Science.gov

Sample records for head gimbal assembly

  1. SU-C-BRB-01: Development of Dynamic Gimbaled X-Ray Head Swing Irradiation Technique

    SciTech Connect

    Ono, T; Miyabe, Y; Yokota, K; Akimoto, M; Mukumoto, N; Ishihara, Y; Nakamura, M; Mizowaki, T; Hiraoka, M; Takahashi, K

    2015-06-15

    Purpose: The Vero4DRT has a unique gimbaled x-ray head with rotating around orthogonal two axes. The purpose of this study was to develop a new irradiation technique using the dynamic gimbaled x-ray head swing function. Methods: The Vero4DRT has maximum field size of 150Χ150 mm2. The expanded irradiation field (expanded-field) for the longitudinal direction which is vertical to the MLC sliding direction, was created by the MLC motion and the gimbaled x-ray head rotation. The gimbaled x-ray head was rotated ± 35 mm, and the expanded-field size was set as 150Χ220 mm2. To irradiate uniform dose distribution, the diamond-shaped radiation field was created and continuously moved for the longitudinal direction. It was achieved by combination of opening and closing of the MLC and gimbal swing rotation. To evaluate dosimetric characteristic of the expanded-field, films inserted in water-equivalent phantoms at 100 mm depth were irradiated and the field size, penumbra, flatness and symmetry were analyzed.In addition, the expanded-field irradiation technique was applied to virtual wedge irradiation. Wedged beam was acquired with the delta–shaped radiation field. 150Χ 220 mm2 fields with 15, 30, 45, and 60 degree wedge were examined. The wedge angles were measured with irradiated film and compared with assumed wedge angles. Results: The field size, penumbra, flatness and symmetry of the expanded-field were 150.0 mm, 8.1–8.4 mm, 2.8% and −0.8% for the lateral direction and 220.1 mm, 6.3–6.4 mm, 3.2% and −0.4% for the longitudinal direction at 100 mm depth. The measured wedge angles were 15.1, 30.2, 45.2 and 60.2 degrees. The differences between assumed and measured angles were within 0.2 degrees. Conclusion: A new technique of the gimbal swing irradiation was developed. To extend applied targets, especially for whole breast irradiation, the expanded-field and virtual wedge irradiations would be effective.

  2. Development of an expanded-field irradiation technique using a gimbaled x-ray head

    SciTech Connect

    Ono, Tomohiro; Miyabe, Yuki Yamada, Masahiro; Yokota, Kenji; Kaneko, Shuji; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro; Sawada, Akira; Kokubo, Masaki

    2014-10-15

    Purpose: The Vero4DRT has a maximum field size of 150.0 × 150.0 mm. The purpose of the present study was to develop expanded-field irradiation techniques using the unique gimbaled x-ray head of the Vero4DRT and to evaluate the dosimetric characteristics thereof. Methods: Two techniques were developed. One features gimbal swing irradiation and multiple static segments consisting of four separate fields exhibiting 2.39° gimbal rotation around two orthogonal axes. The central beam axis for each piecewise-field is shifted 40 mm from the isocenters of the left–right (LR) and superior–inferior (SI) directions, and, thus, the irradiation field size is expanded to 230.8 × 230.8 mm. Adjacent regions were created at the isocenter (a center-adjacent expandedfield) and 20 mm from the isocenter (an off-adjacent expandedfield). The field gaps or overlaps of combined piecewise-fields were established by adjustment of gimbal rotation and movement of the multileaf collimator (MLC). Another technique features dynamic segment irradiation in which the beam is delivered while rotating the gimbal. The dose profile is controlled by a combination of gimbal swing motion and opening and closing of the MLC. This enabled the authors to expand the irradiation field on the LR axis because the direction of MLC motion is parallel to that axis. A field 220.6 × 150.0 mm in dimensions was configured and examined. To evaluate the dosimetric characteristics of the expandedfields, films inserted into water-equivalent phantoms at depths of 50, 100, and 150 mm were irradiated and field sizes, penumbrae, flatness, and symmetry analyzed. In addition, the expanded-field irradiation techniques were applied to intensity-modulated radiation therapy (IMRT). A head-and-neck IMRT field, created using a conventional Linac (the Varian Clinac iX), was reproduced employing an expanded-field of the Vero4DRT. The simulated dose distribution for the expanded-IMRT field was compared to the measured

  3. Bottom head assembly

    DOEpatents

    Fife, Alex Blair

    1998-01-01

    A bottom head dome assembly which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome is described. The bottom head dome has a plurality of openings extending therethrough. The liner also has a plurality of openings extending therethrough, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending therethrough, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore therethrough, and each support stub bore aligns with a respective bottom head dome opening.

  4. Bottom head assembly

    DOEpatents

    Fife, A.B.

    1998-09-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

  5. Development of a four-dimensional image-guided radiotherapy system with a gimbaled X-ray head

    SciTech Connect

    Kamino, Yuichiro . E-mail: daisaku_horiuchi@mhi.co.jp; Takayama, Kenji; Kokubo, Masaki; Narita, Yuichiro; Hirai, Etsuro; Kawawda, Noriyuki; Mizowaki, Takashi; Nagata, Yasushi; Nishidai, Takehiro; Hiraoka, Masahiro

    2006-09-01

    Purpose: To develop and evaluate a new four-dimensional image-guided radiotherapy system, which enables precise setup, real-time tumor tracking, and pursuit irradiation. Methods and Materials: The system has an innovative gimbaled X-ray head that enables small-angle ({+-}2.4{sup o}) rotations (pan and tilt) along the two orthogonal gimbals. This design provides for both accurate beam positioning at the isocenter by actively compensating for mechanical distortion and quick pursuit of the target. The X-ray head is composed of an ultralight C-band linear accelerator and a multileaf collimator. The gimbaled X-ray head is mounted on a rigid O-ring structure with an on-board imaging subsystem composed of two sets of kilovoltage X-ray tubes and flat panel detectors, which provides a pair of radiographs, cone beam computed tomography images useful for image guided setup, and real-time fluoroscopic monitoring for pursuit irradiation. Results: The root mean square accuracy of the static beam positioning was 0.1 mm for 360{sup o} of O-ring rotation. The dynamic beam response and positioning accuracy was {+-}0.6 mm for a 0.75 Hz, 40-mm stroke and {+-}0.4 mm for a 2.0 Hz, 8-mm stroke. The quality of the images was encouraging for using the tomography-based setup. Fluoroscopic images were sufficient for monitoring and tracking lung tumors. Conclusions: Key functions and capabilities of our new system are very promising for precise image-guided setup and for tracking and pursuit irradiation of a moving target.

  6. TH-C-12A-03: Development of Expanded Field Irradiation Technique with Gimbaled X-Ray Head

    SciTech Connect

    Ono, T; Miyabe, Y; Yamada, M; Kaneko, S; Monzen, H; Mizowaki, T; Hiraoka, M; Sawada, A; Kokubo, M

    2014-06-15

    Purpose: The Vero4DRT has a maximum field size of 150×150 mm{sup 2}. The purposes of this study were to develop an expanded field irradiation technique using a unique gimbaled x-ray head of Vero4DRT and to evaluate its dosimetric characteristic. Methods: The expanded field irradiation consisted of four separate fields with 2.39 degree gimbal rotation around orthogonal two axes. The central beam axis for each field shifted 40 mm from the isocenter for longitudinal and lateral directions, and thus, the field size was expanded up to 230×230 mm{sup 2}. Adjacent region were created at the isocenter (center-adjacent expanded-field) and 20 mm from isocenter (offadjacent expanded-field). To create flat dose distribution in the combined piecewise-fields, the overlapping and gaps regions on the isocenter plane were adjusted with the gimbal rotating and the MLC. To evaluate dosimetric characteristic of the expanded-field, films inserted in water-equivalent phantoms at 50, 100 and 150 mm depth were irradiated and the field size, penumbra, flatness and symmetry were analyzed.In addition, the expandedfield irradiation technique was applied to IMRT. A head and neck IMRT field, which was planned for the conventional linac (Varian Clinac iX), was reproduced with the expanded-field of the Vero4DRT. The simulated dose distribution for the expanded IMRT field was compared to the measured dose distribution. Results: The field size, penumbra, flatness and symmetry of center- and off- adjacent expanded-fields were 230.2–232.1 mm, 7.8–10.7 mm, 2.3–6.5% and –0.5–0.4% at 100 mm depth. The 82.1% area of the expanded IMRT dose distribution was within 5% difference between measurement and simulation, which was analyzed upper 50% dose area, and the 3%/3 mm gamma pass rate was 98.4%. Conclusions: The expandedfield technique was developed using the gimbaled x-ray head. To extend applied targets, such as whole breast irradiations or head and neck IMRT, the expanded-field technique

  7. Geometric and dosimetric accuracy of dynamic tumor-tracking conformal arc irradiation with a gimbaled x-ray head

    SciTech Connect

    Ono, Tomohiro; Miyabe, Yuki Yamada, Masahiro; Kaneko, Shuji; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro; Shiinoki, Takehiro; Sawada, Akira; Kokubo, Masaki

    2014-03-15

    Purpose: The Vero4DRT system has the capability for dynamic tumor-tracking (DTT) stereotactic irradiation using a unique gimbaled x-ray head. The purposes of this study were to develop DTT conformal arc irradiation and to estimate its geometric and dosimetric accuracy. Methods: The gimbaled x-ray head, supported on an O-ring gantry, was moved in the pan and tilt directions during O-ring gantry rotation. To evaluate the mechanical accuracy, the gimbaled x-ray head was moved during the gantry rotating according to input command signals without a target tracking, and a machine log analysis was performed. The difference between a command and a measured position was calculated as mechanical error. To evaluate beam-positioning accuracy, a moving phantom, which had a steel ball fixed at the center, was driven based on a sinusoidal wave (amplitude [A]: 20 mm, time period [T]: 4 s), a patient breathing motion with a regular pattern (A: 16 mm, average T: 4.5 s), and an irregular pattern (A: 7.2–23.0 mm, T: 2.3–10.0 s), and irradiated with DTT during gantry rotation. The beam-positioning error was evaluated as the difference between the centroid position of the irradiated field and the steel ball on images from an electronic portal imaging device. For dosimetric accuracy, dose distributions in static and moving targets were evaluated with DTT conformal arc irradiation. Results: The root mean squares (RMSs) of the mechanical error were up to 0.11 mm for pan motion and up to 0.14 mm for tilt motion. The RMSs of the beam-positioning error were within 0.23 mm for each pattern. The dose distribution in a moving phantom with tracking arc irradiation was in good agreement with that in static conditions. Conclusions: The gimbal positional accuracy was not degraded by gantry motion. As in the case of a fixed port, the Vero4DRT system showed adequate accuracy of DTT conformal arc irradiation.

  8. Gimballing Spacecraft Thruster

    NASA Technical Reports Server (NTRS)

    Pickens, Tim; Bossard, John

    2010-01-01

    A gimballing spacecraft reaction-control-system thruster was developed that consists of a small hydrogen/oxygen-burning rocket engine integrated with a Canfield joint. (Named after its inventor, a Canfield joint is a special gimbal mount that is strong and stable yet allows a wide range of motion.) One especially notable aspect of the design of this thruster is integration, into both the stationary legs and the moving arms of the Canfield joint, of the passages through which the hydrogen and oxygen flow to the engine. The thruster was assembled and subjected to tests in which the engine was successfully fired both with and without motion in the Canfield joint.

  9. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.72 Section...-Year-Old Child § 572.72 Head assembly and test procedure. (a) Head assembly. The head consists of the... on SA 106C 001, sheet 8. (b) Head assembly impact response requirements. When the head is impacted...

  10. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.72 Section...-Year-Old Child § 572.72 Head assembly and test procedure. (a) Head assembly. The head consists of the... on SA 106C 001, sheet 8. (b) Head assembly impact response requirements. When the head is impacted...

  11. Use of Cumulative Degradation Factor Prediction and Life Test Result of the Thruster Gimbal Assembly Actuator for the Dawn Flight Project

    NASA Technical Reports Server (NTRS)

    Lo, C. John; Brophy, John R.; Etters, M. Andy; Ramesham, Rajeshuni; Jones, William R., Jr.; Jansen, Mark J.

    2009-01-01

    The Dawn Ion Propulsion System is the ninth project in NASA s Discovery Program. The Dawn spacecraft is being developed to enable the scientific investigation of the two heaviest main-belt asteroids, Vesta and Ceres. Dawn is the first mission to orbit two extraterrestrial bodies, and the first to orbit a main-belt asteroid. The mission is enabled by the onboard Ion Propulsion System (IPS) to provide the post-launch delta-V. The three Ion Engines of the IPS are mounted on Thruster Gimbal Assembly (TGA), with only one engine operating at a time for this 10-year mission. The three TGAs weigh 14.6 kg.

  12. Hand Controller Assembly

    NASA Technical Reports Server (NTRS)

    Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

    2015-01-01

    A user input device for a vehicular electrical system is provided. The user input device includes a handle sized and shaped to be gripped by a human hand and a gimbal assembly within the handle. The gimbal assembly includes a first gimbal component, a second gimbal component coupled to the first gimbal component such that the second gimbal component is rotatable relative to the first gimbal component about a first axis, and a third gimbal component coupled to the second gimbal component such that the third gimbal component is rotatable relative to the second gimbal component about a second axis.

  13. Theoretical three-and four-axis gimbal robot wrists

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Houck, J. A.

    1986-01-01

    In high-performance flight simulations, a four-axis gimbal system allows all possible rotations with acceptable gimbal angle rates while it avoids the so-callled 'gimbal lock' that occurs when gimbal rotational axes are colinear. In this paper, pertinent equations (including quaternions) are assembled for a hypothetical robot wrist, functionally equivalent to this four-axis gimbal system, and also for a true three-axis gimbal robot wrist. These equations are used to simulate the rotation of a robot hand by the robot wrist in response to operator rotational velocity commands to the robot hand. Near gimbal lock (wrist singularity), excessive rotational rates occur. Scaling the rates, which is necessary for the three-gimbal robot wrist to prevent rate limiting, introduces an undesirable time delay in the robot hand rotation with respect to the commanded rotation. However, the merit of the four-gimbal robot wrist is that the fourth gimbal angle keeps the robot wrist away from the singularity so that the robot hand moves exactly as commanded. It appears that in a 'worst-type' maneuver of the robot hand, the fourth gimbal angle can be defined so that none of the gimbal angle rates exceed about twice the commanded rates.

  14. Dosimetric characterization of a multileaf collimator for a new four-dimensional image-guided radiotherapy system with a gimbaled x-ray head, MHI-TM2000

    SciTech Connect

    Nakamura, Mitsuhiro; Sawada, Akira; Ishihara, Yoshitomo; Takayama, Kenji; Mizowaki, Takashi; Kaneko, Shuji; Yamashita, Mikiko; Tanabe, Hiroaki; Kokubo, Masaki; Hiraoka, Masahiro

    2010-09-15

    Purpose: To present the dosimetric characterization of a multileaf collimator (MLC) for a new four-dimensional image-guided radiotherapy system with a gimbaled x-ray head, MHI-TM2000. Methods: MHI-TM2000 has an x-ray head composed of an ultrasmall linear accelerator guide and a system-specific MLC. The x-ray head can rotate along the two orthogonal gimbals (pan and tilt rotations) up to {+-}2.5 deg., which swings the beam up to {+-}41.9 mm in each direction from the isocenter on the isocenter plane perpendicular to the beam. The MLC design is a single-focus type, has 30 pairs of 5 mm thick leaves at the isocenter, and produces a maximum field size of 150x150 mm{sup 2}. Leaf height and length are 110 and 260 mm, respectively. Each leaf end is circular, with a radius of curvature of 370 mm. The distance that each leaf passes over the isocenter is 77.5 mm. Radiation leakage between adjacent leaves is minimized by an interlocking tongue-and-groove (T and G) arrangement with the height of the groove part 55 mm. The dosimetric characterizations including field characteristics, leaf position accuracy, leakage, and T and G effect were evaluated using a well-commissioned 6 MV photon beam, EDR2 films (Kodak, Rochester, NY), and water-equivalent phantoms. Furthermore, the field characteristics and leaf position accuracy were evaluated under conditions of pan or tilt rotation. Results: The differences between nominal and measured field sizes were within {+-}0.5 mm. Although the penumbra widths were greater with wider field size, the maximum width was <5.5 mm even for the fully opened field. Compared to the results of field characteristics without pan or tilt rotation, the variation in field size, penumbra width, flatness, and symmetry was within {+-}1 mm/1% at the maximum pan or tilt rotational angle. The leaf position accuracy was 0.0{+-}0.1 mm, ranging from -0.3 to 0.2 mm at four gantry angles of 0 deg., 90 deg., 180 deg., and 270 deg. with and without pan or tilt rotation

  15. Head assembly for multiposition borehole extensometer

    DOEpatents

    Frank, Donald N.

    1983-01-01

    A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

  16. Development of an ultrasmall C-band linear accelerator guide for a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head.

    PubMed

    Kamino, Yuichiro; Miura, Sadao; Kokubo, Masaki; Yamashita, Ichiro; Hirai, Etsuro; Hiraoka, Masahiro; Ishikawa, Junzo

    2007-05-01

    We are developing a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

  17. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter...

  18. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter...

  19. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter...

  20. 49 CFR 572.162 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly and test procedure. 572.162...

  1. 49 CFR 572.162 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.162...

  2. 49 CFR 572.162 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.162...

  3. 49 CFR 572.162 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.162...

  4. 49 CFR 572.162 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.162...

  5. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-1000) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right... resultant acceleration shall be between 115 g and 137 g; (2) The resultant acceleration-time curve shall...

  6. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right... resultant acceleration shall be between 115 g and 137 g; (2) The resultant acceleration-time curve shall...

  7. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right... resultant acceleration shall be between 115 g and 137 g; (2) The resultant acceleration-time curve shall...

  8. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-1000) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right... resultant acceleration shall be between 115 g and 137 g; (2) The resultant acceleration-time curve shall...

  9. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right... resultant acceleration shall be between 115 g and 137 g; (2) The resultant acceleration-time curve shall...

  10. Electric power supplying well head assembly

    SciTech Connect

    Reed, L. T.

    1985-01-01

    A well head assembly that terminates on the upper end in a horizontal mounting flange on which the flange of a christmas tree array of valves may be sealingly mounted to control the flow of fluid from the well associated therewith, and the well head assembly including slidably engageable first and second electrical conducting cartridges below the mounting flange for supplying electric power to a number of insulated electrical conductors that extend downwardly in the well to an electric motor driven down hole pump or other electrical apparatus. The positioning of the christmas tree array of valves at a minimum height relative to the well head is most desirable in those situations where a number of wells are drilled close together, such as on an off shore island, and equipment must be periodically moved over the array of valves for maintenance or drilling purposes. The well head assembly also includes means for pressurizing a normally open pressure actuated valve in communication with a tubing string operatively associated with the assembly to place the valve in a closed position. closing of the valve eliminates the possibility of continued undesired fluid discharge from the well in the event of a catastrophe or malfunctioning of the well.

  11. 49 CFR 572.152 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly... impact. When the head assembly in paragraph (a) of this section is dropped from a height of 376.0 ±1.0...

  12. Independent Peer Review of Communications, Navigation, and Networking re-Configurable Testbed (CoNNeCT) Project Antenna Pointing Subsystem (APS) Integrated Gimbal Assembly (IGA) Structural Analysis

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Larsen, Curtis E.; Pellicciotti, Joseph W.

    2010-01-01

    Glenn Research Center Chief Engineer's Office requested an independent review of the structural analysis and modeling of the Communications, Navigation, and Networking re-Configurable Testbed (CoNNeCT) Project Antenna Pointing Subsystem (APS) Integrated Gimbal Assembly (IGA) to be conducted by the NASA Engineering and Safety Center (NESC). At this time, the IGA had completed its critical design review (CDR). The assessment was to be a peer review of the NEi-NASTRAN1 model of the APS Antenna, and not a peer review of the design and the analysis that had been completed by the GRC team for CDR. Thus, only a limited amount of information was provided on the structural analysis. However, the NESC team had difficulty separating analysis concerns from modeling issues. The team studied the NASTRAN model, but did not fully investigate how the model was used by the CoNNeCT Project and how the Project was interpreting the results. The team's findings, observations, and NESC recommendations are contained in this report.

  13. Gimbaled multispectral imaging system and method

    DOEpatents

    Brown, Kevin H.; Crollett, Seferino; Henson, Tammy D.; Napier, Matthew; Stromberg, Peter G.

    2016-01-26

    A gimbaled multispectral imaging system and method is described herein. In an general embodiment, the gimbaled multispectral imaging system has a cross support that defines a first gimbal axis and a second gimbal axis, wherein the cross support is rotatable about the first gimbal axis. The gimbaled multispectral imaging system comprises a telescope that fixed to an upper end of the cross support, such that rotation of the cross support about the first gimbal axis causes the tilt of the telescope to alter. The gimbaled multispectral imaging system includes optics that facilitate on-gimbal detection of visible light and off-gimbal detection of infrared light.

  14. 49 CFR 572.132 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on the... acceleration at the location of the accelerometers at the head CG may not be less than 250 G or more than 300 G. The resultant acceleration vs. time history curve shall be unimodal; oscillations occurring after...

  15. 49 CFR 572.132 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on the... acceleration at the location of the accelerometers at the head CG may not be less than 250 G or more than 300 G. The resultant acceleration vs. time history curve shall be unimodal; oscillations occurring after...

  16. 49 CFR 572.132 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on the... acceleration at the location of the accelerometers at the head CG may not be less than 250 G or more than 300 G. The resultant acceleration vs. time history curve shall be unimodal; oscillations occurring after...

  17. 49 CFR 572.132 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on the... acceleration at the location of the accelerometers at the head CG may not be less than 250 G or more than 300 G. The resultant acceleration vs. time history curve shall be unimodal; oscillations occurring after...

  18. 49 CFR 572.132 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on the... acceleration at the location of the accelerometers at the head CG may not be less than 250 G or more than 300 G. The resultant acceleration vs. time history curve shall be unimodal; oscillations occurring after...

  19. Piezoelectric actuated gimbal

    DOEpatents

    Tschaggeny, Charles W.; Jones, Warren F.; Bamberg, Eberhard

    2011-09-13

    A gimbal is described and which includes a fixed base member defining an axis of rotation; a second member concentrically oriented relative to the axis of rotation; a linear actuator oriented in immediate, adjoining force transmitting relation relative to the base member or to the second member, and which applies force along a linear axis which is tangential to the axis of rotation so as to cause the second member to rotate coaxially relative to the fixed base member; and an object of interest mounted to the second member such that the object of interest is selectively moved relative to the base member about the axis of rotation.

  20. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c) Performance criteria. (1... acceleration shall be between 125 g's and 155 g's; (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed...

  1. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c) Performance criteria. (1... acceleration shall be between 125 g's and 155 g's; (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed...

  2. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c) Performance criteria. (1... acceleration shall be between 125 g's and 155 g's; (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed...

  3. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Test procedure. The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c... peak resultant acceleration shall be between 125 g's and 155 g's; (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration...

  4. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Test procedure. The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c... peak resultant acceleration shall be between 125 g's and 155 g's; (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration...

  5. 59. GENERAL VIEW OF HEAD, WHEEL, AND VANE ASSEMBLY OF ...

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

    59. GENERAL VIEW OF HEAD, WHEEL, AND VANE ASSEMBLY OF ELI WINDMILL ON THE GROUND AT THE STOLL RESIDENCE ABOUT 1-1/2 MILES WEST OF NEBRASKA CITY ON STEAM WAGON ROAD. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  6. A precision bearing gimbal system for the Teal Ruby program

    NASA Technical Reports Server (NTRS)

    Lowry, C. H.

    1980-01-01

    A precision bearing gimbal system designed to allow a spaceborne infrared sensor to stare at points on the Earth while in orbit is described. The problems encountered, analytical tools and test methods used, and data applicable to users of similar systems are presented. Assembly procedures, bearing preload effects, moisture control, structural analysis, and noise control are specifically examined.

  7. Thermodynamic parameters governing the self-assembly of head-head-head lanthanide bimetallic helicates.

    PubMed

    Jensen, Thomas B; Scopelliti, Rosario; Bünzli, Jean-Claude G

    2007-01-01

    The heterobitopic ligands L ABX (X=1, 2, 3, 4 or 5), differing only by a Cl or NEt(2) substituent, have been designed to complex with a pair of lanthanide ions to form triple-stranded bimetallic helicates of overall composition [Ln2(L ABX)3]6+. The percentage of HHH (head-head-head) isomer, in which each of the three ligand strands coordinates to the same lanthanide ion with the same coordination unit, is deciding the ability of the ligands to selectively form heterobimetallic complexes containing one luminescent and one magnetic or two different luminescent ions. It deviates significantly from the statistical value of 25 % and ranges from 6-20 % for L AB2 complexes to 93-96 % for L AB4 complexes. The equilibrium between HHT (head-head-tail) and HHH isomers has been investigated in detail for homobimetallic helicates (Ln=Y, La, Ce, Pr, Nd, Sm, Eu, Lu) by means of variable temperature NMR and thermodynamic parameters have been determined. The equilibrium is characterized by small values of DeltaH and DeltaS, which vary in opposite direction along the lanthanide series for complexes with the same ligand in a way that keeps the value of DeltaG almost constant. The results are interpreted in terms of differences in interstrand stacking, ion-dipole interactions and metal-metal repulsion. PMID:17600785

  8. Novel bacteriophage lambda mutation affecting lambda head assembly.

    PubMed Central

    Georgopoulos, C P; Bisig, R; Magazin, M; Eisen, H; Court, D

    1979-01-01

    A novel phage lambda mutation, called dc10, which interferes with proper lambda head assembly has been isolated and characterized. Phage lambda carrying this mutation is (i) unable to form plaques at 30 or 37 degrees C but does so at 42 degrees C and (ii) unable to form plaques at 42 degrees C on pN-constitutive hosts. Both properties are due to dc10 since all phage revertants for one phenotype simultaneously lose the other phenotype and vice versa. The dc10 mutation has been mapped in the B gene and has been shown to be dominant over the corresponding wild-type product. At 30 degrees C the dc10 mutation results in the formation of abnormal petit lambda heads made up of pE, pB, pC, and pNu3. Under pN-constitutive conditions, the dc10 mutation results in the formation of abnormal petit lambda heads made of pE, X1, and X2 only. A model to explain the data is presented. Images PMID:430610

  9. Gimbaled-shoulder friction stir welding tool

    NASA Technical Reports Server (NTRS)

    Carter, Robert W. (Inventor); Lawless, Kirby G. (Inventor)

    2010-01-01

    A gimbaled-shoulder friction stir welding tool includes a pin and first and second annular shoulders coupled to the pin. At least one of the annular shoulders is coupled to the pin for gimbaled motion with respect thereto as the tool is rotated by a friction stir welding apparatus.

  10. Structure and assembly of bacteriophage T4 head.

    PubMed

    Rao, Venigalla B; Black, Lindsay W

    2010-01-01

    The bacteriophage T4 capsid is an elongated icosahedron, 120 nm long and 86 nm wide, and is built with three essential proteins; gp23*, which forms the hexagonal capsid lattice, gp24*, which forms pentamers at eleven of the twelve vertices, and gp20, which forms the unique dodecameric portal vertex through which DNA enters during packaging and exits during infection. The past twenty years of research has greatly elevated the understanding of phage T4 head assembly and DNA packaging. The atomic structure of gp24 has been determined. A structural model built for gp23 using its similarity to gp24 showed that the phage T4 major capsid protein has the same fold as that found in phage HK97 and several other icosahedral bacteriophages. Folding of gp23 requires the assistance of two chaperones, the E. coli chaperone GroEL and the phage coded gp23-specific chaperone, gp31. The capsid also contains two non-essential outer capsid proteins, Hoc and Soc, which decorate the capsid surface. The structure of Soc shows two capsid binding sites which, through binding to adjacent gp23 subunits, reinforce the capsid structure. Hoc and Soc have been extensively used in bipartite peptide display libraries and to display pathogen antigens including those from HIV, Neisseria meningitides, Bacillus anthracis, and FMDV. The structure of Ip1*, one of the components of the core, has been determined, which provided insights on how IPs protect T4 genome against the E. coli nucleases that degrade hydroxymethylated and glycosylated T4 DNA. Extensive mutagenesis combined with the atomic structures of the DNA packaging/terminase proteins gp16 and gp17 elucidated the ATPase and nuclease functional motifs involved in DNA translocation and headful DNA cutting. Cryo-EM structure of the T4 packaging machine showed a pentameric motor assembled with gp17 subunits on the portal vertex. Single molecule optical tweezers and fluorescence studies showed that the T4 motor packages DNA at a rate of up to 2000 bp

  11. Non-Gimbaled Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Vigil, Jeannine S.

    1997-01-01

    The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.

  12. High Gain Antenna Gimbal for the 2003-2004 Mars Exploration Rover Program

    NASA Technical Reports Server (NTRS)

    Sokol, Jeff; Krishnan, Satish; Ayari, Laoucet

    2004-01-01

    The High Gain Antenna Assemblies built for the 2003-2004 Mars Exploration Rover (MER) missions provide the primary communication link for the Rovers once they arrive on Mars. The High Gain Antenna Gimbal (HGAG) portion of the assembly is a two-axis gimbal that provides the structural support, pointing, and tracking for the High Gain Antenna (HGA). The MER mission requirements provided some unique design challenges for the HGAG. This paper describes all the major subsystems of the HGAG that were developed to meet these challenges, and the requirements that drove their design.

  13. Rational controlled morphological transitions in the self-assembled multi-headed giant surfactants in solution.

    PubMed

    Chu, Yang; Zhang, Wei; Lu, Xinlin; Mu, Gaoyan; Zhang, Baofang; Li, Yiwen; Cheng, Stephen Z D; Liu, Tianbo

    2016-07-01

    A series of multi-headed giant surfactants based on polystyrene (PS)-polyhedral oligomeric silsesquioxane(s) (POSS) conjugates, with a different number and topology of POSS heads, are found to self-assemble into different supramolecular structures including vesicles, cylindrical and spherical micelles in H2O/DMF mixed solvents. The transitions among different morphologies can be rationally controlled by tuning the number and topology of POSS heads, as well as the macromolecular concentration. PMID:27331607

  14. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in paragraph (c) of this section, then the resultant head acceleration measured at the location of... more than 160g. (1) The recorded acceleration-time curve for this test is unimodal at or above the 50g... milliseconds. (2) The lateral acceleration vector does not exceed 5g. (c) Head test procedure. The...

  15. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in paragraph (c) of this section, then the resultant head acceleration measured at the location of... more than 160g. (1) The recorded acceleration-time curve for this test is unimodal at or above the 50g... milliseconds. (2) The lateral acceleration vector does not exceed 5g. (c) Head test procedure. The...

  16. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in paragraph (c) of this section, then the resultant head acceleration measured at the location of... more than 160g. (1) The recorded acceleration-time curve for this test is unimodal at or above the 50g... milliseconds. (2) The lateral acceleration vector does not exceed 5g. (c) Head test procedure. The...

  17. Gimballed Shoulders for Friction Stir Welding

    NASA Technical Reports Server (NTRS)

    Carter, Robert; Lawless, Kirby

    2008-01-01

    In a proposed improvement of tooling for friction stir welding, gimballed shoulders would supplant shoulders that, heretofore, have been fixedly aligned with pins. The proposal is especially relevant to self-reacting friction stir welding. Some definitions of terms, recapitulated from related prior NASA Tech Briefs articles, are prerequisite to a meaningful description of the proposed improvement. In friction stir welding, one uses a tool that includes (1) a rotating shoulder on top (or front) of the workpiece and (2) a pin that rotates with the shoulder and protrudes from the shoulder into the depth of the workpiece. In conventional friction stir welding, the main axial force exerted by the tool on the workpiece is reacted through a ridged backing anvil under (behind) the workpiece. When conventional friction stir welding is augmented with an auto-adjustable pin-tool (APT) capability, the depth of penetration of the pin into the workpiece is varied in real time by a position- or forcecontrol system that extends or retracts the pin as needed to obtain the desired effect. In self-reacting (also known as self-reacted) friction stir welding as practiced heretofore, there are two shoulders: one on top (or front) and one on the bottom (or back) of the workpiece. In this case, a threaded shaft protrudes from the tip of the pin to beyond the back surface of the workpiece. The back shoulder is held axially in place against tension by a nut on the threaded shaft. Both shoulders rotate with the pin and remain aligned coaxially with the pin. The main axial force exerted on the workpiece by the tool and front shoulder is reacted through the back shoulder and the threaded shaft into the friction-stir-welding machine head, so that a backing anvil is no longer needed. A key transmits torque between the bottom shoulder and the threaded shaft, so that the bottom shoulder rotates with the shaft. This concludes the prerequisite definitions of terms.

  18. High Performance Piezoelectric Actuated Gimbal (HIERAX)

    SciTech Connect

    Charles Tschaggeny; Warren Jones; Eberhard Bamberg

    2007-04-01

    This paper presents a 3-axis gimbal whose three rotational axes are actuated by a novel drive system: linear piezoelectric motors whose linear output is converted to rotation by using drive disks. Advantages of this technology are: fast response, high accelerations, dither-free actuation and backlash-free positioning. The gimbal was developed to house a laser range finder for the purpose of tracking and guiding unmanned aerial vehicles during landing maneuvers. The tilt axis was built and the test results indicate excellent performance that meets design specifications.

  19. Space Station Freedom Beta Gimbal Control via Sensitivity Models

    NASA Technical Reports Server (NTRS)

    Schoenwald, David A.; Ozguner, Umit; Graham, Ronald E.

    1993-01-01

    Tracking control of the Space Station Freedom solar array beta gimbals is investigated. Of particular interest is the issue of control in the presence of uncertainty in gimbal friction parameters. Sensitivity functions are incorporated into the feedback loop to desensitize the gimbal control law to parameter variations. Simulation results indicated that one such sensitivity function improves the closed-loop performance of the gimbals in the presence of unexpected friction parameter dispersions.

  20. 49 CFR 572.152 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... acceleration measured at the head CG shall not be less than 100 g or more than 120 g. The resultant acceleration vs. time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 17 percent of the peak resultant acceleration. The lateral acceleration shall...

  1. 49 CFR 572.152 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... acceleration measured at the head CG shall not be less than 100 g or more than 120 g. The resultant acceleration vs. time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 17 percent of the peak resultant acceleration. The lateral acceleration shall...

  2. 49 CFR 572.152 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... acceleration measured at the head CG shall not be less than 100 g or more than 120 g. The resultant acceleration vs. time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 17 percent of the peak resultant acceleration. The lateral acceleration shall...

  3. 49 CFR 572.122 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... paragraph (c) of this section, the peak resultant acceleration at the location of the accelerometers at the head CG may not be less than 245 G or more than 300 G. The resultant acceleration vs. time history... peak resultant acceleration. The lateral acceleration shall not exceed 15 g's (zero to peak). (c)...

  4. 49 CFR 572.152 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... acceleration measured at the head CG shall not be less than 100 g or more than 120 g. The resultant acceleration vs. time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 17 percent of the peak resultant acceleration. The lateral acceleration shall...

  5. 49 CFR 572.122 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... paragraph (c) of this section, the peak resultant acceleration at the location of the accelerometers at the head CG may not be less than 245 G or more than 300 G. The resultant acceleration vs. time history... peak resultant acceleration. The lateral acceleration shall not exceed 15 g's (zero to peak). (c)...

  6. 49 CFR 572.122 - Head assembly and test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and the head must be oriented to an incline of 62 ±1 deg. between the “D” plane as shown in Figure N1 and the plane of the impact surface. The 1.57 mm (0.062 in) diameter holes located on either side...

  7. 49 CFR 572.122 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and the head must be oriented to an incline of 62 ±1 deg. between the “D” plane as shown in Figure N1 and the plane of the impact surface. The 1.57 mm (0.062 in) diameter holes located on either side...

  8. 49 CFR 572.122 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and the head must be oriented to an incline of 62 ±1 deg. between the “D” plane as shown in Figure N1 and the plane of the impact surface. The 1.57 mm (0.062 in) diameter holes located on either side...

  9. Design study of TDRS antenna gimbal system for LANDSAT-D

    NASA Technical Reports Server (NTRS)

    Wu, J.

    1977-01-01

    The conceptual design studies of a two axis antenna drive assembly for the TDRSS link communications subsystem for LANDSAT D are presented. The recommended antenna drive assembly is a simple and reliable design substantially similar to the antenna and solar array drives developed and space qualified for programs such as DSCS 2 and FltSatCom. The gimbal design tradeoff is presented, along with drive electronics.

  10. A gimbal platform stabilization for topographic applications

    SciTech Connect

    Michele, Mangiameli Giuseppe, Mussumeci

    2015-03-10

    The aim of this work is the stabilization of a Gimbal platform for optical sensors acquisitions in topographic applications using mobile vehicles. The stabilization of the line of sight (LOS) consists in tracking the command velocity in presence of nonlinear noise due to the external environment. The hardware architecture is characterized by an Ardupilot platform that allows the control of both the mobile device and the Gimbal. Here we developed a new approach to stabilize the Gimbal platform, which is based on neural network. For the control system, we considered a plant that represents the transfer function of the servo system control model for an inertial stabilized Gimbal platform. The transductor used in the feed-back line control is characterized by the Rate Gyro transfer function installed onboard of Ardupilot. For the simulation and investigation of the system performance, we used the Simulink tool of Matlab. Results show that the hardware/software approach is efficient, reliable and cheap for direct photogrammetry, as well as for general purpose applications using mobile vehicles.

  11. Inertial Stabilization Of Periscopic Sights Band Driven Three Axle Gimbal

    NASA Astrophysics Data System (ADS)

    Ellison, Bruce; Richi, James

    1983-10-01

    There are many applications for the use of optical instruments in vehicles, especially in the military. It is required that these instruments function while the vehicle is on the move, in rough terrain. Angular distrubances of the line-of-sight pointing vector can render these instruments useless as observation or pointing devices, due to image blurring. Instruments that must retain resolution in this environment are usually stabilized by means of gimbals. If the entire instrument (such as a large television camera) is to be stabilized, the problem becomes one of a simple stable platform, or, a single axle gimbal. If, however, the instrument is hard mounted to the vehicle and the image is instead to be stabilized by means of a compensating optical component, such as a periscope head mirror, the problem is a little more complex. In a periscopic sight the head mirror must be driven at half-speed to the line-of-sight disturbance to compensate for the angle doubling effect of the mirror. That is, in order to stabilize the line-of-sight, the mirror cannot be inertiallv stable, but must be coupled to a stable mass at a ratio of 1:2. In many applications it is necessary to transmit the elevation angle of the line-of-sight to a fire control system, or, to direct the lines-of-sight of other platforms. In order to do this, transducers are mounted on the "drive axle", (gyros, synchros, tachometers, potentiometers, motors), which detect and trasmit the angular position and rate of the elevation line-of-sight. This drive axle becomes the stable element and is coupled to the mirror axle, at a 2:1 ratio, by means of gears or metallic belts or bands. This is a double axle gimbal system. When subjected to a rotational disturbance such as boat or vehicle motion the inertias of the drive and mirror axles react with one-another to cause a displacement of the line-of-sight pointing vector. This disturbance is a dynamic coupling of inertias. It exists even in the absence of friction

  12. Study and Characterization of Tobacco Mosaic Virus Head-to-tail Assembly Assisted by Aniline Polymerization

    SciTech Connect

    Niu,Z.; Bruckman, M.; Kotakadi, V.; He, J.; Emrick, T.; Russell, T.; Yang, L.; Wang, Q.

    2006-01-01

    One-dimensional composite nanofibres with narrow dispersity, high aspect ratio and high processibility have been fabricated by head-to-tail self-assembly of rod-like tobacco mosaic virus assisted by aniline polymerization, which can promote many potential applications including electronics, optics, sensing and biomedical engineering.

  13. MiniSAR composite gimbal arm development.

    SciTech Connect

    Klarer, Paul Richard; Winscott, Mark

    2005-01-01

    An exploratory effort in the application of carbon epoxy composite structural materials to a multi-axis gimbal arm design is described. An existing design in aluminum was used as a baseline for a functionally equivalent redesigned outer gimbal arm using a carbon epoxy composite material. The existing arm was analyzed using finite element techniques to characterize performance in terms of strength, stiffness, and weight. A new design was virtually prototyped. using the same tools to produce a design with similar stiffness and strength, but reduced overall weight, than the original arm. The new design was prototyped using Rapid Prototyping technology, which was subsequently used to produce molds for fabricating the carbon epoxy composite parts. The design tools, process, and results are discussed.

  14. Problems Encountered During the Recertification of the GLORY Solar Array Dual Axis Gimbal Drive Actuators

    NASA Technical Reports Server (NTRS)

    Saltzman, Marc; Schepis, Jospeh P.; Bruckner, Michael J.

    2009-01-01

    The Glory observatory is the current incarnation of the Vegetation Canopy Lidar (VCL) mission spacecraft bus. The VCL spacecraft bus, having been cancelled for programmatic reasons in 2000, was nearly integrated when it was put into storage for possible future use. The Glory mission was a suitable candidate for using this spacecraft and in 2006 an effort to recertify the two axis solar array gimbal drive after its extended storage was begun. What was expected to be a simple performance validation of the two dual axis gimbal stepper motors became a serious test, diagnosis and repair task once questions arose on the flight worthiness of the hardware. A significant test program logic flow was developed which identified decisions that could be made based on the results of individual recertification tests. Without disassembling the bi-axial gimbals, beginning with stepper motor threshold voltage measurements and relating these to powered drive torque measurements, both performed at the spacecraft integrator s facility, a confusing picture of the health of the actuators came to light. Tests at the gimbal assembly level and tests of the disassembled actuators were performed by the manufacturer to validate our results and torque discrepancies were noted. Further disassembly to the component level of the actuator revealed the source of the torque loss.

  15. Evaluation of a double Gimbal IPACS design

    NASA Technical Reports Server (NTRS)

    Burke, P. R.; Coronato, P. A.

    1986-01-01

    The suitability of various integrated power/attitude control systems (IPACS) rotor materials was analyzed. Three materials were investigated: (1) 6A1-4V-Titanium (the current IPACS rotor material); (2) B120 VCA Titanium; and (3) Custom 455 stainless steel. The preliminary linear vibration analysis was updated to include the weights and stiffnesses of the gimbals design. A belleville washer spring preload mechanism was designed to replace the existing helical spring and interference fit preload mechanism.

  16. Analytical study of the inside-out Gimbal dynamics. Volume 1: Analytical study of inside-out/coincident Gimbal dynamics

    NASA Technical Reports Server (NTRS)

    Rybak, S. C.

    1976-01-01

    The performance capabilities and limitations of the instrument pointing system (IPS) are described. Suggestions of design modifications that result in overall improved IPS performance are included. Since the design and configuration of the IPS was modified a portion of the study was performed with the inside-out Gimbal configuration which was updated to the present coincident Gimbal system configuration. Due to the similarity of the two systems, the results obtained for the inside-out Gimbal also apply to the coincident Gimbal system.

  17. The search for the ultimate gimbal

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1979-01-01

    The need for higher accuracy in pointing systems continues to grow. Fundamental limitations are inherent in the components used for gimbals. This paper discusses some developments which are expected to make it possible to achieve higher accuracy and stability. Ironless armature torque motors are described which exhibit zero hysteresis and no preferred position. Non-contacting signal and power transfer devices to eliminate friction and cable-wrap torques have also been developed. Magnetic bearings can eliminate the last remaining source of erratic frictional effects. Controllers using Kalman estimation techniques can accommodate constant residual effects.

  18. Large-diameter total hip arthroplasty modular heads require greater assembly forces for initial stability

    PubMed Central

    MacLeod, A. R.; Sullivan, N. P. T.; Whitehouse, M. R.

    2016-01-01

    Objectives Modular junctions are ubiquitous in contemporary hip arthroplasty. The head-trunnion junction is implicated in the failure of large diameter metal-on-metal (MoM) hips which are the currently the topic of one the largest legal actions in the history of orthopaedics (estimated costs are stated to exceed $4 billion). Several factors are known to influence the strength of these press-fit modular connections. However, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection. Materials and Methods Ti-6Al-4V trunnions (n = 60) and two different sizes of cobalt-chromium (Co-Cr) heads (28 mm and 36 mm; 30 of each size) were used in the study. Three different levels of assembly force were considered: 4 kN; 5 kN; and 6 kN (n = 10 each). The strength of the press-fit connection was subsequently evaluated by measuring the pull-off force required to break the connection. The statistical differences in pull-off force were examined using a Kruskal–Wallis test and two-sample Mann–Whitney U test. Finite element and analytical models were developed to understand the reasons for the experimentally observed differences. Results 36 mm diameter heads had significantly lower pull-off forces than 28 mm heads when impacted at 4 kN and 5 kN (p < 0.001; p < 0.001), but not at 6 kN (p = 0.21). Mean pull-off forces at 4 kN and 5 kN impaction forces were approximately 20% larger for 28 mm heads compared with 36 mm heads. Finite element and analytical models demonstrate that the differences in pull-off strength can be explained by differences in structural rigidity and the resulting interface pressures. Conclusion This is the first study to show that 36 mm Co-Cr heads have up to 20% lower pull-off connection strength compared with 28 mm heads for equivalent assembly forces. This effect is likely

  19. Centaur engine gimbal friction characteristics under simulated thrust load

    NASA Technical Reports Server (NTRS)

    Askew, J. W.

    1986-01-01

    An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies.

  20. Gimbal bearing design considerations and friction control

    NASA Technical Reports Server (NTRS)

    Kramer, N. R.

    1979-01-01

    The design considerations of bearing selection, bearing fits, bearing installation, and thermal control are discussed for a gimbal with a high stiffness, low friction torque requirement. Tradeoffs between a quad set of small diameter spread apart or a large diameter bearing pair resulted in a cleaner, lighter, stiffer unit with the latter selection. Bearing fits were designed to eliminate clearances with tolerances of .00127 mm 00005 in) on the bearing shafts and housings. The problems in metrology are discussed and a perferred technique for measurement of small cross-section bearings described. A technique for installation to assure proper seating of the bearing is offered. Where transient thermal conditions are involved, a method of controlling bearing friction by active control of bearing temperature gradients including the use of bearing unload test curves is described.

  1. An evaluation of dry film lubricants and substrate materials for use on SSME gimbal bearings

    NASA Technical Reports Server (NTRS)

    Harp, J. A.

    1976-01-01

    Failure of the spherical bearing shaft of the Space Shuttle Main Engine (SSME) gimbal bearing assembly was encountered during Design Verification Specification testing of the full scale engine. Investigation revealed that the failure was caused by a deficiency in the lubrication system. Based upon the materials and gimbal operating conditions, a lubricant of MoS2 and graphite with a ceramic binder was the best lubricant candidate for this particular application; however, the decision to implement the change was not made without verification testing. Scaled down simulation testing was performed. Four different substrate materials and eight different dry film lubricants were subjected to tests under simulated SSME environmental and stress load conditions. The test specimens were evaluated for friction and operating life. Each test specimen was subjected to cyclic operation under load until failure. The force required to move the bearing surfaces relative to each other was monitored throughout the test, thus providing analytical data for derivation of the coefficient of friction. Results indicate that the MoS2/graphite lubricant with ceramic binder proved to be superior from the standpoint of endurance and also from the standpoint of friction reducing capabilities when applied to the titanium substrate material used on SSME. Endurance of this lubricant was approximately 16 times that of the lubricant which was being used when the SSME gimbal failed.

  2. Failure of Harmonic Gears During Verification of a Two-Axis Gimbal for the Mars Reconnaissance Orbiter Spacecraft

    NASA Technical Reports Server (NTRS)

    Johnson, Michael R.; Gehling, Russ; Head, Ray

    2006-01-01

    The Mars Reconnaissance Orbiter (MRO) spacecraft has three two-axis gimbal assemblies that support and move the High Gain Antenna and two solar array wings. The gimbal assemblies are required to move almost continuously throughout the mission's seven-year lifetime, requiring a large number of output revolutions for each actuator in the gimbal assemblies. The actuator for each of the six axes consists of a two-phase brushless dc motor with a direct drive to the wave generator of a size-32 cup-type harmonic gear. During life testing of an actuator assembly, the harmonic gear teeth failed completely, leaving the size-32 harmonic gear with a maximum output torque capability less than 10% of its design capability. The investigation that followed the failure revealed limitations of the heritage material choices that were made for the harmonic gear components that had passed similar life requirements on several previous programs. Additionally, the methods used to increase the stiffness of a standard harmonic gear component set, while accepted practice for harmonic gears, is limited in its range. The stiffness of harmonic gear assemblies can be increased up to a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.

  3. Two gimbal bearing case studies: Some lessons learned

    NASA Technical Reports Server (NTRS)

    Loewenthal, Stuart H.

    1988-01-01

    Two troublesome, torque related problems associated with gimbal actuators are discussed. Large, thin section angular contact bearings can have a surprisingly high torque sensitivity to radial thermal gradients. A predictive thermal-mechanical bearing analysis, as described, was helpful in establishing a safe temperature operating envelope. In the second example, end-of-travel torque limits of an oscillatory gimbal bearing appoached motor stall during limit cycling life tests. Bearing modifications required to restore acceptable torque performance are described. The lessons learned from these case studies should benefit designers of precision gimbals where singular bearing torque related problems are not uncommon.

  4. Space Station Power Generation in Support of the Beta Gimbal Anomaly Resolution

    NASA Technical Reports Server (NTRS)

    Delleur, Ann M.; Propp, Timothy W.

    2003-01-01

    The International Space Station (ISS) is the largest and most complex spacecraft ever assembled and operated in orbit. The first U.S. photovoltaic (PV) module, containing two solar arrays, was launched, installed, and activated in early December 2000. After the first week of continuously rotating the U.S. solar arrays, engineering personnel in the ISS Mission Evaluation Room (MER) observed higher than expected electrical currents on the drive motor in one of the Beta Gimbal Assemblies (BGA), the mechanism used to maneuver a U.S. solar array. The magnitude of the motor currents continued to increase over time on both BGA's, creating concerns about the ability of the gimbals to continue pointing the solar arrays towards the sun, a function critical for continued assembly of the ISS. A number of engineering disciplines convened in May 2001 to address this on-orbit hardware anomaly. This paper reviews the ISS electrical power system (EPS) analyses performed to develop viable operational workarounds that would minimize BGA use while maintaining sufficient solar array power to continue assembly of the ISS. Additionally, EPS analyses performed in support of on-orbit BGA troubleshooting exercises is reviewed. EPS capability analyses were performed using SPACE, a computer code developed by NASA Glenn Research Center (GRC) for the ISS program office.

  5. Piezo-based miniature high resolution stabilized gimbal

    NASA Astrophysics Data System (ADS)

    Karasikov, Nir; Peled, Gal; Yasinov, Roman; Yetkariov, Rita

    2016-05-01

    Piezo motors are characterized by higher mechanical power density, fast response and direct drive. These features are beneficial for miniature gimbals. A gimbal based on such motors was developed. Diameter is 58 mm, weight is 190 grams. The gimbal carries two cameras: a Flir Quark and an HD day camera. The dynamic performance is as high as 3 rad/sec velocity and 100 rad/secΛ2 acceleration. A two axes stabilization algorithm was developed, yielding 80 micro radian stabilization. Further, a panoramic image capture, at a rate of six stabilized field of views per second, was developed. The manuscript reviews the gimbal structure and open architecture, allowing adaptation to other cameras (SWIR etc.), the control algorithm and presents experimental results of stabilization and of panoramic views taken on a vibration platform and on a UAV.

  6. Structure, assembly, and DNA packaging of the bacteriophage T4 head.

    PubMed

    Black, Lindsay W; Rao, Venigalla B

    2012-01-01

    The bacteriophage T4 head is an elongated icosahedron packed with 172 kb of linear double-stranded DNA and numerous proteins. The capsid is built from three essential proteins: gp23*, which forms the hexagonal capsid lattice; gp24*, which forms pentamers at 11 of the 12 vertices; and gp20, which forms the unique dodecameric portal vertex through which DNA enters during packaging and exits during infection. Intensive work over more than half a century has led to a deep understanding of the phage T4 head. The atomic structure of gp24 has been determined. A structural model built for gp23 using its similarity to gp24 showed that the phage T4 major capsid protein has the same fold as numerous other icosahedral bacteriophages. However, phage T4 displays an unusual membrane and portal initiated assembly of a shape determining self-sufficient scaffolding core. Folding of gp23 requires the assistance of two chaperones, the Escherichia coli chaperone GroEL acting with the phage-coded gp23-specific cochaperone, gp31. The capsid also contains two nonessential outer capsid proteins, Hoc and Soc, which decorate the capsid surface. Through binding to adjacent gp23 subunits, Soc reinforces the capsid structure. Hoc and Soc have been used extensively in bipartite peptide display libraries and to display pathogen antigens, including those from human immunodeficiency virus (HIV), Neisseria meningitides, Bacillus anthracis, and foot and mouth disease virus. The structure of Ip1*, one of a number of multiple (>100) copy proteins packed and injected with DNA from the full head, shows it to be an inhibitor of one specific restriction endonuclease specifically targeting glycosylated hydroxymethyl cytosine DNA. Extensive mutagenesis, combined with atomic structures of the DNA packaging/terminase proteins gp16 and gp17, elucidated the ATPase and nuclease functional motifs involved in DNA translocation and headful DNA cutting. The cryoelectron microscopy structure of the T4 packaging

  7. A gimbaled low noise momentum wheel

    NASA Technical Reports Server (NTRS)

    Bichler, U.; Eckardt, T.

    1993-01-01

    The bus actuators are the heart and at the same time the Achilles' heel of accurate spacecraft stabilization systems, because both their performance and their perturbations can have a deciding influence on the achievable pointing accuracy of the mission. The main task of the attitude actuators, which are mostly wheels, is the generation of useful torques with sufficiently high bandwidth, resolution and accuracy. This is because the bandwidth of the whole attitude control loop and its disturbance rejection capability is dependent upon these factors. These useful torques shall be provided, without - as far as possible - parasitic noise like unbalance forces and torques and harmonics. This is because such variable frequency perturbations excite structural resonances which in turn disturb the operation of sensors and scientific instruments. High accuracy spacecraft will further require bus actuators for the three linear degrees of freedom (DOF) to damp structural oscillations excited by various sources. These actuators have to cover the dynamic range of these disturbances. Another interesting feature, which is not necessarily related to low noise performance, is a gimballing capability which enables, in a certain angular range, a three axis attitude control with only one wheel. The herein presented Teldix MWX, a five degree of freedom Magnetic Bearing Momentum Wheel, incorporates all the above required features. It is ideally suited to support, as a gyroscopic actuator in the attitude control system, all High Pointing Accuracy and Vibration Sensitive space missions.

  8. Bottom head to shell junction assembly for a boiling water nuclear reactor

    DOEpatents

    Fife, Alex Blair; Ballas, Gary J.

    1998-01-01

    A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening.

  9. Bottom head to shell junction assembly for a boiling water nuclear reactor

    DOEpatents

    Fife, A.B.; Ballas, G.J.

    1998-02-24

    A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening. 5 figs.

  10. Redundant single gimbal control moment gyroscope singularity analysis

    NASA Technical Reports Server (NTRS)

    Bedrossian, Nazareth S.; Paradiso, Joseph; Bergmann, Edward V.; Rowell, Derek

    1990-01-01

    The robotic manipulator is proposed as the mechanical analog to single gimbal control moment gyroscope systems, and it is shown that both systems share similar difficulties with singular configurations. This analogy is used to group gimbal angles corresponding to any momentum state into different families. The singularity problem associated with these systems is examined in detail. In particular, a method is presented to test for the possibility of nontorque-producing gimbal motion at a singular configuration, as well as to determine the admissible motions in the case when this is possible. Sufficient conditions are derived for instances where the singular system can be reconfigured into a nonsingular state by these nontorque-producing motions.

  11. Engine Gimbal Requirements for Ground Testing of J-2X

    NASA Technical Reports Server (NTRS)

    Kovalcik, Julia; Leahy, Joe

    2009-01-01

    Based on the Apollo-era J-2 that powered the second and third stages of the Saturn V, the current J-2X is the liquid hydrogen and oxygen high-altitude rocket engine in development for both the Ares I Upper Stage and Ares V Earth Departure Stage. During my summer 2009 internship, J-2X was at a stage in its design maturity where verification testing needed to be considered for the benefit of adequate test facility preparation. My task was to focus on gimbal requirements and gimbal related hot-fire test plans. Facility capabilities were also of interest, specifically for hot-fire testing slated to occur at test stands A-1, A-2, and A-3 at Stennis Space Center(SSC) in Bay St. Louis, Mississippi. Gimbal requirements and stage interface conditions were investigated by applying a top-to-bottom systems engineering approach, which involved system level requirements, engine level requirements from both government and engine contractor perspectives, component level requirements, and the J-2X to Upper Stage and Earth Departure Stage interface control documents. Previous hydrogen and oxygen liquid rocket engine gimbal verification methods were researched for a glimpse at lessons learned. Discussion among the J-2X community affected by gimballing was organized to obtain input relative to proper verification of their respective component. Implementing suggestions such as gimbal pattern, angulated dwell time, altitude testing options, power level, and feed line orientation, I was able to match tests to test stands in the A Complex at SSC. Potential test capability gaps and risks were identified and pursued. The culmination of all these efforts was to coordinate with SSC to define additional facility requirements for both the A-3 altitude test stand that is currently under construction and the A-1 sea level test stand which is being renovated

  12. Analytical study of inside-out Gimbal dynamics. Volume 2: Appendix

    NASA Technical Reports Server (NTRS)

    Rybak, S. C.

    1976-01-01

    Stability data, eigenvalue data, and instrument pointing system earth point tracking time histories at various orbital altitudes are presented. These data apply to the inside-out Gimbal system configuration and the coincident Gimbal system configuration.

  13. Gimbals Drive and Control Electronics Design, Development and Testing of the LRO High Gain Antenna and Solar Array Systems

    NASA Technical Reports Server (NTRS)

    Chernyakov, Boris; Thakore, Kamal

    2010-01-01

    Launched June 18, 2009 on an Atlas V rocket, NASA's Lunar Reconnaissance Orbiter (LRO) is the first step in NASA's Vision for Space Exploration program and for a human return to the Moon. The spacecraft (SC) carries a wide variety of scientific instruments and provides an extraordinary opportunity to study the lunar landscape at resolutions and over time scales never achieved before. The spacecraft systems are designed to enable achievement of LRO's mission requirements. To that end, LRO's mechanical system employed two two-axis gimbal assemblies used to drive the deployment and articulation of the Solar Array System (SAS) and the High Gain Antenna System (HGAS). This paper describes the design, development, integration, and testing of Gimbal Control Electronics (GCE) and Actuators for both the HGAS and SAS systems, as well as flight testing during the on-orbit commissioning phase and lessons learned.

  14. Two different approaches for a control law of single gimbal control moment gyros

    NASA Technical Reports Server (NTRS)

    Schiehlen, W. O.

    1972-01-01

    In the field of momentum exchange attitude control systems, single gimbal control moment gyros (SGCMG) are of increasing interest. A gimbal angle approach and a gimbal rate approach are presented for the SGCMG control law including the singularity avoidance. Both approaches are compared and some illustrative examples are given.

  15. A compact magnetic bearing for gimballed momentum wheel

    NASA Technical Reports Server (NTRS)

    Yabu-Uchi, K.; Inoue, M.; Akishita, S.; Murakami, C.; Okamoto, O.

    1983-01-01

    A three axis controlled magnetic bearing and its application to a momentum wheel are described. The four divided stators provide a momentum wheel with high reliability, low weight, large angular momentum storage capacity, and gimbal control. Those characteristics are desirable for spacecraft attitude control.

  16. Optimal open-loop and feedback control using single gimbal control moment gyroscopes

    NASA Technical Reports Server (NTRS)

    Hoelscher, Brian R.; Vadali, Srinvas R.

    1993-01-01

    Methods for control of spacecraft maneuvers through the use of single gimbal control moment gyroscopes are developed. The development employs an integrated model of the spacecraft dynamics with the control moment gyroscope dynamics. Smooth and continuous open-loop control profiles are obtained which minimize a weighted function of maneuver time, magnitude of control effort, and proximity to singular gimbal configurations. Closed-loop state feedback control laws are derived by invoking Lyapunov stability theory. The schemes are presented for implementing the commanded state feedback: gimbal rate control and gimbal acceleration control. The appropriate handling of singular gimbal configurations is also discussed.

  17. Torque command steering law for double-gimbaled control moment gyros applied to rotor energy storage

    NASA Technical Reports Server (NTRS)

    Kennel, H. F.

    1984-01-01

    A steering law is presented which has all the features required for space applications, assuming the CMG outer gimbal freedom is unlimited. The reason is the idea of mounting all the outer gimbal axes of the CMGs parallel to each other. This allows the decomposition of the steering law problem into a linear one for the inner gimbal angle rates and a planar one for the outer gimbal angle rates. The inner gimbal angle rates are calculated first, since they are not affected by the outer gimbal angle rates. For the calculation of the outer rates, the inner rates are then known quantities. An outer gimbal angle distribution function (to avoid singularities internal to the total angular momentum envelope) generates distribution rates next, and finally the pseudoinverse method is used to insure that the desired total torque is delivered.

  18. Treatment with a position feedback-controlled head stabilizer.

    PubMed

    Harris, F A

    1979-08-01

    A position feedback-controlled head stabilizer has been developed to provide cerebral palsied individuals with resistive exercise to strengthen the neck musculature. This apparatus detects "involuntary" head motion and stabilizes the head by applying opposing forces; it also can be used to facilitate muscular contraction by resisting the subject's voluntary movements. The purpose of the present study was to determine whether voluntary head control in cerebral palsied individuals can be improved through systematic exercise using the stabilizer to strengthen the muscles of the neck and improve their balance of action. The findings support the author's contention that this is possible. The apparatus consists of a helmet and shoulder pads, interconnected so that the head is supported in the helmet by a manipulator arm. At its lower end, the manipulator arm is attached to the shoulder pad mounting frame via a gimbal assembly which allows head movement in two planes of tilt (pitch, or forward-and back, and roll, or side-to-side). Feedback control circuitry is so arranged that any deviation of the head from the desired position leads to actuation of pneumatic cylinders, which apply torques to the manipulator gimbal axes so as to oppose or conteract the incipient head movement. It is particularly significant that none of these patients participating in these experiments were at all apprehensive about or resisted being placed in the apparatus. (Even the youngest subject to use the apparatus--five year old-- did not mind being restrained by the shoulder pads or having his head gripped by helment.) While JG utilized the safety release valve quite often during the first few head control training sessions, he soon became confident enough in the action of the stabilizer that he did not even bother to grip the handle of the release valve. While DA had the action of safety valve explained and demonstrated for her, she never bothered to use it even from the outset of her experience

  19. Design and Development of a Two-Axis Thruster Gimbal with Xenon Propellant Lines

    NASA Technical Reports Server (NTRS)

    Asadurian, Armond

    2010-01-01

    A Two-Axis Thruster Gimbal was developed for a two degree-of-freedom tip-tilt gimbal application. This light weight gimbal mechanism is equipped with flexible xenon propellant lines and features numerous thermal control features for all its critical components. Unique thermal profiles and operating environments have been the key design drivers for this mechanism which is fully tolerant of extreme space environmental conditions. Providing thermal controls that are compatible with flexible components and are also capable of surviving launch vibration within this gimbal mechanism has proven to be especially demanding, requiring creativity and significant development effort. Some of these features, design drivers, and lessons learned will be examined herein.

  20. Evolutionarily conserved morphogenetic movements at the vertebrate head-trunk interface coordinate the transport and assembly of hypopharyngeal structures.

    PubMed

    Lours-Calet, Corinne; Alvares, Lucia E; El-Hanfy, Amira S; Gandesha, Saniel; Walters, Esther H; Sobreira, Débora Rodrigues; Wotton, Karl R; Jorge, Erika C; Lawson, Jennifer A; Kelsey Lewis, A; Tada, Masazumi; Sharpe, Colin; Kardon, Gabrielle; Dietrich, Susanne

    2014-06-15

    The vertebrate head-trunk interface (occipital region) has been heavily remodelled during evolution, and its development is still poorly understood. In extant jawed vertebrates, this region provides muscle precursors for the throat and tongue (hypopharyngeal/hypobranchial/hypoglossal muscle precursors, HMP) that take a stereotype path rostrally along the pharynx and are thought to reach their target sites via active migration. Yet, this projection pattern emerged in jawless vertebrates before the evolution of migratory muscle precursors. This suggests that a so far elusive, more basic transport mechanism must have existed and may still be traceable today. Here we show for the first time that all occipital tissues participate in well-conserved cell movements. These cell movements are spearheaded by the occipital lateral mesoderm and ectoderm that split into two streams. The rostrally directed stream projects along the floor of the pharynx and reaches as far rostrally as the floor of the mandibular arch and outflow tract of the heart. Notably, this stream leads and engulfs the later emerging HMP, neural crest cells and hypoglossal nerve. When we (i) attempted to redirect hypobranchial/hypoglossal muscle precursors towards various attractants, (ii) placed non-migratory muscle precursors into the occipital environment or (iii) molecularly or (iv) genetically rendered muscle precursors non-migratory, they still followed the trajectory set by the occipital lateral mesoderm and ectoderm. Thus, we have discovered evolutionarily conserved morphogenetic movements, driven by the occipital lateral mesoderm and ectoderm, that ensure cell transport and organ assembly at the head-trunk interface.

  1. Optical line-of-sight steering using gimbaled mirrors

    NASA Astrophysics Data System (ADS)

    Satyarthi, Satyam

    2014-06-01

    As the resolution and throughput of optical sensors increase, they require higher line-of-sight slew rates and more precise stabilization. Furthermore, smaller and lighter sensor systems are also preferred because on-vehicle space is always at a premium. Consequently, mirror based line-of-sight control and stabilization systems have become more attractive as they are generally lighter and more compact than other systems. A general strategy for deriving the kinematic equations for mirror based imaging systems is established in this paper. Some of the most common mirror con gurations and their basic kinematic equations are also presented. Some challenges and design considerations of gimbaled mirrors line-of-sight steering and stabilization systems are also discussed.

  2. Precision Attitude Determination System (PADS) system design and analysis: Single-axis gimbal star tracker

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.

  3. Structural rearrangements in the phage head-to-tail interface during assembly and infection

    PubMed Central

    Chaban, Yuriy; Lurz, Rudi; Brasilès, Sandrine; Cornilleau, Charlène; Karreman, Matthia; Zinn-Justin, Sophie; Tavares, Paulo; Orlova, Elena V.

    2015-01-01

    Many icosahedral viruses use a specialized portal vertex to control genome encapsidation and release from the viral capsid. In tailed bacteriophages, the portal system is connected to a tail structure that provides the pipeline for genome delivery to the host cell. We report the first, to our knowledge, subnanometer structures of the complete portal–phage tail interface that mimic the states before and after DNA release during phage infection. They uncover structural rearrangements associated with intimate protein–DNA interactions. The portal protein gp6 of bacteriophage SPP1 undergoes a concerted reorganization of the structural elements of its central channel during interaction with DNA. A network of protein–protein interactions primes consecutive binding of proteins gp15 and gp16 to extend and close the channel. This critical step that prevents genome leakage from the capsid is achieved by a previously unidentified allosteric mechanism: gp16 binding to two different regions of gp15 drives correct positioning and folding of an inner gp16 loop to interact with equivalent loops of the other gp16 subunits. Together, these loops build a plug that closes the channel. Gp16 then fastens the tail to yield the infectious virion. The gatekeeper system opens for viral genome exit at the beginning of infection but recloses afterward, suggesting a molecular diaphragm-like mechanism to control DNA efflux. The mechanisms described here, controlling the essential steps of phage genome movements during virus assembly and infection, are likely to be conserved among long-tailed phages, the largest group of viruses in the Biosphere. PMID:25991862

  4. Analysis of a double gimbaled reaction wheel spacecraft attitude stabilization system

    NASA Astrophysics Data System (ADS)

    Salatun, Adi S.; Bainum, Peter M.

    Three axis attitude stabilization of a satellite using a single spinning reaction wheel mounted on a two degree-of-freedom passively and actively torqued gimbal system is investigated. The passive control is assumed to be provided by a spring-loaded damper mounted on each of the gimbal axes, while active control results from both the wheel acceleration and the torque applied about the gimbal axes. The stability of the uncontrolled and passively controlled systems is investigated analytically. For constant wheel speed the pitch motion is decoupled from the roll-yaw and gimbal motions. Control laws for the roll-yaw motion are developed based on pole clustering and linear optimal control theory. For the pitch motion control laws are obtained based on classical second order system theory. Estimation techniques are applied to the roll-yaw system for the case when the complete state may not be directly observable (in the absence of a fine yaw position sensor).

  5. On the design and development of a miniature ceramic gimbal bearing

    NASA Technical Reports Server (NTRS)

    Hanson, Robert A.; Odwyer, Barry; Gordon, Keith M.; Jarvis, Edward W.

    1990-01-01

    A review is made of a program to develop ceramic gimbal bearings for a miniaturized missile guidance system requiring nonmagnetic properties and higher load capacity than possible with conventional AISI 440C stainless steel bearings. A new gimbal design concept is described which utilizes the compressive strength and nonmagnetic properties of silicon nitride (Si3N4) ceramics for the gimbal bearing. Considerable manufacturing development has occurred in the last 5 years making ceramic bearings a viable option in the gimbal design phase. A preliminary study into the feasibility of the proposed design is summarized. Finite element analysis of the brittle ceramic bearing components under thermal stress and high acceleration loading were conducted to ensure the components will not fail catastrophically in service. Finite element analysis was also used to optimize the adhesive joint design. Bearing torque tests run at various axial loads indicate that the average running torque of ceramic bearings varies with load similarly to that of conventional steel bearings.

  6. Thrust vector control of upper stage with a gimbaled thruster during orbit transfer

    NASA Astrophysics Data System (ADS)

    Wang, Zhaohui; Jia, Yinghong; Jin, Lei; Duan, Jiajia

    2016-10-01

    In launching Multi-Satellite with One-Vehicle, the main thruster provided by the upper stage is mounted on a two-axis gimbal. During orbit transfer, the thrust vector of this gimbaled thruster (GT) should theoretically pass through the mass center of the upper stage and align with the command direction to provide orbit transfer impetus. However, it is hard to be implemented from the viewpoint of the engineering mission. The deviations of the thrust vector from the command direction would result in large velocity errors. Moreover, the deviations of the thrust vector from the upper stage mass center would produce large disturbance torques. This paper discusses the thrust vector control (TVC) of the upper stage during its orbit transfer. Firstly, the accurate nonlinear coupled kinematic and dynamic equations of the upper stage body, the two-axis gimbal and the GT are derived by taking the upper stage as a multi-body system. Then, a thrust vector control system consisting of the special attitude control of the upper stage and the gimbal rotation of the gimbaled thruster is proposed. The special attitude control defined by the desired attitude that draws the thrust vector to align with the command direction when the gimbal control makes the thrust vector passes through the upper stage mass center. Finally, the validity of the proposed method is verified through numerical simulations.

  7. Steering law for parallel mounted double-gimbaled control moment gyros. Revision A

    NASA Technical Reports Server (NTRS)

    Kennel, H. F.

    1981-01-01

    Mounting of double-gimbaled control moment gyros (CMG's) of unlimited outer gimbal angle freedom with all their outer gimbal axes parallel allows drastic simplification of the CMG steering law development hardware. The advantages of the parallel mounting for the CMG steering law development are such that a law could be developed which is applicable to any number of CMG's with arbitrary angular momentum. Parallel mounting of the CMG's in conjunction with the steering law can therefore be considered a CMG kit suitable for many missions of differing momentum requirements. It also means that increasing momentum demands during the design phase of a space vehicle can be easily met by the addition of one or more CMG's of the original momentum capacity rather than a redesign to a larger momentum capacity. Another advantage of the parallel mounting is that the failure of any CMG can be treated like any other, i.e., only one failure mode is possible. The CMG steering law distributes the CMG momentum vectors such that all inner gimbal angles are equal which reduces the rate requirements on the outer gimbal axes. The steering law also spreads the outer gimbals which ensures avoidance of singularities internal to the angular momentum envelope.

  8. SU-E-T-465: Dose Calculation Method for Dynamic Tumor Tracking Using a Gimbal-Mounted Linac

    SciTech Connect

    Sugimoto, S; Inoue, T; Kurokawa, C; Usui, K; Sasai, K; Utsunomiya, S; Ebe, K

    2014-06-01

    Purpose: Dynamic tumor tracking using the gimbal-mounted linac (Vero4DRT, Mitsubishi Heavy Industries, Ltd., Japan) has been available when respiratory motion is significant. The irradiation accuracy of the dynamic tumor tracking has been reported to be excellent. In addition to the irradiation accuracy, a fast and accurate dose calculation algorithm is needed to validate the dose distribution in the presence of respiratory motion because the multiple phases of it have to be considered. A modification of dose calculation algorithm is necessary for the gimbal-mounted linac due to the degrees of freedom of gimbal swing. The dose calculation algorithm for the gimbal motion was implemented using the linear transformation between coordinate systems. Methods: The linear transformation matrices between the coordinate systems with and without gimbal swings were constructed using the combination of translation and rotation matrices. The coordinate system where the radiation source is at the origin and the beam axis along the z axis was adopted. The transformation can be divided into the translation from the radiation source to the gimbal rotation center, the two rotations around the center relating to the gimbal swings, and the translation from the gimbal center to the radiation source. After operating the transformation matrix to the phantom or patient image, the dose calculation can be performed as the no gimbal swing. The algorithm was implemented in the treatment planning system, PlanUNC (University of North Carolina, NC). The convolution/superposition algorithm was used. The dose calculations with and without gimbal swings were performed for the 3 × 3 cm{sup 2} field with the grid size of 5 mm. Results: The calculation time was about 3 minutes per beam. No significant additional time due to the gimbal swing was observed. Conclusions: The dose calculation algorithm for the finite gimbal swing was implemented. The calculation time was moderate.

  9. Gimbal system configurations and line-of-sight control techniques for small UAV applications

    NASA Astrophysics Data System (ADS)

    Miller, Rick; Mooty, Greg; Hilkert, J. M.

    2013-05-01

    The proliferation of small Unmanned Air Vehicles (UAVs) in the past decade has been driven, in part, by the diverse applications that various industries have found for these platforms. Originally, these applications were predominately military in nature but now include law enforcement/security, environmental monitoring/remote sensing, agricultural surveying, movie making and others. Many of these require sensors/payloads such as cameras, laser pointers/ illuminators/rangefinders and other systems that must be pointed and/or stabilized and therefore require a precision miniature gimbal or other means to control their line-of-sight (LOS). Until now, these markets have been served by traditional/larger gimbals; however, the latest class of small UAVs demands much smaller gimbals while maintaining high-performance. The limited size and weight of these gimbaled devices result in design challenges unique to the small-gimbal design field. In the past five years, Ascendant Engineering Solutions has engaged in designing, analyzing and building several small-gimbal systems to meet these challenges and has undertaken a number of trade studies to investigate techniques to achieve optimal performance within the inherent limitations mentioned above. These have included investigating various gimbal configurations, feedback sensors such as gyros, IMUs and encoders, drive train configurations, control system techniques, packaging and interconnect, as well as technology such as fast-steering mirrors and image-stabilization algorithms. This paper summarizes the results of these trade studies, attempts to identify inherent trends and limitations in the various design approaches and techniques, and discusses some practical issues such as test and verification.

  10. The heading of a vehicle moving with roll and trim

    NASA Astrophysics Data System (ADS)

    Danilovich, L. N.

    1983-06-01

    A method is developed for deriving accurate formulas for calculating the heading errors of a vehicle moving with roll and trim. It is assumed that a two-degree-of-freedom gyroscope with gimbal suspension without correction is used, the main axis of the gyroscope being deflected from the horizon plane. Results obtained using the aforementioned formulas are presented.

  11. Modeling of biaxial gimbal-less MEMS scanning mirrors

    NASA Astrophysics Data System (ADS)

    von Wantoch, Thomas; Gu-Stoppel, Shanshan; Senger, Frank; Mallas, Christian; Hofmann, Ulrich; Meurer, Thomas; Benecke, Wolfgang

    2016-03-01

    One- and two-dimensional MEMS scanning mirrors for resonant or quasi-stationary beam deflection are primarily known as tiny micromirror devices with aperture sizes up to a few Millimeters and usually address low power applications in high volume markets, e.g. laser beam scanning pico-projectors or gesture recognition systems. In contrast, recently reported vacuum packaged MEMS scanners feature mirror diameters up to 20 mm and integrated high-reflectivity dielectric coatings. These mirrors enable MEMS based scanning for applications that require large apertures due to optical constraints like 3D sensing or microscopy as well as for high power laser applications like laser phosphor displays, automotive lighting and displays, 3D printing and general laser material processing. This work presents modelling, control design and experimental characterization of gimbal-less MEMS mirrors with large aperture size. As an example a resonant biaxial Quadpod scanner with 7 mm mirror diameter and four integrated PZT (lead zirconate titanate) actuators is analyzed. The finite element method (FEM) model developed and computed in COMSOL Multiphysics is used for calculating the eigenmodes of the mirror as well as for extracting a high order (n < 10000) state space representation of the mirror dynamics with actuation voltages as system inputs and scanner displacement as system output. By applying model order reduction techniques using MATLABR a compact state space system approximation of order n = 6 is computed. Based on this reduced order model feedforward control inputs for different, properly chosen scanner displacement trajectories are derived and tested using the original FEM model as well as the micromirror.

  12. Design Considerations of a Slit Diaphragm Flexure Used in a Precision Mirror Gimbal

    SciTech Connect

    Cox, B. C., Kaufman, M. I.

    2011-09-01

    Two precision mirror gimbals were designed using slit diaphragm flexures to provide two-axis precision mirror alignment in space-limited applications. Both gimbals are currently in use in diagnostics at the National Ignition Facility: one design in the Gamma Reaction History (GRH) diagnostic and the other in the Neutron Imaging System (NIS) diagnostic. The GRH gimbal has an adjustment sensitivity of 0.1 mrad about both axes and a total adjustment capability of ±6°; the NIS gimbal has an adjustment sensitivity of 0.8 μrad about both axes and a total adjustment range of ±3°. Both slit diaphragm flexures were electro-discharge machined out of high-strength titanium and utilize stainless steel stiffeners. The stiffener-flexure design results in adjustment axes with excellent orthogonality and centering with respect to the mirror in a single stage; a typical two-axis gimbal flexure requires two stages. Finite element analyses are presented for both flexure designs, and a design optimization of the GRH flexure is discussed.

  13. Precision Pointing Control System (PPCS) system design and analysis. [for gimbaled experiment platforms

    NASA Technical Reports Server (NTRS)

    Frew, A. M.; Eisenhut, D. F.; Farrenkopf, R. L.; Gates, R. F.; Iwens, R. P.; Kirby, D. K.; Mann, R. J.; Spencer, D. J.; Tsou, H. S.; Zaremba, J. G.

    1972-01-01

    The precision pointing control system (PPCS) is an integrated system for precision attitude determination and orientation of gimbaled experiment platforms. The PPCS concept configures the system to perform orientation of up to six independent gimbaled experiment platforms to design goal accuracy of 0.001 degrees, and to operate in conjunction with a three-axis stabilized earth-oriented spacecraft in orbits ranging from low altitude (200-2500 n.m., sun synchronous) to 24 hour geosynchronous, with a design goal life of 3 to 5 years. The system comprises two complementary functions: (1) attitude determination where the attitude of a defined set of body-fixed reference axes is determined relative to a known set of reference axes fixed in inertial space; and (2) pointing control where gimbal orientation is controlled, open-loop (without use of payload error/feedback) with respect to a defined set of body-fixed reference axes to produce pointing to a desired target.

  14. Large Angle Reorientation of a Solar Sail Using Gimballed Mass Control

    NASA Astrophysics Data System (ADS)

    Sperber, E.; Fu, B.; Eke, F. O.

    2016-06-01

    This paper proposes a control strategy for the large angle reorientation of a solar sail equipped with a gimballed mass. The algorithm consists of a first stage that manipulates the gimbal angle in order to minimize the attitude error about a single principal axis. Once certain termination conditions are reached, a regulator is employed that selects a single gimbal angle for minimizing both the residual attitude error concomitantly with the body rate. Because the force due to the specular reflection of radiation is always directed along a reflector's surface normal, this form of thrust vector control cannot generate torques about an axis normal to the plane of the sail. Thus, in order to achieve three-axis control authority a 1-2-1 or 2-1-2 sequence of rotations about principal axes is performed. The control algorithm is implemented directly in-line with the nonlinear equations of motion and key performance characteristics are identified.

  15. On the stability and pointing of an attached double-gimbal experiment package

    NASA Technical Reports Server (NTRS)

    Groom, N. J.; Shaughnessy, J. D.; Nene, V. D.

    1972-01-01

    The pointing capability of a double gimbal experiment isolation and control system of the Apollo telescope mount (ATM) type was investigated. Three composite structural models of an experiment package connected through frictionless gimbals to a carrier vehicle (including a rigid package-rigid carrier model, a rigid package-flexible carrier model, and a flexible package-flexible carrier model) were used, and a linear model of the nominal ATM gimbal control system is considered. A linear stability analysis was performed to verify stability of the control system with nominal gains. Transform techniques were used to compute pointing errors onboard the experiment package due to random crew motions input into the carrier vehicle. Results of the investigation indicate that there is no stability problem due to flexible coupling of the experiment package and the carrier, and that the ATM-type system is capable of pointing accuracies better than 0.1 arc second.

  16. Steering law design for redundant single-gimbal control moment gyroscopes. [for spacecraft attitude control

    NASA Technical Reports Server (NTRS)

    Bedrossian, Nazareth S.; Paradiso, Joseph; Bergmann, Edward V.; Rowell, Derek

    1990-01-01

    Two steering laws are presented for single-gimbal control moment gyroscopes. An approach using the Moore-Penrose pseudoinverse with a nondirectional null-motion algorithm is shown by example to avoid internal singularities for unidirectional torque commands, for which existing algorithms fail. Because this is still a tangent-based approach, however, singularity avoidance cannot be guaranteed. The singularity robust inverse is introduced as an alternative to the pseudoinverse for computing torque-producing gimbal rates near singular states. This approach, coupled with the nondirectional null algorithm, is shown by example to provide better steering law performance by allowing torque errors to be produced in the vicinity of singular states.

  17. Facilitated assembly of the preinitiation complex by separated tail and head/middle modules of the mediator.

    PubMed

    Galdieri, Luciano; Desai, Parima; Vancura, Ales

    2012-01-20

    Mediator is a general coactivator of RNA polymerase II (RNA pol II) bridging enhancer-bound transcriptional factors with RNA pol II. Mediator is organized in three distinct subcomplexes: head, middle, and tail modules. The head and middle modules interact with RNA pol II, and the tail module interacts with transcriptional activators. Deletion of one of the tail subunits SIN4 results in derepression of a subset of genes, including FLR1, by a largely unknown mechanism. Here we show that derepression of FLR1 transcription in sin4Δ cells occurs by enhanced recruitment of the mediator as well as Swi/Snf and SAGA complexes. The tail and head/middle modules of the mediator behave as separate complexes at the induced FLR1 promoter. While the tail module remains anchored to the promoter, the head/middle modules are also found in the coding region. The separation of the tail and head/middle modules in sin4Δ cells is also supported by the altered stoichiometry of the tail and head/middle modules at several tested promoters. Deletion of another subunit of the tail module MED2 in sin4Δ cells results in significantly decreased transcription of FLR1, pointing to the importance of the integrity of the separated tail module in derepression. All tested genes exhibited increased recruitment of the tail domain; however, only genes with increased occupancy of the head/middle modules also displayed increased transcription. The separated tail module thus represents a promiscuous transcriptional factor that binds to many different promoters and is necessary for derepression of FLR1 in sin4Δ cells. PMID:22137896

  18. Facilitated assembly of the preinitiation complex by separated tail and head/middle modules of the mediator.

    PubMed

    Galdieri, Luciano; Desai, Parima; Vancura, Ales

    2012-01-20

    Mediator is a general coactivator of RNA polymerase II (RNA pol II) bridging enhancer-bound transcriptional factors with RNA pol II. Mediator is organized in three distinct subcomplexes: head, middle, and tail modules. The head and middle modules interact with RNA pol II, and the tail module interacts with transcriptional activators. Deletion of one of the tail subunits SIN4 results in derepression of a subset of genes, including FLR1, by a largely unknown mechanism. Here we show that derepression of FLR1 transcription in sin4Δ cells occurs by enhanced recruitment of the mediator as well as Swi/Snf and SAGA complexes. The tail and head/middle modules of the mediator behave as separate complexes at the induced FLR1 promoter. While the tail module remains anchored to the promoter, the head/middle modules are also found in the coding region. The separation of the tail and head/middle modules in sin4Δ cells is also supported by the altered stoichiometry of the tail and head/middle modules at several tested promoters. Deletion of another subunit of the tail module MED2 in sin4Δ cells results in significantly decreased transcription of FLR1, pointing to the importance of the integrity of the separated tail module in derepression. All tested genes exhibited increased recruitment of the tail domain; however, only genes with increased occupancy of the head/middle modules also displayed increased transcription. The separated tail module thus represents a promiscuous transcriptional factor that binds to many different promoters and is necessary for derepression of FLR1 in sin4Δ cells.

  19. A lightweight high performance dual-axis gimbal for space applications

    SciTech Connect

    Pines, D.J.; Hakala, D.B.; Malueg, R.

    1995-05-05

    This paper describes the design, development and performance of a lightweight precision gimbal with dual-axis slew capability to be used in a closed-loop optical tracking system at Lawrence Livermore National Laboratory-LLNL. The motivation for the development of this gimbal originates from the need to acquire and accurately localize warm objects (T{approximately}500 K) in a cluttered background. The design of the gimbal is centered around meeting the following performance requirements: pointing accuracy with control < 35 {mu}rad-(1-{omega}); slew capability > 0.2 rad/sec; mechanical weight < 5 kg. These performance requirements are derived by attempting to track a single target from multiple satellites in low Earth orbit using a mid-wave infrared camera. Key components in the gimbal hardware that are essential to meeting the performance objectives include a nickel plated beryllium mirro, an accurate lightweight capacitive pickoff device for angular measurement about the elevation axis, a 16-bit coarse/fine resolver for angular measurement about the azimuth axis, a toroidally wound motor with low hysteresis for providing torque about the azimuth axis, and the selection of beryllium parts to insure high stiffness to weight ratios and more efficient thermal conductivity. Each of these elements are discussed in detail to illustrate the design trades performed to meet the tracking and slewing requirements demanded. Preliminary experimental results are also given for various commanded tracking maneuvers.

  20. Frequency nondegeneracy of the Lagrange gyroscope and a balanced gyroscope with a gimbal suspension

    NASA Astrophysics Data System (ADS)

    Tatarinov, Ia. V.

    1987-08-01

    The three-frequency nature of the motion of a specific Lagrange gyroscope (whose center of mass does not coincide with the suspension point) and a specific gimbal-mounted gyroscope is demonstrated. The proof presented here is based on frequency expansions near stable relative equilibriums (regular precessions).

  1. Study on disturbance torque compensation of magnetically suspended control moment gyro gimbal system

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Fang, Jiancheng

    2006-11-01

    This paper analyses the disturbance torque causing by the unbalance vibration of the high speed rotor, and presents a controller of disturbance observer (DOB) with LMS algorithm. This method can effectively control disturbance torque in MSCMG gimbal system. Simulation results show that the method is effective and practical.

  2. Steering law for parallel mounted double-gimbaled control moment gyros

    NASA Technical Reports Server (NTRS)

    Kennel, H. F.

    1975-01-01

    Parallel mounting of double-gimbaled control moment gyros (DG CMG) is discussed in terms of simplification of the steering law. The steering law/parallel mounted DG CMG is considered to be a 'CMG kit' applicable to any space vehicle where the need for DG CMG's has been established.

  3. Compact optical gimbal as a conformal beam director for large field-of-regard lasercom applications

    NASA Astrophysics Data System (ADS)

    Kesner, Jessica E.; Hinrichs, Keith M.; Narkewich, Lawrence E.; Stephens, Timothy

    2015-03-01

    Laser communication offers advantages over traditional RF communication, including reduced size, weight, and power, higher data rates, and resistance to jamming. However, existing beam directors used for large field-of-regard lasercom terminals have limitations. Traditional gimbals require either domes or large conformal windows to achieve large fields of regard. Risley prism-based beam directors have temperature- and wavelength-dependent pointing necessitating tight temperature control and pointing correction techniques. Other methods, like liquid crystal optical phased array beam directors, have low transmittance and low technology readiness levels (TRLs). This paper presents a detailed design and preliminary performance results of a prototype Compact Optical Gimbal (COG) beam director that provides a 2 inch beam over a +/- 65o field-of-regard through a small (~12 inch) flat window. The COG differs from the traditional gimbal in that it includes three-axis steering with off-axis elevation and dither control, and a folded refractive afocal telescope incorporated into the body of the gimbal to minimize size. The COG's optical system does not have the pointing challenges characteristic of Risley prisms, and it utilizes high TRL components, including many commercial off-theshelf parts, to simplify implementation. The compact size and performance support a variety of beam steering applications and platforms.

  4. Two-axis gimbal for air-to-air and air-to-ground laser communications

    NASA Astrophysics Data System (ADS)

    Talmor, Amnon G.; Harding, Harvard; Chen, Chien-Chung

    2016-03-01

    For bi-directional links between high-altitude-platforms (HAPs) and ground, and air-to-air communication between such platforms, a hemispherical +30°C field-of-regard and low-drag low-mass two-axis gimbal was designed and prototyped. The gimbal comprises two servo controlled non-orthogonal elevation over azimuth axis, and inner fast steering mirrors for fine field-of-regard adjustment. The design encompasses a 7.5cm diameter aperture refractive telescope in its elevation stage, folded between two flat mirrors with an exit lens leading to a two mirrors miniature Coude-path fixed to the azimuth stage. Multiple gimbal configurations were traded prior to finalizing a selection that met the requirements. The selected design was manifested onboard a carbon fiber and magnesium composite structure, motorized by custom-built servo motors, and commutated by optical encoders. The azimuth stage is electrically connected to the stationary base via slip ring while the elevation stage made of passive optics. Both axes are aligned by custom-built ceramic-on-steel angular contact duplex bearings, and controlled by embedded electronics featuring a rigid-flex PCB architecture. FEA analysis showed that the design is mechanically robust over a temperature range of +60°C to -80°C, and with first mode of natural frequencies above 400Hz. The total mass of the prototyped gimbal is 3.5kg, including the inner optical bench, which contains fast steering mirrors (FSMs) and tracking sensors. Future version of this gimbal, in prototyping stage, shall weigh less than 3.0kg.

  5. Improving the performance of monocular visual simultaneous localisation and mapping through the use of a gimballed camera

    NASA Astrophysics Data System (ADS)

    Playle, Nicholas

    In this thesis modern vision based localisation methods are discussed and contrasted with existing satellite based approaches. Shortcomings are noted and potential solutions are highlighted. A novel method of using a gimballed camera to perform visual Simultaneous Localisation and Mapping (SLAM) is proposed, along with a control algorithm to point the camera toward feature dense regions. This method is then modularly coupled with existing visual SLAM techniques allowing seamless integration across different platforms. Ground tests are performed to verify operation of the gimbal controller and rotation inverser. Results from experimental flight tests are incorporated as a final means of obtaining information to verify gimbal operation.

  6. Design and development of the Cassini main engine assembly Gimbal mechanism

    NASA Technical Reports Server (NTRS)

    Rudolph, Dale

    1996-01-01

    Cassini is an international cooperative effort between NASA, which is producing the orbiter spacecraft, the European Space Agency, which is providing the Huygens Probe, and the Italian Space Agency, which is responsible for the spacecraft radio antenna and portions of three scientific experiments. In the U.S., the mission is managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. Lockheed-Martin successfully bid on the contract to build the PMS (Propulsion Module Subsystem) for this project. The Cassini spacecraft will be launched on an expedition to Saturn in October, 1997. Its mission is to enter orbit around Saturn in July, 2004, and to explore its moons, rings, and magnetic environment for four years. Cassini will carry the Huygens probe, an instrument package equipped with a parachute, which is designed to study the atmosphere and surface of Saturn's largest moon, Titan.

  7. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-Pressure Fuel Turbopump (LPFTP) on the upper left of the engine assembly, the LPFTP Discharge Duct looping around the assembly, the Gimbal Bearing on the top center of the assembly, the Electrical Interface Panel sits just below the Gimbal Bearing and the Low-Pressure Oxidizer Turbopump is mounted on the top right of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  8. Derivation of line-of-sight stabilization equations for gimbaled-mirror optical systems

    NASA Astrophysics Data System (ADS)

    Debruin, James C.

    1992-01-01

    The gimbaled flat steering mirrors commonly used for pointing the outgoing line-of-sight of optical systems can also be driven to stabilize the line-of-sight, effectively isolating it from vehicle base motion. The stabilization equations provide the relative rates of the gimbal angles as functions of the angular velocity of the base. These equations are of use in feed-forward stabilization systems. Two algorithmic methods of deriving the stabilization equations are presented. These methods are distinguished from others by their use of a kinematic reference frame that is attached to the line-of-sight. The first method is completely general and can be applied to any system. The second is limited to systems of a specific configuration, but allows direct generation of uncoupled stabilization equations. Analysis of an aerial photography system is presented as an example.

  9. Application of a directed search to global steering of single gimballed CMGs

    NASA Technical Reports Server (NTRS)

    Paradiso, Joseph A.

    1991-01-01

    A guided depth-first search that manages null motion about torque-producing trajectories calculated with a singularity-robust (SR) inverse is proposed as a practical feedforward steering law that can globally avoid (or minimize the impact of) singular states in minimally-redundant single gimballed CMG systems. Cost and heuristic functions are defined to guide the search procedure in improving CMG trajectories. On-orbit implementation of the steering law is proposed as an extension to momentum management algorithms. A set of simulation examples is presented, illustrating the search performance for a 4-CMG pyramid-mounted array. Sensitivities of feedforward gimbal trajectories are examined in the presence of unmodeled disturbances, and techniques are proposed for avoiding excessive divergence.

  10. Single gimbal/strapdown inertial navigation system for use on spin stabilized flight test vehicles

    SciTech Connect

    Watts, A.C.; Andreas, R.D.

    1980-01-01

    A hybrid strapdown inertial navigation system intended for use on spin stabilized flight test vehicles is described. The configuration of the navigator which is briefly described consists of three floated rate integrating gyros, one of which is used in conjunction with the gimbal with the remaining two operated in a rate gyro mode. Outputs from the two strapdown gyros and three accelerometers are digitized and processed by a high performance computer. The navigation algorithms utilize a direction cosine matrix formulation for the attitude computation implemented in the digital computer. The implementation of this algorithm for the single gimbal configuration is described. An accuracy model and results for a reentry vehicle flight test trajectory are presented. The flight test performance from launch to reentry is presented.

  11. Rotor's Suspension for Vernier-gimballing magnetically suspended flywheel with conical magnetic bearing.

    PubMed

    Tang, Jiqiang; Xiang, Biao; Wang, Chun'e

    2015-09-01

    A novel Vernier-gimballing magnetically suspended flywheel with conical magnetic bearing (conical MB) can generate great gyroscopic moment by tilting the high-speed rotor. To output the gyroscopic moment, the high-speed rotor must be suspended stably and can be tilted. But when the rotor tilts, the gap between the stator and rotor of conical MB changes nonlinearly, what will cause the magnetic force and current stiffness of this conical MB to be serious nonlinear. To solve these problems, one kind of adaptive controller based on Lyapunov stability theory is designed by regarding the current stiffness of this conical MB as uncertain parameter. The validity of this adaptive control method is verified on a Vernier-gimballing MSFW with 68 Nms angular momentum and 1.7° maximum tilting angle. All experimental results indicated that this adaptive control has better performances on controlling rotor's stable suspension than existing PID control when the rotor translates or tilts. PMID:26089172

  12. Asymptotic properties of certain motions of an asynchronous gyroscope in a gimbal suspension

    NASA Astrophysics Data System (ADS)

    Konosevich, B. I.

    The present study examines the influence of initial perturbations on the stationary motions of an asynchronous gyroscope in a gimbal suspension with a dynamically symmetric rotor and a vertical external axis of the suspension, it being assumed that the gyroscope is on a fixed base. It is shown that if the reducted potential energy has an isolated minimum at the stationary point (a minimum which is determined by the second-order term relative to the corresponding perturbations) the internal gimbal angle and the generalized velocities of gyroscopes of most constructions tend with time to definite limit values in perturbed motion. Explicit expressions for these limit values are obtained for the case of the uniform rotations of a balanced gyroscope.

  13. Internal performance of two nozzles utilizing gimbal concepts for thrust vectoring

    NASA Technical Reports Server (NTRS)

    Berrier, Bobby L.; Taylor, John G.

    1990-01-01

    The internal performance of an axisymmetric convergent-divergent nozzle and a nonaxisymmetric convergent-divergent nozzle, both of which utilized a gimbal type mechanism for thrust vectoring was evaluated in the Static Test Facility of the Langley 16-Foot Transonic Tunnel. The nonaxisymmetric nozzle used the gimbal concept for yaw thrust vectoring only; pitch thrust vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps. The model geometric parameters investigated were pitch vector angle for the axisymmetric nozzle and pitch vector angle, yaw vector angle, nozzle throat aspect ratio, and nozzle expansion ratio for the nonaxisymmetric nozzle. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 12.0.

  14. Apollo Telescope Mount (ATM) gimballed star tracker. [developed for the Skylab program

    NASA Technical Reports Server (NTRS)

    Lana, J. D.

    1974-01-01

    Design and development of six gimballed star trackers for Skylab's Apollo Telescope Mount, which performed successfully on all three manned Skylab missions and accumulated a total usage time of approximately 3,500 hours, is described in terms of configurations, materials and construction, qualification testing, performance, and reliability characteristics. A brief program history and design changes incorporated during the life of the program are also discussed. Extensive drawings, block diagrams, and photographs are provided.

  15. Electrostatic tuning of drive and sense modes in two-gimbal torsional gyroscope

    NASA Astrophysics Data System (ADS)

    Jain, Ankush; Gopal, Ram

    2016-04-01

    This paper demonstrates electrostatic tuning of drive and sense modes in two-gimbal torsional gyroscope. The gyroscope is fabricated by SU-8 based UV-LIGA process and is then packaged in vacuum. The device is first characterized for frequency responses of drive and sense modes using laser Doppler vibrometer (LDV). Finally, electrostatic tuning of drive and sense modes is carried out by varying DC bias voltage applied to the proof-mass.

  16. Optimal Space Station solar array gimbal angle determination via radial basis function neural networks

    NASA Technical Reports Server (NTRS)

    Clancy, Daniel J.; Oezguener, Uemit; Graham, Ronald E.

    1994-01-01

    The potential for excessive plume impingement loads on Space Station Freedom solar arrays, caused by jet firings from an approaching Space Shuttle, is addressed. An artificial neural network is designed to determine commanded solar array beta gimbal angle for minimum plume loads. The commanded angle would be determined dynamically. The network design proposed involves radial basis functions as activation functions. Design, development, and simulation of this network design are discussed.

  17. Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

    2016-01-01

    High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

  18. Comparison of the strapdown and gimbaled seekers utilized in aerial applications

    NASA Astrophysics Data System (ADS)

    Özkan, Bülent; Uçar, Altuğ

    2012-06-01

    In order to orient aerial vehicles such as unmanned aerial vehicles and guided munitions toward intended target points, it often becomes vital to acquire the correct information about the states of the targets during the flight of the vehicles. One of the most widely-used ways to achieve this task is the utilization of seekers. Physically, the measurement capability of seekers is restricted due to some physical, optical, and electronic limitations such as limited field-of-view (FOV), atmospheric transmittance, and noise effects. Regarding these characteristics, basically two types of seekers are employed in the relevant applications: strapdown or body-fixed seekers and gimbaled seekers. The strapdown seekers are directly mounted on the considered vehicle body. Therefore, their measurements become relative to the body fixed reference frame of the missile. For relieving the FOV limitations of the strapdown seekers, the gimbaled seekers are preferred in some of the implementations. In this scheme, the seeker is mounted on a platform supported by two orthogonal gimbals and stabilized by means of rate gyro feedbacks. This way, the FOV range of the seeker is increased considerably. Also, the line of sight (LOS) angle and the LOS angular rate can be measured directly independently of the missile motion. This study deals with the comparison of these two kinds of seekers according to certain criteria involving mounting properties, FOV, angle and rate measurements, guidance method utilization, measurement methods, major sources of measurement errors, and cost. A general evaluation is submitted at the end of the work.

  19. Control Of Flexible Structures-2 (COFS-2) flight control, structure and gimbal system interaction study

    NASA Technical Reports Server (NTRS)

    Fay, Stanley; Gates, Stephen; Henderson, Timothy; Sackett, Lester; Kirchwey, Kim; Stoddard, Isaac; Storch, Joel

    1988-01-01

    The second Control Of Flexible Structures Flight Experiment (COFS-2) includes a long mast as in the first flight experiment, but with the Langley 15-m hoop column antenna attached via a gimbal system to the top of the mast. The mast is to be mounted in the Space Shuttle cargo bay. The servo-driven gimbal system could be used to point the antenna relative to the mast. The dynamic interaction of the Shuttle Orbiter/COFS-2 system with the Orbiter on-orbit Flight Control System (FCS) and the gimbal pointing control system has been studied using analysis and simulation. The Orbiter pointing requirements have been assessed for their impact on allowable free drift time for COFS experiments. Three fixed antenna configurations were investigated. Also simulated was Orbiter attitude control behavior with active vernier jets during antenna slewing. The effect of experiment mast dampers was included. Control system stability and performance and loads on various portions of the COFS-2 structure were investigated. The study indicates possible undesirable interaction between the Orbiter FCS and the flexible, articulated COFS-2 mast/antenna system, even when restricted to vernier reaction jets.

  20. Design and manufacturing considerations for high-performance gimbals used for land, sea, air, and space

    NASA Astrophysics Data System (ADS)

    Sweeney, Mike; Redd, Lafe; Vettese, Tom; Myatt, Ray; Uchida, David; Sellers, Del

    2015-09-01

    High performance stabilized EO/IR surveillance and targeting systems are in demand for a wide variety of military, law enforcement, and commercial assets for land, sea, air, and space. Operating ranges, wavelengths, and angular resolution capabilities define the requirements for EO/IR optics and sensors, and line of sight stabilization. Many materials and design configurations are available for EO/IR pointing gimbals depending on trade-offs of size, weight, power (SWaP), performance, and cost. Space and high performance military aircraft applications are often driven toward expensive but exceptionally performing beryllium and aluminum beryllium components. Commercial applications often rely on aluminum and composite materials. Gimbal design considerations include achieving minimized mass and inertia simultaneous with demanding structural, thermal, optical, and scene stabilization requirements when operating in dynamic operational environments. Manufacturing considerations include precision lapping and honing of ball bearing interfaces, brazing, welding, and casting of complex aluminum and beryllium alloy structures, and molding of composite structures. Several notional and previously developed EO/IR gimbal platforms are profiled that exemplify applicable design and manufacturing technologies.

  1. A new continuous self-calibration scheme for a gimbaled inertial measurement unit

    NASA Astrophysics Data System (ADS)

    Cao, Yuan; Cai, Hong; Zhang, Shifeng; Li, Anliang

    2012-01-01

    A typical calibration scheme for a gimbaled inertial measurement unit (IMU) involves an estimation of error parameters of an IMU mounted on an inertial platform and the platform's misalignment angles. However, traditional calibration methods for the gimbaled IMU have some serious defects. The excitation for a gyro's scale factors and misalignment angles is only the Earth rate in multi-position calibration methods and dynamic errors (unneeded motion of gyro floaters) involved in a continuous calibration process. This paper presents a new continuous self-calibration scheme for the gimbaled IMU. By processing the multi-position and continuous rotation steps alternately, the dynamic errors are suppressed and the excitation is augmented. This is more effective than traditional methods. Additionally, the platform rotation trajectory is designed to provide adequate observability for all parameters through a new methodology. The Lie derivative is used to compute the observability, and the genetic algorithm is utilized to obtain the inertial platform's optimal rotation trajectory based on the measurement of observability for all parameters. Simulation results show that the error coefficients can be effectively calibrated within an hour by the proposed scheme, and it is of high significance for fast launching of missiles and rockets.

  2. Anomalous magnetic responsiveness of giant magnetoresistive heads under specific electromagnetic interference frequencies using quasistatic tester

    NASA Astrophysics Data System (ADS)

    Kruesubthaworn, Anan; Pratoomthip, Aphaiphak; Siritaratiwat, Apirat; Ungvichian, Vichate

    2008-04-01

    The giant magnetoresistive (GMR) heads have been used in the computer industry for decade. Recently, the anomalous performance caused by cell phones or external electromagnetic interference (EMI) is reported [V. Kraz and A. Wallash, J. Electrost. 54, 39 (2002)]; [Kruesubthaworn et al., J. Magn. Magn. Mater. 316, e142 (2007)] This prompts an experimental study of an anomalous magnetic disturbance to the heads under ascending and descending frequency variations. The rf generator with predetermined output is set for 30-1000MHz swept frequency in both directions, with the antenna being horizontal and vertical orientations. Five quasistatic tester (QST) parameters; magnetoresistive (MR) resistance, MR amplitude, asymmetry, Barkhausen noise, and hysteresis are used as markers in the EMI sensitivity study of head gimbal assembly. It is found that the worst change of MR amplitude is 10.2% (marginally over the norm), which occurs at 910MHz during ascending swept frequency and horizontal polarization. The largest variation of hysteresis parameter is 21.8% (1.5 times over the norm) during 940MHz descending swept frequency and horizontal polarization. The remaining parameters have small effects, less than 6.5%. During the EMI exposure, QST transfer curves show significant departure from the frequencies of 500-580, 700-850, and 900-1000MHz. However, the trace separation is returned back to the preexposure condition. The scanning electron microscope evaluation of the GMR head after the exposure appears to be normal. Therefore, these parameter disturbances are not adequate to cause visible damage, but since some parameters are over the manufacturing accepted QST values, it may cause a latently failed head.

  3. Heater head for stirling engine

    DOEpatents

    Corey, John A.

    1985-07-09

    A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

  4. Infrared Optical System For An Antitank Homing Head

    NASA Astrophysics Data System (ADS)

    Christophe-Alain, Bernard; Froissart, Delzongle-Pierre; Perron, Michel

    1983-10-01

    A low cost scanning optical system for an antitank seeker head operating in the 8 to 12 pm wavelength region is described. The overall system consists of a spherical dome and a very simple two aspherical elements telescope. The objective provides a high resolution over a 1° by 2° degrees FOV at a relatively large aperture and remains extremely lightweight and compact. This device is included on a two axis gyroscope to allow the line of sight deviation and the inertial stabilization of the gimbal objective. Considerations which direct material selection are presented. They concern : - transmission and absorption coefficients in the spectral domain - thermal and spectral variation of the refractive index - mechanical and thermal properties to sustain the meteorological and missile speed effect. The reflective IR imager is made of two aspheric primary and secondary mirrors which provide - thermal insensitivity - easy aligment procedure in the visible domain - low production cost by means of replication The innovative optical design program principles are presented and the sensitivity to high order asphericities analysed. Optical blur performances of this device are compared to those of a paraboloidal primary - plane secondary one. The manufacturing process for both the master and the replica are reviewed along with the assembly tests. The 55 mm wide - 50 g weight scanning mirror is shown and its main characteristics discussed. Maximum emphasis is put on the technological solutions choosen for its subminiature motorcoil and its position detector. Both "black and white" and "false coloured" images of an armoured vehicule are shown as recorded by the IR seeker during a real time tracking sequence. A ten micrometer hybrid focal plane detector has been developed jointly by SAT and LIR. This technology promises to offer advantages for advanced missile homing heads. Images ob-tained with this direct coupled Cadmium Mercury Telluride photovoltaic detector and CCD

  5. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, James K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell.

  6. Conceptual design of pointing control systems for space station gimballed payloads

    NASA Technical Reports Server (NTRS)

    Hughes, Robert O.

    1986-01-01

    A conceptual design of the control system for Payload Pointing Systems (PPS) is developed using classic Proportional-Integral-Derivatives (PID) techniques. The major source of system pointing error is due to the disturbance-rich environment of the space station in the form of gimbal baseplate motions. These baseplate vibrations are characterized using Fast Fourier Transform (FFT) techniques. Both time domain and frequency domain dynamic models are developed to assess control system performance. Three basic methods exist for the improvement of PPS pointing performance: increase control system bandwidth, add Image Motion Compensation, and/or reduce (or change) the baseplate disturbance environment.

  7. Development of a Gimballed, dual frequency, space-based, microwave antenna for volume production

    NASA Technical Reports Server (NTRS)

    Leckie, Martin; Laidig, Dave

    1996-01-01

    A dual-frequency, two-axis Gimballed, Microwave Antenna (GMA) has been developed by COM DEV and Motorola for commercial satellites. The need for volume production of over three hundred antennas at a rate of four per week, a compressed development schedule, and the commercial nature of the effort necessitated a paradigm shift to an 'overall' cost-driven design approach. The translation of these demands into antenna requirements, a description of the resulting GMA design, and examples of development issues are detailed herein.

  8. The effect of initial perturbations on the uniform rotations of a balanced asynchronous gyroscope in a gimbal suspension

    NASA Astrophysics Data System (ADS)

    Konosevich, B. I.

    In the problem considered here, the gyroscope is mounted on a stationary base, the rotor is dynamically symmetric, and the whole system is statically balanced relative to the suspension axes. It is shown that if all the three roots of the characteristic equation of the reduced system, linearized in the vicinity of uniform rotation, have negative real components then the gimbal angles are incremented due to the initial perturbations. The increments are limited during the entire duration of subsequent motion. Formulas for the limiting increments of the gimbal angles are given.

  9. Aeroelastic Stability of A Soft-Inplane Gimballed Tiltrotor Model In Hover

    NASA Technical Reports Server (NTRS)

    Nixon, Mark W.; Langston, Chester W.; Singleton, Jeffrey D.; Piatak, David J.; Kvaternik, Raymond G.; Corso, Lawrence M.; Brown, Ross

    2001-01-01

    Soft-inplane rotor systems can significantly reduce the inplane rotor loads generated during the maneuvers of large tiltrotors, thereby reducing the strength requirements and the associated structural weight of the hub. Soft-inplane rotor systems. however, are subject to instabilities associated with ground resonance, and for tiltrotors this instability has increased complexity as compared to a conventional helicopter. Researchers at Langley Research Center and Bell Helicopter-Textron, Inc. have completed ail initial study of a soft-inplane gimballed tiltrotor model subject to ground resonance conditions in hover. Parametric variations of the rotor collective pitch and blade root damping, and their associated effects oil the model stability were examined. Also considered in the study was the effectiveness of ail active swash-plate and a generalized predictive control (GPC) algorithm for stability augmentation of the ground resonance conditions. Results of this study show that the ground resonance behavior of a gimballed soft-inplane tiltrotor can be significantly different from that of a classical soft-inplane helicopter rotor. The GPC-based active swash-plate was successfully implemented, and served to significantly augment damping of the critical modes to an acceptable value.

  10. Steam separator latch assembly

    DOEpatents

    Challberg, R.C.; Kobsa, I.R.

    1994-02-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof. 12 figures.

  11. Steam separator latch assembly

    DOEpatents

    Challberg, Roy C.; Kobsa, Irvin R.

    1994-01-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.

  12. Performance Testing of a Magnetically Suspended Double Gimbal Control Moment Gyro Based on the Single Axis Air Bearing Table

    PubMed Central

    Cui, Peiling; Zhang, Huijuan; Yan, Ning; Fang, Jiancheng

    2012-01-01

    Integrating the advantage of magnetic bearings with a double gimble control moment gyroscope (DGCMG), a magnetically suspended DGCMG (MSDGCMG) is an ideal actuator in high-precision, long life, and rapid maneuver attitude control systems. The work presented here mainly focuses on performance testing of a MSDGCMG independently developed by Beihang University, based on the single axis air bearing table. In this paper, taking into sufficient consideration to the moving-gimbal effects and the response bandwidth limit of the gimbal, a special MSDGCMG steering law is proposed subject to the limits of gimbal angle rate and angle acceleration. Finally, multiple experiments are carried out, with different MSDGCMG angular momenta as well as different desired attitude angles. The experimental results indicate that the MSDGCMG has a good gimbal angle rate and output torque tracking capabilities, and that the attitude stability with MSDGCMG as actuator is superior to 10−3°/s. The MSDGCMG performance testing in this paper, carried out under moving-base condition, will offer a technique base for the future research and application of MSDGCMGs. PMID:23012536

  13. The Determination of Forces and Moments on a Gimballed SRM Nozzle Using a Cold Flow Model

    NASA Technical Reports Server (NTRS)

    Whitesides, R. Harold; Bacchus, David L.; Hengel, John E.

    1994-01-01

    The Solid Rocket Motor Air Flow Facility (SAF) at NASA Marshall Space Flight Center was used to characterize the flow in the critical aft end and nozzle of a solid propellant rocket motor (SRM) as part of the design phase of development. The SAF is a high pressure, blowdown facility which supplies a controlled flow of air to a subscale model of the internal port and nozzle of a SRM to enable measurement and evaluation of the flow field and surface pressure distributions. The ASRM Aft Section/Nozzle Model is an 8 percent scale model of the 19 second burn time aft port geometry and nozzle of the Advanced Solid Rocket Motor, the now canceled new generation space Shuttle Booster. It has the capability to simulate fixed nozzle gimbal angles of 0, 4, and 8 degrees. The model was tested at full scale motor Reynolds Numbers with extensive surface pressure instrumentation to enable detailed mapping of the surface pressure distributions over the nozzle interior surface, the exterior surface of the nozzle nose and the surface of the simulated propellant grain in the aft motor port. A mathematical analysis and associated numerical procedure were developed to integrate the measured surface pressure distributions to determine the lateral and axial forces on the moveable section of the nozzle, the effective model thrust and the effective aerodynamic thrust vector (as opposed to the geometric nozzle gimbal angle). The nozzle lateral and axial aerodynamic loads and moments about the pivot point are required for design purposes and require complex, three dimensional flow analyses. The alignment of the thrust vector with the nozzle geometric centerline is also a design requirement requiring three dimensional analyses which were supported by this experimental program. The model was tested with all three gimbal angles at three pressure levels to determine Reynolds number effects and reproducibility. This program was successful in demonstrating that a measured surface pressure

  14. Precision gimballed mirror control in remote sensing LIDAR for environmental monitoring

    NASA Astrophysics Data System (ADS)

    Singh, Ravindra; Mudgil, Ashwani; Prakash, Chandra; Pal, Suranjan

    2006-12-01

    Differential Absorption Lidar (DIAL) Systems are advantageously used to detect and measure very small concentrations of trace gases in the atmosphere. There is a requirement to interrogate and search for the presence of one or more of toxic agents out of a large number (about 20 or so) of possible agents at distances up to several kilometers with the help of a ground-based multi-wavelength DIAL system employing pulsed, tunable laser sources in the wavelength bands of 2-5 micron and 9.2-10.8 micron. The Laser beams from the two sources are directed in the atmosphere with a predefined divergence to scan the atmosphere. Two methodologies can be implemented to provide the beam steering, one is to mount the entire telescope of transmitting and receiving channel on to a motorized gimbal platform and second is to keep the optical telescope stationary and use a slewing mirror to steer the beam in required direction. The first scheme is named as mass control and second scheme is called mirror control. Both the schemes have relative advantages and disadvantages and in the present DIAL application second scheme is being adopted. The present opto-mechanical configuration of DIAL system employs a 700 x 500 mm 2 (Elliptical) steering mirror for transmitting the collimated beams in a required direction and receiving the reflected beam as well. In the receiving channel a Telescope is used which collects the return beam and focuses the same on to a detector. The slewing mirror is housed in a gimbal mount having a sufficient FOR (Field of Regard) in Azimuth and elevation plane. The paper describes the modeling and simulation of Opto-mechanical and servo-mechanical subsystems of precision gimbaled mirror and also discusses the issues related to design of control system. The requirement specifications in regard to field of regard, slew rates 5°/s, scanning rates 1°/s are to be met with stringent beam pointing and scanning accuracies. The design of this system is categorized as

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  16. Precision Attitude Determination System (PADS) design and analysis. Two-axis gimbal star tracker

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Development of the Precision Attitude Determination System (PADS) focused chiefly on the two-axis gimballed star tracker and electronics design improved from that of Precision Pointing Control System (PPCS), and application of the improved tracker for PADS at geosynchronous altitude. System design, system analysis, software design, and hardware design activities are reported. The system design encompasses the PADS configuration, system performance characteristics, component design summaries, and interface considerations. The PADS design and performance analysis includes error analysis, performance analysis via attitude determination simulation, and star tracker servo design analysis. The design of the star tracker and electronics are discussed. Sensor electronics schematics are included. A detailed characterization of the application software algorithms and computer requirements is provided.

  17. Thermal Analog of Gimbal Lock in a Colloidal Ferromagnetic Janus Rod.

    PubMed

    Gao, Yongxiang; Balin, Andrew Kaan; Dullens, Roel P A; Yeomans, Julia M; Aarts, Dirk G A L

    2015-12-11

    We report an entropy-driven orientational hopping transition in a magnetically confined colloidal Janus rod. In a magnetic field, the sedimented rod randomly hops between horizontal and vertical states: the latter state comes at a substantial gravitational cost at no reduction of magnetic potential energy. The probability distribution over the angles of the rod shows that the presence of an external magnetic field leads to the emergence of a metastable vertical state separated from the ground state by an effective barrier. This barrier does not come from the potential energy but rather from the vast gain in phase space available to the rod as it approaches the vertical state. The loss of rotational degree of freedom that gives rise to this effect is a statistical mechanical analogue of the phenomenon of gimbal lock from classical mechanics. PMID:26705660

  18. Attitude maneuver of spacecraft with a variable-speed double-gimbal control moment gyro

    NASA Astrophysics Data System (ADS)

    Jikuya, Ichiro; Fujii, Kenta; Yamada, Katsuhiko

    2016-10-01

    In this paper, two types of computational procedures are presented for a rest-to-rest spacecraft maneuver using a variable-speed double-gimbal control moment gyro (VSDGCMG). The first procedure is a numerical computational procedure in which a quasi-time-optimal trajectory satisfying several physical constraints is obtained by repeating the Newton's method. The other procedure is an approximate computational procedure in which an analytical solution is obtained by approximately solving a series of linear optimal control problems. The two procedures play complementary roles: the former is suitable for implementation, and the latter can be used to select an initial value for use in the former. The effectiveness of the proposed procedures is demonstrated by plotting the surfaces of maneuvering time for all rotational axes and by plotting time responses for several maneuvering examples.

  19. Calibration of Gimbaled Platforms: The Solar Dynamics Observatory High Gain Antennas

    NASA Technical Reports Server (NTRS)

    Hashmall, Joseph A.

    2006-01-01

    Simple parameterization of gimbaled platform pointing produces a complete set of 13 calibration parameters-9 misalignment angles, 2 scale factors and 2 biases. By modifying the parameter representation, redundancy can be eliminated and a minimum set of 9 independent parameters defined. These consist of 5 misalignment angles, 2 scale factors, and 2 biases. Of these, only 4 misalignment angles and 2 biases are significant for the Solar Dynamics Observatory (SDO) High Gain Antennas (HGAs). An algorithm to determine these parameters after launch has been developed and tested with simulated SDO data. The algorithm consists of a direct minimization of the root-sum-square of the differences between expected power and measured power. The results show that sufficient parameter accuracy can be attained even when time-dependent thermal distortions are present, if measurements from a pattern of intentional offset pointing positions is included.

  20. Failure detection and isolation methods for redundant gimballed inertial measurement units.

    NASA Technical Reports Server (NTRS)

    Solov, E. G.; Thibodeau, J. R., III

    1973-01-01

    Skewed alignment of two redundant conventional inertial measuring units permits nonambiguous detection and isolation of hard and soft failures in real time by an airborne computer. Accelerometer outputs and gimbal readouts are monitored periodically, and attitude rate and velocity error vectors are computed from these data. Magnitudes of these vectors provide failure detection, and projection of these error vectors onto the coordinate axes of the two clusters permits isolation. A detailed Monte Carlo simulation of one version of the mechanization as applied to Space Shuttle boost trajectories demonstrates effectiveness down to very low levels of inertial instrument performance failures. The results indicate that worst case overall navigation performance occurs when accelerometer failures are of the order of 20 sigma and gyro failures are about 100 sigma for conventional state-of-the-art IMU instruments.

  1. ISS Double-Gimbaled CMG Subsystem Simulation Using the Agile Development Method

    NASA Technical Reports Server (NTRS)

    Inampudi, Ravi

    2016-01-01

    This paper presents an evolutionary approach in simulating a cluster of 4 Control Moment Gyros (CMG) on the International Space Station (ISS) using a common sense approach (the agile development method) for concurrent mathematical modeling and simulation of the CMG subsystem. This simulation is part of Training systems for the 21st Century simulator which will provide training for crew members, instructors, and flight controllers. The basic idea of how the CMGs on the space station are used for its non-propulsive attitude control is briefly explained to set up the context for simulating a CMG subsystem. Next different reference frames and the detailed equations of motion (EOM) for multiple double-gimbal variable-speed control moment gyroscopes (DGVs) are presented. Fixing some of the terms in the EOM becomes the special case EOM for ISS's double-gimbaled fixed speed CMGs. CMG simulation development using the agile development method is presented in which customer's requirements and solutions evolve through iterative analysis, design, coding, unit testing and acceptance testing. At the end of the iteration a set of features implemented in that iteration are demonstrated to the flight controllers thus creating a short feedback loop and helping in creating adaptive development cycles. The unified modeling language (UML) tool is used in illustrating the user stories, class designs and sequence diagrams. This incremental development approach of mathematical modeling and simulating the CMG subsystem involved the development team and the customer early on, thus improving the quality of the working CMG system in each iteration and helping the team to accurately predict the cost, schedule and delivery of the software.

  2. Design, fabrication and test of a prototype double gimbal control moment gyroscope for the NASA Space Station

    NASA Technical Reports Server (NTRS)

    Blondin, Joseph; Hahn, Eric; Kolvek, John; Cook, Lewis; Golley, Paul

    1989-01-01

    Recognizing the need to develop future technologies in support of the Space Station, NASA's Advanced Development Program (ADP) placed as its goal the design and fabrication of a prototype 4750 Newton-meter-second (3500 ft-lb-sec) Control Moment Gyroscope (CMG). The CMG uses the principle of momentum exchange to impart control torques for counteracting vehicle disturbances. This paper addresses the selection of the double gimbal CMG over the single gimbal and describes the major subassemblies of the prototype design. Particular attention is given to the choice of the materials, fabrication and design details dictated by the man-rated mission requirement. Physical characteristics and the results of functional testing are presented to demonstrate the level of system performance obtained. Comparisons are made of the measured system responses against design goals and predictions generated by computer simulation.

  3. Magnetic bearing momentum wheels with magnetic gimballing capability for 3-axis active attitude control and energy storage

    NASA Technical Reports Server (NTRS)

    Sindlinger, R. S.

    1977-01-01

    A 3-axis active attitude control system with only one rotating part was developed using a momentum wheel with magnetic gimballing capability as a torque actuator for all three body axes. A brief description of magnetic bearing technology is given. It is concluded that based on this technology an integrated energy storage/attitude control system with one air of counterrotating rings could reduce the complexity and weight of conventional systems.

  4. High-performance two-axis gimbal system for free space laser communications onboard unmanned aircraft systems

    NASA Astrophysics Data System (ADS)

    Locke, Michael; Czarnomski, Mariusz; Qadir, Ashraf; Setness, Brock; Baer, Nicolai; Meyer, Jennifer; Semke, William H.

    2011-03-01

    A custom designed and manufactured gimbal with a wide field-of-view and fast response time is developed. This enhanced custom design is a 24 volt system with integrated motor controllers and drivers which offers a full 180o fieldof- view in both azimuth and elevation; this provides a more continuous tracking capability as well as increased velocities of up to 479° per second. The addition of active high-frequency vibration control, to complement the passive vibration isolation system, is also in development. The ultimate goal of this research is to achieve affordable, reliable, and secure air-to-air laser communications between two separate remotely piloted aircraft. As a proof-of-concept, the practical implementation of an air-to-ground laserbased video communications payload system flown by a small Unmanned Aerial Vehicle (UAV) will be demonstrated. A numerical tracking algorithm has been written, tested, and used to aim the airborne laser transmitter at a stationary ground-based receiver with known GPS coordinates; however, further refinement of the tracking capabilities is dependent on an improved gimbal design for precision pointing of the airborne laser transmitter. The current gimbal pointing system is a two-axis, commercial-off-the-shelf component, which is limited in both range and velocity. The current design is capable of 360o of pan and 78o of tilt at a velocity of 60o per second. The control algorithm used for aiming the gimbal is executed on a PC-104 format embedded computer onboard the payload to accurately track a stationary ground-based receiver. This algorithm autonomously calculates a line-of-sight vector in real-time by using the UAV autopilot's Differential Global Positioning System (DGPS) which provides latitude, longitude, and altitude and Inertial Measurement Unit (IMU) which provides the roll, pitch, and yaw data, along with the known Global Positioning System (GPS) location of the ground-based photodiode array receiver.

  5. Steering Law Design for Redundant Single Gimbal Control Moment Gyro Systems. M.S. Thesis - Massachusetts Inst. of Technology.

    NASA Technical Reports Server (NTRS)

    Bedrossian, Nazareth Sarkis

    1987-01-01

    The correspondence between robotic manipulators and single gimbal Control Moment Gyro (CMG) systems was exploited to aid in the understanding and design of single gimbal CMG Steering laws. A test for null motion near a singular CMG configuration was derived which is able to distinguish between escapable and unescapable singular states. Detailed analysis of the Jacobian matrix null-space was performed and results were used to develop and test a variety of single gimbal CMG steering laws. Computer simulations showed that all existing singularity avoidance methods are unable to avoid Elliptic internal singularities. A new null motion algorithm using the Moore-Penrose pseudoinverse, however, was shown by simulation to avoid Elliptic type singularities under certain conditions. The SR-inverse, with appropriate null motion was proposed as a general approach to singularity avoidance, because of its ability to avoid singularities through limited introduction of torque error. Simulation results confirmed the superior performance of this method compared to the other available and proposed pseudoinverse-based Steering laws.

  6. A double gimballed magnetic bearing momentum wheel for high pointing accuracy and vibration sensitive space applications

    NASA Astrophysics Data System (ADS)

    Bichler, U. J.

    1991-12-01

    A fully controlled magnetic bearing momentum wheel is well suited as gyroscopic actuator in the attitude control system of spacecraft. It offers the following advantages: an active tilting of the momentum vector with respect to the spacecraft ('vernier gimballing') with the following features: very little power required; three axis attitude control of the spacecraft in a fine pointing range with only one wheel on a control moment gyro mode; no separate nutation damping device necessary; cross momentum storage capability; active vibration suppression, enabling isolation of unbalance vibrations of the wheel from the spacecraft which meets the increasing demand for quiet wheels which can be used in microgravity and in manned space missions; active damping of flexible structures through fully controllable translational bearing forces. The MW-X, a five degree of freedom magnetic bearing momentum wheel incorporates all these advantages and is ideally suited to support all high pointing accuracy and vibration sensitive space missions. Possible applications are communication satellites, especially those with inclined orbit, satellites with optical communication links, microgravity missions, space telescopes and high resolution Earth observation satellites. In long term manned space missions low noise wheels can reduce the effect of vibrations and the associated noise on the spacecraft environment and crew.

  7. Compact forceps manipulator using friction wheel mechanism and gimbals mechanism for laparoscopic surgery.

    PubMed

    Suzuki, Takashi; Katayama, Youichi; Kobayashi, Etsuko; Sakuma, Ichiro

    2005-01-01

    This paper reports evaluation of compact forceps manipulator designed for assisting laparoscopic surgery. The manipulator consists of two miniaturized parts; friction wheel mechanism which rotates and translates forceps (62 x 52 x 150[mm3], 0.6 [kg]), and gimbals mechanism which provides pivoting motion of forceps around incision hole on the abdomen (135 x 165 x 300 [mm3], 1.1 [kg]). The four-DOF motion of forceps around the incision hole on the abdomen in laparoscopic surgery is realized. By integration with robotized forceps or a needle insertion robot, it will work as a compact robotic arm in a master-slave system. It can also work under numerical control based on the computerized surgical planning. This table-mounted miniaturized manipulator contributes to the coexistence of clinical staffs and manipulators in the today's crowded operating room. As the results of mechanical performance evaluation with load of 4 [N], positioning accuracy was less than 1.2 [deg] in pivoting motion, less than 4 [deg] in rotation of forceps, less than 1.2 [mm] in longitudinal translation of forceps. As future works, we will modify mechanism for sterilization and safety improvement, and also integrate this manipulator with robotized forceps to build a surgery assisting robotic system.

  8. Head circumference

    MedlinePlus

    ... a child's head circumference Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads Measurement of the head circumference is an ...

  9. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...

  10. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, J.K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell. 6 figures.

  11. Novel fluidic packaging of gimbal-less MEMS mirrors for increased optical resolution and overall performance

    NASA Astrophysics Data System (ADS)

    Milanovic, Veljko; Kasturi, Abhishek; Yang, James

    2016-05-01

    Gimbal-less two-axis quasistatic MEMS mirrors have the ability to reflect optical beams to arbitrary positions and with arbitrary velocity. This technology has become established in many applications including laser based tracking, 3D scanning, biomedical imaging, free-space communication, and LiDAR. However, for certain defense applications, the total angle × diameter product, or the mirror's effective achievable resolution (θ*D product), has not been large enough to address requirements for agile steering in large fields of regard and with a low diffraction-limited beam divergence. Two key limitations have been the relatively low forces available in electrostatic combdrive actuators and the susceptibility of large-diameter MEMS mirrors to shock and vibrations. In this work, we demonstrate that these same MEMS mirrors can have dramatically increased performance when fully immersed and packaged in dielectric liquids with highly favorable torque-increasing, damping-increasing, and optical gain-increasing properties. The rotating electrostatic combdrive has its torque multiplied by liquid's relative permittivity of ~2.5. Furthermore, by selecting the appropriate fluid viscosity, quality factor of the device is reduced and structural damping is tuned to near critical damping. Finally, the increased scan angle due to the ~1.5-1.7 index of refraction of the fluid is an additional benefit. These numerous benefits of the fluidic packaging enabled us to double and in some cases triple the previously achieved θ*D product of two-axis quasistatic MEMS mirrors while still maintaining speeds applicable for above mentioned applications. One of the most exciting benefits of the packaging methodologies is that the damping dramatically increases shock and vibration tolerance, which will be tested next.

  12. Multispectral image-fused head-tracked vision system (HTVS) for driving applications

    NASA Astrophysics Data System (ADS)

    Reese, Colin E.; Bender, Edward J.

    2001-08-01

    Current military thermal driver vision systems consist of a single Long Wave Infrared (LWIR) sensor mounted on a manually operated gimbal, which is normally locked forward during driving. The sensor video imagery is presented on a large area flat panel display for direct view. The Night Vision and Electronics Sensors Directorate and Kaiser Electronics are cooperatively working to develop a driver's Head Tracked Vision System (HTVS) which directs dual waveband sensors in a more natural head-slewed imaging mode. The HTVS consists of LWIR and image intensified sensors, a high-speed gimbal, a head mounted display, and a head tracker. The first prototype systems have been delivered and have undergone preliminary field trials to characterize the operational benefits of a head tracked sensor system for tactical military ground applications. This investigation will address the advantages of head tracked vs. fixed sensor systems regarding peripheral sightings of threats, road hazards, and nearby vehicles. An additional thrust will investigate the degree to which additive (A+B) fusion of LWIR and image intensified sensors enhances overall driving performance. Typically, LWIR sensors are better for detecting threats, while image intensified sensors provide more natural scene cues, such as shadows and texture. This investigation will examine the degree to which the fusion of these two sensors enhances the driver's overall situational awareness.

  13. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  14. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  15. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  16. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  17. Definition and design of an experiment to test raster scanning with rotating unbalanced-mass devices on gimbaled payloads

    NASA Technical Reports Server (NTRS)

    Lightsey, W. D.; Alhorn, D. C.; Polites, M. E.

    1992-01-01

    An experiment designed to test the feasibility of using rotating unbalanced-mass (RUM) devices for line and raster scanning gimbaled payloads, while expending very little power is described. The experiment is configured for ground-based testing, but the scan concept is applicable to ground-based, balloon-borne, and space-based payloads, as well as free-flying spacecraft. The servos used in scanning are defined; the electronic hardware is specified; and a computer simulation model of the system is described. Simulation results are presented that predict system performance and verify the servo designs.

  18. Magnetic bearing momentum wheels with magnetic gimballing capability for 3-axis active attitude control and energy storage

    NASA Technical Reports Server (NTRS)

    Sindlinger, R. S.

    1977-01-01

    Magnetic bearings used for the suspension of momentum wheels provide conclusive advantages: the low friction torques and the absence of abrasion allow the realization of lightweight high speed wheels with high angular momentum and energy storage capacity and virtually unlimited lifetime. The use of actively controlled bearings provides a magnetic gimballing capability by applying the external signals to the two servo loops controlling the rotational degrees of freedom. Thus, an attitude control system can be realized by using only one rotating mass for 3-axis active satellite stabilization.

  19. Reconfiguring the RUM experiment to test circular scanning with rotating unbalanced-mass devices on gimbaled payloads

    NASA Technical Reports Server (NTRS)

    Polites, M. E.; Alhorn, D. C.

    1992-01-01

    This paper describes a ground-based experiment designed to prove the concept of circular scanning a gimbaled payload with rotating unbalanced-mass (RUM) devices. The experiment is a modified version of a similar experiment which demonstrates line and raster scanning with RUM's. In this paper, a description of the experiment hardware is presented and a detailed design of the servos used in scanning is given. A computer simulation model of the entire system is discussed and simulation results are included. These verify the servo designs and show the RUM's to be an extremely power efficient method for circular scanning.

  20. Constrained space camera assembly

    DOEpatents

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  1. Head Injuries

    MedlinePlus

    ... injuries internal head injuries, which may involve the skull, the blood vessels within the skull, or the brain Fortunately, most childhood falls or ... knock the brain into the side of the skull or tear blood vessels. Some internal head injuries ...

  2. Head Lice

    MedlinePlus

    ... or prescription products. Over-the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin ( ... commonly used to treat head lice. Shampoos and lotions that kill head lice contain pesticides and other ...

  3. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  4. Combined pressurized air solar heat sensing head assembly and a pressurized water drive system used to move solar energy collectors in tracking the sun

    SciTech Connect

    Wood, K.G.

    1987-03-03

    This patent describes a pressurized water drive system to move a power transmission in one direction or a opposite direction, comprising: (a) two sealed sections of compact, collapsible, flat hose arranged in a line, each section having one end to be joined to an end of the other section, and each section having a second end having an orifice, and each section being arranged in up and down side by side portions for endwise compression of the hose section. The hose section under compression has water contained in the hose section drained out of the end orifice, where the other section is expanded by receiving water under pressure through the other section orifice; (b) a power take off secured to the two sealed sections where they are joined together; (c) a housing within which the two sealed sections expand and contract, having an elongated opening to accommodate the transitory movement of the power take off, and having openings to provide access to the orifices on the two sealed sections; (d) a water control assembly to direct pressurized water alternately to respective orifices of the two sealed sections of one section of the flat hose and thereby expanding the flat hose, moving the power take off in one direction or in the opposite direction by expanding the other section of flat hose; and (e) a power transmission, connected to the power take off, to transmit the motion of the power take off to solar energy collectors in their tracing of the sun.

  5. Bistable Head Positioning Arm Latch

    NASA Astrophysics Data System (ADS)

    Wasson, Ken; Endo, Juro; Mita, Masahiro; Abelein, Nathan

    A simple, low cost, yet effective device has been developed for immobilizing the head-arm assembly in a disk drive or similar mechanism during power-off conditions. The latching scheme also provides a consistent means of releasing the head-arm assembly from the immobilized position upon power up of the disk drive. The latch uses no electrical power in either immobilized or released state. This design is immune to extreme torque and linear shock forces applied to the disk drive case. The latch system can use the energy stored in the spinning disks to drive the head-arm assembly toward a safe position while simultaneously arming the latch mechanism to secure the head-arm assembly in the safe position upon arrival. A low energy five msec pulse of current drives the latch from one state to the other. Solenoids as presently used in latch mechanisms are bulky, expensive, have variable force characteristics, and often generate contaminants. The latch described in this paper is expected to replace such solenoids. It may also replace small magnet latches, which have limited latch force and apply unwanted torque to a proximate head positioning arm.

  6. The study of control methods in opto-electronic tracking technology for fast object with horizontal gimbal

    NASA Astrophysics Data System (ADS)

    Li, Zhi-jun; Liu, Qiong; Mao, Yao

    2015-10-01

    It is inevitable that tracking high-elevation object exists blind region with horizontal gimbal, need to take some control methods to improve the system for high-elevation target tracking capability and reduce the blind region. This paper compares several common tracking control methods, including compound axis control of dual detector, compound axis control of single detector, compound axis control of single detector with modified guidance, analyzes the principle of operation, advantages and disadvantages, and validates by experiments. The experimental results showed that it is stable and reliable using guide modified compound axis control of single detector when the target position information is more accurate. On the other hand, it is able to meet the needs to track target with high speed and high acceleration using improved compound axis control of single detector when the target position information is not very accurate.

  7. Simple quality assurance method of dynamic tumor tracking with the gimbaled linac system using a light field.

    PubMed

    Miura, Hideharu; Ozawa, Shuichi; Hayata, Masahiro; Tsuda, Shintaro; Yamada, Kiyoshi; Nagata, Yasushi

    2016-01-01

    We proposed a simple visual method for evaluating the dynamic tumor tracking (DTT) accuracy of a gimbal mechanism using a light field. A single photon beam was set with a field size of 30 × 30 mm2 at a gantry angle of 90°. The center of a cube phantom was set up at the isocenter of a motion table, and 4D modeling was performed based on the tumor and infrared (IR) marker motion. After 4D modeling, the cube phantom was replaced with a sheet of paper, which was placed perpen-dicularly, and a light field was projected on the sheet of paper. The light field was recorded using a web camera in a treatment room that was as dark as possible. Calculated images from each image obtained using the camera were summed to compose a total summation image. Sinusoidal motion sequences were produced by moving the phantom with a fixed amplitude of 20 mm and different breathing periods of 2, 4, 6, and 8 s. The light field was projected on the sheet of paper under three conditions: with the moving phantom and DTT based on the motion of the phantom, with the moving phantom and non-DTT, and with a stationary phantom for comparison. The values of tracking errors using the light field were 1.12 ± 0.72, 0.31 ± 0.19, 0.27 ± 0.12, and 0.15 ± 0.09 mm for breathing periods of 2, 4, 6, and 8s, respectively. The tracking accuracy showed dependence on the breath-ing period. We proposed a simple quality assurance (QA) process for the tracking accuracy of a gimbal mechanism system using a light field and web camera. Our method can assess the tracking accuracy using a light field without irradiation and clearly visualize distributions like film dosimetry. PMID:27685142

  8. Simple quality assurance method of dynamic tumor tracking with the gimbaled linac system using a light field.

    PubMed

    Miura, Hideharu; Ozawa, Shuichi; Hayata, Masahiro; Tsuda, Shintaro; Yamada, Kiyoshi; Nagata, Yasushi

    2016-09-08

    We proposed a simple visual method for evaluating the dynamic tumor tracking (DTT) accuracy of a gimbal mechanism using a light field. A single photon beam was set with a field size of 30 × 30 mm2 at a gantry angle of 90°. The center of a cube phantom was set up at the isocenter of a motion table, and 4D modeling was performed based on the tumor and infrared (IR) marker motion. After 4D modeling, the cube phantom was replaced with a sheet of paper, which was placed perpen-dicularly, and a light field was projected on the sheet of paper. The light field was recorded using a web camera in a treatment room that was as dark as possible. Calculated images from each image obtained using the camera were summed to compose a total summation image. Sinusoidal motion sequences were produced by moving the phantom with a fixed amplitude of 20 mm and different breathing periods of 2, 4, 6, and 8 s. The light field was projected on the sheet of paper under three conditions: with the moving phantom and DTT based on the motion of the phantom, with the moving phantom and non-DTT, and with a stationary phantom for comparison. The values of tracking errors using the light field were 1.12 ± 0.72, 0.31 ± 0.19, 0.27 ± 0.12, and 0.15 ± 0.09 mm for breathing periods of 2, 4, 6, and 8s, respectively. The tracking accuracy showed dependence on the breath-ing period. We proposed a simple quality assurance (QA) process for the tracking accuracy of a gimbal mechanism system using a light field and web camera. Our method can assess the tracking accuracy using a light field without irradiation and clearly visualize distributions like film dosimetry.

  9. Protective helmet assembly

    NASA Technical Reports Server (NTRS)

    Dawn, Frederic S. (Inventor); Weiss, Fred R. (Inventor); Eck, John D. (Inventor)

    1992-01-01

    The invention is a protective helmet assembly with improved safety and impact resistance, high resistance to ignition and combustion, and reduced offgassing. The assembly comprises a hard rigid ballistic outer shell with one or more impact absorbing pads fitted to the interior surface. The pads are made of open cell flexible polyimide foam material, each of which is attached to the inner surface of the ballistic outer shell by cooperative VELCRO fastener strips of hook-and-loop material affixed respectively to the rigid outer shell and the impact absorbing pads. The helmet assembly with shell and pads is sized to fit relatively close over a wearer's head.

  10. Head injury.

    PubMed

    Hureibi, K A; McLatchie, G R

    2010-05-01

    Head injury is one of the commonest injuries in sport. Most are mild but some can have serious outcomes. Sports medicine doctors should be able to recognise the clinical features and evaluate athletes with head injury. It is necessary during field assessment to recognise signs and symptoms that help in assessing the severity of injury and making a decision to return-to-play. Prevention of primary head injury should be the aim. This includes protective equipment like helmets and possible rule changes. PMID:20533694

  11. FLUORINE CELL ANODE ASSEMBLY

    DOEpatents

    Cable, R.E.; Goode, W.B. Jr.; Henderson, W.K.; Montillon, G.H.

    1962-06-26

    An improved anode assembly is deslgned for use in electrolytlc cells ln the productlon of hydrogen and fluorlne from a moIten electrolyte. The anode assembly comprises a copper post, a copper hanger supported by the post, a plurality of carbon anode members, and bolt means for clamplng half of the anode members to one slde of the hanger and for clamplng the other half of the anode members to the other slde of the hanger. The heads of the clamplng bolts are recessed withln the anode members and carbon plugs are inserted ln the recesses above the bolt heads to protect the boIts agalnst corroslon. A copper washer is provided under the head of each clamplng boIt such that the anode members can be tightly clamped to the hanger with a resultant low anode jolnt resistance. (AEC)

  12. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  13. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  14. MULTIPLE SHAFT TOOL HEAD

    DOEpatents

    Colbert, H.P.

    1962-10-23

    An improved tool head arrangement is designed for the automatic expanding of a plurality of ferruled tubes simultaneously. A plurality of output shafts of a multiple spindle drill head are driven in unison by a hydraulic motor. A plurality of tube expanders are respectively coupled to the shafts through individual power train arrangements. The axial or thrust force required for the rolling operation is provided by a double acting hydraulic cylinder having a hollow through shaft with the shaft cooperating with an internally rotatable splined shaft slidably coupled to a coupling rigidly attached to the respectlve output shaft of the drill head, thereby transmitting rotary motion and axial thrust simultaneously to the tube expander. A hydraulic power unit supplies power to each of the double acting cylinders through respective two-position, four-way valves, under control of respective solenoids for each of the cylinders. The solenoids are in turn selectively controlled by a tool selection control unit which in turn is controlled by signals received from a programmed, coded tape from a tape reader. The number of expanders that are extended in a rolling operation, which may be up to 42 expanders, is determined by a predetermined program of operations depending upon the arrangement of the ferruled tubes to be expanded in the tube bundle. The tape reader also supplies dimensional information to a machine tool servo control unit for imparting selected, horizontal and/or vertical movement to the tool head assembly. (AEC)

  15. Investigation of application of two-degree-of-freedom dry tuned-gimbal gyroscopes to strapdown navigation systems. [for use in VTOL aircraft

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The work is described which was accomplished during the investigation of the application of dry-tuned gimbal gyroscopes to strapdown navigation systems. A conventional strapdown configuration, employing analog electronics in conjunction with digital attitude and navigation computation, was examined using various levels of redundancy and both orthogonal and nonorthogonal sensor orientations. It is concluded that the cost and reliability performance constraints which had been established could not be met simultaneously with such a system. This conclusion led to the examination of an alternative system configuration which utilizes an essentially new strapdown system concept. This system employs all-digital signal processing in conjunction with the newly-developed large scale integration (LSI) electronic packaging techniques and a new two-degree-of-freedom dry tuned-gimbal instrument which is capable of providing both angular rate and acceleration information. Such a system is capable of exceeding the established performance goals.

  16. System and method for controlling a combustor assembly

    SciTech Connect

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Stevenson, Christian Xavier

    2013-03-05

    A system and method for controlling a combustor assembly are disclosed. The system includes a combustor assembly. The combustor assembly includes a combustor and a fuel nozzle assembly. The combustor includes a casing. The fuel nozzle assembly is positioned at least partially within the casing and includes a fuel nozzle. The fuel nozzle assembly further defines a head end. The system further includes a viewing device configured for capturing an image of at least a portion of the head end, and a processor communicatively coupled to the viewing device, the processor configured to compare the image to a standard image for the head end.

  17. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... acceleration shall be between 120 and 150 G's. (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed 15 percent (zero to peak) of the main pulse. The longitudinal acceleration vector shall not exceed 15 G's....

  18. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... acceleration shall be between 120 and 150 G's. (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed 15 percent (zero to peak) of the main pulse. The longitudinal acceleration vector shall not exceed 15 G's....

  19. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... acceleration shall be between 120 and 150 G's. (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed 15 percent (zero to peak) of the main pulse. The longitudinal acceleration vector shall not exceed 15 G's....

  20. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... acceleration shall be between 120 and 150 G's. (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed 15 percent (zero to peak) of the main pulse. The longitudinal acceleration vector shall not exceed 15 G's....

  1. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... acceleration shall be between 120 and 150 G's. (2) The resultant acceleration-time curve shall be unimodal to the extent that oscillations occurring after the main acceleration pulse shall not exceed 15 percent (zero to peak) of the main pulse. The longitudinal acceleration vector shall not exceed 15 G's....

  2. Failure-tolerant control for small agile satellites using single-gimbal control moment gyros and magnetic torquers

    NASA Astrophysics Data System (ADS)

    Meng, Tao; Matunaga, Saburo

    2012-04-01

    This paper focuses on the attitude control problem of small agile satellites using single-gimbal control moment gyros (CMG) and magnetic torquers (MTQ). CMGs are regarded as effective torque generators for agile satellites because of their torque amplification capability. However, they are vulnerable to failure due to their complex inner mechanism. In this paper, different failure cases of CMGs are analyzed. A flexible failure-tolerant control strategy is developed by automatically redistributing the required control torque among the operating CMGs and MTQs, with a variable limiter to accommodate the actuator dynamics changes introduced by CMG failures. The performances of maneuvers about different directions under different failure cases are also discussed and examined. Numerical simulations demonstrate that the proposed strategy maintains certain agility in the cases of one or two CMGs failing. Moreover, a survival strategy with only one CMG left is also verified. Both sun-pointing stabilization and earth-pointing stabilization can be achieved in this case, which fulfill some basic mission requirements.

  3. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head-neck. 572.83 Section 572.83 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16...

  4. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head-neck. 572.83 Section 572.83 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16...

  5. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head-neck. 572.83 Section 572.83 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16...

  6. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head-neck. 572.83 Section 572.83 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16...

  7. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head-neck. 572.83 Section 572.83 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16...

  8. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure oxidizer Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Fuel Turbopump (LPFTP) is on the upper left of the assembly in this view and the LPFTP Discharge Duct loops from the upper left to upper right then turns back and down the assembly to the High-Pressure Fuel Turbopump on the lower right of the assembly. The Engine Controller and the Main fuel Valve Hydraulic Actuator are on the lower left portion of the assembly. The vertical rod that is in the approximate center of the engine assembly is a piece of ground support equipment call a Gimbal Actuator Replacement Strut which are used on the SSMEs when they are not installed in an orbiter. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. Constrained space camera assembly

    DOEpatents

    Heckendorn, F.M.; Anderson, E.K.; Robinson, C.W.; Haynes, H.B.

    1999-05-11

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity is disclosed. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras. 17 figs.

  10. Verification of the Mechanism of the Head-Positioning Error Caused by Disk Flutter and Slider Supporting Structure for Reducing Head-Positioning Error

    NASA Astrophysics Data System (ADS)

    Imai, Satomitsu

    In magnetic disk drives, the disk flutter due to high-rotational speed causes the increase of the head-positioning error. It is important to clear the mechanism of the head-positioning error caused by the disk flutter. This paper conducts the experiments to verify the mechanism proposed in the former report. The experiment was conducted by comparing the head-positioning error predicted by the proposed mechanism with the measured head-positioning error signal. It is confirmed that the proposed mechanism can predict the head-positioning error within the 10% error. The former reports also said that the flutter transfer ratio defined in the report could decrease the head-positioning error without reducing the amplitude of the disk flutter. This paper also verifies it experimentally. In the experiment, the thickness of the slider was changed to make the flutter transfer ratio small. This paper also proposes the method of making the beam angle of the gimbal slant to make the flutter transfer ratio small. The effectiveness was confirmed by the simulation.

  11. A novel offset cancellation based on parasitic-insensitive switched-capacitor sensing circuit for the out-of-plane single-Gimbaled decoupled CMOS-MEMS gyroscope.

    PubMed

    Chang, Ming-Hui; Huang, Han-Pang

    2013-03-14

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement.

  12. A novel offset cancellation based on parasitic-insensitive switched-capacitor sensing circuit for the out-of-plane single-Gimbaled decoupled CMOS-MEMS gyroscope.

    PubMed

    Chang, Ming-Hui; Huang, Han-Pang

    2013-01-01

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement. PMID:23493122

  13. Head Position and Internally Headed Relative Clauses.

    ERIC Educational Resources Information Center

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  14. Integrated hydraulic cooler and return rail in camless cylinder head

    DOEpatents

    Marriott, Craig D.; Neal, Timothy L.; Swain, Jeff L.; Raimao, Miguel A.

    2011-12-13

    An engine assembly may include a cylinder head defining an engine coolant reservoir, a pressurized fluid supply, a valve actuation assembly, and a hydraulic fluid reservoir. The valve actuation assembly may be in fluid communication with the pressurized fluid supply and may include a valve member displaceable by a force applied by the pressurized fluid supply. The hydraulic fluid reservoir may be in fluid communication with the valve actuation assembly and in a heat exchange relation to the engine coolant reservoir.

  15. Results of a laboratory experiment that tests rotating unbalanced-mass devices for scanning gimbaled payloads and free-flying spacecraft

    NASA Technical Reports Server (NTRS)

    Alhorn, D. C.; Polites, M. E.

    1994-01-01

    Rotating unbalanced-mass (RUM) devices are a new way to scan space-based, balloon-borne, and ground-based gimbaled payloads, like x-ray and gamma-ray telescopes. They can also be used to scan free-flying spacecraft. Circular scans, linear scans, and raster scans can be generated. A pair of RUM devices generates the basic scan motion and an auxiliary control system using torque motors, control moment gyros, or reaction wheels keeps the scan centered on the target and produces some complementary motion for raster scanning. Previous analyses and simulation results show that this approach offers significant power savings compared to scanning only with the auxiliary control system, especially with large payloads and high scan frequencies. However, these claims have never been proven until now. This paper describes a laboratory experiment which tests the concept of scanning a gimbaled payload with RUM devices. A description of the experiment is given and test results that prove the concept are presented. The test results are compared with those from a computer simulation model of the experiment and the differences are discussed.

  16. Portable propellant cutting assembly, and method of cutting propellant with assembly

    NASA Technical Reports Server (NTRS)

    Sharp, Roger A. (Inventor); Hoskins, Shawn W. (Inventor); Payne, Brett D. (Inventor)

    2002-01-01

    A propellant cutting assembly and method of using the assembly to cut samples of solid propellant in a repeatable and consistent manner is disclosed. The cutting assembly utilizes two parallel extension beams which are shorter than the diameter of a central bore of an annular solid propellant grain and can be loaded into the central bore. The assembly is equipped with retaining heads at its respective ends and an adjustment mechanism to position and wedge the assembly within the central bore. One end of the assembly is equipped with a cutting blade apparatus which can be extended beyond the end of the extension beams to cut into the solid propellant.

  17. Head circumference (image)

    MedlinePlus

    Head circumference is a measurement of the circumference of the child's head at its largest area (above the eyebrows and ears and around the back of the head). During routine check-ups, the distance is measured ...

  18. Gas cushion control of OVJP print head position

    DOEpatents

    Forrest, Stephen R

    2014-10-07

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

  19. Heading and head injuries in soccer.

    PubMed

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  20. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  1. Research on modeling of the agile satellite using a single gimbal magnetically suspended CMG and the disturbance feedforward compensation for rotors.

    PubMed

    Cui, Peiling; Yan, Ning

    2012-01-01

    The magnetically suspended Control Moment Gyroscope (CMG) has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this paper, a dynamic model of the agile satellite including a magnetically suspended single gimbal control moment gyroscope is built and the equivalent disturbance torque effected on the rotor is obtained. The feedforward compensation control method is used to depress the disturbance on the rotor. Simulation results are given to show that the rotor displacement is obviously reduced.

  2. Research on Modeling of the Agile Satellite Using a Single Gimbal Magnetically Suspended CMG and the Disturbance Feedforward Compensation for Rotors

    PubMed Central

    Cui, Peiling; Yan, Ning

    2012-01-01

    The magnetically suspended Control Moment Gyroscope (CMG) has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this paper, a dynamic model of the agile satellite including a magnetically suspended single gimbal control moment gyroscope is built and the equivalent disturbance torque effected on the rotor is obtained. The feedforward compensation control method is used to depress the disturbance on the rotor. Simulation results are given to show that the rotor displacement is obviously reduced. PMID:23235442

  3. Optical Fiber Array Assemblies for Space Flight on the Lunar Reconnaissance Orbiter

    NASA Technical Reports Server (NTRS)

    Ott, Jelanie; Matuszeski, Adam

    2011-01-01

    Custom fiber optic bundle array assemblies developed by the Photonics Group at NASA Goddard Space Flight Center were an enabling technology for both the Lunar Orbiter Laser Altimeter (LOLA) and the Laser Ranging (LR) Investigation on the Lunar Reconnaissance Orbiter (LRO) currently in operation. The unique assembly array designs provided considerable decrease in size and weight and met stringent system level requirements. This is the first time optical fiber array bundle assemblies were used in a high performance space flight application. This innovation was achieved using customized Diamond Switzerland AVIM optical connectors. For LOLA, a five fiber array was developed for the receiver telescope to maintain precise alignment for each of the 200/220 micron optical fibers collecting 1,064 nm wavelength light being reflected back from the moon. The array splits to five separate detectors replacing the need for multiple telescopes. An image illustration of the LOLA instrument can be found at the top of the figure. For the laser ranging, a seven-optical-fiber array of 400/440 micron fibers was developed to transmit light from behind the LR receiver telescope located on the end of the high gain antenna system (HGAS). The bundle was routed across two moving gimbals, down the HGAS boom arm, over a deployable mandrel and across the spacecraft to a detector on the LOLA instrument. The routing of the optical fiber bundle and its end locations is identified in the figure. The Laser Ranging array and bundle is currently accepting light at a wavelength of 532 nm sent to the moon from laser stations at Greenbelt MD and other stations around the world to gather precision ranging information from the Earth to the LRO spacecraft. The LR bundle assembly is capable of withstanding temperatures down to -55 C at the connectors, and 20,000 mechanical gimbal cycles at temperatures as cold as -20 C along the length of the seven-fiber bundle (that is packaged into the gimbals). The total

  4. Radial head fractures--an update.

    PubMed

    Pike, Jeffrey M; Athwal, George S; Faber, Kenneth J; King, Graham J W

    2009-03-01

    Radial head fractures are the most common fractures occurring around the elbow. Although radial head fractures can occur in isolation, associated fractures and ligament injuries are common. Assembling the clinical presentation, physical examination, and imaging into an effective treatment plan can be challenging. The characteristics of the radial head fracture influence the technique used to optimize the outcome. Fragment number, displacement, impaction, and bone quality are considered when deciding between early motion, fragment excision, and radial head excision, repair, or replacement. Isolated, minimally displaced fractures without evidence of mechanical block can be treated nonsurgically with early active range of motion (ROM). Partial, displaced radial head fractures without evidence of mechanical block can be treated either nonsurgically or with open reduction internal fixation (ORIF), as current evidence does not prove superiority of either strategy. For displaced fractures with greater than 3 fragments, radial head replacement is recommended. Radial head arthroplasty may be preferred over tenuous fracture fixation in the setting of associated ligament injuries when maintenance of joint stability could be compromised by ineffective fracture fixation. PMID:19258159

  5. Architecture of the Mediator head module

    SciTech Connect

    Imasaki, Tsuyoshi; Calero, Guillermo; Cai, Gang; Tsai, Kuang-Lei; Yamada, Kentaro; Cardelli, Francesco; Erdjument-Bromage, Hediye; Tempst, Paul; Berger, Imre; Kornberg, Guy Lorch; Asturias, Francisco J.; Kornberg, Roger D.; Takagi, Yuichiro

    2011-09-06

    Mediator is a key regulator of eukaryotic transcription, connecting activators and repressors bound to regulatory DNA elements with RNA polymerase II (Pol II). In the yeast Saccharomyces cerevisiae, Mediator comprises 25 subunits with a total mass of more than one megadalton (refs 5, 6) and is organized into three modules, called head, middle/arm and tail. Our understanding of Mediator assembly and its role in regulating transcription has been impeded so far by limited structural information. Here we report the crystal structure of the essential Mediator head module (seven subunits, with a mass of 223 kilodaltons) at a resolution of 4.3 angstroms. Our structure reveals three distinct domains, with the integrity of the complex centred on a bundle of ten helices from five different head subunits. An intricate pattern of interactions within this helical bundle ensures the stable assembly of the head subunits and provides the binding sites for general transcription factors and Pol II. Our structural and functional data suggest that the head module juxtaposes transcription factor IIH and the carboxy-terminal domain of the largest subunit of Pol II, thereby facilitating phosphorylation of the carboxy-terminal domain of Pol II. Our results reveal architectural principles underlying the role of Mediator in the regulation of gene expression.

  6. Crew Assembly

    NASA Video Gallery

    Train to improve your dexterity and hand-eye coordination by assembling a puzzle.The Train Like an Astronaut project uses the excitement of exploration to challenge students to set goals, practice ...

  7. Seal assembly

    SciTech Connect

    Johnson, Roger Neal; Longfritz, William David

    2001-01-01

    A seal assembly that seals a gap formed by a groove comprises a seal body, a biasing element, and a connection that connects the seal body to the biasing element to form the seal assembly. The seal assembly further comprises a concave-shaped center section and convex-shaped contact portions at each end of the seal body. The biasing element is formed from an elastic material and comprises a convex-shaped center section and concave-shaped biasing zones that are opposed to the convex-shaped contact portions. The biasing element is adapted to be compressed to change a width of the seal assembly from a first width to a second width that is smaller than the first width. In the compressed state, the seal assembly can be disposed in the groove. After release of the compressing force, the seal assembly expands. The contact portions will move toward a surface of the groove and the biasing zones will move into contact with another surface of the groove. The biasing zones will bias the contact portions of the seal body against the surface of the groove.

  8. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... conditions: Birth (congenital) defect of the head or brain Brain infection Brain tumor Buildup of fluid inside ...

  9. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... swallowing A change or hoarseness in the voice Head and neck cancers are twice as common in men. Using ...

  10. Head injury. Second edition

    SciTech Connect

    Cooper, P.R.

    1987-01-01

    This book contains 22 chapters. Some of the chapter titles are: Radiographic Evaluation; Epidemiology of Head Injury; Emergency Care and Initial Evaluation; Skull Fracture and Traumatic Cerebrospinal Fluid Fistulas; Mild Head Injury; and Injuries of the Cranial Nerves.

  11. The Head Start Debates

    ERIC Educational Resources Information Center

    Zigler, Edward, Ed.; Styfco, Sally J., Ed.

    2004-01-01

    The future of Head Start depends on how well people learn from and apply the lessons from its past. That's why everyone involved in early education needs this timely, forward-thinking book from the leader of Head Start. The first book to capture the Head Start debates in all their complexity and diversity, this landmark volume brings together the…

  12. Head Start Facilities Manual.

    ERIC Educational Resources Information Center

    Research Assessment Management, Inc., Silver Spring, MD.

    A quality Head Start facility should provide a physical environment responsive both to the needs of the children and families served and to the needs of staff, volunteers, and community agencies that share space with Head Start. This manual is a tool for Head Start grantees and delegate agencies for assessing existing facilities, making…

  13. Foliage penetration obscuration probability density function analysis from overhead canopy photos for gimbaled linear-mode and Geiger-mode airborne lidar

    NASA Astrophysics Data System (ADS)

    Burton, Robin R.

    2010-04-01

    Three-dimensional (3D) Light Detection And Ranging (LIDAR) systems designed for foliage penetration can produce good bare-earth products in medium to medium-heavy obscuration environments, but product creation becomes increasingly more difficult as the obscuration level increases. A prior knowledge of the obscuration environment over large areas is hard to obtain. The competing factors of area coverage rate and product quality are difficult to balance. Ground-based estimates of obscuration levels are labor intensive and only capture a small portion of the area of interest. Estimates of obscuration levels derived from airborne data require that the area of interest has been collected previously. Recently, there has been a focus on lacunarity (scale dependent measure of translational invariance) to quantify the gap structure of canopies. While this approach is useful, it needs to be evaluated relative to the size of the instantaneous field-of-view (IFOV) of the system under consideration. In this paper, the author reports on initial results to generate not just average obscuration values from overhead canopy photographs, but to generate obscuration probability density functions (PDFs) for both gimbaled linear-mode and geiger-mode airborne LIDAR. In general, gimbaled linear-mode (LM) LIDAR collects data with higher signal-to-noise (SNR), but is limited to smaller areas and cannot collect at higher altitudes. Conversely, geiger-mode (GM) LIDAR has a much lower SNR, but is capable of higher area rates and collecting data at higher altitudes. To date, geiger-mode LIDAR obscurant penetration theory has relied on a single obscuration value, but recent work has extended it to use PDFs1. Whether or not the inclusion of PDFs significantly changes predicted results and more closely matches actual results awaits the generation of PDFs over specific ground truth targets and comparison to actual collections of those ground truth targets. Ideally, examination of individual PDFs

  14. Hinge assembly

    DOEpatents

    Vandergriff, D.H.

    1999-08-31

    A hinge assembly is disclosed having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf. 8 figs.

  15. Hinge assembly

    DOEpatents

    Vandergriff, David Houston

    1999-01-01

    A hinge assembly having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf.

  16. Latch assembly

    DOEpatents

    Frederickson, James R.; Harper, William H.; Perez, Raymond

    1986-01-01

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing.

  17. Latch assembly

    DOEpatents

    Frederickson, J.R.; Harper, W.H.; Perez, R.

    1984-08-17

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing. 2 figs.

  18. Valve assembly

    SciTech Connect

    Marshala, D.L.

    1986-12-16

    This patent describes a subsurface pump actuated by a reciprocatable sucker rod for producing well liquids from a subsurface reservoir involving a piston adapted to reciprocate within a cylinder immersed in the reservoir, the piston being provided with a traveling valve. The improvement described here comprises valve means connected to the sucker tod for lifting a body of fluid during upstrokes of the sucker rod, the valve means comprising: a barrel assembly having an internal bore and comprising: a lower barrel member; and an upper barrel assembly connected to the lower barrel and having a beveled seating surface with at least one fluid port therethrough.

  19. Furnace assembly

    DOEpatents

    Panayotou, N.F.; Green, D.R.; Price, L.S.

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  20. Furnace assembly

    DOEpatents

    Panayotou, Nicholas F.; Green, Donald R.; Price, Larry S.

    1985-01-01

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  1. Integrated head package for top mounted nuclear instrumentation

    DOEpatents

    Malandra, Louis J.; Hornak, Leonard P.; Meuschke, Robert E.

    1993-01-01

    A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

  2. Meteoric Head Echoes

    NASA Astrophysics Data System (ADS)

    Hajduk, A.; Galád, A.

    1995-01-01

    Results of the analysis of 3261 radar meteor head echoes observed during the Orionid and Lyrid periods by the high-power radar of the Springhill Meteor Observatory are given. Dependence of the occurence of head echoes on the geometrical factors and physical properties of the meteoroids has been studied. Increas of the head echo rates with the elevation of the shower radiant and with the velocity of meteoroids has been observed.

  3. Deposition head for laser

    DOEpatents

    Lewis, Gary K.; Less, Richard M.

    1999-01-01

    A deposition head for use as a part of apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. The deposition head delivers the laser beam and powder to a deposition zone, which is formed at the tip of the deposition head. A controller comprised of a digital computer directs movement of the deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which the deposition head moves along the tool path.

  4. 49 CFR 572.113 - Neck assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Using neck brackets 78051-303 and -307, mount the head/neck assembly to the part 572 pendulum test... to the plane of motion of the pendulum's longitudinal centerline (see § 572.33, Figure 20, except... (horizontal surface at the base of the skull) rotation with respect to the pendulum's longitudinal...

  5. 49 CFR 572.113 - Neck assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Using neck brackets 78051-303 and -307, mount the head/neck assembly to the part 572 pendulum test... to the plane of motion of the pendulum's longitudinal centerline (see § 572.33, Figure 20, except... (horizontal surface at the base of the skull) rotation with respect to the pendulum's longitudinal...

  6. 49 CFR 572.113 - Neck assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Using neck brackets 78051-303 and -307, mount the head/neck assembly to the part 572 pendulum test... to the plane of motion of the pendulum's longitudinal centerline (see § 572.33, Figure 20, except... (horizontal surface at the base of the skull) rotation with respect to the pendulum's longitudinal...

  7. 49 CFR 572.113 - Neck assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Using neck brackets 78051-303 and -307, mount the head/neck assembly to the part 572 pendulum test... to the plane of motion of the pendulum's longitudinal centerline (see § 572.33, Figure 20, except... (horizontal surface at the base of the skull) rotation with respect to the pendulum's longitudinal...

  8. Sensor assembly

    DOEpatents

    Bennett, Thomas E.; Nelson, Drew V.

    2004-04-13

    A ribbon-like sensor assembly is described wherein a length of an optical fiber embedded within a similar lengths of a prepreg tow. The fiber is ""sandwiched"" by two layers of the prepreg tow which are merged to form a single consolidated ribbon. The consolidated ribbon achieving a generally uniform distribution of composite filaments near the embedded fiber such that excess resin does not ""pool"" around the periphery of the embedded fiber.

  9. Head Injuries in Children

    ERIC Educational Resources Information Center

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  10. A dosimetric comparison of real-time adaptive and non-adaptive radiotherapy: A multi-institutional study encompassing robotic, gimbaled, multileaf collimator and couch tracking

    PubMed Central

    Colvill, Emma; Booth, Jeremy; Nill, Simeon; Fast, Martin; Bedford, James; Oelfke, Uwe; Nakamura, Mitsuhiro; Poulsen, Per; Worm, Esben; Hansen, Rune; Ravkilde, Thomas; Scherman Rydhög, Jonas; Pommer, Tobias; Munck af Rosenschold, Per; Lang, Stephanie; Guckenberger, Matthias; Groh, Christian; Herrmann, Christian; Verellen, Dirk; Poels, Kenneth; Wang, Lei; Hadsell, Michael; Sothmann, Thilo; Blanck, Oliver; Keall, Paul

    2016-01-01

    Purpose A study of real-time adaptive radiotherapy systems was performed to test the hypothesis that, across delivery systems and institutions, the dosimetric accuracy is improved with adaptive treatments over non-adaptive radiotherapy in the presence of patient-measured tumor motion. Methods and materials Ten institutions with robotic(2), gimbaled(2), MLC(4) or couch tracking(2) used common materials including CT and structure sets, motion traces and planning protocols to create a lung and a prostate plan. For each motion trace, the plan was delivered twice to a moving dosimeter; with and without real-time adaptation. Each measurement was compared to a static measurement and the percentage of failed points for γ-tests recorded. Results For all lung traces all measurement sets show improved dose accuracy with a mean 2%/2 mm γ-fail rate of 1.6% with adaptation and 15.2% without adaptation (p < 0.001). For all prostate the mean 2%/2 mm γ-fail rate was 1.4% with adaptation and 17.3% without adaptation (p < 0.001). The difference between the four systems was small with an average 2%/2 mm γ-fail rate of <3% for all systems with adaptation for lung and prostate. Conclusions The investigated systems all accounted for realistic tumor motion accurately and performed to a similar high standard, with real-time adaptation significantly outperforming non-adaptive delivery methods. PMID:27016171

  11. Pushrod assembly

    DOEpatents

    Potter, J.D.

    1984-03-30

    A pushrod assembly including a carriage mounted on a shaft for movement therealong and carrying a pushrod engageable with a load to be moved is described. A magnet is mounted on a supporting bracket for movement along such shaft. Means are provided for adjustably spacing magnet away from the carriage to obtain a selected magnetic attractive or coupling force therebetween. Movement of the supporting bracket and the magnet carried thereby pulls the carriage along with it until the selected magnetic force is exceeded by a resistance load acting on the carriage.

  12. Pushrod assembly

    DOEpatents

    Potter, Jerry D.

    1987-01-01

    A pushrod assembly including a carriage mounted on a shaft for movement therealong and carrying a pushrod engageable with a load to be moved. A magnet is mounted on a supporting bracket for movement along such shaft. Means are provided for adjustably spacing said magnet away from said carriage to obtain a selected magnetic attractive or coupling force therebetween. Movement of the supporting bracket and the magnet carried thereby pulls the carriage along with it until the selected magnetic force is exceeded by a resistance load acting on the carriage.

  13. Shingle assembly

    DOEpatents

    Dinwoodie, Thomas L.

    2007-02-20

    A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. The first edge of one base may be interengageable with the second edge of an adjacent base to be capable of resisting first and second disengaging forces oriented perpendicular to the edges and along planes oriented parallel to and perpendicular to the base. A deflector may be used to help reduce wind uplift forces.

  14. Dump assembly

    DOEpatents

    Goldmann, L.H.

    1984-12-06

    This is a claim for a dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough. 4 figs.

  15. Head Circumference and Neurocognitive Outcomes.

    PubMed

    Millichap, J Gordon

    2015-07-01

    Investigators from Universities of Glasgow and Bristol, UK, determined the value of head circumference (HC) as a screening measure, the incidence of head centile shifting, and the relationship between extremes of head size and later neurodevelopmental problems. PMID:26933592

  16. American Head and Neck Society

    MedlinePlus

    American Head & Neck Society Mission Statement: Advance Education, Research, and Quality of Care for the head and neck oncology patient. American Head & Neck Society | AHNS The mission of the AHNS is ...

  17. Maneuvering impact boring head

    DOEpatents

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  18. Maneuvering impact boring head

    DOEpatents

    Zollinger, W.T.; Reutzel, E.W.

    1998-08-18

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  19. Radial head arthroplasty.

    PubMed

    Kleiner, M T; Ilyas, A M; Jupiter, J B

    2010-02-01

    In conclusion, radial head fractures with 3 or more fragments have a high incidence of complications when treated with ORIF including hardware failure, malunion, nonunion, and the need for re-operation. Radial head arthroplasty has demonstrated good success in the treatment of complex, comminuted radial head fractures which are not amenable to non-opeative treatment or ORIF. Success can be optimized by diligent surgical dissection, avoiding inadvertent nerve injury, placement of an appropriately sized implant, repair of associated injuries, and early protected motion. PMID:20214854

  20. Computed Tomography (CT) -- Head

    MedlinePlus

    ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... Angiography (CTA) Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, ...

  1. Abnormal Head Position

    MedlinePlus

    ... syndrome, Brown’s syndrome, orbital wall fractures, and restricted eye movement associated with thyroid eye disease. 2) Nystagmus: Some patients with nystagmus (jerky eye movements) will acquire a head turn or tilt if ...

  2. Head Lice: Treatment

    MedlinePlus

    ... it may be necessary to use a second bottle. Pay special attention to instructions on the label ... or printed on the label. Nit (head lice egg) combs, often found in lice medicine packages, should ...

  3. Head and Neck Cancer

    MedlinePlus

    ... head and neck cancer. Poor oral and dental hygiene . Poor care of the mouth and teeth has ... sore throat Foul mouth odor not explained by hygiene Hoarseness or change in voice Nasal obstruction or ...

  4. Overview of Head Injuries

    MedlinePlus

    ... to Baby Health Highlights: Sept. 13, 2016 Smokers' Perceptions May Play Role in Addiction Sugar Companies Shifted ... amount of oxygen given and the rate and depth of breaths given by the ventilator. The head ...

  5. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... to 2 weeks. If you have a small fracture and your bones did not move around much, ... to see a bone doctor (orthopedic surgeon). Some fractures require surgery to: Insert pins and plates to ...

  6. Ultrasound: Head (For Parents)

    MedlinePlus

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  7. Head tilt during driving.

    PubMed

    Zikovitz, D C; Harris, L R

    1999-05-01

    In order to distinguish between the use of visual and gravito-inertial force reference frames, the head tilt of drivers and passengers were measured as they went around corners at various speeds. The visual curvature of the corners were thus dissociated from the magnitude of the centripetal forces (0.30-0.77 g). Drivers' head tilts were highly correlated with the visually-available estimate of the curvature of the road (r2=0.86) but not with the centripetal force (r2<0.1). Passengers' head tilts were inversely correlated with the lateral forces (r2=0.3-0.7) and seem to reflect a passive sway. The strong correlation of the tilt of drivers' heads with a visual aspect of the road ahead, supports the use of a predominantly visual reference frame for the driving task. PMID:10722313

  8. Treating Head Lice

    MedlinePlus

    ... and Prevention. Head lice are most common among preschool children attending child care, elementary school children, and ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

  9. Head injury - first aid

    MedlinePlus

    ... and circulation. If necessary, begin rescue breathing and CPR . If the person's breathing and heart rate are normal but the person is unconscious, treat as if there is a spinal injury . Stabilize the head and neck by placing your ...

  10. TCGA head Neck

    Cancer.gov

    Investigators with The Cancer Genome Atlas (TCGA) Research Network have discovered genomic differences – with potentially important clinical implications – in head and neck cancers caused by infection with the human papillomavirus (HPV).

  11. Head Injuries in Soccer.

    ERIC Educational Resources Information Center

    Fields, Karl B.

    1989-01-01

    This article reviews the medical literature on head injuries in soccer and concludes that protective headgear to reduce these injuries may not be as effective as rule changes and other measures, such as padding goal posts. (IAH)

  12. Thermocouple assembly

    DOEpatents

    Thermos, Anthony Constantine; Rahal, Fadi Elias

    2002-01-01

    A thermocouple assembly includes a thermocouple; a plurality of lead wires extending from the thermocouple; an insulating jacket extending along and enclosing the plurality of leads; and at least one internally sealed area within the insulating jacket to prevent fluid leakage along and within the insulating jacket. The invention also provides a method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple including the steps of a) attaching a plurality of lead wires to a thermocouple; b) adding a heat sensitive pseudo-wire to extend along the plurality of lead wires; c) enclosing the lead wires and pseudo-wire inside an insulating jacket; d) locally heating axially spaced portions of the insulating jacket to a temperature which melts the pseudo-wire and fuses it with an interior surface of the jacket.

  13. Swivel assembly

    DOEpatents

    Hall, David R.; Pixton, David S.; Briscoe, Michael; Bradford, Kline; Rawle, Michael; Bartholomew, David B.; McPherson, James

    2007-03-20

    A swivel assembly for a downhole tool string comprises a first and second coaxial housing cooperatively arranged. The first housing comprises a first transmission element in communication with surface equipment. The second housing comprises a second transmission element in communication with the first transmission element. The second housing further comprises a third transmission element adapted for communication with a network integrated into the downhole tool string. The second housing may be rotational and adapted to transmit a signal between the downhole network and the first housing. Electronic circuitry is in communication with at least one of the transmission elements. The electronic circuitry may be externally mounted to the first or second housing. Further, the electronic circuitry may be internally mounted in the second housing. The electronic circuitry may be disposed in a recess in either first or second housing of the swivel.

  14. 49 CFR 572.172 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) in accordance with paragraph (c) of this section, the peak resultant acceleration at the location of... acceleration vs. time history curve shall be unimodal; oscillations occurring after the main pulse must be less than 10 percent of the peak resultant acceleration. The lateral acceleration shall not exceed 15...

  15. 49 CFR 572.172 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) in accordance with paragraph (c) of this section, the peak resultant acceleration at the location of... acceleration vs. time history curve shall be unimodal; oscillations occurring after the main pulse must be less than 10 percent of the peak resultant acceleration. The lateral acceleration shall not exceed 15...

  16. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in) in accordance with paragraph (c) of this section, the peak resultant acceleration at the location... acceleration versus time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 10 percent of the peak resultant acceleration. The lateral acceleration shall...

  17. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in) in accordance with paragraph (c) of this section, the peak resultant acceleration at the location... acceleration versus time history curve shall be unimodal, and the oscillations occurring after the main pulse shall be less than 10 percent of the peak resultant acceleration. The lateral acceleration shall...

  18. 49 CFR 572.172 - Head assembly and test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) in accordance with paragraph (c) of this section, the peak resultant acceleration at the location of... acceleration vs. time history curve shall be unimodal; oscillations occurring after the main pulse must be less than 10 percent of the peak resultant acceleration. The lateral acceleration shall not exceed 15...

  19. Oil and gas well diversionary spool assembly

    SciTech Connect

    Reed, L.T.

    1989-02-14

    In combination with an oil and gas well that includes a casing head from which a string of tubing extends downwardly in a bore hole to a fluid producing zone, a diversionary spool assembly is described situated in a fixed position relative to the well head to control fluid flow from the well and also serve as a temporary mounting for a Christmas tree array of valves when maintenance work is to be performed on the well, the array of valves including an anchor flange on a lower end thereof.

  20. Visual cueing considerations in Nap-of-the-Earth helicopter flight head-slaved helmet-mounted displays

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Kohn, Silvia

    1993-01-01

    The pilot's ability to derive Control-Oriented Visual Field Information from teleoperated Helmet-Mounted displays in Nap-of-the-Earth flight, is investigated. The visual field with these types of displays, commonly used in Apache and Cobra helicopter night operations, originates from a relatively narrow field-of-view Forward Looking Infrared Radiation Camera, gimbal-mounted at the nose of the aircraft and slaved to the pilot's line-of-sight, in order to obtain a wide-angle field-of-regard. Pilots have encountered considerable difficulties in controlling the aircraft by these devices. Experimental simulator results presented here indicate that part of these difficulties can be attributed to head/camera slaving system phase lags and errors. In the presence of voluntary head rotation, these slaving system imperfections are shown to impair the Control-Oriented Visual Field Information vital in vehicular control, such as the perception of the anticipated flight path or the vehicle yaw rate. Since, in the presence of slaving system imperfections, the pilot will tend to minimize head rotation, the full wide-angle field-of-regard of the line-of-sight slaved Helmet-Mounted Display, is not always fully utilized.

  1. Missouri: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Missouri's Early Head Start/Child Care Partnership Project expands access to Early Head Start (EHS) services for children birth to age 3 by developing partnerships between federal Head Start, EHS contractors, and child care providers. Head Start and EHS contractors that participate in the initiative provide services through community child care…

  2. Closure head for a nuclear reactor

    DOEpatents

    Wade, Elman E.

    1980-01-01

    A closure head for a nuclear reactor includes a stationary outer ring integral with the reactor vessel with a first rotatable plug disposed within the stationary outer ring and supported from the stationary outer ring by a bearing assembly. A sealing system is associated with the bearing assembly to seal the annulus defined between the first rotatable plug and the stationary outer ring. The sealing system comprises tubular seal elements disposed in the annulus with load springs contacting the tubular seal elements so as to force the tubular seal elements against the annulus in a manner to seal the annulus. The sealing system also comprises a sealing fluid which is pumped through the annulus and over the tubular seal elements causing the load springs to compress thereby reducing the friction between the tubular seal elements and the rotatable components while maintaining a gas-tight seal therebetween.

  3. Head muscle development.

    PubMed

    Tzahor, Eldad

    2015-01-01

    The developmental paths that lead to the formation of skeletal muscles in the head are distinct from those operating in the trunk. Craniofacial muscles are associated with head and neck structures. In the embryo, these structures derive from distinct mesoderm populations. Distinct genetic programs regulate different groups of muscles within the head to generate diverse muscle specifications. Developmental and lineage studies in vertebrates and invertebrates demonstrated an overlap in progenitor populations derived from the pharyngeal mesoderm that contribute to certain head muscles and the heart. These studies reveal that the genetic program controlling pharyngeal muscles overlaps with that of the heart. Indeed cardiac and craniofacial birth defects are often linked. Recent studies suggest that early chordates, the last common ancestor of tunicates and vertebrates, had an ancestral pharyngeal mesoderm lineage that later during evolution gave rise to both heart and craniofacial structures. This chapter summarizes studies related to the origins, signaling, genetics, and evolution of the head musculature, highlighting its heterogeneous characteristics in all these aspects.

  4. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  5. Lubricating the swordfish head.

    PubMed

    Videler, John J; Haydar, Deniz; Snoek, Roelant; Hoving, Henk-Jan T; Szabo, Ben G

    2016-07-01

    The swordfish is reputedly the fastest swimmer on Earth. The concave head and iconic sword are unique characteristics, but how they contribute to its speed is still unknown. Recent computed tomography scans revealed a poorly mineralised area near the base of the rostrum. Here we report, using magnetic resonance imaging and electron microscopy scanning, the discovery of a complex organ consisting of an oil-producing gland connected to capillaries that communicate with oil-excreting pores in the skin of the head. The capillary vessels transport oil to abundant tiny circular pores that are surrounded by denticles. The oil is distributed from the pores over the front part of the head. The oil inside the gland is identical to that found on the skin and is a mixture of methyl esters. We hypothesize that the oil layer, in combination with the denticles, creates a super-hydrophobic layer that reduces streamwise friction drag and increases swimming efficiency. PMID:27385753

  6. Shaking head means "no".

    PubMed

    Weiler, Stefan; Offinger, Alexander; Exadaktylos, Aristomenis K

    2013-09-10

    A 45-year-old man was admitted to the emergency department because of twitching of the head. The patient took a tablet of sumatriptan every 3-4 h because of increasing head pain after a car accident. Owing to depression, the patient was on long-term treatment with venlafaxine. The patient presented as hypertensive, tachycardic, with dyskinesia and spontaneous myoclonic movements of the right sternocleidomastoid muscle. In a CT scan of the head and cervical spine any fractures, bleeding or damage of the vessels after the accident could be ruled out. After discontinuation of all serotonergic agents, administration of lorazepam symptoms resolved 24 h after the last intake of sumatriptan. Serotonin syndrome is a clinical diagnosis, which requires a high-index of diagnostic suspicion. Clinical features include a broad spectrum of symptoms ranging from mild to life-threatening manifestations. Management is based on removal of precipitating drugs and symptomatic care including benzodiazepines.

  7. Sequential Assembly of Flagellar Radial Spokes

    PubMed Central

    Diener, Dennis R.; Yang, Pinfen; Geimer, Stefan; Cole, Douglas G.; Sale, Winfield S.; Rosenbaum, Joel L.

    2013-01-01

    The unicellular alga Chlamydomonas can assemble two 10 μm flagella in one hour from proteins synthesized in the cell body. Targeting and transporting these proteins to the flagella are simplified by preassembly of macromolecular complexes in the cell body. Radial spokes are flagellar complexes that are partially assembled in the cell body before entering the flagella. On the axoneme, radial spokes are “T” shaped structures with a head of 5 proteins and a stalk of 18 proteins that sediment together at 20S. In the cell body, radial spokes are partially assembled; about half of the radial spoke proteins (RSPs) form a 12S complex. In mutants lacking a single radial spoke protein, smaller spoke subassemblies were identified. When extracts from two such mutants were mixed in vitro the 12S complex was assembled from several smaller complexes demonstrating that portions of the stepwise assembly of radial spoke assembly can be carried out in vitro to elucidate the order of spoke assembly in the cell body. PMID:21692193

  8. Rocket injector head

    NASA Technical Reports Server (NTRS)

    Green, C. W., Jr. (Inventor)

    1968-01-01

    A high number of liquid oxygen and gaseous hydrogen orifices per unit area are provided in an injector head designed to give intimate mixing and more thorough combustion. The injector head comprises a main body portion, a cooperating plate member as a flow chamber for one propellant, a cooperating manifold portion for the second propellant, and an annular end plate for enclosing an annular propellant groove formed around the outer edge of the body. All the openings for one propellant are located at the same angle with respect to a radial plane to permit a short combustion chamber.

  9. Polymeric assemblies for sensitive colorimetric assays

    DOEpatents

    Charych, Deborah

    2000-01-01

    The presently claimed invention relates to polymeric assemblies which visibly change color in the presence of analyte. In particular, the presently claimed invention relates to liposomes comprising a plurality of lipid monomers, which comprises a polymerizable group, a hydrophilic head group and a hydrophobic tail group, and one or more ligands. Overall carbon chain length, and polymerizable group positioning on the monomer influence color change sensitivity to analyte concentrations.

  10. Imaging of head trauma.

    PubMed

    Rincon, Sandra; Gupta, Rajiv; Ptak, Thomas

    2016-01-01

    Imaging is an indispensable part of the initial assessment and subsequent management of patients with head trauma. Initially, it is important for diagnosing the extent of injury and the prompt recognition of treatable injuries to reduce mortality. Subsequently, imaging is useful in following the sequelae of trauma. In this chapter, we review indications for neuroimaging and typical computed tomography (CT) and magnetic resonance imaging (MRI) protocols used in the evaluation of a patient with head trauma. We review the role of CT), the imaging modality of choice in the acute setting, and the role of MRI in the evaluation of patients with head trauma. We describe an organized and consistent approach to the interpretation of imaging of these patients. Important topics in head trauma, including fundamental concepts related to skull fractures, intracranial hemorrhage, parenchymal injury, penetrating trauma, cerebrovascular injuries, and secondary effects of trauma, are reviewed. The chapter concludes with advanced neuroimaging techniques for the evaluation of traumatic brain injury, including use of diffusion tensor imaging (DTI), functional MRI (fMRI), and MR spectroscopy (MRS), techniques which are still under development. PMID:27432678

  11. Sculpting Ceramic Heads.

    ERIC Educational Resources Information Center

    Sapiro, Maurice

    1983-01-01

    Clay sculpture is difficult to produce because of the requirements of kiln firing. The problems can be overcome by modeling the original manikin head and making a plaster mold, pressing molding slabs of clay into the plaster mold to form the hollow clay armature, and sculpting on the armature. (IS)

  12. Orion Touchdown Heading Control

    NASA Technical Reports Server (NTRS)

    Kane, Mark A.

    2010-01-01

    At touchdown Orion must be aligned so that the crew person's feet are forward in the direction of the horizontal velocity. To ensure that this requirement is met active heading control is being implemented on the Orion crew module. This technique reduces probability of roll-over during splashdown, assures axial loads on the crew at touchdown, and alleviates structural requirements on impact allowing for a light-weight structural design. On-board sensors are used to measure current vehicle orientation and horizontal velocity used in generation of the heading error signal. Linear velocity measured by the IMU drifts while under parachutes due to wind gusts and has to be corrected by GPS; this makes GPS critical for successful landing. Jet fire logic is achieved by use of a phase-plane and commands are realized by using roll jets from the reaction control system (RCS); using pre existing hardware eliminates additional hardware and structural requirements. Touchdown performance is measured by an orientation envelope that was co-developed with structures so that the performance requirements overlap adding system redundancy. Heading control also introduces new difficulties to be addressed such as parachute line twist torque as well as increasing vehicle sensitivity to wind shifts and sea states. Solving these difficulties requires added complexity to flight software as well as increasing the propellant required to achieve successful touchdown. while offering promising results, the criticality of GPS along with a significant propellant cost raises questions on the effectiveness of using touchdown heading control.

  13. Latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A.

    1991-01-01

    A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

  14. Inlet nozzle assembly

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Precechtel, Donald R.; Smith, Bob G.; Knight, Ronald C.

    1987-01-01

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  15. Inlet nozzle assembly

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Knight, R.C.; Precechtel, D.R.; Smith, B.G.

    1985-09-09

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  16. Structural assembly in space

    NASA Technical Reports Server (NTRS)

    Stokes, J. W.; Pruett, E. C.

    1980-01-01

    A cost algorithm for predicting assembly costs for large space structures is given. Assembly scenarios are summarized which describe the erection, deployment, and fabrication tasks for five large space structures. The major activities that impact total costs for structure assembly from launch through deployment and assembly to scientific instrument installation and checkout are described. Individual cost elements such as assembly fixtures, handrails, or remote minipulators are also presented.

  17. CT angiography - head and neck

    MedlinePlus

    Computed tomography angiography - brain; CTA - skull; CTA - cranial; TIA-CTA head; Stroke-CTA head; Computed tomography angiography - neck; CTA - neck; Vertebral artery - CTA; Carotid artery stenosis - CTA; ...

  18. Head Injury Screening Tests Approved

    MedlinePlus

    ... 160556.html Head Injury Screening Tests Approved Assess brain function after possible concussions To use the sharing features ... HealthDay News) -- New computer software to assess the brain's function after a traumatic head injury have been approved ...

  19. Head, Neck, and Oral Cancer

    MedlinePlus

    ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ...

  20. Tilt assembly for tracking solar collector assembly

    DOEpatents

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  1. Heads Up to High School Sports

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  2. Minnesota: Early Head Start Initiatiive

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Minnesota provides supplemental state funding to existing federal Head Start and Early Head Start (EHS) grantees to increase their capacity to serve additional infants, toddlers, and pregnant women. The initiative was started in 1997 when the state legislature earmarked $1 million of the general state Head Start supplemental funds for children…

  3. Maryland Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 2000, Maryland has provided state supplemental funds to Head Start and Early Head Start (EHS) programs to improve access. Local EHS programs may use funds, through child care partnerships, to extend the EHS day or year. Maryland's approach to building on EHS includes: (1) Increase the capacity of existing Head Start and EHS programs to…

  4. MAGNETIC RECORDING HEAD

    DOEpatents

    Merrill, L.C.

    1958-06-17

    An electromagetic recording head is described for simultaneous recording of a plurality of signals within a small space on a magnetically semsitized medium. Basically the head structure comprises a non-magnetic centerpiece provided with only first and second groups of spaced cut-out slots respectively on opposite sides of the centerpiece. The two groups of slots are in parallel alignment and the slots of one group are staggered with respect to the slots of the other group so that one slot is not directly opposite another slot. Each slot has a magnet pole piece disposed therein and cooperating with a second pole and coil to provide a magnetic flux gap at the upper end of the slot. As a tape is drawn over the upper end of the centerpiece the individual magnetic circuits are disposed along its width to provide means for simultaneously recording information on separate portions, tracks. of the tape.

  5. Autonomous electrochromic assembly

    SciTech Connect

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  6. Firearm trigger assembly

    SciTech Connect

    Crandall, David L.; Watson, Richard W.

    2010-02-16

    A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly is not in the locked position.

  7. System, Apparatus and Method Employing a Dual Head Laser

    NASA Technical Reports Server (NTRS)

    Coyle, Donald B. (Inventor); Stysley, Paul R. (Inventor); Poulios, Demetrios (Inventor)

    2015-01-01

    A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.

  8. Computer simulation of nanocube self-assemblies

    NASA Astrophysics Data System (ADS)

    Zhang, Xi

    Self-assembly of nanoscale building blocks and molecules into ordered nanostructures is a promising venue for bottom-up materials design. A wide variety of nanoparticles with unique shapes and uniform sizes have been successfully synthesized. However, organizing these nanoparticles into desired, predefined nanostructures is a formidable challenge now facing the materials community. For example, simple 2-D arrays and 3-D superlattices are the prevalent structures from most nanocube self-assemblies. Two practical strategies to impart anisotropy onto nanocubes, namely, attaching polymer tethers to nanoparticle surfaces and introducing directional dipolar interactions, can be applied to achieve more complex assembled structures. In this dissertation, we conduct computer simulations on nanocube self-assemblies induced by polymer tethers and directional dipole interactions, to examine the various parameters involved in such complicated self-assembly processes, including temperature, concentration, solvent condition, cube size, tether length, tether topology, tether placement, tether number, dipole direction, dipole strength and polydispersity, in order to understand how the packing geometry and interactions between nanocubes can be manipulated to confer precise control over the assembled structures and the phase behavior. First, we simulate monotethered nanocubes and find that the nanocubes favor face-to-face packing in poor solvents, stabilizing the lamellae phases. Next, we simulate different architectures of tethered nanocubes and demonstrate that the steric influence of tether beads can be manipulated to interfere with the face-to-face packing of nanocubes and alter the phase behaviors. We also study the self-assembly of nanocubes with dipoles. We find that the head-to-tail alignment of dipoles, coupled with the face-to-face close packing of nanocubes, dictates the assembled structures. The face-face attraction between nanocubes can also be utilized to control the

  9. Measuring head circumference

    PubMed Central

    Harris, Susan R.

    2015-01-01

    Abstract Objective To provide an evidence-based update emphasizing the importance of measuring head circumference (HC) in infants, with a focus on microcephaly. Quality of evidence PubMed and EMBASE (OvidSP) were searched. Search terms used were head circumference and infants and measurement; microcephaly and infants and measurement; idiopathic microcephaly and infants; and congenital microcephaly and infants. Most of the references for this review were published in 2000 or later. Most evidence is level II. Main message Serial measurement of HC should be incorporated into routine well-child care. Measure the distance around the back of the child’s head with a nonelastic tape measure held above the eyebrows and ears, and plot the measurement on an age- and sex-appropriate growth chart. Microcephaly is HC more than 2 SD below the mean. The most common disability associated with microcephaly is intellectual delay; other common concomitant conditions include epilepsy, cerebral palsy, language delay, strabismus, ophthalmologic disorders, and cardiac, renal, urinary tract, and skeletal anomalies. An interdisciplinary approach to microcephaly is warranted. Although there are no specific interventions to enhance brain growth, dietary or surgical interventions might be helpful in some cases. Infants with microcephaly who show developmental delays might benefit from early intervention programs or developmental physical and occupational therapy. Conclusion Early identification of HC concerns by family physicians can be a critical first step in identifying disorders such as microcephaly, leading to referral to pediatric specialists and, as needed, provision of family-centred early intervention services. PMID:26505062

  10. Tensile testing grips are easily assembled under liquid nitrogen

    NASA Technical Reports Server (NTRS)

    Skalka, R. J.; Vandergrift, E. F.

    1967-01-01

    Split-screw grips for tensile testing provide uniform loading on the specimen shoulders. Holes in the heads enable the screws and specimen to be threaded as an assembly into a grip body, closely controlled guides and seats afford positive seating, and precision machining of mating surfaces minimizes misalignment effects.

  11. Active head rotations and eye-head coordination

    NASA Technical Reports Server (NTRS)

    Zangemeister, W. H.; Stark, L.

    1981-01-01

    It is pointed out that head movements play an important role in gaze. The interaction between eye and head movements involves both their shared role in directing gaze and the compensatory vestibular ocular reflex. The dynamics of head trajectories are discussed, taking into account the use of parameterization to obtain the peak velocity, peak accelerations, the times of these extrema, and the duration of the movement. Attention is given to the main sequence, neck muscle EMG and details of the head-movement trajectory, types of head model accelerations, the latency of eye and head movement in coordinated gaze, gaze latency as a function of various factors, and coordinated gaze types. Clinical examples of gaze-plane analysis are considered along with the instantaneous change of compensatory eye movement (CEM) gain, and aspects of variability.

  12. Membrane module assembly

    DOEpatents

    Kaschemekat, Jurgen

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

  13. Cage redesign explains assembly

    PubMed Central

    Theil, Elizabeth C; Turano, Paola

    2013-01-01

    Control of protein self-assembly and disassembly, which is central to metabolism and engineering applications, remains challenging. Here, a perspicacious redesign of interfaces in the multisubunit ferritin protein cage provides single, modifiable subunits that assemble with Cu2+ templating and give insights into the cage assembly code. PMID:23416399

  14. Membrane module assembly

    DOEpatents

    Kaschemekat, J.

    1994-03-15

    A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

  15. Sensor mount assemblies and sensor assemblies

    DOEpatents

    Miller, David H.

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  16. Head stabilization in herons.

    PubMed

    Katzir, G; Schechtman, E; Carmi, N; Weihs, D

    2001-07-01

    We examined head stabilization in relation to body mass and length of legs in four heron species (little egrets, Egretta garzetta; night herons, Nycticorax nycticorax; squacco herons, Ardeola ralloides; and cattle egrets, Bubulcus ibis: Aves: Ardeidae). Head stabilization, under controlled, sinusoidal, perch perturbations was mostly elicited at frequencies lower than 1 Hz. Maximal perturbation amplitudes sustained were positively correlated with leg length and maximal perturbation frequencies sustained were negatively correlated with body mass and with leg length. The species differed significantly in average maximal perturbation amplitudes sustained. Combinations of amplitude and frequency for which stabilization was achieved were bounded by a decreasing concave "envelope" curve in the frequency-amplitude plane, with inter specific differences in "envelope". As physical constraints, we tested maximal vertical acceleration, which translates into a line defined by the product of frequency2 x amplitude, and maximal vertical velocity, which translates into a line defined by the product of frequency x amplitude. Both relations were in good agreement with the experimental results for all but squacco herons. The results support predictions based on mechanical considerations and may explain the predominance of motor patterns employed by herons while foraging.

  17. Self-Assembly of Tetraphenylalanine Peptides.

    PubMed

    Mayans, Enric; Ballano, Gema; Casanovas, Jordi; Díaz, Angélica; Pérez-Madrigal, Maria M; Estrany, Francesc; Puiggalí, Jordi; Cativiela, Carlos; Alemán, Carlos

    2015-11-16

    Three different tetraphenylalanine (FFFF) based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies under a variety of conditions. The FFFF peptide assembles into nanotubes that show more structural imperfections at the surface than those formed by the diphenylalanine (FF) peptide under the same conditions. Periodic DFT calculations (M06L functional) were used to propose a model that consists of three FFFF molecules defining a ring through head-to-tail NH3(+)⋅⋅⋅(-)OOC interactions, which in turn stack to produce deformed channels with internal diameters between 12 and 16 Å. Depending on the experimental conditions used for the peptide incubation, N-fluorenylmethoxycarbonyl (Fmoc) protected FFFF self-assembles into a variety of polymorphs: ultra-thin nanoplates, fibrils, and star-like submicrometric aggregates. DFT calculations indicate that Fmoc-FFFF prefers a parallel rather than an antiparallel β-sheet assembly. Finally, coexisting multiple assemblies (up to three) were observed for Fmoc-FFFF-OBzl (OBzl = benzyl ester), which incorporates aromatic protecting groups at the two peptide terminals. This unusual and noticeable feature is attributed to the fact that the assemblies obtained by combining the Fmoc and OBzl groups contained in the peptide are isoenergetic.

  18. Interconnect assembly for an electronic assembly and assembly method therefor

    DOEpatents

    Gerbsch, Erich William

    2003-06-10

    An interconnect assembly and method for a semiconductor device, in which the interconnect assembly can be used in lieu of wirebond connections to form an electronic assembly. The interconnect assembly includes first and second interconnect members. The first interconnect member has a first surface with a first contact and a second surface with a second contact electrically connected to the first contact, while the second interconnect member has a flexible finger contacting the second contact of the first interconnect member. The first interconnect member is adapted to be aligned and registered with a semiconductor device having a contact on a first surface thereof, so that the first contact of the first interconnect member electrically contacts the contact of the semiconductor device. Consequently, the assembly method does not require any wirebonds, but instead merely entails aligning and registering the first interconnect member with the semiconductor device so that the contacts of the first interconnect member and the semiconductor device make electrically contact, and then contacting the second contact of the first interconnect member with the flexible finger of the second interconnect member.

  19. QTL mapping of leafy heads by genome resequencing in the RIL population of Brassica rapa.

    PubMed

    Yu, Xiang; Wang, Han; Zhong, Weili; Bai, Jinjuan; Liu, Pinglin; He, Yuke

    2013-01-01

    Leaf heads of cabbage (Brassica oleracea), Chinese cabbage (B. rapa), and lettuce (Lactuca sativa) are important vegetables that supply mineral nutrients, crude fiber and vitamins in the human diet. Head size, head shape, head weight, and heading time contribute to yield and quality. In an attempt to investigate genetic basis of leafy head in Chinese cabbage (B. rapa), we took advantage of recent technical advances of genome resequencing to perform quantitative trait locus (QTL) mapping using 150 recombinant inbred lines (RILs) derived from the cross between heading and non-heading Chinese cabbage. The resequenced genomes of the parents uncovered more than 1 million SNPs. Genotyping of RILs using the high-quality SNPs assisted by Hidden Markov Model (HMM) generated a recombination map. The raw genetic map revealed some physical assembly error and missing fragments in the reference genome that reduced the quality of SNP genotyping. By deletion of the genetic markers in which recombination rates higher than 20%, we have obtained a high-quality genetic map with 2209 markers and detected 18 QTLs for 6 head traits, from which 3 candidate genes were selected. These QTLs provide the foundation for study of genetic basis of leafy heads and the other complex traits.

  20. QTL Mapping of Leafy Heads by Genome Resequencing in the RIL Population of Brassica rapa

    PubMed Central

    Yu, Xiang; Wang, Han; Zhong, Weili; Bai, Jinjuan; Liu, Pinglin; He, Yuke

    2013-01-01

    Leaf heads of cabbage (Brassica oleracea), Chinese cabbage (B. rapa), and lettuce (Lactuca sativa) are important vegetables that supply mineral nutrients, crude fiber and vitamins in the human diet. Head size, head shape, head weight, and heading time contribute to yield and quality. In an attempt to investigate genetic basis of leafy head in Chinese cabbage (B. rapa), we took advantage of recent technical advances of genome resequencing to perform quantitative trait locus (QTL) mapping using 150 recombinant inbred lines (RILs) derived from the cross between heading and non-heading Chinese cabbage. The resequenced genomes of the parents uncovered more than 1 million SNPs. Genotyping of RILs using the high-quality SNPs assisted by Hidden Markov Model (HMM) generated a recombination map. The raw genetic map revealed some physical assembly error and missing fragments in the reference genome that reduced the quality of SNP genotyping. By deletion of the genetic markers in which recombination rates higher than 20%, we have obtained a high-quality genetic map with 2209 markers and detected 18 QTLs for 6 head traits, from which 3 candidate genes were selected. These QTLs provide the foundation for study of genetic basis of leafy heads and the other complex traits. PMID:24204591

  1. Firing Properties of Rat Lateral Mammillary Single Units: Head Direction, Head Pitch, and Angular Head Velocity

    PubMed Central

    Stackman, Robert W.; Taube, Jeffrey S.

    2006-01-01

    Many neurons in the rat anterodorsal thalamus (ADN) and postsubiculum (PoS) fire selectively when the rat points its head in a specific direction in the horizontal plane, independent of the animal’s location and ongoing behavior. The lateral mammillary nuclei (LMN) are interconnected with both the ADN and PoS and, therefore, are in a pivotal position to influence ADN/PoS neurophysiology. To further understand how the head direction (HD) cell signal is generated, we recorded single neurons from the LMN of freely moving rats. The majority of cells discharged as a function of one of three types of spatial correlates: (1) directional heading, (2) head pitch, or (3) angular head velocity (AHV). LMN HD cells exhibited higher peak firing rates and greater range of directional firing than that of ADN and PoS HD cells. LMN HD cells were modulated by angular head velocity, turning direction, and anticipated the rat’s future HD by a greater amount of time (~95 msec) than that previously reported for ADN HD cells (~25 msec). Most head pitch cells discharged when the rostrocaudal axis of the rat’s head was orthogonal to the horizontal plane. Head pitch cell firing was independent of the rat’s location, directional heading, and its body orientation (i.e., the cell discharged whenever the rat pointed its head up, whether standing on all four limbs or rearing). AHV cells were categorized as fast or slow AHV cells depending on whether their firing rate increased or decreased in proportion to angular head velocity. These data demonstrate that LMN neurons code direction and angular motion of the head in both horizontal and vertical planes and support the hypothesis that the LMN play an important role in processing both egocentric and allocentric spatial information. PMID:9787007

  2. Does dimeticone clear head lice?

    PubMed

    2007-07-01

    Head lice infestation is common and mainly affects children of primary school age. Treatments include licensed topical preparations containing conventional chemical insecticides and medical devices. Each of these fail to eradicate head lice in some patients and resistance is a problem with chemical insecticides. Dimeticone 4% lotion (Hedrin - Thornton & Ross) is a new treatment licensed "for the eradication of head lice infestations". Here we consider its place in the context of other options.

  3. Magnetically Driven Swimming of Nanoscale Colloidal Assemblies

    NASA Astrophysics Data System (ADS)

    Breidenich, Jennifer; Benkoski, Jason; Baird, Lance; Deacon, Ryan; Land, H. Bruce; Hayes, Allen; Keng, Pei; Pyun, Jeffrey

    2009-03-01

    At microscopic length scales, locomotion can only be generated through asymmetric conformation changes, such as the undulating flagellum employed by protozoa. This simple yet elegant design is optimized according to the dueling needs of miniaturization and the fluid dynamics of the low Reynolds number environment. In this study, we fabricate nanoscale colloidal assemblies that mimic the head + tail structure of flagellates. The assemblies consist of two types of magnetic colloids: 25 nm polystyrene-coated Co nanoparticles, and 250 nm polyethylene glycol coated magnetite nanoparticles. When mixed together in N-dimethylformamide, the Co nanoparticles assemble into flexible, segmented chains ranging in length from 1 - 5 μm. These chains then attach at one end to the larger magnetic beads due to magnetic attraction. This head + tail structure aligns with an external uniform magnetic field and is actuated by an oscillating transverse field. We examine the effects of Co nanoparticle concentration, magnetite bead concentration, magnetic field strength, and oscillation frequency on the formation of swimmers and the speed of locomotion.

  4. Telerobotic truss assembly

    NASA Technical Reports Server (NTRS)

    Sheridan, Philip L.

    1987-01-01

    The ACCESS truss was telerobotically assembled in order to gain experience with robotic assembly of hardware designed for astronaut extravehicular (EVA) assembly. Tight alignment constraints of the ACCESS hardware made telerobotic assembly difficult. A wider alignment envelope and a compliant end effector would have reduced the problem. The manipulator had no linear motion capability, but many of the assembly operations required straight line motion. The manipulator was attached to a motion table in order to provide the X, Y, and Z translations needed. A programmable robot with linear translation capability would have eliminated the need for the motion table and streamlined the assembly. Poor depth perception was a major problem. Shaded paint schemes and alignment lines were helpful in reducing this problem. The four cameras used worked well for only some operations. It was not possible to identify camera locations that worked well for all assembly steps. More cameras or movable cameras would have simplified some operations. The audio feedback system was useful.

  5. Strain measurement aided assembly for a CFRP hexapod

    NASA Astrophysics Data System (ADS)

    Ren, Guorui; Li, Chuang; Wang, Wei; Fan, Xuewu

    2011-12-01

    In order to mount a space optical telescope with long focal length on a spacecraft for an astronomy observation mission, a carbon fiber reinforced plastic (CFRP) hexapod with titanium alloy brackets was designed and fabricated. Each bracket has a pair of heads and each head has two orthogonal flexures as virtual pivots without clearance to provide flexure mounts. Because of no adjustment parts, slight differences among components and roughly assembly would result in misalignment and asymmetrical stress in the hexapod. The stresses and strains of the CFRP hexapod structure under 1G gravity load were analyzed with finite element method. In order to monitor the assembly stress and provide regulating guidance, strain gauges were stuck centrally on the bottom flexures of each bracket. Comparing the measured strains with the computed values, the low stress assembly of the CFRP hexapod has been accomplished successfully.

  6. Grandparent Headed Families and Head Start: Developing Effective Services.

    ERIC Educational Resources Information Center

    Dannison, Linda L.; Smith, Andrea B.

    Numerous challenges face the growing number of grandparent-headed households, including isolation from friends and social supports, and difficulties in caring for grandchildren exhibiting multiple needs. This paper describes a pilot program in which a university and a large county-wide Head Start program formed a partnership to focus on serving…

  7. NASA head sworn in

    NASA Astrophysics Data System (ADS)

    James C. Fletcher was sworn in on May 12, 1986, as administrator of the National Aeronautics and Space Administration (NASA). At a news conference after he was sworn in, Fletcher said that NASA would deal with both its technical problems and its procedural problems before the shuttle will fly again. According to press accounts, he stressed that funds should be made available to replace the Challenger orbiter, which was lost in an explosion on January 28.Fletcher, who had also headed the agency from 1971 to 1977, succeeds James M. Beggs, who was indicted in December 1985 for conspiring to defraud the federal government while serving as a senior executive at the General Dynamics Corporation.

  8. Chryse 'Alien Head'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    26 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an impact crater in Chryse Planitia, not too far from the Viking 1 lander site, that to seems to resemble a bug-eyed head. The two odd depressions at the north end of the crater (the 'eyes') may have formed by wind or water erosion. This region has been modified by both processes, with water action occurring in the distant past via floods that poured across western Chryse Planitia from Maja Valles, and wind action common occurrence in more recent history. This crater is located near 22.5oN, 47.9oW. The 150 meter scale bar is about 164 yards long. Sunlight illuminates the scene from the left/lower left.

  9. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2012-10-23

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assembled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting region of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized to slidably receive the male fastener, with all of the connector heads being identical.

  10. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2011-11-22

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assembled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting region of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized to slidably receive the male fastener, with all of the connector heads being identical.

  11. Liquid-cooled cylinder assembly in internal-combustion engine

    SciTech Connect

    Nakano, H.; Ozu, T.

    1987-02-03

    This patent describes an internal-combustion engine of the piston type having at least one cylinder assembly comprising a cylinder head and a cylinder liner capped at the upper end thereof by the cylinder head. The improvement described here comprises: a reinforcing ring fixedly fitted around the outer cylindrical surface of the upper end part of the cylinder liner; recesses grooved in and at respective positions around the outer cylindrical surface; passageways in the reinforcing ring and communicating with respective the recesses to form cooling-liquid passageways; the upper end part of the cylinder liner having an inverted frustoconical shape with the outer diameter thereof increasing gradually in the direction toward the cylinder head. The inner wall surface of the reinforcing ring is formed to fit tightly around the upper end part in a lead-proof manner for preventing relative displacements between the cylinder head, the cylinder liner, and the reinforcing ring.

  12. Spontaneous symmetry breaking during self-assembly of a double stranded biphenolate-based Ti(IV)-helicate.

    PubMed

    Diebold, Carine; Mobian, Pierre; Huguenard, Clarisse; Allouche, Lionel; Henry, Marc

    2010-07-19

    A binuclear Ti(IV)-based helicate synthesized from a symmetric tetrahydroxyheptaphenylene strand was self-assembled in solution and shown to undergo a spontaneous head-to-tail differentiation according to single-crystal X-ray diffraction.

  13. Kansas: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Kansas Early Head Start (KEHS) provides comprehensive services following federal Head Start Program Performance Standards for pregnant women and eligible families with children from birth to age 4. KEHS was implemented in 1998 using Child Care and Development Block Grant (CCDBG) quality set-aside dollars augmented by a transfer of federal…

  14. Nebraska: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 1999, Nebraska's Early Head Start Infant/Toddler Quality Initiative has supported Early Head Start (EHS) and community child care partnerships to improve the quality and professionalism of infant and toddler care. EHS programs apply to receive funding to establish partnerships with center-based or home-based child care.The initiative has…

  15. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, Earl D. (Inventor); Goodfriend, Roger (Inventor)

    1989-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup-shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduces breakage thereof.

  16. The Start of Head Start

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2010-01-01

    The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

  17. Vision Screening For Head Starters.

    ERIC Educational Resources Information Center

    Foley, Celia

    To determine which children in the Head Start program may have vision problems, Head Start teachers and staff do vision "screening." This booklet demonstrates how to do the screening using the Snellen "E Chart." Trouble signs that the test administrator should be aware of are listed, and vision scores are explained simply. Amblyopia is defined,…

  18. Interview with Joe F. Head

    ERIC Educational Resources Information Center

    West, Kim

    2008-01-01

    This article presents an interview with Joe F. Head, Dean of University Admissions and Enrollment Services at Kennesaw State University (KSU) in Georgia, who has more than 35 years of experience in admissions and enrollment services. After completing an M.Ed. in higher education at Georgia Southern University, Head immediately landed a position as…

  19. Be-heading the Word.

    ERIC Educational Resources Information Center

    Bauer, Laurie

    1990-01-01

    Examines the notion of "head" in syntax and the extent to which it extends to morphology in English, and discusses the notion of headedness and percolation. The argument is made that percolation in English does not work, casting doubt on the notion of head in morphology. (34 references) (GLR)

  20. Wind turbine rotor assembly

    SciTech Connect

    Kaiser, H. W.

    1984-11-20

    A vertical axis wind turbine having a horizontal arm member which supports an upright blade assembly. Bearing structure coupling the blade assembly to the turbine arm permits blade movement about its longitudinal axis as well as flexing motion of the blade assembly about axes perpendicular to the longitudinal axis. A latching mechanism automatically locks the blade assembly to its supporting arm during normal turbine operation and automatically unlocks same when the turbine is at rest. For overspeed prevention, a centrifugally actuated arm functions to unlatch the blade assembly permitting same to slipstream or feather into the wind. Manually actuated means are also provided for unlatching the moving blade assembly. The turbine arm additionally carries a switching mechanism in circuit with a turbine generator with said mechanism functioning to open and hence protect the generator circuit in the event of an overspeed condition of the turbine.

  1. Head Start Impact Study: First Year Findings

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Lopez, Michael

    2005-01-01

    The Congressionally-mandated Head Start Impact Study is being conducted across 84 nationally representative grantee/delegate agencies. Approximately 5,000 newly entering 3- and 4-year-old children applying for Head Start were randomly assigned to either a Head Start group that had access to Head Start program services or to a non-Head Start group…

  2. Stereotactic Body Radiotherapy for Head and Neck Tumors

    ClinicalTrials.gov

    2016-04-18

    Squamous Cell Carcinoma of the Head and Neck; Nasopharyngeal Carcinoma; Salivary Gland Cancer; Head and Neck Sarcoma; Paraganglioma of Head and Neck; Chordoma of Head and Neck; Chondrosarcoma of Head and Neck; Angiofibroma of Head and Neck

  3. Controlling molecular assemblies

    NASA Astrophysics Data System (ADS)

    Dameron, Arrelaine A.

    Using molecules designed to have only specific differences in their functionality, we have explored the influence of molecular conformation on the structural, electronic, and physical properties of self-assembled monolayers using both scanning probe and ensemble techniques. In the former case, we used two structurally similar molecules that differ in the degrees of freedom afforded to each. We found that this influenced the degree of order and conductance of self-assembled monolayers of each molecule, but had little influence of conductance switching of individual molecules inserted in alkanethiolate self-assembled monolayers. We further demonstrated how molecular structure influences phase separation, displace-ability, and molecular mobility of self-assembled monolayers by assembling 1-adamantanethiol on Au{111}. Molecular-resolution imaging of the self-assembled monolayers with the scanning tunneling microscopy confirmed a highly ordered hexagonally close-packed molecular lattice. We found that the 1-adamantanethiolate self-assembled monolayers were susceptible to replacement by the presence of another thiolated species, both from solution and vapor phases. Additionally, we determined that the displacement process is a nucleation and growth mechanism and the structure of the resulting self-assembled monolayers is dependent on the strength of the intermolecular interactions of the displacing molecules. It was hypothesized that 1-adamantanethiolate displacement was driven by a combination of energies gained from the exchange of one self-assembled monolayer for a denser self-assembled monolayer and from the increased stability due to intermolecular interaction forces. Exploiting the susceptibility of the 1-adamantanethiolate self-assembled monolayers to displacement, we have designed a novel patterning strategy, termed 'microdisplacement printing', by combining these sacrificial self-assembled monolayers with microcontact printing. During microdisplacement printing

  4. Composite turbine bucket assembly

    DOEpatents

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  5. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  6. Assembly of the 30S ribosomal subunit: positioning ribosomal protein S13 in the S7 assembly branch.

    PubMed

    Grondek, Joel F; Culver, Gloria M

    2004-12-01

    Studies of Escherichia coli 30S ribosomal subunit assembly have revealed a hierarchical and cooperative association of ribosomal proteins with 16S ribosomal RNA; these results have been used to compile an in vitro 30S subunit assembly map. In single protein addition and omission studies, ribosomal protein S13 was shown to be dependent on the prior association of ribosomal protein S20 for binding to the ribonucleoprotein particle. While the overwhelming majority of interactions revealed in the assembly map are consistent with additional data, the dependency of S13 on S20 is not. Structural studies position S13 in the head of the 30S subunit > 100 A away from S20, which resides near the bottom of the body of the 30S subunit. All of the proteins that reside in the head of the 30S subunit, except S13, have been shown to be part of the S7 assembly branch, that is, they all depend on S7 for association with the assembling 30S subunit. Given these observations, the assembly requirements for S13 were investigated using base-specific chemical footprinting and primer extension analysis. These studies reveal that S13 can bind to 16S rRNA in the presence of S7, but not S20. Additionally, interaction between S13 and other members of the S7 assembly branch have been observed. These results link S13 to the 3' major domain family of proteins, and the S7 assembly branch, placing S13 in a new location in the 30S subunit assembly map where its position is in accordance with much biochemical and structural data.

  7. Head and Neck Cancer: Symptoms and Signs

    MedlinePlus

    ... Symptoms and Signs Request Permissions Print to PDF Head and Neck Cancer - Symptoms and Signs Approved by the Cancer. ... Cancer Research and Advocacy Survivorship Blog About Us Head and Neck Cancer Guide Cancer.Net Guide Head and Neck ...

  8. Keeping Your Head On Target

    PubMed Central

    Wong, Aaron L.; Zee, David S.; Jinnah, H. A.

    2013-01-01

    The mechanisms by which the human brain controls eye movements are reasonably well understood, but those for the head less so. Here, we show that the mechanisms for keeping the head aimed at a stationary target follow strategies similar to those for holding the eyes steady on stationary targets. Specifically, we applied the neural integrator hypothesis that originally was developed for holding the eyes still in eccentric gaze positions to describe how the head is held still when turned toward an eccentric target. We found that normal humans make head movements consistent with the neural integrator hypothesis, except that additional sensory feedback is needed, from proprioceptors in the neck, to keep the head on target. We also show that the complicated patterns of head movements in patients with cervical dystonia can be predicted by deficits in a neural integrator for head motor control. These results support ideas originally developed from animal studies that suggest fundamental similarities between oculomotor and cephalomotor control, as well as a conceptual framework for cervical dystonia that departs considerably from current clinical views. PMID:23825431

  9. Eye and head motion during head turns in spaceflight

    NASA Technical Reports Server (NTRS)

    Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

    1988-01-01

    Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

  10. Perspective: Geometrically frustrated assemblies

    NASA Astrophysics Data System (ADS)

    Grason, Gregory M.

    2016-09-01

    This perspective will overview an emerging paradigm for self-organized soft materials, geometrically frustrated assemblies, where interactions between self-assembling elements (e.g., particles, macromolecules, proteins) favor local packing motifs that are incompatible with uniform global order in the assembly. This classification applies to a broad range of material assemblies including self-twisting protein filament bundles, amyloid fibers, chiral smectics and membranes, particle-coated droplets, curved protein shells, and phase-separated lipid vesicles. In assemblies, geometric frustration leads to a host of anomalous structural and thermodynamic properties, including heterogeneous and internally stressed equilibrium structures, self-limiting assembly, and topological defects in the equilibrium assembly structures. The purpose of this perspective is to (1) highlight the unifying principles and consequences of geometric frustration in soft matter assemblies; (2) classify the known distinct modes of frustration and review corresponding experimental examples; and (3) describe outstanding questions not yet addressed about the unique properties and behaviors of this broad class of systems.

  11. Laser bottom hole assembly

    DOEpatents

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  12. High speed door assembly

    DOEpatents

    Shapiro, Carolyn

    1993-01-01

    A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  13. High speed door assembly

    DOEpatents

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  14. Permanent magnet assembly

    DOEpatents

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

    A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

  15. Liquid rocket valve assemblies

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The design and operating characteristics of valve assemblies used in liquid propellant rocket engines are discussed. The subjects considered are as follows: (1) valve selection parameters, (2) major design aspects, (3) design integration of valve subassemblies, and (4) assembly of components and functional tests. Information is provided on engine, stage, and spacecraft checkout procedures.

  16. Turbine disc sealing assembly

    DOEpatents

    Diakunchak, Ihor S.

    2013-03-05

    A disc seal assembly for use in a turbine engine. The disc seal assembly includes a plurality of outwardly extending sealing flange members that define a plurality of fluid pockets. The sealing flange members define a labyrinth flow path therebetween to limit leakage between a hot gas path and a disc cavity in the turbine engine.

  17. Hangman's fracture in head injury.

    PubMed

    Umebese, P F; Orhewere, F A

    1989-09-01

    Five patients with fracture of pedicle of axis vertebra as a complication of head injury are reported. The ages of the patients ranged from 16-25 years and all of them were victims of road traffic accidents. The head injuries were moderately severe requiring admission. The average Glasgow Coma Scale sum on admission was 11. Simple non-operative management in a well padded stiff collar with sand bags supporting the head in a neutral position in bed resulted in full recovery without complication after an average of 4 weeks recumbency.

  18. Anaphylaxis Due to Head Injury

    PubMed Central

    Bruner, Heather C.; Bruner, David I.

    2015-01-01

    Both anaphylaxis and head injury are often seen in the emergency department, but they are rarely seen in combination. We present a case of a 30-year-old woman who presented with anaphylaxis with urticaria and angioedema following a minor head injury. The patient responded well to intramuscular epinephrine without further complications or airway compromise. Prior case reports have reported angioedema from hereditary angioedema during dental procedures and maxillofacial surgery, but there have not been any cases of first-time angioedema or anaphylaxis due to head injury. PMID:25987924

  19. Assembly: a resource for assembled genomes at NCBI

    PubMed Central

    Kitts, Paul A.; Church, Deanna M.; Thibaud-Nissen, Françoise; Choi, Jinna; Hem, Vichet; Sapojnikov, Victor; Smith, Robert G.; Tatusova, Tatiana; Xiang, Charlie; Zherikov, Andrey; DiCuccio, Michael; Murphy, Terence D.; Pruitt, Kim D.; Kimchi, Avi

    2016-01-01

    The NCBI Assembly database (www.ncbi.nlm.nih.gov/assembly/) provides stable accessioning and data tracking for genome assembly data. The model underlying the database can accommodate a range of assembly structures, including sets of unordered contig or scaffold sequences, bacterial genomes consisting of a single complete chromosome, or complex structures such as a human genome with modeled allelic variation. The database provides an assembly accession and version to unambiguously identify the set of sequences that make up a particular version of an assembly, and tracks changes to updated genome assemblies. The Assembly database reports metadata such as assembly names, simple statistical reports of the assembly (number of contigs and scaffolds, contiguity metrics such as contig N50, total sequence length and total gap length) as well as the assembly update history. The Assembly database also tracks the relationship between an assembly submitted to the International Nucleotide Sequence Database Consortium (INSDC) and the assembly represented in the NCBI RefSeq project. Users can find assemblies of interest by querying the Assembly Resource directly or by browsing available assemblies for a particular organism. Links in the Assembly Resource allow users to easily download sequence and annotations for current versions of genome assemblies from the NCBI genomes FTP site. PMID:26578580

  20. Mechanisms of Virus Assembly

    PubMed Central

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-01-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid, and in some cases surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assembles within their host cells and in vitro. We describe the thermodynamics and kinetics for assembly of protein subunits into icosahedral capsid shells, and how these are modified in cases where the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques that have been used to characterize capsid assembly, and we highlight aspects of virus assembly which are likely to receive significant attention in the near future. PMID:25532951

  1. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  2. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  3. Modeling Viral Capsid Assembly

    PubMed Central

    2014-01-01

    I present a review of the theoretical and computational methodologies that have been used to model the assembly of viral capsids. I discuss the capabilities and limitations of approaches ranging from equilibrium continuum theories to molecular dynamics simulations, and I give an overview of some of the important conclusions about virus assembly that have resulted from these modeling efforts. Topics include the assembly of empty viral shells, assembly around single-stranded nucleic acids to form viral particles, and assembly around synthetic polymers or charged nanoparticles for nanotechnology or biomedical applications. I present some examples in which modeling efforts have promoted experimental breakthroughs, as well as directions in which the connection between modeling and experiment can be strengthened. PMID:25663722

  4. Automated assembly in space

    NASA Technical Reports Server (NTRS)

    Srivastava, Sandanand; Dwivedi, Suren N.; Soon, Toh Teck; Bandi, Reddy; Banerjee, Soumen; Hughes, Cecilia

    1989-01-01

    The installation of robots and their use of assembly in space will create an exciting and promising future for the U.S. Space Program. The concept of assembly in space is very complicated and error prone and it is not possible unless the various parts and modules are suitably designed for automation. Certain guidelines are developed for part designing and for an easy precision assembly. Major design problems associated with automated assembly are considered and solutions to resolve these problems are evaluated in the guidelines format. Methods for gripping and methods for part feeding are developed with regard to the absence of gravity in space. The guidelines for part orientation, adjustments, compliances and various assembly construction are discussed. Design modifications of various fasteners and fastening methods are also investigated.

  5. Counting heads in Cairo.

    PubMed

    1994-09-14

    Representatives of 182 nations gathered in Cairo in September, 1994, at the Un Conference on Population and Development. The resulting 113-page Draft Program of Action contains sober discussions on demographic issues, including projections of population increase in the decades ahead. It focuses on the potential growth of famine, disease, warfare, environmental degradation, and general human misery if the world's population cannot be stabilized at around 8 billion in the next 20 years. The 1994 figure stands at about 5.7 billion, and there will be 12.5 billion people if no action is taken. Previous conferences hosted under the UN helped spark a remarkable decline in fertility rates, especially in Indonesia and Thailand. Even in populous Bangladesh, some 40% of women now use contraceptives, while the fertility rate has dropped from 7 to 4.2 in 2 decades. The proposals debated in Cairo include sustainable development, gender equality, and the empowerment of women. Whatever the country or culture, fertility rates tend to fall dramatically as women become more educated. This has been borne out almost everywhere, most notably in Japan and Singapore. The conference has been criticized by the Vatican as advocating an international standard for easy abortion, encouraging sex education for teenagers, and sanctioning marriages other than between a man and a woman. Some conservative Muslim thinkers have also complained that it promotes Western values and fosters illicit sex. Many supporters of population planning have argued that the empowerment of women will reduce the incidence of abortion. The Cairo document will alienate many across Asia with its references to the plurality of family forms, including the large number of households headed by single parents. The one goal on which everyone can agree is the need to promote policies that will stabilize the global headcount.

  6. Read/write head for a magnetic tape device having grooves for reducing tape floating

    DOEpatents

    Aoki, Kenji

    2005-08-09

    A read/write head for a magnetic tape includes an elongated chip assembly and a tape running surface formed in the longitudinal direction of the chip assembly. A pair of substantially spaced parallel read/write gap lines for supporting read/write elements extend longitudinally along the tape running surface of the chip assembly. Also, at least one groove is formed on the tape running surface on both sides of each of the read/write gap lines and extends substantially parallel to the read/write gap lines.

  7. Zero torque gear head wrench

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  8. Montessori Head Start Implementation Brief.

    ERIC Educational Resources Information Center

    Clifford, Alcillia; Kahn, David

    1995-01-01

    Discusses the use of the Montessori method in Head Start programs, focusing on educational environment, teacher training, parent involvement, and funding. Outlines the phased implementation of a Montessori program and provides a list of Montessori publications and organizations. (MDM)

  9. Cutting head for ultrasonic lithotripsy

    NASA Technical Reports Server (NTRS)

    Anguluo, E. D.; Goodfriend, R. (Inventor)

    1985-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument is described. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduce breakage thereof.

  10. Design, manufacture, and test of coolant pump-motor assembly for Brayton power conversion system

    NASA Technical Reports Server (NTRS)

    Gabacz, L. E.

    1973-01-01

    The design, development, fabrication, and testing of seven coolant circulating pump-motor assemblies are discussed. The pump-motor assembly is driven by the nominal 44.4-volt, 400-Hz, 3-phase output of a nominal 56-volt dc input inverter. The pump-motor assembly will be used to circulate Dow Corning 200 liquid coolant for use in a Brayton cycle space power system. The pump-motor assembly develops a nominal head of 70 psi at 3.7 gpm with an over-all efficiency of 26 percent. The design description, drawings, photographs, reliability results, and developmental and acceptance test results are included.

  11. Dynamic Nanoparticles Assemblies

    PubMed Central

    WANG, LIBING; XU, LIGUANG; KUANG, HUA; XU, CHUANLAI; KOTOV, NICHOLAS A.

    2012-01-01

    CONSPECTUS Importance Although nanoparticle (NP) assemblies are at the beginning of their development, their unique geometrical shapes and media-responsive optical, electronic and magnetic properties have attracted significant interest. Nanoscale assembly bridges multiple sizes of materials: individual nanoparticles, discrete molecule-like or virus-like nanoscale agglomerates, microscale devices, and macroscale materials. The capacity to self-assemble can greatly facilitate the integration of nanotechnology with other technologies and, in particular, with microscale fabrication. In this Account, we describe developments in the emerging field of dynamic NP assemblies, which are spontaneously formed superstructures containing more than two inorganic nanoscale particles that display ability to change their geometrical, physical, chemical, and other attributes. In many ways, dynamic assemblies can represent a bottleneck in the ‘bottom-up’ fabrication of NP-based devices because they can produce a much greater variety of assemblies, but they also provide a convenient tool for variation of geometries and dimensions of nanoparticle assemblies. Classification Superstructures of NPs (and those held together by similar intrinsic forces) are classified into two groups: Class 1 where media and external fields can alter shape, conformation, and order of stable superstructures with a nearly constant number same. The future development of successful dynamic assemblies requires understanding the equilibrium in dynamic NP systems. The dynamic nature of Class 1 assemblies is associated with the equilibrium between different conformations of a superstructure and is comparable to the isomerization in classical chemistry. Class 2 assemblies involve the formation and/or breakage of linkages between the NPs, which is analogous to the classical chemical equilibrium for the formation of a molecule from atoms. Finer classification of NP assemblies in accord with established conventions

  12. Ghost Head Nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Looking like a colorful holiday card, a new image from NASA's Hubble Space Telescope reveals a vibrant green and red nebula far from Earth.

    The image of NGC 2080, taken by Hubble's Wide Field and Planetary Camera 2, designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is available online at http://www.jpl.nasa.gov/images/wfpc . Images like this help astronomers investigate star formation in nebulas.

    NGC 2080, nicknamed 'The Ghost Head Nebula,' is one of a chain of star-forming regions lying south of the 30 Doradus nebula in the Large Magellanic Cloud. 30 Doradus is the largest star-forming complex in the local group of galaxies. This 'enhanced color' picture is composed of three narrow-band-filter images obtained by Hubble on March 28, 2000.

    The red and blue light come from regions of hydrogen gas heated by nearby stars. The green light on the left comes from glowing oxygen. The energy to illuminate the green light is supplied by a powerful stellar wind, a stream of high-speed particles coming from a massive star just outside the image. The central white region is a combination of all three emissions and indicates a core of hot, massive stars in this star-formation region. Intense emission from these stars has carved a bowl-shaped cavity in surrounding gas.

    In the white region, the two bright areas (the 'eyes of the ghost') - named A1 (left) and A2 (right) -- are very hot, glowing 'blobs' of hydrogen and oxygen. The bubble in A1 is produced by the hot, intense radiation and powerful stellar wind from one massive star. A2 contains more dust and several hidden, massive stars. The massive stars in A1 and A2 must have formed within the last 10,000 years, since their natal gas shrouds are not yet disrupted by the powerful radiation of the newborn stars.

    The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center

  13. Neurofilament subunit (NFL) head domain phosphorylation regulates axonal transport of neurofilaments.

    PubMed

    Yates, Darran M; Manser, Catherine; De Vos, Kurt J; Shaw, Christopher E; McLoughlin, Declan M; Miller, Christopher C J

    2009-04-01

    Neurofilaments are the intermediate filaments of neurons and are synthesised in neuronal cell bodies and then transported through axons. Neurofilament light chain (NFL) is a principal component of neurofilaments, and phosphorylation of NFL head domain is believed to regulate the assembly of neurofilaments. However, the role that NFL phosphorylation has on transport of neurofilaments is poorly understood. To address this issue, we monitored axonal transport of phosphorylation mutants of NFL. We mutated four known phosphorylation sites in NFL head domain to either preclude phosphorylation, or mimic permanent phosphorylation. Mutation to preclude phosphorylation had no effect on transport but mutation of three sites to mimic permanent phosphorylation inhibited transport. Mutation of all four sites together to mimic permanent phosphorylation proved especially potent at inhibiting transport and also disrupted neurofilament assembly. Our results suggest that NFL head domain phosphorylation is a regulator of neurofilament axonal transport.

  14. Multicylinder internal combustion engine utilizing split block with unitized cylinder head and liner

    SciTech Connect

    Eitel, J.M.

    1988-08-16

    This patent describes an internal combustion engine of the type having at least one cylinder and a crankshaft, as assembly comprised of first and second mating half sections joined in a common plane which passes through and along the axis of the crankshaft, each of the half sections providing crankcase, crankshaft bearing support, and cylinder water jacket portions, a unitized cylinder head and sleeve construction having a combustion chamber with a top surface therein and cooperative securing and sealing means for securing the unitized cylinder head and sleeve construction to the assembly in a location immediately adjacent the top surface of the combustion chamber, the cooperative securing and sealing means encircling each cylinder head and including tie bolts extending through the cylinder water jacket portions.

  15. Vancomycin assembly: nature's way.

    PubMed

    Hubbard, Brian K; Walsh, Christopher T

    2003-02-17

    Antibiotics are precious resources in the fight to combat bacterial infections caused by pathogenic organisms. Vancomycin is one of the antibiotics of last resort in the treatment of life-threatening infections by gram-positive bacteria. The rules by which nature assembles the glycopeptide (vancomycin) and lipoglycopeptide (teicoplanin) antibiotics are becoming elucidated and verified: first amino acids are synthesized, then joined together and cross-linked. This knowledge opens up approaches for reprogramming strategies at the level of altered monomers, swapped assembly lines, and different post-assembly tailoring enzymes.

  16. TPX assembly plan

    SciTech Connect

    Knutson, D.

    1993-11-01

    The TPX machine will be assembled in the TFTR Test Cell at the Plasma Physics Laboratory, utilizing the existing TFTR machine foundation. Preparation of the area for assembly will begin after completion of the decontamination and decommissioning phase on TFTR and certification that the radiation levels remaining, if any, are consistent with the types of operations planned. Assembly operations begin with the arrival of the first components, and conclude, approximately 24 months later, with the successful completion of the integrated systems tests and the achievement of a first plasma.

  17. DC source assemblies

    DOEpatents

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  18. Heatup of the TMI-2 lower head during core relocation

    SciTech Connect

    Wang, S.K.; Sienicki, J.J.; Spencer, B.W.

    1989-01-01

    An analysis has been carried out to assess the potential of a melting attack upon the reactor vessel lower head and incore instrument nozzle penetration weldments during the TMI core relocation event at 224 minutes. Calculations were performed to determine the potential for molten corium to undergo breakup into droplets which freeze and form a debris bed versus impinging upon the lower head as one or more coherent streams. The effects of thermal-hydraulic interactions between corium streams and water inside the lower plenum, the effects of the core support assembly structure upon the corium, and the consequences of corium relocation by way of the core former region were examined. 19 refs., 24 figs.

  19. [Illustrations of visceral referred pain. "Head-less" Head's zones].

    PubMed

    Henke, C; Beissner, F

    2011-04-01

    Reviewing anatomical, physiological and neurological standard literature for illustrations of referred visceral pain only one type of illustration can frequently be found, which is referred to as Treves and Keith. In fact, the original illustration as a model for most current pictures stems from the German edition of Sir Frederick Treves' famous book "Surgical Applied Anatomy" from 1914, which was reillustrated for didactical reasons for the German readership. While neither Treves and Keith nor the German illustrator Otto Kleinschmidt ever published any work on referred pain this illustration must have been adapted or copied from older sources by the illustrator. Therefore the comprehensive systematic original works before 1914 were reviewed, namely those of Sir Henry Head and Sir James Mackenzie. Due to the name of the phenomenon in the German literature of Head's zones, the illustrations were expected to be based mainly on Head's work. However, a comparison of all available illustrations led to the conclusion that Kleinschmidt chiefly used information from Mackenzie as a model for his illustration. Due to the inexact reproduction of Mackenzie's work by the illustrator some important features were lost that had been reported by the original authors. These include the phenomenon of Head's maximum points, which nowadays has fallen into oblivion.Therefore current charts, based on the illustration by Kleinschmidt from 1914, lack experimental evidence and appear to be a simplification of the observational results of both Head's and Mackenzie's original systematic works.

  20. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... protected by protective helmets. (b) Criteria for head protection. (1) The employer must provide...

  1. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  2. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  3. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  4. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... Institute, Z89.1-1969, Safety Requirements for Industrial Head Protection. (c) Helmets for the...

  5. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  6. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  7. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... Institute, Z89.1-1969, Safety Requirements for Industrial Head Protection. (c) Helmets for the...

  8. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... protected by protective helmets. (b) Criteria for head protection. (1) The employer must provide...

  9. Communicating printed headings to the ear.

    PubMed

    Lorch, Robert F; Chen, Hung-Tao; Jawahir, Aqeel A; Lemarié, Julie

    2016-05-01

    Two experiments compared three methods of translating printed headings into an auditory format. In both experiments, college students listened to a text with instructions to stop the recording whenever they heard a heading and type the hierarchical level and exact wording of the heading. Listeners were poor at identifying headings and their levels if the headings were not distinguished from the rest of the text. However, listeners were very good at identifying headings if any method of signalling was used to distinguish headings and communicate their hierarchical level. The methods included: (1) tones preceding headings, (2) changes of speaker to indicate headings or (3) verbal labels preceding headings. Although all three signalling methods improved identification of a heading's hierarchical level, the labelling method was the most effective means of communicating hierarchical level. Thus, the study identifies a simple method of effectively communicating headings in spoken text. Practitioner Summary: The study attempted to identify effective ways of communicating heading information in spoken text. College students listened to texts in order to detect headings and record their wording and hierarchical level. Performance was excellent when headings were preceded by verbal phrases that signalled the upcoming headings and their levels. PMID:27267653

  10. Reversed theta sequences of hippocampal cell assemblies during backward travel.

    PubMed

    Cei, Anne; Girardeau, Gabrielle; Drieu, Céline; Kanbi, Karim El; Zugaro, Michaël

    2014-05-01

    Hippocampal cell assemblies coding for past, present and future events form theta-timescale (~100 ms) sequences that represent spatio-temporal episodes. However, the underlying mechanisms remain largely unknown. We recorded hippocampal and entorhinal cortical activity as rats experienced backward travel on a model train. Although the firing fields of place cells remained stable, the order in which they were activated in the theta sequence was reversed during backward travel. Thus, hippocampal cell assemblies coordinated their relative timing to correctly predict the sequential traversal of place fields in reverse order. At the single-cell level, theta phase represented distance traveled through the field, even though the head of the rat was oriented opposite to travel direction and entorhinal head-direction cells maintained their preferred firing direction. Our results challenge most theoretical models of theta sequence generation in the hippocampus.

  11. Rnnotator Assembly Pipeline

    SciTech Connect

    Martin, Jeff

    2010-06-03

    Jeff Martin of the DOE Joint Genome Institute discusses a de novo transcriptome assembly pipeline from short RNA-Seq reads on June 3, 2010 at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  12. Interlocked molecules: Aqueous assembly

    NASA Astrophysics Data System (ADS)

    Bai, Linyi; Zhao, Yanli

    2015-12-01

    The quantitative self-assembly of mechanically interlocked molecules in water, instead of organic solvents, opens up the possibility of such systems being used in a biological context where their functions can be interfaced with biomolecular systems.

  13. Integrated thruster assembly program

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The program is reported which has provided technology for a long life, high performing, integrated ACPS thruster assembly suitable for use in 100 typical flights of a space shuttle vehicle over a ten year period. The four integrated thruster assemblies (ITA) fabricated consisted of: propellant injector; a capacitive discharge, air gap torch type igniter assembly; fast response igniter and main propellant valves; and a combined regen-dump film cooled chamber. These flightweight 6672 N (1500 lb) thruster assemblies employed GH2/GO2 as propellants at a chamber pressure of 207 N/sq cm (300 psia). Test data were obtained on thrusted performance, thermal and hydraulic characteristics, dynamic response in pulsing, and cycle life. One thruster was fired in excess of 42,000 times.

  14. External Tank Assembly

    NASA Technical Reports Server (NTRS)

    1977-01-01

    This photograph shows the liquid hydrogen tank and liquid oxygen tank for the Space Shuttle external tank (ET) being assembled in the weld assembly area of the Michoud Assembly Facility (MAF). The ET provides liquid hydrogen and liquid oxygen to the Shuttle's three main engines during the first eight 8.5 minutes of flight. At 154-feet long and more than 27-feet in diameter, the ET is the largest component of the Space Shuttle, the structural backbone of the entire Shuttle system, and the only part of the vehicle that is not reusable. The ET is manufactured at the Michoud Assembly Facility near New Orleans, Louisiana, by the Martin Marietta Corporation under management of the Marshall Space Flight Center.

  15. Microtubule Self- Assembly

    NASA Astrophysics Data System (ADS)

    Jho, Yongseok; Choi, M. C.; Farago, O.; Kim, Mahnwon; Pincus, P. A.

    2008-03-01

    Microtubules are important structural elements for neurons. Microtubles are cylindrical pipes that are self-assembled from tubulin dimers, These structures are intimately related to the neuron transport system. Abnormal microtubule disintegration contributes to neuro-disease. For several decades, experimentalists investigated the structure of the microtubules using TEM and Cryo-EM. However, the detailed structure at a molecular level remain incompletely understood. . In this presentation, we report numerically studies of the self-assembly process using a toy model for tubulin dimers. We investigate the nature of the interactions which are essential to stabilize such the cylindrical assembly of protofilaments. We use Monte Carlo simulations to suggest the pathways for assembly and disassembly of the microtubules.

  16. Core assembly storage structure

    DOEpatents

    Jones, Jr., Charles E.; Brunings, Jay E.

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  17. Station Assembly Animation

    NASA Video Gallery

    This animation depicts the assembly of the International Space Station since Nov. 20, 1998, with the delivery of the Zarya module, through May 16, 2011, with the delivery of the EXPRESS Logistics C...

  18. The proteasome assembly line

    PubMed Central

    Madura, Kiran

    2013-01-01

    The assembly of the proteasome — the cellular machine that eliminates unwanted proteins — is a carefully choreographed affair, involving a complex sequence of steps overseen by dedicated protein chaperones. PMID:19516331

  19. Swipe transfer assembly

    DOEpatents

    Christiansen, Robert M.; Mills, William C.

    1992-01-01

    The swipe transfer assembly is a mechanical assembly which is used in conjunction with glove boxes and other sealed containments. It is used to pass small samples into or out of glove boxes without an open breach of the containment, and includes a rotational cylinder inside a fixed cylinder, the inside cylinder being rotatable through an arc of approximately 240.degree. relative to the outer cylinder. An offset of 120.degree. from end to end allows only one port to be opened at a time. The assembly is made of stainless steel or aluminum and clear acrylic plastic to enable visual observation. The assembly allows transfer of swipes and smears from radiological and other specially controlled environments.

  20. Mesoscale Polymer Assemblies

    NASA Astrophysics Data System (ADS)

    Choudhary, Satyan; Pham, Jonathan; Crosby, Alfred

    2015-03-01

    Materials encompassing structural hierarchy and multi-functionality allow for remarkable physical properties across different length scales. Mesoscale Polymer (MSP) assemblies provide a critical link, from nanometer to centimeter scales, in the definition of such hierarchical structures. Recent focus has been on exploiting these MSP assemblies for optical, electronic, photonics and biological applications. We demonstrate a novel fabrication method for MSP assemblies. Current fabrication methods restrict the length scale and volume of such assemblies. A new method developed uses a simple piezo-actuated motion for de-pinning of a polymer solution trapped by capillary forces between a flexible blade and a rigid substrate. The advantages of new method include ability to make MSP of monodisperse length and to fabricate sufficient volumes of MSP to study their physical properties and functionality in liquid dispersions. We demonstrate the application of MSP as filler for soft materials, providing rheological studies of the MSP with surrounding matrices.

  1. VIRUS instrument collimator assembly

    NASA Astrophysics Data System (ADS)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  2. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  3. High speed door assembly

    SciTech Connect

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  4. Recuperator assembly and procedures

    DOEpatents

    Kang, Yungmo; McKeirnan, Jr., Robert D.

    2008-08-26

    A construction of recuperator core segments is provided which insures proper assembly of the components of the recuperator core segment, and of a plurality of recuperator core segments. Each recuperator core segment must be constructed so as to prevent nesting of fin folds of the adjacent heat exchanger foils of the recuperator core segment. A plurality of recuperator core segments must be assembled together so as to prevent nesting of adjacent fin folds of adjacent recuperator core segments.

  5. Recuperator assembly and procedures

    DOEpatents

    Kang, Yungmo; McKeirnan, Jr., Robert D.

    2006-06-27

    A construction of recuperator core segments is provided which insures proper assembly of the components of the recuperator core segment, and of a plurality of recuperator core segments. Each recuperator core segment must be constructed so as to prevent nesting of fin folds of the adjacent heat exchanger foils of the recuperator core segment. A plurality of recuperator core segments must be assembled together so as to prevent nesting of adjacent fin folds of adjacent recuperator core segments.

  6. SUMC reconfigurable micro-assembler

    NASA Technical Reports Server (NTRS)

    Edwards, A. J.

    1973-01-01

    The development of a reconfigurable micro-assembler to provide the micro-programmer the capability to specify micro-instructions in concise, meaningful terms is discussed. The implementation plan for the development of the micro-assembler was predicted on the existing capabilities of the SUMC Reconfigurable Assembler. Utilizing the reconfigurable assembler as a base, new directives and existing directive modifications were implemented to provide the micro-assembly as a new capability of the reconfigurable assembler. The micro-assembler language allows the specification of all micro-instruction control field settings in one concise assembler source statement. The language appears very similar to a conventional machine instruction assembler language. The machine instruction assembler language has the characteristic of one operation specification per statement whereas, the micro-instruction assembler language allows multiple operations to be designated per statement.

  7. The perception of heading during eye movements

    NASA Technical Reports Server (NTRS)

    Royden, Constance S.; Banks, Martin S.; Crowell, James A.

    1992-01-01

    Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

  8. An update on complex I assembly: the assembly of players

    PubMed Central

    Vartak, Rasika S.; Semwal, Manpreet Kaur; Bai, Yidong

    2015-01-01

    Defects in Complex I assembly is one of the emerging underlying causes of severe mitochondrial disorders. The assembly of Complex I has been difficult to understand due to its large size, dual genetic control and the number of proteins involved. Mutations in Complex I subunits as well as assembly factors have been reported to hinder its assembly and give rise to a range of mitochondria disorders. In this review, we summarize the recent progress made in understanding the Complex I assembly pathway. In particularly, we focus on the known as well as novel assembly factors and their role in assembly of Complex I and human disease. PMID:25030182

  9. Cutting assembly. [Patent application

    DOEpatents

    Treuhaft, M.B.; Oser, M.S.

    1981-06-25

    A mining auger comprises a cutting head carried at one end of a tubular shaft and a plurality of wall segments which in a first position thereof are disposed side by side around said shaft and in a second position thereof are disposed oblique to said shaft. A vane projects outwardly from each wall segment. When the wall segments are in their first position, the vanes together form a substantially continuous helical wall. A cutter is mounted on the peripheral edge of each of the vanes. When the wall segments are in their second position, the cutters on the vanes are disposed radially outward from the perimeter of the cutting head.

  10. Human Assisted Assembly Processes

    SciTech Connect

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  11. Head position control on quasi-static read/write tester

    NASA Astrophysics Data System (ADS)

    Kusumi, Takayuki; Yamakawa, Kiyoshi; Ouchi, Kazuhiro

    2005-02-01

    To develop high-density magnetic recording systems, a simple feedback system without servo writing was applied to a quasi-static read/write tester in which a medium reciprocates against a stand-still head. The head position signal in cross-track direction during the scanning is fed back to the high-precision piezoelectric actuator of the media stage. The stage is controlled so as to make the head/medium alignment error zero. A contact head slider assembled on a parallel-link suspension was used to evaluate the feedback system. The tester shows an accuracy of 1.5 nm in cross-track direction which is preferable for the read/write tests at future high recording densities.

  12. [Head injuries in the Bible].

    PubMed

    Feinsod, M

    1995-12-15

    3 cases of head injury are described in the Bible: the death of Sisera by the hand of Jael (Judges 4: 21; 5: 25); the skull fractures of Avimelech incurred at the tower of Tevetz, (Judges, 9: 53, 54); and the slaying of Goliath by David, (Samuel I 17: 49-51). The various attempts to understand the mechanisms of these head injuries using philology, knowledge of the art of biblical warfare and modern medical considerations are reviewed. We try to identify the site of the mortal blow to Sisera's head, to understand why Avimelech asked to be killed, and to decide whether the giant from Gath was a rugged warrior or just an endocrinological cripple.

  13. Fractures of the Radial Head.

    PubMed

    Burkhart, Klaus Josef; Wegmann, Kilian; Müller, Lars P; Gohlke, Frank E

    2015-11-01

    Radial head fractures are the most common fractures around the elbow. Because they are often accompanied by ligamentous injuries, we recommend considering them to be osteoligamentous injuries rather than simple fractures, even in undisplaced or minimally displaced fractures. Surgeons should always suspect and actively exclude concomitant ligament tears. The incidence of these associated injuries increases with greater severity of the radial head fracture. However, the standard Mason classification system does not adequately address this problem, and all attempts to establish a new classification system that provides concise treatment algorithms have failed. This article discusses the current treatment options and the current controversies in nonsurgical therapy, open reduction and internal fixation (ORIF) and radial head replacement. PMID:26498543

  14. Assemblies of Conformal Tanks

    NASA Technical Reports Server (NTRS)

    DeLay, Tom

    2009-01-01

    Assemblies of tanks having shapes that conform to each other and/or conform to other proximate objects have been investigated for use in storing fuels and oxidizers in small available spaces in upper stages of spacecraft. Such assemblies might also prove useful in aircraft, automobiles, boats, and other terrestrial vehicles in which space available for tanks is limited. The basic concept of using conformal tanks to maximize the utilization of limited space is not new in itself: for example, conformal tanks are used in some automobiles to store windshield -washer liquid and coolant that overflows from radiators. The novelty of the present development lies in the concept of an assembly of smaller conformal tanks, as distinguished from a single larger conformal tank. In an assembly of smaller tanks, it would be possible to store different liquids in different tanks. Even if the same liquid were stored in all the tanks, the assembly would offer an advantage by reducing the mechanical disturbance caused by sloshing of fuel in a single larger tank: indeed, the requirement to reduce sloshing is critical in some applications. The figure shows a prototype assembly of conformal tanks. Each tank was fabricated by (1) copper plating a wax tank mandrel to form a liner and (2) wrapping and curing layers of graphite/epoxy composite to form a shell supporting the liner. In this case, the conformal tank surfaces are flat ones where they come in contact with the adjacent tanks. A band of fibers around the outside binds the tanks together tightly in the assembly, which has a quasi-toroidal shape. For proper functioning, it would be necessary to maintain equal pressure in all the tanks.

  15. Rotary head type reproducing apparatus

    DOEpatents

    Takayama, Nobutoshi; Edakubo, Hiroo; Kozuki, Susumu; Takei, Masahiro; Nagasawa, Kenichi

    1986-01-01

    In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

  16. Rotating head and piston engine

    SciTech Connect

    Gomm, T.J.; Messick, N.C.

    1992-07-21

    This patent describes a rotary piston combustion engine. It comprises a housing means, an engine block housing a single toroidal bore, a piston carrier ring spaced outwardly along the entire perimeter of the toroidal bore with at least one finger extending inwardly for piston attachment, a power transfer cylinder, a power output shaft, an auxiliary shaft with driven gearing means meshing with the driving gearing means, a rotating head with windows for piston passage, a trapezoidal porting means in the engine block and in the rotating head, an exhaust port means.

  17. Head kinematics during shaking associated with abusive head trauma.

    PubMed

    Lintern, T O; Puhulwelle Gamage, N T; Bloomfield, F H; Kelly, P; Finch, M C; Taberner, A J; Nash, M P; Nielsen, P M F

    2015-09-18

    Abusive head trauma (AHT) is a potentially fatal result of child abuse but the mechanisms of injury are controversial. To address the hypothesis that shaking alone is sufficient to elicit the injuries observed, effective computational and experimental models are necessary. This paper investigates the use of a coupled rigid-body computational modelling framework to reproduce in vivo shaking kinematics in AHT. A sagittal plane OpenSim computational model of a lamb was developed and used to interpret biomechanical data from in vivo shaking experiments. The acceleration of the head during shaking was used to provide in vivo validation of the associated computational model. Results of this study demonstrated that peak accelerations occurred when the head impacted the torso and produced acceleration magnitudes exceeding 200ms(-)(2). The computational model demonstrated good agreement with the experimental measurements and was shown to be able to reproduce the high accelerations that occur during impact. The biomechanical results obtained with the computational model demonstrate the utility of using a coupled rigid-body modelling framework to describe infant head kinematics in AHT.

  18. Steric environment around acetylcholine head groups of bolaamphiphilic nanovesicles influences the release rate of encapsulated compounds

    PubMed Central

    Stern, Avital; Guidotti, Matteo; Shaubi, Eleonora; Popov, Mary; Linder, Charles; Heldman, Eliahu; Grinberg, Sarina

    2014-01-01

    Two bolaamphiphilic compounds with identical acetylcholine (ACh) head groups, but with different lengths of an alkyl chain pendant adjacent to the head group, as well as differences between their hydrophobic skeleton, were investigated for their ability to self-assemble into vesicles that release their encapsulated content upon hydrolysis of their head groups by acetylcholinesterase (AChE). One of these bolaamphiphiles, synthesized from vernolic acid, has an alkyl chain pendant of five methylene groups, while the other, synthesized from oleic acid, has an alkyl chain pendant of eight methylene groups. Both bolaamphiphiles formed stable spherical vesicles with a diameter of about 130 nm. The ACh head groups of both bolaamphiphiles were hydrolyzed by AChE, but the hydrolysis rate was significantly faster for the bolaamphiphile with the shorter aliphatic chain pendant. Likewise, upon exposure to AChE, vesicles made from the bolaamphiphile with the shorter alkyl chain pendant released their encapsulated content faster than vesicles made from the bolaamphiphile with the longer alkyl chain pendant. Our results suggest that the steric environment around the ACh head group of bolaamphiphiles is a major factor affecting the hydrolysis rate of the head groups by AChE. Attaching an alkyl chain to the bolaamphiphile near the ACh head group allows self-assembled vesicles to form with a controlled release rate of the encapsulated materials, whereas shorter alkyl chains enable a faster head group hydrolysis, and consequently faster release, than longer alkyl chains. This principle may be implemented in the design of bolaamphiphiles for the formation of vesicles for drug delivery with desired controlled release rates. PMID:24531296

  19. Photovoltaic self-assembly.

    SciTech Connect

    Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

    2010-10-01

    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.

  20. Assembly Test Article (ATA)

    NASA Technical Reports Server (NTRS)

    Ricks, Glen A.

    1988-01-01

    The assembly test article (ATA) consisted of two live loaded redesigned solid rocket motor (RSRM) segments which were assembled and disassembled to simulate the actual flight segment stacking process. The test assembly joint was flight RSRM design, which included the J-joint insulation design and metal capture feature. The ATA test was performed mid-November through 24 December 1987, at Kennedy Space Center (KSC), Florida. The purpose of the test was: certification that vertical RSRM segment mating and separation could be accomplished without any damage; verification and modification of the procedures in the segment stacking/destacking documents; and certification of various GSE to be used for flight assembly and inspection. The RSRM vertical segment assembly/disassembly is possible without any damage to the insulation, metal parts, or seals. The insulation J-joint contact area was very close to the predicted values. Numerous deviations and changes to the planning documents were made to ensure the flight segments are effectively and correctly stacked. Various GSE were also certified for use on flight segments, and are discussed in detail.

  1. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L.; Elliott, Thomas S.

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  2. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, Harry Lawrence; Elliott, Thomas S.

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  3. Power module assembly

    DOEpatents

    Campbell, Jeremy B.; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  4. Wrist joint assembly

    NASA Technical Reports Server (NTRS)

    Kersten, L.; Johnson, J. D. (Inventor)

    1978-01-01

    A wrist joint assembly is provided for use with a mechanical manipulator arm for finely positioning an end-effector carried by the wrist joint on the terminal end of the manipulator arm. The wrist joint assembly is pivotable about a first axis to produce a yaw motion, a second axis is to produce a pitch motion, and a third axis to produce a roll motion. The wrist joint assembly includes a disk segment affixed to the terminal end of the manipulator arm and a first housing member, a second housing member, and a third housing member. The third housing member and the mechanical end-effector are moved in the yaw, pitch, and roll motion. Drive means are provided for rotating each of the housings about their respective axis which includes a cluster of miniature motors having spur gears carried on the output drive shaft which mesh with a center drive gear affixed on the housing to be rotated.

  5. Blade attachment assembly

    DOEpatents

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  6. Liaison based assembly design

    SciTech Connect

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted, increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.

  7. Optical interconnect assembly

    DOEpatents

    Laughlin, Daric; Abel, Philip

    2015-06-09

    An optical assembly includes a substrate with a first row of apertures and a second row of apertures. A first optical die includes a first plurality of optical transducer elements and is mounted on the substrate such that an optical signal interface of each transducer element is aligned with an aperture of the first row of optical apertures. A second optical die includes a second plurality of optical transducer elements and is mounted on the substrate such that an optical signal interface of each of the second plurality of optical transducer elements is aligned with an aperture of the second row of optical apertures. A connector configured to mate with the optical assembly supports a plurality of optical fibers. A terminal end of each optical fiber protrudes from the connector and extends into one of the apertures when the connector is coupled with the optical assembly.

  8. Supported PV module assembly

    DOEpatents

    Mascolo, Gianluigi; Taggart, David F.; Botkin, Jonathan D.; Edgett, Christopher S.

    2013-10-15

    A supported PV assembly may include a PV module comprising a PV panel and PV module supports including module supports having a support surface supporting the module, a module registration member engaging the PV module to properly position the PV module on the module support, and a mounting element. In some embodiments the PV module registration members engage only the external surfaces of the PV modules at the corners. In some embodiments the assembly includes a wind deflector with ballast secured to a least one of the PV module supports and the wind deflector. An array of the assemblies can be secured to one another at their corners to prevent horizontal separation of the adjacent corners while permitting the PV modules to flex relative to one another so to permit the array of PV modules to follow a contour of the support surface.

  9. In vitro kinetochore assembly

    PubMed Central

    Miell, Matthew D D; Straight, Aaron F

    2016-01-01

    The kinetochore is the primary site of interaction between chromosomes and microtubules of the mitotic spindle during chromosome segregation. The kinetochore is a complex of more than 100 proteins that transiently assemble during mitosis at a single defined region on each chromosome, known as the centromere. Kinetochore assembly and activity must be tightly regulated to ensure proper microtubule interaction and faithful chromosome segregation because perturbation of kinetochores often results in aneuploidy and cell lethality. As such, cell free and reconstituted systems to analyze kinetochore formation and function are invaluable in probing the biochemical activities of kinetochores. In vitro approaches to studying kinetochores have enabled the manipulation of kinetochore protein structure, function, interactions and regulation that are not possible in cells. Here we outline a cell-free approach for the assembly of centromeres and recruitment of functional kinetochores that enables their manipulation and analysis. PMID:27193846

  10. Hurricane Rina Headed to Mexico

    NASA Video Gallery

    An animation of NOAA GOES-13 satellite observations from October 23 at 2:45 p.m. EDT through Oct. 25 at 1:30 p.m. EDT shows a strengthening Hurricane Rina in the western Caribbean Sea and headed fo...

  11. Head nurse or hotel manager?

    PubMed

    McAlvanah, M

    1989-01-01

    The responsibility of making room assignments for patients can be both a challenging and frustrating experience for a head nurse. Many factors must be considered when making room assignments while consumer dissatisfaction with the process must be handled creatively and with understanding. PMID:2734042

  12. Graham confirmed as OSTP Head

    NASA Astrophysics Data System (ADS)

    William R. Graham was confirmed by the Senate on October 1, 1986, as the science advisor to President Ronald Reagan and head of the Office of Science and Technology Policy (OSTP). Formerly the deputy administrator of the National Aeronautics and Space Administration (NASA), Graham started his new post on October 6.

  13. MAKING WAVES, DENVER HEAD START.

    ERIC Educational Resources Information Center

    Denver Opportunity, CO.

    THIS DOCUMENT PROVIDES A DESCRIPTIVE SURVEY OF PROJECT HEAD START ACTIVITIES IN DENVER, COLORADO. THE PRIMARY EDUCATIONAL OBJECTIVES OF THE PROGRAM ARE CITED AS (1) CONCEPT DEVELOPMENT THROUGH EXPERIENCES IN AN ENLARGED ENVIRONMENT, (2) SELF-CONCEPT DEVELOPMENT THROUGH SUCCESSFUL INTERACTION WITH TEACHERS AND WITH PEERS, AND (3) THE DEVELOPMENT OF…

  14. Pressure testing of torispherical heads

    SciTech Connect

    Rana, M.D.; Kalnins, A.; Updike, D.P.

    1995-12-01

    Two vessels fabricated from SA516-70 steel with 6% knuckle radius torispherical heads were tested under internal pressure to failure. The D/t ratios of Vessel 1 and Vessel 2 were 238 and 185 respectively. The calculated maximum allowable working pressures of Vessel 1 and 2 heads using the ASME Section 8, Div. 1 rules and measured dimensions were 85 and 110 psi, respectively. Vessel 1 failed at a nozzle weld in the cylindrical shell at 700 psi pressure. Neither buckling nor any other objectionable deformation of the head was observed at a theoretical double-elastic-slope collapse pressure of 241 and a calculated buckling pressure of 270 psi. Buckles were observed developing slowly after 600 psi pressure, and a total of 22 buckles were observed after the test, having the maximum amplitude of 0.15 inch. Vessel 2 failed at the edge of the longitudinal weld of the cylindrical shell at 1,080 psi pressure. Neither buckling nor any other objectionable deformation of the head was observed up to the final pressure, which exceeded the theoretical double-elastic-slope collapse and calculated buckling pressures of 274 psi and 342 psi, respectively.

  15. Model of beam head erosion

    SciTech Connect

    Lee, E.P.

    1980-08-08

    An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.

  16. Head Start Dental Health Curriculum.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    This curriculum for Head Start programs provides preschool learning experiences that teach about dental health. The majority of the curriculum guide is devoted to the following lesson plans: (1) "Introduction of 'Smiley the Super Pup'," an optional puppet character which may be used to review the concepts covered in each lesson; (2) "Visiting the…

  17. Supramolecular Assemblies from Amphiphilic Homopolymers: Testing the Scope

    PubMed Central

    Savariar, Elamprakash N.; Aathimanikandan, Sivakumar V.; Thayumanavan, S.

    2008-01-01

    It has been shown by us in a recent communication that homopolymers, in which each repeat unit contains a hydrophilic and a hydrophobic head group, are capable of forming environment dependent micellar or inverse micellar assemblies. A systematic structure-property relationship study is carried out here to test the scope of the design. We show here that the molecular design is indeed broadly applicable and that there is a significant gain in the critical aggregation concentrations of these polymers, compared to the small molecule counterparts. We also show that the design can be tuned to achieve vesicle-type assemblies, which further expands the repertoire of amphiphilic homopolymers in a variety of areas. Characterizations of these assemblies have been carried out using transmission electron microscopy, dynamic light scattering, static light scattering, and dye incorporation experiments. PMID:17165775

  18. Low inductance connector assembly

    DOEpatents

    Holbrook, Meghan Ann; Carlson, Douglas S

    2013-07-09

    A busbar connector assembly for coupling first and second terminals on a two-terminal device to first and second contacts on a power module is provided. The first terminal resides proximate the first contact and the second terminal resides proximate the second contact. The assembly comprises a first bridge having a first end configured to be electrically coupled to the first terminal, and a second end configured to be electrically coupled to the second contact, and a second bridge substantially overlapping the first bridge and having a first end electrically coupled to the first contact, and a second end electrically coupled to the second terminal.

  19. Lightweight reflector assembly

    NASA Technical Reports Server (NTRS)

    Argoud, M. J.; Jolley, J.; Walker, W. L. (Inventor)

    1977-01-01

    An inexpensive, lightweight reflective assembly member having good optical quality and particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors is described. The reflective assembly consists of a thin sheet of glass with appropriate reflective coating and a cellular glass block substrate bonded together. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface. An adhesive is applied to the abraded surface and a lamina reflective surface is placed under a uniform pressure to conform the reflective surface onto the desired abraded surface of the substrate.

  20. Phylogenetic Comparative Assembly

    NASA Astrophysics Data System (ADS)

    Husemann, Peter; Stoye, Jens

    Recent high throughput sequencing technologies are capable of generating a huge amount of data for bacterial genome sequencing projects. Although current sequence assemblers successfully merge the overlapping reads, often several contigs remain which cannot be assembled any further. It is still costly and time consuming to close all the gaps in order to acquire the whole genomic sequence. Here we propose an algorithm that takes several related genomes and their phylogenetic relationships into account to create a contig adjacency graph. From this a layout graph can be computed which indicates putative adjacencies of the contigs in order to aid biologists in finishing the complete genomic sequence.

  1. Self assembling proteins

    DOEpatents

    Yeates, Todd O.; Padilla, Jennifer; Colovos, Chris

    2004-06-29

    Novel fusion proteins capable of self-assembling into regular structures, as well as nucleic acids encoding the same, are provided. The subject fusion proteins comprise at least two oligomerization domains rigidly linked together, e.g. through an alpha helical linking group. Also provided are regular structures comprising a plurality of self-assembled fusion proteins of the subject invention, and methods for producing the same. The subject fusion proteins find use in the preparation of a variety of nanostructures, where such structures include: cages, shells, double-layer rings, two-dimensional layers, three-dimensional crystals, filaments, and tubes.

  2. Photovoltaic module kit including connector assembly for non-penetrating array installation

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt; Culligan, Matthew

    2013-12-31

    A PV module kit for non-penetrating rooftop installation, including a plurality of PV modules and a plurality of connectors. Each of the PV modules includes a PV laminate and a frame forming a mounting region assembled thereto. The connectors include a male connector having a male fastener extending from a head, and a female connector having a female fastener assempbled within a head. The heads are entirely formed of plastic. The kit provides a mounted array state including a junction at which the mounting regions of at least two of the PV modules are aligned and interconnected by engagement of the male connector with the female connector. The so-formed junction is substantially electrically insulated. The plurality of connectors can further include a spacer connector including a head forming a bore sized slidably receive the male fastener, with all of the connector heads being identical.

  3. Outcomes Following Radial Head Arthroplasty.

    PubMed

    Fowler, John R; Henry, Sarah E; Xu, Peter; Goitz, Robert J

    2016-05-01

    Most current series of radial head arthroplasty include small numbers of patients with short- to medium-term follow-up and significant heterogeneity in patients, treatments, and outcome measures. The purpose of this systematic review was to review outcomes for radial head arthroplasty based on injury chronicity, injury pattern, and type of implant used. The authors systematically searched electronic databases for studies containing radial head arthroplasty or radial head replacement and identified 19 studies for inclusion in the analysis. For each included study, a composite mean was obtained for Mayo Elbow Performance Score (MEPS) and range of motion. Outcomes were said to differ significantly if their confidence intervals did not overlap. The MEPS for acute treatment (90) was higher than that for delayed treatment (81). There was no difference in the pooled MEPS between the isolated (89) and complex injury pattern (87) groups or implant material. There was no difference in range of motion between the acute and delayed or isolated and complex groups, but the average degree of pronation was higher in patients treated with titanium implants (76°) compared with cobalt chromium implants (66°). This systematic review suggests that outcomes are improved following acute arthroplasty for treatment of radial head fractures compared with delayed treatment, based on MEPS. The lack of other significant differences detected is likely due to the significant heterogeneity and inadequate power in current studies. Further prospective studies isolating the different variables will be needed to determine their true effect on outcomes. [Orthopedics. 2016; 39(3):153-160.]. PMID:27045484

  4. Fire resistant PV shingle assembly

    SciTech Connect

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  5. The endoderm indirectly influences morphogenetic movements of the zebrafish head kidney through the posterior cardinal vein and VegfC

    PubMed Central

    Chou, Chih-Wei; Hsu, Hsiao-Chu; You, May-su; Lin, Jamie; Liu, Yi-Wen

    2016-01-01

    Integration of blood vessels and organ primordia determines organ shape and function. The head kidney in the zebrafish interacts with the dorsal aorta (DA) and the posterior cardinal vein (PCV) to achieve glomerular filtration and definitive hematopoiesis, respectively. How the head kidney co-develops with both the axial artery and vein remains unclear. We found that in endodermless sox32-deficient embryos, the head kidney associated with the PCV but not the DA. Disrupted convergent migration of the PCV and the head kidney in sox32-deficient embryos was rescued in a highly coordinated fashion through the restoration of endodermal cells. Moreover, grafted endodermal cells abutted the host PCV endothelium in the transplantation assay. Interestingly, the severely-disrupted head kidney convergence in the sox32-deficient embryo was suppressed by both the cloche mutation and the knockdown of endothelial genes, indicating that an interaction between the endoderm and the PCV restricts the migration of the head kidney. Furthermore, knockdown of either vegfC or its receptor vegfr3 suppressed the head kidney convergence defect in endodermless embryos and perturbed the head kidney-PCV association in wild-type embryos. Our findings thus underscore a role for PCV and VegfC in patterning the head kidney prior to organ assembly and function. PMID:27477767

  6. The endoderm indirectly influences morphogenetic movements of the zebrafish head kidney through the posterior cardinal vein and VegfC.

    PubMed

    Chou, Chih-Wei; Hsu, Hsiao-Chu; You, May-Su; Lin, Jamie; Liu, Yi-Wen

    2016-01-01

    Integration of blood vessels and organ primordia determines organ shape and function. The head kidney in the zebrafish interacts with the dorsal aorta (DA) and the posterior cardinal vein (PCV) to achieve glomerular filtration and definitive hematopoiesis, respectively. How the head kidney co-develops with both the axial artery and vein remains unclear. We found that in endodermless sox32-deficient embryos, the head kidney associated with the PCV but not the DA. Disrupted convergent migration of the PCV and the head kidney in sox32-deficient embryos was rescued in a highly coordinated fashion through the restoration of endodermal cells. Moreover, grafted endodermal cells abutted the host PCV endothelium in the transplantation assay. Interestingly, the severely-disrupted head kidney convergence in the sox32-deficient embryo was suppressed by both the cloche mutation and the knockdown of endothelial genes, indicating that an interaction between the endoderm and the PCV restricts the migration of the head kidney. Furthermore, knockdown of either vegfC or its receptor vegfr3 suppressed the head kidney convergence defect in endodermless embryos and perturbed the head kidney-PCV association in wild-type embryos. Our findings thus underscore a role for PCV and VegfC in patterning the head kidney prior to organ assembly and function. PMID:27477767

  7. American Cancer Society Head and Neck Cancer Survivorship Care Guideline.

    PubMed

    Cohen, Ezra E W; LaMonte, Samuel J; Erb, Nicole L; Beckman, Kerry L; Sadeghi, Nader; Hutcheson, Katherine A; Stubblefield, Michael D; Abbott, Dennis M; Fisher, Penelope S; Stein, Kevin D; Lyman, Gary H; Pratt-Chapman, Mandi L

    2016-05-01

    Answer questions and earn CME/CNE The American Cancer Society Head and Neck Cancer Survivorship Care Guideline was developed to assist primary care clinicians and other health practitioners with the care of head and neck cancer survivors, including monitoring for recurrence, screening for second primary cancers, assessment and management of long-term and late effects, health promotion, and care coordination. A systematic review of the literature was conducted using PubMed through April 2015, and a multidisciplinary expert workgroup with expertise in primary care, dentistry, surgical oncology, medical oncology, radiation oncology, clinical psychology, speech-language pathology, physical medicine and rehabilitation, the patient perspective, and nursing was assembled. While the guideline is based on a systematic review of the current literature, most evidence is not sufficient to warrant a strong recommendation. Therefore, recommendations should be viewed as consensus-based management strategies for assisting patients with physical and psychosocial effects of head and neck cancer and its treatment. CA Cancer J Clin 2016;66:203-239. © 2016 American Cancer Society. PMID:27002678

  8. American Cancer Society Head and Neck Cancer Survivorship Care Guideline.

    PubMed

    Cohen, Ezra E W; LaMonte, Samuel J; Erb, Nicole L; Beckman, Kerry L; Sadeghi, Nader; Hutcheson, Katherine A; Stubblefield, Michael D; Abbott, Dennis M; Fisher, Penelope S; Stein, Kevin D; Lyman, Gary H; Pratt-Chapman, Mandi L

    2016-05-01

    Answer questions and earn CME/CNE The American Cancer Society Head and Neck Cancer Survivorship Care Guideline was developed to assist primary care clinicians and other health practitioners with the care of head and neck cancer survivors, including monitoring for recurrence, screening for second primary cancers, assessment and management of long-term and late effects, health promotion, and care coordination. A systematic review of the literature was conducted using PubMed through April 2015, and a multidisciplinary expert workgroup with expertise in primary care, dentistry, surgical oncology, medical oncology, radiation oncology, clinical psychology, speech-language pathology, physical medicine and rehabilitation, the patient perspective, and nursing was assembled. While the guideline is based on a systematic review of the current literature, most evidence is not sufficient to warrant a strong recommendation. Therefore, recommendations should be viewed as consensus-based management strategies for assisting patients with physical and psychosocial effects of head and neck cancer and its treatment. CA Cancer J Clin 2016;66:203-239. © 2016 American Cancer Society.

  9. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  10. Rotary shaft sealing assembly

    SciTech Connect

    Dietle, Lannie L; Schroeder, John E; Kalsi, Manmohan S; Alvarez, Patricio D

    2013-08-13

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  11. Corium protection assembly

    DOEpatents

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A corium protection assembly includes a perforated base grid disposed below a pressure vessel containing a nuclear reactor core and spaced vertically above a containment vessel floor to define a sump therebetween. A plurality of layers of protective blocks are disposed on the grid for protecting the containment vessel floor from the corium.

  12. Modeling Protein Self Assembly

    ERIC Educational Resources Information Center

    Baker, William P.; Jones, Carleton Buck; Hull, Elizabeth

    2004-01-01

    Understanding the structure and function of proteins is an important part of the standards-based science curriculum. Proteins serve vital roles within the cell and malfunctions in protein self assembly are implicated in degenerative diseases. Experience indicates that this topic is a difficult one for many students. We have found that the concept…

  13. Turbomachine blade assembly

    DOEpatents

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  14. ELEMENTARY SCHOOL ASSEMBLY.

    ERIC Educational Resources Information Center

    DONAHOE, THOMAS J.; MARTIN, RICHARD G.

    SURVEY OF THE SPRINGFIELD, MASSACHUSETTS, SCHOOLS AND GOVERNMENT. THESE WILL FORM THE BASIS FOR DISCUSSION IN ALL SIXTH GRADE CLASSES DURING A 2-MONTH PERIOD. THE CLASSES WILL CHOOSE A STUDENT REPRESENTATIVE TO ATTEND A CITY-WIDE ASSEMBLY OF STUDENTS TO PRESENT THE RESULTS OF THE CLASS DISCUSSIONS. THE QUESTIONS ARE IN THREE AREAS--THE SCHOOL'S…

  15. Lageos assembly operation plan

    NASA Technical Reports Server (NTRS)

    Brueger, J.

    1975-01-01

    Guidelines and constraints procedures for LAGEOS assembly, operation, and design performance are given. Special attention was given to thermal, optical, and dynamic analysis and testing. The operation procedures illustrate the interrelation and sequence of tasks in a flow diagram. The diagram also includes quality assurance functions for verification of operation tasks.

  16. Beyond the Assembly Line.

    ERIC Educational Resources Information Center

    Weitz, Rebecca; Guild, Todd

    1985-01-01

    Describes how Hughes Aircraft trainers followed four steps in meeting the challenges of a flexible manufacturing environment: needs assessment, design strategy, pilot evaluation, and follow-through. Within this environment, 50 self-paced training products were developed for one of the company's wire and back plane harness assembly departments. (CT)

  17. The International Assembly.

    ERIC Educational Resources Information Center

    Gerlach, Jeanne Marcum, Ed.

    2000-01-01

    Looks at the missions and goals of the International Assembly of the National Council of Teachers of English, a global multicultural network promoting communication and cooperation for international exchange of teaching practices, literature, literacy, curriculum development, and research in English. Suggests some criteria to look at when…

  18. Solar collector assembly

    SciTech Connect

    Murphy, J.A.

    1980-09-09

    A solar collector assembly includes shingles which have integral tubes projecting therefrom, and which are mounted in overlapping parallel array. Mounting brackets for the shingles are engaged on roof rafters or the like, and interlocked light transmissive plates overlie the shingles. The plates are also engaged with shingle components. A special fitting for the tube ends is provided.

  19. Walking boot assembly

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.; Chambers, A. B.; Stjohn, R. H. (Inventor)

    1977-01-01

    A walking boot assembly particularly suited for use with a positively pressurized spacesuit is presented. A bootie adapted to be secured to the foot of a wearer, an hermetically sealed boot for receiving the bootie having a walking sole, an inner sole, and an upper portion adapted to be attached to an ankle joint of a spacesuit, are also described.

  20. Dump valve assembly

    DOEpatents

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  1. Segmented stator assembly

    SciTech Connect

    Lokhandwalla, Murtuza; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Shah, Manoj Ramprasad; Quirion, Owen Scott

    2013-04-02

    An electric machine and stator assembly are provided that include a continuous stator portion having stator teeth, and a tooth tip portion including tooth tips corresponding to the stator teeth of the continuous stator portion, respectively. The tooth tip portion is mounted onto the continuous stator portion.

  2. Drugs Approved for Head and Neck Cancer

    MedlinePlus

    ... Professionals Questions to Ask about Your Treatment Research Drugs Approved for Head and Neck Cancer This page ... and neck cancer that are not listed here. Drugs Approved for Head and Neck Cancer Abitrexate (Methotrexate) ...

  3. Heads up display for the Flight Simulator for Advanced Aircraft (FSAA)

    NASA Technical Reports Server (NTRS)

    Brocker, D. H.; Ganzler, B. C.

    1975-01-01

    A heads-up flight director display designed for a V/STOL lift-fan transport simulation study is described. The pilot's visual flight scene had the heads-up display optically superimposed over the usual out-the-window, video flight scene. The flight director display required the development and integration of a flexible, programmable display generator, graphics assembler, display driver, computer interface system, and special collimating optics for the pilot's flight scene. The optical overlay was realistic because both scenes appeared at optical infinity, and the flexibility of this display device establishes its value as a research tool for use in future flight simulation programs.

  4. Head stabilization in whooping cranes

    USGS Publications Warehouse

    Kinloch, M.R.; Cronin, T.W.; Olsen, G.H.; Chavez-Ramirez, Felipe

    2005-01-01

    The whooping crane (Grus americana) is the tallest bird in North America, yet not much is known about its visual ecology. How these birds overcome their unusual height to identify, locate, track, and capture prey items is not well understood. There have been many studies on head and eye stabilization in large wading birds (herons and egrets), but the pattern of head movement and stabilization during foraging is unclear. Patterns of head movement and stabilization during walking were examined in whooping cranes at Patuxent Wildlife Research Center, Laurel, Maryland USA. Four whooping cranes (1 male and 3 females) were videotaped for this study. All birds were already acclimated to the presence of people and to food rewards. Whooping cranes were videotaped using both digital and Hi-8 Sony video cameras (Sony Corporation, 7-35 Kitashinagawa, 6-Chome, Shinagawa-ku, Tokyo, Japan), placed on a tripod and set at bird height in the cranes' home pens. The cranes were videotaped repeatedly, at different locations in the pens and while walking (or running) at different speeds. Rewards (meal worms, smelt, crickets and corn) were used to entice the cranes to walk across the camera's view plane. The resulting videotape was analyzed at the University of Maryland at Baltimore County. Briefly, we used a computerized reduced graphic model of a crane superimposed over each frame of analyzed tape segments by means of a custom written program (T. W. Cronin, using C++) with the ability to combine video and computer graphic input. The speed of the birds in analyzed segments ranged from 0.30 m/s to 2.64 m/s, and the proportion of time the head was stabilized ranged from 79% to 0%, respectively. The speed at which the proportion reached 0% was 1.83 m/s. The analyses suggest that the proportion of time the head is stable decreases as speed of the bird increases. In all cases, birds were able to reach their target prey with little difficulty. Thus when cranes are walking searching for food

  5. The Head-Injured College Student.

    ERIC Educational Resources Information Center

    Holmes, Cooper B.

    Intended for use by professionals as well as head-injured college students and their families, the text provides basic information about head injuries, brain anatomy, the effects of injury to the various areas of the brain, and the major factors in recovery and rehabilitation. It examines the viability of college attendance for the head-injured…

  6. Combustor with non-circular head end

    SciTech Connect

    Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-29

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end.

  7. Headsup: New Directions for Department Heads.

    ERIC Educational Resources Information Center

    Midwood, Dale; Hillier, Dudley

    This resource booklet attempts to describe the new directions of the department head role. In a recent study by Kenneth Leithwood, "The Secondary School Department Head," 1987, department heads identified democratic decision-making, human relations, planning for program and staff development, and teacher supervision as functions crucial to the…

  8. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  9. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  10. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  11. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  12. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  13. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  14. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  15. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  16. 31 CFR 0.106 - Bureau Heads.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... explanation of the applicable post-employment restrictions contained in 18 U.S.C. 207 and 5 CFR part 2641 and... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Bureau Heads. 0.106 Section 0.106... RULES OF CONDUCT General Provisions Responsibilities § 0.106 Bureau Heads. Bureau heads or designees...

  17. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  18. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  19. 31 CFR 0.106 - Bureau Heads.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... explanation of the applicable post-employment restrictions contained in 18 U.S.C. 207 and 5 CFR part 2641 and... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Bureau Heads. 0.106 Section 0.106... RULES OF CONDUCT General Provisions Responsibilities § 0.106 Bureau Heads. Bureau heads or designees...

  20. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  1. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  2. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  3. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  4. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  5. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  6. 31 CFR 0.106 - Bureau Heads.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... explanation of the applicable post-employment restrictions contained in 18 U.S.C. 207 and 5 CFR part 2641 and... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Bureau Heads. 0.106 Section 0.106... RULES OF CONDUCT General Provisions Responsibilities § 0.106 Bureau Heads. Bureau heads or designees...

  7. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  8. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  9. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  10. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  11. A MRI rotary phased array head coil.

    PubMed

    Li, Bing Keong; Weber, Ewald; Crozier, Stuart

    2013-08-01

    A new rotary phased array (RPA) head coil that can provide homogenous brain images comparable to volumetric radiofrequency coils is proposed for magnetic resonance brain imaging applications. The design of the RPA head coil is a departure from conventional circumferential array design method, as coil elements of the RPA head coil have a "paddle-like" structure consisting of a pair of main conductors located on opposite sides, inserted equi-angularly around and over the head. A prototype 2T receive-only 4-element RPA head coil was constructed and experimentally tested against a conventional receive-only 4-element phased array head coil and a commercial receive-only quadrature birdcage head coil. Homogenous phantom images acquired by the RPA head coil show that signal intensity deep at the center of the phantom was improved as compared to the conventional phased array head coil and this improvement allow the RPA head coil to acquire homogenous brain images similar to brain images acquired with the birdcage head coil. In addition, partial parallel imaging was used in conjunction with the RPA head coil to enable rapid imaging.

  12. Alaska Head Start Annual Program Report, 1999.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education and Early Devolopment, Juneau. Head Start State Collaboration Office.

    This annual report details the accomplishments of the Alaska Head Start Program for fiscal year 1999. The report begins with a description of the Head Start program and its core values, and delineates the administrative and program partners of Head Start, its service population, eligibility requirements, funding sources, service models, and…

  13. Alaska Head Start. Annual Report for 1998.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Community and Regional Affairs, Juneau.

    This annual report details the accomplishments of the Alaska Head Start Program for fiscal year 1998. The report begins with a graphic presentation of the locations of Alaska Head Start programs and a table delineating the administrative and program partners of Head Start, its service population, eligibility requirements, funding sources, service…

  14. Tools and methods for automated assembly of miniaturized gear systems

    NASA Astrophysics Data System (ADS)

    Nienhaus, Matthias; Ehrfeld, Wolfgang; Berg, Udo; Schmitz, Felix; Soultan, H.

    2000-10-01

    The assembly of gear systems with the size of a pin head is almost beyond the bound of human tactile skills. The magic formula for series fabrication of this hybrid micro systems is the automation of the assembly process. As a contribution, this paper presents and discusses three different assembly methods comprising specifically developed tools for different types of planetary gears with outer diameters of 1.9 mm. Because of the huge importance for the complete micro assembly process, particular attention will be dedicated to the feeding and magazining of the micro gear components. Starting with metallic gear wheels as bulk good, an extremely miniaturized gear system of the Wolfram type has been automatically assembled by employing the strategy of tolerance compensation movement. As a key component, a modular tong gripper with specifically adapted gripping jaws produced by LIGA technology has been used. Further detailed investigations were spend on handling and assembly of micro injection moulded gear wheels made of POM for a three state planetary gear system. One strategy, following the idea of in situ observation, focuses on the intensive use of electronic pattern recognition. Alternatively, an unusual method based on a novel plastic wafer magazine will be discussed in detail. Hereby the exact position and orientation of injection moulded micro components will be presented from the manufacturing process up to the final micro assembly procedure. By simplifying the moulding of the micro gears as well as their handling, storing and assembly, this method has the potential to revolutionize the series fabrication of products with dimensions in the microscopic range in general.

  15. High head hydro powerplant evaluation

    SciTech Connect

    Gordon, J.L.; Helwig, P.C.; Sturge, L.G.

    1986-12-01

    When the head on a hydroelectric powerplant is between about 250-700 m (800-2,300 ft) the turbine can be either an impulse or reaction Francis unit. For each type of unit the operating characteristics and design of the powerplant will be substantially different. This paper outlines a comparison of the two types of powerplant, which was undertaken for the 136 MW Cat Arm Development in Newfoundland, where a gross head of 386.5 m (1,268 ft) is harnessed. The initial cost-benefit analysis indicated that a Francis unit should be selected, but a Pelton unit was chosen, based on an analysis of the operating characteristics and other unquantifiable benefits.

  16. Head Resistance Due to Radiators

    NASA Technical Reports Server (NTRS)

    Kleinschmidt, R V; Parsons, S R

    1920-01-01

    Part 1 deals with the head resistance of a number of common types of radiator cores at different speeds in free air, as measured in the wind tunnel at the bureau of standards. This work was undertaken to determine the characteristics of various types of radiator cores, and in particular to develop the best type of radiator for airplanes. Some 25 specimens of core were tested, including practically all the general types now in use, except the flat plate type. Part 2 gives the results of wind tunnel tests of resistance on a model fuselage with a nose radiator. Part 3 presents the results of preliminary tests of head resistance of a radiator enclosed in a streamlined casing. Special attention is given to the value of wing radiator and of the radiator located in the open, especially when it is provided with a properly designed streamlined casing.

  17. Tape/head interface study

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Existing high energy tapes, high track density heads, and transport guidance techniques were evaluated and characterized to enable these technologies to be employed in future spacecraft recorders with high confidence. The results of these study efforts demonstrated tracking accuracy tape and head density that will support spacecraft recorders with data rates of a minimum of 150 Mbps and storage capacities ranging from 10 to the 10th to 10 to the 11th bits. Seven high energy tapes of either .25 in width, 1.00 in width, or both, were tested. All tapes were tested at the same speed (30 ips) and the same packing density (33 KBI). The performance of all 1 in tapes was considered superior.

  18. Sealed head access area enclosure

    DOEpatents

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

    A liquid-metal-cooled fast breeder power reactor is provided with a sealed head access area enclosure disposed above the reactor vessel head consisting of a plurality of prefabricated structural panels including a center panel removably sealed into position with inflatable seals, and outer panels sealed into position with semipermanent sealant joints. The sealant joints are located in the joint between the edge of the panels and the reactor containment structure and include from bottom to top an inverted U-shaped strip, a lower layer of a room temperature vulcanizing material, a separator strip defining a test space therewithin, and an upper layer of a room temperature vulcanizing material. The test space is tapped by a normally plugged passage extending to the top of the enclosure for testing the seal or introducing a buffer gas thereinto.

  19. Self-assembly of hybrid structures on nano templates

    NASA Astrophysics Data System (ADS)

    Wang, Ruomiao

    This dissertation describes the investigation on the synthesis of hybrid structures on nano-templates. Fabrication of molecular nano-patterns of organic amphiphiles (e.g. fatty acids) by self-assembly has been discussed here, and their application as templates for two-dimensional in situ synthesis of metal soap molecular pattern has been demonstrated. The synthesis of nanoparticle---nanorod hybrid structure represents another effort to achieve hybrid materials. Therefore, methods to create complex inorganic---organic nano---hybrid are provided by this work. AFM disclosed the pattern structures of the self-assembled monolayers as designed nanoscaled patterns. It is observed two pattern periodicities reflecting the head-to-head and head-to-tail molecular assembly tendencies of the fatty acids and their dependence on the molecular structure and chain length, which exhibits a linear increase in the periodicity with an increasing molecular chain length. The investigation on molecular patterns of self-assembled monolayers of metal arachidates on graphite by AFM and FTIR is described. Metal arachidate self-assemblies show similar stripe pattern and periodicities as those of arachidic acid. The monolayer structure is mainly dictated by graphite, while the type of metal ions mainly affects the domain size, shape and regularity. The results of AFM and FTIR are correlated to the Irving-Williams Series, which predicts bond strength of the metal ions to ligands. The spin coated films from binary solutions of nanoparticles and fatty acids with different chain lengths (Even number of carbon, C18--C26), have been used to study the effect of nanoparticles on self-assemble pattern of fatty acids. C18--C22 acids formed uniform nanorods attached and induced by nanoparticles, while the self-assembled stripe patterns of C24 and C26 were unaffected by the presence of nanoparticles. The nanoparticles were aligned on C26 monolayer. The seeded nucleation mechanism has been studied by AFM

  20. Hot gas engine heater head

    DOEpatents

    Berntell, John O.

    1983-01-01

    A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.