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Viewing 22051 to 22080 of 23234
1975-02-01
Technical Paper
750051
Kurt Obländer, Bertold Mayr
This paper discusses the Mercedes-Benz V-8 engines, their design as compared to US V-8 engines, and development concerning exhaust emission control and fuel consumption. Also covered are special problem areas, and their respective solutions which today have come to be of secondary importance, for example, the lubrication system, defoaming of the lubricant, noises generated by the lubrication system, and the adaptation of the hydraulic valve clearance adjustment to high engine speeds.
1975-02-01
Technical Paper
750174
Ronald J. Herrin
Automotive thermal reactors have obtained high conversion efficiencies on engines with very rich carburetion, but fuel economy and reactor durability have suffered. Improved mixing of exhaust gas and secondary air in the engine exhaust port was examined as a means of improving reactor efficiency at less rich engine air-fuel ratios. Three air-injection systems which span a broad range of mixing capabilities were examined. Mixing characteristics were deduced from anemometry measurements of instantaneous secondary airflow, and emission performance of each system was generalized by a test program employing four steady-state conditions. High-pressure, timed air injection provides the best mixing and the best reactor performance. Sparger (radial discharge) air injection tubes provide fair mixing and better performance than conventional open-ended air injection tubes, which exhibit poor mixing characteristics.
1975-01-01
Standard
ARP695B
This Aerospace Recommended Practice provides design and installation criteria intended to enhance overall safety by mitigating exposure of cabin crew and passengers to risks from: a. Routine use of galley systems. b. Galley components or equipment becoming dislodged under routine or abnormal operating conditions and under survivable crash or ditching conditions. c. Malfunctions of, or defects in, a galley system or associated galley equipment. NOTE: It is not the purpose of this Aerospace Recommended Practice to specify the specific designs or design methods to be followed in the accomplishment of stated objectives.
1974-03-01
Standard
AIR1209
This Aerospace Information Report (AIR) is intended to provide information relating to the construction, calibration, and usage of parallel plate transmission lines in electromagnetic compatibility susceptibility testing.
1974-02-01
Technical Paper
740313
Paul Oppenheimer
Important new braking regulations for motor vehicles and trailers have recently been introduced by Sweden, the Economic Commission for Europe (Geneva), and the European Economic Community (Brussels). This paper describes the relevant rulemaking procedures and the international organizations which provide for industry participation. The technical content of these regulations is summarized and specific examples of difficult, interesting, or unusual demands are highlighted. Some comparisons with the appropriate United States federal standards have been included and the European method of type approval is explained against the background of self-certification in the United States. Several new European proposals for tractor/trailer compatibility, brake apportioning, and antiskid systems are reviewed to illustrate the current status of legislative progress in Europe.
1974-02-01
Technical Paper
740304
Elizabeth A. Heard
The International Organization for Standardization, Technical Committee 22, Subcommittee 13, Working Group 5 was given the task of determining which symbols should be proposed for standardization for fifteen controls, indicators and telltales. A test was devised in which three different symbols for each given control, indicator or telltale could be appraised by licensed drivers in a simulated driving situation. Data from 2593 licensed drivers from France, Germany, the United Kingdom, and the United States were obtained and statistically treated. The procedure and results are herein reported. On the basis of these results, symbols for 12 controls, indicators, and telltales were proposed as standards.
1974-02-01
Technical Paper
740231
J. W. Baxter, L. J. Lawson
This paper considers the need for improving urban transportation and the proposed air quality plans that have been recently announced by the Environmental Protection Agency for several of the more populated regional basins. The “transit diversion mandate” (the need for diversion of a considerable portion of urban travel from the automobile to public transit) is discussed. One proposed diversionary approach, the rubber-tired trolley coach, with its quiet, reliable, and pollution-free characteristics and an advanced LMSC kinetic energy flywheel which can be used to broaden considerably the capabilities of the trolley coach are described.
1974-02-01
Technical Paper
740224
Roger H. Harrison
Construction of a mass transit system is usually among the largest of civil projects, running into billions of dollars. The disruptive act of building exclusive mass transit rights-of-way through densely populated areas will further aggravate existing modes of transportation. The general case of a metropolitan area whose population is in excess of a million people is examined with regard to selection and design of a mass transportation system. Systems that can handle 100,000-200,000 passengers during morning and evening rash hours are discussed.
1974-02-01
Technical Paper
740025
Roosevelt Steptoe
The impacts of locating and operating highways and other transportation facilities in disadvantaged, minority neighborhoods are being assessed in the inquiry that this report is based upon. The major impact areas being investigated are the changes in: land use, population and residential densities, and the growth and development of minority business enterprises. This is a report of a partial inventory of conditions in the study area before the highway; it will be completed for comparison with the data to be assembled for the area after the highway. The partially complete baseline inquiry reveals that the study area has been developed partially in a very piecemeal and haphazard manner. This is evidenced by the existence of large tracts of undeveloped land, a mixture of light industrial and commercial activities with residential neighborhoods, and the fact that a high proportion of the local streets are dead-end and are poorly maintained.
1974-02-01
Technical Paper
740023
Robert H. Cannon
The U.S. Department of Transportation Program of University Research aims to focus interdisciplinary research on all phases of transportation problems. This involves the work of economists, geographers, demographers, city planners, behavioral scientists, as well as technologists. The very best minds in our universities will be needed to help us understand the complex, critical relationships between transportation and the society it serves. This paper outlines the objectives of the Program and DOT's philosophy in granting contracts to the universities. In contrast to many other programs, in this one the federal government is the sponsor of the research-the “customer” is the transportation communities. Thus, proposals involve a high degree of commitment between the universities and their local transportation communities.
1974-02-01
Technical Paper
740168
Y. Bréele
Considerable advances have been made in recent years in the field of hydrogen-air fuel cells, and plans are already being made to use such power generators for urban transportation. This is shown by a study of the possibility of equipping a vehicle of the Renault 4L type with a hydrogen-air cell. This paper describes a detailed study of such an installation. The weight of the power source is acceptable, as are the rates of acceleration. A speed of 80 km/h (50 mph) can be sustained continuously, and an autonomy of between 230 and 560 km (143 and 348 miles) can be attained depending upon the speed of the vehicle, with an effective load of 340 kg (750 lb). Two important obstacles (power source and use of hydrogen) are in the process of being solved by using inexpensive materials and by storing hydrogen by means of hydrides.
1974-02-01
Technical Paper
740617
Roger H. Hemion
The feasibility of approving the use of a rectangular shaped, sealed-beam headlamp as an alternative to round headlamps is discussed in terms of economics, service and maintainability, vehicle design, and styling. A conclusion of primary interest is reached, that design as well as performance standardization is in the interest of the buying public, under certain conditions, and proliferation of designs without compensatory gain should be avoided.
1974-02-01
Technical Paper
740544
William H. Close
This paper analyzes the rationale behind the federal regulation of interstate motor carrier noise. At highway speeds, tire noise is frequently predominant. At low speeds, engine-related noise is predominant. The effects of both these noise sources are considered. The question of enforceability of the regulation is also discussed.
1974-02-01
Technical Paper
740430
Vincent Miller
This paper discusses some of the political and social forces which led to the tremendous surge in earthmoving that we have in Brazil today. The text describes major highway and dam construction and covers new airport and railroad jobs beginning today. It is hoped that this paper will bring a better understanding of today's “Brazilian Miracle” as well as the internecessity of transport and energy in the development of a nation.
1974-02-01
Technical Paper
740928
C. Scott Clark, Robert D. Lingg, Edward Pesci, Edward J. Cleary
1974-02-01
Technical Paper
740931
Michael Onischak, Bernard Baker, Dimitri Gidaspow
ENVIRONMENTAL CARBON DIOXIDE CONTROL by Michael Onischak, Energy Research Corp, Bethel, Conn. A study of environmental carbon dioxide control for NASA EVA missions found solid potassium carbonate to be an effective regenerable absorbent in maintaining low carbon dioxide levels. The supported sorbent was capable of repeated regeneration below 150°C without appreciable degradation. Optimum structures in the form of thin pliable sheets of carbonate, inert support and binder were developed. Interpretation of a new solid-gas pore closing model helped predict the optimum sorbent and analysis of individual sorbent sheet performance in a thin rectangular channel sorber can predict packed bed performance.
1974-02-01
Technical Paper
740925
Edward S. K. Chian, Herbert H. P. Fang*, Martin N. Aschauer
The removal of over 40 toxic compounds, including heavy metals, synthetic pesticides and organic compounds, by cellulose acetate (CA) and crosslinked-polyethylenimine (C-PEI) membranes were examined. With few exceptions both membranes removed 97+ percent of the heavy metals and pesticides tested; the C-PEI membrane was found to be somewhat more effective than the CA membrane. In addition, the C-PEI membrane removed 70+ percent of 13 of the 19 organic compounds tested; only two compounds were removed less than 50 percent. In contrast, however, the CA membrane removed less than 50 percent of 16 of the 19 organic compounds tested, and three compounds were found to exhibit negative removal. The ability of C-PEI membrane to remove organic compounds and its resistance to high temperature and pH have made reverse osmosis an effective separation process for the removal of toxic compounds from water.
1974-02-01
Technical Paper
740927
Jack D. Zeff, Richard Barton, LeRoy H. Reuter
This paper summarizes a study of combining ultra-violet radiation and ozone to purify water contaminated with microorganisms and organic compounds. The objectives of the study were (1) to determine the feasibility of the combination of ultraviolet light and ozone to sterilize and to remove organics from water, (2) define the concentrations of ultraviolet light and ozone required to remove predetermined levels of microbial contamination and organic substances from water, and (3) to describe operating parameters for water sterilization and purification that can be used as a basis for designing operating systems that can be used by the Army and in manned space flight. The study to date has found that the combination of UV and ozone is more effective in destroying test organisms than UV alone. About 2.25 ppm ozone plus UV will destroy about 99.7 percent of the organisms present and 3 ppm of ozone plus UV will result in complete destruction of the organisms.
1974-02-01
Technical Paper
740924
Robert B. Grieves, Dibakar Bhattacharyya, J. W. Paul
1974-02-01
Technical Paper
741156
O. A. Uyehara, P. S. Myers, E. E. Marsh, G. E. Cheklich
Obtaining and maintaining a stratified charge in a practical engine is a difficult problem. Consequently, many approaches have been proposed and reported in the scientific and patent literature. In attempting to assess the most profitable approach for future development work, it is important to group together similar approaches so that one can study their performance as a group. Making such a classification has the additional advantage of helping to standardize terminology used by different investigators. With this thought in mind, a literature study was made and a proposed classification chart prepared for the different engine combustion systems reported in the literature. For the sake of completeness, the finally proposed classification chart includes homogeneous combustion engines as well as heterogeneous combustion engines. Because of their similarity of combustion, rotary engines such as the Wankel engine are considered as “reciprocating” although gas turbines are not included.
1974-02-01
Technical Paper
741159
Egils A. Purins
Single-cylinder experiments were conducted with a 3-valve carbureted pre-chamber stratified charge engine in comparison with a conventional engine. The pre-chamber engine operation is governed by many design and operating variables. This investigation was limited to determining the effect of overall air/fuel ratio, ignition timing and EGR on emissions and fuel economy at a single road load test condition. It was found that, as for the conventional engine, these operating variables are also significant for the pre-chamber engine and that a compromise must be made between good fuel economy and low emissions. The main virtue of the pre-chamber engine was found to be the ability to operate at leaner overall air-fuel ratio. This resulted in lower nitrogen oxide (NO) emissions than the conventional engine without EGR. The unburned hydrocarbons (HC) were found to be higher for the pre-chamber engine up to the conventional engine lean misfire A/F ratio.
1974-02-01
Technical Paper
740932
C. H. Lin, Jack Winnick
A system comprised mainly of 90 electrochemical cells has been designed for use as a CO2 concentrator in a manned spacecraft. Cabin air, with a CO2 partial pressure of about 3 mm Hg is passed across the cathode of an oxygen-hydrogen fuel cell. It is concentrated through the carbonate electrolyte and expelled into the hydrogen-filled anode cavity. The total system, as well as the individual cell design, is described. Experimental results are shown for the full (90 cell) system and also for smaller scale (1 and 3 cell) tests. Excellent consistency among the tests was found. A steady state analytical model has been developed and numerical simulations of the system have been carried out. The model consists of two parts. The first part is established based on the rate equations which govern each of the processes controlling the CO2 transfer in the system. It is a non-linear boundary value problem which is solved by a shooting method.
1974-02-01
Technical Paper
740930
Sam H. Davis
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