WorldWideScience

Sample records for unit gears tested

  1. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    Science.gov (United States)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  2. 29 CFR 1919.28 - Unit proof tests-cranes and gear accessory thereto.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Unit proof tests-cranes and gear accessory thereto. 1919.28... Loads; Heat Treatment; Competent Persons § 1919.28 Unit proof tests—cranes and gear accessory thereto. (a) Except as noted in paragraph (e) of this section, cranes and other hoisting machines, together...

  3. 29 CFR 1919.27 - Unit proof tests-winches, derricks and gear accessory thereto.

    Science.gov (United States)

    2010-07-01

    ..., goosenecks, eye plates, eye bolts, or other attachments), shall be tested with a proof load which shall..., a qualified technical office of an accredited gear certification agency, with the recognition that...

  4. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  5. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  6. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-31

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

  7. 29 CFR 1919.31 - Proof tests-loose gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear (whether...

  8. 46 CFR 167.65-25 - Steering gear tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means of...

  9. Intelligent Test Mechanism Design of Worn Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. The measure equations transformations were made on involute straight gear. Original polar coordinate equations were transformed into rectangular coordinate equations. Big gear abrasion measure principle was introduced. Detection principle diagram was given. Detection route realization method was introduced. OADM12 laser sensor was selected. Detection on big gear abrasion area was realized by detection mechanism. Tested data of unworn gear and worn gear were led in designed calculation program written by Visual Basic language. Big gear abrasion quantity can be obtained. It provides a feasible method for intelligent test and intelligent repair welding on worn big gear.

  10. Development and Assessment of Planetary Gear Unit for Experimental Prototype of Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Urbahs A.

    2017-10-01

    Full Text Available The theoretical calculation for development of planetary gear unit of wind turbine (WT and its experimental tests are presented in the paper. Development of experimental prototypes from composite materials is essential to determine capability of element and its impact on feature. Two experimental scale prototypes of planetary gear unit for WT were developed for such purposes. Hall transducer, servomechanisms and optical tachometers were used to obtain results, comparison analysis of theoretical and actual data was performed as well as quality assessment of experimental prototypes of planetary gear unit. After kinematic and load analysis as well as control of rotation frequency, it is possible to declare that the unit is able to operate at designated quality. Theoretical calculations and test results obtained are used for industrial WT prototype development.

  11. Development and Assessment of Planetary Gear Unit for Experimental Prototype of Vertical Axis Wind Turbine

    Science.gov (United States)

    Urbahs, A.; Urbaha, M.; Carjova, K.

    2017-10-01

    The theoretical calculation for development of planetary gear unit of wind turbine (WT) and its experimental tests are presented in the paper. Development of experimental prototypes from composite materials is essential to determine capability of element and its impact on feature. Two experimental scale prototypes of planetary gear unit for WT were developed for such purposes. Hall transducer, servomechanisms and optical tachometers were used to obtain results, comparison analysis of theoretical and actual data was performed as well as quality assessment of experimental prototypes of planetary gear unit. After kinematic and load analysis as well as control of rotation frequency, it is possible to declare that the unit is able to operate at designated quality. Theoretical calculations and test results obtained are used for industrial WT prototype development.

  12. A New Design of the Universal Test Rig to Measure the Wear Characterizations of Polymer Acetal Gears (Spur, Helical, Bevel, and Worm

    Directory of Open Access Journals (Sweden)

    Samy Yousef

    2015-01-01

    Full Text Available This work aims to study the wear characterization of common types of acetal polymer gears (spur, helical, bevel, and worm using a new TS universal test rig, in order to obtain reliable results and as a reference when compared with acetal nanocomposite gears later. The TS universal test rig consists of three different units that are connected by a main driver shaft and a pair of constantly meshing metal spur gears, which transfer power to the bevel and worm test units. The first unit is used to test the bevel gears, the second unit is used to test the spur and helical gears, and the third unit is used to test the worm gears. The loading mechanism is similarly designed to block the brake mechanism. Hobbing and milling machines were used to machine an injection-moulded polymer flanges and produce the tested gears. All gear pairs, except the worm gear, have identical gear ratios. The experiments were performed at speed 1420 rpm and the torque was 4 Nm. The results showed that the wear rates (in the form of weight loss of spur gears were consistent with the previous results and the other gear types had larger wear rates.

  13. Gearing.

    Science.gov (United States)

    1985-12-01

    trichloroethyl phosphite and a phosphate ester containing a pentachlorphenyl radical. Most of the Asperity heights phosphorous compounds in gear oils...108) found that phosphorous compounds chemisorption. These boundary films can be thinner than ( 1 0 u ts n 0.025 pm (I in ) or several microinches thick...Pinion 1 .. dibutylxanthic acid disulfide. Ŗ %- Lead soaps have been used in lubricants for many 02 years. They resist the wiping and sliding action in

  14. The impact of various distance between axes of worm gear on torque value. Worm gear test stand

    Science.gov (United States)

    Sobek, M.; Baier, A.; Grabowski, Ł.

    2017-08-01

    Transferring both rotational and translational movements in systems used in the automotive industry is a very important and complex issue. In addition, the situation becomes much more difficult and complicated when the design of the transition system requires a high precision of operation as well as a well definite and long operating life. Such requirements are imposed on all components of today’s motor vehicles. However, particular attention is paid to the elements that directly or indirectly affect the safety of persons traveling in the vehicle. Such components are undoubtedly components included as parts of the steering system of the vehicle. Power steering systems have been present in motor vehicles for more than a century. They go through continuous metamorphosis and they are getting better and better. Current power steering systems are based on an electric motor and some kind of transmission. Depending on the position of the drive relative to the steering column, different configurations of the transmission are used. This article will cover issues related to tests of power steering gearing using a worm drive. The worm drive is a very specific example of a propulsion system that uses twisted axles. Normally, in this type of transition you can find two gear units with the axis mounted with a 90° angle between. The components of the worm drive are a worm and a worm gear, also called a worm wheel. In terms of the geometrical form, the worm resembles a helical spur gear. The shape of the worm is similar to the shape of a screw with a trapezoidal thread. A correct matching of these two components ensures proper operation of the entire transmission. Incorrect positioning of the components in relation to each other can significantly reduce the lifetime of the drive unit, and also lead to abnormal work, eg by raising the noise level. This article describes a test method of finding the appropriate distance between the axles of both worm drive units by testing the

  15. Ideas for Testing of Planetary Gear Sets of Automotive Transmissions

    Directory of Open Access Journals (Sweden)

    Achtenová Gabriela

    2017-06-01

    Full Text Available The article describes the concept of modular stand, where is possible to provide tests of gear pairs with fixed axes from mechanical automotive gearboxes, as well as tests of separate planetary sets from automatic gearboxes. Special attention in the article will be paid to the variant dedicated for testing of planetary gear sets. This variant is particularly interesting because: 1 it is rarely described in the literature, and 2 this topology allows big simplification with respect to testing of standard gearwheels. In the planetary closed-loop stand it is possible to directly link two identical planetary sets. Without any bracing flange or other connecting clutches, shafts or gear sets, just two planetary sets face-to-face will be assembled and connected to the electric motor.

  16. Test gear and measurements a collection of useful and tested circuit design ideas'

    CERN Document Server

    Stewart OBE DLitthc, David

    2013-01-01

    This book provides a clear introduction to test gear in the field of electronics. As well as being a first guide to test gear and its use, the book includes much practical information and reference material for the more experienced electronics enthusiast or student.Based on a collection of feature articles originally published in Electronics - the Maplin Magazine, this work by Danny Stewart is sure to be useful to electronics constructors, students and experimenters alike. Details of all the common (and some not-so-common) items of test gear are included, alongside information regarding its us

  17. Appraisal of boundary layer trips for landing gear testing

    Science.gov (United States)

    McCarthy, Philip; Feltham, Graham; Ekmekci, Alis

    2013-11-01

    Dynamic similarity during scaled model testing is difficult to maintain. Forced boundary layer transition via a surface protuberance is a common method used to address this issue, however few guidelines exist for the effective tripping of complex geometries, such as aircraft landing gears. To address this shortcoming, preliminary wind tunnel tests were performed at Re = 500,000. Surface transition visualisation and pressure measurements show that zigzag type trips of a given size and location are effective at promoting transition, thus preventing the formation of laminar separation bubbles and increasing the effective Reynolds number from the critical regime to the supercritical regime. Extension of these experiments to include three additional tripping methods (wires, roughness strips, CADCUT dots) in a range of sizes, at Reynolds number of 200,000 and below, have been performed in a recirculating water channel. Analysis of surface pressure measurements and time resolved PIV for each trip device, size and location has established a set of recommendations for successful use of tripping for future, low Reynolds number landing gear testing.

  18. Validation of Helicopter Gear Condition Indicators Using Seeded Fault Tests

    Science.gov (United States)

    Dempsey, Paula; Brandon, E. Bruce

    2013-01-01

    A "seeded fault test" in support of a rotorcraft condition based maintenance program (CBM), is an experiment in which a component is tested with a known fault while health monitoring data is collected. These tests are performed at operating conditions comparable to operating conditions the component would be exposed to while installed on the aircraft. Performance of seeded fault tests is one method used to provide evidence that a Health Usage Monitoring System (HUMS) can replace current maintenance practices required for aircraft airworthiness. Actual in-service experience of the HUMS detecting a component fault is another validation method. This paper will discuss a hybrid validation approach that combines in service-data with seeded fault tests. For this approach, existing in-service HUMS flight data from a naturally occurring component fault will be used to define a component seeded fault test. An example, using spiral bevel gears as the targeted component, will be presented. Since the U.S. Army has begun to develop standards for using seeded fault tests for HUMS validation, the hybrid approach will be mapped to the steps defined within their Aeronautical Design Standard Handbook for CBM. This paper will step through their defined processes, and identify additional steps that may be required when using component test rig fault tests to demonstrate helicopter CI performance. The discussion within this paper will provide the reader with a better appreciation for the challenges faced when defining a seeded fault test for HUMS validation.

  19. ASSEMBLY DESIGN OPTIMIZATION FOR GEAR PUMP HYDRAULIC UNITS

    Directory of Open Access Journals (Sweden)

    ŞCHEAUA Fanel

    2012-09-01

    Full Text Available This paper presents a model for gear pump assembly design realized in Solid Edge V20. The aim is to highlight modelling aspects for solid part components and how to achieve an assembly from several component parts. Can be noted that computer aided design (CAD software can provide multiple options of representing various designed components, assemblies containing up to hundreds of items and part component motion simulation.

  20. 46 CFR 122.320 - Steering gear, controls, and communication system tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for a...

  1. Face-gear drives: Design, analysis, and testing for helicopter transmission applications

    Science.gov (United States)

    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 is described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, grinding, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. An analytical study showed that the face-gear drive is relatively insensitive to gear misalignment with respect to transmission errors, but the tooth contact is affected by misalignment. A method of localizing the bearing contact to permit operation with misalignment was explored. Two new methods for grinding of the face-gear tooth surfaces were also investigated. The proper choice of shaft stiffness enabled good load sharing in the split-torque transmission design. Face-gear experimental studies were also conducted. These tests demonstrated the feasibility of face-gears in high-speed, high-load applications such as helicopter transmissions.

  2. 29 CFR 1919.30 - Examinations subsequent to unit tests.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Examinations subsequent to unit tests. 1919.30 Section 1919... Treatment; Competent Persons § 1919.30 Examinations subsequent to unit tests. (a) After satisfactory completion of the unit proof load tests required by §§ 1919.27 and 1919.28, the cargo gear and all component...

  3. Passive Muscle-Tendon Unit Gearing is Joint Dependent in Human Medial Gastrocnemius

    Directory of Open Access Journals (Sweden)

    Emma F Hodson-Tole

    2016-03-01

    Full Text Available Skeletal muscles change length and develop force both passively and actively. Gearing allows muscle fibre length changes to be uncoupled from those of the whole muscle-tendon unit. During active contractions this process allows muscles to operate at mechanically favorable conditions for power or economical force production. Here we ask whether gearing is constant in passive muscle; determining the relationship between fascicle and muscle-tendon unit length change in the bi-articular medial gastrocnemius and investigating the influence of whether motion occurs at the knee or ankle joint. Specifically, the same muscle-tendon unit length changes were elicited by rotating either the ankle or knee joint whilst simultaneously measuring fascicle lengths in proximal and distal muscle regions using B-mode ultrasound. In both the proximal and distal muscle region, passive gearing values differed depending on whether ankle or knee motion occurred. Fascicle length changes were greater with ankle motion, likely reflecting anatomical differences in proximal and distal passive tendinous tissues, as well as shape changes of the adjacent mono-articular soleus. This suggests that there is joint-dependent dissociation between the mechanical behaviour of muscle fibres and the muscle-tendon unit during passive joint motions that may be important to consider when developing accurate models of bi-articular muscles.

  4. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  5. Catch per unit efforts and impacts of gears on fish abundance in an oxbow lake ecosystem in Eastern India

    Directory of Open Access Journals (Sweden)

    Dipankar Ghosh

    2017-05-01

    Full Text Available Background: Oxbow lakes are abundant in indigenous fishes, but they are subject to unsustainable fishing practices, potential overexploitation, and indiscriminate use of fine-meshed fishing gear. To quantify the catch per unit effort (CPUE and impact of fishing gears on fish abundance, a survey was carried out in an oxbow lake in eastern India. Methods: The gear-wise CPUE for fish caught in per unit hour of operation was calculated by dividing the total sampling gear catch in biomass, which is the observed value of fish caught by a particular gear, by the total sampling effort hours. A value of P 71%. Cone-framed cast net hauled the maximum catch in biomass (31.51%, and gill nets contributed the maximum number of fish (64.92%. The lower CPUE values of line and hook, gill net, cone-framed cast net and long lines identified them as the most harmful among all gears. Conclusion: Indiscriminate use of gear, particularly line and hook, gill nets, cone-framed cast nets, and long lines, demands regulations and preventions concerning such gear to obtain higher fish abundance.

  6. A New High-Speed, High-Cycle, Gear-Tooth Bending Fatigue Test Capability

    Science.gov (United States)

    Stringer, David B.; Dykas, Brian D.; LaBerge, Kelsen E.; Zakrajsek, Andrew J.; Handschuh, Robert F.

    2011-01-01

    A new high-speed test capability for determining the high cycle bending-fatigue characteristics of gear teeth has been developed. Experiments were performed in the test facility using a standard spur gear test specimens designed for use in NASA Glenn s drive system test facilities. These tests varied in load condition and cycle-rate. The cycle-rate varied from 50 to 1000 Hz. The loads varied from high-stress, low-cycle loads to near infinite life conditions. Over 100 tests were conducted using AISI 9310 steel spur gear specimen. These results were then compared to previous data in the literature for correlation. Additionally, a cycle-rate sensitivity analysis was conducted by grouping the results according to cycle-rate and comparing the data sets. Methods used to study and verify load-path and facility dynamics are also discussed.

  7. Threshold Assessment of Gear Diagnostic Tools on Flight and Test Rig Data

    Science.gov (United States)

    Dempsey, Paula J.; Mosher, Marianne; Huff, Edward M.

    2003-01-01

    A method for defining thresholds for vibration-based algorithms that provides the minimum number of false alarms while maintaining sensitivity to gear damage was developed. This analysis focused on two vibration based gear damage detection algorithms, FM4 and MSA. This method was developed using vibration data collected during surface fatigue tests performed in a spur gearbox rig. The thresholds were defined based on damage progression during tests with damage. The thresholds false alarm rates were then evaluated on spur gear tests without damage. Next, the same thresholds were applied to flight data from an OH-58 helicopter transmission. Results showed that thresholds defined in test rigs can be used to define thresholds in flight to correctly classify the transmission operation as normal.

  8. 75 FR 12462 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Removal of Gear...

    Science.gov (United States)

    2010-03-16

    ...; Removal of Gear Restriction for the U.S./Canada Management Area AGENCY: National Marine Fisheries Service...; removal of gear restrictions. SUMMARY: This action removes temporary gear restrictions in both the Eastern... Management Act (Magnuson- Stevens Act). DATES: Removal of the temporary gear restriction in the Western U.S...

  9. 46 CFR 185.320 - Steering gear, controls, and communication system tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests. 185.320 Section 185.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.320 Steering...

  10. Measuring Software Test Verification for Complex Workpieces based on Virtual Gear Measuring Instrument

    Directory of Open Access Journals (Sweden)

    Yin Peili

    2017-08-01

    Full Text Available Validity and correctness test verification of the measuring software has been a thorny issue hindering the development of Gear Measuring Instrument (GMI. The main reason is that the software itself is difficult to separate from the rest of the measurement system for independent evaluation. This paper presents a Virtual Gear Measuring Instrument (VGMI to independently validate the measuring software. The triangular patch model with accurately controlled precision was taken as the virtual workpiece and a universal collision detection model was established. The whole process simulation of workpiece measurement is implemented by VGMI replacing GMI and the measuring software is tested in the proposed virtual environment. Taking involute profile measurement procedure as an example, the validity of the software is evaluated based on the simulation results; meanwhile, experiments using the same measuring software are carried out on the involute master in a GMI. The experiment results indicate a consistency of tooth profile deviation and calibration results, thus verifying the accuracy of gear measuring system which includes the measurement procedures. It is shown that the VGMI presented can be applied in the validation of measuring software, providing a new ideal platform for testing of complex workpiece-measuring software without calibrated artifacts.

  11. Planter unit test stand

    Science.gov (United States)

    A planter test stand was developed to evaluate individual row-crop metering units in early 2013. This test stand provided the ability to quantify actual seed metering in terms of population, seed spacing, skips, and multiples over a range of meter RPMs and vacuum pressures. Preliminary data has been...

  12. Investigation of Spiral Bevel Gear Condition Indicator Validation Via AC-29-2C Using Damage Progression Tests

    Science.gov (United States)

    Dempsey, Paula J.

    2014-01-01

    This report documents the results of spiral bevel gear rig tests performed under a NASA Space Act Agreement with the Federal Aviation Administration (FAA) to support validation and demonstration of rotorcraft Health and Usage Monitoring Systems (HUMS) for maintenance credits via FAA Advisory Circular (AC) 29-2C, Section MG-15, Airworthiness Approval of Rotorcraft (HUMS) (Ref. 1). The overarching goal of this work was to determine a method to validate condition indicators in the lab that better represent their response to faults in the field. Using existing in-service helicopter HUMS flight data from faulted spiral bevel gears as a "Case Study," to better understand the differences between both systems, and the availability of the NASA Glenn Spiral Bevel Gear Fatigue Rig, a plan was put in place to design, fabricate and test comparable gear sets with comparable failure modes within the constraints of the test rig. The research objectives of the rig tests were to evaluate the capability of detecting gear surface pitting fatigue and other generated failure modes on spiral bevel gear teeth using gear condition indicators currently used in fielded HUMS. Nineteen final design gear sets were tested. Tables were generated for each test, summarizing the failure modes observed on the gear teeth for each test during each inspection interval and color coded based on damage mode per inspection photos. Gear condition indicators (CI) Figure of Merit 4 (FM4), Root Mean Square (RMS), +/- 1 Sideband Index (SI1) and +/- 3 Sideband Index (SI3) were plotted along with rig operational parameters. Statistical tables of the means and standard deviations were calculated within inspection intervals for each CI. As testing progressed, it became clear that certain condition indicators were more sensitive to a specific component and failure mode. These tests were clustered together for further analysis. Maintenance actions during testing were also documented. Correlation coefficients were

  13. Wear Characterization of Carbon Nanotubes Reinforced Acetal Spur, Helical, Bevel and Worm Gears Using a TS Universal Test Rig

    Science.gov (United States)

    Yousef, Samy; Osman, T. A.; Abdalla, Abdelrahman H.; Zohdy, Gamal A.

    2015-12-01

    Although the applications of nanotechnologies are increasing, there remains a significant barrier between nanotechnology and machine element applications. This work aims to remove this barrier by blending carbon nanotubes (CNT) with common types of acetal polymer gears (spur, helical, bevel and worm). This was done by using adhesive oil (paraffin) during injection molding to synthesize a flange and short bars containing 0.02% CNT by weight. The flanges and short bars were machined using hobbing and milling machines to produce nanocomposite polymer gears. Some defects that surfaced in previous work, such as the appearance of bubbles and unmelted pellets during the injection process, were avoided to produce an excellent dispersion of CNT in the acetal. The wear resistances of the gears were measured by using a TS universal test rig using constant parameters for all of the gears that were fabricated. The tests were run at a speed of 1420 rpm and a torque of 4 Nm. The results showed that the wear resistances of the CNT/acetal gears were increased due to the addition of CNT, especially the helical, bevel and worm gears.

  14. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  15. Material Compressing Test of the High Polymer Part Used in Draft Gear of Heavy Load Locomotive

    Directory of Open Access Journals (Sweden)

    Wei Yangang

    2016-01-01

    Full Text Available According to the actual load cases of heavy load locomotive, the material compressing tests of the high polymer parts used in the locomotive are researched. The relationship between stress and strain during the material compressing are acquired by means of comparing the many results of the material compressing tests under different test condition. The relationship between stress and strain during the material compressing is nonlinear in large range of strain, but the relationship is approximately linear in small range of strain. The material of the high polymer made in China and the material of the high polymer imported are compared through the tests. The results show that the compressing property of the material of the high polymer made in China and the material of the high polymer imported are almost same. The research offers the foundation to study the structure elasticity of the draft gear.

  16. Study on signal processing in Eddy current testing for defects in spline gear

    International Nuclear Information System (INIS)

    Lee, Jae Ho; Park, Tae Sug; Park, Ik Keun

    2016-01-01

    Eddy current testing (ECT) is commonly applied for the inspection of automated production lines of metallic products, because it has a high inspection speed and a reasonable price. When ECT is applied for the inspection of a metallic object having an uneven target surface, such as the spline gear of a spline shaft, it is difficult to distinguish between the original signal obtained from the sensor and the signal generated by a defect because of the relatively large surface signals having similar frequency distributions. To facilitate the detection of defect signals from the spline gear, implementation of high-order filters is essential, so that the fault signals can be distinguished from the surrounding noise signals, and simultaneously, the pass-band of the filter can be adjusted according to the status of each production line and the object to be inspected. We will examine the infinite impulse filters (IIR filters) available for implementing an advanced filter for ECT, and attempt to detect the flaw signals through optimization of system design parameters for detecting the signals at the system level

  17. The cycloid Permanent Magnetic Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank T.

    2008-01-01

    This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model...... regarding torque density. The results were promising as compared to other high-performance magnetic-gear designs. A test model was constructed to verify the analytical model....

  18. Design and construction of permanent magnetic gears

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif

    /l]. Measurement from this gear has resulted in a measured total torque density of 23 [Nm/l]. Mechanical versions of this gear type are found with total torque density in the 16 to 31 [Nm/l] range. The third and last gear technology that is investigated is a gear that reminds of a planetary gear. Research shows......This thesis deals with design and development of permanent magnetic gears. The goal of this thesis is to develop knowledge and calculation software for magnetic gears. They use strong NdFeB permanent magnets and a new magnetic gear technology, which will be a serious alternative to classical...... mechanical gears. The new magnetic gear will have a high torque density1 relationship –high efficiency and are maintenance free. In this project was manufactured two test gears which is tested and verified with models developed in this project. Present technological status for magnetic gears is introduced...

  19. Investigation of Spiral Bevel Gear Condition Indicator Validation via AC-29-2C Combining Test Rig Damage Progression Data with Fielded Rotorcraft Data

    Science.gov (United States)

    Dempsey, Paula J.

    2015-01-01

    This is the final of three reports published on the results of this project. In the first report, results were presented on nineteen tests performed in the NASA Glenn Spiral Bevel Gear Fatigue Test Rig on spiral bevel gear sets designed to simulate helicopter fielded failures. In the second report, fielded helicopter HUMS data from forty helicopters were processed with the same techniques that were applied to spiral bevel rig test data. Twenty of the forty helicopters experienced damage to the spiral bevel gears, while the other twenty helicopters had no known anomalies within the time frame of the datasets. In this report, results from the rig and helicopter data analysis will be compared for differences and similarities in condition indicator (CI) response. Observations and findings using sub-scale rig failure progression tests to validate helicopter gear condition indicators will be presented. In the helicopter, gear health monitoring data was measured when damage occurred and after the gear sets were replaced at two helicopter regimes. For the helicopters or tails, data was taken in the flat pitch ground 101 rotor speed (FPG101) regime. For nine tails, data was also taken at 120 knots true airspeed (120KTA) regime. In the test rig, gear sets were tested until damage initiated and progressed while gear health monitoring data and operational parameters were measured and tooth damage progression documented. For the rig tests, the gear speed was maintained at 3500RPM, a one hour run-in was performed at 4000 in-lb gear torque, than the torque was increased to 8000 in-lbs. The HUMS gear condition indicator data evaluated included Figure of Merit 4 (FM4), Root Mean Square (RMS) or Diagnostic Algorithm 1(DA1), + 3 Sideband Index (SI3) and + 1 Sideband Index (SI1). These were selected based on their sensitivity in detecting contact fatigue damage modes from analytical, experimental and historical helicopter data. For this report, the helicopter dataset was reduced to

  20. Advanced Face Gear Surface Durability Evaluations

    Science.gov (United States)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  1. Life test failure of harmonic gears in a Two-axis Gimbal for the Mars Reconnaissance Orbiter Spacecraft

    Science.gov (United States)

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

    2006-01-01

    This paper will present a process for increasing the stiffness of harmonic gear assemblies and recommend a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.

  2. Comparison Virtual Landing Gear Drop Test for Commuter Aircraft Utilize MSC ADAMS And Solidworks Motion Analysis

    Science.gov (United States)

    Hidayat, Dony; Istiyanto, Jos; Agus Sumarsono, Danardono

    2018-04-01

    Loads at main landing gear while touchdown impact is function of aircraft weight and ground reaction load factor. In regulation states ground reaction load factor at Vsink = 3.05 m/s is below 3. Contact/impact force from simulation using MSC ADAMS is 94680 N, while using Solidworks Motion Analysis is 97691 N. The difference between MSC ADAMS and Solidworks Motion Analysis is 3.08%. The ground reaction load factor in MSC ADAMS is 2.78 while in Solidworks Motion Analysis is 2.87.

  3. Evaluation of a vibration diagnostic system for the detection of spur gear pitting failures

    Science.gov (United States)

    Townsend, Dennis P.; Zakrajsek, James J.

    1993-01-01

    A vibration diagnostic system was used to detect spur gear surface pitting fatigue in a closed-loop spur gear fatigue test rig. The diagnostic system, comprising a personal computer with an analog-to-digital conversion board, a diagnostic system unit, and software, uses time-synchronous averaging of the vibration signal to produce a vibration image of each tooth on any gear in a transmission. Several parameters were analyzed including gear pair stress wave and raw baseband vibration, kurtosis, peak ratios, and others. The system provides limits for the various parameters and gives a warning when the limits are exceeded. Several spur gear tests were conducted with this system and vibration data analyzed at 5-min. intervals. The results presented herein show that the system is fairly effective at detecting spur gear tooth surface fatigue pitting failures.

  4. High Pressure Angle Gears: Comparison to Typical Gear Designs

    Science.gov (United States)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  5. Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Antolick, Lance J.; Branning, Jeremy S.; Wade, Daniel R.; Dempsey, Paula J.

    2010-01-01

    The U.S. Army is currently expanding its fleet of Health Usage Monitoring Systems (HUMS) equipped aircraft at significant rates, to now include over 1,000 rotorcraft. Two different on-board HUMS, the Honeywell Modern Signal Processing Unit (MSPU) and the Goodrich Integrated Vehicle Health Management System (IVHMS), are collecting vibration health data on aircraft that include the Apache, Blackhawk, Chinook, and Kiowa Warrior. The objective of this paper is to recommend the most effective gear condition indicators for fleet use based on both a theoretical foundation and field data. Gear diagnostics with better performance will be recommended based on both a theoretical foundation and results of in-fleet use. In order to evaluate the gear condition indicator performance on rotorcraft fleets, results of more than five years of health monitoring for gear faults in the entire HUMS equipped Army helicopter fleet will be presented. More than ten examples of gear faults indicated by the gear CI have been compiled and each reviewed for accuracy. False alarms indications will also be discussed. Performance data from test rigs and seeded fault tests will also be presented. The results of the fleet analysis will be discussed, and a performance metric assigned to each of the competing algorithms. Gear fault diagnostic algorithms that are compliant with ADS-79A will be recommended for future use and development. The performance of gear algorithms used in the commercial units and the effectiveness of the gear CI as a fault identifier will be assessed using the criteria outlined in the standards in ADS-79A-HDBK, an Army handbook that outlines the conversion from Reliability Centered Maintenance to the On-Condition status of Condition Based Maintenance.

  6. Flame photometric detection of sodium leaks: Tests on a fullscale model for the control gear sodium rig

    International Nuclear Information System (INIS)

    Grundy, B.R.; Knowles, P.

    1971-01-01

    The proposed arrangement for detecting sodium leaks from the large flanges of the Control Gear Sodium Rig (Test Section No. 8, MCTR) at REML is to jacket then in a secondary containment from which air samples will be continuously pumped. Pipework feeds the air to a flame photometer which responds if soditun is present. To prove that sodium smoke could be transferred through the system, tests were performed on a fullscale model by burning small amounts of sodium in different jackets. Large signals free from fluctuations were obtained in all tests, peak response occurring in 2 1/4 minutes or less. The signal quickly cleared after isolating the appropriate vessel. A waiting period of several hours was sufficient to reduce the signal to zero, no cleaning of pipework, etc being necessary. In contrast, samples of two lagging materials heated to 400 °C gave no response with the photometer at maximum sensitivity. (author)

  7. A Comparative Study of a Few Tests for Isomorphism in Planetary Gear Trains

    Directory of Open Access Journals (Sweden)

    Rajasri Reddy

    2013-04-01

    Full Text Available Graph theory and Matrix methods are widely used by various kinematicians for synthesis and analysis of PGTs. Characteristic polynomial coefficients are used to detect isomorphism in Planetary Gear Trains (PGT. With the Eigen values and Eigen vectors method multiple matrix calculations are required. In case of Hamming number method a single Hamming matrix is enough to detect isomorphism in two PGTs and also determine structural aspects like symmetry easily [1]. Further using the Hamming matrix for a PGT, the number of possible combinations of levels that can be assigned to a given PGT [2] is identified. A review and comparison of Characteristic polynomial, Eigen vectors and Eigen value and Hamming number methods is presented.

  8. Double Helical Gear Performance Results in High Speed Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  9. Influence of lubricant on the pitting capacity of gears. Comparison and discussion of main pitting test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Bernd-Robert; Oster, Peter; Tobie, Thomas; Hergesell, Maria [Forschungsstelle fuer Zahnraeder und Getriebebau, Technische Univ. Muenchen, Garching (Germany)

    2009-07-01

    The lubricant in a gearbox should provide a separating lubricating film between the meshing teeth. Furthermore its main task is the evacuation of the developing heat. Hence the lubricant is also an important influence parameter on the pitting life time of gearsets. Due to the constantly rising demands for higher power transmission of gearsets, also higher demands are made against the performance of the lubricants. In order to quantify the capability and to choose the appropriate lubricant for each application, reliable testing methods are necessary. Therefor today different testing methods are available. Two of the main pitting testing methods are the Standard Pittingtest according to FVA 2/IV [2] and its advancement, the Practice Relevant Pittingtest according to FVA 371 [4]. For the Practice Relevant Pittingtest test gears with profile modification and lengthwise crowning are used, which are superfinished. For the introduction of the Practice Relevant Pittingtest into industrial application a round robin test was performed in co-operation with FVA and DGMK. This paper is discussing the today usual testing methods regarding the pitting load capacity of lubricants and their characteristics in comparison. Furthermore the results of the round robin test and further example results, including pictures of typical pittings, are presented. In addition it is demonstrated, how to deal with the results. On the basis of test experience, knowledge from research projects and other examples typical questions concerning the different testing methods are discussed. Thereby essential requirements for reliable and reproducible results are pointed out and possible limits for the application of the test methods are represented. (orig.)

  10. Magnet-Sleeve-Sealed Mini Trochoidal-Gear Pump Prototype with Polymer Composite Gear

    Directory of Open Access Journals (Sweden)

    Pedro Javier Gamez-Montero

    2017-09-01

    Full Text Available The trochoidal-gear technology has been growing in groundbreaking fields. Forthcoming applications are demanding to this technology a step forward in the conceiving stage of positive displacement machines. The compendium of the qualities and the inherent characteristics of trochoidal-gear technology, especially towards the gerotor pump, together with scale/size factor and magnetic-driven transmission has led to the idea of a magnet-sleeve-sealed variable flow mini trochoidal-gear pump. From its original concept, to the last phase of the design development, the proof of concept, this new product will intend to overcome problems such as noise, vibration, maintenance, materials, and dimensions. The paper aims to show the technological path followed from the concept, design, and model, to the manufacture of the first prototype, where the theoretical and numerical approaches are not always directly reflected in the prototype performance results. Early in the design process, from a standard-commercial sintered metal mini trochoidal-gear unit, fundamental characteristics and dimensional limitations have been evaluated becoming the strategic parameters that led to its configuration. The main technical challenge to confront is being sealed with non-exterior driveshaft, ensuring that the whole interior is filled and wetted with working fluid and helping the hydrodynamic film formation, the pumping effect, and the heat dissipation. Subsequently, the mini pump architecture, embodiment, methodology, materials, and manufacture are presented. The trend of applications of polymer composite materials and their benefits wanted to be examined with this new mini pump prototype, and a pure polyoxymethylene mini trochoidal-gear set has been designed and manufactured. Finally, both the sintered and the polymer trochoidal-gear units have been experimentally tested in an in-house full-instrumented mini test bench. Although the main goal of the presented work is the

  11. Gear Tooth Wear Detection Algorithm

    Science.gov (United States)

    Delgado, Irebert R.

    2015-01-01

    Vibration-based condition indicators continue to be developed for Health Usage Monitoring of rotorcraft gearboxes. Testing performed at NASA Glenn Research Center have shown correlations between specific condition indicators and specific types of gear wear. To speed up the detection and analysis of gear teeth, an image detection program based on the Viola-Jones algorithm was trained to automatically detect spiral bevel gear wear pitting. The detector was tested using a training set of gear wear pictures and a blind set of gear wear pictures. The detector accuracy for the training set was 75 percent while the accuracy for the blind set was 15 percent. Further improvements on the accuracy of the detector are required but preliminary results have shown its ability to automatically detect gear tooth wear. The trained detector would be used to quickly evaluate a set of gear or pinion pictures for pits, spalls, or abrasive wear. The results could then be used to correlate with vibration or oil debris data. In general, the program could be retrained to detect features of interest from pictures of a component taken over a period of time.

  12. An intersection test for panel unit roots

    NARCIS (Netherlands)

    Hanck, C.

    2013-01-01

    This article proposes a new panel unit root test based on Simes' ( 1986) classical intersection test. The test is robust to general patterns of cross-sectional dependence and yet is straightforward to implement, only requiring p-values of time series unit root tests of the series in the panel, and

  13. Modern gear production

    CERN Document Server

    Watson, H J

    1970-01-01

    Modern Gear Production focuses on the processes and methods in gear making. The book first gives information on the history of gear making and types of gears. Topics such as the classification of gears based on the disposition of their shafts; shafts lying in the same plane with axes intersecting; and shafts lying in parallel planes but with axes inclined to one another are then discussed. The text describes gear groups, tooth forms, and gear materials. Heat treatment of steels, casehardening, nitriding, induction hardening, sulfinuzing, and flame hardening are explained. The book takes a look

  14. Investigation on wear characteristic of biopolymer gear

    Science.gov (United States)

    Ghazali, Wafiuddin Bin Md; Daing Idris, Daing Mohamad Nafiz Bin; Sofian, Azizul Helmi Bin; Basrawi, Mohamad Firdaus bin; Khalil Ibrahim, Thamir

    2017-10-01

    Polymer is widely used in many mechanical components such as gear. With the world going to a more green and sustainable environment, polymers which are bio based are being recognized as a replacement for conventional polymers based on fossil fuel. The use of biopolymer in mechanical components especially gear have not been fully explored yet. This research focuses on biopolymer for spur gear and whether the conventional method to investigate wear characteristic is applicable. The spur gears are produced by injection moulding and tested on several speeds using a custom test equipment. The wear formation such as tooth fracture, tooth deformation, debris and weight loss was observed on the biopolymer spur gear. It was noted that the biopolymer gear wear mechanism was similar with other type of polymer spur gears. It also undergoes stages of wear which are; running in, linear and rapid. It can be said that the wear mechanism of biopolymer spur gear is comparable to fossil fuel based polymer spur gear, thus it can be considered to replace polymer gears in suitable applications.

  15. Testing of the structural evaluation test unit

    International Nuclear Information System (INIS)

    Ammerman, D.J.; Bobbe, J.G.

    1995-01-01

    In the evaluation of the safety of radioactive material transportation it is important to consider the response of Type B packages to environments more severe than that prescribed by the hypothetical accident sequence in Title 10 Part 71 of the Code of Federal Regulations (NRC 1995). The impact event in this sequence is a 9-meter drop onto an essentially unyielding target, resulting in an impact velocity of 13.4 m/s. The behavior of 9 packages when subjected to impacts more severe than this is not well known. It is the purpose of this program to evaluate the structural response of a test package to these environments. Several types of structural response are considered. Of primary importance is the behavior of the package containment boundary, including the bolted closure and 0-rings. Other areas of concern are loss of shielding capability due to lead slump and the deceleration loading of package contents, that may cause damage to them. This type of information is essential for conducting accurate risk assessments on the transportation of radioactive materials. Currently very conservative estimates of the loss of package protection are used in these assessments. This paper will summarize the results of a regulatory impact test and three extra-regulatory impact tests on a sample package

  16. Eddy current tube testing unit

    International Nuclear Information System (INIS)

    Dufayet, J.P.; Duret, G.

    1975-01-01

    The unit described can check a wide variety of tubes in quick succession and its modular design gives it a high degree of versability. Suitably defined working conditions and specific fittings enable most of the faults encountered in the manufacture of a tube to be detected. By appropriate means of selection based on signal amplitude, phase and frequency analyses it is possible to adapt selection criteria to the seriousness of the different categories of defect [fr

  17. Automation of unit for leakage test

    OpenAIRE

    LYCHKOVSKAYA V.S.; TSYGANKOV A.S.; GRINBERG G.M.; STANOVOVA O.A.

    2015-01-01

    Federal state educational standard requirements for training of university students have been considered. Leakage test procedures for components of aerospace vehicles have been described. Automation procedures of existing laboratory leakage test units have been outlined.

  18. Kinematic geometry of gearing

    CERN Document Server

    Dooner, David B

    2012-01-01

    Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat

  19. Practical unit testing with JUnit and Mockito

    CERN Document Server

    Kaczanowski, Tomek

    2013-01-01

    This book explains in detail how to implement unit tests using two very popular open source Java technologies: JUnit and Mockito. It presents a range of techniques necessary to write high quality unit tests - e.g. mocks, parametrized tests and matchers. It also discusses trade-offs related to the choices we have to make when dealing with some real-life code issues. The book stresses the importance of writing readable and maintainable unit tests, and puts a lot of stress on code quality. It shows how to achieve testable code and to eliminate common mistakes by following the Test Driven Development approach. Every topic discussed in the book is illustrated with code examples, and each chapter is accompanied by some exercises. By reading this book you will: Grasp the role and purpose of unit tests Write high-quality, readable and maintainable unit tests Learn how to use JUnit and Mockito (but also other useful tools) Avoid common pitfalls when writing unit tests Recognize bad unit tests, a...

  20. Gear Fault Diagnosis Based on BP Neural Network

    Science.gov (United States)

    Huang, Yongsheng; Huang, Ruoshi

    2018-03-01

    Gear transmission is more complex, widely used in machinery fields, which form of fault has some nonlinear characteristics. This paper uses BP neural network to train the gear of four typical failure modes, and achieves satisfactory results. Tested by using test data, test results have an agreement with the actual results. The results show that the BP neural network can effectively solve the complex state of gear fault in the gear fault diagnosis.

  1. A Nonparametric Test for Seasonal Unit Roots

    OpenAIRE

    Kunst, Robert M.

    2009-01-01

    Abstract: We consider a nonparametric test for the null of seasonal unit roots in quarterly time series that builds on the RUR (records unit root) test by Aparicio, Escribano, and Sipols. We find that the test concept is more promising than a formalization of visual aids such as plots by quarter. In order to cope with the sensitivity of the original RUR test to autocorrelation under its null of a unit root, we suggest an augmentation step by autoregression. We present some evidence on the siz...

  2. Lubrication and cooling for high speed gears

    Science.gov (United States)

    Townsend, D. P.

    1985-01-01

    The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

  3. Evaluation of existing EPRI and INEL test data to determine the worm to worm gear coefficient of friction in Limitorque actuators

    Energy Technology Data Exchange (ETDEWEB)

    Garza, I.A.

    1996-12-01

    About the last sizing parameter for motor operated valves which has not been determined by utility or NRC sponsored testing is actuator efficiency. A by-product of EPRI testing for valve factors is the measurement of the actuator efficiencies. Motor sizing in this testing provides efficiency testing for motors running near synchronous speed. INEL testing, sponsored by the NRC, for stem factors and rate of loading provides complimentary data for motors loaded down to zero speed. This paper analyzes the data from these two test programs to determine the coefficient of friction for the worm to worm gear interface. This allowed the development of an algorithm for determining the efficiency of actuators which have not been tested. This paper compares the results of this algorithm to the test data to provide a measure of the accuracy of this method for calculating actuator efficiency.

  4. Evaluation of existing EPRI and INEL test data to determine the worm to worm gear coefficient of friction in Limitorque actuators

    International Nuclear Information System (INIS)

    Garza, I.A.

    1996-01-01

    About the last sizing parameter for motor operated valves which has not been determined by utility or NRC sponsored testing is actuator efficiency. A by-product of EPRI testing for valve factors is the measurement of the actuator efficiencies. Motor sizing in this testing provides efficiency testing for motors running near synchronous speed. INEL testing, sponsored by the NRC, for stem factors and rate of loading provides complimentary data for motors loaded down to zero speed. This paper analyzes the data from these two test programs to determine the coefficient of friction for the worm to worm gear interface. This allowed the development of an algorithm for determining the efficiency of actuators which have not been tested. This paper compares the results of this algorithm to the test data to provide a measure of the accuracy of this method for calculating actuator efficiency

  5. Unit Testing for Command and Control Systems

    Science.gov (United States)

    Alexander, Joshua

    2018-01-01

    Unit tests were created to evaluate the functionality of a Data Generation and Publication tool for a command and control system. These unit tests are developed to constantly evaluate the tool and ensure it functions properly as the command and control system grows in size and scope. Unit tests are a crucial part of testing any software project and are especially instrumental in the development of a command and control system. They save resources, time and costs associated with testing, and catch issues before they become increasingly difficult and costly. The unit tests produced for the Data Generation and Publication tool to be used in a command and control system assure the users and stakeholders of its functionality and offer assurances which are vital in the launching of spacecraft safely.

  6. Gear bearing drive

    Science.gov (United States)

    Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor); Weinberg, Brian (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  7. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  8. COMPUTER-AIDED DESIGN, MANUFACTURE AND EXPERIMENTAL ANALYSIS OF A PAIR OF ELLIPTICAL SPUR GEARS

    Directory of Open Access Journals (Sweden)

    Mehmet YAZAR

    2016-12-01

    Full Text Available ABSTRACT In this study, geometrical equations of elliptical spur gears, which are too difficult to manufacture by traditional methods and which require specific machines equipped with special techniques, are developed using the methods in the literature. Using these equations, a LISP program on AutoLISP is created to model elliptical spur gears on AutoCAD with desired tooth number and modules. Elliptical spur gears are manufactured with 5 different modules by Wire EDM through the above-mentioned package program. The variations in the center distances of elliptical spur gears, the most important parameter for workability of gears, are experimentally determined by a simple test unit designed and manufactured within the context this study. In addition, the surface roughness and hardness of elliptical spur gears are obtained and hydraulic pump and noise analysis results are discussed. The experimental and computer-aided results show that the elliptical spur gears may widely be used in many industrial and mechanical applications in the future.

  9. 3000-HP Roller Gear Transmission Development Program. Volume 3. Roller Gear Manufacture

    Science.gov (United States)

    1975-07-01

    power is fed through the ramp roller clutch type free- wheel units to spur gears which mesh with the combining spur gear whose centerline is common...when the engine tends to turn faster than the main rotor shaft. It is in the free- wheel mode when the main rotor shaft tends to turn faster than the...gears are cut progrind at this time. Check face runout on each end of largo gears. Not to exceed .002" TIR 30 EBW one end 40 EBW opposite end

  10. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  11. Estimating Gear Teeth Stiffness

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffness’s of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact length is constant....

  12. Geared-elevator flutter study. [wind tunnel tests of transonic flutter effects on control surfaces of supersonic transport tail assemblies, conducted in a NASA-Langley transonic wind tunnel

    Science.gov (United States)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    An experimental and analytical study was made of the transonic flutter characteristics of a supersonic transport tail assembly model having an all-movable, horizontal tail with a geared elevator. Two model configurations, namely, one with a gear-elevator (2.8 to 1.0 gear ratio) and one with locked-elevator (1.0 to 1.0 gear ratio), were flutter tested in the Langley transonic dynamics tunnel with an empennage cantilever-mounted on a sting. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter dynamic pressure boundaries for both configurations were nearly flat over a Mach number range from 0.9 to 1.1. Flutter calculations (mathematical models) were made for the geared-elevator configuration using three subsonic lifting-surface methods. In one method, the elevator was treated as a discrete surface, and in the other two methods, the stabilizer and elevator were treated as a single warped-surface with the primary difference between these two methods being in the mathematical implementation used. A comparison of the experimental and analytical results shows that the discrete-elevator method predicted best the experimental flutter dynamic pressure level. However, the single warped-surface methods predicts more closely the experimental flutter frequencies and Mach number trends.

  13. 46 CFR 61.20-1 - Steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of Inspections...

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

    Science.gov (United States)

    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.

  15. Effect of tooth profile modification on wear in internal gears

    Science.gov (United States)

    Tunalioglu, M. S.; Tuc, B.

    2018-05-01

    Internal gears are often used in the automotive industry when two gears are required to rotate in the same direction. Tooth shapes, slippage speeds at the beginning and end of meshing are different according to the external gears. Manufacturing of internal gears is more difficult than external gears. Thus, it is necessary to determine the working conditions and wear behavior of internal gears carefully. The profile modification method in terms of strength and surface tension of the gear mechanism are performed in order to increase the load-carrying capability. In this study, profile modification method was performed in the internal gears to reduce the wear on the teeth. For this purpose, the wear of the internal gears was theoretically investigated by adapting the Archard wear equation to the internal gears. Closed circuit power circulation system was designed and manufactured to experimentally investigate the wear in internal gears. With this system, wear tests of gears made of St 50 material without profile modification and different profile modifications were made and the results were compared. Experimental study was performed in the same loading and cycle time conditions to validate the theoretical results and it was seen that the results are compatible. According to the experimental results, it is seen that in the internal gears, when profile modification done the wear is decreased in the teeth tip region.

  16. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  17. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  18. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  19. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp...

  20. Gearing Up for Mountain Biking.

    Science.gov (United States)

    Jahnke, Thomas; Hamson, Mike

    1999-01-01

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

  1. CIT photoheliograph functional verification unit test program

    Science.gov (United States)

    1973-01-01

    Tests of the 2/3-meter photoheliograph functional verification unit FVU were performed with the FVU installed in its Big Bear Solar Observatory vacuum chamber. Interferometric tests were run both in Newtonian (f/3.85) and Gregorian (f/50) configurations. Tests were run in both configurations with optical axis horizontal, vertical, and at 45 deg to attempt to determine any gravity effects on the system. Gravity effects, if present, were masked by scatter in the data associated with the system wavefront error of 0.16 lambda rms ( = 6328A) apparently due to problems in the primary mirror. Tests showed that the redesigned secondary mirror assembly works well.

  2. Engagement of Metal Debris into Gear Mesh

    Science.gov (United States)

    handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  3. Tests of an experimental slash ignition unit

    Science.gov (United States)

    James L. Murphy; Harry E. Schimke

    1965-01-01

    A prototype ignition package containing an incendiary powder and designed for slash and brush burning jobs showed some promise, but the unit tested was not superior to such conventional devices as fusees, diesel backpack type flamethrowers, Very pistols, and drip torches.

  4. Some pitfalls in unit root testing

    NARCIS (Netherlands)

    Bakker, B.B.; Koning, Ruud H.

    1991-01-01

    Testing for unit roots is now common practice for economists. The most popular procedure is the approach developed by Dickey and Fuller (1979, 1981), which only requires running appropriately specified regressions. However, application of the Dickey-Fuller procedure requires that the disturbance

  5. Testing for Unit Roots in Market Shares

    NARCIS (Netherlands)

    Franses, P.H.B.F.; Srinivasan, S.; Boswijk, H.P.

    2001-01-01

    A unique characteristic of marketing data sets is the logical consistency requirement in market share models that market shares are bounded by 0 and 1, and they sum to unity. To take account of this logical consistency requirement, we propose to test for unit roots in individual market share series

  6. Sea Turtle Human/Gear Interactions Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories is responsible for new gear development and testing to reduce bycatch and incidental interactions of...

  7. Vibration and Operational Characteristics of a Composite-Steel (Hybrid) Gear

    Science.gov (United States)

    Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan

    2014-01-01

    Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.

  8. 49 CFR 230.90 - Draw gear between steam locomotive and tender.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Draw gear between steam locomotive and tender. 230... Steam Locomotives and Tenders Draw Gear and Draft Systems § 230.90 Draw gear between steam locomotive and tender. (a) Maintenance and testing. The draw gear between the steam locomotive and tender...

  9. Efficiency of fishing gears in the river Halda, Chittagong, Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Arshad-Ul-Alam

    2015-12-01

    Full Text Available To determine the catch efficiency of fishing gears, catch per unit effort (CPUEdata were collected for two years during January 2007 to December 2008 from the river Halda. Analyses were done to examine the variation of CPUE among gears, studied sections, months and years. The mean CPUE for pooled data of all gears was 2.247±0.265 kg.gear-1day-1 and 2.697±0.355 kg.gear-1day-1 for 2007 and 2008 respectively. Among eight gear categories, bag nets yielded the highest CPUE during 2007 (5.957±0.704 kg.gear-1day-1 and seine nets during 2008 (7.288±1.477 kg.gear-1day-1. Among 31 gear types, small meshed bag nets yielded the highest CPUE (18.065±6.660 and 15.69±4.479 kg.gear-1day-1 during 2007 and 2008 respectively. CPUE was highest during March-April and September-November periods. Analysis of variance showed significant difference among catch rates of different fishing gears. The CPUE differed significantly among different months for net fence, gill net, cast net and scoop net during 2007; and for seine net, net fence, bag net and cast net during 2008.

  10. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  11. Digital tape unit test facility software

    Science.gov (United States)

    Jackson, J. T.

    1971-01-01

    Two computer programs are described which are used for the collection and analysis of data from the digital tape unit test facility (DTUTF). The data are the recorded results of skew tests made on magnetic digital tapes which are used on computers as input/output media. The results of each tape test are keypunched onto an 80 column computer card. The format of the card is checked and the card image is stored on a master summary tape via the DTUTF card checking and tape updating system. The master summary tape containing the results of all the tape tests is then used for analysis as input to the DTUTF histogram generating system which produces a histogram of skew vs. date for selected data, followed by some statistical analysis of the data.

  12. High Power Alternator Test Unit (ATU) Electrical System Test

    Science.gov (United States)

    Birchenough, Arthur; Hervol, David

    2007-01-01

    The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was used to simulate the operating conditions and evaluate the performance of the ATU and it s interaction with various LPSF components in accordance with the JIMO AC Power System Requirements. The testing was carried out at the breadboard development level. Results of these tests will be used for the development and validation of analytical models for performance and lifetime prediction.

  13. Investigation of Sideband Index Response to Prototype Gear Tooth Damage

    Science.gov (United States)

    Dempsey, Paula J.

    2013-01-01

    The objective of this analysis was to evaluate the ability of gear condition indicators (CI) to detect contact fatigue damage on spiral bevel gear teeth. Tests were performed in the NASA Glenn Spiral Bevel Gear Fatigue Rig on eight prototype gear sets (pinion/gear). Damage was initiated and progressed on the gear and pinion teeth. Vibration data was measured during damage progression at varying torque values while varying damage modes to the gear teeth were observed and documented with inspection photos. Sideband indexes (SI) and root mean square (RMS) CIs were calculated from the time synchronous averaged vibration data. Results found that both CIs respond differently to varying torque levels, damage levels and damage modes

  14. Eyeball test using abdominal ultrasound unit

    International Nuclear Information System (INIS)

    Choi, Chun Kyu; Lee, Yong Woo; Cheung, Hwan

    1984-01-01

    Ultrasonography is a wide diagnostic use for its desirable quality that it causes no radiation hazard to the patient and allows to test him without causing pains, while affording much valued diagnostic information. Since Mundt reported in 1955 that Ultrasonography can be used for testing the eyeball, it has widely been used for clinical purpose, but in Korea many difficulties are being exist in the sonographic evaluation of the eyeball due to storage of the exclusive Ultrasound units for eyeball diagnosis. This treatise describes eyeball test methods along with clinical instances observed by a compound scanner for abdomen scan mounted with an eyeball transducer of a frequency as high as 5 to 7.5MHz and using water bag

  15. Face Gear Technology for Aerospace Power Transmission Progresses

    Science.gov (United States)

    2005-01-01

    The use of face gears in an advanced rotorcraft transmission design was first proposed by the McDonnell Douglas Helicopter Company during their contracted effort with the U.S. Army under the Advanced Rotorcraft Transmission (ART) program. Face gears would be used to turn the corner between the horizontal gas turbine engine and the vertical output rotor shaft--a function currently done by spiral bevel gears. This novel gearing arrangement would substantially lower the drive system weight partly because a face gear mesh would be used to split the input power between two output gears. However, the use of face gears and their ability to operate successfully at the speeds and loads required for an aerospace environment was unknown. Therefore a proof-of-concept phase with an existing test stand at the NASA Lewis Research Center was pursued. Hardware was designed that could be tested in Lewis' Spiral Bevel Gear Test Rig. The initial testing indicated that the face gear mesh was a feasible design that could be used at high speeds and load. Surface pitting fatigue was the typical failure mode, and that could lead to tooth fracture. An interim project was conducted to see if slight modifications to the gear tooth geometry or an alternative heat treating process could overcome the surface fatigue problems. From the initial and interim tests, it was apparent that for the surface fatigue problems to be overcome the manufacturing process used for this component would have to be developed to the level used for spiral bevel gears. The current state of the art for face gear manufacturing required using less than optimal gear materials and manufacturing techniques because the surface of the tooth form does not receive final finishing after heat treatment as it does for spiral bevel gears. This resulted in less than desirable surface hardness and manufacturing tolerances. An Advanced Research and Projects Agency (ARPA) Technology Reinvestment Project has been funded to investigate

  16. Test Report Emission Test Program EPA Information Collection Request for Delayed Coking Units 736 Coker Unit

    Science.gov (United States)

    ARI Environmental, Inc. (ARI) was retained by Houston Refining LP (HRO) to conduct an emission test program at their refinery located in Houston, Texas. The testing was conducted on on the 736 Delayed Coking Unit (DCU) in response to EPA's ICR.

  17. Unit testing, model validation, and biological simulation.

    Science.gov (United States)

    Sarma, Gopal P; Jacobs, Travis W; Watts, Mark D; Ghayoomie, S Vahid; Larson, Stephen D; Gerkin, Richard C

    2016-01-01

    The growth of the software industry has gone hand in hand with the development of tools and cultural practices for ensuring the reliability of complex pieces of software. These tools and practices are now acknowledged to be essential to the management of modern software. As computational models and methods have become increasingly common in the biological sciences, it is important to examine how these practices can accelerate biological software development and improve research quality. In this article, we give a focused case study of our experience with the practices of unit testing and test-driven development in OpenWorm, an open-science project aimed at modeling Caenorhabditis elegans. We identify and discuss the challenges of incorporating test-driven development into a heterogeneous, data-driven project, as well as the role of model validation tests, a category of tests unique to software which expresses scientific models.

  18. Communication: Molecular gears

    Energy Technology Data Exchange (ETDEWEB)

    Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)

    2016-09-07

    The {sup 1}H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  19. Prediction of potential failures in hydraulic gear pumps

    Directory of Open Access Journals (Sweden)

    E. Lisowski

    2010-07-01

    Full Text Available Hydraulic gear pumps are used in many machines and devices. In hydraulic systems of machines gear pumps are main component ofsupply unit or perform auxiliary function. Gear pumps opposite to vane pumps are less complicated. They consists of such components as:housing, gear wheels, bearings, shaft, seal for rotation motion which are not very sensitive for damage and that is why they are using veryoften. However, gear pumps are break down from time to time. Usually damage of pump cause shutting down of machines and devices.One of the way for identifying potential failures and foreseeing their effects is a quality method. On the basis of these methods apreventing action might be undertaken before failure appear. In this paper potential failures and damages of a gear pump were presented bythe usage of matrix FMEA analysis.

  20. Motor Integrated Permanent Magnet Gear in a Battery Electrical Vehicle

    DEFF Research Database (Denmark)

    Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø

    2015-01-01

    This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV......) and the background for the specifications are elaborated. Simulated as well as measured results of rotational losses of the first and second version are compared. The efficiency of the new design is investigated and compared to three direct drive motors in a few operating points and the MIPMG v.2 seems superior when...

  1. Radioactive Acid Digestion Test Unit (RADTU), 1980

    International Nuclear Information System (INIS)

    Allen, C.R.

    1980-01-01

    The Radioactive Acid Digestion Test Unit (RADTU) was constructed at the Hanford Site, Richland, WA to demonstrate application of the acid digestion process for treating combustible transuranic wastes and scrap materials. Using its original tray digester vessel, RADTU recently completed a six-month campaign of processing potentially contaminated non-glovebox wastes from a Hanford plutonium facility. During the campaign, 2100 kg of largely cellulosic wastes were processed at an average sustained processing rate of 3 kg/h (limited by the acid-waste contact and the water boiloff rate from the acid feeds). On-line operating efficiency was nearly 50%, averaged over 12 hours/day, for five days/week. After shutdown, a new annular high-rate digester was installed for testing that demonstrated a sustained capacity of 8 kg/h to 10 kg/h with greatly improved contact between the digestion acid and the waste. The new unit began processing low-level waste from Hanford's z-Plant during June 1980. Plutonium levels in the waste processed will be increased gradually as operating experience has been gained. Processing recoverable scrap is expected to begin in the last quarter of CY 1980

  2. 14 CFR 25.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... the greater value of landing impact energy. (2) The test attitude of the landing gear unit and the... manner consistent with the development of rational or conservative limit loads. (b) The landing gear may... acting during the landing impact. (c) In lieu of the tests prescribed in this section, changes in...

  3. Prediction of Landing Gear Noise Reduction and Comparison to Measurements

    Science.gov (United States)

    Lopes, Leonard V.

    2010-01-01

    Noise continues to be an ongoing problem for existing aircraft in flight and is projected to be a concern for next generation designs. During landing, when the engines are operating at reduced power, the noise from the airframe, of which landing gear noise is an important part, is equal to the engine noise. There are several methods of predicting landing gear noise, but none have been applied to predict the change in noise due to a change in landing gear design. The current effort uses the Landing Gear Model and Acoustic Prediction (LGMAP) code, developed at The Pennsylvania State University to predict the noise from landing gear. These predictions include the influence of noise reduction concepts on the landing gear noise. LGMAP is compared to wind tunnel experiments of a 6.3%-scale Boeing 777 main gear performed in the Quiet Flow Facility (QFF) at NASA Langley. The geometries tested in the QFF include the landing gear with and without a toboggan fairing and the door. It is shown that LGMAP is able to predict the noise directives and spectra from the model-scale test for the baseline configuration as accurately as current gear prediction methods. However, LGMAP is also able to predict the difference in noise caused by the toboggan fairing and by removing the landing gear door. LGMAP is also compared to far-field ground-based flush-mounted microphone measurements from the 2005 Quiet Technology Demonstrator 2 (QTD 2) flight test. These comparisons include a Boeing 777-300ER with and without a toboggan fairing that demonstrate that LGMAP can be applied to full-scale flyover measurements. LGMAP predictions of the noise generated by the nose gear on the main gear measurements are also shown.

  4. The digital ultrasonic test unit for automatic equipment

    International Nuclear Information System (INIS)

    Hiraoka, T.; Matsuyama, H.

    1976-01-01

    The operations and features of the ultrasonic test unit used and the digital data processing techniques employed are described. This unit is used for a few hundred multi-channel automatic ultrasonic test equipment

  5. A superconducting magnetic gear

    International Nuclear Information System (INIS)

    Campbell, A M

    2016-01-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844–46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further. (paper)

  6. Test report: Electron-proton spectrometer qualification test unit, qualification test

    Science.gov (United States)

    Vincent, D. L.

    1972-01-01

    Qualification tests of the electron-proton spectrometer test unit are presented. The tests conducted were: (1) functional, (2) thermal/vacuum, (3) electromagnetic interference, (4) acoustic, (5) shock, (6) vibration, and (7) humidity. Results of each type of test are presented in the form of data sheets.

  7. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...

  8. 49 CFR 230.89 - Reverse gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse gear...

  9. analysis of gear milling at vari gear milling at various gear milling

    African Journals Online (AJOL)

    eobe

    2 DEPARTMENT OF INDUSTRIAL AND ... conventional machine tools, cutter tool wear, .... speed, and tool wear on case-hardened gear is also .... study. The gear cutter is mounted on the spindle. Spindle speeds and feed rates are essential ...

  10. Diagnostics of power transmissions system with tooth gear

    Directory of Open Access Journals (Sweden)

    Grzegorz WOJNAR

    2008-01-01

    Full Text Available This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and gear shafts at different speeds and gear loads. Results were analyzed and compared but in this paper is presented only selected examples. This paper shows that on the basis of the transverse vibration speed of transmission gear shafts, it is possible to detect defects at an earlier stage than on the basis of the housing vibration accelerations. In the case of measuring gear shaft vibration velocity, the way of the signal generated by the defect of a gear wheel (or bearing is shortened as well as the influence of composed transmittance of the bearing-gear housing system is eliminated. WV time-frequency analysis and complex continuous wavelet transformations were used for detection. The authors introduced a measure of local tooth damage, which was proportional to the size of damage. The results of research presented in this paperconfirmed that the defect's measure is very sensitive to the development of teeth faults.

  11. Hybrid Gear Preliminary Results-Application of Composites to Dynamic Mechanical Components

    Science.gov (United States)

    Handschuh, Robert F.; Roberts Gary D.; Sinnamon, R.; Stringer, David B.; Dykas, Brian D.; Kohlman, Lee W.

    2012-01-01

    Composite spur gears were fabricated and then tested at NASA Glenn Research Center. The composite material served as the web of the gear between the gear teeth and a metallic hub for mounting to the torque-applying shaft. The composite web was bonded only to the inner and outer hexagonal features that were machined from an initially all-metallic aerospace quality spur gear. The Hybrid Gear was tested against an all-steel gear and against a mating Hybrid Gear. As a result of the composite to metal fabrication process used, the concentricity of the gears were reduced from their initial high-precision value. Regardless of the concentricity error, the hybrid gears operated successfully for over 300 million cycles at 10000 rpm and 490 in.*lbs torque. Although the design was not optimized for weight, the composite gears were found to be 20% lighter than the all-steel gears. Free vibration modes and vibration/noise tests were also conduct to compare the vibration and damping characteristic of the Hybrid Gear to all-steel gears. The initial results indicate that this type of hybrid design may have a dramatic effect on drive system weight without sacrificing strength.

  12. Nearly Efficient Likelihood Ratio Tests for Seasonal Unit Roots

    DEFF Research Database (Denmark)

    Jansson, Michael; Nielsen, Morten Ørregaard

    In an important generalization of zero frequency autore- gressive unit root tests, Hylleberg, Engle, Granger, and Yoo (1990) developed regression-based tests for unit roots at the seasonal frequencies in quarterly time series. We develop likelihood ratio tests for seasonal unit roots and show...... that these tests are "nearly efficient" in the sense of Elliott, Rothenberg, and Stock (1996), i.e. that their local asymptotic power functions are indistinguishable from the Gaussian power envelope. Currently available nearly efficient testing procedures for seasonal unit roots are regression-based and require...... the choice of a GLS detrending parameter, which our likelihood ratio tests do not....

  13. The Dilemma of Derelict Gear.

    Science.gov (United States)

    Scheld, A M; Bilkovic, D M; Havens, K J

    2016-01-21

    Every year, millions of pots and traps are lost in crustacean fisheries around the world. Derelict fishing gear has been found to produce several harmful environmental and ecological effects, however socioeconomic consequences have been investigated less frequently. We analyze the economic effects of a substantial derelict pot removal program in the largest estuary of the United States, the Chesapeake Bay. By combining spatially resolved data on derelict pot removals with commercial blue crab (Callinectes sapidus) harvests and effort, we show that removing 34,408 derelict pots led to significant gains in gear efficiency and an additional 13,504 MT in harvest valued at US $21.3 million--a 27% increase above that which would have occurred without removals. Model results are extended to a global analysis where it is seen that US $831 million in landings could be recovered annually by removing less than 10% of the derelict pots and traps from major crustacean fisheries. An unfortunate common pool externality, the degradation of marine environments is detrimental not only to marine organisms and biota, but also to those individuals and communities whose livelihoods and culture depend on profitable and sustainable marine resource use.

  14. HIV Testing in the United States

    Science.gov (United States)

    ... testing is offered at CDC-funded testing sites (accounting for more than 3 million tests) and in ... text Each state Medicaid program determines its own definition of medical necessity, although it generally refers to ...

  15. A Computational Investigation of Gear Windage

    Science.gov (United States)

    Hill, Matthew J.; Kunz, Robert F.

    2012-01-01

    A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear windage loss, including the physics of loss mitigation strategies, and to propose and evaluate new approaches for minimizing loss. Absolute and relative frame CFD simulation, overset gridding, multiphase flow analysis, and sub-layer resolved turbulence modeling were brought to bear in achieving these goals. Several spur gear geometries were studied for which experimental data are available. Various shrouding configurations and free-spinning (no shroud) cases were studied. Comparisons are made with experimental data from the open literature, and data recently obtained in the NASA Glenn Research Center Gear Windage Test Facility. The results show good agreement with experiment. Interrogation of the validative and exploratory CFD results have led, for the first time, to a detailed understanding of the physical mechanisms of gear windage loss, and have led to newly proposed mitigation strategies whose effectiveness is computationally explored.

  16. Drop performance test and evaluation for HANARO shutoff units

    International Nuclear Information System (INIS)

    Jung, Y. H.; Cho, Y. K.; Lee, J. H.; Choi, Y. S.; Woo, J. S.

    2004-01-01

    The function of the shutoff units of the HANARO is to rapidly insert the shutoff rod into the reactor core for safe shutdown of reactor. This paper describes drop performance test and evaluation for a shutoff unit for the technical verification of lifetime extension and localization of the HANARO shutoff units. We have performed preliminary drop performance tests for a shutoff unit at 1/2-core test loop and analyzed through the comparison with the test results performed during design verification test and the results of the periodic performance test in HANARO. It shows that the results of the local fabrication, installation and alignment for the shutoff unit meet the basic performance requirements, Furthermore, the performance evaluation method of the periodic drop test of the HANARO shutoff units is a conservative method comparing with the real drop time

  17. D Modelling with the Samsung Gear 360

    Science.gov (United States)

    Barazzetti, L.; Previtali, M.; Roncoroni, F.

    2017-02-01

    The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing) have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images) in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.

  18. Energy efficiency improvement by gear shifting optimization

    Directory of Open Access Journals (Sweden)

    Blagojevic Ivan A.

    2013-01-01

    Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.

  19. Stuck in gear: age-related loss of variable gearing in skeletal muscle.

    Science.gov (United States)

    Holt, Natalie C; Danos, Nicole; Roberts, Thomas J; Azizi, Emanuel

    2016-04-01

    Skeletal muscles power a broad diversity of animal movements, despite only being able to produce high forces over a limited range of velocities. Pennate muscles use a range of gear ratios, the ratio of muscle shortening velocity to fiber shortening velocity, to partially circumvent these force-velocity constraints. Muscles operate with a high gear ratio at low forces; fibers rotate to greater angles of pennation, enhancing velocity but compromising force. At higher forces, muscles operate with a lower gear ratio; fibers rotate little so limiting muscle shortening velocity, but helping to preserve force. This ability to shift gears is thought to be due to the interplay of contractile force and connective tissue constraints. In order to test this hypothesis, gear ratios were determined in the medial gastrocnemius muscles of both healthy young rats, and old rats where the interaction between contractile and connective tissue properties was assumed to be disrupted. Muscle fiber and aponeurosis stiffness increased with age (PGear ratio decreased with increasing force in young (Pgearing is lost in old muscle. These findings support the hypothesis that variable gearing results from the interaction between contractile and connective tissues and suggest novel explanations for the decline in muscle performance with age. © 2016. Published by The Company of Biologists Ltd.

  20. Unit testing of AngularJS : A look into writing tests for web application

    OpenAIRE

    Karttunen, Joel

    2016-01-01

    This task was assigned by Protacon Solutions Oy with the objective set to study and implement unit testing in AngularJS JavaScript framework as part of the development process of the customer’s application. The thesis focuses on studying the AngularJS framework and if and how its design philosophy complements the unit testing principles. The focus was on studying unit testing via developing unit tests iteratively onto the application created beforehand. The tests were created with Jas...

  1. A New Nonlinear Unit Root Test with Fourier Function

    OpenAIRE

    Güriş, Burak

    2017-01-01

    Traditional unit root tests display a tendency to be nonstationary in the case of structural breaks and nonlinearity. To eliminate this problem this paper proposes a new flexible Fourier form nonlinear unit root test. This test eliminates this problem to add structural breaks and nonlinearity together to the test procedure. In this test procedure, structural breaks are modeled by means of a Fourier function and nonlinear adjustment is modeled by means of an Exponential Smooth Threshold Autore...

  2. Fiscal 1999 technical achievement report. Research and development project on prompt-effect international standards creation (Standardization of test and evaluation of superhigh-precision toothed gear); 1999 nendo shinki sangyo ikusei sokkogata kokusai hyojun kaihatsu jigyo seika hokokusho. Choseimitsu haguruma no seidono shiken hyoka hoho no hyojunka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In ISO1328 that covers specifications on precision of toothed gears, gears are graded according to the magnitude of error, but there is no system established for guaranteeing measured error values for accuracy. Activities are conducted for realizing such a guarantee, for establishing methods for testing and evaluating gear precision measuring devices, and for working out international standards for them. It is decided that the current status be investigated and then a concrete method be proposed as an international standard centering about gear precision measuring digital devices which will stay important in the future. A digital measuring device enhanced in precision is constructed by way of trial, and then it is proved that the newly fabricated device works effectively in the calibration of gear precision measuring devices in general use. Thanks to this process, basic data are collected about the measurement of gear precision using a gear precision measuring digital device, and this enables the preparation of a draft of criteria for international standardization. (NEDO)

  3. AGM-69A Joint Test Unit

    Science.gov (United States)

    1975-11-15

    that the JTU payload will reliably and effectively meet SAC test requirements. However, the inherent absence of a flight termination (command destruct...ubsequent post fuzing anomalies were observed at the Air Force Eastern Test Range ( AFETR ) on five of the six BULLET .BLITZ II missions. The severity of these...some effect on mission planning and trajectory positioning on the test range. With a severe tumble after fuzing, it is possible that the missile will

  4. Successful Project Based Learning (PBL) Across Disciplines Geared Towards Middle School: An Example from a Wetlands PBL Unit in Reno, Nevada, USA

    Science.gov (United States)

    Howard, K. L.; Suchy-Mabrouk, A.; Noble, P. J.; Mensing, S. A.; Ewing-Taylor, J.

    2014-12-01

    A growing need for broad dissemination of current scientific research and improved scientific literacy requires new models of professional development that allow for direct collaboration between educators and university researchers. One example is a project funded by the National Science Foundation (NSF) as part of a study titled, "Reconstructing 2500 years of environmental change at the periphery of Rome: Integrating paleoecology and socioeconomic history to understand human response to climate." This project involves a team of middle school teachers working with researchers at the University of Nevada, Reno (UNR) to gain first-hand knowledge in multidisciplinary research connecting science and society, and applies a similar approach in the classroom. In 2013, the team's science teacher traveled to Italy as a member of the science research group. A series of workshops introduced the remaining teachers to the research project. Teachers collaborated to develop a Project Based Learning (PBL) unit that incorporated Next Generation Science Standards and encompassed English, Social Studies, Math, and Science curricula using a pedagogical approach different from the single subject-based PBL's usually taught in their school district. The PBL unit draws on the NSF study and focuses on exploring the balance between economic and environmental issues surrounding local wetlands. In May 2014, 160 middle school students worked in groups to create and test a question about physio-chemical parameters in a nearby wetland and used these data to discuss local economic development. Initially, students claimed polarized views of environmental issues or economic development interests; however, during a multimedia session showcasing results, students communicated more informed perspectives that clearly incorporated knowledge gained from their own research. Some students were able to make recommendations for good practices involving planned economic development near the wetland

  5. Temelin 1000 MW Units active testing stage - commissioning experience

    International Nuclear Information System (INIS)

    Ubra, O.; Riha, V.

    2003-01-01

    There were three basic stages of the NPP Temelin Units active testing stage- The zero and low power testing, The power ascension testing and Plant Performance Test. The main objective of the start- up process stages and the testing procedures including some operational experience are described in the paper. (author)

  6. A Unit-Test Framework for Database Applications

    DEFF Research Database (Denmark)

    Christensen, Claus Abildgaard; Gundersborg, Steen; de Linde, Kristian

    The outcome of a test of an application that stores data in a database naturally depends on the state of the database. It is therefore important that test developers are able to set up and tear down database states in a simple and efficient manner. In existing unit-test frameworks, setting up...... test can be minimized. In addition, the reuse between unit tests can speed up the execution of test suites. A performance test on a medium-size project shows a 40% speed up and an estimated 25% reduction in the number of lines of test code....

  7. SmartUnit: Empirical Evaluations for Automated Unit Testing of Embedded Software in Industry

    OpenAIRE

    Zhang, Chengyu; Yan, Yichen; Zhou, Hanru; Yao, Yinbo; Wu, Ke; Su, Ting; Miao, Weikai; Pu, Geguang

    2018-01-01

    In this paper, we aim at the automated unit coverage-based testing for embedded software. To achieve the goal, by analyzing the industrial requirements and our previous work on automated unit testing tool CAUT, we rebuild a new tool, SmartUnit, to solve the engineering requirements that take place in our partner companies. SmartUnit is a dynamic symbolic execution implementation, which supports statement, branch, boundary value and MC/DC coverage. SmartUnit has been used to test more than one...

  8. Diagnostics of Technical Condition of Gear Units of Belt Conveyors for the Aggregate of Methods of Nondestructive Testing

    Science.gov (United States)

    Kuzin, Evgeny G.; Gerike, Boris L.; Drozdenko, Yuriy V.; Lupiy, Michael G.; Grigoryeva, Natalya V.

    2017-10-01

    The article reviews the issues of complex use of methods of technical diagnostics of gearboxes for belt conveyors, with the aim of creating an effective system of maintenance. The article is showing the results of the evaluation of the technical condition of the drives of belt conveyors based on vibration monitoring and thermal parameters, and analysis of lubricating oil.

  9. Mastering Unit testing using Mockito and JUnit

    CERN Document Server

    Acharya, Sujoy

    2014-01-01

    A practical and easy-to-follow, yet comprehensive, guide to learning advanced JUnit testing. Each topic is explained and placed in context, and for the more inquisitive, there are more details of the concepts used. This book is for you if you are a developer with some experience in Java application development as well as a basic knowledge of JUnit testing. But for those whose skill set is void of any prior experience with JUnit testing, the book also covers basic fundamentals to get you acquainted with the concepts before putting them into practise.

  10. Proton Testing of Advanced Stellar Compass Digital Processing Unit

    DEFF Research Database (Denmark)

    Thuesen, Gøsta; Denver, Troelz; Jørgensen, Finn E

    1999-01-01

    The Advanced Stellar Compass Digital Processing Unit was radiation tested with 300 MeV protons at Proton Irradiation Facility (PIF), Paul Scherrer Institute, Switzerland.......The Advanced Stellar Compass Digital Processing Unit was radiation tested with 300 MeV protons at Proton Irradiation Facility (PIF), Paul Scherrer Institute, Switzerland....

  11. Gear ratting noise reduction of diesel engine; Diesel engine no gear hauchi soon teigen

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, S; Miura, Y [Hino Motors, Ltd., Tokyo (Japan)

    1997-10-01

    Gear raffling noise of diesel engine at idling condition is required to reduce for keeping quiet environment and comfort of driver and passengers on track and bus. Decrease of gear backlash is generally adopted for reducing gear rattling noise. On the other hand, it has been found that newly devised measurement of gear teeth speed and gear meshing error has clarified phenomena of gear rattling between the crankshaft gear and the camshaft gear of the diesel engine. And it has been also found that gear ratting noise is reduced by changing meshing between the crankshaft gear and the camshaft gear. 2 refs., 10 figs.

  12. Apollo telescope mount thermal systems unit thermal vacuum test

    Science.gov (United States)

    Trucks, H. F.; Hueter, U.; Wise, J. H.; Bachtel, F. D.

    1971-01-01

    The Apollo Telescope Mount's thermal systems unit was utilized to conduct a full-scale thermal vacuum test to verify the thermal design and the analytical techniques used to develop the thermal mathematical models. Thermal vacuum test philosophy, test objectives configuration, test monitoring, environment simulation, vehicle test performance, and data correlation are discussed. Emphasis is placed on planning and execution of the thermal vacuum test with particular attention on problems encountered in conducting a test of this maguitude.

  13. 46 CFR 28.885 - Cargo gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire rope...

  14. Technique for unit testing of safety software verification and validation

    International Nuclear Information System (INIS)

    Li Duo; Zhang Liangju; Feng Junting

    2008-01-01

    The key issue arising from digitalization of the reactor protection system for nuclear power plant is how to carry out verification and validation (V and V), to demonstrate and confirm the software that performs reactor safety functions is safe and reliable. One of the most important processes for software V and V is unit testing, which verifies and validates the software coding based on concept design for consistency, correctness and completeness during software development. The paper shows a preliminary study on the technique for unit testing of safety software V and V, focusing on such aspects as how to confirm test completeness, how to establish test platform, how to develop test cases and how to carry out unit testing. The technique discussed here was successfully used in the work of unit testing on safety software of a digital reactor protection system. (authors)

  15. Unit testing as a teaching tool in higher education

    Directory of Open Access Journals (Sweden)

    Peláez Canek

    2016-01-01

    Full Text Available Unit testing in the programming world has had a profound impact in the way modern complex systems are developed. Many Open Source and Free Software projects encourage (and in some cases, mandate the use of unit tests for new code submissions, and many software companies around the world have incorporated unit testing as part of their standard developing practices. And although not all software engineers use them, very few (if at all object their use. However, there is almost no research available pertaining the use of unit tests as a teaching tool in introductory programming courses. I have been teaching introductory programming courses in the Computer Sciences program at the Sciences Faculty in the National Autonomous University of Mexico for almost ten years, and since 2013 I have been using unit testing as a teaching tool in those courses. The intent of this paper is to discuss the results of this experience.

  16. Engagement of Metal Debris into a Gear Mesh

    Science.gov (United States)

    Handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock, and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  17. Wear of Spur Gears Having a Dithering Motion and Lubricated with a Perfluorinated Polyether Grease

    Science.gov (United States)

    Krantz, Timothy; Oswald, Fred; Handschuh, Robert

    2007-01-01

    Gear contact surface wear is one of the important failure modes for gear systems. Dedicated experiments are required to enable precise evaluations of gear wear for a particular application. The application of interest for this study required evaluation of wear of gears lubricated with a grade 2 perfluorinated polyether grease and having a dithering (rotation reversal) motion. Experiments were conducted using spur gears made from AISI 9310 steel. Wear was measured using a profilometer at test intervals encompassing 10,000 to 80,000 cycles of dithering motion. The test load level was 1.1 GPa maximum Hertz contact stress at the pitch-line. The trend of total wear as a function of test cycles was linear, and the wear depth rate was approximately 1.2 nm maximum wear depth per gear dithering cycle. The observed wear rate was about 600 times greater than the wear rate for the same gears operated at high speed and lubricated with oil.

  18. Correlation of Gear Surface Fatigue Lives to Lambda Ratio (Specific Film Thickness)

    Science.gov (United States)

    Krantz, Timothy Lewis

    2013-01-01

    The effect of the lubrication regime on gear performance has been recognized, qualitatively, for decades. Often the lubrication regime is characterized by the specific film thickness being the ratio of lubricant film thickness to the composite surface roughness. Three studies done at NASA to investigate gearing pitting life are revisited in this work. All tests were done at a common load. In one study, ground gears were tested using a variety of lubricants that included a range of viscosities, and therefore the gears operated with differing film thicknesses. In a second and third study, the performance of gears with ground teeth and superfinished teeth were assessed. Thicker oil films provided longer lives as did improved surface finish. These datasets were combined into a common dataset using the concept of specific film thickness. This unique dataset of more 258 tests provides gear designers with some qualitative information to make gear design decisions.

  19. Investigation of the Maximum Spin-Up Coefficients of Friction Obtained During Tests of a Landing Gear Having a Static-Load Rating of 20,000 Pounds

    Science.gov (United States)

    Batterson, Sidney A.

    1959-01-01

    An experimental investigation was made at the Langley landing loads track to obtain data on the maximum spin-up coefficients of friction developed by a landing gear having a static-load rating of 20,000 pounds. The forward speeds ranged from 0 to approximately 180 feet per second and the sinking speeds, from 2.7 feet per second to 9.4 feet per second. The results indicated the variation of the maximum spin-up coefficient of friction with forward speed and vertical load. Data obtained during this investigation are also compared with some results previously obtained for nonrolling tires to show the effect of forward speed.

  20. Automatic TV X-ray unit for testing aluminium castings

    International Nuclear Information System (INIS)

    Morgunov, V.I.; Firstov, V.G.; Kisin, V.I.; Savostenok, M.I.

    1989-01-01

    The automatic TV X-ray unit for testing of aluminum alloy castings in a flow is described. The unit includes RAP-150/300 X-ray apparatus and PI-60TK TV X-ray device. The biological protection chamber and the common control board are the main functional units. The tests of the unit have shown that as regards its characteristics it is not worse than its foreign-made analogues, for example, devices of the DP-35 and DP-38 type of the 'Seifert' company

  1. The comparison of the unit test tools JUnit and TestNG

    OpenAIRE

    Šarkanj, Aleš

    2011-01-01

    Testing holds an important role in developing software. It is a process ensuring software works as expected. An important part of testing is unit testing as the basic testing level. The purpose of this thesis is comparing JUnit and TestNG, two of the most popular unit testing tools in Java. In the first part we will present testing and its purpose within software development. We will also present the basic terminology and levels of testing. Further on the area of unit testing will be pr...

  2. Quick setup of test unit for accelerator control system

    International Nuclear Information System (INIS)

    Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S.; Morris, J.

    2011-01-01

    Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.

  3. Hybrid Gear Performance Under Loss-of-Lubrication Conditions

    Science.gov (United States)

    Laberge, Kelsen E.; Berkebile, Stephen P.; Handschuh, Robert F.; Roberts, Gary D.

    2017-01-01

    Hybrid composite gear technology is being investigated to increase power density in rotorcraft drive systems. These gears differ from conventional steel gears in that the structural web material is replaced with a lightweight carbon fiber composite. Past studies have focused on performance of this technology under normal operating conditions, however, for this technology to be viable it must also withstand adverse conditions. The study presented here evaluates the performance of hybrid gears under loss-of-lubrication conditions in NASA Glenn Research Centers Contact Fatigue Test Facility. Two experiments are presented using small-scale 3.5 inch (8.9 cm) pitch diameter hybrid gears and compared to a baseline steel gear pair. Results of these tests show that there are limitations to the use of a hexagonal interlock pattern between the steel and composite. There is also evidence that the presence of polymer in the gear during an oil out event has a potential to increase time to failure. Further studies are planned to expand on these initial findings.

  4. Improving Size and Power in Unit Root Testing

    DEFF Research Database (Denmark)

    Haldrup, Niels; Jansson, Michael

    A frequent criticism of unit root tests concerns the poor power and size properties that many of such testsexhibit. However, the past decade or so intensive research has been conducted to alleviate these problems and great advances have been made. The present paper provides a selective survey...... of recent contributions to improve upon both size and power of unit root tests and in so doing the approach of using rigorous statistical optimality criteria in the development of such tests is stressed. In addition to presenting tests where improved size can be achieved by modifying the standard Dickey......-Fuller class of tests, the paper presents theory of optimal testing and the construction of power envelopes for unit root tests underdifferent conditions allowing for serial correlation, deterministic components, assumptions regarding the initial condition, non-Gaussian errors, and the use of covariates....

  5. A simple nonstationary-volatility robust panel unit root test

    NARCIS (Netherlands)

    Demetrescu, Matei; Hanck, Christoph

    2012-01-01

    We propose an IV panel unit root test robust to nonstationary error volatility. Its finite-sample performance is convincing even for many units and strong cross-correlation. An application to GDP prices illustrates the inferential impact of nonstationary volatility. (C) 2012 Elsevier B.V. All rights

  6. A New Symmetrical Unit for Breakwater Armour : First Tests

    NARCIS (Netherlands)

    Salauddin, M.; Broere, A.; Van der Meer, J.W.; Verhagen, H.J.; Bijl, E.

    2015-01-01

    A new and symmetrical single layer armour unit, the crablock, has been designed in the UAE. One breakwater was reconstructed with crablock, but very limited testing had been performed. Just to become more acquainted with this new unit, pre-competitive research at a university has been performed,

  7. Integration testing through reusing representative unit test cases for high-confidence medical software.

    Science.gov (United States)

    Shin, Youngsul; Choi, Yunja; Lee, Woo Jin

    2013-06-01

    As medical software is getting larger-sized, complex, and connected with other devices, finding faults in integrated software modules gets more difficult and time consuming. Existing integration testing typically takes a black-box approach, which treats the target software as a black box and selects test cases without considering internal behavior of each software module. Though it could be cost-effective, this black-box approach cannot thoroughly test interaction behavior among integrated modules and might leave critical faults undetected, which should not happen in safety-critical systems such as medical software. This work anticipates that information on internal behavior is necessary even for integration testing to define thorough test cases for critical software and proposes a new integration testing method by reusing test cases used for unit testing. The goal is to provide a cost-effective method to detect subtle interaction faults at the integration testing phase by reusing the knowledge obtained from unit testing phase. The suggested approach notes that the test cases for the unit testing include knowledge on internal behavior of each unit and extracts test cases for the integration testing from the test cases for the unit testing for a given test criteria. The extracted representative test cases are connected with functions under test using the state domain and a single test sequence to cover the test cases is produced. By means of reusing unit test cases, the tester has effective test cases to examine diverse execution paths and find interaction faults without analyzing complex modules. The produced test sequence can have test coverage as high as the unit testing coverage and its length is close to the length of optimal test sequences. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  9. Nearly Efficient Likelihood Ratio Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael; Nielsen, Morten Ørregaard

    Seemingly absent from the arsenal of currently available "nearly efficient" testing procedures for the unit root hypothesis, i.e. tests whose local asymptotic power functions are indistinguishable from the Gaussian power envelope, is a test admitting a (quasi-)likelihood ratio interpretation. We...... show that the likelihood ratio unit root test derived in a Gaussian AR(1) model with standard normal innovations is nearly efficient in that model. Moreover, these desirable properties carry over to more complicated models allowing for serially correlated and/or non-Gaussian innovations....

  10. Analysis of justification for applying two gear sets within the universal gear reducers

    OpenAIRE

    Rackov Milan; Kuzmanović Siniša; Knežević Ivan; Čavić Maja; Penčić Marko

    2017-01-01

    In the area of universal gear reducers, standard does not prescribe relations between load capacity, gear ratios and axis heights. Therefore, larger load capacity of some gear reducers manufacturers has advantage for lower gear ratio and, vice versa, smaller load capacity of the gearbox achieves higher values of gear ratio. However, there are some manufacturers who produce gear reducers with smaller or larger load capacity for higher or lower gear ratio, within the same axis height. This pape...

  11. Four-gear strata tiltmeter. Evaluation of resolution capacity

    Energy Technology Data Exchange (ETDEWEB)

    Balhar, M.

    1984-01-01

    Provides condensed technical characteristics of a four-gear NPS-1 tiltmeter with high resolution. Unit is necessary to determine azimuths and drop angles of strata. Also provides a summarized substantiation of the focusing micro-unit of the tiltmeter. Based on measurements carried out on a turntable and a model borehole, potential errors in determining stratification features were established.

  12. Interlocking Molecular Gear Chains Built on Surfaces.

    Science.gov (United States)

    Zhao, Rundong; Qi, Fei; Zhao, Yan-Ling; Hermann, Klaus E; Zhang, Rui-Qin; Van Hove, Michel A

    2018-05-17

    Periodic chains of molecular gears in which molecules couple with each other and rotate on surfaces have been previously explored by us theoretically using ab initio simulation tools. On the basis of the knowledge and experience gained about the interactions between neighboring molecular gears, we here explore the transmission of rotational motion and energy over larger distances, namely, through a longer chain of gear-like passive "slave" molecules. Such microscopic gears exhibit quite different behaviors compared to rigid cogwheels in the macroscopic world due to their structural flexibility affecting intermolecular interaction. Here, we investigate the capabilities of such gear chains and reveal the mechanisms of the transmission process in terms of both quantum-level density functional theory (DFT) and simple classical mechanics. We find that the transmission of rotation along gear chains depends strongly on the gear-gear distance: short distances can cause tilting of gears and even irregular "creep-then-jump" (or "stick-slip") motion or expulsion of gears; long gear-gear distances cause weak coupling between gears, slipping and skipping. More importantly, for transmission of rotation at intermediate gear-gear distances, our modeling clearly exhibits the relative roles of several important factors: flexibility of gear arms, axles, and supports, as well as resulting rotational delays, slippages, and thermal and other effects. These studies therefore allow better informed design of future molecular machine components involving motors, gears, axles, etc.

  13. Five-Axis Milling of Large Spiral Bevel Gears: Toolpath Definition, Finishing, and Shape Errors

    Directory of Open Access Journals (Sweden)

    Álvaro Álvarez

    2018-05-01

    Full Text Available In this paper, a five-axis machining process is analyzed for large spiral-bevel gears, an interesting process for one-of-kind manufacturing. The work is focused on large sized spiral bevel gears manufacturing using universal multitasking machines or five-axis milling centers. Different machining strategies, toolpath patterns, and parameters are tested for both gear roughing and finishing operations. Machining time, tools’ wear, and gear surface are analyzed in order to determine which are the best strategies and parameters for large modulus gear manufacturing on universal machines. The case study results are discussed in the last section, showing the capacity of a universal five-axis milling for this niche. Special attention was paid to the possible affectations of the metal surfaces, since gear durability is very sensitive to thermo-mechanical damage, affected layers, and flank gear surface state.

  14. Feedforward Control of Gear Mesh Vibration Using Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Gerald T. Montague

    1994-01-01

    Full Text Available This article presents a novel means for suppressing gear mesh related vibrations. The key components in this approach are piezoelectric actuators and a high-frequency, analog feed forward controller. Test results are presented and show up to a 70% reduction in gear mesh acceleration and vibration control up to 4500 Hz. The principle of the approach is explained by an analysis of a harmonically excited, general linear vibratory system.

  15. Development in Geared Turbofan Aeroengine

    Science.gov (United States)

    Mohd Tobi, A. L.; Ismail, A. E.

    2016-05-01

    This paper looks into the implementation of epicyclic gear system to the aeroengine in order to increase the efficiency of the engine. The improvement made is in the direction of improving fuel consumption, reduction in pollutant gasses and perceived noise. Introduction of epicyclic gear system is capable to achieve bypass ratio of up to 15:1 with the benefits of weight and noise reduction. Radical new aircraft designs and engine installation are being studied to overcome some of the challenges associated with the future geared turbofan and open-rotor engine.

  16. Commercial landscape of noninvasive prenatal testing in the United States.

    Science.gov (United States)

    Agarwal, Ashwin; Sayres, Lauren C; Cho, Mildred K; Cook-Deegan, Robert; Chandrasekharan, Subhashini

    2013-06-01

    Cell-free fetal DNA-based noninvasive prenatal testing (NIPT) could significantly change the paradigm of prenatal testing and screening. Intellectual property (IP) and commercialization promise to be important components of the emerging debate about clinical implementation of these technologies. We have assembled information about types of testing, prices, turnaround times, and reimbursement of recently launched commercial tests in the United States from the trade press, news articles, and scientific, legal, and business publications. We also describe the patenting and licensing landscape of technologies underlying these tests and ongoing patent litigation in the United States. Finally, we discuss how IP issues may affect clinical translation of NIPT and their potential implications for stakeholders. Fetal medicine professionals (clinicians and researchers), genetic counselors, insurers, regulators, test developers, and patients may be able to use this information to make informed decisions about clinical implementation of current and emerging noninvasive prenatal tests. © 2013 John Wiley & Sons, Ltd.

  17. Charge-Control Unit for Testing Lithium-Ion Cells

    Science.gov (United States)

    Reid, Concha M.; Mazo, Michelle A.; Button, Robert M.

    2008-01-01

    A charge-control unit was developed as part of a program to validate Li-ion cells packaged together in batteries for aerospace use. The lithium-ion cell charge-control unit will be useful to anyone who performs testing of battery cells for aerospace and non-aerospace uses and to anyone who manufacturers battery test equipment. This technology reduces the quantity of costly power supplies and independent channels that are needed for test programs in which multiple cells are tested. Battery test equipment manufacturers can integrate the technology into their battery test equipment as a method to manage charging of multiple cells in series. The unit manages a complex scheme that is required for charging Li-ion cells electrically connected in series. The unit makes it possible to evaluate cells together as a pack using a single primary test channel, while also making it possible to charge each cell individually. Hence, inherent cell-to-cell variations in a series string of cells can be addressed, and yet the cost of testing is reduced substantially below the cost of testing each cell as a separate entity. The unit consists of electronic circuits and thermal-management devices housed in a common package. It also includes isolated annunciators to signal when the cells are being actively bypassed. These annunciators can be used by external charge managers or can be connected in series to signal that all cells have reached maximum charge. The charge-control circuitry for each cell amounts to regulator circuitry and is powered by that cell, eliminating the need for an external power source or controller. A 110-VAC source of electricity is required to power the thermal-management portion of the unit. A small direct-current source can be used to supply power for an annunciator signal, if desired.

  18. Research on Gear Shifting Process without Disengaging Clutch for a Parallel Hybrid Electric Vehicle Equipped with AMT

    Directory of Open Access Journals (Sweden)

    Hui-Long Yu

    2014-01-01

    Full Text Available Dynamic models of a single-shaft parallel hybrid electric vehicle (HEV equipped with automated mechanical transmission (AMT were described in different working stages during a gear shifting process without disengaging clutch. Parameters affecting the gear shifting time, components life, and gear shifting jerk in different transient states during a gear shifting process were deeply analyzed. The mathematical models considering the detailed synchronizer working process which can explain the gear shifting failure, long time gear shifting, and frequent synchronizer failure phenomenon in HEV were derived. Dynamic coordinated control strategy of the engine, motor, and actuators in different transient states considering the detailed working stages of synchronizer in a gear shifting process of a HEV is for the first time innovatively proposed according to the state of art references. Bench test and real road test results show that the proposed control strategy can improve the gear shifting quality in all its evaluation indexes significantly.

  19. The Road Side Unit for the A270 Test Site

    NARCIS (Netherlands)

    Passchier, I.; Driessen, B.J.F.; Heijligers, B.M.R.; Netten, B.D.; Schackmann, P.P.M.

    2011-01-01

    The design and implementation of the Road Side Unit for the A270 Test Site is presented. It consists of a sensor platform and V2I communication platform with full coverage of the test site. A service platform enables applications to make use of these facilities. The RSU will be used both for the

  20. Critical values for unit root tests in seasonal time series

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); B. Hobijn (Bart)

    1997-01-01

    textabstractIn this paper, we present tables with critical values for a variety of tests for seasonal and non-seasonal unit roots in seasonal time series. We consider (extensions of) the Hylleberg et al. and Osborn et al. test procedures. These extensions concern time series with increasing seasonal

  1. United States nuclear tests, July 1945 through September 1992

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    This document lists chronologically and alphabetically by name all nuclear tests and simultaneous detonations conducted by the United States from July 1945 through September 1992. Several tests conducted during Operation Dominic involved missile launches from Johnston Atoll. Several of these missile launches were aborted, resulting in the destruction of the missile and nuclear device either on the pad or in the air.

  2. The missing link? Testing a schema account of unitization.

    Science.gov (United States)

    Tibon, Roni; Greve, Andrea; Henson, Richard

    2018-05-09

    Unitization refers to the creation of a new unit from previously distinct items. The concept of unitization has been used to explain how novel pairings between items can be remembered without requiring recollection, by virtue of new, item-like representations that enable familiarity-based retrieval. We tested an alternative account of unitization - a schema account - which suggests that associations between items can be rapidly assimilated into a schema. We used a common operationalization of "unitization" as the difference between two unrelated words being linked by a definition, relative to two words being linked by a sentence, during an initial study phase. During the following relearning phase, a studied word was re-paired with a new word, either related or unrelated to the original associate from study. In a final test phase, memory for the relearned associations was tested. We hypothesized that, if unitized representations act like schemas, then we would observe some generalization to related words, such that memory would be better in the definition than sentence condition for related words, but not for unrelated words. Contrary to the schema hypothesis, evidence favored the null hypothesis of no difference between definition and sentence conditions for related words (Experiment 1), even when each cue was associated with multiple associates, indicating that the associations can be generalized (Experiment 2), or when the schematic information was explicitly re-activated during Relearning (Experiment 3). These results suggest that unitized associations do not generalize to accommodate new information, and therefore provide evidence against the schema account.

  3. 29 CFR 1918.54 - Rigging gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees from...

  4. Zeroing and testing units developed for Gerdien atmospheric ion detectors

    International Nuclear Information System (INIS)

    Kolarz, P.; Marinkovic, B.P.; Filipovic, D.M.

    2005-01-01

    Low current measurements in atmospheric ion detection using a Gerdien condenser are subjected to numerous sources of error. Zeroing and testing units described in this article, connected as modules to this type of detector, enable some of these errors to be found and eliminated. The zeroing unit provides digital compensation of the zero drift with a digital sample and hold circuit of 12-bit resolution. It overcomes difficulties related to zero drift and techniques used in the zero conductivity determination when the accelerating potential or airflow rate are zero. The testing unit is a current reference of nominally 10 -12 A intended for testing and correcting the system on current leakage and other measuring deviations due to changes in atmospheric parameters. This unit is an independent battery-powered module, which provides a charge of 10 -12 C per cycle (frequency of order 1 Hz) to the collecting electrode. The control of Gerdien devices is substantially simplified using the zeroing and testing units realized here. Both units are used during 'zero conductivity' regime only

  5. 50 CFR 648.84 - Gear-marking requirements and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear-marking requirements and gear... Management Measures for the NE Multispecies and Monkfish Fisheries § 648.84 Gear-marking requirements and gear restrictions. (a) Bottom-tending fixed gear, including, but not limited to, gillnets and longlines...

  6. Modelling the Meshing of Cycloidal Gears

    Directory of Open Access Journals (Sweden)

    Nachimowicz Jerzy

    2016-06-01

    Full Text Available Cycloidal drives belong to the group of planetary gear drives. The article presents the process of modelling a cycloidal gear. The full profile of the planetary gear is determined from the following parameters: ratio of the drive, eccentricity value, the equidistant (ring gear roller radius, epicycloid reduction ratio, roller placement diameter in the ring gear. Joong-Ho Shin’s and Soon-Man Kwon’s article (Shin and Know, 2006 was used to determine the profile outline of the cycloidal planetary gear lobes. The result was a scatter chart with smooth lines and markers, presenting the full outline of the cycloidal gear.

  7. Experimental Evaluation of a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter

    2011-01-01

    This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...... and inductances are all in line with finite element calculations. However very high rotational losses are present in the prototype and these losses are higher than the calculations. Some of the losses are present due to poor aspects in the fabrication of the prototype, while others are identified to be caused...... by a non optimal diameter/length aspect ratio. The torque density is superior, the copper losses is only a fraction of the copper losses in other traction motors. With the proposed aspects to reduce the rotational losses is it believed that the unit has a great potential....

  8. The Selected Problems of Studies of Aircraft Landing Gear

    Directory of Open Access Journals (Sweden)

    Rośkowicz Marek

    2016-12-01

    Full Text Available The article portrays the results of experimental studies conducted in the field of static strength test of main landing gear of lightweight aircraft as well as in the area of establishing the pneumatic tyre characteristics of main landing gear. The studies were carried out in compliance with methodologies of performing studies for the purposes of solutions implemented in aviation structures. It was stated that static strength tests of landing gear should not be done with the use of shock absorbers, due to the fact that this element, distinguished by high viscoelastic properties, by being statically loaded, is subject to displacements that do not occur during normal operation of the aircraft. Excessive displacements of shock absorber result in the load distribution in other landing gear elements being incompatible with project assumptions, which in turn leads to this strength test being interrupted, bearing in mind significantly lower loads than anticipated. It was also concluded that in order to determine pneumatic tyre characteristics it is not necessary to carry out tests on the whole landing gear strut, because the results obtained in the compression test of the wheel itself with pneumatic tyre are identical as the results acquired during tests conducted in accordance with methodology. Test preparation process with the use of the wheel itself and its realization is less time-consuming, less expensive and does not entail the necessity to build complex test stands.

  9. Integrating Oil Debris and Vibration Gear Damage Detection Technologies Using Fuzzy Logic

    Science.gov (United States)

    Dempsey, Paula J.; Afjeh, Abdollah A.

    2002-01-01

    A diagnostic tool for detecting damage to spur gears was developed. Two different measurement technologies, wear debris analysis and vibration, were integrated into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual measurement technologies. This diagnostic tool was developed and evaluated experimentally by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spur Gear Fatigue Test Rig. Experimental data were collected during experiments performed in this test rig with and without pitting. Results show combining the two measurement technologies improves the detection of pitting damage on spur gears.

  10. Testing the efficiency of the wine market using unit root tests with sharp and smooth breaks

    Directory of Open Access Journals (Sweden)

    Elie Bouri

    2017-12-01

    Full Text Available This paper examines the efficient market hypothesis for the wine market using a novel unit root test while accounting for sharp shifts and smooth breaks in the monthly data. We find evidence of structural shifts and nonlinearity in the wine indices. Contrary to the results from conventional linear unit root tests, when we account for sharp shifts and smooth breaks, the unit root null for each of the wine indices has been rejected. Overall, our results suggest that the wine market is inefficient when we incorporate breaks. We provide some practical and policy implications of our findings. Keywords: Wine market, Efficiency, Sharp and smooth breaks, Unit root tests

  11. Thermal Behavior of Aerospace Spur Gears in Normal and Loss-of-Lubrication Conditions

    Science.gov (United States)

    Handschuh, Robert F.

    2015-01-01

    Testing of instrumented spur gears operating at aerospace rotorcraft conditions was conducted. The instrumented gears were operated in a normal and in a loss-of-lubrication environment. Thermocouples were utilized to measure the temperature at various locations on the test gears and a test utilized a full-field, high-speed infrared thermal imaging system. Data from thermocouples was recorded during all testing at 1 hertz. One test had the gears shrouded and a second test was run without the shrouds to permit the infrared thermal imaging system to take data during loss-of-lubrication operation. Both tests using instrumented spur gears were run in normal and loss-of-lubrication conditions. Also the result from four other loss-of-lubrication tests will be presented. In these tests two different torque levels were used while operating at the same rotational speed (10000 revolutions per minute).

  12. STATIC TESTS OF UNCONVENTIONAL PROPULSION UNITS FOR ULTRALIGHT AIRPLANES

    Directory of Open Access Journals (Sweden)

    Martin Helmich

    2014-06-01

    Full Text Available This paper presents static tests of a new unconventional propulsion unit for small aviation airplanes. Our laboratory stand – a fan drive demonstrator – enables us to compare various design options. We performed experiments to verify the propulsion functionality and a measurement procedure to determine the available thrust of the propulsion unit and its dependence on engine speed. The results used for subsequent optimization include the operating parameters of the propulsion unit, and the temperature and velocity fields in parts of the air duct.

  13. Testing of motor unit synchronization model for localized muscle fatigue.

    Science.gov (United States)

    Naik, Ganesh R; Kumar, Dinesh K; Yadav, Vivek; Wheeler, Katherine; Arjunan, Sridhar

    2009-01-01

    Spectral compression of surface electromyogram (sEMG) is associated with onset of localized muscle fatigue. The spectral compression has been explained based on motor unit synchronization theory. According to this theory, motor units are pseudo randomly excited during muscle contraction, and with the onset of muscle fatigue the recruitment pattern changes such that motor unit firings become more synchronized. While this is widely accepted, there is little experimental proof of this phenomenon. This paper has used source dependence measures developed in research related to independent component analysis (ICA) to test this theory.

  14. Gear wear monitoring by modulation signal bispectrum based on motor current signal analysis

    Science.gov (United States)

    Zhang, Ruiliang; Gu, Fengshou; Mansaf, Haram; Wang, Tie; Ball, Andrew D.

    2017-09-01

    Gears are important mechanical components for power transmissions. Tooth wear is one of the most common failure modes, which can present throughout a gear's lifetime. It is significant to accurately monitor gear wear progression in order to take timely predictive maintenances. Motor current signature analysis (MCSA) is an effective and non-intrusive approach which is able to monitor faults from both electrical and mechanical systems. However, little research has been reported in monitoring the gear wear and estimating its severity based on MCSA. This paper presents a novel gear wear monitoring method through a modulation signal bispectrum based motor current signal analysis (MSB-MCSA). For a steady gear transmission, it is inevitable to exist load and speed oscillations due to various errors including wears. These oscillations can induce small modulations in the current signals of the driving motor. MSB is particularly effective in characterising such small modulation signals. Based on these understandings, the monitoring process was implemented based on the current signals from a run-to-failure test of an industrial two stages helical gearbox under a moderate accelerated fatigue process. At the initial operation of the test, MSB analysis results showed that the peak values at the bifrequencies of gear rotations and the power supply can be effective monitoring features for identifying faulty gears and wear severity as they exhibit agreeable changes with gear loads. A monotonically increasing trend established by these features allows a clear indication of the gear wear progression. The dismantle inspection at 477 h of operation, made when one of the monitored features is about 123% higher than its baseline, has found that there are severe scuffing wear marks on a number of tooth surfaces on the driving gear, showing that the gear endures a gradual wear process during its long test operation. Therefore, it is affirmed that the MSB-MSCA approach proposed is reliable

  15. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    Science.gov (United States)

    Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

    2011-01-01

    An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.

  16. Getting into Gear

    Science.gov (United States)

    Cobbs, Georgia A.; Cranor-Buck, Edith

    2011-01-01

    This article describes a particular activity, the Motorized Toy unit, which supports science, technology, engineering, and mathematics (STEM) goals and teaches students the basic concept of ratio. The unit addresses both mathematics and science standards and is part of a team-teaching activity. The unit comes from a curriculum titled A World In…

  17. Performance Investigation of a Full-Scale Hybrid Composite Bull Gear

    Science.gov (United States)

    LaBerge, Kelsen; Handschuh, Robert; Roberts, Gary; Thorp, Scott

    2016-01-01

    Hybrid composite gears have been investigated as a weight saving technology for rotorcraft transmissions. These gears differ from conventional steel gears in that the structural material between the shaft interface and the gear rim is replaced with a lightweight carbon fiber composite. The work discussed here is an extension of previous coupon level hybrid gear tests to a full-scale bull gear. The NASA Glenn Research Center High-Speed Helical Gear Rig was modified for this program allowing several hybrid gear web configurations to be tested while utilizing the same gear rim. Testing was performed on both a baseline (steel) web configuration and a hybrid (steel-composite)configuration. Vibration, orbit and temperature data were recorded and compared between configurations. Vibration levels did not differ greatly between the hybrid and steel configurations, nor did temperature differential between inlet and outlet. While orbit shape displayed differences between the hybrid and baseline configurations, the general overall amplitude was comparable. The hybrid configuration discussed here successfully ran at 3300 hp(2,460 kW), however, progressive growth of the orbit while running at this test condition discontinued the test. Researchers continue to search for the cause of this orbit shift.

  18. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test

    OpenAIRE

    Jan Banach; Mirosława Cieślicka; Radosław Muszkieta; Walery Zukow; Robert Stępniak

    2015-01-01

    Banach Jan, Cieślicka Mirosława, Muszkieta Radosław, Zukow Walery, Stępniak Robert. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test. Journal of Education, Health and Sport. 2015;5(5):445-462. ISSN 2391-8306. DOI 10.5281/zenodo.18157 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%285%29%3A445-462 https://pbn.nauka.gov.pl/work...

  19. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test

    OpenAIRE

    Banach, Jan; Cieślicka, Mirosława; Muszkieta, Radosław; Zukow, Walery; Stępniak, Robert

    2015-01-01

    Banach Jan, Cieślicka Mirosława, Muszkieta Radosław, Zukow Walery, Stępniak Robert. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test. Journal of Education, Health and Sport. 2015;5(5):445-462. ISSN 2391-8306. DOI 10.5281/zenodo.18157 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%285%29%3A445-462 https://pbn.nauka.gov.pl/work...

  20. Unit Testing for the Application Control Language (ACL) Software

    Science.gov (United States)

    Heinich, Christina Marie

    2014-01-01

    In the software development process, code needs to be tested before it can be packaged for release in order to make sure the program actually does what it says is supposed to happen as well as to check how the program deals with errors and edge cases (such as negative or very large numbers). One of the major parts of the testing process is unit testing, where you test specific units of the code to make sure each individual part of the code works. This project is about unit testing many different components of the ACL software and fixing any errors encountered. To do this, mocks of other objects need to be created and every line of code needs to be exercised to make sure every case is accounted for. Mocks are important to make because it gives direct control of the environment the unit lives in instead of attempting to work with the entire program. This makes it easier to achieve the second goal of exercising every line of code.

  1. Treatability test plan for the 200-ZP-1 operable unit

    International Nuclear Information System (INIS)

    1994-07-01

    This document presents the treatability test plan for pilot-scale pump and treat testing at the 200-ZP-1 Operable Unit. The approach discussed in this treatability test plan is to conduct a pilot-scale pump and treat test for the contaminant plume associated with the 200-ZP-1 Operable Unit. The primary contaminants of concern are carbon tetrachloride, chloroform, and trichloroethylene (TCE). The pilot-scale treatability testing has as its primary purpose to assess the performance of aboveground treatment systems with respect to the ability to remove the primary contaminants present in groundwater withdrawn from the contaminant plume. The overall scope of this test plan includes: description of the pump and treat system to be tested, as well as the test performance objectives and data quality objectives (DQOs) that will be used to evaluate the effectiveness of the pilot-scale treatment system; discussion of the treatment technology to be tested and supporting development activities, including process flow and conceptual design descriptions and equipment, fabrication, utility, and system startup needs; description of pilot-scale treatment system performance, operating procedures, and operational controls, as well as anticipated monitoring activities, analytes, parameters, analytical procedures, and quality assurance protocols; summaries of other related treatability testing elements, including personnel and environmental health and safety controls, process and secondary waste management and disposition, schedule, and program organization

  2. LHC preparations change gear

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    After the formal approval by CERN Council in December (January, page 1) of the LHC protonproton collider for CERN's 27- kilometre LEP tunnel, preparations for the new machine change gear. Lyndon Evans becomes LHC Project Leader, and CERN's internal structure will soon be reorganized to take account of the project becoming a definite commitment. On the experimental side, the full Technical Proposals for the big general purpose ATLAS and CMS detectors were aired at a major meeting of the LHC Committee at CERN in January. These Technical Proposals are impressive documents each of some several hundred pages. (Summaries of the detector designs will appear in forthcoming issues of the CERN Courier.) The ALICE heavy ion experiment is not far behind, and plans for other LHC experiments are being developed. Playing an important role in this groundwork has been the Detector Research and Development Committee (DRDC), founded in 1990 to foster detector development for the LHC experimental programme and structured along the lines of a traditional CERN Experiments Committee. Established under the Director Generalship of Carlo Rubbia and initially steered by Research Director Walter Hoogland, the DRDC has done sterling work in blazing a trail for LHC experiments. Acknowledging that the challenge of LHC experimentation needs technological breakthroughs as well as specific detector subsystems, DRDC proposals have covered a wide front, covering readout electronics and computing as well as detector technology. Its first Chairman was Enzo larocci, succeeded in 1993 by Michal Turala. DRDC's role was to evaluate proposals, and make recommendations to CERN's Research Board for approval and resource allocation, not an easy task when the LHC project itself had yet to be formally approved. Over the years, a comprehensive portfolio of detector development has been built up, much of which has either led to specific LHC detector subsystems for traditional detector tasks

  3. Startup physics tests at Temelin NPP, Unit 1

    International Nuclear Information System (INIS)

    Sedlacek, M.; Minarcin, M.; Toth, L.; Elko, M.; Hascik, R.

    2002-01-01

    The objective, scope and proceedings of the physics tests of Temelin NPP, Unit 1 physical commissioning are given in this paper. Furthermore, some results of selected physics tests are presented: reactor initial criticality test, determination of reactor power range for physics testing, measurement of control rod cluster assembly group no. 10 reactivity worth in case of limitation system LS(a) actuation, control rod cluster assembly system reactivity worth measurement with single rod cluster assembly of greatest reactivity worth stuck in fully withdrawn position, measurement of differential reactivity worth of control rod cluster assembly group no. 9, boron 'endpoint' determination and measurement of power reactivity coefficient (Authors)

  4. Control room habitability Analysis and Testing for Wolsong Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. B. [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    In response to this recommendation, KHNP has established CRH program and performed tracer gas in leakage tests. These activities are described herein including the emergency ventilation system analysis, acceptance criteria calculation for the test and Control Room Envelope (CRE) discrimination, and the results of the tracer gas tests are presented. CRH analysis including unfiltered in leakage tests according to the methodology in ASTM E741 was performed for Wolsong Unit 1. The results show that the integrity of the control room of Wolsong Unit 1 is in good condition to maintain the reactor in a safe condition under accident conditions, which complies with the US NRC regulatory guides 1.78, 1.196 and 1.197.

  5. Modelling of teeth of a gear transmission for modern manufacturing technologies

    Science.gov (United States)

    Monica, Z.; Banaś, W.; Ćwikla, G.; Topolska, S.

    2017-08-01

    The technological process of manufacturing of gear wheels is influenced by many factors. It is designated depending on the type of material from which the gear is to be produced, its heat treatment parameters, the required accuracy, the geometrical form and the modifications of the tooth. Therefor the parameters selection process is not easy and moreover it is unambiguous. Another important stage of the technological process is the selection of appropriate tools to properly machine teeth in the operations of both roughing and finishing. In the presented work the focus is put first of all on modern production methods of gears using technologically advanced instruments in comparison with conventional tools. Conventional processing tools such as gear hobbing cutters or Fellows gear-shaper cutters are used from the beginning of the machines for the production of gear wheels. With the development of technology and the creation of CNC machines designated for machining of gears wheel it was also developed the manufacturing technology as well as the design knowledge concerning the technological tools. Leading manufacturers of cutting tools extended the range of tools designated for machining of gears on the so-called hobbing cutters with inserted cemented carbide tips. The same have be introduced to Fellows gear-shaper cutters. The results of tests show that is advantaged to use hobbing cutters with inserted cemented carbide tips for milling gear wheels with a high number of teeth, where the time gains are very high, in relation to the use of conventional milling cutters.

  6. Hardness and microstructure analysis of damaged gear caused by adhesive wear

    Science.gov (United States)

    Mahendra, Rizky Budi; Nugroho, Sri; Ismail, Rifky

    2018-03-01

    This study was a result from research on repairing project of damaged elevator gear box. The objective of this research is to analyze the failure part on elevator gearbox at flourmill factory. The equipment was damaged after one year installed and running on factory. Severe wear was occurred on high speed helical gear. These helical gear was one of main part of elevator gearbox in flour mill manufacture. Visually, plastic deformation didn't occurred and not visible on the failure helical gear shaft. Some test would be performed to check the chemical composition, microstructure and hardness of failure helical gear. The material of failure helical gear shaft was a medium carbon steel alloy. The microstructure was showed a martensitic phase formed on the surface to the center area of gear shaft. Otherwise, the depth of hardness layer slight formed on surface and lack depth of hardness layer was a main trigger of severe wear. It was not enough to resist wear due to friction caused by rolling and sliding on surface between high speed gear and low speed gear. Enhancement of hardness layer on surface and depth of hardness layer will make the component has more long life time. Furthermore, to perform next research is needed to analyze the reliability of enhanced hardness on layer and depth of hardness layer on helical gear shaft.

  7. Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael

    This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

  8. Numerical distribution functions of fractional unit root and cointegration tests

    DEFF Research Database (Denmark)

    MacKinnon, James G.; Nielsen, Morten Ørregaard

    We calculate numerically the asymptotic distribution functions of likelihood ratio tests for fractional unit roots and cointegration rank. Because these distributions depend on a real-valued parameter, b, which must be estimated, simple tabulation is not feasible. Partly due to the presence...

  9. Unit Root Testing in Heteroscedastic Panels Using the Cauchy Estimator

    NARCIS (Netherlands)

    Demetrescu, Matei; Hanck, Christoph

    The Cauchy estimator of an autoregressive root uses the sign of the first lag as instrumental variable. The resulting IV t-type statistic follows a standard normal limiting distribution under a unit root case even under unconditional heteroscedasticity, if the series to be tested has no

  10. Stand tests of the grader unit AKD-2

    Energy Technology Data Exchange (ETDEWEB)

    Kocheskhov, S.M.; Bagley, A.V.; Shalkov, A.V.

    1982-01-01

    Results are presented of stand tests of a static operating grader designed for unmanned extraction of deep beds with programmed control of the unit AKD-2 according to hypsometry of the seam occurrence. Malfunctions in a number of grader assemblies are revealed and eliminated. Parameters are defined which characterize the kinematics and dynamics of the grader mechanism.

  11. Statistical modeling of dental unit water bacterial test kit performance.

    Science.gov (United States)

    Cohen, Mark E; Harte, Jennifer A; Stone, Mark E; O'Connor, Karen H; Coen, Michael L; Cullum, Malford E

    2007-01-01

    While it is important to monitor dental water quality, it is unclear whether in-office test kits provide bacterial counts comparable to the gold standard method (R2A). Studies were conducted on specimens with known bacterial concentrations, and from dental units, to evaluate test kit accuracy across a range of bacterial types and loads. Colony forming units (CFU) were counted for samples from each source, using R2A and two types of test kits, and conformity to Poisson distribution expectations was evaluated. Poisson regression was used to test for effects of source and device, and to estimate rate ratios for kits relative to R2A. For all devices, distributions were Poisson for low CFU/mL when only beige-pigmented bacteria were considered. For higher counts, R2A remained Poisson, but kits exhibited over-dispersion. Both kits undercounted relative to R2A, but the degree of undercounting was reasonably stable. Kits did not grow pink-pigmented bacteria from dental-unit water identified as Methylobacterium rhodesianum. Only one of the test kits provided results with adequate reliability at higher bacterial concentrations. Undercount bias could be estimated for this device and used to adjust test kit results. Insensitivity to methylobacteria spp. is problematic.

  12. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    Science.gov (United States)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  13. Effects on Diagnostic Parameters After Removing Additional Synchronous Gear Meshes

    Science.gov (United States)

    Decker, Harry J.

    2003-01-01

    Gear cracks are typically difficult to diagnose with sufficient time before catastrophic damage occurs. Significant damage must be present before algorithms appear to be able to detect the damage. Frequently there are multiple gear meshes on a single shaft. Since they are all synchronous with the shaft frequency, the commonly used synchronous averaging technique is ineffective in removing other gear mesh effects. Carefully applying a filter to these extraneous gear mesh frequencies can reduce the overall vibration signal and increase the accuracy of commonly used vibration metrics. The vibration signals from three seeded fault tests were analyzed using this filtering procedure. Both the filtered and unfiltered vibration signals were then analyzed using commonly used fault detection metrics and compared. The tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 5000 revolutions per minute and torques from 184 to 228 percent of design load. The inability to detect these cracks with high confidence results from the high loading which is causing fast fracture as opposed to stable crack growth. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.

  14. Theory of gearing kinematics, geometry, and synthesis

    CERN Document Server

    Radzevich, Stephen P

    2012-01-01

    The first book of its kind, Theory of Gearing: Kinematics, Geometry, and Synthesis systematically develops a scientific theory of gearing that makes it possible to synthesize novel gears with the desired performance. Written by a leading gearing expert who holds more than 200 patents, it presents a modern methodology for gear design. The proposed theory is based on a key postulate: all the design parameters for an optimal gear pair for a particular application can be derived from (a) a given configuration of the rotation vectors of the driving and driven shafts and (b) the power transmitted by

  15. Aquifer test plan for the 100-HR-3 Operable Unit

    International Nuclear Information System (INIS)

    Swanson, L.C.; Hartman, M.J.

    1994-01-01

    This test plan directs hydrologic testing activities planned at three existing Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) wells in the 100-HR-3 Operable Unit of the Hanford Site. Three additional wells will be installed near these existing wells and used as additional testing arid observation points during the field activities. Figure 1 shows the locations of the three test sites. A primary objective of the testing program is to provide more detailed hydraulic characterization information for the unconfined aquifer and targeted test sites than provided by the initial reconnaissance-level slug testing of Vukelich. A second objective is to evaluate the applicability of slug interference and dipole flow tests for detailed hydraulic characterization in an unconfined aquifer. This aquifer testing program will also be useful for substantiating hydraulic conductivities reported from previous slug tests and evaluating the effects of filter pack volume/configuration on slug test data. Vukelich recommended additional testing to address the latter two issues

  16. Integrating Condition Indicators and Usage Parameters for Improved Spiral Bevel Gear Health Monitoring

    Science.gov (United States)

    Dempsey, Paula J.; Handschuh, Robert F.; Delgado, Irebert, R.

    2013-01-01

    The objective of this study was to illustrate the importance of combining Health Usage Monitoring Systems (HUMS) data with usage monitoring system data when detecting rotorcraft transmission health. Three gear sets were tested in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Damage was initiated and progressed on the gear and pinion teeth. Damage progression was measured by debris generation and documented with inspection photos at varying torque values. A contact fatigue analysis was applied to the gear design indicating the effect temperature, load and reliability had on gear life. Results of this study illustrated the benefits of combining HUMS data and actual usage data to indicate progression of damage for spiral bevel gears.

  17. Concept evaluation of a novel gear selector for automated manual transmissions

    Science.gov (United States)

    Zhong, Zaimin; Kong, Guoling; Yu, Zhuoping; Chen, Xinbo; Chen, Xueping; Xin, Xiangyan

    2012-08-01

    The existing Automatic Mechanical Transmission (AMT), whether electrically or hydraulically actuated, integrates shift actuators with gearbox shell as one unit by installing actuators on the gearbox. The problem it brings about is that the modification of the gearbox shell would be required, which increases the cost of AMT system. This paper proposes a novel gear selector for AMT, the concept of which enables the automation of shift action remotely realized by DC motors through shifting cable that originally used on manual transmission vehicle. Evidently, the advantage of this concept is that the automation of manual transmission could be easily realized by replacing the shift lever with two motors while the original shifting cable and gearbox could be reserved. Then the cost and development period can be shorten remarkably. Firstly, the concept of the novel gear selector is introduced, then the detailed mathematical model of shifting process is studied, and system design and scheme selection of this concept are performed. Optimal control algorithm based on LQR for actuator position feedback control is introduced. The concept and control algorithm are verified on a sample car, and considering the influence of the long path of transmission mechanism, the validation of the stability of this concept is performed through calibration test on mountain pass, and the obtained results show the concept of the novel gear selector for AMT is feasible technically with strong robust on the shifting stability, and it shows enormous potential for industrialization.

  18. Advanced theories of hypoid gears

    CERN Document Server

    Wang, Xudong

    2013-01-01

    In order to develop more efficient types of gears, further investigation into the theories of engagement is necessary. Up until now most of the research work on the theories of engagement has been carried out separately on different groups, and based on individual types of profiles. This book aims at developing some universal theories, which can not only be used for all types of gears, but can also be utilized in other fields such as sculptured surfaces. The book has four characteristics: the investigations are concentrated on mismatched tooth surfaces; all the problems are dealt with from a

  19. Induction Hardening of External Gear

    Science.gov (United States)

    Bukanin, V. A.; Ivanov, A. N.; Zenkov, A. E.; Vologdin, V. V.; Vologdin, V. V., Jr.

    2018-03-01

    Problems and solution of gear induction hardening are described. Main attention is paid to the parameters of heating and cooling systems. ELTA 7.0 program has been used to obtain the required electrical parameters of inductor, power sources, resonant circuits, as well as to choose the quenching media. Comparison of experimental and calculated results of investigation is provided. In order to compare advantages and disadvantages of single- and dual-frequency heating processes, many variants of these technologies were simulated. The predicted structure and hardness of steel gears are obtained by use of the ELTA data base taken into account the Continuous Cooling Transformation diagrams.

  20. Systematic Unit Testing in a Read-eval-print Loop

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2010-01-01

    .  The process of collecting the expressions and their results imposes only little extra work on the programmer.  The use of the tool provides for creation of test repositories, and it is intended to catalyze a much more systematic approach to unit testing in a read-eval-print loop.  In the paper we also discuss...... how to use a test repository for other purposes than testing.  As a concrete contribution we show how to use test cases as examples in library interface documentation.  It is hypothesized---but not yet validated---that the tool will motivate the Lisp programmer to take the transition from casual...

  1. Personal dosimetry performance testing in the United States

    International Nuclear Information System (INIS)

    Soares, Christopher G.

    2008-01-01

    The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11. Now in it's fourth edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Laboratory Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by U.S. Nuclear Regulatory Commission (NRC) regulations. The U.S. Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). One of the goals of this current revision was the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to U.S. personal dosemeter performance testing. The testing philosophy of ANSI/HPS N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. In this paper, the history of performance testing in the U.S. is briefly reviewed. Also described is the revision that produced the fourth edition of this standard, which has taken place over the last three years (2005-2008) by a working group representing national standards laboratories, government laboratories, the military, dosimetry vendors, universities and the nuclear power industry. (author)

  2. Maximum likelihood unit rooting test in the presence GARCH: A new test with increased power

    OpenAIRE

    Cook , Steve

    2008-01-01

    Abstract The literature on testing the unit root hypothesis in the presence of GARCH errors is extended. A new test based upon the combination of local-to-unity detrending and joint maximum likelihood estimation of the autoregressive parameter and GARCH process is presented. The finite sample distribution of the test is derived under alternative decisions regarding the deterministic terms employed. Using Monte Carlo simulation, the newly proposed ML t-test is shown to exhibit incre...

  3. Extra-regulatory impact tests and analyses of the structural evaluation test unit

    International Nuclear Information System (INIS)

    Ludwigsen, J.S.; Ammerman, D.J.

    1995-01-01

    The structural evaluation test unit is roughly equivalent to a 1/3 scale model of a high level waste rail cask. The test unit was designed to just meet the requirements of NRC Regulatory Guide 7.6 when subjected to a 9 m (30 ft) free drop resulting in an impact velocity of 13.4 m/s (30 mph) onto an unyielding target in the end-on orientation. The test unit was then subjected to impacts with higher velocities to determine the amount of built-in conservatism in this design approach. Test impacts of 13.4, 20.1 and 26.8 m/s (30, 45, and 60 mph) were performed. This paper will describe the design, testing, and comparison of measured strains and deformations to the equivalent analytical predictions

  4. HEAT ENGINEERING TESTING OF AIR COOLING UNIT OF HORIZONTAL TYPE

    OpenAIRE

    Rohachov, Valerii Andriiovych; Semeniako, Oleksandr Volodymyrovych; Лазоренко, Р. О.; Середа, Р. М.; Parafeinyk, Volodymyr Petrovych

    2018-01-01

    The results of the thermal tests of the section of air cooler, the heat-exchange surface of which is made up of chess package of bimetal finned tubes are presented. The methods of research are presented, the experimental stand is described, the measurement errors are given. The efficiency of the experimental stand and the accuracy of the experimental data on it are confirmed. Proposed to use the stand for researches of air cooling units with other types and sections of finned tubes.

  5. COTRANSA simulation of Chinshan unit one generator load rejection test

    International Nuclear Information System (INIS)

    Wu, C.H.

    1984-01-01

    A simulation of the plant behavior during a BWR generator load rejection transient using Exxon Nuclear Company's COTRANSA code is presented in this paper. The results are compared to measurements obtained by Taiwan Power Company during a generator load rejection transient, initiated at full power condition, which was one of the Chinshan Unit 1 initial cycle startup tests. Good agreement between the COTRANSA predicted and the measured values, indicates that the COTRANSA code can simulate this transient satisfactorily

  6. History of personal dosimetry performance testing in the United States

    International Nuclear Information System (INIS)

    Soares, C. G.

    2007-01-01

    The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11 (2001). Now in its third edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by US Nuclear Regulatory Commission (NRC) regulations. The US Dept. of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Dept. of Energy Laboratory Accreditation Program (DOELAP). A focus in recent years has been the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonisation to US personal dosemeter processing testing. Since there is no type testing program in the US for personal dosemeters, the testing philosophy of ANSI N13.11 has always combined elements of type testing and routine performance testing. This philosophy is explored in detail in this presentation, along with trends in the development of the document to its present state. In addition, a look will be taken at what the future holds for the next revision of the document, scheduled to begin in 2005. (authors)

  7. Personal dosimetry performance testing in the United States

    International Nuclear Information System (INIS)

    Soares, C.G.

    2005-01-01

    Full text: The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11 (2002). Now in its third edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by US Nuclear Regulatory Commission (NRC) regulations. The US Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). A focus in recent years has been the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to US personal dosimeter processing testing. The testing philosophy of ANSI N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. This unique philosophy is explored in detail in this presentation, along with trends in the development of the document to its present state. In addition, a look will be taken at what the future holds for the next revision of the document, scheduled to begin in 2005. (author)

  8. Computer simulation of gear tooth manufacturing processes

    Science.gov (United States)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  9. Reevaluation of Kori Unit 4 Natural Circulation Test

    Energy Technology Data Exchange (ETDEWEB)

    Yassin, Nassir [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Woo, Sweng Woong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-10-15

    The simulation results showed that the natural circulation flow developed by density difference was capable of removing decay heat from the fuel rod. The maximum pellet centerline temperature of the hot channel showed large margin to the pellet melting temperature. The maximum coolant temperature in the hot channel was well below the saturation temperature. If steam generators provide heat sink to the primary coolant system and thus natural circulation is maintained, the integrity of the fuel in the core can be sustained with large margin. Passive cooling of reactor is inevitable in case of failures in forced cooling system such as loss of electric power for cooling pumps. Fukushima accident showed the importance of the passive core cooling. During the commissioning test of PWRs, natural circulation test is performed to demonstrate the passive core cooling by natural convection. The driving force for coolant flow is developed by the density deference along the loop multiplied by the gravitation. Using the data from 'natural circulation test' and 'RCS flow coast down test' of Kori Unit 4, fuel behavior was reevaluated by FRAPTRAN code. RCS natural circulation test of Kori Unit 4 was reevaluated by FRAPTYRAN simulation to study the fuel behavior during the flow coast down transient and at the equilibrium condition in which decay heat transport and RCS flow were stabilized.

  10. Detection of Pitting in Gears Using a Deep Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Yongzhi Qu

    2017-05-01

    Full Text Available In this paper; a new method for gear pitting fault detection is presented. The presented method is developed based on a deep sparse autoencoder. The method integrates dictionary learning in sparse coding into a stacked autoencoder network. Sparse coding with dictionary learning is viewed as an adaptive feature extraction method for machinery fault diagnosis. An autoencoder is an unsupervised machine learning technique. A stacked autoencoder network with multiple hidden layers is considered to be a deep learning network. The presented method uses a stacked autoencoder network to perform the dictionary learning in sparse coding and extract features from raw vibration data automatically. These features are then used to perform gear pitting fault detection. The presented method is validated with vibration data collected from gear tests with pitting faults in a gearbox test rig and compared with an existing deep learning-based approach.

  11. An enhancement to the NA4 gear vibration diagnostic parameter

    Science.gov (United States)

    Decker, Harry J.; Handschuh, Robert F.; Zakrajsek, James J.

    1994-01-01

    A new vibration diagnostic parameter for health monitoring of gears, NA4*, is proposed and tested. A recently developed gear vibration diagnostic parameter NA4 outperformed other fault detection methods at indicating the start and initial progression of damage. However, in some cases, as the damage progressed, the sensitivity of the NA4 and FM4 parameters tended to decrease and no longer indicated damage. A new parameter, NA4* was developed by enhancing NA4 to improve the trending of the parameter. This allows for the indication of damage both at initiation and also as the damage progresses. The NA4* parameter was verified and compared to the NA4 and FM4 parameters using experimental data from single mesh spur and spiral bevel gear fatigue rigs. The primary failure mode for the test cases was naturally occurring tooth surface pitting. The NA4* parameter is shown to be a more robust indicator of damage.

  12. GEAR UP Aspirations Project Evaluation

    Science.gov (United States)

    Trimble, Brad A.

    2013-01-01

    The purpose of this study was to conduct a formative evaluation of the first two years of the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) Aspirations Project (Aspirations) using a Context, Input, Process, and Product (CIPP) model so as to gain an in-depth understanding of the project during the middle school…

  13. Operation of the radioactive acid digestion test unit

    International Nuclear Information System (INIS)

    Blasewitz, A.G.; Allen, C.R.; Lerch, R.E.; Ely, P.C.; Richardson, G.L.

    1980-01-01

    The Radioactive Acid Digestion Test Unit (RADTU) has been constructed at Hanford to demonstrate the application of the Acid Digestion Process for treating combustible transuranic wastes and scrap materials. The RADTU with its original tray digestion vessel has recently completed a six-month campaign processing potentially contaminated nonglovebox wastes from a Hanford plutonium facility. During this campaign, it processed 2100 kg of largely cellulosic wastes at an average sustained processing rate of 3 kg/h as limited by the water boiloff rate from the acid feeds. The on-line operating efficiency was nearly 50% on a twelve hour/day, five day/week basis. Following this campaign, a new annular high rate digester has been installed for testing. In preliminary tests with simulated wastes, the new digester demonstrated a sustained capacity of 10 kg/h with greatly improved intimacy of contact between the digestion acid and the waste. The new design also doubles the heat transfer surface, which with reduced heat loss area, is expected to provide at least three times the water boiloff rate of the previous tray digester design. Following shakedown testing with simulated and low-level wastes, the new unit will be used to process combustible plutonium scrap and waste from Hanford plutonium facilities for the purposes of volume reduction, plutonium recovery, and stabilization of the final waste form

  14. Simulation-based investigation of the paired-gear method in cod-end selectivity studies

    DEFF Research Database (Denmark)

    Herrmann, Bent; Frandsen, Rikke; Holst, René

    2007-01-01

    In this paper, the paired-gear and covered cod-end methods for estimating the selectivity of trawl cod-ends are compared. A modified version of the cod-end selectivity simulator PRESEMO is used to simulate the data that would be collected from a paired-gear experiment where the test cod-end also ...

  15. WTP Waste Feed Qualification: Glass Fabrication Unit Operation Testing Report

    Energy Technology Data Exchange (ETDEWEB)

    Stone, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Hanford Missions Programs; Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Process Technology Programs; Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Engineering Process Development; Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Engineering Process Development

    2016-07-14

    The waste feed qualification program is being developed to protect the Hanford Tank Waste Treatment and Immobilization Plant (WTP) design, safety basis, and technical basis by assuring waste acceptance requirements are met for each staged waste feed campaign prior to transfer from the Tank Operations Contractor to the feed receipt vessels inside the Pretreatment Facility. The Waste Feed Qualification Program Plan describes the three components of waste feed qualification: 1. Demonstrate compliance with the waste acceptance criteria 2. Determine waste processability 3. Test unit operations at laboratory scale. The glass fabrication unit operation is the final step in the process demonstration portion of the waste feed qualification process. This unit operation generally consists of combining each of the waste feed streams (high-level waste (HLW) and low-activity waste (LAW)) with Glass Forming Chemicals (GFCs), fabricating glass coupons, performing chemical composition analysis before and after glass fabrication, measuring hydrogen generation rate either before or after glass former addition, measuring rheological properties before and after glass former addition, and visual observation of the resulting glass coupons. Critical aspects of this unit operation are mixing and sampling of the waste and melter feeds to ensure representative samples are obtained as well as ensuring the fabrication process for the glass coupon is adequate. Testing was performed using a range of simulants (LAW and HLW simulants), and these simulants were mixed with high and low bounding amounts of GFCs to evaluate the mixing, sampling, and glass preparation steps in shielded cells using laboratory techniques. The tests were performed with off-the-shelf equipment at the Savannah River National Laboratory (SRNL) that is similar to equipment used in the SRNL work during qualification of waste feed for the Defense Waste Processing Facility (DWPF) and other waste treatment facilities at the

  16. Vibration Propagation of Gear Dynamics in a Gear-Bearing-Housing System Using Mathematical Modeling and Finite Element Analysis

    Science.gov (United States)

    Parker, Robert G.; Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.

    2012-01-01

    Vibration and noise caused by gear dynamics at the meshing teeth propagate through power transmission components to the surrounding environment. This study is devoted to developing computational tools to investigate the vibro-acoustic propagation of gear dynamics through a gearbox using different bearings. Detailed finite element/contact mechanics and boundary element models of the gear/bearing/housing system are established to compute the system vibration and noise propagation. Both vibration and acoustic models are validated by experiments including the vibration modal testing and sound field measurements. The effectiveness of each bearing type to disrupt vibration propagation is speed-dependent. Housing plays an important role in noise radiation .It, however, has limited effects on gear dynamics. Bearings are critical components in drivetrains. Accurate modeling of rolling element bearings is essential to assess vibration and noise of drivetrain systems. This study also seeks to fully describe the vibro-acoustic propagation of gear dynamics through a power-transmission system using rolling element and fluid film wave bearings. Fluid film wave bearings, which have higher damping than rolling element bearings, could offer an energy dissipation mechanism that reduces the gearbox noise. The effectiveness of each bearing type to disrupt vibration propagation in explored using multi-body computational models. These models include gears, shafts, rolling element and fluid film wave bearings, and the housing. Radiated noise is mapped from the gearbox surface to surrounding environment. The effectiveness of rolling element and fluid film wave bearings in breaking the vibro-acoustic propagation path from the gear to the housing is investigated.

  17. Materials and lubrication for gear and bearing surfaces in uhv

    International Nuclear Information System (INIS)

    Kirby, R.E.; Collet, G.J.; Garwin, E.L.

    1980-06-01

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing, and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 250 0 C, and at room temperature must operate at pressures in the 10 -9 to 10 -10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined to (by bushings) and rotated on a fixed shaft, while the other gear was driven by a commercial rotary motion feedthrough which was rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. 10 5 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91,000. Materials for gears included stainless steel, beryllium copper, and aluminum alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome, and a MoS 2 -graphite-sodium silicate mixture. The successful gear pair was Ag-plated Al alloy and MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed

  18. Landing Gear Noise Prediction and Analysis for Tube-and-Wing and Hybrid-Wing-Body Aircraft

    Science.gov (United States)

    Guo, Yueping; Burley, Casey L.; Thomas, Russell H.

    2016-01-01

    Improvements and extensions to landing gear noise prediction methods are developed. New features include installation effects such as reflection from the aircraft, gear truck angle effect, local flow calculation at the landing gear locations, gear size effect, and directivity for various gear designs. These new features have not only significantly improved the accuracy and robustness of the prediction tools, but also have enabled applications to unconventional aircraft designs and installations. Systematic validations of the improved prediction capability are then presented, including parametric validations in functional trends as well as validations in absolute amplitudes, covering a wide variety of landing gear designs, sizes, and testing conditions. The new method is then applied to selected concept aircraft configurations in the portfolio of the NASA Environmentally Responsible Aviation Project envisioned for the timeframe of 2025. The landing gear noise levels are on the order of 2 to 4 dB higher than previously reported predictions due to increased fidelity in accounting for installation effects and gear design details. With the new method, it is now possible to reveal and assess the unique noise characteristics of landing gear systems for each type of aircraft. To address the inevitable uncertainties in predictions of landing gear noise models for future aircraft, an uncertainty analysis is given, using the method of Monte Carlo simulation. The standard deviation of the uncertainty in predicting the absolute level of landing gear noise is quantified and determined to be 1.4 EPNL dB.

  19. Improvement in surface fatigue life of hardened gears by high-intensity shot peening

    Science.gov (United States)

    Townsend, Dennis P.

    1992-04-01

    Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

  20. New Siemens applications for designing bevel gears

    Science.gov (United States)

    Goanta, A. M.; Dumitrache, P.

    2017-08-01

    The current situation in the design of gearings is different from software to software and in some cases requires specialized settings with or without additional costs. There are two ways of generating evolving tooting: one is based on the designer’s solid knowledge of geometry and gearing and the other is based on a series of automation subprograms for 3D modelling of gears. The first method is a general one, applicable to all design software that is based on generating a curve evolving specific to a tooth flank, continued with the construction of the symmetrical flank, the pattern multiplication of circular type around the center of the gear and finally generation of the three-dimensional characteristic of each individual tooth. The second method is much faster and requires only general knowledge about the gear but sufficiently advanced to allow permanent dialogue with the subprogram for generating cone gears. Absolute novelty items are brought about by the new NX design applications that lead to getting gears with curved teeth. In conclusion the paper shows how different variants of bevel gears are generated using various subprograms or performance settings, installed over the SIEMENS NX. An essential component of the paper is highlighting generation capacity of gears and gearing intended for predefined types of gear cutting machines such as those for Gleason and Oerlikon teeth.

  1. Testing for purchasing power parity in 21 African countries using several unit root tests

    Science.gov (United States)

    Choji, Niri Martha; Sek, Siok Kun

    2017-04-01

    Purchasing power parity is used as a basis for international income and expenditure comparison through the exchange rate theory. However, empirical studies show disagreement on the validity of PPP. In this paper, we conduct the testing on the validity of PPP using panel data approach. We apply seven different panel unit root tests to test the validity of the purchasing power parity (PPP) hypothesis based on the quarterly data on real effective exchange rate for 21 African countries from the period 1971: Q1-2012: Q4. All the results of the seven tests rejected the hypothesis of stationarity meaning that absolute PPP does not hold in those African Countries. This result confirmed the claim from previous studies that standard panel unit tests fail to support the PPP hypothesis.

  2. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2009-01-01

    Full Text Available An adaptive landing gear is a landing gear (LG capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~validated model of a real, passive landing gear as a reference. Potential for improvement is estimated statistically in terms of the mean and median (significant peak strut forces as well as in terms of the extended safe sinking velocity range. Three control strategies are verified experimentally using a laboratory test stand.

  3. Geared-elevator flutter study. [transonic flutter characteristics of empennage

    Science.gov (United States)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    The paper describes an experimental and analytical study of the transonic flutter characteristics of an empennage flutter model having an all-movable horizontal tail with a geared elevator. Two configurations were flutter tested: one with a geared elevator and one with a locked elevator with the model cantilever-mounted on a sting in the wind tunnel. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter boundary was nearly flat at transonic speeds for both configurations. It was found that an analysis which treated the elevator as a discrete surface predicted flutter dynamic pressure levels better than analyses which treated the stabilizer and elevator as a warped surface. Warped-surface methods, however, predicted more closely the experimental flutter frequencies and Mach number trends.

  4. 3D MODELLING WITH THE SAMSUNG GEAR 360

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2017-02-01

    Full Text Available The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.

  5. Evaluation of Low-Noise, Improved-Bearing-Contact Spiral Bevel Gears

    National Research Council Canada - National Science Library

    Lewicki, Davide

    2003-01-01

    .... Experimental tests were performed on the OH-58D helicopter main-rotor transmission in the NASA Glenn 500-hp Helicopter Transmission Test Stand Low-noise, improved-bearing- contact spiral-bevel gears...

  6. Sublimator Driven Coldplate Engineering Development Unit Test Results

    Science.gov (United States)

    Sheth, Rubik B.; Stephan, Ryan A.; Leimkuehler, Thomas O.

    2010-01-01

    The Sublimator Driven Coldplate (SDC) is a unique piece of thermal control hardware that has several advantages over a traditional thermal control scheme. The principal advantage is the possible elimination of a pumped fluid loop, potentially increasing reliability and reducing complexity while saving both mass and power. Because the SDC requires a consumable feedwater, it can only be used for short mission durations. Additionally, the SDC is ideal for a vehicle with small transport distances and low heat rejection requirements. An SDC Engineering Development Unit was designed and fabricated. Performance tests were performed in a vacuum chamber to quantify and assess the performance of the SDC. The test data was then used to develop correlated thermal math models. Nonetheless, an Integrated Sublimator Driven Coldplate (ISDC) concept is being developed. The ISDC couples a coolant loop with the previously described SDC hardware. This combination allows the SDC to be used as a traditional coldplate during long mission phases and provides for dissimilar system redundancy

  7. Test procedures, AN/AIC-27 system and component units. [for space shuttle

    Science.gov (United States)

    Reiff, F. H.

    1975-01-01

    The AN/AIC-27 (v) intercommunication system is a 30-channel audio distribution which consists of: air crew station units, maintenance station units, and a central control unit. A test procedure for each of the above units and also a test procedure for the system are presented. The intent of the test is to provide data for use in shuttle audio subsystem design.

  8. 30 CFR 74.5 - Tests of coal mine dust personal sampler units.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of coal mine dust personal sampler units... Personal Sampler Unit § 74.5 Tests of coal mine dust personal sampler units. (a) The National Institute for... tests and evaluations to determine whether the pump unit of a CMDPSU that is submitted for approval...

  9. Design of Gear Churning Power Loss Measurement Device

    OpenAIRE

    Wang Bin; Zhou Ya Jie; Wang Ping

    2017-01-01

    To explore the impacts of gear churning power losses, a research was conducted to achieve the internal causes of power losses of churning gear by designing a gear churning power losses measurement device. The gear churning power losses could be influenced by different gear modules, the number of teeth and the axial position of gear. Finally, the impacts of gear churning power losses were discussed by comparing experimental data and theoretical data.

  10. An Investigation into the Cost of Unit Testing on an Embedded System

    OpenAIRE

    Qiu, Wensi

    2011-01-01

    The quality of embedded software is important, especially for life-critical and mission-critical embedded systems. And software testing is a key activity to ensure the quality of embedded software. Both system testing and unit testing are vital to test embedded software. Unit testing is probably more important to ensure there are no latent faults. System testing is almost invariably done on a target system, but unit testing is normally done on a host system, as standard test frame...

  11. Full scale dynamic testing of Kozloduy NPP unit 5 structures

    International Nuclear Information System (INIS)

    Da Rin, E.M.

    1999-01-01

    As described in this report, the Kozloduy NPP western site has been subjected to low level earthquake-like ground shaking - through appropriately devised underground explosions - and the resulting dynamic response of the NPP reactor Unit 5 important structures appropriately measured and digitally recorded. In-situ free-field response was measured concurrently more than 100 m aside the main structures of interest. The collected experimental data provide reference information on the actual dynamic characteristics of the Kozloduy NPPs main structures, as well as give some useful indications on the dynamic soil-structure interaction effects for the case of low level excitation. Performing the present full-scale dynamic structural testing activities took advantage of the experience gained by ISMES during similar tests, lately performed in Italy and abroad (in particular, at the Paks NPP in 1994). The IAEA promoted dynamic testing of the Kozloduy NPP Unit 5 by means of pertinently designed buried explosion-induced ground motions which has provided a large amount of data on the dynamic structural response of its major structures. In the present report, the conducted investigation is described and the acquired digital data presented. A series of preliminary analyses were undertaken for examining in detail the ground excitation levels that were produced by these weak earthquake simulation experiments, as well as for inferring some structural characteristics and behaviour information from the collected data. These analyses ascertained the high quality of the collected digital data. Presumably due to soil-structure dynamic interaction effects, reduced excitation levels were observed at the reactor building foundation raft level with respect to the concurrent free-field ground motions. measured at a 140 m distance from the reactor building centre. Further more detailed and systematic analyses are worthwhile to be performed for extracting more complete information about the

  12. Evaluation of Bending Strength of Carburized Gears Based on Inferential Identification of Principal Surface Layer Defects

    Science.gov (United States)

    Masuyama, Tomoya; Inoue, Katsumi; Yamanaka, Masashi; Kitamura, Kenichi; Saito, Tomoyuki

    High load capacity of carburized gears originates mainly from the hardened layer and induced residual stress. On the other hand, surface decarburization, which causes a nonmartensitic layer, and inclusions such as oxides and segregation act as latent defects which considerably reduce fatigue strength. In this connection, the authors have proposed a formula of strength evaluation by separately quantifying defect influence. However, the principal defect which limits strength of gears with several different defects remains unclarified. This study presents a method of inferential identification of principal defects based on test results of carburized gears made of SCM420 clean steel, gears with both an artificial notch and nonmartensitic layer at the tooth fillet, and so forth. It clarifies practical uses of presented methods, and strength of carburized gears can be evaluated by focusing on principal defect size.

  13. Influence of the shot-peening treatment on the CRF gearing behaviour

    International Nuclear Information System (INIS)

    Molinie, D.; Lemaire, E.; Randrianarivo, L.; Dorier, C.

    1998-01-01

    Surface damage are observed in service on CRF case-hardened cases. Such damage is like surface fatigue which appears in the form of frosting and can come to a micro-spalling or even a spalling damage. Survey and studies realised on gears affected by such damage, led EDF and the manufacturer to search for appropriated solutions since 1985 (optimisation of the gear bottom profile, care of the grinding and the thermochemical processing, use of oils with higher viscosity). Simulations on a running wheel device can reproduce the meshing conditions on simplified specimen. The aim is to study the influence of residual stresses following a severe grinding and shot peening treatments. An empiric selection was realised among different shot peening treatments. Endurance tests are realised on case-hardened gears with or without shot-peening treatments. Compared with standard grinded gears, it appears that the shot-peening selected increases up to 40% the gear lifetime till extended spalling. (authors)

  14. Fabrication and testing history prototypes and production units

    Energy Technology Data Exchange (ETDEWEB)

    1954-09-01

    From April, 1951 to Aug, 1954, New York Shipbuilding Corp. carried out a subcontract with E.I. du Pont de Nemours & Company that was without parallel in the shipyard`s history. The work, designated the NYX Project for reasons of security, was vital to the operations of the Savannah River Plant, Aiken, S.C., which was then being designed and constructed by du Pont for the Atomic Energy Commission. It consisted of three broad parts: developmental and experimental work; fabrication and testing of a prototype unit; fabrication of production units. Five production units were ultimately built, one of them converted from the prototype. All were fabricated from stainless steel, and involved welding techniques, control of thermal distortion and tolerances never previously attempted on assemblies of comparable size. Du Pont`s technical experience and the background of New York Ship in heavy construction, particularly in the fabrication of naval gun turrets, were combined from the outset to resolve the difficult fabrication problems that occurred almost daily. Representatives of both companies worked together as a team in the shops and at supervisory levels to an unprecedented extent. The report is intended primarily to summarize New York Ship`s part in the project, but also includes some of du Pont`s activities since the work of the two organizations was so interrelated. Because of the scope of the program, it will not always be possible to provide detailed information, but rather to record what happened in general terms. Where the reader desires more specific data, he should refer to original plans and records, including various reports compiled during the course of the project.

  15. Multiple unit root tests under uncertainty over the initial condition : some powerful modifications

    NARCIS (Netherlands)

    Hanck, C.

    We modify the union-of-rejection unit root test of Harvey et al. "Unit Root Testing in Practice: Dealing with Uncertainty over the Trend and Initial Condition" (Harvey, Econom Theory 25:587-636, 2009). This test rejects if either of two different unit root tests rejects but controls the inherent

  16. Reduction of belt CVT gear noise by gear train modification. Optimize vibration characteristics of gear train; Belt CVT no gear noise teigen gijutsu. Gear train shindo tokusei no saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Arimatsu, M; Kawakami, T [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    With the reduction of vehicle noise, the requirements for an efficient method to reduce transmission gear noise have become stronger yearly. So far efforts to reduce gear noise have generally focused on ways of improving the gears themselves. In addition to these traditional methods, it proved very beneficial to us to optimize the gear train structure. Nissan has just released the new Belt CVT for 2.0L Front wheel drive vehicles. We have been analyzing vibration of the gear train by using a finite element model since the early development stage, and we could achieve the quiet gears effectively. 2 refs., 9 figs.

  17. Radioactive acid digestion test unit nonradioactive startup operations

    International Nuclear Information System (INIS)

    Allen, C.R.; Cowan, R.G.; Crippen, M.D.; Divine, J.R.

    1978-05-01

    The Radioactive Acid Digestion Test Unit (RADTU) will process 5 kg/hour of combustible solid waste and is designed to handle almost all solid combustible waste found in plutonium processing with plutonium contamination levels up to scrap. The RADTU is designed with special safety features to safely contain high masses of fissile materials and to safely handle unusual materials and reactive chemicals which may find their way into the waste. Nonradioactive operating experience to date has been very satisfactory. RADTU has been operated for extended runs on both a 24-hour per day basis as well as on a one shift per day basis. Some minor operating problems have been encountered as expected in a shakedown operation. In general, solutions to these have been readily found. 12 figures

  18. Gear failure of a PHWR refuelling machine

    International Nuclear Information System (INIS)

    Iorio, A.F.; Crespi, J.C.

    1986-01-01

    After ten year service in Atucha Nuclear Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to transmit motion to the inlet-outlet heavy-water valve of that machine. Visual examination of the gear device revealed an absence of lubricant and several gear teeth were broken off at the root. The gear motion was transmitted from a speed-reducing device with controlled adjustable times in order to produce a right fitness of the valve closure. The main cause of gear failure was due to misalignment produced during assembly or in-service operation. It is suggested to control periodically the level of oil lubricant. (orig./IHOE) [de

  19. Analysis and modification of a single-mesh gear fatigue rig for use in diagnostic studies

    Science.gov (United States)

    Zakrajsek, James J.; Townsend, Dennis P.; Oswald, Fred B.; Decker, Harry J.

    1992-01-01

    A single-mesh gear fatigue rig was analyzed and modified for use in gear mesh diagnostic research. The fatigue rig allowed unwanted vibration to mask the test-gear vibration signal, making it difficult to perform diagnostic studies. Several possible sources and factors contributing to the unwanted components of the vibration signal were investigated. Sensor mounting location was found to have a major effect on the content of the vibration signal. In the presence of unwanted vibration sources, modal amplification made unwanted components strong. A sensor location was found that provided a flatter frequency response. This resulted in a more useful vibration signal. A major network was performed on the fatigue rig to reduce the influence of the most probable sources of the noise in the vibration signal. The slave gears were machined to reduce weight and increase tooth loading. The housing and the shafts were modified to reduce imbalance, looseness, and misalignment in the rotating components. These changes resulted in an improved vibration signal, with the test-gear mesh frequency now the dominant component in the signal. Also, with the unwanted sources eliminated, the sensor mounting location giving the most robust representation of the test-gear meshing energy was found to be at a point close to the test gears in the load zone of the bearings.

  20. Some calculation formulae for the candu 6 hypoid gearing. a physical point of view

    International Nuclear Information System (INIS)

    Doca, C.; Paunoiu, C.

    2015-01-01

    The CANDU 6 reactor.s Adjuster Unit consists of a tubular, stainless steel, neutron absorbing element which is raised and lowered within a guide tube. The Adjuster Unit is suspended from a cable which is wound around the sheave of a drive mechanism. To provide a very fine ''up-down'' displacement of the absorbing element, the adjuster drive mechanism incorporates a hypoid-gearing containing a conical spiroid pinion and a conical spiroid gear , having their axes at rights angle. Here represents the gear.s teeth number. By its conical spiroid pinion, its spiroid gear with double-involute teeth, and its reduction (transmission) ratio , this hypoid-gearing seems to be a special type mechanism, not encountered (by the authors, at least) in the classical engineering textbooks, where the most analyzed examples only are for and . Elaborated from a physical point of view, the paper demonstrates and proposes a number of calculation formulae for the main geometrical elements of a same CANDU 6 hypoid-gearing. Finally, the paper presents a very good (exact, practically) superposition between the values obtained using the proposed calculation formulae, and the known CANDU 6 hypoid-gearing.s geometrical values. Al these general calculation formulae are helpful for well understanding the dynamics and kinematics of the adjuster drive mechanism, and represent the minimum needed knowledge for some possible applications, in other mechanical systems, of the hypoid-gearing with a so large reduction rate . 11N1502NiN15012NNi51N10050i150i. (authors)

  1. 29 CFR 1919.19 - Gear requiring welding.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly heat...

  2. 50 CFR 697.23 - Restricted gear areas.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Restricted gear areas. 697.23 Section 697... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed...) Restricted Gear Area I—(1) Duration—(i) Mobile Gear. From October 1 through June 15 of each fishing year, no...

  3. Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain

    Science.gov (United States)

    2014-01-01

    Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain by Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas...5066 ARL-TR-6795 January 2014 Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain Kelsen E. LaBerge...ELEMENT NUMBER 6. AUTHOR(S) Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER

  4. A Circularly Arranged Sextuple Triptycene Gear Molecule.

    Science.gov (United States)

    Ube, Hitoshi; Yamada, Ryo; Ishida, Jun-Ichi; Sato, Hiroyasu; Shiro, Motoo; Shionoya, Mitsuhiko

    2017-11-22

    Herein we report the synthesis of a circularly arranged sextuple triptycene gear molecule, hexakis(10-dodecyloxy-9-triptycyl)ethynylbenzene, via the trimerization of the corresponding triyne with a cobalt catalyst. The six triptycene gears are closely engaged with each other as confirmed by single crystal X-ray structure analysis, and their motion in solution was established by NMR spectroscopy. Notably, when one bulky RuCp* complex was attached to one triptycene gear, the whole movement of the six gears was highly restricted via their mechanical engagement. Development of such a multigear molecule would provide a structural basis for molecular motion transmission systems with a switching function.

  5. Linear dynamic coupling in geared rotor systems

    Science.gov (United States)

    David, J. W.; Mitchell, L. D.

    1986-01-01

    The effects of high frequency oscillations caused by the gear mesh, on components of a geared system that can be modeled as rigid discs are analyzed using linear dynamic coupling terms. The coupled, nonlinear equations of motion for a disc attached to a rotating shaft are presented. The results of a trial problem analysis show that the inclusion of the linear dynamic coupling terms can produce significant changes in the predicted response of geared rotor systems, and that the produced sideband responses are greater than the unbalanced response. The method is useful in designing gear drives for heavy-lift helicopters, industrial speed reducers, naval propulsion systems, and heavy off-road equipment.

  6. Working on a Standard Joint Unit: A pilot test.

    Science.gov (United States)

    Casajuana, Cristina; López-Pelayo, Hugo; Mercedes Balcells, María; Miquel, Laia; Teixidó, Lídia; Colom, Joan; Gual, Antoni

    2017-09-29

    Assessing cannabis consumption remains complex due to no reliable registration systems. We tested the likelihood of establishing a Standard Joint Unit (SJU) which considers the main cannabinoids with implication on health through a naturalistic approach.  Methodology. Pilot study with current cannabis users of four areas of Barcelona: universities, nightclubs, out-patient mental health service, and cannabis associations. We designed and administered a questionnaire on cannabis use-patterns and determined the willingness to donate a joint for analysis. Descriptive statistics were used to analyze the data. Forty volunteers answered the questionnaire (response rate 95%); most of them were men (72.5%) and young adults (median age 24.5 years; IQR 8.75 years) who consume daily or nearly daily (70%). Most participants consume marihuana (85%) and roll their joints with a median of 0.25 gr of marihuana. Two out of three (67.5%) stated they were willing to donate a joint. Obtaining an SJU with the planned methodology has proved to be feasible. Pre-testing resulted in an improvement of the questionnaire and retribution to incentivize donations. Establishing an SJU is essential to improve our knowledge on cannabis-related outcomes.

  7. Near Earth Asteroid Solar Sail Engineering Development Unit Test Program

    Science.gov (United States)

    Lockett, Tiffany Russell; Few, Alexander; Wilson, Richard

    2017-01-01

    The Near Earth Asteroid (NEA) Scout project is a 30x20x10cm (6U) cubesat reconnaissance mission to investigate a near Earth asteroid utilizing an 86m2 solar sail as the primary propulsion system. This will be the largest solar sail NASA will launch to date. NEA Scout is a secondary payload currently manifested on the maiden voyage of the Space Launch System in 2018. In development of the solar sail subsystem, design challenges were identified and investigated for packaging within a 6U form factor and deployment in cis-lunar space. Analysis furthered understanding of thermal, stress, and dynamics of the stowed system and matured an integrated sail membrane model for deployed flight dynamics. This paper will address design, fabrication, and lessons learned from the NEA Scout solar sail subsystem engineering development unit. From optical properties of the sail material to folding and spooling the single 86m2 sail, the team has developed a robust deployment system for the solar sail. This paper will also address expected and received test results from ascent vent, random vibration, and deployment tests.

  8. Fission Surface Power Technology Demonstration Unit Test Results

    Science.gov (United States)

    Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.

    2016-01-01

    The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.

  9. Load Sharing Behavior of Star Gearing Reducer for Geared Turbofan Engine

    Science.gov (United States)

    Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo

    2017-07-01

    Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.

  10. The contact drag of towed demersal fishing gear components

    Science.gov (United States)

    O'Neill, F. G.; Summerbell, K.; Ivanović, A.

    2018-01-01

    The contact demersal towed fishing gears make with the seabed can lead to penetration of the substrate, lateral displacement of the sediment and a pressure field transmitted through the sediment. It will also contribute to the overall drag of the fishing gear. Consequently, there can be environmental effects such as habitat alteration and benthic mortality, and impacts to the fuel efficiency of the fishing operation which will affect emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we present the results of experimental trials that measure the contact drag of a range of elements that represent some of the components of towed demersal gears that are in contact with the seabed. We show that the contact drag of the gear components depends on their weight, geometry, the type of sediment on which they are towed and whether they are rolling or not. As expected, the contact drag of each gear component increases as its weight increases and the drag of fixed elements is greater than that of the rolling ones. The dependence on aspect ratio is more complex and the drag (per unit area) of narrow cylinders is less than that of wider ones when they roll on the finer sediment or are fixed (not permitted to roll) on the coarser sediment. When they roll on the coarse sediment there is no dependence on aspect ratio. Our results also suggest that fixed components may penetrate the seabed to a lesser depth when they are towed at higher speeds but when they roll there is no such relationship.

  11. Rapid detection of microbial DNA by a novel isothermal genome exponential amplification reaction (GEAR) assay.

    Science.gov (United States)

    Prithiviraj, Jothikumar; Hill, Vincent; Jothikumar, Narayanan

    2012-04-20

    In this study we report the development of a simple target-specific isothermal nucleic acid amplification technique, termed genome exponential amplification reaction (GEAR). Escherichia coli was selected as the microbial target to demonstrate the GEAR technique as a proof of concept. The GEAR technique uses a set of four primers; in the present study these primers targeted 5 regions on the 16S rRNA gene of E. coli. The outer forward and reverse Tab primer sequences are complementary to each other at their 5' end, whereas their 3' end sequences are complementary to their respective target nucleic acid sequences. The GEAR assay was performed at a constant temperature 60 °C and monitored continuously in a real-time PCR instrument in the presence of an intercalating dye (SYTO 9). The GEAR assay enabled amplification of as few as one colony forming units of E. coli per reaction within 30 min. We also evaluated the GEAR assay for rapid identification of bacterial colonies cultured on agar media directly in the reaction without DNA extraction. Cells from E. coli colonies were picked and added directly to GEAR assay mastermix without prior DNA extraction. DNA in the cells could be amplified, yielding positive results within 15 min. Published by Elsevier Inc.

  12. CONOCOPHILLIPS FUEL EFFICIENT HIGH-PERFORMANCE(FEHP) SAE 75W90 REAR AXLE GEAR LUBRICANT

    Science.gov (United States)

    This report is on the Environmental Verification Test of a ConocoPhillips real axle gear lubricant to determine whether it could save vehicle fuel. It determined that a verifyable fuel savings could be measured.

  13. Corrective Action Plan for Corrective Action Unit 543: Liquid Disposal Units, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Restoration

    2006-01-01

    Corrective Action Unit (CAU) 543, Liquid Disposal Units, is listed in Appendix III of the Federal Facility Agreement and Consent Order of 1996. CAU 543 consists of seven Corrective Action Sites (CASs) located in Areas 6 and 15 of the Nevada Test Site, which is approximately 65 miles northwest of Las Vegas, Nevada. CAU 543 consists of the following seven CASs: (sm b ullet) CAS 06-07-01, Decon Pad (sm b ullet) CAS 15-01-03, Aboveground Storage Tank (sm b ullet) CAS 15-04-01, Septic Tank (sm b ullet) CAS 15-05-01, Leachfield (sm b ullet) CAS 15-08-01, Liquid Manure Tank (sm b ullet) CAS 15-23-01, Underground Radioactive Material Area (sm b ullet) CAS 15-23-03, Contaminated Sump, Piping From January 24, 2005 through April 14, 2005, CAU 543 site characterization activities were conducted, and are reported in Appendix A of the CAU 543 Corrective Action Decision Document (CADD) (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2005). The recommended corrective action as stated in the approved CADD is No Further Action for five of the CAU 543 CASs, and Closure In Place for the remaining two CASs

  14. Closure Report for Corrective Action Unit 543: Liquid Disposal Units, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2008-01-01

    This Closure Report (CR) documents closure activities for Corrective Action Unit (CAU) 543, Liquid Disposal Units, according to the Federal Facility Agreement and Consent Order (FFACO, 1996) and the Corrective Action Plan (CAP) for CAU 543 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2007). CAU 543 is located at the Nevada Test Site (NTS), Nevada (Figure 1), and consists of the following seven Corrective Action Sites (CASs): CAS 06-07-01, Decon Pad; CAS 15-01-03, Aboveground Storage Tank; CAS 15-04-01, Septic Tank; CAS 15-05-01, Leachfield; CAS 15-08-01, Liquid Manure Tank; CAS 15-23-01, Underground Radioactive Material Area; CAS 15-23-03, Contaminated Sump, Piping; and CAS 06-07-01 is located at the Decontamination Facility in Area 6, adjacent to Yucca Lake. The remaining CASs are located at the former U.S. Environmental Protection Agency (EPA) Farm in Area 15. The purpose of this CR is to provide a summary of the completed closure activities, to document waste disposal, and to present analytical data confirming that the remediation goals were met. The closure alternatives consisted of closure in place for two of the CASs, and no further action with implementation of best management practices (BMPs) for the remaining five CASs.

  15. 29 CFR 1919.71 - Unit proof test and examination of cranes.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Unit proof test and examination of cranes. 1919.71 Section... § 1919.71 Unit proof test and examination of cranes. (a) Unit proof tests of cranes shall be carried out at the following times: (1) In the cases of new cranes, before initial use and every 4 years...

  16. 29 CFR 1919.73 - Unit proof test and examination of derricks.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Unit proof test and examination of derricks. 1919.73 Section 1919.73 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Devices § 1919.73 Unit proof test and examination of derricks. (a) Unit proof tests of derricks shall be...

  17. 200-BP-5 operable unit treatability test report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The 200-BP-5 Operable Unit was established in response to recommendations presented in the 200 East Groundwater Aggregate Area Management Study Report (AAMSR) (DOE-RL 1993a). Recognizing different approaches to remediation, the groundwater AAMSR recommended separating groundwater from source and vadose zone operable units and subdividing 200 East Area groundwater into two operable units. The division between the 200-BP-5 and 200-PO-1 Operable Units was based principally on source operable unit boundaries and distribution of groundwater plumes derived from either B Plant or Plutonium/Uranium Extraction (PUREX) Plant liquid waste disposal sites.

  18. 200-BP-5 operable unit treatability test report

    International Nuclear Information System (INIS)

    1996-04-01

    The 200-BP-5 Operable Unit was established in response to recommendations presented in the 200 East Groundwater Aggregate Area Management Study Report (AAMSR) (DOE-RL 1993a). Recognizing different approaches to remediation, the groundwater AAMSR recommended separating groundwater from source and vadose zone operable units and subdividing 200 East Area groundwater into two operable units. The division between the 200-BP-5 and 200-PO-1 Operable Units was based principally on source operable unit boundaries and distribution of groundwater plumes derived from either B Plant or Plutonium/Uranium Extraction (PUREX) Plant liquid waste disposal sites

  19. Materials and lubrication for gear and bearing surfaces in UHV

    International Nuclear Information System (INIS)

    Kirby, R.E.; Collet, G.J.; Garwin, E.L.

    1981-01-01

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 250 0 C, and at room temperature must operate at pressures in the 10 -9 to 10 -10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined by bushings to a fixed shaft on which it rotated, while the other gear was driven through a commercial rotary motion feedthrough rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. equal to 10 5 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91 000. Materials for gears included stainless steel, beryllium copper and aluminium alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome and a MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed. (orig.)

  20. Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

    Science.gov (United States)

    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.

  1. A New Acoustic Emission Sensor Based Gear Fault Detection Approach

    Directory of Open Access Journals (Sweden)

    Junda Zhu

    2013-01-01

    Full Text Available In order to reduce wind energy costs, prognostics and health management (PHM of wind turbine is needed to ensure the reliability and availability of wind turbines. A gearbox is an important component of a wind turbine. Therefore, developing effective gearbox fault detection tools is important to the PHM of wind turbine. In this paper, a new acoustic emission (AE sensor based gear fault detection approach is presented. This approach combines a heterodyne based frequency reduction technique with time synchronous average (TSA and spectrum kurtosis (SK to process AE sensor signals and extract features as condition indictors for gear fault detection. Heterodyne technique commonly used in communication is first employed to preprocess the AE signals before sampling. By heterodyning, the AE signal frequency is down shifted from several hundred kHz to below 50 kHz. This reduced AE signal sampling rate is comparable to that of vibration signals. The presented approach is validated using seeded gear tooth crack fault tests on a notational split torque gearbox. The approach presented in this paper is physics based and the validation results have showed that it could effectively detect the gear faults.

  2. Involute Spur Gear Template Development by Parametric Technique ...

    African Journals Online (AJOL)

    Nekky Umera

    cylindrical coordinate systems to create the involute curve profile. Since spur gear ... Template gear development using parametric method means that the dimensions control the ... and rapid prototyping of interlocking gears. Excel is a common ...

  3. VARIABLE MESH STIFFNESS OF SPUR GEAR TEETH USING ...

    African Journals Online (AJOL)

    gear engagement. A gear mesh kinematic simulation ... model is appropnate for VMS of a spur gear tooth. The assumptions for ... This process has been continued until one complete tooth meshing cycle is ..... Element Method. Using MATLAB,.

  4. VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Grzegorz PERUŃ

    2014-09-01

    Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.

  5. United States position paper on sodium fires, design and testing

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Johnson, R.P.

    1983-01-01

    The first Specialists' Meeting on sodium fire technology sponsored by the International Working Group on Fast Reactors (IWGFR) was held in Richland, Washington in 1972. The group concluded that the state-of-technology at that time was inadequate to support the growing LMFBR industry. During the second IWGFR Specialists' Meeting on sodium fires, held in Cadarache, France in 1978, a large quantity of technical information was exchanged and areas were identified where additional work was needed. Advances in several important areas of sodium fire technology have been made in the United States since that time, including improved computer codes, design of a sodium fire protection system for the CRBRP, measurement of water release from heated concrete, and testing and modeling of the sodium-concrete reaction. Research in the U.S. related to sodium fire technology is performed chiefly at the Energy Systems Group of Rockwell International (including Atomics International), the Hanford Engineering Development Laboratory (HEDL), and the Sandia National Laboratories (SNL). The work at the first two laboratories is sponsored by the U.S. Department of Energy, while that at the latter is sponsored by the U.S. Nuclear Regulatory Commission. Various aspects of sodium fire related work is also performed at several other laboratories. The current status of sodium fire technology in the U.S. is summarized in this report

  6. Results of zinc injection test for Hamaoka Unit-1

    International Nuclear Information System (INIS)

    Kani, K.; Masuda, H.; Hayashi, Y.; Sudo, S.; Yamazaki, K.

    1998-01-01

    A zinc injection test was preformed at Hamaoka Nuclear Power Station Unit-1 for suppressing radiation dose rate on primary coolant recirculation piping after the replacement of piping. Zinc ion was injected by using injection system where Depleted Zinc Oxide was dissolved in carbonated water. Controllability of the system was sufficient to maintain concentration of zinc in primary water. The concentration of zinc in the primary coolant was controlled from 1 ppb to 5 ppb gradually. The increasing trend of concentration of Co-60 in the coolant was suppressed at zinc concentration of 3 ppb. It is evaluated that the deposition coefficient of Co-60 onto the surface of primary coolant recirculation piping was suppressed to one-third of previous cycle in average, and one-fourth of that just before injection start at zinc concentration of 5 ppb. We concluded that zinc injection is effective for suppressing dose rate on the primary coolant piping and no adverse effect occurs by zinc injection up to 5 ppb in the primary coolant. (J.P.N.)

  7. Surface contact fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-06-01

    Full Text Available Surface contact fatigue is the most common cause of gear failure. It results in damage to contacting surfaces which can significantly reduce the load-carrying capacity of components, and may ultimately lead to complete failure of a gear. Three types...

  8. Shimmy of Aircraft Main Landing Gears

    NARCIS (Netherlands)

    Besselink, I.J.M.

    2000-01-01

    The landing gear is an important aircraft system, which has to meet many different design requirements. It is a highly loaded structure, which is designed for minimum weight. Shimmy is a dynamic instability of the landing gear, which is caused by the interaction of the dynamic behaviour of the

  9. Tooth bending fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1996-09-01

    Full Text Available . It results in progressive damage to gear teeth and ultimately leads to complete failure of the gear. The characteristics of this failure mode are discussed in detail and a number of actual case studies are presented which show the occurrence of this failure...

  10. A method for gear fatigue life prediction considering the internal flow field of the gear pump

    Science.gov (United States)

    Shen, Haidong; Li, Zhiqiang; Qi, Lele; Qiao, Liang

    2018-01-01

    Gear pump is the most widely used volume type hydraulic pump, and it is the main power source of the hydraulic system. Its performance is influenced by many factors, such as working environment, maintenance, fluid pressure and so on. It is different from the gear transmission system, the internal flow field of gear pump has a greater impact on the gear life, therefore it needs to consider the internal hydraulic system when predicting the gear fatigue life. In this paper, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposing the prediction method based on the virtual simulation. The method use CFD (Computational fluid dynamics) software to analyze pressure distribution of internal flow field of the gear pump, and constructed the unidirectional flow-solid coupling model of gear to acquire the contact stress of tooth surface on Ansys workbench software. Finally, employing nominal stress method and Miner cumulative damage theory to calculated the gear contact fatigue life based on modified material P-S-N curve. Engineering practice show that the method is feasible and efficient.

  11. Corrective Action Plan for Corrective Action Unit 543: Liquid Disposal Units, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Restoration

    2007-01-01

    Corrective Action Unit (CAU) 543: Liquid Disposal Units is listed in Appendix III of the ''Federal Facility Agreement and Consent Order'' (FFACO) which was agreed to by the state of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense (FFACO, 1996). CAU 543 sites are located in Areas 6 and 15 of the Nevada Test Site (NTS), which is approximately 65 miles northwest of Las Vegas, Nevada. CAU 543 consists of the following seven Corrective Action Sites (CASs) (Figure 1): CAS 06-07-01, Decon Pad; CAS 15-01-03, Aboveground Storage Tank; CAS 15-04-01, Septic Tank; CAS 15-05-01, Leachfield; CAS 15-08-01, Liquid Manure Tank; CAS 15-23-01, Underground Radioactive Material Area; and CAS 15-23-03, Contaminated Sump, Piping. All Area 15 CASs are located at the former U.S. Environmental Protection Agency (EPA) Farm, which operated from 1963 to 1981 and was used to support animal experiments involving the uptake of radionuclides. Each of the Area 15 CASs, except CAS 15-23-01, is associated with the disposal of waste effluent from Building 15-06, which was the primary location of the various tests and experiments conducted onsite. Waste effluent disposal from Building 15-06 involved piping, sumps, outfalls, a septic tank with leachfield, underground storage tanks, and an aboveground storage tank (AST). CAS 15-23-01 was associated with decontamination activities of farm equipment potentially contaminated with radiological constituents, pesticides, and herbicides. While the building structures were removed before the investigation took place, all the original tanks, sumps, piping, and concrete building pads remain in place. The Area 6 CAS is located at the Decontamination Facility in Area 6, a facility which operated from 1971 to 2001 and was used to decontaminate vehicles, equipment, clothing, and other materials that had become contaminated during nuclear testing activities. The CAS includes the effluent collection and distribution systems for Buildings

  12. Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

    Directory of Open Access Journals (Sweden)

    Y. Gui

    2014-01-01

    Full Text Available Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

  13. The surface fatigue life of contour induction hardened AISI 1552 gears

    Science.gov (United States)

    Townsend, Dennis P.; Turza, Alan; Chaplin, Mike

    1995-07-01

    Two groups of spur gears manufactured from two different materials and heat treatments were endurance tested for surface fatigue life. One group was manufactured from AISI 1552 and was finished ground to a 0.4 micron (16 micro-in.) rms surface finish and then dual frequency contour induction hardened. The second group was manufactured from CEVM AISI 9310 and was carburized, hardened, and ground to a 0.4 micron (16 micro-in.) rms surface finish. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a maximum Hertz stress of 1.71 GPa (248 ksi), a bulk gear temperature of approximately 350 K (170 F) and a speed of 10,000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The test results showed that the 10 percent surface fatigue (pitting) life of the contour hardened AISI 1552 test gears was 1.7 times that of the carburized and hardened AISI 9310 test gears. Also there were two early failures of the AISI 1552 gears by bending fatigue.

  14. Efficiency comparisons of fish sampling gears for a lentic ecosystem health assessments in Korea

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Han

    2016-12-01

    Full Text Available The key objective of this study was to analyze the sampling efficiency of various fish sampling gears for a lentic ecosystem health assessment. A fish survey for the lentic ecosystem health assessment model was sampled twice from 30 reservoirs during 2008–2012. During the study, fishes of 81 species comprising 53,792 individuals were sampled from 30 reservoirs. A comparison of sampling gears showed that casting nets were the best sampling gear with high species richness (69 species, whereas minnow traps were the worst gear with low richness (16 species. Fish sampling efficiency, based on the number of individual catch per unit effort, was best in fyke nets (28,028 individuals and worst in minnow traps (352 individuals. When we compared trammel nets and kick nets versus fyke nets and casting nets, the former were useful in terms of the number of fish individuals but not in terms of the number of fish species.

  15. 10 CFR 430.24 - Units to be tested.

    Science.gov (United States)

    2010-01-01

    ... this section, for each basic model 1 of conventional cooking tops, conventional ovens and microwave...-registered professional engineer who is not an employee of the manufacturer. The registered professional... consumption of the unit(s). The manufacturer is to keep the registered professional engineer's certifications...

  16. THE GERMLINE STEM CELL NICHE UNIT IN MAMMALIAN TESTES

    Science.gov (United States)

    Oatley, Jon M.; Brinster, Ralph L.

    2014-01-01

    This review addresses current understanding of the germline stem cell niche unit in mammalian testes. Spermatogenesis is a classic model of tissue-specific stem cell function relying on self-renewal and differentiation of spermatogonial stem cells (SSCs). These fate decisions are influenced by a niche microenvironment composed of a growth factor milieu that is provided by several testis somatic support cell populations. Investigations over the last two decades have identified key determinants of the SSC niche including cytokines that regulate SSC functions and support cells providing these factors, adhesion molecules that influence SSC homing, and developmental heterogeneity of the niche during postnatal aging. Emerging evidence suggests that Sertoli cells are a key support cell population influencing the formation and function of niches by secreting soluble factors and possibly orchestrating contributions of other support cells. Investigations with mice have shown that niche influence on SSC proliferation differs during early postnatal development and adulthood. Moreover, there is mounting evidence of an age-related decline in niche function, which is likely influenced by systemic factors. Defining the attributes of stem cell niches is key to developing methods to utilize these cells for regenerative medicine. The SSC population and associated niche comprise a valuable model system for study that provides fundamental knowledge about the biology of tissue-specific stem cells and their capacity to sustain homeostasis of regenerating tissue lineages. While the stem cell is essential for maintenance of all self-renewing tissues and has received considerable attention, the role of niche cells is at least as important and may prove to be more receptive to modification in regenerative medicine. PMID:22535892

  17. Research of Planetary Gear Fault Diagnosis Based on Permutation Entropy of CEEMDAN and ANFIS

    Directory of Open Access Journals (Sweden)

    Moshen Kuai

    2018-03-01

    Full Text Available For planetary gear has the characteristics of small volume, light weight and large transmission ratio, it is widely used in high speed and high power mechanical system. Poor working conditions result in frequent failures of planetary gear. A method is proposed for diagnosing faults in planetary gear based on permutation entropy of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN Adaptive Neuro-fuzzy Inference System (ANFIS in this paper. The original signal is decomposed into 6 intrinsic mode functions (IMF and residual components by CEEMDAN. Since the IMF contains the main characteristic information of planetary gear faults, time complexity of IMFs are reflected by permutation entropies to quantify the fault features. The permutation entropies of each IMF component are defined as the input of ANFIS, and its parameters and membership functions are adaptively adjusted according to training samples. Finally, the fuzzy inference rules are determined, and the optimal ANFIS is obtained. The overall recognition rate of the test sample used for ANFIS is 90%, and the recognition rate of gear with one missing tooth is relatively high. The recognition rates of different fault gears based on the method can also achieve better results. Therefore, the proposed method can be applied to planetary gear fault diagnosis effectively.

  18. Dynamic investigation of a locomotive with effect of gear transmissions under tractive conditions

    Science.gov (United States)

    Chen, Zaigang; Zhai, Wanming; Wang, Kaiyun

    2017-11-01

    Locomotive is used to drag trailers to move or supply the braking forces to slow the running speed of a train. The electromagnetic torque of the motor is always transmitted by the gear transmission system to the wheelset for generation of the tractive or braking forces at the wheel-rail contact interface. Consequently, gear transmission system is significant for power delivery of a locomotive. This paper develops a comprehensive locomotive-track vertical-longitudinal coupled dynamics model with dynamic effect of gear transmissions. This dynamics model enables considering the coupling interactions between the gear transmission motion, the vertical and the longitudinal motions of the vehicle, and the vertical vibration of the track structure. In this study, some complicated dynamic excitations, such as the gear time-varying mesh stiffness, nonlinear gear tooth backlash, the nonlinear wheel-rail normal contact force and creep force, and the rail vertical geometrical irregularity, are considered. Then, the dynamic responses of the locomotive under the tractive conditions are demonstrated by numerical simulations based on the established dynamics model and by experimental test. The developed dynamics model is validated by the good agreement between the experimental and the theoretical results. The calculated results reveal that the gear transmission system has strong dynamic interactions with the wheel-rail contact interface including both the vertical and the longitudinal motions, and it has negligible effect on the vibrations of the bogie frame and carbody.

  19. A Comparative Study of Simulated and Measured Gear-Flap Flow Interaction

    Science.gov (United States)

    Khorrami, Mehdi R.; Mineck, Raymond E.; Yao, Chungsheng; Jenkins, Luther N.; Fares, Ehab

    2015-01-01

    The ability of two CFD solvers to accurately characterize the transient, complex, interacting flowfield asso-ciated with a realistic gear-flap configuration is assessed via comparison of simulated flow with experimental measurements. The simulated results, obtained with NASA's FUN3D and Exa's PowerFLOW® for a high-fidelity, 18% scale semi-span model of a Gulfstream aircraft in landing configuration (39 deg flap deflection, main landing gear on and off) are compared to two-dimensional and stereo particle image velocimetry measurements taken within the gear-flap flow interaction region during wind tunnel tests of the model. As part of the bench-marking process, direct comparisons of the mean and fluctuating velocity fields are presented in the form of planar contour plots and extracted line profiles at measurement planes in various orientations stationed in the main gear wake. The measurement planes in the vicinity of the flap side edge and downstream of the flap trailing edge are used to highlight the effects of gear presence on tip vortex development and the ability of the computational tools to accurately capture such effects. The present study indicates that both computed datasets contain enough detail to construct a relatively accurate depiction of gear-flap flow interaction. Such a finding increases confidence in using the simulated volumetric flow solutions to examine the behavior of pertinent aer-odynamic mechanisms within the gear-flap interaction zone.

  20. Research of Planetary Gear Fault Diagnosis Based on Permutation Entropy of CEEMDAN and ANFIS.

    Science.gov (United States)

    Kuai, Moshen; Cheng, Gang; Pang, Yusong; Li, Yong

    2018-03-05

    For planetary gear has the characteristics of small volume, light weight and large transmission ratio, it is widely used in high speed and high power mechanical system. Poor working conditions result in frequent failures of planetary gear. A method is proposed for diagnosing faults in planetary gear based on permutation entropy of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) Adaptive Neuro-fuzzy Inference System (ANFIS) in this paper. The original signal is decomposed into 6 intrinsic mode functions (IMF) and residual components by CEEMDAN. Since the IMF contains the main characteristic information of planetary gear faults, time complexity of IMFs are reflected by permutation entropies to quantify the fault features. The permutation entropies of each IMF component are defined as the input of ANFIS, and its parameters and membership functions are adaptively adjusted according to training samples. Finally, the fuzzy inference rules are determined, and the optimal ANFIS is obtained. The overall recognition rate of the test sample used for ANFIS is 90%, and the recognition rate of gear with one missing tooth is relatively high. The recognition rates of different fault gears based on the method can also achieve better results. Therefore, the proposed method can be applied to planetary gear fault diagnosis effectively.

  1. Elasto-dynamic analysis of a gear pump-Part III: Experimental validation procedure and model extension to helical gears

    Science.gov (United States)

    Mucchi, E.; Dalpiaz, G.

    2015-01-01

    This work concerns external gear pumps for automotive applications, which operate at high speed and low pressure. In previous works of the authors (Part I and II, [1,2]), a non-linear lumped-parameter kineto-elastodynamic model for the prediction of the dynamic behaviour of external gear pumps was presented. It takes into account the most important phenomena involved in the operation of this kind of machine. The two main sources of noise and vibration are considered: pressure pulsation and gear meshing. The model has been used in order to foresee the influence of working conditions and design modifications on vibration generation. The model's experimental validation is a difficult task. Thus, Part III proposes a novel methodology for the validation carried out by the comparison of simulations and experimental results concerning forces and moments: it deals with the external and inertial components acting on the gears, estimated by the model, and the reactions and inertial components on the pump casing and the test plate, obtained by measurements. The validation is carried out comparing the level of the time synchronous average in the time domain and the waterfall maps in the frequency domain, with particular attention to identify system resonances. The validation results are satisfactory globally, but discrepancies are still present. Moreover, the assessed model has been properly modified for the application to a new virtual pump prototype with helical gears in order to foresee gear accelerations and dynamic forces. Part IV is focused on improvements in the modelling and analysis of the phenomena bound to the pressure evolution around the gears in order to achieve results closer to the measured values. As a matter of fact, the simulation results have shown that a variable meshing stiffness has a notable contribution on the dynamic behaviour of the pump but this is not as important as the pressure phenomena. As a consequence, the original model was modified with the

  2. JTst - An Automated Unit Testing Tool for Java Program

    OpenAIRE

    Kamal Z.  Zamli; Nor A. M.  Isa

    2008-01-01

    Software testing is an integral part of software development lifecycle. Lack of testing can often lead to disastrous consequences including lost of data, fortunes, and even lives. Despite its importance, current software testing practice lacks automation, and is still primarily based on highly manual processes from the generation of test cases up to the actual execution of the test. Although the emergence of helpful automated testing tools in the market is blooming, their adoptions are lackin...

  3. 78 FR 38411 - Vogtle Electric Generating Plant, Unit 4; Inspections, Tests, Analyses, and Acceptance Criteria

    Science.gov (United States)

    2013-06-26

    ... Plant, Unit 4; Inspections, Tests, Analyses, and Acceptance Criteria AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and acceptance criteria completion. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the inspections, tests...

  4. Evaluation of MEMS-Based Wireless Accelerometer Sensors in Detecting Gear Tooth Faults in Helicopter Transmissions

    Science.gov (United States)

    Lewicki, David George; Lambert, Nicholas A.; Wagoner, Robert S.

    2015-01-01

    The diagnostics capability of micro-electro-mechanical systems (MEMS) based rotating accelerometer sensors in detecting gear tooth crack failures in helicopter main-rotor transmissions was evaluated. MEMS sensors were installed on a pre-notched OH-58C spiral-bevel pinion gear. Endurance tests were performed and the gear was run to tooth fracture failure. Results from the MEMS sensor were compared to conventional accelerometers mounted on the transmission housing. Most of the four stationary accelerometers mounted on the gear box housing and most of the CI's used gave indications of failure at the end of the test. The MEMS system performed well and lasted the entire test. All MEMS accelerometers gave an indication of failure at the end of the test. The MEMS systems performed as well, if not better, than the stationary accelerometers mounted on the gear box housing with regards to gear tooth fault detection. For both the MEMS sensors and stationary sensors, the fault detection time was not much sooner than the actual tooth fracture time. The MEMS sensor spectrum data showed large first order shaft frequency sidebands due to the measurement rotating frame of reference. The method of constructing a pseudo tach signal from periodic characteristics of the vibration data was successful in deriving a TSA signal without an actual tach and proved as an effective way to improve fault detection for the MEMS.

  5. A Nonlinear Unit Root Test in the Presence of an Unknown Break

    OpenAIRE

    Popp, Stephan

    2008-01-01

    The Perron test is the most commonly applied procedure to test for a unit root in the presence of a structural break of unknown timing in the trend function. Deriving the Perron-type test regression from an unobserved component model, it is shown that the test regression in fact is nonlinear in coefficient. Taking account of the nonlinearity leads to a test with properties that are exclusively assigned to Schmidt-Phillips LM-type unit root tests.

  6. Fishing-gear restrictions and biomass gains for coral reef fishes in marine protected areas.

    Science.gov (United States)

    Campbell, Stuart J; Edgar, Graham J; Stuart-Smith, Rick D; Soler, German; Bates, Amanda E

    2018-04-01

    Considerable empirical evidence supports recovery of reef fish populations with fishery closures. In countries where full exclusion of people from fishing may be perceived as inequitable, fishing-gear restrictions on nonselective and destructive gears may offer socially relevant management alternatives to build recovery of fish biomass. Even so, few researchers have statistically compared the responses of tropical reef fisheries to alternative management strategies. We tested for the effects of fishery closures and fishing gear restrictions on tropical reef fish biomass at the community and family level. We conducted 1,396 underwater surveys at 617 unique sites across a spatial hierarchy within 22 global marine ecoregions that represented 5 realms. We compared total biomass across local fish assemblages and among 20 families of reef fishes inside marine protected areas (MPAs) with different fishing restrictions: no-take, hook-and-line fishing only, several fishing gears allowed, and sites open to all fishing gears. We included a further category representing remote sites, where fishing pressure is low. As expected, full fishery closures, (i.e., no-take zones) most benefited community- and family-level fish biomass in comparison with restrictions on fishing gears and openly fished sites. Although biomass responses to fishery closures were highly variable across families, some fishery targets (e.g., Carcharhinidae and Lutjanidae) responded positively to multiple restrictions on fishing gears (i.e., where gears other than hook and line were not permitted). Remoteness also positively affected the response of community-level fish biomass and many fish families. Our findings provide strong support for the role of fishing restrictions in building recovery of fish biomass and indicate important interactions among fishing-gear types that affect biomass of a diverse set of reef fish families. © 2017 Society for Conservation Biology.

  7. Improve Gear Fault Diagnosis and Severity Indexes Determinations via Time Synchronous Average

    Directory of Open Access Journals (Sweden)

    Mohamed El Morsy

    2016-11-01

    Full Text Available In order to reduce operation and maintenance costs, prognostics and health management (PHM of the geared system is needed to improve effective gearbox fault detection tools.  PHM system allows less costly maintenance because it can inform operators of needed repairs before a fault causes collateral damage happens to the gearbox. In this article, time synchronous average (TSA technique and complex continuous wavelet analysis enhancement are used as gear fault detection approach. In the first step, extract the periodic waveform from the noisy measured signal is considered as The main value of Time synchronous averaging (TSA for gearbox signals analyses, where it allows the vibration signature of the gear under analysis to be separated from other gears and noise sources in the gearbox that are not synchronous with faulty gear. In the second step, the complex wavelet analysis is used in case of multi-faults in same gear. The signal phased-locked with the angular position of a shaft within the system is done. The main aims for this research is to improve the gear fault diagnosis and severity index determinations based on TSA  of measured signal for investigated passenger vehicle gearbox under different operation conditions. In addition to, correct the variations in shaft speed such that the spreading of spectral energy into an adjacent gear mesh bin helps in detecting the gear fault position (faulted tooth or teeth and improve the Root Mean Square (RMS, Kurtosis, and Peak Pulse as the sensitivity of severity indexes for maintenance, prognostics and health management (PHM purposes. The open loop test stand is equipped with two dynamometers and investigated vehicle gearbox of mid-size passenger car; the total power is taken-off from one side only. Reference Number: www.asrongo.org/doi:4.2016.1.1.6

  8. Out-pile test plan for lifetime extension of shutoff units in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Joe, Y. G.; Lee, J. H.; Jeong, Y. H.; Woo, S. I.; Ryu, J. S.; Kim, Y. G.; Park, Y. C.; Kim, H. G.; Woo, J. S. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    It is estimated that the number of drops of shutoff rods in HANARO will reach the endurance verified numbers before the end of the reactor life. To resolve this situation, we have a plan to prepare of a new spare unit by the performance verification test for the local product, and extend the lifetime of shutoff units installed in the reactor by performing an additional endurance test in the out-pile test facility using an existing spare unit. This paper describes the overall situations and test plan for the out-pile test to extend the lifetime extension of shutoff unit.

  9. Modeling and Analysis of Deformation for Spiral Bevel Gear in Die Quenching Based on the Hardenability Variation

    Science.gov (United States)

    Zhang, Yingtao; Wang, Gang; Shi, Wankai; Yang, Lin; Li, Zhichao

    2017-07-01

    Spiral bevel gears are widely used to transmit energy between intersecting axes. The strength and fatigue life of the gears are improved by carburizing and quenching. A die quenching process is used to control the deformation of the gear. The deformation is determined by the variations in the hardenability for a certain die quenching process. The relationship between hardenability, phase transformation and deformation needs to be studied to minimize deformation during the adjustment of the die quenching process parameters. In this paper, material properties for 22CrMoH steel are determined by the results of Jominy tests, dilatometry experiments and static mechanical property tests. The material models were built based on testing results under the consideration of hardenability variation. An finite element analysis model was developed to couple the phase transformation and deformation history of the complete carburizing and die quenching process for the spiral bevel gears. The final microstructures in the gear were bainite for low hardenability steel and a mixture of bainite and ferrite for high hardenability steel. The largest buckling deformation at the gear bottom surface is 0.375 mm at the outer circle for the low hardenability gear and 0.091 mm at the inner circle for the high hardenability gear.

  10. Vehicle transmission gear 2009; Getriebe in Fahrzeugen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    : functionality, design and development methodology (A. Giacometti); (18) DCT system approach: Choose drive away and shift feeling (O. Einfinger); (19) An example for the use of adaptive methods in powertrain control of heavy duty vehicles (C. Joachim); (20) The effect of lubricating oils on bearing fatigue-life using the Evonik RohMax pitting test procedure (T. Bartels); (21) Influence of lubricant on the pitting capacity of gears - Comparison and discussion of main pitting test methods (B.-R. Hoehn); (22) Reduction of CO{sub 2} emission by means of innovative, tailor-made gear oils (P. Kraneburg); (23) Development of a force element for the emulation of the dynamic behaviour of bevel gears (C. Brecher); (24) A simulation software for the optimisation of the gearing of conical toothed gears (H. Alxneit); (25) Fatigue life optimization for hypoid gears (Ch. Haberer); (26) BorgWarner DualTronic {sup registered} transmission concepts for efficiency, cost and robustness (A. Moser); (27) Hy Tronic - The hybrid system for distributor commercial vehicles on the bases of a modular NKW gear family (S. Wallner); (28) New drive axles for hybrid applications in low-floor city busses (U. Solka); (29) Design, construction and integration of hybrid drive components in commercial vehicles (S. Kerschl); (30) Cold trip to chassis roller dyno (J. Lewis); (31) Model-based development of a dual-clutch transmission using rapid prototyping and SiL (H. Brueckmann); (31) New synchroniser system for modern transmissions (O. Back); (32) Improving shift dynamics and efficiency of MTs, AMTs and DCTs using full servo synchronizers (T. Hackl); (33) N{sup T} {sup registered} LightDiff: Innovative, lightweight concept for bevel-gear differentials (M. Derse); (34) Hybrid concepts of the co-operation GETRAG-BOSCH and their realisation in a demonstrator car (B. Blankenbach); (35) The conservation potential of consumption of the ZF hybrid gear system (R. Kubalczyk); (36) FEV's new parallel hybrid transmission

  11. Comparison of analysis and experiment for dynamics of low-contact-ratio spur gears

    Science.gov (United States)

    Oswald, Fred B.; Rebbechi, Brian; Zakrajsek, James J.; Townsend, Dennis P.; Lin, Hsiang Hsi

    1991-01-01

    Low-contact-ratio spur gears were tested in NASA gear-noise-rig to study gear dynamics including dynamic load, tooth bending stress, vibration, and noise. The experimental results were compared with a NASA gear dynamics code to validate the code as a design tool for predicting transmission vibration and noise. Analytical predictions and experimental data for gear-tooth dynamic loads and tooth-root bending stress were compared at 28 operating conditions. Strain gage data were used to compute the normal load between meshing teeth and the bending stress at the tooth root for direct comparison with the analysis. The computed and measured waveforms for dynamic load and stress were compared for several test conditions. These are very similar in shape, which means the analysis successfully simulates the physical behavior of the test gears. The predicted peak value of the dynamic load agrees with the measurement results within an average error of 4.9 percent except at low-torque, high-speed conditions. Predictions of peak dynamic root stress are generally within 10 to 15 percent of the measured values.

  12. Analysis of 3D printing parameters of gears for hybrid manufacturing

    Science.gov (United States)

    Budzik, Grzegorz; Przeszlowski, Łukasz; Wieczorowski, Michal; Rzucidlo, Arkadiusz; Gapinski, Bartosz; Krolczyk, Grzegorz

    2018-05-01

    The paper deals with analysis and selection of parameters of rapid prototyping of gears by selective sintering of metal powders. Presented results show wide spectrum of application of RP systems in manufacturing processes of machine elements, basing on analysis of market in term of application of additive manufacturing technology in different sectors of industry. Considerable growth of these methods over the past years can be observed. The characteristic errors of printed model with respect to ideal one for each technique were pointed out. Special attention was paid to the method of preparation of numerical data CAD/STL/RP. Moreover the analysis of manufacturing processes of gear type elements was presented. The tested gears were modeled with different allowances for final machining and made by DMLS. Metallographic analysis and strength tests on prepared specimens were performed. The above mentioned analysis and tests were used to compare the real properties of material with the nominal ones. To improve the quality of surface after sintering the gears were subjected to final machining. The analysis of geometry of gears after hybrid manufacturing method was performed (fig.1). The manufacturing process was defined in a traditional way as well as with the aid of modern manufacturing techniques. Methodology and obtained results can be used for other machine elements than gears and constitutes the general theory of production processes in rapid prototyping methods as well as in designing and implementation of production.

  13. 14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...

  14. 50 CFR 622.46 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 622.46... Management Measures § 622.46 Prevention of gear conflicts. (a) No person may knowingly place in the Gulf EEZ any article, including fishing gear, that interferes with fishing or obstructs or damages fishing gear...

  15. 46 CFR 108.641 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary steering...

  16. 14 CFR 25.1515 - Landing gear speeds.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear, as...

  17. 50 CFR 654.25 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 654.25... Measures § 654.25 Prevention of gear conflicts. (a) No person may knowingly place in the management area any article, including fishing gear, that interferes with fishing or obstructs or damages fishing gear...

  18. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall be...

  19. 50 CFR 640.22 - Gear and diving restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear and diving restrictions. 640.22... ATLANTIC Management Measures § 640.22 Gear and diving restrictions. (a) Prohibited gear and methods. (1) A spiny lobster may not be taken in the EEZ with a spear, hook, or similar device, or gear containing such...

  20. 46 CFR 58.25-20 - Piping for steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Piping for steering gear. 58.25-20 Section 58.25-20... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must... the hydraulic system can be readily recharged from within the steering-gear compartment and must be...

  1. DESIGN FOR A BI-PLANETARY GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    Józef DREWNIAK

    2016-06-01

    Full Text Available The article presents the design for a bi-planetary gear train. The project description is supplemented with calculations of kinematics, statics and meshing efficiency of the gear wheels included in the gear train. Excluded are calculations of strength and geometry of gears, shaft and rolling bearing, since they are similar to classical calculations for planetary gears. An assembly drawing in 2D and assembly drawings in 3D of the designed bi-planetary gear train are also shown. This gear train will form the main element of the research in hand.

  2. 50 CFR 654.22 - Gear restrictions.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Management Measures § 654.22 Gear... retaining chamber. (6) A plastic or wire trap must have a degradable panel. (i) A plastic trap will be...

  3. Gulf of Mexico Shrimp Permit Gear Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set contains annual vessel gear characterization of permit holders shrimp vessel. Data includes net type, TED type, BRD type, etc.

  4. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  5. Tooth contact analysis of spur gears. Part 2-Analysis of modified gears

    Directory of Open Access Journals (Sweden)

    Pop Nicolae

    2017-01-01

    Full Text Available The misalignment between gears axes or direction deviations of teeth leads accentuate the edge effect, Modified spur gears which localize the initial bearing contact by proper modifications of the lead profile are used to avoid the development of the edge effect. A semi-analytical method was involved to find the contact area, pressures distribution and depth stresses states for the standard gears and gears with modified lead profile. The lead modifications concerned the crowning of the flank surface and the end relieving of the tooth flanks, both being applied to the pinion teeth only.

  6. High Speed Gear Sized and Configured to Reduce Windage Loss

    Science.gov (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  7. Analysis and test of torque characteristics for force balance and multi input gear motor%力平衡型多输入齿轮马达的转矩特性分析与试验

    Institute of Scientific and Technical Information of China (English)

    闻德生; 潘为圆; 石滋洲; 商旭东; 马光磊; 顾攀

    2017-01-01

    针对传统齿轮马达径向力不平衡、只能输出一种转矩和转矩脉动较高的问题,提出了力平衡型多输入齿轮马达.该马达在一个壳体内有内、外两种马达,可通过不同的连接方式实现4种定转矩和定转速的输出.通过对马达的输出转矩进行理论计算和试验,分析了马达在4种工作方式下的瞬时转矩及转矩脉动,结果表明,单个马达工作时的转矩脉动与啮合齿轮的齿数有关.多个马达同时工作时的转矩脉动与齿轮啮合点的位置及脉动周期有关,当3个内马达共同工作,内、外马达共同工作,内、外马达差动工作时,在内、外马达脉动周期相同的前提下,可调节啮合点的位置,分别使3个小齿轮的轮齿啮合位置相差1/3,内、外马达轮齿啮合位置相差1/2,内、外马达轮齿啮合位置相同,通过瞬时转矩的叠加,使输出合转矩的脉动最小.试验结果表明,在调节齿轮啮合点的位置后,相同工作方式下的转矩脉动程度明显减少,该研究为多输入马达的进一步研究提供了参考.%With the development of economy, hydraulic transmission is an indispensable part of national economy. Hydraulic actuator is the core part of hydraulic transmission, and the gear motor has the advantages of small size, light weight, and strong adaptability to the harsh working conditions, and has a very important role in hydraulic actuator. But gear motor's torque fluctuation is larger, and there are unbalanced radial force, trapped oil phenomenon and big noise, so it is difficult to develop. Based on these reasons, in this paper, a force balance type multi input gear motor is proposed, which has 3 internal motors and 3 outer motors in one case, the inner and outer motors are evenly distributed on the output shaft, and the radial force of the output shaft is balanced by the output shaft, which can significantly reduce the total force on the gear shaft and the bearing, and help to improve

  8. Conductive ink print on PA66 gear for manufacturing condition monitoring sensors

    Science.gov (United States)

    Futagawa, Shintaro; Iba, Daisuke; Kamimoto, Takahiro; Nakamura, Morimasa; Miura, Nanako; Iizuka, Takashi; Masuda, Arata; Sone, Akira; Moriwaki, Ichiro

    2018-03-01

    Failures detection of rotating machine elements, such as gears, is an important issue. The purpose of this study was to try to solve this issue by printing conductive ink on gears to manufacture condition-monitoring sensors. In this work, three types of crack detection sensor were designed and the sprayed conductive ink was directly sintered on polyimide (PI) - coated polyamide (PA) 66 gears by laser. The result showed that it was possible to produce narrow circuit lines of the conductive ink including Ag by laser sintering technique and the complex shape sensors on the lateral side of the PA66 gears, module 1.0 mm and tooth number 48. A preliminary operation test was carried out for investigation of the function of the sensors. As a result of the test, the sensors printed in this work should be effective for detecting cracks at tooth root of the gears and will allow for the development of better equipment and detection techniques for health monitoring of gears.

  9. Identification of the Onset of Cracking in Gear Teeth Using Acoustic Emission

    International Nuclear Information System (INIS)

    Pullin, R; Clarke, A; Eaton, M J; Pearson, M R; Holford, K M

    2012-01-01

    The development of diagnostic methods for gear tooth faults in aerospace power transmission systems is an active research area being driven largely by the interests of military organisations or large aerospace organisations. In aerospace applications, the potential results of gear failure are serious, ranging from increased asset downtime to, at worst, catastrophic failure with life-threatening consequences. New monitoring techniques which can identify the onset of failure at earlier stages are in demand. Acoustic Emission (AE) is the most sensitive condition monitoring tool and is a passive technique that detects the stress wave emitted by a structure as cracks propagate. In this study a gear test rig that allows the fatigue loading of an individual gear tooth was utilised. The rig allows a full AE analysis of damage signatures in gear teeth without the presence of constant background noise due to rotational and frictional sources. Furthermore this approach allows validation of AE results using crack gauges or strain gauges. Utilising a new approach to AE monitoring a sensor was mounted on the gear and used to continuously capture AE data for a complete fatigue load cycle of data, rather than the traditional approach where discrete signals are captured on a threshold basis. Data was captured every 10th load cycle for the duration of the test. A developed fast fourier transform analysis technique was compared with traditional analytical methods. In this investigation the developed techniques were validated against visual inspection and were shown to be far superior to the traditional approach.

  10. Advanced Gear Alloys for Ultra High Strength Applications

    Science.gov (United States)

    Shen, Tony; Krantz, Timothy; Sebastian, Jason

    2011-01-01

    Single tooth bending fatigue (STBF) test data of UHS Ferrium C61 and C64 alloys are presented in comparison with historical test data of conventional gear steels (9310 and Pyrowear 53) with comparable statistical analysis methods. Pitting and scoring tests of C61 and C64 are works in progress. Boeing statistical analysis of STBF test data for the four gear steels (C61, C64, 9310 and Pyrowear 53) indicates that the UHS grades exhibit increases in fatigue strength in the low cycle fatigue (LCF) regime. In the high cycle fatigue (HCF) regime, the UHS steels exhibit better mean fatigue strength endurance limit behavior (particularly as compared to Pyrowear 53). However, due to considerable scatter in the UHS test data, the anticipated overall benefits of the UHS grades in bending fatigue have not been fully demonstrated. Based on all the test data and on Boeing s analysis, C61 has been selected by Boeing as the gear steel for the final ERDS demonstrator test gearboxes. In terms of potential follow-up work, detailed physics-based, micromechanical analysis and modeling of the fatigue data would allow for a better understanding of the causes of the experimental scatter, and of the transition from high-stress LCF (surface-dominated) to low-stress HCF (subsurface-dominated) fatigue failure. Additional STBF test data and failure analysis work, particularly in the HCF regime and around the endurance limit stress, could allow for better statistical confidence and could reduce the observed effects of experimental test scatter. Finally, the need for further optimization of the residual compressive stress profiles of the UHS steels (resulting from carburization and peening) is noted, particularly for the case of the higher hardness C64 material.

  11. Testing for seasonal unit roots in monthly panels of time series

    NARCIS (Netherlands)

    R.M. Kunst (Robert); Ph.H.B.F. Franses (Philip Hans)

    2009-01-01

    textabstractWe consider the problem of testing for seasonal unit roots in monthly panel data. To this aim, we generalize the quarterly CHEGY test to the monthly case. This parametric test is contrasted with a new nonparametric test, which is the panel counterpart to the univariate RURS test that

  12. Operational test procedure for SY tank farm replacement exhauster unit

    International Nuclear Information System (INIS)

    McClees, J.

    1995-01-01

    This operational test procedure will verify that the remaining functions not tested per WHC-SD-WM-ATP-080, or components disturbed during final installation, as well as interfaces with other tank farm equipment and remote monitoring stations are operating correctly

  13. Lumped Parameter Modeling for Rapid Vibration Response Prototyping and Test Correlation for Electronic Units

    Science.gov (United States)

    Van Dyke, Michael B.

    2013-01-01

    Present preliminary work using lumped parameter models to approximate dynamic response of electronic units to random vibration; Derive a general N-DOF model for application to electronic units; Illustrate parametric influence of model parameters; Implication of coupled dynamics for unit/board design; Demonstrate use of model to infer printed wiring board (PWB) dynamics from external chassis test measurement.

  14. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Science.gov (United States)

    2011-12-30

    ... Filtration and Adsorption Units AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... for Air Filtration and Adsorption Units of Postaccident Engineered-Safety-Feature Atmosphere Cleanup... testing of air filtration and iodine adsorption units of engineered-safety-feature (ESF) atmosphere...

  15. Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

    Science.gov (United States)

    Stevenson, L. E.; Scott, L. D.; Oakes, E. T.

    1987-04-01

    The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

  16. 78 FR 53483 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3

    Science.gov (United States)

    2013-08-29

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 052-00025; NRC-2008-0252] Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and acceptance criteria (ITAAC) completion...

  17. 78 FR 53484 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4

    Science.gov (United States)

    2013-08-29

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 052-00026; NRC-2008-0252] Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and acceptance criteria (ITAAC) completion...

  18. 78 FR 65007 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3

    Science.gov (United States)

    2013-10-30

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 052-00026; NRC-2008-0252] Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and acceptance criteria completion...

  19. A unit root test based on smooth transitions and nonlinear adjustment

    OpenAIRE

    Hepsag, Aycan

    2017-01-01

    In this paper, we develop a new unit root testing procedure which considers jointly for structural breaks and nonlinear adjustment. The structural breaks are modelled by means of a logistic smooth transition function and nonlinear adjustment is modelled by means of an ESTAR model. The empirical size of test is quite close to the nominal one and in terms of power; the new unit root test is generally superior to the alternative test. The new unit root test presents good size properties and does...

  20. Systems and Methods for Implementing Bulk Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Wilcox, Brian (Inventor)

    2016-01-01

    Bulk metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a strain wave gear includes: a wave generator; a flexspline that itself includes a first set of gear teeth; and a circular spline that itself includes a second set of gear teeth; where at least one of the wave generator, the flexspline, and the circular spline, includes a bulk metallic glass-based material.

  1. The Power of Unit Root Tests Against Nonlinear Local Alternatives

    DEFF Research Database (Denmark)

    Demetrescu, Matei; Kruse, Robinson

    of Econometrics 112, 359-379) in comparison to the linear Dickey-Fuller test. To this end, we consider different adjustment schemes for deterministic terms. We provide asymptotic results which imply that the error variance has a severe impact on the behavior of the tests in the nonlinear case; the reason...... for such behavior is the interplay of nonstationarity and nonlinearity. In particular, we show that nonlinearity of the data generating process can be asymptotically negligible when the error variance is moderate or large (compared to the "amount of nonlinearity"), rendering the linear test more powerful than...

  2. 78 FR 68817 - Proposed Information Collection; Comment Request; Northeast Region Gear Identification

    Science.gov (United States)

    2013-11-15

    ... gear type being used to help prevent gear conflicts. II. Method of Collection No information is... certain types of fishing gear mark the gear with specified information. The gear marking requirements... for marking several strings of a given gear type, or may use multiple different gear types that...

  3. Integrated Ground Operations Demonstration Units Testing Plans and Status

    Science.gov (United States)

    Johnson, Robert G.; Notardonato, William U.; Currin, Kelly M.; Orozco-Smith, Evelyn M.

    2012-01-01

    Cryogenic propellant loading operations with their associated flight and ground systems are some of the most complex, critical activities in launch operations. Consequently, these systems and operations account for a sizeable portion of the life cycle costs of any launch program. NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite advances in cryogenics, system health management and command and control technologies. This project was developed to mature, integrate and demonstrate advancement in the current state of the art in these areas using two distinct integrated ground operations demonstration units (GODU): GODU Integrated Refrigeration and Storage (IRAS) and GODU Autonomous Control

  4. Gear Tooth Root Stresses of a Very Heavily Loaded Gear Pair-Case Study: Orbiter Body Flap Actuator Pinion and Ring Gear

    Science.gov (United States)

    Krantz, Timothy L.; Handschuh, Robert F.

    2015-01-01

    The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.

  5. Leak testing United States Nuclear Regulatory Commission type b packaging

    International Nuclear Information System (INIS)

    Lacy, K.A.

    1995-01-01

    The Waste Isolation Pilot Plant (WTPP) is a one of its kind research and development facility operated by the Department of Energy, Carlsbad Area Office. Located in southeastern New Mexico, the WTPP is designed to demonstrate the safe, permanent disposal of transuranic (TRU) radioactive nuclear waste, accumulated from 40 years of nuclear weapons production. Before the waste can be disposed of, it must first be safely transported from generator storage sites to the WIPP. To accomplish this, the TRUPACT-II was designed and fabricated. This double containment, non-vented waste packaging successfully completed a rigorous testing program, and in 1989 received a Certificate of Compliance (C of C) from the Nuclear Regulatory Commission (NRC). Currently, the TRUPACT-II is in use at Idaho National Engineering Laboratory to transport waste on site for characterization. The DOE/CAO is responsible for maintaining the TRUPACT-II C of C. The C of C requires performance of nondestructive examination (NDE), e.g., visual testing (VT), dimensional inspections, Liquid Dye Penetrant testing (PT), and Helium Leak Detection (HLD). The Waste Isolation Division (WID) uses HLD for verification of the containment integrity. The following HLD tests are performed on annual basis or when required, i.e. repairs or component replacement: (1) fabrication verification leak tests on both the outer containment vessel (OCV) and the inner containment vessel (ICV); (2) assembly verification leak tests on the OCV and ICV upper main o-rings; and (3) assembly verification leak tests on the OCV and the ICV vent port plugs. These tests are addressed in detail as part of this presentation

  6. Acceptance test for 900 MWe PWR unit replacement steam generators

    International Nuclear Information System (INIS)

    Gourguechon, B.

    1993-01-01

    During the first half of 1994, the Gravelines 1 steam generators will be replaced (SG replacement procedure). The new SG's differ from the former components notably by the alloy used for the tube bundle, in this case, the high chromium content Inconel 690. So, from this standpoint, they are to be considered as PWR 900 replacement SG first models and their thermal efficiency has consequently to be assessed. This will provide an opportunity of ensuring that the performance of the components delivered is in compliance with requirements and of making the necessary provisions if significant deviations are observed. The EFMT branch, which has been in charge of the instrumentation and acceptance of the different SG first models since the first PWR plants were commissioned, will be responsible for the acceptance tests and the ultimate validation of a performance assessment procedure applicable to the future replacement steam generators. The methods and tests proposed for SG expert appraisal are based on consideration of the importance of primary measurement quality for satisfactory SG assessment and of the new test facilities with which the 900 and 1 300 PWR plants are gradually being equipped. These facilities provide an on-site computer environment for tests compatible with the tools (PATTERN, etc.) used at EFMT and in other departments. This test is the first of this kind performed by EFMT and the test facility of a nuclear power plant. (author). 6 figs

  7. On the asymptotic distribution of a unit root test against ESTAR alternatives

    NARCIS (Netherlands)

    Hanck, Christoph

    We derive the null distribution of the nonlinear unit root test proposed in Kapetanios et al. [Kapetanios, G., Shin, Y., Snell, A., 2003. Testing for a unit root in the nonlinear STAR framework, journal of Econometrics 112, 359-379] when nonzero means or both means and deterministic trends are

  8. Research on the Problem of Spur Gear Teeth Contact in the Car Gear Box

    Directory of Open Access Journals (Sweden)

    Viktor Skrickij

    2011-04-01

    Full Text Available The article presents research on the problem of two gear contact in the car gearbox. Contact stiffness is evaluated for the whole period of mesh. Also, contact stresses are evaluated in the contact place. The presented method can be used for calculating spur gear.Article in Lithuanian

  9. THE IMPACT OF THE ELEVATOR GUIDES CONTAMINATION ON THE BRAKING PROCESS DELAY FOR SELECTED PROGRESSIVE GEARS

    Directory of Open Access Journals (Sweden)

    Rafał Longwic

    2017-06-01

    Full Text Available The authors’ tests results on the impact of the guiding system (the guides contamination in the friction lift on the delay of progressive gears braking process are presented in this article. The tests were conducted using a free fall method and a test bench built for that purpose. In order to render all working conditions the guiding system of tested gears was lubricated with the most commonly used lubricating agents. Solid grease (SM, mineral oil (OL, the mixture of solid grease and quartz sand (S50 as well as the mixture of mineral oil and quartz sand (O50 were used.

  10. Flow-Field Investigation of Gear-Flap Interaction on a Gulfstream Aircraft Model

    Science.gov (United States)

    Yao, Chung-Sheng; Jenkins, Luther N.; Bartram, Scott M.; Harris, Jerome; Khorrami, Mehdi R.; Mace, W. Derry

    2014-01-01

    Off-surface flow measurements of a high-fidelity 18% scale Gulfstream aircraft model in landing configuration with the main landing gear deployed are presented. Particle Image Velocimetry (PIV) and Laser Velocimetry (LV) were used to measure instantaneous velocities in the immediate vicinity of the main landing gear and its wake and near the inboard tip of the flap. These measurements were made during the third entry of a series of tests conducted in the NASA Langley Research Center (LaRC) 14- by 22-Foot Subsonic Tunnel (14 x 22) to obtain a comprehensive set of aeroacoustic measurements consisting of both aerodynamic and acoustic data. The majority of the off-body measurements were obtained at a freestream Mach number of 0.2, angle of attack of 3 degrees, and flap deflection angle of 39 degrees with the landing gear on. A limited amount of data was acquired with the landing gear off. LV was used to measure the velocity field in two planes upstream of the landing gear and to measure two velocity profiles in the landing gear wake. Stereo and 2-D PIV were used to measure the velocity field over a region extending from upstream of the landing gear to downstream of the flap trailing edge. Using a special traverse system installed under the tunnel floor, the velocity field was measured at 92 locations to obtain a comprehensive picture of the pertinent flow features and characteristics. The results clearly show distinct structures in the wake that can be associated with specific components on the landing gear and give insight into how the wake is entrained by the vortex at the inboard tip of the flap.

  11. Nitrogen implantation of type 303 stainless steel gears for improved wear and fatigue resistance

    International Nuclear Information System (INIS)

    Kustas, F.M.; Misra, M.S.; Tack, W.T.

    1987-01-01

    Fine-positioning mechanisms are responsible for accurate and reproducible control of aerospace system devices, i.e. filter grading wheels. Low wear and fatigue resistance of mechanism components, such as pinions and gears, can reduce system performance and reliability. Surface modification using ion implantation with nitrogen was used on type 303 stainless steel pinions and gears to increase tribological performance. Wear-life tests of untreated, nitrogen-implanted and nitrogen-implanted-and-annealed gears were performed in a fine-positioning mechanism under controlled environmental conditions. Wear and fatigue resistance were monitored at selected time intervals which were a percentage of the predicted failure life as determined by a numerical stress analysis. Surface analyses including scanning electron microscopy and Auger electron spectroscopy were performed to establish the wear and fatigue mechanisms and the nitrogen concentration-depth distributions respectively. Nitrogen implantation resulted in a significant improvement in both surface wear and fatigue spalling resistance over those of untreated gears. A 40% reduction in surface wear and a 44% reduction in dedendum spalling was observed. In contrast, the nitrogen-implanted-and-annealed gears showed a 46% increase in sliding wear area and an 11% increase in spall density compared with those of untreated gears, indicating that the post-implantation anneal was detrimental to wear and fatigue resistance. (orig.)

  12. Gear Fault Detection Effectiveness as Applied to Tooth Surface Pitting Fatigue Damage

    Science.gov (United States)

    Lewicki, David G.; Dempsey, Paula J.; Heath, Gregory F.; Shanthakumaran, Perumal

    2010-01-01

    A study was performed to evaluate fault detection effectiveness as applied to gear-tooth-pitting-fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study. Three common condition indicators (RMS, FM4, and NA4 [Ed. 's note: See Appendix A-Definitions D were deduced from the time-averaged vibration data and used with the ODM to evaluate their performance for gear fault detection. The NA4 parameter showed to be a very good condition indicator for the detection of gear tooth surface pitting failures. The FM4 and RMS parameters perfomu:d average to below average in detection of gear tooth surface pitting failures. The ODM sensor was successful in detecting a significant 8lDOunt of debris from all the gear tooth pitting fatigue failures. Excluding outliers, the average cumulative mass at the end of a test was 40 mg.

  13. Acceptance test procedure for SY Tank Farm replacement exhauster unit

    Energy Technology Data Exchange (ETDEWEB)

    Becken, G.W.

    1994-12-16

    The proper functioning of a new 241-SY Tank Farm replacement exhauster will be acceptance tested, to establish operability and to provide an operational baseline for the equipment. During this test, a verification of all of the alarm and control circuits associated with the exhaust, which provide operating controls and/or signals to local and remote alarm/annunciator panels, shall be performed. Test signals for sensors that provide alarms, warnings, and/or interlocks will be applied to verify that alarm, warning, and interlock setpoints are correct. Alarm and warning lights, controls, and local and remote readouts for the exhauster will be verified to be adequate for proper operation of the exhauster. Testing per this procedure shall be conducted in two phases. The first phase of testing, to verify alarm, warning, and interlock setpoints primarily, will be performed in the MO-566 Fab Shop. The second phase of testing, to verify proper operation and acceptable interface with other tank farm systems, will be conducted after the exhauster and all associated support and monitoring equipment have been installed in the SY Tank Farm. The exhauster, which is mounted on a skid and which will eventually be located in the SY tank farm, receives input signals from a variety of sensors mounted on the skid and associated equipment. These sensors provide information such as: exhauster system inlet vacuum pressure; prefilter and HEPA filter differential pressures; exhaust stack sampler status; exhaust fan status; system status (running/shut down); and radiation monitoring systems status. The output of these sensors is transmitted to the exhauster annunciator panel where the signals are displayed and monitored for out-of-specification conditions.

  14. On the Correlation of Specific Film Thickness and Gear Pitting Life

    Science.gov (United States)

    Krantz, Timothy L.

    2015-01-01

    The effect of the lubrication regime on gear performance has been recognized, qualitatively, for decades. Often the lubrication regime is characterized by the specific film thickness defined as the ratio of lubricant film thickness to the composite surface roughness. It can be difficult to combine results of studies to create a cohesive and comprehensive dataset. In this work gear surface fatigue lives for a wide range of specific film values were studied using tests done with common rigs, speeds, lubricant temperatures, and test procedures. This study includes previously reported data, results of an additional 50 tests, and detailed information from lab notes and tested gears. The dataset comprised 258 tests covering specific film values (0.47 to 5.2). The experimentally determined surface fatigue lives, quantified as 10-percent life estimates, ranged from 8.7 to 86.8 million cycles. The trend is one of increasing life for increasing specific film. The trend is nonlinear. The observed trends were found to be in good agreement with data and recommended practice for gears and bearings. The results obtained will perhaps allow for the specific film parameter to be used with more confidence and precision to assess gear surface fatigue for purpose of design, rating, and technology development.

  15. Application of Face-Gear Drives in Helicopter Transmissions

    Science.gov (United States)

    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.

  16. An external control unit implemented for stimulator ASIC testing ...

    African Journals Online (AJOL)

    ) for a stimulator ASIC testing purposes. The ECU consists of a graphical user interface (GUI) from the PC, a data transceiver and a power transmitter. The GUI was developed using MATLAB for stimulation data setup. The data transceiver was ...

  17. Measurements for testing of fluoroscopic screens, including the photofluorographic units

    International Nuclear Information System (INIS)

    Balfanz, R.

    1986-01-01

    Image quality control measurements for fluoroscopic screens and photofluorographs have shown that both types of equipment have a long operating life, so that constancy and technical performance tests are absolutely necessary. It is recommended to conclude in-service maintenance contracts with the manufacturers. (DG) [de

  18. Closure plan for the Test Area North-726 chromate water storage and Test Area North-726A chromate treatment units

    International Nuclear Information System (INIS)

    Smith, P.J.; Van Brunt, K.M.

    1992-11-01

    This document describes the proposed plan for closure of the Test Area North-726 chromate water storage and Test Area North-726A chromate treatment units at the Idaho National Engineering Laboratory in accordance with the Resource Conservation and Recovery Act interim status closure requirements. The location, size, capacity, and history of the units are described, and their current status is discussed. The units will be closed by treating remaining waste in storage, followed by thorough decontamination of the systems. Sufficient sampling and analysis, and documentation of all activities will be performed to demonstrate clean closure

  19. An outlier robust unit root test with an application to the extended Nelson-Plosser data

    NARCIS (Netherlands)

    Lucas, André

    1995-01-01

    This paper considers unit root tests based on robust estimators with a high breakdown point and high efficiency. The asymptotic distribution of these tests is derived. Critical values for the test are obtained via simulation. It is found that the size of the classical OLS based Dickey-Fuller test

  20. Results of testing the frontal AK-3 extraction unit

    Energy Technology Data Exchange (ETDEWEB)

    Yakovlev, N I; Dolinskii, A M; Kolesnikov, M A

    1978-10-01

    From August to November 1970, on site testing of a protype frontal AK excavating rig developed by Giprouglemesh for use on gentle sloping seams was conducted in the Novaya mine of the Kuzbass Ugol Consolidated. The AK-3 consists of a cutting assembly in the form of a ring frontal slicer with two drives, hydraulic operated sectionalized support timbers of the enclosed lift type, conjugated timbering with ventilation and conveyor shafts, personnel elevator and hydraulic and electrical ancillary equipment. The production capacity of the rig in longwalls is 2.2 times greater on the average than by using drillhole blasting methods. Tests demonstrated that the main advantage of the Ak-3 was the single operation, continuous flow mode of coal extraction and remote frontal movement of timber sections, which ensured high capacity loading at the face and the capability of automating all procedures and eliminating all workers from the extraction face.

  1. Universal Physical Fitness Testing for United States Guardians Afloat

    Science.gov (United States)

    2016-06-10

    fitness tests assist with establishing a high retention rate and reducing absenteeism .”58 Robert Behn talks about measurements as an “overall...https://www.policeone.com/police- products /fitness-health-wellness/articles/ 1641504-Final-Word-Mandatory-Fitness-Standards-for-In-Service-Officers...30, 2016, http://static.e-publishing.af.mil/ production /1/af_a1/ publication/afi36-2905/afi36-2905.pdf. 95 Major Richard T. Gindhard Jr., “The Air

  2. Modal Testing of the NPSAT1 Engineering Development Unit

    Science.gov (United States)

    2012-07-01

    erkläre ich, dass die vorliegende Master Arbeit von mir selbstständig und nur unter Verwendung der angegebenen Quellen und Hilfsmittel angefertigt...logarithmic scale . As 5 Figure 2 shows, natural frequencies are indicated by large values of the first CMIF (peaks), and multiple modes can be detected by...structure’s behavior. Ewins even states, “that no large- scale modal test should be permitted to proceed until some preliminary SDOF analyses have

  3. Thermal desorption treatability test conducted with VAC*TRAX Unit

    International Nuclear Information System (INIS)

    1996-01-01

    In 1992, Congress passed the Federal Facilities Compliance Act, requiring the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with Resource Conservation and Recovery Act (RCRA) treatment standards. In response to the need for mixed-waste treatment capacity, where off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed waste with treatment options and develop a strategy for treatment of mixed waste. DOE-AL manages nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment units (MTUs) to treat waste at the sites where the wastes are generated. Treatment processes used for mixed wastes must remove the hazardous component (i.e., meet RCRA treatment standards) and contain the radioactive component in a form that will protect the worker, public, and environment. On the basis of the recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (DOE-GJPO) include thermal desorption (TD), evaporative oxidation, and waste water evaporation

  4. Safety review on unit testing of safety system software of nuclear power plant

    International Nuclear Information System (INIS)

    Liu Le; Zhang Qi

    2013-01-01

    Software unit testing has an important place in the testing of safety system software of nuclear power plants, and in the wider scope of the verification and validation. It is a comprehensive, systematic process, and its documentation shall meet the related requirements. When reviewing software unit testing, attention should be paid to the coverage of software safety requirements, the coverage of software internal structure, and the independence of the work. (authors)

  5. Causes of several accidents in gamma radiography testing units

    International Nuclear Information System (INIS)

    Vykrocil, L.

    1979-01-01

    Three cases are described of radiation accidents in gamma flaw-detection work-places in the West Bohemian Region. The causes of the accidents stemmed from the unsatisfactory technical condition of the materials testing equipment used and nonobservance of regulations for work with radioactive sourr.es. It is necessary for precluding similar accident to improve preventive care of gamma flaw-detection equipment and to educate personnel who would be considered for coping with the situation when control over the radiation source is lost. (Ha)

  6. Ground Operations Demonstration Unit for Liquid Hydrogen Initial Test Results

    Science.gov (United States)

    Notardonato, W. U.; Johnson, W. L.; Swanger, A. M.; Tomsik, T.

    2015-01-01

    NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project has designed, assembled, and started testing of a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The system is unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. This paper will present and discuss the results of the initial phase of testing of the GODU LH2 system.

  7. MODELING THE DOUBLE WORM-FACE GEARS

    Directory of Open Access Journals (Sweden)

    BOLOŞ Codruţa

    2015-06-01

    Full Text Available The worm-face gear family, invented 60 years ago, contains in its structure several variants which have the following defining elements: tapered worm, reverse tapered worm and cylindrical worm. This type of gear can be realized with a single wheel and also in engagement with the second embodiment of the front worm wheels. This paper presents the matrix - vectorial mathematical model of the double worm-face gear with cylindrical worm and a graphical modeling which is based on the specific geometrical characteristics accomplished by means of the Autodesk Inventor 3D modeling program. The applicability of the study, considering the solutions which it suggests, aims to create opportunities for the use of modern rapid prototyping and analysis of stress FEM technique.

  8. Operation of the radioactive acid-digestion test unit (RADTU)

    International Nuclear Information System (INIS)

    Blasewitz, A.G.; Allen, C.R.; Lerch, R.E.; Ely, P.C.; Richardson, G.L.

    1981-01-01

    At the Karlsruhe Nuclear Research Center, research and development work concerned with the acid digestion of combustible waste with high plutonium content is being carried out. The main objectives are the reduction of the waste volume, the recovery of the plutonium and the transformation of the process residues into a product suitable for final disposal. For this purpose an inactive demonstration plant with a throughput of 1.5 kg/h has been constructed. In the first version, the reactor of this plant was a tray reactor of the HEDL type. During test operations the sedimentation of a residue was observed on the tray. The density of this residue was higher than that of the residue suspended in the reaction acid. Experiments using tantalum oxide (D=8.4 g/cm 3 ) to simulate the plutonium oxide (D=11.5 g/cm 3 ) have verified this observation. This means that in active operation a sedimentation of plutonium oxide on the tray is to be expected. With respect to these results a new reactor was developed where the settling of the residue is avoided by appropriate design and high circulation velocity of the reaction acid. The reactor consists of a tube 50-80 mm in diameter, which is curved to form a closed loop with an arm length of about 1x1 m. Since October 1979 this ring reactor has been under inactive test operation. Its behaviour is very stable. The velocity of the reaction acid in the heater is 0.5-1 m/s. A settling of residues or tantalum oxide has not been observed. The throughput attained is comparable to that of the tray reactor but the space requirement is three times smaller, and the volume of the reaction acid four times smaller. (author)

  9. Streamlined Approach for Environmental Restoration Work Plan for Corrective Action Unit 461: Joint Test Assembly Sites and Corrective Action Unit 495: Unconfirmed Joint Test Assembly Sites Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Smith

    1998-08-01

    This Streamlined Approach for Environmental Restoration plan addresses the action necessary for the clean closure of Corrective Action Unit 461 (Test Area Joint Test Assembly Sites) and Corrective Action Unit 495 (Unconfirmed Joint Test Assembly Sites). The Corrective Action Units are located at the Tonopah Test Range in south central Nevada. Closure for these sites will be completed by excavating and evaluating the condition of each artillery round (if found); detonating the rounds (if necessary); excavating the impacted soil and debris; collecting verification samples; backfilling the excavations; disposing of the impacted soil and debris at an approved low-level waste repository at the Nevada Test Site

  10. Landing Gear Components Noise Study - PIV and Hot-Wire Measurements

    Science.gov (United States)

    Hutcheson, Florence V.; Burley, Casey L.; Stead, Daniel J.; Becker, Lawrence E.; Price, Jennifer L.

    2010-01-01

    PIV and hot-wire measurements of the wake flow from rods and bars are presented. The test models include rods of different diameters and cross sections and a rod juxtaposed to a plate. The latter is representative of the latch door that is attached to an aircraft landing gear when the gear is deployed, while the single and multiple rod configurations tested are representative of some of the various struts and cables configuration present on an aircraft landing gear. The test set up is described and the flow measurements are presented. The effect of model surface treatment and freestream turbulence on the spanwise coherence of the vortex shedding is studied for several rod and bar configurations.

  11. Start-up test of Fukushima Daini Nuclear Power Station Unit No.3

    International Nuclear Information System (INIS)

    Inomata, Toshio; Umezu, Akira; Kajikawa, Makoto; Koibuchi, Hiroshi; Netsu, Nobuhiko.

    1986-01-01

    In Unit 3 of the Fukushima Nuclear Power Station II (daini), a BWR power plant of output 1,100 MW, commercial operation was started in June 1985. Its start-up test was finished successfully in about nine months. That is, new equipments introduced were demonstration tested. Though the items of testing are increased, the start-up test took short time, resulting in construction period only 54.7 months of the Unit 3, the shortest in the world. During the test, there was no scramming other than the planned. Described are the following: an outline of the Unit 3, the items of its improvement and standardization, including the new equipments, preparations for the start-up test, the start-up test and its evaluation. (Mori, K.)

  12. Vibration behavior optimization of planetary gear sets

    Directory of Open Access Journals (Sweden)

    Farshad Shakeri Aski

    2014-12-01

    Full Text Available This paper presents a global optimization method focused on planetary gear vibration reduction by means of tip relief profile modifications. A nonlinear dynamic model is used to study the vibration behavior. In order to investigate the optimal radius and amplitude, Brute Force method optimization is used. One approach in optimization is straightforward and requires considerable computation power: brute force methods try to calculate all possible solutions and decide afterwards which one is the best. Results show the influence of optimal profile on planetary gear vibrations.

  13. Power Consumption Optimization in Tooth Gears Processing

    Science.gov (United States)

    Kanatnikov, N.; Harlamov, G.; Kanatnikova, P.; Pashmentova, A.

    2018-01-01

    The paper reviews the issue of optimization of technological process of tooth gears production of the power consumption criteria. The authors dwell on the indices used for cutting process estimation by the consumed energy criteria and their applicability in the analysis of the toothed wheel production process. The inventors proposed a method for optimization of power consumptions based on the spatial modeling of cutting pattern. The article is aimed at solving the problem of effective source management in order to achieve economical and ecological effect during the mechanical processing of toothed gears. The research was supported by Russian Science Foundation (project No. 17-79-10316).

  14. A comparison of two gears for quantifying abundance of lotic-dwelling crayfish

    Science.gov (United States)

    Williams, Kristi; Brewer, Shannon K.; Ellersieck, Mark R.

    2014-01-01

    Crayfish (saddlebacked crayfish, Orconectes medius) catch was compared using a kick seine applied two different ways with a 1-m2 quadrat sampler (with known efficiency and bias in riffles) from three small streams in the Missouri Ozarks. Triplicate samples (one of each technique) were taken from two creeks and one headwater stream (n=69 sites) over a two-year period. General linear mixed models showed the number of crayfish collected using the quadrat sampler was greater than the number collected using either of the two seine techniques. However, there was no significant interaction with gear suggesting year, stream size, and channel unit type did not relate to different catches of crayfish by gear type. Variation in catch among gears was similar, as was the proportion of young-of-year individuals across samples taken with different gears or techniques. Negative binomial linear regression provided the appropriate relation between the gears which allows correction factors to be applied, if necessary, to relate catches by the kick seine to those of the quadrat sampler. The kick seine appears to be a reasonable substitute to the quadrat sampler in these shallow streams, with the advantage of ease of use and shorter time required per sample.

  15. Improving bending stress in spur gears using asymmetric gears and shape optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2010-01-01

    Bending stress plays a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape. The bending stress is indirectly related to shape changes made to the cutting tool. This work shows that the bending...... stress can be reduced significantly by using asymmetric gear teeth and by shape optimizing the gear through changes made to the tool geometry. However, to obtain the largest possible stress reduction a custom tool must be designed depending on the number of teeth, but the stress reductions found...

  16. Tooth contact analysis of spur gears. Part 1-SAM analysis of standard gears

    Directory of Open Access Journals (Sweden)

    Creţu Spiridon

    2017-01-01

    Full Text Available The involute gears are sensitive to the misalignment of their axes which determines transmission errors and perturbations of pressures distributions along the tooth flank. The concentrated contacts in gears are no longer as Hertz type. A semi-analytical method was developed to find the contact area, pressures distribution and depth stresses state. The matrix of initial separations is found analytically for standard and non-standard spur gears. The presence of misalignment as well as the flank crowning and flank end relief are included in the numerical analysis process.

  17. Is Malaysian Stock Market Efficient? Evidence from Threshold Unit Root Tests

    OpenAIRE

    Qaiser Munir; Kasim Mansur

    2009-01-01

    This paper investigates the behavior of Kuala Lumpur Stock Exchange Composite Index (KLCI) for the period from 1980:1 to 2008:8 using a two-regime threshold autoregressive (TAR) model with an autoregressive unit root developed by Caner and Hansen [Threshold autoregression with a unit roots, Econometrics 69 (6) (2001) 1555-1596] which allows testing nonlinearity and nonstationarity simultaneously. Our finding indicates that the KLCI is a nonlinear series that is characterized by a unit root pr...

  18. Hydrologic resources management program and underground test area operable unit fy 1997

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. F., LLNL

    1998-05-01

    This report present the results of FY 1997 technical studies conducted by the Lawrence Livermore National Laboratory (LLNL) as part of the Hydrology and Radionuclide Migration Program (HRMP) and Underground Test Area Operable Unit (UGTA). The HRMP is sponsored by the US Department of Energy to assess the environmental (radiochemical and hydrologic) consequences of underground nuclear weapons testing at the Nevada Test Site.

  19. On the stability of the unit root test | Atil | Afrika Statistika

    African Journals Online (AJOL)

    Abstract. We propose to study, by two different approaches, Bayesian and classical, the test of the hypothesis of stationary first order autoregressive model against the random walk model. Therefore, we are going to present the classical approach and the Bayesian approach of this test says the unit root test. The principal ...

  20. Anonymous or confidential HIV counseling and voluntary testing in federally funded testing sites--United States, 1995-1997.

    Science.gov (United States)

    1999-06-25

    Human immunodeficiency virus (HIV) counseling and voluntary testing (CT) programs have been an important part of national HIV prevention efforts since the first HIV antibody tests became available in 1985. In 1995, these programs accounted for approximately 15% of annual HIV antibody testing in the United States, excluding testing for blood donation. CT opportunities are offered to persons at risk for HIV infection at approximately 11,000 sites, including dedicated HIV CT sites, sexually transmitted disease (STD) clinics, drug-treatment centers, hospitals, and prisons. In 39 states, testing can be obtained anonymously, where persons do not have to give their name to get tested. All states provide confidential testing (by name) and have confidentiality laws and regulations to protect this information. This report compares patterns of anonymous and confidential testing in all federally funded CT programs from 1995 through 1997 and documents the importance of both types of testing opportunities.

  1. Efficient Market Hypothesis in South Africa: Evidence from Linear and Nonlinear Unit Root Tests

    Directory of Open Access Journals (Sweden)

    Andrew Phiri

    2015-12-01

    Full Text Available This study investigates the weak form efficient market hypothesis (EMH for five generalized stock indices in the Johannesburg Stock Exchange (JSE using weekly data collected from 31st January 2000 to 16th December 2014. In particular, we test for weak form market efficiency using a battery of linear and nonlinear unit root testing procedures comprising of the classical augmented Dickey-Fuller (ADF tests, the two-regime threshold autoregressive (TAR unit root tests described in Enders and Granger (1998 as well as the three-regime unit root tests described in Bec, Salem, and Carrasco (2004. Based on our empirical analysis, we are able to demonstrate that whilst the linear unit root tests advocate for unit roots within the time series, the nonlinear unit root tests suggest that most stock indices are threshold stationary processes. These results bridge two opposing contentions obtained from previous studies by concluding that under a linear framework the JSE stock indices offer support in favour of weak form market efficiency whereas when nonlinearity is accounted for, a majority of the indices violate the weak form EMH.

  2. 77 FR 38857 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal...

    Science.gov (United States)

    2012-06-29

    ... Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems in Light-Water- Cooled Nuclear Power... Criteria for Air Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems in Light-Water-Cooled... draft regulatory guide (DG), DG-1280, ``Design, Inspection, and Testing Criteria for Air Filtration and...

  3. An analysis of unit tests of a flight software product line

    NARCIS (Netherlands)

    Ganesan, D.; Lindvall, M.; McComas, D.; Bartholomew, M.; Slegel, S.; Medina, B.; Krikhaar, R.; Verhoef, C.; Dharmalingam, G.; Montgomery, L.P.

    2013-01-01

    This paper presents an analysis of the unit testing approach developed and used by the Core Flight Software System (CFS) product line team at the NASA Goddard Space Flight Center (GSFC). The goal of the analysis is to understand, review, and recommend strategies for improving the CFS' existing unit

  4. "Individualized Science" Field Test Findings and Recommendations, the Hooke Unit. Appendix A.

    Science.gov (United States)

    Loue, William E., III

    This informal report contains the findings and recommendations resulting from the field test of the Hooke Unit of the "Individualized Science" program. Data were collected from three schools. Because of an unusual number of weaknesses ranging from formal inconsistencies to manipulative deficiencies, it was concluded that the Hooke Unit is somewhat…

  5. United States Nuclear Tests, July 1945 through September 1992, December 2000

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, Nevada Operations Office

    2000-12-01

    This document list chronologically and alphabetically by name all nuclear tests and simultaneous detonations conducted by the United States from July 1945 through September 1992. Revision 15, dated December 2000.

  6. Description of work for 100-DR-2 Operable Unit Vadose Drilling/test pits

    International Nuclear Information System (INIS)

    Naiknimbalkar, N.

    1993-01-01

    This report describes the scope of work for the boreholes/test pits of the 100-DR-2 Operable Unit. Sampling and field activities include: Soil screening; geologic sampling; soil sampling (physical property); analytical sampling and depths; and geophysical logging

  7. United States Nuclear Tests, July 1945 through September 1992, September 2015

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-09-01

    This document lists chronologically and alphabetically by name all nuclear tests and simultaneous detonations conducted by the United States from July 1945 through September 1992. This is Revision 16, dated September 2015.

  8. 50 CFR 622.31 - Prohibited gear and methods.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prohibited gear and methods. 622.31... Management Measures § 622.31 Prohibited gear and methods. In addition to the prohibited gear/methods specified in this section, see §§ 622.33, 622.34, and 622.35 for seasonal/area prohibited gear/methods and...

  9. Mathematical Modelling of Involute Spur Gears Manufactured by Rack Cutter

    Directory of Open Access Journals (Sweden)

    Tufan Gürkan YILMAZ

    2016-05-01

    Full Text Available In this study, mathematical modelling of asymmetric involute spur gears was situated in by Litvin approach. In this context, firstly, mathematical expressions of rack cutter which manufacture asymmetric involute spur gear, then mathematical expression of asymmetric involute spur gear were obtained by using differential geometry, coordinate transformation and gear theory. Mathematical expressions were modelled in MATLAB and output files including points of involute spur gear’s teeth were designed automatically thanks to macros.

  10. Comparison of wavelet based denoising schemes for gear condition monitoring: An Artificial Neural Network based Approach

    Science.gov (United States)

    Ahmed, Rounaq; Srinivasa Pai, P.; Sriram, N. S.; Bhat, Vasudeva

    2018-02-01

    Vibration Analysis has been extensively used in recent past for gear fault diagnosis. The vibration signals extracted is usually contaminated with noise and may lead to wrong interpretation of results. The denoising of extracted vibration signals helps the fault diagnosis by giving meaningful results. Wavelet Transform (WT) increases signal to noise ratio (SNR), reduces root mean square error (RMSE) and is effective to denoise the gear vibration signals. The extracted signals have to be denoised by selecting a proper denoising scheme in order to prevent the loss of signal information along with noise. An approach has been made in this work to show the effectiveness of Principal Component Analysis (PCA) to denoise gear vibration signal. In this regard three selected wavelet based denoising schemes namely PCA, Empirical Mode Decomposition (EMD), Neighcoeff Coefficient (NC), has been compared with Adaptive Threshold (AT) an extensively used wavelet based denoising scheme for gear vibration signal. The vibration signals acquired from a customized gear test rig were denoised by above mentioned four denoising schemes. The fault identification capability as well as SNR, Kurtosis and RMSE for the four denoising schemes have been compared. Features extracted from the denoised signals have been used to train and test artificial neural network (ANN) models. The performances of the four denoising schemes have been evaluated based on the performance of the ANN models. The best denoising scheme has been identified, based on the classification accuracy results. PCA is effective in all the regards as a best denoising scheme.

  11. Analysis of an employment of a gear ratio rate in CVT control system

    Science.gov (United States)

    Grzegożek, W.; Szczepka, M.

    2016-09-01

    Continuously variable transmissions(CVTs) potentially ensure the selection of such a gear ratio that scooter fuel consumption can reach minimum value. Traditionally these CVT gearboxes are mechanically controlled, causing a gear ratio to be an engine revs function. This solution does not ensure optimum gear ratio. In this paper the solution for fuel optimal control problem is presented. The results obtained during brake stand research of scooter powertrains show the significant values of brake specific fuel consumption for the velocity that is maximum for a scooter according to highway code. With the introduction of CVT gearbox in which the selection of gear ratio can be controlled according to the worked out strategy the solution for fuel consumption problem is possible. Electromechanical actuators ensure the selection of a gear ratio independently of engine revs. Such type of construction solution makes working out the suitable control strategy that ensures decreasing of scooter fuel consumption possible. Presented strategies do not use precise optimization techniques. The CVT efficiency has a strong influence on transient operation. In the paper the control strategy owing to which fuel consumption decreases by over 40% is presented. The strategy was worked out on the basis of fuel consumption map for a defined scooter exploitation model. The possibilities of realization of the worked out strategy were tested on the brake test stand.

  12. Nonlinear modeling of adaptive magnetorheological landing gear dampers under impact conditions

    Science.gov (United States)

    Ahuré Powell, Louise A.; Choi, Young T.; Hu, Wei; Wereley, Norman M.

    2016-11-01

    Adaptive landing gear dampers that can continuously adjust their stroking load in response to various operating conditions have been investigated for improving the landing performance of a lightweight helicopter. In prior work, adaptive magnetorheological (MR) landing gear dampers that maintained a constant peak stroking force of 4000 lbf across sink rates ranging from 6 to 12 ft s-1 were designed, fabricated and successfully tested. In this follow-on effort, it is desired to expand the high end of the sink rate range to hold the peak stroking load constant for sink rates ranging from 6 to 26 ft s-1, thus extending the high end of the speed range from 12 (in the first study) to 26 ft s-1. To achieve this increase, a spring-based relief valve MR landing gear damper was developed. In order to better understand the MR landing gear damper behavior, a modified nonlinear Bingham Plastic model was formulated, and it incorporates Darcy friction, viscous forces across the MR and relief valves to better account for the damper force behavior at higher speeds. In addition, gas pressure inside the MR damper piston is considered so the total damper force includes a gas force. The MR landing gear damper performance is characterized using drop tests, and the experiments are used to validate model predictions data at low and high nominal impact speeds up to 26 ft s-1 (shaft velocity of 9.6 ft s-1).

  13. Characteristics of Reduction Gear in Electric Agricultural Vehicle

    Science.gov (United States)

    Choi, W. S.; Pratama, P. S.; Supeno, D.; Jeong, S. W.; Byun, J. Y.; Woo, J. H.; Lee, E. S.; Park, C. S.

    2018-03-01

    In electric agricultural machine a reduction gear is needed to convert the high speed rotation motion generated by DC motor to lower speed rotation motion used by the vehicle. The reduction gear consists of several spur gears. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modelling and simulation of spur gears in DC motor reduction gear is important to predict the actual motion behaviour. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress. The stress may not attain their maximum values at the same point of contact fatigue. These types of failure can be minimized by analysis of the problem during the design stage and creating proper tooth surface profile with proper manufacturing methods. To improve its life expectation in this study modal and stress analysis of reduction gear is simulated using ANSYS workbench based on finite element method (FEM). The modal analysis was done to understand reduction gear deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on reduction gear to simulate the gear teeth bending stress and contact stress behaviour.

  14. Gear cutting tools fundamentals of design and computation

    CERN Document Server

    Radzevich, Stephen P

    2010-01-01

    Presents the DG/K-based method of surface generation, a novel and practical mathematical method for designing gear cutting tools with optimal parameters. This book proposes a scientific classification for the various kinds of the gear machining meshes, discussing optimal designs of gear cutting tools.

  15. Electrostatic microactuators with integrated gear linkages for mechanical power transmission

    NARCIS (Netherlands)

    Legtenberg, R.; Legtenberg, Rob; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    1996-01-01

    In this paper a surface micromachining process is presented which has been used to fabricate electrostatic microactuators that are interconnected with each other and linked to other movable microstructures by integrated gear linkages. The gear linkages consist of rotational and linear gear

  16. 50 CFR 635.21 - Gear operation and deployment restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear operation and deployment restrictions....21 Gear operation and deployment restrictions. Link to an amendment published at 75 FR 57701, Sept. 22, 2010. The green-stick gear authorization requirements under paragraphs (c)(2)(v)(A), (c)(2)(v)(B...

  17. 46 CFR 182.610 - Main steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all service...

  18. Gear shift map design methodology for automotive transmissions

    NARCIS (Netherlands)

    Ngo, Viet Dac; Hofman, Theo; Steinbuch, Maarten; Serrarens, Alex

    In this paper, a design methodology is developed to condtruct the gear shift map for the automotive transmissions used in conventional and hybrid electric vehicles. The methodology utilizes an optimal gear shift strategy to derive the optimal gear shift patterns over a wide range of driving

  19. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other...

  20. Evaluation Of Vibration-Monitoring Gear-Diagnostic System

    Science.gov (United States)

    Townsend, Dennis P.; Zakrajsek, James J.

    1995-01-01

    Report describes experimental evaluation of commercial electronic system designed to monitor vibration signal from accelerometer on gear-box to detect vibrations indicative of damage to gears. System includes signal-conditioning subsystem and personal computer in which analog-to-digital converter installed. Results show system fairly effective in detecting surface fatigue pits on spur-gear teeth.

  1. Analysis of landing gear noise during approach

    NARCIS (Netherlands)

    Merino Martinez, R.; Snellen, M.; Simons, D.G.

    2016-01-01

    Airframe noise is becoming increasingly important during approach, even reaching higher noise levels than the engines in some cases. More people are a_ected due to low ight altitudes and _xed tra_c routing associated with typical approaches. For most air- craft types, the landing gear system is a

  2. Are Current Accounts of Asian Economies Mean-reverting?: Nonlinear Unit Root Test Approach

    Directory of Open Access Journals (Sweden)

    Bonghan Kim

    2005-12-01

    Full Text Available This paper tests the mean reverting property of current account in the financial crisis-affected 5 counties of southeast Asia using nonlinear unit root tests of Park and shintani(2004. Our approach is based on the idea that a conventional unit root test has lower power in detecting the nonlinear mean reverting behavior if the current account follows a nonlinear mean reversion process. We obtained following empirical results. First, for the pre-crisis period (1981Q1-1996Q4, the current accounts of Indonesia, Malaysia and Philippines are mean-reverting but those of Korea and Thailand are not mean-reverting. Second, for the full sample period (1981Q1-2003Q4, the ADF test fails to reject the unit root of the current account in all countries except Philippines. However, unit root is rejected in favor of nonlinear mean reversion except Thailand. This nonlinear unit root test result implies that crisis-affected Asian countries except Thailand have sustainable paths of current accounts. Third, when the current accounts of East Asian countries are nonlinear mean-reverting, the mean reverting process can be well described by the ESTAR model, instead of the DTAR or DLSTAR model. The nonlinear unit root test results imply smooth nonlinear mean-reversion behaviors of East Asian current accounts. Finally, the shape of estimated impulse response functions becomes steeper as the size of shock increases, which is the very characteristic of the nonlinear process.

  3. Testing iOS apps with HadoopUnit rapid distributed GUI testing

    CERN Document Server

    Tilley, Scott

    2014-01-01

    Smartphone users have come to expect high-quality apps. This has increased the importance of software testing in mobile software development. Unfortunately, testing apps-particularly the GUI-can be very time-consuming. Exercising every user interface element and verifying transitions between different views of the app under test quickly becomes problematic. For example, execution of iOS GUI test suites using Apple's UI Automation framework can take an hour or more if the app's interface is complicated. The longer it takes to run a test, the less frequently the test can be run, which in turn re

  4. Panel Unit Root Tests by Combining Dependent Values: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Xuguang Sheng

    2011-01-01

    Full Text Available We conduct a systematic comparison of the performance of four commonly used value combination methods applied to panel unit root tests: the original Fisher test, the modified inverse normal method, Simes test, and the modified truncated product method (TPM. Our simulation results show that under cross-section dependence the original Fisher test is severely oversized, but the other three tests exhibit good size properties. Simes test is powerful when the total evidence against the joint null hypothesis is concentrated in one or very few of the tests being combined, but the modified inverse normal method and the modified TPM have good performance when evidence against the joint null is spread among more than a small fraction of the panel units. These differences are further illustrated through one empirical example on testing purchasing power parity using a panel of OECD quarterly real exchange rates.

  5. On the non-existence of a Bartlett correction for unit root tests

    DEFF Research Database (Denmark)

    Jensen, Jens Ledet; Wood, Andrew T.A.

    1997-01-01

    There has been considerable recent interest in testing for a unit root in autoregressive models, especially in the context of cointegration models in econometrics. The likelihood ratio test for a unit root has non-standard asymptotic behaviour. In particular, when the errors are Gaussian, the lim...... for improved distributional approximations, and the question of whether W admits a Bartlett correction is of interest. In this note we establish that a Bartlett correction does not exist in the simplest unit root model. © 1997 Elsevier Science B.V....

  6. Indigenous unit for bending and twisting tests of ultra-thin films on a flexible substrate

    Science.gov (United States)

    D'souza, Slavia Deeksha; Hazarika, Pratim; Prakasarao, Ch Surya; Kovendhan, M.; Kumar, R. Arockia; Joseph, D. Paul

    2018-04-01

    An indigenous unit is designed to test the stability of thin films deposited on to a flexible substrate by inducing a required number of bending and twisting under specific conditions. The unit is designed using aluminum and automated by sending pulse width modulated signals to servo motors using ATmega328 microcontroller. We have tested the unit by imparting stress on to a commercial ITO film deposited on a PET substrate. After a definite number of bending and twisting cycles, the electrical and surface properties are studied and the results are discussed.

  7. Design, fabrication, and dynamic testing of a V-groove radiator mechanical development unit

    Science.gov (United States)

    Petrick, S. Walter; Bard, Steven

    1988-01-01

    This paper describes the design, fabrication, and dynamic testing of a V-groove radiator development unit. The intended goal was to survive the dynamic environment of the Mars Observer mission. The development unit was designed to achieve a temperature of 80 K with a heat load of about 80 milliwatts. An analysis was performed to predict the thermal performance of the development unit. The radiator with a mass mockup of a Gamma Ray Spectrometer detector, the most massive of the candidate Mars Observer instrument detectors (1.7 Kg), passed vibration and acoustic testing to the Mars Observer requirements in effect at that time.

  8. Income and CO2 emissions: Evidence from panel unit root and cointegration tests

    International Nuclear Information System (INIS)

    Lee, C.-C.; Lee, J.-D.

    2009-01-01

    This paper re-investigates the stationarity properties of per capita carbon dioxide (CO 2 ) emissions and real Gross Domestic Product (GDP) per capita for 109 countries within seven regional panel sets covering 1971-2003. We apply the recent unit-root test of the panel seemingly unrelated regressions augmented Dickey-Fuller (SURADF) test developed by Breuer et al. [2001. Misleading inferences from panel unit-root tests with an illustration from purchasing power parity. Review of International Economics 9, 482-493; 2002. Series-specific unit-root tests with panel data, Oxford Bulletin of Economics and Statistics 64, 527-546]. The panel SURADF test accounts for the presence of cross-country correlations in the data, and the parameters in the panel specification vary across countries. More importantly, this test allows us to identify how many and which members of the panel contain a unit root. Overall, our empirical results illustrate that real GDP and CO 2 emissions in these countries are a mixture of I(0) and I(1) processes, and that the traditional panel unit-root tests could lead to misleading inferences as well as the conduct of cointegration analysis being perhaps inappropriate. The results of our analysis carry critical implications for the modeling of CO 2 emissions and GDP because of the different orders of integration for the two variables

  9. Journal Bearing Analysis Suite Released for Planetary Gear System Evaluation

    Science.gov (United States)

    Brewe, David E.; Clark, David A.

    2005-01-01

    Planetary gear systems are an efficient means of achieving high reduction ratios with minimum space and weight. They are used in helicopter, aerospace, automobile, and many industrial applications. High-speed planetary gear systems will have significant dynamic loading and high heat generation. Hence, they need jet lubrication and associated cooling systems. For units operating in critical applications that necessitate high reliability and long life, that have very large torque loading, and that have downtime costs that are significantly greater than the initial cost, hydrodynamic journal bearings are a must. Computational and analytical tools are needed for sufficiently accurate modeling to facilitate optimal design of these systems. Sufficient physics is needed in the model to facilitate parametric studies of design conditions that enable optimal designs. The first transient journal bearing code to implement the Jacobsson-Floberg-Olsson boundary conditions, using a mass-conserving algorithm devised by Professor Emeritus Harold Elrod of Columbia University, was written by David E. Brewe of the U.S. Army at the NASA Lewis Research Center1 in 1983. Since then, new features and improved modifications have been built into the code by several contributors supported through Army and NASA funding via cooperative agreements with the University of Toledo (Professor Ted Keith, Jr., and Dr. Desikakary Vijayaraghavan) and National Research Council Programs (Dr. Vijayaraghavan). All this was conducted with the close consultation of Professor Elrod and the project management of David Brewe.

  10. Reactor coolant system hydrostatic test and risk analysis for the first AP1000 unit

    International Nuclear Information System (INIS)

    Cao Hongjun; Yan Xiuping

    2013-01-01

    The cold hydrostatic test scheme of the primary coolant circuit, of the first AP1000 unit was described. Based on the up-stream design documents, standard specifications and design technical requirements, the select principle of test boundary was identified. The design requirements for water quality, pressure, temperature and temporary hydro-test pump were proposed. A reasonable argument for heating and pressurization rate, and cooling and depressurization rate was proposed. The possible problems and risks during the hydrostatic test were analyzed. This test scheme can provide guidance for the revisions and implementations of the follow-up test procedures. It is a good reference for hydrostatic tests of AP1000 units in the future in China. (authors)

  11. Recent Advances in the Analysis of Spiral Bevel Gears

    Science.gov (United States)

    Handschuh, Robert F.

    1997-01-01

    A review of recent progress for the analysis of spiral bevel gears will be described. The foundation of this work relies on the description of the gear geometry of face-milled spiral bevel gears via the approach developed by Litvin. This methodology was extended by combining the basic gear design data with the manufactured surfaces using a differential geometry approach, and provides the data necessary for assembling three-dimensional finite element models. The finite element models have been utilized to conduct thermal and structural analysis of the gear system. Examples of the methods developed for thermal and structural/contact analysis are presented.

  12. Technologies for the marking of fishing gear to identify gear components entangled on marine animals and to reduce abandoned, lost or otherwise discarded fishing gear.

    Science.gov (United States)

    He, Pingguo; Suuronen, Petri

    2018-04-01

    Fishing gears are marked to establish and inform origin, ownership and position. More recently, fishing gears are marked to aid in capacity control, reduce marine litter due to abandoned, lost or otherwise discarded fishing gear (ALDFG) and assist in its recovery, and to combat illegal, unreported and unregulated (IUU) fishing. Traditionally, physical marking, inscription, writing, color, shape, and tags have been used for ownership and capacity purposes. Buoys, lights, flags, and radar reflectors are used for marking of position. More recently, electronic devices have been installed on marker buoys to enable easier relocation of the gear by owner vessels. This paper reviews gear marking technologies with focus on coded wire tags, radio frequency identification tags, Automatic Identification Systems, advanced electronic buoys for pelagic longlines and fish aggregating devices, and re-location technology if the gear becomes lost. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Quantification of Gear Tooth Damage by Optimal Tracking of Vibration Signatures

    Science.gov (United States)

    Choy, F. K.; Veillette, R. J.; Polyshchuk, V.; Braun, M. J.; Hendricks, R. C.

    1996-01-01

    This paper presents a technique for quantifying the wear or damage of gear teeth in a transmission system. The procedure developed in this study can be applied as a part of either an onboard machine health-monitoring system or a health diagnostic system used during regular maintenance. As the developed methodology is based on analysis of gearbox vibration under normal operating conditions, no shutdown or special modification of operating parameters is required during the diagnostic process. The process of quantifying the wear or damage of gear teeth requires a set of measured vibration data and a model of the gear mesh dynamics. An optimization problem is formulated to determine the profile of a time-varying mesh stiffness parameter for which the model output approximates the measured data. The resulting stiffness profile is then related to the level of gear tooth wear or damage. The procedure was applied to a data set generated artificially and to another obtained experimentally from a spiral bevel gear test rig. The results demonstrate the utility of the procedure as part of an overall health-monitoring system.

  14. Effects of Geometry Design Parameters on the Static Strength and Dynamics for Spiral Bevel Gear

    Directory of Open Access Journals (Sweden)

    Zhiheng Feng

    2017-01-01

    Full Text Available Considering the geometry design parameters, a quasi-static mesh model of spiral bevel gears was established and the mesh characteristics were computed. Considering the time-varying effects of mesh points, mesh force, line-of-action vector, mesh stiffness, transmission error, friction force direction, and friction coefficient, a nonlinear lumped parameter dynamic model was developed for the spiral bevel gear pair. Based on the mesh model and the nonlinear dynamic model, the effects of main geometry parameters on the contact and bending strength were analyzed. Also, the effects on the dynamic mesh force and dynamic transmission error were investigated. Results show that higher value for the pressure angle, root fillet radius, and the ratio of tooth thickness tend to improve the contact and bending strength and to reduce the risk of tooth fracture. Improved gears have a better vibration performance in the targeted frequency range. Finally, bench tests for both types of spiral bevel gears were performed. Results show that the main failure mode is the tooth fracture and the life was increased a lot for the spiral bevel gears with improved geometry parameters compared to the original design.

  15. Helical Face Gear Development Under the Enhanced Rotorcraft Drive System Program

    Science.gov (United States)

    Heath, Gregory F.; Slaughter, Stephen C.; Fisher, David J.; Lewicki, David G.; Fetty, Jason

    2011-01-01

    U.S. Army goals for the Enhanced Rotorcraft Drive System Program are to achieve a 40 percent increase in horsepower to weight ratio, a 15 dB reduction in drive system generated noise, 30 percent reduction in drive system operating, support, and acquisition cost, and 75 percent automatic detection of critical mechanical component failures. Boeing s technology transition goals are that the operational endurance level of the helical face gearing and related split-torque designs be validated to a TRL 6, and that analytical and manufacturing tools be validated. Helical face gear technology is being developed in this project to augment, and transition into, a Boeing AH-64 Block III split-torque face gear main transmission stage, to yield increased power density and reduced noise. To date, helical face gear grinding development on Northstar s new face gear grinding machine and pattern-development tests at the NASA Glenn/U.S. Army Research Laboratory have been completed and are described.

  16. Sensor fault-tolerant control for gear-shifting engaging process of automated manual transmission

    Science.gov (United States)

    Li, Liang; He, Kai; Wang, Xiangyu; Liu, Yahui

    2018-01-01

    Angular displacement sensor on the actuator of automated manual transmission (AMT) is sensitive to fault, and the sensor fault will disturb its normal control, which affects the entire gear-shifting process of AMT and results in awful riding comfort. In order to solve this problem, this paper proposes a method of fault-tolerant control for AMT gear-shifting engaging process. By using the measured current of actuator motor and angular displacement of actuator, the gear-shifting engaging load torque table is built and updated before the occurrence of the sensor fault. Meanwhile, residual between estimated and measured angular displacements is used to detect the sensor fault. Once the residual exceeds a determined fault threshold, the sensor fault is detected. Then, switch control is triggered, and the current observer and load torque table estimates an actual gear-shifting position to replace the measured one to continue controlling the gear-shifting process. Numerical and experiment tests are carried out to evaluate the reliability and feasibility of proposed methods, and the results show that the performance of estimation and control is satisfactory.

  17. Test Format and the Variation of Gender Achievement Gaps within the United States

    Science.gov (United States)

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia

    2016-01-01

    Prior research demonstrates the existence of gender achievement gaps and the variation in the magnitude of these gaps across states. This paper characterizes the extent to which the variation of gender achievement gaps on standardized tests across the United States can be explained by differing state accountability test formats. A comprehensive…

  18. A Powerful Test of the Autoregressive Unit Root Hypothesis Based on a Tuning Parameter Free Statistic

    DEFF Research Database (Denmark)

    Nielsen, Morten Ørregaard

    This paper presents a family of simple nonparametric unit root tests indexed by one parameter, d, and containing Breitung's (2002) test as the special case d = 1. It is shown that (i) each member of the family with d > 0 is consistent, (ii) the asymptotic distribution depends on d, and thus refle...

  19. New multi-country evidence on purchasing power parity: multivariate unit root test results

    NARCIS (Netherlands)

    J.J.J. Groen (Jan)

    2000-01-01

    textabstractIn this paper a likelihood-based multivariate unit root testing framework is utilized to test whether the real exchange rates of G10 countries are non-stationary. The framework uses a likelihood ratio statistic which combines the information across all involved countries while retaining

  20. Unit-based functional IDDT testing for aging degradation monitoring in a VLIW processor

    NARCIS (Netherlands)

    Zhao, Yong; Kerkhoff, Hans G.

    2015-01-01

    In this paper, functional unit-based IDDT testing has been applied for a 90nm VLIW processor to monitor its aging degradation. This technique can provide health data for reliability evaluation as used in e.g. prognostic software for lifetime prediction. The test-program development based on the

  1. Software Unit Testing during the Development of Digital Reactor Protection System of HTR-PM

    International Nuclear Information System (INIS)

    Guo Chao; Xiong Huasheng; Li Duo; Zhou Shuqiao; Li Jianghai

    2014-01-01

    Reactor Protection System (RPS) of High Temperature Gas-Cooled Reactor - Pebble bed Module (HTR-PM) is the first digital RPS designed and to be operated in the Nuclear Power Plant (NPP) of China, and its development process has receives a lot of concerns around the world. As a 1E-level safety system, the RPS has to be designed and developed following a series of nuclear laws and technical disciplines including software verification and validation (software V&V). Software V&V process demonstrates whether all stages during the software development are performed correctly, completely, accurately, and consistently, and the results of each stage are testable. Software testing is one of the most significant and time-consuming effort during software V&V. In this paper, we give a comprehensive introduction to the software unit testing during the development of RPS in HTR-PM. We first introduce the objective of the testing for our project in the aspects of static testing, black-box testing, and white-box testing. Then the testing techniques, including static testing and dynamic testing, are explained, and the testing strategy we employed is also introduced. We then introduce the principles of three kinds of coverage criteria we used including statement coverage, branch coverage, and the modified condition/decision coverage. As a 1E-level safety software, testing coverage needs to be up to 100% mandatorily. Then we talk the details of safety software testing during software development in HTR-PM, including the organization, methods and tools, testing stages, and testing report. The test result and experiences are shared and finally we draw a conclusion for the unit testing process. The introduction of this paper can contribute to improve the process of unit testing and software development for other digital instrumentation and control systems in NPPs. (author)

  2. Effects of fisheries closures and gear restrictions on fishing income in a Kenyan coral reef.

    Science.gov (United States)

    McClanahan, Timothy R

    2010-12-01

    The adoption of fisheries closures and gear restrictions in the conservation of coral reefs may be limited by poor understanding of the economic profitability of competing economic uses of marine resources. Over the past 12 years, I evaluated the effects of gear regulation and fisheries closures on per person and per area incomes from fishing in coral reefs of Kenya. In two of my study areas, the use of small-meshed beach seines was stopped after 6 years; one of these areas was next to a fishery closure. In my third study area, fishing was unregulated. Fishing yields on per capita daily wet weight basis were 20% higher after seine-net fishing was stopped. The per person daily fishing income adjacent to the closed areas was 14 and 22% higher than the fishing income at areas with only gear restrictions before and after the seine-net restriction, respectively. Incomes differed because larger fish were captured next to the closed area and the price per weight (kilograms) increased as fish size increased and because catches adjacent to the closure contained fish species of higher market value. Per capita incomes were 41 and 135% higher for those who fished in gear-restricted areas and near-closed areas, respectively, compared with those who fished areas with no restrictions. On a per unit area basis (square kilometers), differences in fishing income among the three areas were not large because fishing effort increased as the number of restrictions decreased. Changes in catch were, however, larger and often in the opposite direction expected from changes in effort alone. For example, effort declined 21% but nominal profits per square kilometer (not accounting for inflation) increased 29% near the area with gear restrictions. Gear restrictions also reduced the cost of fishing and increased the proportion of self-employed fishers. © 2010 Society for Conservation Biology.

  3. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  4. Examining the Islamic stock market efficiency: Evidence from nonlinear ESTAR unit root tests

    Directory of Open Access Journals (Sweden)

    Rahmat Heru Setianto

    2015-04-01

    Full Text Available This paper empirically examines the efficient market hypothesis (EMH in the Islamic stock market namely Jakarta Islamic Index by emphasizing on the random walk behavior and nonlinearity. In the first step, we employ Brock et al. (1996 test to examine the presence of nonlinear behavior in Jakarta Islamic Index. The evidence of nonlinear behavior in the indices, motivate us to use nonlinear ESTAR unit root test procedure recently developed by Kapetanios et al. (2003 and Kruse (2011. The nonlinear unit root test procedure fail to rejects the null hypothesis of unit root for the indices, suggesting that Jakarta Islamic Index characterized by random walk process supporting the theory of efficient market hypothesis. In addition, Lumsdaine and Papel (LP test identified significant structural breaks in the index series.

  5. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2013-01-01

    Full Text Available A method to simulate residual stress field of planetary gear is proposed. In this method, the finite element model of planetary gear is established and divided to tooth zone and profile zone, whose different temperature field is set. The gear's residual stress simulation is realized by the thermal compression stress generated by the temperature difference. Based on the simulation, the finite element model of planetary gear train is established, the dynamic meshing process is simulated, and influence of residual stress on equivalent stress of addendum, pitch circle, and dedendum of internal and external meshing planetary gear tooth profile is analyzed, according to non-linear contact theory, thermodynamic theory, and finite element theory. The results show that the equivalent stresses of planetary gear at both meshing and nonmeshing surface are significantly and differently reduced by residual stress. The study benefits fatigue cracking analysis and dynamic optimization design of planetary gear train.

  6. Power loss analysis in altered tooth-sum spur gearing

    Directory of Open Access Journals (Sweden)

    Sachidananda H. K.

    2018-01-01

    Full Text Available The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing.

  7. Modeling of automotive driveline system for reducing gear rattles

    Science.gov (United States)

    Shangguan, Wen-Bin; Liu, Xue-Lai; Yin, Yuming; Rakheja, Subhash

    2018-03-01

    A nonlinear torsional model for a driveline system with 4 degrees of freedom is proposed for studying gear rattle if a car is at idle. The time-varying meshing stiffness of geared teeth, gear backlash, and the damping from oil film are included in the model. The dynamic responses of the driveline system, such as clutch angular displacement, meshing force and relative displacement between geared teeth, are calculated using the presented model. The influences of stiffness and damping of a clutch on gear rattle of geared teeth in a generic transmission are investigated. Based on the calculation and analysis results, a design guideline to select clutch's stiffness and damping is developed to reduce gear rattle for a car at idle. Taking a generic driveline system of a passenger car as an example, the developed method is experimentally validated by comparing the baseline clutch and revised clutch, in terms of the measured noise inside engine compartment and cab and vibrations at transmission housing.

  8. Model studies of crosswind landing-gear configurations for STOL aircraft

    Science.gov (United States)

    Stubbs, S. M.; Byrdsong, T. A.

    1973-01-01

    A dynamic model was used to directly compare four different crosswind landing gear mechanisms. The model was landed as a free body onto a laterally sloping runway used to simulate a crosswind side force. A radio control system was used for steering to oppose the side force as the model rolled to a stop. The configuration in which the landing gears are alined by the pilot and locked in the direction of motion prior to touchdown gave the smoothest runout behavior with the vehicle maintaining its crab angle throughout the landing roll. Nose wheel steering was confirmed to be better than steering with nose and main gears differentially or together. Testing is continuing to obtain quantitative data to establish an experimental data base for validation of an analytical program that will be capable of predicting full scale results.

  9. Pilot-scale treatability test plan for the 200-UP-1 groundwater Operable Unit

    International Nuclear Information System (INIS)

    Wittreich, C.D.

    1994-05-01

    This document presents the treatability test plan for pilot-scale pump and treat testing at the 200-UP-1 Operable Unit. This treatability test plan has been prepared in response to an agreement between the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology, as documented in Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1989a) Change Control Form M-13-93-03 (Ecology et al. 1994). The agreement also requires that, following completion of the activities described in this test plan, a 200-UP-1 Operable Unit interim remedial measure (IRM) proposed plan be developed for use in preparing an interim action record of decision (ROD). The IRM Proposed Plan will be supported by the results of the testing described in this treatability test plan, as well as by other 200-UP-1 Operable Unit activities (e.g., limited field investigation, development of a qualitative risk assessment). Once issued, the interim action ROD will specify the interim action for groundwater contamination at the 200-UP-1 Operable Unit. The approach discussed in this treatability test plan is to conduct a pilot-scale pump and treat test for the contaminant plume associated with the 200-UP-1 Operable Unit. Primary contaminants of concern are uranium and technetium-99; the secondary contaminant of concern is nitrate. The pilot-scale treatability testing presented in this test plan has as its primary purpose to assess the performance of aboveground treatment systems with respect to the ability to remove the primary contaminants in groundwater withdrawn from the contaminant plume

  10. A novel implantable electromechanical ventricular assist device - First acute animal testing

    NARCIS (Netherlands)

    Kaufmann, R; Rakhorst, G; Mihaylov, D; Elstrodt, J; Nix, C; Reul, H; Rau, G

    1997-01-01

    A novel ventricular assist device (HIA-EMLVAD-AT1, Helmholtz Institute Aachen-electromechanical Left Ventricular Assist Device-Animal Test Version 1), driven by a uniformly and unidirectionally rotating actuator and a patented hypocycloidic pusherplate displacement gear unit, was developed and

  11. Test Results from a Direct Drive Gas Reactor Simulator Coupled to a Brayton Power Conversion Unit

    Science.gov (United States)

    Hervol, David S.; Briggs, Maxwell H.; Owen, Albert K.; Bragg-Sitton, Shannon M.; Godfroy, Thomas J.

    2010-01-01

    Component level testing of power conversion units proposed for use in fission surface power systems has typically been done using relatively simple electric heaters for thermal input. These heaters do not adequately represent the geometry or response of proposed reactors. As testing of fission surface power systems transitions from the component level to the system level it becomes necessary to more accurately replicate these reactors using reactor simulators. The Direct Drive Gas-Brayton Power Conversion Unit test activity at the NASA Glenn Research Center integrates a reactor simulator with an existing Brayton test rig. The response of the reactor simulator to a change in Brayton shaft speed is shown as well as the response of the Brayton to an insertion of reactivity, corresponding to a drum reconfiguration. The lessons learned from these tests can be used to improve the design of future reactor simulators which can be used in system level fission surface power tests.

  12. Bevel gear driver and method having torque limit selection

    Science.gov (United States)

    Cook, Joseph S., Jr.

    1994-08-01

    This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior

  13. Testing the system detection unit for measuring solid minerals bulk density

    Science.gov (United States)

    Voytyuk, I. N.; Kopteva, A. V.

    2017-10-01

    The paper provides a brief description of the system for measuring flux per volume of solid minerals via example of mineral coal. The paper discloses the operational principle of the detection unit. The paper provides full description of testing methodology, as well as practical implementation of the detection unit testing. This paper describes the removal of two data arrays via the channel of scattered anddirect radiation for the detection units of two generations. This paper describes Matlab software to determine the statistical characteristics of the studied objects. The mean value of pulses per cycles, and pulse counting inaccuracy relatively the mean value were determined for the calculation of the stability account of the detection units.

  14. Pilot-scale treatability test plan for the 200-BP-5 operable unit

    International Nuclear Information System (INIS)

    1994-08-01

    This document presents the treatability test plan for pilot-scale pump and treat testing at the 200-BP-5 Operable Unit. This treatability test plan has been prepared in response to an agreement between the U.S. Department of Energy (DOE), the U.S. Environmental Protection Agency (EPA), and the State of Washington Department of Ecology (Ecology), as documented in Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement, Ecology et al. 1989a) Change Control Form M-13-93-03 (Ecology et al. 1994) and a recent 200 NPL Agreement Change Control Form (Appendix A). The agreement also requires that, following completion of the activities described in this test plan, a 200-BP-5 Operable Unit Interim Remedial Measure (IRM) Proposed Plan be developed for use in preparing an Interim Action Record of Decision (ROD). The IRM Proposed Plan will be supported by the results of this treatability test plan, as well as by other 200-BP-5 Operable Unit activities (e.g., development of a qualitative risk assessment). Once issued, the Interim Action ROD will specify the interim action(s) for groundwater contamination at the 200-BP-5 Operable Unit. The treatability test approach is to conduct a pilot-scale pump and treat test for each of the two contaminant plumes associated with the 200-BP-5 Operable Unit. Primary contaminants of concern are 99 Tc and 60 Co for underwater affected by past discharges to the 216-BY Cribs, and 90 Sr, 239/240 Pu, and Cs for groundwater affected by past discharges to the 216-B-5 Reverse Well. The purpose of the pilot-scale treatability testing presented in this testplan is to provide the data basis for preparing an IRM Proposed Plan. To achieve this objective, treatability testing must: Assess the performance of groundwater pumping with respect to the ability to extract a significant amount of the primary contaminant mass present in the two contaminant plumes

  15. Test results of the signal processing and amplifier unit for the emittance measurement system

    International Nuclear Information System (INIS)

    Stawiszynski, L.; Schneider, S.

    1984-01-01

    The signal processing and amplifier unit for the emittance measurement system is the unit with which the beam current on the harp-wires and the slit is measured and converted to a digital output. Temperature effects are very critical at low currents and the purpose of the test measurements described in this report was mainly to establish the accuracy and repeatability of the measurements under the influence of temperature variations

  16. Some Experimental and Simulation Results on the Dynamic Behaviour of Spur and Helical Geared Transmissions with Journal Bearings

    Directory of Open Access Journals (Sweden)

    R. Fargère

    2012-01-01

    Full Text Available Some interactions between the dynamic and tribological behaviour of geared transmissions are examined, and a number of experimental and simulation results are compared. A model is introduced which incorporates most of the possible interactions between gears, shafts and hydrodynamic journal bearings. It combines (i a specific element for wide-faced gears that includes the normal contact conditions between actual mating teeth, that is, with tooth shape deviations and mounting errors, (ii shaft finite elements, and (iii the external forces generated by journal bearings determined by directly solving Reynolds' equation. The simulation results are compared with the measurement obtained on a high-precision test rig with single-stage spur and helical gears supported by hydrodynamic journal bearings. The experimental and simulation results compare well thus validating the simulation strategy both at the global and local scales.

  17. Global Analysis of a Planetary Gear Train

    Directory of Open Access Journals (Sweden)

    Tongjie Li

    2014-01-01

    Full Text Available By using the Poincaré-like cell-to-cell mapping method and shooting method, the global characteristics of a planetary gear train are studied based on the torsional vibration model with errors of transmission, time-varying meshing stiffness, and multiple gear backlashes. The study results reveal that the planetary with a certain set of parameters has four coexisting periodic orbits, which are P-1, P-2, P-4, and P-8, respectively. P-1 and P-2 motions are not of long-term stability, P-8 motion is of local stability, and P-4 motion is of global stability. Shooting method does not have the capacity of searching coexisting periodic orbits in a global scope, and it is easy to omit some periodic orbits which are far away from the main gropes of periodic orbits.

  18. Geared Topological Metamaterials with Tunable Mechanical Stability

    Directory of Open Access Journals (Sweden)

    Anne S. Meeussen

    2016-11-01

    Full Text Available The classification of materials into insulators and conductors has been shaken up by the discovery of topological insulators that conduct robustly at the edge but not in the bulk. In mechanics, designating a material as insulating or conducting amounts to asking if it is rigid or floppy. Although mechanical structures that display topological floppy modes have been proposed, they are all vulnerable to global collapse. Here, we design and build mechanical metamaterials that are stable and yet capable of harboring protected edge and bulk modes, analogous to those in electronic topological insulators and Weyl semimetals. To do so, we exploit gear assemblies that, unlike point masses connected by springs, incorporate both translational and rotational degrees of freedom. Global structural stability is achieved by eliminating geometrical frustration of collective gear rotations extending through the assembly. The topological robustness of the mechanical modes makes them appealing across scales from engineered macrostructures to networks of toothed microrotors of potential use in micromachines.

  19. Construction and start-up tests for Unit No. 5 of Fukushima Daiichi Nuclear Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, T; Sunami, Y; Ishii, N; Yokojima, T [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1978-12-01

    This unit, with an output capacity of 874 MWe, was completed by Toshiba last April on the basis of the actual operation records of the units previously completed and the experience in construction. Since its completion it has continued very excellent operation, with no emergency stop. This article is a description of the Unit 5, about: (1) the design and major points of improvement; (2) the construction work and cleaning of the plant; and (3) the operation tests, the use of the first automatic fuel exchanger, and the plant management system including the rust-preventive measures for two years since the oil-crisis.

  20. Electrohydraulic drive system with planetary superposed gears

    Energy Technology Data Exchange (ETDEWEB)

    Graetz, A.; Klimek, K.H.; Welz, H.

    1989-01-01

    To prevent drive problems in ploughs the drives must be designed in such a way as to compensate for asymmetries. If electromechanical drives are replaced by an electrohydraulic drive system with superposed planetary gears and hydrostatic torque reaction supports the following advantages occur: load-free acceleration, load equalisation between main and auxiliary drive, overload protection, and reduction of systems vibrations. 2 figs., 2 tabs.

  1. Generating Cycloidal Gears for 3D Printing

    OpenAIRE

    Daniels, Sunny

    2016-01-01

    (Shortened version of abstract in article itself) This article describes an algorithm for producing, for any desired resolution and any desired numbers of wheel and pinion teeth, polygonal approximations to the shapes of a pair of cycloidal gears that mesh correctly. An Octave implementation of the algorithm, mostly written in 2014, is included. The Octave implementation contains a (crude, but evidently adequate, at least for reasonable numbers of wheel and pinion teeth) solution of the probl...

  2. Investigation of noise in gear transmissions by the method of mathematical smoothing of experiments

    Science.gov (United States)

    Sheftel, B. T.; Lipskiy, G. K.; Ananov, P. P.; Chernenko, I. K.

    1973-01-01

    A rotatable central component smoothing method is used to analyze rotating gear noise spectra. A matrix is formulated in which the randomized rows correspond to various tests and the columns to factor values. Canonical analysis of the obtained regression equation permits the calculation of optimal speed and load at a previous assigned noise level.

  3. Empirical investigation of purchasing power parity for Turkey: Evidence from recent nonlinear unit root tests

    Directory of Open Access Journals (Sweden)

    Dilem Yıldırım

    2017-06-01

    Full Text Available This study explores the empirical validity of the purchasing power parity (PPP hypothesis between Turkey and its four major trading partners, the European Union, Russia, China and the US. Accounting for the nonlinear nature of real exchange rates, we employ a battery of recently developed nonlinear unit root tests. Our empirical results reveal that nonlinear unit root tests deliver stronger evidence in favour of the PPP hypothesis when compared to the conventional unit root tests only if nonlinearities in real exchange rates are correctly specified. Furthermore, it emerges from our findings that the real exchange rates of the countries having a free trade agreement are more likely to behave as linear stationary processes.

  4. Fat Tail Model for Simulating Test Systems in Multiperiod Unit Commitment

    Directory of Open Access Journals (Sweden)

    J. A. Marmolejo

    2015-01-01

    Full Text Available This paper describes the use of Chambers-Mallows-Stuck method for simulating stable random variables in the generation of test systems for economic analysis in power systems. A study that focused on generating test electrical systems through fat tail model for unit commitment problem in electrical power systems is presented. Usually, the instances of test systems in Unit Commitment are generated using normal distribution, but in this work, simulations data are based on a new method. For simulating, we used three original systems to obtain the demand behavior and thermal production costs. The estimation of stable parameters for the simulation of stable random variables was based on three generally accepted methods: (a regression, (b quantiles, and (c maximum likelihood, choosing one that has the best fit of the tails of the distribution. Numerical results illustrate the applicability of the proposed method by solving several unit commitment problems.

  5. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    Science.gov (United States)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2009-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

  6. Soil washing physical separations test procedure - 300-FF-1 operable unit

    Energy Technology Data Exchange (ETDEWEB)

    Belden, R.D.

    1993-10-08

    This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The {open_quotes}Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,{close_quotes} Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the {open_quotes}300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,{close_quotes} (DOE-RL 1993).

  7. Soil washing physical separations test procedure - 300-FF-1 operable unit

    International Nuclear Information System (INIS)

    Belden, R.D.

    1993-01-01

    This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The open-quotes Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,close quotes Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the open-quotes 300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,close quotes (DOE-RL 1993)

  8. A Generalized Dynamic Model of Geared System: Establishment and Application

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2011-12-01

    Full Text Available In order to make the dynamic characteristic simulation of the ordinary and planetary gears drive more accurate and more efficient , a generalized dynamic model of geared system is established including internal and external mesh gears in this paper. It is used to build a mathematical model, which achieves the auto judgment of the gear mesh state. We do not need to concern about active or passive gears any more, and the complicated power flow analysis can be avoided. With the numerical integration computation, the axis orbits diagram and dynamic gear mesh force characteristic are acquired and the results show that the dynamic response of translational displacement is greater when contacting line direction change is considered, and with the quickly change of direction of contacting line, the amplitude of mesh force would be increased, which easily causes the damage to the gear tooth. Moreover, compared with ordinary gear, dynamic responses of planetary gear would be affected greater by the gear backlash. Simulation results show the effectiveness of the generalized dynamic model and the mathematical model.

  9. Development of field simulator to test and qualify the gyrotron local control unit for ITER-India Gyrotron Test Facility

    International Nuclear Information System (INIS)

    Shah, Ronak; Mandge, Deepak; Rathod, Vipal; Parmar, Rajvi; Dilip, E. Sharan; Yadav, Amit; Sharma, Anjali; Rao, S.L.

    2017-01-01

    High power RF sources such as a Gyrotron system are operated at required output parameter by using various auxiliary power supplies, High voltage power supplies, auxiliary services and a dedicated Local Control Unit (LCU). These sub-systems must be operated in synchronous and safe way to control the gyrotron output parameters. The LCU performs remote, synchronous and safe operation of the all the gyrotron sub-systems. Broadly the LCU functions are operational control, data acquisition, protection and safety of the gyrotron system. At ITER-India gyrotron Test Facility (IIGTF) a local control unit (LCU) is being developed to operate the complete gyrotron system. This paper presents the design, development and various features of the field simulator. It also discuss LCU functionality test cases and results obtained using field simulator

  10. Testing the Birth Unit Design Spatial Evaluation Tool (BUDSET) in Australia: a pilot study.

    Science.gov (United States)

    Foureur, Maralyn J; Leap, Nicky; Davis, Deborah L; Forbes, Ian F; Homer, Caroline E S

    2011-01-01

    To pilot test the Birth Unit Design Spatial Evaluation Tool (BUDSET) in an Australian maternity care setting to determine whether such an instrument can measure the optimality of different birth settings. Optimally designed spaces to give birth are likely to influence a woman's ability to experience physiologically normal labor and birth. This is important in the current industrialized environment, where increased caesarean section rates are causing concerns. The measurement of an optimal birth space is currently impossible, because there are limited tools available. A quantitative study was undertaken to pilot test the discriminant ability of the BUDSET in eight maternity units in New South Wales, Australia. Five auditors trained in the use of the BUDSET assessed the birth units using the BUDSET, which is based on 18 design principles and is divided into four domains (Fear Cascade, Facility, Aesthetics, and Support) with three to eight assessable items in each. Data were independently collected in eight birth units. Values for each of the domains were aggregated to provide an overall Optimality Score for each birth unit. A range of Optimality Scores was derived for each of the birth units (from 51 to 77 out of a possible 100 points). The BUDSET identified units with low-scoring domains. Essentially these were older units and conventional labor ward settings. The BUDSET provides a way to assess the optimality of birth units and determine which domain areas may need improvement. There is potential for improvements to existing birth spaces, and considerable improvement can be made with simple low-cost modifications. Further research is needed to validate the tool.

  11. Test plan for the field evaluation and demonstration of the Contamination Control Unit

    International Nuclear Information System (INIS)

    Winberg, M.R.; Thompson, D.N.

    1993-06-01

    This report describes test details of a full demonstration of the Contamination Control Unit (CCU). The CCU is a mobile trailer capable of employing the use of soil fixatives, dust suppression agents, misting, and vacuum systems. These systems can perform a large number of contamination control functions to support the Office of Waste Technology Development (OTD) Buried Waste Integrated Demonstration (BWID) projects, transuranic (TRU) waste retrieval operations, and emergency response for hazardous and radioactive materials incidents. The demonstration will include both performance testing at the North Holmes Laboratory Facility (NHLF) and field testing in conjunction with the Remote Excavation System Demonstration at the Cold Test Pit. The NHLF will test operational parameters using water only, and the field demonstration at the Cold Test Pit involves full scale operation of vacuum, fixant, misting, and dust suppression systems. Test objectives, detailed experimental procedures, and data quality objectives necessary to perform the field demonstration are included in this test plan

  12. DESIGN IMPROVEMENT OF THE LOCOMOTIVE RUNNING GEARS

    Directory of Open Access Journals (Sweden)

    S. V. Myamlin

    2013-09-01

    Full Text Available Purpose. To determine the dynamic qualities of the mainline freight locomotives characterizing the safe motion in tangent and curved track sections at all operational speeds, one needs a whole set of studies, which includes a selection of the design scheme, development of the corresponding mathematical model of the locomotive spatial fluctuations, construction of the computer calculation program, conducting of the theoretical and then experimental studies of the new designs. In this case, one should compare the results with existing designs. One of the necessary conditions for the qualitative improvement of the traction rolling stock is to define the parameters of its running gears. Among the issues related to this problem, an important place is occupied by the task of determining the locomotive dynamic properties on the stage of projection, taking into account the selected technical solutions in the running gear design. Methodology. The mathematical modeling studies are carried out by the numerical integration method of the dynamic loading for the mainline locomotive using the software package «Dynamics of Rail Vehicles » («DYNRAIL». Findings. As a result of research for the improvement of locomotive running gear design it can be seen that the creation of the modern locomotive requires from engineers and scientists the realization of scientific and technical solutions. The solutions enhancing design speed with simultaneous improvement of the traction, braking and dynamic qualities to provide a simple and reliable design, especially the running gear, reducing the costs for maintenance and repair, low initial cost and operating costs for the whole service life, high traction force when starting, which is as close as possible to the ultimate force of adhesion, the ability to work in multiple traction mode and sufficient design speed. Practical Value. The generalization of theoretical, scientific and methodological, experimental studies aimed

  13. Bringing testing to the people - benefits of mobile unit HIV/syphilis testing in Lima, Peru, 2007-2009.

    Science.gov (United States)

    Lipsitz, Mindy C; Segura, Eddy R; Castro, José Luis; Smith, Edward; Medrano, Carlos; Clark, Jesse L; Lake, Jordan E; Cabello, Robinson

    2014-04-01

    Mobile unit (MU) HIV testing is an alternative method of providing healthcare access. We compared demographic and behavioural characteristics, HIV testing history and HIV prevalence between participants seeking testing at a MU vs. fixed clinic (FC) in Lima, Peru. Our analysis included men and transgender women (TW) in Lima aged ≥ 18 years old seeking HIV testing at their first visit to a community-based MU or FC from October 2007 to November 2009. HIV testing history, HIV serostatus and behavioural characteristics were analysed. A large percentage of MU attendees self-identified as transgender (13%) or heterosexual (41%). MU attendees were more likely to engage in transactional sex (24% MU vs. 10% FC, p < 0.001), use alcohol/drugs during their last sexual encounter (24% MU vs. 20% FC, p < 0.01) and/or be a first-time HIV tester (48% MU vs. 41% FC, p < 0.001). MU HIV prevalence was 9% overall and 5% among first-time testers (49% in TW and 11% in men who have sex with men [MSM] first-time testers). MU testing reached large numbers of at-risk (MSM/TW) populations engaged in unsafe sexual behaviours, making MU outreach a worthy complement to FC testing. Investigation into whether MU attendees would otherwise access HIV testing is warranted to determine the impact of MU testing.

  14. Corrective Action Investigation Plan for Corrective Action Unit 543: Liquid Disposal Units, Nevada Test Site, Nevada: Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

    2004-05-03

    The general purpose of this Corrective Action Investigation Plan is to ensure that adequate data are collected to provide sufficient and reliable information to identify, evaluate, and select technically viable corrective action alternatives (CAAs) for Corrective Action Unit (CAU) 543: Liquid Disposal Units, Nevada Test Site (NTS), Nevada. Located in Areas 6 and 15 on the NTS, CAU 543 is comprised of a total of seven corrective action sites (CASs), one in Area 6 and six in Area 15. The CAS in Area 6 consists of a Decontamination Facility and its components which are associated with decontamination of equipment, vehicles, and materials related to nuclear testing. The six CASs in Area 15 are located at the U.S. Environmental Protection Agency Farm and are related to waste disposal activities at the farm. Sources of possible contamination at Area 6 include potentially contaminated process waste effluent discharged through a process waste system, a sanitary waste stream generated within buildings of the Decon Facility, and radiologically contaminated materials stored within a portion of the facility yard. At Area 15, sources of potential contamination are associated with the dairy operations and the animal tests and experiments involving radionuclide uptake. Identified contaminants of potential concern include volatile organic compounds, semivolatile organic compounds, petroleum hydrocarbons, pesticides, herbicides, polychlorinated biphenyls, metals, and radionuclides. Three corrective action closure alternatives - No Further Action, Close in Place, or Clean Closure - will be recommended for CAU 543 based on an evaluation of all the data quality objective-related data. Field work will be conducted following approval of the plan. The results of the field investigation will support a defensible evaluation of CAAs that will be presented in the Corrective Action Decision Document.

  15. Određivanje krutosti planetarnog prenosnika / Determination of gear mesh stiffness in planetary gearing

    Directory of Open Access Journals (Sweden)

    Vojislav Batinić

    2008-04-01

    Full Text Available Kontaktna krutost zubaca jedan je od glavnih generatora unutrašnjih dinamičkih sila u spregama zupčanika planetarnih prenosnika. Neophodan je pri opisivanju dinamičkog ponašanja planetarnih prenosnika, tj. pri postavljanju jednačina dinamičke ravnoteže. U radu je prikazan metodološki pristup analitičkom i eksperimentalnom određivanju krutosti posmatranog planetarnog prenosnika. / Gear mesh stiffness in planetary gearing is one of the main generators of internal dynamic forces. It is necessary in describing dynamic behavior of planetary trains, i.e. in defining their equations of dynamic balance. This paper presents a methodological approach to experimental and analytical calculation of stiffness in planetary gearing.

  16. Acoustic Measurements of a Large Civil Transport Main Landing Gear Model

    Science.gov (United States)

    Ravetta, Patricio A.; Khorrami, Mehdi R.; Burdisso, Ricardo A.; Wisda, David M.

    2016-01-01

    Microphone phased array acoustic measurements of a 26 percent-scale, Boeing 777-200 main landing gear model with and without noise reduction fairings installed were obtained in the anechoic configuration of the Virginia Tech Stability Tunnel. Data were acquired at Mach numbers of 0.12, 0.15, and 0.17 with the latter speed used as the nominal test condition. The fully and partially dressed gear with the truck angle set at 13 degrees toe-up landing configuration were the two most extensively tested configurations, serving as the baselines for comparison purposes. Acoustic measurements were also acquired for the same two baseline configurations with the truck angle set at 0 degrees. In addition, a previously tested noise reducing, toboggan-shaped fairing was re-evaluated extensively to address some of the lingering questions regarding the extent of acoustic benefit achievable with this device. The integrated spectra generated from the acoustic source maps reconfirm, in general terms, the previously reported noise reduction performance of the toboggan fairing as installed on an isolated gear. With the recent improvements to the Virginia Tech tunnel acoustic quality and microphone array capabilities, the present measurements provide an additional, higher quality database to the acoustic information available for this gear model.

  17. External gear pumps operating with non-Newtonian fluids: Modelling and experimental validation

    Science.gov (United States)

    Rituraj, Fnu; Vacca, Andrea

    2018-06-01

    External Gear Pumps are used in various industries to pump non-Newtonian viscoelastic fluids like plastics, paints, inks, etc. For both design and analysis purposes, it is often a matter of interest to understand the features of the displacing action realized by meshing of the gears and the description of the behavior of the leakages for this kind of pumps. However, very limited work can be found in literature about methodologies suitable to model such phenomena. This article describes the technique of modelling external gear pumps that operate with non-Newtonian fluids. In particular, it explains how the displacing action of the unit can be modelled using a lumped parameter approach which involves dividing fluid domain into several control volumes and internal flow connections. This work is built upon the HYGESim simulation tool, conceived by the authors' research team in the last decade, which is for the first time extended for the simulation of non-Newtonian fluids. The article also describes several comparisons between simulation results and experimental data obtained from numerous experiments performed for validation of the presented methodology. Finally, operation of external gear pump with fluids having different viscosity characteristics is discussed.

  18. Start-up tests of Kashiwazakikariwa Nuclear Power Station Unit No.2 and No.5

    International Nuclear Information System (INIS)

    Fueki, Kensuke; Aoki, Shiro; Tanaka, Yasuhisa; Yahagi, Kimitoshi

    1991-01-01

    The Kashiwazakikariwa Nuclear Power Station Units No.5 and No.2 started commercial operation on April 10 and September 28 of 1990 respectively. As the result of the application of the First and Second LWR Improvement and Standardization Program, the plants were designed aiming at improvement of reliability, operation, and maintenance while maintaining safety. Construction of the plants took 6.5 to 7 years for completion, during which period the last 10 months were spent for the start up tests program. Start up tests were carried out under deliberate management to assure that the plants can operate safely and steadily at the prescribed operating points, and the schedules and tests item modifications adopted in Unit No.2 and No.5 were verified under the start up tests program. (author)

  19. Testing of the Advanced Stirling Radioisotope Generator Engineering Unit at NASA Glenn Research Center

    Science.gov (United States)

    Lewandowski, Edward J.

    2013-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a high-efficiency generator being developed for potential use on a Discovery 12 space mission. Lockheed Martin designed and fabricated the ASRG Engineering Unit (EU) under contract to the Department of Energy. This unit was delivered to NASA Glenn Research Center in 2008 and has been undergoing extended operation testing to generate long-term performance data for an integrated system. It has also been used for tests to characterize generator operation while varying control parameters and system inputs, both when controlled with an alternating current (AC) bus and with a digital controller. The ASRG EU currently has over 27,000 hours of operation. This paper summarizes all of the tests that have been conducted on the ASRG EU over the past 3 years and provides an overview of the test results and what was learned.

  20. Influence of material and gear parameters on the safety of gearing in metallurgical industry

    Directory of Open Access Journals (Sweden)

    S. Medvecká - Beňová

    2015-01-01

    Full Text Available This paper deals with the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load. Steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500 - 650 HBW are used. As a final heat treatment are used surface hardening, cementation and hardening, nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. Results are presented for dual-ratio gearbox with spur gears from operation of an integrated steel company.

  1. The software testing of PPS for shin Ulchin nuclear power plant units 1 and 2

    International Nuclear Information System (INIS)

    Kang, Dong Pa; Park, Cheol Lak; Cho, Chang Hui; Sohn, Se Do; Baek, Seung Min

    2012-01-01

    The testing of software (S/W) is the process of analyzing a software item to detect the differences between existing and required conditions to evaluate the features of the software items. This paper introduces the S/W testing of Plant Protection System (PPS), as a safety system which actuate Reactor Trip (RT) and Engineered Safety Features (ESF) for Shin Ulchin Nuclear Power Plant Units 1 and 2 (SUN 1 and 2)

  2. Purchasing power parity in OECD countries: nonlinear unit root tests revisited

    OpenAIRE

    Juan Carlos Cuestas; Paulo José Regis

    2010-01-01

    The aim of this paper is to provide additional evidence on the purchasing power parity empirical fulfillment in a pool of OECD countries. We apply the Harvey et al. (2008) linearity test and the Kruse (2010) nonlinear unit root test. The results point to the fact that the purchasing power parity theory holds in a greater number of countries than has been reported in previous studies.

  3. The validity of PPP: evidence from Lagrange multiplier unit root tests for ASEAN countries

    OpenAIRE

    Alper ASLAN

    2010-01-01

    The univariate and panel Lagrange Multiplier (LM) unit root tests with one and two structural breaks proposed by Lee and Strazicich (2003, 2004) which are considerably more powerful than traditional tests are employed to investigate whether the purchasing power parity (PPP) theory holds true for ASEAN countries by using both black market and official exchange rates. We find strong evidence in favour of long-run PPP for six ASEAN countries namely, Indonesia, Malaysia, Myanmar, Philippines, Sin...

  4. Field Tests of Wind Turbine Unit with Tandem Wind Rotors and Double Rotational Armatures

    Science.gov (United States)

    Galal, Ahmed Mohamed; Kanemoto, Toshiaki

    This paper discusses the field tests of the wind turbine unit, in which the front and the rear wind rotors drive the inner and the outer armatures of the synchronous generator. The wind rotors were designed conveniently by the traditional procedure for the single wind rotor, where the diameters of the front and the rear wind rotors are 2 m and 1.33 m. The tests were done on a pick-up type truck driven straightly at constant speed. The rotational torque of the unit is directly proportional to the induced electric current irrespective of the rotational speeds of the wind rotors, while the induced voltage is proportional to the relative rotational speed. The performance of the unit is significantly affected not only by the wind velocity, but also by the blade setting angles of both wind rotors and the applied load especially at lower wind velocity.

  5. Analogue particle identifier and test unit for automatic measuring of errors

    International Nuclear Information System (INIS)

    Boden, A.; Lauch, J.

    1979-04-01

    A high accuracy analogue particle identifier is described. The unit is used for particle identification or data correction of experimental based errors in magnetic spectrometers. Signals which are proportional to the energy, the time-of-flight or the position of absorption of the particles are supplied to an analogue computation circuit (multifunction converter). Three computation functions are available for different applications. The output of the identifier produces correction signals or pulses whose amplitudes are proportional to the mass of the particles. Particle identification and data correction can be optimized by the adjustment of variable parameters. An automatic test unit has been developed for adjustment and routine checking of particle identifiers. The computation functions can be tested by this unit with an accuracy of 1%. (orig.) [de

  6. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  7. Nonlinear dynamics modelling of multistage micro-planetary gear transmission

    Directory of Open Access Journals (Sweden)

    Li Jianying

    2018-01-01

    Full Text Available The transmission structure of a 2K-H multistage micro-planetary gear transmission reducer is described in detail, and three assumptions are supposed in dynamic modelling. On basis of these assumptions, a three stages 2K-H micro-planetary gear transmission dynamic model is established, in which the relative displacement each meshing gear pairs can be obtained after including the comprehensive transmission error. According to gear kinematics, the friction arms between the sun gear, the ring gear and the nth planet are also obtained, and the friction coefficient in the mixed elastohydrodynamic lubrication is considered, the transmission system motion differential equations are obtained, including above factors and the time-varying meshing stiffness, damping and backlash, inter-stage coupling stiffness, it can be provided an theoretical foundation for further analysing the parameter sensitivity, dynamic stability and designing.

  8. Economic method for helical gear flank surface characterisation

    Science.gov (United States)

    Koulin, G.; Reavie, T.; Frazer, R. C.; Shaw, B. A.

    2018-03-01

    Typically the quality of a gear pair is assessed based on simplified geometric tolerances which do not always correlate with functional performance. In order to identify and quantify functional performance based parameters, further development of the gear measurement approach is required. Methodology for interpolation of the full active helical gear flank surface, from sparse line measurements, is presented. The method seeks to identify the minimum number of line measurements required to sufficiently characterise an active gear flank. In the form ground gear example presented, a single helix and three profile line measurements was considered to be acceptable. The resulting surfaces can be used to simulate the meshing engagement of a gear pair and therefore provide insight into functional performance based parameters. Therefore the assessment of the quality can be based on the predicted performance in the context of an application.

  9. Acoustic monitoring systems tests at Indian Point Unit 1. Final report

    International Nuclear Information System (INIS)

    Smith, J.R.; Rao, G.V.; Craig, J.

    1979-12-01

    This report describes the results of a program to test acoustic monitoring systems on Indian Point Unit No. 1 under actual plant operating conditions, less the reactor core. The two types of systems evaluated were the monitoring of acoustic emissions generated by growing flaws and the monitoring of acoustic signals from leaks

  10. Closure report for housekeeping category, Corrective Action Unit 349, Area 12, Nevada Test Site

    International Nuclear Information System (INIS)

    1998-01-01

    This Closure Report summarizes the corrective actions which were completed at the Corrective Action Sites within Corrective Action Unit 349 Area 12 at the Nevada Test Site. Current site descriptions, observations and identification of wastes removed are included on FFACO Corrective Action Site housekeeping closure verification forms

  11. Closure report for housekeeping category, Corrective Action Unit 349, Area 12, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This Closure Report summarizes the corrective actions which were completed at the Corrective Action Sites within Corrective Action Unit 349 Area 12 at the Nevada Test Site. Current site descriptions, observations and identification of wastes removed are included on FFACO Corrective Action Site housekeeping closure verification forms.

  12. Closure report for housekeeping category, Corrective Action Unit 348, Nevada Test Site

    International Nuclear Information System (INIS)

    1998-01-01

    This Closure Report summarizes the corrective actions which were completed at twelve Corrective Action Sites within Corrective Action Unit 348 at the Nevada Test Site. Current site descriptions, observations and identification of wastes removed are included on FFACO Corrective Action Site housekeeping closure verification forms

  13. Closure report for housekeeping category, Corrective Action Unit 347, Nevada Test Site

    International Nuclear Information System (INIS)

    1998-01-01

    This Closure Report summarizes the corrective actions which were completed at the Corrective Action Sites within Corrective Action Unit 347 at the Nevada Test Site. Current site descriptions, observations and identification of wastes removed are included on FFACO Corrective Action Site housekeeping closure verification forms

  14. Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

    Science.gov (United States)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Shastry, Rohit; Pinero, Luis; Peterson, Todd; Mathers, Alex

    2012-01-01

    NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

  15. Pilot-scale treatability test plan for the 100-HR-3 operable unit

    International Nuclear Information System (INIS)

    1994-08-01

    This document presents the treatability test plan for pilot-scale pump-and-treat testing at the 100-HR-3 Operable Unit. The test will be conducted in fulfillment of interim Milestone M-15-06E to begin pilot-scale pump-and-treat operations by August 1994. The scope of the test was determined based on the results of lab/bench-scale tests (WHC 1993a) conducted in fulfillment of Milestone M-15-06B. These milestones were established per agreement between the U.S. Department of Energy (DOE), the Washington State Department of Ecology and the U.S. Environmental Protection Agency (EPA), and documented on Hanford Federal of Ecology Facility Agreement and Consent Order Change Control Form M-15-93-02. This test plan discusses a pilot-scale pump-and-treat test for the chromium plume associated with the D Reactor portion of the 100-HR-3 Operable Unit. Data will be collected during the pilot test to assess the effectiveness, operating parameters, and resource needs of the ion exchange (IX) pump-and-treat system. The test will provide information to assess the ability to remove contaminants by extracting groundwater from wells and treating extracted groundwater using IX. Bench-scale tests were conducted previously in which chromium VI was identified as the primary contaminant of concern in the 100-D reactor plume. The DOWEX 21K trademark resin was recommended for pilot-scale testing of an IX pump-and-treat system. The bench-scale test demonstrated that the system could remove chromium VI from groundwater to concentrations less than 50 ppb. The test also identified process parameters to monitor during pilot-scale testing. Water will be re-injected into the plume using wells outside the zone of influence and upgradient of the extraction well

  16. An Approach for the Dynamic Measurement of Ring Gear Strains of Planetary Gearboxes Using Fiber Bragg Gratings

    Directory of Open Access Journals (Sweden)

    Hang Niu

    2017-12-01

    Full Text Available The strain of the ring gear can reflect the dynamic characteristics of planetary gearboxes directly, which makes it an ideal signal to monitor the health condition of the gearbox. To overcome the disadvantages of traditional methods, a new approach for the dynamic measurement of ring gear strains using fiber Bragg gratings (FBGs is proposed in this paper. Firstly, the installation of FBGs is determined according to the analysis for the strain distribution of the ring gear. Secondly, the parameters of the FBG are determined in consideration of the accuracy and sensitivity of the measurement as well as the size of the ring gear. The strain measured by the FBG is then simulated under non-uniform strain field conditions. Thirdly, a dynamic measurement system is built and tested. Finally, the strains of the ring gear are measured in a planetary gearbox under normal and faulty conditions. The experimental results showed good agreement with the theoretical results in values, trends, and the fault features can be seen from the time domain of the measured strain signal, which proves that the proposed method is feasible for the measurement of the ring gear strains of planetary gearboxes.

  17. An Approach for the Dynamic Measurement of Ring Gear Strains of Planetary Gearboxes Using Fiber Bragg Gratings.

    Science.gov (United States)

    Niu, Hang; Zhang, Xiaodong; Hou, Chenggang

    2017-12-16

    The strain of the ring gear can reflect the dynamic characteristics of planetary gearboxes directly, which makes it an ideal signal to monitor the health condition of the gearbox. To overcome the disadvantages of traditional methods, a new approach for the dynamic measurement of ring gear strains using fiber Bragg gratings (FBGs) is proposed in this paper. Firstly, the installation of FBGs is determined according to the analysis for the strain distribution of the ring gear. Secondly, the parameters of the FBG are determined in consideration of the accuracy and sensitivity of the measurement as well as the size of the ring gear. The strain measured by the FBG is then simulated under non-uniform strain field conditions. Thirdly, a dynamic measurement system is built and tested. Finally, the strains of the ring gear are measured in a planetary gearbox under normal and faulty conditions. The experimental results showed good agreement with the theoretical results in values, trends, and the fault features can be seen from the time domain of the measured strain signal, which proves that the proposed method is feasible for the measurement of the ring gear strains of planetary gearboxes.

  18. Landing Gear Door Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  19. New generation methods for spur, helical, and spiral-bevel gears

    Science.gov (United States)

    Litvin, F. L.; Tsung, W.-J.; Coy, J. J.; Handschuh, R. F.; Tsay, C.-B. P.

    1987-01-01

    New methods for generating spur, helical, and spiral-bevel gears are proposed. These methods provide the gears with conjugate gear tooth surfaces, localized bearing contact, and reduced sensitivity to gear misalignment. Computer programs have been developed for simulating gear meshing and bearing contact.

  20. Tooth Fracture Detection in Spiral Bevel Gears System by Harmonic Response Based on Finite Element Method

    Directory of Open Access Journals (Sweden)

    Yuan Chen

    2017-01-01

    Full Text Available Spiral bevel gears occupy several advantages such as high contact ratio, strong carrying capacity, and smooth operation, which become one of the most widely used components in high-speed stage of the aeronautical transmission system. Its dynamic characteristics are addressed by many scholars. However, spiral bevel gears, especially tooth fracture occurrence and monitoring, are not to be investigated, according to the limited published issues. Therefore, this paper establishes a three-dimensional model and finite element model of the Gleason spiral bevel gear pair. The model considers the effect of tooth root fracture on the system due to fatigue. Finite element method is used to compute the mesh generation, set the boundary condition, and carry out the dynamic load. The harmonic response spectra of the base under tooth fracture are calculated and the influence of main parameters on monitoring failure is investigated as well. The results show that the change of torque affects insignificantly the determination of whether or not the system has tooth fracture. The intermediate frequency interval (200 Hz–1000 Hz is the best interval to judge tooth fracture occurrence. The best fault test region is located in the working area where the system is going through meshing. The simulation calculation provides a theoretical reference for spiral bevel gear system test and fault diagnosis.

  1. Fault detection of a spur gear using vibration signal with multivariable statistical parameters

    Directory of Open Access Journals (Sweden)

    Songpon Klinchaeam

    2014-10-01

    Full Text Available This paper presents a condition monitoring technique of a spur gear fault detection using vibration signal analysis based on time domain. Vibration signals were acquired from gearboxes and used to simulate various faults on spur gear tooth. In this study, vibration signals were applied to monitor a normal and various fault conditions of a spur gear such as normal, scuffing defect, crack defect and broken tooth. The statistical parameters of vibration signal were used to compare and evaluate the value of fault condition. This technique can be applied to set alarm limit of the signal condition based on statistical parameter such as variance, kurtosis, rms and crest factor. These parameters can be used to set as a boundary decision of signal condition. From the results, the vibration signal analysis with single statistical parameter is unclear to predict fault of the spur gears. The using at least two statistical parameters can be clearly used to separate in every case of fault detection. The boundary decision of statistical parameter with the 99.7% certainty ( 3   from 300 referenced dataset and detected the testing condition with 99.7% ( 3   accuracy and had an error of less than 0.3 % using 50 testing dataset.

  2. Unit and integration testing of Lustre programs: a case study from the nuclear industry

    International Nuclear Information System (INIS)

    Thevenod-Fosse, P.

    1998-01-01

    LUSTRE belongs to the class of synchronous data flow languages which have been designed for programming reactive and real-time systems having safety-critical requirements. It is implemented in the SCADE tool. SCADE is a software development environment for real-time systems which consists of a graphical and textual editor, and a C code generator. In previous work, a testing approach specific to LUSTRE programs has been defined, which may be applied at either the unit or integration testing levels of a gradual testing process. The paper reports on an industrial case study we have performed to exemplify the feasibility of the testing strategy. The software module, called SRIC (Source Range Instrumentation channel), was developed by SCHNEIDER ELECTRIC in the SCADE environment. SRIC is extracted from a monitoring software system of a nuclear reactor: it approximates 2600 lines of C code automatically generated by SCADE. Section 2 outlines the testing strategy. Then, Section 3 presents the results related to the program SRIC, for which four testing levels were defined (unit testing followed by three successive integration testing levels). First conclusions and direction for future work are proposed in Section 4. (author)

  3. Unit Root Testing and Estimation in Nonlinear ESTAR Models with Normal and Non-Normal Errors.

    Directory of Open Access Journals (Sweden)

    Umair Khalil

    Full Text Available Exponential Smooth Transition Autoregressive (ESTAR models can capture non-linear adjustment of the deviations from equilibrium conditions which may explain the economic behavior of many variables that appear non stationary from a linear viewpoint. Many researchers employ the Kapetanios test which has a unit root as the null and a stationary nonlinear model as the alternative. However this test statistics is based on the assumption of normally distributed errors in the DGP. Cook has analyzed the size of the nonlinear unit root of this test in the presence of heavy-tailed innovation process and obtained the critical values for both finite variance and infinite variance cases. However the test statistics of Cook are oversized. It has been found by researchers that using conventional tests is dangerous though the best performance among these is a HCCME. The over sizing for LM tests can be reduced by employing fixed design wild bootstrap remedies which provide a valuable alternative to the conventional tests. In this paper the size of the Kapetanios test statistic employing hetroscedastic consistent covariance matrices has been derived and the results are reported for various sample sizes in which size distortion is reduced. The properties for estimates of ESTAR models have been investigated when errors are assumed non-normal. We compare the results obtained through the fitting of nonlinear least square with that of the quantile regression fitting in the presence of outliers and the error distribution was considered to be from t-distribution for various sample sizes.

  4. Turbine Engine with Differential Gear Driven Fan and Compressor

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)

    2013-01-01

    A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

  5. The theory and practice of worm gear drives

    CERN Document Server

    Dudás, Ilés

    2005-01-01

    Worm gears are special gears that resemble screws, and can be used to drive other gears. Worm gears, enable two non-touching shafts in a machine to mesh (join) together. This publication, unique in that it combines both theoretical and practical design aspects, including the latest results of research and development, provides detailed treatment of the theory and production of worm drives, as well as the overarching subject of production geometry of helicoidal surfaces.Included are mathematical models for a number of practical applications; a description of dressing equipment r

  6. Offset Compound Gear Inline Two-Speed Drive

    Science.gov (United States)

    Stevens, Mark A. (Inventor); Handschuh, Robert F. (Inventor); Lewicki, David G. (Inventor)

    2014-01-01

    A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

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

    International Nuclear Information System (INIS)

    Delaunois, T.; Lefevre, R.

    1990-01-01

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

  8. Nuclear waste transportation package testing: A review of selected programs in the United States and abroad

    International Nuclear Information System (INIS)

    Snedeker, D.F.

    1990-12-01

    This report provides an overview of some recent nuclear waste transportation package development programs. This information is intended to aid the State of Nevada in its review of US Department of Energy (DOE) nuclear waste transportation programs. This report addresses cask testing programs in the United Kingdom and selected 1/4 and full scale testing in the US. Facilities that can provide cask testing services, both in the US and to a limited extent abroad, are identified. The costs for different type test programs are identified as a means to estimate costs for future test programs. Not addressed is the public impact such testing might have in providing an increased sense of safety or confidence. The British test program was apparently quite successful in demonstrating safety to the public at the time. There is no US test effort that is similar in scope for direct comparison. Also addressed are lessons learned from testing programs and areas that may merit possible future integrated examination. Areas that may require further examination are both technical and institutional. This report provides information which, when combined with other sources of information will enable the State of Nevada to assess the following areas: feasibility of full scale testing; costs of full scale tests; potential benefits of testing; limits that full scale testing impose; and disadvantages of emphasis on testing vs analytical solutions. This assessment will then allow the state to comment on DOE Office of Civilian Radioactive Waste Management (OCRWM) plans for the development and licensing of new shipping cask designs. These plans currently expect contractors to perform engineering testing for materials development, quarter scale model testing to validate analytical assessments and full scale prototype testing of operational features. DOE currently plans no full scale or extra-regulatory destructive testing to aid in cask licensing. 1 tab

  9. Use of Ancillary Tests When Determining Brain Death in Pediatric Patients in the United States.

    Science.gov (United States)

    Lewis, Ariane; Adams, Nellie; Chopra, Arun; Kirschen, Matthew P

    2017-10-01

    Although pediatric brain death guidelines stipulate when ancillary testing should be used during brain death determination, little is known about the way these recommendations are implemented in clinical practice. We conducted a survey of pediatric intensivists and neurologists in the United States on the use of ancillary testing. Although most respondents noted they only performed an ancillary test if the clinical examination and apnea test could not be completed, 20% of 195 respondents performed an ancillary test for other reasons, including (1) to convince a family that objected to the brain death determination that a patient is truly dead (n = 21), (2) personal preference (n = 14), and (3) institutional requirement (n = 5). Our findings suggest that pediatricians use ancillary tests for a variety of reasons during brain death determination. Medical societies and governmental regulatory bodies must reinforce the need for homogeneity in practice.

  10. Initial closed operation of the CELSS Test Facility Engineering Development Unit

    Science.gov (United States)

    Kliss, M.; Blackwell, C.; Zografos, A.; Drews, M.; MacElroy, R.; McKenna, R.; Heyenga, A. G.

    2003-01-01

    As part of the NASA Advanced Life Support Flight Program, a Controlled Ecological Life Support System (CELSS) Test Facility Engineering Development Unit has been constructed and is undergoing initial operational testing at NASA Ames Research Center. The Engineering Development Unit (EDU) is a tightly closed, stringently controlled, ground-based testbed which provides a broad range of environmental conditions under which a variety of CELSS higher plant crops can be grown. Although the EDU was developed primarily to provide near-term engineering data and a realistic determination of the subsystem and system requirements necessary for the fabrication of a comparable flight unit, the EDU has also provided a means to evaluate plant crop productivity and physiology under controlled conditions. This paper describes the initial closed operational testing of the EDU, with emphasis on the hardware performance capabilities. Measured performance data during a 28-day closed operation period are compared with the specified functional requirements, and an example of inferring crop growth parameters from the test data is presented. Plans for future science and technology testing are also discussed. Published by Elsevier Science Ltd on behalf of COSPAR.

  11. Cosmo Cassette: A Microfluidic Microgravity Microbial System For Synthetic Biology Unit Tests and Satellite Missions

    Science.gov (United States)

    Berliner, Aaron J.

    2013-01-01

    Although methods in the design-build-test life cycle of the synthetic biology field have grown rapidly, the expansion has been non-uniform. The design and build stages in development have seen innovations in the form of biological CAD and more efficient means for building DNA, RNA, and other biological constructs. The testing phase of the cycle remains in need of innovation. Presented will be both a theoretical abstraction of biological measurement and a practical demonstration of a microfluidics-based platform for characterizing synthetic biological phenomena. Such a platform demonstrates a design of additive manufacturing (3D printing) for construction of a microbial fuel cell (MFC) to be used in experiments carried out in space. First, the biocompatibility of the polypropylene chassis will be demonstrated. The novel MFCs will be cheaper, and faster to make and iterate through designs. The novel design will contain a manifold switchingdistribution system and an integrated in-chip set of reagent reservoirs fabricated via 3D printing. The automated nature of the 3D printing yields itself to higher resolution switching valves and leads to smaller sized payloads, lower cost, reduced power and a standardized platform for synthetic biology unit tests on Earth and in space. It will be demonstrated that the application of unit testing in synthetic biology will lead to the automatic construction and validation of desired constructs. Unit testing methodologies offer benefits of preemptive problem identification, change of facility, simplicity of integration, ease of documentation, and separation of interface from implementation, and automated design.

  12. Hydromechanical transmission with three simple planetary assemblies, one sun gear being mounted on the output shaft and the other two on a common shaft connected to an input-driven hydraulic module

    Science.gov (United States)

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

    1978-01-01

    A power transmission having three simple 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 sun gears of the first two planetary assemblies, these two sun gears being connected together on a common shaft. 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 is also connected to drive the second ring gear and, furthermore is clutchable to 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 second planetary assembly drives the ring gear of the third planetary assembly, which is clutchable to the output shaft, and the sun gear of the third planetary assembly is mounted rigidly to the output shaft.

  13. Demonstrations of bio-inspired perching landing gear for UAVs

    Science.gov (United States)

    Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

    2016-04-01

    Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

  14. Convergence Hypothesis: Evidence from Panel Unit Root Test with Spatial Dependence

    Directory of Open Access Journals (Sweden)

    Lezheng Liu

    2006-10-01

    Full Text Available In this paper we test the convergence hypothesis by using a revised 4- step procedure of panel unit root test suggested by Evans and Karras (1996. We use data on output for 24 OECD countries over 40 years long. Whether the convergence, if any, is conditional or absolute is also examined. According to a proposition by Baltagi, Bresson, and Pirotte (2005, we incorporate spatial autoregressive error into a fixedeffect panel model to account for not only the heterogeneous panel structure, but also spatial dependence, which might induce lower statistical power of conventional panel unit root test. Our empirical results indicate that output is converging among OECD countries. However, convergence is characterized as conditional. The results also report a relatively lower convergent speed compared to conventional panel studies.

  15. Application tests of a new-type LNG rapid gasification unit

    Directory of Open Access Journals (Sweden)

    Ping Yan

    2017-01-01

    Full Text Available Liquefied natural gas (LNG is stored under low temperature and high pressure. It has to be gasified before it is used. Therefore, LNG gasification unit is essential and it is vital to the high-efficiency utilization of LNG. In this paper, a new-type LNG rapid gasification unit was developed. Adopted in this unit are some innovative technologies authorized with the national patent of invention, such as the umbrella-shape gas flow circle unit, the flue gas circulation system and the water feeding system, which help to guarantee its operation safety and increase its operation efficiency. After it was justified in lab test, the unit for industrial application was designed and manufactured and then tested to verify its design rationality. The results show that the new-type LNG rapid gasification unit meets the design requirements in the aspect of efficiency, exhaust gas loss, radiation loss and fuel gas consumption rate; at a load of 1800–2200 m3/h, its efficiency is over 95%; at a load of 1976.0 m3/h which is close to the design value of 2000 m3/h, its efficiency is 96.34% or even up to 2800 m3/h. This new-type LNG rapid gasification unit is adaptable to a large range of loads and can adapt to the rapid increase of external load. Its fuel gas consumption rate is only 1.5%, which is in the range of energy conservation. It presents the advantages of high heating efficiency, rapid startup, high gasification rate, compact structure, small land occupation and invulnerability to the environment, therefore, it is applicable to the middle and small independent regions which cannot be connected to the natural gas supply pipeline networks due to various reasons.

  16. Is Current Account of Turkey Sustainable ? Evidence from Nonlinear Unit Root Tests

    Directory of Open Access Journals (Sweden)

    Serkan Taştan

    2015-09-01

    Full Text Available In this paper, current account sustainability of Turkey is analyzed in a nonlinear framework. Various nonlinear unit root tests have been used to test for structural break, sign and size nonlinearity. We have tested structural break and size nonlinearity separately and structural break-sign and size-sign nonlinearities simultaneously. Only considering the size nonlinearity, we have found that the current account of Turkey is sustainable. Thus, the size nonlinearity, in other words the speed of reversion to equilibrium, is essential for the current account sustainability of Turkey. We have also found that the speed of adjustment towards equilibrium is symmetric, while considering size and sign nonlinearities simultaneously.

  17. Tests of the 30-MJ superconducting magnetic-energy storage unit

    International Nuclear Information System (INIS)

    Boenig, H.J.; Dean, J.W.; Rogers, J.D.; Schermer, R.I.; Hauer, J.F.

    1983-01-01

    A 30-MJ (8.4 kWh) superconducting magnetic energy storage (SMES) unit with a 10-MW converter was installed during the later months of 1982 at the Bonneville Power Administration (BPA) Tacoma substation in Tacoma, Washington. The unit, which is capable of absorbing and releasing up to 10 MJ of energy at a frequency of 0.35 Hz, was designed to damp the dominant power swing mode of the Pacific AC Intertie. Extensive tests were performed with the unit during the first half of 1983. This paper will review the major components of the storage unit and describe the startup and steady state operating experience with the coil, dewar, refrigerator and converter. The unit has absorbed power up to a level of 11.8 Mw. Real power was modulated following a sinusoidal power demand with frequencies from 0.1 to 1.2 Hz and a power level up to +- 8.3 MW. The unit has performed in accordance with design expectations and no major problems have developed

  18. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 204: STORAGE BUNKERS, NEVADA TEST SITE, NEVADA

    International Nuclear Information System (INIS)

    2006-01-01

    Corrective Action Unit (CAU) 330 consists of four Corrective Action Sites (CASs) located in Areas 6, 22, and 23 of the Nevada Test Site (NTS). The unit is listed in the Federal Facility Agreement and Consent Order (FFACO, 1996) as CAU 330: Areas 6, 22, and 23 Tanks and Spill Sites. CAU 330 consists of the following CASs: CAS 06-02-04, Underground Storage Tank (UST) and Piping CAS 22-99-06, Fuel Spill CAS 23-01-02, Large Aboveground Storage Tank (AST) Farm CAS 23-25-05, Asphalt Oil Spill/Tar Release

  19. Safety Assessment for transient event occurred during the ASTS test of Hanbit Unit 2

    International Nuclear Information System (INIS)

    Yang, Changkeun; Kim, Yohan; Ha, Sangjun

    2014-01-01

    Safety Injection has been actuated during the ASTS (Automatic Seismic Trip System) test of Hanbit Unit 2 on Feb. 28, 2014. It could be bad effect on system integrity. KHNP has been performed safety assessment of system for effect of Safety Injection (SI) actuation occurred during the ASTS test of hanbit Unit 2. Stable state of nuclear power plant system has been confirmed according to Safety Injection and reactor trip event occurred during the ASTS test of hanbit Unit 2. In the result of system safety assessment, major variables of nuclear power plant are located in optimal range and not exceed safety limit. It remains nuclear fuel and the integrity of the power plant is in a safe condition were conformed. After ASTS action, thermal elimination has been processed throughout the turbine until turbine signal occurrence because ASTS is connected to M-G set in the present hanbit Unit 2. Therefore, Safety Injection signal has been actuated by rapid reduction of Steam Generator pressure. In this paper, it is concluded that consideration of equipment and setpoint is needed for that Safety Injection has been not occurred under the unnecessary situation. Stable state of nuclear power plant system has been confirmed for Safety Injection and reactor trip event occurred during the ASTS test of hanbit Unit 2. In the result of system safety assessment, major variables of nuclear power plant are located in optimal range and not exceed safety limit. It remains nuclear fuel and the integrity of the plant is in a safe condition were conformed. It is concluded that consideration of equipment and setpoint is needed for that Safety Injection has been not occurred under the unnecessary situation

  20. Unit evaluation at Yucca Mountain, Nevada Test Site: summary report and recommendation

    International Nuclear Information System (INIS)

    Johnstone, J.K.; Peters, R.R.; Gnirk, P.F.

    1984-06-01

    Of the four potential repository units, identified at Yucca Mountain, two potential units the welded, devitrified portions of the Bullfrog and Tram Members of the Crater Flat Tuff are below the water table. The welded, devitrified Topopah Spring Member of the Paintbrush Tuff and the nonwelded, zeolitized Tuffaceous Beds of Calico Hills are above the water table. The results of a study of the four potential repository units are to provide a technical basis for selecting a single target repository unit for future test and evaluation. The unit evaluation studies compared the units rather than provided and absolute assessment. The four ranking evaluation criteria used were: radionuclide isolation time; allowable repository gross thermal loading; excavation stability; and relative economics. Considered the most important of the criteria as well as the most difficult, radionuclide isolation times were estimated using the limited existing data. The allowable repository gross thermal loadings determined from near-field calculations, were nearly the same for all four units. The gross thermal loading supported other criteria by providing the heat source for succeeding thermally related evaluation studies. A large number of studies evaluated excavation stability, including near-field mechanical and thermomechanical finite element code calculations studies. A large number of studies evaluated excavation stability, including near-field mechanical and thermomechanical finite element code calculations, rock matrix property evaluation, and rock mass classification. Relative economics, a minor criterion, did not play an explicit role in the final ranking. Based on all of the analyses, the final recommendation was that the Topopah Springs be selected as the target unit, followed, in order, by the Calico Hills, Bullfrog, and Tram

  1. Influence of various base oils on friction and power loss in gears; Einfluss verschiedener Grundoele auf Reibung und Verlustleistung in Zahnradgetrieben

    Energy Technology Data Exchange (ETDEWEB)

    Doleschel, A.; Michaelis, K.; Hoehn, B.R.

    2001-03-01

    The frictional behaviour of synthetic lubricants was systematically investigated in a twin disc test rig and a back-to-back gear test rig. For 22 lubricants (mineral oil, polyalfaolefin (PAO), polyglycol (PG), ester and mixtures) the coefficient of friction was measured in the twin disc test rig, dependant on pressure, oil temperature, rolling and sliding velocity. In the gear test rig pressure and velocity was varied for 9 lubricants. The mineral oil shows an estimated coefficient of friction of about {mu} >> 0.045, the synthetic lubricants have a lower coefficient of friction. In the twin disc test rig the lowest coefficient of friction with PG as low as 20% of the coefficient of mineral oil was measured, depending on the mixture of EO:PO. In the gear test rig such low coefficients of friction were not measured, but still values of 60% compared to mineral oil were obtained. Esters show in the twin disc test rig a coefficient of friction in the range of 30% to 100% of the coefficient of friction of mineral oil, in the gear test rig in the range of 60% to 100%. From these investigations a calculation method for the coefficient of friction in disc and gear contacts was derived. With these equations the power loss and efficiency of transmissions in practice, lubricated with synthetic gear oils can be evaluated. (orig.)

  2. Design and Implementation of Electric Steering Gear Inspection System for Unmanned Aerial Vehicles Based on Virtual Instruments

    Directory of Open Access Journals (Sweden)

    Zheng Xing

    2016-01-01

    Full Text Available A kind of UAV electric servo detection system based on Virtual Instrument is designed in this paper, including the hardware platform based on PC-DAQ virtual instrument architecture and the software platform based on LabVIEW function, structure and system implementation methods. The function, structure and system implementation method of software platform is also described. The gear limits checking, zero testing, time domain characteristics test results showed that the system achieves testing requirements well, and can complete detection of electric steering gear automatically, fast, easy and accurate.

  3. Surface micromachined counter-meshing gears discrimination device

    International Nuclear Information System (INIS)

    Polosky, M.A.; Garcia, E.J.; Allen, J.J.

    1998-01-01

    This paper discusses the design, fabrication and testing of a surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock, A 24 bit code is input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect. The motivation for the development of this device is based on occurrences referred to as High Consequence Events, A High Consequence Event is an event where an inadvertent operation of a system could result in the catastrophic loss of life, property, or damage to the environment

  4. Sea turtle gear interaction collected in the Gulf of Mexico , Caribbean and Atlantic from 1989-01-14 to 2015-06-02 (NCEI Accession 0144841)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories is responsible for new gear development and testing to reduce bycatch and incidental interactions of...

  5. Fishing gear-related injury in California marine wildlife.

    Science.gov (United States)

    Dau, Brynie Kaplan; Gilardi, Kirsten V K; Gulland, Frances M; Higgins, Ali; Holcomb, Jay B; Leger, Judy St; Ziccardi, Michael H

    2009-04-01

    We reviewed medical records from select wildlife rehabilitation facilities in California to determine the prevalence of injury in California Brown Pelicans (Pelecanus occidentalis), gulls (Larus spp.), and pinniped species (Zalophus californianus, Mirounga angustirostris, and Phoca vitulina) due to fishing gear entanglement and ingestion from 2001 to 2006. Of 9,668 Brown Pelican, gull, and pinniped cases described during the 6-yr study period (2001-06), 1,090 (11.3%) were fishing gear-related. Pelican injuries caused by fishing gear were most common in the Monterey Bay region, where 59.6% of the pelicans rescued in this area and admitted to a rehabilitation center were injured by fishing gear over the 6-yr period. The highest prevalence of fishing gear-related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds were seen in the San Diego region (3.7%). Despite these higher prevalences of gull and pinniped fishing gear-related injuries in these specific regions, there was no statistical significance in these trends. Juvenile gulls and pinnipeds were more commonly injured by fishing gear than adults (gulls: P = 0.03, odds ratio = 1.29; pinnipeds: P = 0.01, odds ratio = 2.07). Male pinnipeds were twice as likely to be injured by fishing gear as females (P gear-related injury cases that were successfully rehabilitated and released (percentage of cases successfully rehabilitated to the point of release out of the total number of fishing gear-related injury cases) was high in all three species groups (pelicans: 63%; gulls: 54%; pinnipeds: 70%). Fishing gear-related injuries in Brown Pelicans and gulls were highest in the fall, but there was only a significant difference between seasons for fishing gear-related injuries in pelicans. Fishing gear-related injuries in pinnipeds most commonly occurred in summer; however, a statistical difference was not detected between seasons for pinnipeds. Derelict

  6. Variable gearing in a biologically inspired pneumatic actuator array

    International Nuclear Information System (INIS)

    Azizi, Emanuel; Roberts, Thomas J

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. (paper)

  7. Variable gearing in a biologically inspired pneumatic actuator array.

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J

    2013-06-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions.

  8. VARIABLE GEARING IN A BIOLOGICALLY-INSPIRED PNEUMATIC ACTUATOR ARRAY

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J.

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle’s gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system’s gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. PMID:23462288

  9. Revision report about the in-situ tests of 1000 MW unit 5 Kozloduy (Bulgaria)

    International Nuclear Information System (INIS)

    Muzzi, F.

    1995-01-01

    This report refers to the technical revision performed on the technical report about the in-situ tests performed on 1000 Unit 5 nuclear power station of Kozloduy (Bulgaria), within the frame of the IAEA benchmark study for the seismic analysis and testing of an existing Nuclear Power Plant. After a foreword to define the aims of the job and the identification of the scope of the work, a brief description of the plant is made. A brief description of the theory about the modal parameter determination and the soil-structure interaction analysis by experimental tests is made. The following chapters collect some comments about the tests carried out in Kozloduy, with special reference to the general correctness of testing procedure and to data special requirements for the seismic safety margin assessment procedures to be applied on the existing power station

  10. Near Earth Asteroid Scout Solar Sail Engineering Development Unit Test Suite

    Science.gov (United States)

    Lockett, Tiffany Russell; Few, Alexander; Wilson, Richard

    2017-01-01

    The Near Earth Asteroid (NEA) Scout project is a 6U reconnaissance mission to investigate a near Earth asteroid utilizing an 86m(sub 2) solar sail as the primary propulsion system. This will be the largest solar sail NASA has launched to date. NEA Scout is currently manifested on the maiden voyage of the Space Launch System in 2018. In development of the solar sail subsystem, design challenges were identified and investigated for packaging within a 6U form factor and deployment in cis-lunar space. Analysis was able to capture understanding of thermal, stress, and dynamics of the stowed system as well as mature an integrated sail membrane model for deployed flight dynamics. Full scale system testing on the ground is the optimal way to demonstrate system robustness, repeatability, and overall performance on a compressed flight schedule. To physically test the system, the team developed a flight sized engineering development unit with design features as close to flight as possible. The test suite included ascent vent, random vibration, functional deployments, thermal vacuum, and full sail deployments. All of these tests contributed towards development of the final flight unit. This paper will address several of the design challenges and lessons learned from the NEA Scout solar sail subsystem engineering development unit. Testing on the component level all the way to the integrated subsystem level. From optical properties of the sail material to fold and spooling the single sail, the team has developed a robust deployment system for the solar sail. The team completed several deployments of the sail system in preparation for flight at half scale (4m) and full scale (6.8m): boom only, half scale sail deployment, and full scale sail deployment. This paper will also address expected and received test results from ascent vent, random vibration, and deployment tests.

  11. Design and Implementation of the Control System of an Internal Combustion Engine Test Unit

    Directory of Open Access Journals (Sweden)

    Tufan Koç

    2014-02-01

    Full Text Available Accurate tests and performance analysis of engines are required to minimize measurement errors and so the use of the advanced test equipment is imperative. In other words, the reliable test results depend on the measurement of many parameters and recording the experimental data accurately which is depended on engine test unit. This study aims to design the control system of an internal combustion engine test unit. In the study, the performance parameters of an available internal combustion engine have been transferred to computer in real time. A data acquisition (DAQ card has been used to transfer the experimental data to the computer. Also, a user interface has been developed for performing the necessary procedures by using LabVIEW. The dynamometer load, the fuel consumption, and the desired speed can easily be adjusted precisely by using DAQ card and the user interface during the engine test. Load, fuel consumption, and temperature values (the engine inlet-outlet, exhaust inlet-outlet, oil, and environment can be seen on the interface and also these values can be recorded to the computer. It is expected that developed system will contribute both to the education of students and to the researchers’ studies and so it will eliminate a major lack.

  12. Alpha Stable Distribution Based Morphological Filter for Bearing and Gear Fault Diagnosis in Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xinghui Zhang

    2015-01-01

    Full Text Available Gear and bearing play an important role as key components of rotating machinery power transmission systems in nuclear power plants. Their state conditions are very important for safety and normal operation of entire nuclear power plant. Vibration based condition monitoring is more complicated for the gear and bearing of planetary gearbox than those of fixed-axis gearbox. Many theoretical and engineering challenges in planetary gearbox fault diagnosis have not yet been resolved which are of great importance for nuclear power plants. A detailed vibration condition monitoring review of planetary gearbox used in nuclear power plants is conducted in this paper. A new fault diagnosis method of planetary gearbox gears is proposed. Bearing fault data, bearing simulation data, and gear fault data are used to test the new method. Signals preprocessed using dilation-erosion gradient filter and fast Fourier transform for fault information extraction. The length of structuring element (SE of dilation-erosion gradient filter is optimized by alpha stable distribution. Method experimental verification confirmed that parameter alpha is superior compared to kurtosis since it can reflect the form of entire signal and it cannot be influenced by noise similar to impulse.

  13. Determination on Damage Mechanism of the Planet Gear of Heavy Vehicle Final Drive

    Science.gov (United States)

    Ramdan, RD; Setiawan, R.; Sasmita, F.; Suratman, R.; Taufiqulloh

    2018-02-01

    The works focus on the investigation of damage mechanism of fractured in the form of spalling of the planet gears from the final drive assembly of 160-ton heavy vehicles. The objective of this work is to clearly understand the mechanism of damage. The work is the first stage of the on-going research on the remaining life estimation of such gears. The understanding of the damage mechanism is critical in order to provide accurate estimate of the gear’s remaining life with observed initial damage. The analysis was performed based on the metallurgy laboratory works, including visual observation, macro-micro fractography by optical stereo and optical microscope and micro-vickers hardness test. From visual observation it was observed pitting that form lining defect at common position, which is at gear flank position. From spalling sample it was observed ratchet mark at the boundary between macro pitting and the edge of fractured parts. Further observation on the cross-section of the samples by optical microscope confirm that initial micro pitting occur without spalling of the case hardened surface. Spalling occur when pitting achieve certain critical size, and occur at multiple initiation site of crack propagation. From the present research it was concluded that pitting was resulted due to repeated contact fatigue. In addition, development of micro to macro pitting as well as spalling occur at certain direction towards the top of the gear teeth.

  14. An Integrated Optimal Energy Management/Gear-Shifting Strategy for an Electric Continuously Variable Transmission Hybrid Powertrain Using Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    Syuan-Yi Chen

    2016-01-01

    Full Text Available This study developed an integrated energy management/gear-shifting strategy by using a bacterial foraging algorithm (BFA in an engine/motor hybrid powertrain with electric continuously variable transmission. A control-oriented vehicle model was constructed on the Matlab/Simulink platform for further integration with developed control strategies. A baseline control strategy with four modes was developed for comparison with the proposed BFA. The BFA was used with five bacterial populations to search for the optimal gear ratio and power-split ratio for minimizing the cost: the equivalent fuel consumption. Three main procedures were followed: chemotaxis, reproduction, and elimination-dispersal. After the vehicle model was integrated with the vehicle control unit with the BFA, two driving patterns, the New European Driving Cycle and the Federal Test Procedure, were used to evaluate the energy consumption improvement and equivalent fuel consumption compared with the baseline. The results show that [18.35%,21.77%] and [8.76%,13.81%] were improved for the optimal energy management and integrated optimization at the first and second driving cycles, respectively. Real-time platform designs and vehicle integration for a dynamometer test will be investigated in the future.

  15. Hybrid foundry patterns of bevel gears

    Directory of Open Access Journals (Sweden)

    Budzik G.

    2007-01-01

    Full Text Available Possibilities of making hybrid foundry patterns of bevel gears for investment casting process are presented. Rapid prototyping of gears with complex tooth forms is possible with the use of modern methods. One of such methods is the stereo-lithography, where a pattern is obtained as a result of resin curing with laser beam. Patterns of that type are applicable in precision casting. Removing of stereo-lithographic pattern from foundry mould requires use of high temperatures. Resin burning would generate significant amounts of harmful gases. In case of a solid stereo-lithographic pattern, the pressure created during gas burning may cause the mould to crack. A gas volume reduction may be achieved by using patterns of honeycomb structure. However, this technique causes a significant worsening of accuracy of stereo-lithographic patterns in respect of their dimensions and shape. In cooperation with WSK PZL Rzeszów, the Machine Design Department of Rzeszow University of Technology carried out research on the design of hybrid stereo-lithographic patterns. Hybrid pattern consists of a section made by stereo-lithographic process and a section made of casting wax. The latter material is used for stereo-lithographic pattern filling and for mould gating system. The hybrid pattern process consists of two stages: wax melting and then the burn-out of stereolithographic pattern. Use of hybrid patterns reduces the costs of production of stereolithographic patterns. High dimensional accuracy remains preserved in this process.

  16. 78 FR 17188 - Agency Information Collection Activities; Comment Request; Evaluation of the GEAR UP College...

    Science.gov (United States)

    2013-03-20

    ...; Comment Request; Evaluation of the GEAR UP College Savings Account Research Demonstration AGENCY... of Collection: Evaluation of the GEAR UP College Savings Account Research Demonstration. OMB Control..., Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP). This first Information...

  17. Nuclear Facility Accident (NFAC) Unit Test Report For HPAC Version 6.3

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ronald W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Division; Morris, Robert W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Division; Sulfredge, Charles David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Division

    2015-12-01

    This is a unit test report for the Nuclear Facility Accident (NFAC) model for the Hazard Prediction and Assessment Capability (HPAC) version 6.3. NFAC’s responsibility as an HPAC component is three-fold. First, it must present an interactive graphical user interface (GUI) by which users can view and edit the definition of an NFAC incident. Second, for each incident defined, NFAC must interact with RTH to create activity table inputs and associate them with pseudo materials to be transported via SCIPUFF. Third, NFAC must create SCIPUFF releases with the associated pseudo materials for transport and dispersion. The goal of NFAC unit testing is to verify that the inputs it produces are correct for the source term or model definition as specified by the user via the GUI.

  18. Nuclear Facility Accident (NFAC) Unit Test Report For HPAC Version 6.3

    International Nuclear Information System (INIS)

    Lee, Ronald W.; Morris, Robert W.; Sulfredge, Charles David

    2015-01-01

    This is a unit test report for the Nuclear Facility Accident (NFAC) model for the Hazard Prediction and Assessment Capability (HPAC) version 6.3. NFAC's responsibility as an HPAC component is three-fold. First, it must present an interactive graphical user interface (GUI) by which users can view and edit the definition of an NFAC incident. Second, for each incident defined, NFAC must interact with RTH to create activity table inputs and associate them with pseudo materials to be transported via SCIPUFF. Third, NFAC must create SCIPUFF releases with the associated pseudo materials for transport and dispersion. The goal of NFAC unit testing is to verify that the inputs it produces are correct for the source term or model definition as specified by the user via the GUI.

  19. Closure Report for Corrective Action Unit 134: Aboveground Storage Tanks, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    Corrective Action Unit (CAU) 134 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Aboveground Storage Tanks' and consists of the following four Corrective Action Sites (CASs), located in Areas 3, 15, and 29 of the Nevada Test Site: (1) CAS 03-01-03, Aboveground Storage Tank; (2) CAS 03-01-04, Tank; (3) CAS 15-01-05, Aboveground Storage Tank; and (4) CAS 29-01-01, Hydrocarbon Stain

  20. A Bootstrap Neural Network Based Heterogeneous Panel Unit Root Test: Application to Exchange Rates

    OpenAIRE

    Christian de Peretti; Carole Siani; Mario Cerrato

    2010-01-01

    This paper proposes a bootstrap artificial neural network based panel unit root test in a dynamic heterogeneous panel context. An application to a panel of bilateral real exchange rate series with the US Dollar from the 20 major OECD countries is provided to investigate the Purchase Power Parity (PPP). The combination of neural network and bootstrapping significantly changes the findings of the economic study in favour of PPP.