was necessary; the other child developed cervicobrachial neuralgia due to herniated disc protrusion into the cervical spinal canal, but symptoms regressed within several days although calcifications persisted unaltered. These findings and the course of the rare complications documented in the literature suggest the need for the most conservative treatment possible in cases of disc calcifications in children.

  4. Disk storage at CERN

    CERN Document Server

    Mascetti, L; Chan, B; Espinal, X; Fiorot, A; Labrador, H Gonz; Iven, J; Lamanna, M; Presti, G Lo; Mościcki, JT; Peters, AJ; Ponce, S; Rousseau, H; van der Ster, D

    2015-01-01

    CERN IT DSS operates the main storage resources for data taking and physics analysis mainly via three system: AFS, CASTOR and EOS. The total usable space available on disk for users is about 100 PB (with relative ratios 1:20:120). EOS actively uses the two CERN Tier0 centres (Meyrin and Wigner) with 50:50 ratio. IT DSS also provide sizeable on-demand resources for IT services most notably OpenStack and NFS-based clients: this is provided by a Ceph infrastructure (3 PB) and few proprietary servers (NetApp). We will describe our operational experience and recent changes to these systems with special emphasis to the present usages for LHC data taking, the convergence to commodity hardware (nodes with 200-TB each with optional SSD) shared across all services. We also describe our experience in coupling commodity and home-grown solution (e.g. CERNBox integration in EOS, Ceph disk pools for AFS, CASTOR and NFS) and finally the future evolution of these systems for WLCG and beyond.

  5. Disk storage at CERN

    Science.gov (United States)

    Mascetti, L.; Cano, E.; Chan, B.; Espinal, X.; Fiorot, A.; González Labrador, H.; Iven, J.; Lamanna, M.; Lo Presti, G.; Mościcki, JT; Peters, AJ; Ponce, S.; Rousseau, H.; van der Ster, D.

    2015-12-01

    CERN IT DSS operates the main storage resources for data taking and physics analysis mainly via three system: AFS, CASTOR and EOS. The total usable space available on disk for users is about 100 PB (with relative ratios 1:20:120). EOS actively uses the two CERN Tier0 centres (Meyrin and Wigner) with 50:50 ratio. IT DSS also provide sizeable on-demand resources for IT services most notably OpenStack and NFS-based clients: this is provided by a Ceph infrastructure (3 PB) and few proprietary servers (NetApp). We will describe our operational experience and recent changes to these systems with special emphasis to the present usages for LHC data taking, the convergence to commodity hardware (nodes with 200-TB each with optional SSD) shared across all services. We also describe our experience in coupling commodity and home-grown solution (e.g. CERNBox integration in EOS, Ceph disk pools for AFS, CASTOR and NFS) and finally the future evolution of these systems for WLCG and beyond.

  6. Real-time monitoring of wind turbine generator shaft alignment using laser measurement.

    OpenAIRE

    Mankowski, O.; Wang, Q.

    2013-01-01

    Shaft Misalignment is one of the most common sources of trouble of wind turbine drive train when rigid couplings connect the shafts. Ideal alignment of the shaft is difficult to be obtained and the couplings attached to the shaft may present angular or parallel misalignment defined also as lateral and axially misalignment. Despite misalignment is often observed in the practice, there are relatively few studies on wind turbine shaft misalignment in the literature and their results are sometime...

  7. Multimegawatt disk generator system for space applications

    International Nuclear Information System (INIS)

    Solbes, H.; Iwata, H.

    1988-01-01

    The conceptual design of a 100 megawatt - 500 seconds disk MHD generator system suitable as a burst power source for a space based neutral particle beam (NPB) is presented. The system features two disk generators operated in the magnetic field produced by a single circular superconducting magnet. Gelled reactants are used as the energy source. The oxidizer gel includes the alkali seed. The high heat flux areas of the power train are water cooled. Heat is rejected to a hydrogen stream which is also used for cooling of the exit section. The hydrogen is also used to mitigate the effects of the exhaust products of combustion on the platform. The two disk channels are operated in parallel. A dc to dc converter consolidates the channel's output into a single 100 kilovolt dc output. Critical development issues relevant to the development of such power systems are identified and discussed. A R and D plan aimed at establishing the technical feasibility of the proposed system is also presented

  8. New look at the dynamics of twisted accretion disks

    International Nuclear Information System (INIS)

    Hatchett, S.P.; Begelman, M.C.; Sarazin, C.L.

    1981-01-01

    We reexamine the dynamic response of a thin, accretion disk to twisting torques, guided by the earlier analyses by Bardeen and Petterson. We make several corrections to this earlier work, and present a new version of the twist equations consistent with their physical assumptions. By describing the distortion of the disk in terms Cartesian direction cosines rather than the Euler angles used by the earlier authors, we are able to transform the twist equations from a pair of coupled, nonlinear, partial differential equations to a single, linear, complex one. We write down formulae for the external twisting torques likley to be encountered in astrophysic, and we show that even with these driving torques our twist equation remains linear. We find exact, analytic solutions for steady state structure of a disk subject to Lense-Thirring torques by a nonaligned central Kerr black hole and also for the time-dependent problem of the structure of a slaved disk with its oscillating boundary conditions. Finally, we discuss the stability of disks against twisting modes and show that undriven disks and disks subject to time-independent driving torques are stable

  9. Characterizing Protoplanetary Disks in a Young Binary in Orion

    Science.gov (United States)

    Powell, Jonas; Hughes, A. Meredith; Mann, Rita; Flaherty, Kevin; Di Francesco, James; Williams, Jonathan

    2018-01-01

    Planetary systems form in circumstellar disks of gas and dust surrounding young stars. One open question in the study of planet formation involves understanding how different environments affect the properties of the disks and planets they generate. Understanding the properties of disks in high-mass star forming regions (SFRs) is critical since most stars - probably including our Sun - form in those regions. By comparing the disks in high-mass SFRs to those in better-studied low-mass SFRs we can learn about the role environment plays in planet formation. Here we present 0.5" resolution observations of the young two-disk binary system V2434 Ori in the Orion Nebula from the Atacama Large Millimeter/submillimeter Array (ALMA) in molecular line tracers of CO(3-2), HCN(4-3), HCO+(4-3) and CS(7-6). We model each disk’s mass, radius, temperature structure, and molecular abundances, by creating synthetic images using an LTE ray-tracing code and comparing simulated observations with the ALMA data in the visibility domain. We then compare our results to a previous study of molecular line emission from a single Orion proplyd, modeled using similar methods, and to previously characterized disks in low-mass SFRs to investigate the role of environment in disk chemistry and planetary system formation.

  10. Dust Concentration and Emission in Protoplanetary Disks Vortices

    Science.gov (United States)

    Sierra, Anibal; Lizano, Susana; Barge, Pierre

    2017-12-01

    We study the dust concentration and emission in protoplanetary disks vortices. We extend the Lyra-Lin solution for the dust concentration of a single grain size to a power-law distribution of grain sizes n(a)\\propto {a}-p. Assuming dust conservation in the disk, we find an analytic dust surface density as a function of the grain radius. We calculate the increase of the dust-to-gas mass ratio ɛ and the slope p of the dust size distribution due to grain segregation within the vortex. We apply this model to a numerical simulation of a disk containing a persistent vortex. Due to the accumulation of large grains toward the vortex center, ɛ increases by a factor of 10 from the background disk value, and p decreases from 3.5 to 3.0. We find the disk emission at millimeter wavelengths corresponding to synthetic observations with ALMA and VLA. The simulated maps at 7 mm and 1 cm show a strong azimuthal asymmetry. This happens because, at these wavelengths, the disk becomes optically thin while the vortex remains optically thick. The large vortex opacity is mainly due to an increase in the dust-to-gas mass ratio. In addition, the change in the slope of the dust size distribution increases the opacity by a factor of two. We also show that the inclusion of the dust scattering opacity substantially changes the disks images.

  11. Multi-terabyte EIDE disk arrays running Linux RAID5

    International Nuclear Information System (INIS)

    Sanders, D.A.; Cremaldi, L.M.; Eschenburg, V.; Godang, R.; Joy, M.D.; Summers, D.J.; Petravick, D.L.

    2004-01-01

    High-energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. Grid Computing is one method; however, the data must be cached at the various Grid nodes. We examine some storage techniques that exploit recent developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5) include both parity and striping. The striping improves access speed. The parity protects data in the event of a single disk failure, but not in the case of multiple disk failures. We report on tests of dual-processor Linux Software RAID-5 arrays and Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with 250 and 300 GB disks, for use in offline high-energy physics data analysis. The price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be scaled to sizes affordable to small institutions and used when fast random access at low cost is important

  12. Multi-terabyte EIDE disk arrays running Linux RAID5

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, D.A.; Cremaldi, L.M.; Eschenburg, V.; Godang, R.; Joy, M.D.; Summers, D.J.; /Mississippi U.; Petravick, D.L.; /Fermilab

    2004-11-01

    High-energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. Grid Computing is one method; however, the data must be cached at the various Grid nodes. We examine some storage techniques that exploit recent developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5) include both parity and striping. The striping improves access speed. The parity protects data in the event of a single disk failure, but not in the case of multiple disk failures. We report on tests of dual-processor Linux Software RAID-5 arrays and Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with 250 and 300 GB disks, for use in offline high-energy physics data analysis. The price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be scaled to sizes affordable to small institutions and used when fast random access at low cost is important.

  13. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find

  14. The Stability of Galaxy Disks

    NARCIS (Netherlands)

    Westfall, K. B.; Andersen, D. R.; Bershady, M. A.; Martinsson, T. P. K.; Swaters, R. A.; Verheijen, M. A. W.; Seigar, M.S.; Treuthardt, P.

    2014-01-01

    We calculate the stellar surface mass density (Σ*) and two-component (gas+stars) disk stability (QRW) for 25 late-type galaxies from the DiskMass Survey. These calculations are based on fits of a dynamical model to our ionized-gas and stellar kinematic data performed using a Markov Chain Monte Carlo

  15. Vibration of imperfect rotating disk

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2011-01-01

    Roč. 5, č. 2 (2011), s. 205-216 ISSN 1802-680X R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : bladed disk * imperfect disk * travelling waves Subject RIV: BI - Acoustics http://www.kme.zcu.cz/acm/index.php/acm/article/view/86

  16. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  17. The Growth of the Disk Galaxy UGC8802

    Science.gov (United States)

    Chang, R. X.; Shen, S. Y.; Hou, J. L.

    2012-07-01

    The disk galaxy UGC8802 has high neutral gas content and a flat profile of star formation rate compared to other disk galaxies with similar stellar mass. It also shows a steep metallicity gradient. We construct a chemical evolution model to explore its growth history by assuming its disk grows gradually from continuous gas infall, which is shaped by a free parameter—the infall-peak time. By adopting the recently observed molecular surface density related star formation law, we show that a late infall-peak time can naturally explain the observed high neutral gas content, while an inside-out disk formation scenario can fairly reproduce the steep oxygen abundance gradient. Our results show that most of the observed features of UGC8802 can be well reproduced by simply "turning the knob" on gas inflow with one single parameter, which implies that the observed properties of gas-rich galaxies could also be modeled in a similar way.

  18. Method of lining a vertical mine shaft with concrete

    Science.gov (United States)

    Eklund, James D.; Halter, Joseph M.; Rasmussen, Donald E.; Sullivan, Robert G.; Moffat, Robert B.

    1981-01-01

    The apparatus includes a cylindrical retainer form spaced inwardly of the wall of the shaft by the desired thickness of the liner to be poured and having overlapping edges which seal against concrete flow but permit the form to be contracted to a smaller circumference after the liner has hardened and is self-supporting. A curb ring extends downwardly and outwardly toward the shaft wall from the bottom of the retainer form to define the bottom surface of each poured liner section. An inflatable toroid forms a seal between the curb ring and the shaft wall. A form support gripper ring having gripper shoes laterally extendable under hydraulic power to engage the shaft wall supports the retainer form, curb ring and liner until the newly poured liner section becomes self-supporting. Adjusting hydraulic cylinders permit the curb ring and retainer form to be properly aligned relative to the form support gripper ring. After a liner section is self-supporting, an advancing system advances the retainer form, curb ring and form support gripper ring toward a shaft boring machine above which the liner is being formed. The advancing system also provides correct horizontal alignment of the form support gripper ring.

  19. Eddy Current Sensing of Torque in Rotating Shafts

    Science.gov (United States)

    Varonis, Orestes J.; Ida, Nathan

    2013-12-01

    The noncontact torque sensing in machine shafts is addressed based on the stress induced in a press-fitted magnetoelastic sleeve on the shaft and eddy current sensing of the changes of electrical conductivity and magnetic permeability due to the presence of stress. The eddy current probe uses dual drive, dual sensing coils whose purpose is increased sensitivity to torque and decreased sensitivity to variations in distance between probe and shaft (liftoff). A mechanism of keeping the distance constant is also employed. Both the probe and the magnetoelastic sleeve are evaluated for performance using a standard eddy current instrument. An eddy current instrument is also used to drive the coils and analyze the torque data. The method and sensor described are general and adaptable to a variety of applications. The sensor is suitable for static and rotating shafts, is independent of shaft diameter and operational over a large range of torques. The torque sensor uses a differential eddy current measurement resulting in cancellation of common mode effects including temperature and vibrations.

  20. Analysis and optimization of dynamic model of eccentric shaft grinder

    Science.gov (United States)

    Gao, Yangjie; Han, Qiushi; Li, Qiguang; Peng, Baoying

    2018-04-01

    Eccentric shaft servo grinder is the core equipment in the process chain of machining eccentric shaft. The establishment of the movement model and the determination of the kinematic relation of the-axis in the grinding process directly affect the quality of the grinding process, and there are many error factors in grinding, and it is very important to analyze the influence of these factors on the work piece quality. The three-dimensional model of eccentric shaft grinder is drawn by Pro/E three-dimensional drawing software, the model is imported into ANSYS Workbench Finite element analysis software, and the finite element analysis is carried out, and then the variation and parameters of each component of the bed are obtained by the modal analysis result. The natural frequencies and formations of the first six steps of the eccentric shaft grinder are obtained by modal analysis, and the weak links of the parts of the grinder are found out, and a reference improvement method is proposed for the design of the eccentric shaft grinder in the future.

  1. Torsional Vibration of a Shafting System under Electrical Disturbances

    Directory of Open Access Journals (Sweden)

    Ling Xiang

    2012-01-01

    Full Text Available Torsional vibration responses of a nonlinear shafting system are studied by a modified Riccati torsional transfer matrix combining with the Newmark-β method. Firstly, the system is modeled as a chain consisting of an elastic spring with concentrated mass points, from which a multi-segment lumped mass model is established. Secondly, accumulated errors are eliminated from the eigenfrequencies and responses of the system's torsional vibration by this newly developed procedure. The incremental transfer matrix method, combining the modified Riccati torsional transfer matrix with Newmark-β method, is further applied to solve the dynamical equations for the torsional vibration of the nonlinear shafting system. Lastly, the shafting system of a turbine-generator is employed as an illustrating example, and simulation analysis has been performed on the transient responses of the shaft's torsional vibrations during typical power network disturbances, such as three-phase short circuit, two-phase short circuit and asynchronous juxtaposition. The results validate the present method and are instructive for the design of a turbo-generator shaft.

  2. Failure analysis of axle shaft of a fork lift

    Directory of Open Access Journals (Sweden)

    Souvik Das

    2015-04-01

    Full Text Available An axle shaft of fork lift failed at operation within 296 h of service. The shaft transmits torque from discrepancy to wheel through planetary gear arrangement. A section of fractured axle shaft made of induction-hardened steel was analyzed to determine the root cause of the failure. Optical microscopies as well as field emission gun scanning electron microscopy (FEG-SEM along with energy dispersive spectroscopy (EDS were carried out to characterize the microstructure. Hardness profile throughout the cross-section was evaluated by micro-hardness measurements. Chemical analysis indicated that the shaft was made of 42CrMo4 steel grade as per specification. Microstructural analysis and micro-hardness profile revealed that the shaft was improperly heat treated resulting in a brittle case, where crack was found to initiate from the case in a brittle mode in contrast to ductile mode within the core. This behaviour was related to differences in microstructure, which was observed to be martensitic within the case with a micro-hardness equivalent to 735 HV, and a mixture of non-homogeneous structure of pearlite and ferrite within the core with a hardness of 210 HV. The analysis suggests that the fracture initiated from the martensitic case as brittle mode due to improper heat treatment process (high hardness. Moreover the inclusions along the hot working direction i.e. in the longitudinal axis made the component more susceptible to failure.

  3. Shaft Excavation in Frozen Ground at Point 5

    CERN Document Server

    Osborne, J

    2000-01-01

    Construction work on the 112 MCHF civil engineering contract started at Point 5 in August 1998. The new surface buildings and underground structures are necessary to accommodate the CMS detector for the LHC Project. The principal underground works consist of two new shafts, two parallel caverns separated by a supporting pillar, and a number of small connection tunnels and service galleries. The two shafts are to be sunk through approximately 50 m of water-bearing moraine to the underlying molasse rock. From a number of possible construction methods, ground freezing of the moraine was considered to be most appropriate. The ground freezing is used to control the groundwater and to support temporarily the moraine during excavation and lining of the shafts. The aim of this paper is to present the ground-freezing technique and to discuss the advantages and disadvantages of the system in the light of its first few months of running on the Point 5 site.

  4. Bentonite as a waste isolation pilot plant shaft sealing material

    International Nuclear Information System (INIS)

    Daemen, J.; Ran, Chongwei

    1996-12-01

    Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites

  5. Bentonite as a waste isolation pilot plant shaft sealing material

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, J.; Ran, Chongwei [Univ. of Nevada, Reno, NV (United States)

    1996-12-01

    Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites.

  6. The effect of induction motor shaft diameter on motor performance

    Directory of Open Access Journals (Sweden)

    Asım Gökhan Yetgin

    2017-10-01

    Full Text Available Induction motors are used in many areas from the past to the present and in different fields with the development of technology has continued to be used. It is obvious that induction motors as an improvement to the efficiency in terms of energy saving would cause great benefit. In that context, induction motor manufacturers and designers are constantly trying out new methods to improve motor performance and efficiency. In this study, what would be the optimum diameter of the shaft in order to increase the efficiency of the induction motor were investigated. In the study, 5.5 kW, 7.5 kW and 11 kW motors analyzes were also performed. Obtained shaft diameter values were compared with the manufacturer values. In addition, critical points such as the magnetic flux values, weight values and performances of the motors were examined and optimal shaft diameter values for each motor have been determined.

  7. Reclamation of derelict land: procedure for locating abandoned mine shafts

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    A procedure for locating abandoned shafts has been compiled from the experiences of those familiar with the problem. The procedure begins with a careful study of all the maps, aerial photographs and documents related to the mining activity and may include specialized surveys using geophysical, geochemical and aerial photographic methods when specific conditions are known or are likely to exist at the site. Direct methods, of either excavation, probing or drilling are required in each instance to confirm the location. Most of the methods are illustrated with case histories, and seismic and remote sensing methods are discussed in detail in appendices. Also in appendices, specific sources of information relating to mining are listed. Physical characteristics of mine shafts which are likely to have a bearing on the finding of the shaft are discussed, and an outline of the costs of the methods is presented. A glossary of mining terms used in the document and a detailed bibliography are provided.

  8. Shaft seal assembly for high speed and high pressure applications

    Science.gov (United States)

    Hadt, W. F.; Ludwig, L. P. (Inventor)

    1979-01-01

    A seal assembly is provided for reducing the escape of fluids from between a housing and a shaft rotably mounted in the housing. The seal assembly comprises a pair of seal rings resiliently connected to each other and disposed in side-by-side relationship. In each seal ring, both the internal bore surface and the radial face which faces away from the other seal ring are provided with a plurality of equi-spaced recesses. The seal faces referred to are located adjacent a seating surface of the housing. Under normal operating conditions, the seal assembly is stationary with respect to the housing, and the recesses generate life, keep the assembly spaced from the rotating shaft and allow slip therebetween. The seal assembly can seize on the shaft, and slip will then occur between the radial faces and the housing.

  9. Hydrogen Cyanide In Protoplanetary Disks

    Science.gov (United States)

    Walker, Ashley L.; Oberg, Karin; Cleeves, L. Ilsedore

    2018-01-01

    The chemistry behind star and planet formation is extremely complex and important in the formation of habitable planets. Life requires molecules containing carbon, oxygen, and importantly, nitrogen. Hydrogen cyanide, or HCN, one of the main interstellar nitrogen carriers, is extremely dangerous here on Earth. However, it could be used as a vital tool for tracking the chemistry of potentially habitable planets. As we get closer to identifying other habitable planets, we must understand the beginnings of how those planets are formed in the early protoplanetary disk. This project investigates HCN chemistry in different locations in the disk, and what this might mean for forming planets at different distances from the star. HCN is a chemically diverse molecule. It is connected to the formation for other more complex molecules and is commonly used as a nitrogen tracer. Using computational chemical models we look at how the HCN abundance changes at different locations. We use realistic and physically motivated conditions for the gas in the protoplanetary disk: temperature, density, and radiation (UV flux). We analyze the reaction network, formation, and destruction of HCN molecules in the disk environment. The disk environment informs us about stability of habitable planets that are created based on HCN molecules. We reviewed and compared the difference in the molecules with a variety of locations in the disk and ultimately giving us a better understanding on how we view protoplanetary disks.

  10. design, construction and measured performance of a single-stage

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. The design philosophy, construction and measured performances of a single stage, single entry centrifugal pump .... the tachometer spindle to be held against a recess in the motor shaft. The constructed centrifugal ...

  11. Assessment of shaft safety and management system of controlling engineering information

    Energy Technology Data Exchange (ETDEWEB)

    Liu Rui-xin; Xu Yan-chun [Yanzhou Mining Group Ltd., Zoucheng (China)

    2008-02-15

    Evaluating shaft safety and establishing a system for controlling engineering information is very important because more than 90 shafts in thick alluvial areas suddenly have shaft wall fracturing or breaking problems and there are more than a few hundred shafts of similar geologic conditions. Taking shaft control in the Yangzhou Coal Mining Group as an example, an assessment and management system and related software were established. This system includes basic information of the mine, measurement results and analysis, and functions of empirical and theoretical forecasting and finite element analysis, which are confirmed to be very effective for guiding shaft well control engineering in practice. 8 refs., 3 figs., 2 tabs.

  12. Waste Handling Shaft concrete liner degradation conclusions and recommendations

    International Nuclear Information System (INIS)

    1992-10-01

    The primary function of the Waste Handling Shaft (WHS) at the Waste Isolation Pilot Plant (WIPP) is to permit the transfer of radioactive waste from the surface waste handling building to the underground storage area. It also serves as an intake shaft for small volumes of air during normal storage operations and as an emergency escape route. Part of the construction was the placement of a concrete liner and steel reinforced key in 1984. During a routine shaft inspection in May 1990, some degradation of the WHS concrete liner was observed between the depths of 800 and 900 feet below the ground surface. Detailed investigations of the liner had been carried out by Sandia National Laboratories and by Westinghouse Electric Corporation Waste Isolation Division (WID) through Lankard Materials Laboratory. Observations, reports, and data support the conclusion that the concrete degradation, resulting from attack by chemically aggressive brine, is a localized phenomena. It is the opinion of the WID that the degradation is not considered an immediate or near term concern; this is supported by technical experts. WID recommendations have been made which, when implemented, will ensure an extended liner life. Based on the current assessment of available data and the proposed shaft liner monitoring program described in this report, it is reasonable to assume that the operational life of the concrete shaft liner can safely support the 25-year life of the WIPP. Analysis of data indicates that degradation of the shaft's concrete liner is attributed to chemically aggressive brine seeping through construction joints and shrinkage cracks from behind the liner in and around the 834-foot depth. Chemical and mechanical components of concrete degradation have been identified. Chemical attack is comprised of several stages of concrete alteration. The other component, mechanical degradation, results from the expansive forces of crystals forming in the concrete pore space

  13. Cephalomedullary fixation for femoral neck/intertrochanteric and ipsilateral shaft fractures: surgical tips and pitfalls

    Directory of Open Access Journals (Sweden)

    Bali Kamal

    2013-02-01

    Full Text Available 【Abstract】Objective: Surgical management op-tions for femoral shaft fracture and ipsilateral proximal fe-mur fracture vary from single-implant to double-implant fixation. Cephalomedullary fixation in such fractures has rela-tive advantages over other techniques especially because of less soft tissue dissection and immediate postoperative weight bearing with accelerated rehabilitation. However, the surgery is technically demanding and there is a paucity of literature describing the surgical techniques for this fixation. The aim of the study was to describe the surgical technique of cephalomedullary fixation for femoral shaft fracture and ipsilateral proximal femur fracture. Methods: Sixteen cases (10 males and 6 females with a mean age of 41.8 years of ipsilateral proximal femur and shaft fractures were treated by single-stage cephalomedullary fixa-tion at tertiary level trauma center in northern India. The fractures were classified according to AO classification. An intraoperative record of duration of surgery as well as tech-nical challenges unique to each fracture pattern was kept for all the patients. Results: The most common proximal femoral pattern was AO B2.1 observed in 9 of our patients. The AO B2.3 fractures were seen in 4 patients while the AO A1.2 fractures in 3 patients. Four of the AO B2.1 and 2 of the AO B2.3 frac-tures required open reduction with Watson-Jones approach. The mean operative time was around 78 minutes, which tended to decrease as the surgical experience increased. There was only one case of malreduction, which required revision surgery. Conclusion: Combination of ipsilateral femoral shaft fracture and neck/intertrochanteric fracture is a difficult frac-ture pattern for trauma surgeons. Cephalomedullary nail is an excellent implant for such fractures but it requires careful insertion to avoid complications. Surgery is technically de-manding with a definite learning curve. Nevertheless, a ma-jority of these

  14. Co-trimoxazole susceptibility tests improved with separate trimethoprim and sulfamethoxazole disks.

    OpenAIRE

    Amyes, S G

    1981-01-01

    It is impossible to test accurately bacterial susceptibility to the trimethoprim-sulfamethoxazole combination co-trimoxazole with a single combined susceptibility disk. However, a variety of factors still affect the result even when separate trimethoprim and sulfamethoxazole disks are used. Experiments with separate disks showed that the optimum conditions for testing the susceptibilities of enterobacteria to these drugs were to flood-seed an agar plate with an inoculum of 10(4) to 10(5) orga...

  15. Disk tides and accretion runaway

    Science.gov (United States)

    Ward, William R.; Hahn, Joseph M.

    1995-01-01

    It is suggested that tidal interaction of an accreting planetary embryo with the gaseous preplanetary disk may provide a mechanism to breach the so-called runaway limit during the formation of the giant planet cores. The disk tidal torque converts a would-be shepherding object into a 'predator,' which can continue to cannibalize the planetesimal disk. This is more likely to occur in the giant planet region than in the terrestrial zone, providing a natural cause for Jupiter to predate the inner planets and form within the O(10(exp 7) yr) lifetime of the nebula.

  16. 8-inch IBM floppy disk

    CERN Multimedia

    1971-01-01

    The 8-inch floppy disk was a magnetic storage disk for the data introduced commercially by IBM in 1971. It was designed by an IBM team as an inexpensive way to load data into the IBM System / 370. Plus it was a read-only bare disk containing 80 KB of data. The first read-write version was introduced in 1972 by Memorex and could contain 175 KB on 50 tracks (with 8 sectors per track). Other improvements have led to various coatings and increased capacities. Finally, it was surpassed by the mini diskette of 5.25 inches introduced in 1976.

  17. The Evolution of Spiral Disks

    Science.gov (United States)

    Bershady, Matthew A.; Andersen, David R.

    We report on aspects of an observational study to probe the mass assembly of large galaxy disks. In this contribution we focus on a new survey of integral-field Hα velocity-maps of nearby, face on disks. Preliminary results yield disk asymmetry amplitudes consistent with estimates based on the scatter in the local Tully-Fisher relation. We also show how the high quality of integral-field echelle spectroscopy enables determinations of kinematic inclinations to i ~20 °. This holds the promise that nearly-face-on galaxies can be included in the Tully-Fisher relation. Finally, we discuss the prospects for measuring dynamical asymmetries of distant galaxies.

  18. Ipsilateral femoral shaft and vertical patella fracture: a case report

    Science.gov (United States)

    Ozkan, Korhan; Eceviz, Engin; Sahin, Adem; Ugutmen, Ender

    2009-01-01

    Introduction A femoral shaft fracture with an ipsilateral patella fracture has been, to our knowledge, given only cursory attention in English-speaking literature. Case presentation A 15 year old male patient had hitten by a car to his motorcycle came to emergency room and he had been operated for his femoral shaft freacture and vertical patellar fracture which was iniatally missed. Conclusion To us it is vital to obtain CT scan of the patient’s knee if there is an ipsilateral femoral fracture with an ipsilateral knee effusion and a punction which reveals hematoma even in the absence of a fracture line seen in AP and lateral projections. PMID:19829933

  19. TMI-2 auxiliary building elevator shaft and pit decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Bengel, T.G.

    1986-01-01

    Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours.

  20. Granuloma annulare localized to the shaft of the penis

    DEFF Research Database (Denmark)

    Trap, R; Wiebe, B

    1993-01-01

    A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis.......A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis....

  1. Rotary compression process for producing toothed hollow shafts

    Directory of Open Access Journals (Sweden)

    J. Tomczak

    2014-10-01

    Full Text Available The paper presents the results of numerical analyses of the rotary compression process for hollow stepped shafts with herringbone teeth. The numerical simulations were performed by Finite Element Method (FEM, using commercial software package DEFORM-3D. The results of numerical modelling aimed at determining the effect of billet wall thickness on product shape and the rotary compression process are presented. The distributions of strains, temperatures, damage criterion and force parameters of the process determined in the simulations are given, too. The numerical results obtained confirm the possibility of producing hollow toothed shafts from tube billet by rotary compression methods.

  2. Expected long-term outcome after a tibial shaft fracture

    DEFF Research Database (Denmark)

    Faergemann, C; Frandsen, P A; Röck, N D

    1999-01-01

    OBJECTIVE: A prospective study of 207 laymen and professionals answered a questionnaire regarding the expectations of the long-term outcome 6 months after a unilateral tibial shaft fracture. The aim was (1) to disclose the expected outcome after unilateral tibial shaft fracture, and (2) to compare...... these expectations with the outcome measured in patients. METHODS: There were five groups of nonpatients: (1) 42 orthopedic surgeons, (2) 36 physiotherapists, (3) 42 students, (4) 49 white collar workers, and (5) 38 blue collar workers. Outcome was measured by Sickness Impact Profile (SIP). The SIP scores were...

  3. Reactor coolant pump shaft seal behavior during blackout conditions

    International Nuclear Information System (INIS)

    Mings, W.J.

    1985-01-01

    The United States Nuclear Regulatory Commission has classified the problem of reactor coolant pump seal failures as an unresolved safety issue. This decision was made in large part due to experimental results obtained from a research program developed to study shaft seal performance during station blackout and reported in this paper. Testing and analysis indicated a potential for pump seal failure under postulated blackout conditions leading to a loss of primary coolant with a concomitant danger of core uncovery. The work to date has not answered all the concerns regarding shaft seal failure but it has helped scope the problem and focus future research needed to completely resolve this issue

  4. Improved circumferential shaft seal for aircraft gear transmissions

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N.

    1973-01-01

    Operation under simulated aircraft transmission conditions of speeds to 2850 m/min (9350 ft/min), lubricant temperatures to 394 K (250 F), shaft radial runouts to 0.254 mm (0.010 in.) F.I.R. (full indicator reading), and pressure differentials to 1.03 N/cm2 (1.5 psi) revealed that conventional circumferential seals leaked excessively. Modifying the conventional seal by adding helical grooves to the seal bore reduced leakage rates to within the acceptable level of 10 cm3/hr. The leakage rate of this modified seal was not significantly affected by lubricant flooding or by shaft radial runout.

  5. The Fortios disks revisited

    Directory of Open Access Journals (Sweden)

    António M. Monge Soares

    2017-07-01

    Full Text Available We have used EDXRF, Micro-PIXE and optical microscopy (metallographic analysis, complemented with SEM-EDS, to first determine the elemental content, and second, to identify the process used to join the components (disk, peripheral rod and tab of several Iron Age gold buttons. These have a very similar typology and were found at three archaeological sites in the South-Western part of the Iberian Peninsula. A set of 35 buttons from Castro dos Ratinhos (7, Outeiro da Cabeça (23 and Fortios (5 were analyzed and the results published in Trabajos de Prehistoria (Soares et al. 2010. Recently Perea et al. (2016 have published analyses of other 4 gold buttons from Fortios with the same purpose, but only using one technique, SEM-EDS. As they only analysed the rough surface layer, the results are neither effective nor reliable, taking into account the constraints associated with the technique, namely the small depth reached (< 2 ?m by the incident beam and, consequently, its sensitivity to the topography of the analyzed surface. Despite these constraints, they have accepted uncritically their results and, at the same time, question our own analyses and results and the interpretation we have made. Here we discuss the approach of Perea et al. in order to determine not only the elemental content of the Fortios gold buttons, but also to identify the joining process used in their manufacture.

  6. Finite Element Analysis of Flexural Vibrations in Hard Disk Drive Spindle Systems

    Science.gov (United States)

    LIM, SEUNGCHUL

    2000-06-01

    This paper is concerned with the flexural vibration analysis of the hard disk drive (HDD) spindle system by means of the finite element method. In contrast to previous research, every system component is here analytically modelled taking into account its structural flexibility and also the centrifugal effect particularly on the disk. To prove the effectiveness and accuracy of the formulated models, commercial HDD systems with two and three identical disks are selected as examples. Then their major natural modes are computed with only a small number of element meshes as the shaft rotational speed is varied, and subsequently compared with the existing numerical results obtained using other methods and newly acquired experimental ones. Based on such a series of studies, the proposed method can be concluded as a very promising tool for the design of HDDs and various other high-performance computer disk drives such as floppy disk drives, CD ROM drives, and their variations having spindle mechanisms similar to those of HDDs.

  7. Outline and results of study on excavation response of rock mass around shaft in shaft excavation effects project

    International Nuclear Information System (INIS)

    Sugihara, Kozo; Matsui, Hiroya; Sato, Toshinori

    1993-01-01

    A shaft, with a diameter of 6 m and a depth of 150 m, has been newly excavated in sedimentary rock and excavation response of rock mass around the shaft has been measured and analyzed. Excavation response has been evaluated based on the results of measurement of rock mass movement, such as displacement and strain, and change of rock property, such as deformability and permeability. This study indicates that rock property has been changed with in about 1 m from the shaft wall, and rock mass movement and property change has been influenced by rock facies, fracture and re-distributed stress. The relation between property change and these factors is remained to be evaluated in future study. (author)

  8. TRANSITIONAL DISKS AS SIGNPOSTS OF YOUNG, MULTIPLANET SYSTEMS

    International Nuclear Information System (INIS)

    Dodson-Robinson, Sarah E.; Salyk, Colette

    2011-01-01

    Although there has yet been no undisputed discovery of a still-forming planet embedded in a gaseous protoplanetary disk, the cleared inner holes of transitional disks may be signposts of young planets. Here, we show that the subset of accreting transitional disks with wide, optically thin inner holes of 15 AU or more can only be sculpted by multiple planets orbiting inside each hole. Multiplanet systems provide two key ingredients for explaining the origins of transitional disks. First, multiple planets can clear wide inner holes where single planets open only narrow gaps. Second, the confined, non-axisymmetric accretion flows produced by multiple planets provide a way for an arbitrary amount of mass transfer to occur through an apparently optically thin hole without overproducing infrared excess flux. Rather than assuming that the gas and dust in the hole are evenly and axisymmetrically distributed, one can construct an inner hole with apparently optically thin infrared fluxes by covering a macroscopic fraction of the hole's surface area with locally optically thick tidal tails. We also establish that other clearing mechanisms, such as photoevaporation, cannot explain our subset of accreting transitional disks with wide holes. Transitional disks are therefore high-value targets for observational searches for young planetary systems.

  9. Determination of elastic stresses in gas-turbine disks

    Science.gov (United States)

    Manson, S S

    1947-01-01

    A method is presented for the calculation of elastic stresses in symmetrical disks typical of those of a high-temperature gas turbine. The method is essentially a finite-difference solution of the equilibrium and compatibility equations for elastic stresses in a symmetrical disk. Account can be taken of point-to-point variations in disk thickness, in temperature, in elastic modulus, in coefficient of thermal expansion, in material density, and in Poisson's ratio. No numerical integration or trial-and-error procedures are involved and the computations can be performed in rapid and routine fashion by nontechnical computers with little engineering supervision. Checks on problems for which exact mathematical solutions are known indicate that the method yields results of high accuracy. Illustrative examples are presented to show the manner of treating solid disks, disks with central holes, and disks constructed either of a single material or two or more welded materials. The effect of shrink fitting is taken into account by a very simple device.

  10. Gravitational Instabilities in Circumstellar Disks

    Science.gov (United States)

    Kratter, Kaitlin; Lodato, Giuseppe

    2016-09-01

    Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review, we focus on the role of gravitational instability in this process. We begin with a brief overview of the observational evidence for massive disks that might be subject to gravitational instability and then highlight the diverse ways in which the instability manifests itself in protostellar and protoplanetary disks: the generation of spiral arms, small-scale turbulence-like density fluctuations, and fragmentation of the disk itself. We present the analytic theory that describes the linear growth phase of the instability supplemented with a survey of numerical simulations that aim to capture the nonlinear evolution. We emphasize the role of thermodynamics and large-scale infall in controlling the outcome of the instability. Despite apparent controversies in the literature, we show a remarkable level of agreement between analytic predictions and numerical results. In the next part of our review, we focus on the astrophysical consequences of the instability. We show that the disks most likely to be gravitationally unstable are young and relatively massive compared with their host star, Md/M*≥0.1. They will develop quasi-stable spiral arms that process infall from the background cloud. Although instability is less likely at later times, once infall becomes less important, the manifestations of the instability are more varied. In this regime, the disk thermodynamics, often regulated by stellar irradiation, dictates the development and evolution of the instability. In some cases the instability may lead to fragmentation into bound companions. These companions are more likely to be brown dwarfs or stars than planetary mass objects. Finally, we highlight open questions related to the development of a turbulent cascade in thin disks and the role of mode-mode coupling in setting the maximum angular

  11. Bend testing for miniature disks

    International Nuclear Information System (INIS)

    Huang, F.H.; Hamilton, M.L.; Wire, G.L.

    1982-01-01

    A bend test was developed to obtain ductility measurements on a large number of alloy variants being irradiated in the form of miniature disks. Experimental results were shown to be in agreement with a theoretical analysis of the bend configuration. Disk specimens fabricated from the unstrained grip ends of previously tested tensile specimens were used for calibration purposes; bend ductilities and tensile ductilities were in good agreement. The criterion for estimating ductility was judged acceptable for screening purposes

  12. Preliminary Investigations of Eddy Current Effects on a Spinning Disk

    International Nuclear Information System (INIS)

    Piggott, W T; Walston, S; Mayhall, D

    2006-01-01

    The design of the positron source target for the International Linear Collider (ILC) envisions a Ti6Al4V wheel rotating in a large magnetic field (5-10 Tesla) being impacted by a photon beam to produce positrons. One of the many challenges for this system is determining how large a motor will be needed to spin the shaft. The wheel spinning in the magnetic field induces an eddy current in the wheel, which retards the spinning motion of the wheel. Earlier calculations by Mayhall [1] have shown that those eddy forces could be quite large, and resulted in the preliminary design being moved from a solid disk to a rim and spoke design, as shown in Figure 1. A series of experiments with a spinning metal disk were run at the Stanford Linear Accelerator Center (SLAC) to provide experimental validation of the Maxwell 3D simulations. This report will give a brief outline of the experimental setup and results. In addition, earlier work by Smythe [2] will be used to compare with the experimental results

  13. The Fabulous Four Debris Disks

    Science.gov (United States)

    Werner, Michael; Stapelfeldt, Karl

    2004-09-01

    This program is a comprehensive study of the four bright debris disks that were spatially resolved by IRAS: Beta Pictoris, Epsilon Eridani, Fomalhaut, and Vega. All SIRTF instruments and observing modes will be used. The program has three major objectives: (1) Study of the disk spatial structure from MIPS and IRAC imaging; (2) Study of the dust grain composition using the IRS and MIPS SED mode; and (3) companion searches using IRAC. The data from this program should lead to a detailed understanding of these four systems, and will provide a foundation for understanding all of the debris disks to be studied with SIRTF. Images and spectra will be compared with models for disk structure and dust properties. Dynamical features indicative of substellar companions' effects on the disks will be searched for. This program will require supporting observations of PSF stars, some of which have been included explicitly. In the majority of cases, the spectral observations require a preferred orientation to align the slits along the disk position angles. Detector saturation issues are still being worked for this program, and will lead to AOR modifications in subsequent submissions. The results from this program will be analyzed collaboratively by the IRAC, IRS, and MIPS teams and by general GTOs Jura and Werner.

  14. Comparison of central axis and jet ring coolant supply for turbine disk cooling on a SSME-HPOTP model

    Science.gov (United States)

    Kim, Y. W.; Metzger, D. E.

    1992-01-01

    The test facility, test methods and results are presented for an experimental study modeling the cooling of turbine disks in the blade attachment regions with multiple impinging jets, in a configuration simulating the disk cooling method employed on the Space Shuttle Main Engine oxygen turbopump. The study's objective was to provide a comparison of detailed local convection heat transfer rates obtained for a single center-supply of disk coolant with those obtained with the present flight configuration where disk coolant is supplied through an array of 19 jets located near the disk outer radius. Specially constructed disk models were used in a program designed to evaluate possible benefits and identify any possible detrimental effects involved in employing an alternate disk cooling scheme. The study involved the design, construction and testing of two full scale rotating model disks, one plane and smooth for baseline testing and the second contoured to the present flight configuration, together with the corresponding plane and contoured stator disks. Local heat transfer rates are determined from the color display of encapsulated liquid crystals coated on the disk in conjunction with use of a computer vision system. The test program was composed of a wide variety of disk speeds, flowrates, and geometrical configurations, including testing for the effects of disk boltheads and gas ingestion from the gas path region radially outboard of the disk-cavity.

  15. New generation of compact high power disk lasers

    Science.gov (United States)

    Feuchtenbeiner, Stefanie; Zaske, Sebastian; Schad, Sven-Silvius; Gottwald, Tina; Kuhn, Vincent; Kumkar, Sören; Metzger, Bernd; Killi, Alexander; Haug, Patrick; Speker, Nicolai

    2018-02-01

    New technological developments in high power disk lasers emitting at 1030 nm are presented. These include the latest generation of TRUMPF's TruDisk product line offering high power disk lasers with up to 6 kW output power and beam qualities of up to 4 mm*mrad. With these compact devices a footprint reduction of 50% compared to the previous model could be achieved while at the same time improving robustness and increasing system efficiency. In the context of Industry 4.0, the new generation of TruDisk lasers features a synchronized data recording of all sensors, offering high-quality data for virtual analyses. The lasers therefore provide optimal hardware requirements for services like Condition Monitoring and Predictive Maintenance. We will also discuss its innovative and space-saving cooling architecture. It allows operation of the laser under very critical ambient conditions. Furthermore, an outlook on extending the new disk laser platform to higher power levels will be given. We will present a disk laser with 8 kW laser power out of a single disk with a beam quality of 5 mm*mrad using a 125 μm fiber, which makes it ideally suited for cutting and welding applications. The flexibility of the disk laser platform also enables the realization of a wide variety of beam guiding setups. As an example a new scheme called BrightLine Weld will be discussed. This technology allows for an almost spatter free laser welding process, even at high feed rates.

  16. Design of inclined loaded drilled shafts in high-plasticity clay environment.

    Science.gov (United States)

    2011-05-01

    Drilled shaft foundations are principally used to support many structures such as bridge piers, towers, : buildings, transmission towers, and roadway cable barriers. This research focuses on the use of drilled shafts : in the cable median barrier sys...

  17. Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls

    National Research Council Canada - National Science Library

    Wang, Y

    2005-01-01

    The shaft grounding systems used on board HMC ships have substantially reduced the shaft-to-hull resistance and, thus, improved the performance of the shipboard impressed current cathodic protection (ICCP) system...

  18. Load and resistance factor design of drilled shafts in shale for lateral loading.

    Science.gov (United States)

    2014-04-01

    A research project involving 32 drilled shaft load tests was undertaken to establish LRFD procedures for : design of drilled shafts subjected to lateral loads. Tests were performed at two Missouri Department of : Transportation (MoDOT) geotechnical r...

  19. Current indications for open Kuntscher nailing of femoral shaft ...

    African Journals Online (AJOL)

    Current indications for open Kuntscher nailing of femoral shaft fractures. A S Bajwa FCS(SA)ORTH. E Schnaid FCS(SA)ORTH. M E B Sweet MD PhD(rned). University of Witwatersrand, Johannesburg, South Africa. Key Words: Kuntscher nail, intramedullary nail, femoral fracture. We retrospectively reviewed 32 patients with.

  20. Ender’s Nail fixation in paediatric femoral shaft fractures.

    Directory of Open Access Journals (Sweden)

    Rajeev Dwivedi

    2013-12-01

    Flynn criteria 34 had excellent and 6 had satisfactory results. No poor results were seen. Conclusion: Ender’s nail fixation can be preferred method of treatment for femoral shaft fractures in age group 5 -15 years as the results are excellent and satisfactory. It is technically simple and can be done in a closed manner. It spares the vascularity and growth plate.

  1. Outcome of humeral shaft fractures treated by functional cast brace

    Directory of Open Access Journals (Sweden)

    Jitendra Nath Pal

    2015-01-01

    Conclusion: Modified functional cast brace is one of the options in treatment for humeral shaft fractures as it can be applied on the 1 st day of the presentation in most of the situations. Simple objective scoring system was useful particularly in uneducated patients.

  2. Exploratory shaft conceptual design report: Gulf Interior Region salt domes

    International Nuclear Information System (INIS)

    1983-07-01

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Gulf Interior Region of the United States (Louisiana and Mississippi). Conceptualized designs for other possible locations (Paradox Basin in Utah and Permian Basin in Texas) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in-situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homoqeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptural design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  3. Scanning Electron Microscopic Hair Shaft Analysis in Ectodermal Dysplasia Syndromes.

    Science.gov (United States)

    Hirano-Ali, Stefanie A; Reed, Ashley M; Rowan, Brandon J; Sorrells, Timothy; Williams, Judith V; Pariser, David M; Hood, Antoinette F; Salkey, Kimberly

    2015-01-01

    The objective of the current study was to catalog hair shaft abnormalities in individuals with ectodermal dysplasia (ED) syndromes using scanning electron microscopy (SEM) and to compare the findings with those in unaffected controls. This is the second of a two-part study, the first of which used light microscopy as the modality and was previously published. Scanning electron microscopy was performed in a blinded manner on hair shafts from 65 subjects with seven types of ED syndromes and 41 unaffected control subjects. Assessment was performed along the length of the shaft and in cross section. Hair donations were collected at the 28th Annual National Family Conference held by the National Foundation for Ectodermal Dysplasia. Control subjects were recruited from a private dermatology practice and an academic children's hospital outpatient dermatology clinic. SEM identified various pathologic hair shaft abnormalities in each type of ED and in control patients. When hairs with all types of ED were grouped together and compared with those of control patients, the difference in the presence of small diameter and shallow and deep grooves was statistically significant (p < 0.05). When the EDs were separated according to subtype, statistically significant findings were also seen. SEM is a possible adjuvant tool in the diagnosis of ED syndromes. There are significant differences, with high specificity, between the hairs of individuals with ED and those of control subjects and between subtypes. © 2015 Wiley Periodicals, Inc.

  4. simultaneous ipsilateral fracture of the femoral neck and shaft

    African Journals Online (AJOL)

    1971-04-14

    Apr 14, 1971 ... Eight cases with fractures of The shaft and the neck of the ... discovered after a period of 6 months (case 1), 16 days ... The patient made a satisfactory recovery from the ... right hip from 0° to 110° and his knee from 0° to 90°.

  5. Pump shaft failures - a compendium of case studies

    CSIR Research Space (South Africa)

    Bernt, F

    2001-04-01

    Full Text Available During operation, pump shafts usually suffer from degradation as a result of corrosion and/or mechanical degradation, usually in the form of fatigue failures. In many cases corrosion precedes fatigue failure and can actually accelerate the rate...

  6. Shaft extension design at the Underground Research Laboratory, Pinawa, Manitoba

    International Nuclear Information System (INIS)

    Kuzyk, G.W.; Ball, A.E.

    1991-01-01

    AECL Research has constructed an underground laboratory for the research and development required for the Canadian Nuclear Fuel Waste Management Program. The experimental program in the laboratory will contribute to the assessment of the feasibility and safety of nuclear fuel waste disposal deep in stable plutonic rock. In 1988, AECL extended the shaft of the Underground Research Laboratory (URL) from the existing 255 m depth to a depth of 443 m in cooperation with the United States Department of Energy. The project, which involved carrying out research activities while excavation and construction work was in progress, required careful planning. To accommodate the research programs, full-face blasting with a burn cut was used to advance the shaft. Existing facilities at the URL had to be modified to accommodate an expanded underground facility at a new depth. This paper discusses the design criteria, shaft-sinking methods and approaches used to accommodate the research work during this shaft extension project. (11 refs., 11 figs.)

  7. Comparison of tibial shaft ski fractures in children and adults.

    Science.gov (United States)

    Hamada, Tomo; Matsumoto, Kazu; Ishimaru, Daichi; Sumi, Hiroshi; Shimizu, Katsuji

    2014-09-01

    To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Descriptive epidemiological study. Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.

  8. Piezoceramics-based Devices for Active Balancing of Flexible Shafts

    NARCIS (Netherlands)

    Sloetjes, P.J.; de Boer, Andries; Sas, P.; De Munck, M.

    2006-01-01

    This paper focuses on vibration control of flexible shafts by means of rotorfixed piezoelectric materials. The target is to realize compact solutions for the suppression of problematic resonant vibration at so-called flexural critical speeds. For analysis, parametric finite element models of

  9. Displaced tibial shaft fractures treated with ASIF compression internal fixation

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Larsen, T K; Petersen, O C

    1990-01-01

    Fifty-one tibial shaft fractures treated by ASIF compression osteosynthesis were seen at follow-up at a median time of 46 weeks after injury. Twenty-four were open fractures and the patients received prophylactic antibiotics. The median stay in hospital was 15 days for open fractures and 6 days f...

  10. Simultaneous Ipsilateral fracture of the femoral neck and shaft ...

    African Journals Online (AJOL)

    Eight cases with fractures of The shaft and the neck of the same femur are described. Attention is drawn to the high incidence of undiagnosed fractures in cases where these two fractures occur concomitantly. It is emphasized that definitive treatment can only be planned after a full clinical and radiological examination.

  11. Residual stress analysis of drive shafts after induction hardening

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Guilherme Vieira Braga; Rocha, Alexandre da Silva; Nunes, Rafael Menezes, E-mail: lemos_gl@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Algre, RS (Brazil); Hirsch, Thomas Karl [Stiftung Institut für Werkstofftechnik (IWT), Bremen (Germany)

    2014-08-15

    Typically, for automotive shafts, shape distortion manifests itself in most cases after the induction hardening by an effect known as bending. The distortion results in a boost of costs, especially due to machining parts in the hardened state to fabricate its final tolerances. In the present study, residual stress measurements were carried out on automotive drive shafts made of DIN 38B3 steel. The samples were selected in consequence of their different distortion properties by an industrial manufacturing line. One tested shaft was straightened, because of the considerable dimensional variation and the other one not. Firstly, the residual stress measurements were carried out by using a portable diffractometer, in order to avoid cutting the shafts and evaluate the original state of the stresses, and afterwards a more detailed analysis was realized by a conventional stationary diffractometer. The obtained results presented an overview of the surface residual stress profiles after induction hardening and displayed the influence of the straightening process on the redistribution of residual stresses. They also indicated that the effects of the straightening in the residual stresses cannot be neglected. (author)

  12. 30 CFR 57.4261 - Shaft-station waterlines.

    Science.gov (United States)

    2010-07-01

    ....4261 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention... located at underground shaft stations and are part of the mine's fire protection system shall have at...

  13. Examination of reactor coolant pump shaft at Crystal River-3

    International Nuclear Information System (INIS)

    Hayner, G.O.; Frye, C.R.; Clary, M.D.

    1987-01-01

    A detailed examination was performed on a broken RCP shaft assembly. The primary fracture was located in a groove under the upper end of the hydrostatic bearing journal. Additionally, all four impeller-to-shaft bolts and one drive pin failed. Mechanical properties, bulk chemistry, hardness, and microstructure were normal for the A-286 material used for the shaft, bolts and pins. A zone of axial surface cracking was seen just above the top of the hydrostatic bearing journal. According to Yoon et.al. these cracks are caused by thermal fatigue resulting from turbulent hot and cold water mixing in this area and have a self limiting depth. The primary RCP shaft fracture was caused by high cycle fatigue. Crack initiation probably occurred during initial use of the RCP and according to Yoon was caused by a combination postulated effect of comined surface residual stresses and stress concentration in the groove area. Several combinations of effects including broken impeller bolts probably were responsible for the initial crack propagation. Fracture mechanics testing results in 550 0 F air and simulated PWR water were used to estimate the stress intensity range of the primary crack and the crack propagation time by comparison of the fracture surface features. These estimates indicated that the propagation time was probably in the range from ≅ 191 to ≅ 323 days with a maximum stress intensity level of ≅ 30 ksi √(in). (orig.)

  14. KNBK for preparing well shafts for lowering casings

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, V B; Shchukin, R K

    1981-01-01

    The experience of preparing a well for reinforcement in the association ''Kuban'morneftegaz orom'' is shown using traditional KNBK of increasing hardness after the end of drilling the interval and KNBK included in the above-bit area of the flywheel, UBTS or blade stabilizers whose outer diameter is determined by calculation, and guarantees preparation of the shaft for reinforcement during rotary drilling.

  15. TNX/HLW Long Shaft Pumps 1995-2000

    International Nuclear Information System (INIS)

    VanPelt, B.

    2002-01-01

    Problems with long shaft pumps are becoming clearer due to increased use, better instrumentation, more analysis, and increased testing activity. The problems are with reliability and not with hydraulic performance. The root cause of reliability problems is usually excessive vibration caused by design. The outlook for satisfactory pumps is improved as understanding of problems increases. Promising developments are emerging such as the tilt pad bearing. Alternative configurations, such as gas filled columns and submerged motor pumps, will require development. Continued development, in general, should be expected due to changing technology and industry changes. This report describes thirteen distinct pump programs starting with leakage of original mixer pumps in the 1980s and ending with the testing of tilt pad bearings now in progress. Eight of the programs occurred from 1996 to 2000. All involve long shaft pumps; all involve testing at TNX; and all involve a problem of some kind. The co mmon technical issue among the activities is vibration and shaft (or rotor) instability due to journal bearings. In every case, excessive shaft vibration is a reasonable and probable explanation for some or all of the problems

  16. Non-standard equipment for construction of vertical shafts

    Science.gov (United States)

    Yagodkin, F. I.; Prokopov, A. Y.; Pleshko, M. S.; Pankratenko, A. N.

    2017-10-01

    The article deals with the modern problems of construction and reconstruction of vertical shafts of mines, which require innovative technical solutions in the mechanization of mining operations. The examples developed by the authors of the original equipment and technologies, are successfully implemented for the mining industry in Russia.

  17. Seismic fragility capacity of equipment--horizontal shaft pump test

    International Nuclear Information System (INIS)

    Iijima, T.; Abe, H.; Suzuki, K.

    2005-01-01

    The current seismic fragility capacity of horizontal shaft pump is 1.6 x 9.8 m/s 2 (1.6 g), which was decided from previous vibration tests and we believe that it must have sufficient margin. The purpose of fragility capacity test is to obtain realistic seismic fragility capacity of horizontal shaft pump by vibration tests. Reactor Building Closed Cooling Water (RCW) Pump was tested as a typical horizontal shaft pump, and then bearings and liner rings were tested as important parts to evaluate critical acceleration and dispersion. Regarding RCW pump test, no damage was found, though maximum input acceleration level was 6 x 9.8 m/s 2 (6 g). Some kinds of bearings and liner rings were tested on the element test. Input load was based on seismic motion which was same with the RCW pump test, and maximum load was equivalent to over 20 times of design seismic acceleration. There was not significant damage that caused emergency stop of pump but degradation of surface roughness was found on some kinds of bearings. It would cause reduction of pump life, but such damage on bearings occurred under large seismic load condition that was equivalent to over 10 to 20 g force. Test results show that realistic fragility capacity of horizontal shaft pump would be at least four times as higher as current value which has been used for our seismic PSA. (authors)

  18. Construction of full-scale shaft seals in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Martino, J.B.; Dixon, D.A.; Onagi, D.; Kim, C-S; Holowick, B. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

    2011-07-01

    The Underground Research Laboratory (URL) was constructed to investigate concepts related to geological disposal of used nuclear fuel. This involved investigating the rock mass by undertaking in situ experiments using a multi disciplinary technical approach. The decision was made in 2003 to close the URL. Part of the closure process involved installing seals in the access and ventilation shafts at locations where they intersected an ancient thrust fault (Fracture Zone 2 -- FZ2). FZ2 is an active hydraulic pathway in the Lac du Bonnet batholith and this feature is the dominating structural and hydrogeological feature at the URL site. Above FZ2 the groundwater has a low salinity and is dominated by surface-related processes. With increasing depth in the batholith, surface-related effects decrease and the salinity of the groundwater increases to 90 g/L total dissolved solids. The decision to install the seals was made as part of the due diligence for the site closure to ensure that the saline groundwater located at depth down strike and below the thrust fault would not enter the closed underground openings and mix with less saline shallow groundwater. The construction of each seal involved the installation of a heavily reinforced low alkalinity concrete component keyed into the surrounding rock. The concrete supported and restrained a central clay-sand component, which was capped by an unreinforced concrete component. The clay-sand component spans the exposure of the thrust fault in each shaft. This paper describes the construction of the main shaft seal and the ventilation shaft seal. The construction of the shaft seals at the URL was part of the Nuclear Legacy Liabilities Program (NLLP) being funded by Natural Resources Canada (NRCan). (author)

  19. Construction of full-scale shaft seals in crystalline rock

    International Nuclear Information System (INIS)

    Martino, J.B.; Dixon, D.A.; Onagi, D.; Kim, C-S; Holowick, B.

    2011-01-01

    The Underground Research Laboratory (URL) was constructed to investigate concepts related to geological disposal of used nuclear fuel. This involved investigating the rock mass by undertaking in situ experiments using a multi disciplinary technical approach. The decision was made in 2003 to close the URL. Part of the closure process involved installing seals in the access and ventilation shafts at locations where they intersected an ancient thrust fault (Fracture Zone 2 -- FZ2). FZ2 is an active hydraulic pathway in the Lac du Bonnet batholith and this feature is the dominating structural and hydrogeological feature at the URL site. Above FZ2 the groundwater has a low salinity and is dominated by surface-related processes. With increasing depth in the batholith, surface-related effects decrease and the salinity of the groundwater increases to 90 g/L total dissolved solids. The decision to install the seals was made as part of the due diligence for the site closure to ensure that the saline groundwater located at depth down strike and below the thrust fault would not enter the closed underground openings and mix with less saline shallow groundwater. The construction of each seal involved the installation of a heavily reinforced low alkalinity concrete component keyed into the surrounding rock. The concrete supported and restrained a central clay-sand component, which was capped by an unreinforced concrete component. The clay-sand component spans the exposure of the thrust fault in each shaft. This paper describes the construction of the main shaft seal and the ventilation shaft seal. The construction of the shaft seals at the URL was part of the Nuclear Legacy Liabilities Program (NLLP) being funded by Natural Resources Canada (NRCan). (author)

  20. Magnetic shaft seals prevent hazardous leakage from wastewater agitators

    International Nuclear Information System (INIS)

    Traino, F.A.

    1985-01-01

    The US Department of Energy's laboratory in Miamisburg, OH, operated by Monsanto Research Corporation, processes approximately 45,000 gallons per week of low-level radioactive wastewater to meet Federal Environmental Protection Agency quality standards. Preventing the spread of radioactive contamination throughout the operating area demands effective sealing of all process piping, valves, pumps, and agitators. Rotating shafts of pumps and agitators installed a the start of operations in 1947 were sealed by stuffing glands with graphite impregnated asbestos packing. These pumps proved to be unsatisfactory. In the mid-1970's, new process pumps with mechanical seals and some with magnetic drives were installed. Later, in January 1979, new agitator shaft drives with double tandem, spring-loaded mechanical seals were installed, maintenance of these pumps was costly. The agitator drive shafts were redesigned to accommodate magnetic seals of the type successfully used in blowers and vacuum/pressure pumps in other plant locations. One inherent advantage of the magnetic seal is that it operates with a face loading as much as 50% less than a conventional spring-loaded mechanical seal. The lower loading by a predetermined uniform magnetic force contributes to long face life. Other advantages include compactness, ease of assembly with only a few parts, and insensitivity to vibration. The magnetic shaft seals installed on the agitator shafts in February 1983 are still in service without any leakage or need for maintenance. Based on current operating data and a projected five-year meantime between failures, the estimated cost benefit of the magnetic seals over spring-loaded mechanical seals over spring-loaded mechanical seals will be $640 vs $2400 respectively per seal, with 60% less downtime for maintenance

  1. The effects of intraoperative positioning on patients undergoing early definitive care for femoral shaft fractures.

    Science.gov (United States)

    Apostle, K L; Lefaivre, K A; Guy, P; Broekhuyse, H M; Blachut, P A; O'Brien, P J; Meek, R N

    2009-10-01

    To determine if there is a difference in morbidity and mortality in orthopaedic trauma patients with femoral shaft fractures undergoing early definitive care with intramedullary (IM) nails in the supine versus the lateral position. Retrospective cohort study, single centered. One level 1 trauma center. Nine hundred eighty-eight patients representing 1027 femoral shaft fractures treated with IM nails were identified through a prospectively gathered database between 1987 and 2006. Antegrade IM nail insertion with reaming of the femoral canal in either the supine or lateral position. Mortality was the primary outcome. Admission to intensive care unit (ICU) was the secondary outcome measure and a surrogate measure of morbidity. Literature review was performed to identify factors shown to contribute to morbidity and mortality in orthopaedic trauma patients. Intraoperative position in either the supine or lateral position was added to this list. Logistic regression analysis was performed to determine the magnitude and effect of the independent variables on each of the study end points. To determine if a more significant trend toward less favorable outcomes was observed with increasing severity of injury, particularly injuries of the chest and thorax, subgroup analysis was performed for all those with a femur fracture and an Injury Severity Score > or =18 and all those with a femur fracture and an Abbreviated Injury Score chest > or =3. Intraoperative position in either the supine or lateral position was not a significant predictor of mortality or ICU admission for the original cohort or the subgroup of Injury Severity Score > or =18. However, for the subgroup of Abbreviated Injury Score chest > or =3, intraoperative positioning in the lateral position had a statistically significant protective effect against ICU admission (P = 0.044). For polytrauma patients with femoral shaft fractures, surgical stabilization using IM nails inserted with reaming of the femoral canal in

  2. Covering and piercing disks with two centers

    KAUST Repository

    Ahn, Heekap; Kim, Sangsub; Knauer, Christian; Schlipf, Lena; Shin, Chansu; Vigneron, Antoine E.

    2013-01-01

    We give exact and approximation algorithms for two-center problems when the input is a set D of disks in the plane. We first study the problem of finding two smallest congruent disks such that each disk in D intersects one of these two disks. Then we study the problem of covering the set D by two smallest congruent disks. © 2012 Elsevier B.V.

  3. Covering and piercing disks with two centers

    KAUST Repository

    Ahn, Heekap

    2013-04-01

    We give exact and approximation algorithms for two-center problems when the input is a set D of disks in the plane. We first study the problem of finding two smallest congruent disks such that each disk in D intersects one of these two disks. Then we study the problem of covering the set D by two smallest congruent disks. © 2012 Elsevier B.V.

  4. Covering and piercing disks with two centers

    KAUST Repository

    Ahn, Heekap; Kim, Sangsub; Knauer, Christian; Schlipf, Lena; Shin, Chansu; Vigneron, Antoine E.

    2011-01-01

    We consider new versions of the two-center problem where the input consists of a set D of disks in the plane. We first study the problem of finding two smallest congruent disks such that each disk in intersects one of these two disks. Then we study the problem of covering the set D by two smallest congruent disks. We give exact and approximation algorithms for these versions. © 2011 Springer-Verlag.

  5. Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics.

    Science.gov (United States)

    Hayashi, Shinichi; Okada, Yasushi

    2015-05-01

    Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro-tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30-100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging. © 2015 Hayashi and Okada. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  6. Controlled blasting and its implications for the NNWSI project exploratory shaft

    International Nuclear Information System (INIS)

    Van Eeckhout, E.M.

    1987-09-01

    This report reviews controlled blasting techniques for shaft sinking. Presplitting and smooth blasting are the techniques of principal interest. Smooth blasting is preferred for the Nevada Nuclear Waste Storage Investigations exploratory shaft. Shaft damage can be monitored visually or by peak velocity measurements and refractive techniques. Damage into the rock should be limited to 3 ft. 40 refs., 22 figs., 7 tabs

  7. 10 CFR 60.134 - Design of seals for shafts and boreholes.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Design of seals for shafts and boreholes. 60.134 Section....134 Design of seals for shafts and boreholes. (a) General design criterion. Seals for shafts and... closure. (b) Selection of materials and placement methods. Materials and placement methods for seals shall...

  8. Designing vertical shafts for mines with deepening and outlet of rock to the operating level

    Energy Technology Data Exchange (ETDEWEB)

    Durov, Ye.M.

    1983-01-01

    Requirements for designing the cross sections of central shafts are examined, as well as those for determining the productivity of lifts and equipment of the shafts with a condition of use in a subsequent technological layout of their deepening with outlet of the rock to the operating level. Typical cross sections of skip and cellular shafts are given.

  9. Can disk be removed in a disk-and-washer structure

    International Nuclear Information System (INIS)

    Inagaki, Shigemi.

    1981-06-01

    A modified disk-and-washer structure, so to speak a coaxial coupled cavity structure, is proposed. It has not protrusions called disks at the inner surface of the cylinder. The thickness of the washer outer rim increases so much that it rather looks like a chain of accelerating cavities having slit around the outermost wall and through the slit they are coupled in a cylindrical cavity. SUPERFISH calculations show that both accelerating and coupling mode can be made confluent** in π-mode* operation and that the effective shunt impedance obtained under certain condition is 27 Mohm/m which is 10% less than that of KEK PF single cavity or scaled LASL side-coupled cavity. (author)

  10. Plutonium-241 processing: from impure oxide to high purity metal target disks

    International Nuclear Information System (INIS)

    Conner, W.V.; Baaso, D.L.

    1975-01-01

    The preparation of three plutonium-241 metal target disks, using a precision casting technique, is described. The disks were 0.625 inch in diameter and 0.125, 0.025, and 0.010 inch thick. All three disks were prepared simultaneously in a single casting. The variation in thickness of each disk was within +-1 percent of the disk's average thickness. The plutonium-241 was highly pure, and the finished disks contained a total of only 297 parts per million of detectable impurities. Purification of the plutonium oxide ( 241 PuO 2 ) and the conversion of the purified 241 PuO 2 to metal are also described. (U.S.)

  11. Broadband, Low Sidelobe, Zero Height, Slotted Circular Disk Antenna

    African Journals Online (AJOL)

    A rigorous mathematical theory for a rotationally symmetrical slotted circular disk antenna was developed. The theory applies the principle of "Gradient Invariance" of electromagnetic fields to determine the field components that are unique and single valued at any point in space. To detemine the radiation characteristics of ...

  12. Vibration-Based Data Used to Detect Cracks in Rotating Disks

    Science.gov (United States)

    Gyekenyesi, Andrew L.; Sawicki, Jerzy T.; Martin, Richard E.; Baaklini, George Y.

    2004-01-01

    Rotor health monitoring and online damage detection are increasingly gaining the interest of aircraft engine manufacturers. This is primarily due to the fact that there is a necessity for improved safety during operation as well as a need for lower maintenance costs. Applied techniques for the damage detection and health monitoring of rotors are essential for engine safety, reliability, and life prediction. Recently, the United States set the ambitious goal of reducing the fatal accident rate for commercial aviation by 80 percent within 10 years. In turn, NASA, in collaboration with the Federal Aviation Administration, other Federal agencies, universities, and the airline and aircraft industries, responded by developing the Aviation Safety Program. This program provides research and technology products needed to help the aerospace industry achieve their aviation safety goal. The Nondestructive Evaluation (NDE) Group of the Optical Instrumentation Technology Branch at the NASA Glenn Research Center is currently developing propulsion-system-specific technologies to detect damage prior to catastrophe under the propulsion health management task. Currently, the NDE group is assessing the feasibility of utilizing real-time vibration data to detect cracks in turbine disks. The data are obtained from radial blade-tip clearance and shaft-clearance measurements made using capacitive or eddy-current probes. The concept is based on the fact that disk cracks distort the strain field within the component. This, in turn, causes a small deformation in the disk's geometry as well as a possible change in the system's center of mass. The geometric change and the center of mass shift can be indirectly characterized by monitoring the amplitude and phase of the first harmonic (i.e., the 1 component) of the vibration data. Spin pit experiments and full-scale engine tests have been conducted while monitoring for crack growth with this detection methodology. Even so, published data are

  13. Determination of the critical bending speeds of a multy-rotor shaft from the vibration signal analysis

    Science.gov (United States)

    Crâştiu, I.; Nyaguly, E.; Deac, S.; Gozman-Pop, C.; Bârgău, A.; Bereteu, L.

    2018-01-01

    The purpose of this paper is the development and validation of an impulse excitation technique to determine flexural critical speeds of a single rotor shaft and multy-rotor shaft. The experimental measurement of the vibroacoustic response is carried out by using a condenser microphone as a transducer. By the means of Modal Analysis using Finite Element Method (FEM), the natural frequencies and shape modes of one rotor and three rotor specimens are determined. The vibration responses of the specimens, in simple supported conditions, are carried out using algorithms based on Fast Fourier Transform (FFT). To validate the results of the modal parameters estimated using Finite Element Analysis (FEA) these are compared with experimental ones.

  14. Interventions for treating femoral shaft fractures in children and adolescents.

    Science.gov (United States)

    Madhuri, Vrisha; Dutt, Vivek; Gahukamble, Abhay D; Tharyan, Prathap

    2014-12-01

    Fractures of the femoral shaft in children are relatively uncommon but serious injuries that disrupt the lives of children and their carers and can result in significant long-term disability. Treatment involves either surgical fixation, such as intramedullary nailing or external fixation, or conservative treatment involving prolonged immobilisation, often in hospital. To assess the effects (benefits and harms) of interventions for treating femoral shaft fractures in children and adolescents. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (accessed 16 August 2013), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2013 Issue 7), MEDLINE (1946 to August Week 1 2013), EMBASE (1980 to 2012 week 9), CINAHL (16 August 2013), clinical trials registries, conference proceedings and reference lists; and contacted trial authors and experts in the field. Randomised and quasi-randomised controlled trials comparing conservative and surgical interventions for diaphyseal fractures of the femur in children under 18 years of age. Our primary outcomes were functional outcome measures, unacceptable malunion, and serious adverse events. Two authors independently screened and selected trials, assessed risk of bias and extracted data. We assessed the overall quality of the evidence for each outcome for each comparison using the GRADE approach. We pooled data using a fixed-effect model. We included 10 trials (six randomised and four quasi-randomised) involving a total of 527 children (531 fractures). All trials were at some risk of bias, including performance bias as care provider blinding was not practical, but to a differing extent. Just one trial was at low risk of selection bias. Reflecting both the risk of bias and the imprecision of findings, we judged the quality of evidence to be 'low' for most outcomes, meaning that we are unsure about the estimates of effect. Most trials failed to report on self-assessed function or when

  15. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  16. Analysis of optimum wire rope configuration for equal unidirectional torsional stiffness for flexible steering shaft

    Directory of Open Access Journals (Sweden)

    Hussain Najaf

    2016-01-01

    Full Text Available The design and modeling of Low Stiffness Resilience Shaft (LSRS for the Semi-Active Steering (SAS system using wire ropes is discussed in this paper, along with the static structural torsion test simulation of the wire ropes in order to determine the best possible configuration which serves the purpose of an LSRS. The importance of this study arises due to the unidirectional torsional properties of a wire rope. For an effective operational LSRS, the wire ropes need to have similar angular deflection in both the clockwise and anti-clockwise direction. LSRS, an integral component of the SAS is a flexible shaft that can replace the conventional rigid shaft of the steering system and allows active control to be performed. 3D solid models of the simple strand and the 4 strand wire ropes used in finite element analysis were generated in CAD software SolidWorksTM. The single strand and the different configuration of wire ropes required to function the LSRS effectively were then analyzed using Finite element simulation in ANSYSTM. A single wire rope could not be used because its construction has inconsistency in the torsional stiffness in clockwise and anti-clockwise direction. The single-strand right-direction lay wire rope is found to have 16.05% angular deflection percentage difference in the clockwise and anticlockwise directions which indicates that using a single strand wire rope for the LSRS will cause the vehicle to have a variable response in the clockwise and anti clockwise direction upon turning the steering wheel. Due to this inconsistency, two variations namely Variation 1 and Variation 2 with arrangement of 4 strand wire rope were devised so that the angular deflection percentage difference would be negligible. Simulation results indicated that Variation 1 of the two variations with an angular deflection percentage difference of 0.34% in the clockwise and anti-clockwise direction respectively is best suited for the use in LSRS as it has

  17. Shaft sealing issue in CO2 storage sites

    Science.gov (United States)

    Dieudonné, A.-C.; Charlier, R.; Collin, F.

    2012-04-01

    Carbon capture and storage is an innovating approach to tackle climate changes through the reduction of greenhouse gas emissions. Deep saline aquifers, depleted oil and gas reservoirs and unmineable coal seams are among the most studied reservoirs. However other types of reservoir, such as abandonned coal mines, could also be used for the storage of carbon dioxide. In this case, the problem of shaft sealing appears to be particularly critical regarding to the economic, ecologic and health aspects of geological storage. The purpose of the work is to study shaft sealing in the framework of CO2 storage projects in abandoned coal mines. The problem of gas transfers around a sealing system is studied numerically using the finite elements code LAGAMINE, which has been developped for 30 years at the University of Liege. A coupled hydro-mechanical model of unsaturated geomaterials is used for the analyses. The response of the two-phase flow model is first studied through a simple synthetic problem consisting in the injection of gas in a concrete-made column. It stands out of this first modeling that the advection of the gas phase represents the main transfer mechanism of CO2 in highly unsaturated materials. Furthermore the setting of a bentonite barrier seal limits considerably the gas influx into the biosphere. A 2D axisymetric hydromechanical modeling of the Anderlues natural gas storage site is then performed. The geological and hydrogeological contexts of the site are used to define the problem, for the initial and boundary conditions, as well as the material properties. In order to reproduce stress and water saturation states in the shale before CO2 injection in the mine, different phases corresponding to the shaft sinking, the mining and the set up of the sealing system are simulated. The system efficiency is then evaluated by simulating the CO2 injection with the imposed pressure at the shaft wall. According to the modeling, the low water saturation of concrete and

  18. CT recognition of lateral lumbar disk herniation

    International Nuclear Information System (INIS)

    Williams, A.L.; Haughton, V.M.; Daniels, D.L.; Thornton, R.S.

    1982-01-01

    Although computed tomography (CT) has been shown to be useful in diagnosing posterolateral and central lumbar disk herniations, its effectiveness in demonstrating lateral herniated disks has not been emphasized. The myelographic recognition of those herniations may be difficult because root sheaths or dural sacs may not be deformed. A total of 274 CT scans interpreted as showing lumbar disk herniation was reviewed. Fourteen (5%) showed a lateral disk herniation. The CT features of a lateral herniated disk included: (1) focal protrusion of the disk margin within or lateral to the intervertebral foramen: (2) displacement of epidural fat within the intervertebral foramen; (3) absence of dural sac deformity; and (4) soft-tissue mass within or lateral to the intervertebral foramen. Because it can image the disk margin and free disk fragments irrespective of dural sac or root sheath deformity, CT may be more effective than myelography for demonstrating the presence and extent of lateral disk herniation

  19. Numerical Analysis of The Effect of Hydrodynamics and Operating Conditions on Biodiesel Synthesis in a Rotor-Stator Spinning Disk Reactor

    Directory of Open Access Journals (Sweden)

    Wen Zhuqing

    2017-06-01

    Full Text Available A rotor-stator spinning disk reactor for intensified biodiesel synthesis is described and numerically simulated in the present research. The reactor consists of two flat disks, located coaxially and parallel to each other with a gap ranging from 0.1 mm to 0.2 mm between the disks. The upper disk is located on a rotating shaft while the lower disk is stationary. The feed liquids, triglycerides (TG and methanol are injected into the reactor from centres of rotating disk and stationary disk, respectively. Fluid hydrodynamics in the reactor for synthesis of biodiesel from TG and methanol in the presence of a sodium hydroxide catalyst are simulated, using convection-diffusion-reaction multicomponent transport model with the CFD software ANSYS©Fluent v. 13.0. Effect of operating conditions on TG conversion is particularly investigated. Simulation results indicate that there is occurrence of back flow close to the stator at the outlet zone. Small gap size and fast rotational speed generally help to intensify mixing among reagents, and consequently enhance TG conversion. However, increasing rotational speed of spinning disk leads to more backflow, which decreases TG conversion. Large flow rate of TG at inlet is not recommended as well because of the short mean residence time of reactants inside the reactor.

  20. Development of a novel cold forging process to manufacture eccentric shafts

    Science.gov (United States)

    Pasler, Lukas; Liewald, Mathias

    2018-05-01

    Since the commercial usage of compact combustion engines, eccentric shafts have been used to transform translational into rotational motion. Over the years, several processes to manufacture these eccentric shafts or crankshafts have been developed. Especially for single-cylinder engines manufactured in small quantities, built crankshafts disclose advantages regarding tooling costs and performance. Those manufacturing processes do have one thing in common: They are all executed at elevated temperatures to enable the material to be formed to high forming degree. In this paper, a newly developed cold forging process is presented, which combines lateral extrusion and shifting for manufacturing a crank in one forming operation at room temperature. In comparison to the established upsetting and shifting methods to manufacture such components, the tool cavity or crank web thickness remains constant. Therefore, the developed new process presented in this paper consists of a combination of shifting and extrusion of the billet, which allows pushing material into the forming zone during shifting. In order to reduce the tensile stresses induced by the shifting process, compressive stresses are superimposed. It is expected that the process limits will be expanded regarding the horizontal displacement and form filling. In the following report, the simulation and design of the tooling concept are presented. Experiments were conducted and compared with corresponding simulation results afterwards.

  1. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  2. Determining basic parameters of shafts with cage hoisting systems in mines with steep seams

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.

    1982-05-01

    This paper analyzes problems associated with increasing depth of mine shafts in operating coal mines. Schemes of shaft excavation in mines with steep coal seams are analyzed. Removal of mine rock and the ground surface by existing mine shafts is most economical in most cases. Yuzhgiproshakht has investigated a number of hoisting schemes during mine shaft excavation in order to select the optimum shaft diameter which permits shaft reconstruction and deepening to be optimized. The following conditions are analyzed: coal output of a coal mine ranges from 0.9 megatons (Mt) to 1.8 Mt/year, mining depth ranges from 600 m to 1600 m (with intermediary depth of 800, 1000, 1200 and 1400 m also considered). Separate hoisting of coal and rock waste is used. Shaft sinking rate ranges from 10 to 50 m/month. The following hoisting schemes are analyzed: two independent systems which consist of a cage with counterweight, three systems of a cage with counterweight, double cage system and a cage with counterweight. Hoisting schemes are shown in 9 diagrams. Investigations show that a 7 to 8 m diameter of mine shafts is most economic. In mine shafts 7 m in diameter equipped with two cages with counterweights one of the cages is removed to form a free space for the hoisting bucket. In the 8 m shaft equipped with a double cage system and a cage with counterweight the cage with counterweight is removed to form a free place for the hoisting bucket used during shaft excavation.

  3. Parallel Readout of Optical Disks

    Science.gov (United States)

    1992-08-01

    r(x,y) is the apparent reflectance function of the disk surface including the phase error. The illuminat - ing optics should be chosen so that Er(x,y...of the light uniformly illuminat - ing the chip, Ap = 474\\im 2 is the area of photodiode, and rs is the time required to switch the synapses. Figure...reference beam that is incident from the right. Once the hologram is recorded the input is blocked and the disk is illuminat - ed. Lens LI takes the

  4. Coupling with concentric contact around motor shaft for line start synchronous motor

    Science.gov (United States)

    Melfi, Michael J.; Burdeshaw, Galen E.

    2017-10-03

    A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

  5. Classical Measurement Methods and Laser Scanning Usage in Shaft Hoist Assembly Inventory

    Science.gov (United States)

    Jaśkowski, Wojciech; Lipecki, Tomasz; Matwij, Wojciech; Jabłoński, Mateusz

    2018-03-01

    The shaft hoist assembly is the base of underground mining plant. Its efficiency and correct operation is subject to restrictive legal regulations and is controlled on a daily visual assessment by shaft crew and energomechanics. In addition, in the regular interval, the shaft hoist assembly is subject to a thorough inventory, which includes the determination of the geometrical relationships between the hoisting machine, the headframe and the shaft with its housing. Inventory measurements for shaft and headframe are used for years of conventional geodetic methods including mechanical or laser plumbing and tachymetric surveys. Additional precision levelling is also used for measuring shafts of hoisting machines and rope pulleys. Continuous modernization of measuring technology makes it possible to implement the further methods to the above mentioned purposes. The comparison of the accuracy and the economics of performing measurements based on many years of experience with comprehensive inventory of shaft hoist assembly using various research techniques was made and detailed in the article.

  6. Effect of centrifugal force on natural frequency of lateral vibration of rotating shafts

    Science.gov (United States)

    Behzad, M.; Bastami, A. R.

    2004-07-01

    This paper investigates the effect of shaft rotation on its natural frequency. Apart from gyroscopic effect, the axial force originated from centrifugal force and the Poisson effect results in change of shaft natural frequency. D'Alembert principle for shaft in cylindrical co-ordinate system, along with the stress-strain relation, gives the non-homogenous linear differential equation, which can be used to calculate axial stress in the shaft. Numerical results of this study show that axial stress produced by shaft rotation has a major effect on the natural frequency of long high-speed shafts, while shaft diameter has no influence on the results. In addition, change in lateral natural frequency due to gyroscopic effect is compared with the results of this study.

  7. The Disk Mass Project: breaking the disk-halo degeneracy

    NARCIS (Netherlands)

    Verheijen, Marc A. W.; Bershady, Matthew A.; Swaters, Rob A.; Andersen, David R.; Westfall, Kyle B.; DE JONG, R. S.

    2007-01-01

    Little is known about the content and distribution of dark matter in spiral galaxies. To break the degeneracy in galaxy rotation curve decompositions, which allows a wide range of dark matter halo density profiles, an independent measure of the mass surface density of stellar disks is needed. Here,

  8. Asymmetry in gait pattern following tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

    2017-01-01

    INTRODUCTION: Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12...... months post-operatively following intramedullary nailing of a tibial shaft fracture are different compared with a healthy reference population. PATIENTS AND METHODS: The study design was a prospective cohort study. The primary outcome measurement was the gait patterns at 6 and 12 months post......-operatively measured with a 6-metre-long pressure-sensitive mat. The mat registers footprints and present gait speed, cadence as well as temporal and spatial parameters of the gait cycle. Gait patterns were compared to a healthy reference population. RESULTS: 49 patients were included with a mean age of 43.1 years (18...

  9. Bilateral simultaneous femoral neck and shafts fractures - a case report.

    Science.gov (United States)

    Sadeghifar, Amirreza; Saied, Alireza

    2014-10-01

    Simultaneous fractures of the femoral neck and shaft are not common injuries, though they cannot be considered rare. Herein, we report our experience with a patient with bilateral occurance of this injury. Up to the best of our knowkedge this is the first case reported in literature in which correct diagnosis was made initially. Both femurs were fixed using broad 4.5 mm dynamic compression plate and both necks were fixed using 6.5 mm cannulated screws. Femur fixation on one side was converted to retrograde nailing because of plate failure. Both neck fractures healed uneventfully. In spite of rarity of concomitant fractures of femoral neck and shaft, this injury must be approached carefully demanding especial attention and careful device selection.

  10. Interim reclamation report: Basalt Waste Isolation Project exploration shaft site

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-02-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. Extensive studies of the geotechnical aspects of the site were undertaken, including preparations for drilling a large diameter Exploratory Shaft. This report describes the development of the reclamation program for the Exploratory Shaft Facility, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 43 refs., 19 figs., 9 tabs

  11. Vertically loaded pivot bearing for high-speed shafts

    International Nuclear Information System (INIS)

    Zippe, G.; Werner, D.; Keller, A.; Stephan, E.

    1974-01-01

    The pivot bearing subjected to vertical loads has a pivot with a rounded end and a diametral slot and a cup-shaped recess in the bearing box. The end of the pivot and the recess constitute a gap which widens towards the periphery of the bearing. The bearing box carries an attachment with a clearance, the shape of a hollow cylinder and accomodating the pivot and its shaft. To feed the lubricating oil surrounding and filling the bearing there is a groove either in the wall of the clearance or at the end of the pivot in the direction of rotation of the shaft or against it. The oil carried to the support point flows back into the oil bath surrounding the bearing through a slot in the bearing box. (DG) [de

  12. Exploratory shaft facility preliminary designs - Gulf Interior Region salt domes

    International Nuclear Information System (INIS)

    1983-09-01

    The purpose of the Preliminary Design Report, Gulf Interior Region, is to provide a description of the preliminary design for an Exploratory Shaft Facility on the Richton Dome, Mississippi. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description and Construction Cost Estimate

  13. Integrated analysis of rock mass deformation within shaft protective pillar

    Directory of Open Access Journals (Sweden)

    Ewa Warchala

    2016-01-01

    Full Text Available The paper presents an analysis of the rock mass deformation resulting from mining in the vicinity of the shaft protection pillar. A methodology of deformation prediction is based on a deterministic method using Finite Element Method (FEM. The FEM solution is based on the knowledge of the geomechanical properties of the various geological formations, tectonic faults, types of mining systems, and the complexity of the behaviour of the rock mass. The analysis gave the stress and displacement fields in the rock mass. Results of the analysis will allow for design of an optimal mining system. The analysis is illustrated by an example of the shaft R-VIII Rudna Mine KGHM Polish Copper SA.

  14. Exploratory shaft facility preliminary designs - Paradox Basin. Technical report

    International Nuclear Information System (INIS)

    1983-09-01

    The purpose of the Preliminary Design Report, Paradox Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Paradox Basin, Utah. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling Method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers is included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references

  15. Jets, black holes and disks in blazars

    Directory of Open Access Journals (Sweden)

    Ghisellini Gabriele

    2013-12-01

    Full Text Available The Fermi and Swift satellites, together with ground based Cherenkov telescopes, has greatly improved our knowledge of blazars, namely Flat Spectrum Radio Quasars and BL Lac objects, since all but the most powerful emit most of their electro–magnetic output at γ–ray energies, while the very powerful blazars emit mostly in the hard X–ray region of the spectrum. Often they show coordinated variability at different frequencies, suggesting that in these cases the same population of electrons is at work, in a single zone of the jet. The location of this region along the jet is a matter of debate. The jet power correlates with the mass accretion rate, with jets existing at all values of disk luminosities, measured in Eddington units, sampled so far. The most powerful blazars show clear evidence of the emission from their disks, and this has revived methods of finding the black hole mass and accretion rate by modelling a disk spectrum to the data. Being so luminous, blazars can be detected also at very high redshift, and therefore are a useful tool to explore the far universe. One interesting line of research concerns how heavy are their black holes at high redshifts. If we associate the presence of a relativistic jets with a fastly spinning black hole, then we naively expect that the accretion efficiency is larger than for non–spinning holes. As a consequence, the black hole mass in jetted systems should grow at a slower rate. In turn, this would imply that, at high redshifts, the heaviest black holes should be in radio–quiet quasars. We instead have evidences of the opposite, challenging our simple ideas of how a black hole grows.

  16. SOLAR SYSTEM ANALOGS AROUND IRAS-DISCOVERED DEBRIS DISKS

    International Nuclear Information System (INIS)

    Chen, Christine H.; Sheehan, Patrick; Watson, Dan M.; Manoj, P.; Najita, Joan R.

    2009-01-01

    We have rereduced Spitzer IRS spectra and reanalyzed the spectral energy distributions (SEDs) of three nearby debris disks: λ Boo, HD 139664, and HR 8799. We find that the thermal emission from these objects is well modeled using two single temperature black body components. For HR 8799 - with no silicate emission features despite a relatively hot inner dust component (T gr = 150 K) - we infer the presence of an asteroid belt interior to and a Kuiper Belt exterior to the recently discovered orbiting planets. For HD 139664, which has been imaged in scattered light, we infer the presence of strongly forward scattering grains, consistent with porous grains, if the cold, outer disk component generates both the observed scattered light and thermal emission. Finally, careful analysis of the λ Boo SED suggests that this system possesses a central clearing, indicating that selective accretion of solids onto the central star does not occur from a dusty disk.

  17. Displaced tibial shaft fractures treated with ASIF compression internal fixation

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Larsen, T K; Petersen, O C

    1990-01-01

    Fifty-one tibial shaft fractures treated by ASIF compression osteosynthesis were seen at follow-up at a median time of 46 weeks after injury. Twenty-four were open fractures and the patients received prophylactic antibiotics. The median stay in hospital was 15 days for open fractures and 6 days f...... for closed fractures. There were complications in 26 cases, with deep infection in 9 cases. At present we cannot advocate the use of ASIF compression osteosynthesis for displaced tibial fractures....

  18. Torsional Moment Measurement on Bucket Wheel Shaft of Giant Machine

    Directory of Open Access Journals (Sweden)

    Jiří FRIES

    2011-06-01

    Full Text Available Bucket wheel loading at the present time (torsional moment on wheel shaft, peripheral cutting force is determined from electromotor incoming power or reaction force measured on gearbox hinge. Both methods together are weighted by steel construction absorption of driving units and by inertial forces of motor rotating parts. In the article is described direct method of the torsional moment measurement, which eliminates mentioned unfavourable impacts except absorption of steel construction of bucket wheel itself.

  19. Penile Shaft : An Unusual Location For Skin Tags

    Directory of Open Access Journals (Sweden)

    Thami Gurvinder P

    2003-01-01

    Full Text Available Skin tags or acrochordons, commonly observed in the flexural surfaces and various folds of skin, are more frequently encountered in presence of obesity, diagetes and old age. Although lesions are quite characteristic clinically, at times these need to be differentiated from warts, fibromas and other benign tumors of skin and their appendages. A rare case with presence of skin tags over the shaft of penis is described.

  20. Tibial shaft fracture and ankle injury - Case report

    Directory of Open Access Journals (Sweden)

    Caio Zamboni

    Full Text Available ABSTRACT The authors report on a case of tibial shaft fracture associated with ankle injury. The clinical, radiological and surgical characteristics are discussed. Assessment of associated injuries is often overlooked and these injuries are hard to diagnose. When torque occurs in the lower limb, the ankle becomes susceptible to simultaneous injury. It is essential to make careful assessment based on clinical, radiographic, intraoperative and postoperative characteristics in order to attain functional recovery.

  1. 3D MODELING OF DRIVE SHAFT OF A MONORAIL CONVEYOR

    Directory of Open Access Journals (Sweden)

    STĂNĂŞEL Iulian

    2016-11-01

    Full Text Available The conveyors are used to transport various products in successive steps until they reach their destination and to ensure cargo volumes to balance the flow buffer. The conveyors monorail type are used for the transfer of the products, piece by piece and they can be suspended and can operate at heights and different tasks. In this paper is presented a method for the design of the drive shaft of a monorail conveyor, by using CAD-CAE applications.

  2. Monitoring for shaft cracks on reactor recirculation pumps

    International Nuclear Information System (INIS)

    Kowal, M.G.; O'Brien, J.T. Jr.

    1989-01-01

    The article discusses the vibration characteristics associated with a boiling water reactor (BWR) recirculation pump. It also describes the application of diagnostic techniques and shaft crack theory to an on-line diagnostic monitoring system for reactor recirculation pumps employed at Philadelphia Electric Company's Peach Bottom Atomic Power Station. Specific emphasis is placed on the unique monitoring techniques associated with these variable speed vertical pumps

  3. A review of drilled shaft sealing for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1981-01-01

    Questions have been raised concerning the ability of the drillers of the exploratory shaft for the Basalt Waste Isolation program to develop an effective seal against water inflow down the annular space between the shaft casing and shaft wall into the mined chambers. We understand the need for shaft integrity and the concern of those responsible for the shaft planning. The purpose of this report is to give documentation to allay the fears of those who may have questions remaining in their minds concerning the prospects for a dry shaft. Included in this report are discussions of five projects where shaft sealing was effective in drilled shafts and one project where the material which is recommended for the exploratory shaft was used effectively in a conventional shaft. Also discussed is the recommended multitier approach toward shaft sealing which will, if adopted, use all of the current state of the art techniques to assure the watertightness of the shaft. It should be pointed out that none of the projects described here used all of the safeguards which are recommended in this program. If any of the materials and procedures recommended here are omitted, then of course the possibility increases for water migration through the casing-borehole annulus. It is our considered opinion that if the program recommended is adopted there will be no water inflow into the shaft, but if we are wrong or if, through human error, the program is not executed correctly, that we have devices and procedures available to us which will facilitate remedial work to perfect seal in the shaft. 4 refs., 3 figs., 1 tab

  4. What Sets the Radial Locations of Warm Debris Disks?

    Energy Technology Data Exchange (ETDEWEB)

    Ballering, Nicholas P.; Rieke, George H.; Su, Kate Y. L.; Gáspár, András, E-mail: ballerin@email.arizona.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2017-08-20

    The architectures of debris disks encode the history of planet formation in these systems. Studies of debris disks via their spectral energy distributions (SEDs) have found infrared excesses arising from cold dust, warm dust, or a combination of the two. The cold outer belts of many systems have been imaged, facilitating their study in great detail. Far less is known about the warm components, including the origin of the dust. The regularity of the disk temperatures indicates an underlying structure that may be linked to the water snow line. If the dust is generated from collisions in an exo-asteroid belt, the dust will likely trace the location of the water snow line in the primordial protoplanetary disk where planetesimal growth was enhanced. If instead the warm dust arises from the inward transport from a reservoir of icy material farther out in the system, the dust location is expected to be set by the current snow line. We analyze the SEDs of a large sample of debris disks with warm components. We find that warm components in single-component systems (those without detectable cold components) follow the primordial snow line rather than the current snow line, so they likely arise from exo-asteroid belts. While the locations of many warm components in two-component systems are also consistent with the primordial snow line, there is more diversity among these systems, suggesting additional effects play a role.

  5. ediatric femoral shaft fractures treated by flexible intramedullary nailing.

    Science.gov (United States)

    Kapil Mani, K C; Dirgha Raj, R C; Parimal, Acharya

    2015-01-01

    Nowadays pediatric femoral fractures are more commonly managed with operative treatment rather than conservative treatment because of more rapid recovery and avoidance of prolonged immobilization. Children between the ages of 5-13 years are treated either by traction plus hip spica and flexible/elastic stable retrograde intramedullary nail, or external fixators in the case of open fractures. The aim of this study is to evaluate the outcome of pediatric femoral shaft fractures treated by stainless steel flexible intramedullary nail in children between 5 and 13 years of age. There were 32 cases of femoral shaft fractures which were all fixed with stainless steel flexible intramedullary nail under fluoroscopy. Long leg cast was applied at the time of fixation. Partial weight bearing was started 2 weeks after surgery. Patients were evaluated in follow-up study to observe the alignment of fracture, infection, delayed union, nonunion, limb length discrepancy, motion of knee joint, and time to unite the fracture. We were able to follow up 28 out of 32 patients. The patients were 8.14 years of age on average. The mean hospital stay after operation was 4 days and fracture union time was 9.57 weeks. There were 3 cases of varus angulation, 2 cases of anterior angulation, and 4 cases of limb lengthening. Patients aged between 5 and 13 years treated with flexible intramedullary nail for closed femoral shaft fracture have rapid union and recovery, short rehabilitation period, less immobilization and psychological impact, and cost-effective.

  6. HOC Based Blind Identification of Hydroturbine Shaft Volterra System

    Directory of Open Access Journals (Sweden)

    Bing Bai

    2017-01-01

    Full Text Available In order to identify the quadratic Volterra system simplified from the hydroturbine shaft system, a blind identification method based on the third-order cumulants and a reversely recursive method are proposed. The input sequence of the system under consideration is an unobservable independent identically distributed (i.i.d., zero-mean and non-Gaussian stationary signal, and the observed signals are the superposition of the system output signal and Gaussian noise. To calculate the third-order moment of the output signal, a computer loop judgment method is put forward to determine the coefficient. When using optimization method to identify the time domain kernels, we combined the traditional optimization algorithm (direct search method with genetic algorithm (GA and constituted the hybrid genetic algorithm (HGA. Finally, according to the prototype observation signal and the time domain kernel parameters obtained from identification, the input signal of the system can be gained recursively. To test the proposed method, three numerical experiments and engineering application have been carried out. The results show that the method is applicable to the blind identification of the hydroturbine shaft system and has strong universality; the input signal obtained by the reversely recursive method can be approximately taken as the random excitation acted on the runner of the hydroturbine shaft system.

  7. Operating reliability of the shaft seal system of ANDRITZ RCP

    International Nuclear Information System (INIS)

    Grancy, Werner; Zehentner, Martin

    2002-01-01

    The next generation of nuclear power stations will have to fulfil new expectations in terms of safety, operating behaviour and costs. This applies also and especially to reactor coolant pumps for the primary circuit of pressurized water reactor type nuclear power plants (RCP). For 4 decades, ANDRITZ AG has developed and built RCPs and has attached great importance to the design of the complete pump rotor and of its essential surrounding elements, such as e. g. the shaft seal. Many questions concerning design and configuration of the shaft seal system cannot be answered purely theoretically, or they can only be answered partly. Therefore, comprehensive development work and testing was necessary to increase the operating reliability of the seal. Apart from all relevant questions connected with design and functioning of the pump there is one question of top priority: the operating reliability of the shaft seal system. Therefore it is intended to describe the current status of design and development of ANDRITZ RCP for future Korean NPPs, to present the most important design features and to give an introduction concerning experiences for a 3-stage-hydrodynamic seal as well as for a 2-stage-hydrodynamic seal

  8. Sealing considerations for repository shafts in bedded and dome salt

    International Nuclear Information System (INIS)

    1981-12-01

    The report reviews the geologic and hydrologic data base for penetration seal designs referenced to the Los Medanos bedded salt site in New Mexico and to four candidate salt domes in the Gulf Interior. Experience with existing shafts highlights the importance, for shaft decommissioning as well as operation, of achieving an adequate seal at and immediately below the top of salt. Possible construction procedures for repository shafts are reviewed, noting advantages and disadvantages with respect to repository sealing. At this stage, there does not appear to be a clear preference for excavation by drill and blast or by drilling. If conventional drill and blast methods are used, it may be necessary to grout in permeable zones above the salt. An important consideration with respect to sealing is that grouting operations (or freezing should it be used) should not establish connections between the top of salt and water-bearing zones higher in the stratigraphic section. Generally, it is concluded that Los Medanos and the dome salt sites are favorable candidate repository sites from the point of view of sealing

  9. Detection of cracks in shafts with the Approximated Entropy algorithm

    Science.gov (United States)

    Sampaio, Diego Luchesi; Nicoletti, Rodrigo

    2016-05-01

    The Approximate Entropy is a statistical calculus used primarily in the fields of Medicine, Biology, and Telecommunication for classifying and identifying complex signal data. In this work, an Approximate Entropy algorithm is used to detect cracks in a rotating shaft. The signals of the cracked shaft are obtained from numerical simulations of a de Laval rotor with breathing cracks modelled by the Fracture Mechanics. In this case, one analysed the vertical displacements of the rotor during run-up transients. The results show the feasibility of detecting cracks from 5% depth, irrespective of the unbalance of the rotating system and crack orientation in the shaft. The results also show that the algorithm can differentiate the occurrence of crack only, misalignment only, and crack + misalignment in the system. However, the algorithm is sensitive to intrinsic parameters p (number of data points in a sample vector) and f (fraction of the standard deviation that defines the minimum distance between two sample vectors), and good results are only obtained by appropriately choosing their values according to the sampling rate of the signal.

  10. Correlation of operating parameters on turbine shaft vibrations

    Science.gov (United States)

    Dixit, Harsh Kumar; Rajora, Rajeev

    2016-05-01

    The new generation of condition monitoring and diagnostics system plays an important role in efficient functioning of power plants. In most of the rotating machine, defects can be detected by such a system much before dangerous situation occurs. It allows the efficient use of stationary on-line continuous monitoring system for condition monitoring and diagnostics as well. Condition monitoring of turbine shaft can not only reduce expenses of maintenance of turbo generator of power plants but also prevents likely shutdown of plant, thereby increases plant load factor. Turbo visionary parameters are essential part of health diagnosis system of turbo generator. Particularly steam pressure, steam temperature and lube oil temperature are important parameters to monitor because they are having much influence on turbine shaft vibration and also governing systems are available for change values of those parameters. This paper includes influence of turbo visionary parameters i.e., steam temperature, steam pressure, lube oil temperature, turbine speed and load on turbine shaft vibration at turbo generator at 195 MW unit-6,Kota Super Thermal Power Station by measuring vibration amplitude and analyze them in MATLAB.

  11. Coevolution of Binaries and Circumbinary Gaseous Disks

    Science.gov (United States)

    Fleming, David; Quinn, Thomas R.

    2018-04-01

    The recent discoveries of circumbinary planets by Kepler raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disk, and how the disk and binary interact. The central binary excites resonances in the surrounding protoplanetary disk that drive evolution in both the binary orbital elements and in the disk. To probe how these interactions impact both binary eccentricity and disk structure evolution, we ran N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary disks surrounding binaries based on Kepler 38 for 10^4 binary orbital periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disk via a parametric instability and excite disk eccentricity growth. Eccentric binaries strongly couple to the disk causing eccentricity growth for both the disk and binary. Disks around sufficiently eccentric binaries strongly couple to the disk and develop an m = 1 spiral wave launched from the 1:3 eccentric outer Lindblad resonance (EOLR). This wave corresponds to an alignment of gas particle longitude of periastrons. We find that in all simulations, the binary semi-major axis decays due to dissipation from the viscous disk.

  12. THICK-DISK EVOLUTION INDUCED BY THE GROWTH OF AN EMBEDDED THIN DISK

    International Nuclear Information System (INIS)

    Villalobos, Alvaro; Helmi, Amina; Kazantzidis, Stelios

    2010-01-01

    We perform collisionless N-body simulations to investigate the evolution of the structural and kinematical properties of simulated thick disks induced by the growth of an embedded thin disk. The thick disks used in the present study originate from cosmologically common 5:1 encounters between initially thin primary disk galaxies and infalling satellites. The growing thin disks are modeled as static gravitational potentials and we explore a variety of growing-disk parameters that are likely to influence the response of thick disks. We find that the final thick-disk properties depend strongly on the total mass and radial scale length of the growing thin disk, and much less sensitively on its growth timescale and vertical scale height as well as the initial sense of thick-disk rotation. Overall, the growth of an embedded thin disk can cause a substantial contraction in both the radial and vertical direction, resulting in a significant decrease in the scale lengths and scale heights of thick disks. Kinematically, a growing thin disk can induce a notable increase in the mean rotation and velocity dispersions of thick-disk stars. We conclude that the reformation of a thin disk via gas accretion may play a significant role in setting the structure and kinematics of thick disks, and thus it is an important ingredient in models of thick-disk formation.

  13. [Total cervical disk replacement--implant-specific approaches: keel implant (Prodisc-C intervertebral disk prosthesis)].

    Science.gov (United States)

    Korge, Andreas; Siepe, Christoph J; Heider, Franziska; Mayer, H Michael

    2010-11-01

    Dynamic intervertebral support of the cervical spine via an anterolateral approach using a modular artificial disk prosthesis with end-plate fixation by central keel fixation. Cervical median or mediolateral disk herniations, symptomatic cervical disk disease (SCDD) with anterior osseous, ligamentous and/or discogenic narrowing of the spinal canal. Cervical fractures, tumors, osteoporosis, arthrogenic neck pain, severe facet degeneration, increased segmental instability, ossification of posterior longitudinal ligament (OPLL), severe osteopenia, acute and chronic systemic, spinal or local infections, systemic and metabolic diseases, known implant allergy, pregnancy, severe adiposity (body mass index > 36 kg/m2), reduced patient compliance, alcohol abuse, drug abuse and dependency. Exposure of the anterior cervical spine using the minimally invasive anterolateral approach. Intervertebral fixation of retainer screws. Intervertebral diskectomy. Segmental distraction with vertebral body retainer and vertebral distractor. Removal of end-plate cartilage. Microscopically assisted decompression of spinal canal. Insertion of trial implant to determine appropriate implant size, height and position. After biplanar image intensifier control, drilling for keel preparation using drill guide and drill bit, keel-cut cleaner to remove bone material from the keel cut, radiologic control of depth of the keel cut using the corresponding position gauge. Implantation of original implant under lateral image intensifier control. Removal of implant inserter. Functional postoperative care and mobilization without external support, brace not used routinely, soft brace possible for 14 days due to postoperative pain syndromes. Implantation of 100 cervical Prodisc-C disk prostheses in 78 patients (average age 48 years) at a single center. Clinical and radiologic follow-up 24 months postoperatively. Significant improvement based on visual analog scale and Neck Disability Index. Radiologic

  14. Compact objects and accretion disks

    NARCIS (Netherlands)

    Blandford, Roger; Agol, Eric; Broderick, Avery; Heyl, Jeremy; Koopmans, Leon; Lee, Hee-Won

    2002-01-01

    Recent developments in the spectropolarimetric study of compact objects, specifically black holes (stellar and massive) and neutron stars are reviewed. The lectures are organized around five topics: disks, jets, outflows, neutron stars and black holes. They emphasize physical mechanisms and are

  15. Disk Operating System User's Guide

    Science.gov (United States)

    1972-05-01

    This document serves the purpose of bringing together in one place most of the information a user needs to use the DDP-516 Disk Operating System, (DOS). DOS is a core resident, one user, console-oriented operating system which allows the user to cont...

  16. Gas Evolution in Protoplanetary Disks

    NARCIS (Netherlands)

    Woitke, Peter; Dent, Bill; Thi, Wing-Fai; Sibthorpe, Bruce; Rice, Ken; Williams, Jonathan; Sicilia-Aguilar, Aurora; Brown, Joanna; Kamp, Inga; Pascucci, Ilaria; Alexander, Richard; Roberge, Aki

    2009-01-01

    This article summarizes a Splinter Session at the Cool Stars XV conference in St. Andrews with 3 review and 4 contributed talks. The speakers have discussed various approaches to understand the structure and evolution of the gas component in protoplanetary disks. These ranged from observational

  17. Predictions for shepherding planets in scattered light images of debris disks

    International Nuclear Information System (INIS)

    Rodigas, Timothy J.; Hinz, Philip M.; Malhotra, Renu

    2014-01-01

    Planets can affect debris disk structure by creating gaps, sharp edges, warps, and other potentially observable signatures. However, there is currently no simple way for observers to deduce a disk-shepherding planet's properties from the observed features of the disk. Here we present a single equation that relates a shepherding planet's maximum mass to the debris ring's observed width in scattered light, along with a procedure to estimate the planet's eccentricity and minimum semimajor axis. We accomplish this by performing dynamical N-body simulations of model systems containing a star, a single planet, and an exterior disk of parent bodies and dust grains to determine the resulting debris disk properties over a wide range of input parameters. We find that the relationship between planet mass and debris disk width is linear, with increasing planet mass producing broader debris rings. We apply our methods to five imaged debris rings to constrain the putative planet masses and orbits in each system. Observers can use our empirically derived equation as a guide for future direct imaging searches for planets in debris disk systems. In the fortuitous case of an imaged planet orbiting interior to an imaged disk, the planet's maximum mass can be estimated independent of atmospheric models.

  18. On Fallback Disks around Young Neutron Stars

    Science.gov (United States)

    Alpar, M. Ali; Ertan, Ü.; Erkut, M. H.

    2006-08-01

    Some bound matter in the form of a fallback disk may be an initial parameter of isolated neutron stars at birth, which, along with the initial rotation rate and dipole (and higher multipole) magnetic moments, determines the evolution of neutron stars and the categories into which they fall. This talk reviews the possibilities of fallback disk models in explaining properties of isolated neutron stars of different categories. Recent observations of a fallback disk and observational limits on fallback disks will also be discussed.

  19. A large-diameter hollow-shaft cryogenic motor based on a superconducting magnetic bearing for millimeter-wave polarimetry.

    Science.gov (United States)

    Johnson, B R; Columbro, F; Araujo, D; Limon, M; Smiley, B; Jones, G; Reichborn-Kjennerud, B; Miller, A; Gupta, S

    2017-10-01

    In this paper, we present the design and measured performance of a novel cryogenic motor based on a superconducting magnetic bearing (SMB). The motor is tailored for use in millimeter-wave half-wave plate (HWP) polarimeters, where a HWP is rapidly rotated in front of a polarization analyzer or polarization-sensitive detector. This polarimetry technique is commonly used in cosmic microwave background polarization studies. The SMB we use is composed of fourteen yttrium barium copper oxide (YBCO) disks and a contiguous neodymium iron boron (NdFeB) ring magnet. The motor is a hollow-shaft motor because the HWP is ultimately installed in the rotor. The motor presented here has a 100 mm diameter rotor aperture. However, the design can be scaled up to rotor aperture diameters of approximately 500 mm. Our motor system is composed of four primary subsystems: (i) the rotor assembly, which includes the NdFeB ring magnet, (ii) the stator assembly, which includes the YBCO disks, (iii) an incremental encoder, and (iv) the drive electronics. While the YBCO is cooling through its superconducting transition, the rotor is held above the stator by a novel hold and release mechanism. The encoder subsystem consists of a custom-built encoder disk read out by two fiber optic readout sensors. For the demonstration described in this paper, we ran the motor at 50 K and tested rotation frequencies up to approximately 10 Hz. The feedback system was able to stabilize the rotation speed to approximately 0.4%, and the measured rotor orientation angle uncertainty is less than 0.15°. Lower temperature operation will require additional development activities, which we will discuss.

  20. A large-diameter hollow-shaft cryogenic motor based on a superconducting magnetic bearing for millimeter-wave polarimetry

    Science.gov (United States)

    Johnson, B. R.; Columbro, F.; Araujo, D.; Limon, M.; Smiley, B.; Jones, G.; Reichborn-Kjennerud, B.; Miller, A.; Gupta, S.

    2017-10-01

    In this paper, we present the design and measured performance of a novel cryogenic motor based on a superconducting magnetic bearing (SMB). The motor is tailored for use in millimeter-wave half-wave plate (HWP) polarimeters, where a HWP is rapidly rotated in front of a polarization analyzer or polarization-sensitive detector. This polarimetry technique is commonly used in cosmic microwave background polarization studies. The SMB we use is composed of fourteen yttrium barium copper oxide (YBCO) disks and a contiguous neodymium iron boron (NdFeB) ring magnet. The motor is a hollow-shaft motor because the HWP is ultimately installed in the rotor. The motor presented here has a 100 mm diameter rotor aperture. However, the design can be scaled up to rotor aperture diameters of approximately 500 mm. Our motor system is composed of four primary subsystems: (i) the rotor assembly, which includes the NdFeB ring magnet, (ii) the stator assembly, which includes the YBCO disks, (iii) an incremental encoder, and (iv) the drive electronics. While the YBCO is cooling through its superconducting transition, the rotor is held above the stator by a novel hold and release mechanism. The encoder subsystem consists of a custom-built encoder disk read out by two fiber optic readout sensors. For the demonstration described in this paper, we ran the motor at 50 K and tested rotation frequencies up to approximately 10 Hz. The feedback system was able to stabilize the rotation speed to approximately 0.4%, and the measured rotor orientation angle uncertainty is less than 0.15°. Lower temperature operation will require additional development activities, which we will discuss.

  1. Compact disk error measurements

    Science.gov (United States)

    Howe, D.; Harriman, K.; Tehranchi, B.

    1993-01-01

    The objectives of this project are as follows: provide hardware and software that will perform simple, real-time, high resolution (single-byte) measurement of the error burst and good data gap statistics seen by a photoCD player read channel when recorded CD write-once discs of variable quality (i.e., condition) are being read; extend the above system to enable measurement of the hard decision (i.e., 1-bit error flags) and soft decision (i.e., 2-bit error flags) decoding information that is produced/used by the Cross Interleaved - Reed - Solomon - Code (CIRC) block decoder employed in the photoCD player read channel; construct a model that uses data obtained via the systems described above to produce meaningful estimates of output error rates (due to both uncorrected ECC words and misdecoded ECC words) when a CD disc having specific (measured) error statistics is read (completion date to be determined); and check the hypothesis that current adaptive CIRC block decoders are optimized for pressed (DAD/ROM) CD discs. If warranted, do a conceptual design of an adaptive CIRC decoder that is optimized for write-once CD discs.

  2. Study on collapse mechanism of junction between greatly deeper shaft and horizontal drifts (Contract research)

    International Nuclear Information System (INIS)

    Kurosaki, Yukio; Yamachi, Hiroshi; Katsunuma, Yoshio; Nakata, Masao; Kuwahara, Hideki; Yamada, Fumitaka; Matsushita, Kiyoshi; Sato, Toshinori

    2008-03-01

    The Mizunami underground research laboratory is planned to consist of greatly deeper shaft and horizontal drifts. A junction space between a greatly deeper shaft and horizontal drifts forms which would take a complicated mechanical behavior during a junction excavation. However, a quantitative design method of supporting measures for a deep junction has not yet been established. This is because a conventional shaft design has been conducted based on past experience. Detail records have not been left either in what kind of collapses and deformed phenomena occurring in shaft constructions in a past. In order to examine a collapse mechanism of greatly deeper shaft junction, we have conducted literature surveys and interview studies concerned with deep shaft construction works in a past, and investigated what collapses or difficulties had been occurred in deep shaft junctions. Considering the results of investigations with reviews of intellectuals, a collapse mechanism of a super deep shaft junction depends on both a construction procedure of shaft junction and a geological condition at great depth. During a construction of a shaft junction, stress state of rock masses near junction wall would take a complicated stress path. Especially, it should be necessary to take a most careful consideration on that tangential stress acted around a shaft wall may reduce during horizontal drift excavation. On the other hand, where greatly deeper junction intersects faults and/or fractures with a large angle, a collapse called 'Take-nuke' may occur or extraordinary earth pressure acts on a concrete wall. This is the most typical difficulties during shaft construction. In order to recognize a mechanism of these phenomena and to find out a cause of collapse generation, numerical studies that can simulate a practical rock mass behavior around a shaft junction should be carry out. We demonstrate the finite difference method is most adequate for these simulations with intellectual review

  3. CIRCUMSTELLAR DEBRIS DISKS: DIAGNOSING THE UNSEEN PERTURBER

    Energy Technology Data Exchange (ETDEWEB)

    Nesvold, Erika R. [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Rd., Washington, DC 20015 (United States); Naoz, Smadar; Vican, Laura [Department of Physics and Astronomy, UCLA, 475 Portola Plaza, Los Angeles, CA 90095 (United States); Farr, Will M. [School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT (United Kingdom)

    2016-07-20

    The first indication of the presence of a circumstellar debris disk is usually the detection of excess infrared emission from the population of small dust grains orbiting the star. This dust is short-lived, requiring continual replenishment, and indicating that the disk must be excited by an unseen perturber. Previous theoretical studies have demonstrated that an eccentric planet orbiting interior to the disk will stir the larger bodies in the belt and produce dust via interparticle collisions. However, motivated by recent observations, we explore another possible mechanism for heating a debris disk: a stellar-mass perturber orbiting exterior to and inclined to the disk and exciting the disk particles’ eccentricities and inclinations via the Kozai–Lidov mechanism. We explore the consequences of an exterior perturber on the evolution of a debris disk using secular analysis and collisional N -body simulations. We demonstrate that a Kozai–Lidov excited disk can generate a dust disk via collisions and we compare the results of the Kozai–Lidov excited disk with a simulated disk perturbed by an interior eccentric planet. Finally, we propose two observational tests of a dust disk that can distinguish whether the dust was produced by an exterior brown dwarf or stellar companion or an interior eccentric planet.

  4. NASA Lunar and Meteorite Sample Disk Program

    Science.gov (United States)

    Foxworth, Suzanne

    2017-01-01

    The Lunar and Meteorite Sample Disk Program is designed for K-12 classroom educators who work in K-12 schools, museums, libraries, or planetariums. Educators have to be certified to borrow the Lunar and Meteorite Sample Disks by attending a NASA Certification Workshop provided by a NASA Authorized Sample Disk Certifier.

  5. PROTOPLANETARY DISK RESONANCES AND TYPE I MIGRATION

    International Nuclear Information System (INIS)

    Tsang, David

    2011-01-01

    Waves reflected by the inner edge of a protoplanetary disk are shown to significantly modify Type I migration, even allowing the trapping of planets near the inner disk edge for small planets in a range of disk parameters. This may inform the distribution of planets close to their central stars, as observed recently by the Kepler mission.

  6. A COMMON SOURCE OF ACCRETION DISK TILT

    International Nuclear Information System (INIS)

    Montgomery, M. M.; Martin, E. L.

    2010-01-01

    Many different system types retrogradely precess, and retrograde precession could be from a tidal torque by the secondary on a misaligned accretion disk. However, a source that causes and maintains disk tilt is unknown. In this work, we show that accretion disks can tilt due to a force called lift. Lift results from differing gas stream supersonic speeds over and under an accretion disk. Because lift acts at the disk's center of pressure, a torque is applied around a rotation axis passing through the disk's center of mass. The disk responds to lift by pitching around the disk's line of nodes. If the gas stream flow ebbs, then lift also ebbs and the disk attempts to return to its original orientation. To first approximation, lift does not depend on magnetic fields or radiation sources but does depend on the mass and the surface area of the disk. Also, for disk tilt to be initiated, a minimum mass transfer rate must be exceeded. For example, a 10 -11 M sun disk around a 0.8 M sun compact central object requires a mass transfer rate greater than ∼ 8 x 10 -11 M sun yr -1 , a value well below the known mass transfer rates in cataclysmic variable dwarf novae systems that retrogradely precess and exhibit negative superhumps in their light curves and a value well below mass transfer rates in protostellar-forming systems.

  7. Reamed intramedullary exchange nailing in the operative treatment of aseptic tibial shaft nonunion.

    Science.gov (United States)

    Hierholzer, Christian; Friederichs, Jan; Glowalla, Claudio; Woltmann, Alexander; Bühren, Volker; von Rüden, Christian

    2017-08-01

    The aim of this study was to evaluate a standardized treatment protocol regarding the rate of secondary bone union, complications, and functional outcome. This study was started as a prospective study in a single Level I Trauma Centre between 2003 and 2012. The study group consisted of 188 patients with the diagnosis of an aseptic tibial shaft nonunion. Exchange nailing was performed following a standardized surgical protocol. Long-term follow-up was analyzed for rate of bone healing and functional outcome. Osseous healing was achieved in 182 out of 188 patients (97 %). In 165 out of 188 patients (88 %), bone healing was observed timely and uneventfully after a single exchange nailing procedure. An open approach was necessary in 32 patients (17 %). Twenty-three patients (12 %) required additional therapy such as extracorporeal shock wave therapy. Post-operative complications were observed in seven patients (4 %). Almost all patients demonstrated osseous healing within 12 months, with the majority of osseous healing occurring within six months. A relevant shortening of the fractured tibia was observed in 20 out of 188 patients (11 %). After a median follow-up of 23 months (range 12-45 months), outcome was evaluated using the assessment system of Friedman/Wyman. In summary, 154 out of 188 patients (82 %) had a good functional long-term result. Reamed intramedullary exchange nailing including correction of axis alignment is a safe and effective treatment of aseptic tibial shaft nonunion with a high rate of bone healing and a good radiological and functional long-term outcome.

  8. Angular momentum transfer in steady disk accretion

    International Nuclear Information System (INIS)

    Gorbatskij, V.G.

    1977-01-01

    The conditions of steady disk accretion have been investigated. The disk axisymmetric model is considered. It is shown that the gas is let at the outer boundary of the disk with the azimuthal velocity which is slightly less than the Kepler circular one. Gas possesses the motion quality moment which is transferred from the outer layers of the disk to the surface of the star. The steady state of the disk preserved until the inflow of the moment to the star increases its rotation velocity up to magnitudes close to the critical one

  9. Multiple spiral patterns in the transitional disk of HD 100546

    Science.gov (United States)

    Boccaletti, A.; Pantin, E.; Lagrange, A.-M.; Augereau, J.-C.; Meheut, H.; Quanz, S. P.

    2013-12-01

    Context. Protoplanetary disks around young stars harbor many structures related to planetary formation. Of particular interest, spiral patterns were discovered among several of these disks and are expected to be the sign of gravitational instabilities leading to giant planet formation or gravitational perturbations caused by already existing planets. In this context, the star HD 100546 presents some specific characteristics with a complex gaseous and dusty disk that includes spirals, as well as a possible planet in formation. Aims: The objective of this study is to analyze high-contrast and high angular resolution images of this emblematic system to shed light on critical steps in planet formation. Methods: We retrieved archival images obtained at Gemini in the near IR (Ks band) with the instrument NICI and processed the data using an advanced high contrast imaging technique that takes advantage of the angular differential imaging. Results: These new images reveal the spiral pattern previously identified with Hubble Space Telescope (HST) with an unprecedented resolution, while the large-scale structure of the disk is mostly cancelled by the data processing. The single pattern to the southeast in HST images is now resolved into a multi-armed spiral pattern. Using two models of a gravitational perturber orbiting in a gaseous disk, we attempted to constrain the characteristics of this perturber, assuming that each spiral is independent, and drew qualitative conclusions. The non-detection of the northeast spiral pattern observed in HST allows putting a lower limit on the intensity ratio between the two sides of the disk, which if interpreted as forward scattering, yields a larger anisotropic scattering than is derived in the visible. Also, we find that the spirals are likely to be spatially resolved with a thickness of about 5-10 AU. Finally, we did not detect the candidate planet in formation recently discovered in the Lp band, with a mass upper limit of 16-18 MJ

  10. Dusty disks around central stars of planetary nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Geoffrey C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); De Marco, Orsola [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Nordhaus, Jason [Center for Computational Relativity and Gravitation, and National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623 (United States); Green, Joel [Department of Astronomy, The University of Texas, 1 University Station, C1400, Austin, TX 78712-0259 (United States); Rauch, Thomas; Werner, Klaus [Institute for Astronomy and Astrophysics, Kepler Center for Astro and Particle Physics, Eberhard Karls University, Sand 1, D-72076 Tübingen (Germany); Chu, You-Hua, E-mail: gclayton@fenway.phys.lsu.edu, E-mail: orsola@science.mq.edu.au, E-mail: nordhaus@astro.rit.edu, E-mail: joel@astro.as.utexas.edu, E-mail: rauch@astro.uni-tuebingen.de, E-mail: werner@astro.uni-tuebingen.de, E-mail: chu@astro.uiuc.edu [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

    2014-06-01

    Only a few percent of cool, old white dwarfs (WDs) have infrared excesses interpreted as originating in small hot disks due to the infall and destruction of single asteroids that come within the star's Roche limit. Infrared excesses at 24 μm were also found to derive from the immediate vicinity of younger, hot WDs, most of which are still central stars of planetary nebulae (CSPNe). The incidence of CSPNe with this excess is 18%. The Helix CSPN, with a 24 μm excess, has been suggested to have a disk formed from collisions of Kuiper belt-like objects (KBOs). In this paper, we have analyzed an additional sample of CSPNe to look for similar infrared excesses. These CSPNe are all members of the PG 1159 class and were chosen because their immediate progenitors are known to often have dusty environments consistent with large dusty disks. We find that, overall, PG 1159 stars do not present such disks more often than other CSPNe, although the statistics (five objects) are poor. We then consider the entire sample of CSPNe with infrared excesses and compare it to the infrared properties of old WDs, as well as cooler post-asymptotic giant branch (AGB) stars. We conclude with the suggestion that the infrared properties of CSPNe more plausibly derive from AGB-formed disks rather than disks formed via the collision of KBOs, although the latter scenario cannot be ruled out. Finally, there seems to be an association between CSPNe with a 24 μm excess and confirmed or possible binarity of the central star.

  11. Simulation on spread of fire smoke in the elevator shaft for a high-rise building

    Directory of Open Access Journals (Sweden)

    Yunchun Xia

    2014-01-01

    Full Text Available Spread of fire smoke in the elevator shaft of a high-rise building is influenced by many driving facts. We simulate smoke spreading in the elevator shaft, stair room, and pre-chamber with and without different supplied pressurized air. The simulation shows that smoke moves very fast in the elevator shaft. When a 12 floor high-rise building is in fire, smoke can fill up the elevator shaft in less than 1.5 min after a fire started, temperature in the elevator shaft can be higher than 187°C in 5 min, and the concentration of CO can also reach a high level. The elevator shaft has a very low visibility in less than about 100 s.

  12. Health monitoring system for transmission shafts based on adaptive parameter identification

    Science.gov (United States)

    Souflas, I.; Pezouvanis, A.; Ebrahimi, K. M.

    2018-05-01

    A health monitoring system for a transmission shaft is proposed. The solution is based on the real-time identification of the physical characteristics of the transmission shaft i.e. stiffness and damping coefficients, by using a physical oriented model and linear recursive identification. The efficacy of the suggested condition monitoring system is demonstrated on a prototype transient engine testing facility equipped with a transmission shaft capable of varying its physical properties. Simulation studies reveal that coupling shaft faults can be detected and isolated using the proposed condition monitoring system. Besides, the performance of various recursive identification algorithms is addressed. The results of this work recommend that the health status of engine dynamometer shafts can be monitored using a simple lumped-parameter shaft model and a linear recursive identification algorithm which makes the concept practically viable.

  13. Less invasive plate osteosynthesis in humeral shaft fractures.

    Science.gov (United States)

    Apivatthakakul, Theerachai; Phornphutkul, Chanakarn; Laohapoonrungsee, Anupong; Sirirungruangsarn, Yuddhasert

    2009-12-01

    Stable internal fixation of the humeral shaft by less invasive percutaneous plate insertion using two separate (proximal and distal) incisions, indirect reduction by closed manipulation and fixation to preserve the soft tissue and blood supply at the fracture zone. Early mobilization of the shoulder and elbow to ensure a good functional outcome. Humeral shaft fractures (classified according to AO classification as: 12-A, B, C). Humeral shaft fractures extending to the proximal or distal shaft, small or deformed medullary canal or open growth plate. Humeral shaft fractures with primary radial nerve palsy. Proximal humeral shaft fractures extending to the humeral head. Distal humeral fractures extending to the elbow joint. Two incisions proximal and distal to the fracture zone are used. A 3-cm proximal incision lies between the lateral border of the proximal part of the biceps and the medial border of the deltoid. Distally, a 3-cm incision is made along the lateral border of the biceps. The interval between biceps and brachialis is identified. The biceps is retracted medially to expose the musculocutaneous nerve. The brachialis muscle has dual innervation, the medial half being innervated by the musculocutaneous nerve and the lateral half by the radial nerve. The brachialis is split longitudinally at its midline. The musculocutaneous nerve is retracted along with the medial half of the brachialis, while the lateral half of the brachialis serves as a cushion to protect the radial nerve. A deep subbrachial tunnel is created from the distal to the proximal incision. The selected plate is tied with a suture to a hole at the tip of the tunneling instrument for pulling the plate back along the prepared track. The plate is aligned in the correct position on the anterior surface of the humerus. Traction is applied and the fracture reduced to restore alignment by image intensifier, followed by plate fixation with at least two bicortical locking screws or three bicortical

  14. Warm Debris Disks from WISE

    Science.gov (United States)

    Padgett, Deborah L.

    2011-01-01

    "The Wide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6, 12, and 22 microns. We report on a preliminary investigation of main sequence Hipparcos and Tycho catalog stars with 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages warm debris disk candidates are detected among FGK stars and a similar number of A stars within 120 pc. We are in the process of obtaining spectra to determine spectral types and activity level of these stars and are using HST, Herschel and Keck to characterize the dust, multiplicity, and substellar companions of these systems. In this contribution, we will discuss source selection methods and individual examples from among the WISE debris disk candidates. "

  15. MIT miniaturized disk bend test

    International Nuclear Information System (INIS)

    Harling, O.K.; Lee, M.; Sohn, D.S.; Kohse, G.; Lau, C.W.

    1983-01-01

    A miniaturized disk bend test (MDBT) using transmission electron microscopy specimens for the determination of various mechanical properties is being developed at MIT. Recent progress in obtaining strengths and ductilities of highly irradiated metal alloys is reviewed. Other mechanical properties can also be obtained using the MDBT approach. Progress in fatigue testing and in determination of the ductile-to-brittle transition temperature is reviewed briefly. 11 figures

  16. Fracture Failure Analysis of Fuel Pump Transmission Shaft of Dual-Fuel Engine

    Directory of Open Access Journals (Sweden)

    Chen Pei-hong

    2017-01-01

    Full Text Available NTS6ZLCz-129 dual-fuel turbocharged and intercooled engine durability test at 1000h, fuel pump shaft fractured. Fracture analysis, chemical analysis, microstructure examination and finite element stress analysis were carried out on the fractured shaft. The analysis result showed that the shaft fracture cause is forging fold. By improving the forging process, the forging fold was solved, and the durability test can be carried out smoothly.

  17. Fatigue criterion for the design of rotating shafts under combined stress

    Science.gov (United States)

    Loewenthal, S. H.

    1977-01-01

    A revised approach to the design of transmission shafting which considers the flexure fatigue characteristics of the shaft material under combined cyclic bending and static torsion stress is presented. A fatigue failure relation, corroborated by published combined stress test data, is presented which shows an elliptical variation of reversed bending endurance strength with static torsional stress. From this elliptical failure relations, a design formula for computing the diameter of rotating solid shafts under the most common condition of loading is developed.

  18. Gearbox Reliability Collaborative Investigation of Gearbox Motion and High-Speed-Shaft Loads

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jon [National Renewable Energy Lab. (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sethuraman, Latha [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-18

    This paper extends a model-to-test validation effort to examine the effect of different constant rotor torque and moment conditions and intentional generator misalignment on the gearbox motion and high-speed-shaft loads. Fully validating gearbox motion and high-speed-shaft loads across a range of test conditions is a critical precursor to examining the bearing loads, as the gearbox motion and high-speed-shaft loads are the drivers of these bearing loads.

  19. Fullerenes and disk-fullerenes

    International Nuclear Information System (INIS)

    Deza, M; Dutour Sikirić, M; Shtogrin, M I

    2013-01-01

    A geometric fullerene, or simply a fullerene, is the surface of a simple closed convex 3-dimensional polyhedron with only 5- and 6-gonal faces. Fullerenes are geometric models for chemical fullerenes, which form an important class of organic molecules. These molecules have been studied intensively in chemistry, physics, crystallography, and so on, and their study has led to the appearance of a vast literature on fullerenes in mathematical chemistry and combinatorial and applied geometry. In particular, several generalizations of the notion of a fullerene have been given, aiming at various applications. Here a new generalization of this notion is proposed: an n-disk-fullerene. It is obtained from the surface of a closed convex 3-dimensional polyhedron which has one n-gonal face and all other faces 5- and 6-gonal, by removing the n-gonal face. Only 5- and 6-disk-fullerenes correspond to geometric fullerenes. The notion of a geometric fullerene is therefore generalized from spheres to compact simply connected two-dimensional manifolds with boundary. A two-dimensional surface is said to be unshrinkable if it does not contain belts, that is, simple cycles consisting of 6-gons each of which has two neighbours adjacent at a pair of opposite edges. Shrinkability of fullerenes and n-disk-fullerenes is investigated. Bibliography: 87 titles

  20. A Pulsar and a Disk

    Science.gov (United States)

    Kohler, Susanna

    2016-07-01

    Recent, unusual X-ray observations from our galactic neighbor, the Small Magellanic Cloud, have led to an interesting model for SXP 214, a pulsar in a binary star system.Artists illustration of the magnetic field lines of a pulsar, a highly magnetized, rotating neutron star. [NASA]An Intriguing BinaryAn X-ray pulsar is a magnetized, rotating neutron star in a binary system with a stellar companion. Material is fed from the companion onto the neutron star, channeled by the objects magnetic fields onto a hotspot thats millions of degrees. This hotspot rotating past our line of sight is what produces the pulsations that we observe from X-ray pulsars.Located in the Small Magellanic Cloud, SXP 214 is a transient X-ray pulsar in a binary with a Be-type star. This star is spinning so quickly that material is thrown off of it to form a circumstellar disk.Recently, a team of authors led by JaeSub Hong (Harvard-Smithsonian Center for Astrophysics) have presented new Chandra X-ray observations of SXP 214, tracking it for 50 ks (~14 hours) in January 2013. These observations reveal some very unexpected behavior for this pulsar.X-ray PuzzleThe energy distribution of the X-ray emission from SXP 214 over time. Dark shades or blue colors indicate high counts, and light shades or yellow colors indicate low counts. Lower-energy X-ray emission appeared only later, after about 20 ks. [Hong et al. 2016]Three interesting pieces of information came from the Chandra observations:SXP 214s rotation period was measured to be 211.5 s an increase in the spin rate since the discovery measurement of a 214-second period. Pulsars usually spin down as they lose angular momentum over time so what caused this one to spin up?Its overall X-ray luminosity steadily increased over the 50 ks of observations.Its spectrum became gradually softer (lower energy) over time; in the first 20 ks, the spectrum only consisted of hard X-ray photons above 3 keV, but after 20 ks, softer X-ray photons below 2 ke

  1. Fullerenes and disk-fullerenes

    Science.gov (United States)

    Deza, M.; Dutour Sikirić, M.; Shtogrin, M. I.

    2013-08-01

    A geometric fullerene, or simply a fullerene, is the surface of a simple closed convex 3-dimensional polyhedron with only 5- and 6-gonal faces. Fullerenes are geometric models for chemical fullerenes, which form an important class of organic molecules. These molecules have been studied intensively in chemistry, physics, crystallography, and so on, and their study has led to the appearance of a vast literature on fullerenes in mathematical chemistry and combinatorial and applied geometry. In particular, several generalizations of the notion of a fullerene have been given, aiming at various applications. Here a new generalization of this notion is proposed: an n-disk-fullerene. It is obtained from the surface of a closed convex 3-dimensional polyhedron which has one n-gonal face and all other faces 5- and 6-gonal, by removing the n-gonal face. Only 5- and 6-disk-fullerenes correspond to geometric fullerenes. The notion of a geometric fullerene is therefore generalized from spheres to compact simply connected two-dimensional manifolds with boundary. A two-dimensional surface is said to be unshrinkable if it does not contain belts, that is, simple cycles consisting of 6-gons each of which has two neighbours adjacent at a pair of opposite edges. Shrinkability of fullerenes and n-disk-fullerenes is investigated. Bibliography: 87 titles.

  2. FORMATION OF MULTIPLE-SATELLITE SYSTEMS FROM LOW-MASS CIRCUMPLANETARY PARTICLE DISKS

    International Nuclear Information System (INIS)

    Hyodo, Ryuki; Ohtsuki, Keiji; Takeda, Takaaki

    2015-01-01

    Circumplanetary particle disks would be created in the late stage of planetary formation either by impacts of planetary bodies or disruption of satellites or passing bodies, and satellites can be formed by accretion of disk particles spreading across the Roche limit. Previous N-body simulation of lunar accretion focused on the formation of single-satellite systems from disks with large disk-to-planet mass ratios, while recent models of the formation of multiple-satellite systems from disks with smaller mass ratios do not take account of gravitational interaction between formed satellites. In the present work, we investigate satellite accretion from particle disks with various masses, using N-body simulation. In the case of accretion from somewhat less massive disks than the case of lunar accretion, formed satellites are not massive enough to clear out the disk, but can become massive enough to gravitationally shepherd the disk outer edge and start outward migration due to gravitational interaction with the disk. When the radial location of the 2:1 mean motion resonance of the satellite reaches outside the Roche limit, the second satellite can be formed near the disk outer edge, and then the two satellites continue outward migration while being locked in the resonance. Co-orbital satellites are found to be occasionally formed on the orbit of the first satellite. Our simulations also show that stochastic nature involved in gravitational interaction and collision between aggregates in the tidal environment can lead to diversity in the final mass and orbital architecture, which would be expected in satellite systems of exoplanets

  3. Modernization of two gas-fired shaft annealing furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Barthof, G.; Porst, G.; Raczek, S.

    1986-04-01

    The objective was to modernize two existing shaft-type annealing furnaces used for the heat treatment of grey iron castings with the aim of reducing the consumption of gaseous fuel, minimize the formation of scale, decrease maintenance expense and apply more automatic control to the annealing process. This was to be achieved by an optimum combination of new types of construction materials and advanced firing and control equipment. The author describes the furnace in its condition prior to and after reconstruction. The operating results obtained after reconstruction were found to justify the costs incurred. The payback period is roughly one year.

  4. The Tilt of the Elevator Shaft of Bunker Skutina

    Directory of Open Access Journals (Sweden)

    Pavel KALENDA

    2014-06-01

    Full Text Available The measurement of deformations of the elevator shaft in the Skutina fortress between the 2nd floor and the depth of 33 m below the surface took place in 2009. These measurements showed that, in addition to the tides, the diurnal thermoelastic wave deforms the body of the bunker, particularly in the NS direction. The amplitude of this deformation depends mainly on the cloudiness (opposite to the irradiance. Morning and evening deformation curves depend mainly on the time of sunrise and the geometry of the body of the bunker (irradiance of the bunker walls and less of the outside temperature.

  5. Optimising a shaft's geometry by applying genetic algorithms

    Directory of Open Access Journals (Sweden)

    María Alejandra Guzmán

    2005-05-01

    Full Text Available Many engnieering design tasks involve optimising several conflicting goals; these types of problem are known as Multiobjective Optimisation Problems (MOPs. Evolutionary techniques have proved to be an effective tool for finding solutions to these MOPs during the last decade, Variations on the basic generic algorithm have been particulary proposed by different researchers for finding rapid optimal solutions to MOPs. The NSGA (Non-dominated Sorting Generic Algorithm has been implemented in this paper for finding an optimal design for a shaft subjected to cyclic loads, the conflycting goals being minimum weight and minimum lateral deflection.

  6. Experimental study on a magnetofluid sealing liquid for propeller shaft

    Science.gov (United States)

    Zhao, Chang-Fa; Sun, Rong-Hua; Zheng, Jin-Xing

    2003-06-01

    The selecting and preparing method of the basic material of magnetic fluid was introduced. By using a chemical method, the magnetic micropowder Fe3O4 was successfully yielded, and an oil-base as a working carrier and dispersing agent was determined. The preparation process of the magnetic fluid and prescription of the oil-base magnetic fluid were discussed. The simulation experimental rig of magnetic fluid sealing for propeller shaft was designed. The sealing ability experiment was conducted and results were analyzed. The pressure of sealing is up to 2 MPa.

  7. Drilling supervision procedure for the Exploratory Shaft Facility: Final draft

    International Nuclear Information System (INIS)

    1986-11-01

    Drilling supervision will be undertaken in the Exploratory Shaft Facility (ESF) for boreholes drilled primarily for the purpose of hydrologic testing, downhole mechanical/thermal testing, sampling for laboratory testing, and for the placement of instrumentation. The primary purpose of this procedure is documentation of drilling activities prescribed by other procedures. Supervision of drilling includes designation of positions of authority, lines of communication, and methodology of supervising, monitoring, and documenting drilling and associated activities. The rationale for the specific applications of core drilling is provided by the test procedures for each activity. 2 figs

  8. Low Leakage Turbine Shaft Seals for Advanced Combined Cycle Systems.

    Science.gov (United States)

    1984-11-01

    Study of Shaft Face Seal With Self-Acting Lift Augmentation", N71- 11579, Nov. 1970 29p. Povinelli , V.P. and McKibbin, A. H., "Development of...34, N73-24086, May 1973, 28p. Povinelli , V. P. and McKibbin, A. H., "Development of Mainshaft Seals for Advanced Air Breathing Propulsion Systems... Povinelli , V. P., "Current Seal Designs and Future Requirements for Turbine Engine Seals and Bearings", Journal of Aircraft, Vol. 12, No. 4, April 1975

  9. Basalt Waste Isolation Project exploratory shaft site: Final reclamation report

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.

    1990-06-01

    The restoration of areas disturbed by activities of the Basalt Waste Isolation Project (BWIP) constitutes a unique operation at the US Department of Energy's (DOE) Hanford Site, both from the standpoint of restoration objectives and the time frame for accomplishing these objectives. The BWIP reclamation program comprises three separate projects: borehole reclamation, Near Surface Test Facility (NSTF) reclamation, and Exploratory Shaft Facility (ESF) reclamation. The main focus of this report is on determining the success of the revegetation effort 1 year after work was completed. This report also provides a brief overview of the ESF reclamation program. 21 refs., 7 figs., 14 tabs

  10. Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

    International Nuclear Information System (INIS)

    Kwon, Yong Chul; Kang, Jong Hun; Kim, Sang Sik

    2016-01-01

    The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts

  11. Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yong Chul [Gyeongnam Technopark, Changwon (Korea, Republic of); Kang, Jong Hun [Jungwon Univ., Goisan (Korea, Republic of); Kim, Sang Sik [Gyeongsang Natiional Univ., Jinju (Korea, Republic of)

    2016-02-15

    The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts.

  12. Conceptual design of shaft seals for a nuclear waste disposal vault

    International Nuclear Information System (INIS)

    1993-04-01

    The concept of a disposal vault in the Canadian Shield for the effective isolation of nuclear fuel wastes is being assessed as part of the Canadian Nuclear Fuel Waste Management Program. The vault would be accessed from the surface by a number of shafts, which would likely penetrate the vault environment and intersect significant rock fractures and thereby form preferential pathways for the migration of radionuclides from the disposal area to the biosphere. Golder Associates were retained to conduct a conceptual design study of sealing and backfilling the shafts. The first volume of this report reviews current shaft sinking and lining technologies, and recommends the preferred construction methods for the shafts. Factors that could affect the design of a shaft seal system are reviewed, and a conceptual shaft seal is proposed. The second volume addresses the performance assessment of a shaft seal system. While there are no specific performance criteria against which to compare the anticipated containment characteristics of the shaft seal system proposed, the methodology developed for the performance assessment of the reference design should enable the design to be modified to meet performance criteria as they are developed. The report estimates that it will cost $133.7 million in 1986 Canadian dollars to seal three reference shafts, including $18 million for labour and equipment, $103.4 million for backfill and sealing materials, $9.5 million for project indirect costs, and $2.8 million project management. (author). 53 refs., 36 tabs., 43 figs

  13. Design considerations for sealing the shafts of a nuclear fuel waste disposal vault

    International Nuclear Information System (INIS)

    Mortazavi, M.H.S.; Chan, H.T.; Radhakrishna, H.S.

    1985-05-01

    The shafts in an underground disposal system, which constitute potential pathways between the disposal vault and the biosphere, should be effectively sealed if the system is to perform as a hydrodynamic and geochemical barrier for the safe containment of nuclear fuel waste. In the design of the shaft backfill, consideration should be given to ensure that the backfill and the backfill/rock interface remain intact. Design-related problems, including critical pathways for the transport or radionuclides, configuration of shaft backfill and its functional requirements, the state of stress in a backfilled shaft with particular emphasis on the arching and load transfer phenomenon are discussed in this report

  14. Conceptual design of shaft seals for a nuclear waste disposal vault

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-04-01

    The concept of a disposal vault in the Canadian Shield for the effective isolation of nuclear fuel wastes is being assessed as part of the Canadian Nuclear Fuel Waste Management Program. The vault would be accessed from the surface by a number of shafts, which would likely penetrate the vault environment and intersect significant rock fractures and thereby form preferential pathways for the migration of radionuclides from the disposal area to the biosphere. Golder Associates were retained to conduct a conceptual design study of sealing and backfilling the shafts. The first volume of this report reviews current shaft sinking and lining technologies, and recommends the preferred construction methods for the shafts. Factors that could affect the design of a shaft seal system are reviewed, and a conceptual shaft seal is proposed. The second volume addresses the performance assessment of a shaft seal system. While there are no specific performance criteria against which to compare the anticipated containment characteristics of the shaft seal system proposed, the methodology developed for the performance assessment of the reference design should enable the design to be modified to meet performance criteria as they are developed. The report estimates that it will cost $133.7 million in 1986 Canadian dollars to seal three reference shafts, including $18 million for labour and equipment, $103.4 million for backfill and sealing materials, $9.5 million for project indirect costs, and $2.8 million project management. (author). 53 refs., 36 tabs., 43 figs.

  15. Low frequency torsional vibration gaps in the shaft with locally resonant structures

    International Nuclear Information System (INIS)

    Yu Dianlong; Liu Yaozong; Wang Gang; Cai Li; Qiu Jing

    2006-01-01

    The propagation of torsional wave in the shaft with periodically attached local resonators is studied with the transfer matrix theory and the finite element method. The analytical dispersion relation and the complex band structure of such a structure is presented for the first time, which indicates the existence of low frequency gaps. The effect of shaft material on the vibration attenuation in band gap is investigated. The frequency response function of the shaft with finite periodic locally resonant oscillators is simulated with finite element method, which shows large vibration attenuation in the frequency range of the gap as expected. The low frequency torsional gap in shafts provides a new idea for vibration control

  16. Numerical Study on the Tensile Behavior of 3D Four Directional Cylindrical Braided Composite Shafts

    Science.gov (United States)

    Zhao, Guoqi; Wang, Jiayi; Hao, Wenfeng; Liu, Yinghua; Luo, Ying

    2017-10-01

    The tensile behavior of 3D four directional cylindrical braided composite shafts was analyzed with the numerical method. The unit cell models for the 3D four directional cylindrical braided composite shafts with various braiding angles were constructed with ABAQUS. Hashin's failure criterion was used to analyze the tensile strength and the damage evolution of the unit cells. The influence of the braiding angle on the tensile behavior of the 3D four directional cylindrical braided composite shafts was analyzed. The numerical results showed that the tensile strength along the braiding direction increased as the braiding angle decreased. These results should play an integral role in the design of braiding composites shafts.

  17. Advisibility of excavating an additional central shaft to reduce duration of mine construction. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.

    1981-09-01

    This paper evaluates methods of reducing duration and cost of underground black coal mine construction. A proposed scheme of coal deposit opening by a system of three mine shafts is critically analyzed. In comparison to the conventional scheme, the proposed one has one additional mine shaft in the central mine zone. The shaft, equipped with a cage hoisting system, permits the rate of mine drivage in the center of the mine to be increased. The cage hoisting system in the additional shaft is activated before the main skip shaft has been equipped and is in operation. Duration of mine construction is reduced by 6 to 10 months. Exacavation of the additional shaft costs from 2.5 to 3.5 million rubles. A further system of mine construction is also analyzed. The main shaft in the mine center is temporarily equipped with a cage hoisting system. The cage system is used for hoisting rocks removed from mine headings and main workings constructed at the bottom of the main shaft. The main shaft is equipped with skips and hoisting tower at a later stage when construction of main roadways and structures at its bottom has been completed. The proposed system permits mine construction to be reduced by 4 to 5 months without a major increase in investment.

  18. ALMA observations of a misaligned binary protoplanetary disk system in Orion

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jonathan P. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96816 (United States); Mann, Rita K.; Francesco, James Di; Johnstone, Doug; Matthews, Brenda [NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Andrews, Sean M.; Ricci, Luca [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hughes, A. Meredith [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); Bally, John, E-mail: jpw@ifa.hawaii.edu [CASA, University of Colorado, CB 389, Boulder, CO 80309 (United States)

    2014-12-01

    We present Atacama Large Millimeter/Submillimeter Array (ALMA) observations of a wide binary system in Orion, with projected separation 440 AU, in which we detect submillimeter emission from the protoplanetary disks around each star. Both disks appear moderately massive and have strong line emission in CO 3-2, HCO{sup +} 4-3, and HCN 3-2. In addition, CS 7-6 is detected in one disk. The line-to-continuum ratios are similar for the two disks in each of the lines. From the resolved velocity gradients across each disk, we constrain the masses of the central stars, and show consistency with optical-infrared spectroscopy, both indicative of a high mass ratio ∼9. The small difference between the systemic velocities indicates that the binary orbital plane is close to face-on. The angle between the projected disk rotation axes is very high, ∼72°, showing that the system did not form from a single massive disk or a rigidly rotating cloud core. This finding, which adds to related evidence from disk geometries in other systems, protostellar outflows, stellar rotation, and similar recent ALMA results, demonstrates that turbulence or dynamical interactions act on small scales well below that of molecular cores during the early stages of star formation.

  19. OT1_ipascucc_1: Understanding the Origin of Transition Disks via Disk Mass Measurements

    Science.gov (United States)

    Pascucci, I.

    2010-07-01

    Transition disks are a distinguished group of few Myr-old systems caught in the phase of dispersing their inner dust disk. Three different processes have been proposed to explain this inside-out clearing: grain growth, photoevaporation driven by the central star, and dynamical clearing by a forming giant planet. Which of these processes lead to a transition disk? Distinguishing between them requires the combined knowledge of stellar accretion rates and disk masses. We propose here to use 43.8 hours of PACS spectroscopy to detect the [OI] 63 micron emission line from a sample of 21 well-known transition disks with measured mass accretion rates. We will use this line, in combination with ancillary CO millimeter lines, to measure their gas disk mass. Because gas dominates the mass of protoplanetary disks our approach and choice of lines will enable us to trace the bulk of the disk mass that resides beyond tens of AU from young stars. Our program will quadruple the number of transition disks currently observed with Herschel in this setting and for which disk masses can be measured. We will then place the transition and the ~100 classical/non-transition disks of similar age (from the Herschel KP "Gas in Protoplanetary Systems") in the mass accretion rate-disk mass diagram with two main goals: 1) reveal which gaps have been created by grain growth, photoevaporation, or giant planet formation and 2) from the statistics, determine the main disk dispersal mechanism leading to a transition disk.

  20. Breathing-mode resonance of a complex plasma disk

    International Nuclear Information System (INIS)

    Sheridan, T.E.; Buckey, C.R.; Cox, D.J.; Merrill, R.J.; Theisen, W.L.

    2004-01-01

    We have experimentally characterized the breathing mode oscillation of a strongly-coupled, dusty plasma disk. Steady-state oscillations are excited by sinusoidally modulating the plasma density, creating a single-frequency, in-plane driving force. Resonance curves agree well with damped harmonic oscillator theory. A response at the second harmonic is observed and found to increase with the square of the driving force, indicating a quadratic nonlinearity

  1. Innovative phased array ultrasonic inspection solution for large rotor shafts

    Energy Technology Data Exchange (ETDEWEB)

    Maes, G.; Devos, D.; Tremblay, P., E-mail: gmaes@zetec.com [Zetec, Ville de Quebec, Quebec (Canada)

    2016-05-15

    The increasing needs of energy production led to new rotor shaft designs with larger dimensions. A new generation of nuclear power plants is already being deployed worldwide with such heavy components. Their implementation requires new inspection tools in order to guarantee the public safety and to ensure the quality of these critical parts. Due to the long sound path, conventional ultrasonic (UT) techniques cannot provide adequate detectability of the reference reflectors required by the existing codes. Also, some standards require multiple angle beams to be applied in addition to the straight beam inspection, and this leads to long inspection times. This paper will address the implementation and validation of phased array (PA) UT techniques, using a semi-flexible 2D array probe, for the inspection of large mono-block rotor shaft forgings. It will show how the beam focusing and steering capabilities of phased array UT probes can be used to overcome the issues occurring with conventional UT probes. Results of acoustic beam simulation, as well as detectability measurements and data acquisitions on representative test specimens will be presented and compared with conventional UT performance. Various aspects of the hardware and software specification will be addressed, as well as the potential reduction of the total inspection time. (author)

  2. Anterior cruciate ligament reconstruction failure after tibial shaft malunion.

    Science.gov (United States)

    LaFrance, Russell M; Gorczyca, John T; Maloney, Michael D

    2012-02-17

    Anterior cruciate ligament (ACL) reconstruction is common, with >100,000 procedures performed each year in the United States. Several factors are associated with failure, including poor surgical technique, graft incorporation failure, overly aggressive rehabilitation, and trauma. Tibial shaft fracture is also common and frequently requires operative intervention. Failure to reestablish the anatomic alignment of the tibia may cause abnormal forces across adjacent joints, which can cause degenerative joint disease or attritional failure of the surrounding soft tissues. This article describes a case of ACL reconstruction failure after a tibial fracture that resulted in malunion. Excessive force across the graft from lower-extremity malalignment and improper tunnel placement likely contributed to the attritional failure of the graft. This patient required a staged procedure for corrective tibial osteotomy followed by revision ACL reconstruction. This article describes ACL reconstruction failure, tibial shaft malunions, their respective treatments, the technical details of each procedure, and the technical aspects that must be considered when these procedures are done in a staged manner by 2 surgeons. Copyright 2012, SLACK Incorporated.

  3. Shaft cracks detection on operating centrifugal pumps by vibration analysis

    International Nuclear Information System (INIS)

    Serra, Reynaldo Cavalcanti.

    1995-01-01

    This study gives an account of the vibratory behaviour of one centrifugal pump representative of those employed in nuclear reactors whereby its shaft contained a fatigue crack with critical orientation. Two cracks depth were included in the study, aside from the uncracked shaft. Four other machined discontinuities with varying depths were also included to allow a direct comparison. The data acquisition was carried out with a system using eight accelerometers and a tape recorder. The signals were then processed and interpreted with a dynamic signal analysis work station. The data analysis based in the time domain were unsuccessful as a result of the signal complexity. The fundamental frequency and its harmonics were defined from the frequency spectra. The corresponding amplitudes were recorded and tabulated for future reference. A method was proposed to identify the evolution of the discontinuities based on the departures from a reference state and procedure is suggested to substitute the standards and practices presently in use which are unreliable. (author). 46 refs., 48 figs., 24 tabs

  4. Geochemical factors in borehole-shaft plug longevity

    International Nuclear Information System (INIS)

    Roy, D.M.

    1981-01-01

    Geochemical investigations that address factors controlling the longevity of repository sealing materials in a geochemical environment are discussed. Studies are being made of cement-based materials as major candidates for seals for borehole plugging, and shaft and tunnel sealing in certain potential repository environments. Factors controlling the extent of attainment of equilibrium of the plug components with time and the rate of approach to a state of stable equilibrium of the plug component chemical subsystem within the total system are discussed. The effect of these factors on changes in physical, mechanical and thermal properties of a seal system, and the consequent effectiveness of the seal in preventing transport of radioactive waste species are the dominant features to be determined. Laboratory experiments on the effects of anticipated temperature, pressure, and environmental factors (including chemical composition and specific rock type) are described. Thermodynamic studies are used to determine the potentially stable reaction products under conditions similar to those anticipated for the repository boreholes, shafts, and tunnels during and after the operating stage. Multitemperature reaction series are studied, and reaction kinetics are investigated for the purpose of predicting the course of likely reactions. Detailed studies of permeability, diffusion, and interfacial properties and chemical and microphase characterization of the products of experiments are carried out. Characterization studies of old and ancient cements, mortars, and concretes and prototype man-made seal materials are performed to further assess the factors associated with longevity

  5. Plucked Human Hair Shafts and Biomolecular Medical Research

    Directory of Open Access Journals (Sweden)

    Kevin Schembri

    2013-01-01

    Full Text Available The hair follicle is a skin integument at the boundary between an organism and its immediate environment. The biological role of the human hair follicle has lost some of its ancestral importance. However, an indepth investigation of this miniorgan reveals hidden complexity with huge research potential. An essential consideration when dealing with human research is the awareness of potential harm and thus the absolute need not to harm—a rule aptly qualified by the Latin term “primum non nocere” (first do no harm. The plucked hair shaft offers such advantages. The use of stem cells found in hair follicles cells is gaining momentum in the field of regenerative medicine. Furthermore, current diagnostic and clinical applications of plucked hair follicles include their use as autologous and/or three-dimensional epidermal equivalents, together with their utilization as surrogate tissue in pharmacokinetic and pharmacodynamics studies. Consequently, the use of noninvasive diagnostic procedures on hair follicle shafts, posing as a surrogate molecular model for internal organs in the individual patient for a spectrum of human disease conditions, can possibly become a reality in the near future.

  6. Femoral Neck Shaft Angle in Men with Fragility Fractures

    Directory of Open Access Journals (Sweden)

    S. P. Tuck

    2011-01-01

    Full Text Available Introduction. Femoral neck shaft angle (NSA has been reported to be an independent predictor of hip fracture risk in men. We aimed to assess the role of NSA in UK men. Methods. The NSA was measured manually from the DXA scan printout in men with hip (62, 31 femoral neck and 31 trochanteric, symptomatic vertebral (91, and distal forearm (67 fractures and 389 age-matched control subjects. Age, height, weight, and BMD (g/cm2: lumbar spine, femoral neck, and total femur measurements were performed. Results. There was no significant difference in mean NSA between men with femoral neck and trochanteric hip fractures, so all further analyses of hip fractures utilised the combined data. There was no difference in NSA between those with hip fractures and those without (either using the combined data or analysing trochanteric and femoral neck shaft fractures separately, nor between fracture subjects as a whole and controls. Mean NSA was smaller in those with vertebral fractures (129.2° versus 131°: P=0.001, but larger in those with distal forearm fractures (129.8° versus 128.5°: P=0.01. Conclusions. The conflicting results suggest that femoral NSA is not an important determinant of hip fracture risk in UK men.

  7. Foundations of Black Hole Accretion Disk Theory.

    Science.gov (United States)

    Abramowicz, Marek A; Fragile, P Chris

    2013-01-01

    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).

  8. Foundations of Black Hole Accretion Disk Theory

    Directory of Open Access Journals (Sweden)

    Marek A. Abramowicz

    2013-01-01

    Full Text Available This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks, Shakura-Sunyaev (thin disks, slim disks, and advection-dominated accretion flows (ADAFs. After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs.

  9. Fast disk array for image storage

    Science.gov (United States)

    Feng, Dan; Zhu, Zhichun; Jin, Hai; Zhang, Jiangling

    1997-01-01

    A fast disk array is designed for the large continuous image storage. It includes a high speed data architecture and the technology of data striping and organization on the disk array. The high speed data path which is constructed by two dual port RAM and some control circuit is configured to transfer data between a host system and a plurality of disk drives. The bandwidth can be more than 100 MB/s if the data path based on PCI (peripheral component interconnect). The organization of data stored on the disk array is similar to RAID 4. Data are striped on a plurality of disk, and each striping unit is equal to a track. I/O instructions are performed in parallel on the disk drives. An independent disk is used to store the parity information in the fast disk array architecture. By placing the parity generation circuit directly on the SCSI (or SCSI 2) bus, the parity information can be generated on the fly. It will affect little on the data writing in parallel on the other disks. The fast disk array architecture designed in the paper can meet the demands of the image storage.

  10. Secular Evolution in Disk Galaxies

    Science.gov (United States)

    Kormendy, John

    2013-10-01

    Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via the evolution processes that are available to them. They do this by spreading -- the inner parts shrink while the outer parts expand -- provided that some physical process efficiently transports energy or angular momentum outward. The reason is that self-gravitating systems have negative specific heats. As a result, the evolution of stars, star clusters, protostellar and protoplanetary disks, black hole accretion disks and galaxy disks are fundamentally similar. How evolution proceeds then depends on the evolution processes that are available to each kind of self-gravitating system. These processes and their consequences for galaxy disks are the subjects of my lectures and of this Canary Islands Winter School. I begin with a review of the formation, growth and death of bars. Then I review the slow (`secular') rearrangement of energy, angular momentum, and mass that results from interactions between stars or gas clouds and collective phenomena such as bars, oval disks, spiral structure and triaxial dark haloes. The `existence-proof' phase of this work is largely over: we have a good heuristic understanding of how nonaxisymmetric structures rearrange disk gas into outer rings, inner rings and stuff dumped onto the centre. The results of simulations correspond closely to the morphology of barred and oval galaxies. Gas that is transported to small radii reaches high densities. Observations confirm that many barred and oval galaxies have dense central concentrations of gas and star formation. The result is to grow, on timescales of a few Gyr, dense central components that are frequently mistaken for classical (elliptical-galaxy-like) bulges but that were grown slowly out of the disk (not made rapidly by major mergers). The resulting picture of secular galaxy evolution accounts for the richness observed in galaxy structure. We can distinguish between classical and pseudo

  11. Thin disk laser with unstable resonator and reduced output coupler

    Science.gov (United States)

    Gavili, Anwar; Shayganmanesh, Mahdi

    2018-05-01

    In this paper, feasibility of using unstable resonator with reduced output coupling in a thin disk laser is studied theoretically. Unstable resonator is modeled by wave-optics using Collins integral and iterative method. An Yb:YAG crystal with 250 micron thickness is considered as a quasi-three level active medium and modeled by solving rate equations of energy levels populations. The amplification of laser beam in the active medium is calculated based on the Beer-Lambert law and Rigrod method. Using generalized beam parameters method, laser beam parameters like, width, divergence, M2 factor, output power as well as near and far-field beam profiles are calculated for unstable resonator. It is demonstrated that for thin disk laser (with single disk) in spite of the low thickness of the disk which leads to low gain factor, it is possible to use unstable resonator (with reduced output coupling) and achieve good output power with appropriate beam quality. Also, the behavior of output power and beam quality versus equivalent Fresnel number is investigated and optimized value of output coupling for maximum output power is achieved.

  12. Rustler Formation in the waste handling and exhaust shafts, Waste Isolation Pilot Plant (WIPP) site, southeastern New Mexico

    International Nuclear Information System (INIS)

    Holt, R.M.; Powers, D.W.

    1987-01-01

    The Permian Rustler Formation was recently examined in detail in two shafts at the WIPP site: the waste handling shaft (waste shaft) and the exhaust shaft. Fresh exposures of the Rustler in the shafts exhibited abundant primary sedimentary structures. The abundance of primary sedimentary structures observed in the shafts is unequaled in previously described sections. Data are reported here in their stratigraphic context as an initial basis for evaluation of depositional environments of the Rustler and reevaluating the role of dissolution in the formation of the Rustler. 10 refs

  13. Air intake shaft performance tests (Shaft 5): In situ data report (May 1988--July 1995). Waste Isolation Pilot Plant (WIPP) Thermal/Structural Interactions Program

    International Nuclear Information System (INIS)

    Munson, D.E.; Baird, G.T.; Jones, R.L.

    1995-07-01

    Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991

  14. Air intake shaft performance tests (Shaft 5): In situ data report (May 1988--July 1995). Waste Isolation Pilot Plant (WIPP) Thermal/Structural Interactions Program

    Energy Technology Data Exchange (ETDEWEB)

    Munson, D.E. [Sandia National Labs., Albuquerque, NM (United States). Repository Isolation Systems Dept.; Hoag, D.L.; Ball, J.R. [RE/SPEC Inc., Albuquerque, NM (United States); Baird, G.T.; Jones, R.L. [Tech Reps, Inc., Albuquerque, NM (United States)

    1995-07-01

    Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991.

  15. Experiences with the operation of a shaft-helix in connection with a special steel ring lining in the shafts Gorleben 1 and 2

    International Nuclear Information System (INIS)

    Tonscheidt, H.W.; Kahl, J.

    1991-01-01

    When sinking the Gorleben 1 shaft good reasons prevented the method of drilling and blasting to create the excavation. Considering the special conditions and after a successful test, the application of a modified helix was given preference to an impact-ripper, tested on an other freeze shaft project. A report is given on the experiences gained with respect to the following criteria: Assembly, dismantling and transport of the machine in the shaft - conveyance of electric energy - dust problems when cutting the concrete plug and the means engaged to overcome those problems - performance in the different types of rock formation - cutting the circular shape of the excavation with sufficient accuracy - matters of safety in connection with cutting, loading and lining the excavation - consumption and costs of cutters - total costs. A final assessment of the excavation system is made with respect to its possible application with for shaft-sinking projects. (orig.) [de

  16. Optimized design of the chopper disks and the neutron guide in a disk chopper neutron time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Copley, J.R.D.

    1990-01-01

    We consider important aspects of the performance of a disk chopper neutron time-of-flight spectrometer. The intensity at the sample position, and the contributions of the choppers to the resolution of the instrument, are evaluated as a function of the widths of the slots in the chopper disks and the width of the neutron guide between the disks. We find that there is an optimum choice of the ratios of these widths and that this choice depends on a single parameter which, for elastic scattering, is a simple ratio of distances. When pairs of counter-rotating disks are employed, the widths of the slots can be modified by grossly changing the phase relationship between the members of a chopper pair. If the slot widths are changed, the width of the guide should also be altered in order to maintain the spectrometer in an optimized state. This change in the guide width may be effectively achieved using an arrangement of nested guides. Resolution and intensity calculations demonstrate the important gains which may be realized using this approach. (orig.)

  17. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  18. Grain surface chemistry in protoplanetary disks

    International Nuclear Information System (INIS)

    Reboussin, Laura

    2015-01-01

    Planetary formation occurs in the protoplanetary disks of gas and dust. Although dust represents only 1% of the total disk mass, it plays a fundamental role in disk chemical evolution since it acts as a catalyst for the formation of molecules. Understanding this chemistry is therefore essential to determine the initial conditions from which planets form. During my thesis, I studied grain-surface chemistry and its impact on the chemical evolution of molecular cloud, initial condition for disk formation, and protoplanetary disk. Thanks to numerical simulations, using the gas-grain code Nautilus, I showed the importance of diffusion reactions and gas-grain interactions for the abundances of gas-phase species. Model results combined with observations also showed the effects of the physical structure (in temperature, density, AV) on the molecular distribution in disks. (author)

  19. Rotation of gas above the galactic disk

    International Nuclear Information System (INIS)

    Gvaramadze, V.V.; Lominadze, D.G.

    1988-01-01

    The galactic disk is modeled by an oblate spheroid with confocal spherodial isodensity surfaces. An explicit analytic expression is found for the angular velocity of the gas outside the disk. The parameters of a three-component model of a spiral galaxy (oblate spheroid with central hole, bulge, and massive corona) are chosen in such a way as to obtain in the disk a two-hump rotation curve (as in the Galaxy, M 31, and M 81). It is shown that at heights absolute value z ≤ 2 kpc the gas rotates in the same manner as the disk. However, at greater heights the rotation curve ceases to have two humps. Allowance for the pressure gradient of the gas slightly changes the rotation curve directly above the disk (r r/sub disk/)

  20. [Management of disk displacement with condylar fracture].

    Science.gov (United States)

    Yu, Shi-bin; Li, Zu-bing; Yang, Xue-wen; Zhao, Ji-hong; Dong, Yao-jun

    2003-07-01

    To investigate clinical features of disk displacement during the course of condylar fracture and to explore the techniques of disk reposition and suturation. 32 patients (10 females and 22 males) who had disk displacements with condylar fractures were followed up. Reduction and reposition of the dislocated disks simultaneously with fixation of fractures were performed. 7 patients underwent intermaxillary fixation with elastic bands for 1 to 2 weeks. The occlusions were satisfactory in all cases but one for the reason of ramus height loss. No TMJ symptom was found when examined 3 months post operation. Anterior disk displacements were most occurred with high condylar process fractures. Surgical reposition and suturation of disk play an important role for the later TMJ-function.

  1. Circumstellar Gas in Young Planetary Debris Disks

    Science.gov (United States)

    Roberge, A.

    Circumstellar (CS) disks orbiting young stars fall into two categories: primordial disks, composed of unprocessed interstellar dust and gas, and debris disks, produced by the destruction of solid planetary bodies. In the first class, the most abundant gas is H_2; in the second, it appears that the H_2 gas has disappeared, possibly through incorporation into gas giant planets. The lifetime of H_2 gas in a CS disk is therefore of great importance, as it dictates the timescale for the formation of giant planets. FUSE observations of H_2 in CS disk systems have shown that FUV absorption spectroscopy may sensitively probe for small amounts of gas along the line of sight to the star. Most importantly, the FUSE non-detection of H_2 gas in the Beta Pictoris disk suggests that the primordial gas lifetime is less than about 12 Myr, and that gas giant planets must form very quickly. However, this suggestion is based on one system, and needs to be tested in additional systems with a range of ages, especially since there are indications that age is not the only factor in the evolution of a CS disk. We propose for FUSE observations of 3 additional debris disk systems, Fomalhaut, HD3003, and HD2884. Fomalhaut is an intermediate age debris disk, one of the Fabulous Four CS disks first discovered in 1984. The other two disks are younger, with ages similar to that of Beta Pic. All three stars are brighter in the FUV than Beta Pic, permitting us to sensitively probe for traces of H_2 gas. We will also measure the amount of secondary atomic gas produced from planetary bodies in these disks, in an effort to understand the entire evolution of CS gas in young planetary systems.

  2. MOLECULAR GAS IN YOUNG DEBRIS DISKS

    International Nuclear Information System (INIS)

    Moor, A.; Abraham, P.; Kiss, Cs.; Juhasz, A.; Kospal, A.; Pascucci, I.; Apai, D.; Henning, Th.; Csengeri, T.; Grady, C.

    2011-01-01

    Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. Interestingly, the debris disk around the young main-sequence star 49 Ceti possesses a substantial amount of molecular gas and possibly represents the missing link between the two phases. Motivated to understand the evolution of the gas component in circumstellar disks via finding more 49 Ceti-like systems, we carried out a CO J = 3-2 survey with the Atacama Pathfinder EXperiment, targeting 20 infrared-luminous debris disks. These systems fill the gap between primordial and old tenuous debris disks in terms of fractional luminosity. Here we report on the discovery of a second 49 Ceti-like disk around the 30 Myr old A3-type star HD21997, a member of the Columba Association. This system was also detected in the CO(2-1) transition, and the reliable age determination makes it an even clearer example of an old gas-bearing disk than 49 Ceti. While the fractional luminosities of HD21997 and 49 Ceti are not particularly high, these objects seem to harbor the most extended disks within our sample. The double-peaked profiles of HD21997 were reproduced by a Keplerian disk model combined with the LIME radiative transfer code. Based on their similarities, 49 Ceti and HD21997 may be the first representatives of a so far undefined new class of relatively old (∼>8 Myr), gaseous dust disks. From our results, neither primordial origin nor steady secondary production from icy planetesimals can unequivocally explain the presence of CO gas in the disk of HD21997.

  3. Theory of Disk Accretion onto Magnetic Stars

    Directory of Open Access Journals (Sweden)

    Lai Dong

    2014-01-01

    Full Text Available Disk accretion onto magnetic stars occurs in a variety of systems, including accreting neutron stars (with both high and low magnetic fields, white dwarfs, and protostars. We review some of the key physical processes in magnetosphere-disk interaction, highlighting the theoretical uncertainties. We also discuss some applications to the observations of accreting neutron star and protostellar systems, as well as possible connections to protoplanetary disks and exoplanets.

  4. Disk access controller for Multi 8 computer

    International Nuclear Information System (INIS)

    Segalard, Jean

    1970-01-01

    After having presented the initial characteristics and weaknesses of the software provided for the control of a memory disk coupled with a Multi 8 computer, the author reports the development and improvement of this controller software. He presents the different constitutive parts of the computer and the operation of the disk coupling and of the direct access to memory. He reports the development of the disk access controller: software organisation, loader, subprograms and statements

  5. Buoyancy and Pressure Driven Flow of Hot Gases in Vertical Shafts with Natural and Forced Ventilation

    Science.gov (United States)

    Tamm, Gunnar; Jaluria, Yogesh

    2003-11-01

    An experimental investigation has been carried out on the buoyancy and pressure induced flow of hot gases in vertical shafts, in order to simulate the propagation of combustion products in elevator shafts due to fire in multilevel buildings. Various geometrical configurations are studied, with regard to natural and forced ventilation imposed at the top or bottom of the vertical shaft. The aspect ratio is taken at a fixed value of 6 and the inflow conditions for the hot gases, at a vent near the bottom, are varied in terms of the Reynolds and Grashof numbers. Temperature measurements within the shaft allow a detailed study of the steady state thermal fields, from which optimal means for smoke alleviation in high-rise building fires may be developed. Flow visualization is also used to study the flow characteristics. The results obtained indicate a wall plume as the primary transport mechanism. Flow recirculation dominates at high Grashof number flows, while increased Reynolds numbers gives rise to greater mixing in the shaft. The development and stability of the flow and its effect on the spread of smoke and hot gases are assessed for the different shaft configurations and inlet conditions. It is found that the fastest smoke removal and lowest shaft temperatures occur for a configuration with natural ventilation at the top and forced ventilation up from the shaft bottom. It is also shown that forced ventilation can be used to arrest smoke spread, as well as to dilute the effects of the fire.

  6. Interaction between drilled shaft and mechanically stabilized earth (MSE) wall : project summary.

    Science.gov (United States)

    2015-08-31

    Drilled shafts are being constructed within the reinforced zone of mechanically stabilized earth (MSE) walls (Figure 1). The drilled shafts may be subjected to horizontal loads and push against the front of the wall. Distress of MSE wall panels has b...

  7. Effect of the shaft on the aerodynamic performance of urban vertical axis wind turbines

    NARCIS (Netherlands)

    Rezaeiha, A.; Kalkman, I.; Montazeri, H.; Blocken, B.J.E.

    2017-01-01

    The central shaft is an inseparable part of a vertical axis wind turbine (VAWT). For small turbines such as those typically used in urban environments, the shaft could operate in the subcritical regime, resulting in large drag and considerable aerodynamic power loss. The current study aims to (i)

  8. Long-term functional outcome following intramedullary nailing of femoral shaft fractures

    NARCIS (Netherlands)

    el Moumni, Mostafa; Voogd, Emma Heather; ten Duis, Henk Jan; Wendt, Klaus Wilhelm

    Background: The management of femoral shaft fractures using intramedullary nailing is a popular method. The purpose of this study was to evaluate the long-term functional outcome after antegrade or retrograde intramedullary nailing of traumatic femoral shaft fractures. We further determined

  9. Implementation of a flaw model to the fracturing around a vertical shaft

    CSIR Research Space (South Africa)

    Van de Steen, B

    2003-04-01

    Full Text Available -scale excavations. The simulated fracture pattern around a vertical shaft is compared to the fracturing around a shaft at a depth of 3400 m. The simulations suggest that wedge-shaped zones, called dog-ears, a reformed by a progressive splitting-like failure...

  10. Mining a coal seam with caving in a protective pillar of a mine shaft. [Poland

    Energy Technology Data Exchange (ETDEWEB)

    Szymura, G; Dilling, R; Kowalski, A

    1984-01-01

    Mining the 620 seam is evaluated (from 1.5 to 1.7 m thick at a depth of 468 m in the protective pillar of the upcast mine shaft used for ventilation, manriding and transport of materials in the Pstrowski mine in Upper Silesia). The shaft is 496 m deep, has a diameter of 3.5 m and its liners are made of bricks. Ground subsidence caused by underground mining influenced: the head frame above the shaft, residential buildings, a church, railway tracks and a river bed. A system of shortwall mining with caving was used. Deformation of shaft liners was reduced by advanced cutting of a coal block 30x30 m around the shaft. A system of timber cribbings and yielding elements was used. Design of support systems used around the shaft is shown in 3 schemes. Shaft deformation was within permissible limits. The maximum ground subsidence (0.95 m) occurred in the river area. Ground subsidence in the area of the church ranged from 0.75 to 0.81 m and in the head frame area 0.84 m. Accuracy of ground subsidence and shaft deformation forecasting was high. 4 references.

  11. Response to Comment on "Whole-Genome Shotgun Sequencing of Mitochondria from Ancient Hair Shafts"

    DEFF Research Database (Denmark)

    Gilbert, Marcus Thomas Pius; Miller, Webb; Schuster, Stephan C.

    2008-01-01

    Debruyne et al. challenge the findings of our study and imply that we argue that hair shafts are an overall superior source of ancient DNA than bone. However, the authors are misreading and misinterpreting the conclusions of our study; we claim nothing further than that hair shaft represents...

  12. PROTOPLANETARY DISK MASSES FROM STARS TO BROWN DWARFS

    International Nuclear Information System (INIS)

    Mohanty, Subhanjoy; Mortlock, Daniel; Greaves, Jane; Pascucci, Ilaria; Apai, Daniel; Scholz, Aleks; Thompson, Mark; Lodato, Giuseppe; Looper, Dagny

    2013-01-01

    constant mean of log 10 [M disk /M * ] ≈ –2.4 all the way from intermediate-mass stars to VLMS/BDs, supporting previous qualitative suggestions that the ratio is ∼1% throughout the stellar/BD domain. (6) Similar analysis shows that the disk mass in close solar-type Taurus binaries (sep <100 AU) is significantly lower than in singles (by a factor of 10), while that in wide solar-type Taurus binaries (≥100 AU) is closer to that in singles (lower by a factor of three). (7) We discuss the implications of these results for planet formation around VLMS/BDs, and for the observed dependence of accretion rate on stellar mass

  13. Evaluation of powder metallurgy superalloy disk materials

    Science.gov (United States)

    Evans, D. J.

    1975-01-01

    A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

  14. Thermal Comptonization in standard accretion disks

    International Nuclear Information System (INIS)

    Maraschi, L.; Molendi, S.

    1990-01-01

    Using the theory of geometrically thin accretion disks (where the effects of viscosity are parametrized in terms of the total pressure, viscosity parameter, α) equations are presented for the innermost region of the disk (where the pressure is due to radiation, and the main source of opacity is Thompson scattering). It is important to stress that the four equations can be solved without making use of an equation for the temperature. This is not true for the other regions of the disk. An equation given is used to determine the temperature, assuming that the disk is homogeneous and isothermal in the vertical direction. (author)

  15. Hard disks with SCSI interface

    CERN Document Server

    Denisov, O Yu

    1999-01-01

    The testing of 20 models of hard SCSI-disks is carried out: the Fujitsu MAE3091LP; the IBM DDRS-39130, DGHS-318220, DNES-318350, DRHS-36V and DRVS-18V; the Quantum Atlas VI 18.2; the Viking 11 9.1; the Seagate ST118202LW, ST118273LW, ST118273W, ST318203LW, ST318275LW, ST34520W, ST39140LW and ST39173W; and the Western Digital WDE9100-0007, WDE9100-AV0016, WDE9100-AV0030 and WDE9180-0048. All tests ran under the Windows NT 4.0 workstation operating system with Service Pack 4, under video mode with 1024*768 pixel resolution, 32- bit colour depth and V-frequency equal to 85 Hz. The detailed description and characteristics of SCSI stores are presented. Test results (ZD Winstone 99 and ZD WinBench 99 tests) are given in both table and diagram (disk transfer rate) forms. (0 refs).

  16. The Stability of Galaxy Disks

    Science.gov (United States)

    Westfall, K. B.; Andersen, D. R.; Bershady, M. A.; Martinsson, T. P. K.; Swaters, R. A.; Verheijen, M. A. W.

    2014-03-01

    We calculate the stellar surface mass density (Σ*) and two-component (gas+stars) disk stability (QRW) for 25 late-type galaxies from the DiskMass Survey. These calculations are based on fits of a dynamical model to our ionized-gas and stellar kinematic data performed using a Markov Chain Monte Carlo sampling of the Bayesian posterior. Marginalizing over all galaxies, we find a median value of QRW = 2.0±0.9 at 1.5 scale lengths. We also find that QRW is anti-correlated with the star-formation rate surface density (Σ*), which can be predicted using a closed set of empirical scaling relations. Finally, we find that the star-formation efficiency (Σ*/Σg) is correlated with Σ* and weakly anti-correlated with QRW. The former is consistent with an equilibrium prediction of Σ*/Σg ∝ Σ*1/2. Despite its order-of-magnitude range, we find no correlation of Σ*/ΣgΣ*1/2 with any other physical quantity derived by our study.

  17. Study of the conditions affecting the critical speed of a rotating pump shaft

    International Nuclear Information System (INIS)

    Fardeau, P.; Huet, J.L.; Axisa, F.

    1983-01-01

    Knowing the parameters conditioning the critical speed of a pump shaft is important, both for safety and design purposes, since the shafts are often to operate beyond the first critical speed. These aims led CEA, associated with NOVATOME and FRAMATOME (with the cooperation of JEUMONT-SCHNEIDER) to carry out a test program on critical speeds of a full scale nuclear pump shaft. Fluid-structure interaction plays an important part in the setting of critical speed. Due to the coupling between the rotative fluid flow and the transverse vibrations of the shaft, inertial and stiffness forces are created, which are non conservative and proportional to the added mass of the fluid. The hydrostatic bearing effect and the influence of the water carried along by the pump wheel were also investigated, but proved unimportant in the case of the shaft studied. Experimental results are compared with calculations of critical speed. (orig.)

  18. Deep shaft high rate aerobic digestion: laboratory and pilot plant performance

    Energy Technology Data Exchange (ETDEWEB)

    Tran, F; Gannon, D

    1981-01-01

    The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100-160 m); the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high O transfer efficiencies (O.T.E.) of less than or equal to 90% vs. 4-20% in other aerators. This high O.T.E. suggests real potential for Deep-Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. Laboratory and pilot plant Deep-Shaft aerobic digester studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep-Shaft digester are described.

  19. Research and industrialization of near-net rolling technology used in shaft parts

    Science.gov (United States)

    Hu, Zhenghuan; Wang, Baoyu; Zheng, Zhenhua

    2018-03-01

    Shaft part rolling is an efficient and green nearnet shaping technology offering many advantages, including high production efficiency, high material utilization rate, high product quality, and excellent production environment. In this paper, the features of shaft part rolling are introduced along with the working principles of two main shaft part rolling technologies, namely, cross wedge rolling (CWR) and skew rolling (SR). In relation to this technology, some R&D achievements gained by the University of Science and Technology Beijing are summarized. Finally, the latest developments in shaft part rolling are presented, including SR steel balls, precise forming of camshaft blank by CWR, SR phosphorous copper balls at room temperature, and CWR hollow axle sleeve. Although the shaft part rolling technology has been widely used in China, it only accounts for about 15% of applicable parts at present. Nevertheless, this technology has broad application prospects.

  20. Nuclear spent fuel dry storage in the EWA reactor shaft

    International Nuclear Information System (INIS)

    Mieleszczenko, W.; Moldysz, A.; Hryczuk, A.; Matysiak, T.

    2001-01-01

    The EWA reactor was in operation from 1958 until February 1995. Then it was subjected to the decommissioning procedure. Resulting from a prolonged operation of Polish research reactors a substantial amount of nuclear spent fuel of various types, enrichment and degree of burnup have been accumulated. The technology of storage of spent nuclear fuel foresees the two stages of wet storing in a water pool (deferral period from tens to several dozens years) and dry storing (deferral period from 50 to 80 years). In our case the deferral time in the water environment is pretty significant (the oldest fuel elements have been stored in water for more than 40 years). Though the state of stored fuel elements is satisfactory, there is a real need for changing the storage conditions of spent fuel. The paper is covering the description of philosophy and conceptual design for construction of the spent fuel dry storage in the decommissioned EWA reactor shaft. (author)

  1. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    Science.gov (United States)

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

  2. Radial head dislocation during proximal radial shaft osteotomy.

    Science.gov (United States)

    Hazel, Antony; Bindra, Randy R

    2014-03-01

    The following case report describes a 48-year-old female patient with a longstanding both-bone forearm malunion, who underwent osteotomies of both the radius and ulna to improve symptoms of pain and lack of rotation at the wrist. The osteotomies were templated preoperatively. During surgery, after performing the planned radial shaft osteotomy, the authors recognized that the radial head was subluxated. The osteotomy was then revised from an opening wedge to a closing wedge with improvement of alignment and rotation. The case report discusses the details of the operation, as well as ways in which to avoid similar shortcomings in the future. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Design considerations for the Yucca Mountain project exploratory shaft facility

    International Nuclear Information System (INIS)

    Bullock, R.L. Sr.

    1990-01-01

    This paper reports on the regulatory/requirements challenges of this project which exist because this is the first facility of its kind to ever be planned, characterized, designed, and built under the purview of a U.S. Nuclear Regulatory Agency. The regulations and requirements that flow down to the Architect/Engineer (A/E) for development of the Exploratory Shaft Facility (ESF) design are voluminous and unique to this project. The subsurface design and construction of the ESF underground facility may eventually become a part of the future repository facility and, if so, will require licensing by the Nuclear Regulatory Commission (NRC). The Fenix and Scisson of Nevada-Yucca Mountain Project (FSN-YMP) group believes that all of the UMP design and construction related activities, with good design/construct control, can be performed to meet all engineering requirements, while following a strict quality assurance program that will also meet regulatory requirements

  4. Reactor coolant pump shaft seal behavior during station blackout

    International Nuclear Information System (INIS)

    Kittmer, C.A.; Wensel, R.G.; Rhodes, D.B.; Metcalfe, R.; Cotnam, B.M.; Gentili, H.; Mings, W.J.

    1985-04-01

    A testing program designed to provide fundamental information pertaining to the behavior of reactor coolant pump (RCP) shaft seals during a postulated nuclear power plant station blackout has been completed. One seal assembly, utilizing both hydrodynamic and hydrostatic types of seals, was modeled and tested. Extrusion tests were conducted to determine if seal materials could withstand predicted temperatures and pressures. A taper-face seal model was tested for seal stability under conditions when leaking water flashes to steam across the seal face. Test information was then used as the basis for a station blackout analysis. Test results indicate a potential problem with an elastomer material used for O-rings by a pump vendor; that vendor is considering a change in material specification. Test results also indicate a need for further research on the generic issue of RCP seal integrity and its possible consideration for designation as an unresolved safety issue

  5. Proceedings of the workshop on borehole and shaft plugging

    International Nuclear Information System (INIS)

    1980-01-01

    Geologic disposal of radioactive waste relies on the capability of many geological formations to provide long-term containment of the waste. The disposal operations could significantly modify the original conditions. In addition to the underground excavations and the thermal input of the waste their is the problem of boreholes and shafts that constitute a potential by-pass of the geological barriers. It is therefore essential to develop techniques and procedures for effective plugging of all penetrations connecting the disposal zone with the surface or with water bearing layers. It will be necessary to produce plugs which effectively restore the original characteristics of the isolating formations. In addition these plugs must be chemically stable in the existing geochemical environment in order to remain effective for very long periods of time and the plugs of disposal holes can be exposed to high temperatures and radiation doses. All countries with geologic disposal programmes will have to face the problem of borehole and shapt plugging

  6. Cold rolling precision forming of shaft parts theory and technologies

    CERN Document Server

    Song, Jianli; Li, Yongtang

    2017-01-01

    This book presents in detail the theory, processes and equipment involved in cold rolling precision forming technologies, focusing on spline and thread shaft parts. The main topics discussed include the status quo of research on cold rolling precision forming technologies; the design and calculation of process parameters; the numerical simulation of cold rolling forming processes; and the equipment used in cold rolling forming. The mechanism of cold rolling forming is extremely complex, and research on the processes, theory and mechanical analysis of spline cold rolling forming has remained very limited to date. In practice, the forming processes and production methods used are mainly chosen on the basis of individual experience. As such, there is a marked lack of both systematic, theory-based guidelines, and of specialized books covering theoretical analysis, numerical simulation, experiments and equipment used in spline cold rolling forming processes – all key points that are included in this book and ill...

  7. Preclosure radiological safety analysis for the exploratory shaft facilities

    International Nuclear Information System (INIS)

    Ma, C.W.; Miller, D.D.; Jardine, L.J.

    1992-06-01

    This study assesses which structures, systems, and components of the exploratory shaft facility (ESF) are important to safety when the ESF is converted to become part of the operating waste repository. The assessment follows the methodology required by DOE Procedure AP-6.10Q. Failures of the converted ESF during the preclosure period have been evaluated, along with other underground accidents, to determine the potential offsite radiation doses and associated probabilities. The assessment indicates that failures of the ESF will not result in radiation doses greater than 0.5 rem at the nearest unrestricted area boundary. Furthermore, credible accidents in other underground facilities will not result in radiation doses larger than 0.5 rem, even if any structure, system, or component of the converted ESF fails at the same time. Therefore, no structure, system, or component of the converted ESF is important to safety

  8. Analysis of hydraulic bearing effect for vertical-shaft pump

    International Nuclear Information System (INIS)

    Narabayashi, Tadashi; Mawatari, Katsuhiko; Uchida, Ken; Iikura, Takahiko; Hayakawa, Kiyoshi

    1999-01-01

    In inner-rotating non coaxial cylinders, axial flow causes a hydraulic being effect by which the inner cylinder is put at the center of the axis of the outer cylinder, because of the pressure distribution along the surface of the inner cylinder. When the rotating speed becomes higher, whirl force is generated by the pressure distribution in the narrow gap side. Therefore, pocket-type hydraulic being was added between the rotor and the wearing, based on an experiment and flow analysis. The pockets suck a part of discharged water of a pump and pressurize a water along the rotational direction in the pocket. The pressurized water enhance the hydraulic being effect. The analysis results showed good agreement with the experiments, and the analysis method for the hydraulic being for vertical-shaft pump was established. (author)

  9. Project management plan for exploratory shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    1983-08-01

    This Project Management Plan (PMP) provides the basic guidance and describes the organizational structure and procedures for the design, construction, and testing of a large-diameter Exploratory Shaft (ES) in tuffaceous media as a major element within the Nevada Nuclear Waste Storage Investigations (NNWSI) project, which is a part of the National Waste Terminal Storage (NWTS) Program, US Department of Energy (DOE). The PMP encompasses activities identified as construction phase and in situ phase testing to be conducted from the ES through September 30, 1986. Specific topics addressed are the ES project objectives, the management organization and responsibilities, functional support requirements, work plan (including quality assurance aspects), work breakdown structure, milestone schedule, logic diagram, performance criteria, cost estimates, management control systems, procurement plan, test plan, and environmental, health and safety plans

  10. Drilled shaft resistance based on diameter, torque and crowd (drilling resistance vs. rock strength) phase II [summary].

    Science.gov (United States)

    2016-05-01

    Over the past 20 years, drilled shafts have demonstrated increasing popularity over driven : precast piles. Drilled shafts can accommodate a wider range of sizes, and noise and vibration : during construction are significantly reduced. On the other h...

  11. Survey and analytical studies on a 'TAKANUKE' collapse mechanism for greatly deeper shafts (Contract research)

    International Nuclear Information System (INIS)

    Kurosaki, Yukio; Yamachi, Hiroshi; Matsui, Hiroya

    2008-09-01

    Mizunami underground research laboratory (MIU) is planned to be excavated to the depth of 1000m below the ground surface and is now under construction. One of the most serious problems in a greatly deeper shaft is 'TAKANUKE' collapse caused by slip movement of large discontinuities, as we have reported in the report of 'Study on Collapse Mechanism of Junction between Greatly Deeper Shaft and Horizontal Drifts [JAEA-Research 2008-248 (2008)]'. TAKANUKE collapse has been well known among mining engineers in JAPAN. However, an occurring mechanism of the collapse has not yet been revealed and a design code for it also has not been established. In this report, we have conducted numerical studies using finite difference method in order to throw an objective light on a mechanism of TAKANUKE collapse. These studies show two different stress states in upper and lower side of a large discontinuities. In lower side, a minimum principal stress at shaft wall region drastically reduces due to shaft sinking. This might make shaft wall stability difficult in poor geological condition. Such a TAKANUKE collapse can be found in ventilation shaft projects of the ENASAN tunnel. In the another side of discontinuity, a slip movement along discontinuities takes place due to shaft sinking. This slip movement induces a typical TAKANUKE collapse, as we have reported in 2007. In order to evaluate a possibility of TAKANUKE collapse during MIU main shaft sinking, we have conducted a particle body analysis, which can estimate a brittle failure of hard rock, such as MIU construction site. A fault with a steeply dipping over 79 degree to the main shaft, discovered in a survey boring at MIU site, has a low potential of TAKANUKE collapse during shaft sinking. Beside, a fault with dip of 60 degree may easily slip in a form of TAKANUKE collapse. One CD-ROM is attached as an appendix. (J.P.N.)

  12. Treatment of humeral shaft fractures with antegrade intramedullary locking nail.

    Science.gov (United States)

    Tsourvakas, Stefanos; Alexandropoulos, Christos; Papachristos, Ioannis; Tsakoumis, Grigorios; Ameridis, Nikolaos

    2011-12-01

    Antegrade interlocked humeral nailing for stabilization of humeral fractures was introduced many years ago, and studies on this method in the orthopedic literature have shown mixed results. The purpose of this investigation was to document the clinical outcome and complications associated with the use of an antegrade intramedullary nail (T2, Stryker) for the humeral fractures. Between 2005 and 2008, 52 fractures of the humeral shaft were treated operatively with this intramedullary nail in our department. Eight patients were polytraumatized, and four patients had an open fracture. The mean age of patients was 51.7 years. Forty-eight patients had an adequate duration of clinical follow-up (a mean of 18 months) for analysis. Complications were recorded, and the time to union was measured. Shoulder and elbow functions were assessed using the Constant Score and the Morrey Score, respectively. Forty-six fractures healed, with a mean time to clinical union of 10.3 weeks. Two patients developed pseudarthroses. There were four adverse events: two proximal screws backed out, one superficial infection at the insertion point, and one fracture at the distal end of the nail. Ninety-one percentage of patients had an excellent or good shoulder function. Five further operations were necessary: two for treatment of pseudarthroses, two for removal the backed out proximal screws, and one wound debridement for superficial infection. Antegrade humeral nailing is a valid therapeutic option for stabilization of humeral shaft fractures. By strictly adhering to the operation technique, the number and the severity of complications can be reduced. When good fracture alignment and stability are obtained, uneventful bone healing with good functional results is the rule.

  13. Naked Hair Shafts as a Marker of Cicatricial Alopecia.

    Science.gov (United States)

    Doytcheva, Kristina; Tan, Timothy; Guitart, Joan; Gerami, Pedram; Yazdan, Pedram

    2018-07-01

    Naked hair shafts (NHS) are free-floating hair shafts devoid of surrounding epithelium, supporting structures, and/or embedded in inflammation that may result from destruction of hair follicles by scarring processes such as inflammation and fibroplasia. Extensive examination of NHS has not been performed in scalp biopsies of alopecia. We retrospectively evaluated 622 scalp biopsies of alopecia [345 cicatricial alopecias (central centrifugal cicatricial alopecia, lichen planopilaris, discoid lupus erythematosus, acne keloidalis nuchae, and folliculitis decalvans] and 277 non-cicatricial alopecias [alopecia areata, androgenic alopecia, telogen effluvium, and psoriatic alopecia)] for the presence of NHS. NHS occurred in 0.72% (2/277) of non-cicatricial alopecias (1/102 of alopecia areata, 1/150 of androgenic alopecia, 0/17 of telogen effluvium, and 0/8 of psoriatic alopecia) and 20% (72/345) of cicatricial alopecias (27/118 of central centrifugal cicatricial alopecia, 29/109 of lichen planopilaris, 2/75 of discoid lupus erythematosus, 11/16 of acne keloidalis nuchae, and 3/27 of folliculitis decalvans). The presence of NHS was significantly increased in cicatricial alopecias in comparison with non-cicatricial alopecias; P value <0.0001. Among the cicatricial alopecias, 26% (92/345) had mild inflammation and/or fibrosis, of which 9% (9/92) had NHS. There were 73% (253/345) that had moderate to severe inflammation and/or fibrosis, of which 24% (63/253) had NHS, indicating that as the severity of inflammation and fibrosis increases, so does the presence of NHS. NHS rarely occurs in non-cicatricial alopecias. This variation may result from destruction of hair follicles by the inflammatory and scarring processes. The presence of NHS may be a useful adjunctive histopathologic feature in the diagnosis of cicatricial alopecia.

  14. ON THE TRANSITIONAL DISK CLASS: LINKING OBSERVATIONS OF T TAURI STARS AND PHYSICAL DISK MODELS

    International Nuclear Information System (INIS)

    Espaillat, C.; Andrews, S.; Qi, C.; Wilner, D.; Ingleby, L.; Calvet, N.; Hernández, J.; Furlan, E.; D'Alessio, P.; Muzerolle, J.

    2012-01-01

    Two decades ago 'transitional disks' (TDs) described spectral energy distributions (SEDs) of T Tauri stars with small near-IR excesses, but significant mid- and far-IR excesses. Many inferred this indicated dust-free holes in disks possibly cleared by planets. Recently, this term has been applied disparately to objects whose Spitzer SEDs diverge from the expectations for a typical full disk (FD). Here, we use irradiated accretion disk models to fit the SEDs of 15 such disks in NGC 2068 and IC 348. One group has a 'dip' in infrared emission while the others' continuum emission decreases steadily at all wavelengths. We find that the former have an inner disk hole or gap at intermediate radii in the disk and we call these objects 'transitional disks' and 'pre-transitional disks' (PTDs), respectively. For the latter group, we can fit these SEDs with FD models and find that millimeter data are necessary to break the degeneracy between dust settling and disk mass. We suggest that the term 'transitional' only be applied to objects that display evidence for a radical change in the disk's radial structure. Using this definition, we find that TDs and PTDs tend to have lower mass accretion rates than FDs and that TDs have lower accretion rates than PTDs. These reduced accretion rates onto the star could be linked to forming planets. Future observations of TDs and PTDs will allow us to better quantify the signatures of planet formation in young disks.

  15. Disentangling Accretion Disk and Dust Emissions in the Infrared Spectrum of Type 1 AGN

    Energy Technology Data Exchange (ETDEWEB)

    Hernán-Caballero, Antonio [Departamento de Astrofísica y CC. de la Atmósfera, Facultad de CC. Físicas, Universidad Complutense de Madrid, Madrid (Spain); European Southern Observatory, Garching bei München (Germany); Hatziminaoglou, Evanthia [European Southern Observatory, Garching bei München (Germany); Alonso-Herrero, Almudena [Centro de Astrobiología (CSIC-INTA), Madrid (Spain); Mateos, Silvia, E-mail: a.hernan@ucm.es [Instituto de Física de Cantabria (CSIC-UC), Santander (Spain)

    2017-10-31

    We use a semi-empirical model to reproduce the 0.1–10 μm spectral energy distribution (SED) of a sample of 85 luminous quasars. In the model, the continuum emission from the accretion disk as well as the nebular lines are represented by a single empirical template (disk), where differences in the optical spectral index are reproduced by varying the amount of extinction. The near- and mid-infrared emission of the AGN-heated dust is modeled as the combination of two black-bodies (dust). The model fitting shows that the disk and dust components are remarkably uniform among individual quasars, with differences in the observed SED largely accounted for by varying levels of obscuration in the disk as well as differences in the relative luminosity of the disk and dust components. By combining the disk-subtracted SEDs of the 85 quasars, we generate a template for the 1–10 μm emission of the AGN-heated dust. Additionally, we use a sample of local Seyfert 1 galaxies with full spectroscopic coverage in the 0.37–39 μm range to demonstrate a method for stitching together spectral segments obtained with different PSF and extraction apertures. We show that the disk and dust templates obtained from luminous quasars also reproduce the optical-to-mid-infrared spectra of local Seyfert 1s when the contribution from the host galaxy is properly subtracted.

  16. Disentangling Accretion Disk and Dust Emissions in the Infrared Spectrum of Type 1 AGN

    Directory of Open Access Journals (Sweden)

    Antonio Hernán-Caballero

    2017-10-01

    Full Text Available We use a semi-empirical model to reproduce the 0.1–10 μm spectral energy distribution (SED of a sample of 85 luminous quasars. In the model, the continuum emission from the accretion disk as well as the nebular lines are represented by a single empirical template (disk, where differences in the optical spectral index are reproduced by varying the amount of extinction. The near- and mid-infrared emission of the AGN-heated dust is modeled as the combination of two black-bodies (dust. The model fitting shows that the disk and dust components are remarkably uniform among individual quasars, with differences in the observed SED largely accounted for by varying levels of obscuration in the disk as well as differences in the relative luminosity of the disk and dust components. By combining the disk-subtracted SEDs of the 85 quasars, we generate a template for the 1–10 μm emission of the AGN-heated dust. Additionally, we use a sample of local Seyfert 1 galaxies with full spectroscopic coverage in the 0.37–39 μm range to demonstrate a method for stitching together spectral segments obtained with different PSF and extraction apertures. We show that the disk and dust templates obtained from luminous quasars also reproduce the optical-to-mid-infrared spectra of local Seyfert 1s when the contribution from the host galaxy is properly subtracted.

  17. SIZES AND TEMPERATURE PROFILES OF QUASAR ACCRETION DISKS FROM CHROMATIC MICROLENSING

    International Nuclear Information System (INIS)

    Blackburne, Jeffrey A.; Pooley, David; Rappaport, Saul; Schechter, Paul L.

    2011-01-01

    Microlensing perturbations to the flux ratios of gravitationally lensed quasar images can vary with wavelength because of the chromatic dependence of the accretion disk's apparent size. Multiwavelength observations of microlensed quasars can thus constrain the temperature profiles of their accretion disks, a fundamental test of an important astrophysical process which is not currently possible using any other method. We present single-epoch broadband flux ratios for 12 quadruply lensed quasars in 8 bands ranging from 0.36 to 2.2 μm, as well as Chandra 0.5-8 keV flux ratios for five of them. We combine the optical/IR and X-ray ratios, together with X-ray ratios from the literature, using a Bayesian approach to constrain the half-light radii of the quasars in each filter. Comparing the overall disk sizes and wavelength slopes to those predicted by the standard thin accretion disk model, we find that on average the disks are larger than predicted by nearly an order of magnitude, with sizes that grow with wavelength with an average slope of ∼0.2 rather than the slope of 4/3 predicted by the standard thin disk theory. Though the error bars on the slope are large for individual quasars, the large sample size lends weight to the overall result. Our results present severe difficulties for a standard thin accretion disk as the main source of UV/optical radiation from quasars.

  18. Evidence for large temperature fluctuations in quasar accretion disks from spectral variability

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, John J.; Anderson, Scott F.; Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Dexter, Jason, E-mail: jruan@astro.washington.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)

    2014-03-10

    The well-known bluer-when-brighter trend observed in quasar variability is a signature of the complex processes in the accretion disk and can be a probe of the quasar variability mechanism. Using a sample of 604 variable quasars with repeat spectra in the Sloan Digital Sky Survey-I/II (SDSS), we construct difference spectra to investigate the physical causes of this bluer-when-brighter trend. The continuum of our composite difference spectrum is well fit by a power law, with a spectral index in excellent agreement with previous results. We measure the spectral variability relative to the underlying spectra of the quasars, which is independent of any extinction, and compare to model predictions. We show that our SDSS spectral variability results cannot be produced by global accretion rate fluctuations in a thin disk alone. However, we find that a simple model of an inhomogeneous disk with localized temperature fluctuations will produce power-law spectral variability over optical wavelengths. We show that the inhomogeneous disk will provide good fits to our observed spectral variability if the disk has large temperature fluctuations in many independently varying zones, in excellent agreement with independent constraints from quasar microlensing disk sizes, their strong UV spectral continuum, and single-band variability amplitudes. Our results provide an independent constraint on quasar variability models and add to the mounting evidence that quasar accretion disks have large localized temperature fluctuations.

  19. On the conventive instability evolution in a rotating gas disk

    International Nuclear Information System (INIS)

    Nikonov, S.V.; Solov'ev, L.S.

    1986-01-01

    The mechanism of formation of spiral configuration in a rotating gravitating gas disk, caused by the nonlinear development of the convective instability, is considered. The mechanism suggested may be considered as the model of formation of the galaxy spiral configuration in a rotating pregalactic gas disk due to the development of the convective instability. Unlike the popular at present conception of ''density waves'', formation of the spiral configuration, from this point of view, is the single process of the development of instability in the pregalactic gas cloud. The further advantageous star formation in the vicinity of the central region, in a strip and sleeves is caused by higher concentration of gas density and temperature in these regions

  20. Phase models of galaxies consisting of disk and halo

    International Nuclear Information System (INIS)

    Osipkov, L.P.; Kutuzov, S.A.

    1987-01-01

    A method of finding the phase density of a two-component model of mass distribution is developed. The equipotential surfaces and the potential law are given. The equipotentials are lenslike surfaces with a sharp edge in the equatorial plane, which provides the existence of an imbedded thin disk in halo. The equidensity surfaces of the halo coincide with the equipotentials. Phase models for the halo and the disk are constructed separately on the basis of spatial and surface mass densities by solving the corresponding integral equations. In particular the models for the halo with finite dimensions can be constructed. The even part of the phase density in respect to velocities is only found. For the halo it depends on the energy integral as a single argument

  1. Design and Analysis of Drive Shaft using Kevlar/Epoxy and Glass/Epoxy as a Composite Material

    Science.gov (United States)

    Karthikeyan, P.; Gobinath, R.; Kumar, L. Ajith; Jenish, D. Xavier

    2017-05-01

    In automobile industry drive shaft is one of the most important components to transmit power form the engine to rear wheel through the differential gear. Generally steel drive shaft is used in automobile industry, nowadays they are more interested to replace steel drive shaft with that of composite drive shaft. The overall objective of this paper is to analyze the composite drive shaft using to find out the best replacement for conventional steel drive shaft. The uses of advanced composite materials such as Kevlar, Graphite, Carbon and Glass with proper resins ware resulted in remarkable achievements in automobile industry because of its greater specific strength and specific modulus, improved fatigue and corrosion resistances and reduction in energy requirements due to reduction in weight as compared to steel shaft. This paper is to presents, the modeling and analysis of drive shaft using Kevlar/Epoxy and Glass/Epoxy as a composite material and to find best replacement for conventional steel drive shafts with an Kevlar/epoxy or Glass/Epoxy resin composite drive shaft. Modeling is done using CATIA software and Analysis is carried out by using ANSYS 10.0 software for easy understanding. The composite drive shaft reduces the weight by 81.67 % for Kevlar/Epoxy and 72.66% for Glass/Epoxy when compared with conventional steel drive shaft.

  2. Scaling Ratios and Triangles in Siegel Disks

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    1999-01-01

    Let f(z)=e^{2i\\pi \\theta} + z^2, where \\theta is a quadratic irrational. McMullen proved that the Siegel disk for f is self-similar about the critical point, and we show that if \\theta = (\\sqrt{5}-1)/2 is the golden mean, then there exists a triangle contained in the Siegel disk, and with one...

  3. Attention Novices: Friendly Intro to Shiny Disks.

    Science.gov (United States)

    Bardes, D'Ellen

    1986-01-01

    Provides an overview of how optical storage technologies--videodisk, Write-Once disks, and CD-ROM CD-I disks are built into and controlled via DEC, Apple, Atari, Amiga, and IBM PC compatible microcomputers. Several available products are noted and a list of producers is included. (EM)

  4. Circumstellar disks around binary stars in Taurus

    International Nuclear Information System (INIS)

    Akeson, R. L.; Jensen, E. L. N.

    2014-01-01

    We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10 –4 M ☉ . We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F mm ∝M ∗ 1.5--2.0 to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

  5. Circumstellar disks around binary stars in Taurus

    Energy Technology Data Exchange (ETDEWEB)

    Akeson, R. L. [NASA Exoplanet Science Institute, IPAC/Caltech, Pasadena, CA 91125 (United States); Jensen, E. L. N. [Swarthmore College, Department of Physics and Astronomy, Swarthmore, PA 19081 (United States)

    2014-03-20

    We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10{sup –4} M {sub ☉}. We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F{sub mm}∝M{sub ∗}{sup 1.5--2.0} to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

  6. Improper colouring of (random) unit disk graphs

    NARCIS (Netherlands)

    Kang, R.J.; Müller, T.; Sereni, J.S.

    2008-01-01

    For any graph G, the k-improper chromatic number ¿k(G) is the smallest number of colours used in a colouring of G such that each colour class induces a subgraph of maximum degree k. We investigate ¿k for unit disk graphs and random unit disk graphs to generalise results of McDiarmid and Reed

  7. Grinding Glass Disks On A Belt Sander

    Science.gov (United States)

    Lyons, James J., III

    1995-01-01

    Small machine attached to table-top belt sander makes possible to use belt sander to grind glass disk quickly to specified diameter within tolerance of about plus or minus 0.002 in. Intended to be used in place of production-shop glass grinder. Held on driveshaft by vacuum, glass disk rotated while periphery ground by continuous sanding belt.

  8. Recent development of disk lasers at TRUMPF

    Science.gov (United States)

    Schad, Sven-Silvius; Gottwald, Tina; Kuhn, Vincent; Ackermann, Matthias; Bauer, Dominik; Scharun, Michael; Killi, Alexander

    2016-03-01

    The disk laser is one of the most important laser concepts for today's industrial laser market. Offering high brilliance at low cost, high optical efficiency and great application flexibility the disk laser paved the way for many industrial laser applications. Over the past years power and brightness increased and the disk laser turned out to be a very versatile laser source, not only for welding but also for cutting. Both, the quality and speed of cutting are superior to CO2-based lasers for a vast majority of metals, and, most important, in a broad thickness range. In addition, due to the insensitivity against back reflections the disk laser is well suited for cutting highly reflective metal such as brass or copper. These advantages facilitate versatile cutting machines and explain the high and growing demand for disk lasers for applications besides welding applications that can be observed today. From a today's perspective the disk principle has not reached any fundamental limits regarding output power per disk or beam quality, and offers numerous advantages over other high power resonator concepts, especially over fiber lasers or direct diode lasers. This paper will give insight in the latest progress in kilowatt class cw disk laser technology at TRUMPF and will discuss recent power scaling results as well.

  9. Disk Galaxies : Building Blocks of the Universe?

    OpenAIRE

    Bower, Richard

    2016-01-01

    In my talk I look at the origin of disk galaxies from the theoretical perspective. In particular I look at simple ways to use the properties of disk galaxies, and their evolution, to test our current paradigm for galaxy formation within the CDM scenario.

  10. Protoplanetary disks and exoplanets in scattered light

    NARCIS (Netherlands)

    Stolker, T.

    2017-01-01

    High-contrast imaging facilitates the direct detection of protoplanetary disks in scattered light and self-luminous exoplanets on long-period orbits. The combined power of extreme adaptive optics and differential imaging techniques delivers high spatial resolution images of disk morphologies down to

  11. Continuum Reverberation Mapping of AGN Accretion Disks

    Energy Technology Data Exchange (ETDEWEB)

    Fausnaugh, Michael M. [Department of Astronomy, Ohio State University, Columbus, OH (United States); MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States); Peterson, Bradley M. [Department of Astronomy, Ohio State University, Columbus, OH (United States); Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH (United States); Space Telescope Science Institute, Baltimore, MD (United States); Starkey, David A. [SUPA Physics and Astronomy, University of St. Andrews, Scotland (United Kingdom); Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Horne, Keith, E-mail: faus@mit.edu [SUPA Physics and Astronomy, University of St. Andrews, Scotland (United Kingdom); Collaboration: the AGN STORM Collaboration

    2017-12-05

    We show recent detections of inter-band continuum lags in three AGN (NGC 5548, NGC 2617, and MCG+08-11-011), which provide new constraints on the temperature profiles and absolute sizes of the accretion disks. We find lags larger than would be predicted for standard geometrically thin, optically thick accretion disks by factors of 2.3–3.3. For NGC 5548, the data span UV through optical/near-IR wavelengths, and we are able to discern a steeper temperature profile than the T ~ R{sup −3/4} expected for a standard thin disk. Using a physical model, we are also able to estimate the inclinations of the disks for two objects. These results are similar to those found from gravitational microlensing of strongly lensed quasars, and provide a complementary approach for investigating the accretion disk structure in local, low luminosity AGN.

  12. Chemical evolution of the galactic disk

    International Nuclear Information System (INIS)

    Wyse, R.F.G.; Gilmore, G.

    1987-01-01

    The distribution of enriched material in the stars and gas of their Galaxy contains information pertaining to the chemical evolution of the Milky Way from its formation epoch to the present day, and provides general constraints on theories of galaxy formation. The separate stellar components of the Galaxy cannot readily be understood if treated in isolation, but a reasonably self-consistent model for Galactic chemical evolution may be found if one considers together the chemical properties of the extreme spheroid, thick disk and thin disk populations of the Galaxy. The three major stellar components of the Galaxy are characterized by their distinct spatial distributions, metallicity structure, and kinematics, with the newly-identified thick disk being approximately three times more massive than the classical metal-poor, non-rotating extreme spheroid. Stellar evolution in the thick disk straightforwardly provides the desired pre-enrichment for resolution of the thin disk G dwarf problem

  13. Hydrodynamical winds from a geometrically thin disk

    International Nuclear Information System (INIS)

    Fukue, Jun

    1989-01-01

    Hydrodynamical winds emanating from the surface of a geometrically thin disk under the gravitational field of the central object are examined. The attention is focused on the transonic nature of the flow. For a given configuration of streamlines, the flow fields are divided into three regions: the inner region where the gas near the disk plane is gravitationally bound to form a corona; the intermediate wind region where multiple critical points appear and the gas flows out from the disk passing through critical points; and the outer region where the gas is unbound to escape to infinity without passing through critical points. This behavior of disk winds is due to the shape of the gravitational potential of the central object along the streamline and due to the energy source distribution at the flow base on the disk plane where the potential in finite. (author)

  14. Disk Evolution and the Fate of Water

    Science.gov (United States)

    Hartmann, Lee; Ciesla, Fred; Gressel, Oliver; Alexander, Richard

    2017-10-01

    We review the general theoretical concepts and observational constraints on the distribution and evolution of water vapor and ice in protoplanetary disks, with a focus on the Solar System. Water is expected to freeze out at distances greater than 1-3 AU from solar-type central stars; more precise estimates are difficult to obtain due to uncertainties in the complex processes involved in disk evolution, including dust growth, settling, and radial drift, and the level of turbulence and viscous dissipation within disks. Interferometric observations are now providing constraints on the positions of CO snow lines, but extrapolation to the unresolved regions where water ice sublimates will require much better theoretical understanding of mass and angular momentum transport in disks as well as more refined comparison of observations with sophisticated disk models.

  15. Development of Powered Disk Type Sugar Cane Stubble Saver

    Directory of Open Access Journals (Sweden)

    Radite P.A.S.

    2009-04-01

    Full Text Available The objective of this research was to design, fabricate and test a prototype of sugar cane stubble saver based on powered disk mechanism. In this research, a heavy duty disk plow or disk harrow was used as a rotating knife to cut the sugarcane stubble. The parabolic disk was chosen because it is proven reliable as soil working tools and it is available in the market as spare part of disk plow or disk harrow unit. The prototype was mounted on the four wheel tractor’s three point hitch, and powered by PTO of the tractor. Two kinds of disks were used in these experiments, those were disk with regular edge or plain disk and disk with scalloped edge or scalloped disk. Both disks had diameter of 28 inch. Results of field test showed that powered disk mechanism could satisfy cut sugar cane’s stubble. However, scalloped disk type gave smoother stubble cuts compared to that of plain disk. Plain disk type gave broken stubble cut. Higher rotation (1000 rpm resulted better cuts as compared to lower rotation (500 rpm both either on plain disk and scalloped disk. The developed prototype could work below the soil surface at depth of 5 to 10 cm. With tilt angle setting 20O and disk angle 45O the width of cut was about 25 cm.

  16. THE DARK DISK OF THE MILKY WAY

    International Nuclear Information System (INIS)

    Purcell, Chris W.; Bullock, James S.; Kaplinghat, Manoj

    2009-01-01

    Massive satellite accretions onto early galactic disks can lead to the deposition of dark matter in disk-like configurations that co-rotate with the galaxy. This phenomenon has potentially dramatic consequences for dark matter detection experiments. We utilize focused, high-resolution simulations of accretion events onto disks designed to be Galaxy analogues, and compare the resultant disks to the morphological and kinematic properties of the Milky Way's thick disk in order to bracket the range of co-rotating accreted dark matter. In agreement with previous results, we find that the Milky Way's merger history must have been unusually quiescent compared to median Λ cold dark matter expectations and, therefore, its dark disk must be relatively small: the fraction of accreted dark disk material near the Sun is about 20% of the host halo density or smaller and the co-rotating dark matter fraction near the Sun, defined as particles moving with a rotational velocity lag less than 50 km s -1 , is enhanced by about 30% or less compared to a standard halo model. Such a dark disk could contribute dominantly to the low energy (of order keV for a dark matter particle with mass 100 GeV) nuclear recoil event rate of direct detection experiments, but it will not change the likelihood of detection significantly. These dark disks provide testable predictions of weakly interacting massive particle dark matter models and should be considered in detailed comparisons to experimental data. Our findings suggest that the dark disk of the Milky Way may provide a detectable signal for indirect detection experiments, contributing up to about 25% of the dark matter self-annihilation signal in the direction of the center of the Galaxy, lending the signal a noticeably oblate morphology.

  17. Equilibrium figures for beta Lyrae type disks

    International Nuclear Information System (INIS)

    Wilson, R.E.

    1981-01-01

    Accumulated evidence for a geometrically and optically thick disk in the β Lyrae system has now established the disk's basic external configuration. Since the disk has been constant in its main properties over the historical interval of β Lyrae observations and also seems to have a basically well-defined photosphere, it is now time to being consideration of its sturcture. Here, we compute equilibrium figures for self-gravitating disks around stars in binary systems as a start toward eventual computation of complete disk models. A key role is played by centrifugally limited rotation of the central star, which would naturally arise late in the rapid phase of mass transfer. Beta Lyrae is thus postulated to be a double-contact binary, which makes possible nonarbitrary separation of star and disk into separate structures. The computed equilibrium figures are three-dimensional, as the gravitation of the second star is included. Under the approximation that the gravitational potential of the disk is that of a thin wire and that the local disk angular velocity is proportional to u/sup n/ (u = distance from rotation axis), we comptue the total potential and locate equipotential surfaces. The centrifugal potential is written in a particularly convenient form which permits one to change the rotation law discontinuously (for example, at the star-disk coupling point) while ensuring that centrifugal potential and centrifigual force are continuous functions of position. With such a one-parameter rotation law, one can find equilibrium disk figures with dimensions very similar to those found in β Lyrae, but considerations of internal consistency demand at least a two-parameter law

  18. A field trail for sealing abandoned mine shafts and adits with lightweight concrete

    International Nuclear Information System (INIS)

    Skinner, E.H.; Beckett, L.A.

    1994-01-01

    An abandoned mine shaft near Omar, in Logan County, WV, was permanently sealed through a cooperative agreement between the West Virginia Department of Commerce, Labor, and Environmental Resources, Division of Environmental Protection, and the US Bureau of Mines (USBM), Abandoned Mine Lands (AML) Program. An engineered shaft seal design was developed and demonstrated that featured lightweight concrete as a key material component at a wet density of about 45 lb/ft 3 . A reinforced concrete cap designed for 5 psi live load was placed over the shaft seal. Applicable new concrete technologies relating to a 100-yr design life were utilized to assure future integrity of the shaft seal. Waterproofing methods were included in the shaft seal design to provide protection from ambient moisture and corrosive mine waters and to increase the long-term durability of the shaft seal. All construction methods used in the field trial are fully adaptable for the mine-reclamation contractor. The USBM research objectives were to develop a broad generic design that will be widely applicable to other adit-sealing and shaft-sealing problems throughout the mining industry

  19. Parameter optimization method for longitudinal vibration absorber of ship shaft system

    Directory of Open Access Journals (Sweden)

    LIU Jinlin

    2017-05-01

    Full Text Available The longitudinal vibration of the ship shaft system is the one of the most important factors of hull stern vibration, and it can be effectively minimized by installing a longitudinal vibration absorber. In this way, the vibration and noise of ships can be brought under control. However, the parameters of longitudinal vibration absorbers have a great influence on the vibration characteristics of the shaft system. As such, a certain shafting testing platform was studied as the object on which a finite model was built, and the relationship between longitudinal stiffness and longitudinal vibration in the shaft system was analyzed in a straight alignment state. Furthermore, a longitudinal damping model of the shaft system was built in which the parameters of the vibration absorber were non-dimensionalized, the weight of the vibration absorber was set as a constant, and an optimizing algorithm was used to calculate the optimized stiffness and damping coefficient of the vibration absorber. Finally, the longitudinal vibration frequency response of the shafting testing platform before and after optimizing the parameters of the longitudinal vibration absorber were compared, and the results indicated that the longitudinal vibration of the shafting testing platform was decreased effectively, which suggests that it could provide a theoretical foundation for the parameter optimization of longitudinal vibration absorbers.

  20. New Technical Solution for Vertical Shaft Equipping Using Steel Headframe of Multifunction Purpose

    Science.gov (United States)

    Kassikhina, Elena; Pershin, Vladimir; Glazkov, Yurij

    2017-11-01

    The article reviews a novel approach to the design of steel angle headframe for vertical shafts of coal and ore mines on the basis of rational design solutions. Practice of construction of coal and ore mines provides application of various designs for steel angle headframes which are divided into separate large assembly blocks and constructive elements during assembling operations. Design of these blocks and elements, their weight and dimensions effect the chose of the method of assembling on which economic and technological indicators, as well as duration of down-time, depend on during performance of construction operations in shaft. The technical solution on equipment provision for mine vertical shaft using headframe of multifunctional purpose will allow changing the management construction of vertical shaft. The constructive design of the headgear allows application of the effective method of assembly and thus to provide improvement of the technical and economic indexes, and high calendar time rate of the shaft construction due to reduction of duration of works on equipment provision for the shaft and to refurbishment of the shaft in order to carry out horizontal mining.

  1. A study on rock mass behaviour induced by shaft sinking in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Tsusaka, Kimikazu; Tokiwa, Tetsuya; Inagaki, Daisuke; Hatsuyama, Yoshihiro; Koike, Masashi; Ijiri, Yuji

    2012-01-01

    Japan Atomic Energy Agency has been excavating three deep shafts through soft sedimentary rock in the Horonobe Underground Research Laboratory. In this paper, the authors discussed rock mass behaviour induced by a 6.5 m diameter shaft sinking. They conducted geological mapping in an excavation face and boreholes digged around the shaft wall, field measurements such as convergence measurements and monitoring of rock displacements using multi-interval borehole extensometers around a shaft at around 160 m and 220 m in depths, and three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that remarkably large compressive strains occurred within about 1 m into the shaft wall in a radial direction since the rock mass behaviour was controlled by the concrete lining and that the behaviour would predominantly be induced by the fractures closing which opened significantly and propagated during excavation steps before the installation of a concrete lining and the directions where the strains occurred heavily depended on the fracture orientation around the shaft. (author)

  2. Classical Measurement Methods and Laser Scanning Usage in Shaft Hoist Assembly Inventory

    Directory of Open Access Journals (Sweden)

    Jaśkowski Wojciech

    2018-01-01

    Full Text Available The shaft hoist assembly is the base of underground mining plant. Its efficiency and correct operation is subject to restrictive legal regulations and is controlled on a daily visual assessment by shaft crew and energomechanics. In addition, in the regular interval, the shaft hoist assembly is subject to a thorough inventory, which includes the determination of the geometrical relationships between the hoisting machine, the headframe and the shaft with its housing. Inventory measurements for shaft and headframe are used for years of conventional geodetic methods including mechanical or laser plumbing and tachymetric surveys. Additional precision levelling is also used for measuring shafts of hoisting machines and rope pulleys. Continuous modernization of measuring technology makes it possible to implement the further methods to the above mentioned purposes. The comparison of the accuracy and the economics of performing measurements based on many years of experience with comprehensive inventory of shaft hoist assembly using various research techniques was made and detailed in the article.

  3. METHOD OF ACHIEVING ACCURACY OF THERMO-MECHANICAL TREATMENT OF LOW-RIGIDITY SHAFTS

    Directory of Open Access Journals (Sweden)

    Antoni Świć

    2016-03-01

    Full Text Available The paper presents a method combining the processes of straightening and thermal treatment. Technological processes with axial strain were considered, for the case of heated material and without its heating. The essence of the process in the case of heated material consisted in the fact that if under tension all longitudinal forces in the first approximation are uniform - the same strains are generated. The presented technological approach, aimed at reducing the curvature of axial-symmetrical parts, is acceptable as the process of rough, preliminary machining, in the case of shafts with the ratio L/D≤100 (L – shaft length, d – shaft diameter and without a tendency of strengthening. To improve the accuracy and stability of geometric form of low-rigidity parts, a method was developed that combines the processes of straightening and heat treatment. The method consists in that axial strain – tension, is applied to the shaft during heating, and during cooling the product is fixed in a fixture, the cooling rate of the shaft being several-fold greater than that of the fixture. A device is presented for the realisation of the method of controlling the process of plastic deformation of low-rigidity shafts. In the case of the presented device and the adopted calculation scheme, a method was developed that permits the determination of the length of shaft section and of the time of its cooling.

  4. The Mechanical Properties of Candidate Superalloys for a Hybrid Turbine Disk

    Science.gov (United States)

    Gabb, Timothy P.; MacKay, Rebecca A.; Draper, Susan L.; Sudbrack, Chantal K.; Nathal, Michael V.

    2013-01-01

    The mechanical properties of several cast blade superalloys and one powder metallurgy disk superalloy were assessed for potential use in a dual alloy hybrid disk concept of joined dissimilar bore and web materials. Grain size was varied for each superalloy class. Tensile, creep, fatigue, and notch fatigue tests were performed at 704 to 815 degC. Typical microstructures and failure modes were determined. Preferred materials were then selected for future study as the bore and rim alloys in this hybrid disk concept. Powder metallurgy superalloy LSHR at 15 micron grain size and single crystal superalloy LDS-1101+Hf were selected for further study, and future work is recommended to develop the hybrid disk concept.

  5. Atmosphere-entry behavior of a modular, disk-shaped, isotope heat source.

    Science.gov (United States)

    Vorreiter, J. W.; Pitts, W. C.; Stine, H. A.; Burns, J. J.

    1973-01-01

    The authors have studied the entry and impact behavior of an isotope heat source for space nuclear power that disassembles into a number of modules which would enter the earth's atmosphere separately if a flight aborted. These modules are disk-shaped units, each with its own reentry heat shield and protective impact container. In normal operation, the disk modules are stacked inside the generator, but during a reentry abort they separate and fly as individual units of low ballistic coefficient. Flight tests at hypersonic speeds have confirmed that a stack of disks will separate and assume a flat-forward mode of flight. Free-fall tests of single disks have demonstrated a nominal impact velocity of 30 m/sec at sea level for a practical range of ballistic coefficients.

  6. HIDING IN THE SHADOWS: SEARCHING FOR PLANETS IN PRE-TRANSITIONAL AND TRANSITIONAL DISKS

    International Nuclear Information System (INIS)

    Dobinson, Jack; Leinhardt, Zoë M.; Dodson-Robinson, Sarah E.; Teanby, Nick A.

    2013-01-01

    Transitional and pre-transitional disks can be explained by a number of mechanisms. This work aims to find a single observationally detectable marker that would imply a planetary origin for the gap and, therefore, indirectly indicate the presence of a young planet. N-body simulations were conducted to investigate the effect of an embedded planet of one Jupiter mass on the production of instantaneous collisional dust derived from a background planetesimal disk. Our new model allows us to predict the dust distribution and resulting observable markers with greater accuracy than previous works. Dynamical influences from a planet on a circular orbit are shown to enhance dust production in the disk interior and exterior to the planet orbit, while removing planetesimals from the orbit itself, creating a clearly defined gap. In the case of an eccentric planet, the gap opened by the planet is not as clear as the circular case, but there is a detectable asymmetry in the dust disk

  7. Chemistry in an evolving protoplanetary disk: Effects on terrestrial planet composition

    International Nuclear Information System (INIS)

    Moriarty, John; Fischer, Debra; Madhusudhan, Nikku

    2014-01-01

    The composition of planets is largely determined by the chemical and dynamical evolution of the disk during planetesimal formation and growth. To predict the diversity of exoplanet compositions, previous works modeled planetesimal composition as the equilibrium chemical composition of a protoplanetary disk at a single time. However, planetesimals form over an extended period of time, during which elements sequentially condense out of the gas as the disk cools and are accreted onto planetesimals. To account for the evolution of the disk during planetesimal formation, we couple models of disk chemistry and dynamics with a prescription for planetesimal formation. We then follow the growth of these planetesimals into terrestrial planets with N-body simulations of late-stage planet formation to evaluate the effect of sequential condensation on the bulk composition of planets. We find that our model produces results similar to those of earlier models for disks with C/O ratios close to the solar value (0.54). However, in disks with C/O ratios greater than 0.8, carbon-rich planetesimals form throughout a much larger radial range of the disk. Furthermore, our model produces carbon-rich planetesimals in disks with C/O ratios as low as ∼0.65, which is not possible in the static equilibrium chemistry case. These results suggest that (1) there may be a large population of short-period carbon-rich planets around moderately carbon-enhanced stars (0.65 < C/O < 0.8) and (2) carbon-rich planets can form throughout the terrestrial planet region around carbon-rich stars (C/O > 0.8).

  8. PHOTOIONIZATION MODELS OF THE INNER GASEOUS DISK OF THE HERBIG BE STAR BD+65 1637

    Energy Technology Data Exchange (ETDEWEB)

    Patel, P.; Sigut, T. A. A.; Landstreet, J. D., E-mail: ppatel54@uwo.ca [Department of Physics and Astronomy, The University of Western Ontario, London, Ontario Canada N6A 3K7 (Canada)

    2016-01-20

    We attempt to constrain the physical properties of the inner, gaseous disk of the Herbig Be star BD+65 1637 using non-LTE, circumstellar disk codes and observed spectra (3700–10500 Å) from the ESPaDOnS instrument on the Canada–France–Hawaii Telescope. The photoionizing radiation of the central star is assumed to be the sole source of input energy for the disk. We model optical and near-infrared emission lines that are thought to form in this region using standard techniques that have been successful in modeling the spectra of classical Be stars. By comparing synthetic line profiles of hydrogen, helium, iron, and calcium with the observed line profiles, we try to constrain the geometry, density structure, and kinematics of the gaseous disk. Reasonable matches have been found for all line profiles individually; however, no disk density model based on a single power law for the equatorial density was able to simultaneously fit all of the observed emission lines. Among the emission lines, the metal lines, especially the Ca ii IR triplet, seem to require higher disk densities than the other lines. Excluding the Ca ii lines, a model in which the equatorial disk density falls as 10{sup −10} (R{sub *}/R){sup 3} g cm{sup −3} seen at an inclination of 45° for a 50 R{sub *} disk provides reasonable matches to the overall line shapes and strengths. The Ca ii lines seem to require a shallower drop-off as 10{sup −10} (R{sub *}/R){sup 2} g cm{sup −3} to match their strength. More complex disk density models are likely required to refine the match to the BD+65 1637 spectrum.

  9. HERSCHEL OBSERVATIONS AND UPDATED SPECTRAL ENERGY DISTRIBUTIONS OF FIVE SUNLIKE STARS WITH DEBRIS DISKS

    International Nuclear Information System (INIS)

    Dodson-Robinson, Sarah E.; Su, Kate Y. L.; Bryden, Geoff; Harvey, Paul; Green, Joel D.

    2016-01-01

    Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R  > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R  > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μ m infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a min  ∼ 3 μ m, although a min is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10 −5  ⩽  L / L ⊙  ⩽ 2 × 10 −4 , consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

  10. HERSCHEL OBSERVATIONS AND UPDATED SPECTRAL ENERGY DISTRIBUTIONS OF FIVE SUNLIKE STARS WITH DEBRIS DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Dodson-Robinson, Sarah E. [Department of Physics and Astronomy, University of Delaware, 217 Sharp Lab, Newark, DE 19716 (United States); Su, Kate Y. L. [Steward Observatory, Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoff [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Harvey, Paul; Green, Joel D., E-mail: sdr@udel.edu [Astronomy Department, University of Texas, 2515 Speedway Drive C1400, Austin, TX 78712 (United States)

    2016-12-20

    Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R  > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R  > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μ m infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a {sub min} ∼ 3 μ m, although a {sub min} is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10{sup −5} ⩽  L / L {sub ⊙} ⩽ 2 × 10{sup −4}, consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

  11. Thermal Comptonization in standard accretion disks

    International Nuclear Information System (INIS)

    Maraschi, L.; Molendi, S.

    1990-01-01

    The standard model of an accretion disk is considered. The temperature in the inner region is computed assuming that the radiated power derives from Comptonized photons, produced in a homogeneous single-temperature plasma, supported by radiation pressure. The photon production mechanisms are purely thermal, including ion-electron bremsstrahlung, bound-free and bound-bound processes, and e-e bremsstrahlung. Pair production is not included, which limits the validity of the treatment to kT less than 60 keV. Three different approximations for the effects of Comptonization on the energy loss are used, yielding temperatures which agree within 50 percent. The maximum temperature is very sensitive to the accretion rate and viscosity parameters, ranging, for a 10 to the 8th solar mass black hole, between 0.1 and 50 keV for m between 0.1 and 1 and alpha between 0.1 and 1 and, for a 10-solar-mass black hole, between 0.6 and 60 keV for m between 0.1 and 0.9 and alpha between 0.1 and 0.5. For high viscosity and accretion rates, the emission spectra show a flat component following a peak corresponding to the temperature of the innermost optically thick annulus. 28 refs

  12. Influence of Shaft Torsional Stiffness on Dynamic Response of Four-Stage Main Transmission System

    Directory of Open Access Journals (Sweden)

    Yuan Chen

    2018-01-01

    Full Text Available Dynamic response analysis has potential for increasing fatigue life of the components in the transmission of a multistage main transmission system. The calculated data can demonstrate the influence of shaft torsional stiffness on dynamic characteristics of the system. Detecting key shafts of the system and analyzing their sensitivity are important for the design of four-stage helicopter gear box. Lumped mass method is applied for dynamic modeling and Fourier method is used to solve differential equation of the system. Results of the analysis indicate that key shafts can be designed carefully to improve the performance of the transmission system.

  13. Elastomer damper performance - A comparison with a squeeze film for a supercritical power transmission shaft

    Science.gov (United States)

    Zorzi, E. S.; Burgess, G.; Cunningham, R.

    1980-01-01

    This paper describes the design and testing of an elastomer damper on a super-critical power transmission shaft. The elastomers were designed to provide acceptable operation through the fourth bending mode and to control synchronous as well as nonsynchronous vibration throughout the operating range. The design of the elastomer was such that it could be incorporated into the system as a replacement for a squeeze-film damper without a reassembly, which could have altered the imbalance of the shaft. This provided a direct comparison of the elastomer and squeeze-film dampers without having to assess the effect of shaft imbalance changes.

  14. Numerical analysis on the action of centrifuge force in magnetic fluid rotating shaft seals

    Science.gov (United States)

    Zou, Jibin; Li, Xuehui; Lu, Yongping; Hu, Jianhui

    2002-11-01

    The magnetic fluid seal is suitable for high-speed rotating shaft seal applications. Centrifuge force will have evident influence on magnetic fluid rotating shaft seals. The seal capacity of the rotating shaft seal can be improved or increased by some measures. Through hydrodynamic analysis the moving status of the magnetic fluid is worked out. By numerical method, the magnetic field and the isobars in the magnetic fluid of a seal device are computed. Then the influence of the centrifuge force on the magnetic fluid seal is calculated quantitatively.

  15. Numerical analysis on the action of centrifuge force in magnetic fluid rotating shaft seals

    International Nuclear Information System (INIS)

    Zou Jibin; Li Xuehui; Lu Yongping; Hu Jianhui

    2002-01-01

    The magnetic fluid seal is suitable for high-speed rotating shaft seal applications. Centrifuge force will have evident influence on magnetic fluid rotating shaft seals. The seal capacity of the rotating shaft seal can be improved or increased by some measures. Through hydrodynamic analysis the moving status of the magnetic fluid is worked out. By numerical method, the magnetic field and the isobars in the magnetic fluid of a seal device are computed. Then the influence of the centrifuge force on the magnetic fluid seal is calculated quantitatively

  16. Technique to reduce the shaft torque stress at an induction machine

    Directory of Open Access Journals (Sweden)

    Adrian Tulbure

    2005-10-01

    Full Text Available For the active attenuation at load stress in the drive shaft, the control system should receive as input signal the instantaneous shaft torque value. In this context an intelligent observer for shaft tongue of mains operatea induction machine, which is able to responding by variation of LIF (Load Input Function[1] must be developed. Extensive computer simulation prove the effectiveness of the proposed solution. In order to obtain a practical validation, the stimulated regulator has been designed and tested in the Institute of Electrical Engineering in Clausthal/Germany [2]. This paper contains following parts: Developing the mathematical model, Practical realisation, Simulations and measurements, Evaluating the control solutions and Conclusions.

  17. Explosion-proof conservation of the Lohberg shaft 1 and 2; Explosionsfeste Konservierung der Schaechte Lohberg 1 und 2

    Energy Technology Data Exchange (ETDEWEB)

    Hachmann, Andreas [AHA - Andreas Hachmann, Recklinghausen (Germany). Pruefung und Abnahme

    2010-03-15

    In the course of closure of the former Lohberg/Osterfeld colliery backfilling of shafts 1 and 2 with concrete was envisaged according to the original plans. On the basis of a modified plan, however, the two shafts will now be maintained for drainage. Hence a suspended pack was constructed on the 3{sup rd} level for each of the two shafts. Both shafts must be explosion-proof until the water is raised. The structural steel solution described in more detail in this contribution was applied in both shafts. (orig.)

  18. Development Of Design Equations For A Square-tube Subbase Supporting A Shaft-mounted Speed Reducer

    OpenAIRE

    Brown III, William E.

    2002-01-01

    Shaft mounted speed reducers are used in material handling applications, such as conveyor systems for transporting ore out of mine shafts. A subbase joins the reducer with an electric motor, and serves to limit the misalignment between the motor shaft and the reducer input shaft. The entire assembly is supported at two points: the axis of rotation of the reducer output shaft, which is fixed, and a clevis-pin joint under the motor, which prevents rotation of the assembly about the reducer ou...

  19. Outcomes of The Isolated Closed Tibial Shaft Fractures Treated Nonsurgically

    Directory of Open Access Journals (Sweden)

    Dawood Jafari

    2011-05-01

    Full Text Available Background: Fractures of the tibia are important for their commonness and controversy in their management. Both conservative and surgical techniques have been introduced in an effort to speed time to union while minimizing the occurrence of complications. Standard treatment for low-energy tibial shaft fractures includes closed reduction and cast immobilization.The purpose of our study was to analyze retention of reduction after cast immobilization of simple isolated closed tibial fractures.Methods:All cases of the diagnosed isolated closed tibial shaft fracture treated non-surgically at Shafa Yahyaeian Hospital, between 2006 and 2009 were retrieved from medical records. We reviewed all medical records and radiographs of these patients to inquire about the patients’ demographic data used to analyze the outcomes of the non-surgical treatment.Results:Of the 26 patients examined, males were more commonly affected. The mean age was 27.46   (SD=7.58.The most common causes of injury were direct blow and motorcycle to pedestrian accident. Followup duration for each patient had an average of 9.12 months (SD=2.36. Using AO/OTA classification, distributed as 38.5% A1.1, 26.9% A2.1 and 34.6% A3.1 fractures. Most fractures were sustained in the lower third of the tibia (53.85%. All fractures eventually healed in an average of 13.7 weeks (SD=3.24. There was one case of delayed union in the 22nd week. In 92.3% of patients, shortening of bone was less than 1 cm, while in 7.7% patients, was more than 1.5 cm. We observed an anterior or posterior angulation > 10 ° in 2 (7.69% patients. Moreover, in 4 (15.38% patients we found varus angulation > 5°. Therefore, final deformity was observed in 8 (30.77% patients. No patient had non-union, rotational malalignment of more than 10 degrees, an infection, or a compartment syndrome.Conclusion : Our non-surgical treatment’s outcomes were not satisfactory, despite applying all principles for conservative treatment and

  20. Open Tibia Shaft Fractures and Soft-Tissue Coverage: The Effects of Management by an Orthopaedic Microsurgical Team.

    Science.gov (United States)

    VandenBerg, James; Osei, Daniel; Boyer, Martin I; Gardner, Michael J; Ricci, William M; Spraggs-Hughes, Amanda; McAndrew, Christopher M

    2017-06-01

    To compare the timing of soft-tissue (flap) coverage and occurrence of complications before and after the establishment of an integrated orthopaedic trauma/microsurgical team. Retrospective cohort study. A single level 1 trauma center. Twenty-eight subjects (13 pre- and 15 post-integration) with open tibia shaft fractures (OTA/AO 42A, 42B, and 42C) treated with flap coverage between January 2009 and March 2015. Flap coverage for open tibia shaft fractures treated before ("preintegration") and after ("postintegration") implementation of an integrated orthopaedic trauma/microsurgical team. Time from index injury to flap coverage. The unadjusted median time to coverage was 7 days (95% confidence interval, 5.9-8.1) preintegration, and 6 days (95% confidence interval, 4.6-7.4) postintegration (P = 0.48). For preintegration, 9 (69%) of the patients experienced complications, compared with 7 (47%) postintegration (P = 0.23). After formation of an integrated orthopaedic trauma/microsurgery team, we observed a 1-day decrease in median days to coverage from index injury. Complications overall were lowered in the postintegration group, although statistically insignificant. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.