Science.gov

Sample records for engine cold start

  1. Cold starting system for alcohol fueled engine

    SciTech Connect

    Powell, T.M.

    1983-04-26

    To restart an alcohol fueled engine at low temperatures, a quantity of liquid ethanol is supplied to a vaporizing chamber before the engine is stopped. When restarting the engine, some of the alcohol in the vaporizing chamber is delivered to an igniter, and the hot gases resulting from the burning alcohol are conducted past the vaporizing chamber to evaporate the liquid alcohol remaining in the vaporizing chamber. The alcohol vapor thus generated is conducted to the engine induction system to start the engine.

  2. Cold-start minidiesel engine development

    NASA Astrophysics Data System (ADS)

    Collins, Conrad

    1993-09-01

    Military mission performance in a chemically contaminated environment necessitates the wearing of chemically impermeable protective garments. Soldiers encapsulated in these protective garments will succumb to heat stress in a hot environment. Consequently, a microclimate cooling system is being developed. In the design, a vapor compression cycle chills water which is then circulated over the body to absorb heat via a cooling garment. The engine, the prime mover in the system, is a major component. Commercially available engines of approximately 0.5 hp at 4000 rpm, the required size, include model aircraft engines and small outdoor power equipment (string trimmer) engines. However, these engines do not run on JP-8 or diesel fuel, a requirement for military use. Design, evaluation, and results of three engines are detailed. These include: the potential of a high compression, carbureted, glow plug engine operating on diesel fuel; the potential of a high compression, spark assist, fuel injected engine operating on diesel fuel; and a true high compression, fuel injected engine operating on diesel fuel.

  3. Modeling and cold start in alcohol-fueled engines

    SciTech Connect

    Markel, A.J.; Bailey, B.K.

    1998-05-01

    Neat alcohol fuels offer several benefits over conventional gasoline in automotive applications. However, their low vapor pressure and high heat of vaporization make it difficult to produce a flammable vapor composition from a neat alcohol fuel during a start under cold ambient conditions. Various methods have been introduced to compensate for this deficiency. In this study, the authors applied computer modeling and simulation to evaluate the potential of four cold-start technologies for engines fueled by near-neat alcohol. The four technologies were a rich combustor device, a partial oxidation reactor, a catalytic reformer, and an enhanced ignition system. The authors ranked the competing technologies by their ability to meet two primary criteria for cold starting an engine at {minus}25 deg C and also by several secondary parameters related to commercialization. Their analysis results suggest that of the four technologies evaluated, the enhanced ignition system is the best option for further development.

  4. White smoke emissions under cold starting of diesel engines

    SciTech Connect

    Yassine, M.K.; Tagomori, M.K.; Henein, N.A.; Bryzik, W.

    1996-09-01

    More stringent regulations have been enforced over the past few years on diesel exhaust emissions. White smoke emission, a characteristic of diesel engines during cold starting, needs to be controlled in order to meet these regulations. This study investigates the sources and constituents of white smoke. The effects of fuel properties, design and operating parameters on the formation and emissions of white smoke are discussed. A new technique is developed to measure the real time gaseous hydrocarbons (HC) as well as the solid and liquid particulates. Experiments were conducted on a single cylinder direct injection diesel engine in a cold room. The gaseous HC emissions are measured using a high frequency response flame ionization detector. The liquid and solid particulates are collected on a paper filter placed upstream of the sampling line of the FID and their masses are determined. A comparative study is made between white smoke in its three forms for diesel fuel (DF2) and jet fuel (JP8). The fuel accumulated in the engine during cranking plays a major role in the emissions of white smoke under cold starting conditions.

  5. Investigation and demonstration of a rich combustor cold-start device for alcohol-fueled engines

    SciTech Connect

    Hodgson, J W; Irick, D K

    1998-04-01

    The authors have completed a study in which they investigated the use of a rich combustor to aid in cold starting spark-ignition engines fueled with either neat ethanol or neat methanol. The rich combustor burns the alcohol fuel outside the engine under fuel-rich conditions to produce a combustible product stream that is fed to the engine for cold starting. The rich combustor approach significantly extends the cold starting capability of alcohol-fueled engines. A design tool was developed that simulates the operation of the combustor and couples it to an engine/vehicle model. This tool allows the user to determine the fuel requirements of the rich combustor as the vehicle executes a given driving mission. The design tool was used to design and fabricate a rich combustor for use on a 2.8 L automotive engine. The system was tested using a unique cold room that allows the engine to be coupled to an electric dynamometer. The engine was fitted with an aftermarket engine control system that permitted the fuel flow to the rich combustor to be programmed as a function of engine speed and intake manifold pressure. Testing indicated that reliable cold starts were achieved on both neat methanol and neat ethanol at temperatures as low as {minus}20 C. Although starts were experienced at temperatures as low as {minus}30 C, these were erratic. They believe that an important factor at the very low temperatures is the balance between the high mechanical friction of the engine and the low energy density of the combustible mixture fed to the engine from the rich combustor.

  6. Cold starting an alcohol-fueled engine with ultrasonic fuel atomization

    NASA Astrophysics Data System (ADS)

    Bruetsch, R. I.; Hamady, F. J.

    1993-03-01

    A test program was devised at EPA's National Vehicle and Fuel Emissions Laboratory to evaluate a Tonen ultrasonic fuel atomizer system on a Honda B20 engine using both M85 (85% methanol, 15% hydrocarbons) and M100 (neat methanol) fuels to determine whether cold starting a premixed-charge port injected engine on alcohol fuels at low ambient temperatures can be improved. Modification to the engine's intake manifold was performed at the Japanese Automotive Research Institute (JARI) in cooperation with the New Energy Development Organization (NEDO) to install heated injectors in close proximity to the ultrasonic atomizers. The engine is also equipped with the stock port injector system intact and functional. Successful M100 cold starts were obtained down to 20 F (-7 C).

  7. A personal sampler for aircraft engine cold start particles: laboratory development and testing.

    PubMed

    Armendariz, Alfredo; Leith, David

    2003-01-01

    Industrial hygienists in the U.S. Air Force are concerned about exposure of their personnel to jet fuel. One potential source of exposure for flightline ground crews is the plume emitted during the start of aircraft engines in extremely cold weather. The purpose of this study was to investigate a personal sampler, a small tube-and-wire electrostatic precipitator (ESP), for assessing exposure to aircraft engine cold start particles. Tests were performed in the laboratory to characterize the sampler's collection efficiency and to determine the magnitude of adsorption and evaporation artifacts. A low-temperature chamber was developed for the artifact experiments so tests could be performed at temperatures similar to actual field conditions. The ESP collected particles from 0.5 to 20 micro m diameter with greater than 98% efficiency at particle concentrations up to 100 mg/m(3). Adsorption artifacts were less than 5 micro g/m(3) when sampling a high concentration vapor stream. Evaporation artifacts were significantly lower for the ESP than for PVC membrane filters across a range of sampling times and incoming vapor concentrations. These tests indicate that the ESP provides more accurate exposure assessment results than traditional filter-based particle samplers when sampling cold start particles produced by an aircraft engine. PMID:14674798

  8. Cold-start minidiesel engine development. Final report, July 1991-March 1992

    SciTech Connect

    Collins, C.

    1993-09-01

    Military mission performance in a chemically contaminated environment necessitates the wearing of chemically impermeable protective garments. Soldiers encapsulated in these protective garments will succumb to heat stress in a hot environment. Consequently, a microclimate cooling system is being developed. In the design, a vapor compression cycle chills water which is then circulated over the body to absorb heat via a cooling garment. The engine, the prime mover in the system, is a major component. Commercially available engines of approximately 0.5 hp at 4000 rpm, the required size, include model aircraft engines and small outdoor power equipment (string trimmer) engines. However, these engines do not run on JP-8 or diesel fuel, a requirement for military use. This report details design, evaluation, and results of three engines. These include: the potential of a high compression, carbureted, glow plug engine operating on diesel fuel; the potential of a high compression, spark assist, fuel injected engine operating on diesel fuel; and a true high compression, fuel injected engine operating on diesel fuel. Diesel engines, Microclimate cooling system, Diesel fuels, Vapor compression, Cold start, Engines.

  9. Flames and liquid fuel in an SI engine cylinder during cold start

    SciTech Connect

    Campbell, S.; Clasen, E.; Chang, C.; Rhee, K.

    1996-05-01

    The flame propagations in the very first firing and subsequent cycles in an SI engine during cold start were studied to gain a better understanding of reaction fronts associated with liquid fuel (regular unleaded) in the cylinder. This work was performed using the Rutgers high-speed spectral infrared digital imaging system on a single-cylinder engine with optical access. The engine was mounted with a production engine head mated with a conventional pon fuel injection (PFI) system. In the study, four images in respective spectral bands were simultaneously obtained at successive instants of time, which was done for eight sequential cycles. This multiple-band successive-imaging was repeated in intervals of about two minutes over a period of more than twenty-five minutes after the engine start. During this experiment, the temperature changes at the intake port, the water jacket and the exhaust gas were monitored. In addition, pressure-time data was obtained from individual cycles in order to gain some insight into the overall in-cylinder reactions. The first firing cycle exhibited almost invariably weak flame propagation, which was followed by very intense flame fronts in the next cycle. Note that the flame propagation in the first cycle seems to only indicate consumption of the filel vapor available in the cycle. The flames in the third cycle were also intense in some cases, but mostly weaker than those in the second. Upon formation of the flame front in the beginning of combustion, some exceedingly strong local reactions started to grow, but no earlier than l5CA after TDC.

  10. Parametric study on the fuel film breakup of a cold start PFI engine

    NASA Astrophysics Data System (ADS)

    Wang, Y.-P.; Wilkinson, G. B.; Drallmeier, J. A.

    In order to provide more insight on improving the cold start fuel atomization for reducing unburned hydrocarbon emissions, the liquid fuel film breakup phenomenon in the intake valve/port region was investigated in depth for port-fuel-injected engines. Experiments were conducted using high-speed high-resolution imaging techniques to visualize the liquid film atomization and airflow patterns in an axisymmetric steady flow apparatus. The impact of valve/port seat geometry, surface roughness, and fuel properties on airflow separation and fuel film breakup were determined through a parametric study. CFD simulations were also performed with FLUENT to help understand the airflow behavior inside the intake port and valve gap region and its potential impact on fuel film atomization.

  11. Sampling and analysis of aircraft engine cold start particles and demonstration of an electrostatic personal particle sampler.

    PubMed

    Armendariz, Alfredo; Leith, David; Boundy, Maryanne; Goodman, Randall; Smith, Les; Carlton, Gary

    2003-01-01

    Aircraft engines emit an aerosol plume during startup in extremely cold weather that can drift into areas occupied by flightline ground crews. This study tested a personal sampler used to assess exposure to particles in the plume under challenging field conditions. Area and personal samples were taken at two U.S. Air Force (USAF) flightlines during the winter months. Small tube-and-wire electrostatic precipitators (ESPs) were mounted on a stationary stand positioned behind the engines to sample the exhaust. Other ESPs were worn by ground crews to sample breathing zone concentrations. In addition, an aerodynamic particle sizer 3320 (APS) was used to determine the size distribution of the particles. Samples collected with the ESP were solvent extracted and analyzed with gas chromatography-mass spectrometry. Results indicated that the plume consisted of up to 75 mg/m(3) of unburned jet fuel particles. The APS showed that nearly the entire particle mass was respirable, because the plumes had mass median diameters less than 2 micro m. These tests demonstrated that the ESP could be used at cold USAF flightlines to perform exposure assessments to the cold start particles. PMID:14674797

  12. Cold start extra emissions as a function of engine stop time: Evolution over the last 10 years

    NASA Astrophysics Data System (ADS)

    Favez, Jean-Yves; Weilenmann, Martin; Stilli, Jan

    Cars with catalysts show a significant increase in exhaust emissions at engine start. These extra emissions are expressed as the difference, over a particular driving cycle, between emissions generated when the vehicle is started and when the engine or the catalyst are stably warm. Experimental data, suitable for the assessment of cold start emissions, are usually available for completely cooled engines. Most results originate from tests at ambient temperature of 20-30 °C and with an engine stop time of at least 12 h. On the other hand, data including shorter stop times are very rare. The present work investigates the influence of exhaust emissions with shorter stop times, i.e. 0.5, 1, 2 and 4 h. The main goal consists in the comparison of emissions exhausted by recent car models (Euro-4) against emissions assessed in the framework of a similar campaign 10 years ago (FAV1/Euro-1 vehicles). A short survey of the current extra emission estimation methods is presented in this paper. It is shown that some methods are not suited for providing correct estimations in all cases. We discuss the fact that different estimation methods can show either similar or completely different results depending on the evolution behaviour of the hot emissions. Due to new technologies, e.g. the catalyst and improved engine control algorithms, emissions have been considerably reduced over the last 10 years. In this study it is determined how the relative extra emissions, i.e. extra emissions relative to the extra emissions for the standard stop time of 12 h, expressed as a function of stop time have changed. We may claim with caution that for medium stop times of 0.5-4 h the average relative extra emissions of Euro-4 vehicles are well below the average of the relative extra emissions of Euro-1 vehicles.

  13. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, Jiri; McVay, Gary L.; Peden, Charles H.; Exarhos, Gregory J.

    1998-01-01

    A method and apparatus for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO.sub.2 is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine.

  14. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, J.; McVay, G.L.; Peden, C.H.; Exarhos, G.J.

    1998-07-14

    A method and apparatus are disclosed for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO{sub 2} is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine. 4 figs.

  15. Investigation of Diesel combustion using multiple injection strategies for idling after cold start of passenger-car engines

    SciTech Connect

    Payri, F.; Broatch, A.; Salavert, J.M.; Martin, J.

    2010-10-15

    A comprehensive investigation was carried out in order to better understand the combustion behaviour in a low compression ratio DI Diesel engine when multiple injection strategies are applied just after the engine cold starts in low temperature conditions (idling). More specifically, the aim of this study was twofold: on one hand, to understand the effect of the multiple injection strategies on the indicated mean effective pressure; on the other hand, to contribute to the understanding of combustion stability characterized by the coefficient of variation of indicated mean effective pressure. The first objective was fulfilled by analyzing the rate of heat release obtained by in-cylinder pressure diagnosis. The results showed that the timing of the pilot injection closest to the main injection was the most influential parameter based on the behaviour of the rate of heat release (regardless of the multiple injection strategy applied). For the second objective, the combustion stability was found to be correlated with the combustion centroid angle. The results showed a trend between them and the existence of a range of centroid angles where the combustion stability is strong enough. In addition, it was also evident that convenient split injection allows shifting the centroid to such a zone and improves combustion stability after start. (author)

  16. Fabrication and testing of an enhanced ignition system to reduce cold-start emissions in an ethanol (E85) light-duty truck engine

    SciTech Connect

    Gardiner, D; Mallory, R; Todesco, M

    1997-09-01

    This report describes an experimental investigation of the potential for an enhanced ignition system to lower the cold-start emissions of a light-duty vehicle engine using fuel ethanol (commonly referred to as E85). Plasma jet ignition and conventional inductive ignition were compared for a General Motors 4-cylinder, alcohol-compatible engine. Emission and combustion stability measurements were made over a range of air/fuel ratios and spark timing settings using a steady-state, cold-idle experimental technique in which the engine coolant was maintained at 25 C to simulate cold-running conditions. These tests were aimed at identifying the degree to which calibration strategies such as mixture enleanment and retarded spark timing could lower engine-out hydrocarbon emissions and raise exhaust temperatures, as well as determining how such calibration changes would affect the combustion stability of the engine (as quantified by the coefficient of variation, or COV, of indicated mean effective pressure calculated from successive cylinder pressure measurements). 44 refs., 39 figs.

  17. Optimizing the performance of catalytic traps for hydrocarbon abatement during the cold-start of a gasoline engine.

    PubMed

    Puértolas, B; Navlani-García, M; García, T; Navarro, M V; Lozano-Castelló, D; Cazorla-Amorós, D

    2014-08-30

    A key target to reduce current hydrocarbon emissions from vehicular exhaust is to improve their abatement under cold-start conditions. Herein, we demonstrate the potential of factorial analysis to design a highly efficient catalytic trap. The impact of the synthesis conditions on the preparation of copper-loaded ZSM-5 is clearly revealed by XRD, N2 sorption, FTIR, NH3-TPD, SEM and TEM. A high concentration of copper nitrate precursor in the synthesis improves the removal of hydrocarbons, providing both strong adsorption sites for hydrocarbon retention at low temperature and copper oxide nanoparticles for full hydrocarbon catalytic combustion at high temperature. The use of copper acetate precursor leads to a more homogeneous dispersion of copper oxide nanoparticles also providing enough catalytic sites for the total oxidation of hydrocarbons released from the adsorption sites, although lower copper loadings are achieved. Thus, synthesis conditions leading to high copper loadings jointly with highly dispersed copper oxide nanoparticles would result in an exceptional catalytic trap able to reach superior hydrocarbon abatement under highly demanding operational conditions. PMID:25108828

  18. Alcohol cold starting - A theoretical study

    NASA Technical Reports Server (NTRS)

    Browning, L. H.

    1983-01-01

    Two theoretical computer models have been developed to study cold starting problems with alcohol fuels. The first model, a droplet fall-out and sling-out model, shows that droplets must be smaller than 50 microns to enter the cylinder under cranking conditions without being slung-out in the intake manifold. The second model, which examines the fate of droplets during the compression process, shows that the heat of compression can be used to vaporize small droplets (less than 50 microns) producing flammable mixtures below freezing ambient temperatures. While droplet size has the greater effect on startability, a very high compression ratio can also aid cold starting.

  19. FTIR Determination of Pollutants in Automobile Exhaust: An Environmental Chemistry Experiment Comparing Cold-Start and Warm-Engine Conditions

    ERIC Educational Resources Information Center

    Medhurst, Laura L.

    2005-01-01

    An experiment developed from the Advanced Integrated Environmental Laboratory illustrates the differences in automobile exhaust before and after the engine is warmed, using gas-phase Fourier transform infrared spectroscopy (FTIR). The apparatus consists of an Avatar 360 FTIR spectrometer from Nicolet fitted with a variable path length gas cell,…

  20. 40 CFR 86.236-94 - Engine starting and restarting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Engine starting and restarting. 86.236... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.236-94 Engine starting...

  1. 40 CFR 86.236-94 - Engine starting and restarting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Engine starting and restarting. 86.236... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.236-94 Engine starting...

  2. 40 CFR 86.236-94 - Engine starting and restarting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Engine starting and restarting. 86.236... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.236-94 Engine starting...

  3. 40 CFR 86.236-94 - Engine starting and restarting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Engine starting and restarting. 86.236... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.236-94 Engine starting...

  4. Starting apparatus for internal combustion engines

    DOEpatents

    Dyches, G.M.; Dudar, A.M.

    1995-01-01

    This report is a patent description for a system to start an internal combustion engine. Remote starting and starting by hearing impaired persons are addressed. The system monitors the amount of current being drawn by the starter motor to determine when the engine is started. When the engine is started the system automatically deactivates the starter motor. Five figures are included.

  5. Engine management during NTRE start up

    NASA Technical Reports Server (NTRS)

    Bulman, Mel; Saltzman, Dave

    1993-01-01

    The topics are presented in viewgraph form and include the following: total engine system management critical to successful nuclear thermal rocket engine (NTRE) start up; NERVA type engine start windows; reactor power control; heterogeneous reactor cooling; propellant feed system dynamics; integrated NTRE start sequence; moderator cooling loop and efficient NTRE starting; analytical simulation and low risk engine development; accurate simulation through dynamic coupling of physical processes; and integrated NTRE and mission performance.

  6. Cold-start, is it good or bad

    SciTech Connect

    Lanthier, G.

    1993-02-01

    An awful lot has been said on cold-starting a boiler, but from discussions I recently have had I am sure everybody understands what it really means, and from what I can see, that includes some manufacturers too. The reason I wonder is because of the so called horror stories' I hear about cold-start.

  7. Hydrazine engine start system air start performance and controls sizing

    SciTech Connect

    Johnson, A.T.

    1992-01-01

    Hydrazine has been used as an energy source in many applications to fuel in-flight main engine starting. In a current application, an existing hydrazine engine start system (ESS) design was adapted to meet new fuel control requirements. This paper presents a brief system description, historical context, and the motivating factors for the hydrazine controls changes and three case studies of controls design and analysis from the ESS program. 4 refs.

  8. Reducing cold-start emissions by catalytic converter thermal management

    SciTech Connect

    Burch, S D; Potter, T F; Keyser, M A; Brady, M J; Michaels, K F

    1995-01-01

    Vacuum insulation and phase-change thermal storage have been used to enhance the heat retention of a prototype catalytic converter. Storing heat in the converter between trips allows exhaust gases to be converted more quickly, significantly reducing cold-start emissions. Using a small metal hydride, the thermal conductance of the vacuum insulation can be varied continuously between 0.49 and 27 W/m{sup 2}K (R-12 to R-0.2 insulation) to prevent overheating of the catalyst. A prototype was installed in a Dodge Neon with a 2.0-liter engine. Following a standard preconditioning and a 23-hour cold soak, an FTP (Federal Test Procedure) emissions test was performed. Although exhaust temperatures during the preconditioning were not hot enough to melt the phase-change material, the vacuum insulation performed well, resulting in a converter temperature of 146{degrees}C after the 23-hour cold soak at 27{degrees}C. Compared to the same converter at ambient conditions, overall emissions of CO and HC were reduced by 52 % and 29 %, to 0.27 and 0.037 g/mile, respectively. The maximum converter temperature during the FTP cycle was 720{degrees}C. This limited testing was performed with a nearly-fresh palladium-only catalyst, but demonstrates the potential of this vacuum insulation approach for emissions reduction and thermal control. Further testing is ongoing. An initial assessment of several production issues is made, including high-volume fabrication challenges, durability, and cost.

  9. TrustRank: a Cold-Start tolerant recommender system

    NASA Astrophysics Data System (ADS)

    Zou, Haitao; Gong, Zhiguo; Zhang, Nan; Zhao, Wei; Guo, Jingzhi

    2015-02-01

    The explosive growth of the World Wide Web leads to the fast advancing development of e-commerce techniques. Recommender systems, which use personalised information filtering techniques to generate a set of items suitable to a given user, have received considerable attention. User- and item-based algorithms are two popular techniques for the design of recommender systems. These two algorithms are known to have Cold-Start problems, i.e., they are unable to effectively handle Cold-Start users who have an extremely limited number of purchase records. In this paper, we develop TrustRank, a novel recommender system which handles the Cold-Start problem by leveraging the user-trust networks which are commonly available for e-commerce applications. A user-trust network is formed by friendships or trust relationships that users specify among them. While it is straightforward to conjecture that a user-trust network is helpful for improving the accuracy of recommendations, a key challenge for using user-trust network to facilitate Cold-Start users is that these users also tend to have a very limited number of trust relationships. To address this challenge, we propose a pre-processing propagation of the Cold-Start users' trust network. In particular, by applying the personalised PageRank algorithm, we expand the friends of a given user to include others with similar purchase records to his/her original friends. To make this propagation algorithm scalable to a large amount of users, as required by real-world recommender systems, we devise an iterative computation algorithm of the original personalised TrustRank which can incrementally compute trust vectors for Cold-Start users. We conduct extensive experiments to demonstrate the consistently improvement provided by our proposed algorithm over the existing recommender algorithms on the accuracy of recommendations for Cold-Start users.

  10. Modeling Cold Start in a Polymer-Electrolyte Fuel Cell

    NASA Astrophysics Data System (ADS)

    Balliet, Ryan James

    Polymer-electrolyte fuel cells (PEFCs) are electrochemical devices that create electricity by consuming hydrogen and oxygen, forming water and heat as byproducts. PEFCs have been proposed for use in applications that may require start-up in environments with temperatures below 0 degrees C. Doing so requires that the cell heat up, and when its own waste heat is used to do so, the process is referred to here as "cold start.'' However, at low temperatures the cell's product water freezes, and if the temperature does not rise fast enough, the accumulation of ice in the cathode catalyst layer (cCL) can reduce cell performance significantly, extending the time required to heat up. In addition to reducing performance during cold start, under some conditions the accumulation of ice can lead to irreversible structural degradation of the cCL. The objective of this dissertation is to construct and verify a cold-start model for a single PEFC, use it to improve understanding of cold-start behavior, and to demonstrate how this understanding can lead to better start protocols and material properties. The macrohomogeneous model that has been developed to meet the objective is two-dimensional, transient, and nonisothermal. A key differentiating feature is the inclusion of water in all four of the possible phases: ice, liquid, gas, and membrane. In order to predict water content in the ice, liquid, and gas phases that are present in the porous media, the thermodynamics of phase equilibrium are revisited, and a method for relating phase pressures to water content in each of these phases is developed. Verification of the model is performed by comparing model predictions for cell behavior during parametric studies to measured values taken from various sources. In most cases, good agreement is observed between the model and the experiments. Results from the simulations are used to explain the trends that are observed. The verified cold-start model is deployed to determine a cold-start

  11. Cold-start characteristics of polymer electrolyte fuel cells

    SciTech Connect

    Mishler, Jeff; Mukundan, Rangachary; Wang, Yun; Mishler, Jeff; Mukherjee, Partha P

    2010-01-01

    In this paper, we investigate the electrochemical reaction kinetics, species transport, and solid water dynamics in a polymer electrolyte fuel cell (PEFC) during cold start. A simplitied analysis is developed to enable the evaluation of the impact of ice volume fraction on cell performance during coldstart. Supporting neutron imaging data are also provided to reveal the real-time water evolution. Temperature-dependent voltage changes due to the reaction kinetics and ohmic loss are also analyzed based on the ionic conductivity of the membrane at subfreezing temperature. The analysis is valuable for the fundamental study of PEFC cold-start.

  12. PEM Fuel Cell Freeze Durability and Cold Start Project

    SciTech Connect

    Patterson, T.; O'Neill, Jonathan

    2008-01-02

    UTC has taken advantage of the unique water management opportunities inherent in micro-porous bipolar-plates to improve the cold-start performance of its polymer electrolyte fuel cells (PEFC). Diagnostic experiments were used to determine the limiting factors in micro-porous plate PEFC freeze performance and the causes of any performance decay. Alternative cell materials were evaluated for their freeze performance. Freeze-thaw cycling was also performed to determine micro-porous plate PEFC survivability. Data from these experiments has formed the basis for continuing development of advanced materials capable of supporting DOE's cold-start and durability objectives.

  13. Starting apparatus for internal combustion engines

    DOEpatents

    Dyches, Gregory M.; Dudar, Aed M.

    1997-01-01

    An internal combustion engine starting apparatus uses a signal from a curt sensor to determine when the engine is energized and the starter motor should be de-energized. One embodiment comprises a transmitter, receiver, computer processing unit, current sensor and relays to energize a starter motor and subsequently de-energize the same when the engine is running. Another embodiment comprises a switch, current transducer, low-pass filter, gain/comparator, relay and a plurality of switches to energize and de-energize a starter motor. Both embodiments contain an indicator lamp or speaker which alerts an operator as to whether a successful engine start has been achieved. Both embodiments also contain circuitry to protect the starter and to de-energize the engine.

  14. Comparison of exhaust emissions resulting from cold- and hot-start motorcycle driving modes.

    PubMed

    Yao, Yung-Chen; Tsai, Jiun-Horng; Ye, Hui-Fen; Chiang, Hung-Lung

    2009-11-01

    This study investigated the emissions of criteria air pollutants (carbon monoxide [CO], hydrocarbons [HCs], and oxides of nitrogen [NOx]) from motorcycle exhaust at cold- and hot-start driving cycles on a chassis dynamometer. Seven four-stroke carburetors and two fuel-injection motorcycles were tested. As expected, the emission factors (g/km) of CO and HCs increased during cold-start driving. The ratio of emission factors (g/km) for cold- and hot-start driving cycles ranged from 1.1-1.5 (for CO) to 1.2-2.8 (for HCs). However, the difference of NOx emissions between the cold- and hot-start cycles was not pronounced. Further, the cold-/hot-start ratios of CO and HCs from 50-cm3 motorcycles were higher than those of 100- and 125-cm3 motorcycles; however, the carbon dioxide (CO2) emission was the lowest for the four-stroke motorcycles. High engine temperature and poor combustion efficiency of smaller cylinder-capacity motorcycles may contribute a significant amount of exhaust emission. Additionally, the fuel-base emission factor (g/L-fuel) ratios were low compared with the distance-base emission factor (g/km) in cold- and hot-start driving. This indicates that the effect of catalyst efficiency was greater than the effect of fuel combustion in the tested motorcycles. A comparison of emission ratios of motorcycles and passenger cars shows that the warm-up may be more important for cars, especially under low-temperature conditions. However, the motorcycle contributes a large proportion of CO and HC emissions in many Asian counties. The difference between cold- and hot-start emissions may affect inventory PMID:19947115

  15. Statistic analysis of operational influences on the cold start behaviour of PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Oszcipok, M.; Riemann, D.; Kronenwett, U.; Kreideweis, M.; Zedda, M.

    For portable fuel cell systems a multitude of applications have been presented over the past few years. Most of these applications were developed for indoor use, and not optimised for outdoor conditions. The key problem concerning this case is the cold start ability of the polymer electrolyte membrane fuel cell (PEMFC). This topic was first investigated by the automotive industry, which has the same requirements for alternative traction systems as for conventional combustion engines. The technical challenge is the fact that produced water freezes to ice after shut-down of the PEMFC and during start-up when the temperature is below 0 °C. To investigate the basic cold start behaviour isothermal, potentiostatic single cell experiments were performed and the results are presented. The cold start behaviour is evaluated using the calculated cumulated charge transfer through the membrane which directly corresponds with the amount of produced water in the PEMFC. The charge transfer curves were mathematically fitted to obtain only three parameters describing the cold start-up with the cumulated charge transfer density and the results are analysed using the statistical software Cornerstone 4.0. The results of the statistic regression analyses are used to establish a statistic-based prediction model of the cold start behaviour which describes the behaviour of the current density during the experiment. The regression shows that the initial start current mainly depends on the membrane humidity and the operation voltage. After the membrane humidity has reached its maximum, the current density drops down to zero. The current decay also depends on the constant gas flows of the reactant gases. Ionic conductivity of the membrane and charge transfer resistance were investigated by a series of ac impedance spectra during potentiostatic operation of the single cell at freezing temperatures. Cyclic voltammetry and polarisation curves between cold start experiments show degradation

  16. Turbojet-engine Starting and Acceleration

    NASA Technical Reports Server (NTRS)

    Mc Cafferty, R. J.; Straight, D. M.

    1956-01-01

    From considerations of safety and reliability in performance of gas-turbine aircraft, it is clear that engine starting and acceleration are of utmost importance. For this reason extensive efforts have been devoted to the investigation of the factors involved in the starting and acceleration of engines. In chapter III it is shown that certain basic combustion requirements must be met before ignition can occur; consequently, the design and operation of an engine must be tailored to provide these basic requirements in the combustion zone of the engine, particularly in the vicinity of the ignition source. It is pointed out in chapter III that ignition by electrical discharges is aided by high pressure, high temperature, low gas velocity and turbulence, gaseous fuel-air mixture, proper mixture strength, and-an optimum spark. duration. The simultaneous achievement of all these requirements in an actual turbojet-engine combustor is obviously impossible, yet any attempt to satisfy as many requirements as possible will result in lower ignition energies, lower-weight ignition systems, and greater reliability. These factors together with size and cost considerations determine the acceptability of the final ignition system. It is further shown in chapter III that the problem of wall quenching affects engine starting. For example, the dimensions of the volume to be burned must be larger than the quenching distance at the lowest pressure and the most adverse fuel-air ratio encountered. This fact affects the design of cross-fire tubes between adjacent combustion chambers in a tubular-combustor turbojet engine. Only two chambers in these engines contain spark plugs; therefore, the flame must propagate through small connecting tubes between the chambers. The quenching studies indicate that if the cross-fire tubes are too narrow the flame will not propagate from one chamber to another. In order to better understand the role of the basic factors in actual engine operation, many

  17. 40 CFR 86.136-90 - Engine starting and restarting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the engine until it starts. (b) Diesel vehicles. The engine shall be started according to the... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Engine starting and restarting. 86.136... Complete Heavy-Duty Vehicles; Test Procedures § 86.136-90 Engine starting and restarting. (a)...

  18. 40 CFR 86.136-90 - Engine starting and restarting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the engine until it starts. (b) Diesel vehicles. The engine shall be started according to the... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Engine starting and restarting. 86.136... Complete Heavy-Duty Vehicles; Test Procedures § 86.136-90 Engine starting and restarting. (a)...

  19. Promoting cold-start items in recommender systems.

    PubMed

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs. PMID:25479013

  20. Promoting Cold-Start Items in Recommender Systems

    PubMed Central

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs. PMID:25479013

  1. Cold start characteristics of ethanol as an automobile fuel

    DOEpatents

    Greiner, Leonard

    1982-01-01

    An alcohol fuel burner and decomposer in which one stream of fuel is preheated by passing it through an electrically heated conduit to vaporize the fuel, the fuel vapor is mixed with air, the air-fuel mixture is ignited and combusted, and the combustion gases are passed in heat exchange relationship with a conduit carrying a stream of fuel to decompose the fuel forming a fuel stream containing hydrogen gas for starting internal combustion engines, the mass flow of the combustion gas being increased as it flows in heat exchange relationship with the fuel carrying conduit, is disclosed.

  2. 40 CFR 86.1236-85 - Engine starting and restarting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacturer's recommendation). This may be repeated for up to three start attempts. If the vehicle does not start after three attempts, the reason for failure to start shall be determined. If failure to start is... and cranking the engine until it starts. (4) If the vehicle does not start after the...

  3. Cold start fuel consumption of a diesel and a petrol car

    SciTech Connect

    Pearce, T.C.; Waters, M.H.L.

    1980-01-01

    Measurements have been made of the fuel consumption of a petrol and a diesel car when starting from cold. The cars were the 1.1 liter petrol VW Golf and the 1.5 liter diesel version, which have the same passenger accommodation and nearly identical road performance. It was found that the diesel car used less fuel in the warm-up period than the petrol, both when being driven at constant speed on a test track and with the engine idling and the car stationary. (Copyright (c) Crown Copyright 1980.)

  4. Regulated and nonregulated diesel and gasoline cold start emissions at different temperatures

    NASA Astrophysics Data System (ADS)

    Weilenmann, Martin; Soltic, Patrik; Saxer, Christian; Forss, Anna-Maria; Heeb, Norbert

    The emissions of modern cars are usually reduced in warm engine conditions by catalysts. Consequently emissions are significantly higher during the cold start, i.e. the warm-up phase of the car. The duration of this period and the emissions produced during it depend on the ambient temperature as well as on the initial temperature of the car's systems. The cold start emissions of Euro-3 gasoline cars, Euro-2 diesel cars and old pre-Euro-1 gasoline cars were investigated at cold ambient temperatures. Since the goal was to get real-world emissions, the measurements were done with cars belonging to private owners taken straight from the road with no maintenance. The chassis dynamometer tests were carried out at +23, -7 and -20 °C. The test cycle employed is a representative urban ride from a real-world driving behaviour study. Besides the regulated pollutants, methane, benzene and toluene were also measured online by chemical ionisation mass spectrometry.

  5. Shift mechanism for engine starting apparatus

    SciTech Connect

    Colvin, J.A.; Colvill, R.G.; Smock, A.L.

    1986-04-01

    This patent describes a shift lever mechanism for translating axial movement of the plunger of a starter solenoid into axial movement of a pinion of an engine starting apparatus. This apparatus consists of, a starter solenoid having an axially shiftable plunger and a coil winding, a spring opposing pull-in movement of the plunger and a solenoid switch operated to a closed condition when the plunger is completely pulled-in, a shift lever actuator carried by the plunger for axial movement therewith. The actuator has a pair of spaced surfaces, a pivotally mounted shift lever one end of which is adapted to be coupled to the pinion. The opposite end of the shift lever has a pair of opposed shift lever surfaces that respectively engage the surfaces on the actuator. The actuator surfaces and the shift lever surfaces are substantially engaged when the shift lever is in an at rest postion. The surfaces on the shift lever are at different radial distances from the pivot point of the shift lever and are arranged relative to the surfaces on the actuator such that when the solenoid plunger pulls-in the surface on the shift lever that is at the greater radial distance from the pivot point is moved by a surface of the actuator and the other surface on the shift lever becomes separated by a predetermined amount from its cooperating surface on the actuator. The amount of separation is sufficient to allow the solenoid switch to be actuated to an open condition when the solenoid coil winding is deenergized and the spring shifts and plunger to reengage the separated surfaces.

  6. 40 CFR 86.536-78 - Engine starting and restarting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Engine starting and restarting. 86.536... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.536-78 Engine starting and restarting....

  7. 40 CFR 86.536-78 - Engine starting and restarting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Engine starting and restarting. 86.536... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.536-78 Engine starting and restarting....

  8. 40 CFR 86.136-90 - Engine starting and restarting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Engine starting and restarting. 86.136... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... Complete Heavy-Duty Vehicles; Test Procedures § 86.136-90 Engine starting and restarting. (a)...

  9. 40 CFR 86.1236-85 - Engine starting and restarting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Engine starting and restarting. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1236-85 Engine starting and restarting. (a)...

  10. 40 CFR 86.536-78 - Engine starting and restarting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Engine starting and restarting. 86.536... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.536-78 Engine starting and restarting....

  11. 40 CFR 86.536-78 - Engine starting and restarting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Engine starting and restarting. 86.536... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.536-78 Engine starting and restarting....

  12. 40 CFR 86.1236-85 - Engine starting and restarting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Engine starting and restarting. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1236-85 Engine starting and restarting. (a)...

  13. 40 CFR 86.136-90 - Engine starting and restarting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Engine starting and restarting. 86.136... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... Complete Heavy-Duty Vehicles; Test Procedures § 86.136-90 Engine starting and restarting. (a)...

  14. 40 CFR 86.1236-85 - Engine starting and restarting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Engine starting and restarting. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1236-85 Engine starting and restarting. (a)...

  15. 40 CFR 86.136-90 - Engine starting and restarting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Engine starting and restarting. 86.136... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... Complete Heavy-Duty Vehicles; Test Procedures § 86.136-90 Engine starting and restarting. (a)...

  16. 40 CFR 86.536-78 - Engine starting and restarting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Engine starting and restarting. 86.536... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.536-78 Engine starting and restarting....

  17. 40 CFR 1065.525 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... failed to start, unless the owners manual or the service-repair manual describes the longer cranking time... following methods: (1) Start the engine as recommended in the owners manual using a production starter...

  18. 40 CFR 1065.930 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... longer than 15 seconds, as long as the owners manual or the service-repair manual describes the longer... the engine as described in the owners manual. (b) If the engine does not start after 15 seconds...

  19. 40 CFR 1065.930 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... longer than 15 seconds, as long as the owners manual or the service-repair manual describes the longer... the engine as described in the owners manual. (b) If the engine does not start after 15 seconds...

  20. 40 CFR 1065.930 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... longer than 15 seconds, as long as the owners manual or the service-repair manual describes the longer... the engine as described in the owners manual. (b) If the engine does not start after 15 seconds...

  1. 40 CFR 1065.930 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... longer than 15 seconds, as long as the owners manual or the service-repair manual describes the longer... the engine as described in the owners manual. (b) If the engine does not start after 15 seconds...

  2. 40 CFR 1065.930 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... longer than 15 seconds, as long as the owners manual or the service-repair manual describes the longer... the engine as described in the owners manual. (b) If the engine does not start after 15 seconds...

  3. 40 CFR 1066.425 - Engine starting and restarting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Vehicle Preparation and Running a Test § 1066.425 Engine... not that causes the engine to start running. (2) Place the transmission in gear as described by...

  4. 40 CFR 1066.425 - Engine starting and restarting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Vehicle Preparation and Running a Test § 1066.425 Engine... not that causes the engine to start running. (2) Place the transmission in gear as described by...

  5. Cold-start and chemical characterization of emissions from mobile sources in Mexico.

    PubMed

    Schifter, I; Díaz, L; Rodríguez, R

    2010-10-01

    In this work tailpipe and evaporative emissions from a set of normal and high emitter vehicle models, year 2006-2008 (low mileage) certified when new to meet the Tier 1 emission standard, were characterized for criteria pollutants (carbon monoxide, nitrogen oxides and hydrocarbons), and a suite of unregulated emissions including aliphatic and aromatic aldehydes, monocyclic aromatic compounds, 1,3 butadiene, n-hexane and acrolein. Data were obtained under the three different driving conditions of the United States Federal Test Procedure, FTP-75 cycle. High emissions of both regulated and unregulated pollutants were observed in the cold-start phase of the driving cycle for low mileage Tier 1 normal and high emitters engines. Data were compared with results obtained for a set of MY > 1992-2005 that included vehicles with no catalytic converters, Tier 0 and MY 2000-5 Tier 1 emission standard with high mileage. The calculated average cold-start emissions for normal emitters in grams are 0.93, 8.21 and 1.06 for NMHC CO, and NOx, respectively for Tier 1 low mileage vehicles. The reductions in emissions for Tier 1 normal emitters are 76%, 56% and 56% for NMHC, CO and NOx, respectively, but 58%, 30% and 25% for the high emitters. Differences in emission can be ascribed to the mileage accumulation more than technological improvements. Cold-start emissions account in the USA roughly 10% of emissions from gasoline-powered vehicles. In Mexico the fractions are likely to be higher because one must account also for the contribution of Tier 0 and the running exhausts emissions of vehicles with no catalytic converters. PMID:21046954

  6. 40 CFR 1065.525 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... seconds of cranking, stop cranking and determine why the engine failed to start, unless the owners manual or the service-repair manual describes the longer cranking time as normal. (c) Respond to engine... as recommended in the owners manual using a production starter motor or air-start system and...

  7. 40 CFR 1065.525 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... seconds of cranking, stop cranking and determine why the engine failed to start, unless the owners manual or the service-repair manual describes the longer cranking time as normal. (c) Respond to engine... as recommended in the owners manual using a production starter motor or air-start system and...

  8. 40 CFR 1065.525 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... seconds of cranking, stop cranking and determine why the engine failed to start, unless the owners manual or the service-repair manual describes the longer cranking time as normal. (c) Respond to engine... as recommended in the owners manual using a production starter motor or air-start system and...

  9. Pseudo one-dimensional analysis of polymer electrolyte fuel cell cold-start

    SciTech Connect

    Mukherjee, Partha P; Mukundan, Rangachary; Borup, Rodney L; Wang, Yun; Mishlera, Jeff

    2009-01-01

    This paper investigates the electrochemical kinetics, oxygen transport, and solid water formation in polymer electrolyte fuel cell (PEFC) during cold start. Following [Yo Wang, J. Electrochem. Soc., 154 (2007) B1041-B1048], we develop a pseudo one-dimensional analysis, which enables the evaluation of the impact of ice volume fraction and temperature variations on cell performance during cold-start. The oxygen profile, starvation ice volume fraction, and relevant overpotentials are obtained. This study is valuable for studying the characteristics of PEFC cold-start.

  10. Start Your Engines: Surfing with Search Engines for Kids.

    ERIC Educational Resources Information Center

    Byerly, Greg; Brodie, Carolyn S.

    1999-01-01

    Suggests that to be an effective educator and user of the Web it is essential to know the basics about search engines. Presents tips for using search engines. Describes several search engines for children and young adults, as well as some general filtered search engines for children. (AEF)

  11. Experimental facility and methodology for systematic studies of cold startability in direct injection Diesel engines

    NASA Astrophysics Data System (ADS)

    Pastor, J. V.; García-Oliver, J. M.; Pastor, J. M.; Ramírez-Hernández, J. G.

    2009-09-01

    Cold start at low temperatures in current direct injection (DI) Diesel engines is a problem which has not yet been properly solved and it becomes particularly critical with the current trend to reduce the engine compression ratio. Although it is clear that there are some key factors whose control leads to a proper cold start process, their individual relevance and relationships are not clearly understood. Thus, efforts on optimization of the cold start process are mainly based on a trial-and-error procedure in climatic chambers at low ambient temperature, with serious limitations in terms of measurement reliability during such a transient process, low repeatability and experimental cost. This paper presents a novel approach for an experimental facility capable of simulating real engine cold start, at room temperature and under well-controlled low speed and low temperature conditions. It is based on an optical single cylinder engine adapted to reproduce in-cylinder conditions representative of those of a real engine during start at cold ambient temperatures (of the order of -20 °C). Such conditions must be realistic, controlled and repeatable in order to perform systematic studies in the borderline between ignition success and misfiring. An analysis methodology, combining optical techniques and heat release analysis of individual cycles, has been applied.

  12. Evaluation of resistively heated fuel injection technology to reduce cold start emissions and assist starting/driveaway of a methanol-fueled vehicle

    NASA Astrophysics Data System (ADS)

    Piotrowski, Gregory K.; Schaefer, Ronald M.

    1992-03-01

    The report provides the results from a program to evaluate a set of heated fuel injectors on an M100 fueled vehicle in an attempt to lower cold start emissions of unburned fuel and carbon monoxide and to improve cold start ability and drive ability. This technology was evaluated at several different temperatures.

  13. Engineering Floquet Hamiltonians in Cold Atom Systems

    NASA Astrophysics Data System (ADS)

    Polkovnikov, Anatoli

    2016-05-01

    In this talk I will first give a brief overview of the Floquet theory, describing periodically driven systems. Then I will introduce the concept of the high-frequency expansion and will show how it generalizes the celebrated Schrieffer-Wolff transformation to driven systems. Using these tools I will illustrate how one can engineer non-trivial interacting Hamiltonians mostly in the context of cold atom systems and discuss some experimental examples. In the end I will talk about issues of heating and adiabaticity and show that there are very strong parallels between Floquet systems and disordered systems. In particular, I will argue that the heating transition is closely analogous to the many-body localization transition. AFOSR, ARO, NSF.

  14. Low temperature operation and influence parameters on the cold start ability of portable PEMFCs

    NASA Astrophysics Data System (ADS)

    Oszcipok, M.; Zedda, M.; Riemann, D.; Geckeler, D.

    The start up behaviour of PEM fuel cells below 0 °C is one of the most challenging tasks to be solved before commercialisation. The automotive industry started to develop solutions to reduce the start up time of fuel cell systems in the middle of the nineties. The strategies varied from catalytic combustion of hydrogen on the electrode catalyst to fuel starvation or external stack heating via cooling loops to increase the stack temperature. Beside the automotive sector the cold start ability is as well important for portable PEMFC applications for outdoor use. But here the cold start issue is even more complicated, as the fuel cell system should be operated as passive as possible. Below 0 °C freezing of water inside the PEMFC could form ice layers in the electrode and in the gas diffusion layer. Therefore the cell reaction is limited or even inhibited. Product water during the start up builds additional barriers and leads to a strong decay of the output power at isothermal operating conditions. In order to find out which operational and hardware parameters affect this decay, potentiostatic experiments on single cells were performed at isothermal conditions. These experiments comprise investigations of the influence of membrane thickness and different GDL types as well as the effect of gas flow rates and humidification levels of the membrane. As pre stage to physical based models, empirical based prediction models are used to gain a better understanding of the main influence parameters during cold start. The results are analysed using the statistical software Cornerstone 4.0. The experience of single cell investigations are compared to start up behaviour of portable fuel cell stacks which are operated in a climate chamber at different ambient temperatures below 0 °C. Additional flow sharing problems in the fuel cell stack could be seen during cold start up experiments.

  15. The hard start phenomena in hypergolic engines. Volume 1: Bibliography

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    A bibliography of reports pertaining to the hard start phenomenon in attitude control rocket engines on Apollo spacecraft is presented. Some of the subjects discussed are; (1) combustion of hydrazine, (2) one dimensional theory of liquid fuel rocket combustion, (3) preignition phenomena in small pulsed rocket engines, (4) experimental and theoretical investigation of the fluid dynamics of rocket combustion, and (5) nonequilibrium combustion and nozzle flow in propellant performance.

  16. Cold-Start Emissions Control in Hybrid Vehicles Equipped with a Passive Hydrocarbon and NOx Adsorber

    SciTech Connect

    Gao, Zhiming; Kim, Miyoung; Choi, Jae-Soon; Daw, C Stuart; Parks, II, James E; Smith, David E

    2012-01-01

    We presents a study of the potential for using low-cost sorbent materials (i.e. Ag-Beta-zeolite and Fe-Mn-Zr transition metal oxides) to temporally trap hydrocarbons (HCs) and nitrogen oxides (NOx) emissions during cold-start periods in HEVs and PHEVs over transient driving cycles. The adsorption behavior of the candidate sorbent materials was characterized in our laboratory flow reactor experiments. The parameters were then used to develop a one-dimensional, transient device model which has been implemented in the Powertrain Systems Analysis Toolkit (PSAT) to simulate a passive HC and NOx absorber device. The results show that such an absorber can substantially reduce HC and NOx emissions by storing them when the 3-way catalyst is too cool to function and re-releasing them when the exhaust temperature rises. These improved emission controls do not involve any penalty in fuel consumption or require any change in engine operation. The cost of these sorbent materials is also much less than conventional 3-way catalysts.

  17. Combined manual and power starting device for gasoline engines

    SciTech Connect

    Scheckel, W.D.

    1986-10-07

    A combined manual and power starting device is described for a gasoline engine of a type which may be started by rotating the crankshaft thereof, the starting device comprising: a. a first sleeve mounted rotatably on an extended portion of the crankshaft; b. a first overrunning clutch including a driving member formed by a portion of the first sleeve and a driven member fixed to the crankshaft; c. a second sleeve mounted rotatably and slidably on the first sleeve; d. means biasing the second clutch yieldably to an engaged position; e. a rope pulley rotatably mounted in the engine housing coaxially with the crankshaft, and having axially slidable but non-rotatable connection with the second sleeve, f. a rope wound on the pulley and operable by outward manual tension thereon to turn the crankshaft in an engine-starting direction through both of the first and second clutches. The pulley has a hollow hub through which the crankshaft extension projects outwardly from the engine housing, and g. a drive member affixed to the outwardly extended end of the crankshaft extension and operable to be turned by power means.

  18. The use Na, Li, K cations for modification of ZSM-5 zewolite to control hydrocarbon cold-start emission

    SciTech Connect

    Golubeva V.; Rohatgi U.; Korableva, A.; Anischenko, O.; Kustov, L.; Nissenbaum, V; Viola, M.B.

    2012-08-29

    This paper addresses the problem of controlling hydrocarbon emissions from cold-start of engines by investigating the adsorbents which could adsorb the hydrocarbons at cold temperatures and hold them to 250-300 ?. The materials, that has been studied, are based on the modification of ZSM-5 (SiO{sub 2}/Al{sub 2}O{sub 3} = 35) zeolite with Li, K, Na cations. It has been shown that the introduction of Li, Na and K in an amount that is equivalent to the content of Al in zeolite results in occurrence of toluene temperature desorption peaks at high-temperatures. The toluene temperature desorption curves for 5%Li-ZSM-5 and 2.3%Na-ZSM-5 zeolites are identical and have peak toluene desorption rate between 200 to 400 ?. Upon analysis of toluene adsorption isotherms for 2.3%Na-ZSM-5 and 5%Li-ZSM-5, it was concluded that the toluene diffusion inside of the modified zeolites channels is extremely slow and the sorption capacity of 2.3%Na-ZSM-5 is higher than with 5%Li-ZSM-5. The 2.3%Na-ZSM-5 didn't change toluene temperature programmed desorption (TPD) rate of curve after the treatment in environment with 10% ?{sub 2}? at 750-800 ? for about 28 h. The 2.3%Na-ZSM-5 zeolite is very promising as adsorbent to control the cold-start hydrocarbon emissions.

  19. Ice-Crystallization Kinetics during Fuel-Cell Cold-Start

    NASA Astrophysics Data System (ADS)

    Dursch, Thomas James, Jr.

    Proton-exchange-membrane fuel cells (PEMFCs) show promise in automotive applications because of their high efficiency, high power density, and potentially low emissions. To be successful in automobiles, PEMFCs must permit rapid startup with minimal energy from subfreezing temperatures, known as cold-start. In a PEMFC, reduction of oxygen to water occurs in the cathode catalyst layer (CL). Under subfreezing conditions, water generated during startup solidifies and hinders access of gaseous oxygen to the catalytic sites in the cathode CL, severely inhibiting cell performance and potentially causing cell failure. Achieving cold-start is difficult in practice, due to potential flooding, sluggish reaction kinetics, durability loss, and rapid ice crystallization. Currently, however, few studies focus on the fundamentals of ice crystallization during cold-start. Elucidation of the mechanisms and kinetics of ice formation within PEMFC porous media is, therefore, critical to successful cell startup and high performance at low temperatures. First, an experimental method is presented for obtaining isothermal ice-crystallization kinetics in water-saturated gas-diffusion layers (GDLs). Ice formation is initially studied in the GDL because this layer retains a significant amount of product water during cold-start. Isothermal ice-crystallization and ice-nucleation rates are obtained in commercial Toray GDLs as functions of subcooling using differential scanning calorimetry (DSC). A nonlinear ice-crystallization rate expression is developed using Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory, in which the heat-transfer-limited growth rate is determined from the moving-boundary Stefan problem. Predicted ice-crystallization rates are in excellent agreement with experiment. A validated rate expression is thus available for predicting ice-crystallization kinetics in GDLs. Ice-crystallization kinetics is also considered under experimental settings similar to real PEMFC operating

  20. Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.; DellaCorte, Christopher

    2009-01-01

    Foil gas bearings under development for rotorcraft-sized, hot core engine applications have been susceptible to damage from the slow acceleration and rates typically encountered during the pre-ignition stage in conventional engines. Recent laboratory failures have been assumed to be directly linked to operating foil bearings below their lift-off speed while following conventional startup procedures for the engines. In each instance, the continuous sliding contact between the foils and shaft was believed to thermally overload the bearing and cause the engines to fail. These failures highlight the need to characterize required acceleration rates and minimum operating speeds for these applications. In this report, startup experiments were conducted with a large, rotorcraft engine sized foil bearing under moderate load and acceleration rates to identify the proper start procedures needed to avoid bearing failure. The results showed that a bearing under a 39.4 kPa static load can withstand a modest acceleration rate of 500 rpm/s and excessive loitering below the bearing lift-off speed provided an adequate solid lubricant is present.

  1. On-board generation of a highly volatile starting fuel to reduce automobile cold-start emissions.

    PubMed

    Ashford, Marcus D; Matthews, Ronald D

    2006-09-15

    The on-board distillation system (OBDS) was developed to extract, from gasoline, a high-volatility fuel for exclusive use during the starting and warm-up periods. The use of OBDS distillate fuel results in much improved mixture preparation, allowing combinations of air/fuel ratio and ignition timing that are not possible with gasoline, even with a fully warm engine. The volatility of the distillate is a function of the parent fuel volatility; however, the variability in distillate quality can be diminished via manipulation of the OBDS operating conditions. Thus, it is possible to develop aggressive starting calibrations that are relatively immune to variations in pump gasoline volatility. The key benefits provided bythe OBDS fuel relative to standard gasoline were found to be (1) improved mixture preparation allowing a 70% reduction of cranking fuel requirements, elimination of air-fuel mixture enrichment during the warm-up period, and significant extension of warm-up ignition timing retard; (2) a 57% decrease in catalyst light-off time, (3) emissions reductions over the FTP drive cycle of 81% for regulated hydrocarbons (NMOG); (4) emissions index (NMOG) approaching that of SULEV/PZEV vehicles; and (5) an apparent 1% increase in fuel economy over the FTP drive cycle. PMID:17007139

  2. Ice-Crystallization Kinetics during Fuel-Cell Cold-Start

    NASA Astrophysics Data System (ADS)

    Dursch, Thomas James, Jr.

    Proton-exchange-membrane fuel cells (PEMFCs) show promise in automotive applications because of their high efficiency, high power density, and potentially low emissions. To be successful in automobiles, PEMFCs must permit rapid startup with minimal energy from subfreezing temperatures, known as cold-start. In a PEMFC, reduction of oxygen to water occurs in the cathode catalyst layer (CL). Under subfreezing conditions, water generated during startup solidifies and hinders access of gaseous oxygen to the catalytic sites in the cathode CL, severely inhibiting cell performance and potentially causing cell failure. Achieving cold-start is difficult in practice, due to potential flooding, sluggish reaction kinetics, durability loss, and rapid ice crystallization. Currently, however, few studies focus on the fundamentals of ice crystallization during cold-start. Elucidation of the mechanisms and kinetics of ice formation within PEMFC porous media is, therefore, critical to successful cell startup and high performance at low temperatures. First, an experimental method is presented for obtaining isothermal ice-crystallization kinetics in water-saturated gas-diffusion layers (GDLs). Ice formation is initially studied in the GDL because this layer retains a significant amount of product water during cold-start. Isothermal ice-crystallization and ice-nucleation rates are obtained in commercial Toray GDLs as functions of subcooling using differential scanning calorimetry (DSC). A nonlinear ice-crystallization rate expression is developed using Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory, in which the heat-transfer-limited growth rate is determined from the moving-boundary Stefan problem. Predicted ice-crystallization rates are in excellent agreement with experiment. A validated rate expression is thus available for predicting ice-crystallization kinetics in GDLs. Ice-crystallization kinetics is also considered under experimental settings similar to real PEMFC operating

  3. Assessment and correlation of customer and rater response to cold-start and warmup driveability

    SciTech Connect

    Not Available

    1993-08-01

    A program was conducted from January 14 through March 8, 1991, at Southwest Research Institute (SwRI) in San Antonio, Texas, to establish a relationship between demerits observed in CRC Cold-Start and Warmup Driveability assessments to customer satisfaction levels, and to determine which of several performance deficiencies associated with low volatility gasolines are most troublesome to customers during normal vehicle warmup. Customers used their vehicles in daily service, and a subset of the test fleet was evaluated by trained raters using the established CRC test procedure. There were 7,206 driveability performance assessments by customers which were correlated with 661 trained-rater cold-start driveability evaluations. One hundred sixty-seven SwRI employees participated in the program. Hesitation was the most widely observed problem and was the primary cause of dissatisfaction. The gasoline-ethanol and hydrocarbon-only fuel sets had distinctly different malfunction patterns. Hesitation was strongly associated with gasoline ethanol blends, while surge and stumble were strongly associated with hydrocarbon-only fuels. The current total weighted demerit (TWD) system was found to correlate poorly with customer satisfaction; however, customer observations of problems correlated no better with customer satisfaction. If TWD is to be an indicator of customer perception of driveability performance there should be uniform weighting of rater-observed malfunctions, and start-time should be assigned a greater weighting and a shorter grace period.

  4. Cold Start of a Radiator Equipped with Titanium-Water Heat Pipes

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Sanzi, James L.; Siamidis, John

    2008-01-01

    Radiator panels utilizing titanium-water heat pipes are being considered for lunar applications. A traditional sandwich structure is envisioned where heat pipes are embedded between two high thermal conductivity face sheets. The heat pipe evaporators are to be thermally connected to the heat source through one or more manifolds containing coolant. Initial radiator operation on the lunar surface would likely follow a cold soak where the water in the heat pipes is purposely frozen. To achieve heat pipe operation, it will be necessary to thaw the heat pipes. One option is to allow the sunlight impinging on the surface at sunrise to achieve this goal. Testing was conducted in a thermal vacuum chamber to simulate the lunar sunrise and additional modeling was conducted to identify steady-state and transient response. It was found that sunlight impinging on the radiator surface at sunrise was insufficient to solely achieve the goal of thawing the water in the heat pipes. However, starting from a frozen condition was accomplished successfully by applying power to the evaporators. Start up in this fashion was demonstrated without evaporator dryout. Concern is raised over thawing thermosyphons, vertical heat pipes operating in a gravity field, with no wick in the condenser section. This paper presents the results of the simulated cold start study and identifies future work to support radiator panels equipped with titanium-water heat pipes.

  5. Dielectric heating catalytic converter system for reducing cold-start emissions

    SciTech Connect

    Takatsu, Katsumi; Kurogi, Fumiyasu; Matsue, Akihiro; Kasaya, Masashi

    1996-09-01

    To reduce the harmful pollutants in cold start emissions, this study has been considering microwave dielectric technique for rapid catalyst heating. A dielectric material, having a relatively large loss factor at 2.45GHz was selected. This was coated to the exhaust catalyst allowing microwave energy to be deposited efficiently. The developed system has been tested successfully using a single-mode cavity in conjunction with a model gas. Moreover, a concept for practical in-vehicle system using the microwave heated catalyst has been proposed.

  6. Evidence of cold bubble-like structure in START density limit plasmas

    SciTech Connect

    Ribeiro, C.; Jenkins, I.; Martin, R.; Sykes, A.; Walsh, M. J.

    2008-09-15

    Cold bubble (CB) structures were observed in START density limit studies for the first time in a low aspect ratio tokamak. They seem related to minor and major disruption processes, clearly identified here as a trigger to those events. Enormous discrepancies on the CB velocities in several devices are reported. This shows that the physical mechanisms related to the time scales for its propagation should be revised. Several models related to CB formation and its role in the disruptive process or just in a plasma with the presence of sawteeth qualitatively predict a great part of the observations.

  7. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVIII, I--CATERPILLAR STARTING (PONEY) ENGINE (PART II), II--UNDERSTANDING MORE ABOUT STARTING DEVICES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF DIESEL ENGINE STARTING ENGINES. TOPICS ARE (1) STARTING ENGINE MAGNETO (WICO), (2) MAGNETO MAINTENANCE, (3) SPARK PLUGS, (4) GENERAL DESCRIPTION (STARTING DEVICES), (5) OPERATING (STARTING DEVICES), (6) LUBRICATION (STARTING DEVICES), (7)…

  8. Methane, benzene and alkyl benzene cold start emission data of gasoline-driven passenger cars representing the vehicle technology of the last two decades

    NASA Astrophysics Data System (ADS)

    Heeb, Norbert V.; Forss, Anna-Maria; Saxer, Christian J.; Wilhelm, Patrick

    The US urban driving cycle (FTP-75) is widely used to estimate both the emissions under hot engine conditions as well as those associated with the cold start. Applying fast analysis techniques such as chemical ionization mass spectrometry (CI-MS) the warm-up behavior of individual vehicles can be monitored at a time resolution of 1 s. CI-MS has been used to investigate the emissions of methane, benzene and the alkyl benzene class of compounds. The amount of the emissions at cold start influence was deduced from the time-resolved emission data of four gasoline-driven vehicle classes representing the vehicle technology of the last two decades. Overall, the emissions of five EURO-0, 20 EURO-1, 18 EURO-2 and so far of six EURO-3 passenger cars were recorded. The test vehicles were selected from the currently operating Swiss car fleet based on the car sales statistics. The average methane, benzene and alkyl benzene cold start emissions are reported using both, the traditional bag method as well as the regression model. At room temperature a clear reduction of 94%, 81% and 85% was found for the methane, benzene and alkyl benzene cold start emissions from EURO-0 to EURO-3 technology, respectively.

  9. Cold start dynamics and temperature sliding observer design of an automotive SOFC APU

    NASA Astrophysics Data System (ADS)

    Lin, Po-Hsu; Hong, Che-Wun

    This paper presents a dynamic model for studying the cold start dynamics and observer design of an auxiliary power unit (APU) for automotive applications. The APU is embedded with a solid oxide fuel cell (SOFC) stack which is a quiet and pollutant-free electric generator; however, it suffers from slow start problem from ambient conditions. The SOFC APU system equips with an after-burner to accelerate the start-up transient in this research. The combustion chamber burns the residual fuel (and air) left from the SOFC to raise the exhaust temperature to preheat the SOFC stack through an energy recovery unit. Since thermal effect is the dominant factor that influences the SOFC transient and steady performance, a nonlinear real-time sliding observer for stack temperature was implemented into the system dynamics to monitor the temperature variation for future controller design. The simulation results show that a 100 W APU system in this research takes about 2 min (in theory) for start-up without considering the thermal limitation of the cell fracture.

  10. CuH-ZSM-5 as hydrocarbon trap under cold start conditions.

    PubMed

    Navlani-García, M; Puértolas, B; Lozano-Castelló, D; Cazorla-Amorós, D; Navarro, M V; García, T

    2013-06-01

    Cold start tests are carried out to evaluate the performance of copper-exchanged zeolites as hydrocarbon traps under simulated gasoline car exhaust gases, paying special attention to the role of copper in the performance of these zeolites. It is concluded that the partial substitution of the protons in the parent H-ZSM-5 zeolite is highly beneficial for hydrocarbon trapping due to the formation of selective adsorption sites with specific affinity for the different exhaust components. However, it is also observed that uncontrolled exchanging process conditions could lead to the presence of CuO nanoparticles in the zeolite surface, which seem to block the pore structure of the zeolite, decreasing the hydrocarbon trap efficiency. Among all the zeolites studied, the results point out that a CuH-ZSM-5 with a partial substitution of extra-framework protons by copper cations and without any detectable surface CuO nanoparticles is the zeolite that showed the best performance under simulated cold start conditions due to both the high stability and the hydrocarbon retaining capacity of this sample during the consecutive cycles. PMID:23634959

  11. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Starting systems for internal-combustion engines. 62.35... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...-2/11.11 of the ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 62.05-1)....

  12. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Starting systems for internal-combustion engines. 62.35... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...-2/11.11 of the ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 62.05-1)....

  13. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Starting systems for internal-combustion engines. 62.35... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...-2/11.11 of the ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 62.05-1)....

  14. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Starting systems for internal-combustion engines. 62.35... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...-2/11.11 of the ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 62.05-1)....

  15. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Starting systems for internal-combustion engines. 62.35... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...-2/11.11 of the ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 62.05-1)....

  16. Cold-sensitive mutants of Taq DNA polymerase provide a hot start for PCR

    PubMed Central

    Kermekchiev, Milko B.; Tzekov, Anatoly; Barnes, Wayne M.

    2003-01-01

    Although the thermophilic bacterium Thermus aquaticus grows optimally at 70°C and cannot grow at moderate temperatures, its DNA polymerase I has significant activity at 20–37°C. This activity is a bane to some PCRs, since it catalyzes non-specific priming. We report mutations of Klentaq (an N-terminal deletion variant) DNA polymerase that have markedly reduced activity at 37°C yet retain apparently normal activity at 68°C and resistance at 95°C. The first four of these mutations are clustered on the outside surface of the enzyme, nowhere near the active site, but at the hinge point of a domain that has been proposed to move at each cycle of nucleotide incorporation. We show that the novel cold-sensitive mutants can provide a hot start for PCR and exhibit slightly improved fidelity. PMID:14576300

  17. A Comparison of Hypnotic Induction, Task Motivation, and a "Cold Start" Control Group on Hypnotizability.

    PubMed

    Krystek, Stephen; Kumar, V K

    2016-10-01

    Groups of participants (N = 164) were randomly assigned to three conditions: Group 1 received a trance induction, Group 2 received task-motivational instructions, and Group 3-"cold start" control-was simply told, "We will begin the hypnosis procedure now." All participants received the Creative Imagination Scale suggestions and then completed the Creative Imagination Scale and Inventory Scale of Hypnotic Depth. The three conditions did not differ significantly either on the Creative Imagination Scale or in reported hypnotic depth. These results are consistent with prior studies which show that trance induction and task-motivational yield similar results, but they are inconsistent inasmuch as the trance induction and task-motivational groups did not differ from the control group. These results, however, are predictable from socio-cognitive perspectives that the context of hypnosis itself can elicit hypnotic behaviors. PMID:27586049

  18. The hard start phenomena in hypergolic engines. Volume 3: Physical and combustion characteristics of engine residuals

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    An investigation was conducted to determine the cause of starting problems in the hypergolic rocket engines of the Apollo reaction control (RCS) engines. The scope of the investigation was as follows: (1) to establish that chemical reactions occurred during the preignition and post combustion periods, (2) to identify the chemical species of the products of preignition and post combustion reaction, and (3) to determine the explosive nature of the identified species. The methods used in identifying the chemical products are described species. The infrared spectra, X-ray spectra, and other signatures of the compounds are presented. The physical and explosion characteristics of various hypergolic agents are reported.

  19. Re-Engineering Motherhood? Sure Start in the Community

    ERIC Educational Resources Information Center

    Hey, Valerie; Bradford, Simon

    2006-01-01

    This article draws on data collected through two focus groups and eight telephone interviews undertaken as part of an evaluation of a local Sure Start programme. Located in the context of New Labour's valorisation of parenting, and specifically mothering, the article explores the impact of Sure Start policy on discourses of motherhood in this…

  20. 40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manual and the service repair manual indicate that the longer cranking times are normal. (3) If a failure... started according to the manufacturer's recommended starting procedure in the owner's manual, using either... instructions in the owner's manual, including choke setting and “kick-down” from cold fast idle. (2)...

  1. 40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manual and the service repair manual indicate that the longer cranking times are normal. (3) If a failure... started according to the manufacturer's recommended starting procedure in the owner's manual, using either... instructions in the owner's manual, including choke setting and “kick-down” from cold fast idle. (2)...

  2. 40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manual and the service repair manual indicate that the longer cranking times are normal. (3) If a failure... started according to the manufacturer's recommended starting procedure in the owner's manual, using either... instructions in the owner's manual, including choke setting and “kick-down” from cold fast idle. (2)...

  3. The cold start emissions of light-duty-vehicle fleets: a simplified physics-based model for the estimation of CO₂ and pollutants.

    PubMed

    Weilenmann, Martin F; Soltic, Patrik; Hausberger, Stefan

    2013-02-01

    The emissions from hot driving conditions, in which the exhaust-after-treatment systems are working properly, continue to decrease, which is why the emissions of cold starts have gained in importance. Traffic emission models are used to estimate and predict vehicle fleet emissions and the air quality of countries, regions, cities, etc. In addition to the statistical input of fleet activities, these models are mostly based on the use of separate emission sub-models for hot driving and cold start driving. In reality, the cold start models are almost entirely empirical and of limited accuracy. In this work, a model is developed that is based on physical reasoning, i.e., it is based on energy balances. Because many details, such as the thermal conductivities and the engine control decisions, are unknown, the model must be able to address different simplifications. The model can be parameterized with as few as two tests per vehicle. It is applied to several car samples (six to eight vehicles each) of different technical generations and shows reliable prediction for any combination of the driving pattern (including gradient), the ambient temperature, the stop time before the ride and the duration of the ride (if shorter than the warm-up phase). PMID:23268143

  4. Advanced hydrogen/methanol utilization technology demonstration. Phase II: Hydrogen cold start of a methanol vehicle

    SciTech Connect

    1995-05-01

    This is the Phase 11 Final Report on NREL Subcontract No. XR-2-11175-1 {open_quotes}Advanced Hydrogen/Methane Utilization Demonstration{close_quotes} between the National Renewable Energy Laboratory (NREL), Alternative Fuels Utilization Program, Golden, Colorado and Hydrogen Consultants, Inc. (HCI), Littleton, Colorado. Mr. Chris Colucci was NREL`s Technical Monitor. Colorado State University`s (CSU) Engines and Energy Conversion Laboratory was HCI`s subcontractor. Some of the vehicle test work was carried out at the National Center for Vehicle Emissions Control and Safety (NCVECS) at CSU. The collaboration of the Colorado School of Mines is also gratefully acknowledged. Hydrogen is unique among alternative fuels in its ability to burn over a wide range of mixtures in air with no carbon-related combustion products. Hydrogen also has the ability to burn on a catalyst, starting from room temperature. Hydrogen can be made from a variety of renewable energy resources and is expected to become a widely used energy carrier in the sustainable energy system of the future. One way to make a start toward widespread use of hydrogen in the energy system is to use it sparingly with other alternative fuels. The Phase I work showed that strong affects could be achieved with dilute concentrations of hydrogen in methane (11). Reductions in emissions greater than the proportion of hydrogen in the fuel provide a form of leverage to stimulate the early introduction of hydrogen. Per energy unit or per dollar of hydrogen, a greater benefit is derived than simply displacing fossil-fueled vehicles with pure hydrogen vehicles.

  5. Making a Good Start As an Engineering Manager.

    ERIC Educational Resources Information Center

    Baird, Bruce F.

    1983-01-01

    Provides pointers for the new engineering manager on building self-confidence and establishing positive employer/employee relationships. Includes distinctive traits managers should have, ways to ease frustrations (such as giving a challenging first assignment and recognizing good work), a plan to achieve managerial goals, and relationships with…

  6. Human factors engineering report for the cold vacuum drying facility

    SciTech Connect

    IMKER, F.W.

    1999-06-30

    The purpose of this report is to present the results and findings of the final Human Factors Engineering (HFE) technical analysis and evaluation of the Cold Vacuum Drying Facility (CVDF). Ergonomics issues are also addressed in this report, as appropriate. This report follows up and completes the preliminary work accomplished and reported by the Preliminary HFE Analysis report (SNF-2825, Spent Nuclear Fuel Project Cold Vacuum Drying Facility Human Factors Engineering Analysis: Results and Findings). This analysis avoids redundancy of effort except for ensuring that previously recommended HFE design changes have not affected other parts of the system. Changes in one part of the system may affect other parts of the system where those changes were not applied. The final HFE analysis and evaluation of the CVDF human-machine interactions (HMI) was expanded to include: the physical work environment, human-computer interface (HCI) including workstation and software, operator tasks, tools, maintainability, communications, staffing, training, and the overall ability of humans to accomplish their responsibilities, as appropriate. Key focal areas for this report are the process bay operations, process water conditioning (PWC) skid, tank room, and Central Control Room operations. These key areas contain the system safety-class components and are the foundation for the human factors design basis of the CVDF.

  7. 40 CFR 1065.525 - Engine starting, restarting, shutdown, and optional repeating of void discrete modes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the owners manual or the service-repair manual describes the longer cranking time as normal. (c... engine as recommended in the owners manual using a production starter motor or air-start system...

  8. Artist's concept of Apollo 8 start thrust engine and head for home

    NASA Technical Reports Server (NTRS)

    1968-01-01

    North American Rockwell artist's concept illustrating a phase of the scheduled Apollo 8 lunar orbit mission. Here, after 20 hours of lunar orbit, Apollo 8 astronauts start the 20,500 lb. thrust engine and head for home.

  9. Starting System 2. Repair the Starter Rewind Spring. Student Manual. Small Engine Repair Series. First Edition.

    ERIC Educational Resources Information Center

    Hill, Pamela

    This student manual on repairing the starter rewind spring on a small gas engine is the third of three in an instructional package on the starting system in the Small Engine Repair Series for handicapped students. The stated purpose for the booklet is to help students learn what tools and equipment to use in repairing the starter rewind spring and…

  10. An item-oriented recommendation algorithm on cold-start problem

    NASA Astrophysics Data System (ADS)

    Qiu, Tian; Chen, Guang; Zhang, Zi-Ke; Zhou, Tao

    2011-09-01

    Based on a hybrid algorithm incorporating the heat conduction and probability spreading processes (Proc. Natl. Acad. Sci. U.S.A., 107 (2010) 4511), in this letter, we propose an improved method by introducing an item-oriented function, focusing on solving the dilemma of the recommendation accuracy between the cold and popular items. Differently from previous works, the present algorithm does not require any additional information (e.g., tags). Further experimental results obtained in three real datasets, RYM, Netflix and MovieLens, show that, compared with the original hybrid method, the proposed algorithm significantly enhances the recommendation accuracy of the cold items, while it keeps the recommendation accuracy of the overall and the popular items. This work might shed some light on both understanding and designing effective methods for long-tailed online applications of recommender systems.

  11. Control apparatus for internal combustion engine provided with permanent magnet type starting motor

    SciTech Connect

    Naito, S.; Hasegawa, T.

    1988-03-22

    An apparatus for controlling an internal combustion engine provided with a permanent magnet-type starting motor is described comprising: a magnet switch having a switch contact connected between a power source and the starting motor and coil means including series and shunt coils for actuating the contact, a first electric circuit for supplying an electric current from the power source to the starting motor through a key switch and the series coil, a second electric circuit connecting a junction between the key switch and the series coil to the shunt coil for supplying an electric current from the power source through the key switch to the shunt coil, and start controlling means for controlling a given operation of the engine when the starting motor is actuated to rotate for starting the engine. There are comparator means for comparing a voltage at the junction with a predetermined reference voltage thereby determining whether the starting motor is in a predetermined operating condition or not, and means for actuating the starting controlling means upon detecting that the motor is in the predetermined operating condition.

  12. The hard start phenomena in hypergolic engines. Volume 5: RCS engine deformation and destruct tests

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    Tests were conducted to determine the causes of Apollo Reaction Control (RCS) engine failures. Stainless steel engines constructed for use in the destructive tests are described. The tests conducted during the three phase investigation are discussed. It was determined that the explosive reaction that destroys the RCS engines occurs at the time of engine ignition and is apparently due to either the detonation of the heterogeneous constituents of the rocket engine, consisting primarily of unreacted propellant droplets and vapors, and/or the detonation of explosive materials accumulated on the engine walls from previous pulses. Photographs of the effects of explosions on the simulated RCS engines are provided.

  13. Gas residues of engine starting fluid in postmortem sample from an arsonist.

    PubMed

    Schuberth, J

    1997-01-01

    Diethyl ether was found in samples of the blood, urine, and lung from a fire victim. Because the lung also carried a number of low-boiling paraffins, it was inferred that the detected compounds came from engine starting fluid, which the victim apparently had been exposed to while be intentionally used it as an accelerant to start the fire. The reported death illustrates the value of searching post mortem samples for highly volatile residues of possible arson accelerants. PMID:8988590

  14. Method and apparatus for rapid stopping and starting of a thermoacoustic engine

    DOEpatents

    Swift, Gregory W.; Backhaus, Scott N.; Gardner, David L.

    2003-11-11

    A thermoacoustic engine-driven system with a hot heat exchanger, a regenerator or stack, and an ambient heat exchanger includes a side branch load for rapid stopping and starting, the side branch load being attached to a location in the thermoacoustic system having a nonzero oscillating pressure and comprising a valve, a flow resistor, and a tank connected in series. The system is rapidly stopped simply by opening the valve and rapidly started by closing the valve.

  15. Space Shuttle Main Engine Start with Off-Nominal Propellant Inlet Pressures

    NASA Technical Reports Server (NTRS)

    Bradley, Michael

    1997-01-01

    This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal propellant inlet conditions during the Reusable Launch Vehicle (RLV) evaluation tests. The nominal inlet condition range is: 103 to 111 psia and 170.5 to 178 deg. R for the oxidizer and 43 to 47 psia and 37 to 40 deg. R for the fuel. The SSME start was successfully demonstrated with engine inlet pressures of 50 psia liquid oxygen (LOX) with subcooled LOX at 160 deg R and 38 psia fuel at 38 deg. R. Four tests were used to incrementally modify the start sequence to demonstrate the final goal.

  16. Start up system for hydrogen generator used with an internal combustion engine

    NASA Technical Reports Server (NTRS)

    Houseman, J.; Cerini, D. J. (Inventor)

    1977-01-01

    A hydrogen generator provides hydrogen rich product gases which are mixed with the fuel being supplied to an internal combustion engine for the purpose of enabling a very lean mixture of that fuel to be used, whereby nitrous oxides emitted by the engine are minimized. The hydrogen generator contains a catalyst which must be heated to a pre-determined temperature before it can react properly. To simplify the process of heating up the catalyst at start-up time, either some of the energy produced by the engine such as engine exhaust gas, or electrical energy produced by the engine, or the engine exhaust gas may be used to heat up air which is then used to heat the catalyst.

  17. The hard start phenomena in hypergolic engines. Volume 2: Combustion characteristics of propellants and propellant combinations

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    The combustion characteristics of hypergolic propellants are described. A research project was conducted to determine if the reaction control system engine propellants on Apollo spacecraft undergo explosive reaction when subjected to conditions present in the engine at the time of ignition. Combustion characteristics pertinent to the hard-start phenomenon are considered. The thermal stability of frozen mixtures of hydrazine-based fuels with nitrogen tetroxide was analyzed. Results of the tests are presented in the form of tables and graphs.

  18. Initial duct growth determined from cold-start plasma-line data recorded at Arecibo

    NASA Astrophysics Data System (ADS)

    Muldrew, D. B.

    1992-01-01

    The initial development of the HF-enhanced plasma line in a cold ionosphere is investigated. The plasma line is first observed after 3 ms very close to the HF-reflection height and not at the height expected from weak-turbulence theory in a uniformly varying ionosphere. Natural field-aligned ducts with a diameter of a few meters or more can trap Langmuir waves (L waves) generated by the parametric decay instability and propagating nearly parallel to the magnetic field B. The ponderomotive force of the trapped L waves near the highest HF interference maximum causes electrons to be expelled parallel to B and ions to be expelled perpendicular to B. The ion gyroradius is comparable to the smallest duct diameter than can trap L waves. Since it only takes a few milliseconds for the ions to move at their thermal velocity across the duct, the duct can grow in a few milliseconds to a level where L waves capable of backscattering the Arecibo radar can be trapped. Duct growth is eventually limited by Landau damping and/or escape of the ducted L waves.

  19. Optimization of new magnetorheological fluid mount for vibration control of start/stop engine mode

    NASA Astrophysics Data System (ADS)

    Chung, Jye Ung; Phu, Do Xuan; Choi, Seung-Bok

    2015-04-01

    The technologies related to saving energy/or green vehicles are actively researched. In this tendency, the problem for reducing exhausted gas is in development with various ways. Those efforts are directly related to the operation of engine which emits exhausted gas. The auto start/stop of vehicle engine when a vehicle stop at road is currently as a main stream of vehicle industry resulting in reducing exhausted gas. However, this technology automatically turns on and off engine frequently. This motion induces vehicle engine to transmit vibration of engine which has large displacement, and torsional impact to chassis. These vibrations causing uncomfortable feeling to passengers are transmitted through the steering wheel and the gear knob. In this work, in order to resolve this vibration issue, a new proposed magnetorheological (MR) fluid based engine mount (MR mount in short) is presented. The proposed MR mount is designed to satisfy large damping force in various frequency ranges. It is shown that the proposed mount can have large damping force and large force ratio which is enough to control unwanted vibrations of engine start/stop mode.

  20. Remote temperature measurements of a cold start-up on a low pressure steam turbine using phosphor thermography

    SciTech Connect

    Allison, S.W.; Beshears, D.L.; Cates, M.R.; Cunningham, G.T.; Puri, A.; Schuster, L.

    1995-12-31

    The feasibility of using a noncontact, optical method for temperature measurement based on thermographic phosphors was explored during the cold start-up of a low pressure turbine rotor at the TVA Cumberland Steam Plant. A simple optical system delivered low power laser light to a segment of the balance rim and balance weight holes which were coated with phosphor. From analysis of the laser induced fluorescence, temperatures ranging from 37C (99 F) to 121 C (250 F) were determined. There was no discernible condensation of steam on the viewing port optics. This transient temperature history at the exit end of the LP rotor may help to determine the root cause of a recent blade failure experienced in the L-0 blade row of a unit at this plant during an overspeed test.

  1. Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

    NASA Technical Reports Server (NTRS)

    Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

    2015-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

  2. Tradeoffs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems.

    PubMed

    Wohlfahrt, Georg; Cremonese, Edoardo; Hammerle, Albin; Hörtnagl, Lukas; Galvagno, Marta; Gianelle, Damiano; Marcolla, Barbara; di Cella, Umberto Morra

    2013-12-16

    It is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an elevational gradient in the Alps. To this end we used a simple empirical model of the net ecosystem CO2 exchange, calibrated and forced with multi-year empirical data from each site. We show that reductions in the quantity and duration of daylight associated with earlier snowmelts were responsible for diminishing returns, in terms of carbon gain, from longer growing seasons caused by reductions in daytime photosynthetic uptake and increases in nighttime losses of CO2. This effect was less pronounced at high, compared to low, elevations, where the start of the CUP occurred closer to the summer solstice when changes in day length and incident radiation are minimal. PMID:24587563

  3. Start-up and control method and apparatus for resonant free piston Stirling engine

    DOEpatents

    Walsh, Michael M.

    1984-01-01

    A resonant free-piston Stirling engine having a new and improved start-up and control method and system. A displacer linear electrodynamic machine is provided having an armature secured to and movable with the displacer and having a stator supported by the Stirling engine housing in juxtaposition to the armature. A control excitation circuit is provided for electrically exciting the displacer linear electrodynamic machine with electrical excitation signals having substantially the same frequency as the desired frequency of operation of the Stirling engine. The excitation control circuit is designed so that it selectively and controllably causes the displacer electrodynamic machine to function either as a generator load to extract power from the displacer or the control circuit selectively can be operated to cause the displacer electrodynamic machine to operate as an electric drive motor to apply additional input power to the displacer in addition to the thermodynamic power feedback to the displacer whereby the displacer linear electrodynamic machine also is used in the electric drive motor mode as a means for initially starting the resonant free-piston Stirling engine.

  4. Nonlinear dynamics analysis of a membrane Stirling engine: Starting and stable operation

    NASA Astrophysics Data System (ADS)

    Formosa, Fabien

    2009-10-01

    This paper presents the work devoted to the study of the operation of a miniaturized membrane Stirling engine. Indeed, such an engine relies on the dynamic coupling of the motion of two membranes to achieve a prime mover Stirling thermodynamic cycle. The modelling of the system introduces the large vibration amplitudes of the membrane as well as the nonlinear dissipative effects associated to the fluid flow within the engine. The nonlinearities are expressed as polynomial functions with quadratic and cubic terms. This paper displays the stability analysis to predict the starting of the engine and the instability problem which leads to the steady-state behaviour. The centre manifold-normal form theory is used to obtain the simplest expression for the limit cycle amplitudes. The approach allows the reduction of the number of equations of the original system in order to obtain a simplified system, without loosing the dynamics of the original system as well as the contributions of nonlinear terms. The model intends to be used as a semi-analytical design tool for the optimization of miniaturized Stirling machines from the starting to the steady operation.

  5. Automatic choke and starting aid for small two-cycle internal combustion engines

    SciTech Connect

    Scott, W.A.; Hutchinson, M.A.; Baumbarger, G.L.

    1992-04-14

    This patent describes a starting aid for a small internal combustion engine having a carburetor, a carburetor bore operatively associated with the carburetor and defining a longitudinal axis, the bore having one end in communication with a source of combustion air and another end of the bore in communication with a piston cylinder of the internal combustion engine. It comprises: shaft means for selectively restricting flow of intake air into the engine, means for retaining the shaft means ins aid secondary bore, where the shaft means is prohibited from obstructing air intake into the carburetor bore, and the shaft means rotatable to a second position, where the shaft means obstructs air into the carburetor bore.

  6. Cold flow simulation of an internal combustion engine with vertical valves using layering approach

    NASA Astrophysics Data System (ADS)

    Martinas, G.; Cupsa, O. S.; Stan, L. C.; Arsenie, A.

    2015-11-01

    Complying with emission requirements and fuel consumption efficiency are the points which drive any development of internal combustion engine. Refinement of the process of combustion and mixture formation, together with in-cylinder flow refinement, is a requirement, valves and piston bowl and intake exhaust port design optimization is essential. In order to reduce the time for design optimization cycle it is used Computational Fluid Dynamics (CFD). Being time consuming and highly costly caring out of experiment using flow bench testing this methods start to become less utilized. Air motion inside the intake manifold is one of the important factors, which govern the engine performance and emission of multi-cylinder diesel engines. Any cold flow study on IC is targeting the process of identifying and improving the fluid flow inside the ports and the combustion chamber. This is only the base for an optimization process targeting to increase the volume of air accessing the combustion space and to increase the turbulence of the air at the end of the compression stage. One of the first conclusions will be that the valve diameter is a fine tradeoff between the need for a bigger diameter involving a greater mass of air filling the cylinder, and the need of a smaller diameter in order to reduce the blind zone. Here there is room for optimization studies. The relative pressure indicates a suction effect coming from the moving piston. The more the shape of the inlet port is smoother and the diameter of the piston is bigger, the aerodynamic resistance of the geometry will be smaller so that the difference of inlet port pressure and the pressure near to piston face will be smaller. Here again there is enough room for more optimization studies.

  7. ATLANTA COMMUTE VEHICLE SOAK AND START DISTRIBUTIONS AND ENGINE STARTS PER DAY: IMPACT ON MOBILE SOURCE EMISSION RATES

    EPA Science Inventory

    Georgia Institute of Technology School of Civil and Environmental Engineering researchers analyzed the 2004 vehicle activity data obtained from vehicles in the Atlanta Commuter Choice Value Pricing Initiative. The onboard monitoring equipment installed in each participating vehi...

  8. Exhaust emissions of volatile organic compounds of powered two-wheelers: effect of cold start and vehicle speed. Contribution to greenhouse effect and tropospheric ozone formation.

    PubMed

    Costagliola, M Antonietta; Murena, Fabio; Prati, M Vittoria

    2014-01-15

    Powered two-wheeler (PTW) vehicles complying with recent European type approval standards (stages Euro 2 and Euro 3) were tested on chassis dynamometer in order to measure exhaust emissions of about 25 volatile organic compounds (VOCs) in the range C1-C7, including carcinogenic compounds as benzene and 1,3-butadiene. The fleet consists of a moped (engine capacity ≤ 50 cm(3)) and three fuel injection motorcycles of different engine capacities (150, 300 and 400 cm(3)). Different driving conditions were tested (US FPT cycle, constant speed). Due to the poor control of the combustion and catalyst efficiency, moped is the highest pollutant emitter. In fact, fuel injection strategy and three way catalyst with lambda sensor are able to reduce VOC motorcycles' emission of about one order of magnitude with respect to moped. Cold start effect, that is crucial for the assessment of actual emission of PTWs in urban areas, was significant: 30-51% of extra emission for methane. In the investigated speed range, moped showed a significant maximum of VOC emission factor at minimum speed (10 km/h) and a slightly decreasing trend from 20 to 60 km/h; motorcycles showed on the average a less significant peak at 10 km/h, a minimum at 30-40 km/h and then an increasing trend with a maximum emission factor at 90 km/h. Carcinogenic VOCs show the same pattern of total VOCs. Ozone Formation Potential (OFP) was estimated by using Maximum Incremental Reactivity scale. The greatest contribution to tropospheric ozone formation comes from alkenes group which account for 50-80% to the total OFP. VOC contribution effect on greenhouse effect is negligible with respect to CO2 emitted. PMID:24095967

  9. Engineering, Manufacture and Preliminary Testing of the ITER Toroidal Field (TF) Magnet Helium Cold Circulator

    NASA Astrophysics Data System (ADS)

    Rista, P. E. C.; Shull, J.; Sargent, S.

    2015-12-01

    The ITER cryodistribution system provides the supercritical Helium (SHe) forced flow cooling to the magnet system using cold circulators. The cold circulators are located in each of five separate auxiliary cold boxes planned for use in the facility. Barber-Nichols Inc. has been awarded a contract from ITER-India for engineering, manufacture and testing of the Toroidal Field (TF) Magnet Helium Cold Circulator. The cold circulator will be extensively tested at Barber-Nichols’ facility prior to delivery for qualification testing at the Japan Atomic Energy Agency's (JAEA) test facility at Naka, Japan. The TF Cold Circulator integrates features and technical requirements which Barber-Nichols has utilized when supplying helium cold circulators worldwide over a period of 35 years. Features include a vacuum-jacketed hermetically sealed design with a very low helium leak rate, a heat shield for use with both nitrogen & helium cold sources, a broad operating range with a guaranteed isentropic efficiency over 70%, and impeller design features for high efficiency. The cold circulator will be designed to meet MTBM of 17,500 hours and MTBF of 36,000 hours. Vibration and speed monitoring are integrated into a compact package on the rotating assembly with operation and health monitoring in a multi-drop PROFIBUS communication environment using an electrical cabinet with critical features and full local and network PLC interface and control. For the testing in Japan and eventual installation in Europe, the cold circulator must be certified to the Japanese High Pressure Gas Safety Act (JHPGSA) and CE marked in compliance with the European Pressure Equipment Directive (PED) including Essential Safety Requirements (ESR). The test methodology utilized at Barber-Nichols’ facility and the resulting test data, validating the high efficiency of the TF Cold Circulator across a broad operating range, are important features of this paper.

  10. Getting to First Flight: Equipping Space Engineers to Break the Start-Stop-Restart Cycle

    NASA Technical Reports Server (NTRS)

    Singer, Christopher E.; Dumbacher, Daniel L.

    2010-01-01

    The National Aeronautics and Space Administration s (NASA s) history is built on a foundation of can-do strength, while pointing to the Saturn/Apollo Moon missions in the 1960s and 1970s as its apex a sentiment that often overshadows the potential that lies ahead. The chronicle of America s civil space agenda is scattered with programs that got off to good starts with adequate resources and vocal political support but that never made it past a certain milestone review, General Accountability Office report, or Congressional budget appropriation. Over the decades since the fielding of the Space Shuttle in the early 1980s, a start-stop-restart cycle has intervened due to many forces. Despite this impediment, the workforce has delivered engineering feats such as the International Space Station and numerous Shuttle and science missions, which reflect a trend in the early days of the Exploration Age that called for massive infrastructure and matching capital allocations. In the new millennium, the aerospace industry must respond to transforming economic climates, the public will, national agendas, and international possibilities relative to scientific exploration beyond Earth s orbit. Two pressing issues - workforce transition and mission success - are intertwined. As this paper will address, U.S. aerospace must confront related workforce development and industrial base issues head on to take space exploration to the next level. This paper also will formulate specific strategies to equip space engineers to move beyond the seemingly constant start-stop-restart mentality to plan and execute flight projects that actually fly.

  11. Engineering a substrate-specific cold-adapted subtilisin.

    PubMed

    Tindbaek, Nikolaj; Svendsen, Allan; Oestergaard, Peter Rahbek; Draborg, Henriette

    2004-02-01

    One region predicted to be highly flexible for a psychrophilic enzyme, TA39 subtilisin (S39), was transferred in silico to the mesophilic subtilisin, savinase (EC 3.4.21.62), from Bacillus lentus (clausii). The engineered hybrid and savinase were initially investigated by molecular dynamic simulations at 300 K to show binding region and global flexibility. The predicted S39 region consists of 12 residues, which due to homology between the subtilisins, results in a total change of eight residues. By site-directed modifications, the region was transferred to the binding region of savinase, thus a savinase-S39 hybrid, named H5, was constructed. The designed hybrid showed the same temperature optimum and pH profile as savinase, but H5 had higher specific activity on the synthetic substrate N-succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (AAPF) at all temperatures measured and, at the same time, H5 showed a decrease in thermostability. The H5 hybrid showed broader substrate specificity, measured at room temperature, due to an increase in catalytic efficiency on AAPF, AAPA and FAAF compared with savinase (N-succinyl-XXXX-pNA; XXXX = AAPF, AAPA and FAAF). The H5 hybrid showed increased activity at low temperature, increased binding region and global flexibility, as investigated by molecular dynamic simulations, and global destabilization from differential scanning calorimetry measurements. These psychrophilic characteristics indicated an increase in binding site flexibility, probably due to the modifications P129S, S130G, P131E, and thus we show that it is possible to increase low temperature activity and global flexibility by engineered flexibility in the binding region. PMID:15047911

  12. Effect of Starting Microstructure on the Grain Refinement in Cold-Rolled Low-Carbon Steel During Annealing at Two Different Heating Rates

    NASA Astrophysics Data System (ADS)

    Karmakar, Anish; Mandal, Madhumanti; Mandal, Abhisek; Basiruddin Sk, Md.; Mukherjee, Subrata; Chakrabarti, Debalay

    2016-01-01

    Cold-rolled samples of different starting microstructures, namely ferrite-pearlite (F+P) and ferrite-martensite structures, with blocky martensite (F+Mb) and fibrous martensite (F+Mf) morphologies were reheated at two different heating rates (1 and 300 K/s) to sub-critical and inter-critical annealing temperatures [773 K to 1173 K (500 °C to 900 °C)] and immediately water quenched. Grain refinement after annealing of cold-rolled samples depends on the rate of recovery, recrystallization, transformation, and grain growth. Rapid recrystallization during annealing weakened the recrystallization-transformation interaction in F+P sample. Higher rate of ferrite recovery reduced the driving force for recrystallization, which weakened the recrystallization-transformation interaction during annealing of F+Mb sample. As a result, coarser grain structures were obtained after annealing of cold-rolled F+P and F+Mb starting structures. Strong recrystallization-transformation interaction and suppression of grain growth by uniformly distributed carbide particles and austenite islands (after transformation) offered finest ferrite grain size and best combination of strength and ductility in F+Mf sample.

  13. Starting of rocket engine at conditions of simulated altitude using crude monoethylaniline and other fuels with mixed acid

    NASA Technical Reports Server (NTRS)

    Ladanyi, Dezso J; Sloop, John L; Humphrey, Jack C; Morrell, Gerald

    1950-01-01

    Experiments were conducted at sea level and pressure altitude of about 55,000 feet at various temperatures to determine starting characteristics of a commercial rocket engine using crude monoethylaniline and other fuels with mixed acid. With crude monoethylaniline, ignition difficulties were encountered at temperatures below about 20 degrees F. With mixed butyl mercaptans, water-white turpentine, and x-pinene, no starting difficulties were experienced at temperatures as low as minus 74 degrees F. Turpentine and x-pinene, however, sometimes left deposits on the injector face. With blends containing furfuryl alcohol and with other blends, difficulties were experienced either from appreciable deposits or from starting.

  14. The hard start phenomena in hypergolic engines. Volume 4: The chemistry of hydrazine fuels and nitrogen tetroxide propellant systems

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    The various chemical reactions that occur and that could possibly occur in the RCS engines utilizing hydrazine-type fuel/nitrogen tetroxide propellant systems, prior to ignition (preignition), during combustion, and after combustion (postcombustion), and endeavors to relate the hard-start phenomenon to some of these reactions are discussed. The discussion is based on studies utilizing a variety of experimental techniques and apparatus as well as current theories of chemical reactions and reaction kinetics. The chemical reactions were studied in low pressure gas flow reactors, low temperature homogeneous- and heterogeneous-phase reactors, simulated two-dimensional (2-D) engines, and scaled and full size engines.

  15. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVII, I--CATERPILLAR STARTING (PONEY) ENGINE (PART I), II--LEARNING ABOUT BRAKES (PART II).

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION AND OPERATION OF DIESEL ENGINE STARTING ENGINES AND BRAKE SYSTEMS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) GENERAL DESCRIPTION, (2) OPERATION, (3) COMBUSTION SPACE AND VALVE ARRANGEMENT (STARTING ENGINES), (4) TYPES OF BRAKES, AND (5) DOUBLE…

  16. Proceedings: International Symposium on Thermal Engineering and Science for Cold Regions

    NASA Astrophysics Data System (ADS)

    Lunardini, V. J.; Bowen, S. L.

    This document contains a collection of papers from the Fourth International Symposium on Thermal Engineering and Science for Cold Regions. Topics covered include: some topics on melting heat transfer problems; osmotic model of ice segregation; thermosyphon applications in cold regions; an analytic study of liquid solidification in low Peclet number forced flows inside a parallel plate channel concerning axial heat conduction; freezing within laminar fast-growing thermally developing region of a uniform heat flux cooled parallel plate duct; the morphology of ice layers in curved rectangular channels; effect of heat conductor plates on ice formation near a wall; freezing characteristics of water flow in a horizontal cooled tube with the separated region; stability of thick ice formation in pipes; experiments and analysis of pipe freezing; experimental study of freezing of water in a closed circular tube with pressure increasing; and effects of a porous medium in a flow passage with miter bend.

  17. Starting Early: Increasing Elementary (K-8) Student Science Achievement with Retired Scientists and Engineers

    ERIC Educational Resources Information Center

    Wilson, Judith; Krakowsky, Arthur M.; Herget, Charles J.

    2010-01-01

    Teaching Opportunities for Partners in Science (TOPS) is an outreach program using volunteers (the "partners") for: 1) assisting teachers in grades K-8 with preparation and delivery of science and engineering (S&E) lessons in the classroom; 2) providing content knowledge to teachers when needed to teach quality science and engineering lessons; 3)…

  18. Mach 4 free-jet tunnel starting experiments for a hypersonic research engine model causing high blockage

    NASA Technical Reports Server (NTRS)

    Carson, G. T., Jr.; Midden, R. E.

    1976-01-01

    Tests of a full scale hypersonic research engine (HRE) were conducted in the hypersonic tunnel facility at Mach numbers of 5, 6, and 7. Since the HRE would cause a rather high blockage (48.83 percent of the nozzle area), subscale tests were conducted in various available small wind tunnels prior to the full scale tests to study the effects of model blockage on tunnel starting. The results of the Mach 4 subscale tests which utilized a model system at 0.0952 scale which simulated the HRE in the test section of the tunnel are presented. A satisfactory tunnel starting could not be achieved by varying the free jet length or diffuser size nor by inserting the model into the test stream after tunnel starting. However, the installation of a shroud around the HRE model allowed the tunnel to start with the model preset in the tunnel at a tunnel stagnation pressure to atmospheric exit pressure ratio of 13.4. The simulation of the discharge of instrumentation cooling water and the addition of test hardware at the aft end of the HRE model did not have a significant effect on the tunnel starting.

  19. Novel 3D Tissue Engineered Bone Model, Biomimetic Nanomaterials, and Cold Atmospheric Plasma Technique for Biomedical Applications

    NASA Astrophysics Data System (ADS)

    Wang, Mian

    This thesis research is consist of four chapters, including biomimetic three-dimensional tissue engineered nanostructured bone model for breast cancer bone metastasis study (Chapter one), cold atmospheric plasma for selectively ablating metastatic breast cancer (Chapter two), design of biomimetic and bioactive cold plasma modified nanostructured scaffolds for enhanced osteogenic differentiation of bone marrow derived mesenchymal stem cells (Chapter three), and enhanced osteoblast and mesenchymal stem cell functions on titanium with hydrothermally treated nanocrystalline hydroxyapatite/magnetically treated carbon nanotubes for orthopedic applications (Chapter four). All the thesis research is focused on nanomaterials and the use of cold plasma technique for various biomedical applications.

  20. On the use of cyclostationary indicators in IC engine quality control by cold tests

    NASA Astrophysics Data System (ADS)

    Delvecchio, S.; D'Elia, G.; Dalpiaz, G.

    2015-08-01

    This paper addresses the use of first- and second-order cyclostationary (CS1 and CS2) tools to process the vibration signals picked up from internal combustion (IC) engines during cold tests. This type of analysis is needed in order to detect and diagnose irregular operations for quality control purposes. The effectiveness of indicators such as Mean Instantaneous Power (MIP), Degree of Cyclostationarity (DCSα) and Indicator of Cyclostationarity (ICSnx) in detecting assembly faults has been tested on real signals concerning three faulty conditions: inverted piston, connecting rod with incorrectly tightened screws, connecting rod without one bearing cap. In the past several authors have mainly used cyclostationary metrics for diagnostics purposes in rolling bearings and gear systems. Moreover, a signal model, qualitatively reproducing the features of actual cold test signals, has been formulated and used in order to preliminarily study the influence of signal parameters on the Indicators of Cyclostationarity. The results indicate that the cyclostationary tools - mainly CS2 tools - are effective in detecting and diagnosing all tested faulty conditions. In particular, indicator IC⌢S2x is highly sensitive to faults and it is suitable as pass/fail tool in quality control at the end of the engine assembly line. As a further second-order cyclostationary metric, the MIP is effective for detection, as well for fault identification, since it is able to localize regular and fault events within the engine cycle. In addition DCSα effectively characterizes the CS2 periodicities, giving the cyclic order distribution. Since these CS2 tools require a moderate computation cost, they can be considered ready for on-line industrial applications.

  1. Shuttle Centaur engine cooldown evaluation and effects of expanded inlets on start transient

    NASA Technical Reports Server (NTRS)

    1987-01-01

    As part of the integration of the RL10 engine into the Shuttle Centaur vehicle, a satisfactory method of conditioning the engine to operating temperatures had to be established. This procedure, known as cooldown, is different from the existing Atlas Centaur due to vehicle configuration and mission profile differenced. The program is described, and the results of a Shuttle Centaur cooldown program are reported. Mission peculiarities cause substantial variation in propellant inlet conditions between the substantiated Atlas Centaur and Shuttle Centaur with the Shuttle Centaur having much larger variation in conditions. A test program was conducted to demonstrate operation of the RL10 engine over the expanded inlet conditions. As a result of this program, the Shuttle Centaur requirements were proven satisfactory. Minor configuration changes incorporated as a result of this program provide substantial reduction in cooldown propellant consumption.

  2. Distinctives of High Producers of Minority Science and Engineering Doctoral Starts.

    ERIC Educational Resources Information Center

    Brazziel, William F.; Brazziel, Marian E.

    This study examined the distinctive characteristics of colleges and universities shown to be exceptionally successful in sending underrepresented minorities on to doctoral study in science and engineering. The minorities referred to include Indian, Hispanic, and Black Americans. Primary data for the study were generated by the National Research…

  3. Starting and Teaching Basic Robotics in the Classroom: Modern, Engaging Engineering in Technology Education

    ERIC Educational Resources Information Center

    Bianco, Andrew S.

    2014-01-01

    All technology educators have favorite lessons and projects that they most desire to teach. Many teachers might ask why teach robotics when there are many other concepts to cover with the students? The answer to this question is to engage students in science, technology, engineering, and math (commonly referred to as STEM) concepts. In order for…

  4. Stem Cell Hydrogel, Jump-Starting Zika Drug Discovery, and Engineering RNA Recognition.

    PubMed

    Kostic, Milka

    2016-08-18

    Every month the editors of Cell Chemical Biology bring you highlights of the most recent chemical biology literature that impressed them with creativity and potential for follow up work. Our August 2016 selection includes a description of hydrogels with self-tunable stiffness that are used to profile lipid metabolites during stems cell differentiation, a look at whether we can find a drug repurposing solution to Zika virus infection, and an engineered RNA recognition motif (RRM). PMID:27541191

  5. Nonthermal electron-positron pairs and cold matter in the central engines of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Zdziarski, Andrzej A.

    1992-01-01

    The nonthermal e(+/-) pair model of the central engine of active galactic nuclei (AGNs) is discussed. The model assumes that nonthermal e(+/-) pairs are accelerated to highly relativistic energies in a compact region close to the central black hole and in the vicinity of some cold matter. The model has a small number of free parameters and explains a large body of AGN observations from EUV to soft gamma-rays. In particular, the model explains the existence of the UV bump, the soft X-rays excess, the canonical hard X-ray power law, the spectral hardening above about 10 keV, and some of the variability patterns in the soft and hard X-rays. In addition, the model explains the spectral steepening above about 50 keV seen in NGC 4151.

  6. Operationally Efficient Propulsion System Study (OEPSS) Data Book. Volume 8; Integrated Booster Propulsion Module (BPM) Engine Start Dynamics

    NASA Technical Reports Server (NTRS)

    Kemp, Victoria R.

    1992-01-01

    A fluid-dynamic, digital-transient computer model of an integrated, parallel propulsion system was developed for the CDC mainframe and the SUN workstation computers. Since all STME component designs were used for the integrated system, computer subroutines were written characterizing the performance and geometry of all the components used in the system, including the manifolds. Three transient analysis reports were completed. The first report evaluated the feasibility of integrated engine systems in regards to the start and cutoff transient behavior. The second report evaluated turbopump out and combined thrust chamber/turbopump out conditions. The third report presented sensitivity study results in staggered gas generator spin start and in pump performance characteristics.

  7. Rocket engine plume diagnostics using video digitization and image processing - Analysis of start-up

    NASA Technical Reports Server (NTRS)

    Disimile, P. J.; Shoe, B.; Dhawan, A. P.

    1991-01-01

    Video digitization techniques have been developed to analyze the exhaust plume of the Space Shuttle Main Engine. Temporal averaging and a frame-by-frame analysis provide data used to evaluate the capabilities of image processing techniques for use as measurement tools. Capabilities include the determination of the necessary time requirement for the Mach disk to obtain a fully-developed state. Other results show the Mach disk tracks the nozzle for short time intervals, and that dominate frequencies exist for the nozzle and Mach disk movement.

  8. The New Cold Neutron Radiography Facility (CNRF) at the Mianyang Research Reactor of the China Academy of Engineering Physics

    NASA Astrophysics Data System (ADS)

    Bin, Tang; Heyong, Huo; Ke, Tang; Rogers, John; Haste, Martin; Christodoulou, Marios

    A new cold neutron radiography beamline has been designed and constructed for the Mianyang reactor at the Institute of Nuclear Physics and Chemistry of the China Academy of Engineering Physics. This paper describes the components of the system and demonstrates the achievable image resolution.

  9. Spent nuclear fuel project, Cold Vacuum Drying Facility human factors engineering (HFE) analysis: Results and findings

    SciTech Connect

    Garvin, L.J.

    1998-07-17

    This report presents the background, methodology, and findings of a human factors engineering (HFE) analysis performed in May, 1998, of the Spent Nuclear Fuels (SNF) Project Cold Vacuum Drying Facility (CVDF), to support its Preliminary Safety Analysis Report (PSAR), in responding to the requirements of Department of Energy (DOE) Order 5480.23 (DOE 1992a) and drafted to DOE-STD-3009-94 format. This HFE analysis focused on general environment, physical and computer workstations, and handling devices involved in or directly supporting the technical operations of the facility. This report makes no attempt to interpret or evaluate the safety significance of the HFE analysis findings. The HFE findings presented in this report, along with the results of the CVDF PSAR Chapter 3, Hazards and Accident Analyses, provide the technical basis for preparing the CVDF PSAR Chapter 13, Human Factors Engineering, including interpretation and disposition of findings. The findings presented in this report allow the PSAR Chapter 13 to fully respond to HFE requirements established in DOE Order 5480.23. DOE 5480.23, Nuclear Safety Analysis Reports, Section 8b(3)(n) and Attachment 1, Section-M, require that HFE be analyzed in the PSAR for the adequacy of the current design and planned construction for internal and external communications, operational aids, instrumentation and controls, environmental factors such as heat, light, and noise and that an assessment of human performance under abnormal and emergency conditions be performed (DOE 1992a).

  10. The electromagnetic integrated demonstration at the Idaho National Engineering Laboratory cold test pit

    SciTech Connect

    Pellerin, L.; Alumbaugh, D.L.; Pfeifer, M.C.

    1997-04-01

    The electromagnetic integrated demonstration (EMID) is a baseline study in electromagnetic (EM) exploration of the shallow subsurface (< 10 m). Eleven distinct EM systems, covering the geophysical spectrum, acquired data on a grid over the Idaho National Engineering Laboratory (INEL) Cold Test Pit (CTP). The systems are investigated and evaluated for the purpose of identifying and reviewing existing geophysical characterization instrumentation (commercial and experimental), integrating those technologies with multi-dimensional interpretational algorithms, and identifying gaps in shallow subsurface EM imaging technology. The EMID data, are valuable for testing and evaluating new interpretational software, and developing techniques for integrating multiple datasets. The experimental field techniques shows how the acquisition of data in a variety of array configurations can considerably enhance interpretation. All data are available on the world wide web. Educators and students are encouraged to use the data for both classroom and graduate studies. The purpose of this paper is to explain why, where, how and what kind of data were collected. It is left to the reader to assess the value of a given system for their particular application. Information about the EMID is organized into two general categories: survey description and system evaluation.

  11. Students, Start Your Engines.

    ERIC Educational Resources Information Center

    Cutshall, Sandy

    2003-01-01

    A program offered by the National Hot Rod Association's Youth and Educational Services in conjunction with the U.S. Army enables students to learn how the Army can offer a pathway into auto mechanics and related careers. (JOW)

  12. A parametric starting study of an axial-centrifugal gas turbine engine using a one-dimensional dynamic engine model and comparisons to experimental results. Part 2: Simulation calibration and trade-off study

    SciTech Connect

    Owen, A.K.; Daugherty, A.; Garrard, D.

    1999-07-01

    A generic one-dimensional gas turbine engine model, developed at the Arnold Engineering Development Center, has been configured to represent the gas generator of a General Electric axial-centrifugal gas turbine engine in the six-kg/sec airflow class. The model was calibrated against experimental test results for a variety of initial conditions to insure that the model accurately represented the engine over the range of test conditions of interest. These conditions included both assisted (with a starter motor) and unassisted (altitude windmill) starts. The model was then exercised to study a variety of engine configuration modifications designed to improve its starting characteristics and thus quantify potential starting improvements for the next generation of gas turbine engines. This paper presents the model calibration results and the results of the trade-off study. A companion paper discusses the model development and describes the test facilities used to obtain the calibration data.

  13. FY11 annual Report: PHEV Engine Control and Energy Management Strategy

    SciTech Connect

    Chambon, Paul H

    2011-10-01

    Objectives are to: (1) Investigate novel engine control strategies targeted at rapid engine/catalyst warming for the purpose of mitigating tailpipe emissions from plug-in hybrid electric vehicles (PHEV) exposed to multiple engine cold start events; and (2) Validate and optimize hybrid supervisory control techniques developed during previous and on-going research projects by integrating them into the vehicle level control system and complementing them with the modified engine control strategies in order to further reduce emissions during both cold start and engine re-starts. Approach used are: (1) Perform a literature search of engine control strategies used in conventional powertrains to reduce cold start emissions; (2) Develop an open source engine controller providing full access to engine control strategies in order to implement new engine/catalyst warm-up behaviors; (3) Modify engine cold start control algorithms and characterize impact on cold start behavior; and (4) Develop an experimental Engine-In-the-Loop test stand in order to validate control methodologies and verify transient thermal behavior and emissions of the real engine when combined with a virtual hybrid powertrain. Some major accomplishments are: (1) Commissioned a prototype engine controller on a GM Ecotec 2.4l direct injected gasoline engine on an engine test cell at the University of Tennessee. (2) Obtained from Bosch (with GM's approval) an open calibration engine controller for a GM Ecotec LNF 2.0l Gasoline Turbocharged Direct Injection engine. Bosch will support the bypass of cold start strategies if calibration access proves insufficient. The LNF engine and its open controller were commissioned on an engine test cell at ORNL. (3) Completed a literature search to identify key engine cold start control parameters and characterized their impact on the real engine using the Bosch engine controller to calibrate them. (4) Ported virtual hybrid vehicle model from offline simulation environment to

  14. BENCHMARK EVALUATION OF THE START-UP CORE REACTOR PHYSICS MEASUREMENTS OF THE HIGH TEMPERATURE ENGINEERING TEST REACTOR

    SciTech Connect

    John Darrell Bess

    2010-05-01

    The benchmark evaluation of the start-up core reactor physics measurements performed with Japan’s High Temperature Engineering Test Reactor, in support of the Next Generation Nuclear Plant Project and Very High Temperature Reactor Program activities at the Idaho National Laboratory, has been completed. The evaluation was performed using MCNP5 with ENDF/B-VII.0 nuclear data libraries and according to guidelines provided for inclusion in the International Reactor Physics Experiment Evaluation Project Handbook. Results provided include updated evaluation of the initial six critical core configurations (five annular and one fully-loaded). The calculated keff eigenvalues agree within 1s of the benchmark values. Reactor physics measurements that were evaluated include reactivity effects measurements such as excess reactivity during the core loading process and shutdown margins for the fully-loaded core, four isothermal temperature reactivity coefficient measurements for the fully-loaded core, and axial reaction rate measurements in the instrumentation columns of three core configurations. The calculated values agree well with the benchmark experiment measurements. Fully subcritical and warm critical configurations of the fully-loaded core were also assessed. The calculated keff eigenvalues for these two configurations also agree within 1s of the benchmark values. The reactor physics measurement data can be used in the validation and design development of future High Temperature Gas-cooled Reactor systems.

  15. Influence of amount of starting material for DNA extraction on detection of low-level presence of genetically engineered traits.

    PubMed

    Demeke, Tigst; Phan, Anh; Ratnayaka, Indira; Holigroski, Michelle; Jenkins, G Ronald

    2014-05-14

    Two laboratories independently examined how the amount of starting material influences DNA extraction efficiency and, ultimately, the detection of low-level presence of genetically engineered (GE) traits in commercialized grains. GE traits from one maize, two canola, and two soybean samples were used as prototypical models in the study design as well as two commonly used DNA extraction methods, a small scale (0.1 and 0.2 g samples) and a large scale (1.0 and 2.0 g samples). The DNA samples were fortified (spiked) at 0.1 and 0.01% (w/w) levels. The amount of DNA recovery varied between the two laboratories, although a sufficient amount of DNA was obtained to perform replicate PCR analysis by both laboratories. Reliable detection of all five events was achieved by both laboratories at 0.1% level using either small-scale or large-scale DNA extractions. Reliable detection of the GE events was achieved at 0.01% level for soybean and canola but not for maize. Variability was observed among the two laboratories in terms of the Ct values generated. There was no difference between small-scale and large-scale DNA extraction methods for qualitative PCR detections of all five GE events. PMID:24745691

  16. Starting characteristics and combustion performance of magnesium slurry in 6.5-inch-diameter ram-jet engine mounted in connected-pipe facility

    NASA Technical Reports Server (NTRS)

    Gibbs, James B

    1954-01-01

    The starting characteristics and combustion performance of slurry type fuels, consisting of 50 percent magnesium powder in a hydrocarbon carrier, have been investigated in a flight-type, 6.5-inch-diameter ram-jet engine in a connected-pipe facility. Quick, dependable starting of the engine was obtained by the use of a disk which blocked part of the combustor area downstream of the flame holder. Acceptable performance was achieved with a short fuel-air mixing length by the development of a fuel-distribution control sleeve.

  17. 40 CFR 1065.405 - Test engine preparation and maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... evaporative hydrocarbons for eventual combustion in the engine and the test sequence involves a cold-start or hot-start duty cycle, attach a canister to the engine before running an emission test. You may omit... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Test engine preparation...

  18. Cold weather properties and performance of biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is an alternative fuel made from vegetable oil or animal fat that can be employed in compression-ignition (diesel) engines. Biodiesel is more prone to start-up and operability problems during cold weather than conventional diesel fuels (petrodiesel). This work reviews impacts that exposu...

  19. Evaluation of the Start-Up Core Physics Tests at Japan's High Temperature Engineering Test Reactor (Annular Core Loadings)

    SciTech Connect

    John D. Bess; Nozomu Fujimoto; James W. Sterbentz; Luka Snoj; Atsushi Zukeran

    2010-03-01

    The High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Agency (JAEA) is a 30 MWth, graphite-moderated, helium-cooled reactor that was constructed with the objectives to establish and upgrade the technological basis for advanced high-temperature gas-cooled reactors (HTGRs) as well as to conduct various irradiation tests for innovative high-temperature research. The core size of the HTTR represents about one-half of that of future HTGRs, and the high excess reactivity of the HTTR, necessary for compensation of temperature, xenon, and burnup effects during power operations, is similar to that of future HTGRs. During the start-up core physics tests of the HTTR, various annular cores were formed to provide experimental data for verification of design codes for future HTGRs. The Japanese government approved construction of the HTTR in the 1989 fiscal year budget; construction began at the Oarai Research and Development Center in March 1991 and was completed May 1996. Fuel loading began July 1, 1998, from the core periphery. The first criticality was attained with an annular core on November 10, 1998 at 14:18, followed by a series of start-up core physics tests until a fully-loaded core was developed on December 16, 1998. Criticality tests were carried out into January 1999. The first full power operation with an average core outlet temperature of 850ºC was completed on December 7, 2001, and operational licensing of the HTTR was approved on March 6, 2002. The HTTR attained high temperature operation at 950 ºC in April 19, 2004. After a series of safety demonstration tests, it will be used as the heat source in a hydrogen production system by 2015. Hot zero-power critical, rise-to-power, irradiation, and safety demonstration testing , have also been performed with the HTTR, representing additional means for computational validation efforts. Power tests were performed in steps from 0 to 30 MW, with various tests performed at each step to confirm

  20. Engineering carpel-specific cold stress tolerance: a case study in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Freezing temperatures during winter generally do not injure floral buds of horticulturally important crops. Entry into dormancy coupled with cold acclimation provides adequate protection unless the temperatures are exceptionally low. This measure of protection is lost in spring when the floral bud...

  1. FY12 annual Report: PHEV Engine Control and Energy Management Strategy

    SciTech Connect

    Chambon, Paul H

    2012-05-01

    The objectives are: (1) Investigate novel engine control strategies targeted at rapid engine/catalyst warming for the purpose of mitigating tailpipe emissions from plug-in hybrid electric vehicles (PHEV) exposed to multiple engine cold start events; (2) Optimize integration of engine control strategies with hybrid supervisory control strategies in order to reduce cold start emissions and fuel consumption of PHEVs; and (3) Ensure that development of new vehicle technologies complies with existing emission standards.

  2. Developing scaffolds for tissue engineering using the Ca2+-induced cold gelation by an experimental design approach.

    PubMed

    Ribeiro, Artur J A M; Gomes, Andreia C; Cavaco-Paulo, Artur M

    2012-11-01

    The Ca(2+)-induced cold gelation technique was found suitable to prepare highly porous biodegradable scaffolds based on bovine serum albumin (BSA) and alpha-casein from bovine milk for tissue engineering. A 2(3) full factorial design was used to study the influence and impact of each factor on the several responses of the scaffolds. In vitro degradation (ID), swelling ratio (SR), porosity (PO), and pore size (PS) as well cytotoxicity (CT) were evaluated and shown to be dependent on the pH of sample preparation and on the amount of BSA and casein present, making these scaffolds tunable structures. Under optimized working conditions (4.19% of BSA, 0.69% of Casein, pH 7.07), the ID attained was 37.97%, the SR observed was 11.87, the PO was 82.11%, the PS measured was 180.63 μm at surface, and 175.91 μm at fracture, whereas maximum cell viability was 84% in comparison to controls. Moreover, the scaffold supported cell adhesion and proliferation. These results, consistent with the prediction by the experimental design approach, support the use of this methodology to develop tunable scaffolds for tissue engineering using the Ca(2+)-induced cold gelation. PMID:22987762

  3. Start Your Engines...Start Your Year!

    ERIC Educational Resources Information Center

    Adair, Lila M.; Loveless, Garry C.

    1994-01-01

    Provides a first-week activity in which student groups brainstorm and build cars to win a race. Includes rules, suggestions, time line, and evaluation methods. Notes that many misconceptions may arise from the activity but these are dealt with in the next few weeks of class. (MVL)

  4. The start-up of a gas turbine engine using compressed air tangentially fed onto the blades of the basic turbine

    NASA Technical Reports Server (NTRS)

    Slobodyanyuk, L. K.; Dayneko, V. I.

    1983-01-01

    The use of compressed air was suggested to increase the reliability and motor lifetime of a gas turbine engine. Experiments were carried out and the results are shown in the form of the variation in circumferential force as a function of the entry angle of the working jet onto the turbine blade. The described start-up method is recommended for use with massive rotors.

  5. Turbine for ordnance turbojet engine. 2: Cold-air performance with opened stator

    NASA Technical Reports Server (NTRS)

    Kofskey, M. G.; Nusbaum, W. J.; Haas, J. E.

    1974-01-01

    A single-stage axial-flow turbine was investigated to determine the effect of increased stator throat area on the performance level of a turbojet engine turbine. The stator blades were bent to increase the throat area in order to move the compressor operating point in the engine farther away from surge. Results are compared with those obtained with the as-cast stator setting.

  6. A parametric starting study of an axial-centrifugal gas turbine engine using a one-dimensional dynamic engine model and comparisons to experimental results. Part 1: Model development and facility description

    SciTech Connect

    Owen, A.K.; Daugherty, A.; Garrard, D.

    1999-07-01

    A generic one-dimensional gas turbine engine model, developed at the Arnold Engineering Development Center, has been configured to represent the gas generator of a General Electric axial-centrifugal gas turbine engine in the six kg/sec airflow class. The model was calibrated against experimental test results for a variety of initial conditions to insure that the model accurately represented the engine over the range of test conditions of interest. These conditions included both assisted (with a starter motor) and unassisted (altitude windmill) starts. The model was then exercised to study a variety of engine configuration modifications designed to improve its starting characteristics, and, thus, quantify potential starting improvements for the next generation of gas turbine engines. This paper discusses the model development and describes the test facilities used to obtain the calibration data. The test matrix for the ground level testing is also presented. A companion paper presents the model calibration result and the results of the trade-off study.

  7. 40 CFR 86.008-10 - Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Appendix I of this part with a cold-start according to 40 CFR part 1065, subpart F. This is the cold-start... according to 40 CFR 1065.650. (v) Determine your engine's brake-specific emissions using the following... model year Otto-cycle heavy-duty engines and vehicles. 86.008-10 Section 86.008-10 Protection...

  8. 40 CFR 86.008-10 - Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Appendix I of this part with a cold-start according to 40 CFR part 1065, subpart F. This is the cold-start... according to 40 CFR 1065.650. (v) Determine your engine's brake-specific emissions using the following... model year Otto-cycle heavy-duty engines and vehicles. 86.008-10 Section 86.008-10 Protection...

  9. 40 CFR 86.008-10 - Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Appendix I of this part with a cold-start according to 40 CFR part 1065, subpart F. This is the cold-start... according to 40 CFR 1065.650. (v) Determine your engine's brake-specific emissions using the following... model year Otto-cycle heavy-duty engines and vehicles. 86.008-10 Section 86.008-10 Protection...

  10. 40 CFR 86.008-10 - Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Appendix I of this part with a cold-start according to 40 CFR part 1065, subpart F. This is the cold-start... according to 40 CFR 1065.650. (v) Determine your engine's brake-specific emissions using the following... model year Otto-cycle heavy-duty engines and vehicles. 86.008-10 Section 86.008-10 Protection...

  11. Cold flow simulation of the alternate turbopump development turbine of the Space Shuttle main engine high pressure fuel turbopump

    NASA Astrophysics Data System (ADS)

    Rutkowski, Richard J.

    1994-03-01

    Completion of the installation at the Naval Postgraduate School of a cold-flow test facility for the turbine of the Space Shuttle Main Engine High Pressure Fuel Turbopump is reported. The article to be tested is the first stage of the Alternate Turbopump Development model designed and manufactured by Pratt & Whitney. The purpose of the facility is to enable the development of non-intrusive flow measurements and comparison of those measurements with numerical simulations. Flow field characteristics of the turbine stator were predicted using a three-dimensional viscous flow code. A sensitivity study was conducted to determine the effect of inlet profile to flow field solution. Recommendations are made for future use of the test facility and validation of the numerical simulation scheme.

  12. We Have the Spaceship; But Where's the Start Button: Human Engineering Issues in the Age of Long Duration Space Exploration

    NASA Technical Reports Server (NTRS)

    Hamilton, George S.; Adams, Christopher W.

    2005-01-01

    As long duration space exploration and habitation becomes more commonplace, a number of Human Engineering factors (Gravitational Adaptation, 2-D to 3-D Movement Adaptation, Design Form/Function, and Space Ergonomics to name a few) will become more pronounced. More research and development is needed in these areas or the explorers may find themselves in painful or dangerous situations.

  13. Start Your Search Engines. Part 2: When Image is Everything, Here are Some Great Ways to Find One

    ERIC Educational Resources Information Center

    Adam, Anna; Mowers, Helen

    2008-01-01

    There is no doubt that Google is great for finding images. Simply head to its home page, click the "Images" link, enter criteria in the search box, and--voila! In this article, the authors share some of their other favorite search engines for finding images. To make sure the desired images are available for educational use, consider searching for…

  14. W-026 integrated engineering cold run operational test report for balance of plant (BOP)

    SciTech Connect

    Kersten, J.K.

    1998-02-24

    This Cold Run test is designed to demonstrate the functionality of systems necessary to move waste drums throughout the plant using approved procedures, and the compatibility of these systems to function as an integrated process. This test excludes all internal functions of the gloveboxes. In the interest of efficiency and support of the facility schedule, the initial revision of the test (rev 0) was limited to the following: Receipt and storage of eight overpacked drums, four LLW and four TRU; Receipt, routing, and staging of eleven empty drums to the process area where they will be used later in this test; Receipt, processing, and shipping of two verification drums (Route 9); Receipt, processing, and shipping of two verification drums (Route 1). The above listed operations were tested using the rev 0 test document, through Section 5.4.25. The document was later revised to include movement of all staged drums to and from the LLW and TRU process and RWM gloveboxes. This testing was performed using Sections 5.5 though 5.11 of the rev 1 test document. The primary focus of this test is to prove the functionality of automatic operations for all mechanical and control processes listed. When necessary, the test demonstrates manual mode operations as well. Though the gloveboxes are listed, only waste and empty drum movement to, from, and between the gloveboxes was tested.

  15. Benchmark Evaluation of Start-Up and Zero-Power Measurements at the High-Temperature Engineering Test Reactor

    SciTech Connect

    Bess, John D.; Fujimoto, Nozomu

    2014-10-09

    Benchmark models were developed to evaluate six cold-critical and two warm-critical, zero-power measurements of the HTTR. Additional measurements of a fully-loaded subcritical configuration, core excess reactivity, shutdown margins, six isothermal temperature coefficients, and axial reaction-rate distributions were also evaluated as acceptable benchmark experiments. Insufficient information is publicly available to develop finely-detailed models of the HTTR as much of the design information is still proprietary. However, the uncertainties in the benchmark models are judged to be of sufficient magnitude to encompass any biases and bias uncertainties incurred through the simplification process used to develop the benchmark models. Dominant uncertainties in the experimental keff for all core configurations come from uncertainties in the impurity content of the various graphite blocks that comprise the HTTR. Monte Carlo calculations of keff are between approximately 0.9 % and 2.7 % greater than the benchmark values. Reevaluation of the HTTR models as additional information becomes available could improve the quality of this benchmark and possibly reduce the computational biases. High-quality characterization of graphite impurities would significantly improve the quality of the HTTR benchmark assessment. Simulation of the other reactor physics measurements are in good agreement with the benchmark experiment values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  16. Benchmark Evaluation of Start-Up and Zero-Power Measurements at the High-Temperature Engineering Test Reactor

    DOE PAGESBeta

    Bess, John D.; Fujimoto, Nozomu

    2014-10-09

    Benchmark models were developed to evaluate six cold-critical and two warm-critical, zero-power measurements of the HTTR. Additional measurements of a fully-loaded subcritical configuration, core excess reactivity, shutdown margins, six isothermal temperature coefficients, and axial reaction-rate distributions were also evaluated as acceptable benchmark experiments. Insufficient information is publicly available to develop finely-detailed models of the HTTR as much of the design information is still proprietary. However, the uncertainties in the benchmark models are judged to be of sufficient magnitude to encompass any biases and bias uncertainties incurred through the simplification process used to develop the benchmark models. Dominant uncertainties in themore » experimental keff for all core configurations come from uncertainties in the impurity content of the various graphite blocks that comprise the HTTR. Monte Carlo calculations of keff are between approximately 0.9 % and 2.7 % greater than the benchmark values. Reevaluation of the HTTR models as additional information becomes available could improve the quality of this benchmark and possibly reduce the computational biases. High-quality characterization of graphite impurities would significantly improve the quality of the HTTR benchmark assessment. Simulation of the other reactor physics measurements are in good agreement with the benchmark experiment values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.« less

  17. Analysis of Performance of Jet Engine from Characteristics of Components I : Aerodynamic and Matching Characteristics of Turbine Component Determined with Cold Air

    NASA Technical Reports Server (NTRS)

    Goldstein, Arthur W

    1947-01-01

    The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance. For this ring, the stream-filament method for computing velocity distribution permitted efficient sections to be designed, but the design condition of free-vortex flow with uniform axial velocities was not obtained.

  18. Design study of an advanced gas generator. [which can be ignited during start-up period of turbine engines

    NASA Technical Reports Server (NTRS)

    Kim, S.; Trinh, H. P.

    1993-01-01

    A gas generator which can be ignited reliably during the initial start-up period and offers fairly uniform gas temperature at the exit was studied numerically. Various sizes and shapes of the mixing enhancement devices and their positions were examined to evaluate the uniformity of the exit gas temperature and the change of internal pressure drop incurred by introducing the mixing enhancement devices. By introducing a turbulence ring and a splash plate with an appropriate size and position, it was possible to obtain fairly uniform gas temperature distributions and a maximum gas temperature that is within the design limit temperature of 1600 R at the generator exit. However, with the geometry studied, the pressure drop across the generator was great, approximately 1150 psi, to satisfy the assigned design limit temperature. If the design limit temperature is increased to 1650 R, the pressure drop across the generator could be lowered by as much as 350 psi.

  19. Engineering low-temperature expression systems for heterologous production of cold-adapted enzymes.

    PubMed

    Bjerga, Gro Elin Kjæreng; Lale, Rahmi; Williamson, Adele Kim

    2016-01-01

    Production of psychrophilic enzymes in the commonly used mesophilic expression systems is hampered by low intrinsic stability of the recombinant enzymes at the optimal host growth temperatures. Unless strategies for low-temperature expression are advanced, research on psychrophilic enzymes may end up being biased toward those that can be stably produced in commonly used mesophilic host systems. Two main strategies are currently being explored for the development of low-temperature expression in bacterial hosts: (i) low-temperature adaption of existing mesophilic expression systems, and (ii) development of new psychrophilic hosts. These developments include genetic engineering of the expression cassettes to optimize the promoter/operator systems that regulate heterologous expression. In this addendum we present our efforts in the development of such low-temperature expression systems, and speculate about future advancements in the field and potential applications. PMID:26710170

  20. Cold flow testing of the Space Shuttle Main Engine alternate turbopump development high pressure fuel turbine model

    NASA Astrophysics Data System (ADS)

    Gaddis, Stephen W.; Hudson, Susan T.; Johnson, P. D.

    1992-06-01

    NASA's Marshall Space Flight Center has established a cold airflow turbine test program to experimentally determine the performance of liquid rocket engine turbopump drive turbines. Testing of the SSME alternate turbopump development (ATD) fuel turbine was conducted for back-to-back comparisons with the baseline SSME fuel turbine results obtained in the first quarter of 1991. Turbine performance, Reynolds number effects, and turbine diagnostics, such as stage reactions and exit swirl angles, were investigated at the turbine design point and at off-design conditions. The test data showed that the ATD fuel turbine test article was approximately 1.4 percent higher in efficiency and flowed 5.3 percent more than the baseline fuel turbine test article. This paper describes the method and results used to validate the ATD fuel turbine aerodynamic design. The results are being used to determine the ATD high pressure fuel turbopump (HPFTP) turbine performance over its operating range, anchor the SSME ATD steady-state performance model, and validate various prediction and design analyses.

  1. Cold flow testing of the Space Shuttle Main Engine alternate turbopump development high pressure fuel turbine model

    NASA Technical Reports Server (NTRS)

    Gaddis, Stephen W.; Hudson, Susan T.; Johnson, P. D.

    1992-01-01

    NASA's Marshall Space Flight Center has established a cold airflow turbine test program to experimentally determine the performance of liquid rocket engine turbopump drive turbines. Testing of the SSME alternate turbopump development (ATD) fuel turbine was conducted for back-to-back comparisons with the baseline SSME fuel turbine results obtained in the first quarter of 1991. Turbine performance, Reynolds number effects, and turbine diagnostics, such as stage reactions and exit swirl angles, were investigated at the turbine design point and at off-design conditions. The test data showed that the ATD fuel turbine test article was approximately 1.4 percent higher in efficiency and flowed 5.3 percent more than the baseline fuel turbine test article. This paper describes the method and results used to validate the ATD fuel turbine aerodynamic design. The results are being used to determine the ATD high pressure fuel turbopump (HPFTP) turbine performance over its operating range, anchor the SSME ATD steady-state performance model, and validate various prediction and design analyses.

  2. Sure Start

    ERIC Educational Resources Information Center

    Moss, Peter

    2004-01-01

    This paper outlines what is involved in Sure Start, one of New Labour's key social policy interventions. It is argued that there are policy continuities with older redemptive policies which focus on young children. It is also argued that Sure Start could provide a bridgehead for a more socially democratic orientation into early childhood policy.

  3. Start Up Research Effort in Fluid Mechanics. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzle

    NASA Technical Reports Server (NTRS)

    White, Samuel G.; Gilinsky, Mikhail M.

    1997-01-01

    In accordance with the project plan for the report period in the proposal titled above, HU and FML teams investigated two sets of concepts for reduction of noise and improvement in efficiency for jet exhaust nozzles of aircraft engines and screws for mixers, fans, propellers and boats. The main achievements in the report period are: (a) Publication of the paper in the AIAA Journal, which described our concepts and some results. (b) The Award in the Civil Research and Development Foundation (CRDF) competition. This 2 year grant for Hampton University (HU) and Central AeroHydrodynamic Institute (TSAGI, Moscow, Russia) supports the research implementation under the current NASA FAR grant. (c) Selection for funding by NASA HQ review panel of the Partnership Awards Concept Paper. This two year grant also will support our current FAR grant. (d) Publication of a Mobius Strip concept in NASA Technical Briefs, June, 1996, and a great interest of many industrial companies in this invention. Successful experimental results with the Mobius shaped screw for mixers, which save more than 30% of the electric power by comparison with the standard screws. Creation of the scientific-popular video-film which can be used for commercial and educational purposes. (e) Organization work, joint meetings and discussions of the NASA LARC JNL Team and HU professors and administration for the solution of actual problems and effective work of the Fluid Mechanics Laboratory at Hampton University. In this report the main designs are enumerated. It also contains for both concept sets: (1) the statement of the problem for each design, some results, publications, inventions, patents, our vision for continuation of this research, and (2) present and expected problems in the future.

  4. Genetic engineering of the complete carotenoid pathway towards enhanced astaxanthin formation in Xanthophyllomyces dendrorhous starting from a high-yield mutant.

    PubMed

    Gassel, Sören; Breitenbach, Jürgen; Sandmann, Gerhard

    2014-01-01

    The yeast Xanthophyllomyces dendrorhous is one of the rare organisms which can synthesize the commercially interesting carotenoid astaxanthin. However, astaxanthin yield in wild-type and also in classical mutants is still too low for an attractive bioprocess. Therefore, we combined classical mutagenesis with genetic engineering of the complete pathway covering improved precursor supply for carotenogenesis, enhanced metabolite flow into the pathway, and efficient conversion of intermediates into the desired end product astaxanthin. We also constructed new transformation plasmids for the stepwise expression of the genes of 3-hydroxymethyl-3-glutaryl coenzyme A reductase, geranylgeranyl pyrophosphate synthase, phytoene synthase/lycopene cyclase, and astaxanthin synthase. Starting from two mutants with a 15-fold higher astaxanthin, we obtained transformants with an additional 6-fold increase in the final step of pathway engineering. Thus, a maximum astaxanthin content of almost 9 mg per g dry weight was reached in shaking cultures. Under optimized fermenter conditions, astaxanthin production with these engineered transformants should be comparable to Haematococcus pluvialis, the leading commercial producer of natural astaxanthin. PMID:24241897

  5. The Start of Head Start

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2010-01-01

    The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

  6. Design of a cold-flow test facility for the high pressure fuel turbopump turbine of the Space Shuttle main engine

    NASA Astrophysics Data System (ADS)

    Studevan, Colin C.

    1993-12-01

    The design and installation at the Naval Postgraduate School of a cold-flow test facility for the turbine of the high-pressure fuel turbopump of the Space Shuttle Main Engine, is reported. The specific article to be tested is the 'Alternate Development Model' designed and manufactured by Pratt & Whitney. The design of individual components is documented. The installation of the facility subsystem is described in detail. A preliminary estimation of turbine performance is made.

  7. Start Young!

    ERIC Educational Resources Information Center

    Rubin, Penni

    2002-01-01

    Discusses the importance of early interest in science and how effective it is on career choice in adult stages of life. Recommends starting mathematics and science activities in preschool and kindergarten. Describes how to create a career-oriented learning center in the classroom with examples of kitchen chemistry, nutrition/botany, zoology,…

  8. Start Your Online Testing Engines

    ERIC Educational Resources Information Center

    Fletcher, Geoffrey

    2011-01-01

    Ready or not, educators in most states will soon be asked to implement online testing to meet NCLB or common core standards requirements or simply to make better use of student data and ensure that it is used to improve learning. All but five states--Virginia, Texas, Alaska, Nebraska, and Minnesota--have joined two consortia that will share $350…

  9. Human responses to cold.

    PubMed

    Rintamäki, Hannu

    2007-01-01

    The thermoneutral ambient temperature for naked and resting humans is ca. 27 degrees C. Exposure to cold stimulates cold receptors of the skin which causes cold thermal sensations and stimulation of the sympathetic nervous system. Sympathetic stimulation causes vasoconstriction in skin, arms and legs. Diminished skin and extremity blood flow increases the thermal insulation of superficial tissues more than 300% corresponding to 0.9 clo (0.13 degrees C x m(-2) x W(-1)). With thermoregulatory vasoconstriction/ vasodilatation the body heat balance can be maintained within a range of ca. 4 degrees C, the middle of the range being at ca. 21 degrees C when light clothing is used. Below the thermoneutral zone metabolic heat production (shivering) is stimulated and above the zone starts heat loss by evaporation (sweating). Cold induced vasoconstriction increases blood pressure and viscosity and decreases plasma volume consequently increasing cardiac work. Cold induced hypertensive response can be counteracted by light exercise, while starting heavy work in cold markedly increases blood pressure. Under very cold conditions the sympathetic stimulation opens the anastomoses between arterioles and venules which increases skin temperatures markedly but temporarily, especially in finger tips. Adaptation to cold takes ca. 2 weeks, whereafter the physiological responses to cold are attenuated and cold exposure is subjectively considered less stressful. PMID:17929604

  10. Cold Sores

    MedlinePlus

    ... delivered directly to your desktop! more... What Are Cold Sores? Article Chapters What Are Cold Sores? Cold ... January 2012 Previous Next Related Articles: Canker and Cold Sores Aloe Vera May Help Relieve Mouth Sores ...

  11. Press Start

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    This level sets the stage for the design philosophy called “Triadic Game Design” (TGD). This design philosophy can be summarized with the following sentence: it takes two to tango, but it takes three to design a meaningful game or a game with a purpose. Before the philosophy is further explained, this level will first delve into what is meant by a meaningful game or a game with a purpose. Many terms and definitions have seen the light and in this book I will specifically orient at digital games that aim to have an effect beyond the context of the game itself. Subsequently, a historical overview is given of the usage of games with a serious purpose which starts from the moment we human beings started to walk on our feet till our contemporary society. It turns out that we have been using games for all kinds of non-entertainment purposes for already quite a long time. With this introductory material in the back of our minds, I will explain the concept of TGD by means of a puzzle. After that, the protagonist of this book, the game Levee Patroller, is introduced. Based on the development of this game, the idea of TGD, which stresses to balance three different worlds, the worlds of Reality, Meaning, and Play, came into being. Interested? Then I suggest to quickly “press start!”

  12. In-Situ Agglomeration and De-agglomeration by Milling of Nano-Engineered Lubricant Particulate Composites for Cold Spray Deposition

    NASA Astrophysics Data System (ADS)

    Neshastehriz, M.; Smid, I.; Segall, A. E.

    2014-10-01

    Nano-engineered self-lubricating particles comprised of hexagonal-boron-nitride powder (hBN) encapsulated in nickel have been developed for cold spray coating of aluminum components. The nickel encapsulant consists of several nano-sized layers, which are deposited on the hBN particles by electroless plating. In the cold spray deposition, the nickel becomes the matrix in which hBN acts as the lubricant. The coating demonstrated a very promising performance by reducing the coefficient of friction by almost 50% and increasing the wear resistance more than tenfold. The coatings also exhibited higher bond strength, which was directly related to the hardenability of the particles. During the encapsulation process, the hBN particles agglomerate and form large clusters. De-agglomeration has been studied through low- and high-energy ball milling to create more uniform and consistent particle sizes and to improve the cold spray deposition efficiency. The unmilled and milled particles were characterized with Scanning Electron Microscopy, Energy-Dispersive X-Ray Spectroscopy, BET, and hardness tests. It was found that in low-energy ball milling, the clusters were compacted to a noticeable extent. However, the high-energy ball milling resulted in breakup of agglomerations and destroyed the nickel encapsulant.

  13. Comparison of effect of a turbojet engine and three cold-flow configurations on the stability of a full-scale supersonicle inlet

    NASA Technical Reports Server (NTRS)

    Musial, Norman T

    1957-01-01

    Increasing the volume and length of the duct behind the inlet affected the inlet stability at Mach 2.0 and zero angle of attack. Close approximation of the inlet stability limit of the J34 engine-inlet configuration was obtained by a cold-pipe configuration having a length and volume approaching that measured to the engine turbine. Variation of these parameters had a small effect on the minimum subcritical stable mass flow below a cowl-lip-position parameter of 44 degrees and appeared to have a negligible effect on the inlet pressure-recovery - mass-flow curve. Initial buzz frequency and minimum cowl-lip-position parameter for complete buzz-free operation varied with configuration.

  14. Common cold

    MedlinePlus

    ... are the most common reason that children miss school and parents miss work. Parents often get colds ... other children. A cold can spread quickly through schools or daycares. Colds can occur at any time ...

  15. Common Cold

    MedlinePlus

    ... coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In ... people in the United States suffer 1 billion colds. You can get a cold by touching your ...

  16. Cold Stress

    MedlinePlus

    ... be at risk of cold stress. Extreme cold weather is a dangerous situation that can bring on ... the country. In regions relatively unaccustomed to winter weather, near freezing temperatures are considered factors for cold ...

  17. Cold intolerance

    MedlinePlus

    ... intolerance is an abnormal sensitivity to a cold environment or cold temperatures. ... can be a symptom of a problem with metabolism. Some people (often very thin women) do not tolerate cold environments because they have very little body fat and ...

  18. Injector spray characterization of methanol in reciprocating engines

    SciTech Connect

    Dodge, L.; Naegeli, D.

    1994-06-01

    This report covers a study that addressed cold-starting problems in alcohol-fueled, spark-ignition engines by using fine-spray port-fuel injectors to inject fuel directly into the cylinder. This task included development and characterization of some very fine-spray, port-fuel injectors for a methanol-fueled spark-ignition engine. After determining the spray characteristics, a computational study was performed to estimate the evaporation rate of the methanol fuel spray under cold-starting and steady-state conditions.

  19. Reuse fo a Cold War Surveillance Drone to Flight Test a NASA Rocket Based Combined Cycle Engine

    NASA Technical Reports Server (NTRS)

    Brown, T. M.; Smith, Norm

    1999-01-01

    Plans for and early feasibility investigations into the modification of a Lockheed D21B drone to flight test the DRACO Rocket Based Combined Cycle (RBCC) engine are discussed. Modifications include the addition of oxidizer tanks, modern avionics systems, actuators, and a vehicle recovery system. Current study results indicate that the D21B is a suitable candidate for this application and will allow demonstrations of all DRACO engine operating modes at Mach numbers between 0.8 and 4.0. Higher Mach numbers may be achieved with more extensive modification. Possible project risks include low speed stability and control, and recovery techniques.

  20. 2. VIEW NORTHWEST FROM LEFT TO RIGHT: COLD CALIBRATION BLOCKHOUSE, ...

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

    2. VIEW NORTHWEST FROM LEFT TO RIGHT: COLD CALIBRATION BLOCKHOUSE, COLD CALIBRATION TEST STAND FOR FL ENGINE FOR SATURN V. EXHAUST DUCT IN FOREGROUND. - Marshall Space Flight Center, East Test Area, Cold Calibration Test Stand, Huntsville, Madison County, AL

  1. Common Cold

    MedlinePlus

    ... News & Events Volunteer NIAID > Health & Research Topics > Common Cold Skip Website Tools Website Tools Print this page ... Help people who are suffering from the common cold by volunteering for NIAID clinical studies on ClinicalTrials. ...

  2. We Have the Spaceship; But Where's the Start Button: Human Engineering Issues in the Age of Long Duration Space Exploration - Presentation

    NASA Technical Reports Server (NTRS)

    Hamilton, George; Adams, Chris

    2005-01-01

    This viewgraph presentation addresses the following considerations for human factors engineering during long duration human space flight: gravitational adaptation, 2-D to 3-D adaptation, handles, exercise posture, and space ergonomics. The presentation argues that there is an urgent need to advance research is these areas in preparation for future manned missions.

  3. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  4. Automotive Stirling engine systems development

    NASA Technical Reports Server (NTRS)

    Richey, A. E.

    1984-01-01

    The objective of the Automotive Stirling Engine (ASE) program is to develop a Stirling engine for automotive use that provides a 30 percent improvement in fuel economy relative to a comparable internal-combustion engine while meeting emissions goals. This paper traces the engine systems' development efforts focusing on: (1) a summary of engine system performance for all Mod I engines; (2) the development, program conducted for the upgraded Mod I; and (3) vehicle systems work conducted to enhance vehicle fuel economy. Problems encountered during the upgraded Mod I test program are discussed. The importance of the EPA driving cycle cold-start penalty and the measures taken to minimize that penalty with the Mod II are also addressed.

  5. The Starting Early Starting Smart Story.

    ERIC Educational Resources Information Center

    Casey Family Programs, Seattle, WA.

    Starting Early Starting Smart (SESS) is an early childhood public/private initiative designed to identify new, empirical knowledge about the effectiveness of integrating substance abuse prevention, addictions treatment, and mental health services with primary health care and childcare service settings (e.g., Head Start, day care, preschool) to…

  6. 40 CFR 86.1337-2007 - Engine dynamometer test run.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... heat exchanger of the constant volume sampler (if used), and the heated components of any continuous..., transfer the “cold start cycle” exhaust and dilution air bag samples to the analytical system and process... particulate sample pump(s), if applicable), the engine cooling fan(s) and the data collection system. The...

  7. 40 CFR 86.1337-2007 - Engine dynamometer test run.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... heat exchanger of the constant volume sampler (if used), and the heated components of any continuous..., transfer the “cold start cycle” exhaust and dilution air bag samples to the analytical system and process... particulate sample pump(s), if applicable), the engine cooling fan(s) and the data collection system. The...

  8. 40 CFR 86.1337-2007 - Engine dynamometer test run.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... heat exchanger of the constant volume sampler (if used), and the heated components of any continuous..., transfer the “cold start cycle” exhaust and dilution air bag samples to the analytical system and process... particulate sample pump(s), if applicable), the engine cooling fan(s) and the data collection system. The...

  9. 40 CFR 86.1337-96 - Engine dynamometer test run.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... system. The heat exchanger of the constant volume sampler (if used), and the heated components of any... system from the CVS). As soon as possible, transfer the “cold start cycle” exhaust and dilution air bag... applicable), the engine cooling fan(s) and the data collection system. The heat exchanger of the...

  10. 40 CFR 86.1337-96 - Engine dynamometer test run.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... system. The heat exchanger of the constant volume sampler (if used), and the heated components of any... system from the CVS). As soon as possible, transfer the “cold start cycle” exhaust and dilution air bag... applicable), the engine cooling fan(s) and the data collection system. The heat exchanger of the...

  11. 40 CFR 86.1337-96 - Engine dynamometer test run.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... system. The heat exchanger of the constant volume sampler (if used), and the heated components of any... system from the CVS). As soon as possible, transfer the “cold start cycle” exhaust and dilution air bag... applicable), the engine cooling fan(s) and the data collection system. The heat exchanger of the...

  12. 40 CFR 86.008-10 - Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... forth in paragraph (f)(1) of Appendix I of this part with a cold-start according to 40 CFR part 1065... work, W, over each test interval according to 40 CFR 1065.650. (v) Determine your engine's brake...-start test intervals: ER30AP10.000 (3)-(4) (b) This paragraph (b) applies as specified in 40 CFR...

  13. Salinity tolerance in plants. Quantitative approach to ion transport starting from halophytes and stepping to genetic and protein engineering for manipulating ion fluxes

    PubMed Central

    Volkov, Vadim

    2015-01-01

    Ion transport is the fundamental factor determining salinity tolerance in plants. The Review starts from differences in ion transport between salt tolerant halophytes and salt-sensitive plants with an emphasis on transport of potassium and sodium via plasma membranes. The comparison provides introductory information for increasing salinity tolerance. Effects of salt stress on ion transport properties of membranes show huge opportunities for manipulating ion fluxes. Further steps require knowledge about mechanisms of ion transport and individual genes of ion transport proteins. Initially, the Review describes methods to measure ion fluxes, the independent set of techniques ensures robust and reliable basement for quantitative approach. The Review briefly summarizes current data concerning Na+ and K+ concentrations in cells, refers to primary thermodynamics of ion transport and gives special attention to individual ion channels and transporters. Simplified scheme of a plant cell with known transport systems at the plasma membrane and tonoplast helps to imagine the complexity of ion transport and allows choosing specific transporters for modulating ion transport. The complexity is enhanced by the influence of cell size and cell wall on ion transport. Special attention is given to ion transporters and to potassium and sodium transport by HKT, HAK, NHX, and SOS1 proteins. Comparison between non-selective cation channels and ion transporters reveals potential importance of ion transporters and the balance between the two pathways of ion transport. Further on the Review describes in detail several successful attempts to overexpress or knockout ion transporters for changing salinity tolerance. Future perspectives are questioned with more attention given to promising candidate ion channels and transporters for altered expression. Potential direction of increasing salinity tolerance by modifying ion channels and transporters using single point mutations is discussed and

  14. Common cold

    MedlinePlus

    ... often causes a runny nose, nasal congestion, and sneezing. You may also have a sore throat, cough, ... symptoms are: Nasal congestion Runny nose Scratchy throat Sneezing Adults and older children with colds generally have ...

  15. Cold Intolerance

    MedlinePlus

    ... from the Handbook on the Late Effects of Poliomyelitis for Physicians and Survivors © Cold Intolerance Many polio ... index of Handbook on the Late Effects of Poliomyelitis for Physicians and Survivors © Back to top Contact ...

  16. Cold injuries.

    PubMed

    Long, William B; Edlich, Richard F; Winters, Kathryne L; Britt, L D

    2005-01-01

    Exposure to cold can produce a variety of injuries that occur as a result of man's inability to adapt to cold. These injuries can be divided into localized injury to a body part, systemic hypothermia, or a combination of both. Body temperature may fall as a result of heat loss by radiation, evaporation, conduction, and convection. Hypothermia or systemic cold injury occurs when the core body temperature has decreased to 35 degrees C (95 degrees F) or less. The causes of hypothermia are either primary or secondary. Primary, or accidental, hypothermia occurs in healthy individuals inadequately clothed and exposed to severe cooling. In secondary hypothermia, another illness predisposes the individual to accidental hypothermia. Hypothermia affects multiple organs with symptoms of hypothermia that vary according to the severity of cold injury. The diagnosis of hypothermia is easy if the patient is a mountaineer who is stranded in cold weather. However, it may be more difficult in an elderly patient who has been exposed to a cold environment. In either case, the rectal temperature should be checked with a low-reading thermometer. The general principals of prehospital management are to (1) prevent further heat loss, (2) rewarm the body core temperature in advance of the shell, and (3) avoid precipitating ventricular fibrillation. There are two general techniques of rewarming--passive and active. The mechanisms of peripheral cold injury can be divided into phenomena that affect cells and extracellular fluids (direct effects) and those that disrupt the function of the organized tissue and the integrity of the circulation (indirect effects). Generally, no serious damage is seen until tissue freezing occurs. The mildest form of peripheral cold injury is frostnip. Chilblains represent a more severe form of cold injury than frostnip and occur after exposure to nonfreezing temperatures and damp conditions. Immersion (trench) foot, a disease of the sympathetic nerves and blood

  17. E85 Optimized Engine

    SciTech Connect

    Bower, Stanley

    2011-12-31

    A 5.0L V8 twin-turbocharged direct injection engine was designed, built, and tested for the purpose of assessing the fuel economy and performance in the F-Series pickup of the Dual Fuel engine concept and of an E85 optimized FFV engine. Additionally, production 3.5L gasoline turbocharged direct injection (GTDI) EcoBoost engines were converted to Dual Fuel capability and used to evaluate the cold start emissions and fuel system robustness of the Dual Fuel engine concept. Project objectives were: to develop a roadmap to demonstrate a minimized fuel economy penalty for an F-Series FFV truck with a highly boosted, high compression ratio spark ignition engine optimized to run with ethanol fuel blends up to E85; to reduce FTP 75 energy consumption by 15% - 20% compared to an equally powered vehicle with a current production gasoline engine; and to meet ULEV emissions, with a stretch target of ULEV II / Tier II Bin 4. All project objectives were met or exceeded.

  18. Head Start Facilities Manual.

    ERIC Educational Resources Information Center

    Research Assessment Management, Inc., Silver Spring, MD.

    A quality Head Start facility should provide a physical environment responsive both to the needs of the children and families served and to the needs of staff, volunteers, and community agencies that share space with Head Start. This manual is a tool for Head Start grantees and delegate agencies for assessing existing facilities, making…

  19. The Head Start Debates

    ERIC Educational Resources Information Center

    Zigler, Edward, Ed.; Styfco, Sally J., Ed.

    2004-01-01

    The future of Head Start depends on how well people learn from and apply the lessons from its past. That's why everyone involved in early education needs this timely, forward-thinking book from the leader of Head Start. The first book to capture the Head Start debates in all their complexity and diversity, this landmark volume brings together the…

  20. COLD TRAP

    DOEpatents

    Milleron, N.

    1963-03-12

    An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

  1. The Cold War: A Yearbook Perspective.

    ERIC Educational Resources Information Center

    Graebner, William

    1986-01-01

    Shows how the photographs, valedictorian addresses, nicknames, cartoons and other material contained in high school yearbook can yield information regarding the world views of Americans at the start of the Cold War. (JDH)

  2. Ladies and Gentlemen, Start Your Engines.

    ERIC Educational Resources Information Center

    Cates, Ward Mitchell

    1983-01-01

    An approach to problem solving is described that is based on analysis of how fast model race cars can go. The exercises were used to replace standard time/rate/distance exercises, and were found to be greatly enjoyed by both girls and boys. (MP)

  3. The Origins of the Cold War.

    ERIC Educational Resources Information Center

    Paterson, Thomas G.

    1986-01-01

    Briefly reviews conventional reasoning about the start of the Cold War. Describes contemporary revisionist views of the Cold War and the reasons they arose. Maintains that American leaders exaggerated the Soviet ideological and military threat, spurring an American arms build-up which ultimately led to the present-day arms race. (JDH)

  4. Project COLD.

    ERIC Educational Resources Information Center

    Kazanjian, Wendy C.

    1982-01-01

    Describes Project COLD (Climate, Ocean, Land, Discovery) a scientific study of the Polar Regions, a collection of 35 modules used within the framework of existing subjects: oceanography, biology, geology, meterology, geography, social science. Includes a partial list of topics and one activity (geodesic dome) from a module. (Author/SK)

  5. Cold Sores

    MedlinePlus

    ... causes oral herpes, or cold sores. Type 1 herpes virus infects more than half of the U.S. population by the time they reach their 20s. Type 2 usually affects the genital area Some people have no symptoms from the ...

  6. DIESEL ENGINE EFFICIENCY AND EMISSIONS IMPROVEMENT VIA PISTON TEMPERATURE CONTROL - PHASE I

    EPA Science Inventory

    Diesel engine manufacturers need a way to improve fuel economy as well as limit NOx and particulate emissions to meet upcoming federal, state and global regulations. A large percentage of emissions and fuel consumption occurs during cold start and light to medium load ope...

  7. 46 CFR 112.50-3 - Hydraulic starting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hydraulic starting. 112.50-3 Section 112.50-3 Shipping... POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the following: (a) The hydraulic starting system must be...

  8. Bacterial start site prediction.

    PubMed

    Hannenhalli, S S; Hayes, W S; Hatzigeorgiou, A G; Fickett, J W

    1999-09-01

    With the growing number of completely sequenced bacterial genes, accurate gene prediction in bacterial genomes remains an important problem. Although the existing tools predict genes in bacterial genomes with high overall accuracy, their ability to pinpoint the translation start site remains unsatisfactory. In this paper, we present a novel approach to bacterial start site prediction that takes into account multiple features of a potential start site, viz., ribosome binding site (RBS) binding energy, distance of the RBS from the start codon, distance from the beginning of the maximal ORF to the start codon, the start codon itself and the coding/non-coding potential around the start site. Mixed integer programing was used to optimize the discriminatory system. The accuracy of this approach is up to 90%, compared to 70%, using the most common tools in fully automated mode (that is, without expert human post-processing of results). The approach is evaluated using Bacillus subtilis, Escherichia coli and Pyrococcus furiosus. These three genomes cover a broad spectrum of bacterial genomes, since B.subtilis is a Gram-positive bacterium, E.coli is a Gram-negative bacterium and P. furiosus is an archaebacterium. A significant problem is generating a set of 'true' start sites for algorithm training, in the absence of experimental work. We found that sequence conservation between P. furiosus and the related Pyrococcus horikoshii clearly delimited the gene start in many cases, providing a sufficient training set. PMID:10446249

  9. Hot, Cold, and Really Cold.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

    Describes a physics experiment investigating temperature prediction and the relationship between the physical properties of heat units, melting, dissolving, states of matter, and energy loss. Details the experimental setup, which requires hot and cold water, a thermometer, and ice. Notes that the experiment employs a deliberate counter-intuitive…

  10. Smart Start News, 1999.

    ERIC Educational Resources Information Center

    Harris, Monica, Ed.

    1999-01-01

    Smart Start is a comprehensive public-private initiative to help all North Carolina children enter school healthy and ready to succeed, and provides children from birth to age five access to high-quality and affordable child care, health care, and other critical services. This document comprises the first two issues of "Smart Start News," a…

  11. Starting School in August

    ERIC Educational Resources Information Center

    Chmelynski, Carol

    2006-01-01

    In this article, the author discusses the controversial decision of the school board from the Broward County, Florida to start the school year on August 9. School boards across the country that are grappling with the idea of starting school earlier in the year are increasingly running up against strong opposition from parents. In many districts,…

  12. Start with Science

    ERIC Educational Resources Information Center

    Erickson, Susan

    2012-01-01

    The author has found over her 13 years of teaching that starting off the school year with a science investigation has been a great method to learn about her students, to engage them about science before the school year even starts, and to build a foundation for a year of engaging science experiences. This article describes four such activities…

  13. Chilling Out with Colds

    MedlinePlus

    ... most common cold virus, but more than 200 viruses can cause colds. Because there are so many, ... to help you feel better. Take that, cold viruses! continue How Kids Catch Colds Mucus (say: MYOO- ...

  14. Coping with Cold Sores

    MedlinePlus

    ... Here's Help White House Lunch Recipes Coping With Cold Sores KidsHealth > For Kids > Coping With Cold Sores ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

  15. Engine

    SciTech Connect

    Shin, H.B.

    1984-02-28

    An internal combustion engine has a piston rack depending from each piston. This rack is connected to a power output shaft through a mechanical rectifier so that the power output shaft rotates in only one direction. A connecting rod is pivotally connected at one end to the rack and at the other end to the crank of a reduced function crankshaft so that the crankshaft rotates at the same angular velocity as the power output shaft and at the same frequency as the pistons. The crankshaft has a size, weight and shape sufficient to return the pistons back into the cylinders in position for the next power stroke.

  16. COLD TRAPS

    DOEpatents

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  17. Heat storage for a bus petrol internal-combustion engine

    NASA Astrophysics Data System (ADS)

    Vasiliev, Leonard L.; Burak, Victor S.; Kulakov, Andry G.; Mishkinis, Donatas A.; Bohan, Pavel V.

    The heat storage (HS) system for pre-heating a bus petrol internal combustion engine to starting was mathematically modelled and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with a cold climate. We discuss how HS works on the effect of absorption and rejection of heat energy at a solid-liquid phase change of a HS substance. In the first part of the paper a numerical method to calculate the HS mass-dimensional parameters and their characteristics are described. In the experimental part of the paper results are given of experiments on the pre-heating device aiding to start a carburettor engine under operational conditions and analysis of data received. Practical confirmation of the theoretical development of HS devices for a bus engine for starting by pre-heating is given.

  18. Cold-air performance of compressor-drive turbine of Department of Energy upgraded automobile gas turbine engine. 1: Volute-manifold and stator performance

    NASA Technical Reports Server (NTRS)

    Roelke, R. J.; Haas, J. E.

    1981-01-01

    The aerodynamic performance of the inlet manifold and stator assembly of the compressor drive turbine was experimentally determined with cold air as the working fluid. The investigation included measurements of mass flow and stator-exit fluid torque as well as radial surveys of total pressure and flow angle at the stator inlet and annulus surveys of total pressure and flow angle at the stator exit. The stator-exit aftermixed flow conditions and overall stator efficiency were obtained and compared with their design values and the experimental results from three other stators. In addition, an analysis was made to determine the constituent aerodynamic losses that made up the stator kinetic energy loss.

  19. Cold-air performance of a 15.41-cm-tip-diameter axial-flow power turbine with variable-area stator designed for a 75-kW automotive gas turbine engine

    NASA Technical Reports Server (NTRS)

    Mclallin, K. L.; Kofskey, M. G.; Wong, R. Y.

    1982-01-01

    An experimental evaluation of the aerodynamic performance of the axial flow, variable area stator power turbine stage for the Department of Energy upgraded automotive gas turbine engine was conducted in cold air. The interstage transition duct, the variable area stator, the rotor, and the exit diffuser were included in the evaluation of the turbine stage. The measured total blading efficiency was 0.096 less than the design value of 0.85. Large radial gradients in flow conditions were found at the exit of the interstage duct that adversely affected power turbine performance. Although power turbine efficiency was less than design, the turbine operating line corresponding to the steady state road load power curve was within 0.02 of the maximum available stage efficiency at any given speed.

  20. Cold-air performance of free power turbine designed for 112-kilowatt automotive gas-turbine engine. 2: Effects of variable stator-vane-chord setting angle on turbine performance

    NASA Technical Reports Server (NTRS)

    Mclallin, K. L.; Kofskey, M. G.

    1979-01-01

    The cold-air performance of an axial-flow power turbine with a variable stator designed for a 112-kW automotive gas-turbine engine was determined at speeds from 30 to 110 percent of design and at pressure ratios from 1.11 to 2.67. Performance is presented in terms of equivalent mass flow, torque, power, and efficiency for stator-vane-chord setting angles of 26 degs, 30 degs, 35 degs (design), 40 degs, 45 degs, and 50 degs. Turbine braking performance at a nominal stator setting angle of 107 degs is also presented. Turbine efficiency increased with increasing stator setting angle. A 10-point efficiency increase was obtained by opening the stator from the design setting angle of 35 degs to a setting angle of 45 degs.

  1. 49 CFR 611.201 - New Starts eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false New Starts eligibility. 611.201 Section 611.201..., DEPARTMENT OF TRANSPORTATION MAJOR CAPITAL INVESTMENT PROJECTS New Starts § 611.201 New Starts eligibility. (a) To be eligible for an engineering grant under this part for a new fixed guideway or an...

  2. 49 CFR 611.201 - New Starts eligibility.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false New Starts eligibility. 611.201 Section 611.201..., DEPARTMENT OF TRANSPORTATION MAJOR CAPITAL INVESTMENT PROJECTS New Starts § 611.201 New Starts eligibility. (a) To be eligible for an engineering grant under this part for a new fixed guideway or an...

  3. Head Start Curriculum Guide.

    ERIC Educational Resources Information Center

    Smith, Clare Coe; And Others

    One of a series of guides for preschool teachers and aides, the book offers a Head Start curriculum guide to help achieve goals regarding social behavior, general attitudes, academic skills, health, and parent development. Information on curriculum is divided into areas of bloc time outline, classroom arrangement, building concepts (such as…

  4. Home Start Evaluation Study.

    ERIC Educational Resources Information Center

    High/Scope Educational Research Foundation, Ypsilanti, MI.

    Case studies of seven Home Start programs are given as the third section of an evaluation study. Communities involved are Huntsville, Alabama; Fairbanks, Alaska; Fort Defiance, Arizona; Dardanelle, Arkansas; Wichita, Kansas; Gloucester, Massachusetts; and Reno, Nevada. Although each study varies in format, each describes in detail the degree and…

  5. Blogs: Getting Started

    ERIC Educational Resources Information Center

    Dyrud, Marilyn A.; Worley, Rebecca B.; Schultz, Benjamin

    2005-01-01

    Blogs are communication tools, they serve as vehicles to transmit messages. Before deciding to blog, one needs to devise a strategy on how this medium will fit in with his or her communication needs. This will also help later in deciding which features one will need to include in his or her blog. This article discusses ways on how to start and…

  6. Where Do We Start?

    ERIC Educational Resources Information Center

    Zuk, Evelyn M.

    1976-01-01

    Guidelines for starting a public school adult education program are presented and discuss the collection of basic data on community characteristics, community involvement, program administration and funding, curriculum, teacher hiring, program-school relationship, enrollment, policies, and community advisory board. (LH)

  7. Starting in School

    ERIC Educational Resources Information Center

    Albertine, Susan

    2012-01-01

    Through its signature initiative, Liberal Education and America's Promise (LEAP), the Association of American Colleges and Universities (AAC&U) is promoting a vision for learning that begins in school: Starting in School . . . Rigorous and rich curriculum focused on the essential learning outcomes; comprehensive, individualized, and…

  8. Starting Trees from Cuttings.

    ERIC Educational Resources Information Center

    Kramer, David C.

    1983-01-01

    Describes a procedure for starting tree cuttings from woody plants, explaining "lag time," recommending materials, and giving step-by-step instructions for rooting and planting. Points out species which are likely candidates for cuttings and provides tips for teachers for developing a unit. (JM)

  9. International workshop on cold neutron sources

    SciTech Connect

    Russell, G.J.; West, C.D. )

    1991-08-01

    The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

  10. Cold symptoms (image)

    MedlinePlus

    Colds are caused by a virus and can occur year-round. The common cold generally involves a runny nose, nasal congestion, and ... symptoms include sore throat, cough, and headache. A cold usually lasts about 7 days, with perhaps a ...