WorldWideScience

Sample records for programs geared specifically

  1. 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

  2. Investigating GEAR-Up College Readiness Program's Influence on Postsecondary Decisions of Rural Hispanic Youth

    Science.gov (United States)

    Boydstun, Kelli Dawn

    2016-01-01

    This qualitative case study investigated how the GEAR-Up college readiness program influenced the postsecondary decisions of Hispanic students who participated in the GEAR-Up program for the recommended six-year period in a rural school district in Texas. It was not known how long-term participation in the GEAR-Up program at a rural school…

  3. 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.

  4. 75 FR 58373 - Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP)

    Science.gov (United States)

    2010-09-24

    ... Readiness for Undergraduate Programs (GEAR UP) AGENCY: Office of Postsecondary Education, Department of Education. ACTION: Notice of intent to fund down the fiscal year (FY) 2008 grant slate for the GEAR UP Program. SUMMARY: The Secretary intends to use the grant slate developed in FY 2008 for the GEAR UP...

  5. 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

  6. Colorado GEAR UP Program Design and Its Effect on Student Perceptions of Postsecondary Education

    Science.gov (United States)

    Mendelsberg, Scott

    2012-01-01

    Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) is a federal program aimed at equalizing access to higher education for low-income students. GEAR UP, created in 1998, attempts to provide information and support about higher education to students beginning no later than the seventh grade while promoting lasting…

  7. 78 FR 15009 - Extension of Deadline; Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP...

    Science.gov (United States)

    2013-03-08

    ... DEPARTMENT OF EDUCATION Extension of Deadline; Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP)--College Savings Account Research Demonstration Project AGENCY: Office of... published in the Federal Register (78 FR 4838) a notice inviting applications for the GEAR UP College...

  8. 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.

  9. Topology of modified helical gears and Tooth Contact Analysis (TCA) program

    Science.gov (United States)

    Litvin, Faydor L.; Zhang, Jiao

    1989-01-01

    The contents of this report covers: (1) development of optimal geometries for crowned helical gears; (2) a method for their generation; (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact of the crowned helical gears; and (4) modelling and simulation of gear shaft deflection. The developed method for synthesis was used to determine the optimal geometry for a crowned helical pinion surface and was directed to localize the bearing contact and guarantee favorable shape and a low level of transmission errors. Two new methods for generation of the crowned helical pinion surface are proposed. One is based on the application of a tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The other is based on a crowning pinion tooth surface with predesigned transmission errors. The pinion tooth surface can be generated by a computer-controlled automatic grinding machine. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined. The gear shaft deformation was modelled and investigated. It was found that the deflection of gear shafts has the same effect as gear misalignment.

  10. 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

  11. 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.

  12. Spur gears: Optimal geometry, methods for generation and Tooth Contact Analysis (TCA) program

    Science.gov (United States)

    Litvin, Faydor L.; Zhang, Jiao

    1988-01-01

    The contents of this report include the following: (1) development of optimal geometry for crowned spur gears; (2) methods for their generation; and (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact on the crowned spur gears. The method developed for synthesis is used for the determination of the optimal geometry for crowned pinion surface and is directed to reduce the sensitivity of the gears to misalignment, localize the bearing contact, and guarantee the favorable shape and low level of the transmission errors. A new method for the generation of the crowned pinion surface has been proposed. This method is based on application of the tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The crowned pinion surface can also be generated by a generating plane whose motion is provided by an automatic grinding machine controlled by a computer. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined.

  13. Parental Learning and School Readiness in the Gearing Up for Kindergarten Program

    Directory of Open Access Journals (Sweden)

    Sharon Query

    2013-06-01

    Full Text Available Entering kindergarten is a key moment in a young child’s life, and parents are a child’s first teacher. What can guide parents as they assist children with school readiness? Gearing Up for Kindergarten is an intensive parent education and school readiness program designed to help parents and children prepare for school. Gearing Up for Kindergarten is a parent education program that combines early learning opportunities for pre-kindergarten children with parent education opportunities for adults. This study presents findings from evaluation efforts conducted with 59 Gearing Up for Kindergarten adult participants during the 2006-2007 school year. Participants in the program demonstrated (1 high satisfaction with program quality and experiences, (2 impacts on parental knowledge and confidence, and (3 significant and positive changes in parental practices related to school readiness. Implications for parent education and programs intended to strengthen school readiness among pre-kindergarten children are explored. Parent education on school readiness can provide a substantive resource as parents help their children develop and become ready for the school years.

  14. 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.

  15. 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.

  16. A differential evolution algorithm for tooth profile optimization with respect to balancing specific sliding coefficients of involute cylindrical spur and helical gears

    Directory of Open Access Journals (Sweden)

    Hammoudi Abderazek

    2015-09-01

    Full Text Available Profile shift has an immense effect on the sliding, load capacity, and stability of involute cylindrical gears. Available standards such as ISO/DIS 6336 and BS 436 DIN/3990 currently give the recommendation for the selection of profile shift coefficients. It is, however, very approximate and usually given in the form of implicit graphs or charts. In this article, the optimal selection values of profile shift coefficients for cylindrical involute spur and helical gears are described, using a differential evolution algorithm. The optimization procedure is developed specifically for exact balancing specific sliding coefficients at extremes of contact path and account for gear design constraints. The obtained results are compared with those of standards and research of other authors. They demonstrate the effectiveness and robustness of the applied method. A substantial improvement in balancing specific sliding coefficients is found in this work.

  17. ATR Technical Specification Upgrade Program

    International Nuclear Information System (INIS)

    McCracken, R.T.; Durney, J.L.; Freund, G.A.

    1990-01-01

    The Advanced Test Reactor (ATR) is a 250 MW, uranium-aluminum fueled test reactor which began full power operation in 1969. The initial operation was controlled by an Operating Limits document based on the original Safety Analysis Report. Additional safety bases were later developed to support Technical Specifications which were approved and implemented in 1977. The Technical Specifications which were initially developed with content and format specified in ANSI/ANS--15.1, ''The Development of Technical Specifications for Research Reactors.'' The safety basis documentation and the Technical Specifications have been updated as required to maintain them current with the ATR facility configuration. All revisions have been made with a content, format and style consistent with the original. A major, two-phase program to upgrade the content, format and style is in progress. This paper describes the first phase of this program

  18. Logic programming and metadata specifications

    Science.gov (United States)

    Lopez, Antonio M., Jr.; Saacks, Marguerite E.

    1992-01-01

    Artificial intelligence (AI) ideas and techniques are critical to the development of intelligent information systems that will be used to collect, manipulate, and retrieve the vast amounts of space data produced by 'Missions to Planet Earth.' Natural language processing, inference, and expert systems are at the core of this space application of AI. This paper presents logic programming as an AI tool that can support inference (the ability to draw conclusions from a set of complicated and interrelated facts). It reports on the use of logic programming in the study of metadata specifications for a small problem domain of airborne sensors, and the dataset characteristics and pointers that are needed for data access.

  19. 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.

  20. Automatic Construction of Java Programs from Functional Program Specifications

    OpenAIRE

    Md. Humayun Kabir

    2015-01-01

    This paper presents a novel approach to construct Java programs automatically from the input functional program specifications on natural numbers from the constructive proofs of the input specifications using an inductive theorem prover called Poiti'n. The construction of a Java program from the input functional program specification involves two phases. The theorem prover is used to construct a higher order functional (HOF) program from the input specification expressed as an existential the...

  1. Continued Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Delgado, Irebert R.; Dempsey, Paula J.; Antolick, Lance J.; Wade, Daniel R.

    2013-01-01

    This paper details analyses of condition indicator performance for the helicopter nose gearbox within the U.S. Army's Condition-Based Maintenance Program. Ten nose gearbox data sets underwent two specific analyses. A mean condition indicator level analysis was performed where condition indicator performance was based on a 'batting average' measured before and after part replacement. Two specific condition indicators, Diagnostic Algorithm 1 and Sideband Index, were found to perform well for the data sets studied. A condition indicator versus gear wear analysis was also performed, where gear wear photographs and descriptions from Army tear-down analyses were categorized based on ANSI/AGMA 1010-E95 standards. Seven nose gearbox data sets were analyzed and correlated with condition indicators Diagnostic Algorithm 1 and Sideband Index. Both were found to be most responsive to gear wear cases of micropitting and spalling. Input pinion nose gear box condition indicators were found to be more responsive to part replacement during overhaul than their corresponding output gear nose gear box condition indicators.

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. An introduction to programming with specifications

    CERN Document Server

    1991-01-01

    A feature of modern advanced computing is the functional approach to programming. In this book, the authors present an introduction to the mathematics which underline functional programming, emphasizing the understanding of definition and specification--a prerequisite of good programming and problem solving with a computer. The book is self-contained, requiring a low level of mathematical sophistication and may be used as an introduction to the mathematics of programming.Provides an introduction to the functional approach to programming**Emphasizes the problem to be solved, not the pro

  7. 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.

  8. 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

  9. Technical specification optimization program - engineered safety features

    International Nuclear Information System (INIS)

    Andre, G.R.; Jansen, R.L.

    1986-01-01

    The Westinghouse Technical Specification Program (TOP) was designed to evaluate on a quantitative basis revisions to Nuclear Power Plant Technical Specifications. The revisions are directed at simplifying plant operation, and reducing unnecessary transients, shutdowns, and manpower requirements. In conjunction with the Westinghouse Owners Group, Westinghouse initiated a program to develop a methodology to justify Technical Specification revisions; particularly revisions related to testing and maintenance requirements on plant operation for instrumentation systems. The methodology was originally developed and applied to the reactor trip features of the reactor protection system (RPS). The current study further refined the methodology and applied it to the engineered safety features of the RPS

  10. 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.

  11. 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…

  12. 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.

  13. 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.

  14. 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.

  15. 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....

  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. 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.

  1. 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)

  2. The programming language HAL: A specification

    Science.gov (United States)

    1971-01-01

    HAL accomplishes three significant objectives: (1) increased readability, through the use of a natural two-dimensional mathematical format; (2) increased reliability, by providing for selective recognition of common data and subroutines, and by incorporating specific data-protect features; (3) real-time control facility, by including a comprehensive set of real-time control commands and signal conditions. Although HAL is designed primarily for programming on-board computers, it is general enough to meet nearly all the needs in the production, verification and support of aerospace, and other real-time applications.

  3. 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.

  4. (Re-)programming of subtype specific cardiomyocytes.

    Science.gov (United States)

    Hausburg, Frauke; Jung, Julia Jeannine; Hoch, Matti; Wolfien, Markus; Yavari, Arash; Rimmbach, Christian; David, Robert

    2017-10-01

    Adult cardiomyocytes (CMs) possess a highly restricted intrinsic regenerative potential - a major barrier to the effective treatment of a range of chronic degenerative cardiac disorders characterized by cellular loss and/or irreversible dysfunction and which underlies the majority of deaths in developed countries. Both stem cell programming and direct cell reprogramming hold promise as novel, potentially curative approaches to address this therapeutic challenge. The advent of induced pluripotent stem cells (iPSCs) has introduced a second pluripotent stem cell source besides embryonic stem cells (ESCs), enabling even autologous cardiomyocyte production. In addition, the recent achievement of directly reprogramming somatic cells into cardiomyocytes is likely to become of great importance. In either case, different clinical scenarios will require the generation of highly pure, specific cardiac cellular-subtypes. In this review, we discuss these themes as related to the cardiovascular stem cell and programming field, including a focus on the emergent topic of pacemaker cell generation for the development of biological pacemakers and in vitro drug testing. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. 29 CFR 99.235 - Program-specific audits.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Program-specific audits. 99.235 Section 99.235 Labor Office... § 99.235 Program-specific audits. (a) Program-specific audit guide available. In many cases, a program... schedule of prior audit findings consistent with the requirements of § 99.315(b), and a corrective action...

  6. 14 CFR 91.1017 - Amending program manager's management specifications.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Amending program manager's management... Ownership Operations Program Management § 91.1017 Amending program manager's management specifications. (a... specifications; or (2) The program manager applies for the amendment of any management specifications, and the...

  7. 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.

  8. 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....

  9. Enhanced Computer Aided Simulation of Meshing and Contact With Application for Spiral Bevel Gear Drives

    National Research Council Canada - National Science Library

    Litvin, F

    1999-01-01

    An integrated tooth contact analysis (TCA) computer program for the simulation of meshing and contact of gear drives that calculates transmission errors and shift of hearing contact for misaligned gear drives has been developed...

  10. Process and Performance Outcomes of a Nontraditional Postbaccalaureate PharmD Program Geared Toward Internationally Trained Pharmacists.

    Science.gov (United States)

    Prabhu, Sunil; Chung, Eunice; Le, Quang A; Nguyen, Megan; Robinson, Daniel

    2015-10-25

    Established in 2003, the fully accredited international postbaccalaureate doctor of pharmacy (IPBP) program has attracted internationally trained pharmacists from approximately 25 countries and 6 continents, mostly residents of the United States, to attain the doctor of pharmacy (PharmD) degree at the Western University of Health Sciences. While recent trends in the IPBP applicant pool have shown a decline from its peak numbers in 2009 (222 applicants) for the 20 available seats each year, the quality of students remains high. Benchmark measures assessed for this group of students include the internal assessment entrance examination, admissions scores, academic assessments from didactic blocks, and scores on the North American Pharmacy Licensure Examination (NAPLEX), all of which indicate this quality. Moreover, graduates from the program not only consistently demonstrate excellence in the pharmacy curriculum and board examinations, but also go on to establish themselves as competent practitioners and educators. While the long-term future of the program is unknown, the status of the program and its graduates provides ample evidence of its value and ensures its continued success going forward.

  11. 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

  12. 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.

  13. 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

  14. 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)

  15. Formal Specification and Verification of Concurrent Programs

    Science.gov (United States)

    1993-02-01

    of examples from the emerging theory of This book describes operating systems in general programming languages. via the construction of MINIX , a UNIX...look-alike that runs on IBM-PC compatibles. The book con- Wegner72 tains a complete MINIX manual and a complete Wegnerflisting of its C codie. egner

  16. General versus program-specific welfare chauvinism

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt

    2018-01-01

    similarity across programs. The Danish welfare chauvinist attitudes are in general fuelled by lack of shared identity with migrants and sociotropic concerns about the economic burden of migration. The article finds little evidence of narrow self-interest effects; with a notable exception of disability...

  17. 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...

  18. 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...

  19. 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 ...

  20. The Strength Analysis of Differential Planetary Gears of Gearbox for Concrete Mixer Truck

    Science.gov (United States)

    Bae, M. H.; Bae, T. Y.; Kim, D. J.

    2018-03-01

    The power train of mixer gearbox for concrete mixer truck includes differential planetary gears to get large reduction ratio for operating mixer a drum and simple structure. The planetary gears are very important part of a mixer gearbox where strength problems namely gear bending stress, gear compressive stress and scoring failure are the main concern. In the present study, calculating specifications of the differential planetary gears and analyzing the gear bending and compressive stresses as well as scoring factor of the differential planetary gears gearbox for an optimal design of the mixer gearbox in respect to cost and reliability are investigated. The analyses of actual gear bending and compressive stresses of the differential planetary gears using Lewes & Hertz equation and verifications of the calculated specifications of the differential planetary gears evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears. In addition, we also analyze actual gear scoring factor as well as evaluate the possibility of scoring failure of the differential planetary gear.

  1. From design to manufacturing of asymmetric teeth gears using computer application

    Science.gov (United States)

    Suciu, F.; Dascalescu, A.; Ungureanu, M.

    2017-05-01

    The asymmetric cylindrical gears, with involutes teeth profiles having different base circle diameters, are nonstandard gears, used with the aim to obtain better function parameters for the active profile. We will expect that the manufacturing of these gears became possible only after the design and realization of some specific tools. The paper present how the computer aided design and applications developed in MATLAB, for obtain the geometrical parameters, in the same time for calculation some functional parameters like stress and displacements, transmission error, efficiency of the gears and the 2D models, generated with AUTOLISP applications, are used for computer aided manufacturing of asymmetric gears with standard tools. So the specific tools considered one of the disadvantages of these gears are not necessary and implicitly the expected supplementary costs are reduced. The calculus algorithm established for the asymmetric gear design application use the „direct design“ of the spur gears. This method offers the possibility of determining first the parameters of the gears, followed by the determination of the asymmetric gear rack’s parameters, based on those of the gears. Using original design method and computer applications have been determined the geometrical parameters, the 2D and 3D models of the asymmetric gears and on the base of these models have been manufacturing on CNC machine tool asymmetric gears.

  2. 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.

  3. Disease-Specific Care: Spine Surgery Program Development.

    Science.gov (United States)

    Koerner, Katie; Franker, Lauren; Douglas, Barbara; Medero, Edgardo; Bromeland, Jennifer

    2017-10-01

    Minimal literature exists describing the process for development of a Joint Commission comprehensive spine surgery program within a community hospital health system. Components of a comprehensive program include structured communication across care settings, preoperative education, quality outcomes tracking, and patient follow-up. Organizations obtaining disease-specific certification must have clear knowledge of the planning, time, and overall commitment, essential to developing a successful program. Health systems benefit from disease-specific certification because of their commitment to a higher standard of service. Certification standards establish a framework for organizational structure and management and provide institutions a competitive edge in the marketplace. A framework for the development of a spine surgery program is described to help guide organizations seeking disease-specific certification. In developing a comprehensive program, it is critical to define the program's mission and vision, identify key stakeholders, implement clinical practice guidelines, and evaluate program outcomes.

  4. 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

  5. Closing the Gap Between Specification and Programming: VDM++ and SCALA

    Science.gov (United States)

    Havelund, Klaus

    2011-01-01

    We argue that a modern programming language such as Scala offers a level of succinctness, which makes it suitable for program and systems specification as well as for high-level programming. We illustrate this by comparing the language with the Vdm++ specification language. The comparison also identifies areas where Scala perhaps could be improved, inspired by Vdm++. We furthermore illustrate Scala's potential as a specification language by augmenting it with a combination of parameterized state machines and temporal logic, defined as a library, thereby forming an expressive but simple runtime verification framework.

  6. A study on the automated design system for gear

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H. Y.; Nam, G. J.; Oh, B. K. [Chungbuk National Univ., Cheongju (Korea, Republic of)

    2001-07-01

    A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.

  7. A study on the automated design system for gear

    International Nuclear Information System (INIS)

    Cho, H. Y.; Nam, G. J.; Oh, B. K.

    2001-01-01

    A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course

  8. Generation of helical gears with new surfaces topology by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.; Hsiao, C. L.; Handschuh, Robert F.

    1993-01-01

    Analysis of helical involute gears by tooth contact analysis shows that such gears are very sensitive to angular misalignment that leads to edge contact and the potential for high vibration. A new topology of tooth surfaces of helical gears that enables a favorable bearing contact and a reduced level of vibration is described. Methods for grinding of the helical gears with the new topology are proposed. A TCA (tooth contact analysis) program for simulation of meshing and contact of helical gears with the new topology has been developed. Numerical examples that illustrate the proposed ideas are discussed.

  9. Generation of gear tooth surfaces by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  10. 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.

  11. 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...

  12. 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.

  13. 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).

  14. 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...

  15. Risk-based technical specifications program: Site interview results

    International Nuclear Information System (INIS)

    Andre, G.R.; Baker, A.J.; Johnson, R.L.

    1991-08-01

    The Electric Power Research Institute and Pacific Gas and Electric Company are sponsoring a program directed at improving Technical Specifications using risk-based methods. The major objectives of the program are to develop risk-based approaches to improve Technical Specifications and to develop an Interactive Risk Advisor (IRA) prototype. The IRA is envisioned as an interactive system that is available to plant personnel to assist in controlling plant operation. Use of an IRA is viewed as a method to improve plant availability while maintaining or improving plant safety. In support of the program, interviews were conducted at several PWR and BWR plant sites, to elicit opinions and information concerning risk-based approaches to Technical Specifications and IRA requirements. This report presents the results of these interviews, including the functional requirements of an IRA. 2 refs., 6 figs., 2 tabs

  16. 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...

  17. 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.

  18. 47 CFR 76.75 - Specific EEO program requirements.

    Science.gov (United States)

    2010-10-01

    ... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Equal Employment Opportunity Requirements § 76.75 Specific EEO... or sex is prohibited and that they may notify the Equal Employment Opportunity Commission, the... necessary. Nothing in this section shall be interpreted to require a multichannel video programming...

  19. 7 CFR 3052.235 - Program-specific audits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Program-specific audits. 3052.235 Section 3052.235 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER, DEPARTMENT OF AGRICULTURE AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 3052.235...

  20. 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.

  1. Toothed gear pumps for special applications; Zahnradpumpen fuer Sonderanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [WITTE PUMPS und TECHNOLOGY GmbH, Uetersen (Germany)

    2007-07-01

    Gear pumps are utilized in a big variety of industrial processes. This essay discusses the typical applications gear pumps are used for. Based on the general function of gear pumps the technical features of these different pump types are pointed out. The process parameters have been more or less the same for the last decades. Nowadays a higher demand regarding pressures and temperatures, sometimes even a combination of both, can be observed. This development is the challenge to go for special constructions and new materials. The range of applications is extended step by step, always aware of the fact, that these gear pumps are often operating at their specific limits. Finally some examples right from the plant give an overview over this development. (orig.)

  2. 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...

  3. 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...

  4. 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.

  5. The Design of Intelligent Repair Welding Mechanism and Relative Control System of Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available Effective repair of worn big gear has large influence on ensuring safety production and enhancing economic benefits. A kind of intelligent repair welding method was put forward mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. Big gear repair welding mechanism was designed in this paper. The work principle and part selection of big gear repair welding mechanism was introduced. The three dimensional mode of big gear repair welding mechanism was constructed by Pro/E three dimensional design software. Three dimensional motions can be realized by motor controlling ball screw. According to involute gear feature, the complicated curve motion on curved gear surface can be transformed to linear motion by orientation. By this way, the repair welding on worn gear area can be realized. In the design of big gear repair welding mechanism control system, Siemens S7-200 series hardware was chosen. Siemens STEP7 programming software was chosen as system design tool. The entire repair welding process was simulated by experiment simulation. It provides a kind of practical and feasible method for the intelligent repair welding of big worn gear.

  6. A Domain-Specific Programming Language for Secure Multiparty Computation

    DEFF Research Database (Denmark)

    Nielsen, Janus Dam; Schwartzbach, Michael Ignatieff

    2007-01-01

    We present a domain-specific programming language for Secure Multiparty Computation (SMC). Information is a resource of vital importance and considerable economic value to individuals, public administration, and private companies. This means that the confidentiality of information is crucial...... on secret values and results are only revealed according to specific protocols. We identify the key linguistic concepts of SMC and bridge the gap between high-level security requirements and low-level cryptographic operations constituting an SMC platform, thus improving the efficiency and security of SMC...

  7. Sizing Optimization and Strength Analysis for Spread-type Gear Reducers

    Directory of Open Access Journals (Sweden)

    Wei-Hsuan Hsu

    2014-08-01

    Full Text Available A reducer is now developed towards the trend of customization service and cost-saving. In this study, a sizing program for the reducer has been developed in order to replace the manual sizing process. We aim at the total center distance of the gear reducer for optimization to reduce gear volume and weight. Also, we checked constrains such as, tooth root bending, tooth contact strength, gear shaft endangered cross-section, bearing life, gear shaft deflection, and torsion angle deformation, etc., to obtain reliable drive strength. Comparisons of sizes and weights before and after optimization confirm that the purpose for reducing production cost is achieved.

  8. 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

  9. The Development of the Guide to Economic Analysis and Research (GEAR) Online Resource for Low- and Middle-Income Countries' Health Economics Practitioners: A Commentary.

    Science.gov (United States)

    Adeagbo, Chiaki Urai; Rattanavipapong, Waranya; Guinness, Lorna; Teerawattananon, Yot

    2018-05-01

    Public health authorities around the world are increasingly using economic evaluation to set priorities and inform decision making in health policy, especially in the development of health benefit packages. Nevertheless, researchers in low- and middle-income countries (LMICs) encounter many barriers when conducting economic evaluations. In 2015, the Health Intervention and Technology Assessment Program identified key technical and context-specific challenges faced in conducting and using health economic evaluations in LMICs. On the basis of these research findings, the Guide to Economic Analysis and Research (GEAR) online resource (www.gear4health.com) was developed as a reliable aid to researchers in LMICs that would help overcome those challenges. Funded by the Thailand Research Fund and the Bill and Melinda Gates Foundation, GEAR is a free online resource that provides a visual aid tool for planning economic evaluation studies (GEAR mind maps), a repository of national and international economic evaluation guidelines (GEAR guideline comparison), and an active link to a network of volunteer international experts (GEAR: Ask an expert). GEAR will evolve over time to provide relevant, reliable, and up-to-date information through inputs from its users (e.g., periodic survey on methodological challenges) and experts (e.g., in responding to users' questions). The objective of this commentary was to give a brief description of the development and key features of this unique collective information hub aimed at facilitating high-quality research and empowering health care decision makers and stakeholders to use economic evaluation evidence. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  10. Exploring the Relationship between Student Involvement in GEAR UP and Academic Achievement

    Science.gov (United States)

    Kennedy, Renea F.

    2016-01-01

    The purpose of this study was to examine the relationship between GEAR UP academic support services and student achievement. GEAR UP is an evidence-based college readiness program. This study focused on a subset of academic support services designed to impact student achievement including: academic mentoring, math tutoring, English tutoring, study…

  11. The Impact of GEAR UP on College Readiness for Students in Low Income Schools

    Science.gov (United States)

    Bausmith, Jennifer Merriman; France, Megan

    2012-01-01

    The purpose of this study was to evaluate the impact of the Gaining Early Awareness and Readiness for Undergraduate Program (GEAR UP) on college readiness outcomes using a quasi-experimental design. GEAR UP is designed to increase the number of low-income students who are prepared to enter and succeed in postsecondary education by providing 6-year…

  12. An Application of Reverse Engineering in Design of the Spur Gear

    Directory of Open Access Journals (Sweden)

    Adem Çiçek

    2010-06-01

    Full Text Available In this study, it is aimed that the gear parameters required the design of a spur gear are obtained by use of reverse engineering techniques. Therefore, point cloud of tooth profile of the manufactured spur gear is extracted by a coordinate measuring machine (CMM. The gear parameters are derived by processing the obtained point cloud. 3D model of the spur gear are modeled through this parameters in a CAD environment. In the system, a hybrid programming approach is used. Generating and processing the point cloud, extraction of the gear parameters are performed by Visual BASIC programming language. 3D modeling in the CAD environment is performed also by AutoLISP programming language due to programming simplicity. These two softwares are provided to be in harmony by integrating them. In the study, SolidworksTM and AutoCADTM are selected as CAD environments. With this study, an alternative approach for the design of the spur gear is presented and modeling of the gears in the CAD environment is carried out using reverse engineering techniques.

  13. PBF/LOFT Lead Rod Test Program experiment operating specification

    International Nuclear Information System (INIS)

    Varacalle, D.J. Jr.

    1978-11-01

    The PBF/LOFT Lead Rod (LLR) Test Program is being conducted to provide experimental information on the behavior of nuclear fuel under normal and accident conditions in the Power Burst Facility at the Idaho National Engineering Laboratory. Understanding the behavior of light-water reactors (LWR) under loss-of-coolant conditions is a major objective of the NRC Reactor Safety Research Program. The Loss of Fluid Test (LOFT) facility is the major testing facility to evaluate the systems response of an LWR over a wide range of Loss of Coolant Experment (LOCE) conditions. As such, the LOFT core is intended to be used for sequential LOCE tests provided no significant fuel rod failures occur. The PFB/LLR tests are designed to simulate the test conditions for the LOFT Power Ascension Tests L2-2 through L2-5. The test program has been designed to provide a parametric evaluation of the LOFT fuel over a wide range of power. Thus, a relatively accurate assessment of the state of the LOFT core after the completion of each subtest and the anticipated effect of the next test can be obtained by utilizing a combination of LLR test data and analytical predictions. Specifications for the test program are presented

  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. 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.

  16. On long-term fatigue damage and reliability analysis of gears under wind loads in offshore wind turbine drivetrains

    OpenAIRE

    Rasekhi Nejad, Amir; Gao, Zhen; Moan, Torgeir

    2014-01-01

    In this paper, a long-term fatigue damage analysis method for gear tooth root bending in wind turbine’s drivetrains is presented. The proposed method is established based on the ISO gear design codes which are basically developed for gears in general applications, not specifically for wind turbine gears. The ISO procedure is adapted and further improved to include the long-term fatigue damage of wind turbine’s gears. The load duration distribution (LDD) method is used to obtain the short-term...

  17. Gene program-specific regulation of PGC-1{alpha} activity

    DEFF Research Database (Denmark)

    Schmidt, Søren F; Mandrup, Susanne

    2011-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1 α (PGC-1α) activation coordinates induction of the hepatic fasting response through coactivation of numerous transcription factors and gene programs. In the June 15, 2011, issue of Genes & Development, Lustig and colleagues (pp....... 1232-1244) demonstrated that phosphorylation of PGC-1α by the p70 ribosomal protein S6 kinase 1 (S6K1) specifically interfered with the interaction between PGC-1α and HNF4α in liver and blocked the coactivation of the gluconeogenic target genes. This demonstrates how independent fine-tuning of gene...

  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. 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.

  20. Mid-market transformation programs: programs to promote best practices in system specification and installation

    International Nuclear Information System (INIS)

    Rosenberg, Mitchell

    2003-01-01

    This paper summarizes the experience of programs designed to promote the adoption of best practices in equipment specification and installation among distributors and installation contractors in the residential central air conditioning and industrial compressed air equipment markets. For each of those markets, the paper identifies the current understanding of best practices, characterizes energy savings available from their adoption, assesses the nature of barriers to their adoption, and describes the operations and accomplishments of programs designed to address those barriers

  1. Gear noise, vibration, and diagnostic studies at NASA Lewis Research Center

    Science.gov (United States)

    Zakrajsek, J. J.; Oswald, F. B.; Townsend, D. P.; Coy, J. J.

    1990-01-01

    The NASA Lewis Research Center and the U.S. Army Aviation Systems Command are involved in a joint research program to advance the technology of rotorcraft transmissions. This program consists of analytical as well as experimental efforts to achieve the overall goals of reducing weight, noise, and vibration, while increasing life and reliability. Recent analytical activities are highlighted in the areas of gear noise, vibration, and diagnostics performed in-house and through NASA and U.S. Army sponsored grants and contracts. These activities include studies of gear tooth profiles to reduce transmission error and vibration as well as gear housing and rotordynamic modeling to reduce structural vibration and transmission and noise radiation, and basic research into current gear failure diagnostic methodologies. Results of these activities are presented along with an overview of near-term research plans in the gear noise, vibration, and diagnostics area.

  2. Development and validation of a new reference cylindrical gear for pitch measurement

    DEFF Research Database (Denmark)

    Malberg, Maria Pia Sammartini; De Chiffre, Leonardo

    2000-01-01

    A new type of master gear, the Gauge Block Gear (GBG), was developed for the performance verification of coordinate measuring machines (CMMs), for the specific task of pitch and chordal tooth thickness measurement. Its main characteristic is the replacement of the teeth with gauge blocks, in order...

  3. A Comparative Case Study of Student Preparation for Postsecondary Education: How GEAR UP, Socioeconomic Status, and Race Influence Academic and Non-Academic Factors

    Science.gov (United States)

    Lunceford, Christina J.; Sondergeld, Toni A.; Stretavski, Elizabeth L.

    2017-01-01

    The purpose of this study was to gain a better understanding of early preparation for postsecondary education and explore the effectiveness of Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP). This comparative case study included 836 students from two cohorts (GEAR UP and Non GEAR UP). We compared high school attendance,…

  4. Time domain series system definition and gear set reliability modeling

    International Nuclear Information System (INIS)

    Xie, Liyang; Wu, Ningxiang; Qian, Wenxue

    2016-01-01

    Time-dependent multi-configuration is a typical feature for mechanical systems such as gear trains and chain drives. As a series system, a gear train is distinct from a traditional series system, such as a chain, in load transmission path, system-component relationship, system functioning manner, as well as time-dependent system configuration. Firstly, the present paper defines time-domain series system to which the traditional series system reliability model is not adequate. Then, system specific reliability modeling technique is proposed for gear sets, including component (tooth) and subsystem (tooth-pair) load history description, material priori/posterior strength expression, time-dependent and system specific load-strength interference analysis, as well as statistically dependent failure events treatment. Consequently, several system reliability models are developed for gear sets with different tooth numbers in the scenario of tooth root material ultimate tensile strength failure. The application of the models is discussed in the last part, and the differences between the system specific reliability model and the traditional series system reliability model are illustrated by virtue of several numerical examples. - Highlights: • A new type of series system, i.e. time-domain multi-configuration series system is defined, that is of great significance to reliability modeling. • Multi-level statistical analysis based reliability modeling method is presented for gear transmission system. • Several system specific reliability models are established for gear set reliability estimation. • The differences between the traditional series system reliability model and the new model are illustrated.

  5. Induction heating of gears - pulsing dual-frequency concept

    Directory of Open Access Journals (Sweden)

    R. Przyłucki

    2013-04-01

    Full Text Available The paper concerns analysis of gears hardening process. In order to obtain required temperature distribution several variations of single and combined frequencies for selected gear-wheel configurations were considered. The paper includes the calculation models and analysis of geometry and current intensity as well frequency influence on temperature distribution of the tooth surface. All calculations have been carried out by means of the use of Flux3D simulation program, which enables to provide, coupled electromagnetic and temperature fields analysis.

  6. 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.

  7. 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.

  8. Fault feature analysis of cracked gear based on LOD and analytical-FE method

    Science.gov (United States)

    Wu, Jiateng; Yang, Yu; Yang, Xingkai; Cheng, Junsheng

    2018-01-01

    At present, there are two main ideas for gear fault diagnosis. One is the model-based gear dynamic analysis; the other is signal-based gear vibration diagnosis. In this paper, a method for fault feature analysis of gear crack is presented, which combines the advantages of dynamic modeling and signal processing. Firstly, a new time-frequency analysis method called local oscillatory-characteristic decomposition (LOD) is proposed, which has the attractive feature of extracting fault characteristic efficiently and accurately. Secondly, an analytical-finite element (analytical-FE) method which is called assist-stress intensity factor (assist-SIF) gear contact model, is put forward to calculate the time-varying mesh stiffness (TVMS) under different crack states. Based on the dynamic model of the gear system with 6 degrees of freedom, the dynamic simulation response was obtained for different tooth crack depths. For the dynamic model, the corresponding relation between the characteristic parameters and the degree of the tooth crack is established under a specific condition. On the basis of the methods mentioned above, a novel gear tooth root crack diagnosis method which combines the LOD with the analytical-FE is proposed. Furthermore, empirical mode decomposition (EMD) and ensemble empirical mode decomposition (EEMD) are contrasted with the LOD by gear crack fault vibration signals. The analysis results indicate that the proposed method performs effectively and feasibility for the tooth crack stiffness calculation and the gear tooth crack fault diagnosis.

  9. Specific Cell (Re-)Programming: Approaches and Perspectives.

    Science.gov (United States)

    Hausburg, Frauke; Jung, Julia Jeannine; David, Robert

    2018-01-01

    Many disorders are manifested by dysfunction of key cell types or their disturbed integration in complex organs. Thereby, adult organ systems often bear restricted self-renewal potential and are incapable of achieving functional regeneration. This underlies the need for novel strategies in the field of cell (re-)programming-based regenerative medicine as well as for drug development in vitro. The regenerative field has been hampered by restricted availability of adult stem cells and the potentially hazardous features of pluripotent embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Moreover, ethical concerns and legal restrictions regarding the generation and use of ESCs still exist. The establishment of direct reprogramming protocols for various therapeutically valuable somatic cell types has overcome some of these limitations. Meanwhile, new perspectives for safe and efficient generation of different specified somatic cell types have emerged from numerous approaches relying on exogenous expression of lineage-specific transcription factors, coding and noncoding RNAs, and chemical compounds.It should be of highest priority to develop protocols for the production of mature and physiologically functional cells with properties ideally matching those of their endogenous counterparts. Their availability can bring together basic research, drug screening, safety testing, and ultimately clinical trials. Here, we highlight the remarkable successes in cellular (re-)programming, which have greatly advanced the field of regenerative medicine in recent years. In particular, we review recent progress on the generation of cardiomyocyte subtypes, with a focus on cardiac pacemaker cells. Graphical Abstract.

  10. Procedure for the automatic mesh generation of innovative gear teeth

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.

  11. Designing Domain-Specific Heterogeneous Architectures from Dataflow Programs

    Directory of Open Access Journals (Sweden)

    Süleyman Savas

    2018-04-01

    Full Text Available The last ten years have seen performance and power requirements pushing computer architectures using only a single core towards so-called manycore systems with hundreds of cores on a single chip. To further increase performance and energy efficiency, we are now seeing the development of heterogeneous architectures with specialized and accelerated cores. However, designing these heterogeneous systems is a challenging task due to their inherent complexity. We proposed an approach for designing domain-specific heterogeneous architectures based on instruction augmentation through the integration of hardware accelerators into simple cores. These hardware accelerators were determined based on their common use among applications within a certain domain.The objective was to generate heterogeneous architectures by integrating many of these accelerated cores and connecting them with a network-on-chip. The proposed approach aimed to ease the design of heterogeneous manycore architectures—and, consequently, exploration of the design space—by automating the design steps. To evaluate our approach, we enhanced our software tool chain with a tool that can generate accelerated cores from dataflow programs. This new tool chain was evaluated with the aid of two use cases: radar signal processing and mobile baseband processing. We could achieve an approximately 4 × improvement in performance, while executing complete applications on the augmented cores with a small impact (2.5–13% on area usage. The generated accelerators are competitive, achieving more than 90% of the performance of hand-written implementations.

  12. Specialization-Specific Course Assessments Integrated for Program Assessment

    OpenAIRE

    Qurban A. Memon; Adnan Harb; Shakeel Khoja

    2012-01-01

    The program assessment process combines assessments from individual courses to generate final program assessment to match accreditation benchmarks. In developing countries, industrial environment is not diversified to allow graduating engineers to seek jobs in all disciplines or specializations of an engineering program. Hence, it seems necessary to seek evolution of an engineering program assessment for specialized requirements of the industry. This paper describes how specialization-specifi...

  13. 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.

  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. Review on common calibration and measurement practises for measuring gears on CMMs

    DEFF Research Database (Denmark)

    Sammatini-Malberg, Maria-Pia; De Chiffre, Leonardo

    , in order to give an overview of the improvements achieved in the last 25 years. Special attention is paid to gear metrology on coordinate measuring machines (CMMs). Calibration chains for the major gear geometrical quantities developed by Physikalisch-Technische Bundesanstalt (PTB) as well as their recent...... results obtained in gear standards measurement uncertainties are presented. This review also describes the design and development of a new type of master gear: the Gauge Block Gear (GBG).The GBG was developed for the performance verification of CMMs, for the specific task of pitch and chordal tooth...... thickness measurement. Its main characteristic is the replacement of the teeth with gauge blocks, in order to achieve direct traceability of the chordal tooth thickness...

  16. Possiblity of substituting 12XH3A steel in the manufacture of gears for a Sova motorcycle gearing box

    Science.gov (United States)

    Abramov, L. M.; Karabanov, V. P.; Abramov, V. L.; Astakhin, A. S.

    1996-03-01

    The experimental work describes the possibility of substituting the expensive alloying steel 12XH3A for the low-cost material (steel 40X) in manufacturing gears of the motor cycle gearing box. It ban be achieved on the basis of the obtained results and with the help of laser melting treatment of small-alloying steel. We can speak about the dependence of laser melting radiation efficiency on the regimes and procedures. The breakage of the gearing box of the motor cycle 'Sova' may be explained by the low carry ability of its first gearing box gear. This investigation includes the determination of the cause of this problem. One of the most wide spread methods of such decisions is the substitution of the used materials by another. The most important criteria for the new materials are: (1) the increase of mechanical characteristics (solidity, plasticity); (2) the increase of such characteristics as hardness, specific percussive viscosity; (3) the improvement of the technological characteristics; (4) the condencention of the manufacturing expenditures (economical effect). In accordance with these creations some materials (35X, 40X, 20XH, 40XHM steels) were chosen. The best material is 40X steel, because it allows us to treat the gears by laser radiation with the surface melt. Surface melt allows us to produce: (1) martensite structure with high solidity and low percussive viscosity; (2) martensite structure with chrome carbides and high percussive viscosity, but low plasticity; (3) amorphous or monocrystallic structures with the best characteristics. The last structure has the best characteristics because dislocation defects in such material are practically absent. Also, the amorphous surface of the materials is the most interesting. The spirit of the investigation is to define the parameters of production such as radiation power, size of laser spot, and speed of spot.

  17. 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.

  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. 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.

  20. 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...

  1. 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...

  2. A Logic Programming Testbed for Inductive Thought and Specification.

    Science.gov (United States)

    Neff, Norman D.

    This paper describes applications of logic programming technology to the teaching of the inductive method in computer science and mathematics. It discusses the nature of inductive thought and its place in those fields of inquiry, arguing that a complete logic programming system for supporting inductive inference is not only feasible but necessary.…

  3. 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.

  4. 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.

  5. 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.

  6. 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 ...

  7. 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,.

  8. 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...

  9. 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

  10. 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...

  11. 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.

  12. Software requirements specification for the program analysis and control system risk management module

    International Nuclear Information System (INIS)

    SCHAEFER, J.C.

    1999-01-01

    TWR Program Analysis and Control System Risk Module is used to facilitate specific data processes surrounding the Risk Management program of the Tank Waste Retrieval environment. This document contains the Risk Management system requirements of the database system

  13. 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.

  14. Computerized Design of Low-noise Face-milled Spiral Bevel Gears

    Science.gov (United States)

    Litvin, Faydor L.; Zhang, YI; Handschuh, Robert F.

    1994-01-01

    An advanced design methodology is proposed for the face-milled spiral bevel gears with modified tooth surface geometry that provides a reduced level of noise and has a stabilized bearing contact. The approach is based on the local synthesis of the gear drive that provides the 'best' machine-tool settings. The theoretical aspects of the local synthesis approach are based on the application of a predesigned parabolic function for absorption of undesirable transmission errors caused by misalignment and the direct relations between principal curvatures and directions for mating surfaces. The meshing and contact of the gear drive is synthesized and analyzed by a computer program. The generation of gears with the proposed geometry design can be accomplished by application of existing equipment. A numerical example that illustrates the proposed theory is presented.

  15. High Performance Computing - Power Application Programming Interface Specification.

    Energy Technology Data Exchange (ETDEWEB)

    Laros, James H.,; Kelly, Suzanne M.; Pedretti, Kevin; Grant, Ryan; Olivier, Stephen Lecler; Levenhagen, Michael J.; DeBonis, David

    2014-08-01

    Measuring and controlling the power and energy consumption of high performance computing systems by various components in the software stack is an active research area [13, 3, 5, 10, 4, 21, 19, 16, 7, 17, 20, 18, 11, 1, 6, 14, 12]. Implementations in lower level software layers are beginning to emerge in some production systems, which is very welcome. To be most effective, a portable interface to measurement and control features would significantly facilitate participation by all levels of the software stack. We present a proposal for a standard power Application Programming Interface (API) that endeavors to cover the entire software space, from generic hardware interfaces to the input from the computer facility manager.

  16. 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.

  17. On the Boundary between Nonlinear Jump Phenomenon and Linear Response of Hypoid Gear Dynamics

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2011-01-01

    Full Text Available A nonlinear time-varying (NLTV dynamic model of a hypoid gear pair system with time-dependent mesh point, line-of-action vector, mesh stiffness, mesh damping, and backlash nonlinearity is formulated to analyze the transitional phase between nonlinear jump phenomenon and linear response. It is found that the classical jump discontinuity will occur if the dynamic mesh force exceeds the mean value of tooth mesh force. On the other hand, the propensity for the gear response to jump disappears when the dynamic mesh force is lower than the mean mesh force. Furthermore, the dynamic analysis is able to distinguish the specific tooth impact types from analyzing the behaviors of the dynamic mesh force. The proposed theory is general and also applicable to high-speed spur, helical and spiral bevel gears even though those types of gears are not the primary focus of this paper.

  18. 24 CFR 200.936 - Supplementary specific procedural requirements under HUD building products certification program...

    Science.gov (United States)

    2010-04-01

    ... requirements under HUD building products certification program for solid fuel type room heaters and fireplace... Supplementary specific procedural requirements under HUD building products certification program for solid fuel... fireplace stoves certified under the HUD Building Products Certification Program shall be designed...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    International Nuclear Information System (INIS)

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-01-01

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with

  8. 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.

  9. 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...

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Vehicle transmission gear 2009; Getriebe in Fahrzeugen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    with single dry clutch and electric torque support (G. Hellenbroich); (37) New solutions to increase cost-effectiveness of city bus drive lines with modern automatic powershift transmissions (P. Wunderlich); (38) Evaluation of the gearchanging comfort at commercial vehicles (W. Wessel); (39) New structure-optimised transmission systems for advanced commercial vehicles (R. Resch); (40) Depth of details of powertrain models for depocting driveability effects (F. Matthies); (41) A nonlinear transmission approach for dual mass flywheels (C. Benatzky); (42) Clattering and rattling is still a challenge for vehicle transmission developers (M. Dally); (43) Study on the effect of driving cycles on energy efficiency of electric vehicles (J. Fenzhu); (44) Modular modelling and simulation of hybrid power trains (G. Kelz); (45) The integration of electrical axle drives in hybrid vehicle and electric vehicles (H. Schaefer); (46) Energy balance of the optimized CVT hybrid driveline (B.-R. Hoehm); (47) Functional efficiency comparison between split- and parallel-hybrid using advanced energy flow analysis methods (P. Guttenberg); (48) Simulation of the fuel consumption benefits of various transmission arrangements and control strategies within a flywheel based mechanical hybrid system (W. Body); (49) Ideal test specifications for transmissions (T. Kassel); (50) The 'Hybrid Effect': Influence of hybridisation on the durability of automatic transmissions (T. Lavall); (51) Schaeffler lightweight differentials (R. Malik); (52) Integrated all wheel drive in the ZF eight-speed automatic gear (D. Baasch); (53) Optimized structures for amplifying torque vectoring systems (A. Sue); (54) The new sport differential in the Audi S4 (U. Pinschmidt).

  16. 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

  17. 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.

  18. 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.

  19. Construction and Verification of PLC LD-programs by LTL-specification

    Directory of Open Access Journals (Sweden)

    E. V. Kuzmin

    2013-01-01

    Full Text Available An approach to construction and verification of PLC LD-programs for discrete problems is proposed. For the specification of the program behavior, we use the linear-time temporal logic LTL. Programming is carried out in the LD-language (Ladder Diagram according to an LTL-specification. The correctness analysis of an LTL-specification is carried out by the symbolic model checking tool Cadence SMV. A new approach to programming and verification of PLC LD-programs is shown by an example. For a discrete problem, we give a LD-program, its LTL-specification and an SMV-model. The purpose of the article is to describe an approach to programming PLC, which would provide a possibility of LD-program correctness analysis by the model checking method. Under the proposed approach, the change of the value of each program variable is described by a pair of LTL-formulas. The first LTL-formula describes situations which increase the value of the corresponding variable, the second LTL-formula specifies conditions leading to a decrease of the variable value. The LTL-formulas (used for speci- fication of the corresponding variable behavior are constructive in the sense that they construct the PLC-program (LD-program, which satisfies temporal properties expressed by these formulas. Thus, the programming of PLC is reduced to the construction of LTLspecification of the behavior of each program variable. In addition, an SMV-model of a PLC LD-program is constructed according to LTL-specification. Then, the SMV-model is analysed by the symbolic model checking tool Cadence SMV.

  20. NASIS data base management system - IBM 360/370 OS MVT implementation. 4: Program design specifications

    Science.gov (United States)

    1973-01-01

    The design specifications for the programs and modules within the NASA Aerospace Safety Information System (NASIS) are presented. The purpose of the design specifications is to standardize the preparation of the specifications and to guide the program design. Each major functional module within the system is a separate entity for documentation purposes. The design specifications contain a description of, and specifications for, all detail processing which occurs in the module. Sub-modules, reference tables, and data sets which are common to several modules are documented separately.

  1. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. The Impact of Different Teaching Approaches and Languages on Student Learning of Introductory Programming Concepts

    Science.gov (United States)

    Kunkle, Wanda M.

    2010-01-01

    Many students experience difficulties learning to program. They find learning to program in the object-oriented paradigm particularly challenging. As a result, computing educators have tried a variety of instructional methods to assist beginning programmers. These include developing approaches geared specifically toward novices and experimenting…

  7. 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

  8. HAL/SM language specification. [programming languages and computer programming for space shuttles

    Science.gov (United States)

    Williams, G. P. W., Jr.; Ross, C.

    1975-01-01

    A programming language is presented for the flight software of the NASA Space Shuttle program. It is intended to satisfy virtually all of the flight software requirements of the space shuttle. To achieve this, it incorporates a wide range of features, including applications-oriented data types and organizations, real time control mechanisms, and constructs for systems programming tasks. It is a higher order language designed to allow programmers, analysts, and engineers to communicate with the computer in a form approximating natural mathematical expression. Parts of the English language are combined with standard notation to provide a tool that readily encourages programming without demanding computer hardware expertise. Block diagrams and flow charts are included. The semantics of the language is discussed.

  9. 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.

  10. The Rise of International Relations Programs in the Brazilian Federal Universities: Curriculum Specificities and Current Challenges

    Science.gov (United States)

    Ferreira, Marcos Alan S. V.

    2016-01-01

    The aim of this reflection is to study the new international relations (IR) programs introduced by Brazilian federal universities, looking comparatively at their curriculum specificities and current challenges. In recent years, Brazil has seen an increase of IR programs launched in several regions. Since 2003, the Ministry of Education is in the…

  11. 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.

  12. Manual for automatic generation of finite element models of spiral bevel gears in mesh

    Science.gov (United States)

    Bibel, G. D.; Reddy, S.; Kumar, A.

    1994-01-01

    The goal of this research is to develop computer programs that generate finite element models suitable for doing 3D contact analysis of faced milled spiral bevel gears in mesh. A pinion tooth and a gear tooth are created and put in mesh. There are two programs: Points.f and Pat.f to perform the analysis. Points.f is based on the equation of meshing for spiral bevel gears. It uses machine tool settings to solve for an N x M mesh of points on the four surfaces, pinion concave and convex, and gear concave and convex. Points.f creates the file POINTS.OUT, an ASCI file containing N x M points for each surface. (N is the number of node points along the length of the tooth, and M is nodes along the height.) Pat.f reads POINTS.OUT and creates the file tl.out. Tl.out is a series of PATRAN input commands. In addition to the mesh density on the tooth face, additional user specified variables are the number of finite elements through the thickness, and the number of finite elements along the tooth full fillet. A full fillet is assumed to exist for both the pinion and gear.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. 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...

  19. 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

  20. 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...

  1. 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.

  2. contact stress analysis of involute spur gear by finite element method

    African Journals Online (AJOL)

    USER

    section using C- programming. Bending stress analysis has been performed using finite element analysis with ANSYS software. Comparison of bending stress analysis has been performed for symmetric and asymmetric spur gear tooth at critical section. Mushin J. Jweeg, et.al. [7] used 2D contact stress FEA model to ...

  3. Gear selectivity of large-mesh nets and drumlines used to catch ...

    African Journals Online (AJOL)

    Catches of sharks and bycatch in large-mesh nets and baited drumlines used by the Queensland Shark Control Program were examined to determine the efficacy of both gear types and assess fishing strategies that minimise their impacts. There were few significant differences in the size of both sharks and bycatch in the ...

  4. 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.

  5. 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...

  6. 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.

  7. Nonlinear Dynamic Analysis and Optimization of Closed-Form Planetary Gear System

    Directory of Open Access Journals (Sweden)

    Qilin Huang

    2013-01-01

    Full Text Available A nonlinear purely rotational dynamic model of a multistage closed-form planetary gear set formed by two simple planetary stages is proposed in this study. The model includes time-varying mesh stiffness, excitation fluctuation and gear backlash nonlinearities. The nonlinear differential equations of motion are solved numerically using variable step-size Runge-Kutta. In order to obtain function expression of optimization objective, the nonlinear differential equations of motion are solved analytically using harmonic balance method (HBM. Based on the analytical solution of dynamic equations, the optimization mathematical model which aims at minimizing the vibration displacement of the low-speed carrier and the total mass of the gear transmission system is established. The optimization toolbox in MATLAB program is adopted to obtain the optimal solution. A case is studied to demonstrate the effectiveness of the dynamic model and the optimization method. The results show that the dynamic properties of the closed-form planetary gear transmission system have been improved and the total mass of the gear set has been decreased significantly.

  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. 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.

  10. 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.

  11. 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

  12. 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...

  13. 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...

  14. 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

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Specific features of using programmed hardware in emergency protection systems of NPP

    International Nuclear Information System (INIS)

    Konoplev, N.P.; Pogorelov, I.V.; Kirsanov, A.V.

    2005-01-01

    The specific features of using the microprocessor-based technical means and programmed logic integrated circuits (PLIC) in WWER reactor protection systems are considered. The basic causes of occurring the failures in programmed technical means are analyzed. The features of using PLIC in reactor protection systems are discussed. The methods permitting to decrease the probability occurring the common mode failure of programmed technical means are proposed. It is concluded that at creating of reactor protection systems with the use of microprocessors and PLIC it is necessary to apply the principle of the functional diversity [ru

  3. 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.

  4. 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.

  5. 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.

  6. AUTOMATA PROGRAMS CONSTRUCTION FROM SPECIFICATION WITH AN ANT COLONY OPTIMIZATION ALGORITHM BASED ON MUTATION GRAPH

    Directory of Open Access Journals (Sweden)

    Daniil S. Chivilikhin

    2014-11-01

    Full Text Available The procedure of testing traditionally used in software engineering cannot guarantee program correctness; therefore verification is used at the excess requirements to programs reliability. Verification makes it possible to check certain properties of programs in all possible computational states; however, this process is very complex. In the model checking method a model of the program is built (often, manually and requirements in terms of temporal logic are formulated. Such temporal properties of the model can be checked automatically. The main issue in this framework is the gap between the program and its model. Automata-based programming paradigm gives the possibility to overcome this limitation. In this paradigm, program logic is represented using finite-state machines. The advantage of finite-state machines is that their models can be constructed automatically. The paper deals with the application of mutation-based ant colony optimization algorithm to the problem of finite-state machine construction from their specification, defined by test scenarios and temporal properties. The presented approach has been tested on the elevator doors control problem as well as on randomly generated data. Obtained results show the ant colony algorithm is two-three times faster than the previously used genetic algorithm. The proposed approach can be recommended for inferring control programs for critical systems.

  7. 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.

  8. 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.

  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. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. Multiple system responses program: Identification of concerns related to a number of specific regulatory issues

    International Nuclear Information System (INIS)

    Murphy, G.A.; Casada, M.L.; Palko, L.E.; Roberts, M.W.

    1989-10-01

    This document describes the activities and results of the Multiple System Responses (MSR) program conducted by the Nuclear Operations Analysis Center (NOAC) at Oak Ridge National Laboratory (ORNL). The objective of the MSR program was to gather and review documentation for several unresolved safety issues and related programs of interest, and from that documentation, describe any additional potential safety concerns. The MSR program provides information that will aid the NRC staff in making an assessment of the relative safety significance of the concerns through the established prioritization process. Judgments were not made regarding the validity of the concerns expressed by others. Rather, the concerns were documented and potential safety issues were developed and defined as specifically as possible. Twenty-one potential safety issues were developed from the documented concerns. Additional information was gathered to support the NRC efforts in reviewing these issues for prioritization. 73 refs., 2 tabs

  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. Comparison of First Gear Performance for Manual and Automatic Transmissions

    Directory of Open Access Journals (Sweden)

    Kyle Stottlemyer

    2011-01-01

    Full Text Available The purpose of this project is to compare the first gear performance of an automobile for both its manual and automatic transmission options. Each transmission type has a different gear ratio, which yields a different acceleration curve for each transmission throughout the torque-rpm curve of the engine. The method of integral calculus was used to find an equation which could be used to solve for time at any point in the car's acceleration. The automobile velocity versus time was then graphed to compare each transmissions acceleration trend. This process is similar to that which automotive companies may use when determining what type of transmission to pair with a particular vehicle. By observing the trends in the acceleration graphs, it was determined that there are specific advantages and disadvantages to each type of transmission. Which transmission is the “better” choice is dependent on what application the automobile will be used for (e.g. racing, day-to-day driving, towing/hauling.

  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. Perancangan dan Realisasi Kontrol Prototype Landing Gear System Menggunakan PLCmikro berbasis Mikrokontroller PIC16F877A

    Directory of Open Access Journals (Sweden)

    RATNA SUSANA

    2016-02-01

    Full Text Available Abstrak Landing gear system merupakan suatu sistem penggerak pada roda pesawat yang menggunakan electromechanic system dengan sejumlah relay tanpa control terpusat. Melalui penelitian ini, electromechanic system tersebut diubah menjadi landing gear system yang dikendalikan secara terpusat menggunakan mikrokontroller dan diprogram oleh ldmikro berbahasa ladder diagram yang kemudian lebih dikenal dengan nama “PLCmikro”. Input discreate digunakan untuk menggerakkan aktuator solenoid valve agar piston double acting cylinder dapat bekerja sesuai sistem yang diinginkan. Input analog digunakan sebagai informasi ketinggian pesawat minimum agar pesawat tetap aman terbang di udara. Control Landing gear system yang direalisasikan berhasil menggerakkan piston masuk maupun keluar dari tabung, memberikan informasi proses pergerakkan piston yang bermasalah dan posisi roda yang telah masuk atau keluar dari pesawat berupa lampu LED. Sistem ini juga berhasil membaca informasi ketinggian minimum pesawat dari potensiometer serta mengubahnya menjadi informasi suara dan lampu LED.   Kata kunci: Landing gear system, PLCmikro, Ldmikro, ladder diagram, double acting cylinder. Abstract The landing gear system an aircraft wheel drive system that uses electromechanic system with a relay without any centralized control. Through this study, the electromechanic system was changed to landing gear system with a centrally controlled by using microcontroller and programmed with ldmikro ladder diagram language which came to be known by the name of "PLCmikro". Discreate input used to drive the actuator solenoid valve double acting cylinder so that the piston can work as desired system. The analog input is used as the minimum flight altitude information to keep the plane safe to fly in the air. Landing gear control system is realized successfully drive the piston in and out of the tube, providing information processes are problematic piston movement and wheel position that has

  3. Acquired transcriptional programming in functional and exhausted virus-specific CD8 T cells.

    Science.gov (United States)

    Youngblood, Ben; Wherry, E John; Ahmed, Rafi

    2012-01-01

    Failure to control viral infections such as HIV results in T-cell receptor (TCR) and inhibitory receptor driven exhaustion of antigen-specific T cells. Persistent signaling by these receptors during chronic viral infection sculpts the transcriptional regulatory programs of virus-specific T cells. The resulting gene expression profile is tailored to temper the potentially damaging effector functions of cytotoxic T cells and adapt them to an antigen-rich and inflammation-rich environment. Here we review recent studies investigating mechanisms of transcriptional regulation of effector, functional memory, and exhausted T-cell functions during acute versus chronic infections. Patterns of gene expression in virus-specific CD8 T cells are a result of a combination of pro and inhibitory signals from antigen presentation (TCR-mediated) and co-inhibitory receptor ligation (PD-1, 2B4). Further, memory-specific transcriptional regulation of 2B4 expression and signaling impose a self-limiting secondary effector response to a prolonged viral infection. Additionally, differentiation of functional memory CD8 T cells is coupled with acquisition of a repressive epigenetic program for PD-1 expression. However, chronic infection provides a signal that blocks the acquisition of these epigenetic modifications reinforcing the suppression of cytotoxic lymphocyte (CTL) functions in exhausted cells. Current findings suggest that the mechanism(s) that delineate functional memory versus exhaustion are coupled with acquisition of transcriptional programs at the effector stage of differentiation, reinforced by cessation or persistence of TCR signaling.

  4. 78 FR 24707 - Fisheries of the Exclusive Economic Zone off Alaska: Fixed-Gear Commercial Halibut and Sablefish...

    Science.gov (United States)

    2013-04-26

    ... Control Number. List of Subjects in 50 CFR Part 679 Alaska, Fisheries. Dated: April 22, 2013. Alan D... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 679 [Docket No... master regulations of the Individual Fishing Quota Program (IFQ Program) for the fixed-gear commercial...

  5. 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.

  6. 25 CFR 39.137 - May schools operate a language development program without a specific appropriation from Congress?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false May schools operate a language development program... Formula Language Development Programs § 39.137 May schools operate a language development program without a specific appropriation from Congress? Yes, a school may operate a language development program...

  7. 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.

  8. Strategies to overcome HBV-specific T cell exhaustion: checkpoint inhibitors and metabolic re-programming.

    Science.gov (United States)

    Fisicaro, Paola; Boni, Carolina; Barili, Valeria; Laccabue, Diletta; Ferrari, Carlo

    2018-01-29

    HBV-specific T cells play a key role in antiviral protection and failure to control HBV is associated with severely dysfunctional T cell responses. Therefore, functional T cell reconstitution represents a potential way to treat chronically infected patients. The growing understanding of the dysregulated transcriptional/epigenetic and metabolic programs underlying T cell exhaustion allows to envisage functional T cell reconstitution strategies based on the combined/sequential use of compounds able to induce decline of antigen load, checkpoint modulation, metabolic and epigenetic reprogramming with possible boosting of functionally restored responses by specific vaccines. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Critical evaluation of the nonradiological environmental technical specifications. Program description, summary, and recommendations. Vol. 1

    International Nuclear Information System (INIS)

    Adams, S.M.; Cunningham, P.A.; Gray, D.D.; Kumar, K.D.; Witten, A.J.

    1976-01-01

    A comprehensive study of the data collected as part of the environmental Technical Specifications program for eight nuclear power plants was conducted for the Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory commission. This report includes a summary of the screening phase in which the adequacy of the hydrothermal and ecological monitoring data for each plant were evaluated, and the summary and recommendations resulting from a detailed examination of the three nuclear power plants selected in the initial screening

  10. Spermatogenesis-specific features of the meiotic program in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Diane C Shakes

    2009-08-01

    Full Text Available In most sexually reproducing organisms, the fundamental process of meiosis is implemented concurrently with two differentiation programs that occur at different rates and generate distinct cell types, sperm and oocytes. However, little is known about how the meiotic program is influenced by such contrasting developmental programs. Here we present a detailed timeline of late meiotic prophase during spermatogenesis in Caenorhabditis elegans using cytological and molecular landmarks to interrelate changes in chromosome dynamics with germ cell cellularization, spindle formation, and cell cycle transitions. This analysis expands our understanding C. elegans spermatogenesis, as it identifies multiple spermatogenesis-specific features of the meiotic program and provides a framework for comparative studies. Post-pachytene chromatin of spermatocytes is distinct from that of oocytes in both composition and morphology. Strikingly, C. elegans spermatogenesis includes a previously undescribed karyosome stage, a common but poorly understood feature of meiosis in many organisms. We find that karyosome formation, in which chromosomes form a constricted mass within an intact nuclear envelope, follows desynapsis, involves a global down-regulation of transcription, and may support the sequential activation of multiple kinases that prepare spermatocytes for meiotic divisions. In spermatocytes, the presence of centrioles alters both the relative timing of meiotic spindle assembly and its ultimate structure. These microtubule differences are accompanied by differences in kinetochores, which connect microtubules to chromosomes. The sperm-specific features of meiosis revealed here illuminate how the underlying molecular machinery required for meiosis is differentially regulated in each sex.

  11. Towards Interactive Visual Exploration of Parallel Programs using a Domain-Specific Language

    KAUST Repository

    Klein, Tobias

    2016-04-19

    The use of GPUs and the massively parallel computing paradigm have become wide-spread. We describe a framework for the interactive visualization and visual analysis of the run-time behavior of massively parallel programs, especially OpenCL kernels. This facilitates understanding a program\\'s function and structure, finding the causes of possible slowdowns, locating program bugs, and interactively exploring and visually comparing different code variants in order to improve performance and correctness. Our approach enables very specific, user-centered analysis, both in terms of the recording of the run-time behavior and the visualization itself. Instead of having to manually write instrumented code to record data, simple code annotations tell the source-to-source compiler which code instrumentation to generate automatically. The visualization part of our framework then enables the interactive analysis of kernel run-time behavior in a way that can be very specific to a particular problem or optimization goal, such as analyzing the causes of memory bank conflicts or understanding an entire parallel algorithm.

  12. Protect your heart: a culture-specific multimedia cardiovascular health education program.

    Science.gov (United States)

    Shah, Amy; Clayman, Marla L; Glass, Sara; Kandula, Namratha R

    2015-04-01

    South Asians, the second fastest growing racial/ethnic minority in the United States, have high rates of coronary heart disease. Few coronary heart disease prevention efforts target this population. The authors developed and tested a culture-specific, multimedia coronary heart disease prevention education program in English and Hindi for South Asians. Participants were recruited from community organizations in Chicago, Illinois, between June and October of 2011. Bilingual interviewers used questionnaires to assess participants' knowledge and perceptions before and after the patient education program. The change from pretest score to posttest score was calculated using a paired t test. Linear regression was used to determine the association between posttest scores and education and language. Participants' (N = 112) average age was 41 years, 67% had more than a high school education, and 50% spoke Hindi. Participants' mean pretest score was 15 (SD = 4). After the patient education program, posttest scores increased significantly among all participants (posttest score = 24, SD = 4), including those with limited English proficiency. Lower education was associated with a lower posttest score (β = -2.2, 95% CI [-0.68, -3.83]) in adjusted regression. A culture-specific, multimedia patient education program significantly improved knowledge and perceptions about coronary heart disease prevention among South Asian immigrants. Culturally salient multimedia education may be an effective and engaging way to deliver health information to diverse patient populations.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. NDA PDP Program PuO2 increased particle size specification and design

    International Nuclear Information System (INIS)

    Marshall, R.S.; Taggart, D.P.; Becker, G.K.; Woon, W.Y.

    1996-01-01

    Provisions in the National TRU Program Quality Assurance Program Plan require an assessment of performance for nondestructive waste assay (NDA) systems employed in the program. This requirement is in part fulfilled through the use of Performance Demonstration programs. In order to optimize the quality and quantity of information acquired during a given Performance Demonstration Program cycle, the assessment employed is to be carefully specified and designed. The assessment must yield measurement system performance data meaningful with respect to NDA system capability to accommodate attributes of interest known to occur in actual waste forms. The design and specification of the increased particle size PuO 2 PDP working reference materials (WRMs) is directed at providing a straightforward mechanism to assess waste NDA system capability to account for biases introduced by large PuO 2 particles. The increased particle size PuO 2 PDP WRM design addresses actual waste form attributes associated with PuO 2 particle size and distributions thereof, the issue of a known and stable WRM configuration and equally important appropriate certification and tractability considerations

  19. 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.

  20. 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.

  1. Derelict fishing gear in Chesapeake Bay, Virginia: spatial patterns and implications for marine fauna.

    Science.gov (United States)

    Bilkovic, Donna Marie; Havens, Kirk; Stanhope, David; Angstadt, Kory

    2014-03-15

    Derelict fishing gear is a source of mortality for target and non-target marine species. A program employing commercial watermen to remove marine debris provided a novel opportunity to collect extensive spatially-explicit information for four consecutive winters (2008-2012) on the type, distribution, and abundance of derelict fishing gear and bycatch in Virginia waters of Chesapeake Bay. The most abundant form of derelict gear recovered was blue crab pots with almost 32,000 recovered. Derelict pots were widely distributed, but with notable hotspot areas, capturing 40 species and over 31,000 marine organisms. The target species, blue crab, experienced the highest mortality from lost pots with an estimated 900,000 animals killed each year, a potential annual economic loss to the fishery of $300,000. Important fishery species were captured and killed in derelict pots including Atlantic croaker and black sea bass. While some causes of gear loss are unavoidable, others can be managed to minimize loss. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. THE EFFECTIVENESS OF SPORTS SPECIFIC BALANCE TRAINING PROGRAM IN REDUCING RISK OF ANKLE SPRAIN IN BASKETBALL

    Directory of Open Access Journals (Sweden)

    Ai Choo LEE

    2016-12-01

    Full Text Available Background: To investigate the effectiveness of four weeks sports specific balance training program to improve balance, thus reducing the risk of ankle sprain among Sultan Idris Education University basketball players. Method: There were 20 males basketball players (aged 19-24 years volunteered in this study. After screening process, there were14 male players met the inclusion criteria. They were randomized into two groups i.e experimental group (EG: n=7 and control group (CG: n=7. The EG undergone the four weeks sports specific balance training program three times per week while the CG followed their normal standard basketball training program. Balance Error Scoring System (BESS was used to assess static balance while Star Excursion Balance Test (SEBT is utilized to examine the dynamic balance. Pretest and posttest of balance measures were recorded using BESS and SEBT for both EG and CG. The data were analyzed using independent sample t-test (p=0.05. Results: The study findings indicated that there were significant differences between EG and CG for the static balance on firm surface (t=-4.642, p=0.001 and on foam surface (t=-8.590, P=0.000 as well as dynamic balance on left leg stance (t=2.350, P=0.037 and on right leg stance (t=3.145, P=0.008. Conclusion: The study findings indicated that the four weeks sports specific balance training program could improve balance ability in male basketball players, thus may reducing the risk of ankle sprain.

  3. 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.

  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. Towards Interactive Visual Exploration of Parallel Programs using a Domain-Specific Language

    KAUST Repository

    Klein, Tobias; Bruckner, Stefan; Grö ller, M. Eduard; Hadwiger, Markus; Rautek, Peter

    2016-01-01

    The use of GPUs and the massively parallel computing paradigm have become wide-spread. We describe a framework for the interactive visualization and visual analysis of the run-time behavior of massively parallel programs, especially OpenCL kernels. This facilitates understanding a program's function and structure, finding the causes of possible slowdowns, locating program bugs, and interactively exploring and visually comparing different code variants in order to improve performance and correctness. Our approach enables very specific, user-centered analysis, both in terms of the recording of the run-time behavior and the visualization itself. Instead of having to manually write instrumented code to record data, simple code annotations tell the source-to-source compiler which code instrumentation to generate automatically. The visualization part of our framework then enables the interactive analysis of kernel run-time behavior in a way that can be very specific to a particular problem or optimization goal, such as analyzing the causes of memory bank conflicts or understanding an entire parallel algorithm.

  9. Cernavoda NPP Unit 1: Operating experience program and plant specific performance indicators (level 2)

    International Nuclear Information System (INIS)

    Teodor, Vasile; Popa, Viorel

    1998-01-01

    The basis for the Operating Experience Program was set in place since early stages of the commissioning phase (1993), when a system based on the Canadian approach was implemented for reporting, reviewing, assessing and establishing of the necessary corrective action for unplanned events. This system provided excellent opportunity to train staff in unplanned event assessment methodology, and prepare the station for the formal reporting process following criticality in accordance with the licensing requirements. The formal process, set in place after criticality is described in Station Instruction Procedure SI-01365-P13 'Unplanned Event Report' and was developed under the supervision of Safety and Compliance Department. In parallel, a program for information exchange and trending of performance indicators was developed by Technical Services Department. The WANO recommendations following August 1997 Peer Review provided the opportunity for a better understanding and reconsideration of the Operating Experience Program. As a result, all the activities related to this topic were assigned to a new structure, within Safety and Compliance Department. As such an Operating Experience Group was created and a new program is now being developed in an integrated and centralized manner. The content of the paper is the following: - Overview; - Operating Experience Program; - Event Analysis (Unplanned Events Assessment System - UEIR Process- and Systematic Analysis of Operational Events - ACR Process); - Information Exchange Program; - Monitoring of Operating Experience - Plant Specific Performance Indicators; - Purpose; - Level 2 Performance Indicators. Four appendices are added containing: - A. Station performance indicators/targets (Level 2); - B. SPI (Station Performance Indicators - Level 2) - Graphics; - C. UEIR, LRS (Safety and Licensing Review Sheet), UEFR (Unplanned Event Follow-up Report), ACR and OPEX forms. (authors)

  10. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    International Nuclear Information System (INIS)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan

    2012-01-01

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED adj ). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED adj between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED adj that differed by up to 44% from effective dose estimates that were not

  11. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2012-11-15

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose

  12. DCD – a novel plant specific domain in proteins involved in development and programmed cell death

    Directory of Open Access Journals (Sweden)

    Doerks Tobias

    2005-07-01

    Full Text Available Abstract Background Recognition of microbial pathogens by plants triggers the hypersensitive reaction, a common form of programmed cell death in plants. These dying cells generate signals that activate the plant immune system and alarm the neighboring cells as well as the whole plant to activate defense responses to limit the spread of the pathogen. The molecular mechanisms behind the hypersensitive reaction are largely unknown except for the recognition process of pathogens. We delineate the NRP-gene in soybean, which is specifically induced during this programmed cell death and contains a novel protein domain, which is commonly found in different plant proteins. Results The sequence analysis of the protein, encoded by the NRP-gene from soybean, led to the identification of a novel domain, which we named DCD, because it is found in plant proteins involved in development and cell death. The domain is shared by several proteins in the Arabidopsis and the rice genomes, which otherwise show a different protein architecture. Biological studies indicate a role of these proteins in phytohormone response, embryo development and programmed cell by pathogens or ozone. Conclusion It is tempting to speculate, that the DCD domain mediates signaling in plant development and programmed cell death and could thus be used to identify interacting proteins to gain further molecular insights into these processes.

  13. An algorithm and program for finding sequence specific oligo-nucleotide probes for species identification

    Directory of Open Access Journals (Sweden)

    Tautz Diethard

    2002-03-01

    Full Text Available Abstract Background The identification of species or species groups with specific oligo-nucleotides as molecular signatures is becoming increasingly popular for bacterial samples. However, it shows also great promise for other small organisms that are taxonomically difficult to tract. Results We have devised here an algorithm that aims to find the optimal probes for any given set of sequences. The program requires only a crude alignment of these sequences as input and is optimized for performance to deal also with very large datasets. The algorithm is designed such that the position of mismatches in the probes influences the selection and makes provision of single nucleotide outloops. Program implementations are available for Linux and Windows.

  14. 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)

  15. 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.

  16. 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

  17. 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

  18. Resident-Specific Morbidity Reduced Following ACS NSQIP Data-Driven Quality Program.

    Science.gov (United States)

    Turrentine, Florence E; Hanks, John B; Tracci, Megan C; Jones, R Scott; Schirmer, Bruce D; Smith, Philip W

    2018-04-16

    The Accreditation Council for Graduate Medical Education Milestone Project for general surgery provided a more robust method for developing and tracking residents' competence. This framework enhanced systematic and progressive development of residents' competencies in surgical quality improvement. A 22-month interactive, educational program based on resident-specific surgical outcomes data culminated in a quality improvement project for postgraduate year 4 surgery residents. Self- assessment, quality knowledge test, and resident-specific American College of Surgeons National Surgical Quality Improvement Program Quality In-Training Initiative morbidity were compared before and after the intervention. Quality in-training initiative morbidity decreased from 25% (82/325) to 18% (93/517), p = 0.015 despite residents performing more complex cases. All participants achieved level 4 competency (4/4) within the general surgery milestones improvement of care, practice-based learning and improvement competency. Institutional American College of Surgeons National Surgical Quality Improvement Program general surgery morbidity improved from the ninth to the sixth decile. Quality assessment and improvement self-assessment postintervention scores (M = 23.80, SD = 4.97) were not significantly higher than preintervention scores (M = 19.20, SD = 5.26), p = 0.061. Quality Improvement Knowledge Application Tool postintervention test scores (M = 17.4, SD = 4.88), were not significantly higher than pretest scores (M = 13.2, SD = 1.92), p = 0.12. Sharing validated resident-specific clinical data with participants was associated with improved surgical outcomes. Participating fourth year surgical residents achieved the highest score, a level 4, in the practice based learning and improvement competency of the improvement of care practice domain and observed significantly reduced surgical morbidity for cases in which they participated. Copyright © 2018. Published by Elsevier Inc.

  19. Seismic Safety Margins Research Program (Phase I). Project VII. Systems analysis specification of computational approach

    International Nuclear Information System (INIS)

    Wall, I.B.; Kaul, M.K.; Post, R.I.; Tagart, S.W. Jr.; Vinson, T.J.

    1979-02-01

    An initial specification is presented of a computation approach for a probabilistic risk assessment model for use in the Seismic Safety Margin Research Program. This model encompasses the whole seismic calculational chain from seismic input through soil-structure interaction, transfer functions to the probability of component failure, integration of these failures into a system model and thereby estimate the probability of a release of radioactive material to the environment. It is intended that the primary use of this model will be in sensitivity studies to assess the potential conservatism of different modeling elements in the chain and to provide guidance on priorities for research in seismic design of nuclear power plants

  20. 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.

  1. Engaging Underrepresented High School Students in Data Driven Storytelling: An Examination of Learning Experiences and Outcomes for a Cohort of Rising Seniors Enrolled in the Gaining Early Awareness and Readiness for Undergraduate Program (GEAR UP)

    Science.gov (United States)

    Dierker, Lisa; Ward, Nadia; Alexander, Jalen; Donate, Emmanuel

    2017-01-01

    Background: Upward trends in data-oriented careers threaten to further increase the underrepresentation of both females and individuals from racial minority groups in programs focused on data analysis and applied statistics. To begin to develop the necessary skills for a data-oriented career, project-based learning seems the most promising given…

  2. Survey gear calibration independent of spatial fish distribution

    DEFF Research Database (Denmark)

    Lewy, Peter; Nielsen, J. Rasmus; Hovgård, Holger

    2004-01-01

    Trawl surveys provide important information for evaluation of relative stock abundance fluctuations over time. Therefore, when survey gears or vessels are changed, it is important to compare the efficiency and selectivity of old and new gears and vessels. A method for estimation of conversion fac...

  3. Contact stress analysis of involute spur gear by Finite Element ...

    African Journals Online (AJOL)

    In this paper the contact stress in rolling-sliding contact of involute spur gear and the effect of coefficient of friction was analyzed. To achieve this, first, three dimensional involute spur gear pairs were developed in Solid works 2012 Premium and the 3D model was exported to ANSYS workbench 14.5. Next, the analysis was ...

  4. Adaptive landing gear concept—feedback control validation

    Science.gov (United States)

    Mikulowski, Grzegorz M.; Holnicki-Szulc, Jan

    2007-12-01

    The objective of this paper is to present an integrated feedback control concept for adaptive landing gears (ALG) and its experimental validation. Aeroplanes are subjected to high dynamic loads as a result of the impact during each landing. Classical landing gears, which are in common use, are designed in accordance with official regulations in a way that ensures the optimal energy dissipation for the critical (maximum) sink speed. The regulations were formulated in order to ensure the functional capability of the landing gears during an emergency landing. However, the landing gears, whose characteristics are optimized for these critical conditions, do not perform well under normal impact conditions. For that situation it is reasonable to introduce a system that would adapt the characteristics of the landing gears according to the sink speed of landing. The considered system assumes adaptation of the damping force generated by the landing gear, which would perform optimally in an emergency situation and would adapt itself for regular landings as well. This research covers the formulation and design of the control algorithms for an adaptive landing gear based on MR fluid, implementation of the algorithms on an FPGA platform and experimental verification on a lab-scale landing gear device. The main challenge of the research was to develop a control methodology that could operate effectively within 50 ms, which is assumed to be the total duration of the phenomenon. The control algorithm proposed in this research was able to control the energy dissipation process on the experimental stand.

  5. Nonlinear Vibroimpact Characteristics of a Planetary Gear Transmission System

    Directory of Open Access Journals (Sweden)

    Jianxing Zhou

    2016-01-01

    Full Text Available In order to research the vibroimpact characteristics of a planetary gear transmission system under high speed and lightly loaded conditions, a new modeling method is proposed. In the modeling process, linear spring was used to simulate gear mesh elasticity under heavy load cases, and Hertz contact theory was used to calculate the contact force of gear pair under light load cases. Then, effects of the working conditions on the system vibroimpact characteristics are analyzed. The results show that, with input speed growing, the mesh force produced obvious fluctuations on the resonance frequencies of the sun gear and carrier torsion vibration, ring gear’s transverse vibration under the heavy load. Under light load condition, the collision vibration occurs in the gear pair; the changing trend of the contact force shows strongly nonlinear characteristics. The time of mesh-apart in gears pair decreases gradually as the load is increased; until it reaches collision vibration threshold value, the gear pair is no longer mesh-apart. With increasing of the input speed, the time of mesh-apart is decreased gradually; the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline for planetary gear transmission low-noise design.

  6. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent...

  7. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    Science.gov (United States)

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

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  8. Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs.

    Science.gov (United States)

    Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

    2016-03-21

    In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Surface micromachined counter-meshing gears discrimination device

    Science.gov (United States)

    Polosky, Marc A.; Garcia, Ernest J.; Allen, James J.

    2000-12-12

    A surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock. Each of two CMG has a first portion of its perimeter devoted to continuous driving teeth that mesh with respective pinion gears. Each EMG also has a second portion of its perimeter devoted to regularly spaced discrimination gear teeth that extend outwardly on at least one of three levels of the CMG. The discrimination gear teeth are designed so as to pass each other without interference only if the correct sequence of partial rotations of the CMG occurs in response to a coded series of rotations from the pinion gears. A 24 bit code is normally 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.

  10. Study of a spur gear dynamic behavior in transient regime

    Science.gov (United States)

    Khabou, M. T.; Bouchaala, N.; Chaari, F.; Fakhfakh, T.; Haddar, M.

    2011-11-01

    In this paper the dynamic behavior of a single stage spur gear reducer in transient regime is studied. Dynamic response of the single stage spur gear reducer is investigated at different rotating velocities. First, gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. Then, the dynamic response is computed using the Newmark method. After that, a parameter study is made on spur gear powered in the first place by an electric motor and in the second place by four strokes four cylinders diesel engine. Dynamic responses come to confirm a significant influence of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition.

  11. GEAR: A database of Genomic Elements Associated with drug Resistance

    Science.gov (United States)

    Wang, Yin-Ying; Chen, Wei-Hua; Xiao, Pei-Pei; Xie, Wen-Bin; Luo, Qibin; Bork, Peer; Zhao, Xing-Ming

    2017-01-01

    Drug resistance is becoming a serious problem that leads to the failure of standard treatments, which is generally developed because of genetic mutations of certain molecules. Here, we present GEAR (A database of Genomic Elements Associated with drug Resistance) that aims to provide comprehensive information about genomic elements (including genes, single-nucleotide polymorphisms and microRNAs) that are responsible for drug resistance. Right now, GEAR contains 1631 associations between 201 human drugs and 758 genes, 106 associations between 29 human drugs and 66 miRNAs, and 44 associations between 17 human drugs and 22 SNPs. These relationships are firstly extracted from primary literature with text mining and then manually curated. The drug resistome deposited in GEAR provides insights into the genetic factors underlying drug resistance. In addition, new indications and potential drug combinations can be identified based on the resistome. The GEAR database can be freely accessed through http://gear.comp-sysbio.org. PMID:28294141

  12. Young Finnish Unemployed Men's Experiences of Having Participated in a Specific Active Labor Market Program.

    Science.gov (United States)

    Björklund, Ove; Häggström, Elisabeth; Nyström, Lisbet

    2017-09-01

    The purpose of the present study was to describe young Finnish unemployed men's experiences of having participated in a specific active labor market program, intended to fight unemployment and offered at a resource center. Fifteen young unemployed Finnish men in the age range 18 to 27 years were interviewed face-to-face. Purposive sampling was used to increase the variation among informants. The interview texts were analyzed using both manifest and latent qualitative content analysis. The present results reported that the young men felt that they, thanks to the program at the resource center, had acquired daily routines and could ultimately believe in the future. The young men described how they now had a structure, economic support, and that they could return to their daily life. The informants also described how they could see new possibilities and believe in oneself. There is a lack of empirical studies assessing the possible impact of active labor market programs on the unemployed based on participants' own experiences. Further research is needed to describe and elucidate in more detail the effects of targeted support measures and the needs of unemployed men of different ages and living in different contexts.

  13. Comparative transcriptional profiling of the axolotl limb identifies a tripartite regeneration-specific gene program.

    Directory of Open Access Journals (Sweden)

    Dunja Knapp

    Full Text Available Understanding how the limb blastema is established after the initial wound healing response is an important aspect of regeneration research. Here we performed parallel expression profile time courses of healing lateral wounds versus amputated limbs in axolotl. This comparison between wound healing and regeneration allowed us to identify amputation-specific genes. By clustering the expression profiles of these samples, we could detect three distinguishable phases of gene expression - early wound healing followed by a transition-phase leading to establishment of the limb development program, which correspond to the three phases of limb regeneration that had been defined by morphological criteria. By focusing on the transition-phase, we identified 93 strictly amputation-associated genes many of which are implicated in oxidative-stress response, chromatin modification, epithelial development or limb development. We further classified the genes based on whether they were or were not significantly expressed in the developing limb bud. The specific localization of 53 selected candidates within the blastema was investigated by in situ hybridization. In summary, we identified a set of genes that are expressed specifically during regeneration and are therefore, likely candidates for the regulation of blastema formation.

  14. Dendritic cell maturation: functional specialization through signaling specificity and transcriptional programming.

    Science.gov (United States)

    Dalod, Marc; Chelbi, Rabie; Malissen, Bernard; Lawrence, Toby

    2014-05-16

    Dendritic cells (DC) are key regulators of both protective immune responses and tolerance to self-antigens. Soon after their discovery in lymphoid tissues by Steinman and Cohn, as cells with the unique ability to prime naïve antigen-specific T cells, it was realized that DC can exist in at least two distinctive states characterized by morphological, phenotypic and functional changes-this led to the description of DC maturation. It is now well appreciated that there are several subsets of DC in both lymphoid and non-lymphoid tissues of mammals, and these cells show remarkable functional specialization and specificity in their roles in tolerance and immunity. This review will focus on the specific characteristics of DC subsets and how their functional specialization may be regulated by distinctive gene expression programs and signaling responses in both steady-state and in the context of inflammation. In particular, we will highlight the common and distinctive genes and signaling pathways that are associated with the functional maturation of DC subsets. © 2014 The Authors.

  15. Gillnet Tag Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Certain fishery management programs require vessels to obtain gillnet tags to be used with their gillnet gear. Gillnet tag data is a collection of requests and...

  16. Analysis of Pitch Gear Deterioration using Indicators

    DEFF Research Database (Denmark)

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2011-01-01

    This work concerns a case study in the context of risk-based operation and maintenance of offshore wind turbines. For wind turbines with electrical pitch systems, deterioration can generally be observed at the pitch gear teeth; especially at the point where the blades are located during normal...... of the damage, and can be used for Bayesian updating of a damage model used for risk-based decision making. For this decision problem, the risk of failure should be compared to the cost of preventive maintenance. The hypothesis that the maximum pitch motor torque is an indicator of the damage size is supported...... changes in the temperature are the primary cause of the decrease. A model is established to remove the effect of the explained variation, and it is investigated if deterioration can be detected as changes in the peak torque. A small increase could be detected after the maintenance, but before...

  17. Investigating Vibration Properties of a Planetary Gear Set with a Cracked Tooth in a Planet Gear

    Science.gov (United States)

    2014-12-23

    sidebands appear at mfm±nfplanet± kfc or mfm±nfplanet±kfp, where m, n and k are all integers; fp represents rotation frequency of the planet gear and...region from 43 fm to 45 fm. Sidebands are not symmetric and sizable sidebands located at mfm±nfplanet± kfc or mfm±nfplanet±kfp, where m, n and k are

  18. 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.

  19. Utilization of radiation protection gear for absorbed dose reduction: an integrative literature review

    International Nuclear Information System (INIS)

    Soares, Flavio Augusto Penna; Flor, Rita de Cassia; Pereira, Aline Garcia

    2011-01-01

    Objective: The present study was aimed at evaluating the relation between the use of radiation protection gear and the decrease in absorbed dose of ionizing radiation, thereby reinforcing the efficacy of its use by both the patients and occupationally exposed personnel. Materials and Methods: The integrative literature review method was utilized to analyze 21 articles, 2 books, 1 thesis, 1 monograph, 1 computer program, 4 pieces of database research (Instituto Brasileiro de Geografia e Estatistica and Departamento de Informatica do Sistema Unico de Saude) and 2 sets of radiological protection guidelines. Results: Theoretically, a reduction of 86% to 99% in the absorbed dose is observed with the use of radiation protection gear. In practice, however, the reduction may achieve 88% in patients submitted to conventional radiology, and 95% in patients submitted to computed tomography. In occupationally exposed individuals, the reduction is around 90% during cardiac catheterization, and 75% during orthopedic surgery. Conclusion: According to findings of several previous pieces of research, the use of radiation protection gear is a low-cost and effective way to reduce absorbed dose both for patients and occupationally exposed individuals. Thus, its use is necessary for the implementation of effective radioprotection programs in radiodiagnosis centers. (author)

  20. Vibro-Impact Energy Analysis of a Geared System with Piecewise-Type Nonlinearities Using Various Parameter Values

    Directory of Open Access Journals (Sweden)

    Jong-Yun Yoon

    2015-08-01

    Full Text Available Torsional systems with gear pairs such as the gearbox of wind turbines or vehicle driveline systems inherently show impact phenomena due to clearance-type nonlinearities when the system experiences sinusoidal excitation. This research investigates the vibro-impact energy of unloaded gears in geared systems using the harmonic balance method (HBM in both the frequency and time domains. To achieve accurate simulations, nonlinear models with piecewise and clearance-type nonlinearities and drag torques are defined and implemented in the HBM. Next, the nonlinear frequency responses are examined by focusing on the resonance areas where the impact phenomena occur, along with variations in key parameters such as clutch stiffness, drag torque, and inertias of the flywheel and the unloaded gear. Finally, the effects of the parameters on the vibro-impacts at a specific excitation frequency are explained using bifurcation diagrams. The results are correlated with prior research by defining the gear rattle criteria with key parameters. This article suggests a method to simulate the impact phenomena in torsional systems using the HBM and successfully assesses vibro-impact energy using bifurcation diagrams.

  1. Discovering rules for protein-ligand specificity using support vector inductive logic programming.

    Science.gov (United States)

    Kelley, Lawrence A; Shrimpton, Paul J; Muggleton, Stephen H; Sternberg, Michael J E

    2009-09-01

    Structural genomics initiatives are rapidly generating vast numbers of protein structures. Comparative modelling is also capable of producing accurate structural models for many protein sequences. However, for many of the known structures, functions are not yet determined, and in many modelling tasks, an accurate structural model does not necessarily tell us about function. Thus, there is a pressing need for high-throughput methods for determining function from structure. The spatial arrangement of key amino acids in a folded protein, on the surface or buried in clefts, is often the determinants of its biological function. A central aim of molecular biology is to understand the relationship between such substructures or surfaces and biological function, leading both to function prediction and to function design. We present a new general method for discovering the features of binding pockets that confer specificity for particular ligands. Using a recently developed machine-learning technique which couples the rule-discovery approach of inductive logic programming with the statistical learning power of support vector machines, we are able to discriminate, with high precision (90%) and recall (86%) between pockets that bind FAD and those that bind NAD on a large benchmark set given only the geometry and composition of the backbone of the binding pocket without the use of docking. In addition, we learn rules governing this specificity which can feed into protein functional design protocols. An analysis of the rules found suggests that key features of the binding pocket may be tied to conformational freedom in the ligand. The representation is sufficiently general to be applicable to any discriminatory binding problem. All programs and data sets are freely available to non-commercial users at http://www.sbg.bio.ic.ac.uk/svilp_ligand/.

  2. Two dimensional model of a permanent magnet spur gear

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand

    2005-01-01

    This paper presents calculation and measurement results of a high-performance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N/spl middot/m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...... of the loss components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81%. A large magnetic loss component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses...

  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. Ski and snowboard school programs: Injury surveillance and risk factors for grade-specific injury.

    Science.gov (United States)

    Sran, R; Djerboua, M; Romanow, N; Mitra, T; Russell, K; White, K; Goulet, C; Emery, C; Hagel, B

    2018-05-01

    The objective of our study was to evaluate incidence rates and profile of school program ski and snowboard-related injuries by school grade group using a historical cohort design. Injuries were identified via Accident Report Forms completed by ski patrollers. Severe injury was defined as those with ambulance evacuation or recommending patient transport to hospital. Poisson regression analysis was used to examine the school grade group-specific injury rates adjusting for risk factors (sex, activity, ability, and socioeconomic status) and accounting for the effect of clustering by school. Forty of 107 (37%) injuries reported were severe. Adolescents (grades 7-12) had higher crude injury rates (91 of 10 000 student-days) than children (grades 1-3: 25 of 10 000 student-days; grades 4-6: 65 of 10 000 student-days). Those in grades 1-3 had no severe injuries. Although the rate of injury was lower in grades 1-3, there were no statistically significant grade group differences in adjusted analyses. Snowboarders had a higher rate of injury compared with skiers, while higher ability level was protective. Participants in grades 1-3 had the lowest crude and adjusted injury rates. Students in grades 7-12 had the highest rate of overall and severe injuries. These results will inform evidence-based guidelines for school ski/snowboard program participation by school-aged children. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Culture-specific programs for children and adults from minority groups who have asthma.

    Science.gov (United States)

    McCallum, Gabrielle B; Morris, Peter S; Brown, Ngiare; Chang, Anne B

    2017-08-22

    studies ranged from very low to low. For our primary outcome (asthma exacerbations during follow-up), the quality of evidence was low for all outcomes. In adults, use of a culture-specific programme, compared to generic programmes or usual care did not significantly reduce the number of participants from two studies with 294 participants for: exacerbations with one or more exacerbations during follow-up (odds ratio (OR) 0.80, 95% confidence interval (CI) 0.50 to 1.26), hospitalisations over 12 months (OR 0.83, 95% CI 0.31 to 2.22) and exacerbations requiring oral corticosteroids (OR 0.97, 95% CI 0.55 to 1.73). However, use of a culture-specific programme, improved asthma quality of life scores in 280 adults from two studies (mean difference (MD) 0.26, 95% CI 0.17 to 0.36) (although the MD was less then the minimal important difference for the score). In children, use of a culture-specific programme was superior to generic programmes or usual care in reducing severe asthma exacerbations requiring hospitalisation in two studies with 305 children (rate ratio 0.48, 95% CI 0.24 to 0.95), asthma control in one study with 62 children and QoL in three studies with 213 children, but not for the number of exacerbations during follow-up (OR 1.55, 95% CI 0.66 to 3.66) or the number of exacerbations (MD 0.18, 95% CI -0.25 to 0.62) among 100 children from two studies. The available evidence showed that culture-specific education programmes for adults and children from minority groups are likely effective in improving asthma-related outcomes. This review was limited by few studies and evidence of very low to low quality. Not all asthma-related outcomes improved with culture-specific programs for both adults and children. Nevertheless, while modified culture-specific education programs are usually more time intensive, the findings of this review suggest using culture-specific asthma education programmes for children and adults from minority groups. However, more robust RCTs are needed to

  6. Optimized use of cooling holes to decrease the amount of thermal damage on a plastic gear tooth

    Directory of Open Access Journals (Sweden)

    Demagna Koffi

    2016-05-01

    Full Text Available The full potential of plastic gear usage is limited by not only poor mechanical properties but also equally poor temperature limits and poor heat conduction properties. Cooling holes were developed to decrease the amount of thermal damage on the contact surface. These cooling holes promote increased stress and tooth deflection, thus exerting a negative effect. This article compares various cooling holes for plastic gear configurations and proposes novel cooling holes. Thermal and mechanical simulations that consider specific aspects of plastic gear meshing were performed. The main objective of this article was to verify the best methods for reducing thermal damage through cooling holes. The results indicate the best compromise between the temperature reduction and the mechanical properties of the new tooth geometry. The results also indicate that the simple variations in the cooling holes proposed can improve tooth performance.

  7. 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.

  8. Meta-analysis of graduated driver licensing laws: effectiveness of specific program components : traffic tech.

    Science.gov (United States)

    2015-11-01

    Graduated driver licensing (GDL) programs in the United States do not represent a single homogeneous intervention; rather, they contain different combinations and variations of program components. Programs vary by the duration of each stage of the GD...

  9. Promotion Strategy Specific to Organizations Participating in “Back to School” Program

    Directory of Open Access Journals (Sweden)

    Irina SUSANU

    2009-01-01

    Full Text Available Romania’s stationery market records a growth rhythm of about 10-15percent per year. For the beginning of school year 2007-2008, organizations ofthe type forecast a growth of 25%. During the top period, stationery sales growgenerally with about 800-1000 % in comparison with a habitual period of theyear. For distributors, the season of school stationery lasts from July toSeptember, a period where it is accomplished 20-25% of the entire yearturnover. All these events unfold rapidly in a relatively short period of time, 2-3months for distributors and a month for retailers, producing a real storm in theframe of their management. In order to deal with “shopping fury” specific to thetime before the school beginning, organizations of the field are in the positionof applying a series of communication strategies. The purpose of this work is tohighlight a practical example of communication plan specific to organizationsinvolved in “back to school” program.

  10. Technology Innovation of Power Transmission Gearing in Aviation

    Science.gov (United States)

    Handschuh, Robert F.

    2009-01-01

    An overview of rotary wing evolution and innovations over the last 20 years was presented. This overview is provided from a drive system perspective. Examples of technology innovations that have changed and advanced drive systems of rotary wing vehicles will be provided. These innovations include full 6-axis CNC gear manufacture, face gear development to aerospace standards, health and usage monitoring, and gear geometry and bearing improvements. Also, an overview of current state-of-the-art activities being conducted at NASA Glenn is presented with a short look to fixed and rotary wing aircraft and systems needed for the future.

  11. Multi-stage internal gear/turbine fuel pump

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Eugen; Raney, Michael Raymond

    2004-07-06

    A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.

  12. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  13. A MATHEMATICAL MODEL OF CHP 2000 TYPE PROGRESSIVE GEAR

    Directory of Open Access Journals (Sweden)

    Paweł Lonkwic

    2016-12-01

    Full Text Available The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with the loading capacity from 8500 up to 20000 N.

  14. 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.

  15. Natural Characteristics of The Herringbone Gear Transmission System

    Science.gov (United States)

    Zhou, Jianxing; Sun, Wenlei; Cao, Li

    2018-03-01

    According to the structure characteristics of herringbone gear transmission, a more realistic dynamic model of the transmission system is built in consideration of the inner excitation, herringbone gears axial positioning and sliding bearing etc. The natural frequencies of the system are calculated, and the vibration mode is divided into symmetric vibration modes and asymmetric vibration modes. The time history of system dynamic force is obtained by solving the dynamic model. The effects of the connection stiffness of left and right sides of herringbone gears and axial support stiffness on natural characteristics are discussed.

  16. Assessing gear modifications needed to optimize yields in a heavily exploited, multi-species, seagrass and coral reef fishery.

    Science.gov (United States)

    Hicks, Christina C; McClanahan, Timothy R

    2012-01-01

    Effective management is necessary if small-scale fisheries, such as those found in mixed habitats including seagrass and coral reefs, are to continue providing food for many of the poorest communities of the world. Gear-based management, although under represented and under studied, has the potential to be adaptive, address multiple objectives, and be crafted to the socio-economic setting. Management effectiveness in seagrass and coral reef fisheries has generally been evaluated at the scale of the fish community. However, community level indicators can mask species-specific declines that provide significant portions of the fisheries yields and income. Using a unique dataset, containing ten years of species level length frequency catch data from a multi-gear, multi-species seagrass and coral reef fishery in Kenya, we evaluate species specific fishery statuses, compare gear use to gear regulations and estimate the potential needs for further gear restrictions. Despite the high diversity of the fishery, fifteen species represented over 90% of the catch, and only three species represented 60% of the catch. The three most abundant species in the catch, Lethrinus lentjan (Lacepède), Siganus sutor (Valenciennes) and Leptoscarus vaigiensis (Quoy & Gaimard) all showed evidence of growth overfishing. Lethrinus lentjan, with an exploitation rate of 0.82, also shows evidence of recruitment overfishing. Current legal but weakly enforced gear restrictions are capable of protecting a significant portion of the catch up to maturity but optimization of yield will require that the current mesh size be increased from 6.3 to 8.8 and 9.2 cm to increase yields of L. lentjan and S. sutor, respectively. Given the difficulties of enforcing mesh size, we recommend that the economic benefits of these larger mesh sizes be communicated and enforced through co-management. This abstract is also available in Kiswahili (Abstract S1).

  17. Assessing gear modifications needed to optimize yields in a heavily exploited, multi-species, seagrass and coral reef fishery.

    Directory of Open Access Journals (Sweden)

    Christina C Hicks

    Full Text Available Effective management is necessary if small-scale fisheries, such as those found in mixed habitats including seagrass and coral reefs, are to continue providing food for many of the poorest communities of the world. Gear-based management, although under represented and under studied, has the potential to be adaptive, address multiple objectives, and be crafted to the socio-economic setting. Management effectiveness in seagrass and coral reef fisheries has generally been evaluated at the scale of the fish community. However, community level indicators can mask species-specific declines that provide significant portions of the fisheries yields and income. Using a unique dataset, containing ten years of species level length frequency catch data from a multi-gear, multi-species seagrass and coral reef fishery in Kenya, we evaluate species specific fishery statuses, compare gear use to gear regulations and estimate the potential needs for further gear restrictions. Despite the high diversity of the fishery, fifteen species represented over 90% of the catch, and only three species represented 60% of the catch. The three most abundant species in the catch, Lethrinus lentjan (Lacepède, Siganus sutor (Valenciennes and Leptoscarus vaigiensis (Quoy & Gaimard all showed evidence of growth overfishing. Lethrinus lentjan, with an exploitation rate of 0.82, also shows evidence of recruitment overfishing. Current legal but weakly enforced gear restrictions are capable of protecting a significant portion of the catch up to maturity but optimization of yield will require that the current mesh size be increased from 6.3 to 8.8 and 9.2 cm to increase yields of L. lentjan and S. sutor, respectively. Given the difficulties of enforcing mesh size, we recommend that the economic benefits of these larger mesh sizes be communicated and enforced through co-management. This abstract is also available in Kiswahili (Abstract S1.

  18. Rigid MATLAB drivetrain model of a 500 kW wind turbine for predicting maximum gear tooth stresses in a planetary gearbox using multibody gear constraints

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

    2014-01-01

    multiple planetary gears are not taken into account. Finite Element Method (FEM) calculations show that when the wind turbine runs close to the maximum wind speed, the maximum gear tooth stress is in the range of 500–700 MPa, which is considered to be realistic using a “worst-case” method. The presented...... for not only transferring torque but also for calculating the gear tooth and internal body reaction forces. The method is appropriate for predicting gear tooth stresses without considering all the complexity of gear tooth geometries. This means that, e.g. gear tooth load-sharing and load-distribution among...

  19. Dynamic Response of a Planetary Gear System Using a Finite Element/Contact Mechanics Model

    Science.gov (United States)

    Parker, Robert G.; Agashe, Vinayak; Vijayakar, Sandeep M.

    2000-01-01

    The dynamic response of a helicopter planetary gear system is examined over a wide range of operating speeds and torques. The analysis tool is a unique, semianalytical finite element formulation that admits precise representation of the tooth geometry and contact forces that are crucial in gear dynamics. Importantly, no a priori specification of static transmission error excitation or mesh frequency variation is required; the dynamic contact forces are evaluated internally at each time step. The calculated response shows classical resonances when a harmonic of mesh frequency coincides with a natural frequency. However, peculiar behavior occurs where resonances expected to be excited at a given speed are absent. This absence of particular modes is explained by analytical relationships that depend on the planetary configuration and mesh frequency harmonic. The torque sensitivity of the dynamic response is examined and compared to static analyses. Rotation mode response is shown to be more sensitive to input torque than translational mode response.

  20. 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...

  1. 50 CFR 660.319 - Open access fishery gear identification and marking.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Open access fishery gear identification... COAST STATES West Coast Groundfish-Open Access Fisheries § 660.319 Open access fishery gear identification and marking. (a) Gear identification. (1) Open access fixed gear (longline, trap or pot, set net...

  2. 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...

  3. 46 CFR 97.37-33 - 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. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall be...

  4. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout their...

  5. 50 CFR Table 19 to Part 679 - Seabird Avoidance Gear Codes

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Codes 19 Table 19... ALASKA Pt. 679, Table 19 Table 19 to Part 679—Seabird Avoidance Gear Codes VESSEL LOGBOOK CODE SEABIRD AVOIDANCE GEAR OR METHOD. 1 Paired Streamer Lines: Used during deployment of hook-and-line gear to prevent...

  6. Motor-park people shift gear.

    Science.gov (United States)

    Nnoli, C

    1992-01-01

    White, U.S. homosexual males were primarily affected in the early stages of the AIDS pandemic. Some Western researchers argued, however, that the syndrome originated in Africa. Strong political and social response to this notion resulted in only an anemic response to the growing AIDS epidemic in Nigeria. Nonetheless, the Stop AIDS Organization finally launched the Motor Park AIDS Education Program (MPAEP) in 1988, for health and education outreach to populations at risk of STDs and HIV infection. Specifically targeted are long-distance truck drivers, their young male assistants known as motor boys, and the barmaids, prostitutes, and homeless juveniles who frequent motor parks where these drivers rest while on the road. Many of these long-haul drivers have unprotected casual and commercial sex, both homosexual and heterosexual, take drugs, and suffer high rates of STDs. Marginalized, 75% illiterate, and speaking a variety of languages, these populations tend to be largely ignorant of the incurable nature of AIDS. Over 45% of motor park populations are estimated to be infected with an STD, or to have a future re-infection. These drivers are optimal vectors for the spread of HIV both internationally and within Nigeria. MPAEP workers work 6 days/week in the larger interstate motor parks to reach out to their predominantly male customers. They meet a host of primary health needs, and refer STD clients for testing and treatment. Drug use and homosexuality are 2 topics of discussion especially taboo in African society which have nonetheless been vigorously researched by MPAEP. Many drivers are unacknowledged bisexuals who have sex with their motor boys. Workers therefore explain the need to use condoms in same-sex activity without specifically mentioning homosexuality. Many Nigerians deny the existence of HIV and AIDS, are reluctant to speak about sex, and consider MPAEP workers to be intruders. Despite opposition in Muslim- dominated Northern Nigeria, however, program

  7. The Specification of Science Education Programs in the Local Public Library: Focusing on the Programs In G-city

    Directory of Open Access Journals (Sweden)

    In-Ja Ahn*

    2012-06-01

    Full Text Available The city of 'G' has been made a number of achievements with its science program as a part of public library's cultural program during the last 5 years. Recently, the national science centre has been established in the same city, the debate is now needed whether the science program in the public library have reasons to be maintained or to be reduced. The aim of this research is on the operating strategies of the science program in the public library. The research methods include case studies of operational strategies in domestic and foreign science centre, the level of satisfaction of local citizen on the science program, the vision of science program in the advancement of public library in the century. In results, the research proposes that the science program in public library should be maintained, but with locally characterised programs. In addition, the study also advised on the provision of scientific information, the strengthened search functions, and the development of user-centred services for those in science fields.

  8. Computer program design specifications for the Balloon-borne Ultraviolet Stellar Spectrometer (BUSS) science data decommutation program (BAPS48)

    Science.gov (United States)

    Rodriguez, R. M.

    1975-01-01

    The Balloon-Borne Ultraviolet Stellar Spectrometer (BUSS) Science Data Docummutation Program (BAPS48) is a pulse code modulation docummutation program that will format the BUSS science data contained on a one inch PCM tracking tape into a seven track serial bit stream formatted digital tape.

  9. Stress analyses of pump gears produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Cetinel, Hakan [Celal Bayar Univ., Mechanical Engineering Dept. (Turkey); Yilmaz, Burak

    2013-06-01

    In this study, trochoidal type (gerotor) hydraulic pump gears were produced by powder metallurgy (P/M) technique. Several gears with different mechanical properties have been obtained by changing process variables. The tooth contact stresses were calculated analytically under particular operation conditions of the hydraulic pump. The 3D models have been obtained from real gears by using Capability Maturity Model (CMM, 3D scanning) operation and SOLIDWORKS software. Stress analyses were conducted on these 3D models by using ANSYS WORKBENCH software. It was found that the density increases by the increase of sintering duration and mechanical properties were positively affected by the increase of density. Maximum deformation takes place in the region of the outer gear where failure generally occurs with the minimum cross-section area.

  10. 29 CFR 1915.116 - Use of gear.

    Science.gov (United States)

    2010-07-01

    ... manually or by a crane, winch, hoist, or derrick, shall be completely opened. The beam or pontoon left in... employees are in the square of the hatch below. (p) Before loads or empty lifting gear are raised, lowered...

  11. Coefficient of friction of a starved lubricated spur gear pair

    International Nuclear Information System (INIS)

    Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng

    2016-01-01

    The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.

  12. Teaching Planetary Gear Trains with the Aid of Nomographs

    Directory of Open Access Journals (Sweden)

    Essam Lauibi Esmail

    2013-01-01

    Full Text Available Planetary gear trains (PGTs are introduced to undergraduate mechanical engineering students in the course of Theory of Machines. The complexity of the traditional methods for analyzing PGTs has kept many from becoming familiar with the capability of PGTs in mechanisms and machine design. In this paper a unified general formulation for simultaneously visualizing velocities, torques, and power flow through a train is presented on a single nomograph. Therefore, the increasing complex mechanical systems, such as automotive transmissions, are much easier to understand. Nomographs of Fundamental Gear Entities (FGEs are constructed based on the nomographs of their fundamental circuits, without specifying the exact gear dimensions. They are then unified in one system nomograph. Nomographs are promising to provide designers with an efficient tool for the design of geared mechanisms.

  13. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Soňa Benešová

    2013-09-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  14. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Sona Benesova

    2013-05-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  15. Characteristics study of the gears by the CAD/CAE

    Science.gov (United States)

    Wang, P. Y.; Chang, S. L.; Lee, B. Y.; Nguyen, D. H.; Cao, C. W.

    2017-09-01

    Gears are the most important transmission component in machines. The rapid development of the machines in industry requires a shorter time of the analysis process. In traditional, the gears are analyzed by setting up the complete mathematical model firstly, considering the profile of cutter and coordinate systems relationship between the machine and the cutter. It is a really complex and time-consuming process. Recently, the CAD/CAE software is well developed and useful in the mechanical design. In this paper, the Autodesk Inventor® software is introduced to model the spherical gears firstly, and then the models can also be transferred into ANSYS Workbench for the finite element analysis. The proposed process in this paper is helpful to the engineers to speed up the analyzing process of gears in the design stage.

  16. Experimental Research on Vibrations of Double Harmonic Gear Transmission

    Directory of Open Access Journals (Sweden)

    Sava Ianici

    2017-11-01

    Full Text Available Gears transmission can be important sources of vibration in the mechanical system structures and can have a significant share in the overall vibration level. The current trend of significant increase in powers and speeds transmitted by modern mechanical systems, along with the size reduction, may cause a worsening of the behaviour of transmissions with gears in terms of vibration, especially when the optimization criteria were not respected in the design, execution and installation phase. This paper presents a study of vibrations that occur in a double harmonic gear transmission (DHGT, based on experimental research. The experimental researches revealed that in a double harmonic gear transmission the vibrations are initiated and develop in the multipara harmonics engagement of the teeth and in the kinematic couplings materialized between the wave generator and the flexible toothed wheel. These vibrations are later transmitted by means of the shafts and bearings to the transmission housing, respectively, through the walls of it, propagating in the air.

  17. Program specific admission testing and dropout for sports science students: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Lotte Dyhrberg O'Neill

    2014-09-01

    Full Text Available Recent research in medical education suggests that program specific admission testing could have a protective effect against early dropout. Little is known about the effect of program specific admission testing on dropout in other areas of higher education. The aim of this paper was to examine if admission strategy was also independently associated with dropout for sports science students in a university setting. The study design was a prospective cohort study with a 2 year follow-up. The population was 449 sports science students admitted to a university in the years 2002-2007. The analysis used was multivariate logistic regression and the predictors examined were: admission group (grade-based or admission tested as well as educational and socio-demographic variables. The outcome was dropout within 2 years of study start. Admission testing offered superior protection against dropout compared to grade-based admission. This result may fit with elements of previous dropout theory, student-environment fit theory and perhaps also with self-efficacy theory. Nyere forskning inden for medicinsk uddannelse indikerer at uddannelsesspecifikke optagelsesprøver kan have en beskyttende effekt i forhold til tidligt studiefrafald, men for andre universitetsuddannelser end Medicin synes denne sammenhæng endnu ikke at være blevet grundigt belyst. Formålet med dette studie var derfor at undersøge, om optagelsesprøver også beskyttede mod tidligt frafald blandt idrætsstuderende på universitetet. Studiedesignet var et prospektivt kohortestudie med to års opfølgning. Populationen var 449 idrætsstuderende, som blev optaget på Syddansk Universitet i årene 2002-2007. Data blev analyseret med multivariat logistisk regression, og følgende typer af prædiktorer for frafald blev undersøgt: Optagelseskvote (kvote 1 eller kvote 2 udprøvede, andre uddannelsesrelaterede variable samt udvalgte socio-demografiske variable. Effektmålet var studiestatus (frafaldet

  18. Program specific admission testing and dropout for sports science students: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Lotte Dyhrberg O'Neill

    2014-09-01

    Full Text Available Recent research in medical education suggests that program specific admission testing could have a protective effect against early dropout. Little is known about the effect of program specific admission testing on dropout in other areas of higher education. The aim of this paper was to examine if admission strategy was also independently associated with dropout for sports science students in a university setting. The study design was a prospective cohort study with a 2 year follow-up. The population was 449 sports science students admitted to a university in the years 2002-2007. The analysis used was multivariate logistic regression and the predictors examined were: admission group (grade-based or admission tested as well as educational and socio-demographic variables. The outcome was dropout within 2 years of study start. Admission testing offered superior protection against dropout compared to grade-based admission. This result may fit with elements of previous dropout theory, student-environment fit theory and perhaps also with self-efficacy theory. Nyere forskning inden for medicinsk uddannelse indikerer at uddannelsesspecifikke optagelsesprøver kan have en beskyttende effekt i forhold til tidligt studiefrafald, men for andre universitetsuddannelser end Medicin synes denne sammenhæng endnu ikke at være blevet grundigt belyst. Formålet med dette studie var derfor at undersøge, om optagelsesprøver også beskyttede mod tidligt frafald blandt idrætsstuderende på universitetet. Studiedesignet var et prospektivt kohortestudie med to års opfølgning. Populationen var 449 idrætsstuderende, som blev optaget på Syddansk Universitet i årene 2002-2007. Data blev analyseret med multivariat logistisk regression, og følgende typer af prædiktorer for frafald blev undersøgt: Optagelseskvote (kvote 1 eller kvote 2 udprøvede, andre uddannelsesrelaterede variable samt udvalgte socio-demografiske variable. Effektmålet var studiestatus (frafaldet

  19. Language-specific strategy for programming hearing aids - A double-blind randomized controlled crossover study.

    Science.gov (United States)

    Matsumoto, Nozomu; Suzuki, Nobuyoshi; Iwasaki, Satoshi; Ishikawa, Kazuha; Tsukiji, Hiroki; Higashino, Yoshie; Tabuki, Tomoko; Nakagawa, Takashi

    2018-08-01

    Voice-aligned compression (VAC) is a method used in Oticon's hearing aids to provide more comfortable hearing without sacrificing speech discrimination. The complex, non-linear compression curve for the VAC strategy is designed based on the frequency profile of certain spoken Western languages. We hypothesized that hearing aids could be further customized for Japanese-speaking users by modifying the compression curve using the frequency profile of spoken Japanese. A double-blind randomized controlled crossover study was performed to determine whether or not Oticon's modified amplification strategy (VAC-J) provides subjectively preferable hearing aids for Japanese-speaking hearing aid users compared to the same company's original amplification strategy (VAC). The participants were randomized to two groups. The VAC-first group received a pair of hearing aids programmed using the VAC strategy and wore them for three weeks, and then received a pair of hearing aids programmed using VAC-J strategy and wore them for three weeks. The VAC-J-first group underwent the same study, but they received hearing aids in the reverse sequence. A Speech, Spatial and Qualities (SSQ) questionnaire was administered before beginning to use the hearing aids, at the end of using the first pair of hearing aids, and at the end of using the second pair of hearing aids. Twenty-five participants that met the inclusion/exclusion criteria from January 1 to October 31, 2016, were randomized to two groups. Twenty-two participants completed the study. There were no statistically significant differences in the increment of SSQ scores between the participants when using the VAC- or the VAC-J-programmed hearing aids. However, participants preferred the VAC-J strategy to the VAC strategy at the end of the study, and this difference was statistically significant. Japanese-speaking hearing aid users preferred using hearing aids that were fitted with the VAC-J strategy. Our results show that the VAC strategy

  20. 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.

  1. 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.

  2. Darwin-industrien i højt gear

    DEFF Research Database (Denmark)

    Kjærgaard, Peter C.

    2008-01-01

    Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december......Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december...

  3. Investigation of the paired-gear method in selectivity studies

    DEFF Research Database (Denmark)

    Sistiaga, Manu; Herrmann, Bent; Larsen, R.B.

    2009-01-01

    was repeated throughout the eight cases in this investigation. When using the paired-gear method, the distribution of the estimated L50 and SR is wider; the distribution of the estimated split parameter has a higher variability than the true split; the estimated mean L50 and SR can be biased; the estimated...... recommend that the methodology used to obtain selectivity estimates using the paired-gear method be reviewed....

  4. Hydrostatic self-locking bevel differential gear; Hydrostatisch selbstsperrendes Kegelraddifferentialgetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Kalmbach, K.

    2001-07-01

    The product range of the rail vehicle industry comprises the construction of railroad material for long-distance and short-distance transport. This includes, for example, locomotives and cars, subway, light railway and tramway cars as well as rail vehicle equipment. The development of the industry is determined by the demand for transport services and government actions for the extension of railways and procurement of suitable vehicle types. In contrast to road vehicles, differential gears are only used in a negligible percentage of rail vehicles. Primarily in the short-distance rail transport sector, the demand for differential gears is growing due to increased drive power, smaller wheel diameters, lower vehicle mass with higher load capacity, the introduction of low-floor technology as well as the requirement of employing ever more quiet vehicles. In hydrostatic self-locking differential gears, oil is supplied to the gears within the differential gearbox. They only rotate relative to each other when the differential gear performs a compensation movement. In this case, oil is transported in the tooth space to the meshing of the gears, where it is displaced due to the meshing and must drain through tight gaps. The pressure generated by this process acts against the compensation movement of the gear, and the drive torque is transmitted to the wheel that has the higher friction. The achievable locking torque is linearly dependent on the differential speed of the drive wheel. This locking effect is achieved without wear-prone components and works automatically without active external intervention. The design space required corresponds to that of conventional differential gears, as the locking effect is integrated in the existing design. (orig.)

  5. Substance Abuse-Specific Knowledge Transfer or Loss? Treatment Program Turnover versus Professional Turnover among Substance Abuse Clinicians

    Science.gov (United States)

    Eby, Lillian T.; Curtis, Sara L.

    2014-01-01

    This longitudinal study investigated the extent to which substance abuse (SA) clinician turnover is associated with SA-specific knowledge loss due to change in professions (professional turnover) versus SA-specific knowledge transfer due to movement from one SA clinical setting to another (treatment program turnover). For this study, clinicians had to voluntarily leave their current treatment program. Eligible clinicians completed a quantitative survey while employed and a qualitative post-employment exit interview 1 year later. Compared to those that exited the SA profession (N = 99), clinicians who changed treatment programs (N = 120) had greater SA-specific formal knowledge and were more likely to be personally in recovery. No differences were found between the two groups in terms of SA-specific practical knowledge. PMID:25115318

  6. VTVL concept optimisation of the landing gear

    Directory of Open Access Journals (Sweden)

    Camelia Elena MUNTEANU

    2017-03-01

    Full Text Available Vertical takeoff, vertical landing (VTVL is a subject of international interest at the moment thanks to the successful recovery of the Blue Origin vehicle. Aggressive weight targets with a short development time in the aerospace and space industry clearly need an integration of advanced computer aided structural optimization methods. Topological optimization is used from the concept phase of a design process development in order to obtain a fundamental design approach. The aim of the article is to determine the principal directions for distribution of the material for a VTVL landing gear within the specified volume in order to obtain the initial design approach. To achieve the maximum performance within the studied component, the result is then refined from a manufacturability point of view. The use of such methods notably reduces the development iterations between the design and stress departments. Thus, the overall time is reduced which translates into a lower overall cost and shorter time development from the concept to the final product.

  7. Analisa Kekuatan Spiral Bevel Gear Dengan Variasi Sudut Spiral Menggunakan Metode Elemen Hingga

    OpenAIRE

    Deta Rachmat Andika; Agus Sigit Pramono

    2017-01-01

    Seiring perkembangan zaman,  teknologi roda gigi dituntut untuk mampu mentransmisikan daya yang besar dengan efisiensi yang besar pula. Pada jenis intersecting shaft gear, tipe roda gigi payung spiral (spiral bevel gear)  merupakan perkembangan dari roda gigi payung bergigi lurus (straight bevel gear). Kelebihan dari spiral bevel gear antara  lain adalah kemampuan transmisi daya dan efisiensi yang lebih besar pada geometri yang sama serta tidak terlalu berisik. Akan tetapi spiral bevel gear j...

  8. Maternal programming of sex-specific responses to predator odor stress in adult rats.

    Science.gov (United States)

    St-Cyr, Sophie; Abuaish, Sameera; Sivanathan, Shathveekan; McGowan, Patrick O

    2017-08-01

    Prenatal stress mediated through the mother can lead to long-term adaptations in stress-related phenotypes in offspring. This study tested the long-lasting effect of prenatal exposure to predator odor, an ethologically relevant and psychogenic stressor, in the second half of pregnancy. As adults, the offspring of predator odor-exposed mothers showed increased anxiety-like behaviors in commonly used laboratory tasks assessing novelty-induced anxiety, increased defensive behavior in males and increased ACTH stress reactivity in females in response to predator odor. Female offspring from predator odor-exposed dams showed increased transcript abundance of glucocorticoid receptor (NR3C1) on the day of birth and FK506 binding protein 5 (FKBP5) in adulthood in the amygdala. The increase in FKBP5 expression was associated with decreased DNA methylation in Fkbp5 intron V. These results indicate a sex-specific response to maternal programming by prenatal predator odor exposure and a potential epigenetic mechanism linking these responses with modifications of the stress axis in females. These results are in accordance with the mismatch hypothesis stating that an animal's response to cues within its life history reflects environmental conditions anticipated during important developmental periods and should be adaptive when these conditions are concurring. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Specific problems of beginners at study of programming and possibilities of their solution

    OpenAIRE

    Procházková, Petra

    2017-01-01

    This thesis deals with the problems of beginners in the study of programming at University of Economics in Prague, Faculty of Informatics and Statistics. This applies particularly to students who are studying the subject Programming in Java.

  10. An Evaluation of the Availability and Application of Microcomputer Software Programs for Use in Air Force Ground Transportation Squadrons

    Science.gov (United States)

    1988-09-01

    software programs capable of being used on a microcomputer will be considered for analysis. No software intended for use on a miniframe or mainframe...Dial-A-Log consists of a program written in a computer language called L-10 that is run on a DEC-20 miniframe . The combination of the specific...proliferation of software dealing with microcomputers. Instead, they were geared more towards managing the use of miniframe or mainframe computer

  11. 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.

  12. Integrating angle-frequency domain synchronous averaging technique with feature extraction for gear fault diagnosis

    Science.gov (United States)

    Zhang, Shengli; Tang, J.

    2018-01-01

    Gear fault diagnosis relies heavily on the scrutiny of vibration responses measured. In reality, gear vibration signals are noisy and dominated by meshing frequencies as well as their harmonics, which oftentimes overlay the fault related components. Moreover, many gear transmission systems, e.g., those in wind turbines, constantly operate under non-stationary conditions. To reduce the influences of non-synchronous components and noise, a fault signature enhancement method that is built upon angle-frequency domain synchronous averaging is developed in this paper. Instead of being averaged in the time domain, the signals are processed in the angle-frequency domain to solve the issue of phase shifts between signal segments due to uncertainties caused by clearances, input disturbances, and sampling errors, etc. The enhanced results are then analyzed through feature extraction algorithms to identify the most distinct features for fault classification and identification. Specifically, Kernel Principal Component Analysis (KPCA) targeting at nonlinearity, Multilinear Principal Component Analysis (MPCA) targeting at high dimensionality, and Locally Linear Embedding (LLE) targeting at local similarity among the enhanced data are employed and compared to yield insights. Numerical and experimental investigations are performed, and the results reveal the effectiveness of angle-frequency domain synchronous averaging in enabling feature extraction and classification.

  13. Gearing up for transportation engineering summer program (GUTEP) : phase VIII.

    Science.gov (United States)

    2008-12-01

    The numbers of female and minority students enrolled in engineering schools are increasing slowly, however there is still a relatively small percentage drawn to the field of transportation civil engineering. As a consequence, there is a need to educa...

  14. 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.

  15. Recommendations for Guidelines for Environment-Specific Magnetic-Field Measurements, Rapid Program Engineering Project #2

    Energy Technology Data Exchange (ETDEWEB)

    Electric Research and Management, Inc.; IIT Research Institute; Magnetic Measurements; Survey Research Center, University of California; T. Dan Bracken, Inc.

    1997-03-11

    The purpose of this project was to document widely applicable methods for characterizing the magnetic fields in a given environment, recognizing the many sources co-existing within that space. The guidelines are designed to allow the reader to follow an efficient process to (1) plan the goals and requirements of a magnetic-field study, (2) develop a study structure and protocol, and (3) document and carry out the plan. These guidelines take the reader first through the process of developing a basic study strategy, then through planning and performing the data collection. Last, the critical factors of data management, analysis reporting, and quality assurance are discussed. The guidelines are structured to allow the researcher to develop a protocol that responds to specific site and project needs. The Research and Public Information Dissemination Program (RAPID) is based on exposure to magnetic fields and the potential health effects. Therefore, the most important focus for these magnetic-field measurement guidelines is relevance to exposure. The assumed objective of an environment-specific measurement is to characterize the environment (given a set of occupants and magnetic-field sources) so that information about the exposure of the occupants may be inferred. Ideally, the researcher seeks to obtain complete or "perfect" information about these magnetic fields, so that personal exposure might also be modeled perfectly. However, complete data collection is not feasible. In fact, it has been made more difficult as the research field has moved to expand the list of field parameters measured, increasing the cost and complexity of performing a measurement and analyzing the data. The guidelines address this issue by guiding the user to design a measurement protocol that will gather the most exposure-relevant information based on the locations of people in relation to the sources. We suggest that the "microenvironment" become the base unit of area in a study, with

  16. Dual and multi-stimuli responsive polymeric nanoparticles for programmed site-specific drug delivery.

    Science.gov (United States)

    Cheng, Ru; Meng, Fenghua; Deng, Chao; Klok, Harm-Anton; Zhong, Zhiyuan

    2013-05-01

    In the past decades, polymeric nanoparticles have emerged as a most promising and viable technology platform for targeted and controlled drug delivery. As vehicles, ideal nanoparticles are obliged to possess high drug loading levels, deliver drug to the specific pathological site and/or target cells without drug leakage on the way, while rapidly unload drug at the site of action. To this end, various "intelligent" polymeric nanoparticles that release drugs in response to an internal or external stimulus such as pH, redox, temperature, magnetic and light have been actively pursued. These stimuli-responsive nanoparticles have demonstrated, though to varying degrees, improved in vitro and/or in vivo drug release profiles. In an effort to further improve drug release performances, novel dual and multi-stimuli responsive polymeric nanoparticles that respond to a combination of two or more signals such as pH/temperature, pH/redox, pH/magnetic field, temperature/reduction, double pH, pH and diols, temperature/magnetic field, temperature/enzyme, temperature/pH/redox, temperature/pH/magnetic, pH/redox/magnetic, temperature/redox/guest molecules, and temperature/pH/guest molecules have recently been developed. Notably, these combined responses take place either simultaneously at the pathological site or in a sequential manner from nanoparticle preparation, nanoparticle transporting pathways, to cellular compartments. These dual and multi-stimuli responsive polymeric nanoparticles have shown unprecedented control over drug delivery and release leading to superior in vitro and/or in vivo anti-cancer efficacy. With programmed site-specific drug delivery feature, dual and multi-stimuli responsive nanoparticulate drug formulations have tremendous potential for targeted cancer therapy. In this review paper, we highlight the recent exciting developments in dual and multi-stimuli responsive polymeric nanoparticles for precision drug delivery applications, with a particular focus

  17. Programmed Death-1 expression on Epstein Barr virus specific CD8+ T cells varies by stage of infection, epitope specificity, and T-cell receptor usage.

    Directory of Open Access Journals (Sweden)

    Thomas C Greenough

    Full Text Available BACKGROUND: Programmed Death-1 (PD-1 is an inhibitory member of the CD28 family of molecules expressed on CD8+ T cells in response to antigenic stimulation. To better understand the role of PD-1 in antiviral immunity we examined the expression of PD-1 on Epstein-Barr virus (EBV epitope-specific CD8+ T cells during acute infectious mononucleosis (AIM and convalescence. METHODOLOGY/PRINCIPAL FINDINGS: Using flow cytometry, we observed higher frequencies of EBV-specific CD8+ T cells and higher intensity of PD-1 expression on EBV-specific CD8+ T cells during AIM than during convalescence. PD-1 expression during AIM directly correlated with viral load and with the subsequent degree of CD8+ T cell contraction in convalescence. Consistent differences in PD-1 expression were observed between CD8+ T cells with specificity for two different EBV lytic antigen epitopes. Similar differences were observed in the degree to which PD-1 was upregulated on these epitope-specific CD8+ T cells following peptide stimulation in vitro. EBV epitope-specific CD8+ T cell proliferative responses to peptide stimulation were diminished during AIM regardless of PD-1 expression and were unaffected by blocking PD-1 interactions with PD-L1. Significant variability in PD-1 expression was observed on EBV epitope-specific CD8+ T cell subsets defined by V-beta usage. CONCLUSIONS/SIGNIFICANCE: These observations suggest that PD-1 expression is not only dependent on the degree of antigen presentation, but also on undefined characteristics of the responding cell that segregate with epitope specificity and V-beta usage.

  18. Milestone-specific, Observed data points for evaluating levels of performance (MODEL) assessment strategy for anesthesiology residency programs.

    Science.gov (United States)

    Nagy, Christopher J; Fitzgerald, Brian M; Kraus, Gregory P

    2014-01-01

    Anesthesiology residency programs will be expected to have Milestones-based evaluation systems in place by July 2014 as part of the Next Accreditation System. The San Antonio Uniformed Services Health Education Consortium (SAUSHEC) anesthesiology residency program developed and implemented a Milestones-based feedback and evaluation system a year ahead of schedule. It has been named the Milestone-specific, Observed Data points for Evaluating Levels of performance (MODEL) assessment strategy. The "MODEL Menu" and the "MODEL Blueprint" are tools that other anesthesiology residency programs can use in developing their own Milestones-based feedback and evaluation systems prior to ACGME-required implementation. Data from our early experience with the streamlined MODEL blueprint assessment strategy showed substantially improved faculty compliance with reporting requirements. The MODEL assessment strategy provides programs with a workable assessment method for residents, and important Milestones data points to programs for ACGME reporting.

  19. Estimation of seafloor impact from demersal trawls, seines and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael

    a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...

  20. 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.

  1. Scheduler-specific Confidentiality for Multi-Threaded Programs and Its Logic-Based Verification

    NARCIS (Netherlands)

    Huisman, Marieke; Ngo, Minh Tri

    2011-01-01

    Observational determinism has been proposed in the literature as a way to ensure confidentiality for multi-threaded programs. Intuitively, a program is observationally deterministic if the behavior of the public variables is deterministic, i.e., independent of the private variables and the

  2. Scheduler-Specific Confidentiality for Multi-Threaded Programs and Its Logic-Based Verification

    NARCIS (Netherlands)

    Huisman, Marieke; Ngo, Minh Tri; Beckert, B.; Damiani, F.; Gurov, D.

    2012-01-01

    Observational determinism has been proposed in the literature as a way to ensure condentiality for multi-threaded programs. Intuitively, a program is observationally deterministic if the behavior of the public variables is deterministic, i.e., independent of the private variables and the scheduling

  3. 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.

  4. 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.

  5. 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

  6. Advanced Manufacture of Spiral Bevel and Hypoid Gears

    Directory of Open Access Journals (Sweden)

    Vilmos Simon

    2016-11-01

    Full Text Available In this study, an advanced method for the manufacture of spiral bevel and hypoid gears on CNC hypoid generators is proposed. The optmal head-cutter geometry and machine tool settings are determined to introduce the optimal tooth surface modifications into the teeth of spiral bevel and hypoid gears. The aim of these tooth surface modifications is to simultaneously reduce the tooth contact pressure and the transmission errors, to maximize the EHD load carrying capacity of the oil film, and to minimize power losses in the oil film. The proposed advanced method for the manufacture of spiral bevel and hypoid gears is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions and on the use of a CNC hypoid generator. An algorithm is developed for the execution of motions on the CNC hypoid generator using the optimal relations on the cradle-type machine. Effectiveness of the method was demonstrated by using spiral bevel and hypoid gear examples. Significant improvements in the operating characteristics of the gear pairs are achieved.

  7. 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.

  8. Unilateral maxillary molar distalization with zygoma-gear appliance.

    Science.gov (United States)

    Kilkis, Dogan; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin

    2012-08-01

    The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  9. The study about planetary gearbox virtual prototyping with nonlinear gear contact characteristics

    International Nuclear Information System (INIS)

    Yin Huabing; Zhou Guangming

    2010-01-01

    The virtual prototypes of gear transmission system built in most multi-body dynamic software have difficulties in describing the gear mesh characteristics. The gear mesh contact is modelled as rigid contact and this is not accurate for the gear mesh contact, which is elastic or flexible. The gear contact formula used in the multi-body dynamic software does not reveal the gear contact nonlinear stiffness characteristic. The model built with gear meshing contact is difficult to solve because of its time-consuming algorithm. In the paper a new method is put forward to build the virtual prototype of planetary gearbox system according to the nonlinear mesh stiffness and mesh phase obtained through FEM models. This new FEM method of gear mesh stiffness calculation is much more accurate than the common formulas. The gear mesh nonlinear stiffness of sun gear- pinion and pinion-ring gear of all the planetary gear sets in gearbox are obtained through MATALB code, which is used to read and plot the analyzing result data. The gear mesh phase differences between different pinions with suns or rings of different planetary gear set can be also obtained. With all these data modelled in simulink (or other software) and integrated with the multi-body dynamic planetary gearbox model and the gear meshing contact problem in multi-body gear models is solved easily and accurately. The interfaces for gear mesh stiffness and mesh phases are designed for multi-body dynamic model and simulink. The nonlinear planetary gear set prototyping models are integrated to become the whole planetary gear box model and the whole vehicle system model built in multi-body dynamic software can be integrated to simulate different duty conditions. At last high speed input is put into the nonlinear planetary transmission model and the different duty cases are simulated. The dynamic characteristics of different parts are obtained. The dynamic characteristic comparison between nonlinear and linear models is made

  10. Experiences of Students with Specific Learning Disorder (Including ADHD) in Online College Degree Programs: A Phenomenological Study

    Science.gov (United States)

    Bunch, Seleta LeAnn

    2016-01-01

    Enrollment in online degree programs is rapidly expanding due to the convenience and affordability offered to students and improvements in technology. The purpose of this hermeneutical phenomenological study was to understand the shared experiences of students with documented specific learning disorders (including Attention-Deficit/Hyperactivity…

  11. Specific and Optional Curriculum: An Experience in the Undergraduate Program of Chemical Engineering in Cienfuegos University, Cuba

    Science.gov (United States)

    Martínez, Yolanda García; Velázquez, Claudia Alvarado; Castillo, Rolando Delgado

    2016-01-01

    This paper pursues to define the pillars for designing the specific (SC) and optional curricula (OC) of Unit Operations and Processes (UOP) Discipline in the Chemical Engineering Program. To achieve this objective a methodology was developed, which was characterized by the participation of every member in the educational process: professors,…

  12. Gender-Specific HIV Prevention with Urban Early-Adolescent Girls: Outcomes of the Keepin' It Safe Program

    Science.gov (United States)

    Di Noia, Jennifer; Schinke, Steven P.

    2007-01-01

    This study evaluates the efficacy of Keepin' It Safe, a theory-based, gender-specific, CD-ROM-mediated HIV prevention program for urban, early adolescent girls. Intervention effects were examined in a randomized, pretest-posttest wait-list control-group design. Changes in HIV/AIDS knowledge, protective attitudes, and skills for reducing HIV…

  13. Educational Specifications for Pearl Harbor Heights High School, Developed from the Program Delineation Study, January-April 1961.

    Science.gov (United States)

    Hawaii State Dept. of Education, Honolulu.

    The report is a discussion of the curriculum and supportive educational facilities for the state of Hawaii. An administrative view of guidance services and teacher programing is included. Supportive facilities are sketched, showing their relationship to such specific instructional areas as music, shop, home economics, drawing and painting,…

  14. The Effect of Neuro-Linguistic Programming (NLP) on Reading Comprehension in English for Specific Purposes Courses

    Science.gov (United States)

    Farahani, Fahimeh

    2018-01-01

    Neuro-Linguistic Programming (NLP) has potential to help language learners; however, it has received scant attention. The present study was an attempt to investigate the effect of NLP techniques on reading comprehension of English as a Foreign Language (EFL) learners at an English for Specific Purposes (ESP) course. To achieve this goal, two…

  15. Investigation of Spiral Bevel Gear Condition Indicator Validation via AC-29-2C Using Fielded Rotorcraft HUMS Data

    Science.gov (United States)

    Dempsey, Paula J.; Wade, Daniel R.; Antolick, Lance J.; Thomas, Josiah

    2014-01-01

    additional CIs also not in the on-board system, DiffDA1and SI1, also performed well responding to twelve and ten of the fourteen helicopters evaluated respectively. Of the three CIs currently available in the MSPU, DA1, FM4 and SI3, SI3, responded to eight, DA1 responded to six and FM4 responded to four of the fourteen helicopters evaluated. FM4, the poorest performing CI, was not as responsive to damage as the other five CIs. Conversely, when compared to the other two, it was the only CI that responded to damage on two helicopters. CI response could not be correlated to specific failure modes due to limited pictures and subjective descriptions found within the TDA. Flight regime did affect CI response to some gear faults. Due to the range of operating conditions for each regime, more studies are required to determine their sensitivity to regimes.

  16. Image Processing of Welding Procedure Specification and Pre-process program development for Finite Element Modelling

    International Nuclear Information System (INIS)

    Kim, K. S.; Lee, H. J.

    2009-11-01

    PRE-WELD program, which generates automatically the input file for the finite element analysis on the 2D butt welding at the dissimilar metal weld part, was developed. This program is pre-process program of the FEM code for analyzing the residual stress at the welding parts. Even if the users have not the detail knowledge for the FEM modelling, the users can make the ABAQUS INPUT easily by inputting the shape data of welding part, the weld current and voltage of welding parameters. By using PRE-WELD program, we can save the time and the effort greatly for preparing the ABAQUS INPUT for the residual stress analysis at the welding parts, and make the exact input without the human error

  17. 78 FR 53791 - Draft Program-Specific Guidance About Irradiator Licenses

    Science.gov (United States)

    2013-08-30

    ... CONTACT: Tomas Herrera, Office of Federal and State Materials and Environmental Management Programs; U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: 301-415- 7138; email: Tomas.Herrera...

  18. 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.

  19. Worm gearing for valve automation; Schneckengetriebe fuer die Armaturenautomatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Herbstritt, Michael [AUMA Riester GmbH und Co. KG, Muellheim (Germany)

    2010-11-15

    Part-turn gearboxes are indispensable for exertion of the torques necessary for large part-turn valves. Torque demand has increased in the past decade, as a result, for example, of the use of pipelines of ever greater diameters in large conurbations, and of the operation of such pipelines at ever higher pressures. The design principle of a worm gear is useful in this context. Worm gearing systems with initial torques of up to 675,000 Nm are now available. The design of gearing systems capable of handling forces of this magnitude necessitates great know-how and experience. The very maximum of reliability is a basic requirement for actuator systems for applications involving such dimensions, since a failure may have catastrophic consequences. (orig.)

  20. 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.

  1. 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.

  2. 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.

  3. An efficient finite element solution for gear dynamics

    International Nuclear Information System (INIS)

    Cooley, C G; Parker, R G; Vijayakar, S M

    2010-01-01

    A finite element formulation for the dynamic response of gear pairs is proposed. Following an established approach in lumped parameter gear dynamic models, the static solution is used as the excitation in a frequency domain solution of the finite element vibration model. The nonlinear finite element/contact mechanics formulation provides accurate calculation of the static solution and average mesh stiffness that are used in the dynamic simulation. The frequency domain finite element calculation of dynamic response compares well with numerically integrated (time domain) finite element dynamic results and previously published experimental results. Simulation time with the proposed formulation is two orders of magnitude lower than numerically integrated dynamic results. This formulation admits system level dynamic gearbox response, which may include multiple gear meshes, flexible shafts, rolling element bearings, housing structures, and other deformable components.

  4. 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.

  5. 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.

  6. Torsional vibration signal analysis as a diagnostic tool for planetary gear fault detection

    Science.gov (United States)

    Xue, Song; Howard, Ian

    2018-02-01

    This paper aims to investigate the effectiveness of using the torsional vibration signal as a diagnostic tool for planetary gearbox faults detection. The traditional approach for condition monitoring of the planetary gear uses a stationary transducer mounted on the ring gear casing to measure all the vibration data when the planet gears pass by with the rotation of the carrier arm. However, the time variant vibration transfer paths between the stationary transducer and the rotating planet gear modulate the resultant vibration spectra and make it complex. Torsional vibration signals are theoretically free from this modulation effect and therefore, it is expected to be much easier and more effective to diagnose planetary gear faults using the fault diagnostic information extracted from the torsional vibration. In this paper, a 20 degree of freedom planetary gear lumped-parameter model was developed to obtain the gear dynamic response. In the model, the gear mesh stiffness variations are the main internal vibration generation mechanism and the finite element models were developed for calculation of the sun-planet and ring-planet gear mesh stiffnesses. Gear faults on different components were created in the finite element models to calculate the resultant gear mesh stiffnesses, which were incorporated into the planetary gear model later on to obtain the faulted vibration signal. Some advanced signal processing techniques were utilized to analyses the fault diagnostic results from the torsional vibration. It was found that the planetary gear torsional vibration not only successfully detected the gear fault, but also had the potential to indicate the location of the gear fault. As a result, the planetary gear torsional vibration can be considered an effective alternative approach for planetary gear condition monitoring.

  7. HOW TO STEER THE TRANSMISSION RATIO OF PLANETARY CONTINUOUSLY ADJUSTABLE GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    A. M. Dankov

    2016-01-01

    Full Text Available The known attempts to create a continuously-adjustable gear train with solid gears have led to development of some so-called adaptive gears. The most structurally simple version of continuously- adjustable gear train is a two-wheel planetary gear. It is an obvious fact that an active regulation of gear ratio for the gear should be based on the presence of con- trolled elements (parameters and a mechanism for their control. In respect of the mentioned gear one of the controlled elements that is a compound central toothed gear has such controlled parameter as a nominal pitch diameter. In this case it can rotate or remain motionless. Other controlled element which is a planetary carrier has its own radius as a controlled parameter and makes a rotary motion with a great speed of a leading element. The purpose of the control mechanism is to ensure radial displacement of central toothed gear and planet gear sectors in the working gear. The paper describes the mechanism modifications and considers two variants for transfer of control action from its source to an object to be controlled. The transfer is ensured by mechanical gears (two variants and hydraulics.

  8. 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.

  9. Program Criteria Specifications Document. Computer Program TWDA for Design and Analysis of Inverted-T Retaining Walls and Floodwalls.

    Science.gov (United States)

    1981-02-01

    or analysis IloduIls,* each pCr forming one specific step in the design or analysis process. These modules will be callable , in any logical sequence...tempt to 1)l 1cC Cind cut of I bar, hut Will slow the required steel area and bond r i u I rl- t t)s per I oot at Uitablt intervals across the base... bond strength) shall be as required in ACI 318-71 Chapter 12, except that computed shear V shall be multiplied by 2.0 and substituted for V u. Tn

  10. 76 FR 35319 - Competitive and Noncompetitive Non-Formula Federal Assistance Programs-Specific Administrative...

    Science.gov (United States)

    2011-06-17

    ... the recommendation from NSAC. NIFA has decided that the target audience need not be a specific group... marketing strategies; curriculum development; understanding the impact of concentration and globalization... include modules tailored to specific audiences of beginning farmers or ranchers, based on crop or regional...

  11. Magnetic transmission gear finite element simulation with iron pole hysteresis

    Science.gov (United States)

    Filippini, Mattia; Alotto, Piergiorgio; Glehn, Gregor; Hameyer, Kay

    2018-04-01

    Ferromagnetic poles in a magnetic transmission gear require particular attention during their design process. Usually, during the numerical simulation of these devices the effects of hysteresis for loss estimation are neglected and considered only during post-processing calculations. Since the literature lacks hysteresis models, this paper adopts a homogenized hysteretic model able to include eddy current and hysteresis losses in 2D laminated materials for iron poles. In this article the results related to the hysteresis in a magnetic gear are presented and compared to the non-hysteretic approach.

  12. Gear Fault Detection Based on Teager-Huang Transform

    Directory of Open Access Journals (Sweden)

    Hui Li

    2010-01-01

    Full Text Available Gear fault detection based on Empirical Mode Decomposition (EMD and Teager Kaiser Energy Operator (TKEO technique is presented. This novel method is named as Teager-Huang transform (THT. EMD can adaptively decompose the vibration signal into a series of zero mean Intrinsic Mode Functions (IMFs. TKEO can track the instantaneous amplitude and instantaneous frequency of the Intrinsic Mode Functions at any instant. The experimental results provide effective evidence that Teager-Huang transform has better resolution than that of Hilbert-Huang transform. The Teager-Huang transform can effectively diagnose the fault of the gear, thus providing a viable processing tool for gearbox defect detection and diagnosis.

  13. Electron Beam Welding of Gear Wheels by Splitted Beam

    Directory of Open Access Journals (Sweden)

    Dřímal Daniel

    2014-06-01

    Full Text Available This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max..

  14. [Information, knowledge and healthcare practice: professionals participation as the key element of the gear].

    Science.gov (United States)

    Adam, Paula; Permanyer-Miralda, Gaietà; Solà-Morales, Oriol; Canela-Soler, Jaume

    2010-02-01

    This article analyzes the role of ICT within the complicated gear between information, knowledge and healthcare practices, which particular focus on two specific cases: the digitalization process of the healthcare system and the application of knowledge into the healthcare practices. In both cases, international and local experiences suggest, and sometimes demonstrate the importance of the participation, capacity-building and empowerment of healthcare practitioners for the generation, transfer and use of information and knowledge empowered by the digital tools which should bring into the system better performance, more efficacy, efficiency, equity, equality, security, quality. 2010 Elsevier España S.L. All rights reserved.

  15. Computerized Design and Generation of Gear Drives With a Localized Bearing Contact and a Low Level of Transmission Errors

    Science.gov (United States)

    Litvin, F.; Chen, J.; Seol, I.; Kim, D.; Lu, J.; Zhao, X.; Handschuh, R.

    1996-01-01

    A general approach developed for the computerized simulation of loaded gear drives is presented. In this paper the methodology used to localize the bearing contact, provide a parabolic function of transmission errors, and simulate meshing and contact of unloaded gear drives is developed. The approach developed is applied to spur and helical gears, spiral bevel gears, face-gear drives, and worm-gear drives with cylindrical worms.

  16. Program Specificity for Ptf1a in Pancreas versus Neural Tube Development Correlates with Distinct Collaborating Cofactors and Chromatin Accessibility

    Science.gov (United States)

    Meredith, David M.; Borromeo, Mark D.; Deering, Tye G.; Casey, Bradford H.; Savage, Trisha K.; Mayer, Paul R.; Hoang, Chinh; Tung, Kuang-Chi; Kumar, Manonmani; Shen, Chengcheng; Swift, Galvin H.

    2013-01-01

    The lineage-specific basic helix-loop-helix transcription factor Ptf1a is a critical driver for development of both the pancreas and nervous system. How one transcription factor controls diverse programs of gene expression is a fundamental question in developmental biology. To uncover molecular strategies for the program-specific functions of Ptf1a, we identified bound genomic regions in vivo during development of both tissues. Most regions bound by Ptf1a are specific to each tissue, lie near genes needed for proper formation of each tissue, and coincide with regions of open chromatin. The specificity of Ptf1a binding is encoded in the DNA surrounding the Ptf1a-bound sites, because these regions are sufficient to direct tissue-restricted reporter expression in transgenic mice. Fox and Sox factors were identified as potential lineage-specific modifiers of Ptf1a binding, since binding motifs for these factors are enriched in Ptf1a-bound regions in pancreas and neural tube, respectively. Of the Fox factors expressed during pancreatic development, Foxa2 plays a major role. Indeed, Ptf1a and Foxa2 colocalize in embryonic pancreatic chromatin and can act synergistically in cell transfection assays. Together, these findings indicate that lineage-specific chromatin landscapes likely constrain the DNA binding of Ptf1a, and they identify Fox and Sox gene families as part of this process. PMID:23754747

  17. Flood Catastrophe Model for Designing Optimal Flood Insurance Program: Estimating Location-Specific Premiums in the Netherlands.

    Science.gov (United States)

    Ermolieva, T; Filatova, T; Ermoliev, Y; Obersteiner, M; de Bruijn, K M; Jeuken, A

    2017-01-01

    As flood risks grow worldwide, a well-designed insurance program engaging various stakeholders becomes a vital instrument in flood risk management. The main challenge concerns the applicability of standard approaches for calculating insurance premiums of rare catastrophic losses. This article focuses on the design of a flood-loss-sharing program involving private insurance based on location-specific exposures. The analysis is guided by a developed integrated catastrophe risk management (ICRM) model consisting of a GIS-based flood model and a stochastic optimization procedure with respect to location-specific risk exposures. To achieve the stability and robustness of the program towards floods with various recurrences, the ICRM uses stochastic optimization procedure, which relies on quantile-related risk functions of a systemic insolvency involving overpayments and underpayments of the stakeholders. Two alternative ways of calculating insurance premiums are compared: the robust derived with the ICRM and the traditional average annual loss approach. The applicability of the proposed model is illustrated in a case study of a Rotterdam area outside the main flood protection system in the Netherlands. Our numerical experiments demonstrate essential advantages of the robust premiums, namely, that they: (1) guarantee the program's solvency under all relevant flood scenarios rather than one average event; (2) establish a tradeoff between the security of the program and the welfare of locations; and (3) decrease the need for other risk transfer and risk reduction measures. © 2016 Society for Risk Analysis.

  18. As-Built design specification for the CLASFYT program. [production of classification files - crop inventory

    Science.gov (United States)

    Horton, C. L. (Principal Investigator)

    1981-01-01

    The CLASFYT program is described in detail. The program produces a one-channel universal-formatted classification file. Trajectory coefficients and a composite set of tolerance values are calculated from five acquisitions of radiance values in each of the training fields corresponding to up to ten agricultural products. These coefficients and tolerance values are used to classify each pixel in the test field of the same segment to be the same agricultural product as one of the training fields, none of the products or a screened pixel.

  19. A Domain-Specific Language for Programming Self-Reconfigurable Robots

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh; Christensen, David Johan; Støy, Kasper

    2007-01-01

    . Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular......, self-reconfigurable robots, we have developed a declarative, role-based language that allows the programmer to define roles and behavior independently of the concrete physical structure of the robot. Roles are compiled to mobile code fragments that distribute themselves over the physical structure...

  20. A trial of a job-specific workers' health surveillance program for construction workers: study protocol.

    Science.gov (United States)

    Boschman, Julitta S; van der Molen, Henk F; van Duivenbooden, Cor; Sluiter, Judith K; Frings-Dresen, Monique H W

    2011-09-29

    Dutch construction workers are offered periodic health examinations. This care can be improved by tailoring this workers health surveillance (WHS) to the demands of the job and adjust the preventive actions to the specific health risks of a worker in a particular job. To improve the quality of the WHS for construction workers and stimulate relevant job-specific preventive actions by the occupational physician, we have developed a job-specific WHS. The job-specific WHS consists of modules assessing both physical and psychological requirements. The selected measurement instruments chosen, are based on their appropriateness to measure the workers' capacity and health requirements. They include a questionnaire and biometrical tests, and physical performance tests that measure physical functional capabilities. Furthermore, our job-specific WHS provides occupational physicians with a protocol to increase the worker-behavioural effectiveness of their counselling and to stimulate job-specific preventive actions. The objective of this paper is to describe and clarify our study to evaluate the behavioural effects of this job-specific WHS on workers and occupational physicians. The ongoing study of bricklayers and supervisors is a nonrandomised trial to compare the outcome of an intervention (job-specific WHS) group (n = 206) with that of a control (WHS) group (n = 206). The study includes a three-month follow-up. The primary outcome measure is the proportion of participants who have undertaken one or more of the preventive actions advised by their occupational physician in the three months after attending the WHS. A process evaluation will be carried out to determine context, reach, dose delivered, dose received, fidelity, and satisfaction. The present study is in accordance with the TREND Statement. This study will allow an evaluation of the behaviour of both the workers and occupational physician regarding the preventive actions undertaken by them within the scope of a job-specific

  1. A trial of a job-specific workers' health surveillance program for construction workers: study protocol

    Directory of Open Access Journals (Sweden)

    Sluiter Judith K

    2011-09-01

    Full Text Available Abstract Background Dutch construction workers are offered periodic health examinations. This care can be improved by tailoring this workers health surveillance (WHS to the demands of the job and adjust the preventive actions to the specific health risks of a worker in a particular job. To improve the quality of the WHS for construction workers and stimulate relevant job-specific preventive actions by the occupational physician, we have developed a job-specific WHS. The job-specific WHS consists of modules assessing both physical and psychological requirements. The selected measurement instruments chosen, are based on their appropriateness to measure the workers' capacity and health requirements. They include a questionnaire and biometrical tests, and physical performance tests that measure physical functional capabilities. Furthermore, our job-specific WHS provides occupational physicians with a protocol to increase the worker-behavioural effectiveness of their counselling and to stimulate job-specific preventive actions. The objective of this paper is to describe and clarify our study to evaluate the behavioural effects of this job-specific WHS on workers and occupational physicians. Methods/Design The ongoing study of bricklayers and supervisors is a nonrandomised trial to compare the outcome of an intervention (job-specific WHS group (n = 206 with that of a control (WHS group (n = 206. The study includes a three-month follow-up. The primary outcome measure is the proportion of participants who have undertaken one or more of the preventive actions advised by their occupational physician in the three months after attending the WHS. A process evaluation will be carried out to determine context, reach, dose delivered, dose received, fidelity, and satisfaction. The present study is in accordance with the TREND Statement. Discussion This study will allow an evaluation of the behaviour of both the workers and occupational physician regarding the

  2. Research on vibration signal analysis and extraction method of gear local fault

    Science.gov (United States)

    Yang, X. F.; Wang, D.; Ma, J. F.; Shao, W.

    2018-02-01

    Gear is the main connection parts and power transmission parts in the mechanical equipment. If the fault occurs, it directly affects the running state of the whole machine and even endangers the personal safety. So it has important theoretical significance and practical value to study on the extraction of the gear fault signal and fault diagnosis of the gear. In this paper, the gear local fault as the research object, set up the vibration model of gear fault vibration mechanism, derive the vibration mechanism of the gear local fault and analyzes the similarities and differences of the vibration signal between the gear non fault and the gears local faults. In the MATLAB environment, the wavelet transform algorithm is used to denoise the fault signal. Hilbert transform is used to demodulate the fault vibration signal. The results show that the method can denoise the strong noise mechanical vibration signal and extract the local fault feature information from the fault vibration signal..

  3. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike

    2016-01-01

    such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

  4. 14 CFR 23.729 - Landing gear extension and retraction system.

    Science.gov (United States)

    2010-01-01

    ... retracted) position. If switches are used, they must be located and coupled to the landing gear mechanical... burst, or rocks, water, and slush that may enter the landing gear bay. [Doc. No. 4080, 29 FR 17955, Dec...

  5. 75 FR 59058 - Competitive and Noncompetitive Non-Formula Federal Assistance Programs-Specific Administrative...

    Science.gov (United States)

    2010-09-27

    ... DEPARTMENT OF AGRICULTURE National Institute of Food and Agriculture 7 CFR Part 3430 RIN 0524-AA60... the New Era Rural Technology Competitive Grants Program AGENCY: National Institute of Food and Agriculture, USDA. ACTION: Final rule. SUMMARY: The National Institute of Food and Agriculture (NIFA) is...

  6. Safety in the Chemical Laboratory: Safety in the Chemistry Laboratories: A Specific Program.

    Science.gov (United States)

    Corkern, Walter H.; Munchausen, Linda L.

    1983-01-01

    Describes a safety program adopted by Southeastern Louisiana University. Students are given detailed instructions on laboratory safety during the first laboratory period and a test which must be completely correct before they are allowed to return to the laboratory. Test questions, list of safety rules, and a laboratory accident report form are…

  7. GirlPOWER! Strengthening Mentoring Relationships through a Structured, Gender-Specific Program

    Science.gov (United States)

    Pryce, Julia M.; Silverthorn, Naida; Sanchez, Bernadette; DuBois, David L.

    2010-01-01

    The authors examine GirlPOWER! an innovative program that uses structure and group-based activities to enhance one-to-one mentoring relationships for young adolescent girls from the perspective of the focus, purpose, and authorship dimensions of mentoring relationships that Karcher and Nakkula described. The discussion draws on several sources of…

  8. Gear and seasonal bias associated with abundance and size structure estimates for lentic freshwater fishes

    Science.gov (United States)

    Fischer, Jesse R.; Quist, Michael C.

    2014-01-01

    All freshwater fish sampling methods are biased toward particular species, sizes, and sexes and are further influenced by season, habitat, and fish behavior changes over time. However, little is known about gear-specific biases for many common fish species because few multiple-gear comparison studies exist that have incorporated seasonal dynamics. We sampled six lakes and impoundments representing a diversity of trophic and physical conditions in Iowa, USA, using multiple gear types (i.e., standard modified fyke net, mini-modified fyke net, sinking experimental gill net, bag seine, benthic trawl, boat-mounted electrofisher used diurnally and nocturnally) to determine the influence of sampling methodology and season on fisheries assessments. Specifically, we describe the influence of season on catch per unit effort, proportional size distribution, and the number of samples required to obtain 125 stock-length individuals for 12 species of recreational and ecological importance. Mean catch per unit effort generally peaked in the spring and fall as a result of increased sampling effectiveness in shallow areas and seasonal changes in habitat use (e.g., movement offshore during summer). Mean proportional size distribution decreased from spring to fall for white bass Morone chrysops, largemouth bass Micropterus salmoides, bluegill Lepomis macrochirus, and black crappie Pomoxis nigromaculatus, suggesting selectivity for large and presumably sexually mature individuals in the spring and summer. Overall, the mean number of samples required to sample 125 stock-length individuals was minimized in the fall with sinking experimental gill nets, a boat-mounted electrofisher used at night, and standard modified nets for 11 of the 12 species evaluated. Our results provide fisheries scientists with relative comparisons between several recommended standard sampling methods and illustrate the effects of seasonal variation on estimates of population indices that will be critical to

  9. Dynamic load-sharing characteristic analysis of face gear power-split gear system based on tooth contact characteristics

    Science.gov (United States)

    Dong, Hao; Hu, Yahui

    2018-04-01

    The bend-torsion coupling dynamics load-sharing model of the helicopter face gear split torque transmission system is established by using concentrated quality standard, to analyzing the dynamic load-sharing characteristic. The mathematical models include nonlinear support stiffness, time-varying meshing stiffness, damping, gear backlash. The results showed that the errors collectively influenced the load sharing characteristics, only reduce a certain error, it is never fully reached the perfect loading sharing characteristics. The system load-sharing performance can be improved through floating shaft support. The above-method will provide a theoretical basis and data support for its dynamic performance optimization design.

  10. Correcting biases in psychiatric diagnostic practice in Northwest Russia: Comparing the impact of a general educational program and a specific diagnostic training program

    Directory of Open Access Journals (Sweden)

    Rezvyy Grigory

    2008-04-01

    Full Text Available Abstract Background A general education in psychiatry does not necessary lead to good diagnostic skills. Specific training programs in diagnostic coding are established to facilitate implementation of ICD-10 coding practices. However, studies comparing the impact of these two different educational approaches on diagnostic skills are lacking. The aim of the current study was to find out if a specific training program in diagnostic coding improves the diagnostic skills better than a general education program, and if a national bias in diagnostic patterns can be minimised by a specific training in diagnostic coding. Methods A pre post design study with two groups was carried in the county of Archangels, Russia. The control group (39 psychiatrists took the required course (general educational program, while the intervention group (45 psychiatrists were given a specific training in diagnostic coding. Their diagnostic skills before and after education were assessed using 12 written case-vignettes selected from the entire spectrum of psychiatric disorders. Results There was a significant improvement in diagnostic skills in both the intervention group and the control group. However, the intervention group improved significantly more than did the control group. The national bias was partly corrected in the intervention group but not to the same degree in the control group. When analyzing both groups together, among the background factors only the current working place impacted the outcome of the intervention. Conclusion Establishing an internationally accepted diagnosis seems to be a special skill that requires specific training and needs to be an explicit part of the professional educational activities of psychiatrists. It does not appear that that skill is honed without specific training. The issue of national diagnostic biases should be taken into account in comparative cross-cultural studies of almost any character. The mechanisms of such biases are

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

    NARCIS (Netherlands)

    Kuai, Moshen; Cheng, Gang; Pang, Y.; Li, Yong

    2018-01-01

    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

  12. Minimizing tooth bending stress in spur gears with simplified shapes of fillet and tool shape determination

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2015-01-01

    by different standards, with the ISO standard probably being the most common one. Gears are manufactured using two principally different tools: rack tools and gear tools. In this work, the bending stress of involute teeth is minimized by shape optimization made directly on the final gear. This optimized shape...

  13. Light and Heavy Tactical Wheeled Vehicle Fuel Consumption Evaluations Using Fuel Efficient Gear Oils (FEGO)

    Science.gov (United States)

    2016-05-01

    UNCLASSIFIED LIGHT AND HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FUEL EFFICIENT GEAR OILS (FEGO) FINAL... HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FUEL EFFICIENT GEAR OILS (FEGO) FINAL REPORT TFLRF No. 477 by Adam C...August 2014 – March 2016 4. TITLE AND SUBTITLE LIGHT AND HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FEUL EFFICIENT GEAR OILS

  14. 77 FR 36998 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...

    Science.gov (United States)

    2012-06-20

    ... Collection; Comment Request; Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY: National... under the Shrimp Fishery Management Plan (FMP). The regulations for the Gulf Shrimp Vessel and Gear... and Gear Characterization Form. The form will be provided by NMFS at the time of permit application...

  15. 78 FR 40436 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...

    Science.gov (United States)

    2013-07-05

    ... Collection; Comment Request; Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY: National... under the Shrimp Fishery Management Plan (FMP). The regulations for the Gulf Shrimp Vessel and Gear... Gear Characterization Form. The form will be provided by NMFS at the time of permit application and...

  16. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each clutch...

  17. 76 FR 5402 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Gear...

    Science.gov (United States)

    2011-01-31

    ... for OMB Review; Comment Request; Gear Certification ACTION: Notice. SUMMARY: The Department of Labor...) sponsored information collection request (ICR) titled, ``Gear Certification,'' to the Office of Management... cranes, derricks, and accessory gear used in the longshoring, marine terminal, and shipyard industries...

  18. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering gear...

  19. 75 FR 17055 - Gray's Reef National Marine Sanctuary Regulations on the Use of Spearfishing Gear; Correction

    Science.gov (United States)

    2010-04-05

    ... Spearfishing Gear; Correction AGENCY: Office of National Marine Sanctuaries (ONMS), National Ocean Service (NOS... Federal Register on February 19, 2010 (75 FR 7361) on the use and possession of spearfishing gear in Gray..., that included a description of new requirements on the use and possession of spearfishing gear in Gray...

  20. 76 FR 16610 - Proposed Information Collection; Comment Request; Pacific Islands Region Vessel and Gear...

    Science.gov (United States)

    2011-03-24

    ... Collection; Comment Request; Pacific Islands Region Vessel and Gear Identification Requirements AGENCY... and gear, as specified in 50 CFR 665 and 50 CFR 300. Vessels registered for use with a permit issued... require that certain fishing gear must be marked. In the pelagic longline fisheries, the vessel operator...

  1. Three new models for evaluation of standard involute spur gear mesh stiffness

    Science.gov (United States)

    Liang, Xihui; Zhang, Hongsheng; Zuo, Ming J.; Qin, Yong

    2018-02-01

    Time-varying mesh stiffness is one of the main internal excitation sources of gear dynamics. Accurate evaluation of gear mesh stiffness is crucial for gear dynamic analysis. This study is devoted to developing new models for spur gear mesh stiffness evaluation. Three models are proposed. The proposed model 1 can give very accurate mesh stiffness result but the gear bore surface must be assumed to be rigid. Enlighted by the proposed model 1, our research discovers that the angular deflection pattern of the gear bore surface of a pair of meshing gears under a constant torque basically follows a cosine curve. Based on this finding, two other models are proposed. The proposed model 2 evaluates gear mesh stiffness by using angular deflections at different circumferential angles of an end surface circle of the gear bore. The proposed model 3 requires using only the angular deflection at an arbitrary circumferential angle of an end surface circle of the gear bore but this model can only be used for a gear with the same tooth profile among all teeth. The proposed models are accurate in gear mesh stiffness evaluation and easy to use. Finite element analysis is used to validate the accuracy of the proposed models.

  2. Motor Integrated Permanent Magnet Gear with a Wide Torque-Speed Range

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Matzen, Torben N.; Jahns, T. M.

    2009-01-01

    This paper present a new motor integrated permanent magnet gear with a wide torque-speed range. In the paper a 35 kW permanent magnet motor with a base speed of 4000 rpm and a top speed of 14000 rpm is integrated into a permanent magnetic gear with a gearing ratio of 8.67. The design process...

  3. 75 FR 55301 - Proposed Information Collection; Comment Request; Northeast Region Gear Identification Requirements

    Science.gov (United States)

    2010-09-10

    ...., buoys, radar reflectors, or other methods identified in the regulations). The number of gear in the case... be responsible for marking several strings of a given type of gear, or may use multiple different gear types that require marking for identification and visibility. The display of the identifying...

  4. Development of a high-performance magnetic gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank Thorleif

    2005-01-01

    components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81 %. A large magnetic 1055 component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses of magnetic origin...

  5. Use of Protective Gear in Bird Flu Outbreak Response

    Centers for Disease Control (CDC) Podcasts

    CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDC’s journal, Emerging Infectious Diseases.

  6. 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.)

  7. PRINCIPLE "EARLY MATCHING" AERODYNAMIC DESIGN AIRCRAFT WITH LANDING GEAR HOVERCRAFT

    Directory of Open Access Journals (Sweden)

    V. P. Morozov

    2015-01-01

    Full Text Available The principle of "early matching" aircraft aerohydrodynamic layouts with air cushion landing gear is suggested. Application of this principle is considered as an example of adaptation to the ball screw base circuit of light transport aircraft. The principle, other than weight, aerodynamic, technological and operational requirements includes additional project activities related to the installation of ball screws.

  8. 181 checklist and assessment of efficiency of some traditional gears

    African Journals Online (AJOL)

    Department of Fisheries And Aquaculture, University Of Agriculture, P.M.B. 2373,. Makurdi ... The efficiency and use of the gears and crafts was also seasonally ... water, fishing extensively with baskets and ... improved by the introduction of a few .... Fish Culture in undrainable ponds. Reed W, J. Burchard, A.J Hopson and J.

  9. 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.

  10. Gear-based species selectivity and potential interactions between ...

    African Journals Online (AJOL)

    ... and competition between different co-occurring fisheries is therefore important for the implementation of ecosystem based fisheries management interventions. In this study, we used multivariate and ecological approaches to evaluate gear competition and interactions between artisanal and aquarium fishers using a case ...

  11. Impedance Synthesis Based Vibration Analysis of Geared Transmission System

    Directory of Open Access Journals (Sweden)

    Yafeng Ren

    2017-01-01

    Full Text Available The severity of gear noise response depends on the sensitivity of geared rotor system dynamics to the transmission error. As gearbox design trending towards lighter weight and lower noise, the influence of housing compliance on system dynamic characteristics cannot be ignored. In this study, a gear-shaft-bearing-housing coupled impedance model is proposed to account for the effect of housing compliance on the vibration of geared transmission system. This proposed dynamic model offers convenient modeling, efficient computing, and ability to combine computed parameters with experimental ones. The numerical simulations on system dynamic characteristics are performed for both a rigid housing configuration and a flexible one. Natural frequencies, dynamic mesh forces, and dynamic bearing reaction loads are computed, and the housing compliance contribution on system dynamic characteristics is analyzed. Results show that increasing housing compliance will decrease the system natural frequencies and will affect the dynamic bearing reaction loads significantly but have very little influence on the dynamic mesh force. Also, the analysis shows that bearing stiffness has significant influence on the degree of housing contribution on system dynamic characteristics.

  12. Marine Hydrokinetic Power Take-Off Using Magnetic Gearing

    OpenAIRE

    Bird, Jonathan Z.

    2014-01-01

    This paper reviews different power take-off approaches for rotary based marine hydrokinetic power generation. The technology for wind power generation is used as a guide. A discussion on the potential benefits of utilizing magnetic gearing is presented. University of North Carolina at Chapel Hill. Coastal Studies Institute

  13. LOADING OF MECHANICAL TRANSMISSION OF TROLLEYBUS TRACTION DRIVING GEAR

    Directory of Open Access Journals (Sweden)

    A. I. Safonov

    2009-01-01

    Full Text Available The paper analyzes factors that determine dynamic loads of mechanical transmission of trolleybus traction driving gear. The paper proposes a methodology for determination of calculative moments of loading transmission elements. Results of the research are analyzed and recommendations on  dynamic reduction of trolleybus transmission are given in the paper. 

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

    African Journals Online (AJOL)

    There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric ...

  15. 50 CFR 600.510 - Gear avoidance and disposal.

    Science.gov (United States)

    2010-10-01

    ... gear in the EEZ. (3) If these articles or substances are encountered, or in the event of accidental or... Section 600.510 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... include: (1) The name of the reporting vessel. (2) A description of the incident and articles retrieved...

  16. Customization of worm gear drives; Schneckengetriebemotoren werden kundenspezifisch angepasst

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Reinhold

    2009-08-31

    As a result of the diverse wishes of their customers, producers of motors and gears are faced with strongly varying machine and system configurations. It may be necessary to develop components that are not part of the manufacturer's original portfolio but may be obtained by new developments or further development of existing components. (orig.)

  17. From testbed to reality grid computing steps up a gear

    CERN Multimedia

    2004-01-01

    "UK plans for Grid computing changed gear this week. The pioneering European DataGrid (EDG) project came to a successful conclusion at the end of March, and on 1 April a new project, known as Enabling Grids for E-Science in Europe (EGEE), begins" (1 page)

  18. 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.

  19. Dynamics of simple gearing model with flexible planetary pins

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk; Radolfová, Alena

    2016-01-01

    Roč. 821, č. 2016 (2016), s. 284-281 ISSN 1660-9336 R&D Projects: GA TA ČR TA04011656 Institutional support: RVO:61388998 Keywords : lanetary gearings set * vibrations * rig wheel excitation * driving aggregate Subject RIV: BI - Acoustics

  20. 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.

  1. Space Shuttle Program (SSP) Shock Test and Specification Experience for Reusable Flight Hardware Equipment

    Science.gov (United States)

    Larsen, Curtis E.

    2012-01-01

    As commercial companies are nearing a preliminary design review level of design maturity, several companies are identifying the process for qualifying their multi-use electrical and mechanical components for various shock environments, including pyrotechnic, mortar firing, and water impact. The experience in quantifying the environments consists primarily of recommendations from Military Standard-1540, Product Verification Requirement for Launch, Upper Stage, and Space Vehicles. Therefore, the NASA Engineering and Safety Center (NESC) formed a team of NASA shock experts to share the NASA experience with qualifying hardware for the Space Shuttle Program (SSP) and other applicable programs and projects. Several team teleconferences were held to discuss past experience and to share ideas of possible methods for qualifying components for multiple missions. This document contains the information compiled from the discussions

  2. Genomic selection needs to be carefully assessed to meet specific requirements in livestock breeding programs.

    Science.gov (United States)

    Jonas, Elisabeth; de Koning, Dirk-Jan

    2015-01-01

    Genomic selection is a promising development in agriculture, aiming improved production by exploiting molecular genetic markers to design novel breeding programs and to develop new markers-based models for genetic evaluation. It opens opportunities for research, as novel algorithms and lab methodologies are developed. Genomic selection can be applied in many breeds and species. Further research on the implementation of genomic selection (GS) in breeding programs is highly desirable not only for the common good, but also the private sector (breeding companies). It has been projected that this approach will improve selection routines, especially in species with long reproduction cycles, late or sex-limited or expensive trait recording and for complex traits. The task of integrating GS into existing breeding programs is, however, not straightforward. Despite successful integration into breeding programs for dairy cattle, it has yet to be shown how much emphasis can be given to the genomic information and how much additional phenotypic information is needed from new selection candidates. Genomic selection is already part of future planning in many breeding companies of pigs and beef cattle among others, but further research is needed to fully estimate how effective the use of genomic information will be for the prediction of the performance of future breeding stock. Genomic prediction of production in crossbreeding and across-breed schemes, costs and choice of individuals for genotyping are reasons for a reluctance to fully rely on genomic information for selection decisions. Breeding objectives are highly dependent on the industry and the additional gain when using genomic information has to be considered carefully. This review synthesizes some of the suggested approaches in selected livestock species including cattle, pig, chicken, and fish. It outlines tasks to help understanding possible consequences when applying genomic information in breeding scenarios.

  3. Genomic selection needs to be carefully assessed to meet specific requirements in livestock breeding programs

    Directory of Open Access Journals (Sweden)

    Elisabeth eJonas

    2015-02-01

    Full Text Available Genomic selection is a promising development in agriculture, aiming improved production by exploiting molecular genetic markers to design novel breeding programs and to develop new markers-based models for genetic evaluation. It opens opportunities for research, as novel algorithms and lab methodologies are developed. Genomic selection can be applied in many breeds and species. Further research on the implementation of genomic selection in breeding programs is highly desirable not only for the common good, but also the private sector (breeding companies. It has been projected that this approach will improve selection routines, especially in species with long reproduction cycles, late or sex-limited or expensive trait recording and for complex traits. The task of integrating genomic selection into existing breeding programs is, however, not straightforward. Despite successful integration into breeding programs for dairy cattle, it has yet to be shown how much emphasis can be given to the genomic information and how much additional phenotypic information is needed from new selection candidates. Genomic selection is already part of future planning in many breeding companies of pigs and beef cattle among others, but further research is needed to fully estimate how effective the use of genomic information will be for the prediction of the performance of future breeding stock. Genomic prediction of production in crossbreeding and across-breed schemes, costs and choice of individuals for genotyping are reasons for a reluctance to fully rely on genomic information for selection decisions. Breeding objectives are highly dependent on the industry and the additional gain when using genomic information has to be considered carefully. This review synthesizes some of the suggested approaches in selected livestock species including cattle, pig, chicken and fish. It outlines tasks to help understanding possible consequences when applying genomic information in

  4. An integrated draft gear model with the consideration of wagon body structural characteristics

    Science.gov (United States)

    Chang, Gao; Liangliang, Yang; Weihua, Ma; Min, Zhang; Shihui, Luo

    2018-03-01

    With the increase of railway wagon axle load and the growth of marshalling quantity, the problem caused by impact and vibration of vehicles is increasingly serious, which leads to the damage of vehicle structures and the components. In order to improve the reliability of longitudinal connection model for vehicle impact tests, a new railway wagon longitudinal connection model was developed to simulate and analyse vehicle impact tests. The new model is based on characteristics of longitudinal force transmission for vehicles and parts. In this model, carbodies and bogies were simplified to a particle system that can vibrate in the longitudinal direction, which corresponded to a stiffness-damping vibration system. The model consists of three sub-models, that is, coupler and draft gear sub-model, centre plate sub-model and carbody structure sub-model. Compared with conventional draft gear models, the new model was proposed with geometrical and mechanical relations of friction draft gears considered and with behaviours of sticking, sliding and impact between centre plate and centre bowl added. Besides, virtual springs between discrete carbodies were built to describe the structural deformation of carbody. A computation program for longitudinal dynamics based on vehicle impact tests was accomplished to simulate. Comparisons and analyses regarding the train dynamics outputs and vehicle impact tests were conducted. Simulation results indicate that the new wagon longitudinal connection model can provide a practical application environment for wagons, and the outputs of vehicle impact tests agree with those of field tests. The new model can also be used to study on longitudinal vibrations of different vehicles, of carbody and bogie, and of carbody itself.

  5. Site-specific programming of the host epithelial transcriptome by the gut microbiota

    DEFF Research Database (Denmark)

    Sommer, Felix; Nookaew, Intawat; Sommer, Nina

    2015-01-01

    BACKGROUND: The intestinal epithelium separates us from the microbiota but also interacts with it and thus affects host immune status and physiology. Previous studies investigated microbiota-induced responses in the gut using intact tissues or unfractionated epithelial cells, thereby limiting....... The microbial impact on host gene expression was highly site specific, as epithelial responses to the microbiota differed between cell fractions. Specific transcriptional regulators were enriched in each fraction. In general, the gut microbiota induced a more rapid response in the colon than in the ileum...

  6. Specific balance training included in an endurance-resistance exercise program improves postural balance in elderly patients undergoing haemodialysis.

    Science.gov (United States)

    Frih, Bechir; Mkacher, Wajdi; Jaafar, Hamdi; Frih, Ameur; Ben Salah, Zohra; El May, Mezry; Hammami, Mohamed

    2018-04-01

    The purpose of this study was to evaluate the effects of 6 months of specific balance training included in endurance-resistance program on postural balance in haemodialysis (HD) patients. Forty-nine male patients undergoing HD were randomly assigned to an intervention group (balance training included in an endurance-resistance training, n = 26) or a control group (resistance-endurance training only, n = 23). Postural control was assessed using six clinical tests; Timed Up and Go test, Tinetti Mobility Test, Berg Balance Scale, Unipodal Stance test, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scale. All balance measures increased significantly after the period of rehabilitation training in the intervention group. Only the Timed Up and Go, Berg Balance Scale, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scores were improved in the control group. The ranges of change in these tests were greater in the balance training group. In HD patients, specific balance training included in a usual endurance-resistance training program improves static and dynamic balance better than endurance-resistance training only. Implications for rehabilitation Rehabilitation using exercise in haemodialysis patients improved global mobility and functional abilities. Specific balance training included in usual endurance resistance training program could lead to improved static and dynamic balance.

  7. Results of a Pilates exercise program in patients with chronic non-specific low back pain: a randomized controlled trial.

    Science.gov (United States)

    Valenza, M C; Rodríguez-Torres, J; Cabrera-Martos, I; Díaz-Pelegrina, A; Aguilar-Ferrándiz, M E; Castellote-Caballero, Y

    2017-06-01

    To investigate the effects of a Pilates exercise program on disability, pain, lumbar mobility, flexibility and balance in patients with chronic non-specific low back pain. Randomized controlled trial. University laboratory. A total of 54 patients with chronic non-specific low back pain. Patients were randomly allocated to an experimental group ( n=27) included in a Pilates exercise program or to a control group ( n=27) receiving information in a form of a leaflet. Disability (Roland-Morris Disability Questionnaire and Oswestry Disability Index), current, average and pain at it least and at its worst (Visual Analogue Scales), lumbar mobility (modified Shober test), flexibility (finger-to-floor test) and balance (single limb stance test) were measured at baseline and after the intervention. A between-group analysis showed significant differences in the intervention group compared to the control group for both disability scores, the Rolland-Morris questionnaire (mean change±standard deviation of 5.31±3.37 and 2.40±6.78 respectively and between-groups mean difference of 3.2 ± 4.12, p=0.003) and the Oswestry Disability Index ( ppain ( p=0.002) and pain at it least ( p=0.033), flexibility (0.032) and balance (0.043). An 8-week Pilates exercise program is effective in improving disability, pain, flexibility and balance in patients with chronic non-specific low back pain.

  8. Design of problem-specific evolutionary algorithm/mixed-integer programming hybrids: two-stage stochastic integer programming applied to chemical batch scheduling

    Science.gov (United States)

    Urselmann, Maren; Emmerich, Michael T. M.; Till, Jochen; Sand, Guido; Engell, Sebastian

    2007-07-01

    Engineering optimization often deals with large, mixed-integer search spaces with a rigid structure due to the presence of a large number of constraints. Metaheuristics, such as evolutionary algorithms (EAs), are frequently suggested as solution algorithms in such cases. In order to exploit the full potential of these algorithms, it is important to choose an adequate representation of the search space and to integrate expert-knowledge into the stochastic search operators, without adding unnecessary bias to the search. Moreover, hybridisation with mathematical programming techniques such as mixed-integer programming (MIP) based on a problem decomposition can be considered for improving algorithmic performance. In order to design problem-specific EAs it is desirable to have a set of design guidelines that specify properties of search operators and representations. Recently, a set of guidelines has been proposed that gives rise to so-called Metric-based EAs (MBEAs). Extended by the minimal moves mutation they allow for a generalization of EA with self-adaptive mutation strength in discrete search spaces. In this article, a problem-specific EA for process engineering task is designed, following the MBEA guidelines and minimal moves mutation. On the background of the application, the usefulness of the design framework is discussed, and further extensions and corrections proposed. As a case-study, a two-stage stochastic programming problem in chemical batch process scheduling is considered. The algorithm design problem can be viewed as the choice of a hierarchical decision structure, where on different layers of the decision process symmetries and similarities can be exploited for the design of minimal moves. After a discussion of the design approach and its instantiation for the case-study, the resulting problem-specific EA/MIP is compared to a straightforward application of a canonical EA/MIP and to a monolithic mathematical programming algorithm. In view of the

  9. Color-blind Behavioral Specifications for Transformations of Reactive Synchronous Programs

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Larsen, Kim Guldstrand; Wasowski, Andrzej

    2004-01-01

    We describe a language-based approach to derivation of software product lines. A single general model, described as an I/O-alternating transition system, is used as a description of the available functionality. Hierarchically organized behavioral specifications define the actual family members...

  10. A trial of a job-specific workers' health surveillance program for construction workers: study protocol

    NARCIS (Netherlands)

    Boschman, J.S.; van der Molen, H.F.; van Duivenbooden, C.; Sluiter, J.K.; Frings-Dresen, M.H.W.

    2011-01-01

    Dutch construction workers are offered periodic health examinations. This care can be improved by tailoring this workers health surveillance (WHS) to the demands of the job and adjust the preventive actions to the specific health risks of a worker in a particular job. To improve the quality of the

  11. Software development minimum guidance system. Algorithm and specifications of realizing special hardware processor data prefilter program

    International Nuclear Information System (INIS)

    Baginyan, S.A.; Govorun, N.N.; Tkhang, T.L.; Shigaev, V.N.

    1982-01-01

    Software development minimum guidance system for measuring pictures of bubble chamber on the base of a scanner (HPD) and special hardware processor (SHP) is described. The algorithm of selective filter is proposed. The local software structure and functional specifications of its major parts are described. Some examples of processing picture from HBC-1 (JINR) are also presented

  12. Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 5

    Science.gov (United States)

    1984-01-01

    The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. Detail drawings of several assemblies and subassemblies are given. This is the fifth book of volume 4.

  13. 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.

  14. A minimal set of tissue-specific hypomethylated CpGs constitute epigenetic signatures of developmental programming.

    Directory of Open Access Journals (Sweden)

    Alejandro Colaneri

    Full Text Available Cell specific states of the chromatin are programmed during mammalian development. Dynamic DNA methylation across the developing embryo guides a program of repression, switching off genes in most cell types. Thus, the majority of the tissue specific differentially methylated sites (TS-DMS must be un-methylated CpGs.Comparison of expanded Methyl Sensitive Cut Counting data (eMSCC among four tissues (liver, testes, brain and kidney from three C57BL/6J mice, identified 138,052 differentially methylated sites of which 23,270 contain CpGs un-methylated in only one tissue (TS-DMS. Most of these CpGs were located in intergenic regions, outside of promoters, CpG islands or their shores, and up to 20% of them overlapped reported active enhancers. Indeed, tissue-specific enhancers were up to 30 fold enriched in TS-DMS. Testis showed the highest number of TS-DMS, but paradoxically their associated genes do not appear to be specific to the germ cell functions, but rather are involved in organism development. In the other tissues the differentially methylated genes are associated with tissue-specific physiological or anatomical functions. The identified sets of TS-DMS quantify epigenetic distances between tissues, generated during development. We applied this concept to measure the extent of reprogramming in the liver of mice exposed to in utero or early postnatal nutritional stress. Different protocols of food restriction reprogrammed the liver methylome in different but reproducible ways.Thus, each identified set of differentially methylated sites constituted an epigenetic signature that traced the developmental programing or the early nutritional reprogramming of each exposed mouse. We propose that our approach has the potential to outline a number of disease-associated epigenetic states. The composition of differentially methylated CpGs may vary with each situation, behaving as a composite variable, which can be used as a pre-symptomatic marker for

  15. HBCUs Gear Up to Produce Hospitality Managers.

    Science.gov (United States)

    Murray, Chris

    1994-01-01

    Increasingly, historically black colleges and universities (HBCUs) are developing professional programs in hotel and restaurant management and travel and tourism. One objective is to train African Americans to become owners and operators of their own enterprises. An obstacle is the perception that hospitality careers involve menial labor. (MSE)

  16. Seismic safety margins research program. Phase I. Project VII: systems analysis specifications of computational approach

    International Nuclear Information System (INIS)

    Collins, J.D.; Hudson, J.M.; Chrostowski, J.D.

    1979-02-01

    A computational methodology is presented for the prediction of core melt probabilities in a nuclear power plant due to earthquake events. The proposed model has four modules: seismic hazard, structural dynamic (including soil-structure interaction), component failure and core melt sequence. The proposed modules would operate in series and would not have to be operated at the same time. The basic statistical approach uses a Monte Carlo simulation to treat random and systematic error but alternate statistical approaches are permitted by the program design

  17. High Performance Computing - Power Application Programming Interface Specification Version 2.0.

    Energy Technology Data Exchange (ETDEWEB)

    Laros, James H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grant, Ryan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Levenhagen, Michael J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Olivier, Stephen Lecler [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pedretti, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ward, H. Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Younge, Andrew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    Measuring and controlling the power and energy consumption of high performance computing systems by various components in the software stack is an active research area. Implementations in lower level software layers are beginning to emerge in some production systems, which is very welcome. To be most effective, a portable interface to measurement and control features would significantly facilitate participation by all levels of the software stack. We present a proposal for a standard power Application Programming Interface (API) that endeavors to cover the entire software space, from generic hardware interfaces to the input from the computer facility manager.

  18. Formal semantic specifications as implementation blueprints for real-time programming languages

    Science.gov (United States)

    Feyock, S.

    1981-01-01

    Formal definitions of language and system semantics provide highly desirable checks on the correctness of implementations of programming languages and their runtime support systems. If these definitions can give concrete guidance to the implementor, major increases in implementation accuracy and decreases in implementation effort can be achieved. It is shown that of the wide variety of available methods the Hgraph (hypergraph) definitional technique (Pratt, 1975), is best suited to serve as such an implementation blueprint. A discussion and example of the Hgraph technique is presented, as well as an overview of the growing body of implementation experience of real-time languages based on Hgraph semantic definitions.

  19. A content analysis of food references in television programming specifically targeting viewing audiences aged 11 to 14 years.

    Science.gov (United States)

    Roseman, Mary G; Poor, Morgan; Stephenson, Tammy J

    2014-01-01

    Examine food in cable television programming specifically targeting 11- to 14-year-olds ("tweens"). Content analysis of food-related scenes (FRS)-in which food was shown, mentioned, and/or consumed-in 880 minutes of programming was conducted. Five days of afternoon/early evening television programs on the Disney Channel. Food references were compared with USDA MyPlate and classified according to modified Ratio of Recommended to Restricted Food Components. The authors found 331 FRS, averaging 16.6 scenes/h. Preponderance of FRS was physiological needs (40.7%), followed by display (10%), party (8.5%), social event (8%), and retail store (6.6%). Snacks dominated 41% of FRS, and breakfast, lunch, and dinner were much lower in frequency. Half of FRS was visual only, followed by verbal only. Food references were not congruent with MyPlate recommendations; 42% of food items did not fit into MyPlate food groups. Only 24% of food items were fruit or vegetables, which is considerably less than recommended by MyPlate guidelines. Using modified Ratio of Recommended to Restricted Food Components, 66% of food items scored food, which likely influences tweens' attitudes and behaviors. Television programming may consider past approaches to tobacco smoking and health messages on television. More attention is warranted regarding television programming by nutrition educators, researchers, health professionals, and industry specialists. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  20. 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.

  1. Cost Savings From the Provision of Specific Methods of Contraception in a Publicly Funded Program

    Science.gov (United States)

    Rostovtseva, Daria P.; Brindis, Claire D.; Biggs, M. Antonia; Hulett, Denis; Darney, Philip D.

    2009-01-01

    Objectives. We examined the cost-effectiveness of contraceptive methods dispensed in 2003 to 955 000 women in Family PACT (Planning, Access, Care and Treatment), California's publicly funded family planning program. Methods. We estimated the number of pregnancies averted by each contraceptive method and compared the cost of providing each method with the savings from averted pregnancies. Results. More than half of the 178 000 averted pregnancies were attributable to oral contraceptives, one fifth to injectable methods, and one tenth each to the patch and barrier methods. The implant and intrauterine contraceptives were the most cost-effective, with cost savings of more than $7.00 for every $1.00 spent in services and supplies. Per $1.00 spent, injectable contraceptives yielded savings of $5.60; oral contraceptives, $4.07; the patch, $2.99; the vaginal ring, $2.55; barrier methods, $1.34; and emergency contraceptives, $1.43. Conclusions. All contraceptive methods were cost-effective—they saved more in public expenditures for unintended pregnancies than they cost to provide. Because no single method is clinically recommended to every woman, it is medically and fiscally advisable for public health programs to offer all contraceptive methods. PMID:18703437

  2. Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 3

    Science.gov (United States)

    1984-01-01

    The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. This volume contains the drawings and specifications developed for the final design. This volume is divided into 5 books of which this is the third, containing drawings 47A380074 through 47A380126. A full breakdown parts listing is provided as well as a where used list.

  3. Impact of an education program on parental knowledge of specific learning disability

    OpenAIRE

    Karande Sunil; Mehta Vishal; Kulkarni Madhuri

    2007-01-01

    Background :A supportive home environment is one of the factors that can favorably determine the outcome of specific learning disability (SpLD) in a school-going child. However, there is no reliable information available on parental knowledge about SpLD. Aims :To investigate parental knowledge of SpLD and to evaluate the impact of an educational intervention on it. Settings and Design : Prospective questionnaire-based study conducted in our clinic. Materials and Methods : From April to Novemb...

  4. 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

  5. Gear and survey efficiency of patent tongs for oyster populations on restoration reefs.

    Directory of Open Access Journals (Sweden)

    David M Schulte

    Full Text Available Surveys of restored oyster reefs need to produce accurate population estimates to assess the efficacy of restoration. Due to the complex structure of subtidal oyster reefs, one effective and efficient means to sample is by patent tongs, rather than SCUBA, dredges, or bottom cores. Restored reefs vary in relief and oyster density, either of which could affect survey efficiency. This study is the first to evaluate gear (the first full grab and survey (which includes selecting a specific half portion of the first grab for further processing efficiencies of hand-operated patent tongs as a function of reef height and oyster density on subtidal restoration reefs. In the Great Wicomico River, a tributary of lower Chesapeake Bay, restored reefs of high- and low-relief (25-45 cm, and 8-12 cm, respectively were constructed throughout the river as the first large-scale oyster sanctuary reef restoration effort (sanctuary acreage > 20 ha at one site in Chesapeake Bay. We designed a metal frame to guide a non-hydraulic mechanical patent tong repeatedly into the same plot on a restored reef until all oysters within the grab area were captured. Full capture was verified by an underwater remotely-operated vehicle. Samples (n = 19 were taken on nine different reefs, including five low- (n = 8 and four high-relief reefs (n = 11, over a two-year period. The gear efficiency of the patent tong was estimated to be 76% (± 5% standard error, whereas survey efficiency increased to 81% (± 10% due to processing. Neither efficiency differed significantly between young-of-the-year oysters (spat and adults, high- and low-relief reefs, or years. As this type of patent tong is a common and cost-effective tool to evaluate oyster restoration projects as well as population density on fished habitat, knowing the gear and survey efficiencies allows for accurate and precise population estimates.

  6. Gear and survey efficiency of patent tongs for oyster populations on restoration reefs.

    Science.gov (United States)

    Schulte, David M; Lipcius, Romuald N; Burke, Russell P

    2018-01-01

    Surveys of restored oyster reefs need to produce accurate population estimates to assess the efficacy of restoration. Due to the complex structure of subtidal oyster reefs, one effective and efficient means to sample is by patent tongs, rather than SCUBA, dredges, or bottom cores. Restored reefs vary in relief and oyster density, either of which could affect survey efficiency. This study is the first to evaluate gear (the first full grab) and survey (which includes selecting a specific half portion of the first grab for further processing) efficiencies of hand-operated patent tongs as a function of reef height and oyster density on subtidal restoration reefs. In the Great Wicomico River, a tributary of lower Chesapeake Bay, restored reefs of high- and low-relief (25-45 cm, and 8-12 cm, respectively) were constructed throughout the river as the first large-scale oyster sanctuary reef restoration effort (sanctuary acreage > 20 ha at one site) in Chesapeake Bay. We designed a metal frame to guide a non-hydraulic mechanical patent tong repeatedly into the same plot on a restored reef until all oysters within the grab area were captured. Full capture was verified by an underwater remotely-operated vehicle. Samples (n = 19) were taken on nine different reefs, including five low- (n = 8) and four high-relief reefs (n = 11), over a two-year period. The gear efficiency of the patent tong was estimated to be 76% (± 5% standard error), whereas survey efficiency increased to 81% (± 10%) due to processing. Neither efficiency differed significantly between young-of-the-year oysters (spat) and adults, high- and low-relief reefs, or years. As this type of patent tong is a common and cost-effective tool to evaluate oyster restoration projects as well as population density on fished habitat, knowing the gear and survey efficiencies allows for accurate and precise population estimates.

  7. The specifics of opiate abuse in women as a basis of prevention programs and treatment

    Directory of Open Access Journals (Sweden)

    Raketić Diana

    2013-01-01

    Full Text Available The aim of this research is to determine the specifics of opiate addiction in women in our environment, so as to create a specific plan of action in preventing and treatment opiate addiction in women based on the conducted description and results analysis. The sample consists of 32 examinees. Sociodempgraphic questionnaire and widely applied ASI structured interview (McLellan, Cacciola, 1982 were used. The results are in accordance with foreign research. 62.5% of opiate addicted women live with someone who is a drug addict, either as a family member or a partner. 40.6% of the examinees were physically abused, 21.9% were sexually abused as well, and 43.7% were positive for HCV. Positive criminal status and doing illegal business were present in 56% of the examinees. 56.3% of the examinees reported depression, while 84.4% are anxious. 65.6% are unemployed. Research results indicate some significant specifics of opiate addiction in women, with regard to which valuable recommendations for prevention and treatment can be made in our environment. Prevention and treatment must be multidisciplinary with the emphasis on the preserved capacities and the development of positive behavior in opiate addicted women.

  8. Research of HCR Gearing Properties from Warm Scuffing Damage Point of View

    Directory of Open Access Journals (Sweden)

    Kuzmanović Siniša

    2014-12-01

    Full Text Available The issue of design and dimensioning of HCR gearing, particularly of the gearings with an internal engagement, it nowadays, especially in the design of hybrid cars drives, highly topical. This kind of gearing has many advantages in operation, but at the same time it is more complicated in stage of its design and load capacity calculation. Authors in this contribution present some results of temperature scuffing research of internal and external HCR gearing. There are given the equations for calculation of warm scuffing resistance of both external and internal HCR gearing derived according to the integral temperature criterion.

  9. Large rotorcraft transmission technology development program

    Science.gov (United States)

    Mack, J. C.

    1983-01-01

    Testing of a U.S. Army XCH-62 HLH aft rotor transmission under NASA Contract NAS 3-22143 was successfully completed. This test establishes the feasibility of large, high power rotorcraft transmissions as well as demonstrating the resolution of deficiencies identified during the HLH advanced technology programs and reported by USAAMRDLTR-77-38. Over 100 hours of testing was conducted. At the 100% design power rating of 10,620 horsepower, the power transferred through a single spiral bevel gear mesh is more than twice that of current helicopter bevel gearing. In the original design of these gears, industry-wide design methods were employed and failures were experienced which identified problem areas unique to gear size. To remedy this technology shortfall, a program was developed to predict gear stresses using finite element analysis for complete and accurate representation of the gear tooth and supporting structure. To validate the finite element methodology gear strain data from the existing U.S. Army HLH aft transmission was acquired, and existing data from smaller gears were made available.

  10. Low Wind Speed Turbine Developments in Convoloid Gearing: Final Technical Report, June 2005 - October 2008

    Energy Technology Data Exchange (ETDEWEB)

    Genesis Partners LP

    2010-08-01

    This report presents the results of a study conducted by Genesis Partners LP as part of the United States Department of Energy Wind Energy Research Program to develop wind technology that will enable wind systems to compete in regions having low wind speeds. The purpose of the program is to reduce the cost of electricity from large wind systems in areas having Class 4 winds to 3 cents per kWh for onshore systems or 5 cents per kWh for offshore systems. This work builds upon previous activities under the WindPACT project, the Next Generation Turbine project, and Phase I of the Low Wind Speed Turbine (LWST) project. This project is concerned with the development of more cost-effective gearing for speed increasers for wind turbines.

  11. High Performance Computing - Power Application Programming Interface Specification Version 1.4

    Energy Technology Data Exchange (ETDEWEB)

    Laros III, James H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); DeBonis, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grant, Ryan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kelly, Suzanne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Levenhagen, Michael J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Olivier, Stephen Lecler [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pedretti, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    Measuring and controlling the power and energy consumption of high performance computing systems by various components in the software stack is an active research area [13, 3, 5, 10, 4, 21, 19, 16, 7, 17, 20, 18, 11, 1, 6, 14, 12]. Implementations in lower level software layers are beginning to emerge in some production systems, which is very welcome. To be most effective, a portable interface to measurement and control features would significantly facilitate participation by all levels of the software stack. We present a proposal for a standard power Application Programming Interface (API) that endeavors to cover the entire software space, from generic hardware interfaces to the input from the computer facility manager.

  12. A Program for Iron Economy during Deficiency Targets Specific Fe Proteins.

    Science.gov (United States)

    Hantzis, Laura J; Kroh, Gretchen E; Jahn, Courtney E; Cantrell, Michael; Peers, Graham; Pilon, Marinus; Ravet, Karl

    2018-01-01

    Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis ( Arabidopsis thaliana ) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome- b 6 f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency. © 2018 American Society of Plant Biologists. All Rights Reserved.

  13. Characterization of Factors Affecting Attainment of Glycemic Control in Asian Americans With Diabetes in a Culturally Specific Program

    Science.gov (United States)

    Le, Hung; Wong, Sophia; Iftikar, Tracy; Keenan, Hillary; King, George L.; Hsu, William C.

    2014-01-01

    Purpose The purpose of this study is to examine the effectiveness of a culturally specific pilot clinic for Asian Americans (AA) in reaching glycemic target and to characterize factors affecting the attainment of glycemic control in comparison with white counterparts. Methods This electronic health record review included all new AA patients with type 2 diabetes (n = 109) in a culturally specific program and a randomly selected sample of new white patients with type 2 diabetes (n = 218) in the adult clinic within the same time period and diabetes center. Results AA and whites had a comparable proportion of patients with A1C ≤7% (32.1%, 34.9%; P = .621) at baseline and after 12 months of care (48.6%, 56.0%; P = .210), with a similar A1C decline (−0.9% ± 1.6%, −0.8% ± 1.7%, P = .710) by 12 months. Factors associated with the lack of success in reaching target in AA but not in whites included older age, lower educational attainment, less likelihood of having health insurance, and a need for more educational visits. The percentage of AA reaching A1C ≤7%, as compared to whites, worsened among those with highest initial A1C when stratified by ascending quartiles (96.7% vs 85.2%, P = .101; 61.9% vs 58.9%, P = .813; 24.0% vs 37.7%, P = .230; 15.2% vs 35.4%, P = .044). Conclusion While a culturally specific diabetes program in a specialty setting achieved a similar glycemic outcome for AA compared with whites, reasons for not reaching glycemic target differed. The findings suggest that the elimination of diabetes disparities requires not only culturally and linguistically specific programs, but must also identify and address the socio-environmental differences unique to each population. PMID:23771841

  14. Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 4

    Science.gov (United States)

    1984-01-01

    The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator are documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This volume contains 5 books of which this is the fourth, providing drawings 47A380128 through 47A387125. In addition to the parts listing and where-used list, the logic design of the controller software and the code listing of the controller software are provided. Also given are the aerodynamic profile coordinates.

  15. Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 2

    Science.gov (United States)

    1984-01-01

    The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This is the second book of volume four. Some of the items it contains are specs for the emergency shutdown panel, specs for the simulator software, simulator hardware specs, site operator terminal requirements, control data system requirements, software project management plan, elastomeric teeter bearing requirement specs, specs for the controls electronic cabinet, and specs for bolt pretensioning.

  16. Mod-5A Wind Turbine Generator Program Design Report. Volume 4: Drawings and Specifications, Book 1

    Science.gov (United States)

    1984-01-01

    The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 4 contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This is the first of five books of volume four. It contains structural design criteria, generator step-up transformer specs, specs for design, fabrication and testing of the system, specs for the ground control enclosure, systems specs, slip ring specs, and control system specs.

  17. Optimization of PHEV Power Split Gear Ratio to Minimize Fuel Consumption and Operation Cost

    Science.gov (United States)

    Li, Yanhe

    A Plug-in Hybrid Electric Vehicle (PHEV) is a vehicle powered by a combination of an internal combustion engine and an electric motor with a battery pack. The battery pack can be charged by plugging the vehicle to the electric grid and from using excess engine power. The research activity performed in this thesis focused on the development of an innovative optimization approach of PHEV Power Split Device (PSD) gear ratio with the aim to minimize the vehicle operation costs. Three research activity lines have been followed: • Activity 1: The PHEV control strategy optimization by using the Dynamic Programming (DP) and the development of PHEV rule-based control strategy based on the DP results. • Activity 2: The PHEV rule-based control strategy parameter optimization by using the Non-dominated Sorting Genetic Algorithm (NSGA-II). • Activity 3: The comprehensive analysis of the single mode PHEV architecture to offer the innovative approach to optimize the PHEV PSD gear ratio.

  18. The tribological failure diagnosis of spur gear by an expert system

    Science.gov (United States)

    Su, Y. L.; Lin, J. S.; Hsieh, S. K.

    1993-07-01

    The failure of tribo-elements at an early stage, before the designed lifetime, is attributable to the complex interaction of many factors, which can be diagnosed by various techniques. These techniques can be learned in a certain period of time, while the knowledge of failure analysis must have accumulated from a long experience of practical work. For this reason, a computerized expert system program, developed from artificial intelligence (PC Plus, an inference engine shell), was constructed for spur gear tribological failure diagnosis. The knowledge was expressed as many 'if-then' rules and a 'frame' structure of inheritance. Note that the certainty factor of the rules is itself a special characteristic of this system and the 'man-machine' interface is very friendly, the graphical interpretation being an example. The system was finally validated by the twin roller wear test which can be recognized as the motion of a spur gear near the pitch-line region. The failure characteristics of the worn rollers were transferred to the expert system by means of a 'user-friendly' interface to deduce the reason for the failure.

  19. Specific NIST projects in support of the NIJ Concealed Weapon Detection and Imaging Program

    Science.gov (United States)

    Paulter, Nicholas G.

    1998-12-01

    The Electricity Division of the National Institute of Standards and Technology is developing revised performance standards for hand-held (HH) and walk-through (WT) metal weapon detectors, test procedures and systems for these detectors, and a detection/imaging system for finding concealed weapons. The revised standards will replace the existing National Institute of Justice (NIJ) standards for HH and WT devices and will include detection performance specifications as well as system specifications (environmental conditions, mechanical strength and safety, response reproducibility and repeatability, quality assurance, test reporting, etc.). These system requirements were obtained from the Law Enforcement and corrections Technology Advisory Council, an advisory council for the NIJ. Reproducible and repeatable test procedures and appropriate measurement systems will be developed for evaluating HH and WT detection performance. A guide to the technology and application of non- eddy-current-based detection/imaging methods (such as acoustic, passive millimeter-wave and microwave, active millimeter-wave and terahertz-wave, x-ray, etc.) Will be developed. The Electricity Division is also researching the development of a high- frequency/high-speed (300 GH to 1 THz) pulse-illuminated, stand- off, video-rate, concealed weapons/contraband imaging system.

  20. Cell-Type-Specific Gene Programs of the Normal Human Nephron Define Kidney Cancer Subtypes.

    Science.gov (United States)

    Lindgren, David; Eriksson, Pontus; Krawczyk, Krzysztof; Nilsson, Helén; Hansson, Jennifer; Veerla, Srinivas; Sjölund, Jonas; Höglund, Mattias; Johansson, Martin E; Axelson, Håkan

    2017-08-08

    Comprehensive transcriptome studies of cancers often rely on corresponding normal tissue samples to serve as a transcriptional reference. In this study, we performed in-depth analyses of normal kidney tissue transcriptomes from the TCGA and demonstrate that the histological variability in cellularity, inherent in the kidney architecture, lead to considerable transcriptional differences between samples. This should be considered when comparing expression profiles of normal and cancerous kidney tissues. We exploited these differences to define renal-cell-specific gene signatures and used these as a framework to analyze renal cell carcinoma (RCC) ontogeny. Chromophobe RCCs express FOXI1-driven genes that define collecting duct intercalated cells, whereas HNF-regulated genes, specific for proximal tubule cells, are an integral part of clear cell and papillary RCC transcriptomes. These networks may be used as a framework for understanding the interplay between genomic changes in RCC subtypes and the lineage-defining regulatory machinery of their non-neoplastic counterparts. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. Evaluation of a draft standard on performance specifications for health physics instrumentation - program overview

    International Nuclear Information System (INIS)

    Kathren, R.L.; Selby, J.M.; Kenoyer, J.L.; Swinth, K.L.

    1983-01-01

    The draft ANSI Standard N42.17 on performance specifications for health physics instrumentation was written in 1981 by a task group that included both manufacturers and users of these instruments as well as representation from the regulatory bodies; the second draft of this standard is currently being evaluated by Pacific Northwest Laboratory. Objectives of this project include the evaluation of the applicability and practicality of the proposed standard and the determination of the degree of conformance of a cross-section of currently available commercial instruments to the proposed standard. This standard is being tested against such instruments as ionization chambers. G.M. detectors, alpha survey meters, and neutron dose equivalent survey meters. Radiological, electrical, mechanical, safety, and environmental performance criteria are specified and tests to evaluate conformance are detailed. Specific criteria which are discussed in this draft standard include inspection tests (e.g., readout units, scaling and zero set, decontamination, moisture protection, alarm threshold, battery status indication), AC and battery power requirements, alarm reset, stability, geotropism, response time, accuracy, precision, IER, beta, and neutron energy dependence, radiation overloads, angular dependence, extracameral response, nonionizing electromagnetic radiations, magnetic fields, interfering ionizing radiations, and effect of temperature, humidity, ambient pressure, shock, and vibration. The testing procedures were developed with emphasis on the requirements found in ANSI N42.17 with additional criteria from other draft and current ANSI and IEC standards

  2. Experiences of how fishers grab opportunities in (more) free regulation of gear

    DEFF Research Database (Denmark)

    Qvist Eliasen, Søren; Mortensen, Lars O.; Ulrich, Clara

    In the Minidisc project 14 vessels fished under conditions corresponding to free choose of gear. Based on the skippers initial idea of gear adjustment and a subsequent interview 6 months later the experiences of the skippers´ choice of “free” gear, the process for adjusting it and the tools...... for evaluating the efficiency and selectivity are discussed. Only incremental development using elements from previous used gear and other fisheries were found. Gear development took place in an interaction between the skipper and trawl maker, while no research was involved. This indicates that free choice...... of gear (under monitored discard ban) would lead to incremental adjustments. Parts of the fleet would have difficulties in evaluating the gear and subsequently optimise by adjusting. This would leave a need for support for development of evaluation procedures, especially among the small vessels. Radical...

  3. 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.

  4. 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.

  5. The Absolute Deviation Rank Diagnostic Approach to Gear Tooth Composite Fault

    Directory of Open Access Journals (Sweden)

    Guangbin Wang

    2017-01-01

    Full Text Available Aiming at nonlinear and nonstationary characteristics of the different degree with single fault gear tooth broken, pitting, and composite fault gear tooth broken-pitting, a method for the diagnosis of absolute deviation of gear faults is presented. The method uses ADAMS, respectively, set-up dynamics model of single fault gear tooth broken, pitting, and composite fault gear tooth broken-pitting, to obtain the result of different degree of broken teeth, pitting the single fault and compound faults in the meshing frequency, and the amplitude frequency doubling through simulating analysis. Through the comparison with the normal state to obtain the sensitive characteristic of the fault, the absolute value deviation diagnostic approach is used to identify the fault and validate it through experiments. The results show that absolute deviation rank diagnostic approach can realize the recognition of gear single faults and compound faults with different degrees and provide quick reference to determine the degree of gear fault.

  6. 50 CFR 300.109 - Gear disposal.

    Science.gov (United States)

    2010-10-01

    ... mammals and birds, except in cases of emergency involving the safety of the ship or crew, or as specifically authorized by communication from the appropriate USCG commander or authorized officer. These... “Marine Debris—A Potential Threat to Antarctic Marine Mammals” to each member of the crew of the...

  7. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program

    Science.gov (United States)

    Bergamini, Elena; Morelli, Francesca; Marchetti, Flavia; Vannozzi, Giuseppe; Polidori, Lorenzo; Paradisi, Francesco; Traballesi, Marco; Cappozzo, Aurelio

    2015-01-01

    As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i) proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii) developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8) equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group). The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program. PMID:26543852

  8. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program.

    Science.gov (United States)

    Bergamini, Elena; Morelli, Francesca; Marchetti, Flavia; Vannozzi, Giuseppe; Polidori, Lorenzo; Paradisi, Francesco; Traballesi, Marco; Cappozzo, Aurelio; Delussu, Anna Sofia

    2015-01-01

    As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i) proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii) developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8) equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group). The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program.

  9. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program

    Directory of Open Access Journals (Sweden)

    Elena Bergamini

    2015-01-01

    Full Text Available As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8 equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group. The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program.

  10. Artificial Neural Network Model for Monitoring Oil Film Regime in Spur Gear Based on Acoustic Emission Data

    Directory of Open Access Journals (Sweden)

    Yasir Hassan Ali

    2015-01-01

    Full Text Available The thickness of an oil film lubricant can contribute to less gear tooth wear and surface failure. The purpose of this research is to use artificial neural network (ANN computational modelling to correlate spur gear data from acoustic emissions, lubricant temperature, and specific film thickness (λ. The approach is using an algorithm to monitor the oil film thickness and to detect which lubrication regime the gearbox is running either hydrodynamic, elastohydrodynamic, or boundary. This monitoring can aid identification of fault development. Feed-forward and recurrent Elman neural network algorithms were used to develop ANN models, which are subjected to training, testing, and validation process. The Levenberg-Marquardt back-propagation algorithm was applied to reduce errors. Log-sigmoid and Purelin were identified as suitable transfer functions for hidden and output nodes. The methods used in this paper shows accurate predictions from ANN and the feed-forward network performance is superior to the Elman neural network.

  11. Specification and R and D Program on Magnet Alignment Tolerances for NSLS-II

    International Nuclear Information System (INIS)

    Kramer, S.L.; Jain, A.K.

    2009-01-01

    The NSLS-II light source is a proposed 3 GeV storage ring, with the potential for ultra-low emittance. Despite the reduced emittance goal for the bare lattice, the closed orbit amplification factors are on average >55 in both planes, for random quadrupole alignment errors. The high chromaticity will also require strong sextupoles and the low 3 GeV energy will require large dynamic and momentum aperture to insure adequate lifetime. This will require tight alignment tolerances (∼ 30(micro)m) on the multipole magnets during installation. By specifying tight alignment tolerances of the magnets on the support girders, the random alignment tolerances of the girders in the tunnel can be significantly relaxed. Using beam based alignment to find the golden orbit through the quadrupole centers, the closed orbit offsets in the multipole magnets will then be reduced to essentially the alignment errors of the magnets, restoring much of the dynamic aperture and lifetime of the bare lattice. Our R and D program to achieve these tight alignment tolerances of the magnets on the girders using a vibrating wire technique, will be discussed and initial results presented.

  12. The cost of crime to society: new crime-specific estimates for policy and program evaluation.

    Science.gov (United States)

    McCollister, Kathryn E; French, Michael T; Fang, Hai

    2010-04-01

    Estimating the cost to society of individual crimes is essential to the economic evaluation of many social programs, such as substance abuse treatment and community policing. A review of the crime-costing literature reveals multiple sources, including published articles and government reports, which collectively represent the alternative approaches for estimating the economic losses associated with criminal activity. Many of these sources are based upon data that are more than 10 years old, indicating a need for updated figures. This study presents a comprehensive methodology for calculating the cost to society of various criminal acts. Tangible and intangible losses are estimated using the most current data available. The selected approach, which incorporates both the cost-of-illness and the jury compensation methods, yields cost estimates for more than a dozen major crime categories, including several categories not found in previous studies. Updated crime cost estimates can help government agencies and other organizations execute more prudent policy evaluations, particularly benefit-cost analyses of substance abuse treatment or other interventions that reduce crime. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Mental Health of Adults Treated in Adolescence with Scoliosis-Specific Exercise Program or Observed for Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Maciej Płaszewski

    2014-01-01

    Full Text Available Objective. To examine general mental health in adult males and females, who in adolescence participated in a scoliosis-specific therapeutic exercise program or were under observation due to diagnosis of scoliosis. Design. Registry-based, cross-sectional study with retrospective data collection. Methods. Sixty-eight subjects (43 women aged 30.10 (25–39 years, with mild or moderate scoliosis (11–36° Cobb angle, and 76 (38 women nonscoliotic subjects, aged 30.11 (24–38 years, participated. The time period since the end of the exercise or observation regimes was 16.5 (12-26 years. Beck Depression Inventory (BDI and General Health Questionnaire (GHQ-28 scores were analyzed with the χ2 and U tests. Multiple regression analyses for confounders were also performed. Results. Intergroup differences of demographic characteristics were nonsignificant. Scoliosis, gender, participation in the exercise program, employment, and marital status were associated with BDI scores. The presence of scoliosis and participation in the exercise program manifested association with the symptoms. Higher GHQ-28 “somatic symptoms” subscale scores interacted with the education level. Conclusions. Our findings correspond to the reports of a negative impact of the diagnosis of scoliosis and treatment on mental health. The decision to introduce a therapeutic program in children with mild deformities should be made with judgment of potential benefits, risks, and harm.

  14. Development of a model of machine hand eye coordination and program specifications for a topological machine vision system

    Science.gov (United States)

    1972-01-01

    A unified approach to computer vision and manipulation is developed which is called choreographic vision. In the model, objects to be viewed by a projected robot in the Viking missions to Mars are seen as objects to be manipulated within choreographic contexts controlled by a multimoded remote, supervisory control system on Earth. A new theory of context relations is introduced as a basis for choreographic programming languages. A topological vision model is developed for recognizing objects by shape and contour. This model is integrated with a projected vision system consisting of a multiaperture image dissector TV camera and a ranging laser system. System program specifications integrate eye-hand coordination and topological vision functions and an aerospace multiprocessor implementation is described.

  15. Model-Based Requirements Management in Gear Systems Design Based On Graph-Based Design Languages

    Directory of Open Access Journals (Sweden)

    Kevin Holder

    2017-10-01

    Full Text Available For several decades, a wide-spread consensus concerning the enormous importance of an in-depth clarification of the specifications of a product has been observed. A weak clarification of specifications is repeatedly listed as a main cause for the failure of product development projects. Requirements, which can be defined as the purpose, goals, constraints, and criteria associated with a product development project, play a central role in the clarification of specifications. The collection of activities which ensure that requirements are identified, documented, maintained, communicated, and traced throughout the life cycle of a system, product, or service can be referred to as “requirements engineering”. These activities can be supported by a collection and combination of strategies, methods, and tools which are appropriate for the clarification of specifications. Numerous publications describe the strategy and the components of requirements management. Furthermore, recent research investigates its industrial application. Simultaneously, promising developments of graph-based design languages for a holistic digital representation of the product life cycle are presented. Current developments realize graph-based languages by the diagrams of the Unified Modelling Language (UML, and allow the automatic generation and evaluation of multiple product variants. The research presented in this paper seeks to present a method in order to combine the advantages of a conscious requirements management process and graph-based design languages. Consequently, the main objective of this paper is the investigation of a model-based integration of requirements in a product development process by means of graph-based design languages. The research method is based on an in-depth analysis of an exemplary industrial product development, a gear system for so-called “Electrical Multiple Units” (EMU. Important requirements were abstracted from a gear system

  16. Performance evaluation on vibration control of MR landing gear

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D Y; Nam, Y J; Park, M K [Graduate School, Pusan National University, Busan 609-735 (Korea, Republic of); Yamane, R [Kokushikan University, 4-28-1 Setagaya, Setagaya-ku, Tokyo 154-8515 (Japan)], E-mail: ldy5577@yahoo.co.kr, E-mail: mkpark1@pusan.ac.kr

    2009-02-01

    This paper is concerned with the applicability of the developed MR damper to the landing gear system for the attenuating undesired shock and vibration in the landing and taxing phases. First of all, the experimental model of the MR damper is derived based on the results of performance evaluations. Next, a simplified skyhook controller, which is one of the most straightforward, but effective approaches for improving ride comport in vehicles with active suspensions, is formulated. Then, the vibration control performances of the landing gear system using the MR damper are theoretically evaluated in the landing phase of the aircraft. A series of simulation analyses show that the proposed MR damper with the skyhook controller is effective for suppressing undesired vibration of the aircraft body. Finally, the effectiveness of the simulation results are additionally verified via HILS (Hardware-in-the-loop-simulation) method.

  17. Inferring Gear Damage from Oil-Debris and Vibration Data

    Science.gov (United States)

    Dempsey, Paula

    2006-01-01

    A system for real-time detection of surface-fatigue-pitting damage to gears for use in a helicopter transmission is based on fuzzy-logic used to fuse data from sensors that measure oil-borne debris, referred to as "oil debris" in the article, and vibration signatures. A system to detect helicopter-transmission gear damage is beneficial because the power train of a helicopter is essential for propulsion, lift, and maneuvering, hence, the integrity of the transmission is critical to helicopter safety. To enable detection of an impending transmission failure, an ideal diagnostic system should provide real-time monitoring of the "health" of the transmission, be capable of a high level of reliable detection (with minimization of false alarms), and provide human users with clear information on the health of the system without making it necessary for them to interpret large amounts of sensor data.

  18. Longitudinal patterns of predominant asthma disease activity in pediatric patients enrolled in an asthma-specific disease management program.

    Science.gov (United States)

    Scott, Lyne; Nichols, Breck; Choi Kwong, Kenny Yat; Morphew, Tricia; Jones, Craig A

    2008-08-01

    To determine if patterns of predominant asthma disease activity are more closely related than baseline asthma severity to measures of morbidity (acute asthma attack, emergency room visit/hospitalization, missed school days, and/or steroid burst). Retrospective analysis was performed for inner-city Los Angeles asthmatic children (3 to 18 years of age) during their first year of enrollment in an asthma-specific disease management program. All measures of morbidity were more closely related to patterns of predominant disease activity than baseline severity. We conclude that patterns of predominant disease activity are a more significant predictor of asthma morbidity than is baseline severity.

  19. Dynamic Analysis for a Geared Turbofan Engine with Variable Area Fan Nozzle

    Science.gov (United States)

    Csank, Jeffrey T.; Thomas, George L.

    2017-01-01

    Aggressive design goals have been set for future aero-propulsion systems with regards to fuel economy, noise, and emissions. To meet these challenging goals, advanced propulsion concepts are being explored and current operating margins are being re-evaluated to find additional concessions that can be made. One advanced propulsion concept being evaluated is a geared turbofan with a variable area fan nozzle (VAFN), developed by NASA. This engine features a small core, a fan driven by the low pressure turbine through a reduction gearbox, and a shape memory alloy (SMA)-actuated VAFN. The VAFN is designed to allow both a small exit area for efficient operation at cruise, while being able to open wider at high power conditions to reduce backpressure on the fan and ensure a safe level of stall margin is maintained. The VAFN is actuated via a SMA-based system instead of a conventional system to decrease overall weight of the system, however, SMA-based actuators respond relatively slowly, which introduces dynamic issues that are investigated in this work. This paper describes both a control system designed specifically for issues associated with SMAs, and dynamic analysis of the geared turbofan VAFN with the SMA actuators. Also, some future recommendations are provided for this type of propulsion system.

  20. Development of Custom 465® Corrosion-Resisting Steel for Landing Gear Applications

    Science.gov (United States)

    Daymond, Benjamin T.; Binot, Nicolas; Schmidt, Michael L.; Preston, Steve; Collins, Richard; Shepherd, Alan

    2016-04-01

    Existing high-strength low-alloy steels have been in place on landing gear for many years owing to their superior strength and cost performance. However, there have been major advances in improving the strength of high-performance corrosion-resisting steels. These materials have superior environmental robustness and remove the need for harmful protective coatings such as chromates and cadmium now on the list for removal under REACH legislation. A UK government-funded collaborative project is underway targeting a refined specification Custom 465® precipitation hardened stainless steel to replace the current material on Airbus A320 family aircraft main landing gear, a main fitting component developed by Messier-Bugatti-Dowty. This is a collaborative project between Airbus, Messier-Bugatti-Dowty, and Carpenter Technology Corporation. An extensive series of coupon tests on four production Heats of the material have been conducted, to obtain a full range of mechanical, fatigue, and corrosion properties. Custom 465® is an excellent replacement to the current material, with comparable tensile strength and fracture toughness, better ductility, and very good general corrosion and stress corrosion cracking resistance. Fatigue performance is the only significant area of deficit with respect to incumbent materials, fatigue initiation being often related to carbo-titanium-nitride particles and cleavage zones.

  1. Bicycle-Related Shoulder Injuries: Etiology and the Need for Protective Gear.

    Science.gov (United States)

    Goldstein, Yariv; Dolkart, Oleg; Kaufman, Ehud; Amar, Eyal; Sharfman, Zachary T; Rath, Ehud; Mozes, Gavriel; Maman, Eran

    2016-01-01

    The popularity of bicycle riding for recreation, exercise and transportation has grown enormously in recent years, which has led to an increased incidence of bicycle-related injuries. While these injuries involve mainly the musculoskeletal system, data on shoulder-specific injuries incurred while bike riding are lacking. Classifying these shoulder injuries may provide insight and assistance in the creation and implementation of effective protective gear and measures. To investigate the types and mechanisms of shoulder injuries among cyclists. This study retrospectively examined all cyclists who incurred shoulder injuries while riding and were admitted to the emergency department and shoulder clinic between January 2008 and November 2013. The study included 157 subjects with various bicycle-related shoulder injuries treated with either conservative or surgical measures. Eighty-four percent of injuries were caused by a direct blow to the shoulder, 7% by falling on an outstretched hand, 6% were traction injuries, and 3% were due to hyperabduction. Nine different clinical types of injury were observed; the most common injuries were clavicle fractures (32%), followed by acromioclavicular joint dislocations (22%), rotator cuff tears (22%), and humeral fractures (8%). Fifty-one percent of subjects were managed with conservative care and the remaining patients required surgical interventions. Shoulder injuries incurred while riding a bicycle span the entire spectrum of shoulder injuries and often result in debilitating conditions. Although the use of helmets is increasing, there is currently no effective protective gear or measures to prevent riders from suffering shoulder injuries.

  2. 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.

  3. 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.

  4. Manufacturing Technology Research Needs of the Gear Industry

    Science.gov (United States)

    1987-12-31

    needs technical and financial help along with time to regain a little of its former position as a world class industry. The development of the National...8217 Association (BGMA) and the Instituite of Mechanical Engineers (IMechE) have recently jointly established the British Gear Assocation (BGA). Within the BGA is...Issues - Definition - Definition o Quality of Product or Function - Objectives - Bow are we Operating Now? o Response or Lead Time - Financial Impact

  5. Use of Protective Gear in Bird Flu Outbreak Response

    Centers for Disease Control (CDC) Podcasts

    2008-12-29

    CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDC’s journal, Emerging Infectious Diseases.  Created: 12/29/2008 by Emerging Infectious Diseases.   Date Released: 12/29/2008.

  6. Gene Expression Programs in Response to Hypoxia: Cell Type Specificity and Prognostic Significance in Human Cancers.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available BACKGROUND: Inadequate oxygen (hypoxia triggers a multifaceted cellular response that has important roles in normal physiology and in many human diseases. A transcription factor, hypoxia-inducible factor (HIF, plays a central role in the hypoxia response; its activity is regulated by the oxygen-dependent degradation of the HIF-1alpha protein. Despite the ubiquity and importance of hypoxia responses, little is known about the variation in the global transcriptional response to hypoxia among different cell types or how this variation might relate to tissue- and cell-specific diseases. METHODS AND FINDINGS: We analyzed the temporal changes in global transcript levels in response to hypoxia in primary renal proximal tubule epithelial cells, breast epithelial cells, smooth muscle cells, and endothelial cells with DNA microarrays. The extent of the transcriptional response to hypoxia was greatest in the renal tubule cells. This heightened response was associated with a uniquely high level of HIF-1alpha RNA in renal cells, and it could be diminished by reducing HIF-1alpha expression via RNA interference. A gene-expression signature of the hypoxia response, derived from our studies of cultured mammary and renal tubular epithelial cells, showed coordinated variation in several human cancers, and was a strong predictor of clinical outcomes in breast and ovarian cancers. In an analysis of a large, published gene-expression dataset from breast cancers, we found that the prognostic information in the hypoxia signature was virtually independent of that provided by the previously reported wound signature and more predictive of outcomes than any of the clinical parameters in current use. CONCLUSIONS: The transcriptional response to hypoxia varies among human cells. Some of this variation is traceable to variation in expression of the HIF1A gene. A gene-expression signature of the cellular response to hypoxia is associated with a significantly poorer prognosis

  7. An Artificial Intelligence Approach for Gears Diagnostics in AUVs.

    Science.gov (United States)

    Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano

    2016-04-12

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  8. New progressive technology of flat gears processing development

    Directory of Open Access Journals (Sweden)

    Михайло Володимирович Маргуліс

    2015-11-01

    Full Text Available Relevant scientific and technical problems in relation to mechanical engineering is development of new technological processes that make it possible to achieve high accuracy and durability of machine parts that meet the requirements imposed on them. So it is important to develop a new method to make a flat gear teeth by plastic deformation of the ingot. The article deals with the actual problem of improving productivity and quality of plane wheels teeth that are widely used in advanced wave, planetary and other transmissions. A progressive method to produce flat gear teeth gear by plastic deformation of the ingot with two knurl rollers alternately moving reciprocally in the direction not intersecting the axis of the ingot mounting surface has been described in the article. The working surface of the rollers corresponds to the resulting shape of the teeth. The schemes of the teeth installing and knurling have been shown. The necessary material and the heat treatment of the knurling tools have been described. Its use will significantly increase the wear resistance of the working surfaces of the teeth and their durability as well as to increase productivity and its manufacturing costs. The material of the rollers is BC15steel. The surface layer of the knurling tools was subjected to nitration, surface hardness being up to 65 HRC. Knurling is made in the5236P shaper suited for this purpose

  9. Die design and process optimization of plastic gear extrusion

    Science.gov (United States)

    Zhang, Lei; Fu, Zhihong; Yao, Chen; Zang, Gongzheng; Wan, Yue

    2018-01-01

    The flow velocity of the melt in the extruder was simulated by using software Polyflow, and the size of the die channel with the best flow uniformity was obtained. The die profile shape is obtained by reverse design. The length of the shaping section is determined by Ansys transient thermal analysis. According to the simulation results, the design and manufacture of extrusion die of plastic gear and vacuum cooling setting were obtained. The influence of the five process parameters on the precision of the plastic gear were studied by the single factor analysis method, such as the die temperature T, the screw speed R, the die spacing S, the vacuum degree M and the hauling speed V. The optimal combination of process parameters was obtained by using the neural network particle swarm optimization algorithm(T = 197.05 °C, R = 9.04rpm, S = 67mm, M = -0.0194MPa). The tooth profile deviation of the extruded plastic gear can reach 9 level of accuracy.

  10. An Artificial Intelligence Approach for Gears Diagnostics in AUVs

    Directory of Open Access Journals (Sweden)

    Graciliano Nicolás Marichal

    2016-04-01

    Full Text Available In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles, where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  11. Analysis of gear reducer housing using the finite element method

    Science.gov (United States)

    Miklos, I. Zs; Miklos, C. C.; Alic, C. I.; Raţiu, S.

    2018-01-01

    The housing is an important component in the construction of gear reducers, having the role of fixing the relative position of the shafts and toothed wheels. At the same time, the housing takes over, via the bearings, the shaft loads resulting when the toothed wheel is engaging another toothed mechanism (i.e. power transmission through belts or chains), and conveys them to the foundation on which it is anchored. In this regard, in order to ensure the most accurate gearing, a high stiffness of the housing is required. In this paper, we present the computer-aided 3D modelling of the housing (in cast version) of a single stage cylindrical gear reducer, using the Autodesk Inventor Professional software, on the principle of constructive sizing. For the housing resistance calculation, we carried out an analysis using the Autodesk Simulation Mechanical software to apply the finite element method, based on the actual loads, as well as a comparative study of the stress and strain distribution, for several tightening values of the retaining bolts that secure the cover and the foundation housing.

  12. Development of Plastic Gear for Power Transmission : Abnormal Wear on the Tooth Root and Tooth Fracture near Pitch Point

    OpenAIRE

    Terashima, Kenichi; Tsukamoto, Naohisa; Nishida, Noriteru; Shi, Jiasun

    1986-01-01

    Plastic gears have many excellent characteristics which are locking in metallic gears, such as corrosion resistance, self-lubrication, quiet running, and so forth. The meshing behavior of plastic gears is very different from that of metallic gears. Therefore, the life estimation is very difficult for plastic gears. In this paper, generating and growing mechanisms of abnormal wear which appears fatally near the root of plastic tooth are analyzed, and then it is clarified that tooth fractures w...

  13. Molecular Dynamics Simulation of a Multi-Walled Carbon Nanotube Based Gear

    Science.gov (United States)

    Han, Jie; Globus, Al; Srivastava, Deepak; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    We used molecular dynamics to investigate the properties of a multi-walled carbon nanotube based gear. Previous work computationally suggested that molecular gears fashioned from (14,0) single-walled carbon nanotubes operate well at 50-100 gigahertz. The gears were formed from nanotubes with teeth added via a benzyne reaction known to occur with C60. A modified, parallelized version of Brenner's potential was used to model interatomic forces within each molecule. A Leonard-Jones 6-12 potential was used for forces between molecules. The gear in this study was based on the smallest multi-walled nanotube supported by some experimental evidence. Each gear was a (52,0) nanotube surrounding a (37,10) nanotube with approximate 20.4 and 16,8 A radii respectively. These sizes were chosen to be consistent with inter-tube spacing observed by and were slightly larger than graphite inter-layer spacings. The benzyne teeth were attached via 2+4 cycloaddition to exterior of the (52,0) tube. 2+4 bonds were used rather than the 2+2 bonds observed by Hoke since 2+4 bonds are preferred by naphthalene and quantum calculations by Jaffe suggest that 2+4 bonds are preferred on carbon nanotubes of sufficient diameter. One gear was 'powered' by forcing the atoms near the end of the outside buckytube to rotate to simulate a motor. A second gear was allowed to rotate by keeping the atoms near the end of its outside buckytube on a cylinder. The ends of both gears were constrained to stay in an approximately constant position relative to each other, simulating a casing, to insure that the gear teeth meshed. The stiff meshing aromatic gear teeth transferred angular momentum from the powered gear to the driven gear. The simulation was performed in a vacuum and with a software thermostat. Preliminary results suggest that the powered gear had trouble turning the driven gear without slip. The larger radius and greater mass of these gears relative to the (14,0) gears previously studied requires a

  14. A New Model of the Fractional Order Dynamics of the Planetary Gears

    Directory of Open Access Journals (Sweden)

    Vera Nikolic-Stanojevic

    2013-01-01

    Full Text Available A theoretical model of planetary gears dynamics is presented. Planetary gears are parametrically excited by the time-varying mesh stiffness that fluctuates as the number of gear tooth pairs in contact changes during gear rotation. In the paper, it has been indicated that even the small disturbance in design realizations of this gear cause nonlinear properties of dynamics which are the source of vibrations and noise in the gear transmission. Dynamic model of the planetary gears with four degrees of freedom is used. Applying the basic principles of analytical mechanics and taking the initial and boundary conditions into consideration, it is possible to obtain the system of equations representing physical meshing process between the two or more gears. This investigation was focused to a new model of the fractional order dynamics of the planetary gear. For this model analytical expressions for the corresponding fractional order modes like one frequency eigen vibrational modes are obtained. For one planetary gear, eigen fractional modes are obtained, and a visualization is presented. By using MathCAD the solution is obtained.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Consolidated guidance about materials licenses: Program-specific guidance about portable gauge licenses. Final report; Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Vacca, P.C.; Whitten, J.E.; Pelchat, J.M.; Arredondo, S.A.; Matson, E.R.; Lewis, S.H.; Collins, D.J.; Santiago, P.A. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Industrial and Medical Nuclear Safety; Tingle, W. [Dept. of Environment, Health, and Natural Resources, Raleigh, NC (United States). Div. of Radiation Protection

    1997-05-01

    As part of its redesign of the materials licensing process, NRC is consolidating and updating numerous guidance documents into a single comprehensive repository as described in NUREG-1539 and draft NUREG-1541. NUREG-1556, Vol. 1, is the first program-specific guidance developed for the new process and will serve as a template for subsequent program-specific guidance. This document is intended for use by applicants, licensees, and NRC staff and will also be available to Agreement States. This document supersedes the guidance previously found in draft Regulatory Guide DG-0008, ``Applications for the Use of Sealed Sources in Portable Gauging Devices,`` and in NMSs Policy and guidance Directive 2-07, ``Standard Review Plan for Applications for Use of Sealed Sources in Portable Gauging Devices.`` This final report takes a more risk-informed, performance-based approach to licensing portable gauges, and reduces the information(amount and level of detail) needed to support an application to use these devices. It incorporates many suggests submitted during the comment period on draft NUREG-1556, Volume 1. When published, this final report should be used in preparing portable gauge license applications. NRC staff will use this final report in reviewing these applications.

  20. Consolidated guidance about materials licenses: Program-specific guidance about portable gauge licenses. Final report; Volume 1

    International Nuclear Information System (INIS)

    Vacca, P.C.; Whitten, J.E.; Pelchat, J.M.; Arredondo, S.A.; Matson, E.R.; Lewis, S.H.; Collins, D.J.; Santiago, P.A.; Tingle, W.

    1997-05-01

    As part of its redesign of the materials licensing process, NRC is consolidating and updating numerous guidance documents into a single comprehensive repository as described in NUREG-1539 and draft NUREG-1541. NUREG-1556, Vol. 1, is the first program-specific guidance developed for the new process and will serve as a template for subsequent program-specific guidance. This document is intended for use by applicants, licensees, and NRC staff and will also be available to Agreement States. This document supersedes the guidance previously found in draft Regulatory Guide DG-0008, ''Applications for the Use of Sealed Sources in Portable Gauging Devices,'' and in NMSs Policy and guidance Directive 2-07, ''Standard Review Plan for Applications for Use of Sealed Sources in Portable Gauging Devices.'' This final report takes a more risk-informed, performance-based approach to licensing portable gauges, and reduces the information(amount and level of detail) needed to support an application to use these devices. It incorporates many suggests submitted during the comment period on draft NUREG-1556, Volume 1. When published, this final report should be used in preparing portable gauge license applications. NRC staff will use this final report in reviewing these applications