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Sample records for fr27ja10n transmission loading

  1. Split torque transmission load sharing

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Rashidi, M.; Kish, J. G.

    1992-01-01

    Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

  2. Load Distribution in Transmissions "Split"

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Delgado, Irebert R.

    1998-01-01

    The transmission system of a helicopter must meet particularly critical requirements. It must transmit engine power to the rotor, at the same time ensuring a typical speed reduction of 60 to 1. It must also be safe, reliable, light, and reach a high level of performance while, at the same time, it must produce few vibrations and little noise. Helicopter transmissions have achieved high-level performances thanks to the combination of analyses, experiments, and the application of practical field experience. However, the new generation of helicopters will require transmission systems that are even safer, lighter, less noisy, and more reliable.

  3. Effect of tornado loads on transmission lines

    SciTech Connect

    Ishac, M.F.; White, H.B.

    1995-01-01

    Of all the populated areas in Canada, southwestern Ontario has experienced the highest tornado incidence and faces the greatest tornado damage. About 1 or 2 tornadoes per 10,000 km{sup 2} can be expected there annually. The probability of a tornado strike at a given point is very small but the probability of a transmission line being crossed by a tornado is significant. The purpose of this paper is to review the literature related to tornadoes in Ontario and to investigate the effect of tornado loads on transmission lines. Based on this investigation a design basis tornado loading for transmission towers is proposed.

  4. Effect of tornado loads on transmission lines

    SciTech Connect

    Ishac, M.F.; White, H.B.

    1994-12-31

    Of all the populated areas in Canada, southwestern Ontario has experienced the highest tornado incidence and faces the greatest tornado damage. About 1 or 2 tornadoes per 10,000 km{sup 2} can be expected there annually. The probability of a tornado strike at a given point is very small but the probability of a transmission line being crossed by a tornado is significant. The purpose of this paper is to review the literature related to tornadoes in Ontario and to investigate the effect of tornado loads on transmission lines. Based on this investigation a design basis tornado loading for transmission towers is proposed.

  5. Load-resistant coaxial transmission line

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-01-03

    A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line has a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

  6. Final Project Report Load Modeling Transmission Research

    SciTech Connect

    Lesieutre, Bernard; Bravo, Richard; Yinger, Robert; Chassin, Dave; Huang, Henry; Lu, Ning; Hiskens, Ian; Venkataramanan, Giri

    2012-03-31

    The research presented in this report primarily focuses on improving power system load models to better represent their impact on system behavior. The previous standard load model fails to capture the delayed voltage recovery events that are observed in the Southwest and elsewhere. These events are attributed to stalled air conditioner units after a fault. To gain a better understanding of their role in these events and to guide modeling efforts, typical air conditioner units were testing in laboratories. Using data obtained from these extensive tests, new load models were developed to match air conditioner behavior. An air conditioner model is incorporated in the new WECC composite load model. These models are used in dynamic studies of the West and can impact power transfer limits for California. Unit-level and systemlevel solutions are proposed as potential solutions to the delayed voltage recovery problem.

  7. On dynamic loads in parallel shaft transmissions. 2: Parameter study

    NASA Technical Reports Server (NTRS)

    Lin, Edward Hsiang-Hsi; Huston, Ronald L.; Coy, John J.

    1987-01-01

    Solutions to the governing equations of a spur gear transmission model, developed in NASA TM-100180 (AVSCOM TM-87-C-2), are presented. Factors affecting the dynamic load are identified. It is found that the dynamic load increases with operating speed up to a system natural frequency. At operating speeds beyond the natural frequency the dynamic load decreases dramatically. Also. it is found that the applied load and shaft inertia have little effect on the dynamic load. Damping and friction decrease the dynamic load. Finally, tooth stiffness has a significant effect on dynamic loading; the higher the stiffness, the lower the dynamic loading. Also, the higher the stiffness the higher the rotating speed required for dynamic response.

  8. Analysis of thermally loaded transmissive optical elements

    NASA Astrophysics Data System (ADS)

    Michels, Gregory J.; Genberg, Victor L.

    2013-09-01

    The performance metrics of many optical systems are affected by temperature changes in the system through different physical phenomena. Temperature changes cause materials to expand and contract causing deformations of optical components. The resulting stress states in transmissive optics can cause refractive changes that can affect optical performance. In addition, the temperature changes themselves can cause changes in the refractive properties of transmissive optics. Complex distributions of refractive indices that relate to the thermal profile, the thermo-optic refractive index profile, within the optical media can be predicted by the finite element method. One current technique for representing such refractive index profiles is through the generation of optical path difference (OPD) maps by integration along integration paths. While computationally efficient, this method has limitations in its ability to represent the effect of the index changes for rays associated with multiple field points and multiple wavelengths. A more complete representation of the thermo-optic refractive index profile may be passed to the optical analysis software through the use of a user defined gradient index material. The interface consists of a dynamic link library (DLL) which supplies indices of refraction to a user defined gradient index lens as ray tracing calculations are being performed. The DLL obtains its refractive index description from a database derived from the thermal analysis of the optics. This process allows optical analysis software to perform accurate ray tracing for an arbitrary refractive index profile induced by changes in temperature.

  9. Active transmission isolation/rotor loads measurement system

    NASA Technical Reports Server (NTRS)

    Kenigsberg, I. J.; Defelice, J. J.

    1973-01-01

    Modifications were incorporated into a helicopter active transmission isolation system to provide the capability of utilizing the system as a rotor force measuring device. These included; (1) isolator redesign to improve operation and minimize friction, (2) installation of pressure transducers in each isolator, and (3) load cells in series with each torque restraint link. Full scale vibration tests performed during this study on a CH-53A helicopter airframe verified that these modifications do not degrade the systems wide band isolation characteristics. Bench tests performed on each isolator unit indicated that steady and transient loads can be measured to within 1 percent of applied load. Individual isolator vibratory load measurement accuracy was determined to be 4 percent. Load measurement accuracy was found to be independent of variations in all basic isolator operating characteristics. Full scale system load calibration tests on the CH-53A airframe established the feasibility of simultaneously providing wide band vibration isolation and accurate measurement of rotor loads. Principal rotor loads (lift, propulsive force, and torque) were measured to within 2 percent of applied load.

  10. Planet position errors in planetary transmission: Effect on load sharing and transmission error

    NASA Astrophysics Data System (ADS)

    Iglesias, Miguel; Fernández, Alfonso; De-Juan, Ana; Sancibrián, Ramón; García, Pablo

    2013-03-01

    In this paper an advanced model of spur gear transmissions developed by the authors is used to study the influence of carrier planet pin hole position errors on the behaviour of the transmission. The model, initially conceived for external gear modeling, has been extended with internal meshing features, and thus increasing its capabilities to include planetary transmission modeling. The new features are presented, along with the summary of the model general approach. The parameters and characteristics of the planetary transmission used in the paper are introduced. The influence of carrier planet pin hole position errors on the planet load sharing is studied, and several static cases are given as examples in order to show the ability of the model. Tangential and radial planet pin hole position errors are considered independently, and the effect of the load level is also taken into account. It is also given attention to the effect on the transmission error of the transmission. Two different configurations for the planetary transmission are used, attending to the fixed or floating condition of the sun, and the differences in terms of load sharing ratio are shown.

  11. Primary side control of load voltage for transcutaneous energy transmission.

    PubMed

    Fu, Yang; Hu, Liang; Ruan, Xiaodong; Fu, Xin

    2016-03-01

    Transcutaneous energy transmission (TET) is considered as a good way to wirelessly power the implanted devices in human bodies. The load voltage provided from the TET to the implanted device should be kept stable to ensure the device working well, which however, is easily affected by the required power variation for different body movements and coil-couple malposition accompanying skin peristalsis. Commonly, the load voltage applied onto the device should be measured and feedback for power is regulated by implanting sensing and communication units into the body, which causes additional energy cost, increased size and weight of the implanted device. This paper takes the TET for artificial heart as an example to propose a novel primary side control method of the load voltage for TET, which does not require any additional implanted components. In the method, sensing coils are used to measure the malposition between the transmitter coil (TC) and receiver coil, and the magnitude of the TC current outside the human body. The measurement results are used to estimate the load voltage inside the body through calculation, whose value provide a base to develop a PI control system to regulate the input power of TET for the load voltage stability. The proposed method is experimentally validated on an actual TET for artificial heart by varying its load in a wide range under serious coil-couple malposition. With applying the primary side control, the variation of the load voltage is reduced to only 25 % of that without the control.

  12. Experimental Study of Split-Path Transmission Load Sharing

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Delgado, Irebert R.

    1996-01-01

    Split-path transmissions are promising, attractive alternatives to the common planetary transmissions for helicopters. The split-path design offers two parallel paths for transmitting torque from the engine to the rotor. Ideally, the transmitted torque is shared equally between the two load paths; however, because of manufacturing tolerances, the design must be sized to allow for other than equal load sharing. To study the effect of tolerances, experiments were conducted using the NASA split-path test gearbox. Two gearboxes, nominally identical except for manufacturing tolerances, were tested. The clocking angle was considered to be a design parameter and used to adjust the load sharing of an otherwise fixed design. The torque carried in each path was measured for a matrix of input torques and clocking angles. The data were used to determine the optimal value and a tolerance for the clocking angles such that the most heavily loaded split path carried no greater than 53 percent of an input shaft torque of 367 N-m. The range of clocking angles satisfying this condition was -0.0012 +/- 0.0007 rad for box 1 and -0.0023 +/- 0.0009 rad for box 2. This study indicates that split-path gearboxes can be used successfully in rotorcraft and can be manufactured with existing technology.

  13. Inefficiencies of NERC`s transmission loading relief procedures

    SciTech Connect

    Rajaraman, R.; Alvarado, F.L.

    1998-10-01

    The recent proposal by the North American Electric Reliability Council (NERC) for transmission loading relief (TLR) procedures is quite sensible in many ways. It correctly addresses most engineering concerns pertaining to network security. Recent events, however, have brought into question the effectiveness of the procedure, in that it appears to turn a severe localized problem into a regional one. The manner in which the procedure is framed leads to suboptimal economic solutions. Their principal concern is that the NERC procedure does not optimize costs when curtailing trades but, rather, uses an arbitrary curtailment formula. Of secondary concern is the strictly bilateral viewpoint adopted by NERC. Other concerns pertain to system operational rules explicit and implicit in the procedure. Using numerical examples, the authors show that, under transmission congestion conditions, the NERC procedure invites gaming to capture congestion rents and always discourages optimal packaged trades, almost always resulting in less efficient dispatch and higher prices. The NERC TLR procedure may have at least partially contributed to the spectacular price spikes seen in June in the Eastern Interconnection and may be responsible for higher costs to consumers under transmission congestion conditions.

  14. Load speed regulation in compliant mechanical transmission systems using feedback and feedforward control actions.

    PubMed

    Raul, P R; Dwivedula, R V; Pagilla, P R

    2016-07-01

    The problem of controlling the load speed of a mechanical transmission system consisting of a belt-pulley and gear-pair is considered. The system is modeled as two inertia (motor and load) connected by a compliant transmission. If the transmission is assumed to be rigid, then using either the motor or load speed feedback provides the same result. However, with transmission compliance, due to belts or long shafts, the stability characteristics and performance of the closed-loop system are quite different when either motor or load speed feedback is employed. We investigate motor and load speed feedback schemes by utilizing the singular perturbation method. We propose and discuss a control scheme that utilizes both motor and load speed feedback, and design an adaptive feedforward action to reject load torque disturbances. The control algorithms are implemented on an experimental platform that is typically used in roll-to-roll manufacturing and results are shown and discussed.

  15. On dynamic loads in parallel shaft transmissions. 1: Modelling and analysis

    NASA Technical Reports Server (NTRS)

    Lin, Edward Hsiang-Hsi; Huston, Ronald L.; Coy, John J.

    1987-01-01

    A model of a simple parallel-shaft, spur-gear transmission is presented. The model is developed to simulate dynamic loads in power transmissions. Factors affecting these loads are identified. Included are shaft stiffness, local compliance due to contact stress, load sharing, and friction. Governing differential equations are developed and a solution procedure is outlined. A parameter study of the solutions is presented in NASA TM-100181 (AVSCOM TM-87-C-3).

  16. Load transmission through ice rubble on the Gulf Molikpaq

    SciTech Connect

    Timco, G.W. )

    1993-11-01

    A test program has been performed in an ice modeling basin to measure the load apportioning through ice rubble around Gulf's Molikpaq, a steel caisson offshore structure. A model of the Molikpaq and its supporting submarine berm was built at a 1:75 scale. The Molikpaq and berm were instrumented independently, so the load apportioning could be determined. Thirty-six ice-loading events, including rubble formation from level ice as well as impacts through the rubble by extreme ice features, were analyzed. The results of the tests show that the ice rubble can deform and transmit load to the structure at force levels well below those predicted by a rigid-body analysis of the rubble.

  17. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs

    PubMed Central

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network. PMID:26571042

  18. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    PubMed

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

  19. Impacts of Climate Change on Electric Transmission Capacity and Peak Electricity Load in the United States

    NASA Astrophysics Data System (ADS)

    Chester, M.; Bartos, M. D.; Eisenberg, D. A.; Gorman, B.; Johnson, N.

    2015-12-01

    Climate change may hinder future electricity reliability by reducing electric transmission capacity while simultaneously increasing electricity demand. This study estimates potential climate impacts to electric transmission capacity and peak electricity load in the United States. Electric power cables suffer decreased transmission capacity as they get hotter; similarly, during the summer peak period, electricity demand typically increases with hotter ambient air temperatures due to increased cooling loads. As atmospheric carbon concentrations increase, higher air temperatures may strain power infrastructure by reducing transmission capacity and increasing peak electricity loads. Taken together, these coincident impacts may have unpredictable consequences for electric power reliability. We estimate the effects of climate change on both the rated capacity of transmission infrastructure and expected electricity demand for 120 electrical utilities across the United States. We estimate climate-attributable capacity reductions to transmission lines by constructing thermal models of representative conductors, then forcing these models with downscaled CMIP5 temperature projections to determine the relative change in rated ampacity over the twenty-first century. Next, we assess the impact of climate change on electricity demand by using historical relationships between ambient temperature and utility-scale summertime peak load to estimate the extent to which climate change will incur additional peak load increases. We use downscaled temperature projections from 11 CMIP5 GCM models under 3 atmospheric carbon scenarios. We find that by mid-century (2040-2060), climate change may reduce average summertime transmission capacity by 4-6% relative to the 1990-2010 reference period. At the same time, peak summertime loads may rise by roughly 2-12% on average due to increases in daily maximum air temperature. In the absence of energy efficiency gains, demand-side management programs

  20. Proposed design procedure for transmission shafting under fatigue loading

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1978-01-01

    A new standard for the design of transmission shafting is reported. Computed was the diameter of rotating solid steel shafts under combined cyclic bending and steady torsion is presented. The formula is based on an elliptical variation of endurance strength with torque exhibited by combined stress fatigue data. Fatigue factors are cited to correct specimen bending endurance strength data for use in the shaft formula. A design example illustrates how the method is to be applied.

  1. The design and analysis of single flank transmission error testor for loaded gears

    NASA Technical Reports Server (NTRS)

    Houser, D. R.; Bassett, D. E.

    1985-01-01

    Due to geometrical imperfections in gears and finite tooth stiffnesses, the motion transmitted from an input gear shaft to an output gear shaft will not have conjugate action. In order to strengthen the understanding of transmission error and to verify mathematical models of gear transmission error, a test stand that will measure the transmission error of a gear pair at operating loads, but at reduced speeds would be desirable. This document describes the design and development of a loaded transmission error tester. For a gear box with a gear ratio of one, few tooth meshing combinations will occur during a single test. In order to observe the effects of different tooth mesh combinations and to increase the ability to load test gear pairs with higher gear ratios, the system was designed around a gear box with a gear ratio of two.

  2. A Hybrid LCC-VSC HVDC Transmission System Supplying a Passive Load

    NASA Astrophysics Data System (ADS)

    Kotb, Omar

    High Voltage Direct Current (HVDC) transmission systems continue to be an excellent asset in modern power systems, mainly for their ability to overcome the problems of AC transmission, such as the interconnection of asynchronous grids, stability of long transmission lines, and use of long cables for power transmission. In the past 20 years, Voltage Source Converter (VSC)-HVDC transmission systems were developed and installed in many projects, thereby adding more operational benefits to DC transmission option, such as high controllability, ability to supply weak networks, and reduced converter reactive power demand. Nevertheless, VSC-HVDC transmission suffers from the disadvantages of high losses and cost. In this research, a hybrid HVDC employing a Line Commutated Converter (LCC) as rectifier and a VSC as inverter is used to supply a passive network through a DC cable. The hybrid system is best suited for unidirectional power transmission scenarios, such as power transmission to islands and remote load centers, where the construction of new transmission lines is prohibitively expensive. Control modes for the rectifier and inverter are selected and implemented using Proportional Integral (PI) controllers. Special control schemes are developed for abnormal operating conditions such as starting at light load and recovering from AC network faults. The system performance under steady state and transient conditions is investigated by EMTP-RV simulations. The results show the feasibility of the hybrid system.

  3. A Method to Analyze and Optimize the Load Sharing of Split Path Transmissions

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.

    1996-01-01

    Split-path transmissions are promising alternatives to the common planetary transmissions for rotorcraft. Heretofore, split-path designs proposed for or used in rotorcraft have featured load-sharing devices that add undesirable weight and complexity to the designs. A method was developed to analyze and optimize the load sharing in split-path transmissions without load-sharing devices. The method uses the clocking angle as a design parameter to optimize for equal load sharing. In addition, the clocking angle tolerance necessary to maintain acceptable load sharing can be calculated. The method evaluates the effects of gear-shaft twisting and bending, tooth bending, Hertzian deformations within bearings, and movement of bearing supports on load sharing. It was used to study the NASA split-path test gearbox and the U.S. Army's Comanche helicopter main rotor gearbox. Acceptable load sharing was found to be achievable and maintainable by using proven manufacturing processes. The analytical results compare favorably to available experimental data.

  4. The design and analysis of single flank transmission error tester for loaded gears

    NASA Technical Reports Server (NTRS)

    Bassett, Duane E.; Houser, Donald R.

    1987-01-01

    To strengthen the understanding of gear transmission error and to verify mathematical models which predict them, a test stand that will measure the transmission error of gear pairs under design loads has been investigated. While most transmission error testers have been used to test gear pairs under unloaded conditions, the goal of this report was to design and perform dynamic analysis of a unique tester with the capability of measuring the transmission error of gears under load. This test stand will have the capability to continuously load a gear pair at torques up to 16,000 in-lb at shaft speeds from 0 to 5 rpm. Error measurement will be accomplished with high resolution optical encoders and the accompanying signal processing unit from an existing unloaded transmission error tester. Input power to the test gear box will be supplied by a dc torque motor while the load will be applied with a similar torque motor. A dual input, dual output control system will regulate the speed and torque of the system. This control system's accuracy and dynamic response were analyzed and it was determined that proportional plus derivative speed control is needed in order to provide the precisely constant torque necessary for error-free measurement.

  5. Reflection and transmission properties of a metasurface composed of resonant loaded wire dipoles.

    PubMed

    Awan, Z A

    2016-05-20

    A considered metasurface is assumed to consist of a two-dimensional periodic arrangement of inductively loaded wires. The effects of incident angles and inductive loads upon equivalent surface impedance, reflection, and transmission properties of this metasurface have been investigated using numerical simulations. It is shown that at a particular frequency and angle, a metasurface can be cloaked for the incoming incident wave with nearly zero reflection. It is further studied that this approximate zero reflection is independent of the inductances of the inductively loaded wire dipoles.

  6. Dealing with periodical loads and harmonics in operational modal analysis using time-varying transmissibility functions

    NASA Astrophysics Data System (ADS)

    Weijtjens, Wout; Lataire, John; Devriendt, Christof; Guillaume, Patrick

    2014-12-01

    Periodical loads, such as waves and rotating machinery, form a problem for operational modal analysis (OMA). In OMA only the vibrations of a structure of interest are measured and little to nothing is known about the loads causing these vibrations. Therefore, it is often assumed that all dynamics in the measured data are linked to the system of interest. Periodical loads defy this assumption as their periodical behavior is often visible within the measured vibrations. As a consequence most OMA techniques falsely associate the dynamics of the periodical load with the system of interest. Without additional information about the load, one is not able to correctly differentiate between structural dynamics and the dynamics of the load. In several applications, e.g. turbines and helicopters, it was observed that because of periodical loads one was unable to correctly identify one or multiple modes. Transmissibility based OMA (TOMA) is a completely different approach to OMA. By using transmissibility functions to estimate the structural dynamics of the system of interest, all influence of the load-spectrum can be eliminated. TOMA therefore allows to identify the modal parameters without being influenced by the presence of periodical loads, such as harmonics. One of the difficulties of TOMA is that the analyst is required to find two independent datasets, each associated with a different loading condition of the system of interest. This poses a dilemma for TOMA; how can an analyst identify two different loading conditions when little is known about the loads on the system? This paper tackles that problem by assuming that the loading conditions vary continuously over time, e.g. the changing wind directions. From this assumption TOMA is developed into a time-varying framework. This development allows TOMA to not only cope with the continuously changing loading conditions. The time-varying framework also enables the identification of the modal parameters from a single dataset

  7. Code to Optimize Load Sharing of Split-Torque Transmissions Applied to the Comanche Helicopter

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Most helicopters now in service have a transmission with a planetary design. Studies have shown that some helicopters would be lighter and more reliable if they had a transmission with a split-torque design instead. However, a split-torque design has never been used by a U.S. helicopter manufacturer because there has been no proven method to ensure equal sharing of the load among the multiple load paths. The Sikorsky/Boeing team has chosen to use a split-torque transmission for the U.S. Army's Comanche helicopter, and Sikorsky Aircraft is designing and manufacturing the transmission. To help reduce the technical risk of fielding this helicopter, NASA and the Army have done the research jointly in cooperation with Sikorsky Aircraft. A theory was developed that equal load sharing could be achieved by proper configuration of the geartrain, and a computer code was completed in-house at the NASA Lewis Research Center to calculate this optimal configuration.

  8. On transmission errors and profile modifications minimising dynamic tooth loads in multi-mesh gears

    NASA Astrophysics Data System (ADS)

    Velex, Ph.; Chapron, M.; Fakhfakh, H.; Bruyère, J.; Becquerelle, S.

    2016-09-01

    A modular three-dimensional model of multi-mesh gears is used to analyse theoretically the link between dynamic mesh excitations and transmission errors. It is demonstrated that dynamic mesh forces are mostly controlled by the local transmission errors associated with each individual mesh. A design criterion is derived which can be used to define the tooth shape modifications minimising dynamic tooth loads. The results from two examples of application on idler and planetary systems prove that the proposed theory is sound and can be applied to a variety of gear geometries. Finally, the interest and limits of using transmission errors from a single pinion-gear pair in the context of multi-mesh gears are discussed.

  9. Transmission path phase compensation for gear monitoring under fluctuating load conditions

    NASA Astrophysics Data System (ADS)

    Stander, C. J.; Heyns, P. S.

    2006-10-01

    Vibration can be monitored under fluctuating load conditions if provision is made for taking into account the fluctuation in machine speed, the response amplitude modulation caused by the change in input force, and the amplitude and phase effects on the measured response from the transmission path. Methodologies have been developed to compensate for the effects of fluctuating speed and amplitude modulation. However, this article investigates the effect of the transmission path phase. This is discussed in terms of the effect this phase has on synchronous averaging. A new approach is presented to resolve the influence that the transmission path phase has on synchronous averaging. The approach is used for the experimental data measured on a helical gear test rig. A significant improvement in the rate of convergence was obtained by adopting the new approach which compensates for the phase shifting in the measured structural response. This contrasts with conventional synchronous averaging with order tracking which does not compensate for structural response phase shifting.

  10. Recent Enhancements to the NASA Langley Structural Acoustics Loads and Transmission (SALT) Facility

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.; Cabell, Randolph H.; Allen, Albert R.

    2013-01-01

    The Structural Acoustics Loads and Transmission (SALT) facility at the NASA Langley Research Center is comprised of an anechoic room and a reverberant room, and may act as a transmission loss suite when test articles are mounted in a window connecting the two rooms. In the latter configuration, the reverberant room acts as the noise source side and the anechoic room as the receiver side. The noise generation system used for qualification testing in the reverberant room was previously shown to achieve a maximum overall sound pressure level of 141 dB. This is considered to be marginally adequate for generating sound pressure levels typically required for launch vehicle payload qualification testing. Recent enhancements to the noise generation system increased the maximum overall sound pressure level to 154 dB, through the use of two airstream modulators coupled to 35 Hz and 160 Hz horns. This paper documents the acoustic performance of the enhanced noise generation system for a variety of relevant test spectra. Additionally, it demonstrates the capability of the SALT facility to conduct transmission loss and absorption testing in accordance with ASTM and ISO standards, respectively. A few examples of test capabilities are shown and include transmission loss testing of simple unstiffened and built up structures and measurement of the diffuse field absorption coefficient of a fibrous acoustic blanket.

  11. PSO for Multiobjective Economic Load Dispatch (MELD) for Minimizing Generation Cost and Transmission Losses

    NASA Astrophysics Data System (ADS)

    Jain, Narender Kumar; Nangia, Uma; Jain, Aishwary

    2016-06-01

    In this paper, multiobjective economic load dispatch (MELD) problem considering generation cost and transmission losses has been formulated using priority goal programming (PGP) technique. In this formulation, equality constraint has been considered by inclusion of penalty parameter K. It has been observed that fixing its value to 1,000 keeps the equality constraint within limits. The non-inferior set for IEEE 5, 14 and 30-bus systems has been generated by Particle Swarm Optimization (PSO) technique. The best compromise solution has been chosen as the one which gives equal percentage saving for both the objectives.

  12. Impacts of rising air temperatures on electric transmission ampacity and peak electricity load in the United States

    NASA Astrophysics Data System (ADS)

    Bartos, Matthew; Chester, Mikhail; Johnson, Nathan; Gorman, Brandon; Eisenberg, Daniel; Linkov, Igor; Bates, Matthew

    2016-11-01

    Climate change may constrain future electricity supply adequacy by reducing electric transmission capacity and increasing electricity demand. The carrying capacity of electric power cables decreases as ambient air temperatures rise; similarly, during the summer peak period, electricity loads typically increase with hotter air temperatures due to increased air conditioning usage. As atmospheric carbon concentrations increase, higher ambient air temperatures may strain power infrastructure by simultaneously reducing transmission capacity and increasing peak electricity load. We estimate the impacts of rising ambient air temperatures on electric transmission ampacity and peak per-capita electricity load for 121 planning areas in the United States using downscaled global climate model projections. Together, these planning areas account for roughly 80% of current peak summertime load. We estimate climate-attributable capacity reductions to transmission lines by constructing thermal models of representative conductors, then forcing these models with future temperature projections to determine the percent change in rated ampacity. Next, we assess the impact of climate change on electricity load by using historical relationships between ambient temperature and utility-scale summertime peak load to estimate the extent to which climate change will incur additional peak load increases. We find that by mid-century (2040-2060), increases in ambient air temperature may reduce average summertime transmission capacity by 1.9%-5.8% relative to the 1990-2010 reference period. At the same time, peak per-capita summertime loads may rise by 4.2%-15% on average due to increases in ambient air temperature. In the absence of energy efficiency gains, demand-side management programs and transmission infrastructure upgrades, these load increases have the potential to upset current assumptions about future electricity supply adequacy.

  13. Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading

    NASA Astrophysics Data System (ADS)

    Winkelmann, Karol; Jakubowska, Patrycja; Soltysik, Barbara

    2017-03-01

    The study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon is given in the form of a structural response surface (RSM methodology), approximated by an ANOVA table with directional sampling (DS) points. Four design limit states are considered: stress limit criterion for a natural load combination, criterion for an accidental combination (one-sided cable snap), vertical and horizontal translation criteria. According to these cases the HLRF reliability index β is used for structural safety assessment. The RSM approach is well suited for the analysis - it is numerically efficient, not excessively time consuming, indicating a high confidence level. Given the problem conditions, the seismic excitation is shown the sufficient trigger to the loss of load-bearing capacity or stability of the tower.

  14. Use of neural networks for the prediction of frictional drag and transmission of axial load in horizontal wellbores

    NASA Astrophysics Data System (ADS)

    Sadiq, Tanvir; Gharbi, Ridha B.; Juvkam-Wold, Hans C.

    2003-02-01

    The use of mud motors and other tools to accomplish forward motion of the bit in extended reach and horizontal wells allows avoiding large amounts of torque caused by rotation of the whole drill string. The forward motion of the drill string, however, is resisted by excessive amount of friction. In the presence of large compressive axial loads, the drill pipe or coiled tubing tends to buckle into a helix in horizontal boreholes. This causes additional frictional drag resisting the transmission of axial load (resulting from surface slack-off force) to the bit. As the magnitude of the frictional drag increases, a buckled pipe may become locked-up making it almost impossible to drill further. In case of packers, the frictional drag may inhibit the transmission of set-up load to the packer. A prior knowledge of the magnitude of frictional drag for a given axial load and radial clearance can help avoid lock-up conditions and costly failure of the tubular.In this study a neural network model, for the prediction of frictional drag and axial load transmission in horizontal wellbores, is presented. Several neural network architectures were designed and tested to obtain the most accurate prediction. After cross-validation of the Back Propagation Neural Network (BPNN) algorithm, a two-hidden layer model was chosen for simultaneous prediction of frictional drag and axial load transmission. A comparison of results obtained from BPNN and General Regression Neural Network (GRNN) algorithms is also presented.

  15. Binaural Simulation Experiments in the NASA Langley Structural Acoustics Loads and Transmission Facility

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.; Silcox, Richard (Technical Monitor)

    2001-01-01

    A location and positioning system was developed and implemented in the anechoic chamber of the Structural Acoustics Loads and Transmission (SALT) facility to accurately determine the coordinates of points in three-dimensional space. Transfer functions were measured between a shaker source at two different panel locations and the vibrational response distributed over the panel surface using a scanning laser vibrometer. The binaural simulation test matrix included test runs for several locations of the measuring microphones, various attitudes of the mannequin, two locations of the shaker excitation and three different shaker inputs including pulse, broadband random, and pseudo-random. Transfer functions, auto spectra, and coherence functions were acquired for the pseudo-random excitation. Time histories were acquired for the pulse and broadband random input to the shaker. The tests were repeated with a reflective surface installed. Binary data files were converted to universal format and archived on compact disk.

  16. Dynamic analysis of high speed gears by using loaded static transmission error

    NASA Astrophysics Data System (ADS)

    Özgüven, H. Nevzat; Houser, D. R.

    1988-08-01

    A single degree of freedom non-linear model is used for the dynamic analysis of a gear pair. Two methods are suggested and a computer program is developed for calculating the dynamic mesh and tooth forces, dynamic factors based on stresses, and dynamic transmission error from measured or calculated loaded static transmission errors. The analysis includes the effects of variable mesh stiffness and mesh damping, gear errors (pitch, profile and runout errors), profile modifications and backlash. The accuracy of the method, which includes the time variation of both mesh stiffness and damping is demonstrated with numerical examples. In the second method, which is an approximate one, the time average of the mesh stiffness is used. However, the formulation used in the approximate analysis allows for the inclusion of the excitation effect of the variable mesh stiffness. It is concluded from the comparison of the results of the two methods that the displacement excitation resulting from a variable mesh stiffness is more important than the change in system natural frequency resulting from the mesh stiffness variation. Although the theory presented is general and applicable to spur, helical and spiral bevel gears, the computer program prepared is for only spur gears.

  17. Transmission error and load distribution analysis of spur and double helical gear pairs used in a split path helicopter transmission design

    NASA Astrophysics Data System (ADS)

    Hochmann, David; Houser, Donald R.; Thomas, Jacob

    1991-05-01

    Because the reduction of gear noise in next-generation rotorcraft depends on the reduction of transmission errors, attention is presently given to the prediction of such errors and the load distributions of both a spur-gear pair and a double helical gear train used in a split-path helicopter transmission. Two cases are examined: (1) the spur gear mesh between the spur shaft and the lower spur/helical shaft, and (2) the double helical gear mesh between the lower spur/helical shaft and the output bull bear shaft.

  18. Phase-shifting real-time holographic interferometry applied to load transmission evaluation in dried human skull.

    PubMed

    Gesualdi, Marcos R R; Mori, Matsuyoshi; Muramatsu, Mikiya; Liberti, Edson A; Munin, Egberto

    2007-08-01

    Phase-shifting real-time holography with photorefractive Bi(12)SiO(20) crystal as holographic recording medium applied to load transmission evaluation and tension dissipation on a dried human skull under loading is presented. The applied loading stands as a simulation of isolated contraction (SIC) of some masticatories muscles. The four-frames phase-shifting technique and the unwrapping branch-cut technique were used to obtain the phase map. The quantitative results show the feasibility of the employed system in the study of microdisplacements in the skull structure provided by SIC.

  19. [Study on no-load running-in wear of power-shift steering transmission based on oil spectrum analysis].

    PubMed

    Li, He-yan; Wang, Li-yong; Ma, Biao; Zheng, Chang-song; Chen, Man

    2009-04-01

    The running-in process wear rule of power-shift steering transmission can be studied conveniently and timely by using spectral analysis of oil. The configuration characteristic and the running-in mechanism of power-shift steering transmission were introduced firstly in the present paper. According to the discussion of running-in wear factors such as load, rotation speed, time, oil temperature, shifting number and original concentration of running-in oil, the wear calculation mode was established. The no-load running-in experiments of two power-shift steering transmissions were done, with different rotation speed and time. Based on the spectrum analysis of experiment result, the function relation between running-in wear and the oil original concentration and running-in speed was obtained, so the no-load running-in process wear calculation mode of power-shift steering transmission was confirmed. Through the experiment of other two power-shift steering transmissions, it was validated that the Cu element concentration can be calculated accurately by the wear calculation mode, which included the parameters such as oil original concentration, running-in speed, running-in time and gear shift alternate time. So the reference to evaluate the running-in quality and to constitute running-in regulations was gained.

  20. LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring

    PubMed Central

    Tseng, Chinyang Henry

    2016-01-01

    In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee’s AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee’s routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node’s distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee’s AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV. PMID:27258297

  1. LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring.

    PubMed

    Tseng, Chinyang Henry

    2016-05-31

    In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee's AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee's routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node's distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee's AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV.

  2. Characterization of the Reverberation Chamber at the NASA Langley Structural Acoustics Loads and Transmission (SALT) Facility

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.

    2013-01-01

    In 2011 the noise generating capabilities in the reverberation chamber of the Structural Acoustic Loads and Transmission (SALT) facility at NASA Langley Research Center were enhanced with two fiberglass reinforced polyester resin exponential horns, each coupled to Wyle Acoustic Source WAS-3000 airstream modulators. This report describes the characterization of the reverberation chamber in terms of the background noise, diffusivity, sound pressure levels, the reverberation times and the related overall acoustic absorption in the empty chamber and with the acoustic horn(s) installed. The frequency range of interest includes the 80 Hz to 8000 Hz one-third octave bands. Reverberation time and sound pressure level measurements were conducted and standard deviations from the mean were computed. It was concluded that a diffuse field could be produced above the Schroeder frequency in the 400 Hz one-third octave band and higher for all applications. This frequency could be lowered by installing panel diffusers or moving vanes to improve the acoustic modal overlap in the chamber. In the 80 Hz to 400 Hz one-third octave bands a successful measurement will be dependent on the type of measurement, the test configuration, the source and microphone locations and the desired accuracy. It is recommended that qualification measurements endorsed in the International Standards be conducted for each particular application.

  3. Effect of Large Scale Transmission Limitations on Renewable Energy Load Matching for Western U.S.: Preprint

    SciTech Connect

    Diakov, V.; Short, W.; Gilchrist, B.

    2012-06-01

    Based on the available geographically dispersed data for the Western U.S. (excluding Alaska), we analyze to what extent the geographic diversity of these resources can offset their variability. Without energy storage and assuming unlimited energy flows between regions, wind and PV can meet up to 80% of loads in Western U.S. while less than 10% of the generated power is curtailed. Limiting hourly energy flows by the aggregated transmission line carrying capacities decreases the fraction of the load that can be met with wind and PV generation to approximately 70%.

  4. A compact very wideband amplifying filter based on RTD loaded composite right/left-handed transmission lines.

    PubMed

    Abu-Marasa, Mahmoud O Mahmoud; El-Khozondar, Hala Jarallah

    2015-01-01

    The composite right/left-handed (CRLH) transmission line (TL) is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. RH materials have both positive permittivity and positive permeability, and LH materials have both negative permittivity and negative permeability. This paper aims to design and analyze nonlinear CRLH-TL transmission line loaded with resonant tunneling diode (RTD). The main application of this design is a very wideband and compact filter that amplifies the travelling signal. We used OrCAD and ADS software to analyze the proposed circuit. CRLH-TL consists of a microstrip line which is loaded with complementary split-rings resonators (CSRRs), series gaps, and shunt inductor connected parallel to the RTD. The designed structure possess a wide band that ranges from 5 to 10.5 GHz and amplifies signal up to 50 %. The proposed design is of interest to microwave compact component designers.

  5. A dual-mode bandpass filter with multiple controllable transmission-zeros using T-shaped stub-loaded resonators.

    PubMed

    Yao, Zh; Wang, C; Kim, N Y

    2014-01-01

    A dual-mode broadband bandpass filter (BPF) with multiple controllable transmission-zeros using T-shaped stub-loaded resonators (TSSLRs) is presented. Due to the symmetrical plane, the odd-even-mode theory can be adopted to characterize the BPF. The proposed filter consists of a dual-mode TSSLR and two modified feed-lines, which introduce two capacitive and inductive source-load (S-L) couplings. Five controllable transmission zeros (TZs) can be achieved for the high selectivity and the wide stopband because of the tunable amount of coupling capacitance and inductance. The center frequency of the proposed BPF is 5.8 GHz, with a 3 dB fraction bandwidth of 8.9%. The measured insertion and return losses are 1.75 and 28.18 dB, respectively. A compact size and second harmonic frequency suppression can be obtained by the proposed BPF with S-L couplings.

  6. Evaluation of the lubrication properties of biodegradable fluids and their potential to replace mineral oil in heavily loaded hydrostatic transmissions

    SciTech Connect

    Feldmann, D.G.; Hinrichs, J.

    1997-12-31

    Increasing public interest in the environmental impact of technical machinery has led to the development of new hydraulic fluids. In case of leakage these fluids pose less of an environmental threat than mineral oil, because they degrade faster and are less toxic or non-toxic. The following paper describes methods and results of laboratory tests with these new, so called biodegradable fluids, in a hydrostatic transmission on a flywheel testing under high load conditions.

  7. 75 FR 4375 - Transmission Loading Relief Reliability Standard and Curtailment Priorities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... forma open access transmission tariff, particularly sections 13.6 and 14.7. DATES: Comments are due 60... electronically using word processing software should be filed in native applications or print-to-PDF format and... curtailment priorities in Commission-approved Open Access Transmission Tariffs (OATT). The Commission...

  8. The Reusable Load Cell with Protection Applied for Online Monitoring of Overhead Transmission Lines Based on Fiber Bragg Grating

    PubMed Central

    Ma, Guoming; Mao, Naiqiang; Li, Yabo; Jiang, Jun; Zhou, Hongyang; Li, Chengrong

    2016-01-01

    Heavy ice coating of high–voltage overhead transmission lines may lead to conductor breakage and tower collapse causing the unexpected interrupt of power supply. The optical load cell applied in ice monitoring systems is immune to electromagnetic interference and has no need of a power supply on site. Therefore, it has become a hot research topic in China and other countries. In this paper, to solve the problem of eccentric load in measurement, we adopt the shearing structure with additional grooves to improve the strain distribution and acquire good repeatability. Then, the fiber Bragg grating (FBG) with a permanent weldable package are mounted onto the front/rear groove of the elastic element by spot welding, the direction deviation of FBGs is 90° from each other to achieve temperature compensation without an extra FBG. After that, protection parts are designed to guarantee high sensitivity for a light load condition and industrial safety under a heavy load up to 65 kN. The results of tension experiments indicate that the sensitivity and resolution of the load cell is 0.1285 pm/N and 7.782 N in the conventional measuring range (0–10 kN). Heavy load tension experiments prove that the protection structure works and the sensitivity and resolution are not changed after several high load (65 kN) cycles. In addition, the experiment shows that the resolution of the sensor is 87.79 N in the large load range, allowing the parameter to be used in heavy icing monitoring. PMID:27338403

  9. The Reusable Load Cell with Protection Applied for Online Monitoring of Overhead Transmission Lines Based on Fiber Bragg Grating.

    PubMed

    Ma, Guoming; Mao, Naiqiang; Li, Yabo; Jiang, Jun; Zhou, Hongyang; Li, Chengrong

    2016-06-21

    Heavy ice coating of high-voltage overhead transmission lines may lead to conductor breakage and tower collapse causing the unexpected interrupt of power supply. The optical load cell applied in ice monitoring systems is immune to electromagnetic interference and has no need of a power supply on site. Therefore, it has become a hot research topic in China and other countries. In this paper, to solve the problem of eccentric load in measurement, we adopt the shearing structure with additional grooves to improve the strain distribution and acquire good repeatability. Then, the fiber Bragg grating (FBG) with a permanent weldable package are mounted onto the front/rear groove of the elastic element by spot welding, the direction deviation of FBGs is 90° from each other to achieve temperature compensation without an extra FBG. After that, protection parts are designed to guarantee high sensitivity for a light load condition and industrial safety under a heavy load up to 65 kN. The results of tension experiments indicate that the sensitivity and resolution of the load cell is 0.1285 pm/N and 7.782 N in the conventional measuring range (0-10 kN). Heavy load tension experiments prove that the protection structure works and the sensitivity and resolution are not changed after several high load (65 kN) cycles. In addition, the experiment shows that the resolution of the sensor is 87.79 N in the large load range, allowing the parameter to be used in heavy icing monitoring.

  10. Frequency Selective Properties of Coaxial Transmission Lines Loaded with Combined Artificial Inclusions

    PubMed Central

    2014-01-01

    The properties of a modified coaxial transmission line by periodic inclusions will be discussed. The introduction of split ring resonators, conductor stubs, air gaps, and combination of these gives rise to new frequency selective properties, such as stopband or passband behavior, observable in planar as well as volumetric metamaterial structures. These results envisage new potential applications and implementation of devices in coaxial transmission line technology. PMID:24587748

  11. Frequency selective properties of coaxial transmission lines loaded with combined artificial inclusions.

    PubMed

    Falcone, Francisco; Gil, Javier

    2014-01-01

    The properties of a modified coaxial transmission line by periodic inclusions will be discussed. The introduction of split ring resonators, conductor stubs, air gaps, and combination of these gives rise to new frequency selective properties, such as stopband or passband behavior, observable in planar as well as volumetric metamaterial structures. These results envisage new potential applications and implementation of devices in coaxial transmission line technology.

  12. Transmission

    SciTech Connect

    Sugano, K.

    1988-12-27

    A transmission is described which consists of: an input shaft; an output shaft; a first planetary gear set including a first sun gear selectively connectable by a first clutch to the input shaft, a first carrier selectively connectable by a second clutch to the input shaft and a first ring gear connected to the output shaft. The first sun gear selectively held stationary by a first brake, the first carrier is allowed to rotate in the same forward direction as the input shaft when the second clutch is engaged, but prevented from rotating in a reverse direction opposite to the forward direction by a first one-way clutch, the first carrier being selectively held stationary by a second brake; a second planetary gear set including a second sun gear connected to the input shaft, a second carrier connected to the first ring gear and also the the output shaft, and a second ring gear.

  13. A Dual-Mode Bandpass Filter with Multiple Controllable Transmission-Zeros Using T-Shaped Stub-Loaded Resonators

    PubMed Central

    Yao, Zh.; Wang, C.; Kim, N. Y.

    2014-01-01

    A dual-mode broadband bandpass filter (BPF) with multiple controllable transmission-zeros using T-shaped stub-loaded resonators (TSSLRs) is presented. Due to the symmetrical plane, the odd-even-mode theory can be adopted to characterize the BPF. The proposed filter consists of a dual-mode TSSLR and two modified feed-lines, which introduce two capacitive and inductive source-load (S-L) couplings. Five controllable transmission zeros (TZs) can be achieved for the high selectivity and the wide stopband because of the tunable amount of coupling capacitance and inductance. The center frequency of the proposed BPF is 5.8 GHz, with a 3 dB fraction bandwidth of 8.9%. The measured insertion and return losses are 1.75 and 28.18 dB, respectively. A compact size and second harmonic frequency suppression can be obtained by the proposed BPF with S-L couplings. PMID:24688406

  14. Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking.

    PubMed

    Lucas-Cuevas, Angel G; Pérez-Soriano, Pedro; Bush, Michael; Crossman, Aaron; Llana, Salvador; Cortell-Tormo, Juan M; Pérez-Turpin, José A

    2013-01-01

    It is well established nowadays the benefits that physical activity can have on the health of individuals. Walking is considered a fundamental method of movement and using a backpack is a common and economical manner of carrying load weight. Nevertheless, the shock wave produced by the impact forces when carrying a backpack can have detrimental effects on health status. Therefore, the aim of this study was to investigate differences in the accelerations placed on males and females whilst carrying different loads when walking. Twenty nine sports science students (16 males and 13 females) participated in the study under 3 different conditions: no weight, 10% and 20% body weight (BW) added in a backpack. Accelerometers were attached to the right shank and the centre of the forehead. Results showed that males have lower accelerations than females both in the head (2.62 ± 0.43G compared to 2.83 + 0.47G) and shank (1.37 ± 0.14G compared to 1.52 ± 0.15G; p<0.01). Accelerations for males and females were consistent throughout each backpack condition (p>0.05). The body acts as a natural shock absorber, reducing the amount of force that transmits through the body between the foot (impact point) and head. Anthropometric and body mass distribution differences between males and females may result in women receiving greater impact acceleration compared to men when the same load is carried.

  15. Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking

    PubMed Central

    Lucas-Cuevas, Angel G.; Pérez-Soriano, Pedro; Bush, Michael; Crossman, Aaron; Llana, Salvador; Cortell-Tormo, Juan M.; Pérez-Turpin, José A.

    It is well established nowadays the benefits that physical activity can have on the health of individuals. Walking is considered a fundamental method of movement and using a backpack is a common and economical manner of carrying load weight. Nevertheless, the shock wave produced by the impact forces when carrying a backpack can have detrimental effects on health status. Therefore, the aim of this study was to investigate differences in the accelerations placed on males and females whilst carrying different loads when walking. Twenty nine sports science students (16 males and 13 females) participated in the study under 3 different conditions: no weight, 10% and 20% body weight (BW) added in a backpack. Accelerometers were attached to the right shank and the centre of the forehead. Results showed that males have lower accelerations than females both in the head (2.62 ± 0.43G compared to 2.83 + 0.47G) and shank (1.37 ± 0.14G compared to 1.52 ± 0.15G; p<0.01). Accelerations for males and females were consistent throughout each backpack condition (p>0.05). The body acts as a natural shock absorber, reducing the amount of force that transmits through the body between the foot (impact point) and head. Anthropometric and body mass distribution differences between males and females may result in women receiving greater impact acceleration compared to men when the same load is carried. PMID:24146708

  16. Hybrid Dielectric-loaded Nanoridge Plasmonic Waveguide for Low-Loss Light Transmission at the Subwavelength Scale

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Bian, Yusheng; Ren, Liqiang; Guo, Feng; Tang, Shi-Yang; Mao, Zhangming; Liu, Xiaomin; Sun, Jinju; Gong, Jianying; Guo, Xiasheng; Huang, Tony Jun

    2017-01-01

    The emerging development of the hybrid plasmonic waveguide has recently received significant attention owing to its remarkable capability of enabling subwavelength field confinement and great transmission distance. Here we report a guiding approach that integrates hybrid plasmon polariton with dielectric-loaded plasmonic waveguiding. By introducing a deep-subwavelength dielectric ridge between a dielectric slab and a metallic substrate, a hybrid dielectric-loaded nanoridge plasmonic waveguide is formed. The waveguide features lower propagation loss than its conventional hybrid waveguiding counterpart, while maintaining strong optical confinement at telecommunication wavelengths. Through systematic structural parameter tuning, we realize an efficient balance between confinement and attenuation of the fundamental hybrid mode, and we demonstrate the tolerance of its properties despite fabrication imperfections. Furthermore, we show that the waveguide concept can be extended to other metal/dielectric composites as well, including metal-insulator-metal and insulator-metal-insulator configurations. Our hybrid dielectric-loaded nanoridge plasmonic platform may serve as a fundamental building block for various functional photonic components and be used in applications such as sensing, nanofocusing, and nanolasing.

  17. Hybrid Dielectric-loaded Nanoridge Plasmonic Waveguide for Low-Loss Light Transmission at the Subwavelength Scale

    PubMed Central

    Zhang, Bin; Bian, Yusheng; Ren, Liqiang; Guo, Feng; Tang, Shi-Yang; Mao, Zhangming; Liu, Xiaomin; Sun, Jinju; Gong, Jianying; Guo, Xiasheng; Huang, Tony Jun

    2017-01-01

    The emerging development of the hybrid plasmonic waveguide has recently received significant attention owing to its remarkable capability of enabling subwavelength field confinement and great transmission distance. Here we report a guiding approach that integrates hybrid plasmon polariton with dielectric-loaded plasmonic waveguiding. By introducing a deep-subwavelength dielectric ridge between a dielectric slab and a metallic substrate, a hybrid dielectric-loaded nanoridge plasmonic waveguide is formed. The waveguide features lower propagation loss than its conventional hybrid waveguiding counterpart, while maintaining strong optical confinement at telecommunication wavelengths. Through systematic structural parameter tuning, we realize an efficient balance between confinement and attenuation of the fundamental hybrid mode, and we demonstrate the tolerance of its properties despite fabrication imperfections. Furthermore, we show that the waveguide concept can be extended to other metal/dielectric composites as well, including metal-insulator-metal and insulator-metal-insulator configurations. Our hybrid dielectric-loaded nanoridge plasmonic platform may serve as a fundamental building block for various functional photonic components and be used in applications such as sensing, nanofocusing, and nanolasing. PMID:28091583

  18. Hybrid Dielectric-loaded Nanoridge Plasmonic Waveguide for Low-Loss Light Transmission at the Subwavelength Scale.

    PubMed

    Zhang, Bin; Bian, Yusheng; Ren, Liqiang; Guo, Feng; Tang, Shi-Yang; Mao, Zhangming; Liu, Xiaomin; Sun, Jinju; Gong, Jianying; Guo, Xiasheng; Huang, Tony Jun

    2017-01-16

    The emerging development of the hybrid plasmonic waveguide has recently received significant attention owing to its remarkable capability of enabling subwavelength field confinement and great transmission distance. Here we report a guiding approach that integrates hybrid plasmon polariton with dielectric-loaded plasmonic waveguiding. By introducing a deep-subwavelength dielectric ridge between a dielectric slab and a metallic substrate, a hybrid dielectric-loaded nanoridge plasmonic waveguide is formed. The waveguide features lower propagation loss than its conventional hybrid waveguiding counterpart, while maintaining strong optical confinement at telecommunication wavelengths. Through systematic structural parameter tuning, we realize an efficient balance between confinement and attenuation of the fundamental hybrid mode, and we demonstrate the tolerance of its properties despite fabrication imperfections. Furthermore, we show that the waveguide concept can be extended to other metal/dielectric composites as well, including metal-insulator-metal and insulator-metal-insulator configurations. Our hybrid dielectric-loaded nanoridge plasmonic platform may serve as a fundamental building block for various functional photonic components and be used in applications such as sensing, nanofocusing, and nanolasing.

  19. “Computerized Counseling Reduces HIV-1 Viral Load and Sexual Transmission Risk: Findings from a Randomized Controlled Trial”

    PubMed Central

    KURTH, Ann E.; SPIELBERG, Freya; CLELAND, Charles M.; LAMBDIN, Barrot; BANGSBERG, David R.; FRICK, Pamela A.; SEVERYNEN, Anneleen O.; CLAUSEN, Marc; NORMAN, Robert G.; LOCKHART, David; SIMONI, Jane M.; HOLMES, King K.

    2014-01-01

    Objective Evaluate a computerized intervention supporting antiretroviral therapy (ART) adherence and HIV transmission prevention. Design Longitudinal RCT. Settings An academic HIV clinic and a community-based organization in Seattle. Subjects 240 HIV-positive adults on ART; 209 completed nine-month follow-up (87% retention). Intervention Randomization to computerized counseling or assessment-only, 4 sessions over 9 months. Main Outcome Measures HIV-1 viral suppression, and self-reported ART adherence, and transmission risks, compared using generalized estimating equations. Results Overall, intervention participants had reduced viral load (VL): mean 0.17 log10 decline, versus 0.13 increase in controls, p = 0.053, and significant difference in ART adherence baseline to 9 months (p = 0.046). Their sexual transmission risk behaviors decreased (OR = 0.55, p = 0.020), a reduction not seen among controls (OR = 1.1, p = 0.664), and a significant difference in change (p = 0.040). Intervention effect was driven by those most in need: among those with detectable virus at baseline (>30 copies/milliliter, n=89), intervention effect was mean 0.60 log10 VL decline versus 0.15 increase in controls, p=0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, p = 0.038. Conclusions Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior. PMID:24384803

  20. Oscillations in Josephson transmission line stimulated by load in the presence of noise

    NASA Astrophysics Data System (ADS)

    Pankratov, A. L.; Pankratova, E. V.; Shamporov, V. A.; Shitov, S. V.

    2017-03-01

    The joint action of the matching to a common RC-load and thermal noise on the spectral properties of parallel Josephson junction array is studied. It is demonstrated that proper matching suppresses the chaotic dynamics of the system. The efficiency of radiation is found to be highest within a limited frequency band, which corresponds to transformation of the shuttle soliton oscillating regime into the linear wave resonance synchronization mode. In this frequency band the spectral linewidth agrees well with a double of the linewidth for a shuttle fluxon oscillator, divided by a number of the oscillators in the array. When the oscillations demonstrate strong amplitude modulation, the linewidth increases roughly by a factor of five compared with theoretical linewidth formula.

  1. Experimental and theoretical verification of focusing in a large, periodically loaded transmission line negative refractive index metamaterial.

    PubMed

    Iyer, Ashwin; Kremer, Peter; Eleftheriades, George

    2003-04-07

    We have previously shown that a new class of Negative Refractive Index (NRI) metamaterials can be constructed by periodically loading a host transmission line medium with inductors and capacitors in a dual (high-pass) configuration. A small planar NRI lens interfaced with a Positive Refractive Index (PRI) parallel-plate waveguide recently succeeded in demonstrating focusing of cylindrical waves. In this paper, we present theoretical and experimental data describing the focusing and dispersion characteristics of a significantly improved device that exhibits minimal edge effects, a larger NRI region permitting precise extraction of dispersion data, and a PRI region consisting of a microstrip grid, over which the fields may be observed. The experimentally obtained dispersion data exhibits excellent agreement with the theory predicted by periodic analysis, and depicts an extremely broadband region from 960MHz to 2.5GHz over which the refractive index remains negative. At the frequency at which the theory predicts a relative refractive index of -1, the measured field distribution shows a focal spot with a maximum beam width under one-half of a guide wavelength. These results are compared with field distributions obtained through mathematical simulations based on the plane-wave expansion technique, and exhibit a qualitative correspondence. The success of this experiment attests to the repeatability of the original experiment and affirms the viability of the transmission line approach to the design of NRI metamaterials.

  2. Material selection of a ferrimagnetic loaded coaxial delay line for phasing gyromagnetic nonlinear transmission lines.

    PubMed

    Johnson, J M; Reale, D V; Cravey, W H; Garcia, R S; Barnett, D H; Neuber, A A; Dickens, J C; Mankowski, J J

    2015-08-01

    Implementing nonlinear transmission line (NLTL) technology in the design of a high power microwave source has the benefits of producing a comparatively small and lightweight solid-state system where the emission frequency is easily tuned. Usually, smaller in physical size, single NLTLs may produce significantly less power than its vacuum based counterparts. However, combining individual NLTL outputs electrically or in free-space is an attractive solution to achieve greater output power. This paper discusses a method for aligning a four element NLTL antenna array with coaxial geometry using easily adjustable temporal delay lines. These delay lines, sometimes referred to as pulse shock lines or pulse sharpening lines, are placed serially in front of the main NLTL line. The propagation velocity in each delay line is set by the voltage amplitude of an incident pulse as well as the magnetic field bias. Each is adjustable although for the system described in this paper, the voltage is held constant while the bias is changed through applying an external DC magnetic field of varying magnitude. Three different ferrimagnetic materials are placed in the temporal delay line to evaluate which yields the greatest range of electrical delay with the least amount of variability from consecutive shots.

  3. Evidence against proteoglycan mediated collagen fibril load transmission and dynamic viscoelasticity in tendon.

    PubMed

    Fessel, Gion; Snedeker, Jess G

    2009-10-01

    The glycosaminoglycan (GAG) dermatan sulfate and chondroitin sulfate side-chains of small leucine-rich proteoglycans have been increasingly posited to act as molecular cross links between adjacent collagen fibrils and to directly contribute to tendon elasticity. GAGs have also been implicated in tendon viscoelasticity, supposedly affecting frictional loss during elongation or fluid flow through the extra cellular matrix. The current study sought to systematically test these theories of tendon structure-function by investigating the mechanical repercussions of enzymatic depletion of GAG complexes by chondroitinase ABC in a reproducible tendon structure-function model (rat tail tendon fascicles). The extent of GAG removal (at least 93%) was verified by relevant spectrophotometric assays and transmission electron microscopy. Dynamic viscoelastic tensile tests on GAG depleted rat tail tendon fascicle were not mechanically different from controls in storage modulus (elastic behavior) over a wide range of strain-rates (0.05, 0.5, and 5% change in length per second) in either the linear or nonlinear regions of the material curve. Loss modulus (viscoelastic behavior) was only affected in the nonlinear region at the highest strain-rate, and even this effect was marginal (19% increased loss modulus, p=0.035). Thus glycosaminoglycan chains of small leucine-rich proteoglycans do not appear to mediate dynamic elastic behavior nor do they appear to regulate the dynamic viscoelastic properties in rat tail tendon fascicles.

  4. Conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.; Yoon, Kue H.

    1984-04-10

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed perpendicular to the direction of travel of the inner conductor/insulating support assembly.

  5. The truss structure of cancellous bone. Morphological basis of the function of load transmission of the synovial joint.

    PubMed

    Wang, Y; Bi, W

    1995-01-01

    The structure of cancellous bone of synovial joints was studied under the scanning electron microscope in 4 young cadavers. It was discovered that in all specimens, the cancellous bone beneath the whole coverage of the articular cartilage had a honeycomb pattern in appearance formed by many arched trabeculae running in different directions, and that the major orientation of the arched trabeculae was toward the articular surface. The arms of one arched trabecula extended in different directions, forming the tops of other arched trabeculae; the direction of the collagen fibers conformed circumferentially with that of the arch, but the collagen fibers at the intermediate part of the common arm of the adjacent arched trabeculae crossed in a woven pattern, passing from one trabecula to another. It enables the whole end of the articular bone to have the capacity of integral deformation. That is the foundation of the character of compliance which is essential to the contact of the articular surfaces changing from incongrouity to total congrouity during normal load transmission. This special type of construction is just like the truss structure in the architectural engineering, and therefore the authors suggest to name it the "Truss Structure" of the cancellous bone. The relationship between integral deformation and the following two factors, compliance and incongrouity of the articular surface provides an explanation that the truss structure of the cancellous bone is the morphological basis of high load-bearing capacity and character of compliance of the synovial joint.

  6. Effect of cell and microvillus mechanics on the transmission of applied loads to single bonds in dynamic force spectroscopy

    NASA Astrophysics Data System (ADS)

    Gupta, V. K.; Eggleton, C. D.

    2011-07-01

    Receptor-ligand interactions that mediate cellular adhesion are often subjected to forces that regulate their detachment via modulating off-rates. Although the dynamics of detachment is primarily controlled by the physical chemistry of adhesion molecules, cellular features such as cell deformability and microvillus viscoelasticity have been shown to affect the rolling velocity of leukocytes in vitro through experiments and simulation. In this work, we demonstrate via various micromechanical models of two cells adhered by a single (intramolecular) bond that cell deformability and microvillus viscoelasticity modulate transmission of an applied external load to an intramolecular bond, and thus the dynamics of detachment. Specifically, it is demonstrated that the intermolecular bond force is not equivalent to the instantaneous applied force and that the instantaneous bond force decreases with cellular and microvillus compliance. As cellular compliance increases, not only does the time lag between the applied load and the bond force increase, an initial response time is observed during which cell deformation is observed without transfer of force to the bond. It is further demonstrated that following tether formation the instantaneous intramoleular bond force increases linearly at a rate dependent on microvillus viscosity. Monte Carlo simulations with fixed kinetic parameters predict that both cell and microvillus compliance increase the average rupture time, although the average rupture force based on bond length remains nearly unchanged.

  7. Longitudinal load and cascading failure risk assessment (CASE): Bonneville Power Administration`s 230/500-kV Longview-Olympia transmission line. Final report

    SciTech Connect

    Ostendorp, M.

    1998-12-01

    The Electric Power Research Institute`s (EPRI) Cascading Failure Risk Assessment (CASE) methodology was used to determine extreme event, unbalanced loads on Bonneville Power Administration`s (BPA) 230/500-kV, single circuit, Longview-Olympia transmission line and to identify the cascading potential of the line under five different loading conditions. More specifically, BPA wanted to evaluate the cascading potential of the Type 2L, Type 2A1, and Type 238M tangent structures which comprise a significant portion of the line. While other cascading assessment methods primarily focus on the magnitude of the unbalanced loads acting on the first structure from the initiating event, EPRI`s CASE method incorporates the dynamic response and damping characteristics of the transmission line to determine the unbalanced longitudinal loads at any structure away from the initiating failure event. The CASE application constituted an investigation into the nature of the extreme loads that are expected to occur on the 230/500-kV Longview-Olympia transmission line during a cascading failure and the corresponding dynamic response. The goals of the investigation were: to quantify unbalanced longitudinal loads acting on structures adjacent to the broken insulator, shield wire, or conductor failure as well as down-line structures; and to assess the cascading potential of the Longview-Olympia transmission line by considering the energy dissipation at successive spans and supports. The results of the CASE method showed that BPA`s longitudinal loading criteria for the Type 2L, 2A1, and 238 M lattice towers satisfy BPA`s containment failure design philosophy with the addition of fiber optic cable. BPA`s longitudinal loading criteria applied simultaneously with extreme ice or wind does not provide adequate strength to prevent a cascade of less than ten towers.

  8. Longitudinal load and cascading failure risk assessment (CASE): Tennessee Valley Authority`s 161-kV Lowndes-West Point transmission line. Final report

    SciTech Connect

    Ostendorp, M.

    1998-03-01

    The Electric Power Research Institute`s (EPRI) Cascading Failure Risk Assessment (CASE) methodology was used to determine extreme event, unbalanced loads on Tennessee Valley Authority`s (TVA) 161-kV, single circuit, Lowndes-West Point transmission line and to identify the cascading potential of the line under five different loading conditions. More specifically, TVA wanted to evaluate the cascading potential of the Type HS-1G and BHS-1G tangent structures which comprise the majority of the line. While other cascading assessment methods primarily focus on the magnitude of the unbalanced loads acting on the first structure from the initiating event, EPRI`s CASE method incorporates the dynamic response and damping characteristics of the transmission line to determine the unbalanced longitudinal loads at any structure away from the initiating failure event. The CASE application constituted an investigation into the nature of the extreme loads that are expected to occur on the 161-kV Lowndes-West Point transmission line during a cascading failure and the corresponding dynamic response. The goals of the investigation were: to quantify unbalanced longitudinal loads acting on structures adjacent to the broken insulator, shield wire, or conductor failure as well as down-line structures; to assess the cascading potential of the Lowndes-West Point transmission line by considering the energy dissipation at successive spans and supports. The results of the CASE method indicate that the lack of longitudinal strength of the Type HS-1G and BHS-1G steel pole H-frame coupled with the dynamic characteristics of the Lowndes-West Point line was likely to result in a cascading failure for the more severe initiating event and load case combinations.

  9. A graphical and analytical method to determine the transient response for an ideal transmission line, loaded by a time-varying impedance

    SciTech Connect

    Krehl, P.; Novender, W.R.

    1985-04-01

    Based on Bergeron's theory, a graphical and analytical method has been worked out to determine the dynamic load characteristic and load transients for a time-varying load impedance, pulsed by a lossless transmission line. The analytical solution has been compared with the numerical solution of the network analysis code SCEPTRE. A parametric study for a time-decreasing load function, demonstrated by the example of a vacuum-discharge flash X-ray tube, reveals that the dynamic load characteristic I /SUB L/ (U /SUB L/ (t),U/sub 0/,Z/sub 0/,T) and the transients U /SUB L/ (t,U/sub 0/,Z/sub 0/,T) and I /SUB L/ (t,U/sub 0/,Z/sub 0/,T) are dependent on the diode function Z /SUB L/ (t) as well as on the charging voltage U/sub 0/ and the characterics T and Z/sub 0/ of the line.

  10. Study on a discal TEM-TE{sub 11} mode converter loaded high-efficiency magnetically insulated transmission line oscillator

    SciTech Connect

    Zhang, Xiaoping Yuan, Chengwei; Li, Yangmei; Zhang, Jiande; Zhang, Qiang

    2015-12-15

    An integrative high power microwave device is proposed, which consists of a high-efficiency L-band Magnetically Insulated Transmission Line Oscillator (MILO) and a discal TEM–TE{sub 11} mode converter. The MILO with a shrunken load composed of a step-like cathode and a ladder-like beam collector can generate a 1.58 GHz, 5.7 GW microwave with the efficiency of 20.8% at the diode voltage of 560 kV in simulation. The discal converter utilizes a pair of sectorial two-double radial waveguides and a pair of sectorial cross section waveguides to adjust the phase-difference and realizes the mode conversion in a length of less than half wavelength at 1.58 GHz. In the preliminary experiment, the proposed device generates over 2 GW, 1.575 GHz microwave with the pulse duration of over 50 ns in a 420 kV diode voltage; the corresponding efficiency is 14.9%; the radiation pattern is the ideal TE{sub 11} mode.

  11. Automated synthesis of transmission lines loaded with complementary split ring resonators (CSRRs) and open complementary split ring resonators (OCSRRs) through aggressive space mapping (ASM)

    NASA Astrophysics Data System (ADS)

    Selga, Jordi; Rodríguez, Ana; Orellana, Marco; Boria, Vicente; Martín, Ferran

    2014-09-01

    This paper is focused on the application of space mapping optimization to the automated synthesis of transmission lines loaded with complementary split ring resonators (CSRRs) and open complementary split ring resonators (OCSRRs). These structures are of interest for the implementation of resonant-type metamaterial transmission lines and for the design of planar microwave circuits based on such complementary resonators. The paper presents a method to generate the layouts of CSRR- and OCSRR-loaded microstrip lines from the elements of their equivalent circuit models. Using the so-called aggressive space mapping, a specific implementation that uses quasi-Newton type iteration, we have developed synthesis algorithms that are able to provide the topology of these CSRR- and OCSRR-loaded lines in few steps. The most relevant aspect, however, is that this synthesis process is completely automatic, i.e., it does not require any action from the designers, other than initiating the algorithm. Moreover, this technique can be translated to other electrically small planar elements described by lumped element equivalent circuit models.

  12. A New Geometric Method Based on Two-Dimensional Transmission Electron Microscopy for Analysis of Interior versus Exterior Pd Loading on Hollow Carbon Nanofibers

    SciTech Connect

    Shuai, Danmeng; Wang, Chong M.; Genc, Arda; Werth, Charles J.

    2011-04-18

    Hallow carbon nanofibers (CNFs) are being explored as catalyst supports because of their unique properties; catalytic activities with both interior and exterior metal loadings are being evaluated. Electron tomography (3D transmission electron microscopy, 3D TEM) has been used to estimate internal versus external loading of metal nanoclusters. However, this method is time consuming and requires a specialized TEM. We prepared three hollow CNF supported Pd samples with various Pd localizations, and developed a geometric analysis method based on 2D TEM images to estimate Pd internal versus external loading percentages. Results show the similar localization for the same sample in terms of the number, surface area, and mass of Pd nanoclusters but distinct values for different samples. To test our method, we compare results for one segment of a CNF using both 3D scanning transmission electron microscopy (3D TEM) and our new 2D geometic analysis method. Agreement is within 15.1%. Our results also agree with 3D TEM results from the literature for similarly prepared Pd on CNFs (within 5.6%). Our geometric analysis method is proposed as a more straightforward and fast way to evaluate metal nanocluster localizations on tubular supports.

  13. Power flow between a plasma-opening switch and a load separated by a high-inductance magnetically insulated transmission line

    NASA Astrophysics Data System (ADS)

    Swanekamp, S. B.; Grossmann, J. M.; Ottinger, P. F.; Commisso, R. J.; Goyer, J. R.

    1994-09-01

    Results are presented from particle-in-cell simulations of the electron flow launched from a plasma opening switch (POS) into a magnetically insulated transmission line (MITL) as the POS opens. The opening process of the POS is treated by removing plasma from a fixed anode-cathode gap with an opening time of tau(sub rise). To be similar to opening switch experiments at Physics International, the simulations were performed with the same inductance L(sub MITL) between the POS and load. When L(sub MITL)/tau(sub rise) is large compared to the POS flow impedance, this inductance effectively isolates the POS from the load during the opening process and the POS voltage is insensitive to changes in the load impedance. Analysis and simulations show that the peak load power is maximized when the load impedance is equal to the POS flow impedance. In contrast to previous theories and simulations of magnetically insulated flows, a large amount of electron flow in the MITL is concentrated near the anode. This is a result of the high effective impedance imposed on the POS by the inductive load which causes a significant electron current loss in the POS. As a result, many electrons lose insulation on the load side of the POS gap and those that do flow into the MITL have been accelerated to nearly the full POS potential. Electrons then E cross B drift on equipotential lines close to the anode as they enter the MITL and flow toward the load. Current losses in the MITL are observed due to the proximity of the electron flow to the anode. Some electrons flow from the MITL directly into the load and are registered as load current while others E cross B drift back toward the POS along the cathode surface. This is possible because the electron flow launched into the MITL from the POS is large enough to cause sufficient positive image charges on the cathode so that the electric field points out of the cathode surface.

  14. The inter-relation of maternal immune competence, HIV-1 viral load, and nutritional status in preventing vertical transmission: an alternative to chemoprophylaxis?

    PubMed

    Moran, P J; Welles, S L; Williams, M A

    1998-11-01

    As the human immunodeficiency virus (HIV) global pandemic moves towards the end of its second decade, women of reproductive age throughout the world have been shown to be increasingly at risk for acquiring HIV-1 infection. Recently, the focus for preventive measures has expanded to include preventing the perinatal transmission of HIV-1 to fetuses and newborns. This manuscript reviews the available literature that examines risk factors for perinatal transmission, immunopathogenesis of HIV-1 infection, and the role that antioxidant micronutrients play in modulating immune response to HIV-1 disease progression. The available information provides a compelling case for the design of studies that evaluate the extent to which maternal HIV-1 viremia and disease progression are modulated by her nutritional status. Should results from these studies confirm that antioxidant micronutrient status is inversely related to HIV-1 RNA load, particularly in economically vulnerable populations, carefully designed and executed supplementation trials would be warranted.

  15. Polarized light transmission in ferrofluids loaded with carbon nanotubes in the presence of a uniform magnetic field

    NASA Astrophysics Data System (ADS)

    Vales-Pinzón, C.; Alvarado-Gil, J. J.; Medina-Esquivel, R.; Martínez-Torres, P.

    2014-11-01

    Magneto-optic phenomena in ferrofluids have been shown to be related to the formation of chain structures, due to the arrangement of the ferromagnetic particles, induced by an applied magnetic field. In this work, the effects on transmission of polarized light due to anisotropic effects induced by an external magnetic field in ferrofluids with carbon nanotubes are studied. The time response of the system presents two well defined stages, in the first one, which is very short, the fluid behaves as a polarizer. In contrast in the second stage, the effects of light transmission dominate. In this stage the transmitted light intensity grows with time and after a long time reaches a constant stable value. It is shown that these phenomena depend on the carbon nanotubes concentration as well as on the strength of the applied magnetic field. Using a simple model that considers a chain-like structure formation, it is possible to determine the rate of agglomeration of the formed structures and the attenuation coefficient of the transmitted light. The formation of nanostructures leads to variation in the transmitted light, depending on the polarization of the incident light. These magnetic nanostructures can find numerous applications in nanotechnology, optical devices and medicine.

  16. 3-D finite element analysis of the influence of synovial condition in sacroiliac joint on the load transmission in human pelvic system.

    PubMed

    Shi, Dufang; Wang, Fang; Wang, Dongmei; Li, Xiaoqin; Wang, Qiugen

    2014-06-01

    The anterior part of the sacroiliac joint (SIJ) is a synovial joint, with little gliding and rotary movement between the contact surfaces of SIJ during locomotion. Due to its complex structure, especially when considering the surrounding ligaments, it is difficult to construct an accurate three-dimensional (3-D) finite element model for the human pelvis. Most of the pelvic models in the previous studies were simplified with either SIJ fusing together or without the sacral bone. However, the influence of those simplifications on the load transmission in human pelvis has not been studied, so the reliability of those studies remains unclear. In this study, two 3-D pelvic models were constructed: an SIJ fusing model and an SIJ contacting model. In the SIJ fusing model, the SIJ interfaces were fused together. In the SIJ contacting model, the SIJ interfaces were just in contact with each other without fusion. Compared with the SIJ contacting model, the SIJ fusing model have smaller movements in the SIJ. The stress distribution area in the SIJ fusing model on sacroiliac cartilages was also different. Those differences contributed to the decline of tensile force in the SIJ surrounding ligaments and the re-distribution of stress in the pelvic bones. In addition, the SIJ fusing model was far less sensitive to the increase in modulus of the sacroiliac cartilages, and decrease in stiffness of the ligaments surrounding the SIJ. The presence of synovia in the SIJ had greater influence on the load transmission in the human pelvic system. Therefore, the effect of the presence of synovia should not be neglected when the biomechanical behavior of human pelvis is being studied, especially for those studies related to clinical applications.

  17. Non-binding conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    SciTech Connect

    Fischer, W.H.

    1984-04-24

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a non-binding transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement and for moving without binding along corrugations of any slope less than vertical. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed parallel to the motion of travel of the inner conductor/insulating support assembly. 7 figs.

  18. Non-binding conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.

    1984-01-01

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a non-binding transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement and for moving without binding along corrugations of any slope less than vertical. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed parallel to the motion of travel of the inner conductor/insulating support assembly.

  19. Experimental determination of blast-wave pressure loading, thermal radiation protection, and electrical transmission loss for parabolic antenna models in simulated nuclear blast environments

    SciTech Connect

    George, J.H.

    1991-01-01

    A twelve-inch-diameter parabolic antenna model instrumented with eleven differential pressure sensors was tested at the Ballistics Research Laboratory, Aberdeen Proving Ground, Maryland. Transient pressure loading was determined for 37 different antenna model angular positions with respect to the direction of the blast wave at a peak overpressure of 3.0 pounds per square inch; limited data at 4.5 and 6.0 pounds per square inch were also investigated. The first millisecond of shock-wave interaction with the antenna features the most prominent fully reversed triangular pressure pulse. A blast function, F, was developed that accurately approximates the transient behavior of the blast wave resultant force and moment loading on the antenna model. The resultant blast force on the antenna model is minimized when the axis of the paraboloid of the model is rotated 82{degree} with respect to the direction of the blast wave. Four different thermal protective coatings were tested to evaluate the effects of coating color and thickness. Transmission-loss measurements were completed on eight different quartz-polyimide antenna models coated with Caapcoat and Ocean 477 thermal protective coatings.

  20. Small passenger car transmission test: Mercury Lynx ATX transmission

    NASA Technical Reports Server (NTRS)

    Bujold, M. P.

    1981-01-01

    The testing of a Mercury Lynx automatic transmission is reported. The transmission was tested in accordance with a passenger car automatic transmission test code (SAE J65lb) which required drive performance, coast performance, and no load test conditions. Under these conditions, the transmission attained maximum efficiencies in the mid-ninety percent range both for drive performance test and coast performance tests. The torque, speed, and efficiency curves are presented, which provide the complete performance characteristics for the Mercury Lynx automatic transmission.

  1. Small passenger car transmission test: Dodge Omni A-404 transmission

    NASA Technical Reports Server (NTRS)

    Bujold, M. P.

    1980-01-01

    The small passenger car transmission test was initiated to supply electric vehicle manufacturers with technical information regarding the performance of commercially available transmissions. This transmission was tested in accordance with a passenger car automatic transmission test code (SAE J65lb) which required drive performance, coast performance, and no load test conditions. Under these test conditions, the transmission attained maximum efficiencies in the mid eighty percent range for both drive performance test and coast performance tests.

  2. Torque feedback transmission

    SciTech Connect

    Whalen, B.L.

    1987-01-20

    This patent describes an infinitely variable transmission of inline configuration for interconnecting a primer mover with a load for clutch free operation in a range of speed including hydraulic neutral comprising: a. planetary gear train means having a ring gear, planetary gears supported by a planetary gear carrier, and a sun gear, the sun gear being connected mechanically to the load, output shaft means for joining the sun gear to the load; b. variable torque feedback means comprising (i) a variable displacement hydraulic motor whose rotor shaft is in line with the output shaft means and drivingly connected to the prime mover and the planetary gear carrier during the full range of operation of the transmission, and (ii) a fixed displacement hydraulic pump connected hydraulically to the motor, the rotor shaft of the pump being connected mechanically to the ring gear and being axially displaced from the output shaft means; c. means for adjusting the displacement volume within the hydraulic motor for controlling the torque feedback in the transmission to provide infinitely variable coupling between the prime mover and the load over the full range of the transmission including hydraulic neutral; d. a speed reducer between the primer mover and the motor rotor shaft and a speed multiplier between the sun gear and the load; and e. mechanical transmission assembly means between the speed multiplier and the load in line with the motor rotor shaft and the output shaft means for providing selection of drive, reverse, park, and neutral.

  3. Study of Wireless Transmission Protocol Technology for Use in Flight Line Environment to Assist the Data Loading and Downloading on Aircraft

    DTIC Science & Technology

    2004-03-01

    light and brings this light to focus at telescope 2’s focal point . At telescope 2’s focal point , a photo detector or optical fiber is positioned to...SUBJECT TERMS IEEE 802.11b, EDNA, WLAN, FSO , Wireless Transmission Protocol, Radar Warning Receiver, Aircraft, F-16. 16. PRICE CODE 17...30 1. Access Points .......................................................................................31 2. Wireless Client

  4. Potential impact of viral load and genetic makeup of HIV type 1 on mother-to-child transmission: characterization of env-C2V3C3 and nef sequences.

    PubMed

    Pádua, Elizabeth; Parreira, Ricardo; Tendeiro, Rita; Nunes, Baltazar; Castela, João; Soares, Isabel; Mouzinho, Ana; Reis, Eduarda; Paixão, Maria Teresa

    2009-11-01

    HIV-1 mother-to-child transmission (MTCT) was evaluated in terms of the molecular characterization of the env and nef genomic regions and quantification of maternal RNA viral loads. Assignment of viral subtype was achieved by direct sequencing of PCR 1172 products amplified from proviral DNA in 45 HIV-1-nontransmitting mothers (NTM), along with 13 pairs of HIV-1-transmitting mothers (TM) and their infected children (C). Analysis of the env C2V3C3 and nef sequences revealed that subtypes G and B, and their genetic combinations (AG, BG), accounted for over 84.5% of all viruses identified. The genetic structure form envA-nefG was the most commonly observed, with a lower frequency in the NTM (13.3%) compared to the TM (23.1%) group. A greater number of genetic forms was observed among NTM, namely the presence of sequences assigned to subtypes D and F, as well as the intergenetic A/J, and C/U, recombinant forms, along with a mosaic provirus with a complex putative envA-nefEGE genetic structure. No significant differences were found when RNA viral loads were evaluated as a function of the viral subtypes. Nevertheless, a relatively high quantification of HIV-1 RNA was obtained in the NTM group, emphasizing the importance of the compliance and effectiveness of therapeutic schemes to control viral replication and reduce the risk of HIV vertical transmission. V3 sequences displaying features associated with the R5 phenotype dominated in both groups. Both C2V3C3 and Nef's functional domains were conserved during HIV-1 vertical transmission.

  5. Small passenger car transmission test; Ford C4 transmission

    NASA Technical Reports Server (NTRS)

    Bujold, M. P.

    1980-01-01

    A 1979 Ford C4 automatic transmission was tested per a passenger car automatic transmission test code (SAE J651b) which required drive performance, coast performance, and no load test conditions. Under these test conditions, the transmission attained maximum efficiencies in the mid-eighty percent range for both drive performance tests and coast performance tests. The major results of this test (torque, speed, and efficiency curves) are presented. Graphs map the complete performance characteristics for the Ford C4 transmission.

  6. Small passenger car transmission test; Chevrolet LUV transmission

    NASA Technical Reports Server (NTRS)

    Bujold, M. P.

    1980-01-01

    A 1978 Chevrolet LUV manual transmission tested per the applicable portions of a passenger car automatic transmission test code (SAE J65lb) which required drive performance, coast performance, and no load test conditions. Under these test conditions, the transmission attained maximum efficiencies in the upper ninety percent range for both drive performance tests and coast performance tests. The major results of this test (torque, speed, and efficiency curves) are presented. Graphs map the complete performance characteristics for the Chevrolet LUV transmission.

  7. Small passenger car transmission test: Mercury Lynx ATX transmission

    SciTech Connect

    Bujold, M P

    1981-09-01

    The small passenger car transmission test was initiated to supply electric vehicle manufacturers with technical information regarding the performance of commercially available transmissions. This information would enable EV manufacturers to design a more energy efficient vehicle. With this information the manufacturers would be able to estimate vehicle driving range as well as speed and torque requirements for specific road load performance characteristics. This report covers the 1981 Mercury Lynx ATX transaxle. This transmission was tested per a passenger car automatic transmission test code (SAE J65lb) which required drive performance, coast performance, and no load test conditions. Under these test conditions the transmission attained maximum efficiencies in the 93% range for drive performance tests. The major results of this test are the torque, speed and efficiency curves which are located in the data section of this report. These graphs map performance characteristics for the Mercury Lynx ATX transmission.

  8. Small passenger car transmission test-Chevrolet 200 transmission

    NASA Technical Reports Server (NTRS)

    Bujold, M. P.

    1980-01-01

    The small passenger car transmission was tested to supply electric vehicle manufacturers with technical information regarding the performance of commerically available transmissions which would enable them to design a more energy efficient vehicle. With this information the manufacturers could estimate vehicle driving range as well as speed and torque requirements for specific road load performance characteristics. A 1979 Chevrolet Model 200 automatic transmission was tested per a passenger car automatic transmission test code (SAE J651b) which required drive performance, coast performance, and no load test conditions. The transmission attained maximum efficiencies in the mid-eighty percent range for both drive performance tests and coast performance tests. Torque, speed and efficiency curves map the complete performance characteristics for Chevrolet Model 200 transmission.

  9. Dielectric Nonlinear Transmission Line (Postprint)

    DTIC Science & Technology

    2011-12-01

    Technical Paper 3. DATES COVERED (From - To) 2011 4. TITLE AND SUBTITLE Dielectric Nonlinear Transmission Line (POSTPRINT) 5a. CONTRACT NUMBER...14. ABSTRACT A parallel plate nonlinear transmission line (NLTL) was constructed. Periodic loading of nonlinear dielectric slabs provides the...846-9101 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. 239.18 Dielectric Nonlinear Transmission Line David M. French, Brad W. Hoff

  10. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  11. Load cell

    DOEpatents

    Spletzer, B.L.

    1998-12-15

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

  12. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  13. Elastomeric load sharing device

    NASA Technical Reports Server (NTRS)

    Isabelle, Charles J. (Inventor); Kish, Jules G. (Inventor); Stone, Robert A. (Inventor)

    1992-01-01

    An elastomeric load sharing device, interposed in combination between a driven gear and a central drive shaft to facilitate balanced torque distribution in split power transmission systems, includes a cylindrical elastomeric bearing and a plurality of elastomeric bearing pads. The elastomeric bearing and bearing pads comprise one or more layers, each layer including an elastomer having a metal backing strip secured thereto. The elastomeric bearing is configured to have a high radial stiffness and a low torsional stiffness and is operative to radially center the driven gear and to minimize torque transfer through the elastomeric bearing. The bearing pads are configured to have a low radial and torsional stiffness and a high axial stiffness and are operative to compressively transmit torque from the driven gear to the drive shaft. The elastomeric load sharing device has spring rates that compensate for mechanical deviations in the gear train assembly to provide balanced torque distribution between complementary load paths of split power transmission systems.

  14. Transmission eigenvalues

    NASA Astrophysics Data System (ADS)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  15. Automatic transmission

    SciTech Connect

    Miura, M.; Aoki, H.

    1988-02-02

    An automatic transmission is described comprising: an automatic transmission mechanism portion comprising a single planetary gear unit and a dual planetary gear unit; carriers of both of the planetary gear units that are integral with one another; an input means for inputting torque to the automatic transmission mechanism, clutches for operatively connecting predetermined ones of planetary gear elements of both of the planetary gear units to the input means and braking means for restricting the rotation of predetermined ones of planetary gear elements of both of the planetary gear units. The clutches are disposed adjacent one another at an end portion of the transmission for defining a clutch portion of the transmission; a first clutch portion which is attachable to the automatic transmission mechanism portion for comprising the clutch portion when attached thereto; a second clutch portion that is attachable to the automatic transmission mechanism portion in place of the first clutch portion for comprising the clutch portion when so attached. The first clutch portion comprising first clutch for operatively connecting the input means to a ring gear of the single planetary gear unit and a second clutch for operatively connecting the input means to a single gear of the automatic transmission mechanism portion. The second clutch portion comprising a the first clutch, the second clutch, and a third clutch for operatively connecting the input member to a ring gear of the dual planetary gear unit.

  16. AQUIFER TRANSMISSIVITY

    EPA Science Inventory

    Evaluation of groundwater resources requires the knowledge of the capacity of aquifers to store and transmit ground water. This requires estimates of key hydraulic parameters, such as the transmissivity, among others. The transmissivity T (m2/sec) is a hydrauli...

  17. Local load shedding

    SciTech Connect

    Adibi, M.M.; Thorne, D.K. )

    1988-08-01

    Equipment overloads in an underground transmission network are caused by unscheduled outages. Repairs or replacements of damaged cables and/or transformers in urban areas are inherently difficult and time-consuming. Therefore, for overloads greatly in excess of short-time ratings, speed of load shedding is of paramount importance. Under such conditions, the system operator is faced with: recognizing the problem, determining the course of action and shedding the correct amount of load at the right locations. These tasks are difficult to perform, particularly under pressure of time. Reliance on pre-specified load shedding lists is not satisfactory since the load shedding lists do not necessarily match the amounts and locations of the required loads to be shed. Clearly, there has been a need for a local load shedding scheme, which in the first order of importance, would relieve the overloaded equipment within the time limits imposed by the equipment short-time ratings and in the second order of importance, would ''minimize'' the amount of load to be curtailed. This paper describes an approach which meets the dual objective, providing a practical solution to a difficult engineering/operating problem.

  18. Power transmission

    SciTech Connect

    Yale, O.S.

    1989-12-12

    This patent describes a power transmission. It comprises: in combination, a master gear having at least one annular tooth set, means for drivingly engaging the master gear with a power source, driven shaft, a yoke member attached to the shaft and including a screw pump housing extending radially with respect to the shaft with a pair of ports in spaced relation, a pump screw rotatable in the housing and a pump gear attached to the screw and engaging the annular tooth set, and a casing for transmission fluid. The pump housing being located for immersion in the fluid.

  19. HIV Transmission

    MedlinePlus

    ... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... on HIV Syndicated Content Website Feedback HIV/AIDS HIV Transmission Language: English Transmisión del VIH Recommend on ...

  20. Rotorcraft transmission

    NASA Technical Reports Server (NTRS)

    Coy, John J.

    1987-01-01

    The NASA Lewis Research Center and the U.S. Army Aviation Systems Command share an interest in advancing the technology for helicopter propulsion systems. In particular, this presentation outlines that portion of the program that applies to the drive train and its various mechanical components. The major goals of the program are to increase the life, reliability, and maintainability; reduce the weight, noise, and vibration; and maintain the relatively high mechanical efficiency of the gear train. The current activity emphasizes noise reduction technology and analytical code development followed by experimental verification. Selected significant advances in technology for transmissions are reviewed, including advanced configurations and new analytical tools. Finally, the plan for transmission research in the future is presented.

  1. Transmission shift mechanism

    SciTech Connect

    Smith, R.R.

    1989-06-20

    This patent describes a mechanism for selecting the gear of an automatic transmission in a vehicle. The mechanism consists of: a pressure source; a gear selection valve having an inlet means for receiving fluid from the pressure source, first outlet ports, and second outlet ports; a manual override means for opening and blocking communication between the pressure source and the first ports and for simultaneously opening and blocking communication between the pressure source and the second outlet ports; a port selector means within the valve for controlling flow through the second ports, the port selector means being movable to a plurality of positions, each position permitting a selected second outlet port to open; a selector control mans for moving the port selector means from one position to another, the selector control means including a planetary gear set connected by an input shaft to the transmission and connected to a vehicle load by an output shaft, the planetary gear set having a ring gear whose angular position is a function of reaction torque imposed by the load on the output shaft, the selector control means further including an arm assembly connected between the ring gear and the port selector means so that the position of the port selector means is a function of the reaction torque on the output shaft.

  2. Automatic transmission

    SciTech Connect

    Ohkubo, M.

    1988-02-16

    An automatic transmission is described combining a stator reversing type torque converter and speed changer having first and second sun gears comprising: (a) a planetary gear train composed of first and second planetary gears sharing one planetary carrier in common; (b) a clutch and requisite brakes to control the planetary gear train; and (c) a speed-increasing or speed-decreasing mechanism is installed both in between a turbine shaft coupled to a turbine of the stator reversing type torque converter and the first sun gear of the speed changer, and in between a stator shaft coupled to a reversing stator and the second sun gear of the speed changer.

  3. Automatic transmission

    SciTech Connect

    Miki, N.

    1988-10-11

    This patent describes an automatic transmission including a fluid torque converter, a first gear unit having three forward-speed gears and a single reverse gear, a second gear unit having a low-speed gear and a high-speed gear, and a hydraulic control system, the hydraulic control system comprising: a source of pressurized fluid; a first shift valve for controlling the shifting between the first-speed gear and the second-speed gear of the first gear unit; a second shift valve for controlling the shifting between the second-speed gear and the third-speed gear of the first gear unit; a third shift valve equipped with a spool having two positions for controlling the shifting between the low-speed gear and the high-speed gear of the second gear unit; a manual selector valve having a plurality of shift positions for distributing the pressurized fluid supply from the source of pressurized fluid to the first, second and third shift valves respectively; first, second and third solenoid valves corresponding to the first, second and third shift valves, respectively for independently controlling the operation of the respective shift valves, thereby establishing a six forward-speed automatic transmission by combining the low-speed gear and the high-speed gear of the second gear unit with each of the first-speed gear, the second speed gear and the third-speed gear of the first gear unit; and means to fixedly position the spool of the third shift valve at one of the two positions by supplying the pressurized fluid to the third shift valve when the manual selector valve is shifted to a particular shift position, thereby locking the second gear unit in one of low-speed gear and the high-speed gear, whereby the six forward-speed automatic transmission is converted to a three forward-speed automatic transmission when the manual selector valve is shifted to the particular shift position.

  4. Transmission Investment: A Primer

    SciTech Connect

    McGarvey, Joe

    2006-10-15

    This primer highlights recent trends in transmission investment, summarizes the division of jurisdictional authority over transmission, and presents four alternative models for transmission ownership. (author)

  5. Analysis of planetary gear transmission in non-stationary operations

    NASA Astrophysics Data System (ADS)

    Chaari, Fakher; Abbes, Mohamed Slim; Rueda, Fernando Viadero; del Rincon, Alfonso Fernandez; Haddar, Mohamed

    2013-03-01

    Planetary gearboxes operate usually in nonstationary conditions generated mainly by variable loads applied to these transmissions. In order to understand the dynamic behavior of planetary gearboxes in such conditions, a mathematic model is developed including driving unit, transmission and load. The variability of load induces a variable speed of the transmission which is taken into account when characterizing the main dynamic parameter of the transmission which is the mesh stiffness function. This function is not periodic following the variability of the transmission speed. The computation of the dynamic response shows an intimate relation between the vibration amplitude level and the load value. As the load increase the vibration level increase. A combined amplitude and frequency modulation is observed which is well characterized using Short Time Fourier transform more suited than the spectral analysis.

  6. Automatic transmission

    SciTech Connect

    Aoki, H.

    1989-03-21

    An automatic transmission is described, comprising: a torque converter including an impeller having a connected member, a turbine having an input member and a reactor; and an automatic transmission mechanism having first to third clutches and plural gear units including a single planetary gear unit with a ring gear and a dual planetary gear unit with a ring gear. The single and dual planetary gear units have respective carriers integrally coupled with each other and respective sun gears integrally coupled with each other, the input member of the turbine being coupled with the ring gear of the single planetary gear unit through the first clutch, and being coupled with the sun gear through the second clutch. The connected member of the impeller is coupled with the ring gear of the dual planetary gear of the dual planetary gear unit is made to be and ring gear of the dual planetary gear unit is made to be restrained as required, and the carrier is coupled with an output member.

  7. Automatic transmission

    SciTech Connect

    Hamane, M.; Ohri, H.

    1989-03-21

    This patent describes an automatic transmission connected between a drive shaft and a driven shaft and comprising: a planetary gear mechanism including a first gear driven by the drive shaft, a second gear operatively engaged with the first gear to transmit speed change output to the driven shaft, and a third gear operatively engaged with the second gear to control the operation thereof; centrifugally operated clutch means for driving the first gear and the second gear. It also includes a ratchet type one-way clutch for permitting rotation of the third gear in the same direction as that of the drive shaft but preventing rotation in the reverse direction; the clutch means comprising a ratchet pawl supporting plate coaxially disposed relative to the drive shaft and integrally connected to the third gear, the ratchet pawl supporting plate including outwardly projection radial projections united with one another at base portions thereof.

  8. Planetary transmission

    SciTech Connect

    Nerstad, K.A.; Windish, W.E.

    1987-04-21

    A planetary transmission is described comprising: an input shaft; a first planetary gear set having a first sun gear driven by the input shaft, a first planet carrier serving as the output, a first ring gear, and first brake means for selectively holding the fist ring gear stationary; a second planetary gear set having a second sun gear driven by the input shaft, a second planet carrier connected for joint rotation to the first ring gear, a second ring gear, and second brake means for selectively holding the second ring gear stationary; a third planetary gear set having a third sun gear connected for joint rotation to the second planet carrier, a third planet carrier connected for joint rotation to the second ring gear, a third ring gear, and third brake means for selectively holding the third ring gear stationary; and clutch means for connecting the third sun gear to the input shaft and providing a direct drive mode of operation.

  9. Overdrive transmission

    SciTech Connect

    Miller, G.F.

    1986-02-04

    This patent describes an overdrive transmission device for use with a motor vehicle. It consists of: a housing; a driving shaft rotatably mounted within the housing; a planetary gear-train; a driven shaft rotatably mounted in the housing and driven by the planetary gear train; and, a device for selectively connecting the planetary gear carrier to the housing or to the driven shaft for rotation; a hydraulically actuated piston adapted to forcibly contact the clutch friction members of the second clutch; a source of working fluid; a pump in fluid flow communication with the source of working fluid; a first valve downstream of the pump and in fluid flow communication with the pump and the hydraulically activated piston.

  10. Automatic transmission

    SciTech Connect

    Meyman, U.

    1987-03-10

    An automatic transmission is described comprising wheel members each having discs defining an inner space therebetween; turnable blades and vane members located in the inner space between the discs of at least one of the wheel members, the turnable blades being mechanically connected with the vane members. Each of the turnable blades has an inner surface and an outer surface formed by circular cylindrical surfaces having a common axis, each of the turnable blades being turnable about the common axis of the circular cylindrical surfaces forming the inner and outer surfaces of the respective blade; levers turnable about the axes and supporting the blades; the discs having openings extending coaxially with the surfaces which describe the blades. The blades are partially received in the openings of the discs; and a housing accommodating the wheel members and the turnable blades and the vane members.

  11. Defect tolerant transmission lithography mask

    DOEpatents

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  12. LOADING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1958-10-01

    A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

  13. Hydromechanical transmission

    DOEpatents

    Orshansky, Jr. deceased, Elias; Weseloh, William E.

    1978-01-01

    A power transmission having three planetary assemblies, each having its own carrier and its own planet, sun, and ring gears. A speed-varying module is connected in driving relation to the input shaft and in driving relationship to the three sun gears, all of which are connected together. The speed-varying means may comprise a pair of hydraulic units hydraulically interconnected so that one serves as a pump while the other serves as a motor and vice versa, one of the units having a variable stroke and being connected in driving relation to the input shaft, the other unit, which may have a fixed stroke, being connected in driving relation to the sun gears. The input shaft also drives the carrier of the third planetary assembly. A brake grounds the first carrier in the first range and in reverse and causes drive to be delivered to the output through the first ring gear in a hydrostatic mode. The carrier of the third planetary assembly drives the ring gear of the second planetary assembly, and a first clutching means connects the second carrier with the output in a second range, the brake for grounding the first carrier then being released. A second clutching means enables the third ring gear to drive the output shaft in a third range.

  14. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  15. Radio frequency power load and associated method

    NASA Technical Reports Server (NTRS)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2010-01-01

    A radio frequency power load and associated method. A radio frequency power load apparatus includes a container and a fluid having an ion source therein, the fluid being contained in the container. Two conductors are immersed in the fluid. A radio frequency transmission system includes a radio frequency transmitter, a radio frequency amplifier connected to the transmitter and a radio frequency power load apparatus connected to the amplifier. The apparatus includes a fluid having an ion source therein, and two conductors immersed in the fluid. A method of dissipating power generated by a radio frequency transmission system includes the steps of: immersing two conductors of a radio frequency power load apparatus in a fluid having an ion source therein; and connecting the apparatus to an amplifier of the transmission system.

  16. Essentials of filoviral load quantification.

    PubMed

    Cnops, Lieselotte; van Griensven, Johan; Honko, Anna N; Bausch, Daniel G; Sprecher, Armand; Hill, Charles E; Colebunders, Robert; Johnson, Joshua C; Griffiths, Anthony; Palacios, Gustavo F; Kraft, Colleen S; Kobinger, Gary; Hewlett, Angela; Norwood, David A; Sabeti, Pardis; Jahrling, Peter B; Formenty, Pierre; Kuhn, Jens H; Ariën, Kevin K

    2016-07-01

    Quantitative measurement of viral load is an important parameter in the management of filovirus disease outbreaks because viral load correlates with severity of disease, survival, and infectivity. During the ongoing Ebola virus disease outbreak in parts of Western Africa, most assays used in the detection of Ebola virus disease by more than 44 diagnostic laboratories yielded qualitative results. Regulatory hurdles involved in validating quantitative assays and the urgent need for a rapid Ebola virus disease diagnosis precluded development of validated quantitative assays during the outbreak. Because of sparse quantitative data obtained from these outbreaks, opportunities for study of correlations between patient outcome, changes in viral load during the course of an outbreak, disease course in asymptomatic individuals, and the potential for virus transmission between infected patients and contacts have been limited. We strongly urge the continued development of quantitative viral load assays to carefully evaluate these parameters in future outbreaks of filovirus disease.

  17. Automatic transmission

    SciTech Connect

    Miura, M.; Inuzuka, T.

    1986-08-26

    1. An automatic transmission with four forward speeds and one reverse position, is described which consists of: an input shaft; an output member; first and second planetary gear sets each having a sun gear, a ring gear and a carrier supporting a pinion in mesh with the sun gear and ring gear; the carrier of the first gear set, the ring gear of the second gear set and the output member all being connected; the ring gear of the first gear set connected to the carrier of the second gear set; a first clutch means for selectively connecting the input shaft to the sun gear of the first gear set, including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a second clutch means for selectively connecting the input shaft to the sun gear of the second gear set a third clutch means for selectively connecting the input shaft to the carrier of the second gear set including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a first drive-establishing means for selectively preventing rotation of the ring gear of the first gear set and the carrier of the second gear set in only one direction and, alternatively, in any direction; a second drive-establishing means for selectively preventing rotation of the sun gear of the second gear set; and a drum being open to the first planetary gear set, with a cylindrical intermediate wall, an inner peripheral wall and outer peripheral wall and forming the hydraulic servos of the first and third clutch means between the intermediate wall and the inner peripheral wall and between the intermediate wall and the outer peripheral wall respectively.

  18. Power transmission

    SciTech Connect

    Ordo, J.P.; Raszkowski, J.A.; Klemen, D.

    1991-04-23

    This patent describes a transmission. It comprises a housing having first and second end covers; an input shaft rotatably mounted in the first end cover; an output shaft rotatably supported on the input shaft and in the second end cover; first and second countershafts rotatably supported in the end covers for rotation on respective axis parallel with the input shaft and the output shaft; a first head gear continuously rotatable with the input shaft; second and third head gears meshing with the first head gear and continuously rotatable with the first and second countershafts respectively; ratio gears rotatably supported on each of the countershafts including a first ratio gear on the first countershaft and a second ratio gear on the second countershaft; reverse gear means including a first ratio gear on the first countershaft and a second ratio gear on the second countershaft; reverse gear means including a first member rotatable with the first ratio gear means including a first member rotatable with the first ratio gear and a second member rotatably supported on the second countershaft; synchronizer clutch means selectively and alternatively connectible with the second ratio gear and the second member of the reverse gear means; output gear means drivingly connected with the output shaft and including a first ratio output gear meshing with the second ratio gear; first selectively engageable friction clutch means for connecting the first ratio gear with the first countershaft for completing a low forward drive ratio between the input and output shafts; and second selectively engageable friction clutch means for selectively connecting the synchronizer clutch means to the second countershaft and cooperating therewith to selectively alternatively complete a reverse drive ratio between the input shaft and the output shaft and another forward drive ratio between the input and output shafts.

  19. Life and reliability models for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Knorr, R. J.; Coy, J. J.

    1982-01-01

    Computer models of life and reliability are presented for planetary gear trains with a fixed ring gear, input applied to the sun gear, and output taken from the planet arm. For this transmission the input and output shafts are co-axial and the input and output torques are assumed to be coaxial with these shafts. Thrust and side loading are neglected. The reliability model is based on the Weibull distributions of the individual reliabilities of the in transmission components. The system model is also a Weibull distribution. The load versus life model for the system is a power relationship as the models for the individual components. The load-life exponent and basic dynamic capacity are developed as functions of the components capacities. The models are used to compare three and four planet, 150 kW (200 hp), 5:1 reduction transmissions with 1500 rpm input speed to illustrate their use.

  20. LOADED WAVEGUIDES

    DOEpatents

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  1. Digitally Driven Antenna for HF Transmission

    DTIC Science & Technology

    2010-09-01

    ferrite -loaded loop as the receive antenna . The 1-MHz signal is clearly evident in the time-domain received signal on an oscilloscope, and also in the... MICROWAVE THEORY AND TECHNIQUES, VOL. 58, NO. 9, SEPTEMBER 2010 Digitally Driven Antenna for HF Transmission Steven D. Keller, Member, IEEE, W...MHz reference signal on the pulsewidth modulator as the transmitter and a highly inductive 470- H ferrite -loaded loop as the receive antenna . The 1-MHz

  2. Thermal and Structural Analysis of Helicopter Transmission Housings Using NASTRAN

    NASA Technical Reports Server (NTRS)

    Howells, R. W.; Sciarra, J. J.; Ng, G. S.

    1976-01-01

    The application of NASTRAN to improve the design of helicopter transmission housings is described. A finite element model of the complete forward rotor transmission housing for the Boeing Vertol CH-47C helicopter was used to study thermal distortion and stress, stress and deflection due to static and dynamic loads, load paths, and design optimization by the control of structural energy distribution. The analytical results are correlated with test data and used to reduce weight and to improve strength, service life, failsafety, and reliability. The techniques presented, although applied herein to helicopter transmissions, are sufficiently general to be applicable to any power transmission system.

  3. Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    SciTech Connect

    Fink, S.; Porter, K.; Mudd, C.; Rogers, J.

    2011-02-01

    The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.

  4. Advanced Rotorcraft Transmission (ART) Program summary

    NASA Astrophysics Data System (ADS)

    Krantz, T. L.; Kish, J. G.

    1992-07-01

    The Advanced Rotorcraft Transmission (ART) Program was initiated to advance the state of the art for rotorcraft transmissions. The goal of the ART Program was to develop and demonstrate the technologies needed to reduce transmission weight by 25 pct and reduce noise by 10 dB while obtaining a 5000 hr 'mean time between failure'. The research done under the ART Program is summarized. A split path design was selected as best able to meet the program goals. Key part technologies needed for this design were identified, studied, and developed. Two of these technologies are discussed in detail: the load sharing of split path designs including the use of a compliant elastomeric torque splitter and the application of a high ratio, low pitch line velocity gear mesh. Development of an angular contact spherical roller bearing, transmission error analysis, and fretting fatigue testing are discussed. The technologies for a light weight, quiet, and reliable rotorcraft transmission were demonstrated.

  5. Advanced Rotorcraft Transmission (ART) program status

    NASA Technical Reports Server (NTRS)

    Bossler, Robert; Heath, Gregory

    1991-01-01

    Reported herein is work done on the Advanced Rotorcraft Transmission by McDonnell Douglas Helicopter Company under Army/NASA contract. The novel concept pursued includes the use of face gears for power transmission and a torque splitting arrangement. The design reduces the size and weight of the corner-turning hardware and the next reduction stage. New methods of analyzing face gears have increased confidence in their usefulness. Test gears have been designed and manufactured for power transmission testing on the NASA-Lewis spiral bevel test rig. Transmission design effort has included finite element modeling of the split torque paths to assure equal deflection under load. A finite element model of the Apache main transmission has been completed to substantiate noise prediction methods. A positive engagement overrunning clutch design is described. Test spur gears have been made by near-net-shape forging from five different materials. Three housing materials have been procured for evaluation testing.

  6. Advanced Rotorcraft Transmission (ART) program summary

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Kish, J. G.

    1992-01-01

    The Advanced Rotorcraft Transmission (ART) Program was initiated to advance the state of the art for rotorcraft transmissions. The goal of the ART Program was to develop and demonstrate the technologies needed to reduce transmission weight by 25 pct. and reduce noise by 10 dB while obtaining a 5000 hr 'mean time between failure'. The research done under the ART Program is summarized. A split path design was selected as best able to meet the program goals. Key part technologies needed for this design were identified, studied, and developed. Two of these technologies are discussed in detail: the load sharing of split path designs including the use of a compliant elastomeric torque splitter and the application of a high ratio, low pitch line velocity gear mesh. Development of an angular contact spherical roller bearing, transmission error analysis, and fretting fatigue testing are discussed. The technologies for a light weight, quiet, and reliable rotorcraft transmission were demonstrated.

  7. Evaluation of underground dc transmission systems

    NASA Astrophysics Data System (ADS)

    1982-03-01

    Progress in a program for evaluating underground dc transmission systems is reported. A basic load flow model was developed for a large ac power system. This model will be adjusted to produce representations for 4000, 8000, and 12,000 MW energy park. Load flow conditions for dc lines are being calculated. The stability of ac and dc are being examined. Short circuit duties are being calculated. Load flow computer runs are being made to demonstrate the suitability of developed ac and dc options.

  8. Radio Frequency Power Load and Associated Method

    NASA Technical Reports Server (NTRS)

    Srinivasan, V. Karthik (Inventor); Freestone, Todd M. (Inventor); Sims, William Herbert, III (Inventor)

    2014-01-01

    A radio frequency power load and associated method. A radio frequency power load apparatus may include a container with an ionized fluid therein. The apparatus may include one conductor immersed in a fluid and another conductor electrically connected to the container. A radio frequency transmission system may include a radio frequency transmitter, a radio frequency amplifier connected to the transmitter and a radio frequency power load apparatus connected to the amplifier. The apparatus may include a fluid having an ion source therein, one conductor immersed in a fluid, and another conductor electrically connected to the container. A method of dissipating power generated by a radio frequency transmission system may include constructing a waveguide with ionized fluid in a container and connecting the waveguide to an amplifier of the transmission system.

  9. Development of large rotorcraft transmissions

    NASA Technical Reports Server (NTRS)

    Samanich, N. E.; Drago, R. J.; Mack, J. C.

    1984-01-01

    The U.S. Army Heavy Lift Helicopter (HLH) represents a large rotorcraft which was developed by an American aerospace company. In the early 1970's with the HLH Advanced Technology Components (ATC) program, the development of large rotorcraft transmission and drive systems was started. Failures in the spiral bevel gearing were experienced in tests because the employed method of analysis had not considered the effect of rim bending. Consequently, new gears with strengthened rims were designed and fabricated. For a more accurate prediction of the load capacity of the gears, an extensive Finite Element Method (FEM) system was developed. The U.S. Army's XCH-62 HLH aft rotor transmission was finally successfully tested at full design torque and speed. A description of the test program is provided, and the analytical program is discussed. The analytical phase includes the development of a preprocessing program which aids in the review of calculated FEM stresses.

  10. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, R.B.

    1985-08-15

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  11. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, Russell B.

    1987-01-01

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  12. Open Access Transmission Tariff: Effective December 18, 1998 (Revised June 16, 1999).

    SciTech Connect

    United States. Bonneville Power Administration.

    1999-06-16

    Bonneville will provide Network Integration Transmission Service pursuant to the terms and conditions contained in this Tariff and Service Agreement. The service that Bonneville will provide under this Tariff allows a Transmission Customer to integrate, economically dispatch and regulate its current and planned Network Resources to serve its Network Load. Network Integration Transmission Service also may be used by the Transmission Customer to deliver nonfirm energy purchases to its Network Load without additional charge. To the extent that the transmission path for moving power from a Network Resource to a Network Load includes the Eastern and Southern Interties, the terms and conditions for service over such intertie facilities are provided under Part 2 of this Tariff. Also, transmission service for third-party sales which are not designated as Network Load will be provided under Bonneville's Point-to-Point Transmission Service (Part 2 of this Tariff).

  13. Parameters optimization for magnetic resonance coupling wireless power transmission.

    PubMed

    Li, Changsheng; Zhang, He; Jiang, Xiaohua

    2014-01-01

    Taking maximum power transmission and power stable transmission as research objectives, optimal design for the wireless power transmission system based on magnetic resonance coupling is carried out in this paper. Firstly, based on the mutual coupling model, mathematical expressions of optimal coupling coefficients for the maximum power transmission target are deduced. Whereafter, methods of enhancing power transmission stability based on parameters optimal design are investigated. It is found that the sensitivity of the load power to the transmission parameters can be reduced and the power transmission stability can be enhanced by improving the system resonance frequency or coupling coefficient between the driving/pick-up coil and the transmission/receiving coil. Experiment results are well conformed to the theoretical analysis conclusions.

  14. Integrated Transmission and Distribution Control

    SciTech Connect

    Kalsi, Karanjit; Fuller, Jason C.; Tuffner, Francis K.; Lian, Jianming; Zhang, Wei; Marinovici, Laurentiu D.; Fisher, Andrew R.; Chassin, Forrest S.; Hauer, Matthew L.

    2013-01-16

    allows the load flow interactions between the bulk power system and end-use loads to be explicitly modeled. Power system interactions are modeled down to time intervals as short as 1-second. Another practical issue is that the size and complexity of typical distribution systems makes direct integration with transmission models computationally intractable. Hence, the focus of the next main task is to develop reduced-order controllable models for some of the smart grid assets. In particular, HVAC units, which are a type of Thermostatically Controlled Loads (TCLs), are considered. The reduced-order modeling approach can be extended to other smart grid assets, like water heaters, PVs and PHEVs. Closed-loop control strategies are designed for a population of HVAC units under realistic conditions. The proposed load controller is fully responsive and achieves the control objective without sacrificing the end-use performance. Finally, using the T&D simulation platform, the benefits to the bulk power system are demonstrated by controlling smart grid assets under different demand response closed-loop control strategies.

  15. Manual with auxiliary transmission

    SciTech Connect

    Nishimura, S.

    1987-06-23

    This patent describes a vehicular transmission of the type in which a manual transmission has two parallel shafts. One shaft is connected through a transmission clutch to an engine in which manual transmission is connected in series to an auxiliary transmission having high and low speed transmission lines. The auxiliary transmission has a high speed transmission line equipped with a hydraulic clutch and a low speed transmission line equipped with a one-way clutch for allowing the overrun of the output side of the low speed transmission line so that the low speed transmission line is established when the hydraulic clutch is released. The high speed transmission is established when the hydraulic clutch is applied. A sleeve shaft is on one of the two shafts. A transmission gear mechanism connects the sleeve shaft to the other shaft. One shaft has an extension with a fixed gear. A coacting gear is fixed on the sleeve shaft, the hydraulic clutch and coacting gear positioned on the extension of one shaft, an idle gear mechanism in meshing engagement with both the coacting gear and the fixed gear. The idle gear mechanism has a low speed transmission line one-way clutch, and the hydraulic clutch is operable to connect and disconnect the sleeve shaft to and from the one shaft.

  16. Peak load management: Potential options

    SciTech Connect

    Englin, J.E.; De Steese, J.G.; Schultz, R.W.; Kellogg, M.A.

    1989-10-01

    This report reviews options that may be alternatives to transmission construction (ATT) applicable both generally and at specific locations in the service area of the Bonneville Power Administration (BPA). Some of these options have potential as specific alternatives to the Shelton-Fairmount 230-kV Reinforcement Project, which is the focus of this study. A listing of 31 peak load management (PLM) options is included. Estimated costs and normalized hourly load shapes, corresponding to the respective base load and controlled load cases, are considered for 15 of the above options. A summary page is presented for each of these options, grouped with respect to its applicability in the residential, commercial, industrial, and agricultural sectors. The report contains comments on PLM measures for which load shape management characteristics are not yet available. These comments address the potential relevance of the options and the possible difficulty that may be encountered in characterizing their value should be of interest in this investigation. The report also identifies options that could improve the efficiency of the three customer utility distribution systems supplied by the Shelton-Fairmount Reinforcement Project. Potential cogeneration options in the Olympic Peninsula are also discussed. These discussions focus on the options that appear to be most promising on the Olympic Peninsula. Finally, a short list of options is recommended for investigation in the next phase of this study. 9 refs., 24 tabs.

  17. Properties of the tibial component regarding impact load.

    PubMed

    Yoshino, Kazunori; Koga, Yoshio; Segawa, Hiroyuki; Ueno, Yuichi; Tanabe, Yuji; Endo, Naoto; Omori, Go

    2004-06-01

    Load transmission through knee prostheses was examined to clarify how the tibial component behaves under dynamic loading conditions. We did Genesis II total knee arthroplasty using sawbones and measured impact load transmission ratios using the split-Hopkinson pressure bar technique. We also measured the polyethylene strain when an impact load was applied using a strain gauge bonded to the anterior surface of the polyethylene. The impact load transmission ratios of metal-backed and all-polyethylene tibial components were less than 4%. Greater load transmission was observed with metal-backed components, which suggests that some of the applied dynamic load is transferred directly to the tibial cortical bone. Increasing polyethylene thickness decreased impact load transmission ratios in both components, which might lower the cancellous bone stresses beneath tibial implants. Greater strain in the tibial component was observed in all-polyethylene components. Increased polyethylene thickness did not significantly decrease the polyethylene strain, probably because of the nonlinear elastic behavior of the polyethylene material. The distant positioning of the strain gauge may, however, have prevented the detection of local contact strains. Recent clinical studies did not confirm our theoretical predictions, suggesting that other factors contribute more significantly to the clinical outcome in current total knee arthroplasty.

  18. Automatic transmission adapter kit

    SciTech Connect

    Stich, R.L.; Neal, W.D.

    1987-02-10

    This patent describes, in a four-wheel-drive vehicle apparatus having a power train including an automatic transmission and a transfer case, an automatic transmission adapter kit for installation of a replacement automatic transmission of shorter length than an original automatic transmission in the four-wheel-drive vehicle. The adapter kit comprises: an extension housing interposed between the replacement automatic transmission and the transfer case; an output shaft, having a first end which engages the replacement automatic transmission and a second end which engages the transfer case; first sealing means for sealing between the extension housing and the replacement automatic transmission; second sealing means for sealing between the extension housing and the transfer case; and fastening means for connecting the extension housing between the replacement automatic transmission and the transfer case.

  19. Zika and Sexual Transmission

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button Zika and Sexual Transmission Language: English Español Português ... 1 page] Portuguese [PDF - 1 page] Basics of Zika Virus and Sex Transmission Zika can be passed ...

  20. Profile modification to minimize spur gear dynamic loading

    NASA Technical Reports Server (NTRS)

    Lin, H. H.; Townsend, D. P.; Oswald, F. B.

    1989-01-01

    An analytical computer simulation program for dynamic modeling of low-contact-ratio spur gear systems is presented. The procedure computes the static transmission error of the gears operating under load and uses a fast Fourier transform to generate the frequency spectrum of the static transmission error at various tooth profile modifications. The dynamic loading response of an unmodified (perfect involute) gear pair was compared with that of gears with various profile modifications. Correlations were found between various profile modifications and the resulting dynamic loads. An effective error, obtained from frequency domain analysis of the static transmission error of the gears, gave a very good indication of the optimum profile modification to reduce gear dynamic loading. Design curves generated by dynamic simulation at various profile modifications are given for gear systems operated at various loads. Optimum profile modifications can be determined from these design curves for improved gear design.

  1. Profile modification to minimize spur gear dynamic loading

    NASA Technical Reports Server (NTRS)

    Lin, Hsiang Hsi; Townsend, Dennis P.; Oswald, Fred B.

    1987-01-01

    An analytical computer simulation program for dynamic modeling of low-contact-ratio spur gear systems is presented. The procedure computes the static transmission error of the gears operating under load and uses a fast Fourier transform to generate the frequency spectrum of the static transmission error at various tooth profile modifications. The dynamic loading response of an unmodified (perfect involute) gear pair was compared with that of gears with various profile modifications. Correlations were found between various profile modifications and the resulting dynamic loads. An effective error, obtained from frequency domain analysis of the static transmission error of the gears, gave a very good indication of the optimum profile modification to reduce gear dynamic loading. Design curves generated by dynamic simulation at various profile modifications are given for gear systems operated at various loads. Optimum profile modifications can be determined from these design curves for improved gear design.

  2. Coiled transmission line pulse generators

    DOEpatents

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  3. Modeling a data transmission network by means of the Teledacya information subsystems

    NASA Astrophysics Data System (ADS)

    Palmowska, K.

    1982-11-01

    Rapid assessment of the reasonableness of results from various kinds of prognostication fundamentals and assumptions concerning the development of data transmission networks, important with respect to the extent of loading on a long distance telecommunications transmission network was examined. Initial evaluations demonstrated that loading determined according to existing prediction methods has essential importance for the planning of an entire telecommunication network.

  4. Automated manual transmission controller

    DOEpatents

    Lawrie, Robert E.; Reed, Jr., Richard G.; Bernier, David R.

    1999-12-28

    A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

  5. Computerized life and reliability modelling for turboprop transmissions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Radil, K. C.; Lewicki, D. G.; Coy, J. J.

    1988-01-01

    A generalized life and reliability model is presented for parallel shaft geared prop-fan and turboprop aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on classical fatigue theory and the two parameter Weibull failure distribution. A computer program was developed to calculate the transmission life and reliability. The program is modular. In its present form, the program can analyze five different transmission arrangements. However, the program can be modified easily to include additional transmission arrangements. An example is included which compares the life of a compound two-stage transmission with the life of a split-torque, parallel compound two-stage transmission, as calculated by the computer program.

  6. Computerized life and reliability modelling for turboprop transmissions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Radil, K. C.; Lewicki, D. G.; Coy, J. J.

    1988-01-01

    A generalized life and reliability model is presented for parallel shaft geared prop-fan and turboprop aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on classical fatigue theory and the two parameter Weibull failure distribution. A computer program was developed to calculate the transmission life and reliability. The program is modular. In its present form, the program can analyze five different transmission arrangements. However, the program can be modified easily to include additional transmission arrangements. An example is included which compares the life of a compound two-stage transmission with the life of a split-torque, parallel compound two-stage transmission as calculated by the comaputer program.

  7. Bordetella pertussis transmission.

    PubMed

    Trainor, Elizabeth A; Nicholson, Tracy L; Merkel, Tod J

    2015-11-01

    Bordetella pertussis and B. bronchiseptica are Gram-negative bacterial respiratory pathogens. Bordetella pertussis is the causative agent of whooping cough and is considered a human-adapted variant of B. bronchiseptica. Bordetella pertussis and B. bronchiseptica share mechanisms of pathogenesis and are genetically closely related. However, despite the close genetic relatedness, these Bordetella species differ in several classic fundamental aspects of bacterial pathogens such as host range, pathologies and persistence. The development of the baboon model for the study of B. pertussis transmission, along with the development of the swine and mouse model for the study of B. bronchiseptica, has enabled the investigation of different aspects of transmission including the route, attack rate, role of bacterial and host factors, and the impact of vaccination on transmission. This review will focus on B. pertussis transmission and how animal models of B. pertussis transmission and transmission models using the closely related B. bronchiseptica have increased our understanding of B. pertussis transmission.

  8. Application of face-gear drives in helicopter transmissions

    NASA Astrophysics Data System (ADS)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-05-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  9. Application of Face-Gear Drives in Helicopter Transmissions

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  10. Evaluation of load transfer characteristics of a dynamic stabilization device on disc loading under compression.

    PubMed

    Zhang, Qing Hang; Zhou, Yuan Li; Petit, Dominique; Teo, Ee Chon

    2009-06-01

    In the current study, finite element analyses were conducted to examine the biomechanical capability of a newly design dynamic stabilization system, FlexPLUS, to restore the load transmission of degenerated intervertebral L4-L5 lumbar motion segment spine under compression. Detailed three-dimensional FE models of L4-L5 motion segment and the FlexPLUS were developed. Compressive loading up to 1000N was applied to the intact L4-L5 model, the L4-L5 models with slight and moderate degenerated disc, and the implanted L4-L5 model. Further more, the load transmission characteristics of Dynesys and a rigid rod was also simulated for comparison. The resultant load-displacement curves and the load transferred through annulus under various conditions were compared. The predicted axial displacement of L4 top surface against applied compressive force of the intact L4-L5 model agreed well with experimental data. The predicted results showed that degenerated disc has significant effect on the lumbar segment load bearing capacity. Not only the stiffness of the segment was greatly increased, the uniform nature of the disc stress distribution was also altered. The FlexPLUS can effectively reduce the disc loading of degenerated model. Although the non-uniform load distribution pattern through annulus was not improved, the overall stress magnitude was greatly reduced to the level of intact model for grade II degeneration.

  11. Transmission Planning Analysis Tool

    SciTech Connect

    2015-06-23

    Developed to solve specific problem: Assist transmission planning for regional transfers in interconnected power systems. This work was originated in a study for the U.S. Department of State, to recommend transmission reinforcements for the Central American regional system that interconnects 6 countries. Transmission planning analysis is currently performed by engineers with domainspecific and systemspecific knowledge without a unique methodology. The software codes of this disclosure assists engineers by defining systematic analysis procedures to help identify weak points and make decisions on transmission planning of regional interconnected power systems. Transmission Planning Analysis Tool groups PSS/E results of multiple AC contingency analysis and voltage stability analysis and QV analysis of many scenarios of study and arrange them in a systematic way to aid power system planning engineers or transmission operators in effective decision]making process or in the off]line study environment.

  12. Series Transmission Line Transformer

    DOEpatents

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  13. Understanding Ebola Virus Transmission

    PubMed Central

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-01-01

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus. PMID:25654239

  14. Understanding ebola virus transmission.

    PubMed

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-02-03

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  15. Modified acoustic transmission tube apparatus incorporating an active downstream termination.

    PubMed

    Machuca-Tzili, F Arturo; Orduña-Bustamante, Felipe; Pérez-López, Antonio; Pérez-Ruiz, Santiago J; Pérez-Matzumoto, Andrés E

    2017-02-01

    Current techniques for measuring normal incidence sound transmission loss with a modified impedance tube, or transmission tube, require setting up two different absorbing termination loads at the end of the downstream tube [ASTM E2611-09, Standard Test Method for Measurement of Normal Incidence Sound Transmission of Acoustical Materials Based on the Transfer Matrix Method (American Society for Testing and Materials, West Conshohocken, 2009)]. The process of physically handling the two required passive absorbing loads is a possible source of measurement errors, which are mainly due to changes in sample test position, or in test setup re-assembly, between measurements. In this paper, a modified transmission tube apparatus is proposed for non-intrusively changing the downstream acoustic load by means of a combined passive-active termination. It provides a controlled variable sound absorption which simplifies the setup of standard two-load techniques, without the need of physically handling the apparatus during the tests. This virtually eliminates the risk of errors associated with the physical manipulation of the two passive terminations. Transmission loss measurements in some representative test conditions are reported, showing improvements over current implementations, in reducing by approximately 50% the measurement variations associated with the setup of the two required absorbing terminations. Measurement results agree within 0.4 dB (maximum difference in high resolution broadband), and 0.04 dB (mean difference in 1/3-octave bands), with those obtained using standard passive two-load methods.

  16. Update: transmission of HIV-1 from mother to child.

    PubMed

    Fowler, M G

    1997-12-01

    Mother-to-child transmission near the time of birth is the primary route of HIV-1 infection among infants and young children. Throughout the world, 1000 babies a day become infected with HIV, and cumulative global estimates are that 3 million children have been infected since the HIV pandemic began. Although major advances have been made in reducing mother-to-child transmission of HIV-1 in the USA and Europe through the use of an intensive regimen of zidovudine, many research questions remain unresolved. These include (1) viral and host characteristics which hinder or facilitate perinatal HIV transmission (i.e. the role played by viral load, the placenta and obstetric risk factors); (2) the proportion of transmission occurring in utero, intrapartum or during the breast feeding period; and (3) the mode of action of the successful zidovudine regimen. Studies published within the past year have shed light on several of these research topics. In 1996-1997 a number of important studies were published which support a general correlation between maternal viral load and infant HIV infection. The most recent studies do not, however, support the theory that there is a threshold below which transmission cannot occur, and also indicate that zidovudine, given according to the US Public Health Service guidelines, can significantly reduce the risk of transmission across all levels of maternal viral load. Analyses of viral load data from the successful clinical trial with zidovudine (AIDS Clinical Trial Group 076) suggest that its primary action is not by reducing the viral load, and raise the possibility that administering antiretroviral prophylaxis to the infant at the time of highest exposure may be another reason for the reduction in transmission. Obstetric risk factors for mother-to-child HIV transmission have been evaluated in several large cohort studies. A duration of membrane rupture of more than 4 h, and procedures such as amniocentesis, preterm labor, and the presence

  17. Viral load distribution in SARS outbreak.

    PubMed

    Chu, Chung-Ming; Cheng, Vincent C C; Hung, Ivan F N; Chan, Kin-Sang; Tang, Bone S F; Tsang, Thomas H F; Chan, Kwok-Hung; Yuen, Kwok-Yung

    2005-12-01

    An unprecedented community outbreak of severe acute respiratory syndrome (SARS) occurred in the Amoy Gardens, a high-rise residential complex in Hong Kong. Droplet, air, contaminated fomites, and rodent pests have been proposed to be mechanisms for transmitting SARS in a short period. We studied nasopharyngeal viral load of SARS patients on admission and their geographic distribution. Higher nasopharyngeal viral load was found in patients living in adjacent units of the same block inhabited by the index patient, while a lower but detectable nasopharyngeal viral load was found in patients living further away from the index patient. This pattern of nasopharyngeal viral load suggested that airborne transmission played an important part in this outbreak in Hong Kong. Contaminated fomites and rodent pests may have also played a role.

  18. Transmission Line Security Monitor

    ScienceCinema

    None

    2016-07-12

    The Transmission Line Security Monitor is a multi-sensor monitor that mounts directly on high-voltage transmission lines to detect, characterize and communicate terrorist activity, human tampering and threatening conditions around support towers. For more information about INL's critical infrastructure protection research, visit http://www.facebook.com/idahonationallaboratory.

  19. Transmission Line Security Monitor

    SciTech Connect

    2011-01-01

    The Transmission Line Security Monitor is a multi-sensor monitor that mounts directly on high-voltage transmission lines to detect, characterize and communicate terrorist activity, human tampering and threatening conditions around support towers. For more information about INL's critical infrastructure protection research, visit http://www.facebook.com/idahonationallaboratory.

  20. Passenger car transmissions

    SciTech Connect

    Not Available

    1990-01-01

    This book is organized under the following headings. The Mercedes-Benz 5-speed automatic transmission targets and comparison of concepts. 1991 model year Chrysler mini-van all wheel drive vehicle. Mesh stiffness and transmission error of spur and helical gears. High precision cutting tool system for the manufacture of world class powertrain components.

  1. Data Transmission Concepts.

    ERIC Educational Resources Information Center

    Christenson, Chris

    1995-01-01

    Introduces some basic concepts related to the transmission of data from a computer to its peripherals to help distance educators make decisions regarding computer equipment purchases for their institutions. The following data transmission concepts are described: cables, serial and parallel, synchronous and asynchronous, bandwidth, and analog and…

  2. Automatic transmission control method

    SciTech Connect

    Hasegawa, H.; Ishiguro, T.

    1989-07-04

    This patent describes a method of controlling an automatic transmission of an automotive vehicle. The transmission has a gear train which includes a brake for establishing a first lowest speed of the transmission, the brake acting directly on a ring gear which meshes with a pinion, the pinion meshing with a sun gear in a planetary gear train, the ring gear connected with an output member, the sun gear being engageable and disengageable with an input member of the transmission by means of a clutch. The method comprises the steps of: detecting that a shift position of the automatic transmission has been shifted to a neutral range; thereafter introducing hydraulic pressure to the brake if present vehicle velocity is below a predetermined value, whereby the brake is engaged to establish the first lowest speed; and exhausting hydraulic pressure from the brake if present vehicle velocity is higher than a predetermined value, whereby the brake is disengaged.

  3. Load Component Database of Household Appliances and Small Office Equipment

    SciTech Connect

    Lu, Ning; Xie, YuLong; Huang, Zhenyu; Puyleart, Francis; Yang, Steve

    2008-07-24

    This paper discusses the development of a load component database for household appliances and office equipment. To develop more accurate load models at both transmission and distribution level, a better understanding on the individual behaviors of home appliances and office equipment under power system voltage and frequency variations becomes more and more critical. Bonneville Power Administration (BPA) has begun a series of voltage and frequency tests against home appliances and office equipments since 2005. Since 2006, Researchers at Pacific Northwest National Laboratory has collaborated with BPA personnel and developed a load component database based on these appliance testing results to facilitate the load model validation work for the Western Electricity Coordinating Council (WECC). In this paper, the testing procedure and testing results are first presented. The load model parameters are then derived and grouped. Recommendations are given for aggregating the individual appliance models to feeder level, the models of which are used for distribution and transmission level studies.

  4. Is viral shedding a surrogate marker for transmission of genital herpes? A discussion document.

    PubMed

    Griffiths, Paul

    2004-12-01

    While the concept linking herpes simplex virus (HSV) shedding to transmission is plausible, few data support shedding as a surrogate marker. If shedding is to be used as a surrogate marker in future clinical studies, it must be clear how far shedding must be reduced, and what the shape of the transmission:viral load curve (or transmission:detection frequency curve) is before transmission is reduced. It remains unclear whether peak virus load, frequency of detection of virus, or the area under curve of the time:virus load plot is the critical parameter in the transmission of HSV. This paper reports on an international meeting of experts and a debate at the International Herpes Management Forum (IHMF) Annual Meeting (2004), convened to examine whether a surrogate marker for HSV transmission is necessary, and whether there is any evidence, either in studies involving HSV or other viral infections, to suggest that viral shedding could be used as such a surrogate.

  5. Tractor Transmissions. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Agricultural Engineering and Vocational Agriculture, Athens, GA.

    The manual was developed as a reference for teaching students about transmissions in farm tractors. The manual is divided into five sections: (1) transmission history, (2) gears and bearings in transmission, (3) sliding-gear transmissions, (4) planetary gearing, and (5) glossary. The working principles of the sliding-gear transmission, the most…

  6. Continuously-Variable Positive-Mesh Power Transmission

    NASA Technical Reports Server (NTRS)

    Johnson, J. L.

    1982-01-01

    Proposed transmission with continuously-variable speed ratio couples two mechanical trigonometric-function generators. Transmission is expected to handle higher loads than conventional variable-pulley drives; and, unlike variable pulley, positive traction through entire drive train with no reliance on friction to transmit power. Able to vary speed continuously through zero and into reverse. Possible applications in instrumentation where drive-train slippage cannot be tolerated.

  7. Refuge sharing network predicts ectoparasite load in a lizard.

    PubMed

    Leu, Stephan T; Kappeler, Peter M; Bull, C Michael

    2010-09-01

    Living in social groups facilitates cross-infection by parasites. However, empirical studies on indirect transmission within wildlife populations are scarce. We investigated whether asynchronous overnight refuge sharing among neighboring sleepy lizards, Tiliqua rugosa, facilitates indirect transmission of its ectoparasitic tick, Amblyomma limbatum. We fitted 18 neighboring lizards with GPS recorders, observed their overnight refuge use each night over 3 months, and counted their ticks every fortnight. We constructed a transmission network to estimate the cross-infection risk based on asynchronous refuge sharing frequencies among all lizards and the life history traits of the tick. Although self-infection was possible, the network provided a powerful predictor of measured tick loads. Highly connected lizards that frequently used their neighbors' refuges were characterized by higher tick loads. Thus, indirect contact had a major influence on transmission pathways and parasite loads. Furthermore, lizards that used many different refuges had lower cross- and self-infection risks and lower tick loads than individuals that used relatively fewer refuges. Increasing the number of refuges used by a lizard may be an important defense mechanism against ectoparasite transmission in this species. Our study provides important empirical data to further understand how indirectly transmitted parasites move through host populations and influence individual parasite loads.

  8. Load sensing system

    DOEpatents

    Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

    1999-01-01

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

  9. Pregnancy & perinatal transmission update.

    PubMed

    Denison, R

    1998-09-01

    According to a June 1998 report from UNAIDS, the majority of children infected with HIV acquired it from their mothers during or near birth. One way to prevent perinatal transmission of HIV is to increase prevention efforts for women. Other ways to prevent perinatal transmission include using AZT treatment, avoiding breastfeeding, and choosing a C-section delivery instead of a vaginal delivery. One important study, called the Thai study, promoted a shorter course of AZT therapy that was less expensive, more accessible, and still prevented transmission in many cases. Several reasons are cited for why some women continue breastfeeding, despite the increased risk of transmitting HIV to their babies. An important factor in preventing perinatal transmission is the overall health of the mother, and her ability to maintain her health and treatment regimen while caring for a newborn.

  10. Downhole transmission system

    DOEpatents

    Hall, David R.; Fox, Joe

    2008-01-15

    A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. An electrical conductor connects both the transmission elements. The electrical conductor comprises at least three electrically conductive elements insulated from each other. In the preferred embodiment the electrical conductor comprises an electrically conducting outer shield, an electrically conducting inner shield and an electrical conducting core. In some embodiments of the present invention, the electrical conductor comprises an electrically insulating jacket. In other embodiments, the electrical conductor comprises a pair of twisted wires. In some embodiments, the electrical conductor comprises semi-conductive material.

  11. Down hole transmission system

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy

    2007-07-24

    A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. The electrically conducting coil comprises at least two generally fractional loops. In the preferred embodiment, the transmission elements are connected by an electrical conductor. Preferably, the electrical conductor is a coaxial cable. Preferably, the MCEI trough comprises ferrite. In the preferred embodiment, the fractional loops are connected by a connecting cable. In one aspect of the present invention, the connecting cable is a pair of twisted wires. In one embodiment the connecting cable is a shielded pair of twisted wires. In another aspect of the present invention, the connecting cable is a coaxial cable. The connecting cable may be disposed outside of the MCEI circular trough.

  12. Multiplex television transmission system

    NASA Technical Reports Server (NTRS)

    Reed, W. R.

    1967-01-01

    Time-multiplexing system enables several cameras to share a single commercial television transmission channel. This system is useful in industries for visually monitoring several operating areas or instrument panels from a remote location.

  13. Factors that affect the fatigue strength of power transmission shafting

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1984-01-01

    A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

  14. Continuously Variable Transmission

    NASA Technical Reports Server (NTRS)

    Grana, D. C.

    1985-01-01

    Chain slides along two cones, in novel transmission concept. Transmission includes chain drive between two splined shafts. Chain sprockets follow surfaces of two cones. As one chain sprocket moves toward smaller diameter other chain sprocket moves toward larger diameter, thereby changing "gear" ratio. Movement initiated by tension applied to chain by planetary gear mechanism. Device positive, simple, and efficient over wide range of speed ratios.

  15. 77 FR 6554 - Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke-American Transmission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... Energy Regulatory Commission Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke-American Transmission Company, LLC; Notice of Petition for Declaratory Order Take notice that on January 30... (Commission), 18 CFR 381.302, Zephyr Power Transmission, LLC (Zephyr), Pathfinder Power Transmission, LLC...

  16. Multistate differential transmission

    SciTech Connect

    Whalen, B.

    1987-09-01

    A multistate transmission is described having an input shaft and an output shaft comprising: a. planetary gear train means having a ring gear, planetary gears with planetary gear carrier, and a sun gear, the planetary gear train means connected to the output shaft; b. first bypass means connecting the input shaft to the planetary gear train means; c. differential transmission means for receiving its input from the input shaft and having means to adjust the torque and speed output infinitely variable over its range of operation for each state of the transmission; d. power return means for receiving the output of the differential transmission means; e. means including clutch operated speed reversing means for interconnecting the sun gear in the planetary gear train means with the power return means; f. the power return means including a first gear to receive the output of the differential transmission means; g. first multispeed transmission means connecting the means for supporting the carrier shaft to the first bypass means.

  17. National transmission grid study

    SciTech Connect

    Abraham, Spencer

    2003-05-31

    The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).

  18. The Role of Demand Resources In Regional Transmission Expansion Planning and Reliable Operations

    SciTech Connect

    Kirby, Brendan J

    2006-07-01

    Investigating the role of demand resources in regional transmission planning has provided mixed results. On one hand there are only a few projects where demand response has been used as an explicit alternative to transmission enhancement. On the other hand there is a fair amount of demand response in the form of energy efficiency, peak reduction, emergency load shedding, and (recently) demand providing ancillary services. All of this demand response reduces the need for transmission enhancements. Demand response capability is typically (but not always) factored into transmission planning as a reduction in the load which must be served. In that sense demand response is utilized as an alternative to transmission expansion. Much more demand response is used (involuntarily) as load shedding under extreme conditions to prevent cascading blackouts. The amount of additional transmission and generation that would be required to provide the current level of reliability if load shedding were not available is difficult to imagine and would be impractical to build. In a very real sense demand response solutions are equitably treated in every region - when proposed, demand response projects are evaluated against existing reliability and economic criteria. The regional councils, RTOs, and ISOs identify needs. Others propose transmission, generation, or responsive load based solutions. Few demand response projects get included in transmission enhancement plans because few are proposed. But this is only part of the story. Several factors are responsible for the current very low use of demand response as a transmission enhancement alternative. First, while the generation, transmission, and load business sectors each deal with essentially the same amount of electric power, generation and transmission companies are explicitly in the electric power business but electricity is not the primary business focus of most loads. This changes the institutional focus of each sector. Second

  19. Transmission expansion with smart switching under demand uncertainty and line failures

    SciTech Connect

    Schumacher, Kathryn M.; Chen, Richard Li-Yang; Cohn, Amy E. M.

    2016-06-07

    One of the major challenges in deciding where to build new transmission lines is that there is uncertainty regarding future loads, renewal generation output and equipment failures. We propose a robust optimization model whose transmission expansion solutions ensure that demand can be met over a wide range of conditions. Specifically, we require feasible operation for all loads and renewable generation levels within given ranges, and for all single transmission line failures. Furthermore, we consider transmission switching as an allowable recovery action. This relatively inexpensive method of redirecting power flows improves resiliency, but introduces computational challenges. Lastly, we present a novel algorithm to solve this model. Computational results are discussed.

  20. Load Model Data Tool

    SciTech Connect

    David Chassin, Pavel Etingov

    2013-04-30

    The LMDT software automates the process of the load composite model data preparation in the format supported by the major power system software vendors (GE and Siemens). Proper representation of the load composite model in power system dynamic analysis is very important. Software tools for power system simulation like GE PSLF and Siemens PSSE already include algorithms for the load composite modeling. However, these tools require that the input information on composite load to be provided in custom formats. Preparation of this data is time consuming and requires multiple manual operations. The LMDT software enables to automate this process. Software is designed to generate composite load model data. It uses the default load composition data, motor information, and bus information as an input. Software processes the input information and produces load composition model. Generated model can be stored in .dyd format supported by GE PSLF package or .dyr format supported by Siemens PSSE package.

  1. Load Induced Blindness

    PubMed Central

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005d`) was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus—a phenomenon of load induced blindness. PMID:18823196

  2. BERTHA: A versatile transmission line and circuit code

    NASA Astrophysics Data System (ADS)

    Hinshelwood, D. D.

    1983-11-01

    An improved version of the NRL transmission line code of W. H. Lupton is presented. The capabilities of the original program were extended to allow magnetically insulated transmission lines, plasma opening switches, imploding plasma loads and discrete element electrical networks, for example, to be modeled. BERTHA is used to simulate any system that is represented by a configuration of transmission line elements. The electrical behavior of the system is calculated by repeatedly summing the reflected and transmitted waves at the ends of each element. This program is versatile, easy to use and easily implemented on desktop microcomputers.

  3. Effect of extended tooth contact on the modeling of spur gear transmissions

    NASA Astrophysics Data System (ADS)

    Oswald, Fred B.; Coy, John J.; Lin, Hsiang Hsi; Wang, Jifeng

    1993-05-01

    In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated and the individual tooth load is overstated, especially for heavily-loaded gears. The static transmission error and dynamic load of heavily-loaded, low-contact-ratio spur gears is compared with this effect both neglected and included. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.

  4. Effect of extended tooth contact on the modeling of spur gear transmissions

    NASA Astrophysics Data System (ADS)

    Lin, Hsiang H.; Wang, Jifeng; Oswald, Fred B.; Coy, John J.

    1993-06-01

    In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated and the individual tooth load is overstated, especially for heavily-loaded gears. The static transmission error and dynamic load of heavily-loaded, low-contact-ratio spur gears is compared with this effect both neglected and included. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.

  5. Effect of extended tooth contact on the modeling of spur gear transmissions

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Coy, John J.; Lin, Hsiang Hsi; Wang, Jifeng

    1993-01-01

    In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated and the individual tooth load is overstated, especially for heavily-loaded gears. The static transmission error and dynamic load of heavily-loaded, low-contact-ratio spur gears is compared with this effect both neglected and included. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.

  6. Dynamics of a split torque helicopter transmission

    NASA Astrophysics Data System (ADS)

    Rashidi, Majid; Krantz, Timothy

    A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

  7. Dynamics of a split torque helicopter transmission

    NASA Technical Reports Server (NTRS)

    Rashidi, Majid; Krantz, Timothy

    1992-01-01

    A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

  8. Life and dynamic capacity modeling for aircraft transmissions

    NASA Technical Reports Server (NTRS)

    Savage, Michael

    1991-01-01

    A computer program to simulate the dynamic capacity and life of parallel shaft aircraft transmissions is presented. Five basic configurations can be analyzed: single mesh, compound, parallel, reverted, and single plane reductions. In execution, the program prompts the user for the data file prefix name, takes input from a ASCII file, and writes its output to a second ASCII file with the same prefix name. The input data file includes the transmission configuration, the input shaft torque and speed, and descriptions of the transmission geometry and the component gears and bearings. The program output file describes the transmission, its components, their capabilities, locations, and loads. It also lists the dynamic capability, ninety percent reliability, and mean life of each component and the transmission as a system. Here, the program, its input and output files, and the theory behind the operation of the program are described.

  9. Test load verification through strain data analysis

    NASA Technical Reports Server (NTRS)

    Verderaime, V.; Harrington, F.

    1995-01-01

    A traditional binding acceptance criterion on polycrystalline structures is the experimental verification of the ultimate factor of safety. At fracture, the induced strain is inelastic and about an order-of-magnitude greater than designed for maximum expected operational limit. At this extreme strained condition, the structure may rotate and displace at the applied verification load such as to unknowingly distort the load transfer into the static test article. Test may result in erroneously accepting a submarginal design or rejecting a reliable one. A technique was developed to identify, monitor, and assess the load transmission error through two back-to-back surface-measured strain data. The technique is programmed for expediency and convenience. Though the method was developed to support affordable aerostructures, the method is also applicable for most high-performance air and surface transportation structural systems.

  10. Infinitely variable steering transmission

    SciTech Connect

    Reed, B.O.

    1989-04-04

    A steering transmission is described comprising: first and second drive units each driven at a substantially constant speed for producing respective first and second unidirectional, continuous outputs infinitely variable between a minimum speed and a maximum speed; a first output planetary gear drivingly connected to a first transmission output; a second output planetary gear set drivingly connected to a second transmission output; an input gear set; means interconnecting the first and second output planetary gear sets; means connecting the first drive unit to the first output planetary gear set; means applying the second drive unit output to the second output planetary gear set; means applying a substantially constant speed input to the input gear set; means for selectively conditioning the input gear set to drive the one output planetary gear set at a speed having a first predetermined fixed ratio to the constant speed input, whereby to operate the transmission in one speed range; and means for selectively applying the first drive unit output to second output planetary gear set, whereby to operate the transmission in another speed range different from the one speed range.

  11. Aerosol Transmission of Filoviruses

    PubMed Central

    Mekibib, Berhanu; Ariën, Kevin K.

    2016-01-01

    Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013–2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses. PMID:27223296

  12. Automotive transmission linkage system

    SciTech Connect

    Yen, F.Y.; Ardayfio, D.D.

    1990-10-02

    This patent describes a system for converting a manual multi-speed transmission to operate as an automatic-manual transmission, the system being disposed within a vehicle, the transmission having a conventional gearshift lever and a clutch pedal. It comprises: a gearshift position selection panel, the panel being located apart from the gearshift lever, the panel enabling a driver to select the desired gear position of the gearshift lever by manipulating the panel without the necessity of the driver handling the gearshift lever; a controller which transforms the gearshift selection of the driver to an output signal, the signal corresponding to the gearshift position selected by the driver; and actuating means for mechanically repositioning the gearshift lever automatically in accordance with the output signal.

  13. Disease transmission in horses.

    PubMed

    Samper, Juan C; Tibary, Ahmed

    2006-08-01

    Bacterial, viral and protozoal infections may cause severe reproductive losses. The present paper reviews the risk factors, clinical signs and preventive measures for the most important venereal or potential sexually transmitted diseases in horses. The stallion and use of semen for artificial insemination represent major risk factors for the transmission of bacterial contaminants of the penis, including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae, known to cause endometritis and infertility in the mare. The role of the stallion in disease transmission is also due to the non-clinical manifestation of diseases such as contagious equine metritis and equine viral arteritis. Dourine has been eradicated from many countries, but continues to be a problem in other areas of the globe. Strategies for the prevention of introduction and transmission of diseases in breeding operation are discussed.

  14. New Gear Transmission Error Measurement System Designed

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.

    2001-01-01

    The prime source of vibration and noise in a gear system is the transmission error between the meshing gears. Transmission error is caused by manufacturing inaccuracy, mounting errors, and elastic deflections under load. Gear designers often attempt to compensate for transmission error by modifying gear teeth. This is done traditionally by a rough "rule of thumb" or more recently under the guidance of an analytical code. In order for a designer to have confidence in a code, the code must be validated through experiment. NASA Glenn Research Center contracted with the Design Unit of the University of Newcastle in England for a system to measure the transmission error of spur and helical test gears in the NASA Gear Noise Rig. The new system measures transmission error optically by means of light beams directed by lenses and prisms through gratings mounted on the gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. A photodetector circuit converts the light to an analog electrical signal. To increase accuracy and reduce "noise" due to transverse vibration, there are parallel light paths at the top and bottom of the gears. The two signals are subtracted via differential amplifiers in the electronics package. The output of the system is 40 mV/mm, giving a resolution in the time domain of better than 0.1 mm, and discrimination in the frequency domain of better than 0.01 mm. The new system will be used to validate gear analytical codes and to investigate mechanisms that produce vibration and noise in parallel axis gears.

  15. Phalange Tactile Load Cell

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  16. Heterosexual transmission of HIV.

    PubMed

    Johnson, A M; Laga, M

    1988-01-01

    Recent developments concerning heterosexual transmission of HIV (review of 1988 literature only) suggest improved understanding of the pattern of spread and role of risk behaviors and biological cofactors in its transmission. 3 distinct patterns if HIV infection are known: heterosexual spread in sub-Saharan Africa and the Caribbean, spread primarily among homosexuals and injecting drug users in Europe, North American and much of Latin America and Australia, and both homosexual and heterosexual transmission in Asia, the Pacific, the Middle East and Eastern Europe, where prevalence is low. In Africa an estimated 80% of cases are acquired heterosexually. Important risk factors are number of sex partners, sex with prostitutes, being a prostitute, being a sex partner of an infected person, and having a history of other sexually transmitted diseases. Prevalence rates have risen rapidly in Zaire and Kenya. In Africa, acquisition of HIV is related to sexual activity only. In contrast, in the U.S., heterosexual cases make up only 4% of all cases, and in Europe only 6%. Data on types of sexual transmission of HIV are mounting, in aggregate suggestive of a marked heterogeneity in infectivity and possibly susceptibility between individuals. Among couples where the man is positive, in some places individuals appear to be highly infective, notably those from Kinshasa, Zaire and Haiti, while other series of discordant couples the receptive partner remained seronegative for several years. Transmission from women to men appears to be less efficient than from men to women, as has been observed with other STDs such as gonorrhea. Biological cofactors implicated in enhanced HIV transmission appear to be advanced CDC Stage IV AIDS disease, with low T-helper lymphocyte counts and high antigenemia; concomitant STDS, especially those with genital ulceration; lack of circumcision; oral contraceptive use; practice of anal intercourse; inconsistent or no use of condoms. Theoretical models for

  17. Transmission line capital costs

    SciTech Connect

    Hughes, K.R.; Brown, D.R.

    1995-05-01

    The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy`s Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs.

  18. Advanced rotorcraft transmission program

    NASA Technical Reports Server (NTRS)

    Bill, Robert C.

    1990-01-01

    The Advanced Rotorcraft Transmission (ART) program is an Army-funded, joint Army/NASA program to develop and demonstrate lightweight, quiet, durable drivetrain systems for next generation rotorcraft. ART addresses the drivetrain requirements of two distinct next generation aircraft classes: Future Air Attack Vehicle, a 10,000 to 20,000 lb. aircraft capable of undertaking tactical support and air-to-air missions; and Advanced Cargo Aircraft, a 60,000 to 80,000 lb. aircraft capable of heavy life field support operations. Both tiltrotor and more conventional helicopter configurations are included in the ART program. Specific objectives of ART include reduction of drivetrain weight by 25 percent compared to baseline state-of-the-art drive systems configured and sized for the next generation aircraft, reduction of noise level at the transmission source by 10 dB relative to a suitably sized and configured baseline, and attainment of at least a 5000 hr mean-time-between-removal. The technical approach for achieving the ART goals includes application of the latest available component, material, and lubrication technology to advanced concept drivetrains that utilize new ideas in gear configuration, transmission layout, and airframe/drivetrain integration. To date, candidate drivetrain systems were carried to a conceptual design stage, and tradeoff studies were conducted resulting in selection of an ART transmission configuration for each of the four contractors. The final selection was based on comparative weight, noise, and reliability studies. A description of each of the selected ART designs is included. Preliminary design of each of the four selected ART transmission was completed, as have mission impact studies wherein comparisons of aircraft mission performance and life cycle costs are undertaken for the next generation aircraft with ART and with the baseline transmission.

  19. Tooth contact shift in loaded spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Savage, M.; Altidis, P. C.; Lewicki, D. G.; Coy, J. J.; Litvin, F. L.

    1989-01-01

    An analytical method is presented to predict the shifts of the contact ellipses of spiral bevel gear teeth under load. The contact ellipse shift is the motion of the tooth contact position from the ideal pitch point to its location under load. The shifts are due to the elastic motions of the gear and pinion supporting shafts and bearings. The calculations include the elastic deflections of the gear shafts and the deflections of the four shaft bearings. The method assumes that the surface curvature of each tooth is constant near the unloaded pitch point. Results from these calculations will help designers reduce transmission weight without seriously reducing transmission performance.

  20. Tooth Contact Shift in Loaded Spiral Bevel Gears

    NASA Technical Reports Server (NTRS)

    Savage, M.; Altidis, P. C.; Lewicki, D. G.; Coy, J. J.; Litvin, F. L.

    1989-01-01

    An analytical method is presented to predict the shifts of the contact ellipses of spiral bevel gear teeth under load. The contact ellipse shift is the motion of the tooth contact position from the ideal pitch point to its location under load. The shifts are due to the elastic motions of the gear and pinion supporting shafts and bearings. The calculations include the elastic deflections of the gear shafts and the deflections of the four shaft bearings. The method assumes that the surface curvature of each tooth is constant near the unloaded pitch point. Results from these calculations will help designers reduce transmission weight without seriously reducing transmission performance.

  1. Licklider Transmission Protocol Implementation

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott C.; Krupiarz, Chris

    2011-01-01

    This software is an implementation of the Licklider Transmission Protocol (LTP), a communications protocol intended to support the Bundle Protocol in Delay-Tolerant Network (DTN) operations. LTP is designed to provide retransmission-based reliability over links characterized by extremely long message round-trip times and/or frequent interruptions in connectivity. Communication in interplanetary space is the most prominent example of this sort of environment, and LTP is principally aimed at supporting long-haul reliable transmission over deep-space RF links. Like any reliable transport service employing ARQ (Automatic Repeat re-Quests), LTP is stateful. In order to assure the reception of a block of data it has sent, LTP must retain for possible retransmission all portions of that block which might not have been received yet. In order to do so, it must keep track of which portions of the block are known to have been received so far, and which are not, together with any additional information needed for purposes of retransmitting part, or all, of the block. Long round-trip times mean substantial delay between the transmission of a block of data and the reception of an acknowledgement from the block s destination, signaling arrival of the block. If LTP postponed transmission of additional blocks of data until it received acknowledgement of the arrival of all prior blocks, valuable opportunities to use what little deep space transmission bandwidth is available would be forever lost. For this reason, LTP is based in part on a notion of massive state retention. Any number of requested transmission conversations (sessions) may be concurrently in flight at various displacements along the link between two LTP engines, and the LTP engines must necessarily retain transmission status and retransmission resources for all of them. Moreover, if any of the data of a given block are lost en route, it will be necessary to retain the state of that transmission during an additional

  2. Mechanical transmission of poleroviruses.

    PubMed

    Hoffmann, K; Verbeek, M; Romano, A; Dullemans, A M; van den Heuvel, J F; van der Wilk, F

    2001-02-01

    Previously, transmission of poleroviruses has relied solely on the use of their aphid vectors. Biolistic inoculation allowed for the first time the mechanical transmission of Beet western yellows virus (BWYV) and Potato leafroll virus (PLRV) to several host plants. Inoculation with purified preparations and viral RNA extracts of PLRV resulted in 30-50% systemically infected Nicotiana occidentalis P1 plants and 15-30% infected Nicotiana clevelandii plants. Particle bombardment was also used successfully to infect N. clevelandii plants with in vitro RNA transcripts of full-length cDNA of BWYV.

  3. Reception-Conversion Subsystem (RXCV) for microwave power transmission system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    As part of a program to demonstrate the feasibility of power transmission from space, an approximately 25 sq m Reception-Conversion Subsystem was designed and tested. The device collects high power microwave energy, converts it into dc, and dissipates it in an instrumented demonstration load.

  4. Transmission of Norovirus Within Households in Quininde, Ecuador.

    PubMed

    Gastañaduy, Paul A; Vicuña, Yosselin; Salazar, Fabian; Broncano, Nely; Gregoricus, Nicole; Vinjé, Jan; Chico, Martha; Parashar, Umesh D; Cooper, Philip J; Lopman, Ben

    2015-09-01

    We studied the transmission of norovirus infection in households in Quininde, Ecuador. Among household contacts of norovirus positive children with diarrhea, norovirus negative children with diarrhea and asymptomatic controls, infection attack rates were 33%, 8% and 18%, respectively (N = 45, 36, 83). Infection attack rates were higher when index children had a higher viral load.

  5. Load regulating expansion fixture

    DOEpatents

    Wagner, Lawrence M.; Strum, Michael J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.

  6. Load regulating expansion fixture

    DOEpatents

    Wagner, L.M.; Strum, M.J.

    1998-12-15

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.

  7. Load sensing system

    DOEpatents

    Sohns, C.W.; Nodine, R.N.; Wallace, S.A.

    1999-05-04

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast inventories of stored nuclear material can be continuously monitored and inventoried of minimal cost. 4 figs.

  8. Dynamic localized load balancing

    NASA Astrophysics Data System (ADS)

    Balandin, Sergey I.; Heiner, Andreas P.

    2003-08-01

    Traditionally dynamic load balancing is applied in resource-reserved connection-oriented networks with a large degree of managed control. Load balancing in connectionless networks is rather rudimentary and is either static or requires network-wide load information. This paper presents a fully automated, traffic driven dynamic load balancing mechanism that uses local load information. The proposed mechanism is easily deployed in a multi-vendor environment in which only a subset of routers supports the function. The Dynamic Localized Load Balancing (DLLB) mechanism distributes traffic based on two sets of weights. The first set is fixed and is inverse proportional to the path cost, typically the sum of reciprocal bandwidths along the path. The second weight reflects the utilization of the link to the first next hop along the path, and is therefore variable. The ratio of static weights defines the ideal load distribution, the ratio of variable weights the node-local load distribution estimate. By minimizing the difference between variable and fixed ratios the traffic distribution, with the available node-local knowledge, is optimal. The above mechanism significantly increases throughput and decreases delay from a network-wide perspective. Optionally the variable weight can include load information of nodes downstream to prevent congestion on those nodes. The latter function further improves network performance, and is easily implemented on top of the standard OSPF signaling. The mechanism does not require many node resources and can be implemented on existing router platforms.

  9. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, Hiroyuki; Lin-Liu, Yuh-Ren; DeGrassie, John S.

    1991-01-01

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

  10. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.

    1991-08-27

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.

  11. Optimized Minimal Inductance Transmission Line Configuration for Z-Pinch Experiments

    SciTech Connect

    Hurricane, O

    2003-10-16

    Successful dynamic Z-pinch experiments generally require good current delivery to the target load. Power flow losses through highly inductive transmission line configurations reduce the current available to the load. In this Brief Report, a variational calculus technique is used to determine the transmission line configuration that produces the least possible inductance and therefore the best possible current delivery for Z-pinch experiments.

  12. Propagation along azimuthally magnetized ferrite-loaded circular waveguides

    NASA Technical Reports Server (NTRS)

    Mueller, R. S.; Rosenbaum, F. J.

    1977-01-01

    The paper describes the modal dispersion characteristics of electromagnetic waves traveling along the azimuthally magnetized ferrite-loaded coaxial transmission line and the ferrite-loaded wire. The modal dispersion curves are used to determine the pass and stop bands of normal propagation. Boundary-value problems were solved with Bolle-Heller functions. The dispersion characteristics of transverse electric modes are presented as plots of the normalized propagation constant vs the normalized frequency.

  13. Responses of transmission-line networks to electrostatic discharge electromagnetic pulses

    NASA Astrophysics Data System (ADS)

    Zhou, Xing; Wang, Qingguo; Li, Yang

    2013-03-01

    A modelling method of transmission-line networks based on Baum-Liu-Tesche (BLT) equation is investigated, and a use of BLT equation for calculating transmission-line load responses in the time domain is discussed. From the frequency-domain BLT equation, the expressions for the propagation function at each terminal load are derived. Using the propagation function and time-domain convolution calculation, the transient load responses in the time domain are gained. For special cases of a dendriform network and an annular network, the transient load responses excited by electrostatic discharge (ESD) pulse are calculated. Compared with test results, and the agreement of the calculation is excellent. The modelling and calculating method could be used to investigate the load responses of transmission-line networks, and estimate the influence of electromagnetic pulses on networks.

  14. Influence of linear profile modification and loading conditions on the dynamic tooth load and stress of high contact ratio gears

    NASA Technical Reports Server (NTRS)

    Lee, Chinwai; Lin, Hsiang Hsi; Oswald, Fred B.; Townsend, Dennis P.

    1990-01-01

    A computer simulation for the dynamic response of high-contact-ratio spur gear transmissions is presented. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented examines various profile modifications under realistic loading conditions. The effect of these modifications on the dynamic load (force) between mating gear teeth and the dynamic root stress is presented. Since the contact stress is dependent on the dynamic load, minimizing dynamic loads will also minimize contact stresses. It is shown that the combination of profile modification and the applied load (torque) carried by a gear system has a significant influence on gear dynamics. The ideal modification at one value of applied load will not be the best solution for a different load. High-contact-ratio gears were found to require less modification than standard low-contact-ratio gears. High-contact-ratio gears are more adversely affected by excess modification than by under modification. In addition, the optimal profile modification required to minimize the dynamic load (hence the contact stress) on a gear tooth differs from the optimal modification required to minimize the dynamic root (bending) stress. Computer simulation can help find the design tradeoffs to determine the best profile modification to satisfy the conflicting constraints of minimizing both the load and root stress in gears which must operate over a range of applied loads.

  15. Continuously variable transmission

    SciTech Connect

    Itoh, H.; Okada, M.

    1986-11-25

    This patent describes a continuously variable transmission for transmitting a torque from an engine to a final reduction gear, comprising: an input shaft connected with the engine at one end thereof; a continuously variable transmission means having a driving pulley with a fixed member and a movable member, the movable member being actuated by an hydraulic cylinder to form a V-shaped opening between the fixed member and movable member, a driven pulley with another fixed member and another movable member. The other movable member is similarly actuated by another hydraulic cylinder to form another V-shaped opening between the other fixed member and the other movable member, and a belt member spanning the pulleys provides for a continuously variable transmission ratio; a planetary gear unit including a sun gear, a plurality of pinion gears which mesh with the sun gear and are connected with the driven pulley and a ring gear which meshes with the plurality of pinion gears; and a rotation transmitting means for transmitting rotation of the input shaft to the planetary gear unit. The rotation transmitting means is provided between the input shaft and the planetary gear unit and includes a shaft connected with the sun gear of the planetary gear unit and a first gear connected with the input shaft. The first gear is located between the engine and the continuously variable transmission means.

  16. Autonomous data transmission apparatus

    DOEpatents

    Kotlyar, Oleg M.

    1997-01-01

    A autonomous borehole data transmission apparatus for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters.

  17. Borehole data transmission apparatus

    DOEpatents

    Kotlyar, Oleg M.

    1993-01-01

    A borehole data transmission apparatus whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

  18. Borehole data transmission apparatus

    DOEpatents

    Kotlyar, O.M.

    1993-03-23

    A borehole data transmission apparatus is described whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

  19. Transmission of Mumps

    MedlinePlus

    ... Links World Health Organization Medline Plus Transmission of Mumps Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir Español: Transmisión de las paperas Mumps Virus Still Around Mumps still occurs in the ...

  20. Automatic transmission line monitor

    NASA Technical Reports Server (NTRS)

    Parsons, W. E.; Richards, L. O.

    1971-01-01

    Monitor improves complex network reliability in computer data links and command transmission lines. System evaluates circuit performance against preselected criteria, identifies and stores data indicating out-of-tolerance conditions, conducts closed loop testing, and provides for operation under command of digital computer that determines restoration priorities.

  1. Laser power transmission

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.

    1992-01-01

    An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

  2. Facsimile Transmission Standards

    DTIC Science & Technology

    1993-10-01

    transmettre les cartes tactiques et les compte rendu de situation. La presente note technique expose les 6lements nec~ssaires A la transmission de t~l6copies...Group MI machines introduced digital scanning techniques in which the single photoelectric cell was replaced with a Charged Coupled Device (CCD) array

  3. Dilemmas of Cultural Transmission

    ERIC Educational Resources Information Center

    Kováts-Németh, Mária

    2016-01-01

    The fundamental problem of the 21st century is that in the modern civilization "the transmission of values is not stable." There is nothing, except for the natural sense of justice and some legal traditions, which would exercise selective power on social behavior. At a critical time in 1949 Albert Szent-Györgyi drew the attention to the…

  4. Automatic Transmission Vehicle Injuries

    PubMed Central

    Fidler, Malcolm

    1973-01-01

    Four drivers sustained severe injuries when run down by their own automatic cars while adjusting the carburettor or throttle linkages. The transmission had been left in the “Drive” position and the engine was idling. This accident is easily avoidable. PMID:4695693

  5. Transmission planning in China

    SciTech Connect

    Dong, Jun; Zhang, Jing

    2009-07-15

    Though China is well along in restructuring its power markets, it still has some way to travel before economic considerations receive adequate weight in transmission planning decisions. Adoption of more sophisticated tools such as multi-agent modeling will help China continue in its progress in achieving this. (author)

  6. Multistage Planetary Power Transmissions

    NASA Technical Reports Server (NTRS)

    Hadden, G. B.; Dyba, G. J.; Ragen, M. A.; Kleckner, R. J.; Sheynin, L.

    1986-01-01

    PLANETSYS simulates thermomechanical performance of multistage planetary performance of multistage planetary power transmission. Two versions of code developed, SKF version and NASA version. Major function of program: compute performance characteristics of planet bearing for any of six kinematic inversions. PLANETSYS solves heat-balance equations for either steadystate or transient thermal conditions, and produces temperature maps for mechanical system.

  7. Autonomous data transmission apparatus

    DOEpatents

    Kotlyar, O.M.

    1997-03-25

    A autonomous borehole data transmission apparatus is described for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters. 4 figs.

  8. Categories and Music Transmission

    ERIC Educational Resources Information Center

    Gatien, Greg

    2009-01-01

    Lucy Green's (2008) "Music, Informal Learning, and the School: A New Classroom Pedagogy" gives rise to an interesting corollary. Does the manner of music's transmission inform one's understanding of a musical category? While categories of music can be difficult to define according to strict musical characteristics, a better understanding of…

  9. Transmission Acoustic Vibration Testing.

    DTIC Science & Technology

    1985-07-01

    DRVENO Fiue6 xeimna eroCosScin HOUIN The baeiehuig(iue7 sasn odZ4Amgei umalycsigwihn 5 pud ro omciig h hosn isteoiihmcie.ndwih 0 ons h mahie catnosfte...tooth load, P is power, and the suL- scripts indicate reference level. These relationships reflect that doubling the speed, load or power increases...USAAVRACON-TR-83-D-34 UNCLASSIFIED D AAK5I92- - 82-CSSF/61/3 NL I0013EI sonl*.lf.~fmommmmoii-m NNNNNEl 1.8. 1111L2 111. NATION -W EUO TNAOS-16 *~)fl 11111

  10. Function of the medial meniscus in force transmission and stability.

    PubMed

    Walker, Peter S; Arno, Sally; Bell, Christopher; Salvadore, Gaia; Borukhov, Ilya; Oh, Cheongeun

    2015-06-01

    We studied the combined role of the medial meniscus in distributing load and providing stability. Ten normal knees were loaded in combinations of compressive and shear loading as the knee was flexed over a full range. A digital camera tracked the motion, from which femoral-tibial contacts were determined by computer modelling. Load transmission was determined from the Tekscan for the anterior horn, central body, posterior horn, and the uncovered cartilage in the centre of the meniscus. For the three types of loading; compression only, compression and anterior shear, compression and posterior shear; between 40% and 80% of the total load was transmitted through the meniscus. The overall average was 58%, the remaining 42% being transmitted through the uncovered cartilage. The anterior horn was loaded only up to 30 degrees flexion, but played a role in controlling anterior femoral displacement. The central body was loaded 10-20% which would provide some restraint to medial femoral subluxation. Overall the posterior horn carried the highest percentage of the shear load, especially after 30 degrees flexion when a posterior shear force was applied, where the meniscus was estimated to carry 50% of the shear force. This study added new insights into meniscal function during weight bearing conditions, particularly its role in early flexion, and in transmitting shear forces.

  11. CRITICAL LOADS METHODS

    EPA Science Inventory

    I summarize the results of an interagency project that 1) defines a generic approach to quantifying and reporting critical loads, and 2) exercises that generic approach by examining a data rich system -- the critical loads of sulfur deposition and it's effect on the chronic acidi...

  12. Strip and load data

    NASA Technical Reports Server (NTRS)

    Jones, R. H.

    1984-01-01

    The method of taking batch data files and loading these files into the ADABAS data base management system (DBMS) is examined. This strip and load process allows the user to quickly become productive. Techniques for data fields and files definition are also included.

  13. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1977-01-01

    Design analysis of a microbial load monitor system flight engineering model was presented. Checkout of the card taper and media pump system was fabricated as well as the final two incubating reading heads, the sample receiving and card loading device assembly, related sterility testing, and software. Progress in these areas was summarized.

  14. Load induced blindness.

    PubMed

    Macdonald, James S P; Lavie, Nilli

    2008-10-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of perceptual load in a letter-search task and assessed its effect on the conscious perception of a search-irrelevant shape stimulus appearing in the periphery, using a direct measure of awareness (present/absent reports). Detection sensitivity (d') was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus--a phenomenon of load induced blindness.

  15. Load Induced Blindness

    ERIC Educational Resources Information Center

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of…

  16. Transportation and handling loads

    NASA Technical Reports Server (NTRS)

    Ostrem, F. E.

    1971-01-01

    Criteria and recommended practices are presented for the prediction and verification of transportation and handling loads for the space vehicle structure and for monitoring these loads during transportation and handling of the vehicle or major vehicle segments. Elements of the transportation and handling systems, and the forcing functions and associated loads are described. The forcing functions for common carriers and typical handling devices are assessed, and emphasis is given to the assessment of loads at the points where the space vehicle is supported during transportation and handling. Factors which must be considered when predicting the loads include the transportation and handling medium; type of handling fixture; transport vehicle speed; types of terrain; weather (changes in pressure of temperature, wind, etc.); and dynamics of the transportation modes or handling devices (acceleration, deceleration, and rotations of the transporter or handling device).

  17. Renewable Resource Integration Project - Scoping Study of Strategic Transmission, Operations, and Reliability Issues

    SciTech Connect

    Eto, Joseph; Budhraja, Vikram; Ballance, John; Dyer, Jim; Mobasheri, Fred; Eto, Joseph

    2008-07-01

    California is on a path to increase utilization of renewable resources. California will need to integrate approximately 30,000 megawatts (MW) of new renewable generation in the next 20 years. Renewable resources are typically located in remote locations, not near the load centers. Nearly two/thirds or 20,000 MW of new renewable resources needed are likely to be delivered to Los Angeles Basin transmission gateways. Integration of renewable resources requires interconnection to the power grid, expansion of the transmission system capability between the backbone power grid and transmission gateways, and increase in delivery capacity from transmission gateways to the local load centers. To scope the transmission, operations, and reliability issues for renewables integration, this research focused on the Los Angeles Basin Area transmission gateways where most of new renewables are likely. Necessary actions for successful renewables integration include: (1) Expand Los Angeles Basin Area transmission gateway and nomogram limits by 10,000 to 20,000 MW; (2) Upgrade local transmission network for deliverability to load centers; (3) Secure additional storage, demand management, automatic load control, dynamic pricing, and other resources that meet regulation and ramping needed in real time operations; (4) Enhance local voltage support; and (5) Expand deliverability from Los Angeles to San Diego and Northern California.

  18. [Transmission and prevention].

    PubMed

    Reboulot, B

    1992-01-01

    This work provides an overview of current knowledge of AIDS transmission and attitudes toward prevention in France. Most HIV infections are transmitted sexually. AIDS became established in the homosexual community in California because of mutual infection by members of the community with large numbers of sexual partners. The possibility of heterosexual transmission was not immediately recognized by all observers. Different publications estimate the risk of seroconversion after 1 episode of heterosexual coitus at between 1:100 and 1:1000/ Heterosexual transmission is bidirectional, but male-female transmission appears easier. Factors favoring transmission identified in AFrican studies include multiple partners, sexually transmitted diseases, anal penetration, relations during menstruation, and age. No epidemiologic study has concluded that kissing with mutual salivary contact can lead to infection, but oral-genital sex may pose a risk. As of October 1991, 966 cases of posttransfusion AIDS had been diagnosed in France, and an estimated 6000-9000 HIV seropositive persons were infected through transfusion. 239 AIDS cases were reported in hemophiliacs and others with coagulation disorders. 1200 of 3500 French hemophiliacs receiving transfusions before 1985 are seropositive. The risk of developing AIDS from a transfusions in France is currently estimated at 1/250,000. HIV transmission among drug addicts results from sharing contaminated needles and syringes. The risk of infection for health workers treating those who are HIV positive appears small; only about 30 documented cases have been reported worldwide, including 3 of 10,000 cases in France. The risk that an infected mother will have a seropositive baby is estimated at 25% in France. The number of seropositive women in the world is estimated at over 3 million, with 80% in sub-Saharan Africa. As of October 1991, 16,0000-36,000 seropositive women and 1500 seropositive children were estimated to live in France

  19. Advanced transmission studies

    NASA Technical Reports Server (NTRS)

    Coy, John J.; Bill, Robert C.

    1988-01-01

    The NASA Lewis Research Center and the U.S. Army Aviation Systems Command share an interest in advancing the technology for helicopter propulsion systems. In particular, this paper presents highlights from that portion of the program in drive train technology and the related mechanical components. The major goals of the program are to increase the life, reliability, and maintainability; reduce the weight, noise, and vibration; and maintain the relatively high mechanical efficiency of the gear train. The current activity emphasizes noise reduction technology and analytical code development followed by experimental verification. Selected significant advances in technology for transmissions are reviewed, including advanced configurations and new analytical tools. Finally, the plan for future transmission research is presented.

  20. Drill string transmission line

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe

    2006-03-28

    A transmission line assembly for transmitting information along a downhole tool comprising a pin end, a box end, and a central bore traveling between the pin end and the box end, is disclosed in one embodiment of the invention as including a protective conduit. A transmission line is routed through the protective conduit. The protective conduit is routed through the central bore and the ends of the protective conduit are routed through channels formed in the pin end and box end of the downhole tool. The protective conduit is elastically forced into a spiral or other non-linear path along the interior surface of the central bore by compressing the protective conduit to a length within the downhole tool shorter than the protective conduit.

  1. Sixteen speed powershift transmission

    SciTech Connect

    McAskill, J.P.

    1991-06-25

    This patent describes a transmission. It includes a transmission housing; a first shaft rotatably mounted in the housing and having a third gear fixed for rotation therewith and fourth and fifth gears rotatably mounted thereto, the fourth and fifth gears meshing with the first and second gears, respectively; first and second clutch means for selectively fixing the fourth and fifth gears, respectively, for rotation with the second shaft; a third shaft rotatably mounted in the housing and having a sixth gear fixed for rotation therewith and seventh and eighth gears rotatably mounted thereto, the seventh and eighth gears meshing with the first and second gears, respectively; third and fourth clutch means for selectively fixing the seventh and eighth gears respectively, for rotation with the third shaft.

  2. Data transmission networks

    NASA Technical Reports Server (NTRS)

    Alexovich, Robert

    1990-01-01

    A task order was written by the High Resolution, High Frame Rate Video Technology (HHVT) project engineers to investigate data compression techniques that could be applied to the HHVT system, and both existing and planned downlink/uplink capabilities of the Space Shuttle and Space Station Freedom. The following tasks were included: (1) Investigate signal channel availability and determine both the maximum possible data rate and the average data rate; (2) Identify time blocks for HHVT video transmission assuming time sharing and interruptions in the communication links; (3) Determine the bit error rates to be expected; and (4) Define the transmit and receive interfaces. A summary chart of the data transmission capabilities for Tracking and Data Relay Satellite System (TDRSS), the Space Shuttle, Space Station Freedom, Spacelab, and USLab are also presented.

  3. The Cost of Transmission for Wind Energy: A Review of Transmission Planning Studies

    SciTech Connect

    Mills, Andrew D.; Wiser, Ryan; Porter, Kevin

    2009-02-02

    The rapid development of wind power that the United States has experienced over the last several years has been coupled with a growing concern that wind development will require substantial additions to the nation's transmission infrastructure. Transmission is particularly important for wind power due to the locational dependence of wind resources, the relatively low capacity factor of wind plants, and the mismatch between the short lead time to build a new wind project and the longer lead time often needed to plan, permit, and construct transmission. It is clear that institutional issues related to transmission planning, siting, and cost allocation will pose major obstacles to accelerated wind power deployment, but also of concern is the potential cost of this infrastructure build out. Simply put, how much extra cost will society bear to deliver wind power to load centers? Without an answer to this question, there can be no consensus on whether or not the cost of developing transmission for wind will be a major barrier to further wind deployment, or whether the institutional barriers to transmission expansion are likely to be of more immediate concern. In this report, we review a sample of 40 detailed transmission studies that have included wind power. These studies cover a broad geographic area, and were completed from 2001-2008. Our primary goal in reviewing these studies is to develop a better understanding of the transmission costs needed to access growing quantities of wind generation. A secondary goal is to gain a better appreciation of the differences in transmission planning approaches in order to identify those methodologies that seem most able to estimate the incremental transmission costs associated with wind development. Finally, we hope that the resulting dataset and discussion might be used to inform the assumptions, methods, and results of higher-level assessment models that are sometimes used to estimate the cost of wind deployment (e.g. NEMS and

  4. Cable load sensing device

    DOEpatents

    Beus, Michael J.; McCoy, William G.

    1998-01-01

    Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable "no-load" condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or weight of the load supported by the cable.

  5. Load Balancing Scientific Applications

    SciTech Connect

    Pearce, Olga Tkachyshyn

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  6. Facsimile Transmission of Microforms.

    DTIC Science & Technology

    1983-12-30

    author and Whould not be construed as an official Department of the Army position, policy, or decision, unless so designated by other documentation...beconstrued as an official Department of the Army position, policy, or decision, unless so designated by other documentation. ,, -- UNCLASSIFIED SECURITY...researcher. Some form of tele- facsimile transmission of microform is needed. This study is designed to to describe the current state of the technology, and

  7. Compact change speed transmission

    SciTech Connect

    Iwanaga, K.; Yamaguchi, T.

    1989-06-06

    A change speed transmission is described comprising: a stationary part; an input member; an output member; first and second planetary gear sets; clutch and brake means for selectively controlling the first and second planetary gear sets to provide a plurality of forward speed rations and a reverse speed ratio between the input and output member; the clutch and brake means including a first clutch, a first one-way clutch, and a second one-way clutch which, when the first clutch is engaged, provide a path of transmission of reaction to the stationary part thereby establishing a path of transmission of torque through at least a part of the first and second planetary gear sets to achieve a predetermined one speed ratio of the forward speed ratios; the clutch and brake means including also a brake and a second slutch which, when both of the brake and the second clutch are engaged, hinder the action of the second one-way clutch and that of the first one-way clutch, respectively, thereby providing engine braking during running with the predetermined one speed ratio; the first clutch including means forming a drum-shaped member disposed radially outwardly of and receiving at least one of the first and second planetary gear sets, and an actuating piston of the first clutch; and the second clutch including an actuating piston slidably disposed within the actuating piston of the first clutch.

  8. Intercultural Transmission of Values: The Role of Transmission Belts.

    ERIC Educational Resources Information Center

    Schonpflug, Ute

    2001-01-01

    Explored the effect of "transmission belts" (conditions favorable to cultural transmission within particular socioeconomic and cultural contexts) on the similarity of values between Turkish fathers and their sons. Data from father-son dyads in Germany indicated that transmission of values related to the collective value categories of…

  9. Transmission access and pricing with multiple separate energy forward markets

    SciTech Connect

    Gribik, P.R.; Angelidis, G.A.; Kovacs, R.R.

    1999-08-01

    California`s congestion management protocols provide comparable access and prices to all users of the transmission system (power exchange and bilateral contract parties). The users implicitly bid for capacity on major transmission paths between zones. The Independent System Operator (ISO) allocates the available transmission capacity on these paths so that it maximizes the value of this capacity as measured by the users` bids. Everyone scheduling flow on a congested path is charged the marginal-cost-based price for using the path. The ISO keeps each party`s portfolio of generation and load individually in balance when adjusting schedules to relieve congestion on interzonal paths. By keeping the portfolios of the different parties separate, the ISO clears its transmission market without arranging energy trades between parties. Parties are responsible for arranging their own trades. The ISO does not become involved in the energy forward markets.

  10. Experimental investigation and model development for a harmonic drive transmission.

    SciTech Connect

    Preissner, C.; Shu, D.; Royston, T. J.; Univ. of Illinois at Chicago

    2007-01-01

    Harmonic drive transmissions (HDTs) are compact, low-backlash, high-ratio, high-resolution rotary motion transmissions. One application to benefit from these attributes is the revolute joint robot. Engineers at the Advanced Photon Source (APS) are investigating the use of this type of robot for the positioning of an x-ray detector; understanding the properties of the robot components is crucial to modeling positioner behavior. The robot bearing elements had been investigated previously, leaving the transmission as the missing component. While the benefits of HDTs are well known, the disadvantages, including fluctuating dissipation characteristics and nonlinear stiffness, are not understood as well. These characteristics can contribute uncontrolled dynamics to the overall robot performance. A dynamometer has been constructed at the APS to experimentally measure the HDT's response. Empirical torque and position data were recorded for multiple transmission load cases and input conditions. In turn, a computer model of the dynamometer HDT system was constructed to approximate the observed response.

  11. Pulse transmission transmitter including a higher order time derivate filter

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-23

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission transmitter includes: a clock; a pseudorandom polynomial generator coupled to the clock, the pseudorandom polynomial generator having a polynomial load input; an exclusive-OR gate coupled to the pseudorandom polynomial generator, the exclusive-OR gate having a serial data input; a programmable delay circuit coupled to both the clock and the exclusive-OR gate; a pulse generator coupled to the programmable delay circuit; and a higher order time derivative filter coupled to the pulse generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  12. 29 CFR 1926.958 - External load helicopters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false External load helicopters. 1926.958 Section 1926.958 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Power Transmission and Distribution §...

  13. Predicting the Response of Electricity Load to Climate Change

    SciTech Connect

    Sullivan, Patrick; Colman, Jesse; Kalendra, Eric

    2015-07-28

    Our purpose is to develop a methodology to quantify the impact of climate change on electric loads in the United States. We perform simple linear regression, assisted by geospatial smoothing, on paired temperature and load time-series to estimate the heating- and coolinginduced sensitivity to temperature across 300 transmission zones and 16 seasonal and diurnal time periods. The estimated load sensitivities can be coupled with climate scenarios to quantify the potential impact of climate change on load, with a primary application being long-term electricity scenarios. The method allows regional and seasonal differences in climate and load response to be reflected in the electricity scenarios. While the immediate product of this analysis was designed to mesh with the spatial and temporal resolution of a specific electricity model to enable climate change scenarios and analysis with that model, we also propose that the process could be applied for other models and purposes.

  14. Load research manual. Volume 3. Load research for advanced technologies

    SciTech Connect

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. The manual includes guides to load research literature and glossaries of load research and statistical terms. In Volume 3, special load research procedures are presented for solar, wind, and cogeneration technologies.

  15. LOADING MACHINE FOR REACTORS

    DOEpatents

    Simon, S.L.

    1959-07-01

    An apparatus is described for loading or charging slugs of fissionable material into a nuclear reactor. The apparatus of the invention is a "muzzle loading" type comprising a delivery tube or muzzle designed to be brought into alignment with any one of a plurality of fuel channels. The delivery tube is located within the pressure shell and it is also disposed within shielding barriers while the fuel cantridges or slugs are forced through the delivery tube by an externally driven flexible ram.

  16. 16. UPPER PASSENGER LOADING ZONE, NOTE LOADING ZONE BELOW WITH ...

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

    16. UPPER PASSENGER LOADING ZONE, NOTE LOADING ZONE BELOW WITH TURN STILES - Jefferson National Expansion Memorial Arch, Mississippi River between Washington & Poplar Streets, Saint Louis, Independent City, MO

  17. Jerky loads on surface-hardened gears

    NASA Technical Reports Server (NTRS)

    Rettig, H.; Wirth, X.

    1978-01-01

    Damage occurs again and again in practice in the form of transmissions with surface hardened gears which break after a very long operating time (explained by seldom occurring jerky loads). Gear drives are frequently exposed to jerky stresses which are greater than their fatigue limit. These stresses are considered in gear calculations, first, by shock factors when the transmission is to be designed as high endurance with regard to overloads and, second, in the form of operating ratios when the design is to be time enduring with regard to overloads. The size of the operating ratio depends not only on torque characteristics, drive and processing machine, but also on the material and heat treatment.

  18. A proposal to Improve Electric Power Transmission Efficiency of the Transmission line from Yekepa to Buchanan of the CLSG Power System Redevelopment Interconnection Project Using FACTS Devices

    NASA Astrophysics Data System (ADS)

    Jackson, Samuel Mulbah

    This Work examined improving the electric power transmission efficiency of a portion of the CLSG (Cote d'Ivoire, Liberia, Sierra Leone, and Guinea) Interconnection Redevelopment Project of 1141 km high voltage transmission line. As with all ac transmission, present, new, and upgraded, they exhibit four electrical properties: resistance, inductance, capacitance, and conductance. These parameters affect the transmission line's ability to fulfil its function as part of the power system. A transmission system functions are to transport electric power from a generating source to a central point, to transport bulk power from a central point to wholesale delivery points (sub transmission substations), and to act as a tie points with interconnecting transmission lines from other power systems for emergency or economic reasons. In this work a portion of the CLSG Interconnection was simulated in MATLAB using different loading conditions. In determining voltage, current, and power, all sending end and receiving end quantities were determined at different sending end power levels. This was done on an incremental basis starting from 25 MW to 300 MW at 0.8 power factor. The results obtained from these produced data that were then used to plot graphs, among them the voltage profiles of the line at different loading conditions. The line loadability curves produced at different loading conditions were also plotted. So these curves provided illumination on the behavior and deficiencies of the line. Those deficiencies meant that there was a need for modification so as to keep the system in a safe operating voltage condition at different loading conditions. The line was compensated where needed, employing shunt capacitive compensation under different loading conditions for the purpose of making the receiving end voltage equal with the sending end voltage or within usable voltage levels. The line compensation provided a flat voltage profile at those loading conditions.

  19. Strategic bidding for load serving entity in electricity markets

    NASA Astrophysics Data System (ADS)

    AlZahrani, Hashim A.

    The objective of this thesis is to study different options of load serving entities (LSEs) in electricity markets. Two models of pool-based electricity market have been studied. The difference between them is in the effect of transmission constraints. Transmission Constraints are neglected in the first model. Various bidding scenarios are presented in the first model to study the effect of retail, interruptible, and bidding prices on the profit of single LSE utilizing Monte Carlo simulation method. Genetic algorithm optimization tool is used to get the optimal bidding. In the second model, a new approach is presented to study the impact of transmission constraints (TCs) on the profit of LSE and its bidding strategy utilizing IEEE 30 bus system. Different pricing settlements then tested the effects of TCs to investigate the best pricing option. It has been shown that the first rejected bid settlement is the best selection for load serving entity.

  20. Breast-feeding and Transmission of HIV-1.

    PubMed

    John-Stewart, Grace; Mbori-Ngacha, Dorothy; Ekpini, Rene; Janoff, Edward N; Nkengasong, John; Read, Jennifer S; Van de Perre, Phillippe; Newell, Marie-Louise

    2004-02-01

    Breast-feeding substantially increases the risk of HIV-1 transmission from mother to child, and although peripartum antiretroviral therapy prophylaxis significantly decreases the risk of mother-to-child transmission around the time of delivery, this approach does not affect breast-feeding transmission. Increased maternal RNA viral load in plasma and breast milk is strongly associated with increased risk of transmission through breast-feeding, as is breast health, and it has been suggested that exclusive breast-feeding could be associated with lower rates of breast-feeding transmission than mixed feeding of both breast- and other milk or feeds. Transmission through breast-feeding can take place at any point during lactation, and the cumulative probability of acquisition of infection increases with duration of breast-feeding. HIV-1 has been detected in breast milk in cell-free and cellular compartments; infant gut mucosal surfaces are the most likely site at which transmission occurs. Innate and acquired immune factors may act most effectively in combination to prevent primary HIV-1 infection by breast milk.

  1. Spur, helical, and spiral bevel transmission life modeling

    NASA Technical Reports Server (NTRS)

    Savage, Michael; Rubadeux, Kelly L.; Coe, Harold H.; Coy, John J.

    1994-01-01

    A computer program, TLIFE, which estimates the life, dynamic capacity, and reliability of aircraft transmissions, is presented. The program enables comparisons of transmission service life at the design stage for optimization. A variety of transmissions may be analyzed including: spur, helical, and spiral bevel reductions as well as series combinations of these reductions. The basic spur and helical reductions include: single mesh, compound, and parallel path plus revert star and planetary gear trains. A variety of straddle and overhung bearing configurations on the gear shafts are possible as is the use of a ring gear for the output. The spiral bevel reductions include single and dual input drives with arbitrary shaft angles. The program is written in FORTRAN 77 and has been executed both in the personal computer DOS environment and on UNIX workstations. The analysis may be performed in either the SI metric or the English inch system of units. The reliability and life analysis is based on the two-parameter Weibull distribution lives of the component gears and bearings. The program output file describes the overall transmission and each constituent transmission, its components, and their locations, capacities, and loads. Primary output is the dynamic capacity and 90-percent reliability and mean lives of the unit transmissions and the overall system which can be used to estimate service overhaul frequency requirements. Two examples are presented to illustrate the information available for single element and series transmissions.

  2. Spur, helical, and spiral bevel transmission life modeling

    NASA Astrophysics Data System (ADS)

    Savage, Michael; Rubadeux, Kelly L.; Coe, Harold H.; Coy, John J.

    1994-04-01

    A computer program, TLIFE, which estimates the life, dynamic capacity, and reliability of aircraft transmissions, is presented. The program enables comparisons of transmission service life at the design stage for optimization. A variety of transmissions may be analyzed including: spur, helical, and spiral bevel reductions as well as series combinations of these reductions. The basic spur and helical reductions include: single mesh, compound, and parallel path plus revert star and planetary gear trains. A variety of straddle and overhung bearing configurations on the gear shafts are possible as is the use of a ring gear for the output. The spiral bevel reductions include single and dual input drives with arbitrary shaft angles. The program is written in FORTRAN 77 and has been executed both in the personal computer DOS environment and on UNIX workstations. The analysis may be performed in either the SI metric or the English inch system of units. The reliability and life analysis is based on the two-parameter Weibull distribution lives of the component gears and bearings. The program output file describes the overall transmission and each constituent transmission, its components, and their locations, capacities, and loads. Primary output is the dynamic capacity and 90-percent reliability and mean lives of the unit transmissions and the overall system which can be used to estimate service overhaul frequency requirements. Two examples are presented to illustrate the information available for single element and series transmissions.

  3. Impacts of Demand-Side Resources on Electric Transmission Planning

    SciTech Connect

    Hadley, Stanton W.; Sanstad, Alan H.

    2015-01-01

    Will demand resources such as energy efficiency (EE), demand response (DR), and distributed generation (DG) have an impact on electricity transmission requirements? Five drivers for transmission expansion are discussed: interconnection, reliability, economics, replacement, and policy. With that background, we review the results of a set of transmission studies that were conducted between 2010 and 2013 by electricity regulators, industry representatives, and other stakeholders in the three physical interconnections within the United States. These broad-based studies were funded by the US Department of Energy and included scenarios of reduced load growth due to EE, DR, and DG. While the studies were independent and used different modeling tools and interconnect-specific assumptions, all provided valuable results and insights. However, some caveats exist. Demand resources were evaluated in conjunction with other factors, and limitations on transmission additions between scenarios made understanding the role of demand resources difficult. One study, the western study, included analyses over both 10- and 20-year planning horizons; the 10-year analysis did not show near-term reductions in transmission, but the 20-year indicated fewer transmission additions, yielding a 36percent capital cost reduction. In the eastern study the reductions in demand largely led to reductions in local generation capacity and an increased opportunity for low-cost and renewable generation to export to other regions. The Texas study evaluated generation changes due to demand, and is in the process of examining demand resource impacts on transmission.

  4. Lock-up control system for automobile automatic power transmissions

    SciTech Connect

    Matsuoka, T.; Sumida, S.

    1986-04-08

    This patent describes a lock-up control system for an automobile's automatic power transmission. This system consists of a hydraulic torque converter including an input member and an output member, multiple stage transmission gear, the transmission gear means being provided with gear stages which are selected by changing power transmitting paths therein. An engine speed sensor for sensing engine load. A gear stage selector connected with the engine speed sensing means and the load sensor to receive output signals from the speed sensor and the load sensing means. A lock-up zone discriminator is connected with the engine speed sensor and the load sensor to receive the output signals from each of the sensors. The lock-up zone discriminator includes lock-up control map means having at least one lock-up release data line and at least one lock-up engage data line which are drawn on the basis of engine speed and engine load for at least one of the gear stages. The lock-up engage data line is located at a higher engine speed side than the release data line. In the lock-up zone are discriminating means for comparing the output signals with the data lines and generating a control signal for controlling engagement of the lock-up means, gear shift means for selectively shifting the gear stage by changing the power transmitting path in the multiple stage transmission gear means. Electro-megnetic means are responsive to the signal from the gear stage selecting means for controlling the gear shift means. Lock-up control means for releasing the lock-up means are irrespective of the control signal from the lock-up zone discriminating means when en engine throttle valve is full closed and enlarging the lock-up zone so that the lock-up means is engaged when the engine throttle valve is opened again to a position included in the enlarged lock-up zone.

  5. Planetary Transmission Diagnostics

    NASA Technical Reports Server (NTRS)

    Lewicki, David G. (Technical Monitor); Samuel, Paul D.; Conroy, Joseph K.; Pines, Darryll J.

    2004-01-01

    This report presents a methodology for detecting and diagnosing gear faults in the planetary stage of a helicopter transmission. This diagnostic technique is based on the constrained adaptive lifting algorithm. The lifting scheme, developed by Wim Sweldens of Bell Labs, is a time domain, prediction-error realization of the wavelet transform that allows for greater flexibility in the construction of wavelet bases. Classic lifting analyzes a given signal using wavelets derived from a single fundamental basis function. A number of researchers have proposed techniques for adding adaptivity to the lifting scheme, allowing the transform to choose from a set of fundamental bases the basis that best fits the signal. This characteristic is desirable for gear diagnostics as it allows the technique to tailor itself to a specific transmission by selecting a set of wavelets that best represent vibration signals obtained while the gearbox is operating under healthy-state conditions. However, constraints on certain basis characteristics are necessary to enhance the detection of local wave-form changes caused by certain types of gear damage. The proposed methodology analyzes individual tooth-mesh waveforms from a healthy-state gearbox vibration signal that was generated using the vibration separation (synchronous signal-averaging) algorithm. Each waveform is separated into analysis domains using zeros of its slope and curvature. The bases selected in each analysis domain are chosen to minimize the prediction error, and constrained to have the same-sign local slope and curvature as the original signal. The resulting set of bases is used to analyze future-state vibration signals and the lifting prediction error is inspected. The constraints allow the transform to effectively adapt to global amplitude changes, yielding small prediction errors. However, local wave-form changes associated with certain types of gear damage are poorly adapted, causing a significant change in the

  6. Synthesis of camptothecin-loaded gold nanomaterials

    NASA Astrophysics Data System (ADS)

    Xing, Zhimin; Liu, Zhiguo; Zu, Yuangang; Fu, Yujie; Zhao, Chunjian; Zhao, Xiuhua; Meng, Ronghua; Tan, Shengnan

    2010-04-01

    Camptothecin-loaded gold nanomaterials have been synthesized by the sodium borohydride reduction method under a strong basic condition. The obtained gold nanomaterials have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-vis absorption spectroscopy. The camptothecin-loaded gold colloidal solution was very stable and can be stored for more than two months at room temperature without obvious changes. The color of the colloidal solution can change from wine red to purple and blue during the acidifying process. It was revealed that the release of camptothecin and the aggregation of gold nanoparticles can be controlled by tuning the solution pH. The present study implied that the gold nanomaterials can be used as the potential carrier for CPT delivery.

  7. Estimation of dynamic rotor loads for the rotor systems research aircraft: Methodology development and validation

    NASA Technical Reports Server (NTRS)

    Duval, R. W.; Bahrami, M.

    1985-01-01

    The Rotor Systems Research Aircraft uses load cells to isolate the rotor/transmission systm from the fuselage. A mathematical model relating applied rotor loads and inertial loads of the rotor/transmission system to the load cell response is required to allow the load cells to be used to estimate rotor loads from flight data. Such a model is derived analytically by applying a force and moment balance to the isolated rotor/transmission system. The model is tested by comparing its estimated values of applied rotor loads with measured values obtained from a ground based shake test. Discrepancies in the comparison are used to isolate sources of unmodeled external loads. Once the structure of the mathematical model has been validated by comparison with experimental data, the parameters must be identified. Since the parameters may vary with flight condition it is desirable to identify the parameters directly from the flight data. A Maximum Likelihood identification algorithm is derived for this purpose and tested using a computer simulation of load cell data. The identification is found to converge within 10 samples. The rapid convergence facilitates tracking of time varying parameters of the load cell model in flight.

  8. Gearbox design for uncertain load requirements using active robust optimization

    NASA Astrophysics Data System (ADS)

    Salomon, Shaul; Avigad, Gideon; Purshouse, Robin C.; Fleming, Peter J.

    2016-04-01

    Design and optimization of gear transmissions have been intensively studied, but surprisingly the robustness of the resulting optimal design to uncertain loads has never been considered. Active Robust (AR) optimization is a methodology to design products that attain robustness to uncertain or changing environmental conditions through adaptation. In this study the AR methodology is utilized to optimize the number of transmissions, as well as their gearing ratios, for an uncertain load demand. The problem is formulated as a bi-objective optimization problem where the objectives are to satisfy the load demand in the most energy efficient manner and to minimize production cost. The results show that this approach can find a set of robust designs, revealing a trade-off between energy efficiency and production cost. This can serve as a useful decision-making tool for the gearbox design process, as well as for other applications.

  9. Offset Waveguide Transmission Measurements

    NASA Technical Reports Server (NTRS)

    Cravey, Robin

    1997-01-01

    This report describes measurements to determine transmission losses in S-band (2.60-3.95 GHz) waveguide sections due to misalignment of the sections relative to each other. The experiments were performed in support of the Hydrostar program to determine the feasibility of using deployable waveguide sections in a large space radiometer. The waveguide sections would possibly be hinged and folded for launch, then deployed in space to form long sections of waveguide. Since very low losses are required for radiometer applications, the effects of potential misalignment after deployment of the waveguide sections may be significant. These measurements were performed in the Electromagnetic Properties Measurement Laboratory in the Electromagnetics Research Branch.

  10. Dynamics of a split torque helicopter transmission

    NASA Astrophysics Data System (ADS)

    Krantz, Timothy L.

    1994-06-01

    Split torque designs, proposed as alternatives to traditional planetary designs for helicopter main rotor transmissions, can save weight and be more reliable than traditional designs. This report presents the results of an analytical study of the system dynamics and performance of a split torque gearbox that uses a balance beam mechanism for load sharing. The Lagrange method was applied to develop a system of equations of motion. The mathematical model includes time-varying gear mesh stiffness, friction, and manufacturing errors. Cornell's method for calculating the stiffness of spur gear teeth was extended and applied to helical gears. The phenomenon of sidebands spaced at shaft frequencies about gear mesh fundamental frequencies was simulated by modeling total composite gear errors as sinusoid functions. Although the gearbox has symmetric geometry, the loads and motions of the two power paths differ. Friction must be considered to properly evaluate the balance beam mechanism. For the design studied, the balance beam is not an effective device for load sharing unless the coefficient of friction is less than 0.003. The complete system stiffness as represented by the stiffness matrix used in this analysis must be considered to precisely determine the optimal tooth indexing position.

  11. Engineering the electrical characteristics of resonant type metamaterial transmission lines

    NASA Astrophysics Data System (ADS)

    Martin, F.; Bonache, J.; Gil, M.; Sisó, G.

    2008-04-01

    This paper is focused on the control of the electrical characteristics of resonant type metamaterial transmission lines, that is, transmission lines loaded with complementary split ring resonators (CSRRs). The key parameters of metamaterial transmission lines for microwave and millimetre wave circuit design are the characteristic impedance and the phase constant (rather than the effective magnetic permeability or dielectric permittivity). Thanks to the presence of reactive elements loading the host line, metamaterial transmission lines exhibit a major design flexibility that can be useful for circuit design purposes. Specifically, we can tailor the dispersion diagram and the characteristic impedance to some extent. By virtue of this, it is possible the design of microwave and millimetre wave components with superior performance in terms of bandwidth, or the design of multi-band components, both of interest in modern wireless communication systems. Thanks to the small electrical size of the unit cell of such lines, the resulting metamaterial-based components are also very small and fully compatible with planar technology (that is, no lumped elements are used). Different examples are provided to illustrate the possibilities of resonant type metamaterial transmission lines. This includes hybrid couplers, power dividers and phase shifters, among others. The paper includes also the theoretical foundations of the approach.

  12. [Oral transmission of Chagas' disease].

    PubMed

    Toso M, Alberto; Vial U, Felipe; Galanti, Norbel

    2011-02-01

    The traditional transmission pathways of Chagas' disease are vectorial, transfusional, transplacental and organ transplantation. However, oral transmission is gaining importance. The first evidence of oral transmission was reported in Brazil in 1965. Nowadays the oral route is the transmission mode in 50% of cases in the Amazon river zone. Oral infection is produced by the ingestion of infected triatomine bugs or their feces, undercooked meat from infested host animals and food contaminated with urine or anal secretion of infected marsupials. Therefore travelers to those zones should be advised about care to be taken with ingested food. In Chile, this new mode of transmission should be considered in public health policies.

  13. The Born transmission eigenvalue problem

    NASA Astrophysics Data System (ADS)

    Cakoni, Fioralba; Colton, David; Rezac, Jacob D.

    2016-10-01

    In this paper we study the distribution of transmission eigenvalues in the complex plane for obstacles whose contrast is small in magnitude. We use a first order approximation of the refractive index to derive and study an approximate interior transmission problem. In the case of spherically stratified media, we prove existence and discreteness of transmission eigenvalues and derive a condition under which the complex part of transmission eigenvalues cannot lie in a strip parallel to the real axis. For obstacles with general shape, we demonstrate that if transmission eigenvalues exist then they form a discrete set.

  14. Household Transmission of Influenza Virus.

    PubMed

    Tsang, Tim K; Lau, Lincoln L H; Cauchemez, Simon; Cowling, Benjamin J

    2016-02-01

    Human influenza viruses cause regular epidemics and occasional pandemics with a substantial public health burden. Household transmission studies have provided valuable information on the dynamics of influenza transmission. We reviewed published studies and found that once one household member is infected with influenza, the risk of infection in a household contact can be up to 38%, and the delay between onset in index and secondary cases is around 3 days. Younger age was associated with higher susceptibility. In the future, household transmission studies will provide information on transmission dynamics, including the correlation of virus shedding and symptoms with transmission, and the correlation of new measures of immunity with protection against infection.

  15. Evolution and manipulation of parasitoid egg load.

    PubMed

    Gandon, Sylvain; Varaldi, Julien; Fleury, Frédéric; Rivero, Ana

    2009-11-01

    In proovigenic parasitoids such as Leptopilina boulardi, the female emerges with a limited egg load and no further eggs are produced during its adult life. A female thus runs the risk of exhausting this limited supply of eggs before the end of her life. Given that the production of an egg is costly, what is the evolutionarily stable egg load at emergence? This question has attracted a lot of attention in the last decade. Here, we analyze a model that allows us to track both the evolution and the population dynamics of a solitary, proovigenic parasitoid. First, we show how host-parasitoid dynamics feedbacks on the evolution of parasitoid egg load. Second, we use this model to consider the situation in which the parasitoid can be infected by a virus that manipulates the oviposition behavior of the females. In particular, we model the effect of the LbFV virus in L. boulardi, a virus that is known to enhance its horizontal transmission by increasing superparasitism (i.e., the laying of eggs in a host already parasitized). Specifically, we model (1) the effect of the virus on parasitoid egg load strategies, and (2) the evolution of egg load manipulation by the virus. This analysis yields two alternative, yet not mutually exclusive, adaptive explanations for the observation that females infected by the virus harbor higher egg loads than uninfected females. Infected females could either respond plastically to the infection status, or be manipulated by the virus. Further experimental work is required to distinguish between these two hypotheses. In a broader context, we present a general theoretical framework that allows us to study the epidemiology, the evolution, the coevolution, and the evolution of manipulation of various reproductive strategies of parasitoids.

  16. Dynamic Responses and Vibration Control of the Transmission Tower-Line System: A State-of-the-Art Review

    PubMed Central

    Chen, Bo; Guo, Wei-hua; Li, Peng-yun; Xie, Wen-ping

    2014-01-01

    This paper presented an overview on the dynamic analysis and control of the transmission tower-line system in the past forty years. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission tower-line system under dynamic excitations are also put forward. It also reviews the analytical models and approaches of the transmission tower, transmission lines, and transmission tower-line systems, respectively, which contain the theoretical model, finite element (FE) model and the equivalent model; shows the advances in wind responses of the transmission tower-line system, which contains the dynamic effects under common wind loading, tornado, downburst, and typhoon; and discusses the dynamic responses under earthquake and ice loads, respectively. The vibration control of the transmission tower-line system is also reviewed, which includes the magnetorheological dampers, friction dampers, tuned mass dampers, and pounding tuned mass dampers. PMID:25105161

  17. Dynamic responses and vibration control of the transmission tower-line system: a state-of-the-art review.

    PubMed

    Chen, Bo; Guo, Wei-hua; Li, Peng-yun; Xie, Wen-ping

    2014-01-01

    This paper presented an overview on the dynamic analysis and control of the transmission tower-line system in the past forty years. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission tower-line system under dynamic excitations are also put forward. It also reviews the analytical models and approaches of the transmission tower, transmission lines, and transmission tower-line systems, respectively, which contain the theoretical model, finite element (FE) model and the equivalent model; shows the advances in wind responses of the transmission tower-line system, which contains the dynamic effects under common wind loading, tornado, downburst, and typhoon; and discusses the dynamic responses under earthquake and ice loads, respectively. The vibration control of the transmission tower-line system is also reviewed, which includes the magnetorheological dampers, friction dampers, tuned mass dampers, and pounding tuned mass dampers.

  18. Automated manual transmission clutch controller

    DOEpatents

    Lawrie, Robert E.; Reed, Jr., Richard G.; Rausen, David J.

    1999-11-30

    A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

  19. Simplified power shift transmission

    SciTech Connect

    Michael, R.A.

    1987-04-21

    A multi-speed transmission is described for transferring power between a first shaft and a second shaft, the transmission comprising: a compound planetary assembly including a sun gear, a ring gear concentric with the sun gear, a reaction gear concentric with the ring gear, a planetary gear carrier rotatably supporting first and second sets of planet gears, the first planet gear set intermeshing with the ring gear. The sun gear and the second planet gear set intermesh with the first planet gear set and the reaction gear, means for selectively coupling the first shaft with the sun gear and the reaction gear, and means for selectively preventing rotation of the ring gear, and reaction gear and the planetary carrier; a simple planetary assembly comprising a sun gear component concentric with the sun gear of the compound planetary assembly, a ring gear component concentric with both of the sun gears, and a planetary gear carrier component rotatably supporting a set of planet gears, the planet gear set meshing with the sun gear and the ring gear of the simple planetary.

  20. Automatic transmission structure

    SciTech Connect

    Iwase, Y.; Morisawa, K.

    1987-03-24

    An automatic transmission is described comprising: an output shaft of the transmission including a stepped portion; a parking gear spline-connected with the output shaft on a first side of the stepped portion; a plurality of governor values mounted on a rear side of the parking gear and radially disposed around the output shaft on the first side of the stepped portion; a speed meter drive gear spline-connected with the output shaft on a second side of the stepped portion and on a rear side of the governor valves; and an annular spacer fitted on the output shaft on the second side of the stepped portion between the governor valves and the speed meter drive gear to abut on each of the governor valves and the speed meter drive gear. The annular member is constructed separately from the speed meter drive gear and has an outer diameter larger than an outer diameter of the speed meter drive gear thereby resulting in a contact area between the annular space and the speed meter drive gear which is smaller than a contact area between the annular spacer and the rear side of the governor valves; the drive gear being axially secured relative to the output shaft by a bearing thereby enabling a fixed axial positioning of the annular spacer on the output shaft.

  1. Transmission shift control assembly

    SciTech Connect

    Dzioba, D.L.

    1989-04-18

    This patent describes a transmission shift control assembly mounted on a steering column having a longitudinal axis comprising: bracket means secured to the steering column; transmission shift cable means having a portion secured to the bracket means and a portion linearly movable relative to the secured portion; mounting means on the bracket cable drive arm means having an axis and being rotatably mounted on the rotary axis on the mounting means oblique to the longitudinal axis and including a cable connecting portion secured to the movable portion of the cable means and lever mounting means adjacent the mounting means; operator control means including lever means, pin means for pivotally mounting the lever means on the lever mounting means on an axis substantially perpendicular to the rotary axis and positioning arm means formed on the lever means and extending from the pin means; and detent gate means disposed on the bracket means in position to abut the positioning arm means for limiting the extent of pivotal movement of the lever means.

  2. Colorado Electrical Transmission Grid

    DOE Data Explorer

    Zehner, Richard E.

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: Xcel Energy Publication Date: 2012 Title: Colorado XcelEnergy NonXcel Transmission Network Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science (CIRES), University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains transmission network of Colorado Spatial Domain: Extent: Top: 4540689.017558 m Left: 160606.141934 m Right: 758715.946645 m Bottom: 4098910.893397m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System ’1984 (WGS ’1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shapefile

  3. Broadband transmission EPR spectroscopy.

    PubMed

    Hagen, Wilfred R

    2013-01-01

    EPR spectroscopy employs a resonator operating at a single microwave frequency and phase-sensitive detection using modulation of the magnetic field. The X-band spectrometer is the general standard with a frequency in the 9-10 GHz range. Most (bio)molecular EPR spectra are determined by a combination of the frequency-dependent electronic Zeeman interaction and a number of frequency-independent interactions, notably, electron spin - nuclear spin interactions and electron spin - electron spin interactions, and unambiguous analysis requires data collection at different frequencies. Extant and long-standing practice is to use a different spectrometer for each frequency. We explore the alternative of replacing the narrow-band source plus single-mode resonator with a continuously tunable microwave source plus a non-resonant coaxial transmission cell in an unmodulated external field. Our source is an arbitrary wave digital signal generator producing an amplitude-modulated sinusoidal microwave in combination with a broadband amplifier for 0.8-2.7 GHz. Theory is developed for coaxial transmission with EPR detection as a function of cell dimensions and materials. We explore examples of a doublet system, a high-spin system, and an integer-spin system. Long, straigth, helical, and helico-toroidal cells are developed and tested with dilute aqueous solutions of spin label hydroxy-tempo. A detection limit of circa 5 µM HO-tempo in water at 800 MHz is obtained for the present setup, and possibilities for future improvement are discussed.

  4. Evaluation of a load cell model for dynamic calibration of the rotor systems research aircraft

    NASA Technical Reports Server (NTRS)

    Duval, R. W.; Bahrami, H.; Wellman, B.

    1985-01-01

    The Rotor Systems Research Aircraft uses load cells to isolate the rotor/transmission system from the fuselage. An analytical model of the relationship between applied rotor loads and the resulting load cell measurements is derived by applying a force-and-moment balance to the isolated rotor/transmission system. The model is then used to estimate the applied loads from measured load cell data, as obtained from a ground-based shake test. Using nominal design values for the parameters, the estimation errors, for the case of lateral forcing, were shown to be on the order of the sensor measurement noise in all but the roll axis. An unmodeled external load appears to be the source of the error in this axis.

  5. Integration of MHD load models with circuit representations the Z generator.

    SciTech Connect

    Jennings, Christopher A.; Ampleford, David J.; Jones, Brent Manley; McBride, Ryan D.; Bailey, James E.; Jones, Michael C.; Gomez, Matthew Robert.; Cuneo, Michael Edward; Nakhleh, Charles; Stygar, William A.; Savage, Mark Edward; Wagoner, Timothy C.; Moore, James K.

    2013-03-01

    MHD models of imploding loads fielded on the Z accelerator are typically driven by reduced or simplified circuit representations of the generator. The performance of many of the imploding loads is critically dependent on the current and power delivered to them, so may be strongly influenced by the generators response to their implosion. Current losses diagnosed in the transmission lines approaching the load are further known to limit the energy delivery, while exhibiting some load dependence. Through comparing the convolute performance of a wide variety of short pulse Z loads we parameterize a convolute loss resistance applicable between different experiments. We incorporate this, and other current loss terms into a transmission line representation of the Z vacuum section. We then apply this model to study the current delivery to a wide variety of wire array and MagLif style liner loads.

  6. Time of flight measurements of unirradiated and irradiated nuclear graphite under cyclic compressive load

    NASA Astrophysics Data System (ADS)

    Bodel, W.; Atkin, C.; Marsden, B. J.

    2017-04-01

    The time-of-flight technique has been used to investigate the stiffness of nuclear graphite with respect to the grade and grain direction. A loading rig was developed to collect time-of-flight measurements during cycled compressive loading up to 80% of the material's compressive strength and subsequent unloading of specimens along the axis of the applied stress. The transmission velocity (related to Young's modulus), decreased with increasing applied stress; and depending on the graphite grade and orientation, the modulus then increased, decreased or remained constant upon unloading. These tests were repeated while observing the microstructure during the load/unload cycles. Initial decreases in transmission velocity with compressive load are attributed to microcrack formation within filler and binder phases. Three distinct types of behaviour occur on unloading, depending on the grade, irradiation, and loading direction. These different behaviours can be explained in terms of the material microstructure observed from the microscopy performed during loading.

  7. Permeability Evolution in Natural Fractures Subject to Cyclic Loading and Gouge Formation

    NASA Astrophysics Data System (ADS)

    Vogler, Daniel; Amann, Florian; Bayer, Peter; Elsworth, Derek

    2016-09-01

    Increasing fracture aperture by lowering effective normal stress and by inducing dilatant shearing and thermo-elastic effects is essential for transmissivity increase in enhanced geothermal systems. This study investigates transmissivity evolution for fluid flow through natural fractures in granodiorite at the laboratory scale. Processes that influence transmissivity are changing normal loads, surface deformation, the formation of gouge and fracture offset. Normal loads were varied in cycles between 1 and 68 MPa and cause transmissivity changes of up to three orders of magnitude. Similarly, small offsets of fracture surfaces of the order of millimeters induced changes in transmissivity of up to three orders of magnitude. During normal load cycling, the fractures experienced significant surface deformation, which did not lead to increased matedness for most experiments, especially for offset fractures. The resulting gouge material production may have caused clogging of the main fluid flow channels with progressing loading cycles, resulting in reductions of transmissivity by up to one order of magnitude. During one load cycle, from low to high normal loads, the majority of tests show hysteretic behavior of the transmissivity. This effect is stronger for early load cycles, most likely when surface deformation occurs, and becomes less pronounced in later cycles when asperities with low asperity strength failed. The influence of repeated load cycling on surface deformation is investigated by scanning the specimen surfaces before and after testing. This allows one to study asperity height distribution and surface deformation by evaluating the changes of the standard deviation of the height, distribution of asperities and matedness of the fractures. Surface roughness, as expressed by the standard deviation of the asperity height distribution, increased during testing. Specimen surfaces that were tested in a mated configuration were better mated after testing, than

  8. A load factor formula

    NASA Technical Reports Server (NTRS)

    Miller, Roy G

    1927-01-01

    The ultimate test of a load factor formula is experience. The chief advantages of a semi rational formula over arbitrary factors are that it fairs in between points of experience and it differentiates according to variables within a type. Structural failure of an airplane apparently safe according to the formula would call for a specific change in the formula. The best class of airplanes with which to check a load factor formula seems to be those which have experienced structural failure. Table I comprises a list of the airplanes which have experienced failure in flight traceable to the wing structure. The load factor by formula is observed to be greater than the designed strength in each case, without a single exception. Table II comprises the load factor by formula with the designed strength of a number of well-known service types. The formula indicates that by far the majority of these have ample structural strength. One case considered here in deriving a suitable formula is that of a heavy load carrier of large size and practically no reserve power.

  9. The integration of renewable energy sources into electric power transmission systems

    SciTech Connect

    Barnes, P.R.; Dykas, W.P.; Kirby, B.J.; Purucker, S.L.; Lawler, J.S.

    1995-07-01

    Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission upgrades beyond the construction of a substation to connect to the grid. Except in the Southwest, significant investment to strengthen transmission systems will be required to support the development of high-capacity renewable sources of 1000 MW or greater in areas remote from major load centers. Cost estimates for new transmission facilities to integrate and dispatch some of these high-capacity renewable sources ranged from several million dollars to approximately one billion dollars, with the latter figure an increase in total investment of 35%, assuming that the renewable source is the only user of the transmission facility.

  10. Millikelvin thermal and electrical performance of lossy transmission line filters

    SciTech Connect

    Slichter, Daniel; Naaman, Ofer; Siddiqi, Irfan

    2009-03-11

    We report on the scattering parameters and Johnson noise emission of low-pass stripline filters employing a magnetically loaded silicone dielectric down to 25 mK. The transmission characteristic of a device with f-3dB=1.3 GHz remains essentially unchanged upon cooling. Another device with f-edB=0.4 GHz, measured in its stopband, exhibits a steady state noise power emission consistent with a temperature difference of a few mK relative to a well-anchored cryogenic microwave attenuator at temperatures down to 25 mK, thus presenting a matched thermal load.

  11. Great Plains Wind Energy Transmission Development Project

    SciTech Connect

    Brad G. Stevens, P.E.; Troy K. Simonsen; Kerryanne M. Leroux

    2012-06-09

    In fiscal year 2005, the Energy & Environmental Research Center (EERC) received funding from the U.S. Department of Energy (DOE) to undertake a broad array of tasks to either directly or indirectly address the barriers that faced much of the Great Plains states and their efforts to produce and transmit wind energy at the time. This program, entitled Great Plains Wind Energy Transmission Development Project, was focused on the central goal of stimulating wind energy development through expansion of new transmission capacity or development of new wind energy capacity through alternative market development. The original task structure was as follows: Task 1 - Regional Renewable Credit Tracking System (later rescoped to Small Wind Turbine Training Center); Task 2 - Multistate Transmission Collaborative; Task 3 - Wind Energy Forecasting System; and Task 4 - Analysis of the Long-Term Role of Hydrogen in the Region. As carried out, Task 1 involved the creation of the Small Wind Turbine Training Center (SWTTC). The SWTTC, located Grand Forks, North Dakota, consists of a single wind turbine, the Endurance S-250, on a 105-foot tilt-up guyed tower. The S-250 is connected to the electrical grid on the 'load side' of the electric meter, and the power produced by the wind turbine is consumed locally on the property. Establishment of the SWTTC will allow EERC personnel to provide educational opportunities to a wide range of participants, including grade school through college-level students and the general public. In addition, the facility will allow the EERC to provide technical training workshops related to the installation, operation, and maintenance of small wind turbines. In addition, under Task 1, the EERC hosted two small wind turbine workshops on May 18, 2010, and March 8, 2011, at the EERC in Grand Forks, North Dakota. Task 2 involved the EERC cosponsoring and aiding in the planning of three transmission workshops in the midwest and western regions. Under Task 3, the

  12. Truck loading rack blending

    SciTech Connect

    Boubenider, E.

    1995-12-01

    Blending, the combining of two or more components to make a single product, has become widely used in most loading rack applications. Blending should not be confused with additive injection, which is the injection of very small doses of enhancers, detergents and dyes into a product stream. Changes in the environmental protection laws in the early 90`s have put increasing demands on marketing terminals with regards to reformulated fuels and environmental protection concerns. As a result of these new mandates, terminals have turned to blending at the loading rack as an economical and convenient means in meeting these new requirements. This paper will discuss some of these mandates and how loading rack blending is used for different applications. Various types of blending will also be discussed along with considerations for each method.

  13. Shuttle car loading system

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr. (Inventor)

    1985-01-01

    A system is described for loading newly mined material such as coal, into a shuttle car, at a location near the mine face where there is only a limited height available for a loading system. The system includes a storage bin having several telescoping bin sections and a shuttle car having a bottom wall that can move under the bin. With the bin in an extended position and filled with coal the bin sections can be telescoped to allow the coal to drop out of the bin sections and into the shuttle car, to quickly load the car. The bin sections can then be extended, so they can be slowly filled with more while waiting another shuttle car.

  14. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1978-01-01

    Attempts are made to provide a total design of a Microbial Load Monitor (MLM) system flight engineering model. Activities include assembly and testing of Sample Receiving and Card Loading Devices (SRCLDs), operator related software, and testing of biological samples in the MLM. Progress was made in assembling SRCLDs with minimal leaks and which operate reliably in the Sample Loading System. Seven operator commands are used to control various aspects of the MLM such as calibrating and reading the incubating reading head, setting the clock and reading time, and status of Card. Testing of the instrument, both in hardware and biologically, was performed. Hardware testing concentrated on SRCLDs. Biological testing covered 66 clinical and seeded samples. Tentative thresholds were set and media performance listed.

  15. Comparison of transmission error predictions with noise measurements for several spur and helical gears

    NASA Astrophysics Data System (ADS)

    Houser, Donald R.; Oswald, Fred B.; Valco, Mark J.; Drago, Raymond J.; Lenski, Joseph W., Jr.

    1994-06-01

    Measured sound power data from eight different spur, single and double helical gear designs are compared with predictions of transmission error by the Load Distribution Program. The sound power data was taken from the recent Army-funded Advanced Rotorcraft Transmission project. Tests were conducted in the NASA gear noise rig. Results of both test data and transmission error predictions are made for each harmonic of mesh frequency at several operating conditions. In general, the transmission error predictions compare favorably with the measured noise levels.

  16. Comparison of Transmission Error Predictions with Noise Measurements for Several Spur and Helical Gears

    NASA Technical Reports Server (NTRS)

    Houser, Donald R.; Oswald, Fred B.; Valco, Mark J.; Drago, Raymond J.; Lenski, Joseph W., Jr.

    1994-01-01

    Measured sound power data from eight different spur, single and double helical gear designs are compared with predictions of transmission error by the Load Distribution Program. The sound power data was taken from the recent Army-funded Advanced Rotorcraft Transmission project. Tests were conducted in the NASA gear noise rig. Results of both test data and transmission error predictions are made for each harmonic of mesh frequency at several operating conditions. In general, the transmission error predictions compare favorably with the measured noise levels.

  17. The Effects of Load Distribution and Gradient on Load Carriage

    DTIC Science & Technology

    2010-12-01

    Postural adjustments while standing with two types of loaded backpack. Ergonomics, 30(10), 1425–1430. Bobet, J. & Norman, R. W. (1984). Effects of...Danise, B., Milanese, S., Pirunsan, U., & Trott, P. (2002). Adolescent standing postural response to backpack loads: a randomized controlled...loads are authorized. Numerous studies conclude that backpack loads have a huge impact on soldiers’ load carrying ability. The platoon’s combat

  18. Ocean Tide Loading Computation

    NASA Technical Reports Server (NTRS)

    Agnew, Duncan Carr

    2005-01-01

    September 15,2003 through May 15,2005 This grant funds the maintenance, updating, and distribution of programs for computing ocean tide loading, to enable the corrections for such loading to be more widely applied in space- geodetic and gravity measurements. These programs, developed under funding from the CDP and DOSE programs, incorporate the most recent global tidal models developed from Topex/Poscidon data, and also local tide models for regions around North America; the design of the algorithm and software makes it straightforward to combine local and global models.

  19. Astrocytes Potentiate Synaptic Transmission

    NASA Astrophysics Data System (ADS)

    Nadkarni, Suhita

    2005-03-01

    A recent experimental study shows that astrocytes, a subtype of glia, are able to influence the spontaneous activity in the brain via calcium dependent glutamate release. We model the coupling mechanism between an astrocyte and a neuron based on experimental data. This coupling is dynamic and bi-directional, such that the modulations in intracellular calcium concentrations in astrocytes affect neuronal excitability and vice versa via a glutamatergic pathway. We demonstrate through simple neural-glial circuits that increases in the intracellular calcium concentration in astrocytes nearby can enhance spontaneous activity in a neuron, a significant mechanism said to be involved in plasticity and learning. The pattern of this marked increase in spontaneous firing rate in our model quantitatively follows that observed in the experiment. Further, depending on the type of synaptic connections diverging from the neuron, it can either inhibit or excite the ensuing dynamics and potentiate synaptic transmission, thus reinstating the integral role played by astrocytes in normal neuronal dynamics.

  20. Television Transmission Technology

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The VKP-7990 Multistage Depressed Collector (MDC) Klystron is a result of cooperative development by Varian Associates, Inc., the National Association of Broadcasters, Lewis Research Center, the Public Broadcasting System and TV transmitter manufacturers. The effort was initiated to make power amplifying devices with efficiencies comparable to VHF available to UHF operators. The klystron is a vacuum tube used to generate and amplify ultrahigh frequencies but at low efficiencies because most of the energy is dissipated as waste heat. Lewis had earlier developed the MDC to enhance the efficiency of communications satellite transmissions. Varian Microwave Power Tube Products, which has since become Communications and Power Industries, and Lewis combined the MDC and the klystron, resulting in a product which increases efficiency by recovering some of the residual energy that normally would be lost as heat. The MDC klystron cuts the electric power consumption of UHF-TV transmitters in half; there are 90 units in operation in 36 UHF-TV stations.

  1. Transmission seal development

    NASA Technical Reports Server (NTRS)

    Brien, M.

    1977-01-01

    An experimental evaluation was performed on a high-speed (72.9 m/s, 14,349 ft/min) transmission seal of the synergistic type. During testing of the seal, oil leakage occurred at positive bearing cavity pressures. Modifications were made in an attempt to eliminate the leakage but none were completely successful. Leakage appears to be the result of questionable positioning of the sealing elements resulting in inadequate shaft contact by the oil side sealing element. This condition may be related to the nonsymmetrical shape of the elastomeric retainer and to dimensional changes caused by swelling of the elastomeric retainer from exposure to the sealed fluid. Indications of a speed dependent leakage characteristic were also observed.

  2. The automated command transmission

    NASA Astrophysics Data System (ADS)

    Inoue, Y.; Satoh, S.

    A technique for automated command transmission (ACT) to GEO-stationed satellites is presented. The system is intended for easing the command center workload. The ACT system determines the relation of the commands to on-board units, connects the telemetry with on-board units, defines the control path on the spacecraft, identifies the correspondence of back-up units to primary units, and ascertains sunlight or eclipse conditions. The system also has the address of satellite and command decoders, the ID and content for the mission command sequence, group and inhibit codes, a listing of all available commands, and restricts the data to a command sequence. Telemetry supplies data for automated problem correction. All other missions operations are terminated during system recovery data processing after a crash. The ACT system is intended for use with the GMS spacecraft.

  3. Transfer Mechanisms for Heavy Loads

    NASA Technical Reports Server (NTRS)

    Cassisi, V.

    1986-01-01

    Soft hydraulic system gently maneuvers loads. Upper and lower load-transfer mechanisms attach through mounting holes in vertical beam adjustable or gross positioning. Fine positioning of load accomplished by hydraulic cylinders that move trunnion support and trunnion clamp through short distances. Useful in transferring large loads in railroads, agriculture, shipping, manufacturing, and even precision assembly of large items.

  4. Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Zakrajsek, James J.

    2001-01-01

    NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

  5. Complex dynamics of blackouts in power transmission systems.

    PubMed

    Carreras, B A; Lynch, V E; Dobson, I; Newman, D E

    2004-09-01

    In order to study the complex global dynamics of a series of blackouts in power transmission systems a dynamical model of such a system has been developed. This model includes a simple representation of the dynamical evolution by incorporating the growth of power demand, the engineering response to system failures, and the upgrade of generator capacity. Two types of blackouts have been identified, each having different dynamical properties. One type of blackout involves the loss of load due to transmission lines reaching their load limits but no line outages. The second type of blackout is associated with multiple line outages. The dominance of one type of blackout over the other depends on operational conditions and the proximity of the system to one of its two critical points. The model displays characteristics such as a probability distribution of blackout sizes with power tails similar to that observed in real blackout data from North America.

  6. Technology of optical azimuth transmission

    NASA Astrophysics Data System (ADS)

    Lu, Honggang; Hu, Chunsheng; Wang, Xingshu; Gao, Yang

    2012-11-01

    It often needs transfer a reference from one place to another place in aerospace and guided missile launching. At first, principles of several typical optical azimuth transmission methods are presented. Several typical methods are introduced, such as Theodolite (including gyro-theodolite) collimation method, Camera series method, Optical apparatus for azimuth method and polarization modulated light transmission method. For these typical azimuth transmission methods, their essential theories are elaborated. Then the devices, the application fields and limitations of these typical methods' are presented. Theodolite (including gyro-theodolite) collimation method is used in the ground assembly of spacecraft. Camera series method and optical apparatus for azimuth method are used in azimuth transmission between different decks of ship. Polarization modulated light transmission method is used in azimuth transmission of rocket and guided missile. At the last, the further developments of these methods are discussed.

  7. LOADING AND UNLOADING DEVICE

    DOEpatents

    Treshow, M.

    1960-08-16

    A device for loading and unloading fuel rods into and from a reactor tank through an access hole includes parallel links carrying a gripper. These links enable the gripper to go through the access hole and then to be moved laterally from the axis of the access hole to the various locations of the fuel rods in the reactor tank.

  8. Multidimensional spectral load balancing

    DOEpatents

    Hendrickson, Bruce A.; Leland, Robert W.

    1996-12-24

    A method of and apparatus for graph partitioning involving the use of a plurality of eigenvectors of the Laplacian matrix of the graph of the problem for which load balancing is desired. The invention is particularly useful for optimizing parallel computer processing of a problem and for minimizing total pathway lengths of integrated circuits in the design stage.

  9. Powertrain Embedded Diagnostic and Predictive Capability for an Automotive Transmission

    DTIC Science & Technology

    2012-08-01

    lock- washer, riveted to the 3rd range planetary sun gear had also been damaged during the testing. The rivets were sheared off by a sharp edge of... gear -path and the mechanical gear path to the output planetary ring gears . This creates a torsional shock that is probably difficult to estimate and...transmissions were operated around the clock under the most demanding speed and load set-points until critical gear or bearing failures resulted in loss

  10. Helicopter Transmission Research at NASA Lewis Research Center

    DTIC Science & Technology

    1988-11-10

    surface fatigue life and power-to-weight ratio of transmissions. High-contact-ratio (HCR) gears have at least two pairs of teeth in contact at all times...pairs of teeth , the individual tooth loading is less for HCR than for LCR designs, 3 thereby enabling a higher power-to-weight ratio. HCR gears...stresses, and surface damage factors. The program can analyze a variety of both epicyclic and single mesh systems with spur and helical gear teeth

  11. Load research manual. Volume 1. Load research procedures

    SciTech Connect

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

  12. Experimental validation of the direct transmissibility approach to classical transfer path analysis on a mechanical setup

    NASA Astrophysics Data System (ADS)

    Guasch, Oriol; García, Carlos; Jové, Jordi; Artís, Pere

    2013-05-01

    Transmissibility functions have received renewed interest given the important role they play in operational modal analysis and operational transfer path analysis. However, transmissibilities can also be used in the framework of classical transmission path analysis. This avoids some of the problems associated to the latter, such as the measurement of operational loads, or the need to remove the active parts of the system to measure frequency response functions. The key of the transmissibility approach to classical transfer path analysis relies on the notion of direct or blocked transmissibilities, which can be computed from standard measurable transmissibilities. The response at any degree of freedom to a system external load can then be decomposed in terms of the remaining degrees of freedom responses and the system direct transmissibilities. Although the theory supporting this approach has been known for long, no experimental validation test has been reported to date. It is the purpose of this paper to provide such a test by applying the method to a simple mechanical system for which an analytical solution can be derived. For different configurations, it will be shown that direct transmissibilities computed from measured transmissibilities compare fairly well with analytical results. This opens the door to apply the method to more complex situations of practical interest with confidence.

  13. Airborne transmission of Bordetella pertussis.

    PubMed

    Warfel, Jason M; Beren, Joel; Merkel, Tod J

    2012-09-15

    Pertussis is a contagious, acute respiratory illness caused by the bacterial pathogen Bordetella pertussis. Although it is widely believed that transmission of B. pertussis occurs via aerosolized respiratory droplets, no controlled study has ever documented airborne transmission of pertussis. We set out to determine if airborne transmission occurs between infected and naive animals, utilizing the baboon model of pertussis. Our results showed that 100% of exposed naive animals became infected even when physical contact was prevented, demonstrating that pertussis transmission occurs via aerosolized respiratory droplets.

  14. Combined use of the air monitoring system in production and transmission of electricity

    SciTech Connect

    Jakl, F.; Bakic, K.; Valencic, L.

    1997-08-01

    The paper presents a double use of the EIS (Environmental Information System) network for scheduling of thermal electricity generation with regard to ecological conditions (air quality in the vicinity of thermal power plants), and for control of the thermal loading of important transmission lines with regard to meteorological conditions. The Slovenian ecological monitoring system was set up fifteen years ago with the task of assuring acquisition of data about air pollution in the vicinity of thermal power plants. In the meantime it has been constantly upgraded and improved. At the end of 1994 immission, emission and meteorological data started to be on-line transmitted to the National Dispatching Centre. Problems with space and restrictions encountered at the construction of new transmission lines made researchers look for solutions that would allow a greater loading of transmission lines without threatening the system reliability. A method was consequently theoretically implemented about the monitoring of the thermal loading of the most important 400 kV transmission lines supported with meteorological data obtained from the EIS measuring system. Transmission of data from EIS into the Dispatching Centre, supported with an adequate software, will facilitate efficient control of the system at consideration of ecological limitations (electricity production in thermal power plants) and at the same time a more efficient exploitation of transmission lines in view of meteorological conditions. The main idea of this paper is the use of the same meteorological system for controlling both, thermal power generation and loading of important 400 kV overhead lines.

  15. Full circuit calculation for electromagnetic pulse transmission in a high current facility

    NASA Astrophysics Data System (ADS)

    Zou, Wenkang; Guo, Fan; Chen, Lin; Song, Shengyi; Wang, Meng; Xie, Weiping; Deng, Jianjun

    2014-11-01

    We describe herein for the first time a full circuit model for electromagnetic pulse transmission in the Primary Test Stand (PTS)—the first TW class pulsed power driver in China. The PTS is designed to generate 8-10 MA current into a z -pinch load in nearly 90 ns rise time for inertial confinement fusion and other high energy density physics research. The PTS facility has four conical magnetic insulation transmission lines, in which electron current loss exists during the establishment of magnetic insulation. At the same time, equivalent resistance of switches and equivalent inductance of pinch changes with time. However, none of these models are included in a commercially developed circuit code so far. Therefore, in order to characterize the electromagnetic transmission process in the PTS, a full circuit model, in which switch resistance, magnetic insulation transmission line current loss and a time-dependent load can be taken into account, was developed. Circuit topology and an equivalent circuit model of the facility were introduced. Pulse transmission calculation of shot 0057 was demonstrated with the corresponding code FAST (full-circuit analysis and simulation tool) by setting controllable parameters the same as in the experiment. Preliminary full circuit simulation results for electromagnetic pulse transmission to the load are presented. Although divergences exist between calculated and experimentally obtained waveforms before the vacuum section, consistency with load current is satisfactory, especially at the rising edge.

  16. Measuring alignment of loading fixture

    DOEpatents

    Scavone, Donald W.

    1989-01-01

    An apparatus and method for measuring the alignment of a clevis and pin type loading fixture for compact tension specimens include a pair of substantially identical flat loading ligaments. Each loading ligament has two apertures for the reception of a respective pin of the loading fixture and a thickness less than one-half of a width of the clevis opening. The pair of loading ligaments are mounted in the clevis openings at respective sides thereof. The loading ligaments are then loaded by the pins of the loading fixture and the strain in each loading ligament is measured. By comparing the relative strain of each loading ligament, the alignment of the loading fixture is determined. Preferably, a suitable strain gage device is located at each longitudinal edge of a respective loading ligament equidistant from the two apertures in order to determine the strain thereat and hence the strain of each ligament. The loading ligaments are made substantially identical by jig grinding the loading ligaments as a matched set. Each loading ligament can also be individually calibrated prior to the measurement.

  17. HIV community viral load trends in South Carolina.

    PubMed

    Chakraborty, Hrishikesh; Weissman, Sharon; Duffus, Wayne A; Hossain, Akhtar; Varma Samantapudi, Ashok; Iyer, Medha; Albrecht, Helmut

    2017-03-01

    Community viral load is an aggregate measure of HIV viral load in a particular geographic location, community, or subgroup. Community viral load provides a measure of disease burden in a community and community transmission risk. This study aims to examine community viral load trend in South Carolina and identify differences in community viral load trends between selected population subgroups using a state-wide surveillance dataset that maintains electronic records of all HIV viral load measurements reported to the state health department. Community viral load trends were examined using random mixed effects models, adjusting for age, race, gender, residence, CD4 counts, HIV risk group, and initial antiretroviral regimen during the study period, and time. The community viral load gradually decreased from 2004 to 2013 ( p < 0.0001). The number of new infections also decreased ( p = 0.0001) over time. A faster rate of decrease was seen among men compared to women ( p < 0.0001), men who have sex with men ( p = 0.0001) compared to heterosexuals, patients diagnosed in urban areas compared to that in rural areas ( p = 0.0004), and patients prescribed single-tablet regimen compared to multiple-tablet regimen ( p < 0.0001). While the state-wide community viral load decreased over time, the decline was not uniform among residence at diagnosis, HIV risk group, and single-tablet regimen versus multiple-tablet regimen subgroups. Slower declines in community viral load among females, those in rural areas, and heterosexuals suggest possible disparities in care that require further exploration. The association between using single-tablet regimen and faster community viral load decline is noteworthy.

  18. Load support system analysis high speed input pinion configuration

    NASA Technical Reports Server (NTRS)

    Gassel, S. S.; Pirvics, J.

    1979-01-01

    An analysis and a series of computerized calculations were carried out to explore competing prototype design concepts of a shaft and two taper-roller bearings systems to support the high-speed input pinion of an advanced commercial helicopter transmission. The results were used to evaluate designs both for a straddle arrangement where the pinion gear is located between the bearings and for a cantilever arrangement where the pinion is outboard of the two bearings. Effects of varying parameters including applied gear load, preload, wall thickness, interference fits, bearing spacing and pinion gear location on system rigidity, load distribution and bearing rating life were assessed. A comparison of the bearing load distributions for these designs demonstrated that the straddle more equally distributes both radial and axial loads. The performance of these designs over a range of shaft rotational speeds, with lubrication and friction effects included, is also discussed.

  19. Boost type PWM HVDC transmission system

    SciTech Connect

    Ooi, B.T.; Wang, X. . Dept. of Electrical Engineering)

    1991-10-01

    This paper reports that conventional HVdc is built around the mercury arc rectifier or the thyristor which requires line commutation. The advances of fast, high power GTO's and future devices such as MCT's with turn off capabilities, are bringing PWM techniques within the range of HVdc applications. By combining PWM techniques to the boost type bridge topology, one has an alternate system of HVdc Transmission. On the ac side, the converter station has active controls over: the voltage amplitude, the voltage angle and the frequency. On the dc side, parallel connections facilitate multi-terminal load sharing by simple local controls so that redundant communication channels are not required. Bidirectional power through each station is accomplished by the reversal of the direction of dc current flow. These claims have been substantiated by experimental results from laboratory size multi-terminal models.

  20. Initial Studies Toward Real-Time Transmission Path Rating

    SciTech Connect

    Singh, Ruchi; Diao, Ruisheng; Cai, Niannian; Huang, Zhenyu; Tuck, Brian; Guo, Xinxin

    2012-07-26

    Demand continues to increase while transmission line construction is being constrained by multiple factors— economic, environmental, and political. Effective and efficient utilization of transmission lines is thus of great importance in an open access environment. Large blocks of power are transferred from areas with inexpensive generation to heavy load demand areas or areas with high generation costs. This results in some transmission paths being loaded closer to their path ratings, which limits further power transfer between areas. Traditionally, rating of important paths was determined off line by assuming the worst-case study scenario; once determined, it could be used for years. With increasing uncertainty arising from rapid growth of renewable energy and smart technologies, path rating studies are needed in near-real time to account for the latest system status and support a reliable and economic power grid. This paper adopts a simplified procedure based on standards of the North American Electric Reliability Corporation (NERC) to determine total transfer capability (TTC) or transfer limit for the purpose of demonstrating the benefits and necessity of real-time path rating. Initial studies are conducted to compute TTC of a two-area test system and a 39-bus test system. Results indicate that path rating can be significantly affected by loading conditions, generator schedules, system topology and other factors.

  1. Evaluation of self-assembled HCPT-loaded PEG- b-PLA nanoparticles by comparing with HCPT-loaded PLA nanoparticles

    NASA Astrophysics Data System (ADS)

    Yang, Xiangrui; Wu, Shichao; Wang, Yange; Li, Yang; Chang, Di; Luo, Yin; Ye, Shefang; Hou, Zhenqing

    2014-12-01

    We present a dialysis technique to prepare the 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly( d, l-lactide) (PEG- b-PLA) and PLA, respectively. Both HCPT-loaded PEG- b-PLA NPs and HCPT-loaded PLA NPs were characterized by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that the HCPT-loaded PEG- b-PLA NPs and HCPT-loaded PLA NPs presented a hydrodynamic particle size of 120.1 and 226.8 nm, with a polydispersity index of 0.057 and 0.207, a zeta potential of -31.2 and -45.7 mV, drug encapsulation efficiency of 44.52% and 44.94%, and drug-loaded content of 7.42% and 7.49%, respectively. The HCPT-loaded PEG- b-PLA NPs presented faster drug release rate compared to the HCPT-loaded PLA NPs. The HCPT-loaded PEG- b-PLA NPs presented higher cytotoxicity than the HCPT-loaded PLA NPs. These results suggested that the HCPT-loaded PEG- b-PLA NPs presented better characteristics for drug delivery compared to HCPT-loaded PLA NPs.

  2. Planetary gear profile modification design based on load sharing modelling

    NASA Astrophysics Data System (ADS)

    Iglesias, Miguel; Fernández Del Rincón, Alfonso; De-Juan, Ana Magdalena; Garcia, Pablo; Diez, Alberto; Viadero, Fernando

    2015-07-01

    In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.

  3. A Generalized Lossy Transmission-Line Model for Tunable Graphene-Based Transmission Lines with Attenuation Phenomenon

    PubMed Central

    Wu, Yongle; Qu, Meijun; Liu, Yuanan

    2016-01-01

    To investigate the frequency shift phenomenon by inserting graphene, a generalized lossy transmission-line model and the related electrical parameter-extraction theory are proposed in this paper. Three kinds of graphene-based transmission lines with attenuation phenomenon including microstrip line, double-side parallel strip line, and uniplanar coplanar waveguide are analyzed under the common conditions where different chemical potentials are loaded on graphene. The values of attenuation constant and phase constant, and the real and imaginary parts of the characteristic impedance of transmission lines are extracted to analyze in details. When the attenuation constant and the reactance part of the characteristic impedance are approximately equal to zero, this kind of transmission line has low or zero insertion loss. On the contrary, the transmission line is under the radiation mode with obvious insertion loss. The phase constant changes linearly under the transmission mode and can be varied with changing of chemical potentials which attributes to the property of frequency tunability. Furthermore, a bandwidth reconfigurable uniplanar coplanar waveguide power divider is simulated to demonstrate that this theory can be applied to the design of three-port devices. In summary, this work provides a strong potential approach and design theory to help design other kinds of terahertz and mid-infrared reconfigurable devices. PMID:27553759

  4. A Generalized Lossy Transmission-Line Model for Tunable Graphene-Based Transmission Lines with Attenuation Phenomenon.

    PubMed

    Wu, Yongle; Qu, Meijun; Liu, Yuanan

    2016-08-24

    To investigate the frequency shift phenomenon by inserting graphene, a generalized lossy transmission-line model and the related electrical parameter-extraction theory are proposed in this paper. Three kinds of graphene-based transmission lines with attenuation phenomenon including microstrip line, double-side parallel strip line, and uniplanar coplanar waveguide are analyzed under the common conditions where different chemical potentials are loaded on graphene. The values of attenuation constant and phase constant, and the real and imaginary parts of the characteristic impedance of transmission lines are extracted to analyze in details. When the attenuation constant and the reactance part of the characteristic impedance are approximately equal to zero, this kind of transmission line has low or zero insertion loss. On the contrary, the transmission line is under the radiation mode with obvious insertion loss. The phase constant changes linearly under the transmission mode and can be varied with changing of chemical potentials which attributes to the property of frequency tunability. Furthermore, a bandwidth reconfigurable uniplanar coplanar waveguide power divider is simulated to demonstrate that this theory can be applied to the design of three-port devices. In summary, this work provides a strong potential approach and design theory to help design other kinds of terahertz and mid-infrared reconfigurable devices.

  5. Impedance matching wireless power transmission system for biomedical devices.

    PubMed

    Lum, Kin Yun; Lindén, Maria; Tan, Tian Swee

    2015-01-01

    For medical application, the efficiency and transmission distance of the wireless power transfer (WPT) are always the main concern. Research has been showing that the impedance matching is one of the critical factors for dealing with the problem. However, there is not much work performed taking both the source and load sides into consideration. Both sides matching is crucial in achieving an optimum overall performance, and the present work proposes a circuit model analysis for design and implementation. The proposed technique was validated against experiment and software simulation. Result was showing an improvement in transmission distance up to 6 times, and efficiency at this transmission distance had been improved up to 7 times as compared to the impedance mismatch system. The system had demonstrated a near-constant transfer efficiency for an operating range of 2cm-12cm.

  6. Electric power transmission for a Hanford Nuclear Energy Center (HNEC)

    SciTech Connect

    Harty, H.; Dowis, W.J.

    1983-06-01

    The original study of transmission for a Hanford Nuclear Energy Center (HNEC), which was completed in September 1975, was updated in June 1978. The present 1983 revision takes cognizance of recent changes in the electric power situation of the PNW with respect to: (1) forecasts of load growth, (2) the feasibility of early use of 1100 kV transmission, and (3) the narrowing opportunities for siting nuclear plants in the region. The purpose of this update is to explore and describe additions to the existing transmission system that would be necessary to accommodate three levels of generation at HNEC. Comparisons with a PNW system having new thermal generating capacity distributed throughout the marketing region are not made as was done in earlier versions.

  7. Three-Phase Load Flow for Unbalanced Systems.

    NASA Astrophysics Data System (ADS)

    Chang, Yih-Ping

    Traditionally, transmission systems are assumed to be balanced in power system analysis. A single phase positive sequence circuit is used in transmission system load flow analysis to simplify the study. However, when untransposed transmission lines are used in a power system due to economic considerations, space limitation; or when large unbalanced load is on the system; or when an unbalance contingency occurs on the system, this assumption may not hold true. The unbalance condition in some isolated systems are so precarious that disaster can result. One such incident occurred on a generator unit of the third nuclear power plant of Taipower in 1985. In that particular case, the turbine blades were broken and a spark ignited the liquid hydrogen when the blade vibration resonated with the 120.5 Hz rotor current. One cause of this rotor current generation is system unbalance. The unbalanced three-phase load flow program is needed in today's power system analysis. An advanced three-phase unbalanced transmission load flow program, capable of locating the unbalanced problem of large electric network systems, was proposed to be developed and tested in this research. Features of this program include simultaneous power flow of multiple voltage levels on an individual phase basis; PV bus generator, cogenerator, transformer simulation, and load modeling. It is found that delta-grounded wye step-up transformer reduces the convergence speed greatly. When too many delta-grounded wye step-up transformers exist in a large scale system and a quick approximate result of the unbalance conditions is needed, these step-up transformers can be substituted by grounded-wye to grounded-wye type transformers. This is tested on a Taipower system case which included 345KV, 161KV and 69KV feeders, network transformers, 34 PV bus generators and 188 three-phase buses. Impending unbalance problems in Taipower system were located. When not too many delta-grounded wye type transformers are in the

  8. Mine shaft conveyance load-monitoring system

    SciTech Connect

    Beus, M.J.; McCoy, W.G.

    1995-12-31

    Technology to enhance safety features for mine shafts and elevators is being investigated by researchers at the US Bureau of Mines. The objective of this research is to prevent injuries and fatalities related to hoist and elevator operations. Mine Safety and Health Administration statistics indicate that several factors contribute to hoisting accidents. A significant number of these factors are related to lack of adequate information on the position of the conveyance coupled with slack or overloaded rope resulting from obstructions or misalignments in the hoistway. Typically, this information is determined from sensors located in the hoist room. Subsequently, hoist and elevator control may be compromised and accidents result. This paper describes development of a slack rope sensor and data-transmission and collection hardware to sense conditions and acquire data directly from the hoisting conveyance. A new type of load cell senses wire rope tension at the conveyance. A new type of load cell senses wire rope tension at the conveyance. A multichannel signal processing board has been designed and fabricated and is undergoing both static testing to evaluate long-term stability and dynamic testing under simulated hoisting conditions. Analog signals from the sensors are sampled at 100-ms intervals. Data transmission between the moving conveyance and the hoistroom is accomplished via a 2,400-baud FM radio modem. Data are acquired at the conveyance or in the hoistroom through a serial communications port on a laptop computer. Software has been written to acquire, analyze, and process the data. The resulting system will allow operating personnel to determine conveyance load, and thus rope tension and slack or overload rope conditions, in relation to conveyance position in the hoistway.

  9. Multi-speed transmission

    SciTech Connect

    Ashikawa, N.; Nakayama, H.; Sumi, M.

    1986-12-02

    This patent describes a multi-speed transmission having forward speed gear trains and at least one reverse speed gear train, comprising, a pair of parallel fork shafts, one the shaft being fixed, the other the shaft being slidable along its axial direction, means to selectively engage the gear trains and means to retain the selective engagement means in the selected position. The means selectively engages the gear trains including a first shift fork connected to the fixed fork shaft so as to slide to either side of its disengaged neutral position, a second shift fork connected to the slideable fork shaft so as to slide to either side of its disengaged neutral position, and a third shift fork connected to the slidable fork shaft so as to slide in one direction by motion of the slideable fork shaft to only one side of its disengaged neutral position. Also included is a reverse shift fork connected to the slideable fork shaft and adapted to be actuated by motion of the slideable fork shaft in a direction opposite to the direction of the motion which engages the third shift fork.

  10. Electronically controlled automatic transmission

    SciTech Connect

    Ohkubo, M.; Shiba, H.; Nakamura, K.

    1989-03-28

    This patent describes an electronically controlled automatic transmission having a manual valve working in connection with a manual shift lever, shift valves operated by solenoid valves which are driven by an electronic control circuit previously memorizing shift patterns, and a hydraulic circuit controlled by these manual valve and shift valves for driving brakes and a clutch in order to change speed. Shift patterns of 2-range and L-range, in addition to a shift pattern of D-range, are memorized previously in the electronic control circuit, an operation switch is provided which changes the shift pattern of the electronic control circuit to any shift pattern among those of D-range, 2-range and L-range at time of the manual shift lever being in a D-range position, a releasable lock mechanism is provided which prevents the manual shift lever from entering 2-range and L-range positions, and the hydraulic circuit is set to a third speed mode when the manual shift lever is in the D-range position. The circuit is set to a second speed mode when it is in the 2-range position, and the circuit is set to a first speed mode when it is in the L-range position, respectively, in case where the shift valves are not working.

  11. Virus transmission via food.

    PubMed

    Cliver, D O

    1997-01-01

    Viruses are transmitted to humans via foods as a result of direct or indirect contamination of the foods with human faeces. Viruses transmitted by a faecal-oral route are not strongly dependent on foods as vehicles of transmission, but viruses are important among agents of foodborne disease. Vehicles are most often molluscs from contaminated waters, but many other foods are contaminated directly by infected persons. The viruses most often foodborne are the hepatitis A virus and the Norwalk-like gastroenteritis viruses. Detection methods for these viruses in foods are very difficult and costly; the methods are not routine. Indicators that would rapidly and reliably suggest the presence of viral contamination of foods are still being sought. Contamination can be prevented by keeping faeces out of food or by treating vehicles such as water in order to inactivate virus that might be carried to food in this way. Virus cannot multiply in food, but can usually be inactivated by adequate heating. Other methods of inactivating viruses within a food are relatively unreliable, but viruses in water and on exposed surfaces can be inactivated with ultraviolet light or with strong oxidizing agents.

  12. Transmission of digital data

    USGS Publications Warehouse

    Showen, Charles R.

    1971-01-01

    The Geological Survey, Water Resources Division, established a pilot project to evaluate equipment that would transmit date recorded on 16-channel paper tapes over voice-grade telephone lines from field offices to the Washington, D.C., Automatic Data Processing Unit (A.D.P. Unit). Such equipment would allow computer-processed data for current-purpose hydrologic data stations to be made available in a more timely manner. The specifications for the equipment were prepared in March 1970; invitations to bid were solicited, a contract was awarded and the equipment was delivered in November 1970. The equipment included two reader/transmitter units, and one receiver/recorder unit. The reader/transmitter units transmit manually entered fixed information, i.e. station number, beginning date and time, and ending date and time, and photoelectrically read and transmit the 16-channel paper tape data. The receiver/recorder unit records the transmitted information on IBM-compatible magnetic tape. This report summarizes the information gained from a year of pilot operation of the equipment, with and without a computer terminal at the field level, and makes recommendations for establishing a data-transmission system in the Water Resources Division.

  13. Transmissive Microshutter Arrays

    NASA Astrophysics Data System (ADS)

    Kutyrev, A. S.; Moseley, H. S.; Fettig, R. K.; Kuhn, J. L.; Woodgate, B. E.; Kimble, R. A.; Orloff, J. H.

    1999-12-01

    We report further progress on the development of a two-dimensional array of microshutters, which can be used as a high efficiency, high contrast field selection device for a multi-object spectrometer for the Next Generation Space Telescope (NGST). The device is a close packed array of shutters, with a typical size of 100 microns square and an area filling factor of up to 80%. Each shutter, made of single crystal silicon or silicon nitride with an appropriate optical coating, pivots on a torsion flexure along one edge. Each of the shutters is individually selectable. Although these devices can be used as reflection devices, their primary mode of operation is in transmission, which provides the minimum possible level of scattered light. An original double-shutter mechanism is employed for actuation. Small shutter arrays have been built using a Focus Ion Beam milling machine is a 3 x 3 double shutter actuation with a micro-manipulator under electron microscope observation has been demonstrated. An important aspect of this study has been to demonstrate the reliability of the structures over its expected lifetime. We analyzed stiffness, strength and fatigue issues of two good candidate materials, single crystal silicon and silicon nitride. Both appear to be suitable from the mechanical point of view. This project is supported by NASA grants.

  14. EC Transmission Line Materials

    SciTech Connect

    Bigelow, Tim S

    2012-05-01

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH&CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. [Ref. 2] Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  15. Load measurement system with load cell lock-out mechanism

    NASA Technical Reports Server (NTRS)

    Le, Thang; Carroll, Monty; Liu, Jonathan

    1995-01-01

    In the frame work of the project Shuttle Plume Impingement Flight Experiment (SPIFEX), a Load Measurement System was developed and fabricated to measure the impingement force of Shuttle Reaction Control System (RCS) jets. The Load Measurement System is a force sensing system that measures any combination of normal and shear forces up to 40 N (9 lbf) in the normal direction and 22 N (5 lbf) in the shear direction with an accuracy of +/- 0.04 N (+/- 0.01 lbf) Since high resolution is required for the force measurement, the Load Measurement System is built with highly sensitive load cells. To protect these fragile load cells in the non-operational mode from being damaged due to flight loads such as launch and landing loads of the Shuttle vehicle, a motor driven device known as the Load Cell Lock-Out Mechanism was built. This Lock-Out Mechanism isolates the load cells from flight loads and re-engages the load cells for the force measurement experiment once in space. With this highly effective protection system, the SPIFEX load measurement experiment was successfully conducted on STS-44 in September 1994 with all load cells operating properly and reading impingement forces as expected.

  16. Fluid transmission line dynamics 1983; Proceedings of the Winter Annual Meeting, Boston, MA, November 13-18, 1983

    NASA Astrophysics Data System (ADS)

    Franke, M. E.; Drzewiecki, T. M.

    1983-11-01

    Various topics on fluid transmission line dynamics are addressed. The subjects discussed include: comparison of theoretical and experimental fluid line responses with source and load impedances; a first-order square root approximation for fluid transmission lines; modal approximations for the fluid dynamics of hydraulic and pneumatic transmission lines; and time domain simulation of fluid transmission lines using minimum order state variable models. Also considered are: the simulation of transmission line dynamics in nonlinear electrohydraulic systems; effect of transmission line dynamics on the response of servovalve-controlled actuators; and acoustic load impedance effects on centrifugal pump pulsations in a water flow loop. For individual items see A84-22297 to A84-22300

  17. Automatic transmission for motor vehicles

    SciTech Connect

    Miura, M.; Sakakibara, S.

    1989-06-27

    An automatic transmission for a motor vehicle is described, comprising: a transmission housing; a hydraulic torque converter having rotational axes, an input shaft, an output shaft and a direct coupling clutch for directly coupling the input shaft to the output shaft; an auxiliary transmission mechanism provided coaxially with the hydraulic torque converter and having an input shaft, an output shaft with an input end and an output end and an overdrive mechanism of planetary gear type having a reduction ratio smaller than 1, the input shaft and the output shaft of the auxiliary transmission being located close to and on the side of the hydraulic torque converter with respect to the auxiliary transmission, respectively, and being coupled with a planetary gear carrier and a ring gear of the overdrive mechanism, respectively, a one-way clutch being provided between the planetary gear carrier and a sun gear of the overdrive mechanism, a clutch being provided between the planetary gear carrier and a position radially and outwardly of the one-way clutch for engaging the disengaging the planetary carrier and the sun gear, a brake being provided between the transmission housing and the sun gear and positioned radially and outwardly of the clutch for controlling engagement of the sun gear with a stationary portion of the transmission housing, and the output end of the output shaft being disposed between the auxiliary transmission mechanism and the hydraulic torque converter.

  18. A Quantitative Transmission Line Experiment

    ERIC Educational Resources Information Center

    Johnston, D. C.; Silbernagel, B. G.

    1969-01-01

    Describes modifications of a commercially available strip-type transmission line, which makes possible reproducible measurements of standing waves on the line. Experimental data yield values for the characteristic impedance, phase velocity and line wavelength of radiation in the transmission line, and the dielectric constant of material in the…

  19. Direct current power transmission systems

    SciTech Connect

    Padiyar, K.R.

    1991-01-01

    This book represents text on HVDC transmission available. It deals with the various aspects of the state of the art in HVDC transmission technology. This book presents many aspects of interactions of AC/DC systems. Modeling and analysis of DC systems are also discussed in detail.

  20. Hendra virus ecology and transmission.

    PubMed

    Field, Hume E

    2016-02-01

    Hendra virus causes acute and highly fatal infection in horses and humans. Pteropid bats (flying-foxes) are the natural host of the virus, with age and species being risk factors for infection. Urine is the primary route of excretion in flying-foxes, with viral RNA more frequently detected in Pteropus alecto and P. conspicillatus than other species. Infection prevalence in flying-foxes can vary between and within years, with a winter peak of excretion occurring in some regions. Vertical transmission and recrudescing infection has been reported in flying-foxes, but horizontal transmission is evidently the primary mode of transmission. The most parsimonious mode of flying-fox to horse transmission is equine contact (oro-nasal, conjunctival) with infected flying-fox urine, either directly, or via urine-contaminated pasture or surfaces. Horse to horse transmission is inefficient, requiring direct contact with infected body fluids. Flying-fox to human transmission has not been recorded; all human cases have been associated with close and direct contact with infected horses. Canine cases (subclinical) have also been limited to equine case properties. Notwithstanding the recent availability of an effective vaccine for horses, a comprehensive understanding of Hendra virus ecology and transmission is essential to limit inter-species transmission.

  1. HVDC power transmission technology assessment

    SciTech Connect

    Hauth, R.L.; Tatro, P.J.; Railing, B.D.; Johnson, B.K.; Stewart, J.R.; Fink, J.L.

    1997-04-01

    The purpose of this study was to develop an assessment of the national utility system`s needs for electric transmission during the period 1995-2020 that could be met by future reduced-cost HVDC systems. The assessment was to include an economic evaluation of HVDC as a means for meeting those needs as well as a comparison with competing technologies such as ac transmission with and without Flexible AC Transmission System (FACTS) controllers. The role of force commutated dc converters was to be assumed where appropriate. The assessment begins by identifying the general needs for transmission in the U.S. in the context of a future deregulated power industry. The possible roles for direct current transmission are then postulated in terms of representative scenarios. A few of the scenarios are illustrated with the help of actual U.S. system examples. non-traditional applications as well as traditional applications such as long lines and asynchronous interconnections are discussed. The classical ``break-even distance`` concept for comparing HVDC and ac lines is used to assess the selected scenarios. The impact of reduced-cost converters is reflected in terms of the break-even distance. This report presents a comprehensive review of the functional benefits of HVDC transmission and updated cost data for both ac and dc system components. It also provides some provocative thoughts on how direct current transmission might be applied to better utilize and expand our nation`s increasingly stressed transmission assets.

  2. A radial transmission line material measurement apparatus

    SciTech Connect

    Warne, L.K.; Moyer, R.D.; Koontz, T.E.; Morris, M.E.

    1993-05-01

    A radial transmission line material measurement sample apparatus (sample holder, offset short standards, measurement software, and instrumentation) is described which has been proposed, analyzed, designed, constructed, and tested. The purpose of the apparatus is to obtain accurate surface impedance measurements of lossy, possibly anisotropic, samples at low and intermediate frequencies (vhf and low uhf). The samples typically take the form of sections of the material coatings on conducting objects. Such measurements thus provide the key input data for predictive numerical scattering codes. Prediction of the sample surface impedance from the coaxial input impedance measurement is carried out by two techniques. The first is an analytical model for the coaxial-to-radial transmission line junction. The second is an empirical determination of the bilinear transformation model of the junction by the measurement of three full standards. The standards take the form of three offset shorts (and an additional lossy Salisbury load), which have also been constructed. The accuracy achievable with the device appears to be near one percent.

  3. Sikorsky Aircraft Advanced Rotorcraft Transmission (ART) program

    NASA Technical Reports Server (NTRS)

    Kish, Jules G.

    1993-01-01

    The objectives of the Advanced Rotorcraft Transmission program were to achieve a 25 percent weight reduction, a 10 dB noise reduction, and a 5,000 hour mean time between removals (MTBR). A three engine Army Cargo Aircraft (ACA) of 85,000 pounds gross weight was used as the baseline. Preliminary designs were conducted of split path and split torque transmissions to evaluate weight, reliability, and noise. A split path gearbox was determined to be 23 percent lighter, greater than 10 dB quieter, and almost four times more reliable than the baseline two stage planetary design. Detail design studies were conducted of the chosen split path configuration, and drawings were produced of a 1/2 size gearbox consisting of a single engine path of the split path section. Fabrication and testing was then conducted on the 1/2 size gearbox. The 1/2 size gearbox testing proved that the concept of the split path gearbox with high reduction ratio double helical output gear was sound. The improvements were attributed to extensive use of composites, spring clutches, advanced high hot hardness gear steels, the split path configuration itself, high reduction ratio, double helical gearing on the output stage, elastomeric load sharing devices, and elimination of accessory drives.

  4. Sikorsky Aircraft Advanced Rotorcraft Transmission (ART) program

    NASA Astrophysics Data System (ADS)

    Kish, Jules G.

    1993-03-01

    The objectives of the Advanced Rotorcraft Transmission program were to achieve a 25 percent weight reduction, a 10 dB noise reduction, and a 5,000 hour mean time between removals (MTBR). A three engine Army Cargo Aircraft (ACA) of 85,000 pounds gross weight was used as the baseline. Preliminary designs were conducted of split path and split torque transmissions to evaluate weight, reliability, and noise. A split path gearbox was determined to be 23 percent lighter, greater than 10 dB quieter, and almost four times more reliable than the baseline two stage planetary design. Detail design studies were conducted of the chosen split path configuration, and drawings were produced of a 1/2 size gearbox consisting of a single engine path of the split path section. Fabrication and testing was then conducted on the 1/2 size gearbox. The 1/2 size gearbox testing proved that the concept of the split path gearbox with high reduction ratio double helical output gear was sound. The improvements were attributed to extensive use of composites, spring clutches, advanced high hot hardness gear steels, the split path configuration itself, high reduction ratio, double helical gearing on the output stage, elastomeric load sharing devices, and elimination of accessory drives.

  5. Electrical Load Modeling and Simulation

    SciTech Connect

    Chassin, David P.

    2013-01-01

    Electricity consumer demand response and load control are playing an increasingly important role in the development of a smart grid. Smart grid load management technologies such as Grid FriendlyTM controls and real-time pricing are making their way into the conventional model of grid planning and operations. However, the behavior of load both affects, and is affected by load control strategies that are designed to support electric grid planning and operations. This chapter discussed the natural behavior of electric loads, how it interacts with various load control and demand response strategies, what the consequences are for new grid operation concepts and the computing issues these new technologies raise.

  6. 32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER ...

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

    32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER SLAB AND UNDERSIDE OF LAUNCHER BRIDGE LOOKING SOUTHWEST. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  7. Shot loading trainer analysis

    SciTech Connect

    Peterson, T.K.

    1995-02-15

    This document presents the results from the analysis of the shot loading trainer (SLT). This device will be used to test the procedure for installing shot into the annulus of the Project W-320 shipping container. To ensure that the shot is installed uniformly around the container, vibrators will be used to settle the shot. The SLT was analyzed to ensure that it would not jeopardize worker safety during operation. The results from the static analysis of the SLT under deadweight and vibrator operating loads show that the stresses in the SLT are below code allowables. The results from the modal analysis show that the natural frequencies of the SLT are far below the operating frequencies of the vibrators, provided the SLT is mounted on pneumatic tires. The SLT was also analyzed for wind, seismic, deadweight, and moving/transporting loads. Analysis of the SLT is in accordance with SDC-4.1 for safety class 3 structures (DOE-RL 1993) and the American Institute of Steel Construction (AISC) Manual of Steel Construction (AISC 1989).

  8. Buffet Load Alleviation

    NASA Technical Reports Server (NTRS)

    Ryall, T. G.; Moses, R. W.; Hopkins, M. A.; Henderson, D.; Zimcik, D. G.; Nitzsche, F.

    2004-01-01

    High performance aircraft are, by their very nature, often required to undergo maneuvers involving high angles of attack. Under these conditions unsteady vortices emanating from the wing and the fuselage will impinge on the twin fins (required for directional stability) causing excessive buffet loads, in some circumstances, to be applied to the aircraft. These loads result in oscillatory stresses, which may cause significant amounts of fatigue damage. Active control is a possible solution to this important problem. A full-scale test was carried out on an F/A-18 fuselage and fins using piezoceramic actuators to control the vibrations. Buffet loads were simulated using very powerful electromagnetic shakers. The first phase of this test was concerned with the open loop system identification whereas the second stage involved implementing linear time invariant control laws. This paper looks at some of the problems encountered as well as the corresponding solutions and some results. It is expected that flight trials of a similar control system to alleviate buffet will occur as early as 2001.

  9. Load regulating latch

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T. (Inventor)

    1977-01-01

    A load regulating mechanical latch is described that has a pivotally mounted latch element having a hook-shaped end with a strike roller-engaging laterally open hook for engaging a stationary strike roller. The latch element or hook is pivotally mounted in a clevis end of an elongated latch stem that is adapted for axial movement through an opening in a support plate or bracket mounted to a structural member. A coil spring is disposed over and around the extending latch stem and the lower end of the coil spring engages the support bracket. A thrust washer is removably attached to the other end of the latch stem and engages the other end of the coil spring and compresses the coil spring thereby preloading the spring and the latch element carried by the latch stem. The hook-shaped latch element has a limited degree of axial travel for loading caused by structural distortion which may change the relative positions of the latch element hook and the strike roller. Means are also provided to permit limited tilt of the latch element due to loading of the hook.

  10. Load responsive hydrodynamic bearing

    DOEpatents

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  11. Regional Transmission Projects: Finding Solutions

    SciTech Connect

    The Keystone Center

    2005-06-15

    The Keystone Center convened and facilitated a year-long Dialogue on "Regional Transmission Projects: Finding Solutions" to develop recommendations that will help address the difficult and contentious issues related to expansions of regional electric transmission systems that are needed for reliable and economic transmission of power within and across regions. This effort brought together a cross-section of affected stakeholders and thought leaders to address the problem with the collective wisdom of their experience and interests. Transmission owners sat at the table with consumer advocates and environmental organizations. Representatives from regional transmission organizations exchanged ideas with state and federal regulators. Generation developers explored common interests with public power suppliers. Together, the Dialogue participants developed consensus solutions about how to begin unraveling some of the more intractable issues surrounding identification of need, allocation of costs, and reaching consensus on siting issues that can frustrate the development of regional transmission infrastructure. The recommendations fall into three broad categories: 1. Recommendations on appropriate institutional arrangements and processes for achieving regional consensus on the need for new or expanded transmission infrastructure 2. Recommendations on the process for siting of transmission lines 3. Recommendations on the tools needed to support regional planning, cost allocation, and siting efforts. List of Dialogue participants: List of Dialogue Participants: American Electric Power American Transmission Company American Wind Energy Association California ISO Calpine Corporation Cinergy Edison Electric Institute Environmental Defense Federal Energy Regulatory Commission Great River Energy International Transmission Company ISO-New England Iowa Public Utility Board Kanner & Associates Midwest ISO National Association of Regulatory Utility Commissioners National Association

  12. Energy Transmission and Infrastructure

    SciTech Connect

    Mathison, Jane

    2012-12-31

    The objective of Energy Transmission and Infrastructure Northern Ohio (OH) was to lay the conceptual and analytical foundation for an energy economy in northern Ohio that will: • improve the efficiency with which energy is used in the residential, commercial, industrial, agricultural, and transportation sectors for Oberlin, Ohio as a district-wide model for Congressional District OH-09; • identify the potential to deploy wind and solar technologies and the most effective configuration for the regional energy system (i.e., the ratio of distributed or centralized power generation); • analyze the potential within the district to utilize farm wastes to produce biofuels; • enhance long-term energy security by identifying ways to deploy local resources and building Ohio-based enterprises; • identify the policy, regulatory, and financial barriers impeding development of a new energy system; and • improve energy infrastructure within Congressional District OH-09. This objective of laying the foundation for a renewable energy system in Ohio was achieved through four primary areas of activity: 1. district-wide energy infrastructure assessments and alternative-energy transmission studies; 2. energy infrastructure improvement projects undertaken by American Municipal Power (AMP) affiliates in the northern Ohio communities of Elmore, Oak Harbor, and Wellington; 3. Oberlin, OH-area energy assessment initiatives; and 4. a district-wide conference held in September 2011 to disseminate year-one findings. The grant supported 17 research studies by leading energy, policy, and financial specialists, including studies on: current energy use in the district and the Oberlin area; regional potential for energy generation from renewable sources such as solar power, wind, and farm-waste; energy and transportation strategies for transitioning the City of Oberlin entirely to renewable resources and considering pedestrians, bicyclists, and public transportation as well as drivers

  13. Transmission gearing arrangement

    SciTech Connect

    Klemen, D.

    1987-08-04

    A gearing arrangement is described for an automotive power transmission comprising: an input shaft and an output shaft; first, second, and third simple planetary gear sets. Each has a sun gear, a ring gear, and a planet gears meshing with the sun and the ring gears and rotatably supported on a planet carrier; means rigidly interconnecting the ring gear of the third gear set and the carrier of the second gear set; means rigidly interconnecting the ring gear of the second gear set and the carrier of the first gear set; means rigidly connecting the output shaft and the carrier of the third gear set; a first intermediate shaft rigidly interconnecting the sun gears of the second and the third gear sets for unitary rotation; a second intermediate shaft rigidly connected to the carrier of the second gear set; a third intermediate shaft continuously connected to the input shaft and to the sun gear of the first gear set; first, second, and third brake means operative to selectively brake rotation of the ring gears of the first, the second, and the third gear sets, respectively; a first rotating clutch selectively operable to connect the input shaft and the first intermediate shaft for unitary rotation; a second rotating clutch selectively operable to connect the input shaft and the second intermediate shaft for unitary rotation; a fourth simple planetary gear set including a sun gear and a ring gear and planet gears meshing with the sun and the ring gears and rotatably supported on a planet carrier; means rigidly connecting the sun gear of the fourth gear set to the third intermediate shaft; means rigidly connecting the ring gear of the fourth gear set to the carrier of the first gear set; and a fourth brake means selectively operable to brake the carrier of the fourth gear set. The nine forward ratios are obtainable while preserving a single transition shifting over the entire nine forward ratios.

  14. Multistate differential transmission

    SciTech Connect

    Whalen, B.L.

    1989-05-30

    This patent describes a multistate transmission suitable for a colinear configuration having a stationary housing and an input shaft and an output shaft comprising: a first pair of planetary gear trains comprising a first common ring gear having a torque reducing gear train consisting of a sun gear and a planetary gears connected by way of a carrier to the output shaft and a reversing planetary gear train consisting of a sun gear and planetary gears; a second pair of planetary a trains comprising a second common ring gear having a torque reducing gear train consisting of a sun gear and planetary gears connected by way of a carrier to the sun gear in the reversing planetary gear train in the first pair of planetary gear trains and a reversing planetary gear train consisting of a sun gear and planetary gears; carrier means connecting the sun gears in the first pair of planetary gear trains to the housing through a free wheeling clutch to provide for rotation in one direction only and to one side of a first operational clutch. The other side of the clutch is connected to the sun gear in the reversing planetary gear train in the first pair of planetary gear trains; means connecting the planetary gears in the reversing mechanism of the second pair of planetary gear trains to the housing through a second operational clutch and to one side of a third operational clutch. The other side of the third operational clutch is connected to the sun gear in the reversing planetary gear grain in the second pair of planetary gear trains.

  15. [Mentalization and attachment transmission].

    PubMed

    Böhmann, Johann; Fritsch, Sophia; Lück, Monika; Stumpe, Anna; Taubner, Svenja; Vesterling, Christina

    2014-01-01

    The present study was investigating the predictive role of maternal mentalizing and general as well as depressive symptom burden for attachment security at the end of the first year on a sample of 44 mother-child-dyads from a low-risk community study. Maternal mentalizing was assessed in a multidimensional way as Reflective Functioning (off-line) and Mind-Mindedness (on-line). The design was longitudinal measuring maternal Mind-Mindedness from a videotaped mother-child-play-interaction at the age of three months. General and depressive symptom burden was assessed using the SCL-90-R when the children were nine months old. Maternal attachment and Reflective-Functioning, using the Adult-Attachment-Interview, as well as children's attachment behavior, using the Strange-Situation-Test, were investigated at the age of twelve months. Secure maternal attachment was associated with higher Reflective Functioning, higher frequency of Mind-Mindedness and lower general and depressive symptom burden. A moderation-analysis showed a statistical trend (p = .08) that the interaction of the frequency of mind-related comments, general symptom severity and maternal attachment has a predictive value for infantile attachment security. Results can be tentatively interpreted that mothers with insecure attachment who had a lower general symptom burden and who related to their three-months old babies with a high frequency of mind-related-comments were more likely to have securely attached children. Thus, results may serve as a groundwork for projects aiming to prevent the transmission of insecure attachment by strengthening maternal Mind-Mindedness and working on the reduction of maternal general symptom burden.

  16. Multi-ratio transmission

    SciTech Connect

    Polak, J.C.

    1987-07-14

    A preselected multi-ratio power transmission is described comprising: input means for transmitting drive forces; output means; first, second and third friction clutch means each selectively engageable with the input means for accepting drive forces. First input gear means drivingly connects with the first friction clutch means; second input gear means drivingly connects with the second friction clutch means; third input gear means drivingly connects with the third clutch means; first output gear means drivingly connects with the first input gear means; second output gear means drivingly connects with the first and second input gear means; third output means drivingly connects between the third input gear means and the output means; and one double-acting synchronizer clutch for selectively engaging the first output gear means with the output means and alternately the second output gear means with the output means. The first friction clutch means and the one double-acting synchronizer clutch cooperates during engagement to establish two forward drive ratios between the input and output means. The second friction clutch means and the one double-acting synchronizer clutch cooperates during engagement to establish two other forward drive ratios between the input and output means. The third friction clutch means is engageable to provide another forward drive ratio between the input means and the output means; and the one double-acting synchronizer clutch is relieved of transmitting drive forces during the engagement of the third friction clutch means and being manipulable for alternate connection with either the first output gear or the second output gear while the third friction clutch means is engaged.

  17. Critical points and transitions in an electric power transmission model for cascading failure blackouts.

    PubMed

    Carreras, B. A.; Lynch, V. E.; Dobson, I.; Newman, D. E.

    2002-12-01

    Cascading failures in large-scale electric power transmission systems are an important cause of blackouts. Analysis of North American blackout data has revealed power law (algebraic) tails in the blackout size probability distribution which suggests a dynamical origin. With this observation as motivation, we examine cascading failure in a simplified transmission system model as load power demand is increased. The model represents generators, loads, the transmission line network, and the operating limits on these components. Two types of critical points are identified and are characterized by transmission line flow limits and generator capability limits, respectively. Results are obtained for tree networks of a regular form and a more realistic 118-node network. It is found that operation near critical points can produce power law tails in the blackout size probability distribution similar to those observed. The complex nature of the solution space due to the interaction of the two critical points is examined.(c) 2002 American Institute of Physics.

  18. Transmission expansion with smart switching under demand uncertainty and line failures

    DOE PAGES

    Schumacher, Kathryn M.; Chen, Richard Li-Yang; Cohn, Amy E. M.

    2016-06-07

    One of the major challenges in deciding where to build new transmission lines is that there is uncertainty regarding future loads, renewal generation output and equipment failures. We propose a robust optimization model whose transmission expansion solutions ensure that demand can be met over a wide range of conditions. Specifically, we require feasible operation for all loads and renewable generation levels within given ranges, and for all single transmission line failures. Furthermore, we consider transmission switching as an allowable recovery action. This relatively inexpensive method of redirecting power flows improves resiliency, but introduces computational challenges. Lastly, we present a novelmore » algorithm to solve this model. Computational results are discussed.« less

  19. Biology of HIV Mucosal Transmission

    PubMed Central

    Wu, Li

    2008-01-01

    Purpose of review HIV-1 mucosal transmission plays a critical role in HIV-1 infection and AIDS pathogenesis. This review summarizes the latest advances in biological studies of HIV-1 mucosal transmission, highlighting the implications of these studies in the development of microbicides to prevent HIV-1 transmission. Recent findings New studies of initial HIV-1 infection using improved culture models updated the current view of mucosal transmission. Mechanistic studies enhanced our understanding of cell-cell transmission of HIV-1 mediated by the major target cells, including dendritic cells, CD4+ T cells, and macrophages. Increasing evidence indicated the significance of host factors and immune responses in HIV-1 mucosal infection and transmission. Summary Recent progress in HIV-1 mucosal infection and transmission enriches our knowledge of virus-host interactions and viral pathogenesis. Functional studies of HIV-1 interactions with host cells can provide new insights into the design of more effective approaches to combat HIV-1 infection and AIDS. PMID:18802490

  20. The evolution of transmission mode

    PubMed Central

    Forbes, Mark R.; Hauffe, Heidi C.; Kallio, Eva R.; Okamura, Beth; Sait, Steven M.

    2017-01-01

    This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289251

  1. Transparent bulk-size nanocomposites with high inorganic loading

    SciTech Connect

    Chen, Shi; Gaume, Romain

    2015-12-14

    With relatively high nanoparticle loading in polymer matrices, hybrid nanocomposites made by colloidal dispersion routes suffer from severe inhomogeneous agglomeration, a phenomenon that deteriorates light transmission even when the refractive indices of the inorganic and organic phases are closely matched. The dispersion of particles in a matrix is of paramount importance to obtain composites of high optical quality. Here, we describe an innovative, yet straightforward method to fabricate monolithic transparent hybrid nanocomposites with very high particle loading and high refractive index mismatch tolerance between the inorganic and organic constituents. We demonstrate 77% transmission at 800 nm in a 2 mm-thick acrylate polymer nanocomposite containing 61 vol. % CaF{sub 2} nanoparticles. Modeling shows that similar performance could easily be obtained with various inorganic phases relevant to a number of photonic applications.

  2. PSHFT - COMPUTERIZED LIFE AND RELIABILITY MODELLING FOR TURBOPROP TRANSMISSIONS

    NASA Technical Reports Server (NTRS)

    Savage, M.

    1994-01-01

    The computer program PSHFT calculates the life of a variety of aircraft transmissions. A generalized life and reliability model is presented for turboprop and parallel shaft geared prop-fan aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on the statistical two parameter Weibull failure distribution method and classical fatigue theories. The computer program developed to calculate the transmission model is modular. In its present form, the program can analyze five different transmissions arrangements. Moreover, the program can be easily modified to include additional transmission arrangements. PSHFT uses the properties of a common block two-dimensional array to separate the component and transmission property values from the analysis subroutines. The rows correspond to specific components with the first row containing the values for the entire transmission. Columns contain the values for specific properties. Since the subroutines (which determine the transmission life and dynamic capacity) interface solely with this property array, they are separated from any specific transmission configuration. The system analysis subroutines work in an identical manner for all transmission configurations considered. Thus, other configurations can be added to the program by simply adding component property determination subroutines. PSHFT consists of a main program, a series of configuration specific subroutines, generic component property analysis subroutines, systems analysis subroutines, and a common block. The main program selects the routines to be used in the analysis and sequences their operation. The series of configuration specific subroutines input the configuration data, perform the component force and life analyses (with the help of the generic component property analysis subroutines), fill the

  3. Radio-frequency and microwave load comprising a carbon-bonded carbon fiber composite

    DOEpatents

    Lauf, Robert J.; McMillan, April D.; Johnson, Arvid C.; Everleigh, Carl A.; Moorhead, Arthur J.

    1998-01-01

    A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads.

  4. Radio-frequency and microwave load comprising a carbon-bonded carbon fiber composite

    DOEpatents

    Lauf, R.J.; McMillan, A.D.; Johnson, A.C.; Everleigh, C.A.; Moorhead, A.J.

    1998-04-21

    A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads. 9 figs.

  5. Electrical transmission line diametrical retainer

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2004-12-14

    The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within down hole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to with stand the tension and compression of drill pipe during routine drilling cycles.

  6. Hidden hazards of HCV transmission.

    PubMed

    Pondé, Robério Amorim de Almeida

    2011-02-01

    Hepatitis C virus infection is a global health problem that has important epidemiological and clinical consequences. It has been well established that exposure to infected blood is the main risk factor for HCV transmission. However, in 20% of cases the agent transmission occurs by unknown route or in the presence of an unidentified source of infection. Understanding of the epidemiology of HCV is needed to help us define future control and preventive strategies. Herein, we discuss about diagnosis of HCV infection and hepatitis C surveillance in the context of its transmission.

  7. Midwest Transmission Workshop I Summary

    SciTech Connect

    Kevin Bryan

    2001-05-01

    OAK-B135 The meeting was opened with a review of the purposes of the workshop: (1) Present and discuss key studies and assessments of transmission upgrades, additions and related issues for the upper Midwest, including work that addresses the full range of views on these topics; (2) Understand the various transmission issues in the upper Midwest and discuss options for addressing the issues; and (3) Identify the decision makers and entities that need to play an active role if transmission issues are to be resolved, and agree on next steps for engaging these individuals and organizations through education, outreach, and information dissemination.

  8. Endoscopic transmission of Helicobacter pylori.

    PubMed

    Tytgat, G N

    1995-01-01

    The contamination of endoscopes and biopsy forceps with Helicobacter pylori occurs readily after endoscopic examination of H. pylori-positive patients. Unequivocal proof of iatrogenic transmission of the organism has been provided. Estimates for transmission frequency approximate to 4 per 1000 endoscopies when the infection rate in the endoscoped population is about 60%. Iatrogenic transmission has also been shown to be the cause of the so-called 'acute mucosal lesion' syndrome in Japan. Traditional cleaning and alcohol rinsing is insufficient to eliminate endoscope/forceps contamination. Only meticulous adherence to disinfection recommendations guarantees H. pylori elimination.

  9. Intertwined arbovirus transmission activity: reassessing the transmission cycle paradigm

    PubMed Central

    Diaz, Luis A.; Flores, Fernando S.; Quaglia, Agustín; Contigiani, Marta S.

    2013-01-01

    Arboviruses are emerging/reemerging infectious agents worldwide. The factors within this scenario include vector and host population fluctuations, climatic changes, anthropogenic activities that disturb ecosystems, an increase in international flights, human mobility, and genetic mutations that allow spill-over phenomenon. Arboviruses are maintained by biologic transmission among vectors and hosts. Sometimes this biological transmission is specific and includes one vector and host species such as Chikungunya (CHIKV), Dengue (DENV), and urban Yellow Fever (YFV). However, most of the arboviruses are generalist and they use many vectors and hosts species. From this perspective, arboviruses are maintained through a transmission network rather than a transmission cycle. This allows us to understand the complexity and dynamics of the transmission and maintenance of arboviruses in the ecosystems. The old perspective that arboviruses are maintained in close and stable transmission cycles should be modified by a new more integrative and dynamic idea, representing the real scenario where biological interactions have a much broader representation, indicating the constant adaptability of the biological entities. PMID:23335900

  10. Effect of advanced component technology on helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Townsend, Dennis P.

    1989-01-01

    Experimental tests were performed on the NASA/Bell Helicopter Textron (BHT) 500 hp advanced technology transmission (ATT) at the NASA Lewis Research Center. The ATT was a retrofit of the OH-58C helicopter 236 kW (317 hp) main rotor transmission, upgraded to 373 kW (500 hp), with a design goal of retaining long life with a minimum increase in cost, weight, and size. Vibration, strain, efficiency, deflection, and temperature experiments were performed and the results were compared to previous experiments on the OH-58A, OH-58C, and UH-60A transmissions. The high-contact-ratio gears and the cantilevered-mounted, flexible ring gear of the ATT reduced vibration compared to that of the OH-58C. The ATT flexible ring gear improved planetary load sharing compared to that of the rigid ring gear of the UH-60A transmission. The ATT mechanical efficiency was lower than that of the OH-58A transmission, probably due to the high-contact-ratio planetary gears.

  11. Canby Area Service Project : Substation and Associated Transmission Line : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-02-01

    Bonneville Power Administration (BPA) provides power to Surprise Valley Electrification Corporation (SVEC) in Modoc County, California. BPA uses PacificCorp's substation and transmission facilities between Alturas and Canby, California to transfer power to SVEC's Canby Substation. In the next year, SVEC expects increased industrial, agricultural, and residential electric loads on their 69-kV transmission system south of Canby. SVEC's substation can accommodate only about 10 percent of the expected additional electric load. BPA's proposed action is intended to meet SVEC's increasing electric load. BPA proposes to meet SVEC's increasing energy load by tapping into BPA's existing BPA Malin-Warner 230-kV transmission line, and building an 7.9-mile transmission line to a new BPA substation. BPA proposes to build the new substation next to the west side of SVEC's Canby Substation (Figure 1). This new substation will allow SVEC to move the additional power over their existing transmission or distribution lines. This report is the environmental assessment of the potential impact of the proposed project. The assessment determined that no environmental impact statement'' is not required.

  12. Canby Area Service Project substation and associated transmission line. Environmental Assessment

    SciTech Connect

    Not Available

    1992-02-01

    Bonneville Power Administration (BPA) provides power to Surprise Valley Electrification Corporation (SVEC) in Modoc County, California. BPA uses PacificCorp`s substation and transmission facilities between Alturas and Canby, California to transfer power to SVEC`s Canby Substation. In the next year, SVEC expects increased industrial, agricultural, and residential electric loads on their 69-kV transmission system south of Canby. SVEC`s substation can accommodate only about 10 percent of the expected additional electric load. BPA`s proposed action is intended to meet SVEC`s increasing electric load. BPA proposes to meet SVEC`s increasing energy load by tapping into BPA`s existing BPA Malin-Warner 230-kV transmission line, and building an 7.9-mile transmission line to a new BPA substation. BPA proposes to build the new substation next to the west side of SVEC`s Canby Substation (Figure 1). This new substation will allow SVEC to move the additional power over their existing transmission or distribution lines. This report is the environmental assessment of the potential impact of the proposed project. The assessment determined that no ``environmental impact statement`` is not required.

  13. Control system and method for a power delivery system having a continuously variable ratio transmission

    DOEpatents

    Frank, Andrew A.

    1984-01-01

    A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.

  14. Control system and method for a power delivery system having a continuously variable ratio transmission

    DOEpatents

    Frank, A.A.

    1984-07-10

    A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine. 4 figs.

  15. Variable loading roller

    DOEpatents

    Williams, D.M.

    1988-01-21

    An automatic loading roller for transmitting torque in traction drive devices in manipulator arm joints includes a two-part camming device having a first cam portion rotatable in place on a shaft by an input torque and a second cam portion coaxially rotatable and translatable having a rotating drive surface thereon for engaging the driven surface of an output roller with a resultant force proportional to the torque transmitted. Complementary helical grooves in the respective cam portions interconnected through ball bearings interacting with those grooves effect the rotation and translation of the second cam portion in response to rotation of the first. 14 figs.

  16. Multidimensional spectral load balancing

    SciTech Connect

    Hendrickson, B.; Leland, R.

    1993-01-01

    We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.

  17. Microbial Load Monitor

    NASA Technical Reports Server (NTRS)

    Gibson, S. F.; Royer, E. R.

    1979-01-01

    The Microbial Load Monitor (MLM) is an automated and computerized system for detection and identification of microorganisms. Additionally, the system is designed to enumerate and provide antimicrobic susceptibility profiles for medically significant bacteria. The system is designed to accomplish these tasks in a time of 13 hours or less versus the traditional time of 24 hours for negatives and 72 hours or more for positives usually required for standard microbiological analysis. The MLM concept differs from other methods of microbial detection in that the system is designed to accept raw untreated clinical samples and to selectively identify each group or species that may be present in a polymicrobic sample.

  18. Plug Loads Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple plug loads inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Vending Machine Misers, Delamp Vending Machine, Desktop to Laptop retrofit, CRT to LCD monitors retrofit, Computer Power Management Settings, and Energy Star Refrigerator retrofit. This tool calculates energy savings, demand reduction, cost savings, building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  19. Variable loading roller

    DOEpatents

    Williams, Daniel M.

    1989-01-01

    An automatic loading roller for transmitting torque in traction drive devices in manipulator arm joints includes a two-part camming device having a first cam portion rotatable in place on a shaft by an input torque and a second cam portion coaxially rotatable and translatable having a rotating drive surface thereon for engaging the driven surface of an output roller with a resultant force proportional to the torque transmitted. Complementary helical grooves on the respective cam portions interconnected through ball bearings interacting with those grooves effect the rotation and translation of the second cam portion in response to rotation of the first.

  20. Load distributions in photoeleastic bolted-joint models

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Liu, D.

    1982-01-01

    An attempt is made to study the stresses in multiple-bolt connectors, focusing on the stress distribution in a two-pin connector, the two pins being in line and in parallel with the direction of the applied load. The photoelastic modeling approach with two-dimensional transmission photoelasticity is used. The joint models and model fringe patterns are discussed, with special attention given to the existence of a photoelastic isotropic point and to the separation of stresses.

  1. Light aircraft sound transmission study

    NASA Technical Reports Server (NTRS)

    Heitman, K.; Bernhard, R. J.

    1983-01-01

    The plausibility of using the two microphone sound intensity technique to study noise transmission into light aircraft was investigated. In addition, a simple model to predict the interior sound pressure level of the cabin was constructed.

  2. Transmission series power flow control

    SciTech Connect

    Nelson, R.J.; Bian, J.; Williams, S.L.

    1995-01-01

    This paper presents the characteristics of two gate turn-off (GTO) thyristor voltage-sourced inverter based series power flow control devices, namely the Series Power Flow Controller (SPFC) and the Unified Power Flow Controller (UPFC). These devices represent series extensions of the STATCON, an inverter-based shunt device developed under a tailored collaboration by EPRI, TVA and the Westinghouse Science and Technology Center, which will soon be placed in service on the TVA 161kV transmission system for transmission voltage control. Operation of the SPFC and UPFC is illustrated through the use of easily-constructed circle diagrams on the P-Q plane. The circle diagrams provide the transmission planning engineer with a simple means to assess the performance of these devices on the transmission system. A concluding example illustrates that the UPFC provides a level of power now control which is unattainable with more conventional devices.

  3. Transmission series power flow control

    SciTech Connect

    Nelson, R.J.; Bian, J.; Williams, S.L.

    1994-12-31

    This paper presents the characteristics of two gate turn-off (GTO) thyristor voltage-sourced inverter-based series power flow control devices, namely the Series Power Flow Controller (SPFC) and the Unified Power Flow Controller (UPFC). These devices represent series extensions of the STATCON, an inverter-based shunt device developed under a tailored collaboration by EPRI, TVA and the Westinghouse Science and Technology Center, which will soon be placed in service on the TVA 161kV transmission system for transmission voltage control. Operation of the SPFC and UPFC is illustrated through the use of easily-constructed circle diagrams on the P-Q plane. The circle diagrams provide the transmission planning engineer with a simple means to assess the performance of these devices on the transmission system. A concluding example illustrates that the UPFC provides a level of power flow control which is unattainable with more conventional devices.

  4. Cultural transmission of civic attitudes.

    PubMed

    Miles-Touya, Daniel; Rossi, Máximo

    2016-01-01

    In this empirical paper we attempt to measure the separate influence on civic engagement of educational attainment and cultural transmission of civic attitudes. Unlike most of the previous empirical works on this issue, we are able to approximate the cultural transmission of civic attitudes. We observe that civic returns to education are overstated when the transmission of civic attitudes is ignored. Moreover, the transmission of civic attitudes significantly enhances civic involvement and reinforces civic returns to education. Our findings are in line with the proposals of civic virtue theorists or grass movements who suggest that citizenship education should be included in the compulsory school curricula since, if not, families or local communities will only transmit their particular view of the world.

  5. Transmission of Information: An Overview.

    ERIC Educational Resources Information Center

    Thoma, George R.

    1981-01-01

    Outlines the basic principles underlying the transmission of information, including analog and digital modulation, limitations to communications, configurations of communications networks, optical fiber cables, and earth satellites. Six references are cited. (FM)

  6. Fomite transmission in head lice.

    PubMed

    Burkhart, Craig N; Burkhart, Craig G

    2007-06-01

    Control of various infestations requires an accurate understanding of transmission. After thousands of years of lice infestation, scientific documentation of indirect contact transmission has been substantiated. Lice can be transferred in the egg, instar, and adult stages. Lice have now been shown in the laboratory to be readily dislodged by air movements such as blow-drying one's hair, combing, and toweling. Moreover, passive transfer to adjoining fabric is also frequently observed. Louse transmission by fomites occurs more frequently than has been commonly believed. Close proximity suffices to increase the likeliness of a new infestation. Thus louse control measures should take account of fomite transmission and include screening of all individuals within an infested person's immediate circle of contact, laundering of everything within the infested individuals' bed or quarantining of such material for 10 days, thorough vacuuming of floors, carpets, upholstery, with a standard vacuum cleaner.

  7. Hybrid-Vehicle Transmission System

    NASA Technical Reports Server (NTRS)

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  8. Load Control System Reliability

    SciTech Connect

    Trudnowski, Daniel

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  9. Factors that affect the fatigue strength of power transmission shafting and their impact on design

    NASA Technical Reports Server (NTRS)

    Leowenthal, S. H.

    1986-01-01

    A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

  10. Free-Space Power Transmission

    NASA Technical Reports Server (NTRS)

    1989-01-01

    NASA Lewis Research Center organized a workshop on technology availability for free-space power transmission (beam power). This document contains a collection of viewgraph presentations that describes the effort by academia, industry, and the national laboratories in the area of high-frequency, high-power technology applicable to free-space power transmission systems. The areas covered were rectenna technology, high-frequency, high-power generation (gyrotrons, solar pumped lasers, and free electron lasers), and antenna technology.

  11. Diversified transmission multichannel detection system

    SciTech Connect

    Tournois, P.; Engelhard, P.

    1984-07-03

    A detection system for imaging by sonar or radar signals. The system associates diversified transmissions with an interferometric base. This base provides an angular channel formation means and each signal formed in this way is processed by matched filtering in a circuit containing copy signals characterizing the space coloring obtained by the diversified transmission means. The invention is particularly applicable to side or front looking detection sonars.

  12. Creating Airy beams employing a transmissive spatial light modulator.

    PubMed

    Latychevskaia, Tatiana; Schachtler, Daniel; Fink, Hans-Werner

    2016-08-01

    We present a detailed study of two novel methods for shaping the light optical wavefront by employing a transmissive spatial light modulator (SLM). Conventionally, optical Airy beams are created by employing SLMs in the so-called all-phase mode. In the first method, a numerically simulated lens phase distribution is loaded directly onto the SLM, together with the cubic phase distribution. An Airy beam is generated at the focal plane of the numerical lens. We provide for the first time, to the best of our knowledge, quantitative properties of the formed Airy beam. We derive the formula for deflection of the intensity maximum of the so-formed Airy beam, which is different from the quadratic deflection typical of Airy beams. We cross-validate the derived formula by both simulations and experiment. The second method is based on the fact that a system consisting of a transmissive SLM sandwiched between two polarizers can create a transmission function with negative values. This observation alone has the potential for various other wavefront modulations where the transmission function requires negative values. As an example for this method, we demonstrate that a wavefront can be modulated by passing the SLM system with transmission function with negative values by loading an Airy function distribution directly onto the SLM. Since the Airy function is a real-valued function but also with negative values, an Airy beam can be generated by direct transfer of the Airy function distribution onto such an SLM system. In this way, an Airy beam is generated immediately behind the SLM. As both new methods do not employ a physical lens, the two setups are more compact than conventional setups for creating Airy beams. We compare the performance of the two novel methods and the properties of the created Airy beams.

  13. Commissioning of 84 GHz Kstar Ech Transmission Line System

    NASA Astrophysics Data System (ADS)

    Bae, Y. S.; Han, W.-S.; Yang, H.-L.; Park, S.; Jeong, J.-H.; Namkung, W.; Cho, M.-H.

    2009-04-01

    The installation of 84 GHz Electron Cyclotron Heating (ECH) system has been completed in Korea Superconducting Tokamak Advanced Research (KSTAR). The 84 GHz EC-wave is transmitted from the gyrotron to the antenna system through evacuated HE11-mode circular corrugated waveguides with inner diameter of 31.75 mm and miter bends with flat mirror. The L-box chamber is designed and installed to match the output beam of TEM00 mode from the gyrotron into the 31.75-mm circular corrugated waveguide by a large ellipsoidal mirror inside the chamber. The ellipsoidal mirror can be adjusted in two perpendicular axes and moved in or out for the minor misalignment. The elliptical polarization of EC-wave required for the specific mode coupling at the plasma edge is obtained by means of subsequent two grooved mirrors inside the miter bend. The torus vacuum window, which is half-wavelength thick diamond disk, is installed for the vacuum isolation of the transmission line vacuum from the KSTAR vacuum vessel. For the RF power measurement, two dummy loads are installed near the gyrotron and near the KSTAR tokamak, respectively. The dummy load near the KSTAR tokamak will be used for the transmission efficiency measurement of the transmission line system. This paper describes the evacuation test result of the transmission line from the L-box to the torus diamond window, the transmission efficiency measurement of 84-GHz millimeter wave, and the measurement of elliptical polarization parameters as a function of the grooved mirror angles. Also, the requirement of the polarization control for the EC-wave injection and mode coupling is discussed.

  14. Advanced Rotorcraft Transmission (ART) program

    NASA Technical Reports Server (NTRS)

    Heath, Gregory F.; Bossler, Robert B., Jr.

    1993-01-01

    Work performed by the McDonnell Douglas Helicopter Company and Lucas Western, Inc. within the U.S. Army/NASA Advanced Rotorcraft Transmission (ART) Program is summarized. The design of a 5000 horsepower transmission for a next generation advanced attack helicopter is described. Government goals for the program were to define technology and detail design the ART to meet, as a minimum, a weight reduction of 25 percent, an internal noise reduction of 10 dB plus a mean-time-between-removal (MTBR) of 5000 hours compared to a state-of-the-art baseline transmission. The split-torque transmission developed using face gears achieved a 40 percent weight reduction, a 9.6 dB noise reduction and a 5270 hour MTBR in meeting or exceeding the above goals. Aircraft mission performance and cost improvements resulting from installation of the ART would include a 17 to 22 percent improvement in loss-exchange ratio during combat, a 22 percent improvement in mean-time-between-failure, a transmission acquisition cost savings of 23 percent of $165K, per unit, and an average transmission direct operating cost savings of 33 percent, or $24K per flight hour. Face gear tests performed successfully at NASA Lewis are summarized. Also, program results of advanced material tooth scoring tests, single tooth bending tests, Charpy impact energy tests, compact tension fracture toughness tests and tensile strength tests are summarized.

  15. Essays on electricity transmission investment and financial transmission rights

    NASA Astrophysics Data System (ADS)

    Shang, Wenzhuo

    The U.S. electric power industry has been going through fundamental restructuring and realignment since the 1990's. Many issues and problems have emerged during the transition, and both economists and engineers have been looking for the solutions fervently. In this dissertation, which consists primarily of three essays, we apply economics theory and techniques to the power industry and address two related issues, transmission investment and financial transmission rights (FTRs). The first essay takes the decentralized perspective and investigates the efficiency attribute of market-based transmission investment under perfect competition. We clarify, for the first time, the nature of the externality created by loop flows that causes transmission investment to be inefficient. Our findings have important implications for better understanding of transmission market design and creating incentives for efficient transmission investment. In the second essay, we define several rules for allocating transmission investment cost within the framework of cooperative game theory. These rules provide fair, stable or efficient cost allocations in theory and are good benchmarks against which the allocation mechanism in practice can be compared and improved upon. In the last essay, we make exploratory efforts in analyzing and assessing empirically the performance of the Midwest independent system operator (MISO) FTR auction market. We reveal some stylized facts about this young market and find that it is not efficient under the risk-neutrality assumption. We also point out and correct the drawbacks in previous related work and suggest about more complete empirical work in future. In all, this dissertation makes both theoretic and empirical analysis of the two hot issues related to the power industry and comes up with findings that have important implications for the development of this industry.

  16. Mutation Load under Vegetative Reproduction and Cytoplasmic Inheritance

    PubMed Central

    Kondrashov, A. S.

    1994-01-01

    For reasons that remain unclear, even multicellular organisms usually originate from a single cell. Here I consider the balance between deleterious mutations and selection against them in a population with obligate vegetative reproduction, when every offspring is initiated by more than one cell of a parent. The mutation load depends on the genomic deleterious mutation rate U, strictness of selection, number of cells which initiate an offspring n, and the relatedness among the initial cells. The load grows with increasing U, n and strictness of selection, and declines when an offspring is initiated by more closely related cells. If Un >> 1, the load under obligate vegetative reproduction may be substantially higher than under sexual or asexual reproduction, which may account for its rarity. In nature obligate vegetative reproduction seems to be more common and long term in taxa whose cytological features ensure a relatively low load under it. The same model also describes the mutation load under two other modes of inheritance: (1) uniparental transmission of organelles and (2) reproduction by division of multinuclear cells, where each daughter cell receives many nuclei. The load declines substantially when the deleterious mutation rate per organelle genome gets lower or when the number of nuclei in a cell sometimes drops. This may explain the small sizes of organelle genomes in sexual lineages and the presence of karyonic cycles in asexual unicellular multinuclear eukaryotes. PMID:8056318

  17. Influence of load by high power on the optical coupler

    NASA Astrophysics Data System (ADS)

    Bednarek, Lukas; Poboril, Radek; Vanderka, Ales; Hajek, Lukas; Nedoma, Jan; Vasinek, Vladimir

    2016-12-01

    Nowadays, aging of the optical components is a very current topic. Therefore, some investigations are focused on this area, so that the aging of the optical components is accelerated by thermal, high power and gamma load. This paper deals by findings of the influence of the load by laser with high optical power on the transmission parameters of the optical coupler. The investigated coupler has one input and eight outputs (1x8). Load by laser with high optical power is realized using a fiber laser with a cascade configuration EDFA amplifiers. The output power of the amplifier is approximately 250 mW. Duration of the load is moving from 104 hours to 139 hours. After each load, input power and output powers of all branches are measured. Following parameters of the optical coupler are calculated using formulas: the insertion losses of the individual branches, split ratio, total losses, homogeneity of the losses and cross-talk between different branches. All measurements are performed at wavelengths 1310 nm and 1550 nm. Individual optical powers are measured 20 times, due to the exclusion of statistical error of the measurement. After measuring, the coupler is connected to the amplifier for next cycle of the load. The paper contains an evaluation of the results of the coupler before and after four cycles of the burden.

  18. Multi-band Monopole Antennas Loaded with Metamaterial TL

    NASA Astrophysics Data System (ADS)

    Song, Zhi-jie; Liang, Jian-gang

    2015-05-01

    A novel metamaterial transmission line (TL) by loading complementary single Archimedean spiral resonator pair (CSASRP) is investigated and used to design a set of multi-frequency monopole antennas. The particularity is that the CSASRP which features dual-shunt branches in the equivalent circuit model is directly etched in the signal strip. By smartly controlling the element parameters, three antennas are designed and one of them covering UMTS and Bluetooth bands is fabricated and measured. The antenna exhibits impedance matching better than -10 dB and normal monopolar radiation patterns at working bands of 1.9-2.22 and 2.38-2.5 GHz. Moreover, the loaded element also contributes to the radiation, which is the major advantage of this prescription over previous lumped-element loadings. The proposed antenna is also more compact over previous designs.

  19. Design of naltrexone-loaded hydrolyzable crosslinked nanoparticles

    PubMed Central

    Yin, Wusheng; Akala, Emmanuel O.; Taylor, Robert E.

    2010-01-01

    A hydrolyzable crosslinker (N,O-dimethacryloylhydroxylamine (MANHOMA)) was synthesized by a modified method and was characterized using 1H-NMR, FTIR, and melting point determination. Naltrexone-loaded nanoparticles were prepared by copolymerization of poly(ethylene glycol)1000 monomethyl ether mono methacrylate (PEO-MA), methyl methacrylate (MMA) and N,O-dimethacryloylhydroxylamine (MANHOMA) in 0.4% poly(vinyl alcohol) aqueous solution. The nanoparticles were characterized by FTIR, particle size determination and transmission electron microscope (TEM). The TEM photomicrographs of the nanoparticles show a crosslinked core surrounded by a ring formed by the polyethylene glycol tail of PEO-MA. The loading efficiency of the nanoparticles and in vitro drug availability from the nanoparticles were investigated. The naltrexone-loaded hydrolyzable crosslinked nanoparticles were able to sustain the release of naltrexone for different periods of time, depending on the monomer feed composition. PMID:12204561

  20. Commercial building energy use monitoring for utility load research

    SciTech Connect

    Mazzucchi, R.P.

    1987-01-01

    This paper describes a method to acquire empirical data regarding commercial building energy performance for utility load research. The method was devised and implemented for a large scale monitoring program being conducted for a federal electricity marketing and transmission agency in the Pacific Northwest states. An important feature of this method is its hierarchical approach, wherein building types, end-use loads, and key building characteristics are classified to accommodate analysis at many levels. Through this common taxonomy and measurement protocol, energy-use metering projects of varying detail and comprehensiveness can be coordinated. The procedures devised for this project have been implemented for approximately 150 buildings to date by specially trained contractors. Hence, this paper provides real-world insights of the complexity and power of end use measurements from commercial buildings to address utility load research topics. 6 refs.

  1. Cooling loads in laboratories

    SciTech Connect

    Wilkins, C.K.; Cook, M.R.

    1999-07-01

    The heating, ventilating, and air-conditioning (HVAC) system for a laboratory must be designed with consideration for safety, air cleanliness, and space temperature. The primary safety concern is to ensure proper coordination between fume hood exhaust and makeup air supply. Air cleanliness is maintained by properly filtering supply air, by delivering adequate room air changes, and by ensuring proper pressure relationships between the laboratory and adjacent spaces. Space temperature is maintained by supplying enough cooling air to offset the amount of heat generated in the room. Each of these factors must be considered, and the one that results in the largest ventilation rate is used to establish the supply and exhaust airflows. The project described in this paper illustrates a case where cooling load is the determining factor in the sizing of the air systems.

  2. Offshore tanker loading system

    SciTech Connect

    Baan, J. de; Heijst, W.J. van.

    1994-01-04

    The present invention relates to an improved flexible loading system which provides fluid communication between a subsea pipeline and a surface vessel including a hose extending from the subsea pipeline to a first buoyancy tank, a second hose extending from the first buoyancy tank to a central buoyancy tank, a second buoyancy tank, means connecting said second buoyancy tank to the sea floor and to the central buoyancy tank whereby the forces exerted on said central buoyant tank by said second hose and said connecting means are balanced to cause said central buoyancy tank to maintain a preselected position, a riser section extending upwardly from said central buoyancy tank and means on the upper termination for engagement by a vessel on the surface to raise said upper termination onto the vessel to complete the communication for moving fluids between the subsea pipeline and the vessel. In one form the means for connecting between the sea floor to the second buoyancy tank includes an anchor on the sea floor and lines extending from the anchor to the second buoyancy tank and from the second buoyancy tank to the central buoyancy tank. In another form of the invention the means for connecting is a third hose extending from a second subsea pipeline to the second buoyancy tank and a fourth hose extending from the second buoyancy tank to the central buoyancy tank. The central buoyancy tank is preferred to be maintained at a level below the water surface which allows full movement of the vessel while connected to the riser section. A swivel may be positioned in the riser section and a pressure relief system may be included in the loading system to protect it from sudden excess pressures. 17 figs.

  3. Cross-reactive acquired immunity influences transmission success of the Lyme disease pathogen, Borrelia afzelii.

    PubMed

    Jacquet, Maxime; Durand, Jonas; Rais, Olivier; Voordouw, Maarten J

    2015-12-01

    Cross-reactive acquired immunity in the vertebrate host induces indirect competition between strains of a given pathogen species and is critical for understanding the ecology of mixed infections. In vector-borne diseases, cross-reactive antibodies can reduce pathogen transmission at the vector-to-host and the host-to-vector lifecycle transition. The highly polymorphic, immunodominant, outer surface protein C (OspC) of the tick-borne spirochete bacterium Borrelia afzelii induces a strong antibody response in the vertebrate host. To test how cross-immunity in the vertebrate host influences tick-to-host and host-to-tick transmission, mice were immunized with one of two strain-specific recombinant OspC proteins (A3, A10), challenged via tick bite with one of the two B. afzelii ospC strains (A3, A10), and infested with xenodiagnostic ticks. Immunization with a given rOspC antigen protected mice against homologous strains carrying the same major ospC group allele but provided little or no cross-protection against heterologous strains carrying a different major ospC group allele. There were cross-immunity effects on the tick spirochete load but not on the probability of host-to-tick transmission. The spirochete load in ticks that had fed on mice with cross-immune experience was reduced by a factor of two compared to ticks that had fed on naive control mice. In addition, strain-specific differences in mouse spirochete load, host-to-tick transmission, tick spirochete load, and the OspC-specific IgG response revealed the mechanisms that determine variation in transmission success between strains of B. afzelii. This study shows that cross-immunity in infected vertebrate hosts can reduce pathogen load in the arthropod vector with potential consequences for vector-to-host pathogen transmission.

  4. Strain-specific antibodies reduce co-feeding transmission of the Lyme disease pathogen, Borrelia afzelii.

    PubMed

    Jacquet, Maxime; Durand, Jonas; Rais, Olivier; Voordouw, Maarten J

    2016-03-01

    Vector-borne pathogens use a diversity of strategies to evade the vertebrate immune system. Co-feeding transmission is a potential immune evasion strategy because the vector-borne pathogen minimizes the time spent in the vertebrate host. We tested whether the Lyme disease pathogen, Borrelia afzelii, can use co-feeding transmission to escape the acquired immune response in the vertebrate host. We induced a strain-specific, protective antibody response by immunizing mice with one of two variants of OspC (A3 and A10), the highly variable outer surface protein C of Borrelia pathogens. Immunized mice were challenged via tick bite with B. afzelii strains A3 or A10 and infested with larval ticks at days 2 and 34 post-infection to measure co-feeding and systemic transmission respectively. Antibodies against a particular OspC variant significantly reduced co-feeding transmission of the targeted (homologous) strain but not the non-targeted (heterologous) strain. Cross-immunity between OspC antigens had no effect in co-feeding ticks but reduced the spirochaete load twofold in ticks infected via systemic transmission. In summary, OspC-specific antibodies reduced co-feeding transmission of a homologous but not a heterologous strain of B. afzelii. Co-feeding transmission allowed B. afzelii to evade the negative consequences of cross-immunity on the tick spirochaete load.

  5. On the modelling of excitations in geared systems by transmission errors

    NASA Astrophysics Data System (ADS)

    Velex, P.; Ajmi, M.

    2006-03-01

    This paper introduces an original theoretical approach to the modelling of pinion-gear excitations valid for three-dimensional models of single-stage geared transmissions. Shape deviations and errors on gears are considered and the associated equations of motion account for time-varying mesh stiffness, and also torsional, flexural and axial couplings. Starting from the instantaneous contact conditions between the teeth, the equations of motion are re-formulated in terms of quasi-static transmission errors under load and no-load transmission errors. The range of application of transmission error-based formulations is analysed and some new equations are proposed which make it possible to introduce rigorously meshing excitations via transmission errors. Using an extended finite element model of a spur and helical gear test rig, the dynamic results from the formulations based on transmission errors are compared with the reference solutions. Both sets of results are found to be in close agreement, thus validating the proposed theory. The paper concludes with a critical analysis of the interests and limitations concerning the concept of transmission errors as excitation terms in gear dynamics.

  6. Seismic Performance Research of Transmission Tower in Consideration of the Pile-soil-structure System

    NASA Astrophysics Data System (ADS)

    Liu, Chuncheng; Mao, Long; Wang, Chongyang; Zha, Chuanming

    2016-11-01

    The seismic performance of transmission tower in consideration of pile-soil- structure dynamic interaction is researched through numerical simulation. Based on a transmission tower of a specific project, pile-soil-transmission tower coupled system is established. By using the method of time history, the pile-soil- transmission tower system dynamic response under seismic load were calculated, and comparing with the results without considering interaction system. Results show that, after considering interaction of the system, the period of the structure have extended and the mode of the structure lagged. On soft sites, compare with no considering the interaction, the results have a big difference, the relative increment of the maximum displacement at the top of the tower is 39.82%, respectively. Therefore it is suggested that the pile-soil-structure dynamic interaction should be fully considered in aseismic design of transmission tower on soft sites and medium soft sites.

  7. Lightly loaded lubricated impacts: Idle gear rattle

    NASA Astrophysics Data System (ADS)

    Tangasawi, O.; Theodossiades, S.; Rahnejat, H.

    2007-12-01

    Idle gear rattle is associated with the characteristic noise that unselected impacting gears radiate to the environment. It is induced by engine order vibration in the presence of backlash in the unengaged gear pairs, resulting in oscillatory response within their backlash range. A tribo-dynamic model of a front wheel drive manual transmission has been developed to study idle rattle, considering the hydrodynamic contact film reaction and flank friction. The model includes the torsional motions of the idle gears and the lateral motions of the supporting output shafts. The hydrodynamic lubricant film formed between the gear teeth under light impact loads behaves as a nonlinear spring-damper mechanism, whilst the inclusion of the shafts' bearing compliances introduces additional nonlinear terms, which are modelled as piecewise linear functions. The aim of the paper is to extend the existing methodology reported by the authors on idle rattle investigations of geared lubricated systems, based on torsional vibrations only, by considering the system response, which is eventually transferred to the gearbox case through the bearings. These are preliminary results found, which conform closely to experimental measurements taken from a vehicle equipped with a manual transmission of the same type.

  8. Variable response load limiting device

    NASA Technical Reports Server (NTRS)

    Mcsmith, Dwight D. (Inventor)

    1988-01-01

    An energy absorbing device used as a load limiting member in a structure to control its response to applied loads is described. It functions by utilizing a spool assembly having flanged ends and an interior cavity of sufficiently large diameter to cause it to deform plastically at a prescribed load. In application, the spool is utilized as a pivot point for the legs of an airplane seat. When properly designed and integrated into the seat arrangement the spool will twist about its axis, deforming plastically when the impact load exceeds the spool yield value. Through this deformation, the spool absorbs the kinetic energy of the movement of the seat at a substantially constant rate, thereby controlling the level of loads transmitted to the seat occupant. By proper sizing and collection of materials, it is possible to control load response in a predictable manner.

  9. Application of the mobility power flow approach to structural response from distributed loading

    NASA Technical Reports Server (NTRS)

    Cuschieri, J. M.

    1988-01-01

    The problem of the vibration power flow through coupled substructures when one of the substructures is subjected to a distributed load is addressed. In all the work performed thus far, point force excitation was considered. However, in the case of the excitation of an aircraft fuselage, distributed loading on the whole surface of a panel can be as important as the excitation from directly applied forces at defined locations on the structures. Thus using a mobility power flow approach, expressions are developed for the transmission of vibrational power between two coupled plate substructures in an L configuration, with one of the surfaces of one of the plate substructures being subjected to a distributed load. The types of distributed loads that are considered are a force load with an arbitrary function in space and a distributed load similar to that from acoustic excitation.

  10. Dynamic load balancing of applications

    DOEpatents

    Wheat, S.R.

    1997-05-13

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers is disclosed. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated. 13 figs.

  11. Dynamic load balancing of applications

    DOEpatents

    Wheat, Stephen R.

    1997-01-01

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated.

  12. Structural dynamics payload loads estimates

    NASA Technical Reports Server (NTRS)

    Engels, R. C.

    1982-01-01

    Methods for the prediction of loads on large space structures are discussed. Existing approaches to the problem of loads calculation are surveyed. A full scale version of an alternate numerical integration technique to solve the response part of a load cycle is presented, and a set of short cut versions of the algorithm developed. The implementation of these techniques using the software package developed is discussed.

  13. Alaska Village Electric Load Calculator

    SciTech Connect

    Devine, M.; Baring-Gould, E. I.

    2004-10-01

    As part of designing a village electric power system, the present and future electric loads must be defined, including both seasonal and daily usage patterns. However, in many cases, detailed electric load information is not readily available. NREL developed the Alaska Village Electric Load Calculator to help estimate the electricity requirements in a village given basic information about the types of facilities located within the community. The purpose of this report is to explain how the load calculator was developed and to provide instructions on its use so that organizations can then use this model to calculate expected electrical energy usage.

  14. In vitro loading of apoferritin.

    PubMed

    de Silva, D; Miller, D M; Reif, D W; Aust, S D

    1992-03-01

    This study compared the effect of loading apoferritin either with ferrous ammonium sulfate in various buffers or with ceruloplasmin and chelated ferrous iron. It was shown that loading of apoferritin with ferrous ammonium sulfate was dependent on buffer and pH, and was directly related to the rate of iron autoxidation. The ceruloplasmin-dependent loading of apoferritin, however, was unaffected by these factors. Isoelectric focusing and amino acid analysis of the differently loaded ferritins showed that ferrous ammonium sulfate loading of apoferritin resulted in the depletion of the basic amino acids, lysine and histidine, probably as a result of protein oxidation. No significant differences in amino acid composition was noted for ceruloplasmin-loaded ferritin. Furthermore, ferritin loaded with ferrous ammonium sulfate released more iron than either native or ceruloplasmin-loaded ferritin when either paraquat or EDTA was used as an iron mobilizing agent. We suggest that the loading of apoferritin with ferrous ammonium sulfate occurred as a result of iron autoxidation and may result in oxidation of amino acids and loss of integrity of the protein, and that ceruloplasmin may act as a catalyst for the incorporation of iron into apoferritin in a manner more closely related to that occurring in vivo.

  15. High-Power Rf Load

    DOEpatents

    Tantawi, Sami G.; Vlieks, Arnold E.

    1998-09-01

    A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

  16. Clustering, climate and dengue transmission.

    PubMed

    Junxiong, Pang; Yee-Sin, Leo

    2015-06-01

    Dengue is currently the most rapidly spreading vector-borne disease, with an increasing burden over recent decades. Currently, neither a licensed vaccine nor an effective anti-viral therapy is available, and treatment largely remains supportive. Current vector control strategies to prevent and reduce dengue transmission are neither efficient nor sustainable as long-term interventions. Increased globalization and climate change have been reported to influence dengue transmission. In this article, we reviewed the non-climatic and climatic risk factors which facilitate dengue transmission. Sustainable and effective interventions to reduce the increasing threat from dengue would require the integration of these risk factors into current and future prevention strategies, including dengue vaccination, as well as the continuous support and commitment from the political and environmental stakeholders.

  17. Remote control apparatus for transmission

    SciTech Connect

    Ebina, A.

    1989-01-10

    A remote control apparatus for a transmission is described, comprising: means for sending a signal representing an operation state of a change lever; auxiliary power means, remote-controlled by the change lever, for changing a gear position of the transmission and sending a signal representing the gear position; and control means for controlling an operation of the auxiliary power means in accordance with the change lever operation state signal and gear position signal, the control means being provided with neutral position holding means comprises signal transmission delay means. This comprises means for detecting that the shift path on which the striker presently exists is different from the shift path instructed according to the change lever operating signal, then detecting that the striker has reached the first neutral position according to the neutral position signal and generating a neutral position detection signal.

  18. Estimating Nitrogen Loads, BMPs, and Target Loads Exceedance Risks

    EPA Science Inventory

    The Wabash River (WR) watershed, IN, drains two-thirds of the state’s 92 counties and has primarily agricultural land use. The nutrient and sediment loads of the WR significantly increase loads of the Ohio River ultimately polluting the Gulf of Mexico. The objective of this study...

  19. Plasmodium vivax Transmission in Africa

    PubMed Central

    Howes, Rosalind E.; Reiner Jr., Robert C.; Battle, Katherine E.; Longbottom, Joshua; Mappin, Bonnie; Ordanovich, Dariya; Tatem, Andrew J.; Drakeley, Chris; Gething, Peter W.; Zimmerman, Peter A.; Smith, David L.; Hay, Simon I.

    2015-01-01

    Malaria in sub-Saharan Africa has historically been almost exclusively attributed to Plasmodium falciparum (Pf). Current diagnostic and surveillance systems in much of sub-Saharan Africa are not designed to identify or report non-Pf human malaria infections accurately, resulting in a dearth of routine epidemiological data about their significance. The high prevalence of Duffy negativity provided a rationale for excluding the possibility of Plasmodium vivax (Pv) transmission. However, review of varied evidence sources including traveller infections, community prevalence surveys, local clinical case reports, entomological and serological studies contradicts this viewpoint. Here, these data reports are weighted in a unified framework to reflect the strength of evidence of indigenous Pv transmission in terms of diagnostic specificity, size of individual reports and corroboration between evidence sources. Direct evidence was reported from 21 of the 47 malaria-endemic countries studied, while 42 countries were attributed with infections of visiting travellers. Overall, moderate to conclusive evidence of transmission was available from 18 countries, distributed across all parts of the continent. Approximately 86.6 million Duffy positive hosts were at risk of infection in Africa in 2015. Analysis of the mechanisms sustaining Pv transmission across this continent of low frequency of susceptible hosts found that reports of Pv prevalence were consistent with transmission being potentially limited to Duffy positive populations. Finally, reports of apparent Duffy-independent transmission are discussed. While Pv is evidently not a major malaria parasite across most of sub-Saharan Africa, the evidence presented here highlights its widespread low-level endemicity. An increased awareness of Pv as a potential malaria parasite, coupled with policy shifts towards species-specific diagnostics and reporting, will allow a robust assessment of the public health significance of Pv, as well

  20. Plasmodium vivax Transmission in Africa.

    PubMed

    Howes, Rosalind E; Reiner, Robert C; Battle, Katherine E; Longbottom, Joshua; Mappin, Bonnie; Ordanovich, Dariya; Tatem, Andrew J; Drakeley, Chris; Gething, Peter W; Zimmerman, Peter A; Smith, David L; Hay, Simon I

    2015-11-01

    Malaria in sub-Saharan Africa has historically been almost exclusively attributed to Plasmodium falciparum (Pf). Current diagnostic and surveillance systems in much of sub-Saharan Africa are not designed to identify or report non-Pf human malaria infections accurately, resulting in a dearth of routine epidemiological data about their significance. The high prevalence of Duffy negativity provided a rationale for excluding the possibility of Plasmodium vivax (Pv) transmission. However, review of varied evidence sources including traveller infections, community prevalence surveys, local clinical case reports, entomological and serological studies contradicts this viewpoint. Here, these data reports are weighted in a unified framework to reflect the strength of evidence of indigenous Pv transmission in terms of diagnostic specificity, size of individual reports and corroboration between evidence sources. Direct evidence was reported from 21 of the 47 malaria-endemic countries studied, while 42 countries were attributed with infections of visiting travellers. Overall, moderate to conclusive evidence of transmission was available from 18 countries, distributed across all parts of the continent. Approximately 86.6 million Duffy positive hosts were at risk of infection in Africa in 2015. Analysis of the mechanisms sustaining Pv transmission across this continent of low frequency of susceptible hosts found that reports of Pv prevalence were consistent with transmission being potentially limited to Duffy positive populations. Finally, reports of apparent Duffy-independent transmission are discussed. While Pv is evidently not a major malaria parasite across most of sub-Saharan Africa, the evidence presented here highlights its widespread low-level endemicity. An increased awareness of Pv as a potential malaria parasite, coupled with policy shifts towards species-specific diagnostics and reporting, will allow a robust assessment of the public health significance of Pv, as well

  1. Intercultural Transmission and Intergenerational Transmission in Immigrant Families.

    ERIC Educational Resources Information Center

    Nauck, Bernhard

    2001-01-01

    Examined the impact of intergenerational transmission processes on the intercultural contact and ethnic identification of second generation adolescents from five migrant groups in Germany, distinguishing four possible outcomes of intercultural contact (integration, assimilation, segregation, and marginalization). Data from interviews with same-sex…

  2. Electrical Transmission on the Lunar Surface. Part 1; DC Transmission

    NASA Technical Reports Server (NTRS)

    Gordon, Lloyd B.

    2001-01-01

    This report summarizes a portion of the results from a grant at Auburn University to study the electrical and thermal energy management for lunar facilities. Over the past year (June 1989 to May 1990) the following topics have been investigated: June 1989 to November 1989 - Literature survey, assessment of lunar power needs, and overview study of the requirements of a lunar power system; November 1989 to April 1990 - Develop models for the study of dc electrical power transmission lines for the lunar surface; March 1990 to May 1990 - Develop models for the study of ac electrical power transmission lines for the lunar surface. Because of the large amount of information in the model development and application to a wide parameter space this report is being bound separately. This report specifically contains the model development and parameter study for dc electrical power transmission lines. The end of the funding year (May 1990) will conclude with an annual report including the literature survey, the overview of the requirements of a lunar power system, and summaries of the dc and ac models of electrical transmission lines.

  3. Influence of tendon tears on ultrasound echo intensity in response to loading

    PubMed Central

    Frisch, Kayt E.; Marcu, David; Baer, Geoffrey S.; Thelen, Darryl G.; Vanderby, Ray

    2014-01-01

    Acoustoelastic (AE) ultrasound image analysis is a promising non-invasive approach that uses load-dependent echo intensity changes to characterize stiffness of tendinous tissue. The purpose of this study was to investigate whether AE can detect localized changes in tendon stiffness due to partial and full-thickness tendon tears. Ovine infraspinatus tendons with different levels of damage (Intact, 33%, 66% and full thickness cuts initiated on the articular and bursal sides) were cyclically loaded in a mechanical testing system while cine ultrasound images were recorded. The load-induced changes in echo intensity on the bursal and articular side of the tendon were determined. Consistent with AE theory, the undamaged tendons exhibited an increase in echo intensity with tendon loading, reflecting the strain-stiffening behavior of the tissue. In the intact condition, the articular region demonstrated a significantly greater increase in echo intensity during loading than the bursal region. Cuts initiated on the bursal side resulted in a progressive decrease in echo intensity of the adjacent tissue, likely reflecting the reduced load transmission through that region. However, image intensity information was less sensitive for identifying load transmission changes that result from partial thickness cuts initiated on the articular side. We conclude that AE approaches may be useful to quantitatively assess load-dependent changes in tendon stiffness, and that disruption of AE behavior may be indicative of substantial tendon damage. PMID:25468301

  4. Power transmission line monitoring system

    SciTech Connect

    Seppa, T.O.

    1993-08-17

    A method for monitoring the sag of an overhead power transmission line comprising the steps of: measuring the tension of the power line; producing an electrical signal representative of the tension measurement; processing said electrical signal in accordance with a predetermined tension-sag relationship to produce a second signal which is a function of sag of the power line; transmitting said second electrical signal to a distant location in a predetermined transmission mode; receiving the second signal at the distant location whereby current in the power line is adjusted in accordance with the received second signal.

  5. Electromagnetic Transmission Through Resonant Structures

    NASA Astrophysics Data System (ADS)

    Young, Steven M.

    Electromagnetic resonators store energy in the form of oscillatory electric and magnetic fields and gradually exchange that energy by coupling with their environment. This coupling process can have profound effects on the transmission and reflection properties of nearby interfaces, with rapid transitions from high transmittance to high reflectance over narrow frequency ranges, and has been exploited to design useful optical components such as spectral filters and dielectric mirrors. This dissertation includes analytic, numeric, and experimental investigations of three different electromagnetic resonators, each based on a different method of confining electromagnetic fields near the region of interest. First, we show that a structure with two parallel conducting plates, each containing a subwavelength slit, supports a localized resonant mode bound to the slits and therefore exhibits (in the absence of nonradiative losses), perfect resonant transmission over a narrow frequency range. In practice, the transmission is limited by conduction losses in the sidewalls; nevertheless, experimental results at 10 GHz show a narrowband transmission enhancement by a factor of 104 compared to the non-resonant transmission, with quality factor (ratio of frequency to peak width) Q ~ 3000. Second, we describe a narrowband transmission filter based on a single-layer dielectric grating. We use a group theory analysis to show that, due to their symmetry, several of the grating modes cannot couple to light at normal incidence, while several others have extremely large coupling. We then show how selectively breaking the system symmetry using off-normal light incidence can produce transmission peaks by enabling weak coupling to some of the previously protected modes. The narrowband filtering capabilities are validated by an experimental demonstration in the long wavelength infrared, showing transmission peaks of quality factor Q ~ 100 within a free-spectral range of 8-15 mum. Third, we

  6. Equalization of data transmission cable

    NASA Technical Reports Server (NTRS)

    Zobrist, G. W.

    1975-01-01

    The paper describes an equalization approach utilizing a simple RLC network which can obtain a maximum slope of -12dB/octave for reshaping the frequency characteristics of a data transmission cable, so that data may be generated and detected at the receiver. An experimental procedure for determining equalizer design specifications using distortion analysis is presented. It was found that for lengths of 16 PEV-L cable of up to 5 miles and data transmission rates of up to 1 Mbs, the equalization scheme proposed here is sufficient for generation of the data with acceptable error rates.

  7. 47 CFR 80.89 - Unauthorized transmissions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Unauthorized transmissions. 80.89 Section 80.89... transmissions. Stations must not: (a) Engage in superfluous radio-communication. (b) Use telephony on 243 MHz... transmission of distress, alarm, urgency, or safety signals or messages, or to test transmissions. (e)...

  8. 40 CFR 86.128-79 - Transmissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Transmissions. 86.128-79 Section 86...-Duty Vehicles; Test Procedures § 86.128-79 Transmissions. (a) All test conditions, except as noted... automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with...

  9. 47 CFR 80.89 - Unauthorized transmissions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Unauthorized transmissions. 80.89 Section 80.89... transmissions. Stations must not: (a) Engage in superfluous radio-communication. (b) Use telephony on 243 MHz... transmission of distress, alarm, urgency, or safety signals or messages, or to test transmissions. (e)...

  10. 40 CFR 86.128-79 - Transmissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Transmissions. 86.128-79 Section 86...-Duty Vehicles; Test Procedures § 86.128-79 Transmissions. (a) All test conditions, except as noted... automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with...

  11. 40 CFR 86.128-79 - Transmissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Transmissions. 86.128-79 Section 86...-Duty Vehicles; Test Procedures § 86.128-79 Transmissions. (a) All test conditions, except as noted... automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with...

  12. 40 CFR 86.128-79 - Transmissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Transmissions. 86.128-79 Section 86...-Duty Vehicles; Test Procedures § 86.128-79 Transmissions. (a) All test conditions, except as noted... automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with...

  13. 47 CFR 80.89 - Unauthorized transmissions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Unauthorized transmissions. 80.89 Section 80.89... transmissions. Stations must not: (a) Engage in superfluous radio-communication. (b) Use telephony on 243 MHz... transmission of distress, alarm, urgency, or safety signals or messages, or to test transmissions. (e)...

  14. 40 CFR 86.128-79 - Transmissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Transmissions. 86.128-79 Section 86...-Duty Vehicles; Test Procedures § 86.128-79 Transmissions. (a) All test conditions, except as noted... automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with...

  15. 47 CFR 80.89 - Unauthorized transmissions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Unauthorized transmissions. 80.89 Section 80.89... transmissions. Stations must not: (a) Engage in superfluous radio-communication. (b) Use telephony on 243 MHz... transmission of distress, alarm, urgency, or safety signals or messages, or to test transmissions. (e)...

  16. Crane-Load Contact Sensor

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert; Mata, Carlos; Cox, Robert

    2005-01-01

    An electronic instrument has been developed as a prototype of a portable crane-load contact sensor. Such a sensor could be helpful in an application in which the load rests on a base in a horizontal position determined by vertical alignment pins (see Figure 1). If the crane is not positioned to lift the load precisely vertically, then the load can be expected to swing once it has been lifted clear of the pins. If the load is especially heavy, large, and/or fragile, it could hurt workers and/or damage itself and nearby objects. By indicating whether the load remains in contact with the pins when it has been lifted a fraction of the length of the pins, the crane-load contact sensor helps the crane operator determine whether it is safe to lift the load clear of the pins: If there is contact, then the load is resting against the sides of the pins and, hence, it may not be safe to lift; if contact is occasionally broken, then the load is probably not resting against the pins, so it should be safe to lift. It is assumed that the load and base, or at least the pins and the surfaces of the alignment holes in the load, are electrically conductive, so the instrument can use electrical contact to indicate mechanical contact. However, DC resistance cannot be used as an indicator of contact for the following reasons: The load and the base are both electrically grounded through cables (the load is grounded through the lifting cable of the crane) to prevent discharge of static electricity. In other words, the DC resistance between the load and the pins is always low, as though they were always in direct contact. Therefore, instead of DC resistance, the instrument utilizes the AC electrical impedance between the pins and the load. The signal frequency used in the measurement is high enough (.1 MHz) that the impedance contributed by the cables and the electrical ground network of the building in which the crane and the base are situated is significantly greater than the contact

  17. Enhanced Wireless Power Transmission Using Strong Paramagnetic Response.

    PubMed

    Ahn, Dukju; Kiani, Mehdi; Ghovanloo, Maysam

    2014-03-01

    A method of quasi-static magnetic resonant coupling has been presented for improving the power transmission efficiency (PTE) in near-field wireless power transmission, which improves upon the state of the art. The traditional source resonator on the transmitter side is equipped with an additional resonator with a resonance frequency that is tuned substantially higher than the magnetic field excitation frequency. This additional resonator enhances the magnetic dipole moment and the effective permeability of the power transmitter, owing to a phenomenon known as the strong paramagnetic response. Both theoretical calculations and experimental results show increased PTE due to amplification of the effective permeability. In measurements, the PTE was improved from 57.8% to 64.2% at the nominal distance of 15 cm when the effective permeability was 2.6. The power delivered to load was also improved significantly, with the same 10 V excitation voltage, from 0.38 to 5.26 W.

  18. Transport composite fuselage technology: Impact dynamics and acoustic transmission

    NASA Technical Reports Server (NTRS)

    Jackson, A. C.; Balena, F. J.; Labarge, W. L.; Pei, G.; Pitman, W. A.; Wittlin, G.

    1986-01-01

    A program was performed to develop and demonstrate the impact dynamics and acoustic transmission technology for a composite fuselage which meets the design requirements of a 1990 large transport aircraft without substantial weight and cost penalties. The program developed the analytical methodology for the prediction of acoustic transmission behavior of advanced composite stiffened shell structures. The methodology predicted that the interior noise level in a composite fuselage due to turbulent boundary layer will be less than in a comparable aluminum fuselage. The verification of these analyses will be performed by NASA Langley Research Center using a composite fuselage shell fabricated by filament winding. The program also developed analytical methodology for the prediction of the impact dynamics behavior of lower fuselage structure constructed with composite materials. Development tests were performed to demonstrate that the composite structure designed to the same operating load requirement can have at least the same energy absorption capability as aluminum structure.

  19. Transmission of electrons inside the cryogenic pumps of ITER injector

    SciTech Connect

    Veltri, P. Sartori, E.

    2016-02-15

    Large cryogenic pumps are installed in the vessel of large neutral beam injectors (NBIs) used to heat the plasma in nuclear fusion experiments. The operation of such pumps can be compromised by the presence of stray secondary electrons that are generated along the beam path. In this paper, we present a numerical model to analyze the propagation of the electrons inside the pump. The aim of the study is to quantify the power load on the active pump elements, via evaluation of the transmission probabilities across the domain of the pump. These are obtained starting from large datasets of particle trajectories, obtained by numerical means. The transmission probability of the electrons across the domain is calculated for the NBI of the ITER and for its prototype Megavolt ITer Injector and Concept Advancement (MITICA) and the results are discussed.

  20. Optical nonreciprocal transmission in an asymmetric silicon photonic crystal structure

    SciTech Connect

    Wu, Zheng; Chen, Juguang; Ji, Mengxi; Huang, Qingzhong; Xia, Jinsong; Wang, Yi E-mail: ywangwnlo@mail.hust.edu.cn; Wu, Ying E-mail: ywangwnlo@mail.hust.edu.cn

    2015-11-30

    An optical nonreciprocal transmission (ONT) is realized by employing the nonlinear effects in a compact asymmetric direct-coupled nanocavity-waveguide silicon photonic crystal structure with a high loaded quality factor (Q{sub L}) of 42 360 and large extinction ratio exceeding 30 dB. Applying a single step lithography and successive etching, the device can realize the ONT in an individual nanocavity, alleviating the requirement to accurately control the resonance of the cavities. A maximum nonreciprocal transmission ratio of 21.1 dB as well as a working bandwidth of 280 pm in the telecommunication band are obtained at a low input power of 76.7 μW. The calculated results by employing a nonlinear coupled-mode model are in good agreement with the experiment.

  1. HIGH FREQUENCY POWER TRANSMISSION LINE FOR CYCLOTRONS AND THE LIKE

    DOEpatents

    Armstrong, W.J.

    1954-04-20

    High-frequency power transmission systems, particularly a stacked capacitance alternating power current transmission line wherein maximum utilization of the effective conductios skin of the line conductors is achieved while enabling a low impedance to be obtained are reported. The transmission line consists of a number of flat metal strips with interleaved dielectric strips. The metal dielectric strips are coiled spirally with the axis of the spiral extending along the length of the strips, and the alternating metal strips at the output end have outwardly extending aligned lugs which are directly strapped together and connected to the respective terminals on the load. At the input end of the transmission line, similarly, the alternate metal strips are directly strapped together and connected to an altereating current source. With the arrangement described each metal strip conducts on both sides, so that the metal strips are designed to have a thickness corresponding to twice the depth of the "skin effect" conducting lamina of each conductor at the source frequency.

  2. Eastern Wind Integration and Transmission Study: Executive Summary and Project Overview

    SciTech Connect

    none,

    2010-01-01

    This study evaluates the future operational and integration impacts of three different 20 percent wind energy penetration scenarios and one 30 percent wind penetration scenario, including a high-level analysis of transmission to deliver the wind energy to load centers, in the study year 2024.

  3. An HIV epidemic model based on viral load dynamics: value in assessing empirical trends in HIV virulence and community viral load.

    PubMed

    Herbeck, Joshua T; Mittler, John E; Gottlieb, Geoffrey S; Mullins, James I

    2014-06-01

    Trends in HIV virulence have been monitored since the start of the AIDS pandemic, as studying HIV virulence informs our understanding of HIV epidemiology and pathogenesis. Here, we model changes in HIV virulence as a strictly evolutionary process, using set point viral load (SPVL) as a proxy, to make inferences about empirical SPVL trends from longitudinal HIV cohorts. We develop an agent-based epidemic model based on HIV viral load dynamics. The model contains functions for viral load and transmission, SPVL and disease progression, viral load trajectories in multiple stages of infection, and the heritability of SPVL across transmissions. We find that HIV virulence evolves to an intermediate level that balances infectiousness with longer infected lifespans, resulting in an optimal SPVL∼4.75 log10 viral RNA copies/mL. Adaptive viral evolution may explain observed HIV virulence trends: our model produces SPVL trends with magnitudes that are broadly similar to empirical trends. With regard to variation among studies in empirical SPVL trends, results from our model suggest that variation may be explained by the specific epidemic context, e.g. the mean SPVL of the founding lineage or the age of the epidemic; or improvements in HIV screening and diagnosis that results in sampling biases. We also use our model to examine trends in community viral load, a population-level measure of HIV viral load that is thought to reflect a population's overall transmission potential. We find that community viral load evolves in association with SPVL, in the absence of prevention programs such as antiretroviral therapy, and that the mean community viral load is not necessarily a strong predictor of HIV incidence.

  4. Staphylococcal Adhesion, Detachment and Transmission on Nanopillared Si Surfaces.

    PubMed

    Hizal, Ferdi; Choi, Chang-Hwan; Busscher, Henk J; van der Mei, Henny C

    2016-11-09

    Nanostructured surfaces are extensively considered with respect to their potential impact on bacterial adhesion from aqueous suspensions or air, but in real-life bacteria are often transmitted between surfaces. Mechanistically, transmission involves detachment of adhering bacteria from a donor and adhesion to a receiver surface, controlled by the relative values of the adhesion forces exerted by both surfaces. We here relate staphylococcal adhesion, detachment and transmission to, from, and between smooth and nanopillared-Si surfaces with staphylococcal adhesion forces. Nanopillared-Si surfaces were prepared with pillar-to-pillar distances of 200, 400, and 800 nm. On smooth surfaces, staphylococcal adhesion forces, measured using bacterial-probe Atomic-Force-Microscopy, amounted to 4.4-6.8 and 1.8-2.1 nN (depending on the AFM-loading force) for extracellular-polymeric-substances (EPS) producing and non-EPS producing strains, respectively. Accordingly the EPS producing strain adhered in higher numbers than the non-EPS producing strain. Fractional adhesion forces on nanopillared-Si surfaces relative to the smooth surface ranged from 0.30 to 0.95, depending on AFM-loading force, strain and pillar-to-pillar distance. However, for each strain, the number of adhering bacteria remained similar on all nanopillared surfaces. Detachment of adhering staphylococci decreased significantly with increasing adhesion forces, while staphylococcal transmission to a receiver surface also decreased with increasing adhesion force exerted by the donor. In addition, the strain with ability to produce EPS was killed in high percentages and induced to produce EPS during transmission on nanopillared-Si surfaces, presumably by high local cell-wall stresses. This must be accounted for in applications of nanostructured surfaces: whereas killing may be favorable, EPS production may reduce antimicrobial efficacy.

  5. Concurrent in situ ion irradiation transmission electron microscope

    DOE PAGES

    Hattar, K.; Bufford, D. C.; Buller, D. L.

    2014-08-29

    An in situ ion irradiation transmission electron microscope has been developed and is operational at Sandia National Laboratories. This facility permits high spatial resolution, real time observation of electron transparent samples under ion irradiation, implantation, mechanical loading, corrosive environments, and combinations thereof. This includes the simultaneous implantation of low-energy gas ions (0.8–30 keV) during high-energy heavy ion irradiation (0.8–48 MeV). In addition, initial results in polycrystalline gold foils are provided to demonstrate the range of capabilities.

  6. New Monolithic High Solar Rejection EUV Transmission Filter

    NASA Astrophysics Data System (ADS)

    Fleury-Frenette, Karl; Renotte, Etienne; Lenaerts, C.; Rossi, Laurence; Jacques, Lionel; Halain, Jean-Philippe; Rochus, Pierre

    A new high solar rejection transmission filter for the extreme UV has been developed for the Solar Orbiter Extreme Ultraviolet Imager (EUI). To provide enhanced resilience to high thermal load, a monolithic architecture approach has been taken in order to limit the thermal contact resistance between the filtering sub-micron thin film, its supporting mesh, and holding frame. Some aspects of the manufacturing process involving thin film deposition and photolithography will be presented along with optical performance and space environmental test results. New avenues for improving the thermo-optical properties of the filter will also be discussed.

  7. Trypanosoma cruzi-Infected Pregnant Women without Vector Exposure Have Higher Parasitemia Levels: Implications for Congenital Transmission Risk

    PubMed Central

    Rendell, Victoria R.; Gilman, Robert H.; Valencia, Edward; Galdos-Cardenas, Gerson; Verastegui, Manuela; Sanchez, Leny; Acosta, Janet; Sanchez, Gerardo; Ferrufino, Lisbeth; LaFuente, Carlos; Abastoflor, Maria del Carmen; Colanzi, Rony; Bern, Caryn

    2015-01-01

    Background Congenital transmission is a major source of new Trypanosoma cruzi infections, and as vector and blood bank control continue to improve, the proportion due to congenital infection will grow. A major unanswered question is why reported transmission rates from T. cruzi-infected mothers vary so widely among study populations. Women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown. Better understanding of these factors could enable prioritization of screening programs to target women most at risk of transmission to their infants. Methodology/Principal Findings We screened pregnant women presenting for delivery in a large urban hospital in Bolivia and followed infants of infected women for congenital Chagas disease. Of 596 women screened, 128 (21.5%) had confirmed T. cruzi infection; transmission occurred from 15 (11.7%) infected women to their infants. Parasite loads were significantly higher among women who transmitted compared to those who did not. Congenital transmission occurred from 31.3% (9/29), 15.4% (4/26) and 0% (0/62) of women with high, moderate and low parasite load, respectively (χx2 for trend 18.2; p<0.0001). Twin births were associated with higher transmission risk and higher maternal parasite loads. Infected women without reported vector exposure had significantly higher parasite loads than those who had lived in an infested house (median 26.4 vs 0 parasites/mL; p<0.001) with an inverse relationship between years of living in an infested house and parasite load. Conclusions/Significance We hypothesize that sustained vector-borne parasite exposure and repeated superinfection by T. cruzi may act as an immune booster, allowing women to maintain effective control of the parasite despite the down-regulation of late pregnancy. PMID:25807498

  8. Perceptual Load Alters Visual Excitability

    ERIC Educational Resources Information Center

    Carmel, David; Thorne, Jeremy D.; Rees, Geraint; Lavie, Nilli

    2011-01-01

    Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load…

  9. Spring loaded locator pin assembly

    DOEpatents

    Groll, Todd A.; White, James P.

    1998-01-01

    This invention deals with spring loaded locator pins. Locator pins are sometimes referred to as captured pins. This is a mechanism which locks two items together with the pin that is spring loaded so that it drops into a locator hole on the work piece.

  10. Robust Multimodal Cognitive Load Measurement

    DTIC Science & Technology

    2014-03-26

    dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes in working memory load during the performance of a cognitive task...dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes in working memory load during the performance of a cognitive task with...approximate entropies, wavelet-based complexity measures, correlation dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes

  11. Cerebrovascular Injury in Blast Loading

    DTIC Science & Technology

    2010-01-01

    TITLE: Cerebrovascular injury in blast loading PRINCIPAL INVESTIGATOR: Kenneth L. Monson, PhD...SUBTITLE Cerebrovascular injury in blast loading 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-08-1-0295 5c. PROGRAM ELEMENT NUMBER 6...and pH control. 15. SUBJECT TERMS Blast brain injury; cerebrovascular injury and dysfunction; shock tube 16. SECURITY CLASSIFICATION OF: 17

  12. Spring loaded locator pin assembly

    DOEpatents

    Groll, T.A.; White, J.P.

    1998-03-03

    This invention deals with spring loaded locator pins. Locator pins are sometimes referred to as captured pins. This is a mechanism which locks two items together with the pin that is spring loaded so that it drops into a locator hole on the work piece. 5 figs.

  13. Norovirus transmission on cruise ship.

    PubMed

    Isakbaeva, Elmira T; Widdowson, Marc-Alain; Beard, R Suzanne; Bulens, Sandra N; Mullins, James; Monroe, Stephan S; Bresee, Joseph; Sassano, Patricia; Cramer, Elaine H; Glass, Roger I

    2005-01-01

    An outbreak of norovirus gastroenteritis affected passengers on two consecutive cruises of ship X and continued on 4 subsequent cruises despite a 1-week sanitization. We documented transmission by food and person-to-person contact; persistence of virus despite sanitization onboard, including introductions of new strains; and seeding of an outbreak on land.

  14. Atlas Transmission Line Breakdown Analysis

    DTIC Science & Technology

    1999-06-01

    The Atlas facility will use 24 radially converging, vertically oriented and tapered, oil insulated, triplate transmission lines between the Marx ...taper from a height of 1.75 m at the Marx end to 0.32 m at the output end. The aluminum conductors, held together by 20 insulating spacers, are

  15. Progressive transmission and compression images

    NASA Technical Reports Server (NTRS)

    Kiely, A. B.

    1996-01-01

    We describe an image data compression strategy featuring progressive transmission. The method exploits subband coding and arithmetic coding for compression. We analyze the Laplacian probability density, which closely approximates the statistics of individual subbands, to determine a strategy for ordering the compressed subband data in a way that improves rate-distortion performance. Results are presented for a test image.

  16. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P.

    2003-06-10

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  17. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P.

    2003-01-01

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  18. Steady State Performance Analysis of Hydrostatic Transmission System using Two Motor Summation Drive

    NASA Astrophysics Data System (ADS)

    Dasgupta, K.; Kumar, N.; Kumar, R.

    2013-10-01

    Hydrostatic transmission (HST) system used in heavy earth moving machineries (HEMMs) has high power density, wide range of speed control and good overall efficiency. Hydrostatically coupled two motor summation drive is an alternative power transmission system, compared to existing closed-loop HST system with low speed high torque motor, used in HEMM. Such drive arrangement has made the possibility to design the transmission system, used in heavy vehicles, in an efficient way to cover wide range of torque-speed demand. This article studies the concept of two motor summation drive and its steady state performance. Experiments have been carried out to analyze the performance of such system. The characteristics of single and two motor drive systems are compared at different load-torque and speed levels. It is concluded that two motor hydrostatic drive systems is more effective at high load-torque and low speed compared to single motor drive system.

  19. Umbilical cable recovery load analysis

    NASA Astrophysics Data System (ADS)

    Yan, Shu-wang; Jia, Zhao-lin; Feng, Xiao-wei; Li, Shi-tao

    2013-06-01

    Umbilical cable is a kind of integrated subsea cable widely used in the exploration and exploitation of oil and gas field. The severe ocean environment makes great challenges to umbilical maintenance and repair work. Damaged umbilical is usually recovered for the regular operation of the offshore production system. Analysis on cables in essence is a two-point boundary problem. The tension load at the mudline must be known first, and then the recovery load and recovery angle on the vessel can be solved by use of catenary equation. The recovery analysis also involves umbilical-soil interaction and becomes more complicated. Calculation methods for recovery load of the exposed and buried umbilical are established and the relationship between the position of touch down point and the recovery load as well as the recovery angle and recovery load are analyzed. The analysis results provide a theoretical reference for offshore on-deck operation.

  20. Microstrip transmission line tapers on ferrites

    SciTech Connect

    Albuquerque, M.R.; dAssuncao, A.G.; Lima, F.

    1997-04-01

    The spectral domain approach is employed to perform a theoretical investigation of tapered microstrip lines on magnetized ferrite substrates. A linear variation of the conducting strip width along the direction of propagation is considered. The analysis takes into account the effects of the applied dc magnetic bias field in the transmission characteristics of these structures. The properties of the taper are determined by a model based on a segmentation of the considered line into uniform microstrip line subsections. Normalized phase constants and characteristic impedances are obtained by using the Hertz vector potentials method and Galerkin numerical technique. Numerical results are presented to show the taper input parameters as a function of the load impedance, geometrical dimensions, operating frequency, and ferrite parameters, considering the orientation and magnitude changes of the biasing magnetic-field {bold H}{sub 0}. The results agree fairly well with those available in the literature for tapered microstrip lines on isotropic dielectric substrates. {copyright} {ital 1997 American Institute of Physics.}

  1. Impact of Pre-adapted HIV Transmission

    PubMed Central

    Carlson, Jonathan M.; Du, Victor Y.; Pfeifer, Nico; Bansal, Anju; Tan, Vincent Y.F.; Power, Karen; Brumme, Chanson J.; Kreimer, Anat; DeZiel, Charles E.; Fusi, Nicolo; Schaefer, Malinda; Brockman, Mark A.; Gilmour, Jill; Price, Matt A.; Kilembe, William; Haubrich, Richard; John, Mina; Mallal, Simon; Shapiro, Roger; Frater, John; Harrigan, P. Richard; Ndung’u, Thumbi; Allen, Susan; Heckerman, David; Sidney, John; Allen, Todd M.; Goulder, Philip J.R.; Brumme, Zabrina L.; Hunter, Eric; Goepfert, Paul A.

    2016-01-01

    Human Leukocyte Antigen class I (HLA) restricted CD8+ T lymphocyte (CTL) responses are critical to HIV-1 control. Although HIV can evade these responses, the longer-term impact of viral escape mutants remains unclear, since these variants can also reduce intrinsic viral fitness. To address this question, we here develop a metric to determine the degree of HIV adaptation to an HLA profile. We demonstrate that transmission of viruses pre-adapted to the HLA molecules expressed in the recipient is associated with impaired immunogenicity, elevated viral load and accelerated CD4 decline. Furthermore, the extent of pre-adaptation among circulating viruses explains much of the variation in outcomes attributed to expression of certain HLA alleles. Thus, viral pre-adaptation exploits “holes” in the immune response. Accounting for these holes may be critical for vaccine strategies seeking to elicit functional responses from viral variants, and to HIV cure strategies requiring broad CTL responses to achieve successful eradication of HIV reservoirs. PMID:27183217

  2. Characterization of nanomaterials with transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Anjum, D. H.

    2016-08-01

    The field of nanotechnology is about research and development on materials whose at least one dimension is in the range of 1 to 100 nanometers. In recent years, the research activity for developing nano-materials has grown exponentially owing to the fact that they offer better solutions to the challenges faced by various fields such as energy, food, and environment. In this paper, the importance of transmission electron microscopy (TEM) based techniques is demonstrated for investigating the properties of nano-materials. Specifically the nano-materials that are investigated in this report include gold nano-particles (Au-NPs), silver atom-clusters (Ag-ACs), tantalum single-atoms (Ta-SAs), carbon materials functionalized with iron cobalt (Fe-Co) NPs and titania (TiO2) NPs, and platinum loaded Ceria (Pt-CeO2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF-STEM), electron energy-loss spectroscopy (EELS), and BF-TEM electron tomography (ET). With the help presented of results in this report, it is proved herein that as many TEM techniques as available in a given instrument are essential for a comprehensive nano-scale analysis of nanomaterials.

  3. A Q-Modulation Technique for Efficient Inductive Power Transmission.

    PubMed

    Kiani, Mehdi; Lee, Byunghun; Yeon, Pyungwoo; Ghovanloo, Maysam

    2015-12-01

    A fully-integrated power management ASIC for efficient inductive power transmission has been presented capable of automatic load transformation using a method, called Q-modulation. Q-modulation is an adaptive scheme that offers load matching against a wide range of loading (RL ) and coupling distance (d23 ) variations in inductive links to maintain high power transfer efficiency (PTE). It is suitable for inductive powering implantable microelectronic devices (IMDs), recharging mobile electronics, and electric vehicles. In Q-modulation, the zero-crossings of the induced current in the receiver (Rx) LC-tank are detected and a low-loss switch chops the Rx LC-tank for part of the power carrier cycle to form a high-Q LC-tank and store the maximum energy, which is then transferred to RL by opening the switch. By adjusting the duty cycle (D), the loaded-Q of the Rx LC-tank can be dynamically modulated to compensate for variations in RL . A Q-modulation power management (QMPM) prototype chip was fabricated in a 0.35-μm standard CMOS process, occupying 4.8 mm(2). In a 1.45 W wireless power transfer setup, using a class-E power amplifier (PA) operating at 2 MHz, the QMPM successfully increased the inductive link PTE and the overall power efficiency by 98.5% and 120.7% at d23 = 8 cm, respectively, by compensating for 150 Ω variation in RL at D = 45%.

  4. High Cycle Fatigue in the Transmission Electron Microscope.

    PubMed

    Bufford, Daniel C; Stauffer, Douglas; Mook, William M; Syed Asif, S A; Boyce, Brad L; Hattar, Khalid

    2016-08-10

    One of the most common causes of structural failure in metals is fatigue induced by cyclic loading. Historically, microstructure-level analysis of fatigue cracks has primarily been performed post mortem. However, such investigations do not directly reveal the internal structural processes at work near micro- and nanoscale fatigue cracks and thus do not provide direct evidence of active microstructural mechanisms. In this study, the tension-tension fatigue behavior of nanocrystalline Cu was monitored in real time at the nanoscale by utilizing a new capability for quantitative cyclic mechanical loading performed in situ in a transmission electron microscope (TEM). Controllable loads were applied at frequencies from one to several hundred hertz, enabling accumulations of 10(6) cycles within 1 h. The nanometer-scale spatial resolution of the TEM allows quantitative fatigue crack growth studies at very slow crack growth rates, measured here at ∼10(-12) m·cycle(-1). This represents an incipient threshold regime that is well below the tensile yield stress and near the minimum conditions for fatigue crack growth. Evidence of localized deformation and grain growth within 150 nm of the crack tip was observed by both standard imaging and precession electron diffraction orientation mapping. These observations begin to reveal with unprecedented detail the local microstructural processes that govern damage accumulation, crack nucleation, and crack propagation during fatigue loading in nanocrystalline Cu.

  5. High cycle fatigue in the transmission electron microscope

    DOE PAGES

    Bufford, Daniel C.; Stauffer, Douglas; Mook, William M.; ...

    2016-06-28

    One of the most common causes of structural failure in metals is fatigue induced by cyclic loading. Historically, microstructure-level analysis of fatigue cracks has primarily been performed post mortem. However, such investigations do not directly reveal the internal structural processes at work near micro- and nanoscale fatigue cracks and thus do not provide direct evidence of active microstructural mechanisms. In this paper, the tension–tension fatigue behavior of nanocrystalline Cu was monitored in real time at the nanoscale by utilizing a new capability for quantitative cyclic mechanical loading performed in situ in a transmission electron microscope (TEM). Controllable loads were appliedmore » at frequencies from one to several hundred hertz, enabling accumulations of 106 cycles within 1 h. The nanometer-scale spatial resolution of the TEM allows quantitative fatigue crack growth studies at very slow crack growth rates, measured here at ~10–12 m·cycle–1. This represents an incipient threshold regime that is well below the tensile yield stress and near the minimum conditions for fatigue crack growth. Evidence of localized deformation and grain growth within 150 nm of the crack tip was observed by both standard imaging and precession electron diffraction orientation mapping. Finally, these observations begin to reveal with unprecedented detail the local microstructural processes that govern damage accumulation, crack nucleation, and crack propagation during fatigue loading in nanocrystalline Cu.« less

  6. High cycle fatigue in the transmission electron microscope

    SciTech Connect

    Bufford, Daniel C.; Stauffer, Douglas; Mook, William M.; Syed Asif, S. A.; Boyce, Brad L.; Hattar, Khalid

    2016-06-28

    One of the most common causes of structural failure in metals is fatigue induced by cyclic loading. Historically, microstructure-level analysis of fatigue cracks has primarily been performed post mortem. However, such investigations do not directly reveal the internal structural processes at work near micro- and nanoscale fatigue cracks and thus do not provide direct evidence of active microstructural mechanisms. In this paper, the tension–tension fatigue behavior of nanocrystalline Cu was monitored in real time at the nanoscale by utilizing a new capability for quantitative cyclic mechanical loading performed in situ in a transmission electron microscope (TEM). Controllable loads were applied at frequencies from one to several hundred hertz, enabling accumulations of 106 cycles within 1 h. The nanometer-scale spatial resolution of the TEM allows quantitative fatigue crack growth studies at very slow crack growth rates, measured here at ~10–12 m·cycle–1. This represents an incipient threshold regime that is well below the tensile yield stress and near the minimum conditions for fatigue crack growth. Evidence of localized deformation and grain growth within 150 nm of the crack tip was observed by both standard imaging and precession electron diffraction orientation mapping. Finally, these observations begin to reveal with unprecedented detail the local microstructural processes that govern damage accumulation, crack nucleation, and crack propagation during fatigue loading in nanocrystalline Cu.

  7. Modified multi-load method for nonlinear source characterisation

    NASA Astrophysics Data System (ADS)

    Rämmal, Hans; Bodén, Hans

    2007-02-01

    Linear frequency domain prediction codes are useful for calculation of low-frequency sound transmission in duct and pipe systems. To calculate insertion loss of mufflers or the level of radiated sound information about the acoustic source is needed. The source model used in the low-frequency plane wave range is the linear time invariant one-port model. The acoustic source data is usually obtained from experimental tests where multi-load methods and especially the two-load method are most commonly used. The exhaust pulsations of for example an IC-engine are of high level, and the engine is not a perfectly linear and time invariant source. It is therefore of interest to develop source models and experimental techniques that try to take this nonlinearity into account. In this paper a modified version of the two-load method to improve the characterisation of nonlinear acoustic one-port sources has been developed and tested. Simulation results as well as experimental data from various source configurations for a modified compressor and experimental data from 6-cylinder turbocharged truck diesel engine were used to validate the method. The influence of parameters controlling the linearity of the system was investigated. The time-variance of the source model was varied and the accuracy of source characterisation results using the two-load method and the modified two-load method was evaluated.

  8. HIV transmission law in the age of treatment-as-prevention.

    PubMed

    Haire, Bridget; Kaldor, John

    2015-12-01

    Evidence that treating people with HIV early in infection prevents transmission to sexual partners has reframed HIV prevention paradigms. The resulting emphasis on HIV testing as part of prevention strategies has rekindled the debate as to whether laws that criminalise HIV transmission are counterproductive to the human rights-based public health response. It also raises normative questions about what constitutes 'safe(r) sex' if a person with HIV has undetectable viral load, which has significant implications for sexual practice and health promotion. This paper discusses a recent high-profile Australian case where HIV transmission or exposure has been prosecuted, and considers how the interpretation of law in these instances impacts on HIV prevention paradigms. In addition, we consider the implications of an evolving medical understanding of HIV transmission, and particularly the ability to determine infectiousness through viral load tests, for laws that relate to HIV exposure (as distinct from transmission) offences. We conclude that defensible laws must relate to appreciable risk. Given the evidence that the transmissibility of HIV is reduced to negligible level where viral load is suppressed, this needs to be recognised in the framing, implementation and enforcement of the law. In addition, normative concepts of 'safe(r) sex' need to be expanded to include sex that is 'protected' by means of the positive person being virally suppressed. In jurisdictions where use of a condom has previously mitigated the duty of the person with HIV to disclose to a partner, this might logically also apply to sex that is 'protected' by undetectable viral load.

  9. Cognitive Load Theory: How Many Types of Load Does It Really Need?

    ERIC Educational Resources Information Center

    Kalyuga, Slava

    2011-01-01

    Cognitive load theory has been traditionally described as involving three separate and additive types of load. Germane load is considered as a learning-relevant load complementing extraneous and intrinsic load. This article argues that, in its traditional treatment, germane load is essentially indistinguishable from intrinsic load, and therefore…

  10. The singular point transition concept: A novel continuously variable transmission comprising planetary gear trains and a variator

    NASA Astrophysics Data System (ADS)

    Gomà Ayats, J. R.; Diego-Ayala, U.; Artes, F. Fenollosa

    2012-01-01

    The singular point transition concept relates a novel type of continuously variable transmission. This transmission comprises a pair of planetary gear trains and a couple of electric motors, used to control the overall speed ratio. Its singularity lies in the topology of operation, with less than 10% of nominal power circulating through the electric path. This low power level is achieved by segmenting the range of operation of the transmission. To validate this technology, a test bed was built. The transmission presented here is able to provide any output/input speed ratio within the interval of 0:1.55, meaning that it also offers the function of an infinite variable transmission. Description of the system and results of experimental tests are presented. The results showed that the transmission is able to function in the whole range of operation. They also showed that under load conditions the fraction of power transmitted through the electric path is maintained around the design value.

  11. Lumped transmission line avalanche pulser

    DOEpatents

    Booth, R.

    1995-07-18

    A lumped linear avalanche transistor pulse generator utilizes stacked transistors in parallel within a stage and couples a plurality of said stages, in series with increasing zener diode limited voltages per stage and decreasing balanced capacitance load per stage to yield a high voltage, high and constant current, very short pulse. 8 figs.

  12. Lumped transmission line avalanche pulser

    DOEpatents

    Booth, Rex

    1995-01-01

    A lumped linear avalanche transistor pulse generator utilizes stacked transistors in parallel within a stage and couples a plurality of said stages, in series with increasing zener diode limited voltages per stage and decreasing balanced capacitance load per stage to yield a high voltage, high and constant current, very short pulse.

  13. Transmission and transmission control device for providing downshifting

    SciTech Connect

    Ito, H.; Akashi, T.

    1986-11-18

    This patent describes a transmission for a vehicle, comprising a transmission mechanism, and an automatic control device; the transmission mechanism comprising: an input shaft; an output shaft, a first on-off clutch; a second on-off clutch; a first one way clutch; a second one way clutch; a first gear train having a first reduction gear ratio; a second gear train having a second reduction gear ratio smaller than the first reduction gear ratio; a third gear train having a third reduction gear ratio smaller than the second reduction gear ratio; and a fourth gear train having a fourth reduction gear ratio smaller than the third reduction gear ratio. A first synchronizer connects the input shaft and the output shaft via a series connection of the first on-off clutch, the first one way clutch, and the first gear train when the first synchronizer is shifted to a first side of a neutral position thereof so as to transmit rotational power from the input shaft to the output shaft in a normal rotational direction at a first speed stage and which connects the input shaft and the output shaft via series connection of the first on-off clutch.

  14. Solid state characterisation of silver sulfadiazine loaded on montmorillonite/chitosan nanocomposite for wound healing.

    PubMed

    Aguzzi, Carola; Sandri, Giuseppina; Bonferoni, Cristina; Cerezo, Pilar; Rossi, Silvia; Ferrari, Franca; Caramella, Carla; Viseras, César

    2014-01-01

    Biopolymer chitosan/montmorillonite nanocomposites loaded with silver sulfadiazine for wound healing purposes were prepared via intercalation solution technique. Structure and morphology of loaded nanocomposites were studied and compared with pure components and unloaded nanocomposites. X-ray diffraction, Fourier transformed infrared spectroscopy, high resolution transmission electron microscopy coupled with energy-dispersion X-ray analysis, thermal and elemental analysis were employed for the characterisation. The results confirmed that the drug was effectively loaded in the three-dimensional nanocomposite structures, in which chitosan chains were adsorbed in monolayers into the clay mineral interlayer spaces.

  15. The evolution of plant virus transmission pathways.

    PubMed

    Hamelin, Frédéric M; Allen, Linda J S; Prendeville, Holly R; Hajimorad, M Reza; Jeger, Michael J

    2016-05-07

    The evolution of plant virus transmission pathways is studied through transmission via seed, pollen, or a vector. We address the questions: under what circumstances does vector transmission make pollen transmission redundant? Can evolution lead to the coexistence of multiple virus transmission pathways? We restrict the analysis to an annual plant population in which reproduction through seed is obligatory. A semi-discrete model with pollen, seed, and vector transmission is formulated to investigate these questions. We assume vector and pollen transmission rates are frequency-dependent and density-dependent, respectively. An ecological stability analysis is performed for the semi-discrete model and used to inform an evolutionary study of trade-offs between pollen and seed versus vector transmission. Evolutionary dynamics critically depend on the shape of the trade-off functions. Assuming a trade-off between pollen and vector transmission, evolution either leads to an evolutionarily stable mix of pollen and vector transmission (concave trade-off) or there is evolutionary bi-stability (convex trade-off); the presence of pollen transmission may prevent evolution of vector transmission. Considering a trade-off between seed and vector transmission, evolutionary branching and the subsequent coexistence of pollen-borne and vector-borne strains is possible. This study contributes to the theory behind the diversity of plant-virus transmission patterns observed in nature.

  16. Airplane Ice Detector Based on a Microwave Transmission Line

    NASA Technical Reports Server (NTRS)

    Ngo, Phong; Arndt, G. Dickey; Carl, James R.

    2004-01-01

    An electronic instrument that could detect the potentially dangerous buildup of ice on an airplane wing is undergoing development. The instrument is based on a microwave transmission line configured as a capacitance probe: at selected spots, the transmission-line conductors are partly exposed to allow any ice and/or liquid water present at those spots to act as predominantly capacitive electrical loads on the transmission line. These loads change the input impedance of the transmission line, as measured at a suitable excitation frequency. Thus, it should be possible to infer the presence of ice and/or liquid water from measurements of the input impedance and/or electrical parameters related to the input impedance. The sensory transmission line is of the microstrip type and thus thin enough to be placed on an airplane wing without unduly disturbing airflow in flight. The sensory spots are small areas from which the upper layer of the microstrip has been removed to allow any liquid water or ice on the surface to reach the transmission line. The sensory spots are spaced at nominal open-circuit points, which are at intervals of a half wavelength (in the transmission line, not in air) at the excitation frequency. The excitation frequency used in the experiments has been 1 GHz, for which a half wavelength in the transmission line is .4 in. (.10 cm). The figure depicts a laboratory prototype of the instrument. The impedance-related quantities chosen for use in this version of the instrument are the magnitude and phase of the scattering parameter S11 as manifested in the in-phase (I ) and quadrature (Q) outputs of the phase detector. By careful layout of the transmission line (including the half-wavelength sensor spacing), one can ensure that the amplitude and phase of the input to the phase detector keep shifting in the same direction as ice forms on one or more of the sensor areas. Although only one transmission-line sensor strip is used in the laboratory version, in a

  17. Space Shuttle fatigue loads spectra for prelaunch and liftoff loads

    NASA Technical Reports Server (NTRS)

    Goldish, Judith; Ortasse, Raphael

    1994-01-01

    Fatigue loads spectra for the prelaunch and liftoff flight segments of the Space Shuttle were developed. A variety o methods were used to determine the distributions of several important parameters, such as time of exposure on the launch, pad, month of launch, and wind speed. Also, some lessons learned that would be applicable to development of fatigue loads spectra for other reusable space vehicles are presented.

  18. Spinning Reserve from Responsive Load

    SciTech Connect

    Kueck, John D; Kirby, Brendan J; Laughner, T; Morris, K

    2009-01-01

    As power system costs rise and capacity is strained demand response can provide a significant system reliability benefit at a potentially attractive cost. The 162 room Music Road Hotel in Pigeon Forge Tennessee agreed to host a spinning reserve test. The Tennessee Valley Authority (TVA) supplied real-time metering and monitoring expertise to record total hotel load during both normal operations and testing. Preliminary testing showed that hotel load can be curtailed by 22% to 37% depending on the outdoor temperature and the time of day. The load drop was very rapid, essentially as fast as the 2 second metering could detect.

  19. Exploiting a Transmission Grating Spectrometer

    SciTech Connect

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  20. Transmission of Influenza A Viruses

    PubMed Central

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  1. Cultural transmission of social essentialism

    PubMed Central

    Rhodes, Marjorie; Leslie, Sarah-Jane; Tworek, Christina M.

    2012-01-01

    Social essentialism entails the belief that certain social categories (e.g., gender, race) mark fundamentally distinct kinds of people. Essentialist beliefs have pernicious consequences, supporting social stereotyping and contributing to prejudice. How does social essentialism develop? In the studies reported here, we tested the hypothesis that generic language facilitates the cultural transmission of social essentialism. Two studies found that hearing generic language about a novel social category diverse for race, ethnicity, age, and sex led 4-y-olds and adults to develop essentialist beliefs about that social category. A third study documented that experimentally inducing parents to hold essentialist beliefs about a novel social category led them to produce more generic language when discussing the category with their children. Thus, generic language facilitates the transmission of essentialist beliefs about social categories from parents to children. PMID:22869722

  2. Transmission of influenza A viruses.

    PubMed

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-05-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to 'novel' viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages.

  3. Transmission optical coherence tomography sensing

    NASA Astrophysics Data System (ADS)

    Trull, A. K.; van der Horst, J.; Bijster, J. G.; Kalkman, J.

    2016-04-01

    We demonstrate that Fourier-domain transmission OCT is a versatile tool to measure optical material properties of turbid media. We develop an analytical expression for the transmission OCT signal. Based on this analysis we determine the group refractive index, group velocity dispersion, absorption coefficient, and scattering coefficient. The optical dispersion is accurately measured for glasses, liquids, and water/glucose mixtures. The optical attenuation is measured in the spatial domain and compared to Mie calculations combined with concentration dependent scattering effects. In the wave vector domain the spectral dependence of the optical attenuation is measured and compared to literature values. The developed technique can be used for optical sensing of attenuation and dispersion.

  4. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  5. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  6. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  7. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  8. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  9. Monitoring Atmospheric Transmission with FLAME

    NASA Astrophysics Data System (ADS)

    Zimmer, Peter C.; McGraw, J. T.; Zirzow, D. C.; Koppa, M.; Buttler-Pena, K.

    2014-01-01

    Calibration of ground-based observations in the optical and near-infrared requires precise and accurate understanding of atmospheric transmission, at least as precise and accurate as that required for the spectral energy distributions of science targets. Traditionally this has used the Langley extrapolation method, observing targets and calibrators over a range of airmass and extrapolating to zero airmass by assuming a plane-parallel homogeneous atmosphere. The technique we present uses direct measurements of the atmosphere to derive the transmission along the line of sight to science targets at a few well-chosen wavelengths. The Facility Lidar Atmospheric Monitor of Extinction (FLAME) is a 0.5m diameter three Nd:YAG wavelength (355nm, 532nm & 1064nm) elastic backscatter lidar system. Laser pulses are transmitted into the atmosphere in the direction of the science target. Photons scattered back toward the receiver by molecules, aerosols and clouds are collected and time-gated so that the backscatter intensity is measured as a function of range to the scattering volume. The system is housed in a mobile calibration lab, which also contains auxiliary instrumentation to provide a NIST traceable calibration of the transmitted laser power and receiver efficiency. FLAME was designed to create a million photons per minute signal from the middle stratosphere, where the atmosphere is relatively calm and dominated by molecules of the well-mixed atmosphere (O2 & N2). Routine radiosonde measurements of the density at these altitudes constrain the scattering efficiency in this region and, combined with calibration of the transmitter and receiver, the only remaining unknown quantity is the two-way transmission to the stratosphere. These measurements can inform atmospheric transmission models to better understand the complex and ever-changing observatory radiative transfer environment. FLAME is currently under active development and we present some of our ongoing measurements.

  10. Transmission risk of human trichinellosis.

    PubMed

    Takumi, Katsuhisa; Teunis, Peter; Fonville, Manoj; Vallee, Isabelle; Boireau, Pascal; Nöckler, Karsten; van der Giessen, Joke

    2009-02-23

    Trichinella is a food-borne parasitic zoonoses and human cases are still reported in Europe mainly due to the consumption of pig meat originating from small backyard farms. Infections originating from industrialized pig farming have not been reported for decades in Europe, due to control measures to prevent the transmission of Trichinella from wildlife by indoor housing and good management practices. Therefore, risk-based monitoring programs might replace individual carcass control in industrialized pig farming as described in EU legislation SANCO 2075/2005. Transmission of Trichinella species between wildlife and the risk that may pose to humans via consumption of contaminated pork meat has not been studied quantitatively. One pathway by which human trichinellosis can occur is the rat-pig-human route. To evaluate the transmission risk though this pathway the dose responses of rat, pig, and human were studied. Experimental T. spiralis infection was performed in rats with doses of as few as 10 parasites and the data set was analysed using a newly developed dose response model that describes larvae per gram (LPG). Experimental T. spiralis infection in pig was analysed in a similar way. Furthermore nine published outbreaks of human trichinellosis were analysed to determine the dose response in humans. The risk of human trichinellosis via the rat-pig-human transmission was simulated by the Monte Carlo method. A pair of female and male parasites representing the lowest infection pressure from the environment, led to the probability of human trichinellosis by consumption of 100g of raw pork meat equal to 5% via the studied rat-pig-human pathway. In the absence of rodent control near the farm, a low infection pressure from wildlife presents a relatively high risk of human trichinellosis via consumption of uncooked pork meat.

  11. Advanced Rotorcraft Transmission program summary

    NASA Technical Reports Server (NTRS)

    Bossler, Robert B., Jr.; Heath, Gregory F.

    1992-01-01

    The current status of the Advanced Rotorcraft Transmission (ART) program is reviewed. The discussion includes a general configuration and face gear description, weight analysis, stress analysis, reliability analysis, acoustic analysis, face gear testing, and planned torque split testing. Design descriptions include the face gear webs sized for equal stiffness, a positive engagement clutch, the lubrication system, and a high contact ratio planetary. Test results for five gear materials and three housing materials are presented.

  12. Performance Study of OFDM Transmissions

    NASA Astrophysics Data System (ADS)

    Ledesma Goyzueta, Rodolfo

    2010-10-01

    The purpose of this study is to explore the important features of OFDM under different channel conditions and to analyze the outcomes. In order to procure this goal, multiple simulations are performed using GNU Octave. The simulations of OFDM transmissions are carried out under Additive White Gaussian Noise (AWGN) and/or Rayleigh fading. Besides, PACE is employed to mitigate the effects of Rayleigh fading.

  13. Exoplanet transmission spectroscopy using KMOS

    NASA Astrophysics Data System (ADS)

    Parviainen, Hannu; Aigrain, Suzanne; Thatte, Niranjan; Barstow, Joanna K.; Evans, Thomas M.; Gibson, Neale

    2015-11-01

    KMOS (K-Band Multi Object Spectrograph) is a novel integral field spectrograph installed in the Very Large Telescope's (VLT's) ANTU unit. The instrument offers an ability to observe 24 2.8 arcsec × 2.8 arcsec subfields positionable within a 7.2 arcmin patrol field, each subfield producing a spectrum with a 14 × 14-pixel spatial resolution. The main science drivers for KMOS are the study of galaxies, star formation, and molecular clouds, but its ability to simultaneously measure spectra of multiple stars makes KMOS an interesting instrument for exoplanet atmosphere characterization via transmission spectroscopy. We set to test whether transmission spectroscopy is practical with KMOS, and what are the conditions required to achieve the photometric precision needed, based on observations of a partial transit of WASP-19b, and full transits of GJ 1214b and HD 209458b. Our analysis uses the simultaneously observed comparison stars to reduce the effects from instrumental and atmospheric sources, and Gaussian processes to model the residual systematics. We show that KMOS can, in theory, deliver the photometric precision required for transmission spectroscopy. However, this is shown to require (a) pre-imaging to ensure accurate centring and (b) a very stable night with optimal observing conditions (seeing ˜0.8 arcsec). Combining these two factors with the need to observe several transits, each with a sufficient out-of-transit baseline (and with the fact that similar or better precision can be reached with telescopes and instruments with smaller pressure), we conclude that transmission spectroscopy is not the optimal science case to take advantage of the abilities offered by KMOS and VLT.

  14. Advanced Rotorcraft Transmission program summary

    NASA Astrophysics Data System (ADS)

    Bossler, Robert B., Jr.; Heath, Gregory F.

    1992-07-01

    The current status of the Advanced Rotorcraft Transmission (ART) program is reviewed. The discussion includes a general configuration and face gear description, weight analysis, stress analysis, reliability analysis, acoustic analysis, face gear testing, and planned torque split testing. Design descriptions include the face gear webs sized for equal stiffness, a positive engagement clutch, the lubrication system, and a high contact ratio planetary. Test results for five gear materials and three housing materials are presented.

  15. Midwest Transmission Workshop II Summary

    SciTech Connect

    Kevin Bryan

    2002-12-05

    OAK-B135 After introductions of all participants, Abby Arnold, RESOLVE, reviewed the purpose of the meeting and the agenda. The purpose of the workshop was to share the results of the Midwest Independent System Operator (MISO) scenario development for wind and other fuel sources and the corresponding implications for transmission throughout the MISO control area. The workshop agenda is included in Attachment A.

  16. High efficiency ground data transmission

    NASA Technical Reports Server (NTRS)

    Dickinson, W. B.

    1973-01-01

    It is demonstrated that state-of-the-art communications technology can be implemented and reliably operated on a global basis to increase the transmission rates and efficiencies on circuits with bandwidths greater than the typical speech channel. Optimization is affected by optimum clock recovery procedures, multilevel pulse amplitude modulation, single sideband amplitude modulation, transversal filter equalizers, data scrambling, and active compensation for phase instability.

  17. High current pulse transmission cable

    SciTech Connect

    Parsons, W.M.

    1990-09-28

    This invention is comprised of a transmission cable for carrying high current pulses in which an even numbered plurality of electrical conductors surrounds a central ground conductor. Each electrical conductor is connected so that it at any instant in time it will carry current of opposite polarity to the polarity carried by adjacent conductors. This arrangement cancels practically all of the external fields generated by current in the conductors.

  18. Flavivirus transmission focusing on Zika.

    PubMed

    Vasilakis, Nikos; Weaver, Scott C

    2017-02-01

    Flaviviruses are among the most diverse viruses with over 85 species recognized. Taxonomically, this genus is one of the 4 recognized genera within the family Flaviviridae. Most flaviviruses of human public health significance, for example, dengue, yellow fever and Zika viruses, are arthropod-borne (arboviruses) and have two evolutionarily and ecologically distinct transmission cycles: a sylvatic transmission cycle, where the virus circulates between zoonotic vertebrate reservoir and amplification hosts and arboreal mosquitoes; and an urban transmission cycle, where the virus circulates between humans and peridomestic Aedes spp. mosquitoes. Zika virus (ZIKV), a flavivirus closely related to West Nile, dengue, Spondweni, Japanese encephalitis and yellow fever viruses, remained in obscurity since its discovery in 1947, but has recently emerged to cause a series of epidemics in the South Pacific, and most recently reaching nearly pandemic levels with its introduction in the Americas. Available epidemiologic and experimental evidence points to Aedes aegypti as the principal urban vector, possibly supplemented by Aedes albopictus in some locations. Unfortunately, the former is one of the most difficult mosquitoes to control owing to its highly anthropophilic behavior.

  19. Dislocation substructures and nonproportional hardening. [TEM observations under tension-torsion cyclic loading

    SciTech Connect

    Shiinghwa Doong; Socie, D.F.; Robertson, I.M. )

    1990-10-01

    The dislocation substructures created in 1100 aluminum, OFHC copper, and type 304 and 310 stainless steels by in-phase (proportional) and 90 deg out-of-phase (nonproportional) tension-torsion cyclic loading were examined with a transmission-electron microscope. Multislip structures (cells and subgrains) are observed in aluminum under both in-phase and 90 deg out-of-phase tension-torsion loading. For copper and stainless steel, single-slip structures (planar dislocations, matrix veins, and ladders) are observed after proportional loading, whereas multislip structures (cells and labyrinths) are observed after nonproportional loading. The increased cyclic hardening of copper and stainless steels under nonproportional loading is attributed to the change of dislocation substructures. Based on these observations, formulation of a nonproportionality parameter for constitutive modeling is discussed.

  20. Maximizing TDRS Command Load Lifetime

    NASA Technical Reports Server (NTRS)

    Brown, Aaron J.

    2002-01-01

    The GNC software onboard ISS utilizes TORS command loads, and a simplistic model of TORS orbital motion to generate onboard TORS state vectors. Each TORS command load contains five "invariant" orbital elements which serve as inputs to the onboard propagation algorithm. These elements include semi-major axis, inclination, time of last ascending node crossing, right ascension of ascending node, and mean motion. Running parallel to the onboard software is the TORS Command Builder Tool application, located in the JSC Mission Control Center. The TORS Command Builder Tool is responsible for building the TORS command loads using a ground TORS state vector, mirroring the onboard propagation algorithm, and assessing the fidelity of current TORS command loads onboard ISS. The tool works by extracting a ground state vector at a given time from a current TORS ephemeris, and then calculating the corresponding "onboard" TORS state vector at the same time using the current onboard TORS command load. The tool then performs a comparison between these two vectors and displays the relative differences in the command builder tool GUI. If the RSS position difference between these two vectors exceeds the tolerable lim its, a new command load is built using the ground state vector and uplinked to ISS. A command load's lifetime is therefore defined as the time from when a command load is built to the time the RSS position difference exceeds the tolerable limit. From the outset of TORS command load operations (STS-98), command load lifetime was limited to approximately one week due to the simplicity of both the onboard propagation algorithm, and the algorithm used by the command builder tool to generate the invariant orbital elements. It was soon desired to extend command load lifetime in order to minimize potential risk due to frequent ISS commanding. Initial studies indicated that command load lifetime was most sensitive to changes in mean motion. Finding a suitable value for mean motion