Energy Technology Data Exchange (ETDEWEB)

In an ignition timing control apparatus for controlling the ignition timing of each cylinder in order to reduce knock generation in a multi-cylinder engine, a lag-angle correction is made for the ignition timing of a cylinder in which a knock is generated and at the same time, a slight lag-angle correction is made for the ignition timing of the other cylinders in which no knock is generated. When the operating condition of engine is rapidly changed for example, under the condition in which knock is liable to occur in all cylinders as at rapid acceleration time, a lag-angle correction is made by the same amount as in the knock generating cylinder, for the ignition timing of cylinders in which no knock is generated. When no knock is generated for a predetermined time, a lead-angle correction is made for the ignition timing subjected to the ...

Science.gov (United States)

... Tactical Electronic Warfare Division (Code 5700) Visualization Laboratory Transportable step frequency radar Vehicle development laboratory ...

Science.gov (United States)

... as the now-famous Missionaries and Cannibals task: three missionaries and three cannibals must cross a river. They have ...

International Nuclear Information System (INIS)

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating ...

Science.gov (United States)

... A Primer for Cyberspace ... 4. TITLE AND SUBTITLE War in the Information Age: A Primer for Cyberspace Operations in 21st Century Warfare 5a. ...

Science.gov (United States)

... I3a. -YPE OF REPORT T7b 7,ME COVEE 14 DATE OF REPORT (Year, Month. ... the addition of various materials to the standard flare in order to ...

Energy Technology Data Exchange (ETDEWEB)

Power output of a hydrogen-diesel dual-fuel engine is limited by the onset of knock as the percentage of heat input derived from hydrogen increased beyond a certain limit. Earlier work carried out at the Internal Combustion Engines Laboratory, Indian Institute of Technology, Madras, indicates that this knock sets in when the induced hydrogen exceeds about 60% of input energy at a pilot diesel quantity of 30% of full load diesel amount. At higher rates of hydrogen induction, the richer hydrogen-air mixture is more prone to knocking. Hardly any information is available on the possibilities of improving the knock limited power output of a hydrogen-diesel dual-fuel engine. Water can serve as a powerful internal coolant in decreasing the unburned mixture temperature because of its high latent heat. This paper presents the results of our investigation on improving the knock limited power ...

Science.gov (United States)

Cyberspace and its associated operations present both opportunities and challenges for military and United States Government decision-makers and planners. The Pentagon has formally recognized cyberspace as a domain of warfare. Cyberspace is man-made, dyna...

International Nuclear Information System (INIS)

The cross section of hard semiexclusive A(e,e"'N)(A-1) reactions for fixed missing energy and momentum is calculated within the eikonal approximation. Relativistic dynamics and kinematics of high energy processes are unambiguously accounted for by using the analysis of appropriate Feynman diagrams. A significant dependence of the final state interactions on the missing energy is found, which is important for interpretation of forthcoming color transparency experiments. A new, more stringent kinematic restriction on the region where the contribution of short-range nucleon correlations is enhanced in semiexclusive knock-out processes is derived. It is also demonstrated that the use of light-cone variables leads to a considerable simplification of the description of high energy knock-out reactions. copyright 1997 The American Physical Society.

Energy Technology Data Exchange (ETDEWEB)

A study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on vehicle acceleration performance. Twelve participating laboratories, representing both the oil and the automotive industries, tested a total of 182 vehicles as part of the 1989 CRC Octane Number Requirement Survey. The vehicles consisted of 78 with electronic knock control systems and 104 without. All testing was performed using the 1989/1990 CRC FBRU fuel series. The results showed that acceleration performance of vehicles with knock sensors was significantly affected by gasoline octane quality. Octane effects on acceleration performance were most pronounced at maximum-throttle (detent) conditions and at octane levels below the vehicles' octane requirements; however, some knock-sensor vehicles did show improved acceleration performance with fuels at octane levels ...

Energy Technology Data Exchange (ETDEWEB)

The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.

Science.gov (United States)

PMID:11433457

Energy Technology Data Exchange (ETDEWEB)

This review examines the characteristics of the compression-ignition type of dual-fuel engine and the combustion phenomena that affect these characteristics. The specific areas covered involve normal combustion processes, the nature and origin of engine knock, operation with LNG, and the effect of intake temperature on combustion efficiency and exhaust composition.

Energy Technology Data Exchange (ETDEWEB)

In this investigation natural gas has been used as an alternative fuel in diesel engines. Experiments have been performed to study the performance of the dual fuel engine with different diesel quantities as pilot injection. It was suggested in this research that combustion in the dual fuel engine occurred in four stages: the delay period, the slow stage of combustion, the rapid stage of combustion and the fourth stage of combustion. Because of the slower flame speed of natural gas and also because of the prolonged delay period, the combustion of the gas-air continued well into the expansion stroke. These resulted in lower efficiency and higher brake specific fuel consumption, and also higher exhaust gas temperature and higher carbon monoxide in the exhaust when the engine ran on dual fuel. The carbon dioxide and black smoke in the exhaust decreased as the gas was introduced in the engine. The ratio of alternative to diesel fuel was varied at the same load also at different load ...

Science.gov (United States)

In November 1977, 627 soldiers belonging primarily to the First Battalion, 82nd Airborne Division, stationed at Fort Bragg, were sent to the Canal Zone, Panama, for jungle warfare training. A medical surveillance program incorporating pre- and post-evaluations over a 6-month period with dermatologic examinations, questionnaires, and serologic tests was established. Ten cases of cutaneous leishmaniasis (1.6/100 men) were diagnosed by positive Leishmania culture. The demonstrated lack of sensitivity and specificity of the indirect fluorescent antibody test and the direct agglutination test render these serological methods useless as diagnostic screening methods in the early stages of this disease. PMID:7406101

International Nuclear Information System (INIS)

Experimental results on study of helium concentration influence on degree of molybdenum radiation hardening for various method of cyclotron doping differing in degree and damage character are presented. It is established that accumulation of helium atoms in molybdenum for simultaneous formation of radiation defects caused by low energetic primary-knocked atoms leads to higher degree of hardening than for high energetic ion irradiation. It is shown that with increase of helium atom concentration the degree of radiation hardening for the same level of damage increases. 4 refs.; 3 figs. (author).

Energy Technology Data Exchange (ETDEWEB)

The use of jojoba methyl ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or liquefied petroleum gas (LPG) at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or LPG as the main fuel and jojoba methyl ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic variability data of 100 engine cycles in terms of maximum pressure and its pressure rise rate average and standard ...

Science.gov (United States)

Russian field surgery with its long history and distinctive characteristics has accumulated great experience in the long-time practice of warfare. Chinese field surgery was established and developed on the basis of studying from the Russian model, which opened up new areas of traffic medicine, molecular traumatology and assessment of biological effects on weapon destruction and carried out in-depth research on wound ballistics, blast injury, burns and combined injury etc. through decades of construction with continuous development and innovation, and a series of major achievements have been made in these fields. By making comparative study on the historical evolution, structure system, characteristics of campaigns and development of society between Chinese and Russian field surgery, it can be found that there are great gaps between them and we should strengthen the research for more rapid development. PMID:20510098

Energy Technology Data Exchange (ETDEWEB)

Physicians are exercising their responsibility as healers in their efforts to prevent nuclear war. Death for Hiroshima survivors was experienced in four stages: the immediate impact of destruction, the acute impact of radiation, delayed radiation effects, and later identification as an atomic bomb survivor. Each phase had its physical and psychological impacts and negates Hiroshima as a model for rational behavior despite those who claim survival is possible for those who are prepared. The psychic effects of modern nuclear, chemical, and germ warfare need to be challenged with a symbolization of life and immortality. Studies of psychological reactions to the terror children felt during practice air-raid drills indicate that the fears can be surpressed and re-emerge in adult life as a linking of death with collective annihilation. Other themes which emerge are feelings of impermanence, craziness, identification with the bomb, and a double existence. Psychic numbing ...

Energy Technology Data Exchange (ETDEWEB)

A detailed chemical kinetic reaction mechanism is developed to describe incineration of the chemical warfare nerve agent sarin (GB), based on commonly used principles of bond additivity and hierarchical reaction mechanisms. The mechanism is based on previous kinetic models of organophosphorus compounds such as TMP, DMMP and DIMP that are often used as surrogates to predict incineration of GB. Kinetic models of the three surrogates and GB are then used to predict their consumption in a perfectly stirred reactor fueled by natural gas to simulate incineration of these chemicals. Computed results indicate that DIMP is the only one of these surrogates that adequately describes combustion of GB under comparable conditions. The kinetic pathways responsible for these differences in reactivity are identified and discussed. The most important reaction in GB and DIMP that makes them more reactive than TMP or DMMP is found to be a six-center molecular elimination reaction ...

Energy Technology Data Exchange (ETDEWEB)

A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image of each identified nuclide. The APSTNG also ...

Energy Technology Data Exchange (ETDEWEB)

The nitrogen content of 10 medicinal plant species has been determined by fast-neutron activation analysis (FNAA). Correction factors for the effects of the /sup 16/O(p,..cap alpha..)/sup 13/N knock-on proton-induced reaction and the (n,2n) reactions, which produce interfering positron-emitting radionuclides, have also been determined. The total relative interference from the /sup 16/O(p,..cap alpha..)/sup 13/N and (n,2n) reactions of K, Cl, Fe and Br was found to be 5.1 to 32.1% for the plant samples.

Energy Technology Data Exchange (ETDEWEB)

This study investigated the effect of hydrogen content in producer gas on the performance and exhaust emissions of a supercharged producer gas-diesel dual-fuel engine. Two types of producer gases were used in this study, one with low hydrogen content (H{sub 2} = 13.7%) and the other with high hydrogen content (H{sub 2} = 20%). The engine was tested for use as a co-generation engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant injection pressure and injection quantity for different fuel-air equivalence ratios and at various injection timings. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking ...

Energy Technology Data Exchange (ETDEWEB)

This report documents the concluding efforts at the Engineering Sciences Laboratory of TRW on two specific areas of current research activity within the more general context of proposed lean-burn operation of Otto-cycle-type automotive engines. These areas are: (1) achievement of knock-free performance, both under available fuels and current compression ratios and also under higher-octane fuels (e.g., alcohols) and higher-compression-ratio design (for greater thermal efficiency); and (2) identification of counterstrategies for two-wall (crevice-type) quenching of flame propagation, a phenomenon now widely acknowledged to be the major source of unburned-hydrocarbon emissions exhausted from homogeneous-charge cyclinders. There are certainly other highly active areas of research in Otto-cycle engines, such as turbocharging, ignition devices, and valve design, but the two above-cited topics were the topics of this project.

Energy Technology Data Exchange (ETDEWEB)

ABB Industrietechnik AG recently has introduced an augmented version of its Cyldeyt cylinder pressure monitoring system aimed at spark-ignited and diesel/gas, dual-fuel engines. In addition to recording and evaluating cylinder pressure as a means of assessing engine condition, the new Cyldet version now evaluates the cylinder pressure signals to provide protection against pre-ignition related damage. When pre-ignition reaches critical levels, the Cyldet computer relays alarm signals in two stages to the overriding engine control system of the power plant. On receiving the first-stage alarm signal, the engine control system is programmed to adjust one or more engine settings to eliminate preignition - a typical adjustment is to lower charge-air temperature, for example. If such measures fail to eliminate pre-ignition, in the case of a dual-fuel engine, a second alarm signal triggers a reduction in engine load or, as last resort, changeover of the engine to 100% diesel fuel charge. This ...

Energy Technology Data Exchange (ETDEWEB)

Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...

International Nuclear Information System (INIS)

In the present paper it is assumed that above a limiting value of fission fluency (burn-up) a more intensive process of irradiation introduced chemical interaction occurs. A significant part of fission gas product is thus expected to be chemically bounded in the matrix of UO_2 fuel. The fission gas atoms substituting, for example, uranium atoms in the crystallographic lattice can form weak facets. At a certain saturation condition, division of the grains can occur at the weak facets and the increase in fission-gas products release may be expected. The fact that the process of grain division for high burn-ups (70-80 MWd/kgU) forms an extremely fine structure up to the temperature as high as 1100 "oC and simultaneously the observed decreases in fission gas concentration in the fuel supports this concept. The analysis of fission gas concentration change due to the formation of nanostructures in UO_2 fuel at high burn-ups in terms of total surface area change in a function of burn-up and ...

Science.gov (United States)

Two branches of research are conducted in this thesis. The first deals with nonlinear combustion response as a mechanism for triggering combustion instabilities in solid rocket motors. A nonlinear wave equation is developed to study a wide class of combustion response functions to second-order in fluctuation amplitude. Conditions for triggering are derived from analysis of limit cycles, and regions of triggering are found in parametric space. Introduction of linear cross-coupling and quadratic self-coupling among the acoustic modes appears to be how the nonlinear combustion response produces triggering to a stable limit cycle. Regions of initial conditions corresponding to stable pulses were found, suggesting that stability depends on initial phase angle and harmonic content, as well as the composite amplitude, of the pulse. Also, dependence of nonlinear stability upon system parameters is considered. The second part of this thesis presents research for a controller to improve the ...

Energy Technology Data Exchange (ETDEWEB)

We report an analysis of four strains of baker's yeast (Saccharomyces cerevisiae) using biocavity laser spectroscopy. The four strains are grouped in two pairs (wild type and altered), in which one strain differs genetically at a single locus, affecting mitochondrial function. In one pair, the wild-type rho+ and a rho0 strain differ by complete removal of mitochondrial DNA (mtDNA). In the second pair, the wild-type rho+ and a rho- strain differ by knock-out of the nuclear gene encoding Cox4, an essential subunit of cytochrome c oxidase. The biocavity laser is used to measure the biophysical optic parameter Deltalambda, a laser wavelength shift relating to the optical density of cell or mitochondria that uniquely reflects its size and biomolecular composition. As such, Deltalambda is a powerful parameter that rapidly interrogates the biomolecular state of single cells and mitochondria. Wild-type cells and mitochondria produce Gaussian-like distributions ...

Energy Technology Data Exchange (ETDEWEB)

Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with tertiary C-H bonds in the parent fuel. In addition, the rates of ...

Energy Technology Data Exchange (ETDEWEB)

A phenomenological model of turbulent combustion has been developed and validated against data from wide ranging tests on a Ricardo E6 engine. Most tests used iso-octane, with a range of air fuel ratios and ignition timings, for tests at full throttle (with and without knock) and at part throttle. Some full throttle tests were also conducted with methanol and toluene. The engine performance was characterized by mean and coefficient of variation (CoV) of: the peak pressure, the maximum rate of pressure rise, the IMEP, the burn rate and flame speed measurements. The results have been used to argue that the cycle-by-cycle variations in combustion should be characterized by the CoV of IMEP in preference to the CoV of the maximum cylinder pressure. Evidence is also presented to support the observation that the cycle-by-cycle variations in combustion are lower when the early combustion is more rapid. It has also been shown that the CoV of IMEP is a minimum in the region ...

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Li{sub 2}TiO{sub 3} is regarded as one of the most suitable candidates for the solid tritium breeder material of D-T fusion reactors. It is known that, in an operating fusion reactor, the radiation damage in Li{sub 2}TiO{sub 3} will be caused by fast neutrons, energetic tritons and helium ions generated in {sup 6}Li(n,{alpha}){sup 3}H reaction. The irradiation damage caused by such radiation may result in the microstructural changes, and the changes may affect the characteristics of Li{sub 2}TiO{sub 3} such as tritium release behavior. Thus the study of irradiation defects and microstructural changes caused by irradiation in Li{sub 2}TiO{sub 3} is essential to evaluate its irradiation performance. Simulation of the fusion reactor environment and hence the study of a synergistic effect of atomic displacement damage in Li{sub 2}TiO{sub 3} are approached by a simultaneous irradiation with 'triple' ion beams which consist of O{sup 2+}, ...