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By L. B. Pankratz

Thermodynamic data on the halides were reviewed, evaluated, and compiled at the Bureau of Mines Albany Research Center. Values for Cp°, S°, H-H°298, -(G°-H°298)/T, ?Hf°, ?Gf°, and log Kf are given in tabular form. CP°, H-H°298, ?Hf°, and AGf° are also expressed algebraically.

Jan 1, 1984

By Kenneth L. Bickel

During an underground mine fire, the importance of controlling the spread of smoke and toxic gases with suitable ventilation structures has been proven. However, under certain conditions, control of the propagation of the fire itself may be even more critical in insuring a safe mine evacuation. Fire doors offer the means for accomplishing both objectives. In 1978, the Bureau of Mines initiated research to evaluate the state of fire-door technology and develop and test a fire door suitable for large openings (10 by 12 ft or larger) in noncoal underground mines. This report discusses current fire-door technology in the context of the underground mine environment and the design, fabrication, lab testing, and in-mine field testing of a mineworthy fire door. This door has a 1.5-h fire resistance rating and limits temperature rise across the door to 2500 F during the first 30 min of fire exposure.

Jan 1, 1987

By Ralph P. Carter

It is apparent that coal will play an increasingly important role in satisfying the nation's energy requirements for the remainder of this century. Both deep mining and surface mining will be practiced to develop known U.S. coal reserves, but until significant improvements in the productivity of deep mining emerge, surface mining is likely to be predominant. This report addresses the problems of coal extraction and surface mine reclamation in the 11-state Midwestern coal resource region, where surface stripping of high-sulfur, bituminous coal has been a well-developed industry for most of this century. Midwestern coal markets have declined in recent years. In part this is a result of widespread conversions to more convenient and (apparently) economical liquid and gaseous fuels, but the decline in Midwestern coal use is also attributable to the impact of current air pollution control regulations that prohibit emissions of sulfur oxides and particulate matter. A part of the regional demand for Midwestern coal has been transferred to the Northern Great Plains where extensive low-sulfur coal reserves are currently being developed.

Jan 1, 1974

By Jeanne A. Smith, Suzanne D. Smith

Annoyance, fatigue, and musculoskeletal pain have been reported during prolonged exposures to propulsion-generated vibration in military propeller aircraft1. The objective of this study was to determine the vibration mitigation properties of selected seat cushions and the effects of occupant seating posture during exposure to higher frequency multi-axis vibration associated with military propeller aircraft. Methods A Navy E-2C Hawkeye crew seat was mounted onto the Six Degree-of-Freedom Motion Simulator (SIXMODE). Six seat pan cushion configurations were tested during exposure to an E-2C vibration signal collected in the field1. Seat pan cushions 1 – 5 were used with the original E-2C seat back cushion. Cushion configuration 6 included seat pan cushion 5 with a prototype seat back cushion. Triaxial accelerometer pads were mounted onto the seat pan and seat back cushions to measure the vibration entering the human. Data were collected for seven subjects seated upright with their backs in contact with the seat (back-on) and not in contact with the seat (back-off). Spectral analysis techniques were used to analyze data at the two dominant frequencies associated with the propulsion system (propeller rotation frequency (PRF) ~18.5 Hz, and blade passage frequency (BPF) ~73.5 Hz). Overall accelerations were also calculated between 1 and 80 Hz. Vibration Total Values (VTVs) were calculated using the weighted seat pan and seat back (back-on only) accelerations and compared to the comfort reactions given in ISO 2631-1: 19972. Results In general, the highest accelerations observed at the seat pan occurred in the fore-and-aft (X) direction at both the PRF and the BPF for all cushions and both postures. The most pronounced effect was at the BPF in the X direction, where all configurations showed significantly lower seat pan accelerations than configuration 1 (original E-2C cushion) with the back-on posture. Configuration 5 was the exception with the back-off posture (Fig. 1A, Repeated Measures ANOVA, P<0.05). The most pronounced effect of posture occurred at the PRF in the X direction, where all cushion configurations showed significantly lower seat pan accelerations with the back-off posture (Fig. 1B). All configurations except configuration 2 showed similar VTVs as compared to Configuration 1 (Fig. 2, P<0.05). Configuration 2 tended to show the lowest weighted acceleration levels. The overall VTVs (back-on only, Fig. 2B) showed significantly higher accelerations as compared to both the back-on and back-off seat pan point VTVs (Figs. 2A &

Jan 6, 2006

By Gary J. Cwick

Mineral resources of the Rice Valley Wilderness Study Area (WSA), in the Mojave Desert of southeastern California, were investigated by the U.S. Bureau of Mines and U.S. Geological Survey during 1980. The study consisted of an examination of mines, prospects, and mineralized areas by the Bureau: of Mines and geological, geochemical, and geophysical investigations by the Geological Survey. Little indicated potential for the presence of mineral resources exists in the valley floor segment of the study area. The Big Maria Mountains section of the study area has some potential for mineral resource development. Decorative building stone from both bedded quartzite deposits and weathered limestone surface rubble (driftwood stone) has been produced from the Big Maria Mountains segment of the study area. Total production is unrecorded but probably small. A 700,000 ton (640,000 t) quartzite resource was inferred and 4,500 tons (4,100 t) of driftwood stone within the study area was estimated. A relatively pure limestone deposit inside the study area contains an inferred resource of 14 million tons (13 million t). One prospect suggests a potential for the presence of manganese resources although none were estimated. The likelihood of discovering oil, gas, coal, uranium or geothermal energy is low; potential sources are not known to exist.

Jan 1, 1982

By Sean Gallagher, William S. Marras, Alan S. Litsky, Deborah Burr

This paper describes a comparison of the fatigue failure responses of older versus younger lumbar spine cadaver motion segment specimens. These specimens were repeatedly subjected to loads simulating those experienced by the spine in lifting a 9 kg load in different torso flexion postures (0, 22.5, and 45 degrees of flexion). An older sample of 36 motion segments (average age 81 years + 8 SD) is compared with a younger sample of 18 motion segments (average age: 47 years + 9 SD) with respect to the number of cycles to failure and results of survival analyses evaluating the effects of flexion and bone mineral content with and without the younger data set. Compared to the older sample of spines, the younger sample exhibited many more cycles to fatigue failure in all the torso flexion conditions (10020 versus 8267 average cycles to failure in 0 degrees flexion, 7124 versus 3262 in 22.5 degrees flexion, and 3229 versus 263 cycles to failure in 45 degrees flexion). The increased cycles to failure in young specimens is likely due to the increased bone mineral content (BMC) in younger motion segments (30.7 g + 11.1 g per motion segment versus 27.8 + 9.4 g). Cox regression analyses modeling both flexion effects and BMC indicate that betas are similar when just older spines are modeled and when younger specimens are included in the analysis. Betas for survival analysis models with and without younger specimens generally show little change for flexion (2.716 versus 2.756 for 22.5 degrees [0 degrees referent], 3.926 versus 3.380 for 45 degrees [0 degrees referent]). Bone mineral content shows a similar protective effect in both models (Betas: -0.127 versus -0.087). Overall, comparison of the models indicate that risk ratios are similar for 22.5 degrees flexion, slightly increased for 45 degrees flexion and slightly more protective influence predicted for BMC in the combined sample versus the older sample alone.

By V. Castranova

"A pneumoconiosis is best defined as the accumulation of dust in the lungs and the tissue's reaction to iu presence. Thus, silicosis is the name given to the fibrotic disease of the lungs caused by inhalation of dust containing silicon dioxide, primarily in the free crystalline form. Coal workers' pneumoconiosis (CWP), which was originally thought to be a variant of silicosis, results from inhalation of coal mine dust that usually contains relatively small amounts of free crystalline silica.HISTORYSilicosis is the older and more well known of these mineral pneumoconiosis. In contrast, CWP was not recognized as different from silicosis until the pivotal work of Collis and Gilchrist. 26 They noted that coal trimmers, i.e., special stevedores who leveled coal in the holds of ships at the Cardiff and Swansea docks in Wales, developed identical nodules on the chest radiograph to those of underground miners. The difference was that these men had never worked underground and that the coal was washed before it was loaded into ships; thus, it was unlikely that these men were exposed to silica. Gough54 examined the lungs of coal trimmers who died and found that the histologic appearance of the pulmonary lesions was distinctly different from the whorled nodules seen in silicosis. Gough,"" and subsequently Heppleston,"" then showed that the lung lesions in coal trimmers were similar to those in underground coal miners and different from those of classical silicosis. Nagelschmidt 78 analyzed the mineral content of miners' lungs that became available at autopsy. These studies caused him to propose a scheme in which the relative proportions of silica, other minerals, and/or coal deposited in the lungs determined the type of pulmonary response which develops, i.e., classical silicosis, mixed-dust disease, or CWP."

Nov 1, 1995

By W. W. Weller

Thermodynamic values for scandium and its compounds are very sparse. This is evident upon examination of any of the commonly used compilations of thermodynamic data. For example, National Bureau of Standards Circular 5004 lists only four heat of formation values, two free energy of formation values, and four heat-capacity values for scandium compounds. The entropy of crystalline scandium is one of the most fundamental values that has been lacking. This Bureau of Mines paper reports heat-capacity data for scandium metal in the temperature range from 50° to 298° K., together with the entropy value at 298.15° K. derived from these data through application of the third law of thermodynamics.

Jan 1, 1962

By E. O. RHODES

This report is one of a series written by members of the Solid Fuels Mission to Germany describing wartime developments in the mining, prepara- tion, and utilization of coal. This mission was organized early in 1945 under the auspices of the Technical Industrial Intelligence Committee, which cooperated with a counterpart British Committee. In some instances; engi- neers from other allied countries cooperated. The Solid Fuels Mission operated under the direction of a steering committee headed by Dr. C. J. Potter, Deputy Solid Fuels Administrator. The personnel of the mission consisted of H. F. Yancey, in charge, J. W. Buch, Thomas Fraser, L. L. Newman, and L. D. Schmidt of the Bureau of Minos; H. H. Lowry, Director of the Coal Research Laboratory, Carnegie Institute of Technology; H. J. Rose, Vice-President and Director of Research, Bituminous Coal Research, Inc.; and F. H. Reed, Chief Chemist, Illinois Geological Survey. E. 0. Rhodes, Manager, Development Section, Tar Products Division, Koppers Co., Inc., served on the mission for the Chemical Subcommittee of 1.I.I.C. in Europe. His assignment was the investigation of the coal-tar industry. In this connection he prepared this report on the German Low- Temperature Tar Industry as a companion to his provious report on the German High-Temperature Tar Industry (Bureau of Mines Information Circular 7409). Because of Mr. Rhodes' extensive experience in these fields and the impor- tance of the subject material to the coal producers and those utilizing coal-tar products, both reports are issued by the Bureau of Mines. Over fifty reports were written by the members of the Solid Fuels Mis- elon. These, together with microfilms of supporting data obtained in the course of the investigations, are on file at the Foreign Documents Group, Technical Reports Section, Bureau of Mines, Pittsburgh, Pa., where they are available for examination. Copies of reports available in printed form may be ordered from the Department of Commerce, Office of Technical Services, Washington 25, D. C. Check or money order accompanying order for printed reports should be made payable to the Treasurer of the United States. A Bibliography of Scientific and Industrial Reports, covering all ma- terials and subjects and giving instructions for obtaining the desired items, has been published weekly by the Office of Technical Services. Effective July 1, 1948, the Bibliography of Scientific and Industrial Reports will be prepared monthly instead of weekly and on a more selective basis. issue, which will be the first monthly issue, will be available about July The July month thereafter through June 1949. Annual subscriptions and orders for individual copies starting with the July 1948 issue should be addressed to the Department of Commerce, Office of Technical Servicos, Washington 25, ur, and be accompanied by chock or money order made payable to the Troas- Bibliof the United States. Annual subscriptions for monthly issues of the Bibliography of Scientific and Industrial Roports will be $10. Individual issues will cost $1 per copy. Foreign subscriptions will be $14 per year and $1.50 por copy. tions listed in the Bibliography of Scientific and Industrial Reports should All orders for reports in microfilm or photostatic type of reproduc- ורי

Feb 1, 1949

An accelerated and coordinated program of coal research is believed by many to be a necessary step in assuring coal&apos;s proper position in the expanding energy market. The President&apos;s Advisory Committee on Energy Supplies and Resources Policy, for example, made the following recommendation: We recognize that coal is a great national asset and endorse a cooperative study to determine what research and development could be undertaken. The coal industry and both Federal and State Governments should participate in this study and its costs. Representatives of the coal industry have agreed that such a study should be initiated. Accordingly, Felix E. Wormser, Assistant Secretary - Mineral Resources, United States Department of the Interior, requested the Bureau of Mines and Bituminous Coal Research, Inc., to conduct a survey of current research on bituminous coal. In addition to this survey, studies were made to determine research projects that would be of value to the coal industry.

Jan 1, 1956

By Michael Sokaski

The Cliff Springs prospect in the northern part of the Slate Range Wilderness Study Area (WSA) contains only minor amounts of gold and silver. Clay near this prospect contains insufficient aluminum to be of economic interest, although alunite claims are recorded in the vicinity. Mineralized rock at the Crescent Mine adjacent to the WSA contains gold, silver and lead occurrences. The host rock may be present in the extreme southwestern part of the WSA, which is covered by alluvium. Substantial sand and gravel deposits are present but these occurrences are remote from markets. Much of the USA is underlain by volcanic rocks and alluvium and consequently the mineral resource potential there remains unknown.

Jan 1, 1983

By Peter G. Kovalchik, Lawrence W. Scott, Thomas H. Dubaniewicz, Mark A. Fuller

Mine trailing cables operated above safe thermal limits can cause premature insulation failure, increasing electrocution and fire hazards. Previous U.S. Bureau of Mines Pittsburgh Research Center research showed that, under static test conditions, electrical current levels permitted under present regulations may not limit cable temperatures to less than the 90 °C rating of reeled trailing cable. Continuing research under the National Institute for Occupational Safety and Health (NIOSH) addresses thermal characteristics of reeled trailing cable under dynamic test conditions more representative of field conditions, where operators constantly reel in and pay out cable. This research is in support of efforts by industry associations and the Mine Safety and Health Administration to establish safety guidelines for cyclically rated reeled machines. This paper describes a unique approach to measuring temperatures within reeled cable under dynamic test conditions. Fiber-optic sensors embedded within the metallic conductors measure temperatures at 1-m intervals along the entire length of cable. Temperature measurements are reported to be accurate to within 1±° C. The test setup requires access to only one end of the trailing cable, allowing researchers to freely reel in and pay out cable while temperature measurements are made, simulating field conditions. Manufacture of a fiberoptic-embedded trailing cable is described, along with initial test results that indicate the fiber-optic approach is viable.

By Thomas Fraser, William L. Crentz

"INTRODUCTION Sulfur is a most damaging impurity in many of our American coals. From the older coal industry of Europe and Britain we can apparently learn but little about the problem of preparing and using high-sulfur coal. Although washing has long been established there for controlling ash content, sulfur is referred to rarely, as the important deposits are singularly low in sulfur.On the other hand, widely distributed coal deposits of America differ tremendously in sulfur content. Many of the more extensive beds contain too much sulfur for metallurgical use, and almost everywhere except in the Rocky Mountain and Pacific coast regions sulfur control is at least a potential problem. American coal-preparation engineers are confronted not only with great variations in the total quantity of sulfur in coal but with an intricately varying pattern of the physical and chemical forms in which the sulfur occurs. It must be conceded that the baffling problem of sulfur reduction in coal is as yet substantially unsolved, for there are but few isolated instances in which we have been able to prepare a satisfactory metallurgical fuel from coals containing as much as 2.0 percent sulfur in the raw state.It has been assumed generally that organic sulfur, being chemically combined with carbonaceous matter, is distributed throughout the coal matter and that it remains unchanged in the clean-coal part of the product during washing.Sulfur that may be washed out of the coal is that part that is combined with the iron in pyrite lenticles associated with the coal. In most of our coals it has been found that, besides the visible bands, lenses, and flakes of pyrite, extremely small and even microscopic particles of pyrite 4/ are distributed through the coal matter. Only the free, relatively coarse pyrite particles .are removed by conventional coal-washing devices, and usually most of the sulfur is still left in the product."

Dec 1, 1947

By Charles E. Larson

Square Butte has no history of mineral development or production. Surface mapping, radiometric surveys and chemical analyses of rock samples reveal no mineral potential. The area has a speculative potential for petroleum and natural gas. INTRODUCTION The Square Butte Instant Wilderness Study Area, in Chouteau County, Montana, consists of 1,946 acres (788 ha) about 35 miles (56 km) southeast of Fort Benton and 50 miles (80 km) northwest of Lewistown (fig. 1). This study was performed under provisions of the Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976), in conjunction with the U.S. Geological Survey, which is responsible for regional geological, geochemical, and geophysical investigations, and the U.S. Bureau of Mines, which determines the mineral potential of existing mines, prospects, or mineralized areas.

Jan 1, 1982

By John L. Nieber

This information circular describes a computer program called VARSAT2D, a comprehensive unsaturated fluid flow simulator developed by the U.S. Bureau of Mines. VARSAT2D solves for either a vertical or horizontal, transient or steady-state solution in variably saturated, heterogeneous, anisotropic porous media using the Galerkin finite-element approach. Simplex triangular elements are used. Moisture retention characteristics are described by specifying either the Brooks and Corey, Brutsaert, or Van Genuchten power functions, with hysteresis described using the Maulem independent domain model. Boundary conditions may include any combination of time-varying seepage, pressure along solution domain, boundaries and/or at internal node points, unit hydraulic gradient at the lower boundary, and a uniform source and/or sink. This program should be a welcome addition for mining and environmental hydrologists, researchers, and engineers interested in modeling unsaturated fluid flow.

Jan 1, 1994

By E. G. Meiter, S. H. Katz

"Railroad locomotives produce heat, gas, and smoke, which cause considerable discomfort to engine men and firemen while passing through tunnels. In order to try and improve these conditions, the Bureau of Mines has investigated the composition of atmospheres in cabs of freight locomotives while in tunnels; and some of the higher temperatures in the cabs were noted; physiological effects upon men were determined and gas masks and respirators were devised to eliminate the effects of irritating and poisonous gases and smoke. Those investigations were conducted in tunnels of the Baltimore & Ohio, Pennsylvania, and Union Pacific railroads; while that described in this paper was carried out in tunnels of the Chesapeake & Ohio, Railroad, situated in the Blue Ridge and Allegheny Mountains in Virginia and West Virginia, Freight locomotives used by this railroad are of the Mallet type, which have two separate cylinders: and two separate sets of driving wheels on each side. In locomotive language they are of the 2-6-6-2 type. All of the cylinders act as simple engines when starting or in slow, heavy hauling; but at faster speeds the pair of cylinders on each side operate compound, Mallet locomotives are the largest and most powerful now operated.The tendency in train operation has always been to increase the burden upon locomotives, Present traffic needs frequently load even the Mallet engine to capacity, and yet the weight of trains tends to increase. It has been suggested as a means of securing greater power units that Mallets be constructed to operate only as simple engines. This would increase the amount of steam given off as the amount of coal burned and the resulting volume of flue gas emitted."

Jul 1, 1924

By Orlando Martino

This regional report covers the mineral industries of Canada and 40 countries and territories in Latin America and the Caribbean Basin. Also included is a brief description of the mineral potential of Antarctica. The Latin American region encompasses an area twice that of the United States. Latin America and Canada have a rich and diversified endowment of mineral fuels, metals, and industrial minerals. Tables 1 and 2 provide a summary view of Latin America and Canada&apos;s output of its major mineral commodities in world mineral supply in 1991 (revised) and 1992. Table 3 shows the relative importance of a selected group of minerals produced in Latin America in the world mineral economy.

Jan 1, 1994

By Donald W. Mitchell

Certification tests for urethane-foam systems and techniques for apply-ing foam safely in mines are described. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam. Foam that passes the certification tests can be applied on stoppings, continuous sections of ribs of relatively wide passageways (with no foam on the roof), short sections of roof such as overcasts, roof cavities, and intersections (with no foam on the ribs), and between buntons on one wall of a shaft. Foam on the ribs and adjoining roof presents a fire hazard. Stoppings covered with foam passing the certification tests are resistant to penetration of heat, flame, and smoke than similar stopping without foam. Flame propagation can be arrested by water sprays. Spontaneous ignition of foam can be prevented.

Jan 1, 1966

By Claud Johnson, Kristine M. Krajnak

Vibration transmitted to the upper limb by the chronic use of hand tools can result in cold-induced vasospasms finger blanching and cyanosis, similar to that seen with Raynaud’s phenomenon (4). These vasospasms, commonly referred to as vibration white finger (VWF), are in part the result of an increased sensitivity of peripheral arteries to the vasoconstricting effects of norepinephrine (e.g., (1-3)). However, alterations in vasodilating factors could also contribute to vasospasms. The goal of these studies was to determine if exposure to a single bout of vibration alters concentrations of the vasodilator, nitric oxide (NO), in a rat tail model of vibration. To determine if vibration exposure alters NO, we exposed animals to a single bout of vibration and measured concentrations of the synthetic enzymes, nitric oxide synthetase (NOS)-1 and NOS-3 in the ventral tail artery. We also directly assessed arterial concentrations of NO using a nitrate/nitrite assay. Methods General apparatus. Animals were placed in Broome-style restrainers, and their tail was secured to a vibrating or stable platform. Rats were exposed to a single 4 h bout of tail vibration (125 Hz, acceleration of 49 m/sec2 r.m.s.) or restraint control. Animals were euthanized with an overdose of pentobarbital (100 mg/kg) and the ventral tail artery was dissected and frozen. Experiment 1: Male Sprague Dawley rats (6 weeks old, n = 32) were used for all exposures. All animals were maintained in AAALAC accredited facilities, and all procedures were approved by the NIOSH Animal Care and Use Committee, and were in compliance with the CDC Regulations for the Care and Use of Laboratory Animals. Animals were euthanized 1 or 24 h after the completion of the exposure. Western analyses were performed on total proteins (80 µg/lane) isolated from the C16-18 artery segments. Band densities were detected by chemiluminescence and quantified using Scion Image, and analyzed using 2-way ANOVAs. Experiment 2. Nitrate/nitrite concentrations.. Male Sprague Dawley rats (n = 24, 6 weeks of age) were maintained and exposed as described above. All animals were euthanized 24 h after the exposure and the ventral artery was collected. Nitrate/nitrite concentrations were measured in ventral artery tissue homogenates using the nitrate/nitrite colormetric Assay Kit (Caymen). Results Analyses of band densities revealed that there was an effect of time (F(1, 17) = 6.03, p < 0.03) on NOS-1 protein in arteries exposed to vibration, with NOS levels being lower in arteries collected 24 h after the exposure than arteries collected 1 h after the exposure. Although NOS-1 proteins concentrations were slightly lower in control arteries collected 24 h after an exposure than arteries collected 1 h after exposure, post-hoc contrasts indicated they were not significantly different than 1 h controls. In contrast, NOS-1 band densities from arteries collected 24 h after the exposure were lower than those collected 1 h after the exposure (p < 0.01; Figure 1). NOS-3

Jan 6, 2006

By Alan Mayton, Bertrand Valero, Farid Amirouche

Handling of heavy vehicles such as tractors, trucks and buses require a large roll stiffness which causes large high accelerations at the seat level during impacts. To provide comfort and minimize the energy transfer from the chassis and the seat a pneumatic active seat suspension is proposed. An active seat suspension design and control algorithm under development at the University of Illinois at Chicago, UIC, is being developed and tested. Preliminary results are presented in this paper. The design of a passive suspension typically consists of optimizing the value of two parameters: the stiffness and the damping of the suspension. The general dynamic performance of the suspension is limited to the conditions under which these parameters were obtained. A change in the input conditions might lead to poor suspension and an amplification of the vibration transmitted to the body. The focus of this paper is a robust, semi-active suspension system with a variable controlled damping and using the body response an index measure to minimize the acceleration at the interface of the seat and operator. A summary of existing suspensions, such as MR and ER fluids, and spring loaded and dual valve shock absorbent will be discussed to highlight the need of a semi-active pneumatic suspension system design. Methods A model of the proposed suspension was developed in MATLB (Simulink) and different control strategies for the valve position in relation to the cylinder pressure tested. The effects of stiffening and softening resulting from pressure changes in the cylinder were examined. The vertical accelerations of the seat was computed for different control strategies and configurations of the suspension and compared to the response of a passive seat suspension. A lump -mass model was created to represent the human body including the head, the upper, middle and lower torso as well as the legs. The connective forces between body segments were modeled through modal analysis techniques from previous experiments at the Vehicle Technology Laboratory. ISO standards and absorbed power were used to evaluate the different configuration of the seat suspension system in relation to the dynamic response of the operator. Results Initial results of the semi-active suspension system show a significant reduction in the RMS value of the acceleration of the seat. A reduction of the total absorbed power by the operator is expected to provide an insight into the control strategies adapted in the active suspension.

Jan 6, 2006