The Demise of Skid Row.

ERIC Educational Resources Information Center

Siegal, Harvey A.; Inciardi, James A.

1982-01-01

Describes the history and evolution of the American skid row; analyzes the changes it has undergone, particularly in the face of urban renewal; and speculates on its future. Includes opinions of the inhabitants of skid row which were obtained from interviews. (MJL)

Variations in skid resistance over time.

DOT National Transportation Integrated Search

1980-01-01

The purpose of this project was to quantify the magnitude of changes in skid resistance over time, to isolate the variables that seem most important with respect to the changes, and, to the degree possible, formulate a model for converting skid resis...

Evaluation of skid test automatic digital recording system.

DOT National Transportation Integrated Search

1974-01-01

The Virginia skid vehicle has been equipped with a digital data recording system to provide rapid reduction of skid measurement data. It was found that five to ten minutes are required to evaluate a single measurement using the original analog strip ...

Test procedures and data input techniques for skid testing.

DOT National Transportation Integrated Search

1974-01-01

The purpose of this report is to describe the system for obtaining and handling skid data, including skid testing procedures and data input procedures. While all testing devices used in Virginia are covered (other than the British portable tester), t...

Field evaluation of skid resistant surfaces : final report : part I.

DOT National Transportation Integrated Search

1970-06-01

This project was undertaken to establish a thin bituminous surface course that would possess good skid resistant qualities as well as, being both economical and durable. : This is the final report on the evaluation of skid resistant surfaces which wa...

Acceptance Test Procedure for New Pumping Instrumentation and Control Skid Q

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

2000-03-27

This Acceptance Test Procedure (ATP) provides for the inspection and testing of the new Pumping Instrumentation and Control (PIC) skid designed as ''Q''. The ATP will be performed after the construction of the PIC skid in the fabrication shop.

90. VIEW OF OXIDIZER APRON AND SOUTH SIDE OF SKID ...

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

90. VIEW OF OXIDIZER APRON AND SOUTH SIDE OF SKID 9, SKID 7, AND SKID 9A. COOLING TOWER ON NORTH SIDE OF OXIDIZER APRON. LEFT TO RIGHT IN BACKGROUND: METEOROLOGICAL TOWER, SLC-3W MST, SURPLUS ATLAS E/F LAUNCHER, PYROTECHNIC SHED (BLDG. 757), STORAGE SHED (BLDG. 776), CABLE TRAYS, AND TOP OF LAUNCH OPERATIONS BUILDING (BLDG. 763). - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Estimation of Skidding Offered by Ackermann Mechanism

NASA Astrophysics Data System (ADS)

Rao, Are Padma; Venkatachalam, Rapur

2016-04-01

Steering for a four wheeler is being provided by Ackermann mechanism. Though it cannot always provide correct steering conditions, it is very popular because of its simple nature. A correct steering would avoid skidding of the tires, and thereby enhance their lives as the wear of the tires is reduced. In this paper it is intended to analyze Ackermann mechanism for its performance. A method of estimating skidding due to improper steering is proposed. Two parameters are identified using which the length of skidding can be estimated.

Relationships between skid numbers, paving materials and mix design, and accumulated traffic.

DOT National Transportation Integrated Search

1977-01-01

The objectives of this study were to determine the periods of time over which materials used in pavement surfaces provide adequate skid resistance and to classify various aggregate sources on the basis of the skid resistance qualities of the material...

Evaluation of skid inventory data for development of trends : pilot study : final report.

DOT National Transportation Integrated Search

1983-12-01

This study examined historical data of the skid resistance inventory in Louisiana from 1974 through 1981 to determine trends. The data showed that no trend exists when using number of vehicle passes versus skid number difference on any surface presen...

Skid resistance study : final report.

DOT National Transportation Integrated Search

1977-06-01

This is a report of a research project involving, in Phase I, the skid resistance of asphaltic concrete overlays. Phase II is a report of a pilot study set up in order to determine the best way to perform a skid resistance inventory of the highway ne...

Evaluation of the new Virginia Dept. of Highways and Transportation skid testing trailer.

DOT National Transportation Integrated Search

1975-01-01

The purpose of this study was to evaluate the new skid trailer obtained by the Virginia Department of Highways & Transportation and to determine how the survey skid testing program should be conducted in light of the findings. Specifically, those thi...

New findings regarding the significance of pavement skid resistance for road safety on Swiss freeways.

PubMed

Lindenmann, H P

2006-01-01

The significance of the influence of poor pavement skid resistance values on accident frequency in wet pavement conditions has been the object of many studies over several years. The various investigations have produced very diverse findings. Only seldom, however, has detailed consideration been given to the central question of whether pavement skid resistance is a decisive parameter in the occurrence of local accident "black spots." Until now, the focus has been more on describing a relationship between pavement skid resistance and accident frequency. In the course of the network-wide survey of the states of pavements and of accident occurrence on Switzerland's freeways from 1999 to 2003, it emerged that a relationship with inadequate pavement skid resistance was provable for only a small proportion of accident black spots. These findings were used to frame a guideline for authorities and highway operators about how to treat skid resistance when assessing pavements and accident occurrence on freeways.

Validation of asphalt mixture pavement skid prediction model and development of skid prediction model for surface treatments.

DOT National Transportation Integrated Search

2017-04-01

Pavement skid resistance is primarily a function of the surface texture, which includes both microtexture and macrotexture. Earlier, under the Texas Department of Transportation (TxDOT) Research Project 0-5627, the researchers developed a method to p...

Virginia Department of Highways and Transportation skid testing equipment correlation results, 1974, 1975, and 1978.

DOT National Transportation Integrated Search

1978-01-01

The purpose of this study was to modify, as required, the previously established relationships between the VHTRC skid trailer, the VHTRC stopping distance car, and the first VDHT skid trailer, and to develop appropriate relationships with the above t...

Skidding Coefficients on an Alluvial Soil

Treesearch

W. N. Darwin

1965-01-01

The Southern Hardwoods Laboratory is studying the influence of ground conditions and load characteristics on the performance of skidding vehicles in southern bottom lands. The exploratory test was aimed at evaluating the effects of bark on skidding coefficients, but it also yielded information on other log characteristics and on effects of soil moisture.

Effectiveness and costs of overland skid trail BMPs

Treesearch

Clay Sawyers; W. Michael Aust; M. Chad Bolding; William A. Lakel III

2012-01-01

Forestry Best Management Practices (BMPs) are designed to protect water quality; however, little data exists comparing the efficacy and costs of different BMP options for skid trail closure. Study objectives were to evaluate erosion control effectiveness and implementation costs of five overland skid trail closure techniques. Closure techniques were: waterbar only (...

Friction and wear characteristics of wire-brush skids

NASA Technical Reports Server (NTRS)

Dreher, R. C.

1979-01-01

The testing technique consisted of towing the skids with a ground test vehicle over asphalt and concrete surfaces at ground speeds up to 80 km/hr (50 mph) and bearing pressures up to 689 kPa (100 psi) over sliding distances up to 1585 m (5200 ft). Results indicate that the friction coefficient developed by wire brush skids is essentially independent of ground speed, is slightly increased with increasing bearing pressure, is noticeably affected by surface texture, and is not degraded by surface wetness. Skid wear is shown to increase with increasing bearing pressure and with increasing ground speed and is dependent on the nature of the surface. Runway surface damage caused by the skids was in the form of an abrasive scrubbing action rather than physical damage.

The effect of aggregate type and mix design on the wet skid resistance of bituminous pavement : recommendations for Virginia's Wet Accident Reduction Program.

DOT National Transportation Integrated Search

1995-01-01

This report (1) identified and characterized Virginia's nonpolishing aggregates in terms of their wet skid resistance, (2) compared the standard ASTM E 274-90 skid test to the British Accelerated Polishing Machine (BAPM) and British PendulumTester (B...

14 CFR 29.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions... along the bottom of both skids, the vertical reactions must be applied as prescribed in paragraph (a) of this section. (c) Drag reactions in the level landing attitude. In the level attitude, and with the...

14 CFR 29.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions... along the bottom of both skids, the vertical reactions must be applied as prescribed in paragraph (a) of this section. (c) Drag reactions in the level landing attitude. In the level attitude, and with the...

14 CFR 27.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions... along the bottom of both skids, the vertical reactions must be applied as prescribed in paragraph (a) of this section. (c) Drag reactions in the level landing attitude. In the level attitude, and with the...

14 CFR 27.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions... along the bottom of both skids, the vertical reactions must be applied as prescribed in paragraph (a) of this section. (c) Drag reactions in the level landing attitude. In the level attitude, and with the...

Soil Wetness Influences Log Skidding

Treesearch

William N. Darwin

1960-01-01

One of the least explored variables in timber harvesting is the effect of ground conditions on log production . The Southern Hardwoods Laboratory is studying this variable and its influence on performance of skidding vehicles in Southern bottom lands. The test reported here was designed to evaluate the effects of bark features on skidding coefficients, but it also...

Evaluation of drilled-ball bearings at DN values to three million. 2: Experimental skid study and endurance tests

NASA Technical Reports Server (NTRS)

Holmes, P. W.

1972-01-01

Both drilled-and solid-ball 120-mm-bore bearings were tested at speeds up to 24,000 rpm to determine skid characteristics. The thrust loads were varied from 5000 lb down to 370 lb. No gross skidding occurred, and the behavior of the two bearing types was generally similar; however, two drilled-ball bearing failures occurred during the skid tests. In the endurance tests, 25 cycles of start, run (for one hour), and stop were completed before a drilled-ball bearing failed. In all three cases, the ball had failed in flexure fatigue.

Alternative skid trail retirement options for steep terrain logging

Treesearch

Mathew F. Smidt; Randall K. Kolka

2001-01-01

In winter 1999-2000 trials of deep tillage and recontouring of skid trails were implemented on three sites in northeastern Kentucky, USA to examine their potential as skid trail retirement options. While effective, current Best Management Practices (BMPs) for trail retirement do not address two potential benefits of retirement: recovery of normal hill slope hydrology...

Alternative skid trail retirement options for steep terrain logging

Treesearch

Mathew F. Smidt; Randall K. Kelka

2001-01-01

In winter 1999-2000 trials of deep tillage and recontouring of skid trails were implemented on three sites in northeastern Kentucky, USA to examine their potential as skid trail retirement options. While effective, current Best Management Practices (BMPs) for trail retirement do not address two potential benefits of retirement: recovery of normal hill slope\\r\\...

Ground skidding and harvested stand attributes in Appalachian hardwood stands in West Virginia

Treesearch

Andrew F. Egan; John E. Baumgras

2003-01-01

A statewide logging-in-progress study was conducted in West Virginia to examine the associations among several ground skidding and harvested stand attributes. There was a strong positive association between skidding distance and cycle time, and a significant negative relationship between the percent of trees removed in the stand and total cycle time. The number of...

19 CFR 10.41a - Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of international...

Code of Federal Regulations, 2014 CFR

2014-04-01

... for inspection by Customs officials upon reasonable notice. (3) If the container does not exit the U.S... 19 Customs Duties 1 2014-04-01 2014-04-01 false Lift vans, cargo vans, shipping tanks, skids... Traffic § 10.41a Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of...

19 CFR 10.41a - Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of international...

Code of Federal Regulations, 2012 CFR

2012-04-01

... for inspection by Customs officials upon reasonable notice. (3) If the container does not exit the U.S... 19 Customs Duties 1 2012-04-01 2012-04-01 false Lift vans, cargo vans, shipping tanks, skids... Traffic § 10.41a Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of...

19 CFR 10.41a - Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of international...

Code of Federal Regulations, 2013 CFR

2013-04-01

... for inspection by Customs officials upon reasonable notice. (3) If the container does not exit the U.S... 19 Customs Duties 1 2013-04-01 2013-04-01 false Lift vans, cargo vans, shipping tanks, skids... Traffic § 10.41a Lift vans, cargo vans, shipping tanks, skids, pallets, and similar instruments of...

Skid Prevention for EVs Based on the Emulation of Torque Reduction Characteristics of Separately-excited DC Motor

NASA Astrophysics Data System (ADS)

Kodama, Shinya; Hori, Yoichi

It is well-known that the separately-excited DC motor has effective torque (current) reduction characteristics in response to rapid increase in the rotational speed of the motor. These characteristics have been utilized in adhesion control of electric railway trains with separately-excited DC motor. Up to now, we have proposed a new skid prevention method for EVs, utilizing these characteristics and have made experiments with the hardware skid simulator “Motor-Generator setup”. In this paper, we applied this skid prevention control to our new vehicle “UOT CADWELL EV" equipped with BLDC motors and showed its effectiveness.

Cost of skid roads for arch logging in West Virginia

Treesearch

George R., Jr. Trimble; Carl R. Barr

1960-01-01

In the mountain hardwood country of the northern Appalachians, tree-length skidding with tractor and arch has proved to be economical logging. One essential part of this type of logging is that tree-length logs are winched to the skid roads: tractor and arch do not run around through the woods. Winching distance is commonly 200 to 300 feet; and occasionally an extra...

An adaptable walking-skid for seabed ROV under strong current disturbance

NASA Astrophysics Data System (ADS)

Si, Jianting; Chin, Chengsiong

2014-09-01

This paper proposed a new concept of an adaptable multi-legged skid design for retro-fitting to a remotely-operated vehicle (ROV) during high tidal current underwater pipeline inspection. The sole reliance on propeller-driven propulsion for ROV is replaced with a proposed low cost biomimetic solution in the form of an attachable hexapod walking skid. The advantage of this adaptable walking skid is the high stability in positioning and endurances to strong current on the seabed environment. The computer simulation flow studies using Solidworks Flow Simulation shown that the skid attachment in different compensation postures caused at least four times increase in overall drag, and negative lift forces on the seabed ROV to achieve a better maneuvering and station keeping under the high current condition (from 0.5 m/s to 5.0 m/s). A graphical user interface is designed to interact with the user during robot-in-the-loop testing and kinematics simulation in the pool.

Projectile Roll Dynamics and Control With a Low-Cost Skid-to-Turn Maneuver System

DTIC Science & Technology

2013-03-01

scheme. The mechatronics of the maneuver system was provided. The suitability of this design for survival at gun launch was assessed through...Projectile Roll Dynamics and Control With a Low-Cost Skid-to-Turn Maneuver System by Frank Fresconi, Ilmars Celmins, Mark Ilg, and James...5069 ARL-TR-6363 March 2013 Projectile Roll Dynamics and Control With a Low-Cost Skid-to-Turn Maneuver System Frank Fresconi, Ilmars

Final Environmental Assessment for the Skid Strip Area Development Plan at Cape Canaveral Air Force Station Florida

DTIC Science & Technology

2009-07-01

including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215...Canaveral Air Force Station (CCAFS) Skid Strip. Since the facility no longer operates as a missile skid strip, it is referred to as the "Airfield...construction of a new 65 foot tall control tower; construction of a new Airfield Manager (AM) Operations Building that would adjoin the new tower; and

Validation of Filtration Skid During Land-Based & Shipboard Tests

DTIC Science & Technology

2012-10-12

b. ABSTRACT c. THIS PAGE 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Re . 8-98) v Prescribed by ANSI Std. Z39.18 12...skid device that it had previously developed. A prototype unit was developed and deployed on the bulk carrier M/ V Indiana Harbor, and commissioning...a preliminary design of a filter skid device that it had previously developed. A prototype unit was developed and deployed on the bulk carrier M/ V

88. VIEW OF OXIDIZER APRON ON EAST SIDE OF LSB ...

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

88. VIEW OF OXIDIZER APRON ON EAST SIDE OF LSB (BLDG. 751). LIQUID OXYGEN TOPPING TANK ON RIGHT; GASEOUS NITROGEN IN CENTER; LIQUID OXYGEN RAPID-LOAD TANK ON LEFT. SKID 9 ON RIGHT; SKID 7 IN CENTER; SKID 9A ON LEFT. FEATURES LEFT TO RIGHT IN BACKGROUND: LAUNCH DECK, UMBILICAL MAST, MST, AND NORTH CAMERA TOWER. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Vertical Drop Testing and Analysis of the Wasp Helicopter Skid Gear

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fuchs, Yvonne T.

2007-01-01

This report describes an experimental program to assess the impact performance of a skid gear for use on the Wasp kit-built helicopter, which is marketed by HeloWerks, Inc. of Hampton, Virginia. In total, five vertical drop tests were performed. The test article consisted of a skid gear mounted beneath a steel plate. A seating platform was attached to the upper surface of the steel plate, and two 95th percentile Hybrid III male Anthropomorphic Test Devices (ATDs) were seated on the platform and secured using a four-point restraint system. The test article also included ballast weights to ensure the correct position of the Center-of-Gravity (CG). Twenty-six channels of acceleration data were collected per test at 50,000 samples per second. The five drop tests were conducted on two different gear configurations. The details of these test programs are presented, as well as an occupant injury assessment. Finally, a finite element model of the skid gear test article was developed for execution in LS-DYNA, an explicit nonlinear transient dynamic code, for predicting the skid gear and occupant dynamic responses due to impact.

LANL Skid Testing Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickson, Peter

2014-04-09

Our improved understanding of the processes occurring during complex drop / skid events has explained the previously observed scatter in skid and drop test data, and provided new insights into effective mitigation strategies. However, it has been perceived to undermine our current safety assumptions, which is inaccurate. We have no reason to believe that our safety margin from HEVR (the event of concern) is any different to that previously assumed – we just have a much better experimental and theoretical basis by which to measure it more accurately. Until this work is complete or, at least, more mature, we cannotmore » draw any conclusions on whether we are more or less safe than we thought, but we know that use of cushioned surfaces, along with sensible housekeeping, mitigates the potential activation of the skid-grit mechanism.« less

ETF Facility evaporator skid orifice sizing design analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

ELLINGSON, S.D.

1999-08-31

This document releases and records the design analysis for sizing the Orifice plate being installed on the Effluent Treatment Facility (ETF) evaporator skid per Engineering Change Notice (ECN) 651583.

Skid correction program : user's manual.

DOT National Transportation Integrated Search

2012-06-01

This document outlines methods for use by UDOT personnel to address pavements with unacceptable skid numbers. The program involves coordination between Safety, Pavement Management, Region, and Maintenance managers. A process has been recommended usin...

Design of bituminous mixes with high skid resistance.

DOT National Transportation Integrated Search

1979-01-01

Certain highway locations need exceptionally high skid resistance because of the alignment, geometry, and drainage of the roadway and the complex turning maneuvers required. Several beam specimens made of bituminous mixes incorporating unconventional...

Full-Tree Skidding Favors Black Spruce Reproduction Under Certain Peatland Conditions

Treesearch

William F. Johnston

1980-01-01

Two trials on different sites indicate that clearcut black spruce reproduces well after full-tree skidding only on nonbrushy sites that have fairly abundant sphagnum seedbeds and adequate natural seeding.

Methodology for utilizing survey skid data.

DOT National Transportation Integrated Search

1975-01-01

This report sets forth procedures for utilizing survey skid data with consideration given to testing variabilities and relationships between the three testing devices used in Virginia namely, the Virginia Department of Highways & Transportation's tra...

Blended aggregate bituminous mixes.

DOT National Transportation Integrated Search

1975-01-01

Virginia has provided skid resistant pavements in the limestone area of the state by placing thin overlays of sand mixes incorporating local materials, by sprinkling highly skid resistant aggregates on limestone bituminous mixes prior to rolling, and...

Recovery of residue tops in selectively cut northern hardwood stands.

Treesearch

James A. Johnson; Rodger A. Arola; Edwin S. Miyata

1982-01-01

Tests the feasibility and economics of compacting hardwood tops with a prototype shearing and bunching device prior to skidding. Presents productivity levels and costs associated with compacting, skidding, and chipping hardwood tops.

Design of bituminous surface mixes with high skid resistance.

DOT National Transportation Integrated Search

1974-01-01

The Virginia Highway Research Council has proposed a study of the skid resistance of bituminous surfaces incorporating relatively hard and expensive aggregates. The hardness of the aggregates to be used aluminum oxide (Exolon) and calcined kaolin -- ...

Orbiter post-tire failure and skid testing results

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.; Stubbs, Sandy M.

1989-01-01

An investigation was conducted at the NASA Langley Research Center's Aircraft Landing Dynamics Facility (ALDF) to define the post-tire failure drag characteristics of the Space Shuttle Orbiter main tire and wheel assembly. Skid tests on various materials were also conducted to define their friction and wear rate characteristics under higher speed and bearing pressures than any previous tests. The skid tests were conducted to support a feasibility study of adding a skid to the orbiter strut between the main tires to protect an intact tire from failure due to overload should one of the tires fail. Roll-on-rim tests were conducted to define the ability of a standard and a modified orbiter main wheel to roll without a tire. Results of the investigation are combined into a generic model of strut drag versus time under failure conditions for inclusion into rollout simulators used to train the shuttle astronauts.

Development of an electric, battery powered, skid-steer loader

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alcock, R.; Froehlich, D.P.; Christianson, L.L.

1985-01-01

A battery powered, skid-steer loader was developed for farm chore routines and materials handling activities. Outlined are details on drive train, hydraulics, loader, frame, cab, controls, battery and controller. Preliminary performance characteristics of the hydraulics are presented.

Installation report on porous friction course hot plant mix.

DOT National Transportation Integrated Search

1972-01-01

An investigation was initiated in the spring of 1972 to develop surface mixes with high skid resistance for use at special locations. The porous friction course will hopefully provide high skid coefficients where water drainage and hydroplaning may b...

Comparison of skid resistance testing to stopping distance testing.

DOT National Transportation Integrated Search

1998-01-01

This report is intended to statistically summarize the results of a side-by-side test of the skid resistance testing trailer utilized by the Oregon Department of Transportation (ODOT), and the stopping distance car utilized by the Oregon State Police...

An evaluation of the NCSA hydrochloric acid leaching procedure.

DOT National Transportation Integrated Search

1970-02-01

In the past several years the National Crushed stone Association : has been conducting a research study into the skid resistance of carbonate : aggregate. The aim of the study has been the establishment of a relationship : between the skid resistance...

100. INTERIOR OF SKID 9A: VENT VALVE AND RELIEF VALVE ...

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

100. INTERIOR OF SKID 9A: VENT VALVE AND RELIEF VALVE FOR RAPID-LOAD LIQUID OXYGEN TANK - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Skidder load capacity and fuel consumption HP-41C program

Treesearch

Ross A. Phillips

1983-01-01

This program gives the log weight that the skidder can move and gives fuel consumption either in liters or gallons per turn. Slope of the skid trail, skidder weight, and skid distance must be entered into the program.

Development and fabrication of the Virginia skid-resistance measurement vehicle (model 2).

DOT National Transportation Integrated Search

1970-01-01

The inefficiency of the Virginia Highway Research Council, Model 1, skid measurement trailer, and the increasing effort expended by the American Society for Testing and Materials toward the development of more stringent specifications for pavement sk...

Non-contact skid resistance measurement : final report, December 2009.

DOT National Transportation Integrated Search

2009-12-01

In this research, a correlation between the SN40R collected by locked wheel skid tester and the : texture data or Mean Profile Depth (MPD) collected by a vehicle mounted laser operating at highway : speeds was developed. The proposed correlation betw...

Wet weather highway accident analysis and skid resistance data management system (volume I).

DOT National Transportation Integrated Search

1992-06-01

The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.; JOHNS, B.R.

1999-12-21

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

2000-02-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-08-11

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.

1999-05-05

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-10-26

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.; KOCH, M.R.

2000-01-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Wet weather highway accident analysis and skid resistance data management system (volume II : user's manual).

DOT National Transportation Integrated Search

1992-06-01

The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

146. FUEL LINE TO SKID 2 (FUEL LOADER) IN FUEL ...

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

146. FUEL LINE TO SKID 2 (FUEL LOADER) IN FUEL CONTROL ROOM (215), LSB (BLDG. 751). LIQUID NITROGEN/HELIUM HEAT EXCHANGER ON RIGHT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

82. GENERAL VIEW FROM NORTH OF FUEL STORAGE AND TRANSFER ...

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

82. GENERAL VIEW FROM NORTH OF FUEL STORAGE AND TRANSFER CONTROL SKID (SKID 2) ON SOUTH END OF SLC-3W FUEL APRON - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Durability of certain configurations for providing skid resistance on concrete pavements.

DOT National Transportation Integrated Search

1974-01-01

The main objective of this study was to establish the factors that influence the durability of the surface configurations that are used or can be used to provide high and long lasting skid resistance for portland cement concrete pavements. In the dev...

An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

PubMed

Pardillo Mayora, José M; Jurado Piña, Rafael

2009-07-01

Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions.

Highway pavement performance test for colored thin anti-skidding layers

NASA Astrophysics Data System (ADS)

Gao, Wei; Cui, Wei; Xu, Ming

2018-03-01

Based on the actual service condition of highway pavement colored thin anti-skidding layers, with materials of color quartz sand and two-component acrylic resin as basis, we designed such tests as the bond strength, shearing strength, tear strength, fatigue performance and aggregate polished value, and included the freeze-thaw cycle and de-icing salt and other factors in the experiment, connecting with the climate characteristics of circumpolar latitude and low altitude in Heilongjiang province. Through the pavement performance test, it is confirmed that the colored thin anti-skidding layers can adapt to cold and humid climate conditions, and its physical mechanical properties are good.

The contribution of micro- and macro-texture to the skid resistance of flexible pavement.

DOT National Transportation Integrated Search

2016-02-01

Skid resistance is an important characteristic of the pavement surface to reduce the number of road accidents. The : mechanisms involved in the activation of the frictional force required for a safe braking of the vehicle depend on both : the macro- ...

Pyrogasification of blended animal manures to produce combustable gas and biochar

USDA-ARS?s Scientific Manuscript database

The objective of this study is to evaluate the efficiency of a skid-mounted pyrogasificaiton system for producing combustible gas from from animal manures: chicken litter, swine solids, and swine solids blended with rye grass. The skid-mounted pyrolysis system by the US Innovation Group, Inc. (USIG,...

149. SOUTHEAST CORNER OF FUEL CONTROL ROOM (215), LSB (BLDG. ...

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

149. SOUTHEAST CORNER OF FUEL CONTROL ROOM (215), LSB (BLDG. 751), WITH SKID 2 IN FOREGROUND; FUEL LINE TO LAUNCH VEHICLE ENTERING WALL ON LEFT BEHIND SKID 2 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

NASA Technical Reports Server (NTRS)

Horne, W. B.

1977-01-01

Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

An evaluation of the effects of tread depth, pavement texture, and water film thickness on skid number-speed gradients : supplement.

DOT National Transportation Integrated Search

1975-03-01

The raw data and the initial curves for the study entitled, "An Evaluation of the Effects of Tread Depth, Pavement Texture, and Water Film Thickness on Skid Number-Speed Gradients" are so voluminous that they are included in the Supplement rather tha...

77 FR 21662 - Amendment of Class D Airspace; Cocoa Beach, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-11

...-0099; Airspace Docket No. 12-ASO-11] Amendment of Class D Airspace; Cocoa Beach, FL AGENCY: Federal... Class D airspace at Cape Canaveral Skid Strip, Cocoa Beach, FL, by correcting the geographic coordinates... of Cape Canaveral Skid Strip, Cocoa Beach, FL. Also, the geographic coordinates for the airport need...

Soil response to skidder trafficking and slash application

Treesearch

Brian M. Parkhurst; W. Michael Aust; M. Chad Bolding; Scott M. Barrett; Emily A. Carter

2018-01-01

Ground-based timber harvesting systems are common in the United States. Harvesting machinery can negatively influence soils by increasing erosion and decreasing site productivity. Skid trails can become compacted and erosive. Slash applications to skid trails are effective for erosion control, yet few investigations have examined effects of slash on soil physical...

Function investigation of stone mastic asphalt (SMA) mixture partly containing basic oxygen furnace (BOF) slag.

PubMed

Chen, Zongwu; Wu, Shaopeng; Pang, Ling; Xie, Jun

2016-07-04

In this paper, the effect of the size gradations of basic oxygen furnace (BOF) slag on the functional performances of stone mastic asphalt (SMA) mixture including skid and deformation resistances was investigated. The industrially produced BOF slag coarse aggregates (BSCA) with size gradations of 4.75-9.5 mm and 9.5-16 mm were used. SMA mixtures were designed according to Marshall procedure. British pendulum number (BPN), indicating the skid resistance of asphalt mixture, was measured by a British pendulum skid resistance device. Flow number (FN) and Marshall quotient (MQ), reflecting the deformation resistance of asphalt mixture, were determined, respectively, based on the results of dynamic creep test and Marshall test (stability and flow value). Showed that BSCA with a size gradation of 9.5-16 mm performed better in improving the skid and deformation resistance of SMA mixture than BSCA with a size gradation of 4.75-9.5 mm. Furthermore, BSCA with combined size gradations, namely, 4.75-16 mm, worked the best. These conclusions would benefit the future extensive utilization of BSCA in asphalt pavement.

3-D Transient Heat Transfer Analysis of Slab Heating Characteristics in a Reheating Furnace in Hot Strip Mills

NASA Astrophysics Data System (ADS)

Jang, J. Y.; Lee, Y. W.; Lin, C. N.; Wang, C. H.

2016-05-01

A three-dimensional mathematical transient heat transfer model for the prediction of temperature distribution within the slab has been developed by considering the thermal radiation in the walking-beam-type reheating furnace chamber. The steel slabs are heated up through the non-firing, preheating, 1st-heating, 2nd-heating, and soaking zones in the furnace, respectively, where the furnace wall temperature is function of time. Comparison with the in-situ experimental data from Steel Company in Taiwan shows that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace. The effects of different skid button height (H=60mm, 90mm, and 120mm) and different gap distance between two slabs (S=50mm, 75mm, and 100mm) on the slab skid mark formation and temperature profiles are investigated. It is found that the skid mark severity decreases with an increase in the skid button height. The effect of gap distance is important only for the slab edge planes, while it is insignificant for the slab central planes.

Analysis and experimental kinematics of a skid-steering wheeled robot based on a laser scanner sensor.

PubMed

Wang, Tianmiao; Wu, Yao; Liang, Jianhong; Han, Chenhao; Chen, Jiao; Zhao, Qiteng

2015-04-24

Skid-steering mobile robots are widely used because of their simple mechanism and robustness. However, due to the complex wheel-ground interactions and the kinematic constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop an analysis and experimental kinematic scheme for a skid-steering wheeled vehicle based-on a laser scanner sensor. The kinematics model is established based on the boundedness of the instantaneous centers of rotation (ICR) of treads on the 2D motion plane. The kinematic parameters (the ICR coefficient , the path curvature variable and robot speed ), including the effect of vehicle dynamics, are introduced to describe the kinematics model. Then, an exact but costly dynamic model is used and the simulation of this model's stationary response for the vehicle shows a qualitative relationship for the specified parameters and . Moreover, the parameters of the kinematic model are determined based-on a laser scanner localization experimental analysis method with a skid-steering robotic platform, Pioneer P3-AT. The relationship between the ICR coefficient and two physical factors is studied, i.e., the radius of the path curvature and the robot speed . An empirical function-based relationship between the ICR coefficient of the robot and the path parameters is derived. To validate the obtained results, it is empirically demonstrated that the proposed kinematics model significantly improves the dead-reckoning performance of this skid-steering robot.

Modeling of traction-coupling properties of wheel propulsor

NASA Astrophysics Data System (ADS)

Sakhapov, R. L.; Nikolaeva, R. V.; Gatiyatullin, M. H.; Makhmutov, M. M.

2017-12-01

In conditions of operation of aggregates on soils with low bearing capacity, the main performance indicators of their operation are determined by the properties of retaining the functional qualities of the propulsor. Therefore, the parameters of the anti-skid device can not be calculated by only one criterion. The equipment of propellers with anti-skid devices, which allow to reduce the compaction effect of the propulsion device on the soil, seems to be a rational solution to the problem of increasing traction and coupling properties of the driving wheels. The mathematical model is based on the study of the interaction of the driving wheel with anti-skid devices and a deformable bearing surface, which takes into account the wheel diameter, skid coefficient, the parameters of the anti-skid device, the physical and mechanical properties of the soil. As a basic mathematical model that determines the dependence of the coupling properties on the wheel parameters, the model obtained as a result of integration and reflecting the process of soil deformation from the shear stress is adopted. The total value of the resistance forces will determine the force of the hitch pressure on the horizontal soil layers, and the value of its deformation is the degree of wheel slippage. When the anti-skid devices interact with the soil, the traction capacity of the wheel is composed of shear forces, soil shear and soil deformation forces with detachable hooks. As a result of the interaction of the hook with the soil, the latter presses against the walls of the hook with the force equal to the sum of the hook load and the resistance to movement. During operation, the linear dimensions of the hook will decrease, which is not taken into account by the safety factor. Abrasive wear of the thickness of the hook is approximately proportional to the work of friction caused by the movement of the hook when inserted into the soil and slipping the wheel.

Full-Tree SKidding Black Spruce: Another Way to Favor Reproduction

Treesearch

William F. Johnston

1975-01-01

An alternative to burning is needed for clearcut peatlands where only slash disposal is required to rapidly reproduce black spruce. A 2-year trial in north-central Minnesota indicates that reproduction will be rapid after full-tree skidding on nonbrushy sites taht have well-distribted sphagnum seedbeds and ample natural seeding. Broadcast burning is still recommended...

Forestry best management practices and sediment control at skidder stream crossings

Treesearch

Laura R. Wear; W. Michael Aust; M. Chad Bolding; Brian D. Strahm; Andrew C. Dolloff

2015-01-01

Stream crossings for skid trails have high sediment delivery ratios. Forestry Best Management Practices (BMPs) have proven to be effective for erosion control, but few studies have quantified the impact of various levels of BMPs on sedimentation. In this study, three skid-trail stream-crossing BMP treatments were installed on nine operational stream crossings (three...

77 FR 4914 - Consumer Information Regulations; Fees for Use of Traction Skid Pads

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... found at 49 CFR 575.104. To aid consumers in making an informed choice in the purchase of passenger car..., App. B. Several commercial facilities also have traction skid pads. The current fees charged for use... these tires for purchase by manufacturers. Based on NHTSA's assessment using a ``market price'' analysis...

Felling and skidding productivity and harvesting cost in southern pine forests

Treesearch

R.A. Kluender; B.J. Stokes

1996-01-01

Sixteen stands were harvested at various levels of basal area removed (intensity). Chainsaw felling productivity was more sensitive to stem diameter than harvest intensity. Skidding productivity was highest when removing large trees at high intensity. Harvesting cost was more sensitive to stem size than harvest intensity, although harvest intensity was a very important...

46 CFR 160.042-2 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... requirements. (a) The requirements of this subpart provide for a standard life raft skid for use on ocean and coastwise vessels in conjunction with the stowage of Type A rafts which may be used on such vessels. (b) Life raft skids shall be constructed and arranged so as to properly support a Type A life raft in the...

Flail-Delimbing of Loblolly Pine - A Case Study

Treesearch

Bryce J. Stokes

1985-01-01

Flail-delimbing was tested in small-diameter loblolly pine. Most of the limbs left on the stems were less than 6 inches long. Over 75 percent of the delimbed stems had three or fewer remaining limbs. The cost was determined by comparing skidding-flailing with skidding only. The cost difference was approximately $6.00 per unit.

14 CFR 29.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2012 CFR

2012-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 29.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

14 CFR 27.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2012 CFR

2012-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 27.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

14 CFR 29.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2014 CFR

2014-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 29.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

14 CFR 27.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2014 CFR

2014-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 27.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

14 CFR 29.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2013 CFR

2013-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 29.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

14 CFR 27.501 - Ground loading conditions: landing gear with skids.

Code of Federal Regulations, 2013 CFR

2013-01-01

... exceed those obtained in a drop test of the gear with— (i) A drop height of 1.5 times that specified in § 27.725; and (ii) An assumed rotor lift of not more than 1.5 times that used in the limit drop tests...) The ground reactions rationally distributed along the bottom of the skid tube. (b) Vertical reactions...

46 CFR Appendix A to Part 520 - Standard Terminology and Codes

Code of Federal Regulations, 2011 CFR

2011-10-01

... DTB Firkin FIR Flo-Bin FLO Frame FRM Flask FSK Forward Reel FWR Garment on Hanger GOH Heads of Beef... Private Vehicle POV Pipe Rack PRK Quarters of Beef QTR Rail (semiconductor) RAL Rack RCK Reel REL Roll ROL Reverse Reel RVR Sack SAK Shook SHK Sides of Beef SID Skid SKD Skid, Elev, Lift Trk SKE Sleeve SLV Spin...

46 CFR Appendix A to Part 520 - Standard Terminology and Codes

Code of Federal Regulations, 2012 CFR

2012-10-01

... DTB Firkin FIR Flo-Bin FLO Frame FRM Flask FSK Forward Reel FWR Garment on Hanger GOH Heads of Beef... Private Vehicle POV Pipe Rack PRK Quarters of Beef QTR Rail (semiconductor) RAL Rack RCK Reel REL Roll ROL Reverse Reel RVR Sack SAK Shook SHK Sides of Beef SID Skid SKD Skid, Elev, Lift Trk SKE Sleeve SLV Spin...

46 CFR Appendix A to Part 520 - Standard Terminology and Codes

Code of Federal Regulations, 2013 CFR

2013-10-01

... DTB Firkin FIR Flo-Bin FLO Frame FRM Flask FSK Forward Reel FWR Garment on Hanger GOH Heads of Beef... Private Vehicle POV Pipe Rack PRK Quarters of Beef QTR Rail (semiconductor) RAL Rack RCK Reel REL Roll ROL Reverse Reel RVR Sack SAK Shook SHK Sides of Beef SID Skid SKD Skid, Elev, Lift Trk SKE Sleeve SLV Spin...

46 CFR Appendix A to Part 520 - Standard Terminology and Codes

Code of Federal Regulations, 2014 CFR

2014-10-01

... DTB Firkin FIR Flo-Bin FLO Frame FRM Flask FSK Forward Reel FWR Garment on Hanger GOH Heads of Beef... Private Vehicle POV Pipe Rack PRK Quarters of Beef QTR Rail (semiconductor) RAL Rack RCK Reel REL Roll ROL Reverse Reel RVR Sack SAK Shook SHK Sides of Beef SID Skid SKD Skid, Elev, Lift Trk SKE Sleeve SLV Spin...

46 CFR Appendix A to Part 520 - Standard Terminology and Codes

Code of Federal Regulations, 2010 CFR

2010-10-01

... DTB Firkin FIR Flo-Bin FLO Frame FRM Flask FSK Forward Reel FWR Garment on Hanger GOH Heads of Beef... Private Vehicle POV Pipe Rack PRK Quarters of Beef QTR Rail (semiconductor) RAL Rack RCK Reel REL Roll ROL Reverse Reel RVR Sack SAK Shook SHK Sides of Beef SID Skid SKD Skid, Elev, Lift Trk SKE Sleeve SLV Spin...

Skidding with horses to thin young stands in western Washington.

Treesearch

Norman P. Worthington

1957-01-01

Increased use of commercial thinning to provide an additional source of needed raw material and to boost overall yields from forest lands has again brought horses into the northwest woods. They are particularly well adapted to skidding small logs under the light, frequent cuts typical of a thinning operation. Horses can, moreover, work at close quarters in a young...

Felling and skidding cost estimates for thinnings to reduce gypsy moth impacts

Treesearch

Michael D. Erickson; Curt C. Hassler; Chris B. LeDoux

1991-01-01

The gypsy moth is a serious threat to the hardwood forests of the eastern United States. Although chemical treatments currently exist which can be used to help control the impacts of the moth, silvicultural control measures are just now being proposed and tested. Felling and skidding cost estimates for harvesting merchantable timber under two such proposed...

Economic comparisons of haul road construction versus forwarding versus longer skid distances

Treesearch

Michael D. Erickson; Curt C. Hassler; Chris B. LeDoux

1992-01-01

There currently exists no set of basic guidelines for Appalachian loggers to use in the decision making process for selecting the best way to harvest a tract of timber. Specifically, guidelines are needed for deciding between the alternatives of constructing truck haul roads to access an area or other alternatives such as skidding or forwarding timber longer distances...

Logging costs and cutting methods in young-growth ponderosa pine in California

Treesearch

Philip M. McDonald; William A. Atkinson; Dale O. Hall

1969-01-01

Mixed-conifer stands at the Challenge Experimental Forest, Calif., were cut to four specifications: seed-tree, group selection, single tree selection, and clearcut. Logging costs and production rates were compared and evaluated. Cutting method had little effect on felling or skidding production; felling ranged from 1,802 to 2,019 bd ft per hour, and skidding from 3,138...

78. GENERAL VIEW OF SLC3W FUEL APRON FROM NORTH. HELIUM ...

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

78. GENERAL VIEW OF SLC-3W FUEL APRON FROM NORTH. HELIUM AND NITROGEN STORAGE TANKS AND CONTROL SKIDS IN LEFT CENTER. FUEL STORAGE TANK AND CONTROL SKID IN RIGHT BACKGROUND. SLC-3E MST IN DISTANT RIGHT BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Effects of soil compaction on residual stand growth in central Appalachian hardwood forest: a preliminary case study

Treesearch

Jingxin Wang; Chris LeDoux; Michael Vanderberg; Li Yaoxiang

2006-01-01

A preliminary study that quantified the impacts of soil compaction on residual tree growth associated with ground-based skidding traffic intensity and turn payload size was investigated in the central Appalachian hardwood forest. The field study was carried out on a 20-acre tract of the West Virginia University Research Forest. Skid trails were laid out in 170' -...

Long-term stand growth after helicopter and ground-based skidding in a tupelo-cypress wetland: 21-year results

Treesearch

D.E. Evans; W.M. Aust; J.A. Peterson

2013-01-01

Three disturbance treatments were implemented on a tupelo-cypress forested wetland in southwestern Alabama on the Tensaw River in 1986: (1) clearcutting with helicopter log removal (HELI), (2) HELI followed by rubber-tired skidder traffic simulation (SKID), and (3) HELI followed by removal of all vegetation during the first two growing seasons via glyphosate herbicide...

Reclamation of skid roads with fiber mats and native vegetation: effects on erosion

Treesearch

shawn T. Grushecky; David w. McGill; William Grafton; John Edwards; Lisa Tager

2007-01-01

A research study was established to test the effectiveness of fiber mats and native seed mixtures in reducing soil erosion from newly-constructed skid roads in the Elk River Watershed in central West Virginia. Twelve road sections of equal grade were paired with a randomly-selected section receiving a fiber mat and native grass seed while the other road section was not...

114. WEST SIDE OF LIQUID OXYGEN CONTROL ROOM (205). LIQUID ...

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

114. WEST SIDE OF LIQUID OXYGEN CONTROL ROOM (205). LIQUID NITROGEN (LN2) SUBCOOLER ON LEFT; SKID 8, LIQUID OXYGEN CONTROLLER FOR SWITCHING BETWEEN RAPID-LOAD AND TOPPING ON RIGHT. LIQUID OXYGEN LINE FROM SKID 9A AT RIGHT EDGE OF PHOTO. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades.

Treesearch

Ronald Heninger; William Scott; Alex Dobkowski; Richard Miller; Harry Anderson; Steve Duke

2002-01-01

We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at...

'Skidding' of the CRRES G-9 barium release

NASA Technical Reports Server (NTRS)

Huba, J. D.; Mitchell, H. G.; Fedder, J. A.; Bernhardt, P. A.

1992-01-01

A simulation study and experimental data of the CRRES G-9 ionospheric barium release are presented. The simulation study is based on a 2D electrostatic code that incorporates time-dependent coupling to the background plasma. It is shown that the densest portion of the barium ion cloud 'skids' about 15 km within the first three seconds following the release, consistent with the optical data analyses.

Effects of Mechanical Soil Disturbance on Rill Connectivity and Soil Erosion Following Logging on Burned Hillslopes in Central California

NASA Astrophysics Data System (ADS)

Olsen, W.; Wagenbrenner, J. W.; Demirtas, I.; Robichaud, P. R.

2016-12-01

Soil erosion rates in forests increase after severe fires and may pose a threat to aquatic resources. While research has shown that the harvest of burned trees ("salvage logging") may elevate post-fire erosion, it is less clear how disturbance from logging affects rill erosion and sediment yields. We studied 14 catchments (900-7400 m2 "swales") in the area burned by the 2013 Rim Fire in the California Sierra Nevada, nine of which were burned and logged, and five that were burned and unlogged. We installed silt fences, surveyed mechanical disturbance and rill networks, and measured ground cover following logging that occurred between fall 2014 and fall 2015. The logged swales had 20-162 trees ha-1 removed, and high traffic skid trails covered 8-28% of the swale area while low traffic skid trails covered 0-13% of the area. Feller-buncher tracks were minimal at 0-6% of the swale area. Following logging, wood cover increased, while vegetation cover remained about the same. Rills densities ranged from 0.3-22 m m-2 in logged swales and 2.2-16 m m-2 in unlogged swales. Higher bare soil percentages led to increased rill density in all swales. Rills that initiated in high traffic skid trails averaged 42 m in the swales, while rills from untrafficked burned soil averaged 26 m. The number of rills from high traffic skid trails increased with the amount of skid trail area, and often were diverted by waterbars toward the swale outlets. Sediment yields increased with rill density, and did not appear to respond to the modest increase in wood cover post-logging. Results indicate that rill erosion is a dominant sediment transport mechanism for both burned forests and salvage logged forests at the hillslope to small catchment scale. Mitigating skidding disturbance, appropriate placement of waterbars, and reducing the connectivity of bare soil after logging will be important to reduce rilling and sediment yields related to salvage logging.

Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

NASA Astrophysics Data System (ADS)

Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

2018-03-01

With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to < 50 μm, and < 10 μm. Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

Development of Mainshaft High-Speed Cylindrical Roller Bearings for Gas Turbine Engines.

DTIC Science & Technology

1978-10-01

roller motion, that calculation may then be eliminated for subsequent, similar runs. TIhis option provides the user a corresponding savings in computer...to W BEARING DN X !0.6 Figl"re 2..’ Test of Grou p-N Bearing No, ,5 Shows" Increased Skid as l~oad Is N" l)’creans4’d but With No Skid at Anyt Loand

Productivity and cost of manual felling and cable skidding in central Appalachian hardwood forests

Treesearch

Jingxin Wang; Charlie Long; Joe McNeel; John Baumgras; John Baumgras

2004-01-01

A field production study was conducted for a manual harvesting system using a chainsaw and cable skidder in a central Appalachian hardwood forest site. A partial cut was performed on a 50-acre tract with an average slope of 25 percent. Felling time pre tree was most affected by diameter at breast height and the distance between harvested trees while skidding cycle time...

69. GENERAL VIEW OF SOUTH SIDE OF SLC3W LIQUID OXYGEN ...

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

69. GENERAL VIEW OF SOUTH SIDE OF SLC-3W LIQUID OXYGEN APRON. EQUIPMENT SKIDS IN FOREGROUND. LARGE LIQUID OXYGEN TANKS FLANKING NITROGEN GAS STORAGE TANKS VISIBLE BEHIND SKIDS. LAUNCH DECK VISIBLE IMMEDIATELY WEST. MST IN PARKED POSITION AT NORTHERN TERMINUS OF RAILS IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Engineering Design Handbook for Air Cleaning for Chemical Demilitarization

DTIC Science & Technology

1978-03-01

so that the housing will be horizontal when supported from a single crane hook . Mounting on skids also provides space for laying drainpipes under the...and mounted on skids to facilitate handling and installation by cranes and forklifts (see figures 4-24 and 4-31). The lifting eyes must be located...environmental conditions prevailing during chemical demil operations. Many filter media cannot withstand acid or caustic fumes. Fiberglass, a conunon constituent

70. VIEW OF FUEL APRON FROM EAST SIDE OF LAUNCH ...

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

70. VIEW OF FUEL APRON FROM EAST SIDE OF LAUNCH PAD. ROCKET FUEL TANKS ON LEFT; GASEOUS NITROGEN AND HELIUM TANKS IN CENTER; AND A LARGE LIQUID NITROGEN TANK ON RIGHT. SKID 1 FOR GASEOUS NITROGEN TRANSFER AND SKID 5 FOR HELIUM TRANSFER IN THE CENTER RIGHT PORTION OF THE PHOTOGRAPH. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Influence of skid trails and haul roads on understory plant richness and composition in managed forest landscapes in Upper Michigan, USA

Treesearch

David S. Buckley; Thomas R. Crow; Elizabeth A. Nauertz; Kurt E. Schulz

2003-01-01

We evaluated impacts of disturbance in interior haul roads and skid trails on understory vegetation by documenting the areal extent of these features and plant composition along 10 m x 100 m belt transects. Ten belt transects were sampled in each of three comparable northern hardwood forests under even-aged management. These forests were approximately 80 years old and...

Skid resistance performance of asphalt wearing courses with electric arc furnace slag aggregates.

PubMed

Kehagia, Fotini

2009-05-01

Metallurgical slags are by-products of the iron and steel industry and are subdivided into blast furnace slag and steel slag according to the different steel-producing processes. In Greece, slags are mostly produced from steelmaking using the electric arc furnace process, and subsequently are either disposed in a random way or utilized by the cement industry. Steel slag has been recently used, worldwide, as hard aggregates in wearing courses in order to improve the skidding resistance of asphalt pavements. At the Highway Laboratory, Department of Civil Engineering of Aristotle University of Thessaloniki research has been carried out in the field of steel slags, and especially in electric arc furnace (EAF) slag, to evaluate their possible use in highway engineering. In this paper, the recent results of anti-skidding performance of steel slag aggregates in highway pavements are presented.

Composite skid landing gear design investigation

NASA Astrophysics Data System (ADS)

Shrotri, Kshitij

A Composite Skid Landing Gear Design investigation has been conducted. Limit Drop Test as per Federal Aviation Regulations (FAR) Part 27.725 and Crash test as per MIL STD 1290A (AV) were simulated using ABAQUS to evaluate performance of multiple composite fiber-matrix systems. Load factor developed during multiple landing scenarios and energy dissipated during crash were computed. Strength and stiffness based constraints were imposed. Tsai-Wu and LaRC04 physics based failure criteria were used for limit loads. Hashin's damage initiation criteria with Davila-Camanho's energy based damage evolution damage evolution law were used for crash. Initial results indicate that all single-composite skid landing gear may no be feasible due to strength concerns in the cross member bends. Hybridization of multiple composites with elasto-plastic aluminum 7075 showed proof of strength under limit loads. Laminate tailoring for load factor optimization under limit loads was done by parameterization of a single variable fiber orientation angle for multiple laminate families. Tsai-Wu failure criterion was used to impose strength contraints. A quasi-isotropic N = 4 (pi/4) 48 ply IM7/8552 laminate was shown to be the optimal solution with a load failure will be initiated as matrix cracking under compression and fiber kinking under in-plane shear and longitudinal compression. All failures under limit loads being reported in the metal-composite hybrid joint region, the joint was simulated by adhesive bonding and filament winding, separately. Simply adhesive bonding the metal and composite regions does not meet strength requirements. A filament wound metal-composite joint shows proof of strength. Filament wound bolted metal-composite joint shows proof of strength. Filament wound composite bolted to metal cross member radii is the final joining methodology. Finally, crash analysis was conducted as per requirements from MIL STD 1290A (AV). Crash at 42 ft/sec with 1 design gross weight (DGW) lift was simulated using ABAQUS. Plastic and friction energy dissipation in the reference aluminum skid landing gear was compared with plastic, friction and damage energy dissipation in the hybrid composite design. Damage in composites was modeled as progressive damage with Hashin's damage initiation criteria and an energy based damage evolution law. The latter meets requirements of aircraft kinetic energy dissipation up to 20 ft/sec (67.6 kJ) as per MIL STD 1290A (AV). Weight saving possibility of up to 49% over conventional metal skid landing gear is reported. The final design recommended includes Ke49/PEEK skids, 48 ply IM7/8552 (or IM7/PEEK) cross member tapered beams and Al 7075 cross member bend radii, the latter bolted to the filament wound composite-metal tapered beam. Concerns in composite skid landing gear designs, testing requirements and future opportunities are addressed.

An Analytic Tool to Investigate the Effect of Binder on the Sensitivity of HMX-Based Plastic Bonded Explosives in the Skid Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayden, D. W.

This project will develop an analytical tool to calculate performance of HMX based PBXs in the skid test. The skid-test is used as a means to measure sensitivity for large charges in handling situations. Each series of skid tests requires dozens of drops of large billets. It is proposed that the reaction (or lack of one) of PBXs in the skid test is governed by the mechanical properties of the binder. If true, one might be able to develop an analytical tool to estimate skid test behavior for new PBX formulations. Others over the past 50 years have tried tomore » develop similar models. This project will research and summarize the works of others and couple the work of 3 into an analytical tool that can be run on a PC to calculate drop height of HMX based PBXs. Detonation due to dropping a billet is argued to be a dynamic thermal event. To avoid detonation, the heat created due to friction at impact, must be conducted into the charge or the target faster than the chemical kinetics can create additional energy. The methodology will involve numerically solving the Frank-Kamenetskii equation in one dimension. The analytical problem needs to be bounded in terms of how much heat is introduced to the billet and for how long. Assuming an inelastic collision with no rebound, the billet will be in contact with the target for a short duration determined by the equations of motion. For the purposes of the calculations, it will be assumed that if a detonation is to occur, it will transpire within that time. The surface temperature will be raised according to the friction created using the equations of motion of dropping the billet on a rigid surface. The study will connect the works of Charles Anderson, Alan Randolph, Larry Hatler, Alfonse Popolato, and Charles Mader into a single PC based analytic tool. Anderson's equations of motion will be used to calculate the temperature rise upon impact, the time this temperature is maintained (contact time) will be obtained from the work of Hatler et. al., and the reactive temperature rise will be obtained from Mader's work. Finally, the assessment of when a detonation occurs will be derived from Bowden and Yoffe's thermal explosion theory (hot spot).« less

External Device to Incrementally Skid the Habitat (E-DISH)

NASA Technical Reports Server (NTRS)

Brazell, J. W.; Introne, Steve; Bedell, Lisa; Credle, Ben; Holp, Graham; Ly, Siao; Tait, Terry

1994-01-01

A Mars habitat transport system was designed as part of the NASA Mars exploration program. The transport system, the External Device to Incrementally Skid the Habitat (E - DISH), will be used to transport Mars habitats from their landing sites to the colony base and will be detached after unloading. The system requirements for Mars were calculated and scaled for model purposes. Specific model materials are commonly found and recommendations for materials for the Mars design are included.

Project W-320, 241-C-106 sluicing HVAC calculations, Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bailey, J.W.

1998-08-07

This supporting document has been prepared to make the FDNW calculations for Project W-320, readily retrievable. The report contains the following calculations: Exhaust airflow sizing for Tank 241-C-106; Equipment sizing and selection recirculation fan; Sizing high efficiency mist eliminator; Sizing electric heating coil; Equipment sizing and selection of recirculation condenser; Chiller skid system sizing and selection; High efficiency metal filter shielding input and flushing frequency; and Exhaust skid stack sizing and fan sizing.

Vertical Drop Testing and Analysis of the WASP Helicopter Skid Gear

NASA Technical Reports Server (NTRS)

Fuchs, Yvonne T.; Jackson, Karen E.

2008-01-01

Human occupant modeling and injury risk assessment have been identified as areas of research for improved prediction of rotorcraft crashworthiness within the NASA Aeronautics Program's Subsonic Rotary Wing Project. As part of this effort, an experimental program was conducted to assess the impact performance of a skid gear for use on the WASP kit-built helicopter, which is marketed by HeloWerks, Inc. of Hampton, Virginia. Test data from a drop test at an impact velocity of 8.4 feet-per-second were used to assess a finite element model of the skid gear test article. This assessment included human occupant analytic models developed for execution in LS-DYNA. The test article consisted of an aluminum skid gear mounted beneath a steel plate. A seating platform was attached to the upper surface of the steel plate, and two 95th percentile Hybrid III male Aerospace Anthropomorphic Test Devices (ATDs) were seated on the platform and secured using a four-point restraint system. The goal of the test-analysis correlation is to further the understanding of LS-DYNA ATD occupant models and responses in the vertical (or spinal) direction. By correlating human occupant experimental test data for a purely vertical impact with the LS-DYNA occupant responses, improved confidence in the use of these tools and better understanding of the limitations of the automotive-based occupant models for aerospace application can begin to be developed.

Vertical Drop Testing and Analysis of the WASP Helicopter Skid Gear

NASA Technical Reports Server (NTRS)

Fuchs, Yvonne T.; Jackson, Karen E.

2008-01-01

Human occupant modeling and injury risk assessment have been identified as areas of research for improved prediction of rotorcraft crashworthiness within the NASA Aeronautics Program s Subsonic Rotary Wing Project. As part of this effort, an experimental program was conducted to assess the impact performance of a skid gear for use on the WASP kit-built helicopter, which is marketed by HeloWerks, Inc. of Hampton, Virginia. Test data from a drop test at an impact velocity of 8.4 feet-per-second were used to assess a finite element model of the skid gear test article. This assessment included human occupant analytic models developed for execution in LS-DYNA. The test article consisted of an aluminum skid gear mounted beneath a steel plate. A seating platform was attached to the upper surface of the steel plate, and two 95th percentile Hybrid III male Aerospace Anthropomorphic Test Devices (ATDs) were seated on the platform and secured using a four-point restraint system. The goal of the test-analysis correlation is to further the understanding of LS-DYNA ATD occupant models and responses in the vertical (or spinal) direction. By correlating human occupant experimental test data for a purely vertical impact with the LS-DYNA occupant responses, improved confidence in the use of these tools and better understanding of the limitations of the automotive-based occupant models for aerospace application can begin to be developed.

Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helsen, Jan; Guillaume, Patrick; Guo, Yi

Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer periodmore » of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.« less

Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helsen, Jan; Guillaume, Patrick; Guo, Yi

Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer periodmore » of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.« less

A Comparative Study of Soviet versus Western Helicopters. Part 2. Evaluation of Weight, Maintainability, and Design Aspects of Major Components

DTIC Science & Technology

1983-03-01

transmnission ratingob gearbox ult uldiatc gOr tail-rotor gearbox Vr vertical tailh hub w wheelhr horizontal tail w/ wheel -type landing-gear legslob...depends on ýhe type of landing gear (skid, fixed- wheel , or retractable). The RTL approach takes into consideration not only gross weight, but also...depending on the helicopter configuration (single- rotor, tandem, or side-by-side), and the type of landing gear ( wheel or skid). For a single-rotor

Flightfax - Army Aviation Risk-Management Information. Volume 25, Number 11, August 1997. Snow

DTIC Science & Technology

1997-08-01

but why haven’t Loach that would ensure our surviving a multiple- you been acknowledging the radio calls?" A quick wire strike. check confirmed that...helicopter upright with only the collective and Loach on post with skid shoes, the skid cleats would pedals. have snagged the middle wire and flipped...is more cost effective to overhaul until because masking violated FAA Mr. Ken Muzzo, DSN 490-2257 (314-260- the retirement life is reached. The

Development of Minimum Physical Fitness Standards for the Canadian Armed Forces. Phase 3

DTIC Science & Technology

1988-03-01

while mounting stairs more than tripled their energy expenditures . Similarly, Astrand and Rodahl (1977) determined that continuous stair climbing...evacuation tasks were restructured to be one-person tasks (i.e., wheels on the land stretcher; a push-skid for the sea evacuation stairs stretcher). Other...kg stoker stretcher 12.5 m to the base of a flight of stairs . The subject then pushed a skid carrying one subject’s share of the mass up and down a

Tire-to-Surface Friction-Coefficient Measurements with a C-123B Airplane on Various Runway Surfaces

NASA Technical Reports Server (NTRS)

Sawyer, Richard H.; Kolnick, Joseph J.

1959-01-01

An investigation was conducted to obtain information on the tire-to-surface friction coefficients available in aircraft braking during the landing run. The tests were made with a C-123B airplane on both wet and dry concrete and bituminous pavements and on snow-covered and ice surfaces at speeds from 12 to 115 knots. Measurements were made of the maximum (incipient skidding) friction coefficient, the full-skidding (locked wheel) friction coefficient, and the wheel slip ratio during braking.

Slip-based terrain estimation with a skid-steer vehicle

NASA Astrophysics Data System (ADS)

Reina, Giulio; Galati, Rocco

2016-10-01

In this paper, a novel approach for online terrain characterisation is presented using a skid-steer vehicle. In the context of this research, terrain characterisation refers to the estimation of physical parameters that affects the terrain ability to support vehicular motion. These parameters are inferred from the modelling of the kinematic and dynamic behaviour of a skid-steer vehicle that reveals the underlying relationships governing the vehicle-terrain interaction. The concept of slip track is introduced as a measure of the slippage experienced by the vehicle during turning motion. The proposed terrain estimation system includes common onboard sensors, that is, wheel encoders, electrical current sensors and yaw rate gyroscope. Using these components, the system can characterise terrain online during normal vehicle operations. Experimental results obtained from different surfaces are presented to validate the system in the field showing its effectiveness and potential benefits to implement adaptive driving assistance systems or to automatically update the parameters of onboard control and planning algorithms.

A robust nonlinear skid-steering control design applied to the MULE (6x6) unmanned ground vehicle

NASA Astrophysics Data System (ADS)

Kaloust, Joseph

2006-05-01

The paper presents a robust nonlinear skid-steering control design concept. The control concept is based on the recursive/backstepping control design technique and is capable of compensating for uncertainties associated with sensor noise measurements and/or system dynamic state uncertainties. The objective of this control design is to demonstrate the performance of the nonlinear controller under uncertainty associate with road traction (rough off-road and on-road terrain). The MULE vehicle is used in the simulation modeling and results.

Application of boron/epoxy reinforced aluminum stringers and boron/epoxy skid gear for the CH54B helicopter tail cone. Phase 2: Fabrication, inspection and flight test

NASA Technical Reports Server (NTRS)

Welge, R. T.

1972-01-01

A CH-54B Skycrane helicopter was fabricated with boron/epoxy reinforced stringers in the tail cone and boron/epoxy tubes in the tail skid. The fabrication of the tail cone was made with conventional tooling, production shop personnel, and no major problems. The flight test program includes a stress and vibration survey using strain gages and vibration transducers located in critical areas. The program to inspect and monitor the reliability of the components is discussed.

Review of modern methods for continuous friction measurement on airfield pavements

NASA Astrophysics Data System (ADS)

Iwanowski, Paweł; Blacha, Krzysztof; Wesołowski, Mariusz

2018-05-01

The safety of traffic, including both road and air traffic on a ground manoeuvre area, depends on many factors. These mainly include the anti-slip properties of a road or airfield pavement on which the traffic takes place. The basic pavement parameter that determines its characteristics in terms of anti-slip properties is the skid resistance, which constitutes the ratio of the wheel downforce and the friction on the contact surface. There are currently many devices for continuous measurement of the skid resistance (Continuous Friction-Measuring Equipment - CFME) around the world. Most of them, in principle, do not vary much from one another. Most of the devices measure the measuring wheel’s downforce on the pavement and the friction on the wheel-pavement contact surface. The skid resistance is the result of this measurement. The devices vary in many aspects, such as the type and size of the used measuring tyre, pavement-wheel slip or tyre pressure. This does not mean that the results obtained from various devices mbe directly compared. On the other hand, each device allows determining the pavement’s anti-slip conditions in terms of the requirements specified for the given type of devices, thereby enabling pavement classification in these terms. The classification allows for comparing the results obtained from various measuring devices. The paper presents an overview of equipment used in Poland and around the world to measure the skid resistance on airfield pavements. The authors draw attention to the requirements for pavements in terms of their roughness, with division into road and airfield pavements.

Analysis and Experimental Kinematics of a Skid-Steering Wheeled Robot Based on a Laser Scanner Sensor

PubMed Central

Wang, Tianmiao; Wu, Yao; Liang, Jianhong; Han, Chenhao; Chen, Jiao; Zhao, Qiteng

2015-01-01

Skid-steering mobile robots are widely used because of their simple mechanism and robustness. However, due to the complex wheel-ground interactions and the kinematic constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop an analysis and experimental kinematic scheme for a skid-steering wheeled vehicle based-on a laser scanner sensor. The kinematics model is established based on the boundedness of the instantaneous centers of rotation (ICR) of treads on the 2D motion plane. The kinematic parameters (the ICR coefficient χ, the path curvature variable λ and robot speed v), including the effect of vehicle dynamics, are introduced to describe the kinematics model. Then, an exact but costly dynamic model is used and the simulation of this model’s stationary response for the vehicle shows a qualitative relationship for the specified parameters χ and λ. Moreover, the parameters of the kinematic model are determined based-on a laser scanner localization experimental analysis method with a skid-steering robotic platform, Pioneer P3-AT. The relationship between the ICR coefficient χ and two physical factors is studied, i.e., the radius of the path curvature λ and the robot speed v. An empirical function-based relationship between the ICR coefficient of the robot and the path parameters is derived. To validate the obtained results, it is empirically demonstrated that the proposed kinematics model significantly improves the dead-reckoning performance of this skid–steering robot. PMID:25919370

The identification and repair of anomalous measurements in the measurement of big diameter based on rolling-wheel method

NASA Astrophysics Data System (ADS)

Chen, Haiou; Yu, Xiaofen

2011-05-01

Rolling-wheel method is an effective way of measuring big diameter. After amending the temperature error and pressure error, the uncertainty of measurement can not be φ =5um/m stably because of the influence of skid. The traditional method of identifying skid loses sight of the influences of the unstable motor speed, the appearance form error and the eccentric of installation of the big axis and rolling wheel and so on, so the method has its limitation. In this paper, a new method of multiple identification and repair is introduced, namely n diameters are measured and Chauvenet standard is used for identifying the anomalous measurements one by one, and then the average value of the remaining data is used for repairing identified anomalous measurements, and the next round identification and repair is carried out until the accuracy requirement of the measurement is satisfied. The result of experiments indicates that the method can identify anomalous measurements whose offsets caused by the skid are greater than 0.2φ , and the uncertainty of measurement has improved substantially.

Coal combine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krutki, M.; Olender, K.; Sedlaczek, J.

1981-03-24

The invention solves the problem of eliminating the transfer of the combine weight onto a conveyor through a chain instead of through a railing, in the combines which are advanced by means of a link chain meshing with a rack fixed alongside of the conveyor. To this end the slide skid (7) forcing the chain (1) to mesh with the rack (8) is provided with a tubular slipper (10). The tubular slipper (10) encloses a railing (11) situated in the gates of the conveyor (9) close to the rack (8). The tubular slipper (10) is mounted on a cranked axlemore » (12). The cranked axle (12) has - on the end of the pin embedded in the slide skid (7) a splined tip (16) embedded in a grooved hole (17) which has a common geometrical axis (15) with the pin of the cranked axle (12), the said pin being embedded in the slide skid (7). The tubular slipper (10) mounted on the pin (14) of the cranked axle (12) is protected against slipping off into the tubular slipper (10).« less

Thermodynamic Analysis on of Skid-Mounted Coal-bed Methane Liquefaction Device using Cryogenic Turbo-Expander

NASA Astrophysics Data System (ADS)

Chen, Shuangtao; Niu, Lu; Zeng, Qiang; Li, Xiaojiang; Lou, Fang; Chen, Liang; Hou, Yu

2017-12-01

Coal-bed methane (CBM) reserves are rich in Sinkiang of China, and liquefaction is a critical step for the CBM exploration and utilization. Different from other CBM gas fields in China, CBM distribution in Sinkiang is widespread but scattered, and the pressure, flow-rate and nitrogen content of CBM feed vary significantly. The skid-mounted liquefaction device is suggested as an efficient and economical way to recover methane. Turbo-expander is one of the most important parts which generates the cooling capacity for the cryogenic liquefaction system. Using turbo-expander, more cooling capacity and higher liquefied fraction can be achieved. In this study, skid-mounted CBM liquefaction processes based on Claude cycle are established. Cryogenic turbo-expander with high expansion ratio is employed to improve the efficiency of CBM liquefaction process. The unit power consumption per liquefaction mole flow-rate for CBM feed gas is used as the object function for process optimization, compressor discharge pressure, flow ratio of feed gas to turbo-expander and nitrogen friction are analyzed, and optimum operation range of the liquefaction processes are obtained.

Gait of dairy cows on floors with different slipperiness.

PubMed

Telezhenko, E; Magnusson, M; Bergsten, C

2017-08-01

This study assessed the slip resistance of different types of solid flooring in cattle housing using a range of technical tests and gait analysis. Dynamic and static coefficient of friction, skid resistance, and abrasiveness were tested on concrete flooring with a smooth finish, a grooved pattern, or a tamped pattern, acid-resistant mastic asphalt, soft rubber mats, and a worn slatted concrete floor. Coefficients of friction and skid resistance were tested under clean and slurry-soiled conditions. Linear kinematic variables were assessed in 40 cows with trackway measurements after the cows passed over the floors in a straight walk. All gait variables were assessed as deviations from those obtained on the slatted concrete floor, which was used as a baseline. The coefficient of friction tests divided the floors into 3 categories: concrete flooring, which had a low coefficient of friction (0.29-0.41); mastic asphalt flooring, which had medium values (0.38-0.45); and rubber mats, which had high values (0.49-0.57). The highest abrasion (g/10 m) was on the asphalt flooring (4.48), and the concrete flooring with a tamped pattern had significantly higher abrasiveness (2.77) than the other concrete floors (1.26-1.60). Lowest values on the skid-resistance tests (dry/wet) were for smooth concrete (79/35) and mastic asphalt (65/47), especially with a slurry layer on the surface. Gait analysis mainly differentiated floors with higher friction and abrasion by longer strides and better tracking. Step asymmetry was lower on floors with high skid-resistance values. The most secure cow gait, in almost every aspect, was observed on soft rubber mats. Relationships between gait variables and physical floor characteristics ranged from average to weak (partial correlations 0.54-0.16). Thus, none of the physical characteristics alone was informative enough to characterize slip resistance. With reference to gait analysis, the abrasiveness of the hard surfaces was more informative than the coefficient of friction, but the effect of pattern was better detected by skid-resistance measurements. Consequently, several physical characteristics are needed to objectively describe the slip resistance of cattle floors. Soft rubber mats gave better tracking than hard, solid floors, even with a grooved surface or a tamped pattern. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Closure Report for Corrective Action Unit 340: NTS Pesticide Release Sites Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. M. Obi

The purpose of this report is to provide documentation of the completed corrective action and to provide data confirming the corrective action. The corrective action was performed in accordance with the approved Corrective Action Plan (CAP) (U.S. Department of Energy [DOE], 1999) and consisted of clean closure by excavation and disposal. The Area 15 Quonset Hut 15-11 was formerly used for storage of farm supplies including pesticides, herbicides, and fertilizers. The Area 23 Quonset Hut 800 was formerly used to clean pesticide and herbicide equipment. Steam-cleaning rinsate and sink drainage occasionally overflowed a sump into adjoining drainage ditches. One ditchmore » flows south and is referred to as the quonset hut ditch. The other ditch flows southeast and is referred to as the inner drainage ditch. The Area 23 Skid Huts were formerly used for storing and mixing pesticide and herbicide solutions. Excess solutions were released directly to the ground near the skid huts. The skid huts were moved to a nearby location prior to the site characterization performed in 1998 and reported in the Corrective Action Decision Document (CADD) (DOE, 1998). The vicinity and site plans of the Area 23 sites are shown in Figures 2 and 3, respectively.« less

Effect of aggregate graining compositions on skid resistance of Exposed Aggregate Concrete pavement

NASA Astrophysics Data System (ADS)

Wasilewska, Marta; Gardziejczyk, Wladysław; Gierasimiuk, Pawel

2018-05-01

The paper presents the evaluation of skid resistance of EAC (Exposed Aggregate Concrete) pavements which differ in aggregate graining compositions. The tests were carried out on concrete mixes with a maximum aggregate size of 8 mm. Three types of coarse aggregates were selected depending on their resistance to polishing which was determined on the basis of the PSV (Polished Stone Value). Basalt (PSV 48), gabbro (PSV 50) and trachybasalt (PSV 52) aggregates were chosen. For each type of aggregate three graining compositions were designed, which differed in the content of coarse aggregate > 4mm. Their content for each series was as follows: A - 38%, B - 50% and C - 68%. Evaluation of the skid resistance has been performed using the FAP (Friction After Polishing) test equipment also known as the Wehner/Schulze machine. Laboratory method enables to compare the skid resistance of different types of wearing course under specified conditions simulating polishing processes. In addition, macrotexture measurements were made on the surface of each specimen using the Elatexure laser profile. Analysis of variance showed that at significance level α = 0.05, aggregate graining compositions as well as the PSV have a significant influence on the obtained values of the friction coefficient μm of the tested EAC pavements. The highest values of the μm have been obtained for EAC with the lowest amount of coarse aggregates (compositions A). In these cases the resistance to polishing of the aggregate does not significantly affect the friction coefficients. This is related to the large areas of cement mortar between the exposed coarse grains. Based on the analysis of microscope images, it was observed that the coarse aggregates were not sufficiently exposed. It has been proved that PSV significantly affected the coefficient of friction in the case of compositions B and C. This is caused by large areas of exposed coarse aggregate. The best parameters were achieved for the EAC pavements with graining composition B and C and trachybasalt aggregate.

Definition of simulated driving tests for the evaluation of drivers' reactions and responses.

PubMed

Bartolozzi, Riccardo; Frendo, Francesco

2014-01-01

This article aims at identifying the most significant measures in 2 perception-response (PR) tests performed at a driving simulator: a braking test and a lateral skid test, which were developed in this work. Forty-eight subjects (26 females and 22 males) with a mean age of 24.9 ± 3.0 years were enrolled for this study. They were asked to perform a drive on the driving simulator at the University of Pisa (Italy) following a specific test protocol, including 8-10 braking tests and 8-10 lateral skid tests. Driver input signals and vehicle model signals were recorded during the drives and analyzed to extract measures such as the reaction time, first response time, etc. Following a statistical procedure (based on analysis of variance [ANOVA] and post hoc tests), all test measures (3 for the braking test and 8 for the lateral skid test) were analyzed in terms of statistically significant differences among different drivers. The presented procedure allows evaluation of the capability of a given test to distinguish among different drivers. In the braking test, the reaction time showed a high dispersion among single drivers, leading to just 4.8 percent of statistically significant driver pairs (using the Games-Howell post hoc test), whereas the pedal transition time scored 31.9 percent. In the lateral skid test, 28.5 percent of the 2 × 2 comparisons showed significantly different reaction times, 19.5 percent had different response times, 35.2 percent had a different second peak of the steering wheel signal, and 33 percent showed different values of the integral of the steering wheel signal. For the braking test, which has been widely employed in similar forms in the literature, it was shown how the reaction time, with respect to the pedal transition time, can have a higher dispersion due to the influence of external factors. For the lateral skid test, the following measures were identified as the most significant for application studies: the reaction time for the reaction phase, the second peak of the steering wheel angle for the first instinctive response, and the integral of the steering wheel angle for the complete response. The methodology used to analyze the test measures was founded on statistically based and objective evaluation criteria and could be applied to other tests. Even if obtained with a fixed-base simulator, the obtained results represent useful information for applications of the presented PR tests in experimental campaigns with driving simulators.

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

DOE PAGES

Knudsen, P.; Ganni, V.; Dixon, K.; ...

2015-08-10

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knudsen, P.; Ganni, V.; Dixon, K.

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

21 CFR 888.4540 - Orthopedic manual surgical instrument.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., femoral neck punch, socket pusher, reamer, rongeur, scissors, screwdriver, bone skid, staple driver, bone screw starter, surgical stripper, tamp, bone tap, trephine, wire twister, and wrench. (b) Classification...

21 CFR 888.4540 - Orthopedic manual surgical instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., femoral neck punch, socket pusher, reamer, rongeur, scissors, screwdriver, bone skid, staple driver, bone screw starter, surgical stripper, tamp, bone tap, trephine, wire twister, and wrench. (b) Classification...

21 CFR 888.4540 - Orthopedic manual surgical instrument.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., femoral neck punch, socket pusher, reamer, rongeur, scissors, screwdriver, bone skid, staple driver, bone screw starter, surgical stripper, tamp, bone tap, trephine, wire twister, and wrench. (b) Classification...

21 CFR 888.4540 - Orthopedic manual surgical instrument.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., femoral neck punch, socket pusher, reamer, rongeur, scissors, screwdriver, bone skid, staple driver, bone screw starter, surgical stripper, tamp, bone tap, trephine, wire twister, and wrench. (b) Classification...

21 CFR 888.4540 - Orthopedic manual surgical instrument.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., femoral neck punch, socket pusher, reamer, rongeur, scissors, screwdriver, bone skid, staple driver, bone screw starter, surgical stripper, tamp, bone tap, trephine, wire twister, and wrench. (b) Classification...

Behavior of aircraft antiskid braking systems on dry and wet runway surfaces. A slip-velocity-controlled, pressure-bias-modulated system

NASA Technical Reports Server (NTRS)

Stubbs, S. M.; Tanner, J. A.; Smith, E. G.

1979-01-01

The braking and cornering response of a slip velocity controlled, pressure bias modulated aircraft antiskid braking system is investigated. The investigation, conducted on dry and wet runway surfaces, utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC 9 series 10 airplane. The landing gear strut was replaced by a dynamometer. The parameters, which were varied, included the carriage speed, tire loading, yaw angle, tire tread condition, brake system operating pressure, and runway wetness conditions. The effects of each of these parameters on the behavior of the skid control system is presented. Comparisons between data obtained with the skid control system and data obtained from single cycle braking tests without antiskid protection are examined.

Path-following control of wheeled planetary exploration robots moving on deformable rough terrain.

PubMed

Ding, Liang; Gao, Hai-bo; Deng, Zong-quan; Li, Zhijun; Xia, Ke-rui; Duan, Guang-ren

2014-01-01

The control of planetary rovers, which are high performance mobile robots that move on deformable rough terrain, is a challenging problem. Taking lateral skid into account, this paper presents a rough terrain model and nonholonomic kinematics model for planetary rovers. An approach is proposed in which the reference path is generated according to the planned path by combining look-ahead distance and path updating distance on the basis of the carrot following method. A path-following strategy for wheeled planetary exploration robots incorporating slip compensation is designed. Simulation results of a four-wheeled robot on deformable rough terrain verify that it can be controlled to follow a planned path with good precision, despite the fact that the wheels will obviously skid and slip.

Path-Following Control of Wheeled Planetary Exploration Robots Moving on Deformable Rough Terrain

PubMed Central

Ding, Liang; Gao, Hai-bo; Deng, Zong-quan; Li, Zhijun; Xia, Ke-rui; Duan, Guang-ren

2014-01-01

The control of planetary rovers, which are high performance mobile robots that move on deformable rough terrain, is a challenging problem. Taking lateral skid into account, this paper presents a rough terrain model and nonholonomic kinematics model for planetary rovers. An approach is proposed in which the reference path is generated according to the planned path by combining look-ahead distance and path updating distance on the basis of the carrot following method. A path-following strategy for wheeled planetary exploration robots incorporating slip compensation is designed. Simulation results of a four-wheeled robot on deformable rough terrain verify that it can be controlled to follow a planned path with good precision, despite the fact that the wheels will obviously skid and slip. PMID:24790582

Pegasus XL CYGNSS Arrival at CCAFS

NASA Image and Video Library

2016-12-02

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

Pegasus XL CYGNSS Prepared for Launch Aboard Orbital ATK's L-101

NASA Image and Video Library

2016-12-10

At Cape Canaveral Air Force Station's Skid Strip the Orbital ATK L-1011 Stargazer aircraft is being prepared to launch NASA's Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. The eight micro satellites are aboard an Orbital ATK Pegasus XL rocket strapped to the underside of the Stargazer. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

Pegasus XL CYGNSS Arrival at CCAFS

NASA Image and Video Library

2016-12-02

The Orbital ATK L-1011 Stargazer aircraft begins its descent to the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

40 CFR 204.51 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... compressor or compressor means any wheel, skid, truck, or railroad car mounted, but not self-propelled... reciprocating rotary or turbine engine rigidly connected in permanent alignment and mounted on a common frame...

40 CFR 204.51 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... compressor or compressor means any wheel, skid, truck, or railroad car mounted, but not self-propelled... reciprocating rotary or turbine engine rigidly connected in permanent alignment and mounted on a common frame...

40 CFR 204.51 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... compressor or compressor means any wheel, skid, truck, or railroad car mounted, but not self-propelled... reciprocating rotary or turbine engine rigidly connected in permanent alignment and mounted on a common frame...

40 CFR 266.20 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... contain. (c) Anti-skid/deicing uses of slags, which are generated from high temperature metals recovery...) Fertilizers that contain recyclable materials are not subject to regulation provided that: (1) They are zinc...

40 CFR 266.20 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... contain. (c) Anti-skid/deicing uses of slags, which are generated from high temperature metals recovery...) Fertilizers that contain recyclable materials are not subject to regulation provided that: (1) They are zinc...

Antiskid braking system

NASA Technical Reports Server (NTRS)

Pazdera, J. S.

1974-01-01

Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

Evaluation of Skid Resistance of Wearing Course Made Of Stone Mastic Asphalt Mixture in Laboratory Conditions

NASA Astrophysics Data System (ADS)

Wasilewska, Marta

2017-10-01

This paper presents the comparison of skid resistance of wearing course made of SMA (Stone Mastic Asphalt) mixtures which differ in resistance to polishing of coarse aggregate. Dolomite, limestone, granite and trachybasalt were taken for investigation. SMA mixtures have the same nominal size of aggregate (11 mm) and very similar aggregate particle-size distribution in mineral mixtures. Tested SMA11 mixtures were designed according to EN 13108-5 and Polish National Specification WT-2: 2014. Evaluation of the skid resistance has been performed using the FAP (Friction After Polishing) test equipment also known as the Wehner/Schulze machine. Laboratory method enables to compare the skid resistance of different types of mixtures under specified conditions simulating polishing processes. Tests were performed on both the specimens made of each coarse aggregate and SMA11 mixtures containing these aggregates. Measuring of friction coefficient μm was conducted before and during polishing process up to 180 0000 passes of polishing head. Comparison of the results showed differences in sensitivity to polishing among particular mixtures which depend on the petrographic properties of rock used to produce aggregate. Limestone and dolomite tend to have a fairly uniform texture with low hardness which makes these rock types susceptible to rapid polishing. This caused lower coefficient of friction for SMA11 mixtures with limestone and dolomite in comparison with other test mixtures. These significant differences were already registered at the beginning of the polishing process. Limestone aggregate had lower value of μm before starting the process than trachybasalt and granite aggregate after its completion. Despite the differences in structure and mineralogical composition between the granite and trachybasalt, slightly different values of the friction coefficient at the end of polishing were obtained. Images of the surface were taken with the optical microscope for better understanding of the phenomena occurring on the surface of specimen. Results may be valuable information when selecting aggregate to asphalt mixtures at the stage of its design and maintenance of existing road pavements.

EPA Nonregulatory Nonroad Duty Cycles

EPA Pesticide Factsheets

EPA nonregulatory, nonroad duty cycles for equipment such as agricultural tractors, backhoe loaders,crawlers tractors, excavators, arc welding skid steer loaders, and wheel loaders. Also,test procedures, laboratory methods, and emissions for this equipmen

48 CFR 47.305-1 - Solicitation requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... much of the following data as is applicable to the particular acquisition: (a) Modes of transportation... packaging; e.g., box, carton, crate, drum, bundle, skids, and when applicable, package number from the...

48 CFR 47.305-1 - Solicitation requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... much of the following data as is applicable to the particular acquisition: (a) Modes of transportation... packaging; e.g., box, carton, crate, drum, bundle, skids, and when applicable, package number from the...

48 CFR 47.305-1 - Solicitation requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... much of the following data as is applicable to the particular acquisition: (a) Modes of transportation... packaging; e.g., box, carton, crate, drum, bundle, skids, and when applicable, package number from the...

48 CFR 47.305-1 - Solicitation requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... much of the following data as is applicable to the particular acquisition: (a) Modes of transportation... packaging; e.g., box, carton, crate, drum, bundle, skids, and when applicable, package number from the...

48 CFR 47.305-1 - Solicitation requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... much of the following data as is applicable to the particular acquisition: (a) Modes of transportation... packaging; e.g., box, carton, crate, drum, bundle, skids, and when applicable, package number from the...

Blended aggregate study : final report.

DOT National Transportation Integrated Search

1980-03-01

Louisiana produces no naturally occurring skid resistant aggregate and, therefore, must import these aggregates at great expense. : In an effort to extend the yield of these aggregates, a laboratory investigation was initiated to determine the feasib...

More Experiments and Calculations.

ERIC Educational Resources Information Center

Siddons, J. C.

1984-01-01

Describes two experiments that illustrate basic ideas but would be difficult to carry out. Also presents activities and experiments on rainbow cups, electrical charges, electrophorus calculation, pulse electrometer, a skidding car, and on the Oersted effect. (JN)

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2010 CFR

2010-07-01

... assemblies, umbilicals, manifolds, termination skids, production and pipeline risers, platforms, templates... on the OCS. Facilities include production and pipeline risers, templates, pilings, and any other...

46 CFR 160.042-1 - Applicable specification.

Code of Federal Regulations, 2010 CFR

2010-10-01

... specification. (a) The following specification, of the issue in effect on the date life raft skids are manufactured, forms a part of this subpart: (1) Coast Guard specification: 160.018, Life Rafts. (b) [Reserved] ...

KSC-20161214-JBS-MH-01-0001-L_1011_Pegasus_XL_CYGNSS-3139565_HEVC

NASA Image and Video Library

2016-12-14

The Orbital ATK L-1011 Stargazer aircraft is at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 15. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

SNS Cryogenic Test Facility Kinney Vacuum Pump Commissioning and Operation at 2 K

NASA Astrophysics Data System (ADS)

DeGraff, B.; Howell, M.; Kim, S.; Neustadt, T.

2017-12-01

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) has built and commissioned an independent Cryogenic Test Facility (CTF) in support of testing in the Radio-frequency Test Facility (RFTF). Superconducting Radio-frequency Cavity (SRF) testing was initially conducted with the CTF cold box at 4.5 K. A Kinney vacuum pump skid consisting of a roots blower with a liquid ring backing pump was recently added to the CTF system to provide testing capabilities at 2 K. System design, pump refurbishment and installation of the Kinney pump will be presented. During the commissioning and initial testing period with the Kinney pump, several barriers to achieve reliable operation were experienced. Details of these lessons learned and improvements to skid operations will be presented. Pump capacity data will also be presented.

SNS Cryogenic Test Facility Kinney Vacuum Pump Commissioning and Operation at 2 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Degraff, Brian D.; Howell, Matthew P.; Kim, Sang-Ho

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) has built and commissioned an independent Cryogenic Test Facility (CTF) in support of testing in the Radio-frequency Test Facility (RFTF). Superconducting Radio-frequency Cavity (SRF) testing was initially conducted with the CTF cold box at 4.5 K. A Kinney vacuum pump skid consisting of a roots blower with a liquid ring backing pump was recently added to the CTF system to provide testing capabilities at 2 K. System design, pump refurbishment and installation of the Kinney pump will be presented. During the commissioning and initial testing period with the Kinneymore » pump, several barriers to achieve reliable operation were experienced. Details of these lessons learned and improvements to skid operations will be presented. Pump capacity data will also be presented.« less

Pegasus XL CYGNSS Arrival at CCAFS

NASA Image and Video Library

2016-12-02

The Orbital ATK L-1011 Stargazer aircraft touches down at 3:57 p.m. EST at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

Latex-modified concrete overlay containing Type K cement.

DOT National Transportation Integrated Search

2005-01-01

Hydraulic cement concrete overlays are usually placed on bridges to reduce the infiltration of water and chloride ions and to improve skid resistance, ride quality, and surface appearance. Constructed in accordance with prescription specifications, s...

Development of surface friction guidelines for LADOTD : tech summary.

DOT National Transportation Integrated Search

2012-04-01

The current Louisiana Department of Transportation and Development (LADOTD) surface friction guidelines deal with the polished : stone values (PSV) of coarse aggregates (which is a relative British Pendulum skid-resistance number measured on polished...

Historical overview of friction testing in Connecticut.

DOT National Transportation Integrated Search

2010-03-01

A historical overview of pavement friction testing in Connecticut is presented. : Photographs of early pavement friction testers are provided, including vintage photos : of a skid trailer from a Federal Highway Administration (formally Bureau of Publ...

Data system for planning maintenance resurfacing.

DOT National Transportation Integrated Search

1973-01-01

Planning for maintenance resurfacing in the Virginia Department of Highways is becoming an increasingly complex and important function. Increasing highway mileage and traffic volumes, as well as other requirements such as maintaining a minimum skid r...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2013 CFR

2013-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2014 CFR

2014-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2012 CFR

2012-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

Underinflated tires in the United States

DOT National Transportation Integrated Search

2007-02-09

Underinflated tires impact a drivers ability to control a vehicle against skidding, blowouts, and other tire failures. While not a leading cause of highway accidents and fatalities, a NHTSA study shows that, in 1999, underinflated tires contribute...

Automated skid data system.

DOT National Transportation Integrated Search

1975-01-01

The Data Systems and Analysis Section of the Virginia Highway & Transportation Research Council has been involved for sometime in the development of automated information systems for various types of roadway data. One of these systems, and the system...

A pavement management research program for Oregon highways : final report.

DOT National Transportation Integrated Search

1989-12-01

An extensive program was developed to measure pavement deflection skid resistance, and rideability throughout Oregon. The data from those "objective" measures were then evaluated for correlations with observed pavement distress and traffic factors. :...

Validation of TxDOT flexible pavement skid prediction model : workshop : student guide.

DOT National Transportation Integrated Search

2017-05-01

Course Materials: : Background summary of Research Project 0-5627. : Short presentation of research tasks and findings from Research Project 0-6746. : Aggregate characterization with Aggregate Imaging Measurement System (AIMS) and Micro-D...

Improving Word Similarity by Augmenting PMI with Estimates of Word Polysemy

DTIC Science & Technology

2011-12-29

radiator, brake , throttle, speeding, uptown, curb, auto, skid, balloon, truck, refrigerator, driver, downtown, parachute, gasoline, steering, spin...chauffeur, garage, motor, trolley, locomotive, conductor, automobile, limousine, freight, headlight, train, driver, brake , siding, passenger, engine

Relating surface texture of rigid pavement with noise and skid resistance

DOT National Transportation Integrated Search

2004-01-01

Although pavements are initially designed to be durable for specified traffic loads, they must also satisfy other functional characteristics, primarily safety, smoothness and comfort (noise generation). Frequently, there are necessary trade-offs for ...

Performance specification for high performance concrete overlays on bridges.

DOT National Transportation Integrated Search

2004-01-01

Hydraulic cement concrete overlays are usually placed on bridges to reduce the infiltration of water and chloride ions and to improve skid resistance, ride quality, and surface appearance. Constructed in accordance with prescription specifications, s...

14 CFR 25.1303 - Flight and navigation instruments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... a slip-skid indicator is required on large airplanes with a third attitude instrument system useable through flight attitudes of 360° of pitch and roll and installed in accordance with § 121.305(k) of this...

Engaging homeless youth in community-based participatory research: a case study from Skid Row, Los Angeles.

PubMed

Garcia, Analilia P; Minkler, Meredith; Cardenas, Zelenne; Grills, Cheryl; Porter, Charles

2014-01-01

Growing evidence highlights the benefits to youth of involvement in community-based participatory research. Less attention has been paid, however, to the contributions youth can make to helping change health-promoting policy through such work. We describe a multi-method case study of a policy-focused community-based participatory research project in the Skid Row area of downtown Los Angeles, California, where a small group of homeless youth worked with adult mentors to develop and conduct a survey of 96 homeless youth and used the findings to help secure health-promoting policy change. We review the partnership's work at each stage of the policy-making process; its successes in changing policy regarding recreation, juvenile justice, and education; and the challenges encountered, especially with policy enforcement. We share lessons learned, including the importance of strong adult mentors and of policy environments conducive to sustainable, health-promoting change for marginalized youth.

Acceptance test report for portable exhauster POR-007/Skid E

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriskovich, J.R.

1998-07-24

This document describes Acceptance Testing performed on Portable Exhauster POR-007/Skid E. It includes measurements of bearing vibration levels, pressure decay testing, programmable logic controller interlocks, high vacuum, flow and pressure control functional testing. The purpose of Acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-0490, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reports (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuummore » exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document.« less

The Huygens probe is prepared for transport from the Skid Strip, CCAS

NASA Technical Reports Server (NTRS)

1997-01-01

The Huygens probe, which will study the clouds, atmosphere and surface of Saturn's largest moon, Titan, as part of the Cassini mission to Saturn, is prepared for transport from the Skid Strip, Cape Canaveral Air Station (CCAS), after being off-loaded from a plane. The probe was designed and developed for the European Space Agency (ESA) by a European industrial consortium led by Aerospatiale as prime contractor. Over the past year, it was integrated and tested at the facilities of Daimler Benz Aerospace Dornier Satellitensysteme in Germany. The probe will be mated to the Cassini orbiter, which was designed and assembled at NASA's Jet Propulsion Laboratory in California. The Cassini launch is targeted for October 6 from CCAS aboard a Titan IVB/Centaur expendable launch vehicle. After arrival at Saturn in 2004, the probe will be released from the Cassini orbiter to slowly descend through the Titan atmosphere to the moon's surface.

Astronauts greet the U.S. Women's World Cup Soccer Team at the Skid Strip

NASA Technical Reports Server (NTRS)

1999-01-01

Members of the U.S. Women's World Cup Soccer Team were greeted upon their arrival at the Skid Strip at Cape Canaveral Air Station by Astronauts (right) Steven W. Lindsey, Heidemarie M. Stefanyshyn-Piper and Scott E. Parzynski. The team are here to view the launch of Space Shuttle mission STS-93, scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

View of Cosmic Ray Experiment near the Apollo 15 Lunar Module

NASA Image and Video Library

1972-04-21

AS16-107-17442 (22 April 1972) --- A close-up view of the Apollo 16 Cosmic Ray Detector (CRD) experiment deployed at the +Y strut of the Lunar Module (LM). The crewmembers moved it to this position from near the deployment site of the Apollo Lunar Surface Experiments Package (ALSEP) because, in the words of astronaut John W. Young, commander, "The panels were getting a little warm." Note that the LM did not skid upon landing, as evidenced by the landing contact probe's folded back (neatly) position and the lack of skid marks. While astronauts Young, and Charles M. Duke Jr., lunar module pilot; descended in the Apollo 16 Lunar Module (LM) "Orion" to explore the Descartes highlands landing site on the moon, astronaut Thomas K. Mattingly II, command module pilot, remained with the Command and Service Modules (CSM) "Casper" in lunar orbit.

Mapping the optimal forest road network based on the multicriteria evaluation technique: the case study of Mediterranean Island of Thassos in Greece.

PubMed

Tampekis, Stergios; Sakellariou, Stavros; Samara, Fani; Sfougaris, Athanassios; Jaeger, Dirk; Christopoulou, Olga

2015-11-01

The sustainable management of forest resources can only be achieved through a well-organized road network designed with the optimal spatial planning and the minimum environmental impacts. This paper describes the spatial layout mapping for the optimal forest road network and the environmental impacts evaluation that are caused to the natural environment based on the multicriteria evaluation (MCE) technique at the Mediterranean island of Thassos in Greece. Data analysis and its presentation are achieved through a spatial decision support system using the MCE method with the contribution of geographic information systems (GIS). With the use of the MCE technique, we evaluated the human impact intensity to the forest ecosystem as well as the ecosystem's absorption from the impacts that are caused from the forest roads' construction. For the human impact intensity evaluation, the criteria that were used are as follows: the forest's protection percentage, the forest road density, the applied skidding means (with either the use of tractors or the cable logging systems in timber skidding), the timber skidding direction, the visitors' number and truck load, the distance between forest roads and streams, the distance between forest roads and the forest boundaries, and the probability that the forest roads are located on sights with unstable soils. In addition, for the ecosystem's absorption evaluation, we used forestry, topographical, and social criteria. The recommended MCE technique which is described in this study provides a powerful, useful, and easy-to-use implement in order to combine the sustainable utilization of natural resources and the environmental protection in Mediterranean ecosystems.

Evaluation of remedial treatments at skid accident locations.

DOT National Transportation Integrated Search

1974-01-01

The Virginia Department of Highways has for many years been concerned with the slipperiness of highway pavements, and has undertaken remedial action at numerous high wet accident locations. The purpose of this study was to evaluate the remedial actio...

Harmonization of texture and skid-resistance measurements.

DOT National Transportation Integrated Search

2008-09-30

Due to safety concerns associated with friction testing on both high and low-speed facilities, testing at variable speeds has been previously investigated by the Florida DOT. The American Society for Testing and materials (ASTM) has endorsed this con...

Laboratory evaluation of friction loss and compactability of asphalt mixtures.

DOT National Transportation Integrated Search

2012-04-01

This study aimed to develop prediction models for friction loss and laboratory compaction of asphalt : mixtures. In addition, the study evaluated the effect of compaction level and compaction method of skid : resistance and the internal structure of ...

Quantitative relationship between crash risks and pavement skid resistance.

DOT National Transportation Integrated Search

2014-05-01

Faced with continuously increasing maintenance due to aging infrastructure, the Texas Department of : Transportation (TxDOT) is evaluating the potential impact of reduced funding on highway safety. The main : objective of this report is to develop a ...

Skid-mounted support system for temporary guide signs.

DOT National Transportation Integrated Search

2014-11-01

A common issue during phased highway construction projects is the need to temporarily relocate : large guide signs on the roadside or install new guide signs for temporary use. The conventional concrete : foundations used for these signs are costly a...

An evaluation of the effects of tread depth.

DOT National Transportation Integrated Search

1975-01-01

Thirty-one sites representing the types of pavement surfaces on the highways of Virginia were tested by the Virginia Highway and Transportation Research Council skid trailer in an effort: (1) to determine the influence that tire tread depth, pavement...

99. LIQUID OXYGEN LINE AND SAMPLING VALVE FOR RAPIDLOAD ON ...

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

99. LIQUID OXYGEN LINE AND SAMPLING VALVE FOR RAPID-LOAD ON WEST SIDE OF SKID 9A - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Guide to the texturing of concrete bridge decks.

DOT National Transportation Integrated Search

1984-01-01

The findings from this study were based on limited data. Requests for candidate structures for the inspections indicated that relatively few suitable bridges were available. Only 6 of those bridges could be skid tested. A further limitation was that,...

Crash Lethality Model

DTIC Science & Technology

2012-06-06

Statistical Data ........................................................................................... 45 31 Parametric Model for Rotor Wing Debris...Area .............................................................. 46 32 Skid Distance Statistical Data...results. The curve that related the BC value to the probability of skull fracture resulted in a tight confidence interval and a two tailed statistical p

Development of surface friction guidelines for LADOTD : research project capsule.

DOT National Transportation Integrated Search

2011-02-01

The current friction guideline of the Louisiana Department of : Transportation and Development (LADOTD) for a wearing course mixture : design deals with the polished stone value (PSV) of coarse aggregate : (which is a relative British Pendulum skid-r...

Effect of tree thinning and skidding trails on hydrological connectivity in two Japanese forest catchments

NASA Astrophysics Data System (ADS)

López-Vicente, Manuel; Sun, Xinchao; Onda, Yuichi; Kato, Hiroaki; Gomi, Takashi; Hiraoka, Marino

2017-09-01

Land use composition and patterns influence the hydrological response in mountainous and forest catchments. In plantation forest, management operations (FMO) modify the spatial and temporal dynamics of overland flow processes. However, we found a gap in the literature focussed on modelling hydrological connectivity (HC) in plantation forest under different FMO. In this study, we simulated HC in two steep paired forest subcatchments (K2 and K3, 33.2 ha), composed of Japanese cypress (Chamaecyparis obtusa Endl.) and Japanese cedar (Cryptomeria japonica D. Don) plantations (59% of the total area) against a tree thinning intensity of 50% at different time. Additionally, construction of new skidding trails and vegetation recovery was simulated on five thinning-based scenarios that covered a 40-month test period (July 2010 - October 2013). As a future scenario, six check-dams located in the main streams were proposed to reduce sediment and radionuclide delivery. An updated version of Borselli's index of runoff and sediment connectivity was run, using the D-infinity flow accumulation algorithm and exploiting three 0.5-m resolution digital elevation models. On the basis of the pre-FMO scenario, HC increased at catchment scale owing to tree thinning and the new skidding trails. This change was more noticeable within the area affected by the FMO, where HC increased by 11.4% and 10.5% in the cypress and cedar plantations in K2 respectively and by 8.8% in the cedar plantation in K3. At hillslope plot and stream scales, the evolution in the values of HC was less evident, except the increment (by 5.4%) observed in the streams at K2 after the FMO. Progressive vegetation recovery after the FMO triggered a slight reduction of connectivity in all compartments of both subcatchments. Forest roads and especially skidding trails presented the highest values of HC, appearing as the most efficient features connecting the different vegetation patches with the stream network. The spatial and temporal evolution of HC over the five past scenarios correlated well with the observed changes in runoff yield, as well as with the available values of rainfall interception and throughfall before, during, and after the FMO. The simulation of the proposed scenario recommends the construction of check-dams as effective landscape features to somewhat reduce HC and thus to decrease the sediment and radionuclide delivery rates from the two subcatchments.

Surface friction measurements of fine-graded asphalt mixtures : final report, June 2008.

DOT National Transportation Integrated Search

2008-06-01

Skid resistance is generated by the development of friction between the vehicle tire and : roadway surface, and is partially dependent upon the characteristics of the pavement : texture. Microtexture and macrotexture are the critical components of pa...

79. VIEW FROM SOUTH OF NITROGEN AND HELIUM STORAGE TANKS ...

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

79. VIEW FROM SOUTH OF NITROGEN AND HELIUM STORAGE TANKS AND CONTROL SKIDS ON SLC-3W FUEL APRON - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Installation and performance of lightweight aggregate asphaltic concrete test sections.

DOT National Transportation Integrated Search

1970-01-01

In 1966 and 1968 test sections of asphaltic concrete overlays fabricated with coarse lightweight aggregate and fine limestone were installed in the Roanoke-Bedford area. The experimental mixes used were designed in an attempt to develop skid resistan...

Research notes : thin polymer overlays on bridge decks.

DOT National Transportation Integrated Search

2007-11-01

Winters in Oregon are hard on our bridges. Vehicles with studded tires gouge the pavement and abrade the deck surface. This abrasion often leads to reduced skid resistance. As the bridge deck ages, cracks often develop. Deicing chemicals used in wint...

Evaluation of design and construction issues of thin HMA overlays.

DOT National Transportation Integrated Search

2015-04-01

While the overall implementation of thin HMA overlays in Texas has been successful, some issues need to be addressed: : appropriate blending of SAC A and SAC B aggregate to ensure adequate skid resistance; best practices to achieve adequate bonding :...

Long term validation of an accelerated polishing test procedure for HMA pavements.

DOT National Transportation Integrated Search

2013-04-01

The Ohio Department of Transportation (ODOT) has set strategic goals to improve driving safety by maintaining : smooth pavement surfaces with high skid resistance. ODOT has taken the initiative to monitor pavement : friction on Ohio roadways and reme...

33. View aft of main deck, port side, taken from ...

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

33. View aft of main deck, port side, taken from just aft of forecastle bulkhead showing foremast, fore shrouds, pig house, midship house and boat skids. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

46 CFR 160.042-3 - Construction.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Construction. 160.042-3 Section 160.042-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Skids, Liferaft, for Merchant Vessels § 160.042-3 Construction...

46 CFR 160.042-3 - Construction.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Construction. 160.042-3 Section 160.042-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Skids, Liferaft, for Merchant Vessels § 160.042-3 Construction...

46 CFR 160.042-3 - Construction.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Construction. 160.042-3 Section 160.042-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Skids, Liferaft, for Merchant Vessels § 160.042-3 Construction...

46 CFR 160.042-3 - Construction.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Construction. 160.042-3 Section 160.042-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Skids, Liferaft, for Merchant Vessels § 160.042-3 Construction...

Validation of TxDOT flexible pavement skid prediction model : project summary.

DOT National Transportation Integrated Search

2017-01-01

This study had two main objectives: : Investigate and examine surface and friction characteristics of 35 test sections of asphalt mixtures and 35 test sections of surface-treated roads in Texas. The test sections covered a wide range of mixtures ...

Evaluation of skid measurements used by TxDOT : technical report.

DOT National Transportation Integrated Search

2013-05-01

Accurate estimates of wet roadway friction are critical to the safety of the traveling public, project selection, and for managing the wet weather accident reduction program. Currently, Texas is the only state that uses a one-channel, torque-type whe...

Evaluation of the on-flex expansion joint sealing system for bridge decks.

DOT National Transportation Integrated Search

1984-01-01

The findings from this study were based on limited data. Requests for candidate structures for the inspections indicated that relatively few suitable bridges were available. Only 6 of those bridges could be skid tested. A further limitation was that,...

Harvesting Productionin Uneven-Aged Loblolly-Shortleaf Pine Stands:The Crossett Farm Forestry Forties

Treesearch

R. Kluender; B. Stokes; S. Woodfin

1992-01-01

Twostands managed using uneven-aged techniques werehar- vested aspar-t of a5-year entry schedule. Felling and skidding productivity varied significantly with average stem diameter and volume and was affected by diameter distribution of the removed material.

70. DETAIL OF OXYGEN TRANSFER PRESSURE GAUGE IN UPPER LEFT ...

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

70. DETAIL OF OXYGEN TRANSFER PRESSURE GAUGE IN UPPER LEFT CORNER OF SKID ON RIGHT IN CA-133-1-C-69 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Automated Detection of Selective Logging in Amazon Forests Using Airborne Lidar Data and Pattern Recognition Algorithms

NASA Astrophysics Data System (ADS)

Keller, M. M.; d'Oliveira, M. N.; Takemura, C. M.; Vitoria, D.; Araujo, L. S.; Morton, D. C.

2012-12-01

Selective logging, the removal of several valuable timber trees per hectare, is an important land use in the Brazilian Amazon and may degrade forests through long term changes in structure, loss of forest carbon and species diversity. Similar to deforestation, the annual area affected by selected logging has declined significantly in the past decade. Nonetheless, this land use affects several thousand km2 per year in Brazil. We studied a 1000 ha area of the Antimary State Forest (FEA) in the State of Acre, Brazil (9.304 ○S, 68.281 ○W) that has a basal area of 22.5 m2 ha-1 and an above-ground biomass of 231 Mg ha-1. Logging intensity was low, approximately 10 to 15 m3 ha-1. We collected small-footprint airborne lidar data using an Optech ALTM 3100EA over the study area once each in 2010 and 2011. The study area contained both recent and older logging that used both conventional and technologically advanced logging techniques. Lidar return density averaged over 20 m-2 for both collection periods with estimated horizontal and vertical precision of 0.30 and 0.15 m. A relative density model comparing returns from 0 to 1 m elevation to returns in 1-5 m elevation range revealed the pattern of roads and skid trails. These patterns were confirmed by ground-based GPS survey. A GIS model of the road and skid network was built using lidar and ground data. We tested and compared two pattern recognition approaches used to automate logging detection. Both segmentation using commercial eCognition segmentation and a Frangi filter algorithm identified the road and skid trail network compared to the GIS model. We report on the effectiveness of these two techniques.

29 CFR 1917.115 - Platforms and skids.

Code of Federal Regulations, 2010 CFR

2010-07-01

... safe condition. Safe working loads, which shall be posted or marked on or adjacent to platforms and... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... nets, to protect employees against falls. (b) Any employee working below a second-story platform or...

Field evaluation of asphalt mixture skid resistance and its relationship to aggregate characteristics.

DOT National Transportation Integrated Search

2010-12-01

This report documents the findings from the research that was carried out as part of Phase II of Texas : Department of Transportation (TxDOT) Project 0-5627. The research included measuring and analyzing the : mechanical and physical properties of ag...

Evaluation of thin epoxy system overlays for concrete bridge decks : interim report No. 1.

DOT National Transportation Integrated Search

1986-05-01

Four epoxy overlay systems were applied to concrete bridge decks in north Louisiana to evaluate their performance as skid resistant surfaces primarily and also as concrete sealers. Dural Flexolith, Poly-Carb Flexogrid, and Con/Chem Cono/Crete were pl...

46 CFR 160.042-3 - Construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (a) The trackways of the skids shall be constructed of 6″×31/2″×1/2″ structural angles, or of... project over the side of the vessel. (b) The lower end of the life raft shall be supported by a base plate...

Performance of soil-aggregate-fabric systems in frost-susceptible roads, Linn County, Iowa.

DOT National Transportation Integrated Search

1980-05-01

Thousands of miles of unimproved secondary roads in the upper midwest are annually plagued by frost action in their subgrades. Among the economic losses incurred are costs of repair and maintenance of the damaged roadway. Considerable loss of skid re...

Social networks, time homeless, and social support: A study of men on Skid Row.

PubMed

Green, Harold D; Tucker, Joan S; Golinelli, Daniela; Wenzel, Suzanne L

2013-12-18

Homeless men are frequently unsheltered and isolated, disconnected from supportive organizations and individuals. However, little research has investigated these men's social networks. We investigate the structure and composition of homeless men's social networks, vis-a-vis short- and long-term homelessness with a sample of men drawn randomly from meal lines on Skid Row in Los Angeles. Men continuously homeless for the past six months display networks composed of riskier members when compared to men intermittently homeless during that time. Men who report chronic, long-term homelessness display greater social network fragmentation when compared to non-chronically homeless men. While intermittent homelessness affects network composition in ways that may be addressable with existing interventions, chronic homelessness fragments networks, which may be more difficult to address with those interventions. These findings have implications for access to social support from network members which, in turn, impacts the resources homeless men require from other sources such as the government or NGOs.

Skid steer fuel cell powered unmanned ground vehicle (Burro)

NASA Astrophysics Data System (ADS)

Meldrum, Jay S.; Green, Christopher A.

2008-04-01

The use of alternative energy technology for vehicle propulsion and auxiliary power is becoming more important. Work is being performed at Michigan Technological University's Keweenaw Research Center on an Army Research Laboratory cooperative agreement to develop two unmanned ground vehicles for military applications. A wide range of alternative energy technologies were investigated. Hydrogen-powered proton exchange membrane fuel cells were identified as the most appropriate alternative energy source. This is due to some development and commercialization which makes the technology "drop-in plug-in" for immediate use. We have previously presented research work on a small unmanned ground vehicle demonstration platform where the fuel cell is the only power source. We now present research work on the integration of a fuel cell onto a larger skid steer platform. The dual-power capability of this vehicle can provide a modest level of propulsion in "engine-off mode" and may also be used to power directed energy devices which have applications in countermine and similar threat technologies.

Social networks, time homeless, and social support: A study of men on Skid Row

PubMed Central

Green, Harold D.; Tucker, Joan S.; Golinelli, Daniela; Wenzel, Suzanne L.

2014-01-01

Homeless men are frequently unsheltered and isolated, disconnected from supportive organizations and individuals. However, little research has investigated these men’s social networks. We investigate the structure and composition of homeless men’s social networks, vis-a-vis short- and long-term homelessness with a sample of men drawn randomly from meal lines on Skid Row in Los Angeles. Men continuously homeless for the past six months display networks composed of riskier members when compared to men intermittently homeless during that time. Men who report chronic, long-term homelessness display greater social network fragmentation when compared to non-chronically homeless men. While intermittent homelessness affects network composition in ways that may be addressable with existing interventions, chronic homelessness fragments networks, which may be more difficult to address with those interventions. These findings have implications for access to social support from network members which, in turn, impacts the resources homeless men require from other sources such as the government or NGOs. PMID:24466427

Astronauts Stefanyshyn-Piper, Lindsey and Currie greet First Lady Hillary Clinton at the Skid Strip

NASA Technical Reports Server (NTRS)

1999-01-01

First Lady Hillary Rodham Clinton is greeted by Astronauts (from left) Heidemarie M. Stefanyshyn-Piper, Steven W. Lindsey, and Nancy Jane Currie upon Mrs. Clinton's arrival at the Skid Strip at Cape Canaveral Air Station. She and her daughter, Chelsea (far right) are here to view the launch of Space Shuttle mission STS- 93, scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

Astronauts Stefanyshyn-Piper, Lindsey and Currie greet First Lady Hillary Clinton at the Skid Strip

NASA Technical Reports Server (NTRS)

1999-01-01

First Lady Hillary Rodham Clinton is greeted by Astronaut Nancy Jane Currie upon Mrs. Clinton's arrival at the Skid Strip at Cape Canaveral Air Station. Waiting at left are Astronauts Heidemarie M. Stefanyshyn-Piper and Steven W. Lindsey. Mrs. Clinton and her daughter, Chelsea (far right) are here to view the launch of Space Shuttle mission STS-93, scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five- day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

Assessment of the performance of several roadway mixes under rain, snow, and winter maintenance activities.

DOT National Transportation Integrated Search

2004-01-01

The purpose of this study was to assess the relative functional performance, including skid resistance and splash and spray, of five hot-mix-asphalt (HMA) surfaces and a tinned portland cement concrete highway surface during controlled wet and wintry...

Mechanized thinning of northern hardwood pole stands: methods and economics.

Treesearch

Frank E. Biltonen; Wiliam A. Hillstrom; Helmuth M. Steinhilb; Richard M. Godman

1976-01-01

Describes a study of various thinning treatments in northern hardwood pole stands, using mechanized felling, skidding, and field chipping, as well as chain saw felling. Cost analyses showed that a profit can be made although it is less than can be made with clearcutting.

Field evaluation of asphalt mixture skid resistance and its relationship to aggregate characteristics.

DOT National Transportation Integrated Search

2011-08-01

This report documents the findings from the research that was carried out as part of Phase II of : TxDOT Project 0-5627. The research included measurements and analysis of mechanical and physical : properties of aggregates used in surface mixes in th...

Investigation of accident reduction by grooved concrete pavement : final report.

DOT National Transportation Integrated Search

1979-06-01

This report is a category 2 experimental project evaluation written in conjunction with EHS-I-10-3(93)158 and EHS-I-12-1(44)0 contracted to groove hardened PCC pavement. In it the wear characteristics, pavement texture, skid resistance, and the accid...

80. DETAIL OF TYPICAL PRESSURE GAUGE IN NITROGEN AND HELIUM ...

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

80. DETAIL OF TYPICAL PRESSURE GAUGE IN NITROGEN AND HELIUM STORAGE AND TRANSFER CONTROL SKIDS ON NORTH END OF SLC-3W FUEL APRON - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

14 CFR 151.77 - Runway paving: General rules.

Code of Federal Regulations, 2010 CFR

2010-01-01

... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous surface...

14 CFR 151.77 - Runway paving: General rules.

Code of Federal Regulations, 2011 CFR

2011-01-01

... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous surface...

14 CFR 151.77 - Runway paving: General rules.

Code of Federal Regulations, 2012 CFR

2012-01-01

... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous surface...

14 CFR 151.77 - Runway paving: General rules.

Code of Federal Regulations, 2014 CFR

2014-01-01

... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous surface...

14 CFR 151.77 - Runway paving: General rules.

Code of Federal Regulations, 2013 CFR

2013-01-01

... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous surface...

73. DETAIL OF LIQUID OXYGEN STORAGE PRESSURE GAUGE IN UPPER ...

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

73. DETAIL OF LIQUID OXYGEN STORAGE PRESSURE GAUGE IN UPPER LEFT CORNER OF WEST SIDE OF CENTER SKID IN CA-133-1-C-69 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

81. GENERAL VIEW FROM NORTH OF FUEL STORAGE TANK ON ...

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

81. GENERAL VIEW FROM NORTH OF FUEL STORAGE TANK ON SOUTH END OF SLC-3W FUEL APRON. CORNER OF CONTROL SKID VISIBLE ON LEFT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Student Drivers Will Find This Defensive Course Difficult

ERIC Educational Resources Information Center

Nation's Schools, 1972

1972-01-01

Map and description of 40-acre defensive driving range being built for secondary school driver education programs in the Burke County Public Schools of North Carolina. Features include a beginner course, streets, driveways, expressway, gravel road, a driver education building, and an emergency skid area. (Author/DN)

Performance of thin bonded epoxy overlays on asphalt and concrete bridge deck surfaces.

DOT National Transportation Integrated Search

2014-06-01

This study is the evaluation of two thin bonded epoxy overlays: SafeLane (marketed by Cargill), and Flexogrid : (developed by PolyCarb). SafeLane is advertised as an anti-skid/anti-icing overlay that stores deicing chemicals for : release during wint...

L-O-S-T: Logging Optimization Selection Technique

Treesearch

Jerry L. Koger; Dennis B. Webster

1984-01-01

L-O-S-T is a FORTRAN computer program developed to systematically quantify, analyze, and improve user selected harvesting methods. Harvesting times and costs are computed for road construction, landing construction, system move between landings, skidding, and trucking. A linear programming formulation utilizing the relationships among marginal analysis, isoquants, and...

75 FR 31418 - Intermountain Region, Payette National Forest, Council Ranger District; Idaho; Mill Creek-Council...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-03

... noncommercial vegetation management and road system modifications and maintenance. DATES: Comments concerning..., timber harvest (especially large diameter ponderosa pine) and road construction have affected forest.... There would be no equipment entry in riparian conservation areas (RCAs) except on existing roads or skid...

Setting analyst: A practical harvest planning technique

Treesearch

Olivier R.M. Halleux; W. Dale Greene

2001-01-01

Setting Analyst is an ArcView extension that facilitates practical harvest planning for ground-based systems. By modeling the travel patterns of ground-based machines, it compares different harvesting settings based on projected average skidding distance, logging costs, and site disturbance levels. Setting Analyst uses information commonly available to consulting...

29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

Code of Federal Regulations, 2013 CFR

2013-07-01

... temporary period not to exceed 6 months they need not have fire-resisting foundations or saddles but shall...) Dispensing. (1) Filling of fuel containers for trucks or motor vehicles from bulk storage containers shall be.... (2) Filling of portable containers or containers mounted on skids from storage containers shall be...

29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

Code of Federal Regulations, 2012 CFR

2012-07-01

... temporary period not to exceed 6 months they need not have fire-resisting foundations or saddles but shall...) Dispensing. (1) Filling of fuel containers for trucks or motor vehicles from bulk storage containers shall be.... (2) Filling of portable containers or containers mounted on skids from storage containers shall be...

29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

Code of Federal Regulations, 2011 CFR

2011-07-01

... temporary period not to exceed 6 months they need not have fire-resisting foundations or saddles but shall...) Dispensing. (1) Filling of fuel containers for trucks or motor vehicles from bulk storage containers shall be.... (2) Filling of portable containers or containers mounted on skids from storage containers shall be...

29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

Code of Federal Regulations, 2014 CFR

2014-07-01

... temporary period not to exceed 6 months they need not have fire-resisting foundations or saddles but shall...) Dispensing. (1) Filling of fuel containers for trucks or motor vehicles from bulk storage containers shall be.... (2) Filling of portable containers or containers mounted on skids from storage containers shall be...

49 CFR 178.255-11 - Tank mountings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Tank mountings. 178.255-11 Section 178.255-11... Portable Tanks § 178.255-11 Tank mountings. (a) Tanks shall be designed and fabricated with mountings to... requirement. (b) All tank mountings such as skids, fastenings, brackets, cradles, lifting lugs, etc., intended...

49 CFR 178.255-11 - Tank mountings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Tank mountings. 178.255-11 Section 178.255-11... Portable Tanks § 178.255-11 Tank mountings. (a) Tanks shall be designed and fabricated with mountings to... requirement. (b) All tank mountings such as skids, fastenings, brackets, cradles, lifting lugs, etc., intended...

49 CFR 178.255-11 - Tank mountings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Tank mountings. 178.255-11 Section 178.255-11... Portable Tanks § 178.255-11 Tank mountings. (a) Tanks shall be designed and fabricated with mountings to... requirement. (b) All tank mountings such as skids, fastenings, brackets, cradles, lifting lugs, etc., intended...

49 CFR 178.255-11 - Tank mountings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Tank mountings. 178.255-11 Section 178.255-11... Portable Tanks § 178.255-11 Tank mountings. (a) Tanks shall be designed and fabricated with mountings to... requirement. (b) All tank mountings such as skids, fastenings, brackets, cradles, lifting lugs, etc., intended...

9 CFR 91.14 - Ports of embarkation and export inspection facilities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... requirements: (1) Materials. Floors of pens, alleys, and chutes shall be made of impervious materials and finished so as to be skid-resistant. Impervious floors are those constructed of a material that resists the absorption of fluids. Such materials include concrete, asphalt, brick, metal, or other synthetic material...

9 CFR 91.14 - Ports of embarkation and export inspection facilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... requirements: (1) Materials. Floors of pens, alleys, and chutes shall be made of impervious materials and finished so as to be skid-resistant. Impervious floors are those constructed of a material that resists the absorption of fluids. Such materials include concrete, asphalt, brick, metal, or other synthetic material...

9 CFR 91.14 - Ports of embarkation and export inspection facilities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... requirements: (1) Materials. Floors of pens, alleys, and chutes shall be made of impervious materials and finished so as to be skid-resistant. Impervious floors are those constructed of a material that resists the absorption of fluids. Such materials include concrete, asphalt, brick, metal, or other synthetic material...

49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... mile before any brake application. Skid number means the frictional resistance of a pavement measured... control designed so that a leakage-type failure of a pressure component in a single subsystem (except... pounds). S5.8Service brake system design durability. Each motorcycle shall be capable of completing all...

Pyrolysis of blended animal manures to produce combustible gas and value-added charcoal adsorbent

USDA-ARS?s Scientific Manuscript database

Blended swine solids, chicken litter, and rye grass were pyrolyzed using a skid-mounted sytem. Produced gas composition was analyzed for major hydrocarbons and S-containing compounds. Charcoal was analyzed for its surface functional groups, contact angles, HHV, and total element contents. Some of th...

Polymer concrete overlay on Beulah Road Bridge : interim report no. 1--installation and initial condition of overlay.

DOT National Transportation Integrated Search

1982-01-01

The installation of a thin polymer concrete overlay on the Beulah Road bridge demonstrates that an overlay of low permeability and high skid resistance can be successfully installed by maintenance forces with a minimum of disruption to traffic, appro...

Department of Defense Energy Security Initiatives

DTIC Science & Technology

2009-01-01

Ventura County installed an 87 kW rooftop amorphous silicon thin-film photovoltaic (PV) laminate system on a building in Port Hueneme, California, and...of waste into energy equal to about 100 gallons of JP-8. It is skid mounted and deployable on a military 5-ton flatbed trailer. Solid Oxide Fuel

29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

Code of Federal Regulations, 2010 CFR

2010-07-01

..., Containers—All vessels, such as tanks, cylinders, or drums, used for transportation or storing liquefied... outlet piping of settling shall be guarded against by a flexible connection or special fitting. (h... known in the industry as “skid tanks”) shall be designed, installed, and used in accordance with these...

Effect of Weight Transfer on a Vehicle's Stopping Distance.

ERIC Educational Resources Information Center

Whitmire, Daniel P.; Alleman, Timothy J.

1979-01-01

An analysis of the minimum stopping distance problem is presented taking into account the effect of weight transfer on nonskidding vehicles and front- or rear-wheels-skidding vehicles. Expressions for the minimum stopping distances are given in terms of vehicle geometry and the coefficients of friction. (Author/BB)

A laboratory experiment in evaluating means of imparting a harsh texture to portland cement concrete surfaces.

DOT National Transportation Integrated Search

1970-01-01

The purpose of this study was to explore methods of obtaining a rough, durable texture on test slabs fabricated in the laboratory in an attempt to provide high skid resistance. The exploration involved the investigation of types of texture, time of t...

36 CFR 1004.22 - Unsafe operation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 1004.22 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.22..., traffic, weather, road and light conditions and road character. (2) Operating a motor vehicle in a manner which unnecessarily causes its tires to squeal, skid or break free of the road surface. (3) Failing to...

78 FR 10685 - Reports, Forms, and Recordkeeping Requirements: Agency Information Collection Activity Under OMB...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

... Traffic Safety Administration Title: Tire Pressure Monitoring Systems Special Studies. OMB Number: 2174...: Improperly inflated tires pose a safety risk, increasing the chance of skidding, hydroplaning, longer stopping distances, and crashes due to flat tires and blowouts. In an effort to decrease the number of...

Effect of ground skidding on oak advance regeneration

Treesearch

Jeffrey W. Stringer

2006-01-01

Vigorous advance regeneration is required to naturally regenerate oaks. However, a reduction in the number of advance regeneration stems from harvesting activities could be an important factor in determining successful oak regeneration. This study assessed the harvest survivability of advance regeneration of oak (Quercus spp.) and co-occurring...

Evaluation of the construction and performance of polymer concrete overlays on five bridges : interim report no. 1.

DOT National Transportation Integrated Search

1983-01-01

The installation of thin polymer concrete overlays on five bridges on I-85 near Williamsburg, Virginia, has demonstrated that an overlay of low permeability and high skid resistance can be successfully installed by a contractor with a minimum of disr...

9 CFR 91.14 - Ports of embarkation and export inspection facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... paragraph (b) of this section, shall meet the following requirements: (1) Materials. Floors of pens, alleys, and chutes shall be made of impervious materials and finished so as to be skid-resistant. Impervious floors are those constructed of a material that resists the absorption of fluids. Such materials include...

An Interactive Simulation System for Modeling Stands, Harvests, and Machines

Treesearch

Jingxin Wang; W. Dale Greene

1999-01-01

A interactive computer simulation program models stands, harvest, and machine factors and evaluates their interatcitons while performing felling, skidding, or fowarding activities. A stand generator allows the user to generate either natural or planted stands. Fellings with chainsaw, drive-to-tree feller-bunchers, or harvesters and extraction with grapple skidders or...

Methods for increasing the harshness of texture on old concrete pavements : canvass of what the states are doing.

DOT National Transportation Integrated Search

1974-01-01

This report is a compilation of responses from different states setting forth what they are doing to restore the texture and thereby improve the skid resistance of old portland cement concrete pavements. All of the methods reported in use seem to wor...

Effectiveness of best management practices for sediment reduction at operation forest stream crossings

Treesearch

Laura R. Wear; Michael W. Aust; M. Chad Bolding; Brian D. Strahm; C. Andrew Dolloff

2013-01-01

Temporary skid trail stream crossings have repeatedly been identified as having considerable potential to introduce sediment to streams. Forestry Best Management Practices (BMPs) have proven to be effective for controlling erosion and subsequent sedimentation, yet few studies have quantified sedimentation associated with various levels of BMPs for skidder stream...

The Effects of Digital Control on Longitudinal Autopilots for Bank-to-Turn and Skid-Turn Missiles.

DTIC Science & Technology

1985-12-01

Control of Dynamic Systems Addison-Wesley Publishing Company, 1961. 7. Karadimas , C., Design and Analysis of Discrete Lateral Autogilots for BTT...GREECE 8. LT Karadimas , Christos H.N 1 Kolokotroni 156 Piraeus GREECE ’-- 138 ............-.... *9. LT Karadimt trf s, Antont os HRN 201 Glenwood Circle

The effects of group selection harvest size on logging productivity

Treesearch

Curt C. Hassler; Shawn T. Grushecky; Chris B. LeDoux

2000-01-01

Because increasing demands are being placed on industry to harvest timber by aesthetically, economically, and ecologically acceptable means, we investigated the effects of a ground-based group selection harvest on logging productivity. Results show that size of opening had little or no effect on skidding productivity. However, significant skidder operator differences...

Sediment production in a coastal watershed: legacy, land use, recovery, and rehabilitation

Treesearch

Elizabeth T. Keppeler

2012-01-01

Sediment production has been measured for nearly half a century at the Caspar Creek Experimental Watersheds. Examination of this sediment record provides insights into the relative magnitudes and durations of sediment production from management practices including road construction, selection harvest and tractor skidding, and later road decommissioning. The 424-ha...

Following the fate of harvest-damaged trees 13 years after harvests

Treesearch

Randy G. Jensen; John M. Kabrick

2014-01-01

Logging damage to residual trees during harvest operations can reduce the future volume, quality, and value of wood products. Timber harvests in 1996 on the Missouri Ozark Forest Ecosystem Project (MOFEP) provided a rare opportunity to follow the fate of trees wounded by felling or by skidding with rubber-tired skidders.

49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... application. Skid number means the frictional resistance of a pavement measured in accordance with ASTM E274... brake system consisting of two or more subsystems actuated by a single control designed so that a...), but not less than 0 Newtons (0 pounds). S5.8Service brake system design durability. Each motorcycle...

25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

Code of Federal Regulations, 2010 CFR

2010-04-01

... value and design life or increase the skid resistance of the pavement. 8. Tribally-owned, post-secondary... following planning and design activities: 1. Planning and design of IRR transit facilities eligible for IRR construction funding. 2. Planning and design of IRR roads and bridges. 3. Planning and design of transit...

49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... application. Skid number means the frictional resistance of a pavement measured in accordance with ASTM E274... brake system consisting of two or more subsystems actuated by a single control designed so that a...), but not less than 0 Newtons (0 pounds). S5.8Service brake system design durability. Each motorcycle...

25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

Code of Federal Regulations, 2014 CFR

2014-04-01

... value and design life or increase the skid resistance of the pavement. 8. Tribally-owned, post-secondary... following planning and design activities: 1. Planning and design of IRR transit facilities eligible for IRR construction funding. 2. Planning and design of IRR roads and bridges. 3. Planning and design of transit...

49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... mile before any brake application. Skid number means the frictional resistance of a pavement measured... subsystems actuated by a single control designed so that a leakage-type failure of a pressure component in a...), but not less than 0 Newtons (0 pounds). S5.8Service brake system design durability. Each motorcycle...

25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

Code of Federal Regulations, 2012 CFR

2012-04-01

... value and design life or increase the skid resistance of the pavement. 8. Tribally-owned, post-secondary... following planning and design activities: 1. Planning and design of IRR transit facilities eligible for IRR construction funding. 2. Planning and design of IRR roads and bridges. 3. Planning and design of transit...

49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... current, and which may include a non-electrical source of power designed to charge batteries and... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured in... subsystems actuated by a single control, designed so that a single failure in any subsystem (such as a...

76 FR 79114 - Tire Fuel Efficiency Consumer Information Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-21

... reference ASTM International E 501-08, ``Standard Specification for Standard Rib Tire for Pavement Skid... noted that the language of the preamble and the final rule appeared to be designed to address two... revised is when design changes to a tire affect the accuracy of the rating information and necessitate the...

25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

Code of Federal Regulations, 2013 CFR

2013-04-01

... value and design life or increase the skid resistance of the pavement. 8. Tribally-owned, post-secondary... following planning and design activities: 1. Planning and design of IRR transit facilities eligible for IRR construction funding. 2. Planning and design of IRR roads and bridges. 3. Planning and design of transit...

49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... mile before any brake application. Skid number means the frictional resistance of a pavement measured... subsystems actuated by a single control designed so that a leakage-type failure of a pressure component in a...), but not less than 0 Newtons (0 pounds). S5.8Service brake system design durability. Each motorcycle...

49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... current, and which may include a non-electrical source of power designed to charge batteries and... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured in..., designed so that a single failure in any subsystem (such as a leakage-type failure of a pressure component...

49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... current, and which may include a non-electrical source of power designed to charge batteries and... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured in... subsystems actuated by a single control, designed so that a single failure in any subsystem (such as a...

25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

Code of Federal Regulations, 2011 CFR

2011-04-01

... value and design life or increase the skid resistance of the pavement. 8. Tribally-owned, post-secondary... following planning and design activities: 1. Planning and design of IRR transit facilities eligible for IRR construction funding. 2. Planning and design of IRR roads and bridges. 3. Planning and design of transit...

49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... current, and which may include a non-electrical source of power designed to charge batteries and... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured in..., designed so that a single failure in any subsystem (such as a leakage-type failure of a pressure component...

49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... current, and which may include a non-electrical source of power designed to charge batteries and... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured in..., designed so that a single failure in any subsystem (such as a leakage-type failure of a pressure component...

75 FR 8001 - Airworthiness Directives; Hawker Beechcraft Corporation (Type Certificate No. A00010WI Previously...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... the essential bus. The disabled equipment could include the autopilot, anti-skid system, hydraulic indicator, spoiler system, pilot primary flight display, audio panel, or the 1 air data computer. This... system, pilot primary flight display, audio panel, or the 1 air data computer. This failure could lead to...

Trends in streamflow and suspended sediment after logging, North Fork Caspar Creek

Treesearch

Jack Lewis; Elizabeth T. Keppeler

2007-01-01

Streamflow and suspended sediment were intensively monitored at fourteen gaging stations before and after logging a second-growth redwood (Sequoia sempervirens) forest. About 50 percent of the watershed was harvested, primarily by clear-cutting with skyline-cable systems. New road construction and tractor skidding were restricted to gently-sloping...

Final report : Polymer concrete overlay on Beulah Road Bridge : condition of overlay after one year in service.

DOT National Transportation Integrated Search

1983-01-01

An evaluation of the thin polymer concrete overlay placed on the Beulah Road bridge indicates that the overlay is securely bonded to the base concrete and is providing low permeability and high skid resistance after 1 year of service life. The lane c...

Survival Strategies of Older Homeless Men.

ERIC Educational Resources Information Center

Cohen, Carl I.; And Others

1988-01-01

Examined how 281 homeless men aged 50 and older living on skid row were able to procure basic necessities such as money, food, shelter, and health care. Found men had and used informal supports to survive. Inability to fulfill needs was primarily associated with physical health, depression, lack of contacts with institutions and agencies, and…

Relevance of Lick Creek ecosystem-based management treatments to National Forest management

Treesearch

Cathy Stewart

1999-01-01

Treatments applied at Lick Creek were the first landscape-scale applications of ecosystem management on the Bitterroot National Forest. The coordinated effort between educators, researchers, resource managers, and the public helped gain acceptance and understanding of new approaches to management, both internally and externally. The longer skidding distances, high...

Nature Photography - Birds

NASA Image and Video Library

2016-12-12

A flock of egrets soars above the Skid Strip at Cape Canaveral Air Force Station, near NASA's Kennedy Space Center in Florida. The center shares a boundary with the Merritt Island National Wildlife Refuge. The refuge is home to more than 65 amphibian and reptile species, along with 330 native and migratory bird species, 25 mammal and 117 fish species.

46 CFR 160.042-5 - Procedure for approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... approval. (a) Life raft skids are not subject to formal approval by the Commandant, but for each merchant vessel on which Type A life rafts are to be installed, plans showing the construction and arrangement of the life raft stowage and launching device on the vessel are required to be submitted for approval to...

36 CFR 292.41 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Earth's crust prior to the Holocene epoch. Selective cutting means single tree or group selection... equipment means any contrivance which travels over ground, snow or water on wheels, tracks, skids, or by... the Mining Act of 1872, 30 U.S.C. 22 et seq., and the Mineral Leasing Act of 1920, 30 U.S.C. 181 et...

36 CFR 292.41 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Earth's crust prior to the Holocene epoch. Selective cutting means single tree or group selection... equipment means any contrivance which travels over ground, snow or water on wheels, tracks, skids, or by... the Mining Act of 1872, 30 U.S.C. 22 et seq., and the Mineral Leasing Act of 1920, 30 U.S.C. 181 et...

36 CFR 292.41 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Earth's crust prior to the Holocene epoch. Selective cutting means single tree or group selection... equipment means any contrivance which travels over ground, snow or water on wheels, tracks, skids, or by... the Mining Act of 1872, 30 U.S.C. 22 et seq., and the Mineral Leasing Act of 1920, 30 U.S.C. 181 et...

Sustainable Deforestation Evaluation Model and System Dynamics Analysis

PubMed Central

Feng, Huirong; Lim, C. W.; Chen, Liqun; Zhou, Xinnian; Zhou, Chengjun; Lin, Yi

2014-01-01

The current study used the improved fuzzy analytic hierarchy process to construct a sustainable deforestation development evaluation system and evaluation model, which has refined a diversified system to evaluate the theory of sustainable deforestation development. Leveraging the visual image of the system dynamics causal and power flow diagram, we illustrated here that sustainable forestry development is a complex system that encompasses the interaction and dynamic development of ecology, economy, and society and has reflected the time dynamic effect of sustainable forestry development from the three combined effects. We compared experimental programs to prove the direct and indirect impacts of the ecological, economic, and social effects of the corresponding deforest techniques and fully reflected the importance of developing scientific and rational ecological harvesting and transportation technologies. Experimental and theoretical results illustrated that light cableway skidding is an ecoskidding method that is beneficial for the sustainable development of resources, the environment, the economy, and society and forecasted the broad potential applications of light cableway skidding in timber production technology. Furthermore, we discussed the sustainable development countermeasures of forest ecosystems from the aspects of causality, interaction, and harmony. PMID:25254225

[Violent offenders with or without antisocial personality disorder. A comparison].

PubMed

de Tribolet-Hardy, F; Vohs, K; Domes, G; Regli, D; Habermeyer, E

2011-01-01

The influence of legal offences on the diagnosis of antisocial personality disorder (ASPD) is a common discussion. A population of imprisoned delinquents diagnosed with ASPD was compared to delinquents without ASPD concerning sociodemographic, criminological and clinical characteristics to determine if ASPD can differentiate delinquents apart from committing legal offences. A total of 36 violent offenders with diagnosed ASPD and 29 violent offenders without ASPD were recruited in the prison of Straubing (Germany); 28 control subjects without previous convictions were recruited in the German population. All subjects were examined with the SKID-I and SKID-II, GAF, BIS-11, EPI and K-FAF. Violent offenders with ASPD differ from violent offenders without ASPD concerning the following parameters: high values of impulsivity, aggression, irritability, neuroticism and extraversion; low levels of psychosocial functioning, cumulative "broken home" indicators and antisocial behaviour before the age of 11 ("early starters"). Some features are suitable for the discrimination between offenders with or without ADPD, but our results indicate that samples are better distinguished by a dimensional approach, oriented toward their degree of characteristics.

Evaluation of high pressure water blast with rotating spray bar for removing paint and rubber deposits from airport runways, and review of runway slipperiness problems created by rubber contamination

NASA Technical Reports Server (NTRS)

Horne, W. B.; Griswold, G. D.

1975-01-01

A high pressure water blast with rotating spray bar treatment for removing paint and rubber deposits from airport runways is studied. The results of the evaluation suggest that the treatment is very effective in removing above surface paint and rubber deposits to the point that pavement skid resistance is restored to trafficked but uncontaminated runway surface skid resistance levels. Aircraft operating problems created by runway slipperiness are reviewed along with an assessment of the contributions that pavement surface treatments, surface weathering, traffic polishing, and rubber deposits make in creating or alleviating runway slipperiness. The results suggest that conventional surface treatments for both portland cement and asphaltic concrete runways are extremely vulnerable to rubber deposit accretions which can produce runway slipperiness conditions for aircraft operations as or more slippery than many snow and ice-covered runway conditions. Pavement grooving surface treatments are shown to be the least vulnerable to rubber deposits accretion and traffic polishing of the surface treatments examined.

Sustainable deforestation evaluation model and system dynamics analysis.

PubMed

Feng, Huirong; Lim, C W; Chen, Liqun; Zhou, Xinnian; Zhou, Chengjun; Lin, Yi

2014-01-01

The current study used the improved fuzzy analytic hierarchy process to construct a sustainable deforestation development evaluation system and evaluation model, which has refined a diversified system to evaluate the theory of sustainable deforestation development. Leveraging the visual image of the system dynamics causal and power flow diagram, we illustrated here that sustainable forestry development is a complex system that encompasses the interaction and dynamic development of ecology, economy, and society and has reflected the time dynamic effect of sustainable forestry development from the three combined effects. We compared experimental programs to prove the direct and indirect impacts of the ecological, economic, and social effects of the corresponding deforest techniques and fully reflected the importance of developing scientific and rational ecological harvesting and transportation technologies. Experimental and theoretical results illustrated that light cableway skidding is an ecoskidding method that is beneficial for the sustainable development of resources, the environment, the economy, and society and forecasted the broad potential applications of light cableway skidding in timber production technology. Furthermore, we discussed the sustainable development countermeasures of forest ecosystems from the aspects of causality, interaction, and harmony.

Certified and uncertified logging concessions compared in Gabon: changes in stand structure, tree species, and biomass.

PubMed

Medjibe, V P; Putz, Francis E; Romero, Claudia

2013-03-01

Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 trees/ha) and 11.4 m(3)/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in tree species composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities.

On the required complexity of vehicle dynamic models for use in simulation-based highway design.

PubMed

Brown, Alexander; Brennan, Sean

2014-06-01

This paper presents the results of a comprehensive project whose goal is to identify roadway design practices that maximize the margin of safety between the friction supply and friction demand. This study is motivated by the concern for increased accident rates on curves with steep downgrades, geometries that contain features that interact in all three dimensions - planar curves, grade, and superelevation. This complexity makes the prediction of vehicle skidding quite difficult, particularly for simple simulation models that have historically been used for road geometry design guidance. To obtain estimates of friction margin, this study considers a range of vehicle models, including: a point-mass model used by the American Association of State Highway Transportation Officials (AASHTO) design policy, a steady-state "bicycle model" formulation that considers only per-axle forces, a transient formulation of the bicycle model commonly used in vehicle stability control systems, and finally, a full multi-body simulation (CarSim and TruckSim) regularly used in the automotive industry for high-fidelity vehicle behavior prediction. The presence of skidding--the friction demand exceeding supply--was calculated for each model considering a wide range of vehicles and road situations. The results indicate that the most complicated vehicle models are generally unnecessary for predicting skidding events. However, there are specific maneuvers, namely braking events within lane changes and curves, which consistently predict the worst-case friction margins across all models. This suggests that any vehicle model used for roadway safety analysis should include the effects of combined cornering and braking. The point-mass model typically used by highway design professionals may not be appropriate to predict vehicle behavior on high-speed curves during braking in low-friction situations. However, engineers can use the results of this study to help select the appropriate vehicle dynamic model complexity to use in the highway design process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Soil response to skidder and dozer traffic as indicated by soil stress residuals

Treesearch

Brian Parkhurst; Mike Aust; Chad Bolding; Scott Barrett; Andrew Vinson; John Klepac; Emily Carter

2015-01-01

Ground-based timber harvesting systems are common throughout many regions of the United States. Machine movements during harvesting can negatively impact soils leading to increased erosion and soil compaction. This is especially true of skid trails that have been established to facilitate tree removals. Several techniques have the potential to reduce soil compaction...

Silvicultural treatments and logging costs for minimizing gypsy moth impacts

Treesearch

Michael D. Erickson; Curt C. Hassler; Chris B. LeDoux

1991-01-01

Gypsy moth defoliation is a serious threat to eastern hardwood forests. Felling and skidding costs for harvesting timber in silvicultural thinnings designed to reduce the impacts of the moth were evaluated. Cost of felling the nonmerchantable component of the thinnings to achieve treatment objectives are reported, along with a discussion of the economic feasibility of...

Channel incision and suspended sediment delivery at Caspar Creek, Mendocino County, California

Treesearch

Nicholas J. Dewey; Thomas E. Lisle; Leslie M. Reid

2003-01-01

Tributary and headwater valleys in the Caspar Creek watershed,in coastal Mendocino County, California,show signs of incision along much of their lengths.An episode of incision followed initial-entry logging which took place between 1860 and 1906. Another episode of incision cut into skid-trails created for second-entry logging in the 1970's.

High-temperature pyrolysis of blended animal manures for producing renewable energy and value-added biochar

USDA-ARS?s Scientific Manuscript database

In this study, we used a commercial pilot-scale, skid-mounted pyrolysis reactor system to produce combustible gas and biochar at 620ºC from three sources (chicken litter, swine solids, mixture of swine solids with rye grass). Pyrolysis of swine solids produced gas with the greatest higher heating va...

Development and Analysis of SRIC Harvesting Systems

Treesearch

Bryce J. Stokes; Bruce R. Hartsough

1993-01-01

This paper reviews several machine combinations for harvesting short-rotation, intensive-culture (SRIC) plantations. Productivity and cost information for individual machines was obtained from published sources. Three felling and skidding systems were analyzed for two stands, a 7.6-cm (3-in) average d.b.h. sycamore and a 15.2-cm (6-in) average d.b.h. eucalyptus. The...

The effect of timber harvesting guidelines on felling and skidding productivity in northern Minnesota

Treesearch

Denys Goychuk; Michael A. Kilgore; Charles R. Blinn; Jay Coggins; Randall K. Kolka

2011-01-01

Substantial investment has been made in the development and application of scientifically based best management practices (i.e., guidelines) intended to protect and enhance the ecological, environmental, and aesthetic attributes of forest resources. When correctly applied, guidelines can increase environmental benefits on site and to adjacent resources, as well as...

77 FR 28243 - Amendment of Class D Airspace; Cocoa Beach, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

...-0099; Airspace Docket No. 12-ASO-11] Amendment of Class D Airspace; Cocoa Beach, FL AGENCY: Federal... Federal Register on April 11, 2012 that amends Class D airspace at Cocoa Beach, FL. DATES: Effective 0901...), amends Class D airspace at Cape Canaveral Skid Strip, Cocoa Beach, FL. A typographical error was made in...

14 CFR 135.159 - Equipment requirements: Carrying passengers under VFR at night or under VFR over-the-top conditions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... chapter. (2) Helicopters with a third attitude instrument system usable through flight attitudes of ±80.... (3) Helicopters with a maximum certificated takeoff weight of 6,000 pounds or less. (b) A slip skid...) Notwithstanding provisions of paragraphs (b), (c), and (d), helicopters having a maximum certificated takeoff...

14 CFR 135.159 - Equipment requirements: Carrying passengers under VFR at night or under VFR over-the-top conditions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... chapter. (2) Helicopters with a third attitude instrument system usable through flight attitudes of ±80.... (3) Helicopters with a maximum certificated takeoff weight of 6,000 pounds or less. (b) A slip skid...) Notwithstanding provisions of paragraphs (b), (c), and (d), helicopters having a maximum certificated takeoff...

14 CFR 135.159 - Equipment requirements: Carrying passengers under VFR at night or under VFR over-the-top conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... chapter. (2) Helicopters with a third attitude instrument system usable through flight attitudes of ±80.... (3) Helicopters with a maximum certificated takeoff weight of 6,000 pounds or less. (b) A slip skid...) Notwithstanding provisions of paragraphs (b), (c), and (d), helicopters having a maximum certificated takeoff...

14 CFR 135.159 - Equipment requirements: Carrying passengers under VFR at night or under VFR over-the-top conditions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... chapter. (2) Helicopters with a third attitude instrument system usable through flight attitudes of ±80.... (3) Helicopters with a maximum certificated takeoff weight of 6,000 pounds or less. (b) A slip skid...) Notwithstanding provisions of paragraphs (b), (c), and (d), helicopters having a maximum certificated takeoff...

Mobile lighting apparatus

DOEpatents

Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

2013-05-14

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Removal of Inorganic, Microbial, and Particulate Contaminants from a Fresh Surface Water: Village Marine Tec. Expeditionary Unit Water Purifier, Generation 1

EPA Science Inventory

The Village Marine Tec. Generation 1 Expeditionary Unit Water Purifier (EUWP) is a mobile skid-mounted system employing ultrafiltration (UF) and reverse osmosis (RO) to produce drinking water from a variety of different water quality sources. The UF components were evaluated to t...

Natural regeneration response to initial treatments

Treesearch

G. E. Gruell; W. C. Schmidt; S. F. Arno; W. J. Reich; James Menakis

1999-01-01

During the 1907 to 1911 harvest, logs were transported to landings by means of log chutes, horse skidding, and steam donkey yarding. Slash was disposed of by piling and burning, which the purchaser considered to be an unnecessary practice (Koch 1998). Usually this type of logging and postlogging treatment results in relatively light site disturbance, and the photo...

Interpretations of vegetative change through 1989: The photopoints

Treesearch

G. E. Gruell; W. C. Schmidt; S. F. Arno; W. J. Reich

1999-01-01

The 1907 to 1911 logging operations and subsequent lack of surface fires dramatically changed the patterns of plant succession at Lick Creek. Large quantities of overstory pines were felled, creating sizable openings. Logs were skidded and slash was burned in piles (Koch 1998) locally scraping off or consuming surface vegetation, pine needle litter, and humus, and...

Cutting Tool For Shaving Weld Beads

NASA Technical Reports Server (NTRS)

Hoffman, David S.; Mcferrin, David C.; Daniel, Ronald L., Jr.; Coby, John B., Jr.; Dawson, Sidney G.

1995-01-01

Cutting tool proposed for use in shaving weld beads flush with adjacent surfaces of weldments. Modified version of commercial pneumatically driven rotary cutting tool, cutting wheel of which turns at speeds sufficient for machining nickel alloys, titanium, and stainless steels. Equipped with forward-mounted handle and rear-mounted skid plate to maximize control and reduce dependence on skill of technician.

75 FR 27422 - Airworthiness Directives; Hawker Beechcraft Corporation (Type Certificate No. A00010WI Previously...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

... system, pilot primary flight display, audio panel, or the 1 air data computer. This failure could lead to... include the autopilot, anti-skid system, hydraulic indicator, spoiler system, pilot primary flight display, audio panel, or the 1 air data computer. This failure could lead to a significant increase in pilot...

Forest access roads: design, maintenance, and soil loss

Treesearch

Lloyd W. Swift

1988-01-01

The Regional Guide for,the South (United States Department of Agriculture 1984b) recognizes that roads and skid trails are the major sources of sediment from forestry-related activities. The overall environmental impact statement for Region 8 (United States Department of Agriculture 1984a) estimates an existing national forest road network of 56,300 km (3 1,000 miles)...

Evaluation of the construction and performance of multiple layer polymer concrete overlays : interim report no. 2, condition of the overlays after five years in service.

DOT National Transportation Integrated Search

1987-01-01

This interim report presents the results after 5 years of a study undertaken to evaluate multiple layer polymer concrete overlays over a 10-year period. The report indicates that an overlay of low permeability and high skid resistance can be successf...

76 FR 2309 - Consumer Information Regulations; Fees for Use of Traction Skid Pads

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-13

....regulations.gov , including any personal information provided. Privacy Act: Anyone is able to search the....). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://www.dot.gov/privacy.html . Docket: For access to the...

Cradle-to-gate life cycle impacts of redwood forest resource harvesting in northern California

Treesearch

Han-Sup Han; Elaine Oneil; Richard D. Bergman; Ivan L. Eastin; Leonard R. Johnson

2015-01-01

The first life cycle impact assessment for redwood (Sequoia sempervirens) forest management activities (i.e. a cradle-to-sawmill gate input) including the growing, harvesting, and hauling of redwood sawlogs to a sawmill was completed. In the stump-to-truck timber harvesting analysis, primary transport activities such as skidding and yarding consumed...

Nature Photography - Birds

NASA Image and Video Library

2016-12-12

A flock of egrets touches down near the Skid Strip at Cape Canaveral Air Force Station, near NASA's Kennedy Space Center in Florida. The center shares a boundary with the Merritt Island National Wildlife Refuge. The refuge is home to more than 65 amphibian and reptile species, along with 330 native and migratory bird species, 25 mammal and 117 fish species.

Logging damage using an individual tree selection practice in Appalachian hardwood stands

Treesearch

Neil I. Lamson; H. Clay Smith; Gary W. Miller

1985-01-01

Four West Virginia hardwood stands, managed using individual-tree selection for the past 30 years, were examined after the third and, in one instance, the fourth periodic harvest to determine the severity of logging damage. On existing skid roads, trees were removed with a rubber-tired skidder or a crawler tractor with a rubber-tired arch. Logging damage reduced...

Measuring low rates of erosion from forest fuel reduction operations

Treesearch

William J. Elliot; Ina Sue Miller

2004-01-01

A study was carried out to evaluate three methods for measuring low levels of hillside soil erosion associated with forest fuel management activities, and to measure erosion from cable logging and skid trails. The tipping bucket device with a sediment basin appears to be a better tool for this application than silt fences or rillmeter analysis. The greatest erosion...

Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp

ERIC Educational Resources Information Center

Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.

2015-01-01

We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrell, P.C.

This SARP describes the RTG Transportation System Package, a Type B(U) packaging system that is used to transport an RTG or similar payload. The payload, which is included in this SARP, is a generic, enveloping payload that specifically encompasses the General Purpose Heat Source (GPHS) RTG payload. The package consists of two independent containment systems mounted on a shock isolation transport skid and transported within an exclusive-use trailer.

14 CFR Appendix B to Part 152 - List of Advisory Circulars Incorporated by § 152.11

Code of Federal Regulations, 2014 CFR

2014-01-01

... Transport. 150/5300-8—Planning and Design Criteria for Metropolitan STOL Ports. 150/5320-6B—Airport Pavement.../5320-12—Methods for the Design, Construction, and Maintenance of Skid Resistant Airport Pavement... Communications. 150/5210-10—Airport Fire and Rescue Equipment Building Guide. 150/5300-2C—Airport Design...

14 CFR Appendix B to Part 152 - List of Advisory Circulars Incorporated by § 152.11

Code of Federal Regulations, 2011 CFR

2011-01-01

... Transport. 150/5300-8—Planning and Design Criteria for Metropolitan STOL Ports. 150/5320-6B—Airport Pavement.../5320-12—Methods for the Design, Construction, and Maintenance of Skid Resistant Airport Pavement... Communications. 150/5210-10—Airport Fire and Rescue Equipment Building Guide. 150/5300-2C—Airport Design...

14 CFR Appendix B to Part 152 - List of Advisory Circulars Incorporated by § 152.11

Code of Federal Regulations, 2013 CFR

2013-01-01

... Transport. 150/5300-8—Planning and Design Criteria for Metropolitan STOL Ports. 150/5320-6B—Airport Pavement.../5320-12—Methods for the Design, Construction, and Maintenance of Skid Resistant Airport Pavement... Communications. 150/5210-10—Airport Fire and Rescue Equipment Building Guide. 150/5300-2C—Airport Design...

14 CFR Appendix B to Part 152 - List of Advisory Circulars Incorporated by § 152.11

Code of Federal Regulations, 2010 CFR

2010-01-01

... Transport. 150/5300-8—Planning and Design Criteria for Metropolitan STOL Ports. 150/5320-6B—Airport Pavement.../5320-12—Methods for the Design, Construction, and Maintenance of Skid Resistant Airport Pavement... Communications. 150/5210-10—Airport Fire and Rescue Equipment Building Guide. 150/5300-2C—Airport Design...

Guidelines for design, installation, and maintenance of a waterproof wearing surface for timber bridge decks

Treesearch

Richard E. Weyers; Joseph R. Loferski; J. Daniel Dolan; John E. Haramis; Joseph H. Howard; Lola Hislop

2001-01-01

To enhance long-term timber bridge performance, timber material must be protected from moisture. Wearing surfaces made of asphalt pavement with and without a waterproof membrane have been used to provide protection from moisture on timber decks. This type of wearing surface also protects the deck from other damage while providing a smooth, skid-resistant surface....

14 CFR Appendix B to Part 152 - List of Advisory Circulars Incorporated by § 152.11

Code of Federal Regulations, 2012 CFR

2012-01-01

... Transport. 150/5300-8—Planning and Design Criteria for Metropolitan STOL Ports. 150/5320-6B—Airport Pavement.../5320-12—Methods for the Design, Construction, and Maintenance of Skid Resistant Airport Pavement... Communications. 150/5210-10—Airport Fire and Rescue Equipment Building Guide. 150/5300-2C—Airport Design...

Off-road transport of pinyon/juniper

Treesearch

J. Klepac; B. Rummer

2012-01-01

A 8-wheel forwarder was observed while transporting pinyon pine (P. edulis) and Utah juniper (J. osteosperma) from woods to landing in southern Utah. The forwarder was part of a 2-machine system used to treat pinyon-juniper stands. Trees were felled using a rubber tracked skid steer with a shear head, then transported to a collection point with a Ponsse Buffalo King 20...

Tightening the Purchasing Process: Superintendents Get More Involved in Buying Policies

ERIC Educational Resources Information Center

Rivero, Victor

2009-01-01

Over the last 18 months, school district purchasing offices across the country have been tightening the reins like never before while more top-level administrators get involved in the budget process. "When the economy really hit the skids, states got hit hard, so a lot of school districts were forced to make severe budget cuts," says John Musso,…

Harvesting short rotation woody crops with a shear

Treesearch

Wellington Cardoso; Dana Mitchell; Tom Gallagher; Daniel and de Souza

2014-01-01

A time and motion study was performed on a skid steer equipped with a 14-inch tree shear attachment. The machine was used to install initial coppice harvesting treatments on three stands across the south. The study included one willow and two cottonwood sites. The stands averaged from 2 to 4 years old. Approximately 200 trees were shear harvested from each of the...

Logging costs and production rates for the group selection cutting method

Treesearch

Philip M. McDonald

1965-01-01

Young-growth, mixed-conifer stands were logged by a group-selection method designed to create openings 30, 60, and 90 feet in diameter. Total costs for felling, limbing, bucking, and skidding on these openings ranged from $7.04 to $7.99 per thousand board feet. Cost differences between openings were not statistically significant. Logging costs for group selection...

KSC-01pp1075

NASA Image and Video Library

2001-06-05

KENNEDY SPACE CENTER, Fla. -- The High Energy Solar Spectroscopic Imager (HESSI) spacecraft, which will be launched by a Pegasus XL rocket, arrives at the Skid Strip at Cape Canaveral Air Force Station. Part of NASA's Small Explorer Program, HESSI's primary mission is to explore the basic physics of particle acceleration and explosive energy release in solar flares. Launch is scheduled for no earlier than June 14

Effects of forest management practices on the federally endangered running buffalo clover (Trifolium stoloniferum Muhl. Ex. A. Eaton)

Treesearch

Darlene Madarish; Thomas M. Schuler

2002-01-01

Running buffalo clover (Trifolium stoloniferum Muhl. ex. A. Eaton), a federally endangered plant species, often occurs in habitats affected by periodic disturbance such as mowing or grazing. At the Femow Experimental Forest in West Virginia, USA, it is most often associated with skid roads where uneven-aged silvicultural techniques are being tested....

Cycle-time equations for five small tractors operating in low-volume small-diameter hardwood stands

Treesearch

Chris B. LeDoux; Neil K. Huyler; Neil K. Huyler

1992-01-01

Prediction equations for estimating cycle time were developed for five small tractors studied under various silvicultural treatments and operating conditions. The tractors studied included the Pasquali 933, a Holder A60F, a Forest Ant Forwarder (Skogsman), a Massey-Ferguson, and a Sam4 Minitarus. Skidding costs were estimated based on the cycle-time equations. Using...

Potential for a small, tracked vehicle in small tree management activities

Treesearch

Jeff Halbrook; Harry Lee

2002-01-01

Small diameter timber offers unique challenges for resource managers. Soil disturbance, residual stand damage, and high equipment capital are often associated with using large logging equipment to extract this timber. In an ongoing project at the University of Idaho, an All Season Vehicle (ASV) RC 30 has been modified for use as a low impact skidding device. Several...

Shelterwood-Strip Harvesting Pattern With Full-Tree Skidding to Regenerate Red Pine

Treesearch

John W. Benzie; Z.A. Zasada

1972-01-01

Describes a harvesting and regeneration pattern for red pine stands to make efficient use of mechanized full-tree harvesting. The system is not just an engineering operation to extract trees, but a forest management operatioin to harvest mature timber, prepare the site for regeneration, and provide environmental conditions favoring tree growth and multiple-use of the...

Greasing the Skids of the Musical Mind: Connecting Music Learning to Mind Brain Education

ERIC Educational Resources Information Center

Bugos, Jennifer A.

2015-01-01

Researchers suggest that musical training prepares the mind for learning; however, there are many obstacles to the implementation of research to practice in music education. The purpose of this article is to apply key principles of mind brain education to music education and to evaluate how music prepares the mind for learning. Practical teaching…

Harvesting impacts as a function of removal intensity

Treesearch

Bryce J. Stokes; R.A. Kluender; J.F. Klepac; D.A. Lortz

1997-01-01

Single-tree selection, group selection, shelterwood, seed-tree, and clearcut harvesting methods were evaluated for residual site impacts. The stands were harvested during the summer of 1993 on the Ouachita National Forest in Arkansas. Manual felling and rubber-tired skidders were used to harvest all 23 stands. Percentage of area in primary skid trails was 8.2, 9.6, 13....

High tonnage harvesting and skidding for loblolly pine energy plantations

Treesearch

Patrick Jernigan; Tom Gallagher; Dana Mitchell; Mathew Smidt; Larry Teeter

2016-01-01

The southeastern United States has a promising source for renewable energy in the form of woody biomass. To meet the energy needs, energy plantations will likely be utilized. These plantations will contain a high density of small-stem pine trees. Since the stems are relatively small when compared with traditional product removal, the harvesting costs will increase. The...

Felling and skidding costs associated with thinning a commercial Appalachian hardwood stand in northern West Virginia

Treesearch

Samuel M. Brock; Kenneth D. Jones; Gary W. Miller

1986-01-01

Detailed cost information on thinning operations is needed to develop economic guidelines for managing immature central Appalachian hardwood stands. Three thinning treatments were applied in a 50-yr-old mixed-oak, cove hardwood stand in northern West Virginia. A commercial logging contractor using chain saws and a rubber-tired skidder conducted the logging operations....

Productivity of rubber-tired skidders in southern pine forests

Treesearch

R. Kluender; D. Lortz; W. McCoy; B. Stokes; J. Klepac

1997-01-01

Sixteen stands were harvested at intensities (proportion of basal area removed) ranging from 0.27 to 1.00. Logging contractors used one or two rubber-tired cable and/or grapple skidders. Harvested sites were similar in slope, tree size, and stand composition. Thirteen of the stands had even-aged structures while the other three were uneven-aged. Skidding time per cycle...

Residual tree damage during selection cuts using two skidding systems in the Missouri Ozarks

Treesearch

Robert L. Ficklin; John P. Dwyer; Bruce E. Cutter; Tom Draper

1997-01-01

Today, there is an interest in using alternative silvicultural systems like selection and two-aged management, because the public finds these systems more acceptable than clearcutting. However, repeated entries into forest stands to remove timber increase the risk of residual stand damage. Harvest techniques are desirable that (1) reduce the risk of stand damage and (2...

Modelling and study of active vibration control for off-road vehicle

NASA Astrophysics Data System (ADS)

Zhang, Junwei; Chen, Sizhong

2014-05-01

In view of special working characteristics and structure, engineering machineries do not have conventional suspension system typically. Consequently, operators have to endure severe vibrations which are detrimental both to their health and to the productivity of the loader. Based on displacement control, a kind of active damping method is developed for a skid-steer loader. In this paper, the whole hydraulic system for active damping method is modelled which include swash plate dynamics model, proportional valve model, piston accumulator model, pilot-operated check valve model, relief valve model, pump loss model, and cylinder model. A new road excitation model is developed for the skid-steer loader specially. The response of chassis vibration acceleration to road excitation is verified through simulation. The simulation result of passive accumulator damping is compared with measurements and the comparison shows that they are close. Based on this, parallel PID controller and track PID controller with acceleration feedback are brought into the simulation model, and the simulation results are compared with passive accumulator damping. It shows that the active damping methods with PID controllers are better in reducing chassis vibration acceleration and pitch movement. In the end, the test work for active damping method is proposed for the future work.

Automatic Detection and Classification of Audio Events for Road Surveillance Applications.

PubMed

Almaadeed, Noor; Asim, Muhammad; Al-Maadeed, Somaya; Bouridane, Ahmed; Beghdadi, Azeddine

2018-06-06

This work investigates the problem of detecting hazardous events on roads by designing an audio surveillance system that automatically detects perilous situations such as car crashes and tire skidding. In recent years, research has shown several visual surveillance systems that have been proposed for road monitoring to detect accidents with an aim to improve safety procedures in emergency cases. However, the visual information alone cannot detect certain events such as car crashes and tire skidding, especially under adverse and visually cluttered weather conditions such as snowfall, rain, and fog. Consequently, the incorporation of microphones and audio event detectors based on audio processing can significantly enhance the detection accuracy of such surveillance systems. This paper proposes to combine time-domain, frequency-domain, and joint time-frequency features extracted from a class of quadratic time-frequency distributions (QTFDs) to detect events on roads through audio analysis and processing. Experiments were carried out using a publicly available dataset. The experimental results conform the effectiveness of the proposed approach for detecting hazardous events on roads as demonstrated by 7% improvement of accuracy rate when compared against methods that use individual temporal and spectral features.

[Epidemiological risk of introduction of dangerous and exotic infectious diseases on the territory of the XXII Olympic Winter Games and XI Paralympic Winter Games 2014 in Sochi].

PubMed

Kuz'kin, B P; Ezhlova, E B; Kulichenko, A N; Maletskaia, O V; Demina, Iu V; Taran, T V; Pakskina, N D; Kharchenko, T V; Grizhebovskiĭ, G M; Savel'ev, V N; Orobeĭ, V G; Klindukhov, V P; Grechanaia, T V; Tesheva, S Ch; Brukhanova, G D

2015-01-01

To assess the epidemiological risk of introduction of serious infectious diseases in the pre-Olympic period defined list of dangerous and exotic infections and held assessment of potential danger threatening. Initial external information to assess the potential risk of skidding were reports, forecasts, posted on the official websites. The risk of skidding and epidemiological complications conditionally designated as high, moderate and minimal risk importation of measles virus-Rate was considered as high. In confirmation of the forecast for the period of the Olympic Games in Sochi have been registered about 100 cases of measles. Moderate risk of importation was determined for poliomyelitis due to wild poliovirus, Lassa fever, cholera, plague, and the minimal--for Dengue fever, yellow fever, the Middle East and respiratory syndrome, diseases caused by viruses Marburg and Ebola. Based on of analysis of previous Olympic Games and subsequent co-events related to the activity of the infectious diseases in the world, mate-cluded that even a slight risk of importation of infectious diseases requires maximum alertness and readiness to conduct adequate epidemiological issues incorporated.

The mathematical model of dynamic stabilization system for autonomous car

NASA Astrophysics Data System (ADS)

Saikin, A. M.; Buznikov, S. E.; Shabanov, N. S.; Elkin, D. S.

2018-02-01

Leading foreign companies and domestic enterprises carry out extensive researches and developments in the field of control systems for autonomous cars and in the field of improving driver assistance systems. The search for technical solutions, as a rule, is based on heuristic methods and does not always lead to satisfactory results. The purpose of this research is to formalize the road safety problem in the terms of modern control theory, to construct the adequate mathematical model for solving it, including the choice of software and hardware environment. For automatic control of the object, it is necessary to solve the problem of dynamic stabilization in the most complete formulation. The solution quality of the problem on a finite time interval is estimated by the value of the quadratic functional. Car speed, turn angle and additional yaw rate (during car drift or skidding) measurements are performed programmatically by the original virtual sensors. The limit speeds at which drift, skidding or rollover begins are calculated programmatically taking into account the friction coefficient identified in motion. The analysis of the results confirms both the adequacy of the mathematical models and the algorithms and the possibility of implementing the system in the minimal technical configuration.

Ponderosa pine growth response to soil strength in the volcanic ash soils of central Oregon.

Treesearch

R.T. Parker; D.A. Maguire; D.D. Marshall; P. Cochran

2007-01-01

Mechanical harvesting and associated logging activities have the capacity to compact soil across large portions of harvest units. Two thinning treatments (felled only versus felled and skidded) in 70- to 80-year-old ponderosa pine stands were replicated at three sites with volcanic soils in central Oregon. Growth in diameter, height, and volume of residual trees were...

The effects of stream crossings on total suspended sediment in North Carolina Piedmont forests

Treesearch

Johnny Boggs; Ge Sun; Steve McNulty

2017-01-01

This study determined total suspended sediment (TSS) at six stream crossings that represented a range of site conditions and forest operations in the Piedmont of North Carolina. Two wood and three steel bridgemats and one culvert were installed to cross the streams. The road classes for the crossings included four temporary skid trails and two permanent forest haul...

Tractor-logging costs and production in old-growth redwood forests

Treesearch

Kenneth N. Boe

1963-01-01

A cost accounting analysis of full-scale logging operations in old-growth redwood during 2 years revealed that it cost $12.24 per M bd. ft. (gross Scribner log scale) to get logs on trucks. Road development costs averaged another $5.19 per M bd. ft. Felling-bucking production was calculated by average tree d.b.h. Both skidding and loading outputs per hour were...

Predicting bunching costs for the Radio Horse 9 winch

Treesearch

Chris B. LeDoux; Bruce W. Kling; Patrice A. Harou; Patrice A. Harou

1987-01-01

Data from field studies and a prebunching cost simulator have been assembled and converted into a general equation that can be used to estimate the prebunching cost of the Radio Horse 9 winch. The methods can be used to estimate prebunching cost for bunching under the skyline corridor for swinging with cable systems, for bunching to skid trail edge to be picked up by a...

Soil bulk density changes caused by mechanized harvesting: A case study in central Appalachia

Treesearch

Jingxin Wang; Chris B. LeDoux; Pam Edwards; Mark Jones; Mark Jones

2005-01-01

A mechanized harvesting system consisting of a feller-buncher and a grapple skidder was examined to quantify soil bulk density changes in a central Appalachian hardwood forest site. Soil bulk density was measured using a nuclear gauge pre-harvest and post-harvest systematically across the harvest unit and on transects across skid trails. Bulk density also was measured...

49 CFR 231.23 - Unidirectional passenger-train cars adaptable to van-type semi-trailer use.

Code of Federal Regulations, 2011 CFR

2011-10-01

... than eight (8) inches from face of car, except when “A” frame is used and extends beyond end of car, a platform of anti-skid design covering the extended portion of the “A” frame may be used as brake step. (3..., or equivalent, wrought iron, steel or other metal of equivalent strength. Minimum clear depth, eight...

49 CFR 231.23 - Unidirectional passenger-train cars adaptable to van-type semi-trailer use.

Code of Federal Regulations, 2010 CFR

2010-10-01

... than eight (8) inches from face of car, except when “A” frame is used and extends beyond end of car, a platform of anti-skid design covering the extended portion of the “A” frame may be used as brake step. (3..., or equivalent, wrought iron, steel or other metal of equivalent strength. Minimum clear depth, eight...

Watershed Analysis Results for Mendocino Redwood Company Lands in Coastal Mendocino and Sonoma Counties

Treesearch

Christopher G. Surfleet

2007-01-01

To assess the needs for conservation, restoration and condition of aquatic habitat within its land Mendocino Redwood Company (MRC) has been conducting watershed analysis. From watershed analysis completed to date, we estimate 73percent of the total sediment inputs over the last 30 to 40 years are road and skid trail associated. Of that percentage 30 percent is road and...

Cost of thinning 50-year-old Douglas-fir for pulpwood at Voight Creek Experimental Forest.

Treesearch

Norman P. Worthington

1961-01-01

Analyses of time and cost data gathered on the Voight Creek Experimental Forest from six thinnings in a 50-year-old stand of Douglas-fir showed that average skidding distance and diameter of average tree cut were the chief factors affecting the production time in thinning these pulpwood stands. Cut per acre had negligible influence. Contractors' production...

Graywater Discharges from Vessels

DTIC Science & Technology

2011-11-01

soaps and detergents used in any capacity that will be discharged as part of graywater must be nontoxic and phosphate -free, and should be...mounted on one skid. The Evac MBR process is fully automated and controlled through a PLC. Evac uses high quality Kubota membranes. Kubota membranes...the best solution. • Non- corrosive . By choosing to use non- corrosive materials (including a special space age polymer yielding strength and

Harvesting costs and production rates for seed-tree removal in young-growth, mixed-conifer stands

Treesearch

Philip M. McDonald

1969-01-01

Ponderosa pine seed trees left from a previous cutting on the Challenge Experimental Forest, California, were removed in October 1963. Logging costs and production rates were compared with those for a seed-tree cutting on an area nearby. Production rates for seed-tree removal greatly exceeded those for the operation as a whole. Skidding production increased by 38...

The Shock and Vibration Digest. Volume 15, Number 3

DTIC Science & Technology

1983-03-01

High Temperature Gas-Cooled Reactor Core with Block-type Fuel (2nd Report: An Analytical Method of Two-dmentmnal Vibration of Interacting CohunM) T...Computer-aided techniquei, Detign techniquei A wite of computer programs hat been developed which allow« advanced fatigue analyiit procedures to be...valuei with those developed by bearing analysis computer programs were used to formulate an understanding of the mechanisms that induce ball skidding

Logging damage associated with thinning central Appalachian hardwood stands with a wheeled skidder

Treesearch

Gary W. Miller; Neil I. Lamson; Samuel M. Brock

1984-01-01

In north central West Virginia, unmanaged 53-year-old, mixed oak-cove hardwood stands were thinned to 75, 60, and 45 percent residual stocking. Cut trees were skidded tree-length with a rubber-tired skidder. Logging destroyed or severely bent 26, 29, and 34 percent of the unmarked stems in the 75, 60, and 45 percent stocking plots, respectively. Because 94 percent of...

Pizza Boy vs the Highway Department

NASA Astrophysics Data System (ADS)

Ilyes, Mark A.; Filizzi, James M.

2005-10-01

Many physics teachers and physics education researchers have found that students are highly motivated by classroom or laboratory experiences involving practical, "real-life" scenarios. Rather than attempting to verify a known relationship, they are asked to use an existing relationship to solve some practical problem. The purpose of this experimental investigation is to determine the speed of a car prior to applying the brakes and skidding into a flatbed tractor-trailer.

Logging damage to residual trees following commercial harvesting to different overstory retention levels in a mature hardwood stand in Tennessee

Treesearch

Wayne K. Clatterbuck

2006-01-01

Partial cutting in mature hardwood stands often causes physical damage to residual stems through felling and skidding resulting in a decline in bole quality and subsequent loss of tree value. This study assessed the logging damage to residual trees following commercial harvesting in a fully stocked, mature oak-hickory stand cut to three overstory basal area retention...

A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

NASA Technical Reports Server (NTRS)

Barthlome, D. E.

1975-01-01

Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

Plastic (wire-combed) grooving of a slip-formed concrete runway overlay at Patrick Henry Airport: An initial evaluation

NASA Technical Reports Server (NTRS)

Marlin, E. C.; Horne, W. B.

1977-01-01

A wire-comb technique is described for transversely grooving the surface of a freshly laid (plastic state) slip-formed concrete overlay installed at Patrick Henry Airport. This method of surface texturing yields better water drainage and pavement skid resistance than that obtained with an older conventional burlap drag concrete surface treatment installed on an adjacent portion of the runway.

Applicability of Thermal Storage Systems to Air Force Facilities

DTIC Science & Technology

1990-09-01

Analisis of Region 6 Upper Limit Retrofit Scenario 30% Reduction .... ............. 4.52 4.58 Economic Analysis of Region 7 Upper Limit Retrofit Scenario...or a dynamic-direct contact type. They usually include all the controls, chilling and storage equipment in one self-contained, skid mounted, factory ...SCS technology. One promising trend in reducing system construction costs is the factory -packaged thermal storage cooling unit. As of February 1989

Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United States

Treesearch

Joseph W. Wagenbrenner; Lee H. MacDonald; Robert N. Coats; Peter R. Robichaud; Robert E. Brown

2015-01-01

Post-fire salvage logging adds another set of environmental effects to recently burned areas, and previous studies have reported varying impacts on vegetation, soil disturbance, and sediment production with limited data on the underlying processes. Our objectives were to determine how: (1) ground-based post-fire logging affects surface cover, soil water repellency,...

Comparison of four harvesting systems in a loblolly pine plantation

Treesearch

J. Klepac; Dana Mitchell

2016-01-01

Felling and skidding operations were monitored while clearcut harvesting a 12-acre area of a 14-year old loblolly pine (Pinus taeda) plantation. The study area contained 465 trees per acre for trees 2.0 inches Diameter at Breast Height (DBH) and larger with a Quadratic Mean Diameter (QMD) of 7.26 inches. Two feller-bunchers (tracked and rubber-tired) and two skidders (...

Mitigating Hillslope Erosion After Post-fire Salvage Logging Operations

NASA Astrophysics Data System (ADS)

Robichaud, P. R.; Bone, E. D.; Brown, R. E.

2017-12-01

In the past decades, wildfires around the world have continued to increase in size, severity, and cost. Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. Salvage logging is often a post-fire forest management action to recoup the economic loss of the burned timber, yet concerns arise on the impacts of this activity on water quality. Recently, several studies have been conducted to determine the effect of salvage logging on hillslope erosion. Logging skid trails have been cited as being the cause of high erosion during and after salvage operations. We investigated the impacts of adding operational logging slash to skid trails to reduce hillslope erosion after salvage operations on the 2015 North Star Fire, Washington. We implemented well-designed rapid response approach to compare slash treatment effectiveness by monitoring sediment yield and runoff response from hillslopes with a concentrated flow (rill) experiment. Various runoff amounts are incrementally added to 4 m hillslope plots with and without slash treatments. Our initial results suggest that adding logging slash increased ground cover significantly which contributed to an order of magnitude decrease in hillslope erosion. Integrating erosion mitigation strategies into salvage logging operations should be commonplace when hillslope erosion is a concern.

An approach to accidents modeling based on compounds road environments.

PubMed

Fernandes, Ana; Neves, Jose

2013-04-01

The most common approach to study the influence of certain road features on accidents has been the consideration of uniform road segments characterized by a unique feature. However, when an accident is related to the road infrastructure, its cause is usually not a single characteristic but rather a complex combination of several characteristics. The main objective of this paper is to describe a methodology developed in order to consider the road as a complete environment by using compound road environments, overcoming the limitations inherented in considering only uniform road segments. The methodology consists of: dividing a sample of roads into segments; grouping them into quite homogeneous road environments using cluster analysis; and identifying the influence of skid resistance and texture depth on road accidents in each environment by using generalized linear models. The application of this methodology is demonstrated for eight roads. Based on real data from accidents and road characteristics, three compound road environments were established where the pavement surface properties significantly influence the occurrence of accidents. Results have showed clearly that road environments where braking maneuvers are more common or those with small radii of curvature and high speeds require higher skid resistance and texture depth as an important contribution to the accident prevention. Copyright © 2013 Elsevier Ltd. All rights reserved.

Studies of friction and wear characteristics of various wires for wire-brush skids

NASA Technical Reports Server (NTRS)

Dreher, R. C.

1977-01-01

The friction and wear characteristics of 22 types and sizes of wires for potential use in wire-brush skids were studied. These characteristics were determined by placing brushes made from candidate wires on a belt sander whose moving belt simulated landing roll-out distance. At the same time, the drag force and wear behavior were monitored. Data were obtained over distances up to 3048 m (10,000 ft) at preselected bearing pressures of 172 to 1034 kPa (25 to 150 psi). In general, the friction coefficient developed by the candidate wires was found to be independent of bearing pressure and ranged between 0.4 and 0.6 under the test conditions of this investigation. The friction coefficient was not degraded when the surface was wetted and appears to be independent of wire diameter except perhaps when wire size is relatively large compared with the surface asperities. Generally, the high friction demonstrated by the soft materials was accompanied by high wear rates; conversely, the hard materials provided greater wear resistance but offered lower friction. For all test wires, the wear was shown to increase with increasing bearing pressure, in general, for the same bearing pressure, wear increased with increasing wire diameter and decreased when the surface was wetted.

Influence of pavement condition on horizontal curve safety.

PubMed

Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

2013-03-01

Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Air Force Weapons Laboratory Skid Resistance Research Program, 1969- 1974

DTIC Science & Technology

1975-05-01

M(d) The slope measuring device consists of a rectangular section of aluminum (10-ft lonq, 5/8-in thick, and 2-1/2-in high) with machinists levels...pipe lines, meters, weight buckets, spray bars, and other containers of flow lines. i. Thermometric Equipment, An armored thermometer with a range from...shall be further equipped with an approved dial-scale mercury-actuated thermometer, an electric pyrometer, or other approved thermometric instruments

Practical guides for seeding grass on skid roads, trails, and landings, following logging on east-side forests of Washington and Oregon.

Treesearch

J.O. Gjertson

1949-01-01

Seeding to perennial grasses is an effective method for stabilizing soil, preventing invasion by undesirable plants, and increasing forage production on ground denuded during logging. A survey in 1948 of 52 areas seeded between 1940 and 1946 found 80 percent of the seedings to be medium or better in success, and 45 percent good or very good in success. A careful check...

Mobility Performance Algorithms for Small Unmanned Ground Vehicles

DTIC Science & Technology

2009-05-01

obstacles need to be developed; specifically, models and data for wheeled vehicle skid steering, interior building floor and roof surfaces, and stair ...an 80-lb SUGV; PackBot® at 50 lb, and GatorTM at 2500 lb. Additionally, the FCS projects that 40% of the military fleet may eventually be robotic ...sensor input analysis and decision-making time. Fields (2002a) discusses representing interaction of humans and robots in the OneSAF Testbed Baseline

Comparisons of sediment losses from a newly constructed cross-country natural gas pipeline and an existing in-road pipeline

Treesearch

Pamela J. Edwards; Bridget M. Harrison; Daniel J. Holz; Karl W.J. Williard; Jon E. Schoonover

2014-01-01

Sediment loads were measured for about one year from natural gas pipelines in two studies in north central West Virginia. One study involved a 1-year-old pipeline buried within the bed of a 25-year-old skid road, and the other involved a newly constructed cross-country pipeline. Both pipelines were the same diameter and were installed using similar trenching and...

Design Analysis of a Prepackaged Nuclear Power Plant for an Ice Cap Location

DTIC Science & Technology

1959-01-15

requirements and heating load 1.3 Site Conditions 1,U Air Transportability 1.5 Standby Power Availability 1.6 Building Structuree and Foundations 2,0...Skid with Reactor and Steam Generator Generator Weight Distribution Foundation Load Diagram (Secondary) Turbine Generator Package - Typical...Requirements and Heating Load The plant shall be capable of producing a minimum of 1500 Kw net ^ electrical energy at 4160/2400 volts, three phase

Landing Procedure in Model Ditching Tests of Bf 109

NASA Technical Reports Server (NTRS)

Sottorf, W.

1949-01-01

The purpose of the model tests is to clarify the motions in the alighting on water of a land plane. After discussion of the model laws, the test method and test procedure are described. The deceleration-time-diagrams of the landing of a model of the Bf 109 show a high deceleration peek of greater than 20g which can be lowered to 4 to 6g by radiator cowling and brake skid.

KSC-01pp1062

NASA Image and Video Library

2001-06-02

KENNEDY SPACE CENTER, Fla. -- An L-1011 aircraft called the Stargazer lands at the Skid Strip, Cape Canaveral Air Force Station. Underneath its belly it carries the Orbital Sciences Corp. Pegasus XL launch vehicle with the High Energy Solar Spectroscopic Imager (HESSI) attached. The Pegasus XL will launch the HESSI no earlier than June 12 from CCAFS. The primary mission of HESSI is to explore the basic physics of particle acceleration and energy release in solar flares

Tip-over Prevention Through Heuristic Reactive Behaviors for Unmanned Ground Vehicles

DTIC Science & Technology

2014-05-01

Systems Center Pacific Unmanned Systems Group 53406 Woodward Road San Diego, CA 92152 ABSTRACT Skid-steer teleoperated robots are commonly used by...Reactive Behaviors Further author information: (Send correspondence to K.T.) K.T.: E-mail: kurt.talke@navy.mil, SPIE Proc. 9084: Unmanned Systems ...5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Space and Naval Warfare Systems Center

Wheel brakes and their application to aircraft

NASA Technical Reports Server (NTRS)

Dowty, G H

1928-01-01

The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

Residual stocking not seriously reduced by logging damage from thinning of West Virginia cherry-maple stands

Treesearch

Neil I. Lamson; H. Clay Smith; Gary W. Miller

1984-01-01

In north-central West Virginia, unmanaged 60-year-old cherry-maple stands were thinned to 75, 60, and 45 percent residual stocking. Cut trees were skidded tree length by a rubber-tired skidder. Logging destroyed or severely bent over 22, 23, and 45 percent of the unmarked stems in the 75, 60, and 45 percent stocked plots. Because 99 percent of the destroyed and bent...

Soil water erosion processes in mountain forest catchment - analysis by using terrestrial laser scanning

NASA Astrophysics Data System (ADS)

Dąbek, Paweł; Żmuda, Romuald; Szczepański, Jakub; Ćmielewski, Bartłomiej; Patrzałek, Ciechosław

2013-04-01

The paper presents the results of the analysis of the water erosion processes of soil occurring in forestry mountain catchment area in the region of West Sudetes Mountain in Poland. The research was carried out within the experimental area of skid trails (operational trails), which were used to the end of 2010 in obtaining wood and its mechanical transport to the place of storage. As a consequence of forestry works that were carried out it was changing the natural structure of ground and its surface on the wooded slopes, which, combined with the favorable hydro-meteorological conditions contributed to the intensification of the water erosion processes of soil on surface of trails. For the implementation of the research project of the analysis of water erosion processes in the forestry catchment area innovative was used terrestrial laser scanning. Using terrestrial laser scanning has enabled the analysis of the dynamics of erosion processes both in time, as well as in spatial and quantitative terms. Scanning was performed at a resolution of 4 mm, resulting in 62 500 points per 1 square meter. After filtering the data were interpolated to other resolution of 1 cm, which can identify even the smallest linear and surface effects of erosion. While installed on the experimental area, along the skid trails, anti-erosion barriers in order to reduce transport eroded material and allow its accumulation. Allowed to precisely determine the location of areas of accumulation, the rate and amount of accumulated material. The result of the analyses that was carried out is identification areas of denudation of the eroded material, and also determine the intensity of the erosion processes and their quantitative analysis. The long-term researches on hydrological conditions and forest complexes functioning show that forest effectively stores water, limits linear and surface flow and delays water outflow from a catchment. Carried out a research project using the terrestrial laser scanning shows that anthropogenic activities in the form of forest management and their effects in the form of dense network of forest roads and skid trails and obtaining wood diminish correct functioning of a forest or even increase the phenomenon of erosion. Submit the results of the analysis consider the problem of dynamics and intensity of erosion processes in mountain areas, and show the effectiveness of the methodology of research.

Basewide Engineering Evaluation-Cost Analysis for Soil Vapor Extraction. General Evaluation Document

DTIC Science & Technology

1993-09-01

Agricultural (low density) a 3.7%/ Residential Leand McFR6 Open Space (recreational) Suron ding Solid Waste Disposal Faiiy(transfer sttin Areas 12...designed, manufactured , and sold as integrated units by vendors of SVE systems. Smaller systems, such as those with total 42 GENERAL EVALUATION...the 2,000 scfm and larger capacity range, can be supplied either as portable units (e g., on multiple trailers), or manufactured on one to three skids

KSC-01pp1061

NASA Image and Video Library

2001-06-02

KENNEDY SPACE CENTER, Fla. -- An L-1011 aircraft called the Stargazer gets ready to land at the Skid Strip, Cape Canaveral Air Force Station. Underneath its belly it carries the Orbital Sciences Corp. Pegasus XL launch vehicle with the High Energy Solar Spectroscopic Imager (HESSI) attached. The Pegasus XL will launch the HESSI no earlier than June 12 from CCAFS. The primary mission of HESSI is to explore the basic physics of particle acceleration and energy release in solar flares

Fast instantaneous center of rotation estimation algorithm for a skied-steered robot

NASA Astrophysics Data System (ADS)

Kniaz, V. V.

2015-05-01

Skid-steered robots are widely used as mobile platforms for machine vision systems. However it is hard to achieve a stable motion of such robots along desired trajectory due to an unpredictable wheel slip. It is possible to compensate the unpredictable wheel slip and stabilize the motion of the robot using visual odometry. This paper presents a fast optical flow based algorithm for estimation of instantaneous center of rotation, angular and longitudinal speed of the robot. The proposed algorithm is based on Horn-Schunck variational optical flow estimation method. The instantaneous center of rotation and motion of the robot is estimated by back projection of optical flow field to the ground surface. The developed algorithm was tested using skid-steered mobile robot. The robot is based on a mobile platform that includes two pairs of differential driven motors and a motor controller. Monocular visual odometry system consisting of a singleboard computer and a low cost webcam is mounted on the mobile platform. A state-space model of the robot was derived using standard black-box system identification. The input (commands) and the output (motion) were recorded using a dedicated external motion capture system. The obtained model was used to control the robot without visual odometry data. The paper is concluded with the algorithm quality estimation by comparison of the trajectories estimated by the algorithm with the data from motion capture system.

Sequence and batch language programs and alarm-related ``C`` programs for the 242-A MCS. Revision 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, J.F.

1995-03-01

A Distributive Process Control system was purchased by Project B-534, ``242-A Evaporator/Crystallizer Upgrades``. This control system, called the Monitor and Control System (MCS), was installed in the 242-A Evaporator located in the 200 East Area. The purpose of the MCS is to monitor and control the Evaporator and monitor a number of alarms and other signals from various Tank Farm facilities. Applications software for the MCS was developed by the Waste Treatment Systems Engineering (WTSE) group of Westinghouse. The standard displays and alarm scheme provide for control and monitoring, but do not directly indicate the signal location or depict themore » overall process. To do this, WTSE developed a second alarm scheme which uses special programs, annunciator keys, and process graphics. The special programs are written in two languages; Sequence and Batch Language (SABL), and ``C`` language. The WTSE-developed alarm scheme works as described below: SABL relates signals and alarms to the annunciator keys, called SKID keys. When an alarm occurs, a SABL program causes a SKID key to flash, and if the alarm is of yellow or white priority then a ``C`` program turns on an audible horn (the D/3 system uses a different audible horn for the red priority alarms). The horn and flashing key draws the attention of the operator.« less

Radon assay for SNO+

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumleskie, Janet

The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

Radon assay for SNO+

NASA Astrophysics Data System (ADS)

Rumleskie, Janet

2015-12-01

The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

Evaluation, Analysis, and Documentation Support for the 10kW Signature Suppressed Lightweight Electric Energy Plant (SLEEP)

DTIC Science & Technology

1988-03-14

HAEMP. This issue will be resolved during the Technical Test. (8) Will the 10kW SLEEP handle brief overload conditions? Air conditioners and other...signal units; air defense units; combat arms command, control, and commnunications units; and logistics functions in the brigade area. Priority...Skid mounting o Lifting attachments and tiedowns o Transportable by USAF C-130, C-141 and all US Army aircraft o Capability for low velocity air drop

Runway Rubber Removal Specification Development: Field Evaluation Procedures Development.

DTIC Science & Technology

1984-07-01

removal was sufficient enough to restore full pave- ment skid resistance (based on tests with a DBV). With regard to high-pressure water rubber ...over a test surface, the rubber slider resists motion-. The force, parallel to the test surface, which acts on the slider registers an output on a dial...PROCEDURE 1. Check rubber shoe for wear . Replace when the edge is worn by more than 3/16 in as measured with a rule laid flat across the slider width. 2

Safety Grooving

NASA Technical Reports Server (NTRS)

1985-01-01

Safety grooving, the cutting of grooves in concrete to increase traction and prevent injury, was first developed to reduce aircraft accidents on wet runways. Represented by the International Grooving and Grinding Association (IG&GA), the industry expanded into highway and pedestrian applications. The technique originated at Langley, which assisted in testing the grooving at airports and on highways. Skidding was reduced, stopping distance decreased, and a vehicle's cornering ability on curves was increased. The process has been extended to animal holding pens, steps, parking lots and other potentially slippery surfaces.

X-15 landing on lakebed

NASA Technical Reports Server (NTRS)

1960-01-01

In this 17-second video clip, the X-15 is shown in flight and then landing on Rogers Dry Lakebed adjacent to Edwards Air Force Base. It is followed by an F-104A chase aircraft, whose pilot provided a second set of eyes to the X-15 pilot on landing in case of any problems. The video shows the skids on the back of the X-15 contacting the lakebed, with the aircraft's nose then rotating downward until the nose landing gear was on the lakebed.

KSC-01pp1041

NASA Image and Video Library

2001-05-30

Workers supervise the off-loading of segments of a Lockheed Martin Atlas II rocket at the Skid Strip at Cape Canaveral Air Force Station.; The rocket will be used to launch the Geostationary Operational Environmental Satellite-M (GOES-M), the latest in the current series of advanced geostationary weather satellites in service.; GOES-M is being prepared for launch at the Astrotech Space Operations facility located in the Spaceport Florida Industrial Park in Titusville, Fla. The launch is scheduled for July 15 from Pad 36-A, Cape Canaveral Air Force Station

KSC-01pp1040

NASA Image and Video Library

2001-05-30

Workers supervise the off-loading of segments of a Lockheed Martin Atlas II rocket at the Skid Strip at Cape Canaveral Air Force Station.; The rocket will be used to launch the Geostationary Operational Environmental Satellite-M (GOES-M), the latest in the current series of advanced geostationary weather satellites in service.; GOES-M is being prepared for launch at the Astrotech Space Operations facility located in the Spaceport Florida Industrial Park in Titusville, Fla. The launch is scheduled for July 15 from Pad 36-A, Cape Canaveral Air Force Station

Air Force Heroes in Vietnam

DTIC Science & Technology

1979-01-01

gave me a little more weight on the brakes. I think I must have been skidding on that steel planking . It was a little bit slick from the dampness. I...have a history of outstanding performance and a unique blend of flying experience and leadership ability. To be the boss of a squadron in combat is...hitting something they wanted to hang on to. it was a vital target and its loss would hurt them." Merl and his backseater, Captain Kevin "Mike" Gilroy

Mobility-Dependent Motion Planning for High Speed Robotic Vehicles

DTIC Science & Technology

2008-07-25

of the vehicle’s mobility in such type of terrain. Moreover, autonomous driv- ing of wheeled vehicles at high speeds adds a new level of complexity due...dynamic effects such as wheel slip, skidding, ballistic behavior, rollover, and vehicle-terrain interaction phenomena. Navigation algorithms must also...description of mobility was defined as the probability that for a given 6 ini ial v 10 ity at an initial po ition h robo will hav a non-n gative ve- loci y

Fleet/TYCOM Level Survey of Armament Handling Problems - Task One of the Naval Aviation Armament Support Equipment Program Management Study

DTIC Science & Technology

1977-06-21

7. AUTHOR(#) 6. CONTRACT OR GRANT NUMBER(#) PILA /UDERIAN 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK...mechanically complex (i.e. contains an internal combustion engine) and/or comes in direct support of the aircraft is managed and maintained by the AIMD. The...an internal combustion engine. Accordingly, only the Aero 33D/E Trailer, Aero 51B Trailer, 21A/C Bomb Skid, and Aero 47A Weapons Loader are maintained

In Situ Catalytic Groundwater Treatment Using Palladium Catalysts and Horizontal Flow Treatment Wells

DTIC Science & Technology

2008-01-01

may enter the soil , and subsequently the groundwater, along any portion of this unlined channel. The area south of the buildings has not been...the 1960s in the northwestern corner of Site 19, and an estimated 250,000 gallons of JP-4 jet fuel were released. Soil was excavated and...16,000 Pd catalyst treatment system $61,000 Pd catalyst with eggshell coating (20 kg @ $245 per lb) $11,000 Skid-mounted reactor system and

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft takes off from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Latest Highlights from our Direct Measurement Video Collection

NASA Astrophysics Data System (ADS)

Vonk, M.; Bohacek, P. H.

2014-12-01

Recent advances in technology have made videos much easier to produce, edit, store, transfer, and view. This has spawned an explosion in a production of a wide variety of different types of pedagogical videos. But with the exception of student-made videos (which are often of poor quality) almost all of the educational videos being produced are passive. No matter how compelling the content, students are expected to simply sit and watch them. Because we feel that being engaged and active are necessary components of student learning, we have been working to create a free online library of Direct Measurement Videos (DMV's). These videos are short high-quality videos of real events, shot in a way that allows students to make measurements directly from the video. Instead of handing students a word problem about a car skidding on ice, we actually show them the car skidding on ice. We then ask them to measure the important quantities, make calculations based on those measurements and solve for unknowns. DMV's are more interesting than their word problem equivalents and frequently inspire further questions about the physics of the situation or about the uncertainty of the measurement in ways that word problems almost never do. We feel that it is simply impossible to a video of a roller coaster or a rocket and then argue that word problems are better. In this talk I will highlight some new additions to our DMV collection. This work is supported by NSF TUES award #1245268

Automated method for measuring the extent of selective logging damage with airborne LiDAR data

NASA Astrophysics Data System (ADS)

Melendy, L.; Hagen, S. C.; Sullivan, F. B.; Pearson, T. R. H.; Walker, S. M.; Ellis, P.; Kustiyo; Sambodo, Ari Katmoko; Roswintiarti, O.; Hanson, M. A.; Klassen, A. W.; Palace, M. W.; Braswell, B. H.; Delgado, G. M.

2018-05-01

Selective logging has an impact on the global carbon cycle, as well as on the forest micro-climate, and longer-term changes in erosion, soil and nutrient cycling, and fire susceptibility. Our ability to quantify these impacts is dependent on methods and tools that accurately identify the extent and features of logging activity. LiDAR-based measurements of these features offers significant promise. Here, we present a set of algorithms for automated detection and mapping of critical features associated with logging - roads/decks, skid trails, and gaps - using commercial airborne LiDAR data as input. The automated algorithm was applied to commercial LiDAR data collected over two logging concessions in Kalimantan, Indonesia in 2014. The algorithm results were compared to measurements of the logging features collected in the field soon after logging was complete. The automated algorithm-mapped road/deck and skid trail features match closely with features measured in the field, with agreement levels ranging from 69% to 99% when adjusting for GPS location error. The algorithm performed most poorly with gaps, which, by their nature, are variable due to the unpredictable impact of tree fall versus the linear and regular features directly created by mechanical means. Overall, the automated algorithm performs well and offers significant promise as a generalizable tool useful to efficiently and accurately capture the effects of selective logging, including the potential to distinguish reduced impact logging from conventional logging.

Safety halls--an evaluation.

PubMed

Nyberg, Anders; Gregersen, Nils Petter; Nolén, Sixten; Engström, Inger

2005-01-01

In most countries, drivers licensing systems usually include teaching some aspects of using safety equipment (e.g., airbags and seat belts). However, there is now evidence worldwide that such education is inadequate, as indicated by, for example, the overrepresentation of young drivers who do not use seat belts. A randomized controlled study was conducted in Sweden to evaluate the effects of visiting a facility known as a "safety hall" in combination with the mandatory skid training. The results were assessed to determine the effects of the knowledge and attitudes of learner drivers in the following subjects: airbags, securing loads, seat belts, sitting posture, speed, and tires. An experimental group and a control group comprising 658 and 668 learners, respectively, answered identical questionnaires on three different occasions (pretest, posttest 1, and posttest 2). The results show that, for most of the topics considered, knowledge and attitudes in both groups were better at posttest 2 than at the pretest, and in general, the best knowledge and attitudes were found in the experimental group. The combined safety/skid training seems to have had the greatest effect on seat belts and loads. The findings also indicate that the safety halls can be further improved to achieve an even better effect. The use of safety halls has improved the knowledge and attitudes of learner drivers concerning several important areas related to traffic safety. Since knowledge and attitudes are important predictors of behavior, implementing safety halls can be expected to lead to improvements, especially regarding the use of safety belts and securing loads.

Multi-mode reliability-based design of horizontal curves.

PubMed

Essa, Mohamed; Sayed, Tarek; Hussein, Mohamed

2016-08-01

Recently, reliability analysis has been advocated as an effective approach to account for uncertainty in the geometric design process and to evaluate the risk associated with a particular design. In this approach, a risk measure (e.g. probability of noncompliance) is calculated to represent the probability that a specific design would not meet standard requirements. The majority of previous applications of reliability analysis in geometric design focused on evaluating the probability of noncompliance for only one mode of noncompliance such as insufficient sight distance. However, in many design situations, more than one mode of noncompliance may be present (e.g. insufficient sight distance and vehicle skidding at horizontal curves). In these situations, utilizing a multi-mode reliability approach that considers more than one failure (noncompliance) mode is required. The main objective of this paper is to demonstrate the application of multi-mode (system) reliability analysis to the design of horizontal curves. The process is demonstrated by a case study of Sea-to-Sky Highway located between Vancouver and Whistler, in southern British Columbia, Canada. Two noncompliance modes were considered: insufficient sight distance and vehicle skidding. The results show the importance of accounting for several noncompliance modes in the reliability model. The system reliability concept could be used in future studies to calibrate the design of various design elements in order to achieve consistent safety levels based on all possible modes of noncompliance. Copyright © 2016 Elsevier Ltd. All rights reserved.

The comparison respond of braking torque control between PID and SMC controller for electric powered wheelchair descending on slope condition

NASA Astrophysics Data System (ADS)

Asyraf, S. M.; Heerwan, P. M.; Izhar, I. M.

2018-04-01

During descending on a slope, the speed of Electric Powered Wheelchair (EPW) tends to changed rapidly. Normally, most EPW is provided with mechanical braking system which transfers human pulling force of the lever creating friction at the tire. However, the task is difficult for the users are elderly or paralyses. However, even for normal user with good strength, in fear condition they tend to give sudden braking which leads to tire locking up and skidding, eventually EPW unstable. These problems will cause accident and injuries to the users if speed does not properly control. In this paper, the automated braking torque control method was proposed in EPW as alternative to solve this problem and increase the mobility and stability especially during descending on slope in other to help the user of the EPW as their daily transportation. In this research, Proportional-Integral-Derivative and Sliding Mode Control controller are compared to determine the best response for torque braking control. The rapid change of speed can be controlled by the braking torque using proposed controllers based on the desired constant speed set by the control designer. Moreover, the sudden braking that caused tire to lock up and skid can be avoided. Furthermore, result from SMC shows this controller have good time respond to maintain the speed based on desired value when descending at slope condition by controlling the braking torque compared to the PID controller.

The STS-88 crew talks to media before DEPARTing for Houston

NASA Technical Reports Server (NTRS)

1998-01-01

The STS-88 crew meet with news media at the Cape Canaveral Air Station Skid Strip before leaving for Houston. From left, they are Mission Specialists Sergei Konstantinovich Krikalev and James H. Newman, Commander Robert D. Cabana (at microphone), Mission Specialists Jerry L. Ross and Nancy J. Currie, and Pilot Frederick W. 'Rick' Sturckow. The STS-88 crew returned Dec. 15 from a 12-day mission on orbit constructing the first elements of the International Space Station, the U.S.-built Unity connecting module and Russian-built Zarya control module.

AGARD Conference Proceedings on Guidance and Control of Precision Guided Weapons Held in Geilo, Norway from 3-6 May 1988

DTIC Science & Technology

1989-01-11

EFFECT OF BANK-TO-TURN VERSUS SKID-TO-TURN STEERING ON THE MANOEUVRABILITY OF AUTONOMOUS PRECISION GUIDED MUUNITION AGAINST GROUND TARGETS by B.J.Damen...space. Basic Relationships of an Interferometer Gyro The Sagnac effect in the fiber optic gyro causes a phase shift in the sensor col during rotation with... a read-out coupler and an.avalanche photodiode for optical detection. The opto module is rigidly connected with the sensor module via a fiber link

A Preliminary Evaluation of the Potential Utility of the Surface Condition Analyzer (SCAN) System for Monitoring Runway Water Depth as Relating to Runway Traction.

DTIC Science & Technology

1980-01-01

one year with the savings realized in reduced wear on arresting gear. 2.2 Evaluation of the Potential Utility of the SCAN System for Monitoring Runway...without loss of accuracy due to build-up of rubber and other contaminants on the sensor surface? 2. Can water depth be measured representatively on a...Hargett, E.R., 1974: Skid- Resistance Evaluation of Seven Antihydroplaning Surfaces, Air Force Weapons Laboratory, Kirtland AP. NM4 87117, 39 pp

Environmental Assessment for the Beddown and Flight Operations of Unmanned Aircraft Systems at Cape Canaveral Air Force Station, Florida

DTIC Science & Technology

2011-07-01

Banana River to the west. PURPOSE AND NEED: The purpose of this action is to . establish a U.S. CBP A&M Southeastern Region Operations Center that...barrier island bordered by the Atlantic Ocean to the east and the Banana River to the west. CCAFS is home to the 45th Space Wing (45 SW) Mission...Hangar C Cape Canaveral AFS Skid Strip Figure 3-2. Cape Canaveral AFS Land Use July 20113-5Final EA Atlantic Ocean Banana River Legend CCAFS

Stability analysis of Caisson Cofferdam Based on Strength Reduction Method

NASA Astrophysics Data System (ADS)

Xu, B. B.; Zhang, N. S.

2018-05-01

The working mechanism of the caisson cofferdam depends on the self-weight of the structure and internal filling to ensure its skid resistance and overturn resistance stability. Using the strength reduction method, the safety factor of the caisson cofferdam can be obtained. The potential slide surface can be searched automatically without constraining the range of the arc center. According to the results, the slippage surface goes through the bottom of the caisson. Based on the judgement criterion of the strength reduction method, the final safety factor is about 1.65.

Proceedings of the European ISTVS Conference (6th), OVK Symposium (4th), on "Off Road Vehicles in Theory and Practice". Held at Vienna, Austria on 28-30 September 1994. Volume 2.

DTIC Science & Technology

1994-09-30

experimental proof-of-concept series hybrid thermo-mechano-elec- tromechanical and/or electromechanical All-Wheel-Driven (AWD) pro- pulsion, All-Wheel...caterpillar-tracks’ motorized sprocket-, road- and tensioner- wheels form a complete proof-of-concept series hybrid thermo- mechano-electromechanical and/or...tromechanical AWA supension spheres and skid-steering conversion spheres used as integral spheres together with future new concept hybrid thermo

Some Landing Studies Pertinent to Glider-Reentry Vehicles

NASA Technical Reports Server (NTRS)

Houbolt, John C.; Batterson, Sidney A.

1960-01-01

Results are presented of some landing studies that may serve as guidelines in the consideration of landing problems of glider-reentry configurations. The effect of the initial conditions of sinking velocity, angle of attack, and pitch rate on impact severity and the effect of locating the rear gear in various positions are discussed. Some information is included regarding the influence of landing-gear location on effective masses. Preliminary experimental results on the slideout phase of landing include sliding and rolling friction coefficients that have been determined from tests of various skids and all-metal wheels.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer touches down at the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is being readied for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Launch Attempt - Prepared for Takeoff - Scrubb

NASA Image and Video Library

2016-12-12

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is ready for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is ready for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Launch Attempt; Scrubbed - Take Off

NASA Image and Video Library

2016-12-12

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft takes off from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

KSC-02pd1946

NASA Image and Video Library

2002-12-17

KENNEDY SPACE CENTER, FLA. - An Orbital Sciences L-1011 aircraft arrives at the Cape Canaveral Air Force Station Skid Strip. Attached underneath the aircraft is the Pegasus XL Expendable Launch Vehicle, which will be transported to the Multi-Payload Processing Facility for testing and verification. The Pegasus will undergo three flight simulations prior to its scheduled launch in late January 2003. The Pegasus XL will carry NASA's Solar Radiation and Climate Experiment (SORCE) into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere. .

KSC-02pd1951

NASA Image and Video Library

2002-12-17

KENNEDY SPACE CENTER, FLA. -- Workers at the Cape Canaveral Air Force Station Skid Strip stand next to the Pegasus XL Expendable Launch Vehicle underneath the Orbital Sciences L-1011 aircraft. The Pegasus will be transported to the Multi-Payload Processing Facility for testing and verification. The Pegasus will undergo three flight simulations prior to its scheduled launch in late January 2003. The Pegasus XL will carry NASA's Solar Radiation and Climate Experiment (SORCE) into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere. .

Recreational Stream Crossing Effects on Sediment Delivery and Macroinvertebrates in Southwestern Virginia, USA

NASA Astrophysics Data System (ADS)

Kidd, Kathryn R.; Aust, W. Michael; Copenheaver, Carolyn A.

2014-09-01

Trail-based recreation has increased over recent decades, raising the environmental management issue of soil erosion that originates from unsurfaced, recreational trail systems. Trail-based soil erosion that occurs near stream crossings represents a non-point source of pollution to streams. We modeled soil erosion rates along multiple-use (hiking, mountain biking, and horseback riding) recreational trails that approach culvert and ford stream crossings as potential sources of sediment input and evaluated whether recreational stream crossings were impacting water quality based on downstream changes in macroinvertebrate-based indices within the Poverty Creek Trail System of the George Washington and Jefferson National Forest in southwestern Virginia, USA. We found modeled soil erosion rates for non-motorized recreational approaches that were lower than published estimates for an off-road vehicle approach, bare horse trails, and bare forest operational skid trail and road approaches, but were 13 times greater than estimated rates for undisturbed forests and 2.4 times greater than a 2-year old clearcut in this region. Estimated soil erosion rates were similar to rates for skid trails and horse trails where best management practices (BMPs) had been implemented. Downstream changes in macroinvertebrate-based indices indicated water quality was lower downstream from crossings than in upstream reference reaches. Our modeled soil erosion rates illustrate recreational stream crossing approaches have the potential to deliver sediment into adjacent streams, particularly where BMPs are not being implemented or where approaches are not properly managed, and as a result can negatively impact water quality below stream crossings.

Carbon emissions performance of commercial logging in East Kalimantan, Indonesia.

PubMed

Griscom, Bronson; Ellis, Peter; Putz, Francis E

2014-03-01

Adoption of reduced-impact logging (RIL) methods could reduce CO2 emissions by 30-50% across at least 20% of remaining tropical forests. We developed two cost effective and robust indices for comparing the climate benefits (reduced CO2 emissions) due to RIL. The indices correct for variability in the volume of commercial timber among concessions. We determined that a correction for variability in terrain slope was not needed. We found that concessions certified by the Forest Stewardship Council (FSC, N = 3), when compared with noncertified concessions (N = 6), did not have lower overall CO2 emissions from logging activity (felling, skidding, and hauling). On the other hand, FSC certified concessions did have lower emissions from one type of logging impact (skidding), and we found evidence of a range of improved practices using other field metrics. One explanation of these results may be that FSC criteria and indicators, and associated RIL practices, were not designed to achieve overall emissions reductions. Also, commonly used field metrics are not reliable proxies for overall logging emissions performance. Furthermore, the simple distinction between certified and noncertified concessions does not fully represent the complex history of investments in improved logging practices. To clarify the relationship between RIL and emissions reductions, we propose the more explicit term 'RIL-C' to refer to the subset of RIL practices that can be defined by quantified thresholds and that result in measurable emissions reductions. If tropical forest certification is to be linked with CO2 emissions reductions, certification standards need to explicitly require RIL-C practices. © 2013 John Wiley & Sons Ltd.

Investigation of using steel slag in hot mix asphalt for the surface course of flexible pavements

NASA Astrophysics Data System (ADS)

Nguyen, Hien Q.; Lu, Dai X.; Le, Son D.

2018-04-01

The rapid development of heavy industry in Vietnam leads to the establishments of steel industry. Steel slag, a by-product of steelwork industry, under Vietnamese’s law, was considered as a deleterious solid waste which needed to be processed and landfilled. However, this has changed recently, and steel slag is now seen as a normal or non-deleterious solid waste, and has been studied for reuse in the construction industry. In this study, steel slag was used, as a replacement for mineral aggregate, in hot mix asphalt. Two hot mix asphalt mixtures with an equivalent nominal aggregate size of 12.5 (C12.5) and 19 mm (C19) were produced using steel slag. In addition, one conventional hot mix asphalt mixture of C19 was produced using mineral aggregate for comparison purpose. Investigation in laboratory condition and trial sections was carried out on Marshall tests, surface roughness, skid resistance, and modulus of the pavement before and after applying a new surface course of hot mix asphalt. The study showed that all steel slag asphalt mixtures passed the Marshall stability and flow test requirements. The skid resistance of steel slag hot mix asphalt mixtures for the surface course satisfied the Vietnamese specification for asphalt. Moreover, the pavement sections with the surface course of steel slag hot mix asphalt showed a considerable higher modulus than that of the conventional one. Only the roughness of the surface course paved with C19 did not pass the requirement of the specification.

KSC-2009-1756

NASA Image and Video Library

2009-02-20

CAPE CANAVERAL, Fla. – The Russian AH-124-100 aircraft arrives at Cape Canaveral Air Force Station's skid strip in Florida carrying the Centaur stage of the Atlas V rocket that will launch NASA's Lunar Reconnaissance Orbiter, or LRO, and NASA's Lunar CRater Observation and Sensing Satellite, known as LCROSS. The two spacecraft will be integrated with the Atlas V and tested for final flight worthiness. Launch is scheduled for the spring. LCROSS and LRO are the first missions in NASA's plan to return humans to the moon and begin establishing a lunar outpost by 2020. Photo credit: NASA/Troy Cryder

Summary of NASA landing-gear research

NASA Technical Reports Server (NTRS)

Fisher, B. D.; Sleeper, R. K.; Stubbs, S. M.

1978-01-01

This paper presents a brief summary of the airplane landing gear research underway at NASA. The technology areas include: ground handling simulator, antiskid braking systems, space shuttle nose-gear shimmy, active control landing gear, wire brush skid landing gear, air cushion landing systems, tire/surface friction characteristics, tire mechanical properties, tire-tread materials, powered wheels for taxiing, and crosswind landing gear. This paper deals mainly with the programs on tire-tread materials, powered wheel taxiing, air cushion landing systems, and crosswind landing gear research with particular emphasis on previously unreported results of recently completed flight tests. Work in the remaining areas is only mentioned.

Adaptive controller for regenerative and friction braking system

DOEpatents

Davis, R.I.

1990-10-16

A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

President Clinton's Arrival at CCAS and Visit to KSC for Launch of STS-95

NASA Technical Reports Server (NTRS)

1998-01-01

Live footage shows President Bill Clinton and First Lady Hillary Rodham Clinton arriving in Airforce 1 on the Skid Strip, viewing the launch, and tracking the plume of Space Shuttle Discovery, on mission STS-95. The viewing takes place on the roof of the Launch Control Center (LCC). Also present on the roof to watch this event are Astronaut Robert Cabana and Eileen Collins (both in flight suit), and the NASA Administrator Daniel Goldin. The President is shown giving a speech to the Launch Team and shaking hands with employees in the LCC.

Adaptive controller for regenerative and friction braking system

DOEpatents

Davis, Roy I.

1990-01-01

A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Optimal design for slip deceleration control in anti-lock braking system

NASA Astrophysics Data System (ADS)

Mishra, Sheelam; Kumar, Pankaj; Rahman, Mohd. Saifur

2018-05-01

ABS (Anti-lock Braking System) is the most advanced braking system implemented in modern cars to avoid the slipping or skidding of the vehicle on the road. Moreover, it reduces the stopping distance of the vehicle because it avoids the locking of the wheel during braking. It enables the driver to steer the vehicle during braking. But every system has its downsides and likewise ABS too, it is not efficient during normal braking or snowy conditions. Our aim is to overcome these downsides and optimize Anti-lock Braking System to make it even better.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft gains altitude after takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft begins its takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft touches down at the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane provided photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket is scheduled for 8:40 a.m. EST.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft takes off from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Launch Attempt - Prepared for Takeoff - Scrubb

NASA Image and Video Library

2016-12-12

A pathfinder aircraft prepares for takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

An Orbital ATK L-1011 Stargazer aircraft descends toward the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket occurred at 8:37 a.m. EST.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft descends for touchdown at the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane provided photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Effect of yaw angle on steering forces for the lunar roving vehicle wheel

NASA Technical Reports Server (NTRS)

Green, A. J.

1974-01-01

A series of tests was conducted with a Lunar Roving Vehicle (LRV) wheel operating at yaw angles ranging from -5 to +90 deg. The load was varied from 42 to 82 lb (187 to 365 N), and the speed was varied from 3.5 to 10.0 ft/sec (1.07 to 3.05 m/sec). It was noted that speed had an effect on side thrust and rut depth. Side thrust, rut depth, and skid generally increased as the yaw angle increased. For the range of loads used, the effect of load on performance was not significant.

KSC-02pd1949

NASA Image and Video Library

2002-12-17

KENNEDY SPACE CENTER, FLA. -- Workers at the Cape Canaveral Air Force Station Skid Strip get ready to remove the Pegasus XL Expendable Launch Vehicle attached underneath the Orbital Sciences L-1011 aircraft. The Pegasus will be transported to the Multi-Payload Processing Facility for testing and verification. The Pegasus will undergo three flight simulations prior to its scheduled launch in late January 2003. The Pegasus XL will carry NASA's Solar Radiation and Climate Experiment (SORCE) into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere. .

Aeromagnetic survey by a model helicopter at the ruin of ironwork refinement

NASA Astrophysics Data System (ADS)

Funaki, M.; Nishioka, T.

2007-12-01

 It is difficult to detect the magnetic anomaly resulting from the small scale of magnetic sources as archeological or historical ruins by a helicopter due to the restraint of the low altitude flights in the narrow area. Although a relatively small unmanned helicopters has been commercialized for agriculture use etc., it is too expensive for aeromagnetic surveys. We have developed a small autonomous unmanned helicopter which modified a model helicopter for aeromagnetic survey. A model helicopter (Hirobo Co.; SF40) with a 40cc gasoline engine, length of 143cm from the nose to the tail and dry weight of 15 kg is selected in this study. The irradiated magnetic field from the bottom-center of skid of SF40 was the total magnetic field (R)=3511 nT, inclination (I)=12 degrees and declination (D)=138 degrees. It was reduced to about 1 nT at 3 m downward from the skid during the hovering. When SF40 was covered with a magnetic shield film (Amolic sheet), the distance to measure 1nT diminished to 2 m. As shielding whole body with the film is not effective for reliable and safety flights, the only servomotors having the strong magnetization were shielded by the film. The autonomous flights based on GPS data succeeded. As the control system was too large and heavy for SF40, we are developing more simple and small navigation system for this project. Magnetometer system consists of a 3-axis fluxgate magnetometer, data logger, GPS and battery, recording every second of x, y and z magnetic fields, latitude, longitude, altitude and satellite number during 3 hours. The total weight of the system is 400g. The system was hanged to 2m lower from the skid by a rope (Bird magnetometer) or 2m front form the nose by a carbon fiber pipe (Stinger magnetometer) in order to avoid the magnetic field of SF40. However, the bird magnetometer was not suitable due to the strong noise resulting from the swing of the sensor. An archeological ruin of the ironwork refinement aged 15th century in western Japan was measured by the stinger magnetometer. The survey area was 70x20m with a gentle slop. The helicopter was controlled by the manual keeping up the roughly same altitude (the 4-8m height from the surface) and speed (1m/s). The result showed the strong anomalies of 500 nT at the NW corner of the area where consists with the refinement. From these viewpoints the model helicopter is useful to find the ironwork refinements instead of the identification based on the feeling and the experience of archeologists.

Sidecut radius and the mechanics of turning—equipment designed to reduce risk of severe traumatic knee injuries in alpine giant slalom ski racing

PubMed Central

Spörri, Jörg; Kröll, Josef; Gilgien, Matthias; Müller, Erich

2016-01-01

Background There is limited empirical knowledge about the effect of ski geometry, particularly in the context of injury prevention in alpine ski racing. We investigated the effect of sidecut radius on biomechanical variables related to the mechanics of turning. Methods During a field experiment, six European Cup level athletes skied on three different pairs of giant slalom (GS) skis varying in sidecut radii (30 m, 35 m and 40 m). Using a video-based three-dimensional (3D) kinematic system, a 22-point body segment model of the athletes was reconstructed in 3D, and the variables ground reaction force, centre of mass (COM) speed, COM turn radius, ski turn radius, edge angle, fore/aft position and skid angle were calculated. Results While steering out of the fall line after gate passage, ground reaction force significantly differed between the 30 m and 40 m skis and between the 35 m and 40 m skis. These differences were mainly explainable by larger COM turn radii when skiing on the 40 m ski. During the same turn phase, significant differences in ski turn radius also were found, but there were no differences in edge angle, fore/aft position and skid angle. Summary The sidecut-induced reduction in ground reaction force and the sidecut-induced increase in centre of mass and ski turn radius observed in this study provides indirect evidence of reduced self-steering of the ski. Self-steering plays a central role in the mechanism of anterior cruciate ligament rupture in alpine ski racing. PMID:26702014

Recovery of forest structure and spectral properties after selective logging in lowland Bolivia.

PubMed

Broadbent, Eben N; Zarin, Daniel J; Asner, Gregory P; Peña-Claros, Marielos; Cooper, Amanda; Littell, Ramon

2006-06-01

Effective monitoring of selective logging from remotely sensed data requires an understanding of the spatial and temporal thresholds that constrain the utility of those data, as well as the structural and ecological characteristics of forest disturbances that are responsible for those constraints. Here we assess those thresholds and characteristics within the context of selective logging in the Bolivian Amazon. Our study combined field measurements of the spatial and temporal dynamics of felling gaps and skid trails ranging from <1 to 19 months following reduced-impact logging in a forest in lowland Bolivia with remote-sensing measurements from simultaneous monthly ASTER satellite overpasses. A probabilistic spectral mixture model (AutoMCU) was used to derive per-pixel fractional cover estimates of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), and soil. Results were compared with the normalized difference in vegetation index (NDVI). The forest studied had considerably lower basal area and harvest volumes than logged sites in the Brazilian Amazon where similar remote-sensing analyses have been performed. Nonetheless, individual felling-gap area was positively correlated with canopy openness, percentage liana coverage, rates of vegetation regrowth, and height of remnant NPV. Both liana growth and NPV occurred primarily in the crown zone of the felling gap, whereas exposed soil was limited to the trunk zone of the gap. In felling gaps >400 m2, NDVI, and the PV and NPV fractions, were distinguishable from unlogged forest values for up to six months after logging; felling gaps <400 m2 were distinguishable for up to three months after harvest, but we were entirely unable to distinguish skid trails from our analysis of the spectral data.

Conversion and control of an all-terrain vehicle for use as an autonomous mobile robot

NASA Astrophysics Data System (ADS)

Jacob, John S.; Gunderson, Robert W.; Fullmer, R. R.

1998-08-01

A systematic approach to ground vehicle automation is presented, combining low-level controls, trajectory generation and closed-loop path correction in an integrated system. Development of cooperative robotics for precision agriculture at Utah State University required the automation of a full-scale motorized vehicle. The Triton Predator 8- wheeled skid-steering all-terrain vehicle was selected for the project based on its ability to maneuver precisely and the simplicity of controlling the hydrostatic drivetrain. Low-level control was achieved by fitting an actuator on the engine throttle, actuators for the left and right drive controls, encoders on the left and right drive shafts to measure wheel speeds, and a signal pick-off on the alternator for measuring engine speed. Closed loop control maintains a desired engine speed and tracks left and right wheel speeds commands. A trajectory generator produces the wheel speed commands needed to steer the vehicle through a predetermined set of map coordinates. A planar trajectory through the points is computed by fitting a 2D cubic spline over each path segment while enforcing initial and final orientation constraints at segment endpoints. Acceleration and velocity profiles are computed for each trajectory segment, with the velocity over each segment dependent on turning radius. Left and right wheel speed setpoints are obtained by combining velocity and path curvature for each low-level timestep. The path correction algorithm uses GPS position and compass orientation information to adjust the wheel speed setpoints according to the 'crosstrack' and 'downtrack' errors and heading error. Nonlinear models of the engine and the skid-steering vehicle/ground interaction were developed for testing the integrated system in simulation. These test lead to several key design improvements which assisted final implementation on the vehicle.

Characteristics of single-vehicle crashes with e-bikes in Switzerland.

PubMed

Hertach, Patrizia; Uhr, Andrea; Niemann, Steffen; Cavegn, Mario

2018-08-01

In Switzerland, the usage and accident numbers of e-bikes have strongly increased in recent years. According to official statistics, single-vehicle accidents constitute an important crash type. Up to date, very little is known about the mechanisms and causes of these crashes. To gain more insight, a survey was conducted among 3658 e-cyclists in 2016. The crash risk and injury severity were analysed using logistic regression models. 638 (17%) e-cyclists had experienced a single-vehicle accident in road traffic since the beginning of their e-bike use. Risk factors were high riding exposure, male sex, and using the e-bike mainly for the purpose of getting to work or school. There was no effect of age on the crash risk. Skidding, falling while crossing a threshold, getting into or skidding on a tram/railway track and evasive actions were the most important accident mechanisms. The crash causes mentioned most often were a slippery road surface, riding too fast for the situation and inability to keep the balance. Women, elderly people, riders of e-bikes with a pedal support up to 45 km/h and e-cyclists who considered themselves to be less fit in comparison to people of the same age had an increased risk of injury. This study confirms the high relevance of single-vehicle crashes with e-bikes. Measures to prevent this type of accident could include the sensitisation of e-cyclists regarding the most common accident mechanisms and causes, a regular maintenance of bicycle pathways, improvements regarding tram and railway tracks and technological advancements of e-bikes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

KSC-02pd2005

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- Workers prepare a Pegasus XL Expendable Launch Vehicle for detachment from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle nestled beneath, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

KSC-02pd2001

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- Workers prepare to remove a Pegasus XL Expendable Launch Vehicle from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle attached, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

Immersible solar heater for fluids

DOEpatents

Hazen, T.C.; Fliermans, C.B.

1994-01-01

An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

Immersible solar heater for fluids

DOEpatents

Kronberg, James W.

1995-01-01

An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

Pegasus XL CYGNSS Second Launch Attempt, Drop & Launch of Rocket

NASA Image and Video Library

2016-12-15

The Orbital ATK Pegasus XL rocket carrying NASA's Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is released and the first stage ignites at 8:37 a.m. EST. The rocket was released from the Orbital ATK L-1011 Stargazer aircraft flying over the Atlantic Ocean offshore from Daytona Beach, Florida following takeoff from the Skid Strip at Cape Canaveral Air Force Station. This image was taken from a NASA F-18 chase plane provided by Armstrong Flight Research Center in California. The CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Pegasus XL CYGNSS Second Launch Attempt

NASA Image and Video Library

2016-12-15

A pathfinder aircraft, at left, prepares for takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft, in view at right, carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

KSC-02pd2002

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- A Pegasus XL Expendable Launch Vehicle is moments away from being removed from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle attached, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

KSC-02pd2003

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- Workers begin the process to remove a Pegasus XL Expendable Launch Vehicle from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle attached, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

Pilot Neil Armstrong with X-15 #1

NASA Technical Reports Server (NTRS)

1960-01-01

Dryden pilot Neil Armstrong is seen here next to the X-15 ship #1 (56-6670) after a research flight. Armstrong made his first X-15 flight on November 30, 1960, in the #1 X-15. He made his second flight on December 9, 1960, in the same aircraft. This was the first X-15 flight to use the ball nose, which provided accurate measurement of air speed and flow angle at supersonic and hypersonic speeds. The servo-actuated ball nose can be seen in this photo in front of Armstrong's right hand. The X-15 employed a non-standard landing gear. It had a nose gear with a wheel and tire, but the main landing consisted of skids mounted at the rear of the vehicle. In the photo, the left skid is visible, as are marks on the lakebed from both skids. Because of the skids, the rocket-powered aircraft could only land on a dry lakebed, not on a concrete runway. The X-15 was a rocket-powered aircraft. The original three aircraft were about 50 ft long with a wingspan of 22 ft. The modified #2 aircraft (X-15A-2 was longer.) They were a missile-shaped vehicles with unusual wedge-shaped vertical tails, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was rated at 57,000 lb of thrust, although there are indications that it actually achieved up to 60,000 lb. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as testbeds to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at approximately 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

KSC-02pd2016

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- A Pegasus XL Expendable Launch Vehicle is prepared for towing to the Multi-Purpose Payload Facility (MPPF) where it will undergo testing, verification, and three flight simulations prior to its scheduled launch. The vehicle, nestled beneath an Orbital Sciences L-1011 aircraft, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. It is commissioned to carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit in late January 2003. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

Expansion of industrial logging in Central Africa.

PubMed

Laporte, Nadine T; Stabach, Jared A; Grosch, Robert; Lin, Tiffany S; Goetz, Scott J

2007-06-08

Industrial logging has become the most extensive land use in Central Africa, with more than 600,000 square kilometers (30%) of forest currently under concession. With use of a time series of satellite imagery for the period from 1976 to 2003, we measured 51,916 kilometers of new logging roads. The density of roads across the forested region was 0.03 kilometer per square kilometer, but areas of Gabon and Equatorial Guinea had values over 0.09 kilometer per square kilometer. A new frontier of logging expansion was identified within the Democratic Republic of Congo, which contains 63% of the remaining forest of the region. Tree felling and skid trails increased disturbance in selectively logged areas.

KSC-97PC1510

NASA Image and Video Library

1997-10-07

Still celebrating his recent homecoming and reunion with his family, astronaut C. Michael Foale picks up his 3-year-son Ian, while his 5-year-old daughter, Jenna, stands by at the Skid Strip on Cape Canaveral Air Station. They are scheduled to depart shortly for the astronauts’ home base at Johnson Space Center in Houston, Texas. Foale spent approximately four-and-a-half months on the Russian Space Station Mir. He returned to Earth on Oct. 6 aboard the Space Shuttle orbiter Atlantis at the conclusion of the STS-86 mission. STS-86 was the seventh docking of the Space Shuttle with the Mir. Foale was replaced on the Mir by STS-86 Mission Specialist David A. Wolf

Studies of some unconventional systems for solving various landing problems. [air cushion landing system

NASA Technical Reports Server (NTRS)

Leland, T. J.; Mcgehee, J. R.; Dreher, R. C.

1981-01-01

Solutions to various landing problems were obtained through unconventional systems. The first, of these is the air cushion landing system, where efforts were concentrated on development of adequate braking and steering systems and an improved understanding of scaling laws and behavior. The second was concentrated on use of a wire brush skid as a drag producing device, which was shown to have good friction coefficients and reasonable wear rates at ground bearing pressures up to 689 kPa and forward speeds up to 80 km/hr. The third showed great promise in an active control landing gear where significant load reductions were possible during landing impact and subsequent rollout.

Immersible solar heater for fluids

DOEpatents

Kronberg, J.W.

1995-07-11

An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater. 11 figs.

KSC-02pd2007

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- Workers supervise the placement of a transporter below a Pegasus XL Expendable Launch Vehicle before its detachment from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle nestled beneath, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

Making aerospace technology work for the automotive industry, introduction

NASA Technical Reports Server (NTRS)

Olson, W. T.

1978-01-01

NASA derived technology already in use in the automotive industry include: (1) developments in electronics design, computer systems, and quality control methods for line testing of cars and trucks; (2) a combustion analysis computer program for automotive engine research and development; (3) an infrared scanner and television display for analyzing tire design and performance, and for studying the effects of heat on the service life of V-belts, shock mounts, brakes, and rubber bearings; (4) exhaust gas analyzers for trouble shooting and emissions certification; (5) a device for reducing noise from trucks; and (6) a low cost test vehicle for measuring highway skid resistance. Services offered by NASA to facilitate access to its technology are described.

Skid Landings of Airplanes on Rocker-Type Fuselages

NASA Technical Reports Server (NTRS)

Mayo, Wilbur L.

1961-01-01

A study is made of the landing of an airplane on a fuselage with "planned" curvature of its lower surface. Initial contact is considered to stop the vertical motion of a point remote from the center of gravity, thus causing rocking on the curved lower surface which converts sinking-speed energy into angular energy in pitch for dissipation by damping forces. Analysis is made of loads and motions for a given fuselage shape, and the contours required to give desired load histories are determined. Most of the calculations involve initial contact at the tail, but there are two cases of unflared landings with initial contact at the nose. The calculations are checked experimentally for the tail - low case.

KSC-02pd2018

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- A Pegasus XL Expendable Launch Vehicle sits atop a transporter following its arrival in the Multi-Purpose Payload Facility (MPPF) where it will undergo testing, verification, and three flight simulations prior to its scheduled launch. The vehicle, nestled beneath an Orbital Sciences L-1011 aircraft, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. It is commissioned to carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit in late January 2003. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

KSC-02pd2012

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- Workers complete the final steps to detach a Pegasus XL Expendable Launch Vehicle from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle nestled beneath, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).

KSC-02pd2010

NASA Image and Video Library

2002-12-18

KENNEDY SPACE CENTER, FLA. -- A transporter is repositioned below a Pegasus XL Expendable Launch Vehicle before it is detached from the underside of an Orbital Sciences L-1011 aircraft. The aircraft, with the launch vehicle nestled beneath, arrived at the Cape Canaveral Air Force Station Skid Strip on Dec. 17. The Pegasus XL will undergo three flight simulations prior to its scheduled launch in late January 2003. It will carry NASA's Solar Radiation and Climate Experiment (SORCE) spacecraft into orbit. Built by Orbital Sciences Space Systems Group, SORCE will study and measure solar irradiance as a source of energy in the Earth's atmosphere with instruments built by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).