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1

Heavy Lifting  

NSDL National Science Digital Library

In this activity, learners work in NASA teams to build balloon-powered rockets using identical parts and compete to launch the greatest number of paper clips to "space" (the ceiling). The rockets learners build model the Ares V heavy lift launchers that carry heavy payloads into orbit. This lesson plan includes background information, tips, discussion questions and answers, and a "Mission Report" sheet for learners.

Shearer, Deborah A.; Gregory L. Vogt, Ed D.

2012-06-26

2

Heavy Lift Launch Vehicle Concept  

NASA Technical Reports Server (NTRS)

During the Space Shuttle development phase, Marshall plarners concluded a Heavy Lift Launch Vehicle (HLLV) would be needed for successful Space Industrialization. Shown here in this 1976's artist's conception is an early version of the HLLV during launch.

2004-01-01

3

Heavy-lift airship dynamics  

NASA Technical Reports Server (NTRS)

The basic aerodynamic and dynamic properties of an example heavy-lift airship (HLA) configuration are analyzed using a nonlinear, multibody, 6-degrees-of-freedom digital simulation. The slung-payload model is described, and a preliminary analysis of the coupled vehicle-payload dynamics is presented. Trim calculations show the importance of control mixing selection and suggest performance deficiencies in crosswind stationkeeping for the unloaded example HLA. Numerically linearized dynamics of the unloaded vehicle exhibit a divergent yaw mode and an oscillatory pitch mode whose stability characteristic is sensitive to flight speed. An analysis of the vehicle-payload dynamics shows significant coupling of the payload dynamics with those of the basic HLA. It is shown that significant improvement in the vehicle's dynamic behavior can be achieved with the incorporation of a simple flight controller having proportional, rate, and integral-error feedbacks.

Tischler, M. B.; Ringland, R. F.; Jex, H. R.

1983-01-01

4

Heavy Lift & Propulsion Technology (HL&PT)  

NASA Video Gallery

Cris Guidi delivers a presentation from the Heavy Lift & Propulsion Technology (HL&PT) study team on May 25, 2010, at the NASA Exploration Enterprise Workshop held in Galveston, TX. The purpose of ...

5

NASA Heavy Lift Rotorcraft Systems Investigation  

NASA Technical Reports Server (NTRS)

The NASA Heavy Lift Rotorcraft Systems Investigation examined in depth several rotorcraft configurations for large civil transport, designed to meet the technology goals of the NASA Vehicle Systems Program. The investigation identified the Large Civil Tiltrotor as the configuration with the best potential to meet the technology goals. The design presented was economically competitive, with the potential for substantial impact on the air transportation system. The keys to achieving a competitive aircraft were low drag airframe and low disk loading rotors; structural weight reduction, for both airframe and rotors; drive system weight reduction; improved engine efficiency; low maintenance design; and manufacturing cost comparable to fixed-wing aircraft. Risk reduction plans were developed to provide the strategic direction to support a heavy-lift rotorcraft development. The following high risk areas were identified for heavy lift rotorcraft: high torque, light weight drive system; high performance, structurally efficient rotor/wing system; low noise aircraft; and super-integrated vehicle management system.

Johnson, Wayne; Yamauchi, Gloria K.; Watts, Michael E.

2005-01-01

6

Variable-Compliance Couplings For Heavy Lifting  

NASA Technical Reports Server (NTRS)

New coupling devices contain manual or electronically controlled, motorized drives that vary stiffnesses. Short, clamped lengths of cable provide compliance. Using threaded rods, cables stretched, relaxed, or folded to make coupling more or less stiff. In more-advanced device, brackets holding cables moved by stepping motor via gearbox and ball screw. Motor operates under computer control with position feedback. Control computer commands greater stiffness during operations requiring precise positioning, and greater compliance to accommodate manufacturing tolerances. Intended for use in wrist joints of robotic manipulators and other industrial equipment that must lift heavy objects.

Kerley, James; Eklund, Wayne; Burkhardt, Raymond; Richardson, George W.

1992-01-01

7

Current Status of NASA's Heavy Lift Plans  

NASA Technical Reports Server (NTRS)

Numerous studies since the Apollo Program of the 1960s have highlighted the benefits of - and the need for - a national heavy lift launch capability to support human exploration, science, national security, and commercial development of space. NASA's most recent and most refined effort to develop that heavy lift capability is the Ares V. Ares V is a key element of NASA's Constellation Program. It s overall goal s part of approved national space policy is to retire the Space Shuttle and develop its successor, complete the International Space Station, and resume human exploration beyond low Earth orbit (LEO), beginning with exploration of the Moon as a step to other destinations in the Solar System. Ares V s first role is that of cargo vehicle to carry a lunar lander into Earth orbit, rendezvous with astronauts launched on the smaller Ares I crew launch vehicle, and perform the trans lunar injection (TLI) mission to send the mated crew and lander vehicles to the Moon. The design reference missions (DRMs) envisioned for it also include direct lunar cargo flights and a human Mars mission. Although NASA's priority from the start of the Constellation Program to the present has been development of the Ares I and Orion crew vehicle to replace the retiring Shuttle fleet, the Ares team has made significant progress in understanding the performance, design trades, technology needs, mission scenarios, ground and flight operations, cost, and other factors associated with heavy lift development. The current reference configuration was selected during the Lunar Capabilities Concept Review (LCCR) in fall 2008. That design has served since then as a point of departure for further refinements and trades among five participating NASA field centers. Ares V development to date has benefited from progress on the Ares I due to commonality between the vehicles. The Ares I first stage completed a successful firing of a 5-segment solid rocket motor. The Ares I-X launch Numerous studies since the Apollo Program of the 1960s have highlighted the benefits of and the need for - a national heavy lift launch capability to support human exploration, science, national security, and commercial development of space. NASA s most recent and most refined effort to develop that heavy lift capability is the Ares V. Ares V is a key element of NASA s Constellation Program. It s overall goal s part of approved national space policy is to retire the Space Shuttle and develop its successor, complete the International Space Station, and resume human exploration beyond low Earth orbit (LEO), beginning with exploration of the Moon as a step to other destinations in the Solar System. Ares V s first role is that of cargo vehicle to carry a lunar lander into Earth orbit, rendezvous with astronauts launched on the smaller Ares I crew launch vehicle, and perform the trans lunar injection (TLI) mission to send the mated crew and lander vehicles to the Moon. The design reference missions (DRMs) envisioned for it also include direct lunar cargo flights and a human Mars mission. Although NASA s priority from the start of the Constellation Program to the present has been development of the Ares I and Orion crew vehicle to replace the retiring Shuttle fleet, the Ares team has made significant progress in understanding the performance, design trades, technology needs, mission scenarios, ground and flight operations, cost, and other factors associated with heavy lift development. The current reference configuration was selected during the Lunar Capabilities Concept Review (LCCR) in fall 2008. That design has served since then as a point of departure for further refinements and trades among five participating NASA field centers. Ares V development to date has benefited from progress on the Ares I due to commonality between the vehicles. The Ares I first stage completed a successful firing of a 5-segment solid rocket motor. The Ares I-X launch successfully demonstrated in suborbital flighhe ability to assemble, prepare, launch, control and recover the Ares I configuration and compare

Creech, Steve

2010-01-01

8

Heavy Lift Launch Capability with a New Hydrocarbon Engine  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office at NASA's George C. Marshall Space Flight Center was tasked to define the thrust requirement of a new liquid oxygen rich staged combustion cycle hydrocarbon engine that could be utilized in a launch vehicle to meet NASA s future heavy lift needs. Launch vehicle concepts were sized using this engine for different heavy lift payload classes. Engine out capabilities for one of the heavy lift configurations were also analyzed for increased reliability that may be desired for high value payloads or crewed missions. The applicability for this engine in vehicle concepts to meet military and commercial class payloads comparable to current ELV capability was also evaluated.

Threet, Grady E., Jr.; Holt, James B.; Philips, Alan D.; Garcia, Jessica A.

2011-01-01

9

Civil markets for buoyant heavy-lift vehicles  

NASA Technical Reports Server (NTRS)

Worldwide civil markets for heavy lift airships were investigated. Substantial potential market demand was identified for payloads of from 13 to 800 tons. The largest markets appear to be in applications to relieve port congestion, construction of power generating plants, and, most notably, logging. Because of significant uncertainties both in vehicle and market characteristics, further analysis will be necessary to verify the identified market potential of heavy lift airship concepts.

Mettam, P. J.; Hansen, D.; Ardema, M. D.

1981-01-01

10

Heavy Lift Launch Capability with a New Hydrocarbon Engine (NHE)  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office (ACO) at NASA Marshall Space Flight Center has analyzed over 2000 Ares V and other heavy lift concepts in the last 3 years. These concepts were analyzed for Lunar Exploration Missions, heavy lift capability to Low Earth Orbit (LEO) as well as exploratory missions to other near earth objects in our solar system. With the pending retirement of the Shuttle fleet, our nation will be without a civil heavy lift launch capability, so the future development of a new heavy lift capability is imperative for the exploration and large science missions our Agency has been tasked to deliver. The majority of the heavy lift concepts analyzed by ACO during the last 3 years have been based on liquid oxygen / liquid hydrogen (LOX/LH2) core stage and solids booster stage propulsion technologies (Ares V / Shuttle Derived and their variants). These concepts were driven by the decisions made from the results of the Exploration Systems Architecture Study (ESAS), which in turn, led to the Ares V launch vehicle that has been baselined in the Constellation Program. Now that the decision has been made at the Agency level to cancel Constellation, other propulsion options such as liquid hydrocarbon fuels are back in the exploration trade space. NASA is still planning exploration missions with the eventual destination of Mars and a new heavy lift launch vehicle is still required and will serve as the centerpiece of our nation s next exploration architecture s infrastructure. With an extensive launch vehicle database already developed on LOX/LH2 based heavy lift launch vehicles, ACO initiated a study to look at using a new high thrust (> 1.0 Mlb vacuum thrust) hydrocarbon engine as the primary main stage propulsion in such a launch vehicle.

Threet, Grady E., Jr.; Holt, James B.; Philips, Alan D.; Garcia, Jessica A.

2011-01-01

11

Plasma volume change during heavy-resistance weight lifting  

Microsoft Academic Search

Summary  Blood samples were obtained from six young men before, and over a 60-min period following a bout of heavy-resistance weight lifting to determine changes in plasma volume. Weight lifting consisted of three sets of four exercises (arm curl, bench press, bent-arm row, and squat) performed using 70% of one-repetition maximum for as many repetitions as possible. Plasma volume change was

Mitchell A. Collins; David W. Hill; Kirk J. Cureton; J. Jesse DeMello

1986-01-01

12

Designs and Technology Requirements for Civil Heavy Lift Rotorcraft  

NASA Technical Reports Server (NTRS)

The NASA Heavy Lift Rotorcraft Systems Investigation examined in depth several rotorcraft configurations for large civil transport, designed to meet the technology goals of the NASA Vehicle Systems Program. The investigation identified the Large Civil Tiltrotor as the configuration with the best potential to meet the technology goals. The design presented was economically competitive, with the potential for substantial impact on the air transportation system. The keys to achieving a competitive aircraft were low drag airframe and low disk loading rotors; structural weight reduction, for both airframe and rotors; drive system weight reduction; improved engine efficiency; low maintenance design; and manufacturing cost comparable to fixed-wing aircraft. Risk reduction plans were developed to provide the strategic direction to support a heavy-lift rotorcraft development. The following high risk areas were identified for heavy lift rotorcraft: high torque, light weight drive system; high performance, structurally efficient rotor/wing system; low noise aircraft; and super-integrated vehicle management system.

Johnson, Wayne; Yamauchi, Gloria K.; Watts, Michael E.

2006-01-01

13

Small helicopter could find niche in remote heavy lift operations  

SciTech Connect

A new helicopter specifically designed for external vertical lift operations, such as moving transportable rig components or seismic equipment in remote locations, operates more efficiently than most other medium or heavy-lift helicopters, according to manufacturer Kaman Aerospace. The single-pilot helicopter was designed as an aerial truck for efficient lifting of heavy loads but with the operating costs of a light-lift craft. The K-Max helicopter can lift more pounds of cargo per gallon of fuel consumed than other similar helicopters, according to Kaman. For example, to transport a 5,000-lb load at an elevation of 8,000 ft, the K-Max helicopter consumes 85 gal of fuel/hr. Under the same load conditions, the next most efficient commercially available helicopter consumes 160 gal of fuel/hr and requires two pilots. The 4,500-lb helicopter can lift 5,000 lb to an altitude of 8,000 ft or about 6,000 lb at low altitudes.

Not Available

1994-02-21

14

Fracture analysis of forks of a heavy duty lift truck  

Microsoft Academic Search

The fracture of the two forks of a heavy duty lift truck in operation at a harbour is described and discussed. The failure analysis included: mechanical tests for characterisation of the material, including tensile and Charpy tests; the study of a previous repair by welding carried out in one of the forks and the identification of consequential weld defects; the

M. V Figueiredo; F. M. F Oliveira; J. P. M Gonçalves; P. M. S. T de Castro; A. A Fernandes

2001-01-01

15

Feasibility of United States Flag Heavy Lift Shipping. Volume II. Report.  

National Technical Information Service (NTIS)

Heavy lift is defined as ship cargo units exceeding 100 tons or 80 feet length, or 15 feet width. This study identifies and describes the heavy lift units and market demands for heavy lift services, and estimated the 1978 international traffic available t...

B. V. Andrews

1977-01-01

16

Augmented heavy lift assist devices for enhanced safety performance  

NASA Astrophysics Data System (ADS)

Heavy lift assist devices are an important part of manufacturing facilities that involve large, heavy or bulky material. Many devices are available that provide lift but not motive force augmentation. In these devices, the physical strength of the operator is used to move and position the work piece. Due to large work piece inertial characteristics, inertial contributions from the lift device itself, and misuse of the assist manipulator, injuries may still occur. In this research, an approach is presented that provides reduced-authority actuation to the motive joints of the lift device that allows for augmentation of the human motion forces, provides a means of correcting injurious ergonomic interactions, and allows for high rate energy dissipation for payload trajectory control and emergency situations. The approach is to provide low torque input controlled by operator hand motions. These hand motions move the payload under a centralized trajectory generation scheme that uses modulated braking commands to impose motion constraints, such as object avoidance, resonance attenuation and ergonomic trajectory enhancement. The system is implemented in an virtual reality robot simulator that allows for the investigation of dynamic characteristics prior to the prototype stage.

Luecke, Greg R.; Tan, Kok-Leong; Simpson, Gary

1998-12-01

17

Current developments lighter than air systems. [heavy lift airships  

NASA Technical Reports Server (NTRS)

Lighter than air aircraft (LTA) developments and research in the United States and other countries are reviewed. The emphasis in the U.S. is on VTOL airships capable of heavy lift, and on long endurance types for coastal maritime patrol. Design concepts include hybrids which combine heavier than air and LTA components and characteristics. Research programs are concentrated on aerodynamics, flight dynamics, and control of hybrid types.

Mayer, N. J.

1981-01-01

18

Heavy-Lift for a New Paradigm in Space Operations  

NASA Technical Reports Server (NTRS)

NASA is developing an unprecedented heavy-lift capability to enable human exploration beyond low Earth orbit (LEO). This capability could also significantly enhance numerous other missions of scientific, national security, and commercial importance. That capability is currently configured as the Ares V cargo launch vehicle. This capability will eclipse the capability the United States lost with the retirement of the Saturn V. It is capable of launching roughly 53 percent more payload mass to trans lunar injection (TLI) and 30 percent more payload mass to LEO than its Apollo Program predecessor. Ares V is a major element of NASA's Constellation Program, which also includes the Ares I crew launch vehicle (CLV), Orion crew exploration vehicle (CEV), and a lunar lander for crew and cargo. As currently configured, Ares V will be capable of launching 413,800 pounds (187.7 mT) to LEO, 138,500 pounds (63 mT) direct to the Moon or 156,700 pounds (71.1 mT) in its dual-launch architecture role with Ares I. Its 33-foot (10 m) shroud provides unprecedented payload volume. Assessment of astronomy and planetary science payload requirements since spring 2008 has indicated that a Saturn V-class heavy-lift vehicle has the potential to support a range of payloads and missions. This vehicle configuration enables some missions previously considered difficult or impossible and enhances many others. Collaborative design/architecture inputs, exchanges, and analyses have already begun between scientists and payload developers. This early dialogue between NASA engineers and payload designers allows both communities to shape their designs and operational concepts to be mutually supportive to the extent possible with the least financial impact. This paper provides an overview of the capabilities of a heavy-lift vehicle to launch payloads with increased mass and/or volume and reduce technical and cost risk in both design and operations.

Morris, Bruce; Burkey, Martin

2010-01-01

19

Heavy Lift Vehicle (HLV) Avionics Flight Computing Architecture Study  

NASA Technical Reports Server (NTRS)

A NASA multi-Center study team was assembled from LaRC, MSFC, KSC, JSC and WFF to examine potential flight computing architectures for a Heavy Lift Vehicle (HLV) to better understand avionics drivers. The study examined Design Reference Missions (DRMs) and vehicle requirements that could impact the vehicles avionics. The study considered multiple self-checking and voting architectural variants and examined reliability, fault-tolerance, mass, power, and redundancy management impacts. Furthermore, a goal of the study was to develop the skills and tools needed to rapidly assess additional architectures should requirements or assumptions change.

Hodson, Robert F.; Chen, Yuan; Morgan, Dwayne R.; Butler, A. Marc; Sdhuh, Joseph M.; Petelle, Jennifer K.; Gwaltney, David A.; Coe, Lisa D.; Koelbl, Terry G.; Nguyen, Hai D.

2011-01-01

20

Ares V: Progress Toward a Heavy Lift Capability for the Heavy Lift Capability for the Moon and Beyond  

NASA Technical Reports Server (NTRS)

The NASA Ares Projects are developing the launch vehicles to move the United States and humanity beyond low earth orbit. Ares 1 is a crewed vehicle, and Ares V is a heavy-lift vehicle being designed to send crews and cargo to the Moon. The Ares V design is evolving and maturing toward an authority-to-proceed milestone in 2011. The Ares V vehicle will be considered a national asset, opening new worlds and creating unmatched opportunities for human exploration, science, national security, and space business.

Sumrall, Phil

2008-01-01

21

Heavy Lift Launch Vehicles for 1995 and Beyond  

NASA Technical Reports Server (NTRS)

A Heavy Lift Launch Vehicle (HLLV) designed to deliver 300,000 lb to a 540 n mi circular polar orbit may be required to meet national needs for 1995 and beyond. The vehicle described herein can accommodate payload envelopes up to 50 ft diameter by 200 ft in length. Design requirements include reusability for the more expensive components such as avionics and propulsion systems, rapid launch turnaround time, minimum hardware inventory, stage and component flexibility and commonality, and low operational costs. All ascent propulsion systems utilize liquid propellants, and overall launch vehicle stack height is minimized while maintaining a reasonable vehicle diameter. The ascent propulsion systems are based on the development of a new liquid oxygen/hydrocarbon booster engine and liquid oxygen/liquid hydrogen upper stage engine derived from today's SSME technology. Wherever possible, propulsion and avionics systems are contained in reusable propulsion/avionics modules that are recovered after each launch.

Toelle, R. (compiler)

1985-01-01

22

Study of Civil Markets for Heavy-Lift Airships  

NASA Technical Reports Server (NTRS)

The civil markets for heavy lift airships (HLAs) were defined by first identifying areas of most likely application. The operational suitability of HLAs for the applications identified were then assessed. The operating economics of HLAs were established and the market size for HLA services estimated by comparing HLA operating and economic characteristics with those of competing modes. The sensitivities of the market size to HLA characteristics were evaluated and the number and sizes of the vehicles required to service the more promising markets were defined. Important characteristics for future HLAs are discussed that were derived from the study of each application, including operational requirements, features enhancing profitability, military compatibility, improved design requirements, approach to entry into service, and institutional implications for design and operation.

Mettam, P. J.; Hansen, D.; Chabot, C.; Byrne, R.

1978-01-01

23

Occupational health impacts: offshore crane lifts in life cycle assessment  

Microsoft Academic Search

Background, Aim, and Scope  The identification and assessment of environmental tradeoffs is a strongpoint of life cycle assessment (LCA). A tradeoff made\\u000a in many product systems is the exchange of potential for occupational accidents with the additional use of energy and materials.\\u000a Net benefits of safety measures with respect to human health are best illustrated if the consequences avoided and health

Johan Pettersen; Edgar G. Hertwich

2008-01-01

24

Impact of Airfoils on Aerodynamic Optimization of Heavy Lift Rotorcraft  

NASA Technical Reports Server (NTRS)

Rotor airfoils were developed for two large tiltrotor designs, the Large Civil Tilt Rotor (LCTR) and the Military Heavy Tilt Rotor (MHTR). The LCTR was the most promising of several rotorcraft concepts produced by the NASA Heavy Lift Rotorcraft Systems Investigation. It was designed to carry 120 passengers for 1200 nm, with performance of 350 knots cruise at 30,000 ft altitude. A parallel design, the MHTR, had a notional mission of 40,000 Ib payload, 500 nm range, and 300 knots cruise at 4000 ft, 95 F. Both aircraft were sized by the RC code developed by the U. S. Army Aeroflightdynamics Directorate (AFDD). The rotors were then optimized using the CAMRAD II comprehensive analysis code. Rotor airfoils were designed for each aircraft, and their effects on performance analyzed by CAMRAD II. Airfoil design criteria are discussed for each rotor. Twist and taper optimization are presented in detail for each rotor, with discussions of performance improvements provided by the new airfoils, compared to current technology airfoils. Effects of stall delay and blade flexibility on performance are also included.

Acree, Cecil W., Jr.; Martin Preston B.; Romander, Ethan A.

2006-01-01

25

Feasibility of United States Flag Heavy Lift Shipping. Volume I. Summary.  

National Technical Information Service (NTIS)

This report briefly summarizes the technical report and appendices. The study described the demand for shipping of heavy lift units, defined as over 100 tons, or 80' length, or 15' width. Small ships for lift, float and roll cargo handling, conversions of...

B. V. Andrews

1977-01-01

26

Performance, Loads and Stability of Heavy Lift Tiltrotors  

NASA Technical Reports Server (NTRS)

Summaries of rotor performance are presented for a 124,000-lb Large Civil Tilt Rotor (LCTR) design, along with isolated-rotor and fully-coupled wing/rotor aeroelastic stability. A major motivation of the present research is the effect of size on rotor dynamics. Simply scaling up existing rotor designs to the vehicle size under study would result in unacceptable rotor weight. The LCTR was the most promising of several large rotorcraft concepts produced by the NASA Heavy Lift Rotorcraft Systems Investigation. It was designed to carry 120 passengers for 1200 nm, with performance of 350 knots at 30,000 ft altitude. Design features included a low-mounted wing and hingeless rotors, with a very low cruise tip speed of 350 ft/sec. The LCTR was sized by the'RC code developed by the U. S. Army Aeroflightdynamics Directorate. The rotor was then optimized using the CAMRAD II comprehensive analysis code. The blade and wing structures were designed by Pennsylvania State University to meet the rotor loads calculated by CAMRAD II and wing loads required for certification. Aeroelastic stability was confirmed by further CAMRAD II analysis, based on the optimized rotor and wing designs.

Acree, Cecil W., Jr.; Johnson, Wayne

2006-01-01

27

Knee osteoarthritis: influence of work involving heavy lifting, kneeling, climbing stairs or ladders, or kneeling\\/squatting combined with heavy lifting  

Microsoft Academic Search

The purpose of the study was to evaluate the evidence for an association between knee osteoarthritis (kneeOA) and physical work demands. Systematic searches were made, and epidemiological studies on kneeOA and heavy lifting, kneeling and climbing stairs published in 1966 to 2007 inclusive were reviewed. The quality of the studies was assessed and an overall evaluation of the degree of

L K Jensen

2008-01-01

28

Influence of breathing technique on arterial blood pressure during heavy weight lifting  

Microsoft Academic Search

Arterial hypertension occurring during heavy resistance exercise may be a risk factor for stroke in healthy young adults. Any training method that ameliorates the pressor effect of exercise should reduce the risk of stroke. The objective of this study was to observe the influence of breathing technique on arterial blood pressure (BP) generated during heavy, dynamic weight lifting. BP was

Joseph A. Narloch; Murray E. Brandstater

1995-01-01

29

The effect of heavy rain on an airfoil at high lift  

NASA Technical Reports Server (NTRS)

No serious studies of the relationship of heavy rain to aircraft safety were made until 1981 when it was suggested that the torrential rain which often occurs at the time of severe wind shear might substantially increase the danger to aircraft operating at slow speeds and high lift in the vicinity of airports. While these data were not published until early 1983, appropriate measures were taken by NASA to study the effect of heavy rain on the lift of wings typical of commercial aircraft. One of the aspects of these tests that seemed confirmed by the data was the existence of a velocity effect on the lift data. The data seemed to indicate that when all the normal non-dimensional aerodynamic parameters were used to sort out the data, the effect of velocity was not accounted for, as it usually is, by the effect of dynamic pressure. Indeed, the measured lift coefficients at high lift indicated a dropoff in lift coefficient for the same free-stream water content as velocity was increased. indicated a drop-off in lift coefficient for the same free-stream water content as velocity was increased.

Donaldson, Coleman DUP.; Sullivan, Roger D.

1987-01-01

30

The relative importance of whole body vibration and occupational lifting as risk factors for low-back pain  

PubMed Central

Aims: To explore the impact of occupational exposure to whole body vibration (WBV) on low back pain (LBP) in the general population and to estimate the burden of LBP attributable to occupational WBV in comparison with that due to occupational lifting. Methods: A questionnaire including sections on WBV at work, LBP, and potential risk factors was mailed to a community sample of 22 194 men and women of working age. Sources and durations of exposure to occupational WBV were ascertained for the past week and personal vibration doses (eVDV) were estimated. Analysis was confined to subjects reporting exposures in the past week as typical of their work. Associations of LBP with eVDV, driving industrial vehicles, and occupational lifting were explored by logistic regression and attributable numbers were calculated. Results: Significant associations were found between daily lifting of weights greater than 10 kg at work and LBP, troublesome LBP (which made it difficult to put on hosiery), and sciatica (prevalence ratios 1.3 to 1.7); but the risk of these outcomes in both sexes varied little by eVDV and only weak associations were found with riding on industrial vehicles. Assuming causal associations, the numbers of cases of LBP in Britain attributable to occupational WBV were estimated to be 444 000 in men and 95 000 in women. This compared with an estimated 940 000 male cases and 370 000 female cases of LBP from occupational lifting. Conclusions: The burden of LBP in Britain from occupational exposure to WBV is smaller than that attributable to lifting at work.

Palmer, K; Griffin, M; Syddall, H; Pannett, B; Cooper, C; Coggon, D

2003-01-01

31

Engine-Out Capabilities Assessment of Heavy Lift Launch Vehicles  

NASA Technical Reports Server (NTRS)

Engine-out (EO) is a condition that might occur during flight due to the failure of one or more engines. Protection against this occurrence can be called engine-out capability (EOC) whereupon significantly improved loss of mission may occur, in addition to reduction in performance and increased cost. A standardized engine-out capability has not been studied exhaustively as it pertains to space launch systems. This work presents results for a specific vehicle design with specific engines, but also uniquely provides an approach to realizing the necessity of EOC for any launch vehicle system design. A derived top-level approach to engine-out philosophy for a heavy lift launch vehicle is given herein, based on an historical assessment of launch vehicle capabilities. The methodology itself is not intended to present a best path forward, but instead provides three parameters for assessment of a particular vehicle. Of the several parameters affected by this EOC, the three parameters of interest in this research are reliability (Loss of Mission (LOM) and Loss of Crew (LOC)), vehicle performance, and cost. The intent of this effort is to provide insight into the impacts of EO capability on these parameters. The effects of EOC on reliability, performance and cost are detailed, including how these important launch vehicle metrics can be combined to assess what could be considered overall launch vehicle affordability. In support of achieving the first critical milestone (Mission Concept Review) in the development of the Space Launch System (SLS), a team assessed two-stage, large-diameter vehicles that utilized liquid oxygen (LOX)-RP propellants in the First Stage and LOX/LH2 propellant in the Upper Stage. With multiple large thrust-class engines employed on the stages, engine-out capability could be a significant driver to mission success. It was determined that LOM results improve by a factor of five when assuming EOC for both Core Stage (CS) (first stage) and Upper Stage (US) EO, assuming a reference launch vehicle with 5 RP engines on the CS and 3 LOX/LH2 engines on the US. The benefit of adding both CS and US engine-out capability is significant. When adding EOC for either first or second stages, there is less than a 20% benefit. Performance analysis has shown that if the vehicle is not protected for EO during the first part of the flight and only protected in the later part of the flight, there is a diminishing performance penalty, as indicated by failures occurring in the first stage at different times. This work did not consider any options to abort. While adding an engine for EOC drives cost upward, the impact depends on the number of needed engines manufactured per year and the launch manifest. There is a significant cost savings if multiple flights occur within one year. Flying two flights per year would cost approximately $4,000 per pound less than the same configuration with one flight per year, assuming both CS and US EOC. The cost is within 15% of the cost of one flight per year with no engine-out capability for the same vehicle. This study can be extended to other launch vehicles. While the numbers given in this paper are specific to a certain vehicle configuration, the process requires only a high level of data to allow an analyst to draw conclusions. The weighting of each of the identified parameters will determine the optimization of each launch vehicle. The results of this engine-out assessment provide a means to understand this optimization while maintaining an unbiased perspective.

Holladay, Jon; Baggett, Keithe; Thrasher, Chad; Bellamy, K. Scott; Feldman, Stuart

2012-01-01

32

The effects of atmospheric turbulence on a quadrotor heavy lift airship  

NASA Technical Reports Server (NTRS)

The response of a quadrotor heavy lift airship to atmospheric turbulence is evaluated using a four-point input model. Results show interaction between gust inputs and the characteristic modes of the vehicle's response. Example loop closures demonstrate tradeoffs between response regulation and structural loads. Vehicle responses to a tuned discrete wave front compare favorably with the linear results and illustrate characteristic HLA motion.

Tischler, M. B.; Jex, H. R.

1982-01-01

33

Two-axis hydraulic joint for high speed, heavy lift robotic operations  

SciTech Connect

A hydraulically driven universal joint was developed for a heavy lift, high speed nuclear waste remediation application. Each axis is driven by a simple hydraulic cylinder controlled by a jet pipe servovalve. Servovalve behavior is controlled by a force feedback control system, which damps the hydraulic resonance. A prototype single joint robot was built and tested. A two joint robot is under construction.

Vaughn, M.R.; Robinett, R.D.; Phelan, J.R.; VanZuiden, D.M.

1994-04-01

34

Lumbar spine loads during the lifting of extremely heavy weights.  

PubMed

The reaction moments at the knee, hip, and L4/L5 joints, and the compressive and shearing forces on L4/L5 are documented in powerlifters competing in a national powerlifting championship. Analyses were made of 13 female and 44 male competitors. The joint moments and forces were estimated from a linked segment model (WATBAK) that incorporated functional low back extensor musculature with a moment arm of 6 cm and a line action that was oriented 5 degrees posteriorly to the L4/L5 compression axis. This oblique orientation of the extensor muscles reduced the anterior shearing load on the vertebral motion unit. Average compressive loads on L4/L5 were estimated up to 17,192 N while the highest average L4/L5 and hip moments were 988 and 1047 N.m, respectively. The sumo deadlift style resulted in a 10% reduction in the joint moment and 8% reduction in the load shear force at the L4/L5 level when compared with the conventional lifting style. Formulation of linear regression equations to predict the load lifted using reaction joint moments yielded substantial unexplained variability, though significant relationships were found. This analysis suggested that there is large variability in the pattern of loading joints among national class powerlifters. PMID:1758295

Cholewicki, J; McGill, S M; Norman, R W

1991-10-01

35

Baggage handler seniority and musculoskeletal symptoms: is heavy lifting in awkward positions associated with the risk of pain?  

PubMed Central

Objectives Heavy lifting is associated with musculoskeletal disorders but it is unclear whether it is related to acute reversible effects or to chronic effects from cumulated exposure. The aim of this study was to examine whether musculoskeletal symptoms in Danish airport baggage handlers were associated with their seniority as baggage handler, indicating chronic effects from cumulated workload. Methods We established a group of baggage handlers employed at Copenhagen Airport during the period 1983–2012 (n=3092) and a reference group of men in other unskilled occupations with less heavy work (n=2478). Data regarding work history, lifestyle and musculoskeletal symptoms were collected using a self-administered questionnaire (response rate 70.1% among baggage handlers and 68.8% among the reference group). Results The ORs of self-reported musculoskeletal symptoms during the last 12?months in the neck/upper back, lower back, shoulders, elbows, wrists, hips and knees were significantly higher in baggage handlers than in the reference group. These differences were explained by significant linear effects of baggage handler seniority for six anatomical regions. Adjustment for age, body mass index, smoking and leisure-time physical activity did not change these results. The findings were stable over age strata and among present and former baggage handlers. Conclusions The risk of musculoskeletal symptoms in six anatomical regions increased with increasing seniority as a baggage handler. This is consistent with the assumption that cumulated heavy lifting may cause chronic or long-lasting musculoskeletal symptoms. However, we cannot exclude that other factors related to baggage handler seniority may explain some of the associations.

Bern, Stine Hvid; Brauer, Charlotte; M?ller, Karina Lauenborg; Koblauch, Henrik; Thygesen, Lau Caspar; Simonsen, Erik Bruun; Alkjaer, Tine; Bonde, Jens Peter; Mikkelsen, Sigurd

2013-01-01

36

Performance of Advanced Heavy-Lift, High-Speed Rotorcraft Configurations  

NASA Technical Reports Server (NTRS)

The aerodynamic performance of rotorcraft designed for heavy-lift and high-speed cruise is examined. Configurations considered include the tiltrotor, the compound helicopter, and the lift-offset rotor. Design conditions are hover and 250-350 knot cruise, at 5k/ISA+20oC (civil) or 4k/95oF (military); with cruise conditions at 4000 or 30,000 ft. The performance was calculated using the comprehensive analysis CAMRAD II, emphasizing rotor optimization and performance, including wing-rotor interference. Aircraft performance was calculated using estimates of the aircraft drag and auxiliary propulsion efficiency. The performance metric is total power, in terms of equivalent aircraft lift-to-drag ratio L/D = WV/P for cruise, and figure of merit for hover.

Johnson, Wayne; Yeo, Hyeonsoo; Acree, C. W., Jr.

2007-01-01

37

Heavy Lift Helicopter - Cargo Handling ATC Program. Volume II. Fabrication of Test Hardware and Fixtures (Integrated Test Rig).  

National Technical Information Service (NTIS)

This report formally documents the efforts and results of the cargo handling system segment of the Heavy Lift Helicopter (HLH) Advanced Technology Component (ATC) development program. The purpose of the HLH/ATC was to minimize technical, cost and schedule...

J. Shefrin W. F. Hill

1974-01-01

38

Lunar Lander Offloading Operations Using a Heavy-Lift Lunar Surface Manipulator System  

NASA Technical Reports Server (NTRS)

This study investigates the feasibility of using a heavy-lift variant of the Lunar Surface Manipulator System (LSMS-H) to lift and handle a 12 metric ton payload. Design challenges and requirements particular to handling heavy cargo were examined. Differences between the previously developed first-generation LSMS and the heavy-lift version are highlighted. An in-depth evaluation of the tip-over risk during LSMS-H operations has been conducted using the Synergistic Engineering Environment and potential methods to mitigate that risk are identified. The study investigated three specific offloading scenarios pertinent to current Lunar Campaign studies. The first involved offloading a large element, such as a habitat or logistics module, onto a mobility chassis with a lander-mounted LSMS-H and offloading that payload from the chassis onto the lunar surface with a surface-mounted LSMS-H. The second scenario involved offloading small pressurized rovers with a lander-mounted LSMS-H. The third scenario involved offloading cargo from a third-party lander, such as the proposed ESA cargo lander, with a chassis-mounted LSMS-H. In all cases, the analyses show that the LSMS-H can perform the required operations safely. However, Chariot-mounted operations require the addition of stabilizing outriggers, and when operating from the Lunar surface, LSMS-H functionality is enhanced by adding a simple ground anchoring system.

Jefferies, Sharon A.; Doggett, William R.; Chrone, Jonathan; Angster, Scott; Dorsey, John T.; Jones, Thomas C.; Haddad, Michael E.; Helton, David A.; Caldwell, Darrell L., Jr.

2010-01-01

39

A Longitudinal Study of Low-Back Pain as Associated with Occupational Weight Lifting Factors  

Microsoft Academic Search

A review of the biomechanics of weight lifting as it relates to low-back stresses is presented first. This serves as the basis for the development of a Lifting Strength Rating (LSR) methodology. Then a study is reported wherein the LSR methodology is used to evaluate 103 jobs having various amounts of required two-handed load lifting. The 411 people populating these

DON B. CHAFFIN; KYUNG S. PARK

1973-01-01

40

Generic multi-body formulation of heavy lift airship equations of motion  

NASA Technical Reports Server (NTRS)

This paper describes the formulation of a comprehensive set of equations which describe the dynamic behavior of a generic heavy lift airship (HLA). They are being used in a digital computer simulation to investigate the response dynamics and flying qualities of HLAs operating with various payloads in a variety of operational environments. A key feature is the separate treatment of each component body making up the HLA. This allows the analyst to vary the configuration (e.g., number of lift-propulsion units, presence or absence of slung payload, etc.) without rewriting the equations. It further provides measures of key structural and control loads acting on the HLA and eases the task of modeling wind disturbances.

Ringland, R. F.; Tischler, M. B.; Ashkenas, I. L.; Jex, H. R.

1980-01-01

41

Lifting of heavy oil with inert-gas-operated chamber pumps  

SciTech Connect

A description is given of an unconventional gas lift system which can replace rod pumping for shallow (<3,000 ft.) heavy oil production. The heart of this system is an insert chamber downhole, whose only moving parts are two standing valves. Produced fluid entering the chamber is periodically expelled into a production annulus by pressurized gas injected from the surface down a small injection string. Natural gas, inert gas, or even air can be used for pumping. This study analyzes the operation of the chamber lifting system and shows how to optimize the system design and the operating variables to obtain maximum production at minimum cost. With the close spacing of thermal wells (2-5 acres), the combination of a single inert gas generator and associated compressor to supply a large number of wells equipped with chamber pumps is feasible. Several types of inert gas generators are described. 7 refs.

Dewan, J.T.; Elfarr, J.

1981-01-01

42

Exploration Launch Projects RS-68B Engine Requirements for NASA's Heavy Lift Ares V  

NASA Technical Reports Server (NTRS)

NASA's Vision for Exploration requires a safe, efficient, reliable, and versatile launch vehicle capable of placing large payloads into Earth orbit for transfer to the Moon and destinations beyond. The Ares V Cargo Launch Vehicle (CaLV) will provide this heavy lift capability. The Ares V launch concept is shown in Fig. 1. When it stands on the launch pad at Kennedy Space Center late in the next decade, the Ares V stack will be almost 360 feet tall. As currently envisioned, it will lift 133,000 to 144,000 pounds to trans-lunar injection, depending on the length of loiter time on Earth orbit. This presentation will provide an overview of the Constellation architecture, the Ares launch vehicles, and, specifically, the latest developments in the RS-68B engine for the Ares V.

Sumrall, John P.; McArthur, J. Craig; Lacey, Matt

2007-01-01

43

Ares V: Designing the Heavy Lift Capability to Explore the Moon  

NASA Technical Reports Server (NTRS)

NASA's Vision for Exploration requires a safe, efficient, reliable, and versatile launch vehicle capable ofplacing large payloads into Earth orbit for transfer to the Moon and destinations beyond. The Ares V Cargo Launch Vehicle (CaLV) will provide this heavy lift capability. The Ares V launch concept is shown. When it stands on the launch pad at Kennedy Space Center late in the next decade, the Ares V stack will be almost 360 feet fall. As currently envisioned, it will lift 136 metric tons (300,000 pounds) to a 30-by-160 nautical mile orbit at 28.5-degrees inclination, or 55 metric tons (120,000 pounds) to trans-lunar injection. This paper will cover the latest developments in the Ares V project in 2007 and discuss future activities.

Sumrall, John P.; McArthur, Craig

2007-01-01

44

Low cost heavy lift launch vehicle for lunar exploration based on the Energia launcher  

NASA Astrophysics Data System (ADS)

Different mission strategies for large-scale lunar explorations using a low-cost heavy-lift launch vehicle based on the Energia launcher are examined. Using a parametrical cost model developed at the Berlin University of Technology, total life costs were determined for landing on the moon a cargo of 15 tons for $25,000/kg, showing it to be about half the cost of a comparable Saturn V/Apollo mission. It is noted that this opportunity for international cooperation is limited: the two complete Energia launchers which are presently stored will have to be launched within the next 3 to 5 years.

Lassmann, J.

1992-08-01

45

Definition of avionics concepts for a heavy lift cargo vehicle, volume 2  

NASA Technical Reports Server (NTRS)

A cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles is defined. The technology needs and requirements of future Heavy Lift Cargo Vehicles (HLCVs) are analyzed and serve as the basis for sizing of the avionics facility although the lab is not limited in use to support of HLCVs. Volume 2 is the technical volume and provides the results of the vehicle avionics trade studies, the avionics lab objectives, the lab's functional requirements and design, physical facility considerations, and a summary cost estimate.

1989-01-01

46

Definition of avionics concepts for a heavy lift cargo vehicle. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

A cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles is examined. The technology needs and requirements of future Heavy Lift Cargo Vehicles (HLCVs) are analyzed and serve as the basis for sizing of the avionics facility, although the lab is not limited in use to support of HLCVs. Volume 1 provides a summary of the vehicle avionics trade studies, the avionics lab objectives, a summary of the lab's functional requirements and design, physical facility considerations, and cost estimates.

1989-01-01

47

Foundation for Heavy Lift - Early Developments in the Ares V Launch Vehicle  

NASA Technical Reports Server (NTRS)

The Ares V Cargo Launch Vehicle (CaLV) is NASA's primary vessel for safe, reliable delivery of the Lunar Surface Access Module (LSAM) and other resources into Earth orbit, as articulated in the U.S. Vision for Space Exploration. The Ares V launch concept is shown. The foundation for this heavy-lift companion to the Ares I Crew Launch Vehicle (CLV) is taking shape within NASA and with its government and industry partners. This paper will address accomplishments in the Ares V Launch Vehicle during 2006 and 2007 and offer a preview of future activities.

McArthur, J. Craig; Pannell, Bill; Lacey, Matt

2007-01-01

48

Symmetric linear systems. [twin-lift helicopter control models for heavy construction use  

NASA Technical Reports Server (NTRS)

Employment as a means of transportation in the civilian construction trades represents one of the many applications of the helicopter. However, a major limitation to its use in heavy construction has been that the mass which can be effectively and safely transported is severely restricted. The construction of the so-called 'heavy lift' helicopter provided one solution to this problem. But it has been found that there are physical and economic limitations to the payload which can be transported. The proposal has been made to overcome these limitations by making use of multiple helicopters to move a single mass. A study of the feasibility of this proposal showed that automatic control would be needed to make the concept successful. The present investigation is concerned with some initial models in regard to the twinlift problem, taking into account the control theoretic problems.

Lewis, J.; Martin, C.

1983-01-01

49

Advanced transportation system studies. Technical area 2: Heavy lift launch vehicle development. Volume 2; Technical Results  

NASA Technical Reports Server (NTRS)

Sections 10 to 13 of the Advanced Transportation System Studies final report are included in this volume. Section 10 contains a copy of an executive summary that was prepared by Lockheed Space Operations Company (LSOC) to document their support to the TA-2 contract during the first-year period of performance of the contract, May 1992 through May 1993. LSOC participated on the TA-2 contract as part of the concurrent engineering launch system definition team, and provided outstanding heavy lift launch vehicle (HLLV) ground operations requirements and concept assessments for Lockheed Missiles and Space Company (LMSC) through an intercompany work transfer as well as providing specific HLLV ground operations assessments at the direction of NASA KSC through KSC funding that was routed to the TA-2 contract. Section 11 contains a copy of a vehicle-independent, launch system health management requirements assessment. The purpose of the assessment was to define both health management requirements and the associated interfaces between a generic advanced transportation system launch vehicle and all related elements of the entire transportation system, including the ground segment. Section 12 presents the major TA-2 presentations provided to summarize the significant results and conclusions that were developed over the course of the contract. Finally, Section 13 presents the design and assessment report on the first lunar outpost heavy lift launch vehicle.

1995-01-01

50

A Near-Term, High-Confidence Heavy Lift Launch Vehicle  

NASA Technical Reports Server (NTRS)

The use of well understood, legacy elements of the Space Shuttle system could yield a near-term, high-confidence Heavy Lift Launch Vehicle that offers significant performance, reliability, schedule, risk, cost, and work force transition benefits. A side-mount Shuttle-Derived Vehicle (SDV) concept has been defined that has major improvements over previous Shuttle-C concepts. This SDV is shown to carry crew plus large logistics payloads to the ISS, support an operationally efficient and cost effective program of lunar exploration, and offer the potential to support commercial launch operations. This paper provides the latest data and estimates on the configurations, performance, concept of operations, reliability and safety, development schedule, risks, costs, and work force transition opportunities for this optimized side-mount SDV concept. The results presented in this paper have been based on established models and fully validated analysis tools used by the Space Shuttle Program, and are consistent with similar analysis tools commonly used throughout the aerospace industry. While these results serve as a factual basis for comparisons with other launch system architectures, no such comparisons are presented in this paper. The authors welcome comparisons between this optimized SDV and other Heavy Lift Launch Vehicle concepts.

Rothschild, William J.; Talay, Theodore A.

2009-01-01

51

NASA's Space Launch System: A Heavy-Lift Platform for Entirely New Missions  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration s (NASA's) Space Launch System (SLS) will contribute a new capability for human space flight and scientific missions beyond low-Earth orbit. The SLS Program, managed at NASA s Marshall Space Fight Center, will develop the heavy-lift vehicle that will launch the Orion Multi-Purpose Crew Vehicle (MPCV), equipment, supplies, and major science missions. Orion will carry crews to space, provide emergency abort capability, sustain the crew during space travel, and provide safe reentry from deep-space return velocities. Supporting Orion s first autonomous flight to lunar orbit and back in 2017 and its first crewed flight in 2021, the SLS ultimately offers a flexible platform for both human and scientific exploration. The SLS plan leverages legacy infrastructure and hardware in NASA s inventory, as well as continues with advanced propulsion technologies now in development, to deliver an initial 70 metric ton (t) lift capability in 2017, evolving to a 130-t capability after 2021, using a block upgrade approach. This paper will give an overview of the SLS design and management approach against a backdrop of the missions it will support. It will detail the plan to deliver the initial SLS capability to the launch pad in the near term, as well as summarize the innovative approaches the SLS team is applying to deliver a safe, affordable, and sustainable long-range capability for entirely new missions opening a new realm of knowledge and a world of possibilities for multiple partners. Design reference missions that the SLS is being planned to support include asteroids, Lagrange Points, and Mars, among others. The Agency is developing its mission manifest in parallel with the development of a heavy-lift flagship that will dramatically increase total lift and volume capacity beyond current launch vehicle options, reduce trip times, and provide a robust platform for conducting new missions destined to rewrite textbooks with the information they deliver, while creating a framework for further collaboration among domestic and international partners, and potentially spurring economic expansion into new markets.

Creech, Stephen A.

2012-01-01

52

NASA's Space Launch System: A Heavy-Lift Platform for Entirely New Missions  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration's (NASA's) Space Launch System (SLS) will contribute a new capability for human space flight and scientific missions beyond low-Earth orbit (LEO). The SLS Program, managed at NASA s Marshall Space Flight Center, will develop the heavy-lift vehicle that will launch the Orion Multi-Purpose Crew Vehicle (MPCV), equipment, supplies, and major science missions for exploration and discovery. Orion will carry crews to space, provide emergency abort capability, sustain the crew during space travel, and provide safe reentry from deep-space return velocities. Supporting Orion s first autonomous flight to lunar orbit and back in 2017 and its first crewed flight in 2021, the SLS ultimately offers a flexible platform for both human and scientific exploration. The SLS plan leverages legacy infrastructure and hardware in NASA s inventory, as well as continues with advanced technologies now in development, to deliver an initial 70 metric ton (t) lift capability in 2017, evolving to a 130-t capability, using a block upgrade approach. This paper will give an overview of the SLS design and management approach against a backdrop of the missions it will support. It will detail the plan to deliver the initial SLS capability to the launch pad in the near term, as well as summarize the innovative approaches the SLS team is applying to deliver a safe, affordable, and sustainable long-range capability for entirely new missions-opening a new realm of knowledge and a world of possibilities for multiple partners. Design reference missions that the SLS is being planned to support include Mars, Jupiter, Lagrange Points, and near-Earth asteroids (NEAs), among others. The Agency is developing its mission manifest in parallel with the development of a heavy-lift flagship that will dramatically increase total lift and volume capacity beyond current launch vehicle options, reduce trip times, and provide a robust platform for conducting new missions destined to rewrite textbooks with the information they deliver, while creating a framework for further collaboration among domestic and international partners, and potentially spurring economic expansion into new markets.

Creech, Stephen D.

2012-01-01

53

Next Generation Heavy-Lift Launch Vehicle: Large Diameter, Hydrocarbon-Fueled Concepts  

NASA Technical Reports Server (NTRS)

With the passage of the 2010 NASA Authorization Act, NASA was directed to begin the development of the Space Launch System (SLS) as a follow-on to the Space Shuttle Program. The SLS is envisioned as a heavy lift launch vehicle that will provide the foundation for future large-scale, beyond low Earth orbit (LEO) missions. Supporting the Mission Concept Review (MCR) milestone, several teams were formed to conduct an initial Requirements Analysis Cycle (RAC). These teams identified several vehicle concept candidates capable of meeting the preliminary system requirements. One such team, dubbed RAC Team 2, was tasked with identifying launch vehicles that are based on large stage diameters (up to the Saturn V S-IC and S-II stage diameters of 33 ft) and utilize high-thrust liquid oxygen (LOX)/RP engines as a First Stage propulsion system. While the trade space for this class of LOX/RP vehicles is relatively large, recent NASA activities (namely the Heavy Lift Launch Vehicle Study in late 2009 and the Heavy Lift Propulsion Technology Study of 2010) examined specific families within this trade space. Although the findings from these studies were incorporated in the Team 2 activity, additional branches of the trade space were examined and alternative approaches to vehicle development were considered. Furthermore, Team 2 set out to define a highly functional, flexible, and cost-effective launch vehicle concept. Utilizing this approach, a versatile two-stage launch vehicle concept was chosen as a preferred option. The preferred vehicle option has the capability to fly in several different configurations (e.g. engine arrangements) that gives this concept an inherent operational flexibility which allows the vehicle to meet a wide range of performance requirements without the need for costly block upgrades. Even still, this concept preserves the option for evolvability should the need arise in future mission scenarios. The foundation of this conceptual design is a focus on low cost and effectiveness rather than efficiency or cutting-edge technology. This paper details the approach and process, as well as the trade space analysis, leading to the preferred vehicle concept.

Holliday, Jon; Monk, Timothy; Adams, Charles; Campbell, Ricky

2012-01-01

54

Simulation of Heavy Lift Airship dynamics over large ranges of incidence and speed  

NASA Technical Reports Server (NTRS)

A nonlinear, multibody, six-degrees-of-freedom digital simulation has been developed to study generic Heavy Lift Airship (HLA) dynamics and control. The basic aerodynamic functions developed to model the hull, tail, and rotor loads continuously over all incidence ranges are reviewed and applied to a Quadrotor HLA with a low fineness ratio hull and a small vee-tail. Trim calculations for a test vehicle suggest control power deficiencies in crosswind stationkeeping for the unloaded vehicle. Gust responses show the importance of correctly calculating loads due to accelerated relative motion of air and hull. Numerically linearized dynamics for the test vehicle show the existence of a divergent yaw mode, and an oscillatory pitch mode whose stability characteristics are sensitive to flight speed. A considerable improvement in the vehicle's stability and response results from a simple multi-axis closed-loop control system operating on the rotors and propeller blades.

Tischler, M. B.; Jex, H. R.; Ringland, R. F.

1981-01-01

55

Structure and properties of polyethylene films used in heavy lift balloons  

NASA Technical Reports Server (NTRS)

The following features of five polyethylene films used by NASA in the construction of heavy lift balloons have been examined: molecular weight, molecular weight distribution, branching, melting behavior, density, surface texture, birefringence, orientation of crystalline regions, unlaxial deformation in the machine and transverse directions, and the effect of sample geometry and strain rate on deformation behavior. The goal of this exploratory study was to determine whether there are significant differences in any of the above mentioned features, or combination of features between the films. The acquisition of such information is a first step towards determining whether there are any specific correlations between film characteristics and the incidence of catastrophic failure of balloons during ascent through the troposphere. This exploratory study has resulted in the identification of similarities and differences between various features of the films.

Khoury, F.; Crissman, J. M.; Fanconi, B. M.; Wagner, H. L.; Botz, L. H.

1985-01-01

56

Heavy-lift vehicle-launched Space Station method and apparatus  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a single heavy-lift launch to place a complete, operational space station on-orbit. A payload including the space station takes the place of a shuttle orbiter using the launch vehicle of the shuttle orbiter. The payload includes a forward shroud, a core module, a propulsion module, and a transition module between the core module and the propulsion module. The essential subsystems are preintegrated and verified on Earth. The core module provides means for attaching international modules with minimum impact to the overall design. The space station includes six control moment gyros for selectably operating in either LVLH (local-vertical local-horizontal) or SI (solar inertial) flight modes.

Wade, Donald C. (inventor); Delafuente, Horacio M. (inventor); Berka, Reginald B. (inventor); Rickman, Steven L. (inventor); Castro, Edgar O. (inventor); Nagy, Kornel (inventor); Wesselski, Clarence J. (inventor); Pelischek, Timothy E. (inventor); Schliesing, John A. (inventor)

1995-01-01

57

The Business Case for Spiral Development in Heavy Lift Launch Vehicle Systems  

NASA Technical Reports Server (NTRS)

Performance capabilities of a specific combination of the Space Shuttle external tank and various liquid engines in an in-line configuration, two-stage core vehicle with multiple redesigned solid rocket motor strap-ons are reexamined. This concept proposes using existing assets, hardware, and capabilities that are already crew-rated, flight certified, being manufactured under existing contracts, have a long history of component and system ground testing, and have been flown for over 20 yr. This paper goes beyond describing potential performance capabilities of specific components to discuss the overall system feasibility-from end to end, start to finish-describing the inherent cost advantages of the Spiral Development concept, which builds on existing capabilities and assets, as opposed to starting up a "fresh sheet" heavy-lift launch vehicle program from scratch.

Farr, Rebecca A.; Christensen, David L.; Keith, Edward L.

2005-01-01

58

Final design report of a personnel launch system and a family of heavy lift launch vehicles  

NASA Technical Reports Server (NTRS)

The objective was to design both a Personnel Launch System (PLS) and a family of Heavy Lift Launch Vehicles (FHLLVs) that provide low cost and efficient operation in missions not suited for the Shuttle. The PLS vehicle is designed primarily for space station crew rotation and emergency crew return. The final design of the PLS vehicle and its interior is given. The mission of the FHLLVs is to place large, massive payloads into Earth orbit with payload flexibility being considered foremost in the design. The final design of three launch vehicles was found to yield a payload capacity range from 20 to 200 mt. These designs include the use of multistaged, high thrust liquid engines mounted on the core stages of the rocket.

Tupa, James; Merritt, Debbie; Riha, David; Burton, Lee; Kubinski, Russell; Drake, Kerry; Mann, Darrin; Turner, Ken

1991-01-01

59

Heavy lift vehicles for transportation to a low earth orbit Space Station for assembly of a Human to Mars Mission  

Microsoft Academic Search

Heavy lift vehicle configurations are proposed which will meet the requirements for transporting the elements of a Human to Mars Mission to a low earth orbit Space Station for assembly. Both near term derivative type vehiles as well as advanced technology vehicles are considered. The capability of these vehicles to accommodate the precursor missions are also examined. The implications on

Frank E. Swalley

1989-01-01

60

A New Heavy-Lift Capability for Space Exploration: NASA's Ares V Cargo Launch Vehicle  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) is developing new launch systems in preparation for the retirement of the Space Shuttle by 2010, as directed in the United States (U.S.) Vision for Space Exploration. The Ares I Crew Launch Vehicle (CLV) and the Ares V heavy-lift Cargo Launch Vehicle (CaLV) systems will build upon proven, reliable hardware derived from the Apollo Saturn (1961 to 1975) and Space Shuttle (1972 to 2010) programs to deliver safe, reliable, affordable space transportation solutions. This approach leverages existing aerospace talent and a unique infrastructure, as well as the vast amount of legacy knowledge gained from almost a half-century of hard-won experience in the space enterprise. Beginning early next decade, the Ares I will launch the new Crew Exploration Vehicle (CEV) to the International Space Station (ISS) or to low-Earth orbit for trips to the Moon and, ultimately, Mars. Late next decade, the Ares V's Earth Departure Stage will carry larger payloads such as the lunar lander into orbit, and the Crew Exploration Vehicle will dock with it for missions to the Moon, where astronauts will explore new territories and conduct science and technology experiments. Both the Ares I and Ares V systems are being designed to support longer future trips to Mars. The Exploration Launch Projects Office, located at NASA's Marshall Space Flight Center, is designing, developing, testing, and evaluating both launch vehicle systems in partnership with other NASA Centers, Government agencies, and industry contractors. This paper provides top-level information regarding the genesis and evolution of the baseline configuration for the Ares V heavy-lift system. It also touches on risk-based management strategies, such as building on powerful hardware and promoting common features between the Ares I and Ares V systems to reduce technical, schedule, and cost risks, as well as development and operations costs. Finally, it gives a summary of several notable accomplishments over the past year, since the Exploration Launch Projects effort officially kicked off in October 2005, and looks ahead at work planned for 2007 and beyond.

Sumrall, John P.

2006-01-01

61

Update on the Ares V to support heavy lift for U.S. space exploration policy  

NASA Astrophysics Data System (ADS)

When NASA's Ares V cargo launch vehicle (Fig. 1) begins flying late next decade, its capabilities will significantly exceed the 1960s-era Saturn V. It will send more crew and cargo to more places on the lunar surface than Apollo and provide ongoing support to a permanent lunar outpost that will open the Moon to greater exploration, science and adventure than ever before. Moreover, it will restore the United States' heavy-lift capability, which can support human and robotic exploration for decades to come. Ares V remains in a pre-design analysis cycle stage pending a planned Authority to Proceed (ATP) in late 2010. Ares V benefits from the decision to draw from heritage hardware and its commonality with the Ares I crew launch vehicle, which completed its preliminary design review (PDR) in September 2008. Most of the work on Ares V to date has been focused on refining the vehicle design through a variety of internal studies. This paper will provide background information on the Ares V evolution, emphasizing the vehicle configuration as it exists today.

Sumrall, John P.; Creech, Steve

2010-04-01

62

Update on the Ares V to Support Heavy Lift for U.S. Space Exploration Policy  

NASA Technical Reports Server (NTRS)

When NASA's Ares V cargo launch vehicle begins flying late next decade, its capabilities will significantly exceed the 1960s-era Saturn V. It will send more crew and cargo to more places on the lunar surface than Apollo and provide ongoing support to a permanent lunar outpost that will open the Moon to greater exploration, science and adventure than ever before. Moreover, it will restore the United States heavy-lift capability, which can support human and robotic exploration for decades to come. Ares V remains in a pre-design analysis cycle stage pending a planned Authority to Proceed (ATP) in late 2010. Ares V benefits from the decision to draw from heritage hardware and its commonality with the Ares I crew launch vehicle, which completed its preliminary design review (PDR) in September 2008. Most of the work on Ares V to date has been focused on refining the vehicle design through a variety of internal studies. This paper will provide background information on the Ares V evolution, emphasizing the vehicle configuration as it exists today.

Sumrall, John P.; Creech, Steve

2008-01-01

63

Navier-Stokes Simulation of a Heavy Lift Slowed-Rotor Compound Helicopter Configuration  

NASA Technical Reports Server (NTRS)

Time accurate numerical simulations were performed using the Reynolds-averaged Navier-Stokes (RANS) flow solver OVERFLOW for a heavy lift, slowed-rotor, compound helicopter configuration, tested at the NASA Langley 14- by 22-Foot Subsonic Tunnel. The primary purpose of these simulations is to provide support for the development of a large field of view Particle Imaging Velocimetry (PIV) flow measurement technique supported by the Subsonic Rotary Wing (SRW) project under the NASA Fundamental Aeronautics program. These simulations provide a better understanding of the rotor and body wake flows and helped to define PIV measurement locations as well as requirements for validation of flow solver codes. The large field PIV system can measure the three-dimensional velocity flow field in a 0.914m by 1.83m plane. PIV measurements were performed upstream and downstream of the vertical tail section and are compared to simulation results. The simulations are also used to better understand the tunnel wall and body/rotor support effects by comparing simulations with and without tunnel floor/ceiling walls and supports. Comparisons are also made to the experimental force and moment data for the body and rotor.

Allan, Brian G.; Jenkins, Luther N.; Yao, Chung-Sheng; Bartram, Scott M.; Hallissy, Jim B.; Harris, Jerome; Noonan, Kevin W.; Wong, Oliver D.; Jones, Henry E.; Malovrh, Brendon D.; reis, Deane G.; Mace, W. Derry

2009-01-01

64

Advanced Transportation System Studies Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development Contract. Volume 2; Technical Results  

NASA Technical Reports Server (NTRS)

The sections in this report include: Single Stage to Orbit (SSTO) Design Ground-rules; Operations Issues and Lessons Learned; Vertical-Takeoff/Landing Versus Vertical-Takeoff/Horizontal-Landing; SSTO Design Results; SSTO Simulation Results; SSTO Assessment Results; SSTO Sizing Tool User's Guide; SSto Turnaround Assessment Report; Ground Operations Assessment First Year Executive Summary; Health Management System Definition Study; Major TA-2 Presentations; First Lunar Outpost Heavy Lift Launch Vehicle Design and Assessment; and the section, Russian Propulsion Technology Assessment Reports.

1995-01-01

65

Heavy Lift Helicopter - Cargo Handling ATC Program. Volume I. Detail Design Structural and Weights Analysis, and Static and Dynamic Load Analysis.  

National Technical Information Service (NTIS)

This report presents formal documentation of efforts and results of the cargo handling system segment of the Heavy Lift Helicopter (HLH) Advanced Technology Component (ATC) development program. The purpose of the HLH/ATC program was to minimize technical ...

B. Solak J. Shefrin L. Simpson R. Campbell W. Nutley

1976-01-01

66

One Engine Inoperative (OEI) and Autorotation For Heavy Lift Rotorcraft Systems  

NASA Technical Reports Server (NTRS)

Federal Aviation Administration will certainly require the Heavy Lift Rotorcraft to be operated under Category A performance and operations requirements. Because of the weight, no operation will be allowed except Category A according to FAA Part 29.1(c). This means that any where along the flight path, the aircraft must be able to land safely following an engine failure or continue flight. A repeatable flight profile must be developed and executed to ensure that the aircraft can be safely landed or flown away depending on its location on the flight profile. This means that there will be no Height-Velocity testing required as is currently required for Part 29 Category B. Since all the configurations shown to date are different than existing rotorcraft, each type would have to develop their individual requirements under existing special conditions FAA Part 21.17(b). This means the FAA will take the opportunity to negotiate additional requirements or change requirements to ensure safety. For example, since the tiltrotor did not fit normal rotorcraft category, new rules were negotiated between the applicant and the FAA. As a result of this negotiation, performance requirements for Category A were increased. The rules were written in terms of guaranteed performance instead of Category A requirements. Detailed discussion will follow later. The proposed tiltrotor would likely follow along with the current tiltrotor rules with the possibility of increase Category A performance requirements. Compounding with addition of wing and auxiliary thrust to both the tandem and coaxial rotor would result in new special condition aircraft. To my knowledge, no compound tandem or compound coaxial rotor has ever been certified by FAA.

Wood, Tom

2012-01-01

67

Performance and Design Investigation of Heavy Lift Tiltrotor with Aerodynamic Interference Effects  

NASA Technical Reports Server (NTRS)

The aerodynamic interference effects on tiltrotor performance in cruise are investigated using comprehensive calculations, to better understand the physics and to quantify the effects on the aircraft design. Performance calculations were conducted for 146,600-lb conventional and quad tiltrotors, which are to cruise at 300 knots at 4000 ft/95 deg F condition. A parametric study was conducted to understand the effects of design parameters on the performance of the aircraft. Aerodynamic interference improves the aircraft lift-to-drag ratio of the baseline conventional tiltrotor. However, interference degrades the aircraft performance of the baseline quad tiltrotor, due mostly to the unfavorable effects from the front wing to the rear wing. A reduction of rotor tip speed increased the aircraft lift-to-drag ratio the most among the design parameters investigated.

Yeo, Yyeonsoo; Johnson, Wayne

2007-01-01

68

Advanced transportation system studies technical area 2(TA-2): Heavy lift launch vehicle development. volume 1; Executive summary  

NASA Technical Reports Server (NTRS)

The purpose of the TA-2 contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. This document is part of the final report for the TA-2 contract. The final report consists of three volumes: Volume 1 is the Executive Summary, Volume 2 is Technical Results, and Volume 3 is Program Cost Estimates. The document-at-hand, Volume 1, provides a summary description of the technical activities that were performed over the entire contract duration, covering three distinct launch vehicle definition activities: heavy-lift (300,000 pounds injected mass to low Earth orbit) launch vehicles for the First Lunar Outpost (FLO), medium-lift (50,000-80,000 pounds injected mass to low Earth orbit) launch vehicles, and single-stage-to-orbit (SSTO) launch vehicles (25,000 pounds injected mass to a Space Station orbit).

McCurry, J.

1995-01-01

69

Mortality and cancer morbidity after heavy occupational fluoride exposure.  

PubMed

A cohort of 431 male cryolite workers employed for at least six months between 1924 and 1961 was identified from personnel records at the Copenhagen cryolite factory. During this period, heavy fluoride exposure resulted in at least 74 cases of skeletal fluorosis. All workmen in the cohort were followed up in Denmark until July 1, 1981. During 1941-1981, 206 men died, while only 149.3 deaths were expected from national mortality statistics. Significant excesses were seen in the following causes of death: violent death and all cancers, in particular cancer of the respiratory system. When compared with specific mortality rates for the Copenhagen area, violent death (and suicide taken alone) remained in significant excess among employees hired before 1940. Cancer morbidity data for the 35-year period 1943-1977 showed 78 cases of malignant neoplasms in the cryolite workers against 53.2 expected for Denmark as a whole and 67.9 for Copenhagen. The excess was almost entirely due to an excess number of respiratory cancers. Cancer morbidity showed no apparent correlation with length of employment or time from first exposure. Because detailed information on predictors for respiratory cancer was unavailable, a possible residual effect of fluoride cannot be excluded. However, any major carcinogenic effect of heavy fluoride exposure would be very unlikely. PMID:3964992

Grandjean, P; Juel, K; Jensen, O M

1985-01-01

70

Scaling laws for testing of high lift airfoils under heavy rainfall  

NASA Technical Reports Server (NTRS)

The results of studies regarding the effect of rainfall about aircraft are briefly reviewed. It is found that performance penalties on airfoils have been identified in subscale tests. For this reason, it is of great importance that scaling laws be dveloped to aid in the extrapolation of these data to fullscale. The present investigation represents an attempt to develop scaling laws for testing subscale airfoils under heavy rain conditions. Attention is given to rain statistics, airfoil operation in heavy rain, scaling laws, thermodynamics of condensation and/or evaporation, rainfall and airfoil scaling, aspects of splash back, film thickness, rivulets, and flap slot blockage. It is concluded that the extrapolation of airfoil performance data taken at subscale under simulated heavy rain conditions to fullscale must be undertaken with caution.

Bilanin, A. J.

1985-01-01

71

[Occupational neurotoxicology due to heavy metals-especially manganese poisoning].  

PubMed

The most hazardous manganese exposures occur in mining and smelting of ore. Recently, the poisoning has been frequently reported to be associated with welding. In occupational exposure, manganese is absorbed mainly by inhalation. Manganese preferentially accumulates in tissues rich in mitochondria. It also penetrates the blood brain barrior and accumulate in the basal ganglia, especially the globus pallidus, but also the striatum. Manganese poisoning is clinically characterized by the central nervous system involvement including psychiatric symptomes, extrapyramidal signs, and less frequently other neurological manifestations, Psychiatric symptomes are well described in the manganese miners and incrude sleep disturbance, disorientation, emotional lability, compulsive acts, hallucinations, illusions, and delusions. The main characteristic manifestations usually begin shortly after the appearance of these psychiatric symptomes. The latter neurological signs are progressive bradykinesia, dystonia, and disturbance of gait. Bradykinesia is one of the most important findings. There is a remarkable slowing of both active and passive movements of the extremities. Micrographia is frequently observed and a characteristic finding. The patients may show some symmetrical tremor, which usually not so marked. The dystonic posture of the limbs is often accompanied by painfull cramps. This attitudal hypertonia has a tenndency to decrease or disappear in the supine position and to increase in orthostation. Cog-wheel rigidity is also elisited on the passive movement of all extremities. Gait disturbance is also characteristic in this poisoning. In the severe cases, cook gait has been reported. The patient uses small steps, but has a tendency to elevate the heels and to rotate them outward. He progress without pressing on the flat of his feet, but only upon the metatarsophalangeal articulations, mainly of the fourth and fifth toes. Increased signal in T1-weighted image in the basal ganglia has been reported in patients with the poisoning. Thus, increasd signal intensities as a target site dose can be a more useful biomakers of the manganese than other biological indicies such as ambient manganese concentration or blood manganese concentration on individual basis. Manganese poisoning ultimately becomes chronic. However, if the disease is diagnosed while still at the early stages and the patient is removed from exposure, the course may be reversed. Once well established, it becomes progressive and irreversible, even when exposure is terminated. Levodopa therapy is not effective for the management of manganese poisoning. Levodopa unresponsiveness may be usefull to distinguish manganese-induced parkinsonism from Parkinson disease. PMID:17585589

Inoue, Naohide

2007-06-01

72

Lift measurement  

US Patent & Trademark Office Database

A method of determining the lift generated by a lift-generating member is presented. The lift-generating member being coupled to a component within the lift load path with the lift load path component experiencing strain as a result of the lift generated by the lift-generating member. The method involves the steps of coupling at least one strain measurement means to the lift load path component, obtaining strain measurements from the strain measurement means, and calculating the lift generated by the lift-generating member from strain measurements.

2010-02-09

73

Aeroelastic effects in multi-rotor vehicles with application to a hybrid heavy lift system. Part 1: Formulation of equations of motion  

NASA Technical Reports Server (NTRS)

This report presents a set of governing coupled differential equations for a model of a hybrid aircraft. The model consists of multiple rotor systems connected by an elastic interconnecting structure, with options to add any combination of or all of the following components; i.e., thrusters, a buoyant hull, and an underslung weight. The dynamic equations are written for the individual blade with hub motions, for the rigid body motions of the whole model, and also for the flexible modes of the interconnecting structure. One of the purposes of this study is to serve as the basis of a numerical study aimed at determining the aeroelastic stability and structural response characteristics of a Hybrid Heavy Lift Airship (HHLA). It is also expected that the formulation may be applicable to analyzing stability and responses of dual rotor helicopters such as a Heavy Lift Helicopter (HLH). Futhermore, the model is capable of representing coupled rotor/body aeromechanical problems of single rotor helicopters.

Venkatesan, C.; Friedman, P.

1984-01-01

74

Advanced Transportation System Studies Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development Contract. Volume 2; Technical Results  

NASA Technical Reports Server (NTRS)

The purpose of the Advanced Transportation System Studies (ATSS) Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. This document is Volume 2 of the final report for the contract. It provides documentation of selected technical results from various TA-2 analysis activities, including a detailed narrative description of the SSTO concept assessment results, a user's guide for the associated SSTO sizing tools, an SSTO turnaround assessment report, an executive summary of the ground operations assessments performed during the first year of the contract, a configuration-independent vehicle health management system requirements report, a copy of all major TA-2 contract presentations, a copy of the FLO launch vehicle final report, and references to Pratt & Whitney's TA-2 sponsored final reports regarding the identification of Russian main propulsion technologies.

1995-01-01

75

A logistics and potential hazard study of propellant systems for a Saturn 5 derived heavy lift (three-stage core) launch vehicle  

NASA Technical Reports Server (NTRS)

The Bush Administration has directed NASA to prepare for a return to the Moon and on to Mars - the Space Exploration Initiative. To meet this directive, powerful rocket boosters will be required in order to lift payloads that may reach the half-million pound range into low earth orbit. In this report an analysis is presented on logistics and potential hazards of the propellant systems envisioned for future Saturn 5 derived heavy lift launch vehicles. In discussing propellant logistics, particular attention has been given to possible problems associated with procurement, transportation, and storage of RP-1, HL2, and LOX, the heavy lift launch vehicle propellants. Current LOX producing facilities will need to be expanded and propellant storage and some support facilities will require relocation if current Launch Pads 39A and/or 39B are to be used for future heavy noise-abatement measures. Included in the report is a discussion of suggested additional studies, primarily economic and environmental, which should be undertaken in support of the goals of the Space Exploration Initiative.

Whitney, E. Dow

1992-01-01

76

A logistics and potential hazard study of propellant systems for a Saturn 5 derived heavy lift (three-stage core) launch vehicle  

NASA Astrophysics Data System (ADS)

The Bush Administration has directed NASA to prepare for a return to the Moon and on to Mars - the Space Exploration Initiative. To meet this directive, powerful rocket boosters will be required in order to lift payloads that may reach the half-million pound range into low earth orbit. In this report an analysis is presented on logistics and potential hazards of the propellant systems envisioned for future Saturn 5 derived heavy lift launch vehicles. In discussing propellant logistics, particular attention has been given to possible problems associated with procurement, transportation, and storage of RP-1, HL2, and LOX, the heavy lift launch vehicle propellants. Current LOX producing facilities will need to be expanded and propellant storage and some support facilities will require relocation if current Launch Pads 39A and/or 39B are to be used for future heavy noise-abatement measures. Included in the report is a discussion of suggested additional studies, primarily economic and environmental, which should be undertaken in support of the goals of the Space Exploration Initiative.

Whitney, E. Dow

1992-09-01

77

A comparative study and application of continuously variable transmission to a single main rotor heavy lift helicopter  

NASA Astrophysics Data System (ADS)

Rotorcraft transmission design is limited by empirical weight trends that are proportional to the power/torque raised to the two-thirds coupled with the relative inexperience industry has with the employment of variable speed transmission to heavy lift helicopters of the order of 100,000 lbs gross weight and 30,000 installed horsepower. The advanced rotorcraft transmission program objectives are to reduce transmission weight by at least 25%, reduce sound pressure levels by at least 10 dB, have a 5000 hr mean time between removal, and also incorporate the use of split torque technology in rotorcraft drivetrains of the future. The major obstacle that challenges rotorcraft drivetrain design is the selection, design, and optimization of a variable speed transmission in the goal of achieving a 50% reduction in rotor speed and its ability to handle high torque with light weight gears, as opposed to using a two-speed transmission which has inherent structural problems and is highly unreliable due to the embodiment of the traction type transmission, complex clutch and brake system. This thesis selects a nontraction pericyclic continuously variable transmission (P-CVT) as the best approach for a single main rotor heavy lift helicopter. The objective is to target and overcome the above mentioned obstacle for drivetrain design. Overcoming this obstacle provides advancement in the state of the art of drivetrain design over existing planetary and split torque transmissions currently used in helicopters. The goal of the optimization process was to decrease weight, decrease noise, increase efficiency, and increase safety and reliability. The objective function utilized the minimization of the weight and the major constraint is the tooth bending stress of the facegears. The most important parameters of the optimization process are weight, maintainability, and reliability which are cross-functionally related to each other, and these parameters are related to the torques and operating speeds. The analysis of the split torque type P-CVT achieved a weight reduction of 42.5% and 40.7% over planetary and split torque transmissions respectively. In addition, a 19.5 dB sound pressure level reduction was achieved using active gear struts, and also the use of fabricated steel truss like housing provided a higher maintainability and reliability, low cost, and low weight over cast magnesium housing currently employed in helicopters. The static finite element analysis of the split torque type P-CVT, both 2-D and 3-D, yielded stresses below the allowable bending stress of the material. The goal of the finite element analysis is to see if the designed product has met its functional requirements. The safety assessment of the split torque type P-CVT yielded a 99% probability of mission success based on a Monte Carlo simulation using stochastic-petri net analysis and a failure hazard analysis. This was followed by an FTA/RBD analysis which yielded an overall system failure rate of 140.35 failures per million hours, and a preliminary certification and time line of certification was performed. The use of spherical facegears and pericyclic kinematics has advanced the state of the art in drivetrain design primarily in the reduction of weight and noise coupled with high safety, reliability, and efficiency.

Hameer, Sameer

78

Occupational Exposure to Mineral Turpentine and Heavy Fuels: A Possible Risk Factor for Alzheimer's Disease  

PubMed Central

Background The association between solvents and Alzheimer's disease (AD) has been the subject of several studies. Yet, only few studies have examined the various solvents separately, and the controls have rarely been monitored long enough. For these reasons and others, we believe that further studies are required. Objectives The objective of this study was to identify solvents associated with the clinicoradiological diagnostic of AD or mixed-type dementia (MD). Methods A retrospective case-control study was performed in 156 patients followed up at the Memory Diagnostic Center of Bertinot Juel Hospital (France). The inclusion criteria were known occupation(s), a Mini-Mental State Examination (MMSE) score ?10 at the first visit, a neuropsychological evaluation performed and a diagnosis established in our Memory Diagnostic Center. The diagnostics were crossed with 9 solvents belonging to two classes of solvents. Exposure was evaluated using French national job-exposure matrices. Results Certain petroleum-based solvents and fuels (i.e. mineral turpentine, diesel fuel, fuel oil and kerosene) were associated with a diagnosis of AD or MD. This association was still significant after adjustment for age, sex and education (adjusted OR: 6.5; 95% CI: 2-20). Conclusion Occupational exposure to mineral turpentine and heavy fuels may be a risk factor for AD and MD.

Helou, Rafik; Jaecker, Pierre

2014-01-01

79

COST-BENEFIT ANALYSIS OF THE OVERHEAD CEILING LIFTS IN REDUCING MUSCULOSKELETAL INJURY AMOUNG DIRECT PATIENT CARE STAFF Hasanat Alamgir, Occupational Health and Safety Agency for Healthcare (OHSAH)  

Microsoft Academic Search

Patient and\\/or resident handling is a major cause of injury to healthcare workers. Ceiling lifts are frequently advocated to mitigate risk of injury to healthcare workers when lifting, transferring, or repositioning patients. A longitudinal study was conducted in three extended care facilities to evaluate the efficacy and cost-benefit of overhead lifts in reducing the risk of musculoskeletal injury (MSI) among

Catherine Kidd; Annalee Yassi

80

Satellite Power Systems (SPS) concept definition study. Volume 5: Transportation and operations analysis. [heavy lift launch and orbit transfer vehicles for orbital assembly  

NASA Technical Reports Server (NTRS)

The development of transportation systems to support the operations required for the orbital assembly of a 5-gigawatt satellite is discussed as well as the construction of a ground receiving antenna (rectenna). Topics covered include heavy lift launch vehicle configurations for Earth-to LEO transport; the use of chemical, nuclear, and electric orbit transfer vehicles for LEO to GEO operations; personnel transport systems; ground operations; end-to-end analysis of the construction, operation, and maintenance of the satellite and rectenna; propellant production and storage; and payload packaging.

Hanley, G.

1978-01-01

81

Eyelid lift  

MedlinePLUS

... lift to improve their appearance. This is called cosmetic or elective surgery. The eyelid lift may be done alone or ... Codere F, Tucker N. Cosmetic blepharoplasty and browplasty. In: ... Skin. 2nd ed . Philadelphia, PA: Elsevier Mosby; 2010:chap 39.

82

A survey of occupational health hazards among 7,610 female workers in China's electronics industry.  

PubMed

To investigate the occupational hazards among Chinese female workers in the electronics industry, the authors systematically sampled a total of 8,300 female workers at random across 4 provinces in a variety of electronics factories. A detailed questionnaire was used to collect information on occupational hazards and the occurrence of occupation-related diseases. The results show that 4,283 female workers (51.9%) were exposed to 1 or more occupational hazards. The most common chemical hazard was organic solvent, and the second most common was heavy metals. The ergonomic hazards included repetitive movements, poor standing posture, and the lifting of heavy goods. More than 60% of the female workers self-reported occupation-related diseases. These results showed that occupational health hazards were common in the electronics industry in China and that they caused serious occupation-related health problems for the female workers therein. PMID:23697691

Yu, Wenlan; Lao, Xiang Qian; Pang, Shulan; Zhou, Jianjiao; Zhou, Anshou; Zou, Jianfang; Mei, Liangying; Yu, Ignatius Tak-sun

2013-01-01

83

Does that look heavy to you? Perceived weight judgment in lifting actions in younger and older adults  

PubMed Central

When interpreting other people's movements or actions, observers may not only rely on the visual cues available in the observed movement, but they may also be able to “put themselves in the other person's shoes” by engaging brain systems involved in both “mentalizing” and motor simulation. The ageing process brings changes in both perceptual and motor abilities, yet little is known about how these changes may affect the ability to accurately interpret other people's actions. Here we investigated the effect of ageing on the ability to discriminate the weight of objects based on the movements of actors lifting these objects. Stimuli consisted of videos of an actor lifting a small box weighing 0.05–0.9 kg or a large box weighting 3–18 kg. In a four-alternative forced-choice task, younger and older participants reported the perceived weight of the box in each video. Overall, older participants were less sensitive than younger participants in discriminating the perceived weight of lifted boxes, an effect that was especially pronounced in the small box condition. Weight discrimination performance was better for the large box compared to the small box in both groups, due to greater saliency of the visual cues in this condition. These results suggest that older adults may require more salient visual cues to interpret the actions of others accurately. We discuss the potential contribution of age-related changes in visual and motor function on the observed effects and suggest that older adults' decline in the sensitivity to subtle visual cues may lead to greater reliance on visual analysis of the observed scene and its semantic context.

Maguinness, Corrina; Setti, Annalisa; Roudaia, Eugenie; Kenny, Rose Anne

2013-01-01

84

Large Spun Formed Friction-Stir Welded Tank Domes for Liquid Propellant Tanks Made from AA2195: A Technology Demonstration for the Next Generation of Heavy Lift Launchers  

NASA Technical Reports Server (NTRS)

Improving structural efficiency while reducing manufacturing costs are key objectives when making future heavy-lift launchers more performing and cost efficient. The main enabling technologies are the application of advanced high performance materials as well as cost effective manufacture processes. This paper presents the status and main results of a joint industrial research & development effort to demonstrate TRL 6 of a novel manufacturing process for large liquid propellant tanks for launcher applications. Using high strength aluminium-lithium alloy combined with the spin forming manufacturing technique, this development aims at thinner wall thickness and weight savings up to 25% as well as a significant reduction in manufacturing effort. In this program, the concave spin forming process is used to manufacture tank domes from a single flat plate. Applied to aluminium alloy, this process allows reaching the highest possible material strength status T8, eliminating numerous welding steps which are typically necessary to assemble tank domes from 3D-curved panels. To minimize raw material costs for large diameter tank domes for launchers, the dome blank has been composed from standard plates welded together prior to spin forming by friction stir welding. After welding, the dome blank is contoured in order to meet the required wall thickness distribution. For achieving a material state of T8, also in the welding seams, the applied spin forming process allows the required cold stretching of the 3D-curved dome, with a subsequent ageing in a furnace. This combined manufacturing process has been demonstrated up to TRL 6 for tank domes with a 5.4 m diameter. In this paper, the manufacturing process as well as test results are presented. Plans are shown how this process could be applied to future heavy-lift launch vehicles developments, also for larger dome diameters.

Stachulla, M.; Pernpeinter, R.; Brewster J.; Curreri, P.; Hoffman, E.

2010-01-01

85

The relationship between maximal lifting capacity and maximum acceptable lift in strength-based soldiering tasks.  

PubMed

Psychophysical assessments, such as the maximum acceptable lift, have been used to establish worker capability and set safe load limits for manual handling tasks in occupational settings. However, in military settings, in which task demand is set and capable workers must be selected, subjective measurements are inadequate, and maximal capacity testing must be used to assess lifting capability. The aim of this study was to establish and compare the relationship between maximal lifting capacity and a self-determined tolerable lifting limit, maximum acceptable lift, across a range of military-relevant lifting tasks. Seventy male soldiers (age 23.7 ± 6.1 years) from the Australian Army performed 7 strength-based lifting tasks to determine their maximum lifting capacity and maximum acceptable lift. Comparisons were performed to identify maximum acceptable lift relative to maximum lifting capacity for each individual task. Linear regression was used to identify the relationship across all tasks when the data were pooled. Strong correlations existed between all 7 lifting tasks (rrange = 0.87-0.96, p < 0.05). No differences were found in maximum acceptable lift relative to maximum lifting capacity across all tasks (p = 0.46). When data were pooled, maximum acceptable lift was equal to 84 ± 8% of the maximum lifting capacity. This study is the first to illustrate the strong and consistent relationship between maximum lifting capacity and maximum acceptable lift for multiple single lifting tasks. The relationship developed between these indices may be used to help assess self-selected manual handling capability through occupationally relevant maximal performance tests. PMID:22643137

Savage, Robert J; Best, Stuart A; Carstairs, Greg L; Ham, Daniel J

2012-07-01

86

Patient lifts.  

PubMed

In this issue, we evaluate conventional patient lifts that operate by hand cranking, hand pumping, or battery-powered motors and are intended for use in the home or in institutions. We did not evaluate lifts that are designed to be used solely in bathrooms or vehicles or those that permanently affix to walls, floors or ceilings. Some of the evaluated lifts are intended primarily for use in specific environments (e.g., one can be easily disassembled into small components for automobile transport). We evaluated 15 patient lifts from eight manufacturers, basing our ratings on performance, safety, and human factors design. Because different designs make lifts preferable for different environments, we rated the lifts for both home and institutional use based on their size, ruggedness, ease of storage, maneuverability, and cost. Seven units-the Arjo 218150; the Handi-Move 1200; the Hoyer C-CBL; the Invacare 9901, 9916 and 9917; and the Porto-Lift PL-1 are rated Acceptable for both home and institutional use. The Trans-Aid S1-600 and the Versa Lift are rated Acceptable for institutional use and Acceptable-Not Recommended for home use because of their size and cost. The Arjo B and the Hoyer Travel Lift are rated Acceptable for home use and Acceptable-Not Recommended for institutional use because they will not comfortably accommodate patients of all sizes; the Arjo B has additional limitations. The Hoyer C-HLA, the Invacare 9902, and the Trans-Aid LAT-2 are rated Conditionally Acceptable for home use on the condition that they are not used to transfer patients who weigh more than 200 lb; all three units are rated Conditionally Acceptable-Not Recommended for institutional use since there is no reliable way to ensure that they will not be used on heavier patients. The Century C-3 lift is rated Conditionally Acceptable for institutional use on the condition that it is used with the base fully extended; because the fully extended base makes the unit awkward to maneuver in narrow corridors or passages, we rated the unit Coonditionally Acceptable-Not Recommended for home use. We also assessed the optional electronic scales provided with the lifts and found the Arjo, Century, and Versa Lift scales acceptable; the Hoyer and Trans-Aid scales are also acceptable, but we do not recommend them for use in areas where exposure to fluid spills or moisture is likely to occur. Users should base purchasing decisions on a thorough understanding of our conclusions, which can be gained only by reading this evaluation in its entirety. PMID:2372319

1990-03-01

87

Biomechanical Basis for Manual Lifting Guidelines.  

National Technical Information Service (NTIS)

The biomechanics of the lower back was reviewed as a basis for establishing a load handling limit. Topics included occupational biomechanics of load lifting, biomechanical basis for back injury, compressive strength of lumbar spinal column, biomechanical ...

A. Garg

1989-01-01

88

Back Injuries Associated with Lifting.  

National Technical Information Service (NTIS)

This bulletin summarizes the results of a survey of workers in blue-collar occupations who injured their backs while lifting, placing, lowering, carrying, or holding objects. The findings of this survey, which was conducted by the Bureau of Labor Statisti...

1982-01-01

89

New Capabilities to Achieve Future Major Astrophysical Goals in Space: In-Space Servicing and the Ares V Heavy Lift Launch Vehicle  

NASA Astrophysics Data System (ADS)

The astronomy community, NASA Centers, and the National Academy of Sciences are beginning the processes to design, assess, and advocate a generation of very large, very capable astronomical observatories for the post-JWST time period; that is, about 2020 and beyond. Simultaneously, commercial companies and entrepreneurs, as well as NASA's human spaceflight program, are investing in capabilities that may be adapted - and, indeed, may be necessary - to enable the most ambitious science missions in space. In this presentation, we describe the history of and recent progress in space robotics, notably DARPA's Orbital Express program, which demonstrated in Spring, 2007 effective in-space acquisition, rendezvous, docking, and instrument transfer. We also will summarize recent concepts for modest augmentation of the Orion/Crew Exploration Vehicle that would permit astronaut and/or robotic servicing of the science community's most valuable space assets. Finally, we will outline our proposed study of the Ares V heavy lift launch vehicle, which has the potential to put a 8 m monolithic telescope - or even larger segmented/deployable optic - into the Sun-Earth L2 orbit.

Thronson, Harley A., Jr.; Postman, M.; Stahl, P.; Lester, D.; Lillie, C.; Moe, R.; Schweitzer, A.; Varsi, G.; Espero, T.

2007-12-01

90

The influence of the occupational exposure to heavy metals and tobacco smoke on the selected oxidative stress markers in smelters.  

PubMed

The aim of the study was to verify if there is any association between exposure to Cu, Zn, Cd, Pb, As and the formation of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products (AOPP), and whether in this process cigarette smoking plays a role. The investigations were performed in the 352 smelters occupationally exposed to heavy metals and 73 persons of control group. Metals concentration was determined by atomic absorption spectrometry. MDA and AOPP concentrations were determined by spectrophotometric methods. The concentration of 8-OHdG was determined by ELISA method. It was demonstrated an increased Cu concentration in smoking smelters compared to non-smoking control group. It was noted no differences in Zn and Mg concentrations between the examined groups. Pb concentration was more than sixfold higher in the group of smoking smelters and about fivefold higher in the group of non-smoking smelters compared to the control groups (smokers and non-smokers). It was shown that Cd concentration in the blood was nearly fivefold higher in the smoking control group compared to the non-smoking control group and more than threefold higher in the group of smoking smelters compared to non-smoking. It was shown an increased As concentration (more than fourfold) and decreased Ca concentration in both groups of smelters compared to control groups. In groups of smelters (smokers and non-smokers), twofold higher MDA and AOPP concentrations, and AOPP/albumin index compared to control groups (smokers and non-smokers) were shown. Tobacco smoke is the major source of Cd in the blood of smelters. Occupational exposure causes accumulation of Pb in the blood. Occupational exposure to heavy metals causes raise of MDA concentration and causes greater increase in AOPP concentration than tobacco smoke. PMID:24789476

Sciskalska, Milena; Zalewska, Marta; Grzelak, Agnieszka; Milnerowicz, Halina

2014-06-01

91

Assessment of Muscle Strength and Prediction of Lifting Capacity in U.S. Army Personnel.  

National Technical Information Service (NTIS)

The purpose of this study was to determine muscular strength tests which would be appropriate for Army occupational selection and predictive of job lifting and lifting-carrying tasks. A maximum lift to 132 cm, dead lift to knuckle height and a short term ...

D. S. Sharp J. A. Vogel J. E. Wright J. F. Patton

1984-01-01

92

Energy expenditure of dockers performing heavy loading/discharging works and of other occupational groups in ports.  

PubMed

The examinations conducted in 1986-1990 comprised 1123 harbour workers in ports of Gda?sk and Gdynia. The mean age of all persons examined was 42.38 +/- 11.27, the mean period of the employment at port was 19.38 +/- 7.20 years. In the group stevedore-trimmers the corresponding values were 38.13 +/- 10.81 and 14.27 +/- 5.76 years, respectively. Average body height in the whole group of men investigated was 173.46 +/- 6.43 cm. The lowest body mass found in stevedores and trimmers was 76.36 +/- 11.43 kg, the highest in supervisors and controllers was 82.32 +/- 10.76 kg. The energy expenditure of the occupational work in the groups examined fell within a wide range from 493.25 +/- 45.09 kcal (2064.19 +/- 177.05 kJ) to 2335.79 +/- 326.02 kcal (9778.62 +/- 1234.34 kJ). The energy expenditure of stacking-yard tenders, shipping clerks, tallymen, foremen, hoistmen and cranemen fluctuated within the range of 493.25 +/- 45.09 kcal (2064.19 +/- 177.05 kJ) and 614.08 +/- 67.23 kcal (2567.06 +/- 254.74 kJ). In the group of maintenance workers of mechanical equipment: from 886.98 +/- 144.09 kcal (3722.85 +/- 378.03 kJ) to 1268.65 +/- 231.45 kcal (5309.11 +/- 824.00 kJ). In the largest group of mechanical equipment operators it was 1142.06 +/- 102.45 kcal (4646.45 +/- 386.05 kJ) on the average. The energy expenditures of stevedores and trimmers in all loading operations fell in the range from 1714.5 kcal (7176.9 kJ) to 2678.5 kcal (11213.9 kJ) and per eight hour shift they averaged 2047.03 +/- 257.25 kcal (8568.90 +/- 1076.85 kJ). Such results of the energy expenditures of stevedores and trimmers occupational jobs qualify it as heavy and in several loading operations as very heavy, the remaining groups perform work counted light and mean, periodically moderate. Out of all the occupational groups of the harbour workers examined, the labour of stevedores and trimmers was characterized by the highest energy expenditure, statistically higher than in other groups of dockers. It was found that the lower was the energy expenditure at work in a given group, the higher was the average body mass and the incidence of overweight and obesity in the groups of workers examined. PMID:2135914

Wa?kiewicz, J

1990-01-01

93

The Effect of Lifting Speed on Cumulative and Peak Biomechanical Loading for Symmetric Lifting Tasks  

PubMed Central

Background To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ?80%. Conclusion Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

Greenland, Kasey O.; Merryweather, Andrew S.; Bloswick, Donald S.

2013-01-01

94

Physiological and subjective responses to maximal repetitive lifting employing stoop and squat technique  

Microsoft Academic Search

Summary  To establish safe levels for physical strain in occupational repetitive lifting, it is of interest to know the specific maximal working capacity. Power output, O2 consumption, heart rate and ventilation were measured in ten experienced forestry workers during maximal squat and stoop repetitive lifting. The two modes of repetitive lifting were also compared with maximal treadmill running. In addition, electromyogram

Kfire B. Hagen; Jostein Hallen; Karin Harms-Ringdahl

1993-01-01

95

Revised NIOSH equation for the design and evaluation of manual lifting tasks  

Microsoft Academic Search

In 1985, the National Institute for Occupational Safety and Health (NIOSH) convened an ad hoc committee of experts who reviewed the current literature on lifting, recommend criteria for defining lifting capacity, and in 1991 developed a revised lifting equation. Subsequently, NIOSH developed the documentation for the equation and played a prominent role in recommending methods for interpreting the results of

THOMAS R. WATERS; VERN PUTZ-ANDERSON; ARUN GARG; LAWRENCE J. FINE

1993-01-01

96

A shadowgraph study of the National Launch System's 1 1/2 stage vehicle configuration and Heavy Lift Launch Vehicle configuration. [Using the Marshall Space Flight Center's 14-Inch Trisonic Wind Tunnel  

NASA Technical Reports Server (NTRS)

A shadowgraph study of the National Launch System's (NLS's) 1 1/2 stage and heavy lift launch vehicle (HLLV) configurations is presented. Shadowgraphs are shown for the range of Mach numbers from Mach 0.6 to 5.0 at various angles-of-attack and roll angles. Since the 1 1/2 stage configuration is generally symmetric, no shadowgraphs of any roll angle are shown for this configuration. The major flow field phenomena over the NLS 1 1/2 stage and HLLV configurations are shown in the shadowgraphs. These shadowgraphs are used in the aerothermodynamic analysis of the external flow conditions the launch vehicle would encounter during the ascent stage of flight. The shadowgraphs presented in this study were obtained from configurations tested in the Marshall Space Flight Center's 14-Inch Trisonic Wind Tunnel during 1992.

Pokora, Darlene C.; Springer, Anthony M.

1994-01-01

97

An experimental evaluation of psychophysical criteria for repetitive lifting work.  

PubMed

Two experiments were performed to test the reliability and validity of psychophysically determined maximum acceptable workloads for setting lifting standards. The perceived workload in a repetitive diagonal lifting task was found to be a positively accelerated function of the weight lifted and of the work pace respectively. A twofold increase in objective workload resulted in a four- to fivefold increase in perceived workload. This relation was independent of previous occupational experience of lifting work. The psychophysically assessed maximum acceptable workloads for this type of lifting task appeared to be satisfactorily reproducible when subjects had to adjust work pace or when they were left free to adjust both the weight and the work pace. However, the results raised several questions concerning the applicability of the psychophysical assessment of maximum acceptable lifting work. Slight changes in the instructions given to the subjects had a definite effect on the selection of workloads. Furthermore, the workloads selected by subjects with previous occupational experience of lifting work - i e, warehouse workers - were systematically lower than those selected by subjects without such previous experience - i e, office employees. At the same time, the warehouse workers rated perceived exertion higher than the office employees, indicating that previous occupational experience of lifting work enhanced the subjective assessment of physical effort. There were no consistent relations between the workloads found acceptable by the subjects and their physical characteristics and performance capacity. PMID:15676636

Gamberale, F; Ljungberg, A S; Annwall, G; Kilbom, A

1987-12-01

98

Effects of Psychophysical Lifting Training on Maximal Repetitive Lifting Capacity.  

National Technical Information Service (NTIS)

The purpose of this investigation was to determine the effectiveness of psychophysical lifting training on maximal repetitive lifting capacity. Maximal repetitive lifting capacity was defined as the maximum box mass that could be lifted for a full hour to...

M. A. Sharp S. J. Legg

1987-01-01

99

Lower-body lift.  

PubMed

The lower-body lift, designed for patients with multiple lower-body contour deformities, uses a circumferential bikini-line incision to simultaneously lift relaxed trunk and thigh tissues. The author describes 2 lower-body lift procedures, focusing primarily on the high-lateral-tension abdominoplasty with transverse-thigh/buttock lift, which he developed in 1996. (Aesthetic Surg J 2001;21:355-370.). PMID:19331916

Lockwood, T E

2001-07-01

100

Construction Diver Lift Systems.  

National Technical Information Service (NTIS)

A diver-operated lift system has been developed for underwater construction divers. The system consists of three different open-bottom lift bags with the following lift ranges: 200 to 550 pounds, 500 to 1,250 pounds, and 1,000 to 3,000 pounds. The system ...

H. G. Thomson

1993-01-01

101

High lift selected concepts  

NASA Technical Reports Server (NTRS)

The benefits to high lift system maximum life and, alternatively, to high lift system complexity, of applying analytic design and analysis techniques to the design of high lift sections for flight conditions were determined and two high lift sections were designed to flight conditions. The influence of the high lift section on the sizing and economics of a specific energy efficient transport (EET) was clarified using a computerized sizing technique and an existing advanced airplane design data base. The impact of the best design resulting from the design applications studies on EET sizing and economics were evaluated. Flap technology trade studies, climb and descent studies, and augmented stability studies are included along with a description of the baseline high lift system geometry, a calculation of lift and pitching moment when separation is present, and an inverse boundary layer technique for pressure distribution synthesis and optimization.

Henderson, M. L.

1979-01-01

102

30526 artificial lift  

SciTech Connect

This book focuses on the four major methods of artificial lift: sucker-rod pumping, gas lift, electrical submersible pumping (ESP) and hydraulic pumping. Though more than 80% of artificially lifted wells worldwide are rod-pumped, the large majority of these wells are low-volume, stripper-type producers. For this reason, sucker-rod pumping papers comprise less than 40% of the 26 SPE papers selected.

Not Available

1989-01-01

103

Feasibility study of modern airships, phase 1. Volume 2: Parametric analysis (task 3). [lift, weight (mass)  

NASA Technical Reports Server (NTRS)

Various types of lighter-than-air vehicles from fully buoyant to semibuoyant hybrids were examined. Geometries were optimized for gross lifting capabilities for ellipsoidal airships, modified delta planform lifting bodies, and a short-haul, heavy-lift vehicle concept. It is indicated that: (1) neutrally buoyant airships employing a conservative update of materials and propulsion technology provide significant improvements in productivity; (2) propulsive lift for VTOL and aerodynamic lift for cruise significantly improve the productivity of low to medium gross weight ellipsoidal airships; and (3) the short-haul, heavy-lift vehicle, consisting of a simple combination of an ellipsoidal airship hull and existing helicopter componentry, provides significant potential for low-cost, near-term applications for ultra-heavy lift missions.

Lancaster, J. W.

1975-01-01

104

Does the asymmetry multiplier in the 1991 NIOSH lifting equation adequately control the biomechanical loading of the spine?  

Microsoft Academic Search

The aim of this research was to evaluate whether the asymmetry multiplier incorporated in the 1991 National Institute for Occupational Safety and Health lifting equation adequately controls the biomechanical spine loads during asymmetric lifting. Sixteen male subjects lifted a box from four initial locations varying in terms of the angular deviation from the mid-sagittal plane (0, 30, 60 and 90°).

S. A. Lavender; Y. C. Li; R. N. Natarajan; G. B. J. Andersson

2009-01-01

105

Associations of Occupational Tasks with Knee and Hip Osteoarthritis: The Johnston County Osteoarthritis Project  

PubMed Central

Objective This cross-sectional study examined associations of occupational tasks with radiographic and symptomatic osteoarthritis (OA) in a community-based sample. Methods Participants from the Johnston County Osteoarthritis Project (n = 2729) self-reported the frequency of performing 10 specific occupational tasks at the longest job ever held (never/seldom/sometimes vs often/always) and lifetime exposure to jobs that required spending > 50% of their time doing 5 specific tasks or lifting 22, 44, or 110 pounds 10 times weekly. Multivariable logistic regression models examined associations of each occupational task separately with radiographic and symptomatic knee and hip OA, controlling for age, race, gender, body mass index, prior knee or hip injury, and smoking. Results Radiographic hip and knee OA were not significantly associated with any occupational tasks, but several occupational tasks were associated with increased odds of both symptomatic knee and hip OA: lifting > 10 pounds, crawling, and doing heavy work while standing (OR 1.4–2.1). More occupational walking and standing and less sitting were also associated with symptomatic knee OA, and more bending/twisting/reaching was associated with symptomatic hip OA. Exposure to a greater number of physically demanding occupational tasks at the longest job was associated with greater odds of both symptomatic knee and hip OA. Conclusion Our results confirm an association of physically demanding occupational tasks with both symptomatic knee and hip OA, including several specific activities that increased the odds of OA in both joint groups. These tasks represent possibilities for identifying and targeting at-risk individuals with preventive interventions.

ALLEN, KELLI D.; CHEN, JIU-CHIUAN; CALLAHAN, LEIGH F.; GOLIGHTLY, YVONNE M.; HELMICK, CHARLES G.; RENNER, JORDAN B.; JORDAN, JOANNE M.

2014-01-01

106

Observing object lifting errors modulates cortico-spinal excitability and improves object lifting performance.  

PubMed

Observing the actions of others has been shown to modulate cortico-spinal excitability and affect behaviour. However, the sensorimotor consequences of observing errors are not well understood. Here, participants watched actors lift identically weighted large and small cubes which typically elicit expectation-based fingertip force errors. One group of participants observed the standard overestimation and underestimation-style errors that characterise early lifts with these cubes (Error video--EV). Another group watched the same actors performing the well-adapted error-free lifts that characterise later, well-practiced lifts with these cubes (No error video--NEV). We then examined actual object lifting performance in the subjects who watched the EV and NEV. Despite having similar cognitive expectations and perceptions of heaviness, the group that watched novice lifters making errors themselves made fewer overestimation-style errors than those who watched the expert lifts. To determine how the observation of errors alters cortico-spinal excitability, we measured motor evoked potentials in separate group of participants while they passively observed these EV and NEV. Here, we noted a novel size-based modulation of cortico-spinal excitability when observing the expert lifts, which was eradicated when watching errors. Together, these findings suggest that individuals' sensorimotor systems are sensitive to the subtle visual differences between observing novice and expert performance. PMID:23953062

Buckingham, Gavin; Wong, Jeremy D; Tang, Minnie; Gribble, Paul L; Goodale, Melvyn A

2014-01-01

107

High lift aerodynamics  

NASA Technical Reports Server (NTRS)

The current program is aimed at providing a physical picture of the flow physics and quantitative turbulence data of the interaction of a high Reynolds number wake with a flap element. The impact of high lift on aircraft performance is studied for a 150 passenger transport aircraft with the goal of designing optimum high lift systems with minimum complexity.

Sullivan, John; Schneider, Steve; Campbell, Bryan; Bucci, Greg; Boone, Rod; Torgerson, Shad; Erausquin, Rick; Knauer, Chad

1994-01-01

108

Catwalk grate lifting tool  

DOEpatents

A device is described for lifting catwalk grates comprising an elongated bent member with a handle at one end and a pair of notched braces and a hook at the opposite end that act in conjunction with each other to lock onto the grate and give mechanical advantage in lifting the grate. 10 figs.

Gunter, L.W.

1992-08-11

109

Lift Sling Emplacement Device.  

National Technical Information Service (NTIS)

The present invention relates generally to the field of retrieval of sunken objects and also to the field of securing and lifting devices. Attachment of lifting lines to sunken objects using remote controlled manipulators is one of the most difficult task...

D. J. Hackman D. W. Caudy R. L. Wernli C. S. Albro

1981-01-01

110

NOVA: Lift and Drag  

NSDL National Science Digital Library

This interactive tutorial examines the aerodynamic forces of lift and drag. Students explore the two principles that combine to produce lift: the Bernoulli Effect and Newton's Third Law. The tutorial discusses why wing shape alone cannot create lift. Airplanes stay aloft because the wing pushes air down; the corresponding reaction occurs as air pushes the wing up. This paired action/reaction, along with wing shape and airspeed, interact to produce flight. This resource is part of the NOVA digital collection on space and flight.

2011-10-03

111

Human exposure to heavy metals. Rare earth pneumoconiosis in occupational workers. [From Carbon arc lamps in photoengraving  

SciTech Connect

A male subject exposed for many years to rare earth (RE)-containing fumes and dusts emitted from carbon arc lamps in photoengraving laboratories was investigated to rule out RE pneumoconiosis. While chest x-ray films showed a severe pulmonary fibrosis, clinical analysis showed obvious high RE concentrations in the pulmonary and lymph node biopsy specimens compared with the corresponding tissues of 11 unexposed subjects. In addition to other elements, levels of thorium (Th), which is generally present as an impurity of RE compounds, were also determined to estimate the radiation dose which may be involved in inducing pneumoconiosis. The results show that the levels of Th are more than two orders of magnitude lower than the maximum permissible concentration for occupational exposure to natural 232Th, suggesting that the long-term accumulation of RE in the lungs played a role in the pathogenesis of the observed pulmonary fibrosis of the worker.

Vocaturo, G.; Colombo, F.; Zanoni, M.; Rodi, F.; Sabbioni, E.; Pietra, R.

1983-05-01

112

29 CFR 1915.114 - Chain falls and pull-lifts.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Gear and Equipment for Rigging and Materials Handling § 1915.114 Chain falls and pull-lifts. The provisions of this section shall apply to...

2013-07-01

113

Nail Lifting (Onycholysis)  

MedlinePLUS

... as various forms of eczema (including hand dermatitis), psoriasis, and lichen planus. Nail lifting may also occur with underlying medical problems, including thyroid disease, pregnancy, some forms of infection, and rarely ...

114

Dynamic Lift of Airfoils  

NASA Astrophysics Data System (ADS)

We present initial wind tunnel measurements which investigate the dynamic stall effect as it is caused by fluctuations of the wind direction in turbulent wind. In order to quantify this effect, the lift of an FX79-W-151A airfoil is determined by the integral of pressure distribution at the wind tunnel walls while rotating the airfoil with defined angular velocity. The rotation speed is varied by numeric control. The pressure measurement is performed by two sets of 40 pressure sensors. The temporal resolution is in the range of msec. For stochastic analysis the experiment is repeated several hundred times. In contrast to static lift values, there is an increase (overshoot) of lift before flow separation on the suction side occurs. The lift magnitude depends on the rate of change of the airfoil's angle of attack. This knowledge is relevant for the estimation of extreme mechanical loads for wind turbine blades.

Barth, Stephan

2005-11-01

115

Vertical vector face lift.  

PubMed

Facial rejuvenation using local anesthesia has evolved in the past decade as a safer option for patients seeking fewer complications and minimal downtime. Mini- and short-scar face lifts using more conservative incision lengths and extent of undermining can be effective in the younger patient with lower face laxity and minimal loose, elastotic neck skin. By incorporating both an anterior and posterior approach and using an incision length between the mini and more traditional face lift, the Vertical Vector Face Lift can achieve longer-lasting and natural results with lesser cost and risk. Submentoplasty and liposuction of the neck and jawline, fundamental components of the vertical vector face lift, act synergistically with superficial musculoaponeurotic system plication to reestablish a more youthful, sculpted cervicomental angle, even in patients with prominent jowls. Dramatic results can be achieved in the right patient by combining with other procedures such as injectable fillers, chin implants, laser resurfacing, or upper and lower blepharoplasties. PMID:21276163

Somoano, Brian; Chan, Joanna; Morganroth, Greg

2011-01-01

116

Theory of lifting surfaces  

NASA Technical Reports Server (NTRS)

The general basis of the theory of lifting surfaces is discussed. The problem of the flow of a fluid about a lifting surface of infinite span is examined in terms of the existence of vortexes in the current. A general theory of permanent flow is discussed. Formulas for determining the influence of aspect ratio that may be applied to all wings, whatever their plane form, are given.

Prandtl , L

1920-01-01

117

A Lighter-Than-Air System Enhanced with Kinetic Lift  

NASA Technical Reports Server (NTRS)

A hybrid airship system is proposed in which the buoyant lift is enhanced with kinetic lift. The airship would consist of twin hulls in which the buoyant gas is contained. The twin hulls would be connected in parallel by a wing having an airfoil contour. In forward flight, the wing would provide kinetic lift that would add to the buoyant lift. The added lift would permit a greater payload/altitude combination than that which could be supported by the buoyant lift alone. The buoyant lift is a function of the volume of gas and the flight altitude. The kinetic lift is a function of the airfoil section, wing area, and the speed and altitude of flight. Accordingly there are a number of factors that can be manipulated to arrive at a particular design. Particular designs could vary from small, lightweight systems to very large, heavy-load systems. It will be the purpose of this paper to examine the sensitivity of such a design to the several variables. In addition, possible uses made achievable by such a hybrid system will be suggested.

Spearman, M. Leroy

2002-01-01

118

Impact of Technology on Heavy Lift Tiltrotors  

Microsoft Academic Search

Rotor performance and aeroelastic stability are presented for a 124,000-lb Large Civil Tilt Rotor (LCTR) design. It was designed to carry 120 passengers for 1200 nm, with performance of 350 knots at 30,000 ft altitude. Design features include a low-mounted wing and hingeless rotors, with a very low cruise tip speed of 350 ft\\/sec. The rotor and wing design processes

C. W. Acree

119

Ares V: Progress Toward Unprecedented Heavy Lift  

NASA Technical Reports Server (NTRS)

Ares V represents the vehicle that will again make possible human exploration beyond low Earth orbit. The Ares V is part of NASA s Constellation Program architecture developed to support the International Space Station (ISS), establish a permanent human presence on the Moon, and explore it to an extent far greater than was possible with the Apollo Program. Ares V will carry the lunar lander to orbit where it will join the Orion crew spacecraft, launched by the smaller Ares I launch vehicle. Then the Ares V upper stage will send the Orion and lander to the Moon. Ares V is also intended to launch automated cargo landers to the Moon. The Ares vehicles are designed to employ the proven technologies and experience from the Space Shuttle, Delta IV, and earlier U.S. programs, as well as sharing common components where feasible. The Ares V is in an early stage of concept development. However, commonality allows it to benefit from development work already under way on the Ares I, including the first stage booster, and upper stage, J-2X upper stage engine. This paper will discuss progress to date on the Ares V and its potential for freeing payload designers from current mass and volume constraints. Progress includes development progress on Ares I elements that will be shared by the two launch vehicles. The Ares I first stage recently completed a successful test firing of Development Motor 1 (DM-1). The J-2X engine is proceeding with manufacturing of components for the first development engines that will be used for testing. Several component-level tests have been completed or are under way that will help verify designs and confirm solutions to design challenges. The Ares V Earth departure stage will benefit from the Ares I upper stage development, including design, manufacturing, and materials testing. NASA is also working with government and industry to collect data on flights and testing of the operational RS-68 engine and potential upgrades. The Ares V team continues to evaluate technical options, vehicle configurations, and operations concepts for the Ares V. The team recently completed a Fall Face-to-Face meeting that served as a stepping-stone to the Systems Requirements Review (SRR). This four-day meeting served as an information exchange for the various teams at several NASA field centers and supporting contractors.

Sumrall, Phil

2010-01-01

120

Occupancy Sensors.  

National Technical Information Service (NTIS)

Occupancy sensors secure power to the lights in unoccupied spaces to conserve energy. This TechData Sheet presents occupancy sensor types, applications, and the potential economic savings of retrofit projects. Manufacturers of occupancy sensors claim ener...

A. Leitherer M. Rocha

1996-01-01

121

Occupational allergens  

Microsoft Academic Search

Occupational agents are important in a significant number of respiratory diseases. More than 250 occupational substances have\\u000a been reported to cause occupational asthma. Occupational allergens are the subset of agents causing occupational diseases\\u000a through an IgE-mediated mechanism. These allergens may be classified as being of either high or low molecular weight. The\\u000a more common occupational allergens and the industries at

Francis Lachowsky; Manuel Lopez

2001-01-01

122

Musculoskeletal disorders and occupational exposures: how should we judge the evidence concerning the causal association?  

PubMed

Musculoskeletal disorders (MSDs) affecting the back, upper and lower extremities are widespread in the general population, implying a variety of causal factors. Multiple causes are not mutually exclusive, and a high background rate does not preclude associations with specific factors that are uncommon in the general population. MSDs have well-documented associations with occupational ergonomic stressors such as repetitive motion, heavy lifting, non-neutral postures, and vibration. Organizational features of the work environment, such as time pressure and low decision latitude, may also play a role, at least by potentiating the effects of physical loading. Numerous systematic reviews have mostly concurred with these overall findings. Nevertheless, some continue to debate whether MSDs are sometimes work-related, even for those performing jobs with repetitive and routinized tasks, heavy lifting, and/or pronounced postural strain. This article discusses (1) some epidemiologic features of MSDs that underlie that debate; and (2) the question of what should appropriately be considered a gold standard for scientific evidence on an etiological question such as the health effects of a non-voluntary exposure, such as an occupational or environmental agent. In particular, randomized clinical trials have little relevance for determining the health effects of non-therapeutic risk factors. PMID:24553854

Punnett, Laura

2014-03-01

123

Hydraulic lifting device  

NASA Technical Reports Server (NTRS)

A piston and cylinder assembly is disclosed which is constructed of polyvinyl chloride that uses local water pressure to perform small lifting tasks. The chamber is either pressurized to extend the piston or depressurized to retract the piston. The present invention is best utilized for raising and lowering toilet seats.

Terrell, Kyle (inventor)

1990-01-01

124

JWST Lifting System  

NASA Technical Reports Server (NTRS)

A document describes designing, building, testing, and certifying a customized crane (Lifting Device LD) with a strong back (cradle) to facilitate the installation of long wall panels and short door panels for the GHe phase of the James Webb Space Telescope (JWST). The LD controls are variable-frequency drive controls designed to be adjustable for very slow and very-short-distance movements throughout the installation. The LD has a lift beam with an electric actuator attached at the end. The actuator attaches to a rectangular strong back (cradle) for lifting the long wall panels and short door panels from a lower angle into the vertical position inside the chamber, and then rotating around the chamber for installation onto the existing ceiling and floor. The LD rotates 360 (in very small increments) in both clockwise and counterclockwise directions. Eight lifting pads are on the top ring with 2-in. (.5-cm) eye holes spaced evenly around the ring to allow for the device to be suspended by three crane hoists from the top of the chamber. The LD is operated by remote controls that allow for a single, slow mode for booming the load in and out, with slow and very slow modes for rotating the load.

Tolleson, William

2012-01-01

125

Evaluation of ceiling lifts in health care settings: patient outcome and perceptions.  

PubMed

Ceiling lifts have been introduced into health care settings to reduce manual patient lifting and thus occupational injuries. Although growing evidence supports the effectiveness of ceiling lifts, a paucity of research links indicators, such as quality of patient care or patient perceptions, to the use of these transfer devices. This study explored the relationship between ceiling lift coverage rates and measures of patient care quality (e.g., incidence of facility-acquired pressure ulcers, falls, urinary infections, urinary incontinence, and assaults [patient to staff] in acute and long-term care facilities), as well as patient perceptions of satisfaction with care received while using ceiling lifts in a complex care facility. Qualitative semi-structured interviews were used to generate data. A significant inverse relationship was found between pressure ulcer rates and ceiling lift coverage; however, this effect was attenuated by year. No significant relationships existed between ceiling lift coverage and patient outcome indicators after adding the "year" variable to the model. Patients generally approved of the use of ceiling lifts and recognized many of the benefits. Ceiling lifts are not detrimental to the quality of care received by patients, and patients prefer being transferred by ceiling lifts. The relationship between ceiling lift coverage and pressure ulcer rates warrants further investigation. PMID:19842612

Alamgir, Hasanat; Li, Olivia Wei; Gorman, Erin; Fast, Catherine; Yu, Shicheng; Kidd, Catherine

2009-09-01

126

Helicopter Toy and Lift Estimation  

ERIC Educational Resources Information Center

A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

Shakerin, Said

2013-01-01

127

Summary of Lift and Lift/Cruise Fan Powered Lift Concept Technology.  

National Technical Information Service (NTIS)

A summary is presented of some of the lift and lift/cruise fan technology including fan performance, fan stall, ground effects, ingestion and thrust loss, design tradeoffs and integration, control effectiveness and several other areas related to vertical ...

W. L. Cook

1993-01-01

128

Powered-lift aircraft technology  

NASA Technical Reports Server (NTRS)

Powered lift aircraft have the ability to vary the magnitude and direction of the force produced by the propulsion system so as to control the overall lift and streamwise force components of the aircraft, with the objective of enabling the aircraft to operate from minimum sized terminal sites. Power lift technology has contributed to the development of the jet lift Harrier and to the forth coming operational V-22 Tilt Rotor and the C-17 military transport. This technology will soon be expanded to include supersonic fighters with short takeoff and vertical landing capability, and will continue to be used for the development of short- and vertical-takeoff and landing transport. An overview of this field of aeronautical technology is provided for several types of powered lift aircraft. It focuses on the description of various powered lift concepts and their operational capability. Aspects of aerodynamics and flight controls pertinent to powered lift are also discussed.

Deckert, W. H.; Franklin, J. A.

1989-01-01

129

High lift wake investigation  

NASA Technical Reports Server (NTRS)

The behavior of wakes in adverse pressure gradients is critical to the performance of high-lift systems for transport aircraft. Wake deceleration is known to lead to sudden thickening and the onset of reversed flow; this 'wake bursting' phenomenon can occur while surface flows remain attached. Although known to be important for high-lift systems, few studies of such decelerated wakes exist. In this study, the wake of a flat plate has been subjected to an adverse pressure gradient in a two-dimensional diffuser, whose panels were forced to remain attached by use of slot blowing. Pitot probe surveys, L.D.V. measurements, and flow visualization have been used to investigate the physics of this decelerated wake, through the onset of reversed flow.

Sullivan, J. P.; Schneider, S. P.; Hoffenberg, R.

1996-01-01

130

Occupational Asthma  

Microsoft Academic Search

Occupational asthma is the most common occupational lung disease. Work-aggravated asthma and occupational asthma are two forms\\u000a of asthma causally related to the workplace, while reactive airways dysfunction syndrome is a separate entity and a subtype\\u000a of occupational asthma. The diagnosis of occupational asthma is most often made on clinical grounds. The gold standard test,\\u000a specific inhalation challenge, is rarely

Nicholas J. Kenyon; Brian M. Morrissey; Michael Schivo; Timothy E. Albertson

131

Armature lift windmill  

SciTech Connect

Airfoils are secured to the frame of a vertical axis windmill to provide vertical lift to a rotatable vertical shaft and to armatures of electrical generators, thereby eliminating friction between each armature and its end bearing as well as between the vertical shaft and its end bearing. An indicator provides an indication that the generators of the windmill are generating an alternating electrical current having at least a predetermined voltage magnitude.

Willmouth, R. W.

1985-04-02

132

The subcutaneous forehead lift.  

PubMed

A limited experience (27 patients, all female) is presented utilizing the subcutaneous approach to forehead lifting. This approach has been little utilized and has been condemned in the literature for being dangerous. However, no difficulties in wound healing or alopecia have been encountered, and the procedure has the advantages of more effectively removing the vertical and transverse wrinkles in the glabellar region, raising the brows, and preserving sensation to the scalp posterior to the incision. PMID:2911624

Wolfe, S A; Baird, W L

1989-02-01

133

Lifting Body Flight Vehicles  

NASA Technical Reports Server (NTRS)

NASA has a technology program in place to build the X-33 test vehicle and then the full sized Reusable Launch Vehicle, VentureStar. VentureStar is a Lifting Body (LB) flight vehicle which will carry our future payloads into orbit, and will do so at a much reduced cost. There were three design contenders for the new Reusable Launch Vehicle: a Winged Vehicle, a Vertical Lander, and the Lifting Body(LB). The LB design won the competition. A LB vehicle has no wings and derives its lift solely from the shape of its body, and has the unique advantages of superior volumetric efficiency, better aerodynamic efficiency at high angles-of-attack and hypersonic speeds, and reduced thermal protection system weight. Classically, in a ballistic vehicle, drag has been employed to control the level of deceleration in reentry. In the LB, lift enables the vehicle to decelerate at higher altitudes for the same velocity and defines the reentry corridor which includes a greater cross range. This paper outlines our LB heritage which was utilized in the design of the new Reusable Launch Vehicle, VentureStar. NASA and the U.S. Air Force have a rich heritage of LB vehicle design and flight experience. Eight LB's were built and over 225 LB test flights were conducted through 1975 in the initial LB Program. Three LB series were most significant in the advancement of today's LB technology: the M2-F; HL-1O; and X-24 series. The M2-F series was designed by NASA Ames Research Center, the HL-10 series by NASA Langley Research Center, and the X-24 series by the Air Force. LB vehicles are alive again today.

Barret, Chris

1998-01-01

134

Enhanced Rescue Lift Capability  

NASA Technical Reports Server (NTRS)

The evolving and ever-increasing demands of emergency response and disaster relief support provided by rotorcraft dictate, among other things, the development of enhanced rescue lift capability for these platforms. This preliminary analysis is first-order in nature but provides considerable insight into some of the challenges inherent in trying to effect rescue using a unique form of robotic rescue device deployed and operated from rotary-wing aerial platforms.

Young, Larry A.

2007-01-01

135

Cavitation Induced Lift Fluctuations  

NASA Astrophysics Data System (ADS)

For various reasons, liquid handling devices, such as pumps, turbines, marine propellers and hydrofoils must often operate in the cavitating regime. Considerable research has gone into avoiding cavitation but little effort has been made to understand the complex physics associated with operation in the partially cavitating regime. This is an experimental study of lift oscillations on a NACA 0015 hydrofoil. Fluctuating lift is measured at two different geometric scales in two different water tunnels. The spectral characteristics of the fluctuations are found to vary considerable over a range of 1.0 ?/2×? 8.5. The amplitude of the fluctuations can exceed 100% of the steady state lift and are associated with the periodic shedding of vortical clouds of bubbles into the flow. Two competing mechanisms are found for the induced shedding of cloud cavitation. At high values of ?/2×?, reentrant jet physics dominate, with sheet cavity oscillations at a frequency, based on cavity length, of fl/U equal 0.3. At low values of ?/2×? , bubbly flow shock wave phenomena dominate with a constant Strouhal number based on chord length of fc/U equal 0.2. A significant effect on the wake structure is also noted. Good agreement with numerical simulations based on the LES technique is generally found. Sponsored by the National Science Foundation and the Office of Naval Research.

Arndt, Roger E. A.; Keller, Anreas; Kjeldsen, Morten

1999-11-01

136

Catalytic Generation of Lift Gases for Balloons  

NASA Technical Reports Server (NTRS)

A lift-gas cracker (LGC) is an apparatus that generates a low-molecular-weight gas (mostly hydrogen with smaller amounts of carbon monoxide and/or carbon dioxide) at low gauge pressure by methanol reforming. LGCs are undergoing development for use as sources of buoyant gases for filling zero-gauge-pressure meteorological and scientific balloons in remote locations where heavy, high-pressure helium cylinders are not readily available. LGCs could also be used aboard large, zero-gauge-pressure, stratospheric research balloons to extend the duration of flight.

Zubrin, Robert; Berggren, Mark

2011-01-01

137

Detail of lift wire rope attachment to lift span at ...  

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

Detail of lift wire rope attachment to lift span at southeast corner. Note rope-adjustment turnbuckle with strap keepers to prevent its rotation, which could pull the bridge out of alignment. A single rope and light-gauge attachment at each corner were adequate for lifting the span because most of its weight was balanced by the two counterweights. - Potomac Edison Company, Chesapeake & Ohio Canal Bridge, Spanning C & O Canal South of U.S. 11, Williamsport, Washington County, MD

138

Air Lift: Ski Jump  

NSDL National Science Digital Library

The following resource is from Lessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this lesson, Students will learn about the ski-jumping competition in the Winter Olympics, to explore concepts about gravity, drag and lift. Students will create their own version of a ski jump complete with jumpers.

2010-01-01

139

[Occupational cancer].  

PubMed

Occupational cancer is one of the most important topics in occupational health, because it can be avoided by using appropriate risk management strategies at work. However, due to the lack of suitable surveillance systems in Japan, it goes under-recognized. Burden of disease studies conducted elsewhere can be extrapolated to suggest thousands of deaths are attributable to occupational cancer in Japan. By law, about 20 kinds of cancer have been listed as occupational hazards; among those is asbestos related cancer. In fact, in recent years, thousands of asbestos related cancer cases have been compensated by the government run workers' compensation scheme for occupational accidents and diseases. On the other hand, for the other types of occupational cancer, only few cases are reported. To prevent re-emergence of occupational cancer, such as the recently publicized cholangiocarcinoma epidemics, employees, employers, medical institutions and competent authorities are strongly urged to establish better surveillance systems for occupational cancer. PMID:24605530

Mori, Ippei

2014-02-01

140

Time Use and Occupational Performance Among Persons with Schizophrenia  

Microsoft Academic Search

Schizophrenia is a complex disorder with a heavy impact on daily life. Since the human occupational pattern is a product of person-occupation-environment interaction, it is of importance to explore all these factors to understand the daily occupational pattern among persons with schizophrenia. This study aimed to describe the time use of 10 persons with schizophrenia, reflecting the participants' daily occupations,

Ulrika Bejerholm; Mona Eklund

2004-01-01

141

Occupational Rhinitis  

Microsoft Academic Search

Work-related rhinitis, which includes work-exacerbated rhinitis and occupational rhinitis, may be two to three times more\\u000a common than occupational asthma. Both high molecular weight proteins and low molecular weight chemicals have been implicated\\u000a as causes of occupational rhinitis. A diagnosis is established based on occupational history and, if appropriate, documentation\\u000a of IgE-mediated sensitization to the causative agent. Management of work-related

J. Wesley Sublett; David I. Bernstein

2010-01-01

142

Lifting Bodies on Lakebed  

NASA Technical Reports Server (NTRS)

The wingless, lifting body aircraft sitting on Rogers Dry Lake at what is now NASA's Dryden Flight Research Center, Edwards, California, from left to right are the X-24A, M2-F3 and the HL-10.The lifting body aircraft studied the feasibility of maneuvering and landing an aerodynamic craft designed for reentry from space. These lifting bodies were air launched by a B-52 mother ship, then flew powered by their own rocket engines before making an unpowered approach and landing. They helped validate the concept that a space shuttle could make accurate landings without power. The X-24A flew from April 17, 1969 to June 4, 1971. The M2-F3 flew from June 2, 1970 until December 22, 1972. The HL-10 flew from December 22, 1966 until July 17, 1970, and logged the highest and fastest records in the lifting body program. The X-24 was one of a group of lifting bodies flown by the NASA Flight Research Center (FRC-now Dryden Flight Research Center), Edwards, California, in a joint program with the U.S. Air Force at Edwards Air Force Base from 1963 to 1975. The lifting bodies were used to demonstrate the ability of pilots to maneuver and safely land wingless vehicles designed to fly back to Earth from space and be landed like an airplane at a predetermined site. Lifting bodies' aerodynamic lift, essential to flight in the atmosphere, was obtained from their shape. The addition of fins and control surfaces allowed the pilots to stabilize and control the vehicles and regulate their flight paths. Built by Martin Aircraft Company, Maryland, for the U.S. Air Force, the X-24A was a bulbous vehicle shaped like a teardrop with three vertical fins at the rear for directional control. It weighed 6,270 pounds, was 24.5 feet long and 11.5 feet wide (measuring just the fuselage, not the distance between the tips of the outboard fins). Its first unpowered glide flight was on April 17, 1969, with Air Force Maj. Jerauld Gentry at the controls. Gentry also piloted its first powered flight on March 19, 1970. The X-24A was flown 28 times in the program that, like the HL-10, validated the concept that a Space Shuttle vehicle could be landed unpowered. The fastest speed achieved by the X-24A was 1,036 miles per hour (mph--Mach 1.6). Its maximum altitude was 71,400 feet. It was powered by an XLR-11 rocket engine with a maximum theoretical vacuum thrust of 8,480 pounds. The X-24A was later modified into the X-24B. The bulbous shape of the X-24A was converted into a 'flying flatiron' shape with a rounded top, flat bottom, and double delta platform that ended in a pointed nose. The X-24B demonstrated that accurate unpowered reentry vehicle landings were operationally feasible. Top speed achieved by the X-24B was 1,164 mph and the highest altitude it reached was 74,130 feet. The vehicle is on display at the Air Force Museum, Wright-Patterson Air Force Base, Ohio. The pilot on the last powered flight of the X-24B was Bill Dana, who also flew the last X-15 flight about seven years earlier. The X-24A shape was later borrowed for the X-38 Crew Return Vehicle (CRV) technology demonstrator for the International Space Station. The X-24B is on public display at the Air Force Museum, Wright-Patterson AFB, Ohio. The M2-F3 was a modified version of the M2-F2. NASA pilots said the M2-F2 had lateral control problems, even though it had a stability augmentation control system. When the M2-F2 was rebuilt at Dryden and redesignated the M2-F3, it was modified with an additional third vertical fin-centered between the tip fins-to improve control characteristics. The first flight of the M2-F3, with NASA pilot Bill Dana at the controls, was on June 2, 1970. It was a glide flight to evaluate changes in the vehicle's performance due to the modifications. The modified vehicle exhibited much better lateral stability and control characteristics than had the M2-F2. Over the next 26 missions, the M2-F3 reached a top speed of l,064 mph (Mach 1.6). Bill Dana was the pilot, and the high-speed flight took place on December 13, 1972. The highest altitude reached by the vehicle was 71,500 feet on

1969-01-01

143

Initiating Piloted Mars Expeditions with Medium-Lift Launch Systems  

NASA Astrophysics Data System (ADS)

A method of accomplishing manned expeditions to Mars with existing medium-lift launch systems is discussed. In this architecture, 20-tonne propulsion stages are placed individually in low-Earth orbit, where they are mated to Mars-bound payloads and ignited at successive perigees to execute trans-Mars injection. Spacecraft follow conjunction-class trajectories to the red planet and utilize aerobraking for orbital capture and descent. Return vehicles are fuelled with methane/oxygen bipropellant synthesized primarily from Martian resources. Dispatching expeditions from orbit with individual, high-energy stages - rather than directly from the Earth's surface - allows for the division of mission mass into more manageable components, which can be launched by vehicles that exist today. This plan does not require the development of heavy-lift launch technology: an effective yet costly proposition that may otherwise hinder current space exploration initiatives. Without the need for heavy-lift boosters, manned missions to Mars can be undertaken presently, and within the constraints of today's space exploration budgets. It is concluded that the mission design herein represents a less robust, though more economically viable method for initiating manned Mars exploration than proposals which require heavy-lift technology - an alternative method by which a new planet could be opened to humanity.

Bonin, G. R.

144

Review of occupational hazards associated with aquaculture.  

PubMed

Aquaculture is an emerging sector that is associated with most of the same hazards that are present in agriculture generally, but many fish farming tasks entail added danger, including working around water and working at night. Comprehensive studies of these hazards have not been conducted, and substantial uncertainty exists as to the extent of these hazards. The question addressed in this investigation was, "What is known about potential hazardous occupational exposures to aquatic plant and animal farmers?" In this review, causes of death included drowning, electrocution, crushing-related injury, hydrogen sulfide poisoning, and fatal head injury. Nonfatal injuries were associated with slips, trips, and falls; machines; strains and sprains; chemicals; and fires. Risk factors included cranes (tip over and power line contact), tractors and sprayer-equipped all-terrain vehicles (overturn), heavy loads (lifting), high-pressure sprayers, slippery surfaces, rotting waste (hydrogen sulfide production), eroding levees (overturn hazard), storm-related rushing water, diving conditions (bends and drowning), nighttime conditions, working alone, lack of training, lack of or failure to use personal flotation devices, and all-terrain vehicle speeding. Other hazards included punctures or cuts from fish teeth or spines, needlesticks, exposure to low temperatures, and bacterial and parasitic infections . PMID:20954037

Myers, Melvin L

2010-10-01

145

What is a safe lift?  

PubMed

In a perfect world, a "safe" lift would be 51 pounds if the object is within 7 inches from the front of the body, if it is at waist height, if it is directly in front of the person, if there is a handle on the object, and if the load inside the box/bucket doesn't shift once lifted. If the load to be lifted does not meet all of these criteria, then it is an unsafe lift, and modifications must be made. Modifications would include lightening the load, getting help, or using a mechanical lifting device. There is always a way to turn an unsafe lift into a safer lift. An excellent resource for anyone interested in eliminating some of the hazards associated with lifting is the "Easy Ergonomics" publication from Cal/OSHA. This booklet offers practical advice on how to improve the workplace using engineering and administrative controls, problem-solving strategies and solutions, and a vast amount of ergonomics information and resources. "Easy Ergonomics" can be obtained by calling Cal/OSHA's education and training unit in Sacramento at 800-963-9424. A free copy can be obtained via www.dir.ca.gov/dosh/puborder.asp. PMID:24260936

Espinoza, Kathy

2013-09-01

146

Lifting as an Industrial Hazard  

Microsoft Academic Search

A great deal of accident prevention education has been directed toward the reduction of back injuries. This has not produced any great change in the incidence of this condition, and the author presents evidence that there can be no specific and mandatory method for lifting all loads. Virtually all types of lifting methods are possible and, in fact, are used

JOHN R. BROWN

1973-01-01

147

What's happening in artificial lift  

SciTech Connect

New developments reported this year are primarily in the areas of electrical submersible pumps (ESPs), beam pumps, and gas lift. The available information includes new products, techniques for extending run life, controllers, monitors and various other products. Specific topics in this article include: ESP turn key leases for temporary lifting; Horizontal pumps; Gas diffusion coatings for ESP bushings and sleeves; ESP variable rate current-voltage recording monitor; Power tubing ESP status; Low volume, high efficiency ESP stage; ESP improvements for horizontal and abrasive conditions; ESP computer design program effort; Well analyzer; Beam pump controller with variable frequency drive; Hydraulic pumping units; Mobile swab unit for marginal wells; Device for unseating downhole pumps; Gas lift valve test stand; Plunger lift controllers; Resettable ESP packer; Power generation from wellhead gas; and Artificial lift PC design program.

Lea, J.F. (Amoco Production Research Co., Tulsa, OK (US)); Winkler, H.W.

1991-05-01

148

Summary of Lift and Lift/Cruise Fan Powered Lift Concept Technology  

NASA Technical Reports Server (NTRS)

A summary is presented of some of the lift and lift/cruise fan technology including fan performance, fan stall, ground effects, ingestion and thrust loss, design tradeoffs and integration, control effectiveness and several other areas related to vertical short takeoff and landing (V/STOL) aircraft conceptual design. The various subjects addressed, while not necessarily pertinent to specific short takeoff/vertical landing (STOVL) supersonic designs being considered, are of interest to the general field of lift and lift/cruise fan aircraft designs and may be of importance in the future. The various wind tunnel and static tests reviewed are: (1) the Doak VZ-4 ducted fan, (2) the 0.57 scale model of the Bell X-22 ducted fan aircraft, (3) the Avrocar, (4) the General Electric lift/cruise fan, (5) the vertical short takeoff and landing (V/STOL) lift engine configurations related to ingestion and consequent thrust loss, (6) the XV-5 and other fan-in-wing stall consideration, (7) hybrid configurations such as lift fan and lift/cruise fan or engines, and (8) the various conceptual design studies by air-frame contractors. Other design integration problems related to small and large V/STOL transport aircraft are summarized including lessons learned during more recent conceptual design studies related to a small executive V/STOL transport aircraft.

Cook, Woodrow L.

1993-01-01

149

Lift force of delta wings  

SciTech Connect

On a delta wing, the separation vortices can be stationary due to the balance of the vorticity surface flux and the axial convection along the swept leading edge. These stationary vortices keep the wing from losing lift. A highly swept delta wing reaches the maximum lift at an angle of attack of about 40, which is more than twice as high as that of a two-dimensional airfoil. In this paper, the experimental results of lift forces for delta wings are reviewed from the perspective of fundamental vorticity balance. The effects of different operational and geometrical parameters on the performance of delta wings are surveyed.

Lee, M.; Ho, Chihming (Univ. of Southern California, Los Angeles (USA))

1990-09-01

150

Endobrow-midface lift.  

PubMed

The introduction of endoscopes is responsible for the surge in many of the aesthetic facial plastic surgeries in the past decade. This relatively new technology is widely used in upper-third facial rejuvenation and created a natural evolution into the rejuvenation of the central midthird of the face. After careful patient selection and evaluation, several key maneuvers are accomplished to achieve forehead and midface rejuvenation: (1) a subperiosteal dissection of the scalp to the level of the superior and lateral orbital rims and zygomatic arch, (2) incision and release of orbital periosteum, (3) selective myectomies of the glabella muscles, (4) subperiosteal dissection of the midface (from infraorbital rim to the inferior aspect of the maxilla and laterally over the entire zygomatic arch to the gonial angle beneath the masseteric aponeurosis), and (5) suspension and reposition of the malar fat pad, suborbicularis oculi fat, and soft tissue overlying the angle of the mandible. Endobrow-midface lift is a safe and reliable method to rejuvenate the upper two thirds of the face with excellent results while minimizing the morbidities and complications associated with the traditional open procedures. PMID:15643592

Quatela, Vito C; Choe, Kyle S

2004-08-01

151

Occupational Asthma  

Microsoft Academic Search

\\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a Occupational asthma is the most common occupational lung disease.\\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a Occupational asthma and work-aggravated asthma are the two forms of asthma causally related to the workplace.\\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a Reactive airways dysfunction syndrome is a separate entity and a subtype of occupational asthma.\\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a The diagnosis of occupational asthma is most often made on clinical grounds; the goldstandard test, specific inhalation

Nicholas J. Kenyon; Brian M. Morrissey; Timothy E. Albertson

152

Lift force in bubbly suspensions  

Microsoft Academic Search

Closure relations are presented for the lift coefficient for ordered arrays of 2-D and 3-D bubbles at various bubble volume fractions. These were determined via lattice Boltzmann simulations of bubble rise in periodic boxes, where the bubbles were also subjected to shear. The single-bubble lift coefficient, determined by low-shear computational experiments, varies in a systematic manner with the aspect ratio

Krishnan Sankaranarayanan; Sankaran Sundaresan

2002-01-01

153

Complex contact and lift transformations  

NASA Astrophysics Data System (ADS)

We study mappings from sets of real variables into complex variables, which extend features of lift and contact transformations between real variables that we explored in a previous paper. In particular the relationship between lifts in R and the Cauchy-Riemann equations for functions of n complex variables is discussed. Explicit examples are given to illustrate the anatomy of such transformations, including the occurrence of singularities. Applications to nonlinear partial differential equations arising in fluid mechanics are presented.

Roulstone, I.; Sewell, M. J.

2013-03-01

154

Physiological, Biomechanical, and Medical Aspects of Lifting and Repetitive Lifting: A Review.  

National Technical Information Service (NTIS)

The literature relating to physiological and medical lifting and repetitive lifting is reviewed. Studies on maximal lifting capacity and maximal acceptable lift (MAL, the amount of weight that can be lifted repetitively over and 8h period) show that as th...

J. Knapik

1983-01-01

155

Lifting without Seeing: The Role of Vision in Perceiving and Acting upon the Size Weight Illusion  

PubMed Central

Background Our expectations of an object's heaviness not only drive our fingertip forces, but also our perception of heaviness. This effect is highlighted by the classic size-weight illusion (SWI), where different-sized objects of identical mass feel different weights. Here, we examined whether these expectations are sufficient to induce the SWI in a single wooden cube when lifted without visual feedback, by varying the size of the object seen prior to the lift. Methodology/Principal Findings Participants, who believed that they were lifting the same object that they had just seen, reported that the weight of the single, standard-sized cube that they lifted on every trial varied as a function of the size of object they had just seen. Seeing the small object before the lift made the cube feel heavier than it did after seeing the large object. These expectations also affected the fingertip forces that were used to lift the object when vision was not permitted. The expectation-driven errors made in early trials were not corrected with repeated lifting, and participants failed to adapt their grip and load forces from the expected weight to the object's actual mass in the same way that they could when lifting with vision. Conclusions/Significance Vision appears to be crucial for the detection, and subsequent correction, of the ostensibly non-visual grip and load force errors that are a common feature of this type of object interaction. Expectations of heaviness are not only powerful enough to alter the perception of a single object's weight, but also continually drive the forces we use to lift the object when vision is unavailable.

Buckingham, Gavin; Goodale, Melvyn A.

2010-01-01

156

Face lift postoperative recovery.  

PubMed

The purpose of this paper is to describe what I have studied and experienced, mainly regarding the control and prediction of the postoperative edema; how to achieve an agreeable recovery and give positive support to the patient, who in turn will receive pleasant sensations that neutralize the negative consequences of the surgery.After the skin is lifted, the drainage flow to the flaps is reversed abruptly toward the medial part of the face, where the flap bases are located. The thickness and extension of the flap determines the magnitude of the post-op edema, which is also augmented by medial surgeries (blepharo, rhino) whose trauma obstruct their natural drainage, increasing the congestion and edema. To study the lymphatic drainage, the day before an extended face lift (FL) a woman was infiltrated in the cheek skin with lynfofast (solution of tecmesio) and the absorption was observed by gamma camera. Seven days after the FL she underwent the same study; we observed no absorption by the lymphatic, concluding that a week after surgery, the lymphatic network was still damaged. To study the venous return during surgery, a fine catheter was introduced into the external jugular vein up to the mandibular border to measure the peripheral pressure. Following platysma plication the pressure rose, and again after a simple bandage, but with an elastic bandage it increased even further, diminishing considerably when it was released. Hence, platysma plication and the elastic bandage on the neck augment the venous congestion of the face. There are diseases that produce and can prolong the surgical edema: cardiac, hepatic, and renal insufficiencies, hypothyroidism, malnutrition, etc. According to these factors, the post-op edema can be predicted, the surgeon can choose between a wide dissection or a medial surgery, depending on the social or employment compromises the patient has, or the patient must accept a prolonged recovery if a complex surgery is necessary. Operative measures which prevent extensive edemas are: avoiding transection of the temporal pedicle, or to realizing platysma plication too tight by using strong aspirative drainage instead of elastic bandages. In the post-op, the manual lymphatic drainage is initiated on the third or fifth day, but must be done by a trained professional, in a method contrary to that specified in the books for non-operated individuals. An aesthetician washes the hair and applies decongestive cold tea on the face the second day, and on the fifth, moisturizes the skin and cosmetically conceals any signs of bruising. The psychological support provided by the staff keeps the patient calm and relaxed. Five years experience with this protocol has enabled us to minimize post-op pain. The edema can be predicted with certain consistency (in which surgery there will be more or less edema) and the proper technique can be selected, permitting the patient to choose the best moment for a FL while the surgeon can avoid intra and postoperative measures that increase the edema. After surgery, the patient receives the daily assistance of the staff, which rapidly and efficiently improves this condition. We can predict and control the post-op recovery and the patient feels fine, unlike the past when recovery was abandoned to its natural evolution. If the patient perceived an intensive, positive support on behalf of the entire staff that kept him or her content, then we have succeeded in doing an excellent marketing. This may encourage others to undergo aesthetic surgery, especially those who are convinced that after surgery they might have to endure considerable suffering. PMID:12140694

Mottura, A Aldo

2002-01-01

157

Comparison of serum testosterone and androstenedione responses to weight lifting in men and women  

Microsoft Academic Search

Summary  To determine if a sex difference exists in the androgen response to heavy-resistance exercise, serum testosterone (T) and androstenedione (A) concentrations were measured in 20 men and 20 women before and during a 2-h period following 30 min of weight lifting. Hormone concentrations from venous blood samples were determined by radioimmunoassay. Prior to weight lifting, T for men (3.51±0.24 ng·ml–1)

Lawrence W. Weiss; Kirk J. Cureton; Frederick N. Thompson

1983-01-01

158

Normalized Lift: An Energy Interpretation of the Lift Coefficient Simplifies Comparisons of the Lifting Ability of Rotating and Flapping Surfaces  

PubMed Central

For a century, researchers have used the standard lift coefficient CL to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½?v2, where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex adjustments as is the case for flapping wings and rotating cylinders. This paper interprets the standard lift coefficient of a fixed wing slightly differently, as the work exerted by the wing on the surrounding flow field (L/?·S), compared against the total kinetic energy required for generating said lift, ½v2. This reinterpreted coefficient, the normalized lift, is derived from the work-energy theorem and compares the lifting capabilities of dissimilar lift systems on a similar energy footing. The normalized lift is the same as the standard lift coefficient for fixed wings, but differs for wings with more complex motions; it also accounts for such complex motions explicitly and without complex modifications or adjustments. We compare the normalized lift with the previously-reported values of lift coefficient for a rotating cylinder in Magnus effect, a bat during hovering and forward flight, and a hovering dipteran. The maximum standard lift coefficient for a fixed wing without flaps in steady flow is around 1.5, yet for a rotating cylinder it may exceed 9.0, a value that implies that a rotating cylinder generates nearly 6 times the maximum lift of a wing. The maximum normalized lift for a rotating cylinder is 1.5. We suggest that the normalized lift can be used to evaluate propellers, rotors, flapping wings of animals and micro air vehicles, and underwater thrust-generating fins in the same way the lift coefficient is currently used to evaluate fixed wings.

Burgers, Phillip; Alexander, David E.

2012-01-01

159

Normalized lift: an energy interpretation of the lift coefficient simplifies comparisons of the lifting ability of rotating and flapping surfaces.  

PubMed

For a century, researchers have used the standard lift coefficient C(L) to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½?v(2), where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex adjustments as is the case for flapping wings and rotating cylinders.This paper interprets the standard lift coefficient of a fixed wing slightly differently, as the work exerted by the wing on the surrounding flow field (L/?·S), compared against the total kinetic energy required for generating said lift, ½v(2). This reinterpreted coefficient, the normalized lift, is derived from the work-energy theorem and compares the lifting capabilities of dissimilar lift systems on a similar energy footing. The normalized lift is the same as the standard lift coefficient for fixed wings, but differs for wings with more complex motions; it also accounts for such complex motions explicitly and without complex modifications or adjustments. We compare the normalized lift with the previously-reported values of lift coefficient for a rotating cylinder in Magnus effect, a bat during hovering and forward flight, and a hovering dipteran.The maximum standard lift coefficient for a fixed wing without flaps in steady flow is around 1.5, yet for a rotating cylinder it may exceed 9.0, a value that implies that a rotating cylinder generates nearly 6 times the maximum lift of a wing. The maximum normalized lift for a rotating cylinder is 1.5. We suggest that the normalized lift can be used to evaluate propellers, rotors, flapping wings of animals and micro air vehicles, and underwater thrust-generating fins in the same way the lift coefficient is currently used to evaluate fixed wings. PMID:22629326

Burgers, Phillip; Alexander, David E

2012-01-01

160

Occupational Health  

MedlinePLUS

Occupational health problems occur at work or because of the kind of work you do. These problems can include ... by exposure to radiation Exposure to germs in health care settings Good job safety and prevention practices ...

161

Lift production through asymmetric flapping  

NASA Astrophysics Data System (ADS)

At present, there is a strong interest in developing Micro Air Vehicles (MAV) for applications like disaster management and aerial surveys. At these small length scales, the flight of insects and small birds suggests that unsteady aerodynamics of flapping wings can offer many advantages over fixed wing flight, such as hovering-flight, high maneuverability and high lift at large angles of attack. Various lift generating mechanims such as delayed stall, wake capture and wing rotation contribute towards our understanding of insect flight. We address the effect of asymmetric flapping of wings on lift production. By visualising the flow around a pair of rectangular wings flapping in a water tank and numerically computing the flow using a discrete vortex method, we demonstrate that net lift can be produced by introducing an asymmetry in the upstroke-to-downstroke velocity profile of the flapping wings. The competition between generation of upstroke and downstroke tip vortices appears to hold the key to understanding this lift generation mechanism.

Jalikop, Shreyas; Sreenivas, K. R.

2009-11-01

162

Mist lift analysis summary report  

SciTech Connect

The mist flow open-cycle OTEC concept proposed by S.L. Ridgway has much promise, but the fluid mechanics of the mist flow are not well understood. The creation of the mist and the possibility of droplet growth leading to rainout (when the vapor can no longer support the mist) are particularly troublesome. This report summarizes preliminary results of a numerical analysis initiated at SERI in FY79 to study the mist-lift process. The analysis emphasizes the mass transfer and fluid mechanics of the steady-state mist flow and is based on one-dimensional models of the mist flow developed for SERI by Graham Wallis. One of Wallis's models describes a mist composed of a single size of drops and another considers several drop sizes. The latter model, further developed at SERI, considers a changing spectrum of discrete drop sizes and incorporates the mathematics describing collisions and growth of the droplets by coalescence. The analysis results show that under conditions leading to maximum lift in the single-drop-size model, the multigroup model predicts significantly reduced lift because of the growth of droplets by coalescence. The predicted lift height is sensitive to variations in the mass flow rate and inlet pressure. Inclusion of a coasting section, in which the drops would rise ballistically without change in temperature, may lead to increased lift within the existing range of operation.

Davenport, R.L.

1980-09-01

163

Occupational neurology.  

PubMed Central

The nervous system is vulnerable to the effects of certain chemicals and physical conditions found in the work environment. The activities of an occupational neurologist focus on the evaluation of patients with neurological disorders caused by occupational or environmental conditions. When one is making a differential diagnosis in patients with neurological disorders, the possibility of toxic exposure or encounters with physical factors in the workplace must not be overlooked. Central to an accurate clinical diagnosis is the patient's history. A diagnosis of an occupational or environmental neurological problem requires a careful assessment of the clinical abnormalities and confirmation of these disabilities by objective tests such as nerve conduction velocity, evoked potentials, electroencephalogram, neuropsychological batteries, or nerve biopsy. On the basis of information about hazards in the workplace, safety standards and environmental and biological monitoring can be implemented in the workplace to reduce the risks of undue injury. Clinical manifestations of headache, memory disturbance, and peripheral neuropathy are commonly encountered presentations of the effects of occupational hazards. Physicians in everyday clinical practice must be aware of the signs and symptoms associated with exposure to possible neurotoxins and work methods. Occupational and environmental circumstances must be explored when evaluating patients with neurologic disorders.

Feldman, R. G.

1987-01-01

164

Safe patient handling curriculum in occupational therapy and occupational therapy assistant programs: A descriptive study of school curriculum within the United States of America.  

PubMed

The purpose of this study was to identify safe patient handling (SPH) curricular content in accredited occupational therapy and occupational therapy assistant programs in the United States of America. A survey was emailed to 155 accredited occupational therapy and 137 accredited occupational therapy assistant programs. With a 39% response rate, most programs addressed SPH curricula by including lectures and lab-based experiences with gait belts, slide boards, and manual transfers while stressing ‘safe’ body mechanics. There were limited responses regarding curricular-based hands-on experience, evaluation of sit-to-stand lifts, how to safely transfer bariatric persons, and information on “no-lift” policies. While occupational therapists have a central role in teaching SPH to caregivers, it is important to enhance SPH curricula to reduce exposure to musculoskeletal risk, thereby, increasing the health and safety of the occupational therapy workforce as well those whom the profession serves. PMID:22741190

Slusser, Lisa R; Rice, Martin S; Miller, Barbara Kopp

2012-01-01

165

Occupational neurotoxic diseases in taiwan.  

PubMed

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization. PMID:23251841

Liu, Chi-Hung; Huang, Chu-Yun; Huang, Chin-Chang

2012-12-01

166

Powered-Lift Aerodynamics and Acoustics. [conferences  

NASA Technical Reports Server (NTRS)

Powered lift technology is reviewed. Topics covered include: (1) high lift aerodynamics; (2) high speed and cruise aerodynamics; (3) acoustics; (4) propulsion aerodynamics and acoustics; (5) aerodynamic and acoustic loads; and (6) full-scale and flight research.

1976-01-01

167

Lifting Surface Theory and Hydroelastic Instability.  

National Technical Information Service (NTIS)

A brief review is presented of the unsteady lifting surface theory and of the 'generalized lift operator' technique of inverting the 'downwash' integral equation. The integral equation approach is then employed to predice responses of various foils to pit...

S. Tsakonas W. R. Jacobs M. R. Ali

1973-01-01

168

Maximum Acceptable Weight of Lift  

Microsoft Academic Search

This paper discusses the maximum amount of weight that an individual can be expected to lift comfortably and without strain. Recommendations based on empirical estimates, biomechanical techniques, and psychophysical methods are reviewed, including those of the International Labour Office, the Swiss Accident Insurance Institute, the Danish National Association for Infantile Paralysis, and the U. S. Air Force. The approach used

S. H. Snook; C. H. Irvine

1967-01-01

169

Propeller Lifting-Surface Corrections.  

National Technical Information Service (NTIS)

Correction factors for camber, ideal angle due to loading, and ideal angle due to thickness, which are based on propeller lifting surface theory, are presented for a series of propellers. This series consists of optimum free-running propellers with chordw...

S. B. Denny V. Silovic W. B. Morgan

1968-01-01

170

Fluid-dynamic lift: Practical information on aerodynamic and hydrodynamic lift  

Microsoft Academic Search

The book represents an extensive compendium of basic engineering data on the aerodynamic and hydrodynamic characteristics of the chief types of lifting surfaces used in aircraft and marine craft. The topics covered include the mechanism of circulation in foil sections, the lift of straight wings, maximum lift and stalling, lift characteristics of plain, split, and slotted trailing-edge flaps, performance of

S. F. Hoerner; H. V. Borst

1975-01-01

171

Protect Your Back: Guidelines for Safer Lifting.  

ERIC Educational Resources Information Center

Examines back injury in teachers and child care providers; includes statistics, common causes of back pain (improper alignment, improper posture, improper lifting, and carrying), and types of back pain (acute and chronic). Focuses on preventing back injury, body mechanics for lifting and carrying, and proper lifting and carrying of children. (SD)

Cantu, Carolyn O.

2002-01-01

172

Hospital ward patient-lifting tasks  

Microsoft Academic Search

From a questionnaire survey of the nursing staff in charge of 362 wards in Scotland and 363 wards in England, covering every major medical speciality, information was collected on five major tasks which involve lifting patients. The reliability of six parameters, namely, the method used for lifting patients, the number of patients requiring lifting, the number of staff required per

F. BELL; M. E. DALGITY; M.-J. FENNELL; R. C. B. AITKEN

1979-01-01

173

29 CFR 1926.453 - Aerial lifts.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Aerial lifts. 1926.453 Section 1926...CONSTRUCTION Scaffolds § 1926.453 Aerial lifts. (a) General requirements...Unless otherwise provided in this section, aerial lifts acquired for use on or...

2010-07-01

174

29 CFR 1926.453 - Aerial lifts.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Aerial lifts. 1926.453 Section 1926...CONSTRUCTION Scaffolds § 1926.453 Aerial lifts. (a) General requirements...Unless otherwise provided in this section, aerial lifts acquired for use on or...

2009-07-01

175

Vertical Lift - Not Just For Terrestrial Flight  

NASA Technical Reports Server (NTRS)

Autonomous vertical lift vehicles hold considerable potential for supporting planetary science and exploration missions. This paper discusses several technical aspects of vertical lift planetary aerial vehicles in general, and specifically addresses technical challenges and work to date examining notional vertical lift vehicles for Mars, Titan, and Venus exploration.

Young, Larry A

2000-01-01

176

Occupational Education.  

ERIC Educational Resources Information Center

Although fiscal support for occupational programs in California Community Colleges is provided primarily by state and local district taxes, about ten percent of the total support is provided through federal sources. Federal regulations under the Vocational Education Act (VEA) require the recipients of federal funds to provide consultative,…

Morris, William R.

177

Serrated trailing edges for improving lift and drag characteristics of lifting surfaces  

NASA Technical Reports Server (NTRS)

An improvement in the lift and drag characteristics of a lifting surface is achieved by attaching a serrated panel to the trailing edge of the lifting surface. The serrations may have a saw-tooth configuration, with a 60 degree included angle between adjacent serrations. The serrations may vary in shape and size over the span-wise length of the lifting surface, and may be positioned at fixed or adjustable deflections relative to the chord of the lifting surface.

Vijgen, Paul M. H. W. (inventor); Howard, Floyd G. (inventor); Bushnell, Dennis M. (inventor); Holmes, Bruce J. (inventor)

1992-01-01

178

High-altitude launching of rockets lifted by helium devices and platforms with rotatable wings  

US Patent & Trademark Office Database

A system is disclosed for lifting a rocket into the upper atmosphere and establishing forward flight at several hundred miles per hour, before the rocket engines are ignited and the rocket is released from the lifting system. The main subassemblies of this lifting system comprise: (1) an array of large helium-filled dirigibles, of a size that can provide hundreds or thousands of tons of lifting force; (2) a tank-holding assembly that will be tethered to the dirigibles, and that will contain pumps and high-pressure tanks, to recapture and store the helium for use in subsequent launches; and, (3) a winged platform, with wings that can be rotated vertically during liftoff, and horizontally to establish forward flight after a desired altitude has been reached, and having conventional aircraft engines on each wing. This system enables safer, less expensive, and more efficient launching of rockets and heavy payloads into space, using easily reusable subassemblies.

2006-11-07

179

Prediction of Peak Back Compressive Forces as a Function of Lifting Speed and Compressive Forces at Lift Origin and Destination - A Pilot Study  

PubMed Central

Objectives To determine the feasibility of predicting static and dynamic peak back-compressive forces based on (1) static back compressive force values at the lift origin and destination and (2) lifting speed. Methods Ten male subjects performed symmetric mid-sagittal floor-to-shoulder, floor-to-waist, and waist-to-shoulder lifts at three different speeds (slow, medium, and fast), and with two different loads (light and heavy). Two-dimensional kinematics and kinetics were captured. Linear regression analyses were used to develop prediction equations, the amount of predictability, and significance for static and dynamic peak back-compressive forces based on a static origin and destination average (SODA) back-compressive force. Results Static and dynamic peak back-compressive forces were highly predicted by the SODA, with R2 values ranging from 0.830 to 0.947. Slopes were significantly different between slow and fast lifting speeds (p < 0.05) for the dynamic peak prediction equations. The slope of the regression line for static prediction was significantly greater than one with a significant positive intercept value. Conclusion SODA under-predict both static and dynamic peak back-compressive force values. Peak values are highly predictable and could be readily determined using back-compressive force assessments at the origin and destination of a lifting task. This could be valuable for enhancing job design and analysis in the workplace and for large-scale studies where a full analysis of each lifting task is not feasible.

Greenland, Kasey O; Merryweather, Andrew S

2011-01-01

180

What's new in artificial lift  

SciTech Connect

This is an interesting field because it is the area of the oil industry where devices incorporating new mechanical and electrical design are often very visible and widely used. Also, there seems to be a continuing supply of new concepts involving improved lift methods. This will probably continue even with a current industry downturn because progressive operators will still be interested in lower costs of operation and equipment that can help accomplish this goal. However, it is difficult to present a development emerging as a new product when one may not be aware of competing products with similar features from other sources. This article contains some recent innovations considered significant: Unique pumping units, including portable, slant hole, hydraulically powered with air balance and long stroke varieties; New beam pump equipment, including controllers and gas engines; Downhole hydraulic pumps; Jet hydraulic pumps; Vertical centrifugal power fluid pumps; Electric submersible pumps; Plunger lift equipment.

Lea, J.F.

1986-06-01

181

Quiet powered-lift propulsion  

NASA Technical Reports Server (NTRS)

Latest results of programs exploring new propulsion technology for powered-lift aircraft systems are presented. Topics discussed include results from the 'quiet clean short-haul experimental engine' program and progress reports on the 'quiet short-haul research aircraft' and 'tilt-rotor research aircraft' programs. In addition to these NASA programs, the Air Force AMST YC 14 and YC 15 programs were reviewed.

1979-01-01

182

Automation of Workplace Lifting Hazard Assessment for Musculoskeletal Injury Prevention  

PubMed Central

Objectives Existing methods for practically evaluating musculoskeletal exposures such as posture and repetition in workplace settings have limitations. We aimed to automate the estimation of parameters in the revised United States National Institute for Occupational Safety and Health (NIOSH) lifting equation, a standard manual observational tool used to evaluate back injury risk related to lifting in workplace settings, using depth camera (Microsoft Kinect) and skeleton algorithm technology. Methods A large dataset (approximately 22,000 frames, derived from six subjects) of simultaneous lifting and other motions recorded in a laboratory setting using the Kinect (Microsoft Corporation, Redmond, Washington, United States) and a standard optical motion capture system (Qualysis, Qualysis Motion Capture Systems, Qualysis AB, Sweden) was assembled. Error-correction regression models were developed to improve the accuracy of NIOSH lifting equation parameters estimated from the Kinect skeleton. Kinect-Qualysis errors were modelled using gradient boosted regression trees with a Huber loss function. Models were trained on data from all but one subject and tested on the excluded subject. Finally, models were tested on three lifting trials performed by subjects not involved in the generation of the model-building dataset. Results Error-correction appears to produce estimates for NIOSH lifting equation parameters that are more accurate than those derived from the Microsoft Kinect algorithm alone. Our error-correction models substantially decreased the variance of parameter errors. In general, the Kinect underestimated parameters, and modelling reduced this bias, particularly for more biased estimates. Use of the raw Kinect skeleton model tended to result in falsely high safe recommended weight limits of loads, whereas error-corrected models gave more conservative, protective estimates. Conclusions Our results suggest that it may be possible to produce reasonable estimates of posture and temporal elements of tasks such as task frequency in an automated fashion, although these findings should be confirmed in a larger study. Further work is needed to incorporate force assessments and address workplace feasibility challenges. We anticipate that this approach could ultimately be used to perform large-scale musculoskeletal exposure assessment not only for research but also to provide real-time feedback to workers and employers during work method improvement activities and employee training.

2014-01-01

183

What is a demanding lifting job for manual handling workers in Hong Kong?  

PubMed

Although lifting tasks are traditionally evaluated by researchers, through the use of methods which depend on one or more approaches (i.e., psychophysical, biomechanical and physiological methods), none of these approaches makes use of expert workers in the evaluation of lifting activities. Given that 97% of lower back symptoms are aches, pains and discomfort and rely on self-reports, it is intuitive to use expert workers in evaluating the stressfulness of lifting activities. In this investigation, 217 workers from three industries in the Hong Kong area were surveyed to determine what constitutes a demanding lifting job from a worker standpoint. This was achieved by asking workers to map, in numerical terms, the level of lifting task parameter described in linguistic values. For example, the weight of load was described in three linguistic descriptors, namely, 'light', 'moderate' and 'heavy'. Then, each worker was asked to assess the meaning of these linguistic descriptors in numerical terms, based on their perception and experience with manual handling work. In this study, workers were asked to map the physical analogue of linguistic descriptors for seven lifting task parameters which are utilized in the NIOSH lifting equation, that is, weight of load, horizontal distance, vertical travel distance, vertical origin of lift, angle of asymmetry, frequency of handling and task duration. The data obtained from the workers were then subjected to validity testing in relation to norms and values reported in the published literature. On a preliminary basis, it appears that workers' assessments are logical and valid. The results suggest that the worker-based methodology is a promising approach and that it is worthwhile to pursue this approach further in the evaluation of industrial lifting activities. PMID:12745689

Yeung, S S; Genaidy, A M; Deddens, J; Leung, P C

2003-05-15

184

Hydrostatic force used to handle outsized, heavy objects  

NASA Technical Reports Server (NTRS)

Specially fitted barge is used to load and transport large, heavy objects to a dock side site. There the barge itself can lift, rotate, and position the objects. Typical functions are economically accomplished by water buoyancy.

Craft, G. W.; Starkey, A. W.

1967-01-01

185

Influence of Lift Offset on Rotorcraft Performance  

NASA Technical Reports Server (NTRS)

The influence of lift offset on the performance of several rotorcraft configurations is explored. A lift-offset rotor, or advancing blade concept, is a hingeless rotor that can attain good efficiency at high speed by operating with more lift on the advancing side than on the retreating side of the rotor disk. The calculated performance capability of modern-technology coaxial rotors utilizing a lift offset is examined, including rotor performance optimized for hover and high-speed cruise. The ideal induced power loss of coaxial rotors in hover and twin rotors in forward flight is presented. The aerodynamic modeling requirements for performance calculations are evaluated, including wake and drag models for the high-speed flight condition. The influence of configuration on the performance of rotorcraft with lift-offset rotors is explored, considering tandem and side-by-side rotorcraft as well as wing-rotor lift share.

Johnson, Wayne

2009-01-01

186

Influence of Lift Offset on Rotorcraft Performance  

NASA Technical Reports Server (NTRS)

The influence of lift offset on the performance of several rotorcraft configurations is explored. A lift-offset rotor, or advancing blade concept, is a hingeless rotor that can attain good efficiency at high speed, by operating with more lift on the advancing side than on the retreating side of the rotor disk. The calculated performance capability of modern-technology coaxial rotors utilizing a lift offset is examined, including rotor performance optimized for hover and high-speed cruise. The ideal induced power loss of coaxial rotors in hover and twin rotors in forward flight is presented. The aerodynamic modeling requirements for performance calculations are evaluated, including wake and drag models for the high speed flight condition. The influence of configuration on the performance of rotorcraft with lift-offset rotors is explored, considering tandem and side-by-side rotorcraft as well as wing-rotor lift share.

Johnson, Wayne

2008-01-01

187

Lift enhancement by trapped vortex  

NASA Technical Reports Server (NTRS)

The viewgraphs and discussion of lift enhancement by trapped vortex are provided. Efforts are continuously being made to find simple ways to convert wings of aircraft from an efficient cruise configuration to one that develops the high lift needed during landing and takeoff. The high-lift configurations studied here consist of conventional airfoils with a trapped vortex over the upper surface. The vortex is trapped by one or two vertical fences that serve as barriers to the oncoming stream and as reflection planes for the vortex and the sink that form a separation bubble on top of the airfoil. Since the full three-dimensional unsteady flow problem over the wing of an aircraft is so complicated that it is hard to get an understanding of the principles that govern the vortex trapping process, the analysis is restricted here to the flow field illustrated in the first slide. It is assumed that the flow field between the two end plates approximates a streamwise strip of the flow over a wing. The flow between the endplates and about the airfoil consists of a spanwise vortex located between the suction orifices in the endplates. The spanwise fence or spoiler located near the nose of the airfoil serves to form a separated flow region and a shear layer. The vorticity in the shear layer is concentrated into the vortex by withdrawal of fluid at the suction orifices. As the strength of the vortex increases with time, it eventually dominates the flow in the separated region so that a shear or vertical layer is no longer shed from the tip of the fence. At that point, the vortex strength is fixed and its location is such that all of the velocity contributions at its center sum to zero thereby making it an equilibrium point for the vortex. The results of a theoretical analysis of such an idealized flow field are described.

Rossow, Vernon J.

1992-01-01

188

HL-10 pilots assist with pilot entry into lifting body  

NASA Technical Reports Server (NTRS)

Not every moment of a test pilot's day is serious business. In a moment of levity, NASA pilots Bill Dana (left) and John A. Manke try to drag Air Force test pilot Peter Hoag away from the HL-10 lifting body while Air Force Major Jerauld R. Gentry helps from the cockpit. These four men were the principal pilots for the HL-10 program. This was not the only prank involving the HL-10 and its pilots. Once 'Captain Midnight' (Gentry) and the 'Midnight skulkers' sneaked into the NASA hangar and put 'U.S. Air Force' on the aircraft using stick-on letters. Later, while Gentry was making a lifting-body flight, his 1954 Ford was 'borrowed' from the parking lot, painted with yellow-green zinc-chromate primer, and decorated with large stick-on flowers about one foot in diameter. After Gentry returned from the flight, he was surprised to see what had happened to his car. The HL-10 was one of five heavyweight lifting-body designs flown at NASA's Flight Research Center (FRC--later Dryden Flight Research Center), Edwards, California, from July 1966 to November 1975 to study and validate the concept of safely maneuvering and landing a low lift-over-drag vehicle designed for reentry from space. Northrop Corporation built the HL-10 and M2-F2, the first two of the fleet of 'heavy' lifting bodies flown by the NASA Flight Research Center. The contract for construction of the HL-10 and the M2-F2 was $1.8 million. 'HL' stands for horizontal landing, and '10' refers to the tenth design studied by engineers at NASA's Langley Research Center, Hampton, Va. After delivery to NASA in January 1966, the HL-10 made its first flight on Dec. 22, 1966, with research pilot Bruce Peterson in the cockpit. Although an XLR-11 rocket engine was installed in the vehicle, the first 11 drop flights from the B-52 launch aircraft were powerless glide flights to assess handling qualities, stability, and control. In the end, the HL-10 was judged to be the best handling of the three original heavy-weight lifting bodies (M2-F2/F3, HL-10, X-24A). The HL-10 was flown 37 times during the lifting body research program and logged the highest altitude and fastest speed in the Lifting Body program. On Feb. 18, 1970, Air Force test pilot Peter Hoag piloted the HL-10 to Mach 1.86 (1,228 mph). Nine days later, NASA pilot Bill Dana flew the vehicle to 90,030 feet, which became the highest altitude reached in the program. Some new and different lessons were learned through the successful flight testing of the HL-10. These lessons, when combined with information from it's sister ship, the M2-F2/F3, provided an excellent starting point for designers of future entry vehicles, including the Space Shuttle.

1969-01-01

189

The lift-fan aircraft: Lessons learned  

NASA Technical Reports Server (NTRS)

This report summarizes the highlights and results of a workshop held at NASA Ames Research Center in October 1992. The objective of the workshop was a thorough review of the lessons learned from past research on lift fans, and lift-fan aircraft, models, designs, and components. The scope included conceptual design studies, wind tunnel investigations, propulsion systems components, piloted simulation, flight of aircraft such as the SV-5A and SV-5B and a recent lift-fan aircraft development project. The report includes a brief summary of five technical presentations that addressed the subject The Lift-Fan Aircraft: Lessons Learned.

Deckert, Wallace H.

1995-01-01

190

Maximum acceptable weights for asymmetric lifting of Chinese females  

Microsoft Academic Search

This study used the psychophysical approach to evaluate the effects of asymmetric lifting on the maximum acceptable weight of lift (MAWL) and the resulting heart rate, oxygen uptake and rating of perceived exertion (RPE). A randomized complete block factorial design was employed. Twelve female college students lifted weights at three different lifting frequencies (one-time maximum, 1 and 4 lifts\\/min) in

Swei-Pi Wu

2003-01-01

191

The effects of working height on a manual lifting task  

Microsoft Academic Search

Confusion exists in the manual lifting and handling literature between the effects of working height at the bottom and top of a lift. This study varied both heights and measured the maximum weight lifted for male and female subjects using a non-compact box. Both bottom and top height affected weight lifted. The actual weights lifted and the relationships between male

S. J. KASSAB; C. G. DRURY

1976-01-01

192

Three Lifting Bodies on Lakebed  

NASA Technical Reports Server (NTRS)

The wingless, lifting body aircraft sitting on Rogers Dry Lake at what is now NASA's Dryden Flight Research Center, Edwards, California, from left to right are the X-24A, M2-F3 and the HL-10.The lifting body aircraft studied the feasibility of maneuvering and landing an aerodynamic craft designed for reentry from space. These lifting bodies were air launched by a B-52 mother ship, then flew powered by their own rocket engines before making an unpowered approach and landing. They helped validate the concept that a space shuttle could make accurate landings without power. The X-24A flew from April 17, 1969 to June 4, 1971. The M2-F3 flew from June 2, 1970 until December 20, 1972. The HL-10 flew from December 22, 1966 until July 17, 1970 and logged the highest and fastest records in the lifting body program. The X-24 was one of a group of lifting bodies flown by the NASA Flight Research Center (FRC--now Dryden Flight Research Center), Edwards, California, in a joint program with the U.S. Air Force at Edwards Air Force Base from 1963 to 1975. The lifting bodies were used to demonstrate the ability of pilots to maneuver and safely land wingless vehicles designed to fly back to Earth from space and be landed like an airplane at a predetermined site. Lifting bodies' aerodynamic lift, essential to flight in the atmosphere, was obtained from their shape. The addition of fins and control surfaces allowed the pilots to stabilize and control the vehicles and regulate their flight paths. Built by Martin Aircraft Company, Maryland, for the U.S. Air Force, the X-24A was a bulbous vehicle shaped like a teardrop with three vertical fins at the rear for directional control. It weighed 6,270 pounds, was 24.5 feet long and 11.5 feet wide (measuring just the fuselage, not the distance between the tips of the outboard fins). Its first unpowered glide flight was on April 17, 1969, with Air Force Maj. Jerauld Gentry at the controls. Gentry also piloted its first powered flight on March 19, 1970. The X-24A was flown 28 times in the program that, like the HL-10, validated the concept that a Space Shuttle vehicle could be landed unpowered. The fastest speed achieved by the X-24A was 1,036 miles per hour (mph--Mach 1.6). Its maximum altitude was 71,400 feet. It was powered by an XLR-11 rocket engine with a maximum theoretical vacuum thrust of 8,480 pounds. The X-24A was later modified into the X-24B. The bulbous shape of the X-24A was converted into a 'flying flatiron' shape with a rounded top, flat bottom, and double delta platform that ended in a pointed nose. The X-24B demonstrated that accurate unpowered reentry vehicle landings were operationally feasible. Top speed achieved by the X-24B was 1,164 mph and the highest altitude it reached was 74,130 feet. The vehicle is on display at the Air Force Museum, Wright-Patterson Air Force Base, Ohio. The pilot on the last powered flight of the X-24B was Bill Dana, who also flew the last X-15 flight about seven years earlier. The X-24A shape was later borrowed for the X-38 Crew Return Vehicle (CRV) technology demonstrator for the International Space Station. The X-24B is on public display at the Air Force Museum, Wright-Patterson AFB, Ohio. The M2-F3 was a modified version of the M2-F2. NASA pilots said the M2-F2 had lateral control problems, even though it had a stability augmentation control system. When the M2-F2 was rebuilt at Dryden and redesignated the M2-F3, it was modified with an additional third vertical fin--centered between the tip fins--to improve control characteristics. The first flight of the M2-F3, with NASA pilot Bill Dana at the controls, was on June 2, 1970. It was a glide flight to evaluate changes in the vehicle's performance due to the modifications. The modified vehicle exhibited much better lateral stability and control characteristics than had the M2-F2. Over the next 26 missions, the M2-F3 reached a top speed of l,064 mph (Mach 1.6). Bill Dana was the pilot, and the high-speed flight took place on December 13, 1972. The highest altitude reached by the vehicle was 71,500 feet o

1969-01-01

193

Serrated Trailing Edges for Improving Lift and Drag Characteristics of Lifting Surfaces.  

National Technical Information Service (NTIS)

An improvement in the lift and drag characteristics of a lifting surface is achieved by attaching a serrated panel to the trailing edge of the lifting surface. The serrations may have a saw-tooth configuration, with a 60 degree included angle between adja...

P. M. H. W. Vijgen F. G. Howard D. M. Bushnell B. J. Holmes

1989-01-01

194

Computation of aerodynamic interference between lifting surfaces and lift- and cruise-fans  

NASA Technical Reports Server (NTRS)

Sequence of three computer programs predicts aerodynamic interference on lifting surfaces of transport-type aircraft which are equipped with lift and cruise fans; for example, high-bypass-ratio engine and wing-pylon tail configuration or fuselage-mounted lift-fan and wing-tail configuration.

Dillenius, M. F. E.; Mendenhall, M. R.; Spangler, S. B.

1974-01-01

195

Middle cerebral artery blood flow velocity in elite power athletes during maximal weight-lifting.  

PubMed

Cerebral blood flow velocity (CBFV) has been shown to significantly increase during dynamic exercise (running) secondary to increases in cardiac output. Static exercise (weight-lifting) induces supraphysiological arterial pressures up to 450/380 mmHg, and thus may alter CBFV. Catastrophic brain injuries such as stroke, cerebral hemorrhage, subarachnoid hemorrhage, retinal hemorrhage and retinal detachment have been associated with weight-lifting. A recent study has shown that intra-ocular pressure (IOP), which is an indirect measure of intracranial pressure, elevates to pathophysiologic levels during weight-lifting. Recent CBFV studies instituting Valsalva have demonstrated decreases in CBFV from 21%-52%. To date, no studies have examined CBFV during maximal weight-lifting to elucidate the cerebrovascular responses to extreme pressure alterations. We recruited nine elite power athletes, including a multi-world record holder in powerlifting, for a transcranial Doppler study of middle cerebral artery blood flow velocity at rest and during maximal weight-lifting. All subjects' resting blood flow velocities were within normal ranges (mean 64.4 +/- 9.5 cm sec2). Blood flow velocities were significantly (p < 0.0001) decreased in all subjects during maximal lifting (mean 48.4 +/- 10.1 cm sec2). Linear regression analysis demonstrated a significant inverse linear relationship in the net change of blood velocities from rest to maximal lift for each subject (r = 0.8585, p < 0.001). This study demonstrates that blood flow velocities are significantly decreased during heavy resistance training. The drop in CBFV during weight-lifting was significantly less than previous Valsalva studies, which likely reveals the cardiovascular, baroreflex, and cerebrovascular system adaptations occurring in these elite power athletes. PMID:10874679

Dickerman, R D; McConathy, W J; Smith, G H; East, J W; Rudder, L

2000-06-01

196

Occupational Classification System Manual  

NSDL National Science Digital Library

Researchers may gain insight into the Bureau of Labor Statistics and Census Bureau occupational codes via the Occupational Classification System Manual (OCSM). A list of Major Occupation Group titles (MOGs) is provided as well as links to the Census Occupation Index--an alphabetical list of approximately 30,000 occupational titles. Further guidance in locating the proper occupation classification for research queries is outlined in the articles "Using the OCSM" and "Using the Census Index."

197

In situ lift measurement of sports balls  

Microsoft Academic Search

Aerodynamic lift on sports balls is typically measured in wind tunnels. Wind tunnel measurements may have measurable differences with ball drag occurring in play. Measurements under game conditions have been attempted, but are difficult to interpret from the data scatter and are not controlled. The following considers lift measurements from a ball propelled through static air in a laboratory setting.

Jeffrey R. Kensrud; Lloyd V. Smith

2011-01-01

198

Retractable End Plates for Aircraft Lifting Surfaces  

NASA Technical Reports Server (NTRS)

End plates and winglets improve aerodynamic characteristics of aircraft wings and other fixed lifting surfaces. Retractable end plates automatically actuated by same shaft that deflects lifting surface and require little or no extra power and absolutely no control input from cockpit. Besides being modular in construction, easily fitted to any existing aircraft design with only minor modifications.

Harvey, W. D.; Mangalam, S. M.

1985-01-01

199

WEIGHTED ADAPTIVE LIFTING-BASED WAVELET TRANSFORM  

Microsoft Academic Search

In this paper, we propose a new weighted adaptive lifting (WAL)-based wavelet transform that is designed to solve the problems existing in the previous adaptive directional lifting (ADL) approach. The proposed approach uses the weighted function to make sure that the prediction and update stages are consistent, the directional interpolation to improve the orientation property of interpolated image, and adaptive

Yu Liu; King Ngi Ngan

200

Weighted Adaptive Lifting-Basedwavelet Transform  

Microsoft Academic Search

ABSTRACT In this paper, we propose a new weighted adaptive lifting (WAL)-based wavelet transform that is designed to solve the problems existing in the previous adaptive directional lifting (ADL) approach. The proposed approach uses the weighted function to make,sure that the prediction and update stages are consistent, the directional interpolation to improve the orientation property of interpolated image, and adaptive

Yu Liu; King Ngi Ngan

2007-01-01

201

Theory of Lifting Surfaces. Part 2  

NASA Technical Reports Server (NTRS)

A mathematical model is presented towards a theory of lifting and resistance on wings. It consists of a theory of multiplanes, conditions of flow at a great distance from the wing, lifting systems of minimum resistance, and free stream and stream limited by walls.

Prandtl, L.

1920-01-01

202

Soccer Ball Lift Coefficients via Trajectory Analysis  

ERIC Educational Resources Information Center

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

Goff, John Eric; Carre, Matt J.

2010-01-01

203

Performance, Loads and Stability of Heavy Lift Tiltrotors  

Microsoft Academic Search

Summaries of rotor performance are presented for a 124,000-lb Large Civil Tilt Rotor (LCTR) design, along with isolated-rotor and fully-coupled wing\\/rotor aeroelastic stability. A major motivation of the present research is the effect of size on rotor dynamics. Simply scaling up existing rotor designs to the vehicle size under study would result in unacceptable rotor weight. The LCTR was the

C. W. Acree; Wayne Johnson

204

Heavy LIFting: tumor promotion and radioresistance in NPC.  

PubMed

The epithelial-derived nasopharyngeal carcinoma (NPC) is a rare tumor in most of the world; however, it is common in southern China, northern Africa, and Alaska. NPC is often left undiagnosed and untreated until a late stage of disease. Furthermore, while radiation therapy is effective against this tumor, local recurrence due to radioresistance is an important clinical problem. In this issue, Liu et al. report on their identification of the IL-6 family cytokine leukemia inhibitory factor (LIF) as a serum predictor of local NPC recurrence following radiation therapy. The authors developed this initial finding to discover a role for the LIF/LIFR/mTORC1 signaling axis in NPC tumor cell growth as well as radioresistance. PMID:24270417

Luftig, Micah

2013-12-01

205

Assessment of Navy Heavy-Lift Aircraft Options.  

National Technical Information Service (NTIS)

Helicopters have gradually become able to carry more and heavier cargo, including vehicles. An aircraft that could carry even more than today's helicopters might be especially valuable when access to on-shore facilities is limited and working from shipboa...

J. Gordon P. A. Wilson J. Grossman D. Deamon M. Edwards

2005-01-01

206

Heavy LIFting: tumor promotion and radioresistance in NPC  

PubMed Central

The epithelial-derived nasopharyngeal carcinoma (NPC) is a rare tumor in most of the world; however, it is common in southern China, northern Africa, and Alaska. NPC is often left undiagnosed and untreated until a late stage of disease. Furthermore, while radiation therapy is effective against this tumor, local recurrence due to radioresistance is an important clinical problem. In this issue, Liu et al. report on their identification of the IL-6 family cytokine leukemia inhibitory factor (LIF) as a serum predictor of local NPC recurrence following radiation therapy. The authors developed this initial finding to discover a role for the LIF/LIFR/mTORC1 signaling axis in NPC tumor cell growth as well as radioresistance.

Luftig, Micah

2013-01-01

207

The Ariane-5 ECA Heavy-Lift Launcher  

NASA Astrophysics Data System (ADS)

Ariane-5 ECA made a flawless qualification flight on 12 February 2005, heralding this version of the launcher's readiness to enter the launch-services market. This major step forward was the result of more than two years of very intense efforts within the framework of the Ariane Recovery Plan, endorsed by the ESA Council on Ministerial Level in May 2003, after the failure of the ECA version's maiden flight in December 2002. The recovery involved ESA, CNES, Arianespace and European Industry in a consolidated effort to establish this launcher as the European launch-services "workhorse" for many years to come.

Berkes, Uwe L.

2005-08-01

208

Development of computational methods for heavy lift launch vehicles  

NASA Technical Reports Server (NTRS)

The research effort has been focused on the development of an advanced flow solver for complex viscous turbulent flows with shock waves. The three-dimensional Euler and full/thin-layer Reynolds-averaged Navier-Stokes equations for compressible flows are solved on structured hexahedral grids. The Baldwin-Lomax algebraic turbulence model is used for closure. The space discretization is based on a cell-centered finite-volume method augmented by a variety of numerical dissipation models with optional total variation diminishing limiters. The governing equations are integrated in time by an implicit method based on lower-upper factorization and symmetric Gauss-Seidel relaxation. The algorithm is vectorized on diagonal planes of sweep using two-dimensional indices in three dimensions. A new computer program named CENS3D has been developed for viscous turbulent flows with discontinuities. Details of the code are described in Appendix A and Appendix B. With the developments of the numerical algorithm and dissipation model, the simulation of three-dimensional viscous compressible flows has become more efficient and accurate. The results of the research are expected to yield a direct impact on the design process of future liquid fueled launch systems.

Yoon, Seokkwan; Ryan, James S.

1993-01-01

209

Impact of Aerodynamics and Structures Technology on Heavy Lift Tiltrotors  

NASA Technical Reports Server (NTRS)

Rotor performance and aeroelastic stability are presented for a 124,000-lb Large Civil Tilt Rotor (LCTR) design. It was designed to carry 120 passengers for 1200 nm, with performance of 350 knots at 30,000 ft altitude. Design features include a low-mounted wing and hingeless rotors, with a very low cruise tip speed of 350 ft/sec. The rotor and wing design processes are described, including rotor optimization methods and wing/rotor aeroelastic stability analyses. New rotor airfoils were designed specifically for the LCTR; the resulting performance improvements are compared to current technology airfoils. Twist, taper and precone optimization are presented, along with the effects of blade flexibility on performance. A new wing airfoil was designed and a composite structure was developed to meet the wing load requirements for certification. Predictions of aeroelastic stability are presented for the optimized rotor and wing, along with summaries of the effects of rotor design parameters on stability.

Acree, C. W., Jr.

2006-01-01

210

Ground cloud related weather modification effects. [heavy lift launch vehicles  

NASA Technical Reports Server (NTRS)

The principal concerns about inadvertent weather modification by the solar power satellite system rocket effluents are discussed, namely the possibility that the ground cloud might temporarily modify local weather and the cumulative effects of nearly 500 launches per year. These issues are discussed through the consideration of (1) the possible alteration of the microphysical processes of clouds in the general area due to rocket effluents and debris and cooling water entrained during the launch and (2) the direct dynamical and thermodynamical responses to the inputs of thermal energy and moisture from the rocket exhaust for given ambient meteorological conditions. The huge amount of thermal energy contained in the exhaust of the proposed launch vehicle would in some situations induce a saturated, wet convective cloud or enhance an existing convective activity. Nevertheless, the effects would be limited to the general area of the launch site. The observed long lasting high concentrations of cloud condensation nuclei produced during and after a rocket launch may appreciably affect the frequency of occurrence and persistence of fogs and haze. In view of the high mission frequency proposed for the vehicle launches, a potential exists for a cumulative effect.

Lee, J.

1980-01-01

211

View of West end of central lift span truss web ...  

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

View of West end of central lift span truss web of Tensaw River Bridge, showing web brace of lift girder superstructure, looking west - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

212

14 CFR 29.551 - Auxiliary lifting surfaces.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Auxiliary lifting surfaces. 29.551 Section 29.551 Aeronautics...Component Requirements § 29.551 Auxiliary lifting surfaces. Each auxiliary lifting surface must be designed to withstandâ...

2010-01-01

213

14 CFR 29.551 - Auxiliary lifting surfaces.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Auxiliary lifting surfaces. 29.551 Section 29.551 Aeronautics...Component Requirements § 29.551 Auxiliary lifting surfaces. Each auxiliary lifting surface must be designed to withstandâ...

2009-01-01

214

Method for calculating wing characteristics by lifting-line theory using nonlinear section lift data  

NASA Technical Reports Server (NTRS)

A method is presented for calculating wing characteristics by lifting-line theory using nonlinear section lift data. Material from various sources is combined with some original work into the single complete method described. Multhopp's systems of multipliers are employed to obtain the induced angle of attack directly from the spanwise lift distribution. Equations are developed for obtaining these multipliers for any even number of spanwise stations, and values are tabulated for 10 stations along the semispan for asymmetrical, symmetrical, and antisymmetrical lift distributions. In order to minimize the computing time and to illustrate the procedures involved, simplified computing forms containing detailed examples are given for symmetrical lift distributions. Similar forms for asymmetrical and antisymmetrical lift distributions, although not shown, can be readily constructed in the same manner as those given. The adaptation of the method for use with linear section lift data is also illustrated. The adaptation has been found to require less computing time than most existing methods.

Sivells, James C; Neely, Robert H

1947-01-01

215

An experimental study of the lift, drag and static longitudinal stability for a three lifting surface configuration  

NASA Technical Reports Server (NTRS)

The experimental procedure and aerodynamic force and moment measurements for wind tunnel testing of the three lifting surface configuration (TLC) are described. The influence of nonelliptical lift distributions on lift, drag, and static longitudinal stability are examined; graphs of the lift coefficient versus angle of attack, the pitching moment coefficient, drag coefficient, and lift to drag ratio versus lift coefficient are provided. The TLC data are compared with the conventional tail-aft configuration and the canard-wing configuration; it is concluded that the TLC has better lift and high-lift drag characteristics, lift to drag ratio, and zero-lift moments than the other two configurations. The effects of variations in forward and tail wind incidence angles, gap, stagger, and forward wind span on the drag, lift, longitudinal stability, and zero-lift moments of the configuration are studied.

Ostowari, C.; Naik, D.

1986-01-01

216

Occupant Protection Project  

NASA Technical Reports Server (NTRS)

Topics include occupant protection overview with a focus on crew protection during dynamic phases of flight; occupant protection collaboration; modeling occupant protection; occupant protection considerations; project approach encompassing analysis tools, injury criteria, and testing program development; injury criteria update methodology, unique effects of pressure suits and other factors; and a summary.

Bopp, Genie; Somers, Jeff; Granderson, Brad; Gernhardt, Mike; Currie, Nancy; Lawrence, Chuck

2010-01-01

217

Lift-Enhancing Tabs on Multielement Airfoils  

NASA Technical Reports Server (NTRS)

The use of flat-plate tabs (similar to Gurney flaps) to enhance the lift of multielement airfoils is extended here by placing them on the pressure side and near the trailing edge of the main element rather than just on the furthest downstream wing element. The tabs studied range in height from 0.125 to 1.25% of the airfoil reference chord. In practice, such tabs would be retracted when the high-lift system is stowed. The effectiveness of the concept was demonstrated experimentally and computationally on a two-dimensional NACA 63(sub 2)-215 Mod B airfoil with a single-slotted, 30%-chord flap. Both the experiments and computations showed that the tabs significantly increase the lift at a given angle of attack and the maximum lift coefficient of the airfoil. The computational results showed that the increased lift was a result of additional turning of the flow by the tab that reduced or eliminated now separation on the flap. The best configuration tested, a 0.5%-chord tab placed 0.5% chord upstream of the trailing edge of the main element, increased the maximum lift coefficient of the airfoil by 12% and the maximum lift-to-drag ratio by 40%.

Ross, James C.; Storms, Bruce L.; Carrannanto, Paul G.

1995-01-01

218

Wingless Flight: The Lifting Body Story  

NASA Technical Reports Server (NTRS)

Wingless Flight tells the story of the most unusual flying machines ever flown, the lifting bodies. It is my story about my friends and colleagues who committed a significant part of their lives in the 1960s and 1970s to prove that the concept was a viable one for use in spacecraft of the future. This story, filled with drama and adventure, is about the twelve-year period from 1963 to 1975 in which eight different lifting-body configurations flew. It is appropriate for me to write the story, since I was the engineer who first presented the idea of flight-testing the concept to others at the NASA Flight Research Center. Over those twelve years, I experienced the story as it unfolded day by day at that remote NASA facility northeast of los Angeles in the bleak Mojave Desert. Benefits from this effort immediately influenced the design and operational concepts of the winged NASA Shuttle Orbiter. However, the full benefits would not be realized until the 1990s when new spacecraft such as the X-33 and X-38 would fully employ the lifting-body concept. A lifting body is basically a wingless vehicle that flies due to the lift generated by the shape of its fuselage. Although both a lifting reentry vehicle and a ballistic capsule had been considered as options during the early stages of NASA's space program, NASA initially opted to go with the capsule. A number of individuals were not content to close the book on the lifting-body concept. Researchers including Alfred Eggers at the NASA Ames Research Center conducted early wind-tunnel experiments, finding that half of a rounded nose-cone shape that was flat on top and rounded on the bottom could generate a lift-to-drag ratio of about 1.5 to 1. Eggers' preliminary design sketch later resembled the basic M2 lifting-body design. At the NASA Langley Research Center, other researchers toyed with their own lifting-body shapes. Meanwhile, some of us aircraft-oriented researchers at the, NASA Flight Research Center at Edwards Air Force Base (AFB) in California were experiencing our own fascination with the lifting-body concept. A model-aircraft builder and private pilot on my own time, I found the lifting-body idea intriguing. I built a model based on Eggers' design, tested it repeatedly, made modifications in its control and balance characteristics along the way, then eventually presented the concept to others at the Center, using a film of its flights that my wife, Donna and I had made with our 8-mm home camera.

Reed, R. Dale; Lister, Darlene (Editor); Huntley, J. D. (Editor)

1997-01-01

219

Remote lift fan study program, volume 4  

NASA Technical Reports Server (NTRS)

A study program to select and conduct preliminary design of advanced technology lift fan systems to meet low noise goals of future V/STOL transport aircraft is discussed. This volume contains results of additional studies conducted to support the main preliminary design effort done under the Remote Lift Fan Study Program (Contract NAS3-14406) and a companion effort, the Integral Lift Fan Study (NAS3-14404). These results cover engine emission study, a review of existing engines for research aircraft application and support data for aircraft studies.

1973-01-01

220

Calculating the Lifting Condensation Level (LCL)  

NSDL National Science Digital Library

This Javascript calculator was designed to calculate lifting condensation level (LCL) conditions using only three atmospheric input parameters that are commonly measured and reported during most local televised weather forecasts: surface temperature, surface dewpoint, and surface pressure. Output is pressure and parcel temperature at LCL. Though this calculator was designed to calculate the lifting condensation level for a parcel of air lifted from the surface, you calculate the LCL conditions for an air parcel at any other pressure level by substituting values appropriately. There is also a link to a calculator that will convert temperature reading from Celsius to Fahrenheit to Kelvin units.

1996-01-01

221

Geometry program for aerodynamic lifting surface theory  

NASA Technical Reports Server (NTRS)

A computer program that provides the geometry and boundary conditions appropriate for an analysis of a lifting, thin wing with control surfaces in linearized, subsonic, steady flow is presented. The kernel function method lifting surface theory is applied. The data which is generated by the program is stored on disk files or tapes for later use by programs which calculate an influence matrix, plot the wing planform, and evaluate the loads on the wing. In addition to processing data for subsequent use in a lifting surface analysis, the program is useful for computing area and mean geometric chords of the wing and control surfaces.

Medan, R. T.

1973-01-01

222

Occupational risk factors and reproductive health of women  

Microsoft Academic Search

Results From the examination of studies dealing with exposures of women to chemical agents, pesticides, physical agents, ergonomic factors and stress, it appears that at present the evidence is sufficient to warrant the maximum protection of pregnant women to several well-documented occupational risk factors. These include exposures to anaesthetic gases, antineoplastic drugs, heavy metals, solvents, heavy physical work and irregular

Irene Figa

223

Optimal Lifting Techniques Adopted by Chinese Men when Determining Their Maximum Acceptable Weight of Lift  

Microsoft Academic Search

The purpose of this study was to identify biomechanically the mechanisms adopted by Chinese men when they psychophysically determined their MAWLs (maximum acceptable weights of lift) in different tasks. Twenty-two healthy Chinese men determined their MAWLs at two lifting vertical ranges and three lifting frequencies. Peak L5\\/S1 compressive forces, elbow and shoulder peak reactive moments, acceleration effects, and postures were

Yi-Lang Chen

2000-01-01

224

The Biomechanics of Lifting and Materials Handling.  

National Technical Information Service (NTIS)

Musculoskeletal responses elicited by static lifting were investigated. Kinesiometers were constructed capable of measuring postural changes during standing and seated tasks and which automatically computed cartesian coordinates of anatomical landmarks of...

E. R. Tichauer S. Elbaum F. Glickman C. Gold C. Tauber

1981-01-01

225

Dust Lifting Processes in GM3  

NASA Astrophysics Data System (ADS)

We are currently working on the dust lifting processes in the Mars general circulation model GM3 (the Global Mars multiscale model) developed at York University. The dust lifting initiated by surface wind stresses and convective processes has been used to simulate Martian dust cycle, for example, by Newman et al. [2002] and Basu et al. [2004]. For the surface wind based dust lifting, we apply the dust mobilization and dry deposition schemes from DEAD (The mineral Dust Entrainment And Deposition [Zender at al., 2003]) model to GM3. The dust mobilization scheme is based on near-surface wind stress and saltation sandblasting using the boundary layer meteorology conditions from GM3. The fine dust particles can be ejected into the atmosphere as a result of saltating sand size particles on the surface. Dust in the Martian atmosphere can also be lifted by dust devils. For our next work, we will add dust devils based on thermal convective scheme into GM3.

Wu, D.; McConnell, J. C.; Kaminski, J.; Akingunola, A.

2009-05-01

226

Lift Coefficient of a Randomly Oscillating Hydroplane.  

National Technical Information Service (NTIS)

The measurement of lift on a randomly oscillating hydroplane is described. A comparison is made between oscillating the hydroplane randomly or with regular sinusoidal signals together with the different methods of analysis. In the 'regular' experiments th...

M. J. Smith

1991-01-01

227

Lift Coefficient of Randomly Oscillating Hydroplane.  

National Technical Information Service (NTIS)

This report describes the measurement of lift on a randomly oscillating hydroplane and makes a comparison between oscillating the hydroplane randomly or with regular sinusoidal signals together with the different methods of analysis.

M. J. Smith

1991-01-01

228

Development of a Litter Linen Lift.  

National Technical Information Service (NTIS)

The litter linen lift was designed and developed to provide a simple method for suspending sheets and blankets over litter patients with wounds or sensitive body areas. Prototypes underwent initial and follow-on operational test and evaluation on worldwid...

J. L. Curtis

1973-01-01

229

A lifting surface theory for the analysis of nonplanar lifting systems  

NASA Technical Reports Server (NTRS)

A new nonlinear, nonplanar lifting surface theory is presented. The method is regarded as a lifting surface theory in that the effects of wing thickness are neglected, but none of the usual small perturbation assumptions inherent in most other lifting surface theories are made. The method represents nonplanar lifting systems by distributed vorticity, including the leading edge singular behavior characteristic of thin wings. The method is well suited to the computation of induced drag of nonplanar systems because leading edge suction is calculated from the leading edge singularity. The method has been used to compute the induced drag benefit of winglets (vortex diffusers), and the agreement with NASA experimental data is excellent.

Goldhammer, M. I.

1976-01-01

230

A Method for Calculation of Hydrodynamic Lift for Submerged and Planing Rectangular Lifting Surfaces  

NASA Technical Reports Server (NTRS)

A method is presented for the calculation of lift coefficients for rectangular lifting surfaces of aspect ratios from 0.125 to 10 operating at finite depths beneath the water surface, including the zero depth or planing condition. Theoretical values are compared with experimental values obtained at various depths of submergence with lifting surfaces of aspect ratios from 0.125 to 10. The method can also be applied to hydrofoils with dihedral. Lift coefficients computed by this method are in good agreement with existing experimental data for aspect ratios from 0.125 to 10 and dihedral angles up to 30 deg.

Wadlin, Kenneth L.; Christopher, Kenneth W.

1959-01-01

231

Lifted Partially Premixed Flames in Microgravity  

NASA Technical Reports Server (NTRS)

Lifted Double and Triple flames are established in the UIC-NASA Partially Premixed microgravity rig. The flames examined in this paper are established above a coannular burner because its axisymmetric geometry allows for future implementation of other non-intrusive optical diagnostic techniques easily. Both burner-attached stable flames and lifted flames are established at normal and microgravity conditions in the drop tower facility.

Lock, Andrew J.; Ganguly, Ranjan; Puri, Ishwar K.; Aggarwal, Suesh K.; Hegde, Uday

2004-01-01

232

14 CFR 25.697 - Lift and drag devices, controls.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Lift and drag devices, controls. 25.697 Section...Control Systems § 25.697 Lift and drag devices, controls. (a) Each lift...established under § 25.101(d). Lift and drag devices must maintain the selected...

2010-01-01

233

14 CFR 25.697 - Lift and drag devices, controls.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Lift and drag devices, controls. 25.697 Section...Control Systems § 25.697 Lift and drag devices, controls. (a) Each lift...established under § 25.101(d). Lift and drag devices must maintain the selected...

2009-01-01

234

Lift and wakes of flying snakes  

NASA Astrophysics Data System (ADS)

Flying snakes use a unique method of aerial locomotion: they jump from tree branches, flatten their bodies, and undulate through the air to produce a glide. The shape of their body cross-section during the glide plays an important role in generating lift. This paper presents a computational investigation of the aerodynamics of the cross-sectional shape. Two-dimensional simulations of incompressible flow past the anatomically correct cross-section of the species Chrysopelea paradisi show that a significant enhancement in lift appears at a 35° angle of attack, above Reynolds numbers 2000. Previous experiments on physical models also obtained an increased lift, at the same angle of attack. The flow is inherently three-dimensional in physical experiments, due to fluid instabilities, and it is thus intriguing that the enhanced lift also appears in the two-dimensional simulations. The simulations point to the lift enhancement arising from the early separation of the boundary layer on the dorsal surface of the snake profile, without stall. The separated shear layer rolls up and interacts with secondary vorticity in the near-wake, inducing the primary vortex to remain closer to the body and thus cause enhanced suction, resulting in higher lift.

Krishnan, Anush; Socha, John J.; Vlachos, Pavlos P.; Barba, L. A.

2014-03-01

235

Project Plan for Vertical Lift Machine  

SciTech Connect

This document describes the Project Plan for the development and manufacture of a Vertical Lift Machine. It is assumed by this project plan that the Vertical Lift Machine will be developed, designed, manufactured, and tested by a qualified vendor. LLNL will retain review and approval authority for each step given in this project plan. The Vertical Lift Machine is a single linear axis positioning device capable of lifting objects vertically at controlled rates and positioning them repeatedly at predetermined heights, in relation to other objects suspended from above, for high neutron multiplication experiments. Operation of the machine during the experiments is done remotely. The lift mechanism shall accommodate various platforms (tables) that support the objects to be raised. A frame will support additional subassemblies from above such that the lower subassembly can be raised close to and/or interface with those above. The structure must be stiff and motion of the table linear such that radial alignment is maintained (e.g. concentricity). The safe position for the Vertical Lift Machine is the lift mechanism fully retracted with the subassemblies fully separated. The machine shall reside in this position when not in use. It must return to this safe condition from any position upon failure of power sources, open safety interlocks, or operator initiated SCRAM. The Vertical Lift Machine shall have the capability of return to the safe position with no externally applied power. The Vertical Lift Machine shall have dual operator interfaces, one near the machine and another located in a remote control room. Conventional single key, key-lock switching shall be implemented to lock out the control interface not in use. The interface at the machine will be used for testing and ''dry running'' experimental setup(s) with inert subassemblies (i.e. Setup Mode). The remote interface shall provide full control and data recording capability (i.e. Assembly Mode). The control system will be a combination of Programmable Logic Controller (PLC), or equivalent, and relay logic. The operator shall have the ability to adjust lift/lower velocity and position of the table. All measurements will be made as close to, and in line with, the axis of motion as practical. Measurement data, system parameter information, and interlock status shall be displayed.

Ellsworth, G F

2002-08-05

236

Heavy-Duty Rescue Straps For Coveralls  

NASA Technical Reports Server (NTRS)

New type of strap on coveralls helps rescuers lift victims of industrial accidents. Made of heavy twill. New material, 1 in. wide and has breaking strength of 600 lb, sewn to coveralls with polyester thread in box "X" stitching. Reinforcing nylon webbing, 1 3/4 in. wide sewn with strap at attachment points.

Waddell, Henry M.

1988-01-01

237

Occupational and Environmental History.  

National Technical Information Service (NTIS)

Essential Elements of the Occupational and Environmental History--Whether used for screening or for diagnosis, the occupational and environmental history is essentially made up of three important elements: Present Job, Past Work, and Other Nonoccupational...

K. M. Rest, J. C. Hake, D. H. Cordes

1983-01-01

238

Occupational health in the People's Republic of China.  

PubMed Central

China's drive to modernize its economy will produce new occupational health problems even as it resolves earlier ones. Well aware of this, Chinese occupational health experts are intensifying efforts to improve workers' health and establish a modern occupational health program. Occupational lung disease, occupational cancer, heavy metal poisoning, industrial chemical poisoning, and physical factor-induced diseases (noise and heat) have all been targeted for expanded research which will serve as a basis for standard setting. Hazard control efforts include engineering controls, particularly in new construction, limited use of personal protective equipment, and expansion of environmental and medical monitoring. Worker education and professional activities have been expanded. International exchanges have been initiated and will prove occupational health a promising area of scientific cooperation.

Christiani, D C

1984-01-01

239

Analysis of lifting beam and redesigned lifting lugs for 241-AZ-01A decant pump.  

National Technical Information Service (NTIS)

This supporting document details calculations for the proper design of a lifting beam and redesigned lifting lugs for the 241AZO1A decant pump. This design is in accordance with Standard Architectural-Civil Design Criteria, Design Loads for Facilities (DO...

B. L. Coverdell

1994-01-01

240

Health Occupations: Cluster Guide.  

ERIC Educational Resources Information Center

This teacher's guide is one of a series of publications focusing on the occupational preparation of persons with special education needs. The material was developed and tested by cooperating teachers over a period of three years. Task analysis information is presented using occupational descriptions from the Dictionary of Occupational Titles,…

Central Michigan Univ., Mount Pleasant.

241

Noise impact of advanced high lift systems  

NASA Technical Reports Server (NTRS)

The impact of advanced high lift systems on aircraft size, performance, direct operating cost and noise were evaluated for short-to-medium and medium-to-long range aircraft with high bypass ratio and very high bypass ratio engines. The benefit of advanced high lift systems in reducing noise was found to be less than 1 effective-perceived-noise decibel level (EPNdB) when the aircraft were sized to minimize takeoff gross weight. These aircraft did, however, have smaller wings and lower engine thrusts for the same mission than aircraft with conventional high lift systems. When the advanced high lift system was implemented without reducing wing size and simultaneously using lower flap angles that provide higher L/D at approach a cumulative noise reduction of as much as 4 EPNdB was obtained. Comparison of aircraft configurations that have similar approach speeds showed cumulative noise reduction of 2.6 EPNdB that is purely the result of incorporating advanced high lift system in the aircraft design.

Elmer, Kevin R.; Joshi, Mahendra C.

1995-01-01

242

Design of a versatile, teleoperable, towable lifting machine with robotic capabilities for use in NASA's lunar base operations  

NASA Technical Reports Server (NTRS)

The lifting machine will assist in lifting cargo off of landers sent to the Moon and in the construction of a lunar base. Three possible designs were considered for the overall configuration of the lifting machine: the variable angle crane, the tower crane, and the gantry crane. Alternate designs were developed for the major components of the lifting machine. A teleoperable, variable angle crane was chosen as its final design. The design consists of a telescoping boom mounted to a chassis that is supported by two conical wheels for towing and four outriggers for stability. Attached to the end of the boom is a seven degree of freedom robot arm for light, dexterous, lifting operations. A cable and hook suspends from the end of the boom for heavy, gross, lifting operations. Approximate structural sizes were determined for the lifter and its components. However, further analysis is needed to determine the optimum design dimensions. The design team also constructed a model of the design which demonstrates its features and operating principals.

Harris, Elizabeth; Ogle, James; Schoppe, Dean

1989-01-01

243

Occupational cancer in Britain. Preventing occupational cancer.  

PubMed

Although only a relatively small proportion of cancer is attributable to occupational exposure to carcinogenic agents, the estimated number of deaths due to occupational cancer is high when compared to other deaths due to work-related ill health and injury. However, risk from occupational exposure to carcinogens can be minimised through proportionate but effective risk management. The Health and Safety Executive (HSE) is the regulator of workplace health and safety in Great Britain. As part of its aim to reduce ill health arising from failures to control properly exposure to hazards at work, HSE commissioned the research presented elsewhere in this supplement to enable it to identify priorities for preventing occupational cancer. The research has shown that occupational cancer remains a key health issue and that low-level exposure of a large number of workers to carcinogens is important. The finding that a small number of carcinogens have been responsible for the majority of the burden of occupational cancer provides key evidence in the development of priorities for significant reduction of occupational cancer. Although the research presented in this supplement reflects the consequences of past exposures to carcinogens, occupational cancer remains a problem. The potential for exposure to the agents considered in this research is still present in the workplace and the findings are relevant to prevention of future disease. In this article, the principle approaches for risk reduction are described. It provides supporting information on some of the initiatives already being undertaken, or those being put in place, to reduce occupational cancer in Great Britain. The need also for systematic collection of exposure information and the importance of raising awareness and changing behaviours are discussed. PMID:22710673

Chen, Yiqun; Osman, John

2012-06-19

244

Investigation of effects of surface roughness on symmetric airfoil lift and lift-to-drag ratio  

NASA Astrophysics Data System (ADS)

This research investigated the effects of surface roughness in the form of protuberances on the lift and lift-to-drag ratio of an airfoil with a NACA 0015 profile. Russian researchers first recorded the positive effect on lift from naturally formed surface protuberances in 1984 and reported on their research in 1991. Based on experimental studies, the Russian researchers identified a protuberance geometry on a low aspect ratio wing which created both additional lift and an improved lift-to-drag ratio for a given angle-of-attack over the low to moderate angle-of-attack region. The primary objective of this research was to develop a phenomenological understanding of the flow physics related to the effects of surface roughness on the lift and lift-to-drag ratio of a symmetric airfoil. Two wind tunnel experiments were conducted at the University of Maryland's Glenn L. Martin Wind Tunnel to investigate the effect of protuberance coverage, size, and density. A two-dimensional computational experiment studied the effect of protuberance location, geometry, and spacing using the OVERFLOW Navier-Stokes flow solver. Results indicated that the variation of the aerodynamic lift and the lift-to-drag ratio for symmetric airfoils and wings populated with protuberances is due to the increased pressure induced by a recirculation region downstream of the protuberance. An alternative understanding based on changes in the effective camber and thickness of the airfoil was developed. Wind tunnel and computational results qualitatively validated the lift enhancement on symmetric airfoils due to surface roughness. Results indicated that the magnitude of the lift increment was strongly dependent on airfoil angle-of-attack and protuberance height and had a weak dependence on protuberance width and spacing. Just one configuration, based on a wind tunnel test of a wing with protuberances, generated a larger lift-to-drag ratio compared to a smooth wing. This research concluded that surface protuberances located on the lower surface of a symmetric airfoil are a lift generating mechanism at low to moderate angles-of-attack.

Beierle, Mark Thomas

245

Measuring Lift with the Wright Airfoils  

NASA Astrophysics Data System (ADS)

In this laboratory or demonstration exercise, we mount a small airfoil with its long axis vertical at one end of a nearly frictionless rotating platform.1 Air from a leaf blower2 produces a sidewise lift force L on the airfoil and a drag force D in the direction of the air flow (Fig. 1). The rotating platform is kept in equilibrium by adding weights (the measured values of L) to the lower end of a string passing over a pulley and connected to the other end of the rotating platform (Fig. 2). Our homemade airfoils are similar to those tested by the Wright brothers in 1901. From our lift plots in Fig. 3, we can draw the same conclusions as the Wrights about the influence of an airfoil's curvature and shape on lift.

Heavers, Richard M.; Soleymanloo, Arianne

2011-11-01

246

Artificial lift boosts United Kingdom output  

SciTech Connect

Increasing numbers of North Sea fields are approaching the stage where artificial lift techniques will be needed to bolster falling oil output. Most North Sea reservoirs have enough pressure to produce naturally, though many have required pressure maintenance programs at an early stage. Now reservoir pressures are falling, peripheral wells are watering out, and where water injection is taking place, water breakthrough is occurring. The need for artificial lift is not yet widespread, but it will be shortly. A small number of North Sea companies have been forced over the past 5 yr to introduce artificial lift for various reasons. Reservoirs are commonly over 10,000 ft deep, so pressures are high. Typical temperatures are in the 250/sup 0/F range. Most producing wells are deviated at angles up to 70, and production rates are high. Sand production is common, and frequently fields have a high gas/oil ratio.

Steven, R.R.

1983-05-01

247

Lift and Drag of Wings with Small Span  

NASA Technical Reports Server (NTRS)

The lift coefficient of!a wing of small span at first shows a linear increase for the increasing angle of attack, but to a lesser degree then was to be expected according to the theory of the lifting line; thereafter the lift coefficient increases more rapidly than linearity, as contrasted with the the theory of the lifting line. The induced drag coefficient for a given lift coefficient, on the other hand, is obviously much smaller than it would be according to the theory. A mall change in the theory of the lifting line will cover these deviations.

Weinig, F.

1947-01-01

248

Frequency response of lift control in Drosophila  

PubMed Central

The flight control responses of the fruitfly represent a powerful model system to explore neuromotor control mechanisms, whose system level control properties can be suitably characterized with a frequency response analysis. We characterized the lift response dynamics of tethered flying Drosophila in presence of vertically oscillating visual patterns, whose oscillation frequency we varied between 0.1 and 13 Hz. We justified these measurements by showing that the amplitude gain and phase response is invariant to the pattern oscillation amplitude and spatial frequency within a broad dynamic range. We also showed that lift responses are largely linear and time invariant (LTI), a necessary condition for a meaningful analysis of frequency responses and a remarkable characteristic given its nonlinear constituents. The flies responded to increasing oscillation frequencies with a roughly linear decrease in response gain, which dropped to background noise levels at about 6 Hz. The phase lag decreased linearly, consistent with a constant reaction delay of 75 ms. Next, we estimated the free-flight response of the fly to generate a Bode diagram of the lift response. The limitation of lift control to frequencies below 6 Hz is explained with inertial body damping, which becomes dominant at higher frequencies. Our work provides the detailed background and techniques that allow optomotor lift responses of Drosophila to be measured with comparatively simple, affordable and commercially available techniques. The identification of an LTI, pattern velocity dependent, lift control strategy is relevant to the underlying motion computation mechanisms and serves a broader understanding of insects' flight control strategies. The relevance and potential pitfalls of applying system identification techniques in tethered preparations is discussed.

Graetzel, Chauncey F.; Nelson, Bradley J.; Fry, Steven N.

2010-01-01

249

Frequency response of lift control in Drosophila.  

PubMed

The flight control responses of the fruitfly represent a powerful model system to explore neuromotor control mechanisms, whose system level control properties can be suitably characterized with a frequency response analysis. We characterized the lift response dynamics of tethered flying Drosophila in presence of vertically oscillating visual patterns, whose oscillation frequency we varied between 0.1 and 13 Hz. We justified these measurements by showing that the amplitude gain and phase response is invariant to the pattern oscillation amplitude and spatial frequency within a broad dynamic range. We also showed that lift responses are largely linear and time invariant (LTI), a necessary condition for a meaningful analysis of frequency responses and a remarkable characteristic given its nonlinear constituents. The flies responded to increasing oscillation frequencies with a roughly linear decrease in response gain, which dropped to background noise levels at about 6 Hz. The phase lag decreased linearly, consistent with a constant reaction delay of 75 ms. Next, we estimated the free-flight response of the fly to generate a Bode diagram of the lift response. The limitation of lift control to frequencies below 6 Hz is explained with inertial body damping, which becomes dominant at higher frequencies. Our work provides the detailed background and techniques that allow optomotor lift responses of Drosophila to be measured with comparatively simple, affordable and commercially available techniques. The identification of an LTI, pattern velocity dependent, lift control strategy is relevant to the underlying motion computation mechanisms and serves a broader understanding of insects' flight control strategies. The relevance and potential pitfalls of applying system identification techniques in tethered preparations is discussed. PMID:20462877

Graetzel, Chauncey F; Nelson, Bradley J; Fry, Steven N

2010-11-01

250

Asymmetric Gepner models II. Heterotic weight lifting  

NASA Astrophysics Data System (ADS)

A systematic study of "lifted" Gepner models is presented. Lifted Gepner models are obtained from standard Gepner models by replacing one of the N=2 building blocks and the E factor by a modular isomorphic N=0 model on the bosonic side of the heterotic string. The main result is that after this change three family models occur abundantly, in sharp contrast to ordinary Gepner models. In particular, more than 250 new and unrelated moduli spaces of three family models are identified. We discuss the occurrence of fractionally charged particles in these spectra.

Gato-Rivera, B.; Schellekens, A. N.

2011-05-01

251

The lift-fan powered-lift aircraft concept: Lessons learned  

NASA Technical Reports Server (NTRS)

This is one of a series of reports on the lessons learned from past research related to lift-fan aircraft concepts. An extensive review is presented of the many lift-fan aircraft design studies conducted by both government and industry over the past 45 years. Mission applications and design integration including discussions on manifolding hot gas generators, hot gas dusting, and energy transfer control are addressed. Past lift-fan evaluations of the Avrocar are discussed. Lessons learned from these past efforts are identified.

Deckert, Wallace H.

1993-01-01

252

Listing Occupational Carcinogens  

PubMed Central

The occupational environment has been a most fruitful one for investigating the etiology of human cancer. Many recognized human carcinogens are occupational carcinogens. There is a large volume of epidemiologic and experimental data concerning cancer risks in different work environments. It is important to synthesize this information for both scientific and public health purposes. Various organizations and individuals have published lists of occupational carcinogens. However, such lists have been limited by unclear criteria for which recognized carcinogens should be considered occupational carcinogens, and by inconsistent and incomplete information on the occupations and industries in which the carcinogenic substances may be found and on their target sites of cancer. Based largely on the evaluations published by the International Agency for Research on Cancer, and augmented with additional information, the present article represents an attempt to summarize, in tabular form, current knowledge on occupational carcinogens, the occupations and industries in which they are found, and their target organs. We have considered 28 agents as definite occupational carcinogens, 27 agents as probable occupational carcinogens, and 113 agents as possible occupational carcinogens. These tables should be useful for regulatory or preventive purposes and for scientific purposes in research priority setting and in understanding carcinogenesis.

Siemiatycki, Jack; Richardson, Lesley; Straif, Kurt; Latreille, Benoit; Lakhani, Ramzan; Campbell, Sally; Rousseau, Marie-Claude; Boffetta, Paolo

2004-01-01

253

View uphill of single chair lift, tower 15 in foreground, ...  

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

View uphill of single chair lift, tower 15 in foreground, TOWERS 16 and 17 in the distance, LOOKING SOUTH. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

254

GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE ...  

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

GENERAL VIEW LOOKING WEST SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

255

3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ...  

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

3. GENERAL VIEW LOOKING WEST, SHOWING LIFT BRIDGE. COUNTER WEIGHTS ARE LARGE SQUARES VISIBLE ABOVE BRIDGE. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

256

2. AERIAL VIEW OF ROLLING LIFT BRIDGE. DORCHESTER AVENUE IN ...  

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

2. AERIAL VIEW OF ROLLING LIFT BRIDGE. DORCHESTER AVENUE IN BACKGROUND. SOUTH STATION VISIBLE AT TOP LEFT. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

257

TMI2 reactor vessel plenum final lift  

Microsoft Academic Search

Removal of the plenum assembly from the TMI-2 reactor vessel was necessary to gain access to the core region for defueling. The plenum was lifted from the reactor vessel by the polar crane using three specially designed pendant assemblies. It was then transferred in air to the flooded deep end of the refueling canal and lowered onto a storage stand

1986-01-01

258

Machine for Weight-Lift Testing.  

National Technical Information Service (NTIS)

This report describes the design and building details of a weight lifting machine which is primarily intended for Factor X testing where only occasional use is foreseen and an expensive machine would not be cost effective. The machine allows one to select...

N. M. Aume

1984-01-01

259

Factoring wavelet transforms into lifting steps  

Microsoft Academic Search

This paper is essentially tutorial in nature. We show how any discrete wavelet transform or two band subband ltering with nite lters can be decomposed into a nite sequence of simple lter - ing steps, which we call lifting steps but that are also known as ladder structures. This decomposition corresponds to a factorization of the polyphase matrix of the

Ingrid Daubechies; Wim Sweldens

2000-01-01

260

Image denoising by adaptive lifting schemes  

Microsoft Academic Search

In this paper, we study the problem of image denoising by using an adaptive lifting scheme. Such a scheme can adapt itself well to the analyzed signal, which allows to keep important information for denoising applications. However, it results in a non-isometric transform which can be an important limitation as most of the denoising approaches rely on the estimation of

M. Abid; M. Cagnazzo; B. Pesquet-Popescu

2010-01-01

261

Compound Channels, Transition Expectations, and Liftings  

SciTech Connect

In Section 1 we introduce the notion of lifting as a generalization of the notion of compound state introduced in [21] and [22] and we show that this notion allows a unified approach to the problems of quantum measurement and of signal transmission through quantum channels. The dual of a linear lifting is a transition expectation in the sense of [3] and we characterize those transition expectations which arise from compound states in the sense of [22]. In Section 2 we characterize those liftings whose range is contained in the closed convex hull of product states and we prove that the corresponding quantum Markov chains [2] are uniquely determined by a classical generalization of both the quantum random walks of [4] and the locally diagonalizable states considered in [3]. In Section 4, as a first application of the above results, we prove that the attenuation (beam splitting) process for optical communication treated in [21] can be described in a simpler and more general way in terms of liftings and of transition expectations. The error probabilty of information transmission in the attenuation process is rederived from our new description. We also obtain some new results concerning the explicit computation of error probabilities in the squeezing case.

Accardi, L. [Dipartimento di Matematica, Centro Matematico V. Volterra, Universita di Roma II, Rome (Italy); Ohya, M. [Department of Information Sciences, Science University of Tokyo, Noda City, Chiba 278 (Japan)

1999-01-15

262

Circulation Manifold for Two Adjacent Lifting Sections.  

National Technical Information Service (NTIS)

The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining...

A. Iollo, L. Zannetti

1998-01-01

263

Lifting Surface Theory for Thrust Augmenting Ejectors.  

National Technical Information Service (NTIS)

The circulation theory of airfoil lift has been applied to predict the static performance of thrust augmenting ejectors. The ejector shroud is considered to be 'flying' in the velocity field induced by the entrainment of the primary jets, so that the thru...

P. M. Bevilaqua

1982-01-01

264

Shear flow aerodynamics - Lifting surface theory  

NASA Technical Reports Server (NTRS)

A lifting surface theory based on a parallel shear flow model is presented for steady, incompressible flows. The theory is intended to account approximately for the presence of a boundary layer. The method of Fourier transforms is used to calculate the pressure on a surface of infinite extent and arbitrary contour. Immediately above the surface is a region of sheared flow (the boundary layer), outside of which the flow velocity is constant. The Fourier transform of the pressure on this surface is used to derive the shear flow equivalent to the kernel function of classical potential flow lifting surface theory. The kernel function provides an integral relation between the upwash at a given point on the surface and the pressure everywhere on the surface. This relation is treated as an integral equation for the pressure, and is solved numerically. Computations are presented for the lift and pitching moment on a flat plate in two-dimensional flow, and for flat, rectangular wings of aspect ratio 1, 2, and 5. As expected, the shear layer decreases the lift curve slope; however, the shear layer (whose thickness is constant along the wing chord) has little effect on the center of pressure.

Ventres, C. S.

1975-01-01

265

Video based lifting technique coding system  

Microsoft Academic Search

Despite automation and improved working conditions, many materials in industry are still handled manually. Among the basic activities involved in manual materials handling, lifting is the one most frequently associated with lowback pain (LBP). Biomechanical analysis techniques have been used to better understand the risk factors associated with manual handling, but because these techniques require specialized equipment, highly trained personnel,

SIMON M. HSIANG; GEORGE E. BROGMUS; SUSAN E. MARTIN; ILYA B. BEZVERKHNY

1998-01-01

266

Estimation of an Occupational Choice Model when Occupations Are Misclassified  

ERIC Educational Resources Information Center

This paper develops an empirical occupational choice model that corrects for misclassification in occupational choices and measurement error in occupation-specific work experience. The model is used to estimate the extent of measurement error in occupation data and quantify the bias that results from ignoring measurement error in occupation codes…

Sullivan, Paul

2009-01-01

267

Analysis of lifting beam and redesigned lifting lugs for 241-AZ-01A decant pump  

SciTech Connect

This supporting document details calculations for the proper design of a lifting beam and redesigned lifting lugs for the 241AZO1A decant pump. This design is in accordance with Standard Architectural-Civil Design Criteria, Design Loads for Facilities (DOE-RL 1989) and is safety class three. The design and fabrication is in accordance with American Institute of Steel Construction, Manual of Steel Construction, (AISC, 1989) and the Hanford Hoisting and Rigging Manual (DOE-RL 1993).

Coverdell, B.L.

1994-11-29

268

Occupational lung cancer  

SciTech Connect

The author addresses the attribution of lung cancer to cigarette smoking and the problems of confounding synergistic effects of occupational and other carcinogenic risk factors, as well as the divergent trends of declining smoking rates and increasing rates of lung cancer. He also reviews the existing literature to document associations between lung cancer and occupational exposures. Finally, interventions for prevention of occupational lung cancer are discussed.

Cone, J.E.

1987-04-01

269

[Tuberculosis as occupational disease].  

PubMed

There is enough evidence to declare tuberculosis as an occupational disease among healthcare workers. In Peru, there are regulations granting employment rights regarding tuberculosis as an occupational disease, such as healthcare coverage for temporary or permanent disability. However, these rights have not been sufficiently socialized. This study presents information on the risk of acquiring tuberculosis in the workplace, and a review of the evidence to declare tuberculosis as an occupational disease among health care workers, presenting the current Peruvian law related. PMID:22858771

Mendoza-Ticona, Alberto

2012-06-01

270

Ethics in Occupational Health  

PubMed Central

We know little about perceptions, practices, or constraints of ethics in occupational health because little research has been done. Opinions about the field, however, are abundant. Existing codes of ethical practice in occupational health have not consciously been derived from the fundamental principles of “freedom” and “well-being” or from philosophical premises and methods; rather, they are based on consensus among practitioners. The author outlines useful concepts and methods for making decisions about ethical questions in occupational health.

Haines, Ted

1989-01-01

271

An Evidence-Based Multidisciplinary Practice Guideline to Reduce the Workload due to Lifting for Preventing Work-Related Low Back Pain  

PubMed Central

We developed an evidence-based practice guideline to support occupational safety and health (OSH) professionals in assessing the risk due to lifting and in selecting effective preventive measures for low back pain (LBP) in the Netherlands. The guideline was developed at the request of the Dutch government by a project team of experts and OSH professionals in lifting and work-related LBP. The recommendations for risk assessment were based on the quality of instruments to assess the risk on LBP due to lifting. Recommendations for interventions were based on a systematic review of the effects of worker- and work directed interventions to reduce back load due to lifting. The quality of the evidence was rated as strong (A), moderate (B), limited (C) or based on consensus (D). Finally, eight experts and twenty-four OSH professionals commented on and evaluated the content and the feasibility of the preliminary guideline. For risk assessment we recommend loads heavier than 25 kg always to be considered a risk for LBP while loads less than 3 kg do not pose a risk. For loads between 3–25 kg, risk assessment shall be performed using the Manual handling Assessment Charts (MAC)-Tool or National Institute for Occupational Safety and Health (NIOSH) lifting equation. Effective work oriented interventions are patient lifting devices (Level A) and lifting devices for goods (Level C), optimizing working height (Level A) and reducing load mass (Level C). Ineffective work oriented preventive measures are regulations to ban lifting without proper alternatives (Level D). We do not recommend worker-oriented interventions but consider personal lift assist devices as promising (Level C). Ineffective worker-oriented preventive measures are training in lifting technique (Level A), use of back-belts (Level A) and pre-employment medical examinations (Level A). This multidisciplinary evidence-based practice guideline gives clear criteria whether an employee is at risk for LBP while lifting and provides an easy-reference for (in)effective risk reduction measures based on scientific evidence, experience, and consensus among OSH experts and practitioners.

2014-01-01

272

Maximum Frequency of Lift Acceptable to Male Industrial Workers  

Microsoft Academic Search

This paper describes an experiment which utilized a psychophysical approach to determine maximum frequencies of lift acceptable to male industrial workers. Eight subjects were required to lift continuously either a 35-pound or a 50-pound tote box through a 20-inch distance at each of three different heights. The lifting task was paced by a repeating timer which the subject controlled according

S. H. Snook; C. H. Irvine

1968-01-01

273

Lifting-based multi-view image coding  

Microsoft Academic Search

A number of lifting-based video coding schemes have been recently proposed for scalable video coding. In this paper, we present a novel multi-view image codec based on a wavelet lifting scheme. The proposed lifting scheme with disparity compensated channel filtering is very efficient in terms of compressions performance, memory requirements and implementation. We propose a number of enhancements to the

Nantheera Anantrasirichai; Cedric Nishan Canagarajah; David R. Bull

2005-01-01

274

Combining parallel lifting and retiming architecture for discrete wavelet transform  

Microsoft Academic Search

The implementation based on lifting scheme of discrete wavelet transform has great advantages compared with that based on convolution. However, the critical path of the conventional lifting algorithm based implementation is potentially longer than that of convolution-based implementation. In this paper, an improved lifting algorithm for the wavelet filters and its VLSI architecture are presented, in which parallelism of arithmetic

Zhi-Rong Gao; Cheng-Yi Xiong

2005-01-01

275

M-band biorthogonal interpolating wavelets via lifting scheme  

Microsoft Academic Search

Recently, the lifting scheme was generalized to the multidimensional and multiband cases and was used to design M-band interpolating scaling filters and their duals. Based on this idea, we develop a new lifting pattern, namely, the progressive lifting pattern. This pattern allows us to pairwise generate M-band interpolating filterbanks and wavelets by the order from lowpass to highpass filters. A

Peng-Lang Shui; Zheng Bao

2004-01-01

276

A new adaptive wavelet transform using lifting scheme  

Microsoft Academic Search

This paper presents a new adaptive wavelet transform using lifting scheme. The algorithm proposed uses interpolating method to construct a predict\\/update type lifting scheme based on the optimal criteria. The two-step lifting scheme is adaptively match the property of local signal at each scale. The novel framework introduced chooses the most suitable predictor and updater respectively, which differs from other

Zhi-Zhong Han; Zhen-Bao Liu; Ya-Sen Xu

2011-01-01

277

Barbell lifting wavelet transform for highly scalable video coding  

Microsoft Academic Search

This paper proposes a generic lifting technology (Barbell Lifting), where each predicting or updating signal is generated with a Barbell function instead of always a sample from single direction or bi-direction, to incorporate various motion alignment methods into temporal wavelet transform. The proposed lifting technology embraces fractional pixel motion alignment, variable block size motion alignment and overlapped block motion alignment

Ruiqin Xiong; Feng Wu; Jizheng Xu; Shipeng Li; Ya-Qin Zhang

2004-01-01

278

49 CFR 178.975 - Top lift test.  

Code of Federal Regulations, 2013 CFR

...pair of diagonally opposite lifting devices, so that the hoisting...pair of diagonally opposite lifting devices so that the hoisting...flexible Large Packaging by its lifting devices. (iii) Apply...percent of the cross sectional surface area of the flexible...

2013-10-01

279

14 CFR 25.699 - Lift and drag device indicator.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Lift and drag device indicator. 25.699 Section...Control Systems § 25.699 Lift and drag device indicator. (a) There must...the pilots the position of each lift or drag device having a separate control...

2010-01-01

280

14 CFR 25.699 - Lift and drag device indicator.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Lift and drag device indicator. 25.699 Section...Control Systems § 25.699 Lift and drag device indicator. (a) There must...the pilots the position of each lift or drag device having a separate control...

2009-01-01

281

[Occupational respiratory cancers].  

PubMed

Lung cancer and pleural mesothelioma are the most common occupational cancers. Recent epidemiological studies have estimated that the fraction attributable to occupational factors varies from 13 to 29% for lung cancer in men and is about 85% for pleural mesothelioma in men. Previous occupational exposure to asbestos is the most common occupational exposure in these cancers. Mesothelioma immediately leads the clinician to look for past asbestos exposure. In contrast, the search for an occupational exposure that should be routine in all cases of lung cancer, is generally more difficult because of the number of occupational aetiological factors and the absence of criteria that allow distinction of an occupational cancer from a tobacco related one. Therefore attention should be paid to the identification of occupational exposure in order to set up primary prevention programmes to prevent exposure still present in the working environment and, on the other hand, to identify the subjects entitled to the acknowledgement of occupational disease and/or to obtain the compensation available to asbestos victims. PMID:18449081

Pairon, J-C; Andujar, P; Matrat, M; Ameille, J

2008-02-01

282

Occupational cancer in Italy.  

PubMed Central

This article is a discussion of occupational cancer in Italy. The introduction provides the necessary context of Italian industrialization and occupational health regulation. This is followed by a review of Italian epidemiologic studies of occupational cancer risks considered in terms of relative measures of risk and attributable risk of carcinogenic agents or exposure circumstances. We attempt to establish the number of workers exposed to carcinogens in Italy and the intensity of their exposures. Finally, the Italian system of compensation for occupational cancer is discussed. Several cohort and case-control studies have addressed the issue of occupational risks, mostly among male workers. The results of these studies suggest that the growing incidence of and mortality by mesothelioma is explained by the widespread and intense exposure to asbestos in some Italian industrial settings. A high attributable risk of lung tumors among male populations in industrial areas of northern Italy is explained by occupational exposures. However, insufficient data are available for clear definition of the extent and intensity of occupational exposure to carcinogenic substances. In Italy, we must prioritize and maximize resources in occupational cancer epidemiology and revitalize the role of national institutions. Recent legislation has established new regulations on the handling of carcinogenic substances in industrial settings, a new list of occupational diseases, and a national registry of mesothelioma linked to asbestos exposure. These legislative changes are expected to have positive effects.

Merler, E; Vineis, P; Alhaique, D; Miligi, L

1999-01-01

283

Texas passes first law for safe patient handling in America: landmark legislation protects health-care workers and patients from injury related to manual patient lifting.  

PubMed

On June 17,2005, Texas Governor Rick Perry (R) signed into law Senate Bill 1525, making Texas the first state in the nation to require hospitals and nursing homes to implement safe patient handling and movement programs. Governor Perry is to be commended for this heroic first stand for safe patient handling in America. The landmark legislation will take effect January 1, 2006, requiring the establishment of policy to identify, assess, and develop methods of controlling the risk of injury to patients and nurses associated with lifting, transferring, repositioning, and movement of patients; evaluation of alternative methods from manual lifting to reduce the risk of injury from patient lifting, including equipment and patient care environment; restricting, to the extent feasible with existing equipment, manual handling of all or most of a patient's weight to emergency, life-threatening, or exceptional circumstances; and provision for refusal to perform patient handling tasks believed to involve unacceptable risks of injury to a patient or nurse. Manually lifting patients has been called deplorable, inefficient, dangerous to nurses, and painful and brutal to patients; manual lifting can cause needless suffering and injury to patients, with dangers including pain, bruising, skin tears, abrasions, tube dislodgement, dislocations, fractures, and being dropped by nursing staff during attempts to manually lift. Use of safe, secure, mechanical lift equipment and gentle friction-reducing devices for patient maneuvering tasks could eliminate such needless brutality. Research has proven that manual patient lifting is extremely hazardous to health-care workers, creating substantial risk of low-back injury, whether with one or two patient handlers. Studies on the use of mechanical patient lift equipment, by either nursing staff or lift teams, have proven repeatedly that most nursing staff back injury is preventable, leading to substantial savings to employers on medical and compensation costs. Because the health-care industry has relied on people to do the work of machines, nursing work remains the most dangerous occupation for disabling back injury. Back injury from patient lifting may be the single largest contributor to the nursing shortage, with perhaps 12% of nurses leaving or being terminated because of back injury. The US health-care industry has not kept pace with other industries, which provide mechanical lift equipment for lifting loads equivalent to the weight of patients, or with other countries, such as Australia and England, which are more advanced in their use of modern technology for patient lifting and with no-lifting practices in compliance with government regulations and nursing policies banning manual lifting. With Texas being the first state to succeed in passing legislation for safe patient handling, other states are working toward legislative protection against injury with manual patient lifting. California re-introduced safe patient handling legislation on February 17, 2005, with CA SB 363, Hospitals: Lift Teams, following the September 22, 2004, veto of CA AB 2532 by Governor Arnold Schwarzenegger, who said he believes existing statutory protection and workplace safety standards are sufficient to protect health care workers from injury. Massachusetts HB 2662, Relating to Safe Patient Handling in Certain Health Facilities, was introduced December 1, 2004. Ohio HB 67, signed March 21, 2005 by Governor Bob Taft (R), creates a program for interest-free loans to nursing homes for implementation of a no-manual-lift program. New York companion bills AB 7641 and SB 4029 were introduced in April, 2005, calling for creation of a 2-year study to establish safe patient handling programs and collect data on nursing staff and patient injury with manual patient handling versus lift equipment, to determine best practices for improving health and safety of health-care workers and patients during patient handling. Washington State is planning re-introduction of safe patient handling legislation, after WA HB 1672, Relating to red

Hudson, Mary Anne

2005-01-01

284

Welding. Occupational Competency Analysis Profile.  

ERIC Educational Resources Information Center

This Occupational Competency Analysis Profile (OCAP), which is one of a series of OCAPs developed to identify the skills that Ohio employers deem necessary to entering a given occupation/occupational area, lists the occupational, academic, and employability skills required of individuals entering the occupation of welder. The introduction explains…

Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

285

Liposuction-Assisted Medial Thigh Lift in Obese and Non Obese Patients  

PubMed Central

Introduction: The abdomen, thighs and buttocks are often the areas of greatest concern to patients following massive weight loss due to bariatric surgery. The typical appearance of the patient who has lost a massive amount of weight derives from a combination of factors, including gender-dependent body morphology and a change in body mass index, which lead to skin and soft-tissue excess and poor skin tone. Thigh laxity and redundancy represents a great challenge to both patients and surgeons. Not only because of the difficulty to satisfy the patients, but also due to the higher incidence of complications especially, with those obese patients who have not undergone bariatric surgery before. The problems with such patients are due to the heavy thighs that require both debulking and tight anchorage to prevent scar migration or labial distortion. Aim of the Work: The aim of the present study is to improve the aesthetic outcome and avoid the complications of medial thigh lifting with simultaneous liposuction in obese and non-obese. Patients and Methods: A total of 25 female patients presented during the period from January 2007 to July 2011 complaining of moderate to severe thigh laxity with or without lipodystrophy. In 20 patients medial transverse thigh lift was performed, to treat medial thigh friction and laxity particularly in the upper half. Whereas, in the other five patients were suffering from upper and lower medial thigh bulkiness, vertical thigh lift was performed. Results: All patients recovered well in 2 weeks and showed improvement of thigh contour. Scar downward displacement in one patient. No skin necrosis or seroma. No labial distortion or separation encountered. Conclusion: Simultaneous liposuction and thigh lift gave good results provided proper patients selection, appropriate technique to each patient, meticulous, cautious liposuction and handling of the tissues and most importantly is the deep tight anchorage sutures to guard against the effect of heavy skin flaps.

Aboueldahab, Abdelmohsen Khalaf

2013-01-01

286

Lift force acting on the cylinder in viscous liquid under vibration  

NASA Astrophysics Data System (ADS)

The averaged lift force acting on a solid in viscous liquid in case of translational or rotary vibrations of a cavity is experimentally investigated. Experiments are performed with a heavy cylinder; different types of vibrations, translational and rotational, are investigated. It is found that the vibrations excite the mean lift force which could provide the suspension of solid even in gravity field. The repulsion lift force acts on the body near the walls of the vibrating cavity. It is caused by the viscous hydrodynamic interaction of oscillating body with the wall and is significant at a distance comparable with the thickness of Stokes layer. The intensification of vibration results in the excitation of tangential lift force, which is caused by the brake of the symmetry of the body's oscillations with respect to the cavity wall. In case of rotary vibrations the lift force of high intensity manifests itself in the bulk of the cavity due to the interaction of body with the oscillating shear flow. The mean dynamics of the solid body in a cavity under the rotary vibrations is determined by the combined action of two averaged vibrational effects—levitation of the body in the oscillating shear flow and hydrodynamic interaction of the body with the wall. In case of translational vibrations the dynamics of the solid is mainly determined by interaction with the walls. The experiments demonstrate that the vibrations have strong mean effect on the bodies in liquid; they could be used for efficient control of solid inclusions in microgravity and must be taken into account in space experiments and technologies.

Kozlov, V.; Ivanova, A.; Schipitsyn, V.; Stambouli, M.

2012-10-01

287

OCCUPATION EDUCATION REQUIREMENTS ANALYSIS.  

ERIC Educational Resources Information Center

THE OCCUPATIONAL EDUCATION REQUIREMENTS ANALYSIS (OERA) SYSTEM IS A RESEARCH EFFORT DESIGNED TO DEVELOP A FEASIBLE METHOD OF PROJECTING VOCATIONAL EDUCATION REQUIREMENTS THAT WILL SATISFY LABOR MARKET NEEDS. THE OUTPUTS OF THE OERA WILL BE ANNUAL PROJECTIONS OF EMPLOYMENT DEMANDS IN OCCUPATIONS CLASSIFIED BY VOCATIONAL EDUCATION PROGRAMS. THESE…

GRIEST, JEANNE; MORSCH, WILLIAM C.

288

Occupations, U. S. A.  

ERIC Educational Resources Information Center

The booklet divides job titles, selected from the Dictionary of Occupational Titles, into 15 career clusters: agribusiness and natural resources, business and office education, communication and media, construction, consumer and home economics, fine arts and humanities, health occupations, hospitality and recreation, manufacturing, marine science,…

Geneva Area City Schools, OH.

289

Local Occupational Program Evaluation.  

ERIC Educational Resources Information Center

To evaluate a secondary level occupational education program in New York State, the author used a system termed LOPE (Local Occupational Program Evaluation), which began with the development of a statement of philosophy and measureable objectives based on teacher and administrator input. A questionnaire based on the objectives was administered to…

Pautler, Albert J., Jr.

290

Occupational Standards: International Perspectives.  

ERIC Educational Resources Information Center

These nine papers from a conference of the International Research Network for Training and Development focus on occupational classification, standards, and certification. "Introduction" (Joao Oliveria) presents synopses with highlights from the papers. Part I offers an overview of recent developments in the United States in "Occupational Standards…

Oliveira, Joao, Ed.

291

Occupational asthma: a review.  

PubMed Central

Occupational asthma is the most common form of occupational lung disease in the developed world at the present time. In this review, the epidemiology, pathogenesis/mechanisms, clinical presentations, management, and prevention of occupational asthma are discussed. The population attributable risk of asthma due to occupational exposures is considerable. Current understanding of the mechanisms by which many agents cause occupational asthma is limited, especially for low-molecular-weight sensitizers and irritants. The diagnosis of occupational asthma is generally established on the basis of a suggestive history of a temporal association between exposure and the onset of symptoms and objective evidence that these symptoms are related to airflow limitation. Early diagnosis, elimination of exposure to the responsible agent, and early use of inhaled steroids may play important roles in the prevention of long-term persistence of asthma. Persistent occupational asthma is often associated with substantial disability and consequent impacts on income and quality of life. Prevention of new cases is the best approach to reducing the burden of asthma attributable to occupational exposures. Future research needs are identified.

Lombardo, L J; Balmes, J R

2000-01-01

292

Mental Health Occupational Therapy  

Microsoft Academic Search

This article briefly reviews the history of ideas and practice in psychosocial occupational therapy. It then reports the results of two studies which examined present-day perspectives as reflected in occupational therapy literature and the actural practices of psychosocial therapists. The first study was based on a review of mental health-related articles in AJOT and OTMH; the second represented secondary analyses

Gary Kielhofner; Roann Barris

1984-01-01

293

Going to an Occupational Therapist  

MedlinePLUS

... do things on his own. What Is Occupational Therapy? Everyone has an occupation or job. A kid's ... time. Occupational therapists also may help children with autism learn how to interact with others, or might ...

294

[Market oriented occupational medicine].  

PubMed

The history and the recent state of occupational medicine in Hungary, and its relation with governmental labor organizations are analyzed. In the past 20 years, large "socialist" factories were replaced by smaller companies employing fewer workers. They have been forced to establish contract with occupational health providers. Many of them offer primary care services, whereas family physicians having a board examination in occupational medicine are allowed to work in this field as well. The market of occupational medicine is less regulated, and ethical rules are not always considered. Undercutting prices is a common practice. The recent system could be improved by some regulations which should be respected. There is no reason to make rough changes establishing a new market for profit oriented insurance companies, and to allow employees and employers to work without specification neglecting international agreements. Occupational medicine should be supervised again by the health authorities instead of economists who have quite different, short-term priorities. PMID:22951411

Rurik, Imre; Cseh, Károly

2012-09-01

295

Occupational Infection in Korea  

PubMed Central

Occupational infection is a human disease caused by work-associated exposure to microbial agents through human and environmental contact. According to the literature, occupational infection was the third leading cause of occupational disease (861 cases, 8.0%), and health care, agricultural, forestry, and fishery workers were risk groups in Korea. In addition, most high-risk groups have not been protected by workers' compensation, which could lead to underestimation of the exact spectrum and magnitude of the problem, and may also result in a lack of development and implementation of occupational infection management. Through a review of national guidelines and documentations on prevention and control of occupational infection, a management strategy would promote adherence to worker safety regulations if it is explicit with regard to the agent and mode of infection in each of the high-risk groups.

Ahn, Yeon-Soon; Jeong, Jae Sim

2010-01-01

296

Perspectives in Occupational Dermatology  

PubMed Central

Because large surface areas of the skin are exposed directly to the environment, skin is an organ particularly vulnerable to occupationally induced disease. Statistics show that, excluding accidental injury, nearly half of all occupational illnesses occur in this organ; a fourth of all workers suffering from occupational skin disease lose an average of 10 to 12 workdays. The constant evolution of new industrial chemicals and methods of manufacture continue to bring new skin hazards and disease into the workplace. Occupational health physicians and practitioners, who usually have minimal training in dermatology, must diagnose and treat unfamiliar diseases in a setting of even less familiar, often overwhelming, technology. A thorough understanding of cutaneous defense mechanisms, clinical patterns of occupational skin disease and methods for establishing accurate diagnoses is essential.

Mathias, C. G. Toby; Maibach, Howard I.

1982-01-01

297

What's new in artificial lift; Part 2  

SciTech Connect

In the first article of this two-part series, new developments were presented for electrical submersible pumps and accessories, gas lift, and controls and measurement. This concluding article extends the review of artificial lift innovations to include beam pumping and progressive cavity (PC) pumps. Described here are improvements in beam pumping which include advanced sucker rods and pumping units, fluid level instruments, pump-off control (POC) and efficiency monitoring/management systems, pump sand control, surface pollution containment and a shared-motor for multiple wells. For progressive cavity pump improvements, three companies have introduced new rod guides, a modified tubing anchor catcher, round continuous rods, a PC variable frequency drive and a multilobe pump system. And status of a 20-company sponsored project for PC pump improvement is outlined.

Lea, J.F. (Amoco Production Research, Tulsa, OK (United States)); Winkler, H.W. (Winkler (H.W.), Lubbock, TX (United States))

1994-04-01

298

LIFT Tenant Is Off and Running  

NASA Technical Reports Server (NTRS)

Lewis Incubator for Technology (LIFT) tenant, Analiza Inc., graduated from the incubator July 2000. Analiza develops technology and products for the early diagnosis of diseases, quality control of bio-pharmaceutical therapeutics, and other applications involving protein analyses. Technology links with NASA from existing and planned work are in areas of microfluidics and laser light scattering. Since their entry in LIFT in May, 1997, Analiza has: Received a $750,000 grant from the National Institutes of Health. Collaborated with a Nobel Prize winner on drug design. Collaborated with Bristol-Myers Squibb on the characterization of biological therapeutics. Added a Ph.D. senior scientist and several technicians. Received significant interest from major pharmaceutical companies about collaborating and acquiring Analiza technology.

Steele, Gynelle C.

2001-01-01

299

Drag and lift forces in granular media  

NASA Astrophysics Data System (ADS)

Forces exerted on obstacles moving in granular media are studied. The experiment consists in a horizontal cylinder rotating around the vertical axis in a granular medium. Both drag forces and lift forces experienced by the cylinder are measured. The first striking result is obtained during the first half rotation, before the cylinder crosses its wake. Despite the symmetry of the object, a strong lift force is measured, about 20 times the buoyancy. The scaling of this force is studied experimentally. The second remarkable observation is made after several rotations. The drag force dramatically drops and becomes independent of depth, showing that it no longer scales with the hydrostatic pressure. The rotation of the cylinder induces a structure in the packing, which screens the weight of the grains above

Guillard, F.; Forterre, Y.; Pouliquen, O.

2013-09-01

300

The extended centrolateral endoscopic midface lift.  

PubMed

Most of the advances in face lift techniques in the past decade have been directed at altering the aging changes of the midface. Our technique for endoscopic midface lifting releases the entire central and lateral midface, which allows for a complete resuspension and rejuvenation. This technique utilizes a subperiosteal release of the midface from the infraorbital rim to the inferior aspect of the maxilla and laterally over the entire zygomatic arch to the gonial angle beneath the masseteric aponeurosis. Suspension is achieved superolaterally to the deep temporal fascia and repositions the malar fat pad, SOOF, and soft tissues overlying the angle of the mandible. Over 400 procedures have been performed. We found the degree of improvement in the following order, from greatest to least: (1) correction of midface ptosis and infraorbital hollowing, (2) improvement of the depth of the nasolabial fold, and (3) improvement of the degree of jowling. This technique is one of low morbidity and few complications. PMID:12825160

Quatela, Vito C; Jacono, Andrew A

2003-05-01

301

Lifting surface theory for rectangular wings  

NASA Technical Reports Server (NTRS)

A new incompressible lifting-surface theory is developed for thin rectangular wings. The solution requires the downwash equation to be in the form of Cauchy-type integrals. Lan's method is employed for the chordwise integrals since it properly accounts for the leading-edge singularity, Cauchy singularity and Kutta condition. The Cauchy singularity in the spanwise integral is also accounted for by using the midpoint trapezoidal rule and theory of Chebychev polynomials. The resulting matrix equation, formed by satisfying the boundary condition at control points, is simpler and quicker to compute than other lifting surface theories. Solutions were found to converge with only a small number of control points and to compare favorably with results from other methods.

Dejarnette, F. R.

1976-01-01

302

V/STOL gets a lift  

NASA Technical Reports Server (NTRS)

The concept of a supersonic STOVL that could offer enhanced mission capability, survivability, operational flexibility, and utility over conventional aircraft is presented. Emphasis is currently on design studies, CFD work, small- and large-scale wind tunnel tests, simulation activities, flight experiments, and ground environment experiments. Propulsion system technology centers about the adaptation of existing or off-the-shelf engines. Concepts under study include separate flow in hover, gas-driven lift fan, and shaft-driven lift fan. NASA is examining generic valve and ducting configurations with airflow at ambient temperature and at temperatures up to 1000 F to gather pressure loss and heat transfer data. Advanced civil rotorcraft technologies examined include high-efficiency/dual-mode components such as torque converters; lightweight, quiet transmissions; and variable geometry power turbines; along with dual-function or convertible engines.

Biesiadny, Tom

1991-01-01

303

Drag and lift in nonadiabatic transonic flow  

NASA Astrophysics Data System (ADS)

Transonic flows with heat addition over airfoils have been calculated for different angles of attack. The fluid is a mixture of an inert carrier gas and a small amount of a condensible vapor. For the phase change process coupled to the flow, two limiting cases are investigated: nonequilibrium condensation after significant supersaturation and homogeneous nucleation and equilibrium condensation. Numerical calculations based on the Euler equations are linked with either the classical nucleation theory coupled with microscopic droplet growth laws or an equilibrium process. An improved explicit time-dependent diabatic finite volume method is developed and applied to calculate stationary flows. Reservoir conditions of pressure, temperature, and vapor content are varied to simulate internal flows in transonic wind tunnels, turbomachinery, and atmospheric flight at low altitudes. The pressure drag and the lift may increase or decrease. Homogeneous condensation in internal flows produces a maximum decrease of the pressure drag of about 60% and a maximum lift decrease of 35%.

Schnerr, Guenter H.; Dohrmann, Ulrich

1994-01-01

304

The adjustable vector deep plane midface lift.  

PubMed

Midface lifting is valuable rejuvenative options for many patients and can provide a more youthful and balanced face. This procedure is well suited for the oral and maxillofacial surgeon because of familiarity with the intraoral and temporal surgical approaches, and it does not require any specialized equipment. This procedure has minimal postoperative recovery and a low complication rate. The results of this procedure have remained stable in the author's cohort of patients approaching 2 years. Contraindications include atrophic or minimal malar fat, in which case there is nothing to elevate. The midface lift can be performed as an isolated procedure or as part of multiple facial procedures. The astute surgeon considers midface rejuvenation in all cosmetic cases. PMID:15450283

Niamtu, Joseph

2004-09-01

305

Induction factor optimization through variable lift control  

NASA Astrophysics Data System (ADS)

Due to practical design limitations coupled with the detrimental effects posed by complex wind regimes, modern wind turbines struggle to maintain or even reach ideal operational states. With additional gains through traditional approaches becoming more difficult and costly, active lift control represents a more attractive option for future designs. Here, plasma actuators have been explored experimentally in trailing edge applications for use in attached flow regimes. This authority would be used to drive the axial induction factor toward the ideal given by the Betz limit through distributed lift control thereby enhancing energy capture. Predictions of power improvement achievable by this methodology are made with blade - element momentum theory but will eventually be demonstrated in the field at the Laboratory for Enhanced Wind Energy Design, currently under construction at the University of Notre Dame.

Cooney, John; Corke, Thomas; Nelson, Robert; Williams, Theodore

2011-11-01

306

Lifting to mod $2$ Moore spaces  

Microsoft Academic Search

We try to investigate whether an element of order $2$ in homotopy groups of spheres has a lift to an element of homotopy groups of mod $2$ Moore spaces or not. A typical element of the affirmative property is Thomeier's element of $\\\\pi_{8n+7}(S^{4n+3})$ . And the Whitehead square $[l_{2n+1},l_{2n+1}]$ of the identity class $l_{2n+1}$ of $S^{2n+1}$ is a negative example

Kaoru MORISUGI; Juno MUKAI

2000-01-01

307

Factoring wavelet transforms into lifting steps  

Microsoft Academic Search

This article is essentially tutorial in nature. We show how any discrete wavelet transform or two band subband filtering with\\u000a finite filters can be decomposed into a finite sequence of simple filtering steps, which we call lifting steps but that are\\u000a also known as ladder structures. This decomposition corresponds to a factorization of the polyphase matrix of the wavelet\\u000a or

Ingrid Daubechies; Wim Sweldens

1998-01-01

308

Unified treatment of lifting atmospheric entry  

NASA Technical Reports Server (NTRS)

This paper presents a unified treatment of the effect of lift on peak acceleration during atmospheric entry. Earlier studies were restricted to different regimes because of approximations invoked to solve the same transcendental equation. This paper shows the connection between the earlier studies by employing a general expression for the peak acceleration and obtains solutions to the transcendental equation without invoking the earlier approximations. Results are presented and compared with earlier studies where appropriate.

Nachtsheim, P. R.; Lehman, L. L.

1980-01-01

309

Aerodynamic principles of the direct lifting propeller  

NASA Technical Reports Server (NTRS)

The purpose of this report is to make the complicated processes on the direct-lift propeller amenable to analysis and observation. This is accomplished by placing the physical phenomena, starting with the most elementary process, in the foreground, while limiting the mathematical treatment to the most essential in view of the fundamental defects of the theorems. Comparison with model experiments supplements and corroborates the theoretical results.

Schrenk, Martin

1934-01-01

310

An evaluation of patient lifting techniques  

Microsoft Academic Search

In the present laboratory study five two-person manual lifting techniques were evaluated as to the amount of physical exertion required of the nurses. Ten female volunteers served as nurses; two healthy volunteers (weight: 55 kg and 75 kg) served as passive patients. The working postures and motions were recorded on videotape. The data thus obtained were used in a anatomical-biomechanical analysis. The

G. H. M. WINKELMOLEN; J. A. LANDEWEERD; M. R. DROST

1994-01-01

311

Progress in high-lift aerodynamic calculations  

NASA Technical Reports Server (NTRS)

The current work presents progress in the effort to numerically simulate the flow over high-lift aerodynamic components, namely, multi-element airfoils and wings in either a take-off or a landing configuration. The computational approach utilizes an incompressible flow solver and an overlaid chimera grid approach. A detailed grid resolution study is presented for flow over a three-element airfoil. Two turbulence models, a one-equation Baldwin-Barth model and a two equation k-omega model are compared. Excellent agreement with experiment is obtained for the lift coefficient at all angles of attack, including the prediction of maximum lift when using the two-equation model. Results for two other flap riggings are shown. Three-dimensional results are presented for a wing with a square wing-tip as a validation case. Grid generation and topology is discussed for computing the flow over a T-39 Sabreliner wing with flap deployed and the initial calculations for this geometry are presented.

Rogers, Stuart E.

1993-01-01

312

Dynamic response of Hovercraft lift fans  

NASA Astrophysics Data System (ADS)

Hovercraft lift fans are subjected to varying back pressure due to wave action and craft motions when these vehicles are operating in a seaway. The oscillatory back pressure causes the fans to perform dynamically, exhibiting a hysteresis type of response and a corresponding degradation in mean performance. Since Hovercraft motions are influenced by variations in lift fan pressure and discharge, it is important to understand completely the nature of the dynamic performance of lift fans in order to completely solve the Hovercraft seakeeping problem. The present study was performed to determine and classify the instabilities encountered in a centrifugal fan operating against time-varying back pressure. A model-scale experiment was developed in which the fan discharge was directed into a flow-measuring device, terminating in a rotating valve which produced an oscillatory back pressure superimposed upon a mean aerodynamic resistance. Pressure and local velocity were measured as functions of time at several locations in the fan volute. The measurements permitted the identification of rotating (or propagating) stall in the impeller. One cell and two cell configurations were classified and the transient condition connecting these two configurations was observed. The mechanisms which lead to rotating stall in a centrifugal compressor are presented and discussed with specific reference to Hovercraft applications.

Moran, D. D.

1981-08-01

313

Dying for work: The magnitude of US mortality from selected causes of death associated with occupation  

Microsoft Academic Search

Background Deaths due to occupational disease and injury place a heavy burden on society in terms of economic costs and human suffering. Methods We estimate the annual deaths due to selected diseases for which an occu- pational association is reasonably well established and quantifiable, by calculation of attributable fractions (AFs), with full documentation; the deaths due to occupational injury are

Kyle Steenland; Carol Burnett; Nina Lalich; Elizabeth Ward; Joseph Hurrell

2003-01-01

314

Occupational cancer in Britain  

PubMed Central

Although only a relatively small proportion of cancer is attributable to occupational exposure to carcinogenic agents, the estimated number of deaths due to occupational cancer is high when compared to other deaths due to work-related ill health and injury. However, risk from occupational exposure to carcinogens can be minimised through proportionate but effective risk management. The Health and Safety Executive (HSE) is the regulator of workplace health and safety in Great Britain. As part of its aim to reduce ill health arising from failures to control properly exposure to hazards at work, HSE commissioned the research presented elsewhere in this supplement to enable it to identify priorities for preventing occupational cancer. The research has shown that occupational cancer remains a key health issue and that low-level exposure of a large number of workers to carcinogens is important. The finding that a small number of carcinogens have been responsible for the majority of the burden of occupational cancer provides key evidence in the development of priorities for significant reduction of occupational cancer. Although the research presented in this supplement reflects the consequences of past exposures to carcinogens, occupational cancer remains a problem. The potential for exposure to the agents considered in this research is still present in the workplace and the findings are relevant to prevention of future disease. In this article, the principle approaches for risk reduction are described. It provides supporting information on some of the initiatives already being undertaken, or those being put in place, to reduce occupational cancer in Great Britain. The need also for systematic collection of exposure information and the importance of raising awareness and changing behaviours are discussed.

Chen, Yiqun; Osman, John

2012-01-01

315

Heavy drinking in early adulthood and outcomes at mid life  

Microsoft Academic Search

BackgroundHeavy drinking in early adulthood among Blacks, but not Whites, has been found to be associated with more deleterious health outcomes, lower labor market success and lower educational attainment at mid-life. This study analysed psychosocial pathways underlying racial differences in the impact of early heavy alcohol use on occupational and educational attainment at mid-life.MethodsOutcomes in labor market participation, occupational prestige

F. A. Sloan; P. R. Costanzo; D. Belsky; E. Holmberg; P. S. Malone; Y. Wang; S. Kertesz

2010-01-01

316

Group Lifting Structures For Multirate Filter Banks, I: Uniqueness Of Lifting Factorizations  

SciTech Connect

This paper studies two-channel finite impulse response (FIR) perfect reconstruction filter banks. The connection between filter banks and wavelet transforms is well-known and will not be treated here. Figure 1 depicts the polyphase-with-advance representation of a filter bank [6]. A lifting factorization, is a factorization of polyphase matrices into upper and lower triangular lifting matrices. The existence of such decompositions via the Euclidean algorithm was shown for general FIR perfect reconstruction filter banks in [9] and was subsequently refined for linear phase filter banks in [10], [6]. These latter works were motivated by the ISO JPEG 2000 image coding standard [11], [12], [10], which specifies whole-sample symmetric (WS, or FIR type 1 linear phase) filter banks, as in Figure 2(a), in terms of half-sample symmetric (RS, or FIR type 2) lifting filters.

Brislawn, Christopher M [Los Alamos National Laboratory

2008-01-01

317

Occupational Safety and Health Aspects of Voice and Speech Professions  

Microsoft Academic Search

A well-functioning voice is an essential tool for one third of the labour force. Vocal demands vary to a great extent between the different voice and speech professions. In professions with heavy vocal loading (e.g. school and kindergarten teachers), occupational voice disorders threatening working ability are common. Vocal loading is a combination of prolonged voice use and additional loading factors

Erkki Vilkman

2004-01-01

318

Occupational Therapy (For Parents)  

MedlinePLUS

... centers mental health facilities private practices children's clinics nursing homes Finding Care for Your Child If you think your child might benefit from occupational therapy, ask your doctor to refer you to a ...

319

Occupational hearing loss  

MedlinePLUS

Over time, repeated exposure to loud noise and music can cause hearing loss. Occupational hearing loss is ... Airline ground maintenance Construction Farming Jobs involving loud music or machinery In the U.S., the maximum job ...

320

Occupational Health and Safety  

MedlinePLUS

... Labor Statistics, of the U.S. Department of Labor, agriculture remains one of the most dangerous industries in ... agricultural industry, and for every 100,000 workers, agriculture had the highest rate of fatal occupational injuries: ...

321

Paternal occupation and anencephaly  

SciTech Connect

It has been suggested that paternal occupational exposures to pesticides and solvents increase the risk of neural tube defects in offspring. With the use of Texas livebirth, fetal death, and linked livebirth-death records, the authors conducted a population-based case-control study among 1981-1986 Texas births to examine the association between paternal occupation and anencephalic births. Fathers employed in occupations associated with solvent exposure were more likely to have offspring with anencephaly (odds ratio (OR) = 2.53), with painters having the highest risk (OR = 3.43). A lesser association was found for fathers employed in occupations involving pesticide exposure (OR = 1.28). Further studies are indicated to clarify these associations.

Brender, J.D.; Suarez, L. (Texas Department of Health, Austin (USA))

1990-03-01

322

Wisconsin Occupational Information System.  

National Technical Information Service (NTIS)

The first annual report of the Wisconsin Occupational Information System (WOIS) is a descriptive analysis of activities and procedures utilized during the initial grant period of July 14, 1975-July 13, 1976. This report is divided into eight sections summ...

R. H. Lambert

1976-01-01

323

Occupational health in Brazil  

Microsoft Academic Search

Brazil is a recently industrialised country with marked contrasts in social and economic development. The availability of\\u000a public\\/private services in its different regions also varies. Health indicators follow these trends. Occupational health is\\u000a a vast new field, as in other developing countries. Occupational medicine is a required subject in graduation courses for\\u000a physicians. Specialisation courses for university graduated professionals have

Bernardo Bedrikow; Eduardo Algranti; José Tarcísio Penteado Buschinelli; Luiz Carlos Morrone

1997-01-01

324

Diagnosis of Occupational Rhinitis  

Microsoft Academic Search

Occupational rhinitis refers to nasal disease caused by stimuli in the working environment. As the underlying pathophysiological\\u000a mechanisms may have an allergic, a non-allergic or an unknown background standardized or even clear-cut diagnostic tools are\\u000a not available. The occupational and medical history should give some evidence of a relation between the occurrence of symptoms\\u000a and work. Skin test and immunological

Roy Gerth van Wijk

325

Intermediate skills and occupational mobility  

Microsoft Academic Search

’Intermediate occupations’ describes broadly the range of occupations below the rank of professional and management jobs and above the partly skilled and unskilled occupations and includes craft, technical and supervisory occupations. These are largely differentiated by the levels of education and skill required for entry, the supervisory and technical functions performed within them and the income and standing associated with

Peter Elias; John Bynner

1997-01-01

326

Secondary Health Occupations Education Curriculum.  

ERIC Educational Resources Information Center

This color coded curriculum guide for secondary health occupations in Iowa provides units for the first phase of the curriculum, career exploration of the health occupations. The nine units cover the following topics: (1) introduction to health occupations; (2) health occupations career exploration; (3) communication skills; (4) self-care and…

Matzen, Shelley; Muhl, V. Jane

327

Aerodynamic characteristics of a propeller powered high lift semispan wing  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted on the engine/airframe integration aerodynamics for potential high-lift aircraft configurations. The model consisted of a semispan wing with a double-isolated flap system and a Krueger leading edge device. The advanced propeller and the powered nacelle were tested and aerodynamic characteristics of the combined system are presented. It was found that the lift coefficient of the powered wing could be increased by the propeller slipstream when the rotational speed was increased and high-lift devices were deployed. Moving the nacelle/propeller closer to the wing in the vertical direction indicated higher lift augmentation than a shift in the longitudinal direction. A pitch-down nacelle inclination enhanced the lift performance of the system much better than vertical and horizontal variation of the nacelle locations and showed that the powered wing can sustain higher angles of attack near maximum lift performance.

Takallu, M. A.; Gentry, G. L., Jr.

1992-01-01

328

Determining safe limits for significant task parameters during manual lifting.  

PubMed

This experimental study investigated the effect of lifting task parameters (i.e., lifting weight, frequency, coupling, asymmetric angle, and vertical, horizontal, and travel distances) for various dynamic human lifting activities on the ground reaction forces of workers. Ten male workers loaded containers from different levels asymmetrically during experimental trials. The experimental design evolved using Taguchi's Fractional Factorial Experiments. Three factors (lifting weight, frequency, and vertical distance) were observed to be significant. The results showed that vertical reaction forces increase when workers lift weight from floor to shoulder height frequently. It was also observed that instantaneous loading rate increases with more weight, vertical distance, and frequency; a significant extra loading rate is required to change the lower level of load, frequency, and vertical distance to higher levels. Safe limits for significant factors were determined to result in optimal performance of the manual lifting task. PMID:24702682

Singh, Ravindra Pratrap; Batish, Ajay; Singh, Tejinder Pal

2014-04-01

329

Occupational cancer in Spain.  

PubMed

The knowledge of specific problems of occupational cancer in Spain is scarce. The environment of the workplace has improved over the last few years after a long period distinguished by bad working conditions, incomplete legislation, and insufficient safety measures and control. It has been estimated that 3,083,479 workers (25.4% of employees) were exposed to carcinogens. The most common occupational exposures to carcinogenic agents were solar radiation, environmental tobacco smoke, silica, and wood dust. The highest number of employees were exposed to silica crystalline (404,729), diesel engine exhaust (274,321), rubber products (99,804), benzene (89,932), ethylene dibromide (81,336), agents used in furniture and cabinet making (72,068), and formaldehyde (71,189). The percentage of total cancer deaths attributed to occupational exposure was 4% (6% in men, 0.9% in women). Compared with other European countries, the incidence of lung cancer and leukemia in Spain are one of the lowest, but it is rapidly increasing. The incidence of urinary bladder and larynx cancer, on the contrary, are one of the highest. Few studies on occupational cancer have been conducted in Spain. The main problems are the availability of death certificates and the quality of the information on occupation in mortality of statistics. It is necessary to improve methods of assessment of exposures using expert hygienists and biologic markers of exposure and diseases. Reduction of cancer by limiting or avoiding exposure to known occupational carcinogens is still necessary. PMID:10350510

González, C A; Agudo, A

1999-05-01

330

Occupational cancer in Spain.  

PubMed Central

The knowledge of specific problems of occupational cancer in Spain is scarce. The environment of the workplace has improved over the last few years after a long period distinguished by bad working conditions, incomplete legislation, and insufficient safety measures and control. It has been estimated that 3,083,479 workers (25.4% of employees) were exposed to carcinogens. The most common occupational exposures to carcinogenic agents were solar radiation, environmental tobacco smoke, silica, and wood dust. The highest number of employees were exposed to silica crystalline (404,729), diesel engine exhaust (274,321), rubber products (99,804), benzene (89,932), ethylene dibromide (81,336), agents used in furniture and cabinet making (72,068), and formaldehyde (71,189). The percentage of total cancer deaths attributed to occupational exposure was 4% (6% in men, 0.9% in women). Compared with other European countries, the incidence of lung cancer and leukemia in Spain are one of the lowest, but it is rapidly increasing. The incidence of urinary bladder and larynx cancer, on the contrary, are one of the highest. Few studies on occupational cancer have been conducted in Spain. The main problems are the availability of death certificates and the quality of the information on occupation in mortality of statistics. It is necessary to improve methods of assessment of exposures using expert hygienists and biologic markers of exposure and diseases. Reduction of cancer by limiting or avoiding exposure to known occupational carcinogens is still necessary.

Gonzalez, C A; Agudo, A

1999-01-01

331

The Lifting Body Legacy...X-33  

NASA Technical Reports Server (NTRS)

NASA has a technology program in place to enable the development of a next generation Reusable Launch Vehicle that will carry our future payloads into orbit at a much-reduced cost. The VentureStar, Lifting Body (LB) flight vehicle, is one of the potential reusable launch vehicle configurations being studied. A LB vehicle has no wings and derives its lift solely from the shape of its body, and has the unique advantages of superior volumetric efficiency, better aerodynamic efficiency at high angles-of-attack and hypersonic speeds, and reduced thermal protection system weight. Classically, in a ballistic vehicle, drag has been employed to control the level of deceleration in reentry. In the LB, lift enables the vehicle to decelerate at higher altitudes for the same velocity and defines the reentry corridor which includes a greater cross range. This paper outlines the flight stability and control aspects of our LB heritage which was utilized in the design of the VentureStar LB and its test version, the X-33. NASA and the U.S. Air Force have a rich heritage of LB vehicle design and flight experience. In the initial LB Program, eight LB's were built and over 225 LB test flights were conducted through 1975. Three LB series were most significant in the advancement of today's LB technolocy: the M2-F; the HL-10; and the X-24 series. The M2-F series was designed by NASA Ames Research Center, the HL-10 series by NASA Langley Research Center, and the X-24 series by the U. S. Air Force. LB vehicles are alive again today with the X- 33, X-38, and VentureStar.

Barret, Chris

1999-01-01

332

Occupational health in Brazil.  

PubMed

Brazil is a recently industrialised country with marked contrasts in social and economic development. The availability of public/private services in its different regions also varies. Health indicators follow these trends. Occupational health is a vast new field, as in other developing countries. Occupational medicine is a required subject in graduation courses for physicians. Specialisation courses for university graduated professionals have more than 700 hours of lectures and train occupational health physicians, safety engineers and nursing staff. At the technical level, there are courses with up to 1300 hours for the training of safety inspectors. Until 1986 about 19,000 occupational health physicians, 18,000 safety engineers and 51,000 safety inspectors had been officially registered. Although in its infancy, postgraduation has attracted professionals at university level, through residence programmes as well as masters and doctors degrees, whereby at least a hundred good-quality research studies have been produced so far. Occupational health activities are controlled by law. Undertakings with higher risks and larger number of employees are required to hire specialised technical staff. In 1995 the Ministry of Labour demanded programmes of medical control of occupational health (PCMSO) for every worker as well as a programme of prevention of environmental hazards (PPRA). This was considered as a positive measure for the improvement of working conditions and health at work. Physicians specialising in occupational medicine are the professionals more often hired by the enterprises. Reference centres (CRSTs) for workers' health are connected to the State or City Health Secretariat primary health care units. They exist in more populated areas and are accepted by workers as the best way to accomplish the diagnosis of occupational diseases. There is important participation by the trade unions in the management of these reference centres. For 30 years now employers organisations have also kept specialised services for safety and occupational health. Although they are better equipped they are less well used by the workers than the CRSTs. At the federal level, activities concerned with occupational health are connected to three ministries: Labour, Health and Social Security. The Ministry of Labour enacts legislation on hygiene, safety and occupational medicine, performs inspections through its regional units and runs a number of research projects. The Ministry of Health provides medical care for workers injured or affected by occupational diseases and also has surveillance programmes for certain occupational diseases. The Ministry of Social Security provides rehabilitation and compensation for registered workers. In spite of a decrease in the number of accidents at work during the past 25 years, working conditions have not improved. Changes in the laws of social security in the 1970s discouraged registration and reporting of occupational injuries and diseases. In consequence death rates due to accidents increased. With the implementation of the CRSTs, the recorded incidence of occupational diseases has risen, not only because of improved diagnosis, but also because of stronger pressure from the unions and better organisation of public services and enterprises. PMID:9342620

Bedrikow, B; Algranti, E; Buschinelli, J T; Morrone, L C

1997-01-01

333

HSR High Lift Program and PCD2 Update  

NASA Technical Reports Server (NTRS)

The mission of High-Lift Technology is to develop technology allowing the design of practical high lift concepts for the High-Speed Civil Transport (HSCT) in order to: 1) operate safely and efficiently; and 2) reduce terminal control area and community noise. In fulfilling this mission, close and continuous coordination will be maintained with other High-Speed Research (HSR) technology elements in order to support optimization of the overall airplane (rather than just the high lift system).

Kemmerly, Guy T.; Coen, Peter; Meredith, Paul; Clark, Roger; Hahne, Dave; Smith, Brian

1999-01-01

334

Optimization of Bilayer Lift-Off Resist Process  

Microsoft Academic Search

Bi-layer lift-off metallization techniques offer significant advantages in resolution, removal, process simplicity, undercut control and yield over conventional single-layer lift-off processes. Because of its ease of application, long shelf life and lower tool cost, the polydimethylglutarimide (PMGI) bi-layer process has become an attractive method for the metallization of III-V compound semiconductor devices. The LOR\\/PMGI bi- layer lifts-off cleanly when fabricating

Jeremy Golden; Harris Miller; Dan Nawrocki; Jack Ross

2009-01-01

335

29 CFR 570.54 - Forest fire fighting and forest fire prevention occupations, timber tract occupations, forestry...  

Code of Federal Regulations, 2013 CFR

...occupations, timber tract occupations, forestry service occupations, logging occupations...occupations, timber tract occupations, forestry service occupations, logging occupations...fire prevention, in timber tracts, in forestry services, logging, and the...

2013-07-01

336

On causality in commutant lifting theorem. I  

Microsoft Academic Search

Two functionals µ(A) and\\u000a$$\\\\bar \\\\mu (A)$$\\u000a for an operatorA were introduced in [11] for the study of causality in commutant lifting theory. In this paper we give sufficient and necessary conditions for\\u000a$$\\\\mu (A) = \\\\bar \\\\mu (A)$$\\u000a in a special case. We prove that in this case\\u000a$$\\\\bar \\\\mu (A) \\\\leqslant \\\\sqrt 2 \\\\mu (A)$$\\u000a, and we

Caixing Gu

1993-01-01

337

Simulation of powered-lift flows  

NASA Technical Reports Server (NTRS)

The primary objective is to expose government, industry, and academic scientists to work underway at NASA-Ames towards the application of CFD to the powered lift area. One goal is to produce the technologies which will be required in the application of numerical techniques to, for example, the Supersonic STOVL program. The progress to date on the following specific projects is presented: Jet in ground effect with crossflow; Jet in a crossflow; Delta planform with multiple jets in ground effect; Integration of CFD with thermal and acoustic analyses; Improved flow visualization techniques for unsteady flows; YAV-8B Harrier simulation program; and E-7 simulation program.

Vandalsem, William R.; Chawla, Kalpana; Roth, Karlin R.; Smith, Merritt H.; Rao, Kuditipudi V.; Blum, Thomas C.

1989-01-01

338

Endeavor's First Lift Off for STS-49  

NASA Technical Reports Server (NTRS)

STS-49, the first flight of the Space Shuttle Orbiter Endeavour, lifted off from launch pad 39B on May 7, 1992 at 6:40 pm CDT. The STS-49 mission was the first U.S. orbital flight to feature 4 extravehicular activities (EVAs), and the first flight to involve 3 crew members working simultaneously outside of the spacecraft. The primary objective was the capture and redeployment of the INTELSAT VI (F-3) which was stranded in an unusable orbit since its launch aboard the Titan rocket in March 1990.

1992-01-01

339

Psychiatrists' Perceptions of Occupational Therapy  

Microsoft Academic Search

Objective: This study investigated the relationship of psychiatrists' knowledge about occupational therapy and the number of referrals to occupational therapy.Method: Thirty-four psychiatrists in the Omaha area were surveyed about their knowledge of occupational therapy and the number of referrals they write for occupational therapy services.Results: A positive relationship was found between the lack of knowledge regarding occupational therapy and the

Jessica Schnoes Pottebaum; Amy Svinarich

2005-01-01

340

Lift Fan Nozzle for Joint Strike Fighter Tested in NASA Lewis' Powered Lift Rig  

NASA Technical Reports Server (NTRS)

Under a nonreimbursable space act agreement between the NASA Lewis Research Center and the Allison Advanced Development Company, Allison tested a lift fan nozzle in Lewis' Powered Lift Rig. This test was in support of the Joint Strike Fighter program (formerly the Joint Advanced Strike Technology) sponsored by the Department of Defense, which will develop and field an affordable, multirole, next-generation, strike fighter aircraft for the Navy, Air Force, Marine Corps, and foreign allies. Allison, along with Pratt & Whitney Company, is part of the Lockheed Martin Corporation team that is scheduled to build a concept demonstrator aircraft by fiscal year 2001. The test was initiated in April and successfully completed in mid-July of 1997. Allison supplied a one-third-scale model of the lift fan nozzle, and Lewis provided the facility and the necessary support team. Various configurations, including pitching vectored angles ranging from 15deg forward to 60deg backward, were tested over a range of nozzle pressure ratios. Nozzle flow rates, thrust, and static pressures were measured for each of the configurations. Results from the test met the design requirements for the Joint Strike Fighter program and were in agreement with Allison's internal computational fluid dynamics (CFD) analyses. Data obtained from this test will also be used in the full-scale design of the lift fan system.

Lam, David W.

1998-01-01

341

High-lift aerodynamics: Trends, trades, and options  

NASA Technical Reports Server (NTRS)

The trend toward the utilization of higher maximum lift coefficient with increased aircraft size and cruise velocities is discussed. The impact of this trend on the need for tradeoffs between cruise performance and takeoff, climb, and landing performance is examined. Theoretical methods for the analysis of the two-dimensional characteristics of flap systems are described and compared with experimental data. Four powered-lift concepts are described to outline some of the options currently being developed. Two jet-flap theories are described which provide analytical methods for estimation of the three-dimensional aerodynamic high-lift performance characteristics of powered lift systems.

Margason, R. J.; Morgan, H. L., Jr.

1975-01-01

342

An experimental study of a three lifting surface configuration  

NASA Technical Reports Server (NTRS)

The aerodynamic ramifications of utilizing three lifting surfaces as opposed to the conventional or canard lifting configurations have been studied on a theoretical basis by previous researchers. This paper presents an experimental investigation of various configuration modifications for an unyawed typical business jet at a Reynolds number of 1.3 million. The three surface has better lift and high-lift drag characteristics than either the canard or tail-aft configurations, but the cruise drag is more. The induced drag at cruise is highest for the canard and lowest for the tail-aft configuration. The pitching moment characteristics are somewhat between those of the canard and tail-aft configurations. A decrease in gap adversely affects the pitching moment characteristics. A smaller stagger leads to better aerodynamic and stability characteristics. A decrease in span of the forward wing gives better cruise drag and longitudinal stability characteristics, but has adverse effects on high-lift drag. A variation in the incidence angles of either or both the forward and aft wings changes the zero-lift moments of the configuration, while marginally affecting overall lift and drag. At cruise, the lift to drag ratio is highest for the conventional and lowest for the three surface. For high lift conditions, the order is reversed.

Ostowari, C.; Naik, D.

1986-01-01

343

Boundary Layer Relaminarization and High-Lift Aerodynamics  

NASA Astrophysics Data System (ADS)

Modern high-lift devices are complicated systems that exhibit a variety of complex flow physics phenomena. Thomas( Thomas, F.O., Liu, X., & Nelson, R.C., 1997, ``Experimental Investigation of the Confluent Boundary Layer of a High-Lift System,'' AIAA Paper 97-1934.) outlines several critical flow phenomena, dubbed ``high-lift building block flows'', that can be found in a typical multi-element high-lift system. One such high-lift building block flow is turbulent boundary layer relaminarization, which may be responsible for such phenomena as ``inverse Reynolds number effects.'' Flight test experiments on leading edge transition and relaminarization conducted by Yip, et al(Yip, et al), ``The NASA B737-100 High-Lift Flight Research Program--Measurements and Computations,'' Aeronautical Journal, Paper No. 2125, Nov. 1995. using the NASA Transport Systems Research Vehicle, a Boeing 737-100, have provided tantalizing evidence but not proof of the existence of relaminarization in high-lift systems. To investigate the possibility of boundary layer relaminarization occuring on a high-lift system, a joint wind tunnel/flight test program is in progress with the NASA Dryden Flight Research Center to determine the role, if any, that turbulent boundary layer relaminarization plays in high-lift aerodynamics. Sponsored under NASA grant No. NAG4-123

Bourassa, Corey; Thomas, Flint O.; Nelson, Robert C.

1998-11-01

344

Sectional lift coefficient of a flapping wing in hovering motion  

NASA Astrophysics Data System (ADS)

We investigate the behavior of sectional lift coefficient of a flapping wing of a fruit-fly in hovering motion. Through three-dimensional numerical simulations, we show that during the stroke, the sectional lift coefficient significantly varies in time as well as in the spanwise direction owing to complex interactions between the wing and vortices in the wake. However, the time-averaged sectional lift force coefficient is inversely proportional to the spanwise distance from the rotation center except very near the wing-tip region. This is because the wing-tip vortex significantly decreases the lift force on the wing-tip region during and after midstroke.

Kweon, Jihoon; Choi, Haecheon

2010-07-01

345

An accelerometer balance for the measurement of roll, lift and drag on a lifting model in a shock tunnel  

Microsoft Academic Search

A force balance to measure roll, lift and drag on a lifting aerodynamic body in an ultrashort-duration hypersonic test facility, such as a shock tunnel, has been developed and tested on a flapped, blunt-nosed, triangular lifting body at a freestream Mach number of 8. The flow total enthalpy and the freestream unit Reynolds number were 0.83 MJ kg-1 and 0.98

Viren Menezes; Sharad Trivedi; Abhinav Kumar

2011-01-01

346

Modification of integrated partial payload lifting assembly  

NASA Technical Reports Server (NTRS)

The Integrated Partial Payload Lifting Assembly (IPPLA) is currently used to transport and load experimental payloads into the cargo bay of the Space Shuttle. It is unable to carry the astronaut/passenger tunnel without a structural modification. The purpose of this design is to create a removalbe modification that will allow the IPPLA to lift and carry the passenger tunnel. Modifications evaluated were full-length insert beams which would extend through the existing strongback arms. These beam proposals were eliminated because of high cost and weight. Other proposals evaluated were attachments of cantilever beams to the existing strongback areas. The cantilever proposals reduced cost and weight compared to the full-length modifications. A third method evaluated was to simply make modifications to one side of the IPPLA therefore reducing the materials of the cantilever proposals by 40 percent. The design of the modification selected was completed with two channel beams jointly welded to a centered steel plate. The extension arm modification is inserted into the existing strongback channel beams and bolted into place. Two extension arms are added to one side of the IPPLA to provide the extra length needed to accommodate the passenger tunnel. The center counterbalance will then be offset about 20 inches to center gravity and therefore maintain horizontal status. The extension arm modification was selected because of minimum cost, low weight, and minimal installation time.

Groah, Melodie; Haddock, Michael; Woodworth, Warren

1986-01-01

347

Lifting Mechanism for the Mars Explorer Rover  

NASA Technical Reports Server (NTRS)

A report discusses the design of a rover lift mechanism (RLM) -- a major subsystem of each of the Mars Exploration Rover vehicles, which were landed on Mars in January 2004. The RLM had to satisfy requirements to (1) be foldable as part of an extremely dense packing arrangement and (2) be capable of unfolding itself in a complex, multistep process for disengaging the rover from its restraints in the lander, lifting the main body of the rover off its landing platform, and placing the rover wheels on the platform in preparation for driving the rover off the platform. There was also an overriding requirement to minimize the overall mass of the rover and lander. To satisfy the combination of these and other requirements, it was necessary to formulate an extremely complex design that integrated components and functions of the RLM with those of a rocker-bogie suspension system, the aspects of which have been described in several prior NASA Tech Briefs articles. In this design, suspension components also serve as parts of a 4- bar linkage in the RLM.

Melko, Joseph; Iskenderian, Theodore; Harrington, Brian; Voorhees, Christopher

2005-01-01

348

Lift Every Voice: Music in American Life  

NSDL National Science Digital Library

The University of Virginia Library is hosting a special exhibition called Lift Every Voice, named after a hymn composed by two African-American brothers in the days of the Jim Crow South and aiming to inspire the struggle for equal rights. The Lift Every Voice exhibition commemorates and celebrates a variety of songs that were a part of everyday American life through the centuries. No time to visit Virginia? Then visit the exhibition's Website and enjoy reading about the history behind our country's ballads, hymns, patriotic anthems, minstrels, musicals, and protest songs while listening to audio clips of selected songs (QuickTime, MP3). The text is enriched by digital images of historical papers, compiled by Virginia's Albert H. Small Special Collections Library, including musical scores, photos of musicians, and printed lyrics. The site also contains a section on Thomas Jefferson's relationship to music in the Old South, with digital images of texts from Jefferson's library and, of course, a sample of "Carry Me Back to Old Virginny."

2001-01-01

349

Lift-based paddling in diving grebe.  

PubMed

To examine the hydrodynamic propulsion mechanism of a diving great crested grebe (Podiceps cristatus), the three-dimensional kinematics was determined by digital analysis of sequential video images of dorsal and lateral views. During the acceleration phase of this foot-propelled bird, the feet move through an arc in a plane nearly normal to the bird's line of motion through the water, i.e. the toes move dorsally and medially but not caudally relative to the water. The kinematics of the grebe's lobed feet is different from that in anseriforms, whose feet move in a plane mostly parallel to the bird's line of progress through the water. Our results suggest that the foot-propelled locomotor mechanism of grebes is based primarily on a lift-producing leg and foot stroke, in contrast to the drag-based locomotion assumed previously. We suggest that the lift-based paddling of grebes considerably increases both maximum swimming speed and energetic efficiency over drag-based propulsion. Furthermore, the results implicate a new interpretation of the functional morphology of these birds, with the toes serving as a self-stabilizing multi-slotted hydrofoil during the power phase. PMID:11316488

Johansson, L C; Lindhe Norberg, U M

2001-05-01

350

Use of mechanical patient lifts decreased musculoskeletal symptoms and injuries among health care workers  

PubMed Central

Objective: To evaluate the effectiveness of mechanical patient lifts in reducing musculoskeletal symptoms, injuries, lost workday injuries, and workers' compensation costs in workers at a community hospital. Design: Pre-post intervention study. Setting: Three nursing units of a small community hospital. Patients or subjects: Nursing personnel. Interventions: Mechanical patient lifts were made available and nursing staff trained in their use between August 2000 and January 2001. Main outcome measures: Workers completed symptom surveys at baseline and six months after lift training. Pre-intervention and post-intervention rates of injuries and lost workday injuries using Occupational Safety and Health Administration logs of the three study units, from the period July 1999 through March 2003 were analyzed. Injuries potentially related to lifting patients were included in the analyses. Using workers' compensation data from the same time period, the compensation paid ($ per full time equivalent [FTE]) due to injuries during the pre-intervention and post-intervention period was calculated. Results: Sixty one staff members were surveyed pre-intervention; 36 (59%) completed follow up surveys. Statistically significant improvements in musculoskeletal comfort (p<0.05) were reported for all body parts, including shoulders, lower back, and knees. Injury rates decreased post-intervention, with a relative risk (RR) of 0.37 (95% confidence interval (CI) 0.16 to 0.88); decreased injury rates persisted after adjustment for temporal trends in injury rates on non-intervention units of the study hospital (RR = 0.50, 95% CI 0.20 to 1.26). Adjusted lost day injury rates also decreased (RR = 0.35, 95% CI 0.10 to 1.16). Annual workers' compensation costs averaged $484 per FTE pre-intervention and $151 per FTE post-intervention. Conclusion: Reductions were observed in injury rates, lost workday injury rates, workers' compensation costs, and musculoskeletal symptoms after deployment of mechanical patient lifts. Strengths of this study include the community hospital setting and the inclusion of a variety of different outcomes. Limitations include the pre-post study design and the small sample size.

Li, J; Wolf, L; Evanoff, B

2004-01-01

351

Manual materials handling in mining: the effect of rod heights and foot positions when lifting "in-the-hole" drill rods.  

PubMed

There is a paucity of studies focusing on the lifting of rods or long awkward heavy objects. In-the-hole (ITH) drilling is a heavy repetitive mining task, which has been identified as having a relatively high incidence and severity rate of musculoskeletal injuries. The purpose of this study was to examine how the load experienced by ITH drill operators changed when lifting a vertical drilling rod (1.61m, 35kg) using two rod heights and four different foot positions. In addition, a symmetrical lift with a lifting index (LI) of 1.4 also served as a comparison to determine possible risk of low back injury. Eleven experienced ITH drill operators participated in the study. Each subject was required to lift a vertical drilling rod until the upper body was in an erect posture using four different foot positions (0 degrees =subject facing the rod, 45 degrees =subject oblique to the rod, 90 degrees =subject right side to the rod and freestyle). In addition, two rod height conditions were studied where the base of the vertical rod was supported either (1) at ground level (height of rod CG=0.83m) or (2) on a 20cm rack (height of rod CG=1.03m). Finally, each subject lifted a 21.5kg box in the sagittal plane, which corresponded to an LI of 1.4 in the NIOSH lifting equation. Reflective markers were placed on the subjects, and three video cameras and one force plate were used to record the forces and the motion of the subjects' segments. Two surface electrodes were applied on the right and the left erector spinae (ES) at the level of L3. Back loading was defined by the level of the peak moments, the mechanical work and erector spinae muscle activity (EMG). It was found that the vertical height of the rod had the most significant impact on back loading, while the effect of the initial foot positioning relative to the rod was limited by the technique adopted by the drillers. Moreover, it was found that some of the subjects used techniques less strenuous for the back than others. Finally, the asymmetrical lifting component was found to be the most negative aspect of lifting an ITH drill rod compared to a standard symmetrical lift (NIOSH). PMID:16545338

Plamondon, André; Delisle, Alain; Trimble, Karin; Desjardins, Pierre; Rickwood, Trevor

2006-11-01

352

High-Lift Systems on Commercial Subsonic Airliners  

NASA Technical Reports Server (NTRS)

The early breed of slow commercial airliners did not require high-lift systems because their wing loadings were low and their speed ratios between cruise and low speed (takeoff and landing) were about 2:1. However, even in those days the benefit of high-lift devices was recognized. Simple trailing-edge flaps were in use, not so much to reduce landing speeds, but to provide better glide-slope control without sideslipping the airplane and to improve pilot vision over the nose by reducing attitude during low-speed flight. As commercial-airplane cruise speeds increased with the development of more powerful engines, wing loadings increased and a real need for high-lift devices emerged to keep takeoff and landing speeds within reasonable limits. The high-lift devices of that era were generally trailing-edge flaps. When jet engines matured sufficiently in military service and were introduced commercially, airplane speed capability had to be increased to best take advantage of jet engine characteristics. This speed increase was accomplished by introducing the wing sweep and by further increasing wing loading. Whereas increased wing loading called for higher lift coefficients at low speeds, wing sweep actually decreased wing lift at low speeds. Takeoff and landing speeds increased on early jet airplanes, and, as a consequence, runways worldwide had to be lengthened. There are economical limits to the length of runways; there are safety limits to takeoff and landing speeds; and there are speed limits for tires. So, in order to hold takeoff and landing speeds within reasonable limits, more powerful high-lift devices were required. Wing trailing-edge devices evolved from plain flaps to Fowler flaps with single, double, and even triple slots. Wing leading edges evolved from fixed leading edges to a simple Krueger flap, and from fixed, slotted leading edges to two- and three-position slats and variable-camber (VC) Krueger flaps. The complexity of high-lift systems probably peaked on the Boeing 747, which has a VC Krueger flap and triple-slotted, inboard and outboard trailing-edge flaps. Since then, the tendency in high-lift system development has been to achieve high levels of lift with simpler devices in order to reduce fleet acquisition and maintenance costs. The intent of this paper is to: (1) review available high-lift devices, their functions, and design criteria; (2) appraise high-lift systems presently in service on commercial air liners; (3) present personal study results on high-lift systems; (4) develop a weight and cost model for high-lift systems; and (5) discuss the development tendencies of future high-lift systems.

Rudolph, Peter K. C.

1996-01-01

353

Occupation and gastric cancer  

PubMed Central

Gastric cancer is a cause of significant morbidity and mortality. There are several risk factors, with occupation emerging as one of these. There is considerable evidence that occupations in coal and tin mining, metal processing, particularly steel and iron, and rubber manufacturing industries lead to an increased risk of gastric cancer. Other "dusty" occupations—for example, wood processing, or work in high temperature environments have also been implicated but the evidence is not strong. The mechanism of pathogenesis of gastric cancer is unclear and the identification of causative agents can be difficult. Dust is thought to be a contributor to the pathological process, but well known carcinogens such as N-nitroso compounds have been detected in some environments. Further research on responsible agents is necessary and screening for detection of precursor gastric cancer lesions at the workplace merits consideration.

Raj, A; Mayberry, J; Podas, T

2003-01-01

354

662-E solid waste silo-plug lifting analysis  

Microsoft Academic Search

The Intermediate Level Tritium Vault No. 1, 662-E, Cell No. 1 contains 140 waste silos. Each silo is approximately 25 feet deep, 30 inches in diameter at the top and covered by a reinforced concrete plug. Two No. 4 reinforcing bars project from the top of each plug for lifting. During lifting operations, the 1.5 inch concrete cover over the

Mertz

1993-01-01

355

Lighter-Than-Air System Enhanced with Kinetic Lift.  

National Technical Information Service (NTIS)

A hybrid airship system is proposed in which the buoyant lift is enhanced with kinetic lift. The airship would consist of twin hulls in which the buoyant gas is contained. The twin hulls would be connected in parallel by a wing having an airfoil contour. ...

M. L. Spearman

2002-01-01

356

Lifting surface theory for a helicopter rotor in forward flight  

NASA Technical Reports Server (NTRS)

A lifting surface theory has been developed for a helicopter rotor in forward flight for incompressible flow. The method utilized the concept of the linearized acceleration potential and make use of the vortex lattice procedures. Results in terms of lift coefficient slope for several forward flight conditions are given.

Runyan, H. L.; Tai, H.

1983-01-01

357

Structural Assessment of Steel Waste Disposal Box Lifting Yoke  

SciTech Connect

Prepare a detailed structural analysis of the steel waste disposal box lifting yoke, sufficient to comply with the Hanford Site Hoisting & Rigging Manual (DOE/RL-92-36) Section II and the American National Standard for Below-the-Hook Lifting Devices.

NORTHEY, M.D.

2001-12-14

358

Weighted Adaptive Lifting-Based Wavelet Transform for Image Coding  

Microsoft Academic Search

In this paper, a new weighted adaptive lifting (WAL)-based wavelet transform is presented. The proposed WAL approach is designed to solve the problems existing in the previous adaptive directional lifting (ADL) approach, such as mismatch between the predict and update steps, interpolation favoring only horizontal or vertical direction, and invariant interpolation filter coefficients for all images. The main contribution of

Yu Liu; King Ngi Ngan

2008-01-01

359

Growth hormone responses during intermittent weight lifting exercise in men  

Microsoft Academic Search

Summary  Five normal male volunteers performed two intermittent weight lifting exercises of equal total external work output and duration (20 min) with identical work-rest intervals but different load and frequency of movements. Exercise I consisted of seven sets of seven vertical leg lifts at 85% of the subject's Seven Repetition Maximum (SRM) and, 5 days later, seven sets of 21 vertical

W. P. Vanhelder; M. W. Radomski; R. C. Goode

1984-01-01

360

Physiological responses to weight lifting in different planes  

Microsoft Academic Search

A weight of 10 kg was lifted by 11 normal male volunteers (mean age 34·2 years) from ground to knee, hip, and shoulder levels in the sagittal, lateral and oblique planes. During these lifting manoeuvres intra-abdominal pressure was measured by telemetry and the activity of erector spinae and external oblique were recorded by electromyography. The values obtained for peak and

S. KUMAR

1980-01-01

361

THE LIFTING SCHEME: A CONSTRUCTION OF SECOND GENERATION WAVELETS  

Microsoft Academic Search

We present the lifting scheme, a simple construction of second generation wavelets; these are wavelets that are not necessarily translates and dilates of one fixed function. Such wavelets can be adapted to intervals, domains, surfaces, weights, and irregular samples. We show how the lifting scheme leads to a faster, in-place calculation of the wavelet transform. Several examples are included.

WIM SWELDENS

1997-01-01

362

THE LIFTING SCHEME: A CONSTRUCTION OF SECOND GENERATION WAVELETS  

Microsoft Academic Search

We present the lifting scheme, a simple construction of second generation wavelets; these are wavelets that are not necessarily translates and dilates of one xed function. Such wavelets can be adapted to intervals, domains, surfaces, weights, and irregular samples. We show how the lifting scheme leads to a faster, in-place calculation of the wavelet transform. Several examples are included.

363

Design of IIR orthogonal wavelet filter banks using lifting scheme  

Microsoft Academic Search

Abstract—The lifting scheme is well known to be an efficient tool for constructing second generation wavelets and is often used to design a class of biorthogonal wavelet filter banks. For its efficiency, the lifting implementation has been adopted in the international standard JPEG2000. It is known that the orthogonality of wavelets is an important property for many applications. This paper

Xi Zhang; Wei Wang; Toshinori Yoshikawa; Yoshinori Takei

2006-01-01

364

Segmented computation of wavelet transform via lifting scheme  

Microsoft Academic Search

This paper presents a novel algorithm for segmented (segmentwise) computation of forward and inverse wavelet trans- form via a lifting scheme, applicable to any type of a lifting scheme representation of wavelets. The main idea is to process segments taken from a long one-dimensional signal so that after reconstruction, no border distortion between segments occurs. This is achieved by means

Zdenek Prusa; Pavel Rajmic

2011-01-01

365

Reconfigurable architecture for lifting based discrete wavelet transform  

Microsoft Academic Search

In this paper a novel reconfigurable hardware accelerator for the lifting scheme algorithm is presented. The design is pipelined, scalable and can be easily configured for use of different filter. The lifting scheme has gained a special interest for efficient computation of the Discrete Wavelet Transform (DWT). The reconfigurability of hardware architectures has been a key word to meet different

Hazem H. Ali; Ahmed S. AbdelGader; R. F. Abdou

2004-01-01

366

Single Parameter Lifting Scheme for Custom Design of  

Microsoft Academic Search

For the case of real finite filters we investigate a parameterised form of the lifting scheme containing a single parameter. We show that the scheme generates biorthogonal filter banks having associated wavelets in provided the parameter lies in an open interval containing zero and develop an algorithm for finding the largest such interval. In conjunction with the lifting scheme, the

P. F. Curran; G. McDarby

367

Optimization of the lithographic performance for lift-off processing  

NASA Astrophysics Data System (ADS)

Shipley MICROPOSIT LOL lift-off technology exploits a develop rate difference in a resist, LOL1000 bi-layer system to generate retrograde profiles. This is an enabling technology for 'additive' processing. Deposition follows lithography and the resist is then 'lifted off' to generate a patterned layer.

Yin, Wenyan; Fillmore, Ward; Dempsey, Kevin J.

1999-05-01

368

Barbell-Lifting Based 3-D Wavelet Coding Scheme  

Microsoft Academic Search

This paper provides an overview of the Barbell lifting coding scheme that has been adopted as common software by the MPEG ad hoc group on further exploration of wavelet video coding. The core techniques used in this scheme, such as Barbell lifting, layered motion coding, 3D entropy coding and base layer embedding, are discussed. The paper also analyzes and compares

Ruiqin Xiong; Jizheng Xu; Feng Wu; Shipeng Li

2007-01-01

369

Insect Flight: Lift and Rate of Change of Incidence  

Microsoft Academic Search

Large changes in lift output result when a simulated insect wing, undergoing a downstroke, is subjected to a dynamic change of incidence. Given a large positive rate of change of incidence, transient lift values several times those realized in steady-state operation at the same angle of incidence are obtained. Thus a means exists by which insects achieve several times the

Leon Bennett

1970-01-01

370

The mechanisms of lift enhancement in insect flight  

Microsoft Academic Search

Recent studies have revealed a diverse array of fluid dynamic phenomena that enhance lift production during flapping insect flight. Physical and analytical models of oscillating wings have demonstrated that a prominent vortex attached to the wing’s leading edge augments lift production throughout the translational parts of the stroke cycle, whereas aerodynamic circulation due to wing rotation, and possibly momentum transfer

Fritz-Olaf Lehmann

2004-01-01

371

Weight Lifting and Aortic Dissection: More Evidence for a Connection  

Microsoft Academic Search

Background\\/Aims: In 2003, we reported on a small number of patients in whom acute aortic dissection appeared to be causally related to intense weight lifting. If additional cases could be identified, the phenomenon of weight lifting induced aortic dissection would be further substantiated. We now report a substantially larger number of cases in which aortic dissection is associated with intense

I. Hatzaras; M. Tranquilli; M. Coady; P. M. Barrett; J. Bible; J. A. Elefteriades

2007-01-01

372

34. ALTERNATE DESIGN USING BATTERED AND UNSHEATHED LIFT TOWERS, WITH ...  

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

34. ALTERNATE DESIGN USING BATTERED AND UNSHEATHED LIFT TOWERS, WITH DEEPENED TRUSS ON LIFT SPAN. Pen-and-ink drawing by project architect Alfred Eichler, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

373

49 CFR 178.1050 - Top lift test.  

Code of Federal Regulations, 2013 CFR

...Suspend the Flexible Bulk Container by its lifting devices. (iii) Apply a constant...maximum of 80 percent of the cross sectional surface area of the Flexible Bulk Container...to the Flexible Bulk Container or its lifting devices that renders the Flexible...

2013-10-01

374

Lifting Safety: Tips To Help Prevent Back Injuries  

MedlinePLUS

... safely. Clear a space around the object before lifting it. Look around before you lift, and look around as you carry. Make sure you can see where you are walking. Know where you are going to put down the load. Avoid walking on slippery, uneven surfaces while carrying something. Don't rely on a ...

375

Solid state lift for micrometering in a fuel injector  

DOEpatents

A fuel injector performs main fuel injection by raising fuel pressure in a nozzle chamber to lift a check valve member to a fully open position, and performs preinjection or microinjection by operating a solid state motor to lift the check valve member a much smaller distance.

Milam, David M. (Metamora, IL); Carroll, Thomas S. (Peoria, IL); Lee, Chien-Chang (Rochester Hills, MI); Miller, Charles R. (Metamora, IL)

2002-01-01

376

A lifting line theory for a three-dimensional hydrofoil  

NASA Astrophysics Data System (ADS)

Prandtl's lifting line theory was generalized to the lifting problem of a three-dimensional hydrofoil in the presence of a free surface. Similar to the classical lifting theory, the singularity distribution method was utilized to solve two-dimensional lifting problems for the hydrofoil beneath the free surface at the air-water interface, and a lifting line theory was developed to correct three-dimensional effects of the hydrofoil with a large aspect ratio. Differing from the classical lifting theory, the main focus was on finding the three-dimensional Green function of the free surface induced by the steady motion of a system of horseshoe vortices under the free surface. Finally, numerical examples were given to show the relationship between the lift coefficient and submergence Froude numbers for 2-D and 3-D hydrofoils. If the submergence Froude number is small free surface effect will be significant registered as the increase of lift coefficient. The validity of these approaches was examined in comparison with the results calculated by other methods.

Liang, Hui; Zong, Zhi

2011-06-01

377

Occupational health in the Negev: A model for regional planning  

SciTech Connect

In the Negev region of Israel, I tested a model approach to occupational health planning. This model included components assessing exposures, measuring adverse health outcomes, and evaluating health services. I analyzed employment survey data, compiled an exposure data base, and carried out site visits covering 10,707 employees (over 50% of the regional industrial work force). Site visits identified exposure hazards of inorganic and organic dusts, heavy metals, chemicals, pesticides, and noise. I identified elevated relative regional injury rates by Standard Morbidity Ratios (SMRs) in a variety of industries, including sixfold increases for mining and non-metallic minerals manufacture (SMR 6.8, 99% CI 6.1-7.7). Review of biological monitoring data suggested deficiencies in pesticide and heavy metals surveillance. A survey of primary care clinics estimated 13,707 cases of occupational injury and illness untreated by existing occupational medical services. Based on these findings, I formulated regional occupational health planning goals, including targeting high-risk industries for increased preventive activities. This regional approach, combining multiple measures of occupational health status, can serve as a model for assessing local public health planning needs.

Blanc, P.D. (Ben Gurion Univ. of the Negev, Beer Sheva (Israel))

1989-01-01

378

[Occupational allergies to bromelain].  

PubMed

The protease bromelain originating from the pineapple fruit (Ananas comosus) finds frequent use in industry. Exposure to enzyme dusts has long been known to cause occupational allergies. The present paper reviews the results of the evaluation of literature data concerning occupational airway sensitization due to bromelain. Cases of specific airway sensitization caused by bromelain could be shown clearly by the presented studies. Since the symptoms, results of skin prick tests, detection of specific IgE antibodies and results of specific bronchoprovocation tests are consistent, an immunological mechanism can be assumed. PMID:17342576

van Kampen, V; Merget, R; Brüning, T

2007-03-01

379

Occupational Contact Dermatitis  

PubMed Central

Occupational contact dermatitis accounts for 90% of all cases of work-related cutaneous disorders. It can be divided into irritant contact dermatitis, which occurs in 80% of cases, and allergic contact dermatitis. In most cases, both types will present as eczematous lesions on exposed parts of the body, notably the hands. Accurate diagnosis relies on meticulous history taking, thorough physical examination, careful reading of Material Safety Data Sheets to distinguish between irritants and allergens, and comprehensive patch testing to confirm or rule out allergic sensitization. This article reviews the pathogenesis and clinical manifestations of occupational contact dermatitis and provides diagnostic guidelines and a rational approach to management of these often frustrating cases.

2008-01-01

380

Effects of a Belt on Intra-Abdominal Pressure during Weight Lifting.  

National Technical Information Service (NTIS)

Intra-abdominal pressure (IAP) has been widely hypothesized to reduce potentially injurious compressive forces on spinal discs during lifting. To investigate the effects of a standard lifting belt on IAP and lifting mechanics, IAP and vertical ground reac...

E. A. Harman R. M. Rosenstein P. N. Frykman G. A. Nigro

1988-01-01

381

Correlation of Puma airloads: Lifting-line and wake calculation  

NASA Technical Reports Server (NTRS)

A cooperative program undertaken by organizations in the United States, England, France, and Australia has assessed the strengths and weaknesses of four lifting-line/wake methods and three CFD methods by comparing their predictions with the data obtained in flight trials of a research Puma. The Puma was tested in two configurations: a mixed bladed rotor with instrumented rectangular tip blades, and a configuration with four identical swept tip blades. The results are examined of the lifting-line predictions. The better lifting-line methods show good agreement with lift at the blade tip for the configuration with four swept tips; the moment is well predicted at 0.92 R, but deteriorates outboard. The predictions for the mixed bladed rotor configuration range from fair to good. The lift prediction is better for the swept tip blade than for the rectangular tip blade, but the reasons for this cannot be determined because of the unmodeled effects of the mixed bladed rotor.

Bousman, William G.; Young, Colin; Gilbert, Neil; Toulmay, Francois; Johnson, Wayne; Riley, M. J.

1989-01-01

382

Multiplane face lift with the subperiosteal dissection for orientals.  

PubMed

A subperiosteal face lift rejuvenates the midface and periorbital region by restoring facial muscle tone. Since 1993, the authors have performed this procedure on Oriental patients who have their own distinct facial contours: the brachycephalic cranium and a prominent zygoma and mandibular angle. Although it was thought that these protuberances might disturb the subperiosteal procedure, especially in the anterior midface, the procedure could be performed easily by adopting the ancillary upper buccovestibular and subciliary incisions; the authors found that the protuberances actually act as fulcrums to keep up the lifting vectors reliably. For older patients, the procedure was combined with a deep subcutaneous dissection. A simple lift of the periosteum would not improve a severe nasolabial fold deformity and prominent wrinkles adequately because of "lag-lifting" of the superficial layer. It was concluded that the multiplane face lift, consisting of the subperiosteal and the deep subcutaneous approaches, achieves a natural-appearing rejuvenation of the Oriental aging face. PMID:10597702

Lee, Y; Hong, J J

1999-07-01

383

Lift-off parameters of saltating particles on Mars  

NASA Astrophysics Data System (ADS)

The aeolian events are frequent on Mars. However, we have very limited understanding of aeolian process, because we cannot conduct experiments, as we did on Earth, on martian surface directly right now. In this paper, we studied the lift-off parameters of saltating particles in wind-blown sand on Mars systematically through a numerical way. The main findings are shown as follows: (1) the lift-off speeds of martian particles increase linearly with wind shear velocities; (2) the lift-off speeds of particles on Mars have the same order of magnitude as but a little smaller than those on Earth at the same shear velocity; (3) the lift-off angles on Mars are almost equal to those on Earth and have weak dependence on shear velocities; (4) the lift-off parameters (both speeds and angles) are influenced by particle diameters.

Fu, Lin-Tao; Bo, Tian-Li; Zheng, Xiao-Jing

2014-05-01

384

Offshore desulfurization unit permits gas lift operations  

SciTech Connect

This paper reports on the installation of a desulfurization unit for the Tchibouela oil field, offshore Congo, which allowed produced low-pressure associated gas containing CO{sub 2} to be kept for gas lift operations while, for safety reasons, the large volume of H{sub 2}S at low pressure was removed prior to compression. Since October 1989, the world's first offshore amine sweetening unit has worked satisfactorily and continues to prove that it is an attractive production alternative. For desulfurization, a selective methyldiethanolamine (MDEA) process, developed by Elf Aquitaine, was chosen because it was the only process that met the required specifications at a low pressure of 3.5 bar (51 psi).

Cabes, A.; Elgue, J.; Tournier-Lasserve, J. (Societe Nationale Elf Aquitaine Paris (FR))

1992-01-13

385

Aerothermochemistry Testing for Lifting Reentry Vehicles  

NASA Astrophysics Data System (ADS)

Dedicated ground testing is a fundamental requirement for TPS design since nowadays spacecraft, which have stringent mass budget, need more and more precise and specific testing conditions. Plasma wind tunnels are commonly used for the suitable dissociated flow environments they provide for stagnation point testing. This paper explores the capabilities that such facilities could offer also for off- stagnation point testing to complement aerothermodynamic databases related to lifting reentry vehicles. A methodology for simulating reacting boundary layers in off-stagnation point conditions is assessed with numerical computations. The VKI Plasmatron facility and the measurement techniques developed for the new testing configuration are presented. A testing campaign is run for the CMC materials corresponding to the windward side and the body flap of the IXV. The first experimental results are processed to analyze the testing methodology and its application to flight extrapolation.

Chazot, O.; Panerai, F.; van der Haegen, V.

2011-08-01

386

Transport properties of epitaxial lift off films  

NASA Technical Reports Server (NTRS)

Transport properties of epitaxially lifted-off (ELO) films were characterized using conductivity, Hall, and Shubnikov-de Haas measurements. A 10-15 percent increase in the 2D electron gas concentration was observed in these films as compared with adjacent conventional samples. We believe this result to be caused by a backgating effect produced by a charge build up at the interface of the ELO film and the quartz substrate. This increase results in a substantial decrease in the quantum lifetime in the ELO samples, by 17-30 percent, but without a degradation in carrier mobility. Under persistent photoconductivity, only one subband was populated in the conventional structure, while in the ELO films the population of the second subband was clearly visible. However, the increase of the second subband concentration with increasing excitation is substantially smaller than anticipated due to screening of the backgating effect.

Mena, R. A.; Schacham, S. E.; Young, P. G.; Haugland, E. J.; Alterovitz, S. A.

1993-01-01

387

Oblique waves lift the flapping flag.  

PubMed

The flapping of the flag is a classical model problem for the understanding of fluid-structure interaction: How does the flat state lose stability? Why do the nonlinear effects induce hysteretic behavior? We show in this Letter that, in contrast with the commonly studied model, the full three-dimensional flag with gravity has no stationary state whose stability can be formally studied: The waves are oblique and must immediately be of large amplitude. The remarkable structure of these waves results from the interplay of weight, geometry, and aerodynamic forces. This pattern is a key element in the force balance which allows the flag to hold and fly in the wind: Large amplitude oblique waves are responsible for lift. PMID:22181612

Hœpffner, Jérôme; Naka, Yoshitsugu

2011-11-01

388

A new lifting scheme for lossless image compression  

NASA Astrophysics Data System (ADS)

Since its first introduction, the lifting scheme has become a powerful method to perform wavelet transforms and many other orthogonal transforms. Especially for integer-to-integer wavelet transforms, the lifting scheme is an indispensable tool for lossless image compression. Earlier work has shown that the number of lifting steps can have an impact on the transform performance. The fidelity of integer-to-integer transforms depends entirely on how well they approximate thir original wavelet transforms. The predominant source of errors is due to the rounding-off of the intermediate real result to an integer at each lifting step. Hence, a wavelet transform with a large number of lifting steps would automatically increase the approximation error. In the case of lossy compression, the approximation error is less important because it is usually masked out by the transform coefficient quantization error. However, in the case of lossless compression, the compression performance is certainly affected by the approximation error. Consequently, the number of lifting steps in a wavelet transform is a major concern. The new lifting method presented in this paper reduces the number of lifting steps substantially in lossless data compression. Thus, it also significantly improves the overall rounding errors incurred in the real-to-integer conversion process at each of the lifting steps. The improvement of the overall rounding errors is more pronounced in the integer-to-integer orthogonal wavelet transforms, but the improvement in the integer-to-integer biorthogonal wavelet transforms is also significant. In addition, as a dividend, the new lifting method further saves memory space and decreases signal delay. Many examples on popular wavelet transforms are included.

Hou, Hsieh Sheng

2004-11-01

389

A current global view of environmental and occupational cancers.  

PubMed

This review is focused on current information of avoidable environmental pollution and occupational exposure as causes of cancer. Approximately 2% to 8% of all cancers are thought to be due to occupation. In addition, occupational and environmental cancers have their own characteristics, e.g., specific chemicals and cancers, multiple factors, multiple causation and interaction, or latency period. Concerning carcinogens, asbestos/silica/wood dust, soot/polycyclic aromatic hydrocarbons [benzo(a) pyrene], heavy metals (arsenic, chromium, nickel), aromatic amines (4-aminobiphenyl, benzidine), organic solvents (benzene or vinyl chloride), radiation/radon, or indoor pollutants (formaldehyde, tobacco smoking) are mentioned with their specific cancers, e.g., lung, skin, and bladder cancers, mesothelioma or leukemia, and exposure routes, rubber or pigment manufacturing, textile, painting, insulation, mining, and so on. In addition, nanoparticles, electromagnetic waves, and climate changes are suspected as future carcinogenic sources. Moreover, the aspects of environmental and occupational cancers are quite different between developing and developed countries. The recent follow-up of occupational cancers in Nordic countries shows a good example for developed countries. On the other hand, newly industrializing countries face an increased burden of occupational and environmental cancers. Developing countries are particularly suffering from preventable cancers in mining, agriculture, or industries without proper implication of safety regulations. Therefore, industrialized countries are expected to educate and provide support for developing countries. In addition, citizens can encounter new environmental and occupational carcinogen nominators such as nanomaterials, electromagnetic wave, and climate exchanges. As their carcinogenicity or involvement in carcinogenesis is not clearly unknown, proper consideration for them should be taken into account. For these purposes, new technologies with a balance of environment and gene are required. Currently, various approaches with advanced technologies--genomics, exposomics, etc.--have accelerated development of new biomarkers for biological monitoring of occupational and environmental carcinogens. These advanced approaches are promising to improve quality of life and to prevent occupational and environmental cancers. PMID:21929381

Yang, Mihi

2011-07-01

390

Occupational Therapy and Occupational Science: Past and Future  

Microsoft Academic Search

The history of occupational therapy as generally understood is conspicuously without any reference to the role of science in the founders’ vision of occupational therapy. However, the founders understood the clear need to delineate a scientific basis for understanding the healing power of occupation in terms of both the present and the future of the fledgling profession. This presentation will

Don Gordon

2004-01-01

391

Occupational Orientation: Industrial Oriented Occupations. Experimental Curriculum Materials.  

ERIC Educational Resources Information Center

These experimental curriculum materials, for one of five clusters developed for the occupational orientation program in Illinois, contain teacher references and a series of learning activity packages (LAPs) designed to acquaint the student with the wide range of occupational choices available in the industrial oriented occupations field. The 30…

Illinois State Office of Education, Springfield.

392

Numerical simulation of a powered-lift landing, tracking flow features using overset grids, and simulation of high lift devices on a fighter-lift-and-control wing  

NASA Technical Reports Server (NTRS)

Attached as appendices to this report are documents describing work performed on the simulation of a landing powered-lift delta wing, the tracking of flow features using overset grids, and the simulation of flaps on the Wright Patterson Lab's fighter-lift-and-control (FLAC) wing. Numerical simulation of a powered-lift landing includes the computation of flow about a delta wing at four fixed heights as well as a simulated landing, in which the delta wing descends toward the ground. Comparison of computed and experimental lift coefficients indicates that the simulations capture the qualitative trends in lift-loss encountered by thrust-vectoring aircraft operating in ground effect. Power spectra of temporal variations of pressure indicate computed vortex shedding frequencies close to the jet exit are in the experimentally observed frequency range; the power spectra of pressure also provide insights into the mechanisms of lift oscillations. Also, a method for using overset grids to track dynamic flow features is described and the method is validated by tracking a moving shock and vortices shed behind a circular cylinder. Finally, Chimera gridding strategies were used to develop pressure coefficient contours for the FLAC wing for a Mach no. of 0.18 and Reynolds no. of 2.5 million.

Chawla, Kalpana

1993-01-01

393

In-Flight Subsonic Lift and Drag Characteristics Unique to Blunt-Based Lifting Reentry Vehicles  

NASA Technical Reports Server (NTRS)

Lift and drag measurements have been analyzed for subsonic flight conditions for seven blunt-based reentry-type vehicles. Five of the vehicles are lifting bodies (M2-F1, M2-F2, HL-10, X-24A, and X-24B) and two are wing-body configurations (the X-15 and the Space Shuttle Enterprise). Base pressure measurements indicate that the base drag for full-scale vehicles is approximately three times greater than predicted by Hoerner's equation for three-dimensional bodies. Base drag and forebody drag combine to provide an optimal overall minimum drag (a drag "bucket") for a given configuration. The magnitude of this optimal drag, as well as the associated forebody drag, is dependent on the ratio of base area to vehicle wetted area. Counter-intuitively, the flight-determined optimal minimum drag does not occur at the point of minimum forebody drag, but at a higher forebody drag value. It was also found that the chosen definition for reference area for lift parameters should include the projection of planform area ahead of the wing trailing edge (i.e., forebody plus wing). Results are assembled collectively to provide a greater understanding of this class of vehicles than would occur by considering them individually.

Saltzman, Edwin J.; Wang, K. Charles; Iliff, Kenneth W.

2007-01-01

394

Occupational Injuries, Illnesses and Fatalities  

MedlinePLUS

... News Releases Nonfatal Occupational Injuries and Illnesses Requiring Days Away From Work November 26, 2013 The rate ... PDF 62K) Nonfatal occupational injuries and illnesses requiring days away from work ( HTML ) ( PDF ) Archived Census of ...

395

Stress Management in Occupational Settings.  

National Technical Information Service (NTIS)

Various stress management procedures for use in the occupational setting are summarized, including relaxation, biofeedback, and psychological coping strategies. Most research linking stress to illness is not based on data derived from the occupational env...

G. E. Schwartz

1979-01-01

396

Occupational Literacy Education.  

ERIC Educational Resources Information Center

Intended for teachers of adult basic education as well as teachers in job retraining programs, this book focuses on the development of written and oral language competencies required in occupational and training settings. The first four chapters offer a concise synthesis of recent research on adult learning and on workplace literacy for ten…

Rush, R. Timothy; And Others

397

Prognosis of occupational asthma  

Microsoft Academic Search

ABSTRACT: Several studies on the,prognosis of occupational asthma have shown that a significant proportion of patients continue to experience asthmatic symptoms and nonspecific bronchial hyperresponsiveness after cessation of work. The deter- minants of this unfavourable prognosis of asthma ,are: long duration of exposure before the onset of asthma; long duration of symptoms,before diagnosis; baseline airway obstruction; dual response after specific

P. L. Paggiaro; B. Vagaggini; E. Bacci; L. Bancalari; M. Carrara; A. Di Franco; D. Giannini; F. L. Dente; C. Giuntini

1994-01-01

398

Occupational dermatitis in shoemakers.  

PubMed

In an epidemiological study of occupational dermatitis in 5 different shoe factories, 246 workers were interviewed, examined and patch tested using standard and occupational patch test series. The prevalence of occupational contact dermatitis was 14.6% (36/246): 8.1% (20/246) irritant contact dermatitis (OICD) and 6.5% (16/246) allergic contact dermatitis (OACD). Among the latter, the most common occupational allergens were p-tert-butylphenol-formaldehyde resin and mercaptobenzothiazole. 6% (15/246) presented with hyperkeratosis of the fingertips, while 3.2% (8/246) reported pruritus sine materia (PSM) present only during working hours. 2 workers presented with vitiligo-like leukodermic patches on the backs of their hands and on their forearms. Some jobs were more frequently associated with skin complaints. In the assembly department, OACD was most frequent (11.4%), attributed to contact with adhesives and, to a lesser degree, with rubber and leather. OICD caused by contact with the solvents contained in adhesives and varnishes was most frequent in the assembly and trimming departments (17.1% and 15.6%, respectively). PSM, probably caused by the dust present in the working environment was reported by 33.3% of the workers in the sole-cutting and scraping departments. Hyperkeratosis of the fingertips, as a reaction to the continuous trauma of leather on the skin, was observed most frequently (41.6%) in the sole-cutting department. PMID:8789219

Mancuso, G; Reggiani, M; Berdondini, R M

1996-01-01

399

Health Occupations. Nursing Assistant.  

ERIC Educational Resources Information Center

Materials contained in this package are designed for use with students interested in the occupation of nurses aide. The package has two sections, one which looks closely at the job and the student, and the other--the curriculum phase--which concerns actual student use of learning activity packages (LAPs). These two components together form a "job…

Megow, Joye G.

400

Occupational skin infections  

Microsoft Academic Search

A number of skin infections may complicate different occupations depending on the working environment and level of exposure to a particular agent. These in turn may affect the productivity of an individual worker and ultimately the company as a whole. This review aims to highlight some common and important skin infections that may be acquired at work. Epidemiology, clinical features,

M. J. Harries; J. T. Lear

2004-01-01

401

Evaluating Occupational Programs.  

ERIC Educational Resources Information Center

Stresses the importance of evaluating occupational programs on a regular basis. Offers a brief explanation of the approaches to program evaluation taken at the Dallas County Community College District (TX), South Puget Sound Community College (WA), and Triton College (IL). Offers a list of references on program evaluation. (CBC)

Long, James P.

1987-01-01

402

Occupational Therapy and Neuropsychiatry  

Microsoft Academic Search

It is suggested that increasing evidence of neurophysiological etiologies for mental illness must be taken into account in rationalizing the effectiveness of occupational therapy for psychiatric disorders. The role of activity in metabolizing stress hormones is describes as a possible mechanism of therapeutic effectiveness. The sensory integrative effects of certain activities are also postulated to contribute to improvement in selected

Lorna Jean King

1983-01-01

403

Foodservice Occupations Cluster Guide.  

ERIC Educational Resources Information Center

Intended to assist vocational teachers in developing and implementing a cluster program in food service occupations, this guide contains sections on cluster organization and implementation and instructional emphasis areas. The cluster organization and implementation section covers goal-based planning and includes a proposed cluster curriculum, a…

Oregon State Dept. of Education, Salem.

404

Occupational hazards of farming.  

PubMed

A number of occupational hazards exist for the farmer and farm worker. They include the hazards of farm machinery, biologic and chemical hazards, and social and environmental stresses. Recognizing of these hazards will help the family physician care for farmers and their families. PMID:21248929

White, G; Cessna, A

1989-11-01

405

Hospitality Occupations. Curriculum Guide.  

ERIC Educational Resources Information Center

This curriculum guide on the hospitality occupations was developed to help secondary and postsecondary home economics teachers prepare individuals for entry-level jobs in the hospitality industry. The content is in seven sections. The first section presents organizational charts of a medium-size hotel, food and beverage division, housekeeping and…

California State Dept. of Education, Sacramento. Bureau of Homemaking Education.

406

A hospital-based occupational health service.  

PubMed

Responding to the local business community, Sturdy Memorial Hospital developed an occupational health service. Situated about 35 miles south of Boston, Attleboro has a population of 130,000, with jewelry, chemicals, and light manufacturing as its predominant industries. Featuring plant visits by a medical director with specialty training in occupational and internal medicine, the program provides clinical, ancillary, consultative, educational, and a variety of special services. Clinical services include preplacement examinations and treatment of work-related injuries. Ancillary services are audiometric testing, pulmonary function testing, and screening for heavy-metal exposures. Among the consultative services are evaluations as to whether a disease is work related; counseling on the reproductive hazards in the workplace; and disability evaluations. Work-site visits are conducted by an occupational health nurse who participates in medical surveillance and health promotion programs. Within two years the service has become affiliated with more than 60 firms on a noncontractual , fee-for-service basis. Economic self-sufficiency was established within 18 months of the institution of clinical services. PMID:6726486

McCunney, R J

1984-05-01

407

Aerodynamic characteristics of a large-scale lift-engine fighter model with external swiveling lift-engines  

NASA Technical Reports Server (NTRS)

The aerodynamic characteristics of a six-engine (four lift, two lift-cruise) lift-engine model obtained in the Ames 40- by 80-foot wind tunnel are presented. The model was an approximate one-half scale representation of a lift-engine VTOL fighter aircraft with a variable-sweep wing. The four lift-engines were housed in the aft fuselage with the inlets located above the wing. Longitudinal and lateral-directional force and moment data are presented for a range of exhaust gas momentum ratios (thrust coefficients). Wind tunnel forward speed was varied from 0 to 140 knots corresponding to a maximum Reynolds number of 6.7 million. The data are presented without analysis.

Barrack, J. P.; Kirk, J. V.

1972-01-01

408

Occupational cancer in Britain  

PubMed Central

To estimate the current occupational cancer burden due to past exposures in Britain, estimates of the number of exposed workers at different levels are required, as well as risk estimates of cancer due to the exposures. This paper describes the methods and results for estimating the historical exposures. All occupational carcinogens or exposure circumstances classified by the International Agency for Research on Cancer as definite or probable human carcinogens and potentially to be found in British workplaces over the past 20–40 years were included in this study. Estimates of the number of people exposed by industrial sector were based predominantly on two sources of data, the CARcinogen EXposure (CAREX) database and the UK Labour Force Survey. Where possible, multiple and overlapping exposures were taken into account. Dose–response risk estimates were generally not available in the epidemiological literature for the cancer–exposure pairs in this study, and none of the sources available for obtaining the numbers exposed provided data by different levels of exposure. Industrial sectors were therefore assigned using expert judgement to ‘higher'- and ‘lower'-exposure groups based on the similarity of exposure to the population in the key epidemiological studies from which risk estimates had been selected. Estimates of historical exposure prevalence were obtained for 41 carcinogens or occupational circumstances. These include exposures to chemicals and metals, combustion products, other mixtures or groups of chemicals, mineral and biological dusts, physical agents and work patterns, as well as occupations and industries that have been associated with increased risk of cancer, but for which the causative agents are unknown. There were more than half a million workers exposed to each of six carcinogens (radon, solar radiation, crystalline silica, mineral oils, non-arsenical insecticides and 2,3,7,8-tetrachlorodibenzo-p-dioxin); other agents to which a large number of workers are exposed included benzene, diesel engine exhaust and environmental tobacco smoke. The study has highlighted several industrial sectors with large proportions of workers potentially exposed to multiple carcinogens. The relevant available data have been used to generate estimates of the prevalence of past exposure to occupational carcinogens to enable the occupational cancer burden in Britain to be estimated. These data are considered adequate for the present purpose, but new data on the prevalence and intensity of current occupational exposure to carcinogens should be collected to ensure that future policy decisions be based on reliable evidence.

Van Tongeren, Martie; Jimenez, Araceli S; Hutchings, Sally J; MacCalman, Laura; Rushton, Lesley; Cherrie, John W

2012-01-01

409

A Functional Classification of Occupations.  

ERIC Educational Resources Information Center

The need for more and better manpower information is hampered by the lack of adequate occupational data classification systems. The diversity of interests in occupations probably accounts for the absence of consensus regarding either the general outlines or the specific details of a standardized occupational classification system which would…

McKinlay, Donald Bruce

410

Organised crime, occupations and opportunity  

Microsoft Academic Search

This paper elaborates upon occupations, work relations, work settings, and their connection with organised crime activities. The analysis is based upon data from 120 case studies from the Dutch Organised Crime Monitor, involving 1623 suspects. The paper describes the different kinds of occupations encountered in cases of organised crime and the main characteristics of these occupations. Furthermore, the paper describes

Edward R. Kleemans; Henk G. Van de Bunt

2008-01-01

411

Theoretical Conceptualizations of Occupational Therapy  

Microsoft Academic Search

A descriptive chronology of occupational therapists' conceptualizations of occupational therapy is presented. Major theoretical frames of reference and common theory bases underlying occupational therapy practice are identified. The question of the apparent lack of theoretical conceptualizations of practice based on biomechanical approaches is raised.

Lela A. Llorens

1984-01-01

412

Occupational Therapy for Chronic Pain  

Microsoft Academic Search

The patient with chronic pain presents a dilemma for physical as well as psychiatric health care. Usually coming to the attention of mental health professionals after limited or no successful treatment with medical specialties, these patients present with a variety of factors that disrupt occupational functioning. Occupational therapy is the health profession qualified to analyze occupational function and dysfunction for

Rebecca Liggan Gusich

1984-01-01

413

Occupational hazards in plastic surgery  

Microsoft Academic Search

The occurrence of occupational disorders among plastic surgeons has not had much attention in the literature thus far. A case of a plastic surgeon with distal interphalangeal arthrosis, considered to represent an occupational disorder, is presented. In a review of the literature, possible occupational hazards in plastic surgery are discussed.

J. J. Hage; H. M. Suliman; J. Verhagen; F. G. Bouman

1995-01-01

414

Lifting surface theory for a helicopter rotor in forward flight  

NASA Technical Reports Server (NTRS)

A lifting surface theory was developed for a helicopter rotor in forward flight for compressible and incompressible flow. The method utilizes the concept of the linearized acceleration potential and makes use of the vortex lattice procedure. Calculations demonstrating the application of the method are given in terms of the lift distribution on a single rotor, a two-bladed rotor, and a rotor with swept-forward and swept-back tips. In addition, the lift on a rotor which is vibrating in a pitching mode at 4/rev is given. Compressibility effects and interference effects for a two-bladed rotor are discussed.

Tai, H.; Runyan, H. L.

1984-01-01

415

Nonlinear Stability and Response of Lifting Surfaces Via Volterra Series  

NASA Technical Reports Server (NTRS)

This investigation concerns the time and frequency formulations of non-linear two-dimensional lifting surfaces exposed to an incompressible flow field and subjected to an external pressure pulse. In order to address this problem, Volterra series approach in conjunction with the multidimensional Laplace transform is used. This methodology enabling one to solve the aeroelastic governing equations of lifting surfaces opens the way to connect this methodology with that based on neural networks and NARMAX/NARX networks models. Moreover, this extended way to address this problem constitutes a good basis for treatment of the theory of 3D lifting surfaces.

Marzocca, Piergiovanni; Librescu, Liviu; Silva, Walter A.

2001-01-01

416

Recent research on powered-lift STOL ground effects  

NASA Technical Reports Server (NTRS)

Early studies of powered-lift STOL concepts indicated that a basic problem of aircraft incorporating such concepts would be a serious adverse ground effect on lift. Experience to date with actual powered-lift STOL aircraft, however, has not borne out this concern. This apparent disagreement is examined and recent research data are used to help explain some of the differences observed. Analysis indicates that most of the disagreement can be attributed to the use of wind tunnel data that were not directly applicable to the airplane because the model did not properly represent some of the design features and operating conditions of the airplane.

Campbell, J. P.; Hassell, J. L., Jr.; Thomas, J. L.

1977-01-01

417

Lifting surface theory for a helicopter rotor in forward flight  

NASA Technical Reports Server (NTRS)

A lifting surface theory was developed for a helicopter rotor in forward flight for compressible and incompressible flow. The method utilizes the concept of the linearized acceleration potential and makes use of the vortex lattice procedure. Calculations demonstrating the application of the method are given in terms of the lift distribution on a single rotor, a two-bladed rotor, and a rotor with swept-forward and swept-back tips. In addition, the lift on a rotor which is vibrating in a pitching mode at 4/rev is given. Compressibility effects and interference effects for a two-bladed rotor are discussed.

Tai, H.; Runyan, H. L.

1985-01-01

418

Space Shuttle Discovery lifts off successfully  

NASA Technical Reports Server (NTRS)

As if sprung from the rolling exhaust clouds below, Space Shuttle Discovery shoots into the heavens over the blue Atlantic Ocean from Launch Pad 39B on mission STS-95. Lifting off at 2:19 p.m. EST, Discovery carries a crew of six, including Payload Specialist John H. Glenn Jr., senator from Ohio, who is making his second voyage into space after 36 years. Other crew members are Mission Commander Curtis L. Brown Jr., Pilot Steven W. Lindsey, Payload Specialist Chiaki Mukai, (M.D., Ph.D.), with the National Space Development Agency of Japan (NASDA), Mission Specialist Stephen K. Robinson, Mission Specialist Pedro Duque of Spain, representing the European Space Agency (ESA), and Mission Specialist Scott E. Parazynski. The STS-95 mission includes research payloads such as the Spartan solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as the SPACEHAB single module with experiments on space flight and the aging process. Discovery is expected to return to KSC at 11:49 a.m. EST on Nov. 7.

1998-01-01

419

Dignitaries Await Apollo 11 Lift Off  

NASA Technical Reports Server (NTRS)

From the right, NASA administrator, Dr. Thomas O. Paine talks with U.S. Vice President Spiro T. Agnew while awaiting the launch of Saturn V (AS-506) that carried the Apollo 11 spacecraft to the Moon for man's historic first landing on the lunar surface. At center is astronaut William Anders, a member of the first crew to orbit the moon during the Apollo 8 mission. At left is Lee B. James, director of Program Management at the NASA Marshall Space Flight Center (MSFC) where the Saturn V was developed. The craft lifted off from launch pad 39 at Kennedy Space Flight Center (KSC) on July 16, 1969. The moon bound crew included astronauts Neil A. Armstrong, commander; Michael Collins, Command Module (CM) pilot; and Edwin E. Aldrin Jr., Lunar Module (M) pilot. The mission finalized with splashdown in the Pacific Ocean on July 24, 1969. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished.

1969-01-01

420

US to Lift Cuba Trade Embargo  

NSDL National Science Digital Library

For the first time in four decades, the United States will allow export sales of food and medicine to Cuba. This new agreement, which was drafted by House Republicans, will also allow the export of goods to formerly blacklisted countries including Lybia, North Korea, Sudan, and Iran. Unlike the other four countries, Cuba will not be allowed to export products to the US, nor will it be able to secure American private financing. In the first year after the new rulings go into effect, John Kavulich, president of the U.S.-Cuba Trade and Economic Council, has estimated that exports of American food products could reach between $25 million and $45 million. However the proposed bill has fallen short of the expectations of the Cuban government, which has demanded a complete lifting of the trade embargo. Cuban-American activists on both sides of the issues also find the proposal flawed, stating concerns including the lack of guarantee that the food and medicine will reach the Cubans who need the supplies the most.

Missner, Emily D.

421

Energetics of oscillating lifting surfaces using integral conservation laws  

NASA Technical Reports Server (NTRS)

The energetics of oscillating flexible lifting surfaces in two and three dimensions is calculated by the use of integral conservation laws in inviscid incompressible flow for general and harmonic transverse oscillations. Total thrust is calculated from the momentum theorem and energy loss rate due to vortex shedding in the wake from the principle of conservation of mechanical energy. Total power required to maintain the oscillations and hydrodynamic efficiency are also determined. In two dimensions, the results are obtained in closed form. In three dimensions, the distribution of vorticity on the lifting surface is also required as input to the calculations. Thus, unsteady lifting-surface theory must be used as well. The analysis is applicable to oscillating lifting surfaces of arbitrary planform, aspect ratio, and reduced frequency and does not require calculation of the leading-edge thrust.

Ahmadi, Ali R.; Widnall, Sheila E.

1987-01-01

422

39. Second piece of formwork being readied for lifting into ...  

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

39. Second piece of formwork being readied for lifting into place for arch rib at north abutment, view to northwest. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

423

75. VIEW SHOWING CLEARANCE BENEATH SHOOFLY BRIDGE LIFT SPAN AS ...  

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

75. VIEW SHOWING CLEARANCE BENEATH SHOOFLY BRIDGE LIFT SPAN AS RIVER TOWBOAT PASSES, LOOKING NORTH-NORTHEAST (UPSTREAM), February 9, 1935 - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

424

99. GENERAL VIEW OF LIFT SPAN, LOOKING EASTSOUTHEAST, August 2, ...  

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

99. GENERAL VIEW OF LIFT SPAN, LOOKING EAST-SOUTHEAST, August 2, 1935. (Steamer Delta King is moored at River Lines Terminal.) - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

425

62. VIEW SHOWING THE ERECTION OF SHOOFLY BRIDGE LIFT SPAN ...  

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

62. VIEW SHOWING THE ERECTION OF SHOOFLY BRIDGE LIFT SPAN ON BARGE, LOOKING WEST-NORTHWEST, January 21, 1935 - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

426

Unsteady transonic flow calculations for interfering lifting surface configurations  

NASA Technical Reports Server (NTRS)

Unsteady transonic flow calculations are presented for aerodynamically interfering lifting surface configurations. Calculations are performed by extending the XTRAN3S (Version 1.5) unsteady transonic small-disturbance code to allow the treatment of an additional lifting surface. The research was conducted as a first-step toward developing the capability to treat a complete flight vehicle. Grid generation procedures for swept tapered interfering lifting surface applications of XTRAN3S are described. Transonic calculations are presented for wing-tail and canard-wing configurations for several values of mean angle of attack. The effects of aerodynamic interference on transonic steady pressure distributions and steady and oscillatory spanwise lift distributions are demonstrated. Results due to wing, tail, or canard pitching motions are presented and discussed in detail.

Batina, J. T.

1985-01-01

427

Effects of jets, wakes, and vortices on lifting surfaces  

NASA Technical Reports Server (NTRS)

The interaction of jets, wakes, and vortices on lifting bodies represents a broad spectrum of aerodynamic flow phenomena. A literature survey is presented of 79 research activities in related aerodynamic situations.

Margason, R. J.

1976-01-01

428

Large-Eddy Simulations of Flapping-Induced Lift Enhancement  

NASA Astrophysics Data System (ADS)

This work isolates the heaving motion of flapping flight in order to numerically investigate the fluid-structure interaction at Reynolds numbers relevant to birds and bats. Although there has been much focus on insect flight, larger vertebrates fly at a higher Reynolds number, which leads to different dynamics in terms of flow separation, reattachment, and high-lift mechanisms. In this work, an incompressible large-eddy simulation is used to simulate the periodic heaving of a flat plate at various angles of attack. It is found that the heaving motion can increase the average lift when compared with the steady flow, more so than is expected from the relative angle of attack. The additional lift is attributed to the vortex dynamics at the leading edge. The lift enhancement and flow features are compared with experimental results.

Franck, Jennifer; Swartz, Sharon; Breuer, Kenneth

2011-11-01

429

PRECAST CONCRETE WALL PANELS ARE LIFTED INTO PLACE ON MTR ...  

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

PRECAST CONCRETE WALL PANELS ARE LIFTED INTO PLACE ON MTR STEEL FRAME STRUCTURE. INL NEGATIVE NO. 1330. Unknown Photographer, 1/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

430

4. DETAIL VIEW OF LIFTING GEAR ON MULE AND RACK ...  

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

4. DETAIL VIEW OF LIFTING GEAR ON MULE AND RACK ATTACHMENT BOOKS, LOOKING EAST - Nine Mile Hydroelectric Development, Powerhouse, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

431

15. OVERALL VIEW OF UPSTREAM FACE OF LIFT GATE SECTION ...  

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

15. OVERALL VIEW OF UPSTREAM FACE OF LIFT GATE SECTION WITH TAINTER GATE SECTION OF SPILLWAY TO THE LEFT. VIEW TO SOUTHWEST. - Starved Rock Locks & Dam, Illinois Waterway River mile 231, Peru, La Salle County, IL

432

The unsteady lift of a wing of finite aspect ratio  

NASA Technical Reports Server (NTRS)

Unsteady-lift functions for wings of finite aspect ratio have been calculated by correcting the aerodynamic inertia and the angle of attack of the infinite wing. The calculations are based on the operational method.

Jones, Robert T

1940-01-01

433

Observations on Lifted Flame Oscillations and Flame Stability Near Blowout  

NASA Astrophysics Data System (ADS)

Studies are presented that examine the fluctuations in liftoff height of lifted flames in the presence of air co-flow. At a certain jet exit velocity, a flame will lift from the fuel nozzle and stabilize at some downstream position. The partially-premixed flame front of the lifted flame oscillates in the axial direction, with the oscillations becoming greater in flames stabilized further downstream. These oscillations are also observed in flames where blowout is imminent. This work attempts to determine the role of fuel velocity and air co-flow on flame oscillations in both stable and unstable regimes. The results of video imaging of a lifted methane-air diffusion flame are presented. Images are used to ascertain the changes in the reaction zone that influence these oscillations and relate the movement to blowout.

Moore, Nancy; Lyons, Kevin

2007-11-01

434

Effects of streamline curvature on lift of biplanes  

NASA Technical Reports Server (NTRS)

This report concerns, first, the determination of the lift of a wing which is situated in a curvilinear flow; and second, to calculate the curvature which one wing of a biplane produces in the vicinity of the other.

Prandtl, L

1927-01-01

435

View from floating barracks west of lift bridge to reserve ...  

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

View from floating barracks west of lift bridge to reserve basin on psny. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Reserve Basin & Marine Railway, League Island, Philadelphia, Philadelphia County, PA

436

Detail view of fourth level platform winch used to lift ...  

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

Detail view of fourth level platform winch used to lift platform segments away from the Shuttle assembly during testing. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

437

Discharge and Mechanical Efficiency of Egyptian Water-Lifting Wheels.  

National Technical Information Service (NTIS)

In Egypt and neighboring areas, where waterwheels are used to lift water from irrigation supply canals to field level, two important parameters in evaluating an irrigation system are the discharge per revolution and the mechanical efficiency of the waterw...

R. Slack H. Wahby W. Clyma

1983-01-01

438

DETAIL OF CONNECTION BETWEEN LIFT CABLES AND CONCRETE COUNTERWEIGHT, SHOWING ...  

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

DETAIL OF CONNECTION BETWEEN LIFT CABLES AND CONCRETE COUNTERWEIGHT, SHOWING PROXIMITY OF PAIR OF SPANS. - Lake Shore & Michigan Southern Railway, Bridge No. 6, Spanning Calumet River, east of Chicago Skyway (I-90), Chicago, Cook County, IL

439

DETAIL OF CONNECTION BETWEEN LIFT CABLES AND CONCRETE COUNTERWEIGHT. ...  

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

DETAIL OF CONNECTION BETWEEN LIFT CABLES AND CONCRETE COUNTERWEIGHT. - Lake Shore & Michigan Southern Railway, Bridge No. 6, Spanning Calumet River, east of Chicago Skyway (I-90), Chicago, Cook County, IL

440

14 CFR 25.697 - Lift and drag devices, controls.  

Code of Federal Regulations, 2013 CFR

...operation of the control and the characteristics...give satisfactory flight and performance...conditions of airspeed, engine power, and airplane...The lift device control must be designed...during steady flight at maximum continuous engine power at any...

2014-01-01

441

Analysis of transonic flow about lifting wing-body configurations  

NASA Technical Reports Server (NTRS)

An analytical solution was obtained for the perturbation velocity potential for transonic flow about lifting wing-body configurations with order-one span-length ratios and small reduced-span-length ratios and equivalent-thickness-length ratios. The analysis is performed with the method of matched asymptotic expansions. The angles of attack which are considered are small but are large enough to insure that the effects of lift in the region far from the configuration are either dominant or comparable with the effects of thickness. The modification to the equivalence rule which accounts for these lift effects is determined. An analysis of transonic flow about lifting wings with large aspect ratios is also presented.

Barnwell, R. W.

1975-01-01

442

13. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ...  

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

13. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ON HEADWORKS OF DEER FLAT NAMPA CANAL ON UPPER EMBANKMENT. VIEW TO SOUTHWEST. - Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID

443

NASA safety standard for lifting devices and equipment  

NASA Astrophysics Data System (ADS)

NASA's minimum safety requirements are established for the design, testing, inspection, maintenance, certification, and use of overhead and gantry cranes (including top running monorail, underhung, and jib cranes), mobile cranes, derrick hoists, and special hoist supported personnel lifting devices (these do not include elevators, ground supported personnel lifts, or powered platforms). Minimum requirements are also addressed for the testing, inspection, and use of Hydra-sets, hooks, and slings. Safety standards are thoroughly detailed.

1990-09-01

444

NASA safety standard for lifting devices and equipment  

NASA Technical Reports Server (NTRS)

NASA's minimum safety requirements are established for the design, testing, inspection, maintenance, certification, and use of overhead and gantry cranes (including top running monorail, underhung, and jib cranes), mobile cranes, derrick hoists, and special hoist supported personnel lifting devices (these do not include elevators, ground supported personnel lifts, or powered platforms). Minimum requirements are also addressed for the testing, inspection, and use of Hydra-sets, hooks, and slings. Safety standards are thoroughly detailed.

1990-01-01

445

Methods for Reducing Subsonic Drag Due to Lift  

NASA Technical Reports Server (NTRS)

The results of repeat experimental research on methods for reducing subsonic drag due to lift are discussed. The NASA supercritical airfoils and their application to structurally practical wings with increased aspect radio are described. A design approach and experimental results for wing-tip-mounted winglets are presented. Several methods for utilizing the thrust of jet engines to provide reductions in the drag due to lift are also discussed.

Whitcomb, R. T.

1977-01-01

446

The lift distribution of wings with end plates  

NASA Technical Reports Server (NTRS)

The object of the present report is to ascertain the relationship of the circulation distribution over the wing and of the lift to the height and position of the end plate. The side forces and moments on the end plates were also determined. It is found that moving an end plate of certain length up from the symmetrical position, is followed by a slight increase of the total lift.

Mangler, W

1938-01-01

447

Accidental hanging with delayed death in a lift.  

PubMed

While hanging is a common method of committing suicide in India, accidental hanging is uncommon. However, it does occur when people are engaged in auto-erotic practices. An adult male who was helping passengers trapped in the lift of an outpatient department at a teaching hospital was accidentally hanged. He survived for 39 days. This case highlights a rare but serious hazard in the use of lifts. PMID:10581915

Verma, S K; Agarwal, B B

1999-10-01

448

Weight Lifting in Women with Breast Cancer-Related Lymphedema  

Microsoft Academic Search

The proportion of women who had an increase of 5% or more in limb swelling was similar in the weight-lifting group (11%) and the control group (12%) (cumulative incidence ratio, 1.00; 95% confidence interval, 0.88 to 1.13). As compared with the control group, the weight-lifting group had greater improvements in self-reported severity of lymphedema symptoms (P = 0.03) and upper-

Kathryn H. Schmitz; Rehana L. Ahmed; Andrea Troxel; Andrea Cheville; Rebecca Smith; Lorita Lewis-Grant; Cathy J. Bryan; Catherine T. Williams-Smith; Quincy P. Greene

2010-01-01

449

Weight Lifting in Women with Breast-Cancer–Related Lymphedema  

Microsoft Academic Search

The proportion of women who had an increase of 5% or more in limb swelling was similar in the weight-lifting group (11%) and the control group (12%) (cumulative incidence ratio, 1.00; 95% confidence interval, 0.88 to 1.13). As compared with the control group, the weight-lifting group had greater improvements in self-reported severity of lymphedema symptoms (P = 0.03) and upper-

Kathryn H. Schmitz; Rehana L. Ahmed; Andrea Troxel; Andrea Cheville; Rebecca Smith; Lorita Lewis-Grant; Cathy J. Bryan; Catherine T. Williams-Smith; Quincy P. Greene

2009-01-01

450

Searching for ski-lift injury: an uphill struggle?  

PubMed

Injuries arising from ski-lift malfunction are rare. Most arise from skier error when embarking or disembarking, or from improper lift operation. A search of the literature failed to uncover any studies focusing specifically on ski-lift injuries. The purpose of this study was to identify and characterise ski-lift injury resulting in hospitalisation and comment on barriers to reporting and reporting omissions. New Zealand hospitalised injury discharges 2000-2005 formed the primary dataset. To aid case identification these data were linked to ACC compensated claims for the same period and the data searched for all hospitalised cases of injury arising from ski-lifts. 44 cases were identified representing 2% of snow-skiing/snowboarding cases. 28 cases (64%) were male and 16 (36%) female, the average age was 32 yrs (range 5-73 yrs). The majority of cases were snow-skiers (35 cases, 80%). Most of the injuries were serious, or potentially so, with 1 case of traumatic pneumothorax, one of pulmonary embolism (after jumping from a ski-lift) and 28 cases sustaining fractures (six to the neck-of-femur, one to the lumbar spine and one to the pubis). ICISS scores for all cases ranged from 1.00 to 0.8182 (probability of dying in hospital 0-18.18%). Only 14 (32%) cases could be easily identified from ICD-10-AM e-codes and activity codes in the discharge summary. The ICD-10-AM external cause code for ski-lift injury V98 ("other specified transport accidents") was only assigned to 39% of cases. The type of ski-lift could only be determined in 24 cases (55%). PMID:19428293

Smartt, Pam; Chalmers, David

2010-03-01

451

High-Speed FPGA Implementation for DWT of Lifting Scheme  

Microsoft Academic Search

A new approach for Discrete Wavelet Transform (DWT) has been proposed recently under the name of lifting scheme. This scheme presents many advantages over the convolution-based approach. In this paper, a high speed 9\\/7 lifting DWT algorithm which is implementation on FPGA with multi-stage pipelining structure and rational 9\\/7 coefficients is presented. Compared with the architecture without multi-stage pipeline, the

Wei Wang; Zhiyun Du; Yong Zeng

2009-01-01

452

LiFT: Lightweight Freerider-Tracking Protocol  

Microsoft Academic Search

Abstract: This paper addresses the problem of detecting freeriders in peer-to-peer epidemic con- tent dissemination applications, such as gossip-based and mesh-based systems. We present LiFT, a Lightweight Freerider-Tracking Protocol, relying on accountability: each peer logs a digest of its past interactions with other peers and tracks abnormal behaviors by cross-checking its history log with other peers. LiFT is the,rst protocol

Rachid Guerraoui; Kévin Huguenin; Anne-Marie Kermarrec; Maxime Monod

2009-01-01

453

A simple and effective lift-off with positive photoresist  

Microsoft Academic Search

This paper describes a simple and effective lift-off method which relies upon a single layer of positive photoresist and the insertion of a diffuser in the conventional lithography. The inserted diffuser randomizes the paths of incident ultraviolet light, which creates the re-entrant photoresist profile necessary for proper metal lift-off. This method was applied to photoresists, with different thicknesses from 1.3

Hyung Suk Lee; Jun-Bo Yoon

2005-01-01

454

Moving base simulation of an ASTOVL lift-fan aircraft  

NASA Technical Reports Server (NTRS)

Using a generalized simulation model, a moving-base simulation of a lift-fan short takeoff/vertical landing fighter aircraft was conducted on the Vertical Motion Simulator at Ames Research Center. Objectives of the experiment were to (1) assess the effects of lift-fan propulsion system design features on aircraft control during transition and vertical flight including integration of lift fan/lift/cruise engine/aerodynamic controls and lift fan/lift/cruise engine dynamic response, (2) evaluate pilot-vehicle interface with the control system and head-up display including control modes for low-speed operational tasks and control mode/display integration, and (3) conduct operational evaluations of this configuration during takeoff, transition, and landing similar to those carried out previously by the Ames team for the mixed-flow, vectored thrust, and augmentor-ejector concepts. Based on results of the simulation, preliminary assessments of acceptable and borderline lift-fan and lift/cruise engine thrust response characteristics were obtained. Maximum pitch, roll, and yaw control power used during transition, hover, and vertical landing were documented. Control and display mode options were assessed for their compatibility with a range of land-based and shipboard operations from takeoff to cruise through transition back to hover and vertical landing. Flying qualities were established for candidate control modes and displays for instrument approaches and vertical landings aboard an LPH assault ship and DD-963 destroyer. Test pilot and engineer teams from the Naval Air Warfare Center, Boeing, Lockheed, McDonnell Douglas, and the British Defence Research Agency participated in the program.

Chung, William W. Y.; Borchers, Paul F.; Franklin, James A.

1995-01-01

455

Pilot safety for the X-24A lifting body vehicle  

NASA Technical Reports Server (NTRS)

The design and operational characteristics of the X-24A are described in detail. Primary emphasis is placed on the safety considerations incorporated in the design and flight test stages. It is pointed out that the inherently high drag of the lifting body configuration together with its relatively low lift/drag ratio, generated considerable concern with respect to the pilot's ability to perform safe landings from gliding flight. The resulting safety procedures taken at each stage of development are discussed.

Cochrane, J.; Graham, K.

1971-01-01

456

46 CFR 28.545 - Intact stability when using lifting gear.  

Code of Federal Regulations, 2010 CFR

...Intact stability when using lifting gear. 28.545 Section...Intact stability when using lifting gear. (a) Each vessel which lifts a weight over the side...curve resulting from lifting must be calculated...of this section, the weight of suspended...

2010-10-01

457

46 CFR 28.545 - Intact stability when using lifting gear.  

Code of Federal Regulations, 2010 CFR

...Intact stability when using lifting gear. 28.545 Section...Intact stability when using lifting gear. (a) Each vessel which lifts a weight over the side...curve resulting from lifting must be calculated...of this section, the weight of suspended...

2009-10-01

458

Maximum weights of lift acceptable to male and female industrial workers for extended work shifts  

Microsoft Academic Search

This paper reports the development of maximum acceptable weight of lift databases for male and female industrial workers for 12-hour work periods. Using a psychophysical methodology, 37 males and 37 females, experienced in manual lifting, performed various lifting tasks involving four frequencies, three box sizes, and three height levels. The maximum acceptable weight of lift was significantly influenced by the

ANIL MITAL

1984-01-01