Engine starting and stopping

NASA Astrophysics Data System (ADS)

Curnock, Barry

Different starter systems for jet engines are discussed: electric, cartridge, iso-propyl-nitrate, air, gas turbine, and hydraulic. The fuel system, ignition system, air flow control system, and actual starting mechanism of an air starter motor system are considered. The variation of engine parameters throughout a typical starting sequence are described, with reference to examples for an RB211-535 engine. Physical constraints on engine starting are considered: rotating stall, light up, the window between hang and stall, hang, compressor stall, and the effects of ambient conditions. The following are also discussed: contractual and airworthiness requirements; windmilling; inflight relighting; afterburning light up; combustion stability; and broken shafts. Graphics illustrating the above are presented.

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.

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.

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.

Comparison of Gasoline Direct-Injection (GDI) and Port Fuel Injection (PFI) Vehicle Emissions: Emission Certification Standards, Cold-Start, Secondary Organic Aerosol Formation Potential, and Potential Climate Impacts.

PubMed

Saliba, Georges; Saleh, Rawad; Zhao, Yunliang; Presto, Albert A; Lambe, Andrew T; Frodin, Bruce; Sardar, Satya; Maldonado, Hector; Maddox, Christine; May, Andrew A; Drozd, Greg T; Goldstein, Allen H; Russell, Lynn M; Hagen, Fabian; Robinson, Allen L

2017-06-06

Recent increases in the Corporate Average Fuel Economy standards have led to widespread adoption of vehicles equipped with gasoline direct-injection (GDI) engines. Changes in engine technologies can alter emissions. To quantify these effects, we measured gas- and particle-phase emissions from 82 light-duty gasoline vehicles recruited from the California in-use fleet tested on a chassis dynamometer using the cold-start unified cycle. The fleet included 15 GDI vehicles, including 8 GDIs certified to the most-stringent emissions standard, superultra-low-emission vehicles (SULEV). We quantified the effects of engine technology, emission certification standards, and cold-start on emissions. For vehicles certified to the same emissions standard, there is no statistical difference of regulated gas-phase pollutant emissions between PFIs and GDIs. However, GDIs had, on average, a factor of 2 higher particulate matter (PM) mass emissions than PFIs due to higher elemental carbon (EC) emissions. SULEV certified GDIs have a factor of 2 lower PM mass emissions than GDIs certified as ultralow-emission vehicles (3.0 ± 1.1 versus 6.3 ± 1.1 mg/mi), suggesting improvements in engine design and calibration. Comprehensive organic speciation revealed no statistically significant differences in the composition of the volatile organic compounds emissions between PFI and GDIs, including benzene, toluene, ethylbenzene, and xylenes (BTEX). Therefore, the secondary organic aerosol and ozone formation potential of the exhaust does not depend on engine technology. Cold-start contributes a larger fraction of the total unified cycle emissions for vehicles meeting more-stringent emission standards. Organic gas emissions were the most sensitive to cold-start compared to the other pollutants tested here. There were no statistically significant differences in the effects of cold-start on GDIs and PFIs. For our test fleet, the measured 14.5% decrease in CO 2 emissions from GDIs was much greater than

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

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.

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.

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

40 CFR 1066.425 - Engine starting and restarting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Engine starting and restarting. 1066... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Vehicle Preparation and Running a Test § 1066.425 Engine starting and restarting. (a) Start the vehicle's engine as follows: (1) At the beginning of the test cycle...

40 CFR 1066.425 - Engine starting and restarting.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Engine starting and restarting. 1066... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Vehicle Preparation and Running a Test § 1066.425 Engine starting and restarting. (a) Start the vehicle's engine as follows: (1) At the beginning of the test cycle...

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.

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) Starting...

40 CFR 86.1236-85 - Engine starting and restarting.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 19 2011-07-01 2011-07-01 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) Starting...

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) Starting...

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) Starting...

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)…

40 CFR 86.536-78 - Engine starting and restarting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission... initial 20 second idle period shall begin when the engine starts. (2) Choke operation. (i) Vehicles... transmission shall be placed in gear 15 seconds after the engine is started. If necessary, braking may be...

40 CFR 86.136-90 - 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. 86.136... 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) Otto-cycle...

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) Otto-cycle...

40 CFR 86.136-90 - 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. 86.136... 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) Otto-cycle...

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. (a...

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) Otto-cycle...

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. (a...

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. (a...

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. (a...

Engine-start Control Strategy of P2 Parallel Hybrid Electric Vehicle

NASA Astrophysics Data System (ADS)

Xiangyang, Xu; Siqi, Zhao; Peng, Dong

2017-12-01

A smooth and fast engine-start process is important to parallel hybrid electric vehicles with an electric motor mounted in front of the transmission. However, there are some challenges during the engine-start control. Firstly, the electric motor must simultaneously provide a stable driving torque to ensure the drivability and a compensative torque to drag the engine before ignition. Secondly, engine-start time is a trade-off control objective because both fast start and smooth start have to be considered. To solve these problems, this paper first analyzed the resistance of the engine start process, and established a physic model in MATLAB/Simulink. Then a model-based coordinated control strategy among engine, motor and clutch was developed. Two basic control strategy during fast start and smooth start process were studied. Simulation results showed that the control objectives were realized by applying given control strategies, which can meet different requirement from the driver.

Engine starting apparatus

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

Wang, D.; Zahlan, M.M.

1992-02-11

This patent describes a starting apparatus for cranking an internal combustion engine. It comprises: an electric cranking motor, s shaft connected to the armature of the cranking motor, a ring gear connected to the engine, a pin which is adapted to be mashed with the ring gear of the engine, a speed responsive clutch connected between the pinion and the shaft for connecting and disconnecting the shaft and pinion, the clutch comprising a first clutch member connected to the shaft to rotate therewith and a second clutch member connected to the pinion, the second clutch member having a portion thereofmore » disposed within the first clutch member, at least one weight member connected to the first clutch member by means which permits the weight member to move radially inwardly toward or radially outwardly away from the portion of the second clutch member, and a spring for urging the weight member radially inwardly into clutching engagement with the portion of the second clutch member, the force of the spring being such as to maintain the weight member in clutching engagement with the portion of the second clutch member when the engine is being cranked the cranking motor at cranking speed.« less

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.

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. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

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. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

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. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

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. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

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. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

Time Resolved Measurements of Speciated Tailpipe Emissions from Motor Vehicles: Trends with Emission Control Technology, Cold Start Effects, and Speciation.

PubMed

Drozd, Greg T; Zhao, Yunliang; Saliba, Georges; Frodin, Bruce; Maddox, Christine; Weber, Robert J; Chang, M-C Oliver; Maldonado, Hector; Sardar, Satya; Robinson, Allen L; Goldstein, Allen H

2016-12-20

Experiments were conducted at the California Air Resources Board Haagen-Smit Laboratory to understand changes in vehicle emissions in response to stricter emissions standards over the past 25 years. Measurements included a wide range of volatile organic compounds (VOCs) for a wide range of spark ignition gasoline vehicles meeting varying levels of emissions standards, including all certifications from Tier 0 up to Partial Zero Emission Vehicle. Standard gas chromatography (GC) and high performance liquid chromatography (HLPC) analyses were employed for drive-cycle phase emissions. A proton-transfer-reaction mass spectrometer measured time-resolved emissions for a wide range of VOCs. Cold-start emissions occur almost entirely in the first 30-60 s for newer vehicles. Cold-start emissions have compositions that are not significantly different across all vehicles tested and are markedly different from neat fuel. Hot-stabilized emissions have varying importance depending on species and may require a driving distance of 200 miles to equal the emissions from a single cold start. Average commute distances in the U.S. suggest the majority of in-use vehicles have emissions dominated by cold starts. The distribution of vehicle ages in the U.S. suggests that within several years only a few percent of vehicles will have significant driving emissions compared to cold-start emissions.

Cold starting of fluorescent lamps - part I: a description of the transient regime

NASA Astrophysics Data System (ADS)

Langer, Reinhard; Garner, Richard; Paul, Irina; Horn, Siegfried; Tidecks, Reinhard

2016-10-01

In this paper we give a proposal for the transient behaviour of a cold-started fluorescent lamp, from the generation of the first conductive channel over the normal and abnormal glow discharge and the glow-to-arc (GTA) transition to the arc discharge in the steady state. Starting from the equilibrium voltage-current characteristics of the lamp and considering recent experimental results a qualitative description of the transient regime is developed, which was so far not available in the literature.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... cranking time as normal. (c) Respond to engine stalling with the following steps: (1) If the engine stalls... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Engine starting, restarting, and...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Field Testing and Portable Emission Measurement...

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.

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.

Analysis of turbojet-engine controls for afterburning starting

NASA Technical Reports Server (NTRS)

Phillips, W E , Jr

1956-01-01

A simulation procedure is developed for studying the effects of an afterburner start on a controlled turbojet engine. The afterburner start is represented by introducing a step decrease in the effective exhaust-nozzle area, after which the control returns the controlled engine variables to their initial values. The degree and speed with which the control acts are a measure of the effectiveness of the particular control system. Data are presented from five systems investigated using an electronic analog computer and the developed simulation procedure. These systems are compared with respect to steady-state errors, speed of response, and transient deviations of the system variables.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Detection of combustion start in the controlled auto ignition engine by wavelet transform of the engine block vibration signal

NASA Astrophysics Data System (ADS)

Kim, Seonguk; Min, Kyoungdoug

2008-08-01

The CAI (controlled auto ignition) engine ignites fuel and air mixture by trapping high temperature burnt gas using a negative valve overlap. Due to auto ignition in CAI combustion, efficiency improvements and low level NOx emission can be obtained. Meanwhile, the CAI combustion regime is restricted and control parameters are limited. The start of combustion data in the compressed ignition engine are most critical for controlling the overall combustion. In this research, the engine block vibration signal is transformed by the Meyer wavelet to analyze CAI combustion more easily and accurately. Signal acquisition of the engine block vibration is a more suitable method for practical use than measurement of in-cylinder pressure. A new method for detecting combustion start in CAI engines through wavelet transformation of the engine block vibration signal was developed and results indicate that it is accurate enough to analyze the start of combustion. Experimental results show that wavelet transformation of engine block vibration can track the start of combustion in each cycle. From this newly developed method, the start of combustion data in CAI engines can be detected more easily and used as input data for controlling CAI combustion.

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.

Cold starting of fluorescent lamps - part II: experiments on glow times and electrode damaging

NASA Astrophysics Data System (ADS)

Langer, Reinhard; Paul, Irina; Hilscher, Achim; Horn, Siegfried; Tidecks, Reinhard

2017-01-01

In the present work we present experiments on cold start and the resulting electrode damaging (reducing lamp life) of AC driven fluorescent lamps. The crucial parameter is the glow time, determined from time resolved measurements of lamp voltage and current. The relation between the energy consumed during glow phase and the glow time is studied. It turns out that there is no common threshold of energy until the glow-to-arc transition takes place, but strong energy input into the lamp yields short glow times. The transient behaviour from the glow to the arc regime is investigated and the stable operation points of the arc discharge are determined, yielding an arc discharge voltage-current characteristics of the lamp type investigated. The electrode damage is investigated as a function of the open source voltage and the ballast resistance. Subsequent cold starts lead to an increase of the glow time due to electrode damaging, i.e., the electrode damage accumulates. Different regeneration procedures and their effectiveness are compared. Regeneration burning turns out to be more effective than heating up the electrode. A criterion for avoiding high electrode damage is obtained, indicating that the average power during glow time should exceed 20 W.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... dynamometer shall be equal (nominal ±0.5 seconds) to the time required with a starter motor. Motoring by the dynamometer shall be terminated not more than one second after the engine starts. The 24 ±1-second free idle... after 15 seconds of cranking, cranking shall cease and the reason for failure to start shall be...

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.

Hybrid: Starting

Science.gov Websites

: gray bar STARTING When the vehicle is started, the gasoline engine "warms up." If necessary assists the gasoline engine when additional power is needed. It also acts as a generator, converting also starts the gasoline engine instantly when needed. Main stage: See through car with battery, engine

40 CFR 86.136-90 - Engine starting and restarting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... started. If necessary, braking may be employed to keep the drive wheels from turning. (c) If the vehicle... petroleum-fueled diesel vehicles and the particulate sampling system when testing methanol-fueled diesel... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission...

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.

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.

A novel transient wall heat transfer approach for the start-up of SI engines with gasoline direct injection

NASA Astrophysics Data System (ADS)

Lejsek, David; Kulzer, André; Hammer, Jürgen

2010-11-01

The introduction of CO2-reduction technologies like Start-Stop or the Hybrid-Powertrain and the worldwide stringent emission legislation require a detailed optimization of the engine start-up. The combustion concept development as well as the calibration of the engine control unit makes an explicit thermodynamic analysis of the combustion process during the start-up necessary. Initially, the well-known thermodynamic analysis of in-cylinder pressure at stationary condition was transmitted to the highly non-stationary engine start-up. For this running mode of the engine the current models for calculation of the transient wall heat fluxes were found to be misleading. With a fraction of nearly 45% of the burned fuel energy, the wall heat is very important for the calculation of energy balance and for the combustion process analysis. Based on the measurements of transient wall heat transfer densities during the start-up presented in a former work (Lejsek and Kulzer in Investigations on the transient wall heat transfer at start-up for SI engines with gasoline direct injection. SAE Paper), the paper describes the development of adaptations to the known correlations by Woschni (MTZ 31:491, 1970), Hohenberg (Experimentelle Erfassung der Wandwärme von Kolbenmotoren. TU Graz, Habil., 1980) and Bargende (Ein Gleichungsansatz zur Berechnung der instationären Wandwärmeverluste im Hochdruckteil von Ottomotoren. TH Darmstadt, PhD-Thesis, 1991) for the application during engine start-up. To demonstrate the high accuracy of the model, the results of the cyclic resolved thermodynamic analysis using the presented novel approaches were compared with the results of the measurements. It is shown, that the novel heat flux models for the engine start-up process gives a cyclic resolved thermodynamic analysis to optimize the engine start-up pretty efficient.

Analysis of the repeatability of the exhaust pollutants emission research results for cold and hot starts under controlled driving cycle conditions.

PubMed

Jaworski, Artur; Kuszewski, Hubert; Ustrzycki, Adam; Balawender, Krzysztof; Lejda, Kazimierz; Woś, Paweł

2018-04-20

Measurement of car engines exhaust pollutants emissions is very important because of their harmful effects on the environment. This article presents the assessment of repeatability of the passenger car engine exhaust pollutants emission research results obtained in the conditions of a chassis dynamometer. The research was conducted in a climate chamber, enabling the temperature conditions to be determined from - 20 to + 30 °C. The emission of CO, CH 4 , CO 2 , NO X , THC, and NMHC was subjected to the analysis. The aim of the research is to draw attention to the accuracy of the pollutant emission research results in driving cycles, and the comparison of pollutant emission results and their repeatability obtained in successive NEDC cycles under cold and hot start conditions. The results of the analysis show that, in the case of a small number of measurements, the results repeatability analysis is necessary for a proper interpretation of the pollutant emission results on the basis of the mean value. According to the authors' judgment, it is beneficial to determine the coefficient of variation for a more complete assessment of exhaust emission result repeatability obtained from a small number of measurements. This parameter is rarely presented by the authors of papers on exhaust components emission research.

The cold driver: Cold stress while driving results in dangerous behavior.

PubMed

Morris, Drew M; Pilcher, June J

2016-10-01

Cool vehicle cabin temperatures can induce short-term non-hypothermic cold stress. The current study created a cold condition to examine the impact of cold stress on driving behavior. Forty-four participants drove a high-fidelity driving simulator during a thermal neutral or local torso cooled condition. Participants performed additional tasks to assess attention, psychomotor vigilance, and manual dexterity. Skin temperature was significantly lower in the cold condition while internal temperature was unaffected. Participants who had higher subjective ratings of cold followed lead vehicles closer and started to brake later. Participants in the cold condition followed the lead car 22% (0.82s) closer and started braking 20% (2.35s) later when approaching a stop sign during the car-following task. No change in attention, psychomotor vigilance, or dexterity was observed. The current results suggest that cold environmental conditions can contribute to dangerous driving behaviors. Measures of cold perception were also shown to predict changes in driving behavior. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Qualification of CASMO5 / SIMULATE-3K against the SPERT-III E-core cold start-up experiments

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

Grandi, G.; Moberg, L.

SIMULATE-3K is a three-dimensional kinetic code applicable to LWR Reactivity Initiated Accidents. S3K has been used to calculate several international recognized benchmarks. However, the feedback models in the benchmark exercises are different from the feedback models that SIMULATE-3K uses for LWR reactors. For this reason, it is worth comparing the SIMULATE-3K capabilities for Reactivity Initiated Accidents against kinetic experiments. The Special Power Excursion Reactor Test III was a pressurized-water, nuclear-research facility constructed to analyze the reactor kinetic behavior under initial conditions similar to those of commercial LWRs. The SPERT III E-core resembles a PWR in terms of fuel type, moderator,more » coolant flow rate, and system pressure. The initial test conditions (power, core flow, system pressure, core inlet temperature) are representative of cold start-up, hot start-up, hot standby, and hot full power. The qualification of S3K against the SPERT III E-core measurements is an ongoing work at Studsvik. In this paper, the results for the 30 cold start-up tests are presented. The results show good agreement with the experiments for the reactivity initiated accident main parameters: peak power, energy release and compensated reactivity. Predicted and measured peak powers differ at most by 13%. Measured and predicted reactivity compensations at the time of the peak power differ less than 0.01 $. Predicted and measured energy release differ at most by 13%. All differences are within the experimental uncertainty. (authors)« less

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.

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.

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.

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.

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.

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…

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

Stop/Start: Overview

Science.gov Websites

1 Stop/Start vehicles use a combination of regenerative and conventional friction braking to slow , The gasoline engine in a start-stop hybrid is much like those in conventional vehicles. Unlike other hybrids that use an electric motor to help power the vehicle, the engine in a start-stop hybrid is usually

Case Study of a Discontinued Start-Up Engineering Program: Critical Challenges and Lessons Learned

ERIC Educational Resources Information Center

Friess, Wilhelm A.

2017-01-01

The explanatory case study presented here analyzes the factors that have contributed to the failure of a start-up engineering program launched at an off-campus site, and aimed at imparting the first two years of the BSc Mechanical, Electrical, Computer and Civil Engineering utilizing an integrated curriculum. Findings indicate the root cause for…

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.

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.

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.

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.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and optional repeating of void discrete modes. 1065.525 Section 1065.525 Protection of Environment... repeating of void discrete modes. (a) Start the engine using one of the following methods: (1) Start the... during one of the modes of a discrete-mode test, you may void the results only for that individual mode...

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.

The Behaviour of the Military Battery Type BB248/U Used to Start the Engine of the A.P.C.

DTIC Science & Technology

1979-12-01

UNCLASS IFIED I I ABSTRACT ~ ‘The performance of the lead—acid battery used to start the diesel engine ~~~~he Armoured Personnel Carrier...vehicle engines . One factor limiting the performance of this battery system is the very low Canadian winter temperatures, especially in Northern...information on the conditions of discharge inside the vehicle. For example, the military battery type BB248/U used to start the engine of the Armoured

Stop/Start: Overview

Science.gov Websites

/Start technology conserves energy by shutting off the gasoline engine when the vehicle is at rest, such as at a traffic light, and automatically re-starting it when the driver pushes the gas pedal to go engine when pulling out from a stop and generating electricity which is stored in the battery. Main stage

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

EPA Science Inventory

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)

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…

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 (CO 2 ) 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 CO 2 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 CO 2 . 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.

Full Hybrid: Starting

Science.gov Websites

powers the vehicle at low speeds, it is larger and holds much more energy than batteries used to start also used to start the gasoline engine instantly when needed. Power Split Device: The power split low speeds, it is larger and holds much more energy than batteries used to start conventional vehicles

Reduction of Harmful Emissions During Start and Warming Up of the Engine

NASA Astrophysics Data System (ADS)

Volkov, N.; Chainikov, D.

2018-01-01

The question of decrease in harmful emissions when idling of a truck engine in the conditions of low temperatures is considered. The implementation of the thermogenerator for a power supply of electrical elements is offered in a design of the self-powered heater. The principle of the device operation is based on a thermoelectric effect at which there is heat absorption and thermo-EMF emergence. In a consequence of this process electricity is produced. The exhaust gases of the self-powered heater are the source of the absorbed heat and act as fuel for the thermogenerator. It allows developing energy for a power supply of electrical elements of the heater. It gives the chance not to start the engine for warming up during the long parking, thereby reducing harmful emissions.

Trade-offs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems

NASA Astrophysics Data System (ADS)

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

2013-12-01

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 multiyear 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.

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)

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.

New procedure speeds cold start, protects turbine

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

Mallard, R.E.; Jordan, C.A.

1995-09-01

System dispatch from today`s power plants must consider availability of purchase power (buy and sell), fuel prices, and unit availability and efficiency. To gain the best combination of these factors, steam units must be capable of quick removal and return to service. However, unit startups are expensive, time consuming nd operationally demanding. For example, excessive thermal stresses can be catastrophic to a unit. With those factors in mind, Jacksonville Electric Authority (JEA) developed the ``valve open start`` procedure described here.

Effects of cold temperature and ethanol content on VOC ...

EPA Pesticide Factsheets

Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty spark ignition vehicles operating on summer and winter grade gasoline (E0) and ethanol blended (E10 and E85) fuels. Vehicle testing was conducted using a three-phase LA92 driving cycle in a temperature-controlled chassis dynamometer at two ambient temperatures (-7 °C and 24 °C). The cold start phase and cold ambient temperature increased VOC and MSAT emissions dramatically by up to several orders of magnitude compared to emissions during other phases and warm ambient temperature testing, respectively. As a result, calculated ozone formation potentials during the cold starts were significantly higher during cold temperature tests by 7 to 21 times the warm temperature values. The use of E85 fuel generally led to substantial reductions in hydrocarbons and increases in oxygenates such as ethanol and acetaldehyde compared to E0 and E10 fuels. However, the VOC emissions from E0 and E10 fuels were not significantly different. Cold temperature effects on cold start MSAT emissions varied by individual MSAT compound, but were consistent over a range of modern spark ignition vehicles. This manuscript communicates APPCD research activities on air toxics VOC emissions from mobile sources from the EPAct dynamometer study. Speciated VOC emissions from light-duty vehicles running on gasoline and ethanol blends at cold tem

Evaluating the Impact of E15 on Snowmobile Engine Durability and Vehicle Driveability: September 22, 2010 - August 15, 2013

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

Miers, Scott A.; Blough, Jason R.

The objective of this study was to evaluate the effects of E15 on current and legacy snowmobile engines and vehicles that could occur due to misfueling by the vehicle owner. Three test scenarios were conducted to evaluate the impact of E15, including cold-start performance and emissions, on-snow vehicle driveability, and laboratory exhaust emissions over the useful life of the engine. The eightengines tested represent current and legacy product that may exhibit sensitivity to increased ethanol blended in gasoline. Because a limited number of snowmobile engines were evaluated for this test program, the results are not statistically significant. However, the broadmore » range of engine and mixture preparation technologies, combined with the various test scenarios provide preliminaryinformation to assess potential issues with E15 use in snowmobiles. Cold-start tests were performed at -6.7 degrees C (20 degrees F), -17.8 degrees C (0 degrees F), and -28.9 degrees C (-20 degrees F). The evaluation included time to start or number of pulls to start, engine speed, exhaust gas temperature, and start-up engine emissions concentrations. Statistically significant differences instarting times were not observed for most vehicles. Snowmobile driveability was analyzed using a subjective evaluation on a controlled test course. The drivers could not easily discern which fuel the snowmobiles were using during the subjective evaluation. Durability tests were conducted to measure the emissions and performance of the snowmobiles over the useful life of the vehicles (5,000miles). There were no fuel-related engine failures on E0 or E15. Carbon monoxide emissions were generally reduced by E15 relative to E0, by from 10% to 35%. Occasional misfueling of snowmobiles with E15 is not likely to cause noticeable or immediate problems for consumers. E15 is not approved for snowmobile use, and observations made during this study support the U.S. Environmental ProtectionAgency's decision to not

Cold flow testing of the Space Shuttle Main Engine high pressure fuel turbine model

NASA Technical Reports Server (NTRS)

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

1991-01-01

In order to experimentally determine the performance of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) turbine, a 'cold' air flow turbine test program was established at NASA's Marshall Space Flight Center. As part of this test program, a baseline test of Rocketdyne's HPFTP turbine has been completed. The turbine performance and turbine diagnostics such as airfoil surface static pressure distributions, static pressure drops through the turbine, and exit swirl angles were investigated at the turbine design point, over its operating range, and at extreme off-design points. The data was compared to pretest predictions with good results. The test data has been used to improve meanline prediction codes and is now being used to validate various three-dimensional codes. The data will also be scaled to engine conditions and used to improve the SSME steady-state performance model.

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.

Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen / Liquid Methane Main Engine

NASA Technical Reports Server (NTRS)

Melcher, John C.; Morehead, Robert L.

2014-01-01

The project Morpheus liquid oxygen (LOX) / liquid methane (LCH4) main engine is a Johnson Space Center (JSC) designed 5,000 lbf-thrust, 4:1 throttling, pressure-fed cryogenic engine using an impinging element injector design. The engine met or exceeded all performance requirements without experiencing any in- ight failures, but the engine exhibited acoustic-coupled combustion instabilities during sea-level ground-based testing. First tangential (1T), rst radial (1R), 1T1R, and higher order modes were triggered by conditions during the Morpheus vehicle derived low chamber pressure startup sequence. The instability was never observed to initiate during mainstage, even at low power levels. Ground-interaction acoustics aggravated the instability in vehicle tests. Analysis of more than 200 hot re tests on the Morpheus vehicle and Stennis Space Center (SSC) test stand showed a relationship between ignition stability and injector/chamber pressure. The instability had the distinct characteristic of initiating at high relative injection pressure drop at low chamber pressure during the start sequence. Data analysis suggests that the two-phase density during engine start results in a high injection velocity, possibly triggering the instabilities predicted by the Hewitt stability curves. Engine ignition instability was successfully mitigated via a higher-chamber pressure start sequence (e.g., 50% power level vs 30%) and operational propellant start temperature limits that maintained \\cold LOX" and \\warm methane" at the engine inlet. The main engine successfully demonstrated 4:1 throttling without chugging during mainstage, but chug instabilities were observed during some engine shutdown sequences at low injector pressure drop, especially during vehicle landing.

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.

Broadening the search for minority science and engineering doctoral starts

NASA Astrophysics Data System (ADS)

Brazziel, William E.; Brazziel, Marian E.

1995-06-01

This analysis looked at doctorate completion in science and engineering (S&E) by underrepresented minorities: blacks, Hispanics and Indian Americans. These are the groups we must increasingly depend upon to make up for shortfalls in science and engineering doctorate production among American citizens. These shortfalls derive from truncated birth rates among white people, for the most part. The analysis answered several questions officials will need to know the answers to if we are to plan effectively to develop the talents of these individuals. Specifically, the National Science Foundation asked us to look at the feasibility of involving nontraditional minority science and engineering graduates (baccalaureates at 25+) as doctoral starts, along with minority S&E graduates who had taken jobs with corporations to pay off student loans and military personnel involved in S&E study and S&E work (see NSF report of research under grant SED-9107756). We found that nontraditional minority S&E doctorate recipients matched their traditional counterparts in elapsed time to degree and similar indicators. They had less in the way of support for doctoral study, however. We found that minority S&E graduates who took jobs in corporations were keenly interested in returning to campus to complete degrees. We also found that many bright minority youngsters are studying S&E subjects in the Community College of the Air Force and in U.S. Army SOC colleges. Some have enrolled in baccalaureate programs on university campuses and plan to continue on to the PhD. We concluded that money is important in tapping these talent pools to make up for the demographically driven shortfalls discussed above.

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

46 CFR 112.50-5 - Electric starting.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Electric starting. 112.50-5 Section 112.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-5 Electric starting...

46 CFR 112.50-5 - Electric starting.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Electric starting. 112.50-5 Section 112.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-5 Electric starting...

46 CFR 112.50-5 - Electric starting.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Electric starting. 112.50-5 Section 112.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-5 Electric starting...

46 CFR 112.50-5 - Electric starting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Electric starting. 112.50-5 Section 112.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-5 Electric starting...

46 CFR 112.50-5 - Electric starting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Electric starting. 112.50-5 Section 112.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-5 Electric starting...

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.

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,…

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.

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. © 2013.

Evaluation of NOx emissions of a retrofitted Euro 5 passenger car for the Horizon prize "Engine retrofit".

PubMed

Giechaskiel, Barouch; Suarez-Bertoa, Ricardo; Lähde, Tero; Clairotte, Michael; Carriero, Massimo; Bonnel, Pierre; Maggiore, Maurizio

2018-06-13

The Horizon 2020 prize for the "Engine Retrofit for Clean Air" aims at reducing the pollution in cities by spurring the development of retrofit technology for diesel engines. A Euro 5 passenger car was retrofitted with an under-floor SCR (Selective Catalytic Reduction) for NO x catalyst in combination with a solid ammonia based dosing system as the NO x reductant. The vehicle was tested both on the road and on the chassis dynamometer under various test cycles and ambient temperatures. The NO x emissions were reduced by 350-1100 mg/km (60-85%) in the laboratory depending on the test cycle and engine conditions (cold or hot start), except at type approval conditions. The reduction for cold start urban cycles was < 75 mg/km (< 15%). The on road and laboratory tests were inline. In some high speed conditions significant increase of ammonia (NH 3 ) and nitrous oxide (N 2 O) were measured. No effect was seen on other pollutants (hydrocarbons, carbon monoxide and particles). The results of the present study show that retrofitting high emitting vehicles can significantly reduce vehicle NO x emissions and ultimately pollution in cities. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

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.

Rational Engineering of a Cold-Adapted α-Amylase from the Antarctic Ciliate Euplotes focardii for Simultaneous Improvement of Thermostability and Catalytic Activity

PubMed Central

Yang, Guang; Yao, Hua; Mozzicafreddo, Matteo; Ballarini, Patrizia; Pucciarelli, Sandra

2017-01-01

ABSTRACT The α-amylases are endo-acting enzymes that hydrolyze starch by randomly cleaving the 1,4-α-d-glucosidic linkages between the adjacent glucose units in a linear amylose chain. They have significant advantages in a wide range of applications, particularly in the food industry. The eukaryotic α-amylase isolated from the Antarctic ciliated protozoon Euplotes focardii (EfAmy) is an alkaline enzyme, different from most of the α-amylases characterized so far. Furthermore, EfAmy has the characteristics of a psychrophilic α-amylase, such as the highest hydrolytic activity at a low temperature and high thermolability, which is the major drawback of cold-active enzymes in industrial applications. In this work, we applied site-directed mutagenesis combined with rational design to generate a cold-active EfAmy with improved thermostability and catalytic efficiency at low temperatures. We engineered two EfAmy mutants. In one mutant, we introduced Pro residues on the A and B domains in surface loops. In the second mutant, we changed Val residues to Thr close to the catalytic site. The aim of these substitutions was to rigidify the molecular structure of the enzyme. Furthermore, we also analyzed mutants containing these combined substitutions. Biochemical enzymatic assays of engineered versions of EfAmy revealed that the combination of mutations at the surface loops increased the thermostability and catalytic efficiency of the enzyme. The possible mechanisms responsible for the changes in the biochemical properties are discussed by analyzing the three-dimensional structural model. IMPORTANCE Cold-adapted enzymes have high specific activity at low and moderate temperatures, a property that can be extremely useful in various applications as it implies a reduction in energy consumption during the catalyzed reaction. However, the concurrent high thermolability of cold-adapted enzymes often limits their applications in industrial processes. The α-amylase from the

Rational Engineering of a Cold-Adapted α-Amylase from the Antarctic Ciliate Euplotes focardii for Simultaneous Improvement of Thermostability and Catalytic Activity.

PubMed

Yang, Guang; Yao, Hua; Mozzicafreddo, Matteo; Ballarini, Patrizia; Pucciarelli, Sandra; Miceli, Cristina

2017-07-01

The α-amylases are endo-acting enzymes that hydrolyze starch by randomly cleaving the 1,4-α-d-glucosidic linkages between the adjacent glucose units in a linear amylose chain. They have significant advantages in a wide range of applications, particularly in the food industry. The eukaryotic α-amylase isolated from the Antarctic ciliated protozoon Euplotes focardii ( Ef Amy) is an alkaline enzyme, different from most of the α-amylases characterized so far. Furthermore, Ef Amy has the characteristics of a psychrophilic α-amylase, such as the highest hydrolytic activity at a low temperature and high thermolability, which is the major drawback of cold-active enzymes in industrial applications. In this work, we applied site-directed mutagenesis combined with rational design to generate a cold-active Ef Amy with improved thermostability and catalytic efficiency at low temperatures. We engineered two Ef Amy mutants. In one mutant, we introduced Pro residues on the A and B domains in surface loops. In the second mutant, we changed Val residues to Thr close to the catalytic site. The aim of these substitutions was to rigidify the molecular structure of the enzyme. Furthermore, we also analyzed mutants containing these combined substitutions. Biochemical enzymatic assays of engineered versions of Ef Amy revealed that the combination of mutations at the surface loops increased the thermostability and catalytic efficiency of the enzyme. The possible mechanisms responsible for the changes in the biochemical properties are discussed by analyzing the three-dimensional structural model. IMPORTANCE Cold-adapted enzymes have high specific activity at low and moderate temperatures, a property that can be extremely useful in various applications as it implies a reduction in energy consumption during the catalyzed reaction. However, the concurrent high thermolability of cold-adapted enzymes often limits their applications in industrial processes. The α-amylase from the

Health effects of inhaled gasoline engine emissions.

PubMed

McDonald, Jacob D; Reed, Matthew D; Campen, Matthew J; Barrett, Edward G; Seagrave, JeanClare; Mauderly, Joe L

2007-01-01

Despite their prevalence in the environment, and the myriad studies that have shown associations between morbidity or mortality with proximity to roadways (proxy for motor vehicle exposures), relatively little is known about the toxicity of gasoline engine emissions (GEE). We review the studies conducted on GEE to date, and summarize the findings from each of these studies. While there have been several studies, most of the studies were conducted prior to 1980 and thus were not conducted with contemporary engines, fuels, and driving cycles. In addition, many of the biological assays conducted during those studies did not include many of the assays that are conducted on contemporary inhalation exposures to air pollutants, including cardiovascular responses and others. None of the exposures from these earlier studies were characterized at the level of detail that would be considered adequate today. A recent GEE study was conducted as part of the National Environmental Respiratory Center (www.nercenter.org). In this study several in-use mid-mileage General Motors (Chevrolet S-10) vehicles were purchased and utilized for inhalation exposures. An exposure protocol was developed where engines were operated with a repeating California Unified Driving Cycle with one cold start per day. Two separate engines were used to provide two cold starts over a 6-h inhalation period. The exposure atmospheres were characterized in detail, including detailed chemical and physical analysis of the gas, vapor, and particle phase. Multiple rodent biological models were studied, including general toxicity and inflammation (e.g., serum chemistry, lung lavage cell counts/differentials, cytokine/chemokine analysis, histopathology), asthma (adult and in utero exposures with pulmonary function and biochemical analysis), cardiovascular effects (biochemical and electrocardiograph changes in susceptible rodent models), and susceptibility to infection (Pseudomonas bacteria challenge). GEE resulted in

46 CFR 112.50-3 - Hydraulic starting.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 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 a...

46 CFR 112.50-3 - Hydraulic starting.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 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 a...

46 CFR 112.50-3 - Hydraulic starting.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 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 a...

International workshop on cold neutron sources

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

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 ofmore » 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.« less

NASA's James Webb Space Telescope Science Instruments Begin Final Super Cold Test at Goddard

NASA Image and Video Library

2017-12-08

At NASA's James Webb Space Telescope's final destination in space, one million miles away from Earth, it will operate at incredibly cold temperatures of -387 degrees Fahrenheit, or 40 degrees Kelvin. This is 260 degrees Fahrenheit colder than any place on the Earth’s surface has ever been. So first, this final super cold test at Goddard will prepare the Integrated Science Instrument Module (ISIM), or the “heart” of the telescope, for space. Read more: go.nasa.gov/1KFPwJG Contamination Control Engineer Alan Abeel conducts final inspections and places contamination foils before the start of the test. Credit: NASA/Goddard/Chris Gunn NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

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.

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…

Cold air systems: Sleeping giant

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

MacCracken, C.D.

1994-04-01

This article describes how cold air systems help owners increase the profits from their buildings by reducing electric costs and improving indoor air quality through lower relative humidity levels. Cold air distribution involves energy savings, cost savings, space savings, greater comfort, cleaner air, thermal storage, tighter ducting, coil redesign, lower relative humidities, retrofitting, and improved indoor air quality (IAQ). It opens a door for architects, engineers, owners, builders, environmentalists, retrofitters, designers, occupants, and manufacturers. Three things have held up cold air's usage: multiple fan-powered boxes that ate up the energy savings of primary fans. Cold air room diffusers that providedmore » inadequate comfort. Condensation from ducts, boxes, and diffusers. Such problems have been largely eliminated through research and development by utilities and manufacturers. New cold air diffusers no longer need fan powered boxes. It has also been found that condensation is not a concern so long as the ducts are located in air conditioned space, such as drop ceilings or central risers, where relative humidity falls quickly during morning startup.« less

Starting System 1. Check and Replace the Starter Rewind Rope. Student Manual. Small Engine Repair Series. First Edition.

ERIC Educational Resources Information Center

Hill, Pamela

This student manual on checking and replacing the starter rewind rope is the second 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 checking and replacing the starter rewind rope…

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.

Stirling engine power control

DOEpatents

Fraser, James P.

1983-01-01

A power control method and apparatus for a Stirling engine including a valved duct connected to the junction of the regenerator and the cooler and running to a bypass chamber connected between the heater and the cylinder. An oscillating zone of demarcation between the hot and cold portions of the working gas is established in the bypass chamber, and the engine pistons and cylinders can run cold.

Effects of Cold Temperature and Ethanol Content on VOC Emissions from Light-Duty Gasoline Vehicles.

PubMed

George, Ingrid J; Hays, Michael D; Herrington, Jason S; Preston, William; Snow, Richard; Faircloth, James; George, Barbara Jane; Long, Thomas; Baldauf, Richard W

2015-11-03

Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty spark ignition vehicles operating on summer and winter grade gasoline (E0) and ethanol blended (E10 and E85) fuels. Vehicle testing was conducted using a three-phase LA92 driving cycle in a temperature-controlled chassis dynamometer at two ambient temperatures (-7 and 24 °C). The cold start driving phase and cold ambient temperature increased VOC and MSAT emissions up to several orders of magnitude compared to emissions during other vehicle operation phases and warm ambient temperature testing, respectively. As a result, calculated ozone formation potentials (OFPs) were 7 to 21 times greater for the cold starts during cold temperature tests than comparable warm temperature tests. The use of E85 fuel generally led to substantial reductions in hydrocarbons and increases in oxygenates such as ethanol and acetaldehyde compared to E0 and E10 fuels. However, at the same ambient temperature, the VOC emissions from the E0 and E10 fuels and OFPs from all fuels were not significantly different. Cold temperature effects on cold start MSAT emissions varied by individual MSAT compound, but were consistent over a range of modern spark ignition vehicles.

Dna Sequencing

DOEpatents

Hetrick, Robert Eugene; Hilbert, Harold Sean; Parsons, Michael Howard; Stockhausen, William Francis

1997-10-07

A fuel injection system used in the intake air passageway of an internal combustion engine has a strategy for reducing cold start hydrocarbon emissions. The fuel injector has an actuator which allows the fuel spray pattern to be varied from one which is widely dispersed and atomized to one which is only weakly dispersed. A strategy for varying the spray pattern during the engine warm-up period after cold start is disclosed. The strategy increases evaporation within the passageway so that cold start overfuelling and attendant hydrocarbon emissions are reduced.

A computer simulation of the transient response of a 4 cylinder Stirling engine with burner and air preheater in a vehicle

NASA Technical Reports Server (NTRS)

Martini, W. R.

1981-01-01

A series of computer programs are presented with full documentation which simulate the transient behavior of a modern 4 cylinder Siemens arrangement Stirling engine with burner and air preheater. Cold start, cranking, idling, acceleration through 3 gear changes and steady speed operation are simulated. Sample results and complete operating instructions are given. A full source code listing of all programs are included.

The natural history of community-acquired common colds symptoms assessed over 4-years.

PubMed

Witek, Theodore J; Ramsey, David L; Carr, Andrew N; Riker, Donald K

2015-03-01

The common cold is the most frequently experienced infection among humans, but limited data exist to characterize the onset, duration, severity and intersection of symptoms in community-acquired colds. A more complete understanding of the symptom frequency and burden in naturally occurring colds is needed. We characterized common cold symptoms from 226 cold episodes experienced by 104 male or female subjects. Subjects were enrolled in the work environment in an attempt to start symptom evaluation (frequency and severity) at the earliest sign of their cold. We also assessed the symptom that had the greatest impact on the subject by asking them to identify their single most bothersome symptom. Symptom reporting started within 24 hours of cold onset for most subjects. Sore throat was a harbinger of the illness but was accompanied by multiple symptoms, including nasal congestion, runny nose and headache. Cough was not usually the most frequent symptom, but was present throughout the cold, becoming most bothersome later in the cold. Nasal congestion, pain (eg, sore throat, headache, muscle pains) or feverishness and secretory symptoms (eg, runny nose, sneezing), and even cough, were simultaneously experienced with high incidence over the first 4 days of illness. The single most bothersome symptom was sore throat on day 1, followed by nasal congestion on days 2-5 and cough on days 6 and 7. There is substantial overlap in the appearance of common cold symptoms over the first several days of the common cold. Nasal congestion, secretory and pain symptoms frequently occur together, with cough being somewhat less prominent, but quite bothersome when present. These data establish the typical symptomatology of a common cold and provide a foundation for the rational treatment of cold symptoms typically experienced by cold sufferers.

Effect of diesel exhaust generated by a city bus engine on stress responses and innate immunity in primary bronchial epithelial cell cultures.

PubMed

Zarcone, M C; Duistermaat, E; Alblas, M J; van Schadewijk, A; Ninaber, D K; Clarijs, V; Moerman, M M; Vaessen, D; Hiemstra, P S; Kooter, I M

2018-04-01

Harmful effects of diesel emissions can be investigated via exposures of human epithelial cells, but most of previous studies have largely focused on the use of diesel particles or emission sources that are poorly representative of engines used in current traffic. We studied the cellular response of primary bronchial epithelial cells (PBECs) at the air-liquid interface (ALI) to the exposure to whole diesel exhaust (DE) generated by a Euro V bus engine, followed by treatment with UV-inactivated non-typeable Haemophilus influenzae (NTHi) bacteria to mimic microbial exposure. The effect of prolonged exposures was investigated, as well as the difference in the responses of cells from COPD and control donors and the effect of emissions generated during a cold start. HMOX1 and NQO1 expression was transiently induced after DE exposure. DE inhibited the NTHi-induced expression of human beta-defensin-2 (DEFB4A) and of the chaperone HSPA5/BiP. In contrast, expression of the stress-induced PPP1R15A/GADD34 and the chemokine CXCL8 was increased in cells exposed to DE and NTHi. HMOX1 induction was significant in both COPD and controls, while inhibition of DEFB4A expression by DE was significant only in COPD cells. No significant differences were observed when comparing cellular responses to cold engine start and prewarmed engine emissions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Genes critical for the induction of cold acclimation in wheat (Triticum aestivum L.)

USDA-ARS?s Scientific Manuscript database

Phenotypic studies have shown that cold acclimation in wheat and its relatives start at different temperatures. To gain insight into the underlying mechanisms that regulate the induction of cold-acclimation process in cereals we compared the expression of genes in winter-habit (winter Norstar and w...

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.

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.

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 COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic...

46 CFR 112.50-3 - Hydraulic starting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Hydraulic starting. 112.50-3 Section 112.50-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic...

Flight evaluation of the DEEC secondary control air-start capability

NASA Technical Reports Server (NTRS)

Johnson, J. B.; Nelson, J.

1983-01-01

The air-start capability of a secondary engine control (SEC) was tested for a DEEC-equipped F100 engine and installed in an F-15 airplane. Two air-start schedules were tested. The first was referred to as the group I schedule; the second or revised schedule was the group II start schedule. Using the group I start schedule, an airspeed of 300 knots was required to ensure successful 40- and 25-percent SEC-mode air starts. If N2 were less than 40 percent, a stall would occur when the start bleeds closed 40 sec after initiation of the air start. All JFS-assisted air starts were successful with the group start schedule. For the group II schedule, the time between pressurization and start-bleed closure ranged between 50 and 72 sec depending on altitude. All air starts were successful above 225 knots givin a 75-knot reduction in required airspeed for a successful air start. Spooldown air starts of 40 percent were successful at 200 knots at altitudes up to 10,650 m and at 175 knots at altitudes up to 6100 m. Idle rpm was lower than the desired 65 percent for air starts at higher altitudes and lower airspeeds. All JSF-assisted air starts were successful.

Laser-Free Cold-Atom Gymnastics

NASA Astrophysics Data System (ADS)

Gould, Harvey; Feinberg, Benedict; Munger, Charles T., Jr.; Nishimura, Hiroshi

2017-01-01

We have performed beam transport simulations on ultra cold (2 μK) and cold (130 μK) neutral Cs atoms in the F = M = + 4 (magnetic weak-field seeking) ground state. We use inhomogeneous magnetic fields to focus and accelerate the atoms. Acceleration of neutral atoms by an inhomogeneous magnetic field was demonstrated by Stern and Gerlach in 1922. In the simulations, a two mm diameter cloud of atoms is released to fall under gravity. A magnetic coil focuses the falling atoms. After falling 41 cm, the atoms are reflected in the magnetic fringe field of a solenoid. They return to their starting height, about 0.7 s later, having passed a second time through the focusing coil. The simulations show that > 98 % of ultra cold Cs atoms and > 70 % of cold Cs atoms will survive at least 15 round trips (assuming perfect vacuum). More than 100 simulations were run to optimize coil currents and focusing coil diameter and height. Simulations also show that atoms can be launched into a fountain. An experimental apparatus to test the simulations, is being constructed. This technique may find application in atomic fountain clocks, interferometers, and gravitometers, and may be adaptable for use in microgravity. It may also work with Bose-Einstein condensates of paramagnetic atoms.

Can sensation of cold hands predict Raynaud's phenomenon or paraesthesia?

PubMed

Carlsson, D; Wahlström, J; Burström, L; Hagberg, M; Lundström, R; Pettersson, H; Nilsson, T

2018-05-10

Raynaud's phenomenon and neurosensory symptoms are common after hand-arm vibration exposure. Knowledge of early signs of vibration injuries is needed. To investigate the risk of developing Raynaud's phenomenon and paraesthesia in relation to sensation of cold hands in a cohort of male employees at an engineering plant. We followed a cohort of male manual and office workers at an engineering plant in Sweden for 21 years. At baseline (1987 and 1992) and each follow-up (1992, 1997, 2002, 2008), we assessed sensation of cold, Raynaud's phenomenon and paraesthesia in the hands using questionnaires and measured vibration exposure. We calculated risk estimates with univariate and multiple logistic regression analyses and adjusted for vibration exposure and tobacco usage. There were 241 study participants. During the study period, 21 individuals developed Raynaud's phenomenon and 43 developed paraesthesia. When adjusting the risk of developing Raynaud's phenomenon for vibration exposure and tobacco use, the odds ratios were between 6.0 and 6.3 (95% CI 2.2-17.0). We observed no increased risk for paraesthesia in relation to a sensation of cold hands. A sensation of cold hands was a risk factor for Raynaud's phenomenon. At the individual level, reporting a sensation of cold hands did not appear to be useful information to predict future development of Raynaud's phenomenon given a weak to moderate predictive value. For paraesthesia, the sensation of cold was not a risk factor and there was no predictive value at the individual level.

Procedure Training Aid for the SH-3D/H Normal Start Checklist.

DTIC Science & Technology

1982-02-01

1 Engine .... START Pupoe: To make a Normal Start of No. 1 engine. :4 14. Action Pilot/Copilot verify lite -off by noting rapid rise in T5 and Nq and...Nf increasinq 15. Note Normal starts are characterized by 7 0-75D0 T5 in I seconds after lite -off 16. If T5 is incrasinn too rapidlyv or appears to...Pumps 206 NORMAL START CHECKLIST ITEM NO. 23. No. I Ergine ... TART 14. Action Pilot/Copilot verify lite -off by noting ra ’pid rise in and Ng and Nf

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.

New Technology Sparks Smoother Engines and Cleaner Air

NASA Technical Reports Server (NTRS)

2001-01-01

Automotive Resources, Inc. (ARI) has developed a new device for igniting fuel in engines-the SmartPlug.TM SmartPlug is a self-contained ignition system that may be retrofitted to existing spark-ignition and compression-ignition engines. The SmartPlug needs as little as six watts of power for warm-up, and requires no electricity at all when the engine is running. Unlike traditional spark plugs, once the SmartPlug ignites the engine, and the engine heats up, the power supply for the plug is no longer necessary. In the utility industry, SmartPlugs can be used in tractors, portable generators, compressors, and pumps. In addition to general-purpose applications, such as lawn mowers and chainsaws, SmartPlugs can also be used in the recreational, marine, aviation, and automotive industries. Unlike traditional ignition systems, the SmartPlug system requires no distributor, coil points, or moving parts. SmartPlugs are non-fouling, with a faster and cleaner burn than traditional spark plugs. They prevent detonation and are not sensitive to moisture, allowing them to be used on a variety of engines. Other advantages include no electrical noise, no high voltage, exceptionally high altitude capabilities, and better cold-start statistics than those of standard spark ignition systems. Future applications for the SmartPlug are being evaluated by manufacturers in the snowmobile industry.

Reduce Manual Curation by Combining Gene Predictions from Multiple Annotation Engines, a Case Study of Start Codon Prediction

PubMed Central

Ederveen, Thomas H. A.; Overmars, Lex; van Hijum, Sacha A. F. T.

2013-01-01

Nowadays, prokaryotic genomes are sequenced faster than the capacity to manually curate gene annotations. Automated genome annotation engines provide users a straight-forward and complete solution for predicting ORF coordinates and function. For many labs, the use of AGEs is therefore essential to decrease the time necessary for annotating a given prokaryotic genome. However, it is not uncommon for AGEs to provide different and sometimes conflicting predictions. Combining multiple AGEs might allow for more accurate predictions. Here we analyzed the ab initio open reading frame (ORF) calling performance of different AGEs based on curated genome annotations of eight strains from different bacterial species with GC% ranging from 35–52%. We present a case study which demonstrates a novel way of comparative genome annotation, using combinations of AGEs in a pre-defined order (or path) to predict ORF start codons. The order of AGE combinations is from high to low specificity, where the specificity is based on the eight genome annotations. For each AGE combination we are able to derive a so-called projected confidence value, which is the average specificity of ORF start codon prediction based on the eight genomes. The projected confidence enables estimating likeliness of a correct prediction for a particular ORF start codon by a particular AGE combination, pinpointing ORFs notoriously difficult to predict start codons. We correctly predict start codons for 90.5±4.8% of the genes in a genome (based on the eight genomes) with an accuracy of 81.1±7.6%. Our consensus-path methodology allows a marked improvement over majority voting (9.7±4.4%) and with an optimal path ORF start prediction sensitivity is gained while maintaining a high specificity. PMID:23675487

The numerical assessment of motion strategies for integrated linear motor during starting of a free-piston engine generator

NASA Astrophysics Data System (ADS)

Razali Hanipah, M.; Razul Razali, Akhtar

2017-10-01

Free-piston engine generator (FPEG) provides a novel method for electrical power generation in hybrid electric vehicle applications with scarcely reported prototype development and testing. This paper is looking into the motion control strategy for motoring the FPEG during starting. There are two motion profiles investigated namely, trapezoidal velocity and Scurve velocity. Both motion profiles were investigated numerically and the results have shown that the S-curve motion can only achieve 80% of the stroke when operated at the proposed motoring speed of 10Hz.

Engine performance with a hydrogenated safety fuel

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Young, Alfred W

1933-01-01

This report presents the results of an investigation to determine the engine performance obtained with a hydrogenated safety fuel developed to eliminate fire hazard. The tests were made on a single-cylinder universal test engine at compression ratios of 5.0, 5.5, and 6.0. Most of the tests were made with a fuel-injection system, although one set of runs was made with a carburetor when using gasoline to establish comparative performance. The tests show that the b.m.e.p. obtained with safety fuel when using a fuel-injection system is slightly higher than that obtained with gasoline when using a carburetor, although the fuel consumption with safety fuel is higher. When the fuel-injection system is used with each fuel and with normal engine temperatures the b.m.e.p. with safety fuel is from 2 to 4 percent lower than with gasoline and the fuel consumption about 25 to 30 percent higher. However, a few tests at an engine coolant temperature of 250 F have shown a specific fuel consumption approximating that obtained with gasoline with only a slight reduction in power. The idling of the test engine was satisfactory with the safety fuel. Starting was difficult with a cold engine but could be readily accomplished when the jacket water was hot. It is believed that the use of the safety fuel would practically eliminate crash fires.

Ethics education in the consulting engineering environment: where do we start?

PubMed

Elder, Keith E

2004-04-01

As a result of in-house discussions stimulated by previous Gonzaga engineering ethics conferences, Coffman Engineers began the implementation of what is to be a company-wide ethics training program. While preparing a curriculum aimed at consulting engineers, we found very little guidance as to how to proceed with most available literature being oriented towards the academic environment. We consulted a number of resources that address the teaching of engineering ethics in higher education, but questioned their applicability for the Consulting Engineering environment. This lack of guidance led us to informal research into the ethical knowledge and attitudes of both consulting engineers and engineering students. Some of our findings were unexpected, and suggest that a simpler approach to teaching ethics to working professionals might be preferred to that typically promoted in higher education.

Theoretical and Observational Studies of the Central Engines of AGN

NASA Technical Reports Server (NTRS)

Sivron, Ran

1995-01-01

In Active Galactic Nuclei (AGN) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of AGN, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first model, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative model in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this model the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second model. Our results support the existence of cold matter in, or

Automotive Stirling Engine Development Program Mod I Stirling engine development

NASA Technical Reports Server (NTRS)

Simetkosky, M. A.

1983-01-01

The development of the Mod I 4-cylinder automotive Stirling engine is discussed and illustrated with drawings, block diagrams, photographs, and graphs and tables of preliminary test data. The engine and its drive, cold-engine, hot-engine, external-heat, air/fuel, power-control, electronic-control, and auxiliary systems are characterized. Performance results from a total of 1900 h of tests on 4 prototype engines include average maximum efficiency (at 2000 rpm) 34.5 percent and maximum output power 54.4 kW. The modifications introduced in an upgraded version of the Mod I are explained; this engine has maximum efficiency 40.4 percent and maximum power output 69.2 kW.

Ice-Water Immersion and Cold-Water Immersion Provide Similar Cooling Rates in Runners With Exercise-Induced Hyperthermia

PubMed Central

Clements, Julie M.; Casa, Douglas J.; Knight, J. Chad; McClung, Joseph M.; Blake, Alan S.; Meenen, Paula M.; Gilmer, Allison M.; Caldwell, Kellie A.

2002-01-01

Objective: To assess whether ice-water immersion or cold-water immersion is the more effective treatment for rapidly cooling hyperthermic runners. Design and Setting: 17 heat-acclimated highly trained distance runners (age = 28 ± 2 years, height = 180 ± 2 cm, weight = 68.5 ± 2.1 kg, body fat = 11.2 ± 1.3%, training volume = 89 ± 10 km/wk) completed a hilly trail run (approximately 19 km and 86 minutes) in the heat (wet-bulb globe temperature = 27 ± 1°C) at an individually selected “comfortable” pace on 3 occasions 1 week apart. The random, crossover design included (1) distance run, then 12 minutes of ice-water immersion (5.15 ± 0.20°C), (2) distance run, then 12 minutes of cold-water immersion (14.03 ± 0.28°C), or (3) distance run, then 12 minutes of mock immersion (no water, air temperature = 28.88 ± 0.76°C). Measurements: Each subject was immersed from the shoulders to the hip joints for 12 minutes in a tub. Three minutes elapsed between the distance run and the start of immersion. Rectal temperature was recorded at the start of immersion, at each minute of immersion, and 3, 6, 10, and 15 minutes postimmersion. No rehydration occurred during any trial. Results: Length of distance run, time to complete distance run, rectal temperature, and percentage of dehydration after distance run were similar (P > .05) among all trials, as was the wet-bulb globe temperature. No differences (P > .05) for cooling rates were found when comparing ice-water immersion, cold-water immersion, and mock immersion at the start of immersion to 4 minutes, 4 to 8 minutes, and the start of immersion to 8 minutes. Ice-water immersion and cold-water immersion cooling rates were similar (P > .05) to each other and greater (P < .05) than mock immersion at 8 to 12 minutes, the start of immersion to 10 minutes, and the start of immersion to every other time point thereafter. Rectal temperatures were similar (P > .05) between ice-water immersion and cold-water immersion at the

A methodology to study the possible occurrence of chugging in liquid rocket engines during transient start-up

NASA Astrophysics Data System (ADS)

Leonardi, Marco; Nasuti, Francesco; Di Matteo, Francesco; Steelant, Johan

2017-10-01

An investigation on the low frequency combustion instabilities due to the interaction of combustion chamber and feed line dynamics in a liquid rocket engine is carried out implementing a specific module in the system analysis software EcosimPro. The properties of the selected double time lag model are identified according to the two classical assumptions of constant and variable time lag. Module capabilities are evaluated on a literature experimental set up consisting of a combustion chamber decoupled from the upstream feed lines. The computed stability map results to be in good agreement with both experimental data and analytical models. Moreover, the first characteristic frequency of the engine is correctly predicted, giving confidence on the use of the module for the analysis of chugging instabilities. As an example of application, a study is carried out on the influence of the feed lines on the system stability, correctly capturing that the lines extend the stable regime of the combustion chamber and that the propellant domes play a key role in coupling the dynamics of combustion chamber and feed lines. A further example is presented to discuss on the role of pressure growth rate and of the combustion chamber properties on the possible occurrence of chug instability during engine start-up and on the conditions that lead to its damping or growth.

The Temporary Environment - Cold Regions Habitability

DTIC Science & Technology

1976-10-01

studied: Arny. Air Force and FAA. Mobi/e hrduutei unkta Any industria ! unit that requires travel in the cold weather utilizes Army or civilian equipment ...vironmnts studied andc mecn in succeeding sctic.nis proceeds to a much fitter analysis . &nalyses start with prolic %,omparisuns of action patterns and...fornali/e cinviromnmienltal analysis below the le:vel ol’the behavior setting. l ie does specify smaller units such as cvosetties. syninnorphs. and

Linear Aerospike SR-71 Experiment (LASRE) dumps water after first in-flight cold flow test

NASA Image and Video Library

1998-03-04

The NASA SR-71A successfully completed its first cold flow flight as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California on March 4, 1998. During a cold flow flight, gaseous helium and liquid nitrogen are cycled through the linear aerospike engine to check the engine's plumbing system for leaks and to check the engine operating characterisitics. Cold-flow tests must be accomplished successfully before firing the rocket engine experiment in flight. The SR-71 took off at 10:16 a.m. PST. The aircraft flew for one hour and fifty-seven minutes, reaching a maximum speed of Mach 1.58 before landing at Edwards at 12:13 p.m. PST. "I think all in all we had a good mission today," Dryden LASRE Project Manager Dave Lux said. Flight crew member Bob Meyer agreed, saying the crew "thought it was a really good flight." Dryden Research Pilot Ed Schneider piloted the SR-71 during the mission. Lockheed Martin LASRE Project Manager Carl Meade added, "We are extremely pleased with today's results. This will help pave the way for the first in-flight engine data-collection flight of the LASRE."

Airstart performance of a digital electronic engine control system on an F100 engine

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.

1984-01-01

The digital electronic engine control (DEEC) system installed on an F100 engine in an F-15 aircraft was tested. The DEEC system incorporates a closed-loop air start feature in which the fuel flow is modulated to achieve the desired rate of compressor acceleration. With this logic the DEEC equipped F100 engine can achieve air starts over a larger envelope. The DEEC air start logic, the test program conducted on the F-15, and its results are described.

Consumer attitudes on cough and cold: US (ACHOO) survey results.

PubMed

Blaiss, M S; Dicpinigaitis, P V; Eccles, R; Wingertzahn, M A

2015-08-01

The Attitudes of Consumers Toward Health, Cough, and Cold (ACHOO) survey was developed to better inform health care providers on the natural history and impact of common cold and cough, and related consumer experience and behaviors. Randomly selected US Internet/mobile device users were invited to participate in an online survey (N = 3333) in October 2012. Response quotas modeled upon 2010 US Census data ensured a demographically representative sample. To reduce potential bias from the quota design, 75% of the completed surveys were randomly selected as the primary analysis pool. Survey questions assessed participant demographics, frequency and duration of cough/cold symptoms, impact of symptoms on daily life, treatment preferences, and knowledge about cough/cold pathophysiology. In the past year, 84.6% of respondents had experienced at least one cold. Colds typically started with sore/scratchy throat (39.2%), nasal congestion (9.8%), and runny nose (9.3%) and lasted 3-7 days. Cough, the most common cold symptom (73.1%), had a delayed onset (typically 1-5 days after cold onset) and a long duration (>6 days in 35.2%). Nasal congestion and cough were the most bothersome symptoms. Many respondents waited until symptoms were 'bad enough' (42.6%) or multiple symptoms were present (20.2%) before using nonprescription medications. Drivers of choice included effectiveness in relieving symptoms, safety, and past experience. Respondents rarely consulted clinicians regarding treatment, and more than three-quarters had never received instructions from a clinician on how to choose a nonprescription cough/cold medication. Misperceptions regarding etiology and treatment of the common cold were prevalent. The main limitation is potential recall bias, since respondents had to recall cough/cold episodes over the prior year. The ACHOO survey confirms that cold is a common, bothersome experience and that there are gaps in consumers' knowledge of pathophysiology and appropriate

Cold Flow Propulsion Test Complex Pulse Testing

NASA Technical Reports Server (NTRS)

McDougal, Kris

2016-01-01

When the propellants in a liquid rocket engine burn, the rocket not only launches and moves in space, it causes forces that interact with the vehicle itself. When these interactions occur under specific conditions, the vehicle's structures and components can become unstable. One instability of primary concern is termed pogo (named after the movement of a pogo stick), in which the oscillations (cycling movements) cause large loads, or pressure, against the vehicle, tanks, feedlines, and engine. Marshall Space Flight Center (MSFC) has developed a unique test technology to understand and quantify the complex fluid movements and forces in a liquid rocket engine that contribute strongly to both engine and integrated vehicle performance and stability. This new test technology was established in the MSFC Cold Flow Propulsion Test Complex to allow injection and measurement of scaled propellant flows and measurement of the resulting forces at multiple locations throughout the engine.

Stirling cycle engine and refrigeration systems

NASA Technical Reports Server (NTRS)

Higa, W. H. (Inventor)

1976-01-01

A Stirling cycle heat engine is disclosed in which displacer motion is controlled as a function of the working fluid pressure P sub 1 and a substantially constant pressure P sub 0. The heat engine includes an auxiliary chamber at the constant pressure P sub 0. An end surface of a displacer piston is disposed in the auxiliary chamber. During the compression portion of the engine cycle when P sub 1 rises above P sub 0 the displacer forces the working fluid to pass from the cold chamber to the hot chamber of the engine. During the expansion portion of the engine cycle the heated working fluid in the hot chamber does work by pushing down on the engine's drive piston. As the working fluid pressure P sub 1 drops below P sub 0 the displacer forces most of the working fluid in the hot chamber to pass through the regenerator to the cold chamber. The engine is easily combinable with a refrigeration section to provide a refrigeration system in which the engine's single drive piston serves both the engine and the refrigeration section.

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE PAGES

Drager, Aryeh J.; van den Heever, Susan C.

2017-05-09

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Characterizing convective cold pools: Characterizing Convective Cold Pools

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

Drager, Aryeh J.; van den Heever, Susan C.

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

A Case Study of Land Treatment in a Cold Climate-West Dover, Vermont,

DTIC Science & Technology

1982-12-01

Research & ADA124~i8Engineering Laboratory A case study of land treatment in a cold climate- West Dover, Vermont IT C;0 ~󈨜 03 09 052 CRREL Report 82...44 December 1982 A case study of land treatment in a cold climate- West Dover, Vermont J.R. Bouzoun, D.W. Meals and E.A. Cassell Prepared for OFFICE OF...4. TITLE (end SL : 5. TYPE OF REPORT & PERIOD COVERED A CASE STUDY OF LAND TREATMENT IN A COLD CLIMATE-WEST DOVER, VERMONT 6. PERFORMING ORG. REPORT

Evaluation of the StressWave Cold Working (SWCW) Process on High-Strength Aluminum Alloys for Aerospace

DTIC Science & Technology

2009-02-01

Alloy Spot- welds by Cold Working,” 13 International Pacific Conference on Automotive Engineering (IPC-13), Gyeongju, Korea, August 2005. 7. Kim...so that it remains normal to the indenting direction. The restraint provided around the area to be cold worked minimizes surface upset (albeit...direction. The restraint provided around the area to be cold worked minimizes surface upset (albeit small without a PF). The stabilizing aspect

Differential expression and emerging functions of non-coding RNAs in cold adaptation.

PubMed

Frigault, Jacques J; Morin, Mathieu D; Morin, Pier Jr

2017-01-01

Several species undergo substantial physiological and biochemical changes to confront the harsh conditions associated with winter. Small mammalian hibernators and cold-hardy insects are examples of natural models of cold adaptation that have been amply explored. While the molecular picture associated with cold adaptation has started to become clearer in recent years, notably through the use of high-throughput experimental approaches, the underlying cold-associated functions attributed to several non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), remain to be better characterized. Nevertheless, key pioneering work has provided clues on the likely relevance of these molecules in cold adaptation. With an emphasis on mammalian hibernation and insect cold hardiness, this work first reviews various molecular changes documented so far in these processes. The cascades leading to miRNA and lncRNA production as well as the mechanisms of action of these non-coding RNAs are subsequently described. Finally, we present examples of differentially expressed non-coding RNAs in models of cold adaptation and elaborate on the potential significance of this modulation with respect to low-temperature adaptation.

Diesel engine catalytic combustor system. [aircraft engines

NASA Technical Reports Server (NTRS)

Ream, L. W. (Inventor)

1984-01-01

A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

Local hyperthermia benefits natural and experimental common colds.

PubMed Central

Tyrrell, D.; Barrow, I.; Arthur, J.

1989-01-01

OBJECTIVE--To determine whether inhaling fully humidified air at 43 degrees C gave more benefit to cold sufferers than inhaling air at 30 degrees C. DESIGN--Randomised double blind trial. Setting--General practice and the common cold research unit. SUBJECTS--87 Unselected patients with typical acute nasal and upper respiratory symptoms (general practice study), and 84 volunteers aged 18-50 without a history of chronic or allergic diseases. INTERVENTIONS--Subjects breathed from apparatus delivering 40 litres of room air heated to 43 degrees C or 30 degrees C and fully humidified (relative humidity 100%) per minute. End point--Reduction in severity of disease. MEASUREMENTS and main results--Patients recorded their symptoms (general practice study) and observers recorded symptoms and signs, weight of nasal secretions, isolation of virus, and antibody responses in volunteers. Patients treated for 20 minutes at 43 degrees C had in the succeeding days roughly half the score for symptoms of those treated at 30 degrees C. Volunteers treated for 30 minutes on three occasions when they were starting a cold showed an 18% [corrected] reduction in symptoms. Treatment of volunteers for 20 minutes at the onset of the cold and for 10 minutes on succeeding days showed no difference between 43 degrees C and 30 degrees C. CONCLUSIONS--Nasal hyperthermia can improve the course of a common cold and also give immediate relief of symptoms. PMID:2500196

Automotive and Construction Equipment for Arctic Use: Heating and Cold Starting

DTIC Science & Technology

1991-04-01

heater. Catalytic combustion heaters similar to that shown in Figure 12 produce flameless heat using gasoline, benzene or a similar fuel and have... combustion chamber; physical scientist, is a • engine compartment air; and member of CRREL’s * personnel and cargo compartments. Applied Research Wind...component warping and thermal cracking. When coolant is pumped, heat is not only provided to the cylinders, thereby warming the combustion cha iber and the

Automotive Stirling Engine Mod 1 Design Review, Volume 1

NASA Technical Reports Server (NTRS)

1982-01-01

Risk assessment, safety analysis of the automotive stirling engine (ASE) mod I, design criteria and materials properties for the ASE mod I and reference engines, combustion are flower development, and the mod I engine starter motor are discussed. The stirling engine system, external heat system, hot engine system, cold engine system, and engine drive system are also discussed.

Effect of a resistive load on the starting performance of a standing wave thermoacoustic engine: A numerical study.

PubMed

Ma, Lin; Weisman, Catherine; Baltean-Carlès, Diana; Delbende, Ivan; Bauwens, Luc

2015-08-01

The influence of a resistive load on the starting performance of a standing-wave thermoacoustic engine is investigated numerically. The model used is based upon a low Mach number assumption; it couples the two-dimensional nonlinear flow and heat exchange within the thermoacoustic active cell with one-dimensional linear acoustics in the loaded resonator. For a given engine geometry, prescribed temperatures at the heat exchangers, prescribed mean pressure, and prescribed load, results from a simulation in the time domain include the evolution of the acoustic pressure in the active cell. That signal is then analyzed, extracting growth rate and frequency of the dominant modes. For a given load, the temperature difference between the two sides is then varied; the most unstable mode is identified and so is the corresponding critical temperature ratio between heater and cooler. Next, varying the load, a stability diagram is obtained, potentially with a predictive value. Results are compared with those derived from Rott's linear theory as well as with experimental results found in the literature.

Advanced diesel electronic fuel injection and turbocharging

NASA Astrophysics Data System (ADS)

Beck, N. J.; Barkhimer, R. L.; Steinmeyer, D. C.; Kelly, J. E.

1993-12-01

The program investigated advanced diesel air charging and fuel injection systems to improve specific power, fuel economy, noise, exhaust emissions, and cold startability. The techniques explored included variable fuel injection rate shaping, variable injection timing, full-authority electronic engine control, turbo-compound cooling, regenerative air circulation as a cold start aid, and variable geometry turbocharging. A Servojet electronic fuel injection system was designed and manufactured for the Cummins VTA-903 engine. A special Servojet twin turbocharger exhaust system was also installed. A series of high speed combustion flame photos was taken using the single cylinder optical engine at Michigan Technological University. Various fuel injection rate shapes and nozzle configurations were evaluated. Single-cylinder bench tests were performed to evaluate regenerative inlet air heating techniques as an aid to cold starting. An exhaust-driven axial cooling air fan was manufactured and tested on the VTA-903 engine.

Memory alloy heat engine and method of operation

DOEpatents

Johnson, Alfred Davis

1977-01-01

A heat engine and method of operation employing an alloy having a shape memory effect. A memory alloy element such as one or more wire loops are cyclically moved through a heat source, along a path toward a heat sink, through the heat sink and then along another path in counter-flow heat exchange relationship with the wire in the first path. The portion of the wire along the first path is caused to elongate to its trained length under minimum tension as it is cooled. The portion of the wire along the second path is caused to contract under maximum tension as it is heated. The resultant tension differential between the wires in the two paths is applied as a force through a distance to produce mechanical work. In one embodiment a first set of endless memory alloy wires are reeved in non-slip engagement between a pair of pulleys which are mounted for conjoint rotation within respective hot and cold reservoirs. Another set of endless memory alloy wires are reeved in non-slip engagement about another pair of pulleys which are mounted in the respective hot and cold reservoirs. The pulleys in the cold reservoir are of a larger diameter than those in the hot reservoir and the opposite reaches of the wires between the two sets of pulleys extend in closely spaced-apart relationship in counter-flow heat regenerator zones. The pulleys are turned to move the two sets of wires in opposite directions. The wires are stretched as they are cooled upon movement through the heat regenerator toward the cold reservoirs, and the wires contract as they are heated upon movement through the regenerator zones toward the hot reservoir. This contraction of wires exerts a larger torque on the greater diameter pulleys for turning the pulleys and supplying mechanical power. Means is provided for applying a variable tension to the wires. Phase change means is provided for controlling the angular phase of the pulleys of each set for purposes of start up procedure as well as for optimizing engine

Discovery, Molecular Mechanisms, and Industrial Applications of Cold-Active Enzymes.

PubMed

Santiago, Margarita; Ramírez-Sarmiento, César A; Zamora, Ricardo A; Parra, Loreto P

2016-01-01

Cold-active enzymes constitute an attractive resource for biotechnological applications. Their high catalytic activity at temperatures below 25°C makes them excellent biocatalysts that eliminate the need of heating processes hampering the quality, sustainability, and cost-effectiveness of industrial production. Here we provide a review of the isolation and characterization of novel cold-active enzymes from microorganisms inhabiting different environments, including a revision of the latest techniques that have been used for accomplishing these paramount tasks. We address the progress made in the overexpression and purification of cold-adapted enzymes, the evolutionary and molecular basis of their high activity at low temperatures and the experimental and computational techniques used for their identification, along with protein engineering endeavors based on these observations to improve some of the properties of cold-adapted enzymes to better suit specific applications. We finally focus on examples of the evaluation of their potential use as biocatalysts under conditions that reproduce the challenges imposed by the use of solvents and additives in industrial processes and of the successful use of cold-adapted enzymes in biotechnological and industrial applications.

MELFI-3 Cold Box inspection

NASA Image and Video Library

2015-03-13

ISS043e000724 (03/13/2015) --- ESA (European Space Agency) astronaut Samantha Cristoforetti, Expedition 43 flight engineer works daily on science and maintenance duties on board the International Space Station. She is inspecting the Minus Eighty-degree Laboratory Freezer called by the shorter title "MELFI-3 Cold Box inspection". Astronauts are trained for long periods at the Johnson Space Center and in Russia before their missions in space begin so that they are fully trained for these complex duties.

Improvement of thermal performance of gamma-type stirling engine

NASA Astrophysics Data System (ADS)

Saenyot, Khanuengchat; Chamdee, Peerapong; Raksrithong, Pawin; Locharoenrat, Kitsakorn; Lekchaum, Sarai

2018-06-01

The gamma-type stirling engine was designed and fabricated using three main types of the materials for the engine assembly in order to get better the heat transfer between the cold and hot sides of the engine cylinders. Stainless steel and brass were applied for the hot cylinder, whereas aluminum was used for the cold cylinder. We have achieved the indicated work, engine speed and indicated power of 71.64 mJ, 599 rpm and 0.71 J/s, respectively. Furthermore, we were able to accomplish the constant temperature difference of 300 K with the thermal efficiency of 40 %. The improvement of the engine performance was confirmed by the heat flow simulation via the Solidwork program. Our inexpensive home-made engine is expected to be very useful for the people in the rural areas where the electricity is unable to reach them.

Cold Stress

MedlinePlus

... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

Hypothermic general cold adaptation induced by local cold acclimation.

PubMed

Savourey, G; Barnavol, B; Caravel, J P; Feuerstein, C; Bittel, J H

1996-01-01

To study relationships between local cold adaptation of the lower limbs and general cold adaptation, eight subjects were submitted both to a cold foot test (CFT, 5 degrees C water immersion, 5 min) and to a whole-body standard cold air test (SCAT, 1 degree C, 2 h, nude at rest) before and after a local cold acclimation (LCA) of the lower limbs effected by repeated cold water immersions. The LCA induced a local cold adaptation confirmed by higher skin temperatures of the lower limbs during CFT and a hypothermic insulative general cold adaptation (decreased rectal temperature and mean skin temperature P < 0.05) without a change either in metabolic heat production or in lower limb skin temperatures during SCAT after LCA. It was concluded that local cold adaptation was related to the habituation process confirmed by decreased plasma concentrations of noradrenaline (NA) during LCA (P < 0.05). However, the hypothermic insulative general cold adaptation was unrelated either to local cold adaptation or to the habituation process, because an increased NA during SCAT after LCA (P < 0.05) was observed but was rather related to a "T3 polar syndrome" occurring during LCA.

Demonstration of diesel fired coolant heaters in school bus applications : final report.

DOT National Transportation Integrated Search

2010-04-01

Engine block pre-heating can reduce fuel consumption, decrease pollution, extend engine life, and it is often necessary for reliably starting diesel engines in cold climates. This report describes the application and experience of applying 36 diesel ...

Extended Deterrence, Nuclear Proliferation, and START III

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

Speed, R.D.

2000-06-20

Early in the Cold War, the United States adopted a policy of ''extended nuclear deterrence'' to protect its allies by threatening a nuclear strike against any state that attacks these allies. This threat can (in principle) be used to try to deter an enemy attack using conventional weapons or one using nuclear, chemical, or biological weapons. The credibility of a nuclear threat has long been subject to debate and is dependent on many complex geopolitical factors, not the least of which is the military capabilities of the opposing sides. The ending of the Cold War has led to a significantmore » decrease in the number of strategic nuclear weapons deployed by the United States and Russia. START II, which was recently ratified by the Russian Duma, will (if implemented) reduce the number deployed strategic nuclear weapons on each side to 3500, compared to a level of over 11,000 at the end of the Cold War in 1991. The tentative limit established by Presidents Clinton and Yeltsin for START III would reduce the strategic force level to 2000-2500. However, the Russians (along with a number of arms control advocates) now argue that the level should be reduced even further--to 1500 warheads or less. The conventional view is that ''deep cuts'' in nuclear weapons are necessary to discourage nuclear proliferation. Thus, as part of the bargain to get the non-nuclear states to agree to the renewal of the Nuclear Non-Proliferation Treaty, the United States pledged to work towards greater reductions in strategic forces. Without movement in the direction of deep cuts, it is thought by many analysts that some countries may decide to build their own nuclear weapons. Indeed, this was part of the rationale India used to justify its own nuclear weapons program. However, there is also some concern that deep cuts (to 1500 or lower) in the U.S. strategic nuclear arsenal could have the opposite effect. The fear is that such cuts might undermine extended deterrence and cause a crisis in

Backup control airstart performance on a digital electronic engine control-equipped F100-engine

NASA Technical Reports Server (NTRS)

Johnson, J. B.

1984-01-01

The air start capability of a backup control (BUC) was tested for a digital electronic engine control (DEEC) equipped F100 engine, which was installed in an F-15 aircraft. Two air start schedules were tested. Using the group 1 start schedule, based on a 40 sec timer, an air speed of 300 knots was required to ensure successful 40 and 25% BUC mode spooldown airstarts. If core rotor speed (N2) was less than 40% a stall would occur when the start bleed closed, 40 sec after initiation of the air start. All jet fuel starter (JFS) assisted air starts were successful with the group 1 start schedule. For the group 2 schedule, the time between pressurization and start bleed closure ranged between 50 sec and 72 sec. Idle rps was lower than the desired 65% for air starts at higher altitudes and lower air speeds.

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.

Effects of Mode of Deformation and Extent of Reduction on Evolution of {111}-Fiber During Cold Rolling of Ni-16Cr Alloy

NASA Astrophysics Data System (ADS)

Mehta, K. K.; Mandal, R. K.; Singh, A. K.

2018-07-01

The high ratio of relative resolved shear stress on a twin to planar slip system results in microstructural latent hardening (some kind of overshooting) by the twin system on the primary slip planes, which leads to development of the {111}-fiber in Ni-16Cr alloy. The development of {111}-fiber starts as early as around 16 pct cold reduction in Ni-16Cr alloy and persists with maximum average intensity ranging from 35 to 40 pct additional deformation, i.e., around 50 pct cold reduction in unidirectional (U) and two-step cross (T)-rolling modes. In between 50 and 68 pct reductions in U and T modes, the fiber becomes unstable and starts disappearing. However, in multistep cross (M) rolling, the {111}-fiber formation starts late, i.e., at around 50 pct reduction, and maintains its stability up to additional deformation ranging from 35 to 40 pct, i.e., around 90 pct cold reduction. Thus, the life of {111}-fiber remains stable only within the range from 35 to 40 pct intermediate deformation during cold rolling of Ni-16Cr alloy irrespective of modes of rolling. However, the start and end of fiber stabilities depend on the modes of deformation by rolling. The maximum average intensity of {111}-fiber that can be attained in Ni-16Cr alloy is around 3.6× random in any of the deformation modes.

Effects of Mode of Deformation and Extent of Reduction on Evolution of {111}-Fiber During Cold Rolling of Ni-16Cr Alloy

NASA Astrophysics Data System (ADS)

Mehta, K. K.; Mandal, R. K.; Singh, A. K.

2018-04-01

The high ratio of relative resolved shear stress on a twin to planar slip system results in microstructural latent hardening (some kind of overshooting) by the twin system on the primary slip planes, which leads to development of the {111}-fiber in Ni-16Cr alloy. The development of {111}-fiber starts as early as around 16 pct cold reduction in Ni-16Cr alloy and persists with maximum average intensity ranging from 35 to 40 pct additional deformation, i.e., around 50 pct cold reduction in unidirectional (U) and two-step cross (T)-rolling modes. In between 50 and 68 pct reductions in U and T modes, the fiber becomes unstable and starts disappearing. However, in multistep cross (M) rolling, the {111}-fiber formation starts late, i.e., at around 50 pct reduction, and maintains its stability up to additional deformation ranging from 35 to 40 pct, i.e., around 90 pct cold reduction. Thus, the life of {111}-fiber remains stable only within the range from 35 to 40 pct intermediate deformation during cold rolling of Ni-16Cr alloy irrespective of modes of rolling. However, the start and end of fiber stabilities depend on the modes of deformation by rolling. The maximum average intensity of {111}-fiber that can be attained in Ni-16Cr alloy is around 3.6× random in any of the deformation modes.

Materials engineering

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

Bramley, A.N.

1985-01-01

This book presents the Proceedings of the Second Materials Engineering Conference. This valuable collection of papers deal with the awareness, creative use, economics, reliability, selection, design, testing and warranty of materials. The papers address topics of both immediate and lasting industrial importance at a readily assimilated level and contain information which will lead speedily to improvements in industrial practice. Topics considered include recent developments in the science and technology of high modulus polymers; computer aided design of advanced composites; a systematic approach to materials testing in metal forming; new cold working tool steels; friction surfacing and its applications; fatigue lifemore » assessment and materials engineering; alternative materials for internal combustion engines; adhesives and the engineer; thermoplastic bearings; engineering applications of ZA alloys; and utility and complexity in the selection of polymeric materials.« less

Discovery, Molecular Mechanisms, and Industrial Applications of Cold-Active Enzymes

PubMed Central

Santiago, Margarita; Ramírez-Sarmiento, César A.; Zamora, Ricardo A.; Parra, Loreto P.

2016-01-01

Cold-active enzymes constitute an attractive resource for biotechnological applications. Their high catalytic activity at temperatures below 25°C makes them excellent biocatalysts that eliminate the need of heating processes hampering the quality, sustainability, and cost-effectiveness of industrial production. Here we provide a review of the isolation and characterization of novel cold-active enzymes from microorganisms inhabiting different environments, including a revision of the latest techniques that have been used for accomplishing these paramount tasks. We address the progress made in the overexpression and purification of cold-adapted enzymes, the evolutionary and molecular basis of their high activity at low temperatures and the experimental and computational techniques used for their identification, along with protein engineering endeavors based on these observations to improve some of the properties of cold-adapted enzymes to better suit specific applications. We finally focus on examples of the evaluation of their potential use as biocatalysts under conditions that reproduce the challenges imposed by the use of solvents and additives in industrial processes and of the successful use of cold-adapted enzymes in biotechnological and industrial applications. PMID:27667987

New START, Eyjafjallajökull, and Nuclear Winter

NASA Astrophysics Data System (ADS)

Robock, Alan

2010-11-01

On 8 April 2010, U.S. president Barack Obama and Russian president Dmitry Medvedev signed the Treaty Between the United States of America and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms, committing the United States and Russia to reducing their nuclear arsenals to levels less than 5% of the maximum during the height of the cold war in the 1980s. This treaty is called “New START,” as it is a follow-on to the 1991 Strategic Arms Reductions Treaty (START). On 14 April 2010 the Eyjafjallajökull volcano in Iceland began an explosive eruption phase that shut down air traffic in Europe for 6 days and continued to disrupt it for another month. What do these two events have in common? Nuclear weapons, when targeted at cities and industrial areas, would start fires, producing clouds of sooty smoke. Volcanic eruptions emit ash particles and sulfur dioxide (SO2), which forms sulfate aerosols in the atmosphere. Thus, both the use of nuclear weapons and volcanic eruptions produce particles that can be transported large distances from the source and can affect weather and climate.

Tests Of A Stirling-Engine Power Converter

NASA Technical Reports Server (NTRS)

Dochat, George

1995-01-01

Report describes acceptance tests of power converter consisting of pair of opposed free-piston Stirling engines driving linear alternators. Stirling engines offer potential for extremely long life, high reliability, high efficiency at low hot-to-cold temperature ratios, and relatively low heater-head temperatures.

Dynamic Modeling of Starting Aerodynamics and Stage Matching in an Axi-Centrifugal Compressor

NASA Technical Reports Server (NTRS)

Wilkes, Kevin; OBrien, Walter F.; Owen, A. Karl

1996-01-01

A DYNamic Turbine Engine Compressor Code (DYNTECC) has been modified to model speed transients from 0-100% of compressor design speed. The impetus for this enhancement was to investigate stage matching and stalling behavior during a start sequence as compared to rotating stall events above ground idle. The model can simulate speed and throttle excursions simultaneously as well as time varying bleed flow schedules. Results of a start simulation are presented and compared to experimental data obtained from an axi-centrifugal turboshaft engine and companion compressor rig. Stage by stage comparisons reveal the front stages to be operating in or near rotating stall through most of the start sequence. The model matches the starting operating line quite well in the forward stages with deviations appearing in the rearward stages near the start bleed. Overall, the performance of the model is very promising and adds significantly to the dynamic simulation capabilities of DYNTECC.

Motivation of Students Who Switch from Engineering to Engineering Technology

ERIC Educational Resources Information Center

Ramirez, Nichole

2017-01-01

A set of studies is reported describing the demographics, outcomes, and motivations of students who start in engineering and switch their major to engineering technology. There has been extensive research in engineering persistence, but little focus has been given to the "T" in STEM. Most research combines technology with other science…

Cold Helium Gas Pressurization For Spacecraft Cryogenic Propulsion Systems

NASA Technical Reports Server (NTRS)

Morehead, Robert L.; Atwell. Matthew J.; Hurlbert, Eric A.; Melcher, J. C.

2017-01-01

To reduce the dry mass of a spacecraft pressurization system, helium pressurant may be stored at low temperature and high pressure to increase mass in a given tank volume. Warming this gas through an engine heat exchanger prior to tank pressurization both increases the system efficiency and simplifies the designs of intermediate hardware such as regulators, valves, etc. since the gas is no longer cryogenic. If this type of cold helium pressurization system is used in conjunction with a cryogenic propellant, though, a loss in overall system efficiency can be expected due to heat transfer from the warm ullage gas to the cryogenic propellant which results in a specific volume loss for the pressurant, interpreted as the Collapse Factor. Future spacecraft with cryogenic propellants will likely have a cold helium system, with increasing collapse factor effects as vehicle sizes decrease. To determine the collapse factor effects and overall implementation strategies for a representative design point, a cold helium system was hotfire tested on the Integrated Cryogenic Propulsion Test Article (ICPTA) in a thermal vacuum environment at the NASA Glenn Research Center Plum Brook Station. The ICPTA vehicle is a small lander-sized spacecraft prototype built at NASA Johnson Space Center utilizing cryogenic liquid oxygen/liquid methane propellants and cryogenic helium gas as a pressurant to operate one 2,800lbf 5:1 throttling main engine, two 28lbf Reaction Control Engines (RCE), and two 7lbf RCEs (Figure 1). This vehicle was hotfire tested at a variety of environmental conditions at NASA Plum Brook, ranging from ambient temperature/simulated high altitude, deep thermal/high altitude, and deep thermal/high vacuum conditions. A detailed summary of the vehicle design and testing campaign may be found in Integrated Cryogenic Propulsion Test Article Thermal Vacuum Hotfire Testing, AIAA JPC 2017.

Some Chinese folk prescriptions for wind-cold type common cold.

PubMed

Hai-Long, Zhai; Shimin, Chen; Yalan, Lu

2015-07-01

Although self-limiting, the common cold (gǎn mào) is highly prevalent. There are no effective antivirals to cure the common cold and few effective measures to prevent it, However, for thousands years, Chinese people have treated the common cold with natural herbs, According to the traditional Chinese medicine (TCM) theory ( zhōng yī lǐ lùn), the common cold is considered as an exterior syndrome, which can be further divided into the wind-cold type ( fēng hán xíng), the wind-heat type ( fēng rè xíng), and the summer heat dampness type ( shǔ rè xíng). Since the most common type of common cold caught in winter and spring is the wind-cold type, the article introduced some Chinese folk prescriptions for the wind-cold type common cold with normal and weak physique, respectively. For thousands of years, Chinese folk prescriptions for the common cold, as complementary and alternative medicine (CAM; bǔ chōng yǔ tì dài yī xué), have been proven to be effective, convenient, cheap, and most importantly, safe. The Chinese folk prescriptions ( zhōng guó mín jiān chǔ fāng) for the wind-cold type common cold are quite suitable for general practitioners or patients with the wind-cold type common cold, to treat the disease. Of course, their pharmacological features and mechanisms of action need to be further studied.

4. VIEW TO THE NORTHWEST OF THE COLD BAY ON ...

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

4. VIEW TO THE NORTHWEST OF THE COLD BAY ON THE NORTH (RIGHT) AND THE POST-MORTEM CELLS ON THE SOUTH (LEFT). ALSO ILLUSTRATED ARE THE DIFFERENT ROOF HEIGHTS OF THE BUILDING. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

Testing of materials from the Minnesota Cold Regions pavement research test facility

DOT National Transportation Integrated Search

1996-09-01

The U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) conducted various laboratory tests on pavement materials from the Mn/ ROAD facility. The tests helped to characterize the behavior of materials under season frost conditions, and ...

Orbital Transfer Rocket Engine Technology. Advanced Engine Study, Task D.6 Final Report

DTIC Science & Technology

1992-06-01

PROPERTIES _- -,mr m" , MANUAL a PAQ *E,- 7.3.2.1.2. IA .A.2 ,C -- 70-t’ i Rl I _ N -’.±v-j-. .......-441I 0.2% YS Design Allowable • -’Moo 0 2W0" 6W...Storage External Radiation Environment ( Buried Engine) The engine thrust chamber would be cold to the touch even at full thrust operation from the

Journal of Engineering Thermophysics (Selected Articles),

DTIC Science & Technology

1983-05-13

compressor, prediction of unsteady vibration , and prevention of unsteady vibration . This test was undergone on a turbojet engine. The paper stresses the...induce unsteady engine vibration . While studying the effect of inlet anomaly and variation of the first stage nozzle area of the turbine, the engine...constant revolution speed curve until unsteady vibration or stall appeared. In studying the influence of the starting sequence, starting was

Advanced Natural Gas Reciprocating Engine(s)

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

Pike, Edward

The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cyclemore » efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.« less

Physiological responses and manual performance in humans following repeated exposure to severe cold at night.

PubMed

Ozaki, H; Nagai, Y; Tochihara, Y

2001-04-01

We evaluated human physiological responses and the performance of manual tasks during exposure to severe cold (-25 degrees C) at night (0300-0500 hours) and in the afternoon (1500-1700 hours). Thirteen male students wearing standard cold protective clothing occupied a severely cold room (-25 degrees C) for 20 min, and were then transferred to a cool room (10 degrees C) for 20 min. This pattern of exposure was repeated three times, for a total time of exposure to extreme cold of 60 min. The experiments were started either at 1500 hours or 0300 hours and measurements of rectal temperature, skin temperature, blood pressure, performance in a counting task, hand tremor, and subjective responses were made in each condition. At the end of the experiment at night the mean decrease in rectal temperature [0.68 (SEM 0.04) degree C] was significantly greater than that at the end of the experiment in the afternoon [0.55 (SEM 0.08) degree C, P < 0.01]. After the second cold exposure at night the mean increase in diastolic blood pressure [90 (SEM 2.0) mmHg] was significantly greater than that at the end of the second cold exposure in the afternoon [82 (SEM 2.8) mmHg, P < 0.01]. At the end of the second cold exposure at night, mean finger skin temperature [11.8 (SEM 0.8) degrees C] was significantly higher than that at the comparable time in the afternoon [9.0 (SEM 0.7) degrees C, P < 0.01]. Similarly for the toe, mean skin temperature at the start of the second cold exposure at night [25.6 (SEM 1.5) degrees C] was significantly higher than in the afternoon [20.1 (SEM 0.8) degrees C, P < 0.01]. The increased skin temperatures in the periphery resulted in increased heat loss. Since peripheral skin temperatures were highest at night, the subjects noted diminished sensations of thermal cold and pain at that time. Manual dexterity at the end of the first cold exposure at night [mean 83.7 (SEM 3.6) times.min-1] had decreased significantly more than at the end of the first cold exposure

Ecosystem engineering creates a direct nutritional link between 600-m deep cold-water coral mounds and surface productivity.

PubMed

Soetaert, Karline; Mohn, Christian; Rengstorf, Anna; Grehan, Anthony; van Oevelen, Dick

2016-10-11

Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude. This 'topographically-enhanced carbon pump' leaks organic matter that settles at greater depths. The ubiquitous presence of biogenic and geological topographies along ocean margins suggests that carbon sequestration through this pump is of global importance. These results indicate that enhanced stratification and lower surface productivity, both expected consequences of climate change, may negatively impact the energy balance of CWCs.

Ecosystem engineering creates a direct nutritional link between 600-m deep cold-water coral mounds and surface productivity

NASA Astrophysics Data System (ADS)

Soetaert, Karline; Mohn, Christian; Rengstorf, Anna; Grehan, Anthony; van Oevelen, Dick

2016-10-01

Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude. This ’topographically-enhanced carbon pump’ leaks organic matter that settles at greater depths. The ubiquitous presence of biogenic and geological topographies along ocean margins suggests that carbon sequestration through this pump is of global importance. These results indicate that enhanced stratification and lower surface productivity, both expected consequences of climate change, may negatively impact the energy balance of CWCs.

An Investigation Into: I) Active Flow Control for Cold-Start Performance Enhancement of a Pump-Assisted, Capillary-Driven, Two-Phase Cooling Loop II) Surface Tension of n-Pentanol + Water, a Self-Rewetting Working Fluid, From 25 °C to 85 °C

NASA Astrophysics Data System (ADS)

Bejarano, Roberto Villa

Cold-start performance enhancement of a pump-assisted, capillary-driven, two-phase cooling loop was attained using proportional integral and fuzzy logic controls to manage the boiling condition inside the evaporator. The surface tension of aqueous solutions of n-Pentanol, a self-rewetting fluid, was also investigated for enhancing heat transfer performance of capillary driven (passive) thermal devices was also studied. A proportional-integral control algorithm was used to regulate the boiling condition (from pool boiling to thin-film boiling) and backpressure in the evaporator during cold-start and low heat input conditions. Active flow control improved the thermal resistance at low heat inputs by 50% compared to the baseline (constant flow rate) case, while realizing a total pumping power savings of 56%. Temperature overshoot at start-up was mitigated combining fuzzy-logic with a proportional-integral controller. A constant evaporator surface temperature of 60°C with a variation of +/-8°C during start-up was attained with evaporator thermal resistances as low as 0.10 cm2--K/W. The surface tension of aqueous solutions of n-Pentanol, a self-rewetting working fluid, as a function of concentration and temperature were also investigated. Self-rewetting working fluids are promising in two-phase heat transfer applications because they have the ability to passively drive additional working fluid towards the heated surface; thereby increasing the dryout limitations of the thermal device. Very little data is available in literature regarding the surface tension of these fluids due to the complexity involved in fluid handling, heating, and experimentation. Careful experiments were performed to investigate the surface tension of n-Pentanol + water. The concentration and temperature range investigated were from 0.25%wt. to1.8%wt and 25°C to 85°C, respectively.

Evaluation and ranking of candidate ceramic wafer engine seal materials

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.

1991-01-01

Modern engineered ceramics offer high temperature capabilities not found in even the best superalloy metals. The high temperature properties of several selected ceramics including aluminum oxide, silicon carbide, and silicon nitride are reviewed as they apply to hypersonic engine seal design. A ranking procedure is employed to objectively differentiate among four different monolithic ceramic materials considered, including: a cold-pressed and sintered aluminum oxide; a sintered alpha-phase silicon carbide; a hot-isostatically pressed silicon nitride; and a cold-pressed and sintered silicon nitride. This procedure is used to narrow the wide range of potential ceramics considered to an acceptable number for future detailed and costly analyses and tests. The materials are numerically scored according to their high temperature flexural strength; high temperature thermal conductivity; resistance to crack growth; resistance to high heating rates; fracture toughness; Weibull modulus; and finally according to their resistance to leakage flow, where materials having coefficients of thermal expansion closely matching the engine panel material resist leakage flow best. The cold-pressed and sintered material (Kyocera SN-251) ranked the highest in the overall ranking especially when implemented in engine panels made of low expansion rate materials being considered for the engine, including Incoloy and titanium alloys.

G T-Mohr Start-up Reactivity Insertion Transient Analysis Using Simulink

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

Fard, Mehdi Reisi; Blue, Thomas E.; Miller, Don W.

2006-07-01

As a part of a Department of Energy-Nuclear Engineering Research Initiative (NERI) Project, we at OSU are investigating SiC semiconductor detectors as neutron power monitors for Generation IV power reactors. As a part of this project, we are investigating the power monitoring requirements for a specific type of Generation IV reactor, namely the GT-MHR. To evaluate the power monitoring requirements for the GT-MHR that are most demanding for a SiC diode power monitor, we have developed a Simulink model to study the transient behavior of the GT-MHR. In this paper, we describe the application of the Simulink code to themore » analysis of a series of Start-up Reactivity Insertion Transients (SURITs). The SURIT is considered to be a limiting protectable accident in terms of establishing the dynamic range of a SiC power monitor because of the low count rate of the detector during the start-up and absence of the reactivity feedback mechanism at the beginning of transient. The SURIT is studied with the ultimate goal of identifying combinations of 1) reactor power scram setpoints and 2) cram initiation times (the time in which a scram must be initiated once the setpoint is exceeded) for which the GT-MHR core is protected in the event of a continuous withdrawal of a control rod bank from the core from low powers. The SURIT is initiated by withdrawing a rod bank when the reactor is cold (300 K) and sub-critical at the BOEC (Beginning of Equilibrium Cycle) condition. Various initial power levels have been considered corresponding to various degrees of sub-criticality and various source strengths. An envelope of response is determined to establish which initial powers correspond to the worst case SURIT. (authors)« less

Improving first case start times using Lean in an academic medical center.

PubMed

Deldar, Romina; Soleimani, Tahereh; Harmon, Carol; Stevens, Larry H; Sood, Rajiv; Tholpady, Sunil S; Chu, Michael W

2017-06-01

Lean is a process improvement strategy that can improve efficiency of the perioperative process. The purpose of this study was to identify etiologies of late surgery start times, implement Lean interventions, and analyze their effects. A retrospective review of all first-start surgery cases was performed. Lean was implemented in May 2015, and cases 7 months before and after implementation were analyzed. A total of 4,492 first-start cases were included; 2,181 were pre-Lean and 2,311 were post-Lean. The post-Lean group had significantly higher on-time starts than the pre-Lean group (69.0% vs 57.0%, P < .01). The most common delay etiology was surgeon-related for both groups. Delayed post-Lean cases were significantly less likely to be due to preoperative assessment (14.9% vs 9.9%, P < .01) and more likely due to patient-related (16.5% vs 22.3%, P < .01) or chaplain (1.8% vs 4.0%, P < .01) factors. Delayed starts occurred more often on snowy and cold days, and less often on didactic days (P < .01). Modifying preoperative tasks using Lean methods can improve operating room efficiency and increase on-time starts. Copyright © 2016 Elsevier Inc. All rights reserved.

Automotive Stirling reference engine design report

NASA Technical Reports Server (NTRS)

1981-01-01

The reference Stirling engine system is described which provides the best possible fuel economy while meeting or exceeding all other program objectives. The system was designed to meet the requirements of a 1984 Pontiac Phoenix (X-body). This design utilizes all new technology that can reasonably be expected to be developed by 1984 and that is judged to provide significant improvement, relative to development risk and cost. Topics covered include: (1) external heat system; (2) hot engine system; (3) cold engine system; (4) engine drive system; (5) power control system and auxiliaries; (6) engine instalation; (7) optimization and vehicle simulation; (8) engine materials; and (9) production cost analysis.

JT8D engine performance retention

NASA Technical Reports Server (NTRS)

James, A. D.; Weisel, D. R.

1981-01-01

The attractive performance retention characteristics of the JT8D engine are described. Because of its moderate bypass ratio and turbine temperature, and stiff structural design, the performance retention versus flight cycles of the JT8D engine sets a standard that is difficult for other engines to equal. In addition, the significant benefits of refurbishment of the JT8D engine are presented. Cold section refurbishment offers thrust specific fuel consumption improvements of up to 2 percent and payback in less than a year, making a very attractive investment option for the airlines.

Cold plate

DOEpatents

Marroquin, Christopher M.; O'Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

2018-02-13

A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

Effects of Gasoline Direct Injection Engine Operating Parameters on Particle Number Emissions

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

He, X.; Ratcliff, M. A.; Zigler, B. T.

2012-04-19

A single-cylinder, wall-guided, spark ignition direct injection engine was used to study the impact of engine operating parameters on engine-out particle number (PN) emissions. Experiments were conducted with certification gasoline and a splash blend of 20% fuel grade ethanol in gasoline (E20), at four steady-state engine operating conditions. Independent engine control parameter sweeps were conducted including start of injection, injection pressure, spark timing, exhaust cam phasing, intake cam phasing, and air-fuel ratio. The results show that fuel injection timing is the dominant factor impacting PN emissions from this wall-guided gasoline direct injection engine. The major factor causing high PN emissionsmore » is fuel liquid impingement on the piston bowl. By avoiding fuel impingement, more than an order of magnitude reduction in PN emission was observed. Increasing fuel injection pressure reduces PN emissions because of smaller fuel droplet size and faster fuel-air mixing. PN emissions are insensitive to cam phasing and spark timing, especially at high engine load. Cold engine conditions produce higher PN emissions than hot engine conditions due to slower fuel vaporization and thus less fuel-air homogeneity during the combustion process. E20 produces lower PN emissions at low and medium loads if fuel liquid impingement on piston bowl is avoided. At high load or if there is fuel liquid impingement on piston bowl and/or cylinder wall, E20 tends to produce higher PN emissions. This is probably a function of the higher heat of vaporization of ethanol, which slows the vaporization of other fuel components from surfaces and may create local fuel-rich combustion or even pool-fires.« less

[Cold-induced urticaria].

PubMed

Delorme, N; Drouet, M; Thibaudeau, A; Verret, J L

2002-09-01

Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried.

40 CFR 90.409 - Engine dynamometer test run.

Code of Federal Regulations, 2014 CFR

2014-07-01

...). (3) Record all pre-test data specified in § 90.405(c). (4) Start the test cycle (see § 90.410) within... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine dynamometer test run. 90.409... Test Procedures § 90.409 Engine dynamometer test run. (a) Engine and dynamometer start-up. (1) Only...

40 CFR 90.409 - Engine dynamometer test run.

Code of Federal Regulations, 2010 CFR

2010-07-01

...). (3) Record all pre-test data specified in § 90.405(c). (4) Start the test cycle (see § 90.410) within... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine dynamometer test run. 90.409... Test Procedures § 90.409 Engine dynamometer test run. (a) Engine and dynamometer start-up. (1) Only...

40 CFR 90.409 - Engine dynamometer test run.

Code of Federal Regulations, 2013 CFR

2013-07-01

...). (3) Record all pre-test data specified in § 90.405(c). (4) Start the test cycle (see § 90.410) within... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine dynamometer test run. 90.409... Test Procedures § 90.409 Engine dynamometer test run. (a) Engine and dynamometer start-up. (1) Only...

40 CFR 90.409 - Engine dynamometer test run.

Code of Federal Regulations, 2012 CFR

2012-07-01

...). (3) Record all pre-test data specified in § 90.405(c). (4) Start the test cycle (see § 90.410) within... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine dynamometer test run. 90.409... Test Procedures § 90.409 Engine dynamometer test run. (a) Engine and dynamometer start-up. (1) Only...

40 CFR 90.409 - Engine dynamometer test run.

Code of Federal Regulations, 2011 CFR

2011-07-01

...). (3) Record all pre-test data specified in § 90.405(c). (4) Start the test cycle (see § 90.410) within... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine dynamometer test run. 90.409... Test Procedures § 90.409 Engine dynamometer test run. (a) Engine and dynamometer start-up. (1) Only...

Start time variability and predictability in railroad train and engine freight and passenger service employees.

DOT National Transportation Integrated Search

2014-04-01

Start time variability in work schedules is often hypothesized to be a cause of railroad employee fatigue because unpredictable work start times prevent employees from planning sleep and personal activities. This report examines work start time diffe...

Hydraulically actuated fuel injector including a pilot operated spool valve assembly and hydraulic system using same

DOEpatents

Shafer, Scott F.

2002-01-01

The present invention relates to hydraulic systems including hydraulically actuated fuel injectors that have a pilot operated spool valve assembly. One class of hydraulically actuated fuel injectors includes a solenoid driven pilot valve that controls the initiation of the injection event. However, during cold start conditions, hydraulic fluid, typically engine lubricating oil, is particularly viscous and is often difficult to displace through the relatively small drain path that is defined past the pilot valve member. Because the spool valve typically responds slower than expected during cold start due to the difficulty in displacing the relatively viscous oil, accurate start of injection timing can be difficult to achieve. There also exists a greater difficulty in reaching the higher end of the cold operating speed range. Therefore, the present invention utilizes a fluid evacuation valve to aid in displacement of the relatively viscous oil during cold start conditions.

Load-Dependent Emission Factors and Chemical Characteristics of IVOCs from a Medium-Duty Diesel Engine.

PubMed

Cross, Eben S; Sappok, Alexander G; Wong, Victor W; Kroll, Jesse H

2015-11-17

A detailed understanding of the climate and air quality impacts of mobile-source emissions requires the characterization of intermediate-volatility organic compounds (IVOCs), relatively-low-vapor-pressure gas-phase species that may generate secondary organic aerosol with high yields. Due to challenges associated with IVOC detection and quantification, IVOC emissions remain poorly understood at present. Here, we describe measurements of the magnitude and composition of IVOC emissions from a medium-duty diesel engine. Measurements are made on an engine dynamometer and utilize a new mass-spectrometric instrument to characterize the load dependence of the emissions in near-real-time. Results from steady-state engine operation indicate that IVOC emissions are highly dependent on engine power, with highest emissions at engine idle and low-load operation (≤25% maximum rated power) with a chemical composition dominated by saturated hydrocarbon species. Results suggest that unburned fuel components are the dominant IVOCs emitted at low loads. As engine load increases, IVOC emissions decline rapidly and become increasingly characterized by unsaturated hydrocarbons and oxygenated organics, newly formed from incomplete combustion processes at elevated engine temperatures and pressures. Engine transients, including a cold-start ignition and engine acceleration, show IVOC emission profiles that are different in amount or composition compared to steady-state combustion, underscoring the utility of characterizing IVOC emissions with high time resolution across realistic engine operating conditions. We find possible evidence for IVOC losses on unheated dilution and sampling surfaces, which need to be carefully accounted for in IVOC emission studies.

14 CFR 23.903 - Engines.

Code of Federal Regulations, 2014 CFR

2014-01-01

... engine compartment) of any system that can affect an engine (other than a fuel tank if only one fuel tank...) Starting and stopping (piston engine). (1) The design of the installation must be such that risk of fire or...

14 CFR 23.903 - Engines.

Code of Federal Regulations, 2013 CFR

2013-01-01

... engine compartment) of any system that can affect an engine (other than a fuel tank if only one fuel tank...) Starting and stopping (piston engine). (1) The design of the installation must be such that risk of fire or...

Single-ion quantum Otto engine with always-on bath interaction

NASA Astrophysics Data System (ADS)

Chand, Suman; Biswas, Asoka

2017-06-01

We demonstrate how the reciprocating heat cycle of a quantum Otto engine (QOE) can be implemented using a single ion and an always-on thermal environment. The internal degree of freedom of the ion is chosen as the working fluid, while the motional degree of freedom can be used as the cold bath. We show, that by adiabatically changing the local magnetic field, the work efficiency can be asymptotically made unity. We propose a projective measurement of the internal state of the ion that mimics the release of heat from the working fluid during the engine cycle. In our proposal, the coupling to the hot and the cold baths need not be switched off and on in an alternate fashion during the engine cycle, unlike other existing proposals of QOE. This renders the proposal experimentally feasible using the available tapped-ion engineering technology.

Cold-Weather Engineering, Chapters 1 to 5

DTIC Science & Technology

1949-01-01

adäquate^, except under- extreme con~ ditiOns. of heat loss.. Milkr-Qrie ’pint or mo:re daily;. Eva-? poiiated or powdered milk is- $xistr äs good...as fi;esh milk . Egga^One or two, per day. Dehydrated ¥ggs are- äs good as- fresh eggs.-. Meat-One serving per day> ._ Äth some fat/ Liver...it.i Material for building, maintaining/ and lubricating the human engine is -obtained’ from proteins’ %ae.at;, fish, - milk ,, eggs), and

Cold urticaria. Dissociation of cold-evoked histamine release and urticara following cold challenge.

PubMed

Keahey, T M; Greaves, M W

1980-02-01

Nine patients with acquired cold urticaria were studied to assess the effects of beta-adrenergic agents, xanthines, and corticosteroids on cold-evoked histamine release from skin in vivo. The patients, in all of whom an immediate urticarial response developed after cooling of the forearm, demonstrated release of histamine into the venous blood draining that forearm. Following treatment with aminophylline and albuterol in combination or prednisone alone, suppression of histamine release occurred in all but one patient. In some patients, this was accompanied by a subjective diminution in pruritus or buring, but there was no significant improvement in the ensuing edema or erythema. In one patient, total suppression of histamine release was achieved without any effect on whealing and erythema in response to cold challenge. Our results suggest that histamine is not central to the pathogenesis of vascular changes in acquired cold urticaria.

Design and Test of a Liquid Oxygen / Liquid Methane Thruster with Cold Helium Pressurization Heat Exchanger

NASA Technical Reports Server (NTRS)

Melcher, John C.; Morehead, Robert L.; Atwell, Matthew J.; Hurlbert, Eric A.

2015-01-01

A liquid oxygen / liquid methane 2,000 lbf thruster was designed and tested in conjuction with a nozzle heat exchanger for cold helium pressurization. Cold helium pressurization systems offer significant spacecraft vehicle dry mass savings since the pressurant tank size can be reduced as the pressurant density is increased. A heat exchanger can be incorporated into the main engine design to provide expansion of the pressurant supply to the propellant tanks. In order to study the systems integration of a cold-helium pressurization system, a 2,000 lbf thruster with a nozzle heat exchanger was designed for integration into the Project Morpheus vehicle at NASA Johnson Space Center. The testing goals were to demonstrate helium loading and initial conditioning to low temperatures, high-pressure/low temperature storage, expansion through the main engine heat exchanger, and propellant tank injection/pressurization. The helium pressurant tank was an existing 19 inch diameter composite-overwrap tank, and the targert conditions were 4500 psi and -250 F, providing a 2:1 density advantage compared to room tempatrue storage. The thruster design uses like-on-like doublets in the injector pattern largely based on Project Morpheus main engine hertiage data, and the combustion chamber was designed for an ablative chamber. The heat exchanger was installed at the ablative nozzle exit plane. Stand-alone engine testing was conducted at NASA Stennis Space Center, including copper heat-sink chambers and highly-instrumented spoolpieces in order to study engine performance, stability, and wall heat flux. A one-dimensional thermal model of the integrated system was completed. System integration into the Project Morpheus vehicle is complete, and systems demonstrations will follow.

Pumping Performance or RBCC Engine under Sea Level Static Condition

NASA Astrophysics Data System (ADS)

Kouchi, Toshinori; Tomioka, Sadatake; Kanda, Takeshi

Numerical simulations were conducted to predict the ejector pumping performance of a rocket-ramjet combined-cycle engine under a take-off condition. The numerical simulations revealed that the suction airflow was chocked at the exit of the engine throat when the ejector rocket was driven by cold N2 gas at the chamber pressure of 3MPa. When the ejector-driving gas was changed from cold N2 gas to hot combustion gas, the suction performance decreased remarkably. Mach contours in the engine revealed that the rocket plume constricted when the driving gas was the hot combustion gas. The change of the area of the stream tube area seemed to induce the pressure rise in the duct and decreasing in the pumping performance.

Long pulse EBW start-up experiments in MAST

DOE PAGES

Shevchenko, V. F.; Baranov, Y. F.; Bigelow, T.; ...

2015-03-12

Start-up technique reported here relies on a double mode conversion (MC) for electron Bernstein wave (EBW) excitation. It consists of MC of the ordinary (O) mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X) mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma, passes through electron cyclotron resonance (ECR) and experiences a subsequent X to EBW MC near the upper hybrid resonance (UHR). Finally the excited EBW mode is totally absorbed at the Doppler shifted ECR. The absorption of EBW remains high even inmore » cold rarefied plasmas. Furthermore, EBW can generate significant plasma current giving the prospect of a fully solenoid-free plasma start-up. First experiments using this scheme were carried out on MAST [1]. Plasma currents up to 33 kA have been achieved using 28 GHz 100kW 90ms RF pulses. Recently experimental results were extended to longer RF pulses showing further increase of plasma currents generated by RF power alone. A record current of 73kA has been achieved with 450ms RF pulse of similar power. The current drive enhancement was mainly achieved due to RF pulse extension and further optimisation of the start-up scenario.« less

Long pulse EBW start-up experiments in MAST

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

Shevchenko, V. F.; Baranov, Y. F.; Bigelow, T.

Start-up technique reported here relies on a double mode conversion (MC) for electron Bernstein wave (EBW) excitation. It consists of MC of the ordinary (O) mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X) mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma, passes through electron cyclotron resonance (ECR) and experiences a subsequent X to EBW MC near the upper hybrid resonance (UHR). Finally the excited EBW mode is totally absorbed at the Doppler shifted ECR. The absorption of EBW remains high even inmore » cold rarefied plasmas. Furthermore, EBW can generate significant plasma current giving the prospect of a fully solenoid-free plasma start-up. First experiments using this scheme were carried out on MAST [1]. Plasma currents up to 33 kA have been achieved using 28 GHz 100kW 90ms RF pulses. Recently experimental results were extended to longer RF pulses showing further increase of plasma currents generated by RF power alone. A record current of 73kA has been achieved with 450ms RF pulse of similar power. The current drive enhancement was mainly achieved due to RF pulse extension and further optimisation of the start-up scenario.« less

Long Pulse EBW Start-up Experiments in MAST

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

Shevchenko, V. F.; Bigelow, Tim S; Caughman, J. B. O.

Start-up technique reported here relies on a double mode conversion (MC) for electron Bernstein wave (EBW) excitation. It consists of MC of the ordinary (0) mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X) mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma, passes through electron cyclotron resonance (ECR) and experiences a subsequent X to EBW MC near the upper hybrid resonance (UHR). Finally the excited EBW mode is totally absorbed at the Doppler shifted ECR. The absorption of EBW remains high even inmore » cold rarefied plasmas. Furthermore, EBW can generate significant plasma current giving the prospect of a fully solenoid-free plasma start-up. First experiments using this scheme were carried out on MAST [1]. Plasma currents up to 33 kA have been achieved using 28 GHz 100kW 90ms RF pulses. Recently experimental results were extended to longer RF pulses showing further increase of plasma currents generated by RF power alone. A record current of 73kA has been achieved with 450ms RF pulse of similar power. The current drive enhancement was mainly achieved due to RF pulse extension and further optimisation of the start-up scenario.« less

Assessment of transit supportive land use for new starts projects : FY 1999 new starts report. A supplement to the fiscal year 1999 report on funding levels and allocations of funds for transit major capital investments

DOT National Transportation Integrated Search

1998-11-01

FTA assessed and rated the Transit Supportive Existing Land Use and Future Patterns of 30 candidate New Starts projects, in preliminary engineering and final design, documented in the FY 1999 New Starts Report. These land use assessments (30) examine...

Global transcriptional profiling of a cold-tolerant rice variety under moderate cold stress reveals different cold stress response mechanisms.

PubMed

Zhao, Junliang; Zhang, Shaohong; Yang, Tifeng; Zeng, Zichong; Huang, Zhanghui; Liu, Qing; Wang, Xiaofei; Leach, Jan; Leung, Hei; Liu, Bin

2015-07-01

Gene expression profiling under severe cold stress (4°C) has been conducted in plants including rice. However, rice seedlings are frequently exposed to milder cold stresses under natural environments. To understand the responses of rice to milder cold stress, a moderately low temperature (8°C) was used for cold treatment prior to genome-wide profiling of gene expression in a cold-tolerant japonica variety, Lijiangxintuanheigu (LTH). A total of 5557 differentially expressed genes (DEGs) were found at four time points during moderate cold stress. Both the DEGs and differentially expressed transcription factor genes were clustered into two groups based on their expression, suggesting a two-phase response to cold stress and a determinative role of transcription factors in the regulation of stress response. The induction of OsDREB2A under cold stress is reported for the first time in this study. Among the anti-oxidant enzyme genes, glutathione peroxidase (GPX) and glutathione S-transferase (GST) were upregulated, suggesting that the glutathione system may serve as the main reactive oxygen species (ROS) scavenger in LTH. Changes in expression of genes in signal transduction pathways for auxin, abscisic acid (ABA) and salicylic acid (SA) imply their involvement in cold stress responses. The induction of ABA response genes and detection of enriched cis-elements in DEGs suggest that ABA signaling pathway plays a dominant role in the cold stress response. Our results suggest that rice responses to cold stress vary with the specific temperature imposed and the rice genotype. © 2014 Scandinavian Plant Physiology Society.

Cold-hearted or cool-headed: physical coldness promotes utilitarian moral judgment

PubMed Central

Nakamura, Hiroko; Ito, Yuichi; Honma, Yoshiko; Mori, Takuya; Kawaguchi, Jun

2014-01-01

In the current study, we examine the effect of physical coldness on personal moral dilemma judgment. Previous studies have indicated that utilitarian moral judgment—sacrificing a few people to achieve the greater good for others—was facilitated when: (1) participants suppressed an initial emotional response and deliberately thought about the utility of outcomes; (2) participants had a high-level construal mindset and focused on abstract goals (e.g., save many); or (3) there was a decreasing emotional response to sacrificing a few. In two experiments, we exposed participants to extreme cold or typical room temperature and then asked them to make personal moral dilemma judgments. The results of Experiment 1 indicated that coldness prompted utilitarian judgment, but the effect of coldness was independent from deliberate thought or abstract high-level construal mindset. As Experiment 2 revealed, coldness facilitated utilitarian judgment via reduced empathic feelings. Therefore, physical coldness did not affect the “cool-headed” deliberate process or the abstract high-level construal mindset. Rather, coldness biased people toward being “cold-hearted,” reduced empathetic concern, and facilitated utilitarian moral judgments. PMID:25324800

Recommendations to Improve Employee Thermal Comfort When Working in 40°F Refrigerated Cold Rooms.

PubMed

Ceballos, Diana; Mead, Kenneth; Ramsey, Jessica

2015-01-01

Cold rooms are commonly used for food storage and preparation, and are usually kept around 40°F following food safety guidelines. Some food preparation employees may spend 8 or more hours inside cold rooms. These employees may not be aware of the risks associated with mildly cold temperatures, dampness, and limited ventilation. We performed an evaluation of cold rooms at an airline catering facility because of concerns with exposure to cold temperatures. We spoke with and observed employees in two cold rooms, reviewed daily temperature logs, evaluated employee's physical activity, work/rest schedule, and protective clothing. We measured temperature, percent relative humidity, and air velocities at different work stations inside the cold rooms. We concluded that thermal comfort concerns perceived by cold room employees may have been the result of air drafts at their workstations, insufficient use of personal protective equipment due to dexterity concerns, work practices, and lack of knowledge about good health and safety practices in cold rooms. These moderately cold work conditions with low air velocities are not well covered in current occupational health and safety guidelines, and wind chill calculations do not apply. We provide practical recommendations to improve thermal comfort of cold room employees. Engineering control recommendations include the redesigning of air deflectors and installing of suspended baffles. Administrative controls include the changing out of wet clothing, providing hand warmers outside of cold rooms, and educating employees on cold stress. We also recommended providing more options on personal protective equipment. However, there is a need for guidelines and educational materials tailored to employees in moderately cold environments to improve thermal comfort and minimize health and safety problems.

Recommendations to Improve Employee Thermal Comfort When Working in 40°F Refrigerated Cold Rooms

PubMed Central

Ceballos, Diana; Mead, Kenneth; Ramsey, Jessica

2015-01-01

Cold rooms are commonly used for food storage and preparation, and are usually kept around 40°F following food safety guidelines. Some food preparation employees may spend 8 or more hours inside cold rooms. These employees may not be aware of the risks associated with mildly cold temperatures, dampness, and limited ventilation. We performed an evaluation of cold rooms at an airline catering facility because of concerns with exposure to cold temperatures. We spoke with and observed employees in two cold rooms, reviewed daily temperature logs, evaluated employee’s physical activity, work/rest schedule, and protective clothing. We measured temperature, percent relative humidity, and air velocities at different work stations inside the cold rooms. We concluded that thermal comfort concerns perceived by cold room employees may have been the result of air drafts at their workstations, insufficient use of personal protective equipment due to dexterity concerns, work practices, and lack of knowledge about good health and safety practices in cold rooms. These moderately cold work conditions with low air velocities are not well covered in current occupational health and safety guidelines, and wind chill calculations do not apply. We provide practical recommendations to improve thermal comfort of cold room employees. Engineering control recommendations include the redesigning of air deflectors and installing of suspended baffles. Administrative controls include the changing out of wet clothing, providing hand warmers outside of cold rooms, and educating employees on cold stress. We also recommended providing more options on personal protective equipment. However, there is a need for guidelines and educational materials tailored to employees in moderately cold environments to improve thermal comfort and minimize health and safety problems. PMID:25961447

Research of some operating parameters and the emissions level variation in a spark ignited engine through on-board investigation methods in different loading conditions

NASA Astrophysics Data System (ADS)

Iosif, Ferenti; Baldean, Doru Laurean

2014-06-01

The present paper shows research made on a spark ignited engine with port fuel injection in different operation conditions in order to improve the comprehension about the cold start sequence, acceleration when changing the gear ratios, quality of combustion process and also any measures to be taken for pollutant reduction in such cases. The engineering endeavor encompasses the pollutants investigation during the operation time of gasoline supplied engine with four inline cylinders in different conditions. The temperature and any other parameters were measured with specific sensors installed on the engine or in the exhaust pipes. All the data collected has been evaluated using electronic investigation systems and highly developed equipment. In this manner it has enabled the outline of the idea of how pollutants of engine vary in different operating conditions. Air quality in the everyday environment is very important for the human health, and thus the ambient air quality has a well-known importance in the European pollution standards and legislation. The high level of attention directed to the pollution problem in the European lifestyle is a driving force for all kinds of studies in the field of the reduction of engine emission.

The crabs that live where hot and cold collide.

PubMed

Thurber, Andrew R

2015-07-01

The distribution of Kiwa tyleri with the large male individual in the high-temperature flow (right hand side - fluid flow indicated by shimmering water) and the mixed sex assemblage (left). Note the heavy coat of epibiotic bacteria (grey colouring) on the individual in the hottest section of the vent, as expected from being closest to the sulphide needed to sustain the epibiotic bacteria that this species harvests for its food. Image courtesy of Dr. L. Marsh (Credit: NERC ChEsSo Consortium). In Focus: Marsh, L., Copley, J.T., Tyler, P.A. & Thatje, S. (2015) In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments. Journal of Animal Ecology, 84, 898-913. Southern Ocean hydrothermal vents juxtapose two extremes - intense food-poor cold and scalding food-rich oases. At these vents, Marsh et al. (2015) found a community of Kiwa (Yeti) crabs that separated themselves along this gradient with the largest males sitting in hot, food-rich waters, while smaller males and females co-occur in an intermediate zone of warmth. However, as their eggs start to develop, females embark away from the vent to the food-poor yet stable cold of the Southern Ocean. This species has found an intriguing way to balance foraging risk and population persistence at the interface of hot and cold. © 2015 The Author. Journal of Animal Ecology © 2015 British Ecological Society.

Coal-Fired Rocket Engine

NASA Technical Reports Server (NTRS)

Anderson, Floyd A.

1987-01-01

Brief report describes concept for coal-burning hybrid rocket engine. Proposed engine carries larger payload, burns more cleanly, and safer to manufacture and handle than conventional solid-propellant rockets. Thrust changeable in flight, and stops and starts on demand.

Three-dimensional modeling of diesel engine intake flow, combustion and emissions

NASA Technical Reports Server (NTRS)

Reitz, R. D.; Rutland, C. J.

1992-01-01

A three-dimensional computer code (KIVA) is being modified to include state-of-the-art submodels for diesel engine flow and combustion: spray atomization, drop breakup/coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, soot and radiation, and the intake flow process. Improved and/or new submodels which were completed are: wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo'vich NOx, and spray/wall impingement with rebounding and sliding drops. Results to date show that adding the effects of unsteadiness and compressibility improves the accuracy of heat transfer predictions; spray drop rebound can occur from walls at low impingement velocities (e.g., in cold-starting); larger spray drops are formed at the nozzle due to the influence of vaporization on the atomization process; a laminar-and-turbulent characteristic time combustion model has the flexibility to match measured engine combustion data over a wide range of operating conditions; and finally, the characteristic time combustion model can also be extended to allow predictions of ignition. The accuracy of the predictions is being assessed by comparisons with available measurements. Additional supporting experiments are also described briefly. To date, comparisons with measured engine cylinder pressure and heat flux data were made for homogeneous charge, spark-ignited and compression-ignited engines. The model results are in good agreement with the experiments.

Comparison of free radicals formation induced by cold atmospheric plasma, ultrasound, and ionizing radiation.

PubMed

Rehman, Mati Ur; Jawaid, Paras; Uchiyama, Hidefumi; Kondo, Takashi

2016-09-01

Plasma medicine is increasingly recognized interdisciplinary field combining engineering, physics, biochemistry and life sciences. Plasma is classified into two categories based on the temperature applied, namely "thermal" and "non-thermal" (i.e., cold atmospheric plasma). Non-thermal or cold atmospheric plasma (CAP) is produced by applying high voltage electric field at low pressures and power. The chemical effects of cold atmospheric plasma in aqueous solution are attributed to high voltage discharge and gas flow, which is transported rapidly on the liquid surface. The argon-cold atmospheric plasma (Ar-CAP) induces efficient reactive oxygen species (ROS) in aqueous solutions without thermal decomposition. Their formation has been confirmed by electron paramagnetic resonance (EPR) spin trapping, which is reviewed here. The similarities and differences between the plasma chemistry, sonochemistry, and radiation chemistry are explained. Further, the evidence for free radical formation in the liquid phase and their role in the biological effects induced by cold atmospheric plasma, ultrasound and ionizing radiation are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Kerosene-Fuel Engine Testing Under Way

NASA Image and Video Library

2003-11-17

NASA Stennis Space Center engineers conducted a successful cold-flow test of an RS-84 engine component Sept. 24. The RS-84 is a reusable engine fueled by rocket propellant - a special blend of kerosene - designed to power future flight vehicles. Liquid oxygen was blown through the RS-84 subscale preburner to characterize the test facility's performance and the hardware's resistance. Engineers are now moving into the next phase, hot-fire testing, which is expected to continue into February 2004. The RS-84 engine prototype, developed by the Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., is one of two competing Rocket Engine Prototype technologies - a key element of NASA's Next Generation Launch Technology program.

Kerosene-Fuel Engine Testing Under Way

NASA Technical Reports Server (NTRS)

2003-01-01

NASA Stennis Space Center engineers conducted a successful cold-flow test of an RS-84 engine component Sept. 24. The RS-84 is a reusable engine fueled by rocket propellant - a special blend of kerosene - designed to power future flight vehicles. Liquid oxygen was blown through the RS-84 subscale preburner to characterize the test facility's performance and the hardware's resistance. Engineers are now moving into the next phase, hot-fire testing, which is expected to continue into February 2004. The RS-84 engine prototype, developed by the Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., is one of two competing Rocket Engine Prototype technologies - a key element of NASA's Next Generation Launch Technology program.

Physiological responses to acute cold exposure in young lean men

PubMed Central

Martinez-Tellez, Borja; Sanchez-Delgado, Guillermo; A. Alcantara, Juan M.; Acosta-Manzano, Pedro; Morales-Artacho, Antonio J.; R. Ruiz, Jonatan

2018-01-01

The aim of this study was to comprehensively describe the physiological responses to an acute bout of mild cold in young lean men (n = 11, age: 23 ± 2 years, body mass index: 23.1 ± 1.2 kg/m2) to better understand the underlying mechanisms of non-shivering thermogenesis and how it is regulated. Resting energy expenditure, substrate metabolism, skin temperature, thermal comfort perception, superficial muscle activity, hemodynamics of the forearm and abdominal regions, and heart rate variability were measured under warm conditions (22.7 ± 0.2°C) and during an individualized cooling protocol (air-conditioning and water cooling vest) in a cold room (19.4 ± 0.1°C). The temperature of the cooling vest started at 16.6°C and decreased ~ 1.4°C every 10 minutes until participants shivered (93.5 ± 26.3 min). All measurements were analysed across 4 periods: warm period, at 31% and at 64% of individual´s cold exposure time until shivering occurred, and at the shivering threshold. Energy expenditure increased from warm period to 31% of cold exposure by 16.7% (P = 0.078) and to the shivering threshold by 31.7% (P = 0.023). Fat oxidation increased by 72.6% from warm period to 31% of cold exposure (P = 0.004), whereas no changes occurred in carbohydrates oxidation. As shivering came closer, the skin temperature and thermal comfort perception decreased (all P<0.05), except in the supraclavicular skin temperature, which did not change (P>0.05). Furthermore, the superficial muscle activation increased at the shivering threshold. It is noteworthy that the largest physiological changes occurred during the first 30 minutes of cold exposure, when the participants felt less discomfort. PMID:29734360

Microstructure and texture evolution in cold-rolled and annealed alloy MA-956

NASA Astrophysics Data System (ADS)

Hosoda, Takashi

The microstructural and texture development with thermomechanical processing, performed through a combination of cold-rolling and annealing, in MA-956 plate consisting of a layered and inhomogeneous microstructure was systematically assessed. The alloy contained in mass percent, 20 Cr, 4.8 Al, 0.4 Ti, 0.4 Y2O3, and the balance iron. The starting material was as-hot-rolled plate, 9.7 mm thick. The as-hot-rolled plate was subjected to 40%, 60%, and 80% cold-rolling reduction and subsequently annealed at 1000, 1200, or 1380. Assessment of microstructural and texture developments before and after cold-rolling and annealing was performed using light optical microscopy (LOM), Vickers hardness testing, and electron backscatter diffraction (EBSD). Locally introduced misorientations by cold-rolling in each region were evaluated by Kernel Average Misorientation (KAM) maps. The as-hot-rolled condition contained a layered and inhomogeneous microstructure consisting of thin and coarse elongated grains, and aggregated regions which consisted of fine grains and sub-grains with {100} texture parallel to the longitudinal direction. The microstructure of the 40% cold-rolled condition contained deformation bands, and the 60% and 80% cold-rolled conditions also contained highly deformed regions where the deformation bands were intricately tangled. A predominant orientation of (001) parallel to the rolling direction was developed during cold-rolling, becoming more prominent with increasing reduction. The magnitudes of KAM angles varied through the thickness depending on the initial microstructures. Recrystallization occurred in regions where high KAM angles were dense after annealing and nucleation sites were the aggregation regions, deformation bands, and highly deformed regions. The shape and size of the recrystallized grains varied depending on the nucleation sites.

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...

Method and apparatus for reducing cold-phase emissions by utilizing oxygen-enriched intake air

DOEpatents

Poola, Ramesh B.; Sekar, Ramanujam R.; Stork, Kevin C.

1997-01-01

An oxygen-enriched air intake control system for an internal combustion engine includes air directing apparatus to control the air flow into the intake of the engine. During normal operation of the engine, ambient air flowing from an air filter of the engine flows through the air directing apparatus into the intake of the engine. In order to decrease the amount of carbon monoxide (CO) and hydrocarbon (HC) emissions that tend to be produced by the engine during a short period of time after the engine is started, the air directing apparatus diverts for a short period of time following the start up of the engine at least a portion of the ambient air from the air filter through a secondary path. The secondary path includes a selectively permeable membrane through which the diverted portion of the ambient air flows. The selectively permeable membrane separates nitrogen and oxygen from the diverted air so that oxygen enriched air containing from about 23% to 25% oxygen by volume is supplied to the intake of the engine.

Facility Activation and Characterization for IPD Oxidizer Turbopump Cold-Flow Testing at NASA Stennis Space Center

NASA Technical Reports Server (NTRS)

Sass, J. P.; Raines, N. G.; Farner, B. R.; Ryan, H. M.

2004-01-01

The Integrated Powerhead Demonstrator (IPD) is a 250K lbf (1.1 MN) thrust cryogenic hydrogen/oxygen engine technology demonstrator that utilizes a full flow staged combustion engine cycle. The Integrated Powerhead Demonstrator (IPD) is part of NASA's Next Generation Launch Technology (NGLT) program, which seeks to provide safe, dependable, cost-cutting technologies for future space launch systems. The project also is part of the Department of Defense's Integrated High Payoff Rocket Propulsion Technology (IHPRPT) program, which seeks to increase the performance and capability of today s state-of-the-art rocket propulsion systems while decreasing costs associated with military and commercial access to space. The primary industry participants include Boeing-Rocketdyne and GenCorp Aerojet. The intended full flow engine cycle is a key component in achieving all of the aforementioned goals. The IPD Program achieved a major milestone with the successful completion of the IPD Oxidizer Turbopump (OTP) cold-flow test project at the NASA John C. Stennis Space Center (SSC) E-1 test facility in November 2001. A total of 11 IPD OTP cold-flow tests were completed. Following an overview of the NASA SSC E-1 test facility, this paper addresses the facility aspects pertaining to the activation and the cold-flow testing of the IPD OTP. In addition, some of the facility challenges encountered during the test project are addressed.

Methods of the working processes modelling of an internal combustion engine by an ANSYS IC Engine module

NASA Astrophysics Data System (ADS)

Kurchatkin, I. V.; Gorshkalev, A. A.; Blagin, E. V.

2017-01-01

This article deals with developed methods of the working processes modelling in the combustion chamber of an internal combustion engine (ICE). Methods includes description of the preparation of a combustion chamber 3-d model, setting of the finite-element mesh, boundary condition setting and solution customization. Aircraft radial engine M-14 was selected for modelling. The cycle of cold blowdown in the ANSYS IC Engine software was carried out. The obtained data were compared to results of known calculation methods. A method of engine’s induction port improvement was suggested.

Fourier transform infrared spectroscopy provides an evidence of papain denaturation and aggregation during cold storage.

PubMed

Rašković, Brankica; Popović, Milica; Ostojić, Sanja; Anđelković, Boban; Tešević, Vele; Polović, Natalija

2015-01-01

Papain is a cysteine protease with wide substrate specificity and many applications. Despite its widespread applications, cold stability of papain has never been studied. Here, we used differential spectroscopy to monitor thermal denaturation process. Papain was the most stabile from 45 °C to 60 °C with ΔG°321 of 13.9±0.3 kJ/mol and Tm value of 84±1 °C. After cold storage, papain lost parts of its native secondary structures elements which gave an increase of 40% of intermolecular β-sheet content (band maximum detected at frequency of 1621 cm(-1) in Fourier transform infrared (FT-IR) spectrum) indicating the presence of secondary structures necessary for aggregation. The presence of protein aggregates after cold storage was also proven by analytical size exclusion chromatography. After six freeze-thaw cycles around 75% of starting enzyme activity of papain was lost due to cold denaturation and aggregation of unfolded protein. Autoproteolysis of papain did not cause significant loss of the protein activity. Upon the cold storage, papain underwent structural rearrangements and aggregation that correspond to other cold denatured proteins, rather than autoproteolysis which could have the commercial importance for the growing polypeptide based industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Lessons learned: design, start-up, and operation of cryogenic systems

NASA Astrophysics Data System (ADS)

Bell, W. M.; Bagley, R. E.; Motew, S.; Young, P.-W.

2014-11-01

Cryogenic systems involving a pumped cryogenic fluid, such as liquid nitrogen (LN2), require careful design since the cryogen is close to its boiling point and cold. At 1 atmosphere, LN2 boils at 77.4 K (-320.4 F). These systems, typically, are designed to transport the cryogen, use it for process heat removal, or for generation of gas (GN2) for process use. As the design progresses, it is important to consider all aspects of the design including, cryogen storage, pressure control and safety relief systems, thermodynamic conditions, equipment and instrument selection, materials, insulation, cooldown, pump start-up, maximum design and minimum flow rates, two phase flow conditions, heat flow, process control to meet and maintain operating conditions, piping integrity, piping loads on served equipment, warm-up, venting, and shut-down. "Cutting corners" in the design process can result in stalled start-ups, field rework, schedule hits, or operational restrictions. Some of these "lessoned learned" are described in this paper.

PBF Cooling Tower under construction. Cold water basin is five ...

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

PBF Cooling Tower under construction. Cold water basin is five feet deep. Foundation and basin walls are reinforced concrete. Camera facing west. Pipe openings through wall in front are outlets for return flow of cool water to reactor building. Photographer: John Capek. Date: September 4, 1968. INEEL negative no. 68-3473 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

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 ...

Performance of discrete heat engines and heat pumps in finite time

PubMed

Feldmann; Kosloff

2000-05-01

The performance in finite time of a discrete heat engine with internal friction is analyzed. The working fluid of the engine is composed of an ensemble of noninteracting two level systems. External work is applied by changing the external field and thus the internal energy levels. The friction induces a minimal cycle time. The power output of the engine is optimized with respect to time allocation between the contact time with the hot and cold baths as well as the adiabats. The engine's performance is also optimized with respect to the external fields. By reversing the cycle of operation a heat pump is constructed. The performance of the engine as a heat pump is also optimized. By varying the time allocation between the adiabats and the contact time with the reservoir a universal behavior can be identified. The optimal performance of the engine when the cold bath is approaching absolute zero is studied. It is found that the optimal cooling rate converges linearly to zero when the temperature approaches absolute zero.

Engineering Science Education and the Indian Institutes of Technology: Reframing the Context of the "Cold War and Science" (1950-1970)

ERIC Educational Resources Information Center

Raina, Dhruv

2017-01-01

The last two decades have witnessed a revival of research interest in the Cold War, and on science during the Cold War, from a revised social theoretic perspective. Part of this reframing is evident in explorations of the relationship underpinning the Cold War discourse and modernisation theory. Drawing on this new turn, this article switches the…

14 CFR 23.903 - Engines.

Code of Federal Regulations, 2011 CFR

2011-01-01

... a fuel tank if only one fuel tank is installed), will not: (1) Prevent the continued safe operation... operation of the remaining engines. (d) Starting and stopping (piston engine). (1) The design of the...

14 CFR 23.903 - Engines.

Code of Federal Regulations, 2010 CFR

2010-01-01

... a fuel tank if only one fuel tank is installed), will not: (1) Prevent the continued safe operation... operation of the remaining engines. (d) Starting and stopping (piston engine). (1) The design of the...

Coping with Cold Sores

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cold Sores KidsHealth / For Kids / Cold Sores What's in ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

Cold Stress and the Cold Pressor Test

ERIC Educational Resources Information Center

Silverthorn, Dee U.; Michael, Joel

2013-01-01

Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

Hydrogen-Fuel Engine Component Tests Near Completion

NASA Technical Reports Server (NTRS)

2003-01-01

Gaseous hydrogen is burned off at the E1 Test Stand the night of Oct. 7 during a cold-flow test of the fuel turbopump of the Integrated Powerhead Demonstrator (IPD) at NASA Stennis Space Center (SSC). The gaseous hydrogen spins the pump's turbine during the test, which was conducted to verify the pump's performance. Engineers plan one more test before sending the pump to The Boeing Co. for inspection. It will then be returned to SSC for engine system assembly. The IPD is the first reusable hydrogen-fueled advanced engine in development since the Space Shuttle Main Engine.

Hydrogen-Fuel Engine Component Tests Near Completion

NASA Image and Video Library

2003-11-05

Gaseous hydrogen is burned off at the E1 Test Stand the night of Oct. 7 during a cold-flow test of the fuel turbopump of the Integrated Powerhead Demonstrator (IPD) at NASA Stennis Space Center (SSC). The gaseous hydrogen spins the pump's turbine during the test, which was conducted to verify the pump's performance. Engineers plan one more test before sending the pump to The Boeing Co. for inspection. It will then be returned to SSC for engine system assembly. The IPD is the first reusable hydrogen-fueled advanced engine in development since the Space Shuttle Main Engine.

Study on the Influence of the Cold-End Cooling Water Thickness on the Generative Performance of TEG

NASA Astrophysics Data System (ADS)

Zhou, Li; Guo, Xuexun; Tan, Gangfeng; Ji, Kangping; Xiao, Longjie

2017-05-01

At present, about 40% of the fuel energy is discharged into air with the exhaust gas when an automobile is working, which is a big waste of energy. A thermoelectric generator (TEG) has the ability to harvest the waste heat energy in the exhaust gas. The traditional TEG cold-end is cooled by the engine cooling system, and although its structure is compact, the TEG weight and the space occupied are important factors restricting its application. In this paper, under the premise of ensuring the TEG maximum net output power and reducing the TEG water consumption as much as possible, the optimization of the TEG water thickness in the normal direction of the cold-end surface (WTNCS) is studied, which results in lighter weight, less space occupied and better automobile fuel economy. First, the thermal characteristics of the target diesel vehicle exhaust gas are evaluated based on the experimental data. Then, according to the thermoelectric generation model and the cold-end heat transfer model, the effect of the WTNCS on the cold-end temperature control stability and the system flow resistance are studied. The results show that the WTNCS influences the TEG cold-end temperature. When the engine works in a stable condition, the cold-end temperature decreases with the decrease of the WTNCS. The optimal value of the WTNCS is 0.02 m and the TEG water consumption is 8.8 L. Comparin it with the traditional vehicle exhaust TEG structure, the power generation increased slightly, but the water consumption decreased by about 39.5%, which can save fuel at0.18 L/h when the vehicle works at the speed of 60 km/h.

Efficiency at maximum power of low-dissipation Carnot engines.

PubMed

Esposito, Massimiliano; Kawai, Ryoichi; Lindenberg, Katja; Van den Broeck, Christian

2010-10-08

We study the efficiency at maximum power, η*, of engines performing finite-time Carnot cycles between a hot and a cold reservoir at temperatures Th and Tc, respectively. For engines reaching Carnot efficiency ηC=1-Tc/Th in the reversible limit (long cycle time, zero dissipation), we find in the limit of low dissipation that η* is bounded from above by ηC/(2-ηC) and from below by ηC/2. These bounds are reached when the ratio of the dissipation during the cold and hot isothermal phases tend, respectively, to zero or infinity. For symmetric dissipation (ratio one) the Curzon-Ahlborn efficiency ηCA=1-√Tc/Th] is recovered.

Test Operations Procedure (TOP) 2-2-650 Engine Cold-Starting and Warm-Up Tests

DTIC Science & Technology

2008-02-12

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 12-02-2008 2. REPORT...Page Paragraph 1 . SCOPE................................................................................ 2 2. FACILITIES AND INSTRUMENTATION

Cold Urticaria

MedlinePlus

... severe reactions. For some people with this condition, swimming in cold water could lead to very low ... generally occur with full skin exposure, such as swimming in cold water. Such a reaction could lead ...

J-2X engine test

NASA Image and Video Library

2011-07-26

A plume of steam signals a successful engine start of the J-2X rocket engine on the A-3 Test Stand at Stennis Space Center on July 26. The 3.7-second test was the second on the next-generation engine, which is being developed for NASA by Pratt & Whitney Rocketdyne.

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger

NASA Astrophysics Data System (ADS)

Park, Joonhee; Lee, Joo-Young

2016-04-01

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance ( P < 0.001), preferred hot thermal stimulation ( P = 0.006), and wore heavier clothing during daily life ( P < 0.001) than HSCT. LSCT had significantly lower maximal finger temperatures ( T max) ( P = 0.040), smaller amplitude ( P = 0.029), and delayed onset time of CIVD ( P = 0.080) when compared to HSCT. Some questions examining the self-identified cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude ( P < 0.1). These results indicate that self-identified cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger.

PubMed

Park, Joonhee; Lee, Joo-Young

2016-04-01

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance (P < 0.001), preferred hot thermal stimulation (P = 0.006), and wore heavier clothing during daily life (P < 0.001) than HSCT. LSCT had significantly lower maximal finger temperatures (T max) (P = 0.040), smaller amplitude (P = 0.029), and delayed onset time of CIVD (P = 0.080) when compared to HSCT. Some questions examining the self-identified cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude (P < 0.1). These results indicate that self-identified cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

Common cold

MedlinePlus

... treatments have been tried for colds, such as vitamin C, zinc supplements, and echinacea. Talk to your health ... Accessed February 1, 2017. Hemila H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane ...

A&M. TAN607 second floor plan for cold assembly area. Metallurgical ...

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

A&M. TAN-607 second floor plan for cold assembly area. Metallurgical lab, chemistry lab, nuclear instrument lab, equipment rooms. Ralph M. Parsons 902-ANP-607-A 102. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0607-693-106754 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Make Room for Engineering

ERIC Educational Resources Information Center

Boesdorfer, Sarah; Greenhalgh, Scott

2014-01-01

The "Next Generation Science Standards" (NGSS Lead States 2013) urge science teachers to include engineering practices and ideas in their already full science curriculum, but many teachers do not know where to start. Only 7% of high school science teachers report feeling "very well prepared" to teach engineering. The…

Performance of a Battery Electric Vehicle in the Cold Climate and Hilly Terrain of Vermont

DOT National Transportation Integrated Search

2008-12-23

The goal of this research project was to determine the performance of a battery electric vehicle (BEV) in the cold climate and hilly terrain of Vermont. For this study, a 2005 Toyota Echo was converted from an internal combustion engine (ICE) vehicle...

Comprehensive particle characterization of modern gasoline and diesel passenger cars at low ambient temperatures

NASA Astrophysics Data System (ADS)

Mathis, Urs; Mohr, Martin; Forss, Anna-Maria

Particle measurements were performed in the exhaust of five light-duty vehicles (Euro-3) at +23, -7, and -20 °C ambient temperatures. The characterization included measurements of particle number, active surface area, number size distribution, and mass size distribution. We investigated two port-injection spark-ignition (PISI) vehicles, a direct-injection spark-ignition (DISI) vehicle, a compressed ignition (CI) vehicle with diesel particle filter (DPF), and a CI vehicle without DPF. To minimize sampling effects, particles were directly sampled from the tailpipe with a novel porous tube diluter at controlled sampling parameters. The diluted exhaust was split into two branches to measure either all or only non-volatile particles. Effect of ambient temperature was investigated on particle emission for cold and warmed-up engine. For the gasoline vehicles and the CI vehicle with DPF, the main portion of particle emission was found in the first minutes of the driving cycle at cold engine start. The particle emission of the CI vehicle without DPF was hardly affected by cold engine start. For the PISI vehicles, particle number emissions were superproportionally increased in the diameter size range from 0.1 to 0.3 μm during cold start at low ambient temperature. Based on the particle mass size distribution, the DPF removed smaller particles ( dp<0.5μm) more efficiently than larger particles ( dp>0.5μm). No significant effect of ambient temperature was observed when the engine was warmed up. Peak emission of volatile nanoparticles only took place at specific conditions and was poorly repeatable. Nucleation of particles was predominately observed during or after strong acceleration at high speed and during regeneration of the DPF.

Quantum Otto engine using a single ion and a single thermal bath

NASA Astrophysics Data System (ADS)

Biswas, Asoka; Chand, Suman

2016-05-01

Quantum heat engines employ a quantum system as the working fluid, that gives rise to large work efficiency, beyond the limit for classical heat engines. Existing proposals for implementing quantum heat engines require that the system interacts with the hot bath and the cold bath (both modelled as a classical system) in an alternative fashion and therefore assumes ability to switch off the interaction with the bath during a certain stage of the heat-cycle. However, it is not possible to decouple a quantum system from its always-on interaction with the bath without use of complex pulse sequences. It is also hard to identify two different baths at two different temperatures in quantum domain, that sequentially interact with the system. Here, we show how to implement a quantum Otto engine without requiring to decouple the bath in a sequential manner. This is done by considering a single thermal bath, coupled to a single trapped ion. The electronic degree of freedom of the ion is chosen as a two-level working fluid while the vibrational degree of freedom plays the role of the cold bath. Measuring the electronic state mimics the release of heat into the cold bath. Thus, our model is fully quantum and exhibits very large work efficiency, asymptotically close to unity.

Study on Self-start up of Polymer Electrolyte Fuel Cell Stack at Subzero Temperature

NASA Astrophysics Data System (ADS)

Shirato, Hiroyasu; Hoshina, Hideo; Yamakoshi, Yukiyasu; Tomita, Kazuhiko; Oka, Yoshiaki

This paper aims to boot up polymer electrolyte fuel cells at subzero temperature without energy from outside and compass the conditions. Visualization tests of water drainage and voltage-current density characteristics provided the selection of a serpentine type as a channel of a fuel cell separator for cold region. The successful start-up of the cell at subzero temperature requires suitable current densities corresponding to the ambient temperature since the lower the temperature is, the lower the cell voltage soon after the start-up is. Suitable amount of exhausted energy is also necessary for the successful self start-up. Humidification using potassium acetate 30 mass% solution provides increased impedance of the cell and inhibits the water freezing owing to its dispersal to the electrode compared to no humidification. A stack laminated 25 sheets of the serpentine type separators enables stabilized power generation at normal temperature. The stack is also bootable with no energy from outside at 263K.

Mitigation of Corrosion in 5 Series Al-Mg Alloys in Marine Environments: Grain Boundary Engineering and Cold Spray Coating Approaches

DTIC Science & Technology

2014-03-26

powders for cold spray are nominally ductile materials such as Cu and Al or Al alloys with particles in the 5-45|am size range. It is for...wavelength) as the x-ray source. Since cold spray is a solid state deposition process , the composition and microstructure of the feedstock powder ...surface of the recently deposited coating build up and a thick coating with theoretical bulk properties can be achieved [27]. The cold

CONTEXTUAL AERIAL VIEW OF "COLD" NORTH HALF OF MTR COMPLEX. ...

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

CONTEXTUAL AERIAL VIEW OF "COLD" NORTH HALF OF MTR COMPLEX. CAMERA FACING EASTERLY. FOREGROUND CORNER CONTAINS OIL STORAGE TANKS. WATER TANKS AND WELL HOUSES ARE BEYOND THEM TO THE LEFT. LARGE LIGHT-COLORED BUILDING IN CENTER OF VIEW IS STEAM PLANT. DEMINERALIZER AND WATER STORAGE TANK ARE BEYOND. SIX-CELL COOLING TOWER AND ITS PUMP HOUSE ARE ABOVE IT IN VIEW. SERVICE BUILDINGS INCLUDING CANTEEN ARE ON NORTH SIDE OF ROAD. "EXCLUSION" AREA IS BEYOND ROAD. COMPARE LOCATION OF EXCLUSION-AREA GATE WITH PHOTO ID-33-G-202. INL NEGATIVE NO. 3608. Unknown Photographer, 10/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

40 CFR 91.506 - Engine sample selection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine sample selection. 91.506... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Manufacturer Production Line Testing Program § 91.506 Engine sample selection. (a) At the start of each model year, the marine SI engine...

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…

Human whole body cold adaptation.

PubMed

Daanen, Hein A M; Van Marken Lichtenbelt, Wouter D

2016-01-01

Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold.

Human whole body cold adaptation

PubMed Central

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

ABSTRACT Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold. PMID:27227100

EDITORIAL: Cold Quantum GasesEditorial: Cold Quantum Gases

NASA Astrophysics Data System (ADS)

Vassen, W.; Hemmerich, A.; Arimondo, E.

2003-04-01

This Special Issue of Journal of Optics B: Quantum and Semiclassical Optics brings together the contributions of various researchers working on theoretical and experimental aspects of cold quantum gases. Different aspects of atom optics, matter wave interferometry, laser manipulation of atoms and molecules, and production of very cold and degenerate gases are presented. The variety of subjects demonstrates the steadily expanding role associated with this research area. The topics discussed in this issue, extending from basic physics to applications of atom optics and of cold atomic samples, include: bulletBose--Einstein condensation bulletFermi degenerate gases bulletCharacterization and manipulation of quantum gases bulletCoherent and nonlinear cold matter wave optics bulletNew schemes for laser cooling bulletCoherent cold molecular gases bulletUltra-precise atomic clocks bulletApplications of cold quantum gases to metrology and spectroscopy bulletApplications of cold quantum gases to quantum computing bulletNanoprobes and nanolithography. This special issue is published in connection with the 7th International Workshop on Atom Optics and Interferometry, held in Lunteren, The Netherlands, from 28 September to 2 October 2002. This was the last in a series of Workshops organized with the support of the European Community that have greatly contributed to progress in this area. The scientific part of the Workshop was managed by A Hemmerich, W Hogervorst, W Vassen and J T M Walraven, with input from members of the International Programme Committee who are listed below. The practical aspects of the organization were ably handled by Petra de Gijsel from the Vrije Universiteit in Amsterdam. The Workshop was funded by the European Science Foundation (programme BEC2000+), the European Networks 'Cold Quantum Gases (CQG)', coordinated by E Arimondo, and 'Cold Atoms and Ultraprecise Atomic Clocks (CAUAC)', coordinated by J Henningsen, by the German Physical Society (DFG), by

The impact of cold spells on mortality and effect modification by cold spell characteristics

NASA Astrophysics Data System (ADS)

Wang, Lijun; Liu, Tao; Hu, Mengjue; Zeng, Weilin; Zhang, Yonghui; Rutherford, Shannon; Lin, Hualiang; Xiao, Jianpeng; Yin, Peng; Liu, Jiangmei; Chu, Cordia; Tong, Shilu; Ma, Wenjun; Zhou, Maigeng

2016-12-01

In China, the health impact of cold weather has received little attention, which limits our understanding of the health impacts of climate change. We collected daily mortality and meteorological data in 66 communities across China from 2006 to 2011. Within each community, we estimated the effect of cold spell exposure on mortality using a Distributed Lag Nonlinear Model (DLNM). We also examined the modification effect of cold spell characteristics (intensity, duration, and timing) and individual-specific factors (causes of death, age, gender and education). Meta-analysis method was finally used to estimate the overall effects. The overall cumulative excess risk (CER) of non-accidental mortality during cold spell days was 28.2% (95% CI: 21.4%, 35.3%) compared with non-cold spell days. There was a significant increase in mortality when the cold spell duration and intensity increased or occurred earlier in the season. Cold spell effects and effect modification by cold spell characteristics were more pronounced in south China. The elderly, people with low education level and those with respiratory diseases were generally more vulnerable to cold spells. Cold spells statistically significantly increase mortality risk in China, with greater effects in southern China. This effect is modified by cold spell characteristics and individual-level factors.

Working smarter on cold cases: identifying factors associated with successful cold case investigations.

PubMed

Davis, Robert C; Jensen, Carl J; Burgette, Lane; Burnett, Kathryn

2014-03-01

Cold case squads have garnered much attention; however, they have yet to undergo significant empirical scrutiny. In the present study, the authors interviewed investigators and reviewed 189 solved and unsolved cold cases in Washington, D.C., to determine whether there are factors that can predict cold case solvability. In the interviews, new information from witnesses or information from new witnesses was cited as the most prevalent reason for case clearance. The case reviews determined that there were factors in each of the following domains that predicted whether cases would be solved during cold case investigations: Crime Context, Initial Investigation Results, Basis for Opening Cold Case, and Cold Case Investigator Actions. The results suggest that it is possible to prioritize cold case work based on the likelihood of investigations leading to clearances. © 2014 American Academy of Forensic Sciences.

Two piston V-type Stirling engine

DOEpatents

Corey, John A.

1987-01-01

A two piston Stirling engine which includes a heat exchanger arrangement placing the cooler and regenerator directly adjacent the compression space for minimal cold duct volume; a sealing arrangement which eliminates the need for piston seals, crossheads and piston rods; and a simplified power control system.

The War on Cancer: Cold Spring Harbor Laboratory Is Fighting the Good Fight.

PubMed

Mertz, Leslie

2017-01-01

Located on the north shore of Long Island in New York, Cold Spring Harbor Laboratory (Figure 1) started out with a marine biology emphasis at the end of the 19th century, but it soon established itself as a prominent cancer research facility. That strong emphasis on cancer work continues today as this private, not-for-profit research institution enters its 127th year (Figure 2).

Diving into Cold Pools

NASA Astrophysics Data System (ADS)

van den Heever, S. C.; Grant, L. D.; Drager, A. J.

2017-12-01

Cold pools play a significant role in convective storm initiation, organization and longevity. Given their role in convective life cycles, recent efforts have been focused on improving the representation of cold pool processes within weather forecast models, as well as on developing cold pool parameterizations in order to better represent their impacts within global climate models. Understanding the physical processes governing cold pool formation, intensity and dissipation is therefore critical to these efforts. Cold pool characteristics are influenced by numerous factors, including those associated with precipitation formation and evaporation, variations in the environmental moisture and shear, and land surface interactions. The focus of this talk will be on the manner in which the surface characteristics and associated processes impact cold pool genesis and dissipation. In particular, the results from high-resolution modeling studies focusing on the role of sensible and latent heat fluxes, soil moisture and SST will be presented. The results from a recent field campaign examining cold pools over northern Colorado will also be discussed.

Study on cold head structure of a 300 Hz thermoacoustically driven pulse tube cryocooler

NASA Astrophysics Data System (ADS)

Yu, G. Y.; Wang, X. T.; Dai, W.; Luo, E. C.

2012-04-01

High reliability, compact size and potentially high thermal efficiency make the high frequency thermoacoustically-driven pulse tube cryocooler quite promising for space use. With continuous efforts, the lowest temperature and the thermal efficiency of the coupled system have been greatly improved. So far, a cold head temperature below 60 K has been achieved on such kind of cryocooler with the operation frequency of around 300 Hz. To further improve the thermal efficiency and expedite its practical application, this work focuses on studying the influence of cold head structure on the system performance. Substantial numerical simulations were firstly carried out, which revealed that the cold head structure would greatly influence the cooling power and the thermal efficiency. To validate the predictions, a lot of experiments have been done. The experiments and calculations are in reasonable agreement. With 500 W heating power input into the engine, a no-load temperature of 63 K and a cooling power of 1.16 W at 80 K have been obtained with parallel-plate cold head, indicating encouraging improvement of the thermal efficiency.

Event attribution: Human influence on the record-breaking cold event in January of 2016 in Eastern China

NASA Astrophysics Data System (ADS)

Qian, C.; Wang, J.; Dong, S.; Yin, H.; Burke, C.; Ciavarella, A.; Dong, B.; Freychet, N.; Lott, F. C.; Tett, S. F.

2017-12-01

It is controversial whether Asian mid-latitude cold surges are becoming more likely as a consequence of Arctic warming. Here, we present an event attribution study in mid-latitude Eastern China. A strong cold surge occurred during 21st-25th January 2016 affecting most areas of China, especially Eastern China. Daily minimum temperature (Tmin) records were broken at many stations. The area averaged anomaly of Tmin over the region (20-44N, 100-124E) for this pentad was the lowest temperature recorded since modern meteorological observations started in 1960. This cold event occurred in a background of the warmest winter Tmin since 1960. Given the vast damages caused by this extreme cold event in Eastern China and the previous mentioned controversy, it is compelling to investigate how much anthropogenic forcing agents have affected the probability of cold events with an intensity equal to or larger than the January 2016 extreme event. We use the Met Office Hadley Centre system for Attribution of extreme weather and Climate Events and station observations to investigate the effect of anthropogenic forcings on the likelihood of such a cold event. Anthropogenic influences are estimated to have reduced the likelihood of an extreme cold event in mid-winter with the intensity equal to or stronger than the record of 2016 in Eastern China by about 2/3.

Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock–induced oxidation

PubMed Central

Borowiec, Anne-Sophie; Sion, Benoit; Chalmel, Frédéric; D. Rolland, Antoine; Lemonnier, Loïc; De Clerck, Tatiana; Bokhobza, Alexandre; Derouiche, Sandra; Dewailly, Etienne; Slomianny, Christian; Mauduit, Claire; Benahmed, Mohamed; Roudbaraki, Morad; Jégou, Bernard; Prevarskaya, Natalia; Bidaux, Gabriel

2016-01-01

Testes of most male mammals present the particularity of being externalized from the body and are consequently slightly cooler than core body temperature (4–8°C below). Although, hypothermia of the testis is known to increase germ cells apoptosis, little is known about the underlying molecular mechanisms, including cold sensors, transduction pathways, and apoptosis triggers. In this study, using a functional knockout mouse model of the cold and menthol receptors, dubbed transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8 initiated the cold-shock response by differentially modulating cold- and heat-shock proteins. Besides, apoptosis of germ cells increased in proportion to the cooling level in control mice but was independent of temperature in knockout mice. We also observed that the rate of germ cell death correlated positively with the reactive oxygen species level and negatively with the expression of the detoxifying enzymes. This result suggests that the TRPM8 sensor is a key determinant of germ cell fate under hypothermic stimulation.—Borowiec, A.-S., Sion, B., Chalmel, F., Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly, E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B., Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock–induced oxidation. PMID:27317670

Common Cold

MedlinePlus

... cure for the common cold. But there are treatments that can make you feel better while you wait for the cold to go away on its own: Getting plenty of rest Drinking fluids Gargling with warm salt water Using cough drops or throat sprays Taking over-the-counter pain ...

Key Reliability Drivers of Liquid Propulsion Engines and A Reliability Model for Sensitivity Analysis

NASA Technical Reports Server (NTRS)

Huang, Zhao-Feng; Fint, Jeffry A.; Kuck, Frederick M.

2005-01-01

This paper is to address the in-flight reliability of a liquid propulsion engine system for a launch vehicle. We first establish a comprehensive list of system and sub-system reliability drivers for any liquid propulsion engine system. We then build a reliability model to parametrically analyze the impact of some reliability parameters. We present sensitivity analysis results for a selected subset of the key reliability drivers using the model. Reliability drivers identified include: number of engines for the liquid propulsion stage, single engine total reliability, engine operation duration, engine thrust size, reusability, engine de-rating or up-rating, engine-out design (including engine-out switching reliability, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction), propellant specific hazards, engine start and cutoff transient hazards, engine combustion cycles, vehicle and engine interface and interaction hazards, engine health management system, engine modification, engine ground start hold down with launch commit criteria, engine altitude start (1 in. start), Multiple altitude restart (less than 1 restart), component, subsystem and system design, manufacturing/ground operation support/pre and post flight check outs and inspection, extensiveness of the development program. We present some sensitivity analysis results for the following subset of the drivers: number of engines for the propulsion stage, single engine total reliability, engine operation duration, engine de-rating or up-rating requirements, engine-out design, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction, and engine health management system implementation (basic redlines and more advanced health management systems).

The effect of exhaust-to-coolant heat transfer on warm-up time and fuel consumption of two automobile engines

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

Goettler, H.J.; Vidger, L.J.; Majkrzak

A 1977 Buick V-6 engine and a 1981 Ford Granada automobile were equipped with heat exchangers to transfer energy from the exhaust gases to the cooling water after cold starts in order to shorten engine warm-up periods and improve fuel economy. A parallel concern was the time required to reach satisfactory heat delivery to the passenger compartment. The Buick engine was investigated in the laboratory. The Ford automobile was tested during driving over a 12.4 km length of freeway and over an 8.6 km test route including both in-town and highway segments. Prior to each test run the engines weremore » exposed to ambient air for at least 8 hours at temperatures ranging from -26/sup 0/C to +2/sup 0/C. The use of the heat exchangers resulted in average reductions of fuel consumption of 2.8% during a 7 minute warm-up period for the engine, and of 2.2% for the automobile when tested on the above test routes. The corresponding times for the coolant in the automobile compartment heater to reach maximum temperature were reduced by 16% and 7%. While fuel savings were achieved, their economic value is questionable, particularly in light of a possible retrofit of an existing automobile with an exhaust-to-coolant heat exchanger and the necessary control equipment.« less

Nonfreezing Cold-Induced Injuries

DTIC Science & Technology

2011-01-01

ty in both m i fitary and civilians who work ill cold conditions. Consequently recognition of those at risk , limiting their exposure and the...shown to have a higher risk for local cold injuries when exposed to cold in real life [10]. Felicijan et al found evidence for a significant...in cold conditions. Consequently recognition of those at risk , limiting their exposure and the appropriate and timely use of suitable protective

Analysis of Performance of Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation

NASA Technical Reports Server (NTRS)

Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl

1949-01-01

In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.

Main processes of the Atlantic cold tongue interannual variability

NASA Astrophysics Data System (ADS)

Planton, Yann; Voldoire, Aurore; Giordani, Hervé; Caniaux, Guy

2018-03-01

The interannual variability of the Atlantic cold tongue (ACT) is studied by means of a mixed-layer heat budget analysis. A method to classify extreme cold and warm ACT events is proposed and applied to ten various analysis and reanalysis products. This classification allows 5 cold and 5 warm ACT events to be selected over the period 1982-2007. Cold (warm) ACT events are defined by the presence of negative (positive) sea surface temperature (SST) anomalies at the center of the equatorial Atlantic in late boreal spring, preceded by negative (positive) zonal wind stress anomalies in the western equatorial Atlantic. An ocean general circulation model capable of reconstructing the interannual variability of the ACT correctly is used to demonstrate that cold ACT events develop rapidly from May to June mainly due to intense cooling by vertical mixing and horizontal advection. The simulated cooling at the center of the basin is the result of the combined effects of non-local and local processes. The non-local process is an upwelling associated with an eastward-propagating Kelvin wave, which makes the mixed-layer more shallow and preconditions the upper layers to be cooled by an intense heat loss at the base of the mixed-layer, which is amplified by a stronger local injection of energy from the atmosphere. The early cooling by vertical mixing in March is also shown to be a good predictor of June cooling. In July, horizontal advection starts to warm the mixed-layer abnormally and damps SST anomalies. The advection anomalies, which result from changes in the horizontal temperature gradient, are associated in some cases with the propagation of Rossby waves along the equator. During warm ACT events, processes are reversed, generating positive SST anomalies: a downwelling Kelvin wave triggers stratification anomalies and mixed-layer depth anomalies, amplified by a weaker injection of energy from the atmosphere in May-June. In July, warm ACT events are abnormally cooled due to

Vitamin C and colds

MedlinePlus

Colds and vitamin C ... is that vitamin C can cure the common cold . However, research about this claim is conflicting. Although ... vitamin C may help reduce how long a cold lasts. They do not protect against getting a ...

Co-regulation analysis of co-expressed modules under cold and pathogen stress conditions in tomato.

PubMed

Abedini, Davar; Rashidi Monfared, Sajad

2018-06-01

A primary mechanism for controlling the development of multicellular organisms is transcriptional regulation, which carried out by transcription factors (TFs) that recognize and bind to their binding sites on promoter region. The distance from translation start site, order, orientation, and spacing between cis elements are key factors in the concentration of active nuclear TFs and transcriptional regulation of target genes. In this study, overrepresented motifs in cold and pathogenesis responsive genes were scanned via Gibbs sampling method, this method is based on detection of overrepresented motifs by means of a stochastic optimization strategy that searches for all possible sets of short DNA segments. Then, identified motifs were checked by TRANSFAC, PLACE and Soft Berry databases in order to identify putative TFs which, interact to the motifs. Several cis/trans regulatory elements were found using these databases. Moreover, cross-talk between cold and pathogenesis responsive genes were confirmed. Statistical analysis was used to determine distribution of identified motifs on promoter region. In addition, co-regulation analysis results, illustrated genes in pathogenesis responsive module are divided into two main groups. Also, promoter region was crunched to six subareas in order to draw the pattern of distribution of motifs in promoter subareas. The result showed the majority of motifs are concentrated on 700 nucleotides upstream of the translational start site (ATG). In contrast, this result isn't true in another group. In other words, there was no difference between total and compartmentalized regions in cold responsive genes.

Colds and flus - antibiotics

MedlinePlus

Antibiotics - colds and flu ... treat infections that are caused by a virus. Colds and flu are caused by viruses. If you ... J, Ericson K, Werner S. Treatment of the common cold in children and adults. Am Fam Physician. 2012; ...

Essential Factors Influencing the Bonding Strength of Cold-Sprayed Aluminum Coatings on Ceramic Substrates

NASA Astrophysics Data System (ADS)

Drehmann, R.; Grund, T.; Lampke, T.; Wielage, B.; Wüstefeld, C.; Motylenko, M.; Rafaja, D.

2018-02-01

The present work summarizes the most important results of a research project dealing with the comprehensive investigation of the bonding mechanisms between cold-sprayed Al coatings and various poly- and monocrystalline ceramic substrates (Al2O3, AlN, Si3N4, SiC, MgF2). Due to their exceptional combination of properties, metallized ceramics are gaining more and more importance for a wide variety of applications, especially in electronic engineering. Cold spray provides a quick, flexible, and cost-effective one-step process to apply metallic coatings on ceramic surfaces. However, since most of the existing cold-spray-related publications focus on metallic substrates, only very little is known about the bonding mechanisms acting between cold-sprayed metals and ceramic substrates. In this paper, the essential factors influencing the bonding strength in such composites are identified. Besides mechanical tensile strength testing, a thorough analysis of the coatings and especially the metal/ceramic interfaces was conducted by means of HRTEM, FFT, STEM, EDX, EELS, GAXRD, and EBSD. The influence of substrate material, substrate temperature, and particle size is evaluated. The results suggest that, apart from mechanical interlocking, the adhesion of cold-sprayed metallic coatings on ceramics is based on a complex interplay of different mechanisms such as quasiadiabatic shearing, static recrystallization, and heteroepitaxial growth.

Pulsejet engine dynamics in vertical motion using momentum conservation

NASA Astrophysics Data System (ADS)

Cheche, Tiberius O.

2017-03-01

The momentum conservation law is applied to analyse the dynamics of a pulsejet engine in vertical motion in a uniform gravitational field in the absence of friction. The model predicts the existence of a terminal speed given the frequency of the short pulses. The conditions where the engine does not return to the starting position are identified. The number of short periodic pulses after which the engine returns to the starting position is found to be independent of the exhaust velocity and gravitational field intensity for a certain frequency of pulses. The pulsejet engine and turbojet engine aircraft models of dynamics are compared. Also the octopus dynamics is modelled. The paper is addressed to intermediate undergraduate students of classical mechanics and aerospace engineering.

Analytical methods to predict liquid congealing in ram air heat exchangers during cold operation

NASA Astrophysics Data System (ADS)

Coleman, Kenneth; Kosson, Robert

1989-07-01

Ram air heat exchangers used to cool liquids such as lube oils or Ethylene-Glycol/water solutions can be subject to congealing in very cold ambients, resulting in a loss of cooling capability. Two-dimensional, transient analytical models have been developed to explore this phenomenon with both continuous and staggered fin cores. Staggered fin predictions are compared to flight test data from the E-2C Allison T56 engine lube oil system during winter conditions. For simpler calculations, a viscosity ratio correction was introduced and found to provide reasonable cold ambient performance predictions for the staggered fin core, using a one-dimensional approach.

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.

Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness

PubMed Central

Esposito Corcione, Carola; Freuli, Fabrizio; Frigione, Mariaenrica

2014-01-01

The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness. PMID:28788215

Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness.

PubMed

Corcione, Carola Esposito; Freuli, Fabrizio; Frigione, Mariaenrica

2014-09-22

The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness.

Thermoregulatory and Immune Responses During Cold Exposure: Effects of Repeated Cold Exposure and Acute Exercise

DTIC Science & Technology

2000-03-01

shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were executed to determine if serial cold ...to cold exposure? The results of these studies suggest that 1) serial cold water blunts shivering leadmg™ower core temperatures, 2) thermoregulatory...fatigues (i.e., causes blunted shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were

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…

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

1979-01-01

Designed to help teachers deal with students in a cold environment, this article explains cold physiology and fundamental laws of heat; describes 14 common cold injuries and their current treatment; and lists a number of useful teaching techniques for cold environments. (SB)

Not Just About the Science: Cold War Politics and the International Indian Ocean Expedition

NASA Astrophysics Data System (ADS)

Harper, K.

2016-12-01

The International Indian Ocean Expedition broke ground for a series of multi-national oceanographic expeditions starting in the late 1950s. In and of itself, it would have been historically significant—like the International Geophysical Year (1957-58)—for pulling together the international scientific community during the Cold War. However, US support for this and follow-on Indian Ocean expeditions were not just about the science; they were also about diplomacy, specifically efforts to bring non-aligned India into the US political orbit and out of the clutches of its Cold War enemy, the Soviet Union. This paper examines the behind-the-scenes efforts at the highest reaches of the US government to extract international political gain out of a large-scale scientific effort.

Ion-Atom Cold Collisions and Atomic Clocks

NASA Technical Reports Server (NTRS)

Prestage, John D.; Maleki, Lute; Tjoelker, Robert L.

1997-01-01

Collisions between ultracold neutral atoms have for some time been the subject of investigation, initially with hydrogen and more recently with laser cooled alkali atoms. Advances in laser cooling and trapping of neutral atoms in a Magneto-Optic Trap (MOT) have made cold atoms available as the starting point for many laser cooled atomic physics investigations. The most spectacularly successful of these, the observation of Bose-Einstein Condensation (BEC) in a dilute ultra-cold spin polarized atomic vapor, has accelerated the study of cold collisions. Experimental and theoretical studies of BEC and the long range interaction between cold alkali atoms is at the boundary of atomic and low temperature physics. Such studies have been difficult and would not have been possible without the development and advancement of laser cooling and trapping of neutral atoms. By contrast, ion-atom interactions at low temperature, also very difficult to study prior to modern day laser cooling, have remained largely unexplored. But now, many laboratories worldwide have almost routine access to cold neutral atoms. The combined technologies of ion trapping, together with laser cooling of neutrals has made these studies experimentally feasible and several very important, novel applications might come out of such investigations . This paper is an investigation of ion-atom interactions in the cold and ultra-cold temperature regime. Some of the collisional ion-atom interactions present at room temperature are very much reduced in the low temperature regime. Reaction rates for charge transfer between unlike atoms, A + B(+) approaches A(+) + B, are expected to fall rapidly with temperature, approximately as T(sup 5/2). Thus, cold mixtures of atoms and ions are expected to coexist for very long times, unlike room temperature mixtures of the same ion-atom combination. Thus, it seems feasible to cool ions via collisions with laser cooled atoms. Many of the conventional collisional interactions

Exercise in the Cold

PubMed Central

Fudge, Jessie

2016-01-01

Context: Hypothermia and frostbite injuries occur in cold weather activities and sporting events. Evidence Acquisition: A PubMed search was used to identify original research and review articles related to cold, frostbite, and hypothermia. Inclusion was based on their relevance to prevention and treatment of cold-related injuries in sports and outdoor activities. Dates of review articles were limited to those published after 2010. No date limit was set for the most recent consensus statements or original research. Study Design: Clinical review. Level of Evidence: Level 5. Results: Frostbite and hypothermia are well-documented entities with good prevention strategies and prehospital treatment recommendations that have changed very little with time. A layered approach to clothing is the best way to prevent injury and respond to weather changes. Each athlete, defined as a participant in a cold weather sport or activity, will respond to cold differently depending on anthropometric measurements and underlying medical risk factors. An understanding of wind-chill temperatures, wetness, and the weather forecast allows athletes and event coordinators to properly respond to changing weather conditions. At the first sign of a freezing cold injury, ensure warm, dry clothes and move to a protected environment. Conclusion: Cold injuries can be prevented, and cold weather activities are safe with proper education, preparation, and response to changing weather conditions or injury. PMID:26857732

Cold adaptation increases rates of nutrient flow and metabolic plasticity during cold exposure in Drosophila melanogaster

PubMed Central

McCue, Marshall D.; Sunny, Nishanth E.; Szejner-Sigal, Andre; Morgan, Theodore J.; Allison, David B.; Hahn, Daniel A.

2016-01-01

Metabolic flexibility is an important component of adaptation to stressful environments, including thermal stress and latitudinal adaptation. A long history of population genetic studies suggest that selection on core metabolic enzymes may shape life histories by altering metabolic flux. However, the direct relationship between selection on thermal stress hardiness and metabolic flux has not previously been tested. We investigated flexibility of nutrient catabolism during cold stress in Drosophila melanogaster artificially selected for fast or slow recovery from chill coma (i.e. cold-hardy or -susceptible), specifically testing the hypothesis that stress adaptation increases metabolic turnover. Using 13C-labelled glucose, we first showed that cold-hardy flies more rapidly incorporate ingested carbon into amino acids and newly synthesized glucose, permitting rapid synthesis of proline, a compound shown elsewhere to improve survival of cold stress. Second, using glucose and leucine tracers we showed that cold-hardy flies had higher oxidation rates than cold-susceptible flies before cold exposure, similar oxidation rates during cold exposure, and returned to higher oxidation rates during recovery. Additionally, cold-hardy flies transferred compounds among body pools more rapidly during cold exposure and recovery. Increased metabolic turnover may allow cold-adapted flies to better prepare for, resist and repair/tolerate cold damage. This work illustrates for the first time differences in nutrient fluxes associated with cold adaptation, suggesting that metabolic costs associated with cold hardiness could invoke resource-based trade-offs that shape life histories. PMID:27605506

Implementing Sustainable Engineering Education through POPBL

NASA Astrophysics Data System (ADS)

Lioe, D. X.; Subhashini, G. K.

2013-06-01

This paper presents the implementation of sustainable engineering education to undergraduate student in Asia Pacific University of Technology and Innovation, Malaysia (APU) through Project-Oriented Problem Based Learning (POPBL). Sustainable engineering has already been the paramount term where it is no longer limited to environment, but also to the entire lifetime of the individual engineer. To inculcate every engineering individual with sustainability, education is the way to start off.

Mechanical Autonomous Stochastic Heat Engine

NASA Astrophysics Data System (ADS)

Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

2016-07-01

Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

Mechanical Autonomous Stochastic Heat Engine.

PubMed

Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

2016-07-01

Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia.

PubMed

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Goldfarb, Shari B; Norton, Larry; Sklarin, Nancy T; Lacouture, Mario E

2016-06-01

The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy. Although not yet reported, improper application procedures could result in adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic and clinical characteristics. The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions and interruption of cold cap use, although grade 1 persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting, however, remains unknown. Cold thermal injuries are likely infrequent and preventable AEs that may result from improper device application procedures during cold cap use. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g., permanent alopecia and scarring) or the need to discontinue cold cap use, are not known. Prospective studies are needed to further elucidate the risk and standardize healthcare delivery methods, and to improve patient/supportive/healthcare provider education.

Cold Shock as a Screen for Genes Involved in Cold Acclimatization in Neurospora crassa

PubMed Central

Watters, Michael K.; Manzanilla, Victor; Howell, Holly; Mehreteab, Alexander; Rose, Erik; Walters, Nicole; Seitz, Nicholas; Nava, Jacob; Kekelik, Sienna; Knuth, Laura; Scivinsky, Brianna

2018-01-01

When subjected to rapid drops of temperature (cold shock), Neurospora responds with a temporary shift in its morphology. This report is the first to examine this response genetically. We report here the results of a screen of selected mutants from the Neurospora knockout library for alterations in their morphological response to cold shock. Three groups of knockouts were selected to be subject to this screen: genes previously suspected to be involved in hyphal development as well as knockouts resulting in morphological changes; transcription factors; and genes homologous to E. coli genes known to alter their expression in response to cold shock. A total of 344 knockout strains were subjected to cold shock. Of those, 118 strains were identified with altered responses. We report here the cold shock morphologies and GO categorizations of strains subjected to this screen. Of strains with knockouts in genes associated with hyphal growth or morphology, 33 of 131 tested (25%) showed an altered response to cold shock. Of strains with knockouts in transcription factor genes, 30 of 145 (20%) showed an altered response to cold shock. Of strains with knockouts in genes homologous to E. coli genes which display altered levels of transcription in response to cold shock, a total of 55 of 68 tested (81%) showed an altered cold shock response. This suggests that the response to cold shock in these two organisms is largely shared in common. PMID:29563189

Simulated Real-World Energy Impacts of a Thermally Sensitive Powertrain Considering Viscous Losses and Enrichment (Presentation)

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

Wood, E.; Gonder, J.; Lopp, S.

It is widely understood that cold-temperature engine operation negatively impacts vehicle fuel use due to a combination of increased friction (high-viscosity engine oil) and temporary enrichment (accelerated catalyst heating). However, relatively little effort has been dedicated to thoroughly quantifying these impacts across a large number of driving cycles and ambient conditions. This work leverages high-quality dynamometer data collected at various ambient conditions to develop a modeling framework for quantifying engine cold-start fuel penalties over a wide array of real-world usage profiles. Additionally, mitigation strategies including energy retention and exhaust heat recovery are explored with benefits quantified for each approach.

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

PubMed

Bentley-Phillips, C B; Eady, R A; Greaves, M W

1978-10-01

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Cold-induced ependymin expression in zebrafish and carp brain: implications for cold acclimation.

PubMed

Tang, S J; Sun, K H; Sun, G H; Lin, G; Lin, W W; Chuang, M J

1999-10-01

Cold acclimation has been suggested to be mediated by alternations in the gene expression pattern in the cold-adapted fish. To investigate the mechanism of cold acclimation in fish brain at the molecular level, relevant subsets of differentially expressed genes of interest were identified and cloned by the PCR-based subtraction suppression hybridization. Characterization of the selected cold-induced cDNA clones revealed one encoding ependymin. This gene was shown to be brain-specific. The expression of ependymin was induced by a temperature shift from 25 degrees C to 6 degrees C in Cyprinus carpio or 12 degrees C in Danio rerio. Activation of ependymin was detected 2 h after cold exposure and peaked at more than 10-fold at 12 h. This peak level remains unchanged until the temperature returns to 25 degrees C. Although the amount of soluble ependymin protein in brain was not changed by cold treatment, its level in the fibrous insoluble polymers increased 2-fold after exposure to low temperature. These findings indicate that the increase in ependymin expression is an early event that may play an important role in the cold acclimation of fish.

Job Prospects for Industrial Engineers.

ERIC Educational Resources Information Center

Basta, Nicholas

1986-01-01

Because of the impetus on how to improve productivity in companies, the demand for graduating industrial engineers continues to be strong from a variety of sources. Starting salary offers for graduates have been averaging $26,784. Enrollments in industrial engineering programs are increasing (with 3,923 graduates in 1984). (JN)

77 FR 43117 - Meeting of the Cold War Advisory Committee for the Cold War Theme Study

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-23

... the Cold War Advisory Committee for the Cold War Theme Study AGENCY: National Park Service, Interior... Committee Act, 5 U.S.C. Appendix, that the Cold War Advisory Committee for the Cold War Theme Study will... National Park Service (NPS) concerning the Cold War Theme Study. DATES: The teleconference meeting will be...

Repeatability of a cold stress test to assess cold sensitization.

PubMed

House, C M; Taylor, R J; Oakley, E H N

2015-10-01

Non-freezing cold injury (NFCI) is a syndrome in which damage to peripheral tissues occurs without the tissues freezing following exposure to low ambient temperatures. To assess the test-retest reliability of a cold stress test (CST) used to assess cold sensitization. Volunteers with no self-reported history of NFCI undertook the CST on three occasions. Thermal images were taken of the foot and hand before, immediately after and 5min after immersion of the limb in cold water for 2min. Cold sensitization was graded by the two clinicians and the lead author. Spot temperatures from the toe and finger pads were recorded. There were 30 white and 19 black male participants. The ratings indicated substantial agreement [a Cohen's kappa (κ) value of 0.61-0.8] to within ± one grading category for the hands and feet of the white volunteers and the hands of the black volunteers. Limits of agreement (LoA) analysis for toe and finger pad temperatures indicated high agreement (absolute 95% LoA < 5.5°C). Test-retest reliability for the feet of the black volunteers was not supported by the gradings (κ = 0.38) and toe pad temperatures (absolute 95% LoA = 9.5°C and coefficient of variation = 11%). The test-retest reliability of the CST is considered adequate for the assessment of the cold sensitization of the hands and feet of white and the hands of black healthy non-patients. The study should be repeated with patients who have suffered a NFCI. © Crown copyright 2015.

40 CFR 90.706 - Engine sample selection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine sample selection. 90.706... (CONTINUED) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Manufacturer Production Line Testing Program § 90.706 Engine sample selection. (a) At the start of each model year, the...

Variable Cold-Induced Brown Adipose Tissue Response to Thyroid Hormone Status

PubMed Central

Hasselgren, Per-Olof; Glasgow, Allison; Doyle, Ashley N.; Lee, Alice J.; Fox, Peter; Gautam, Shiva; Hennessey, James V.; Kolodny, Gerald M.

2017-01-01

Background: In addition to its role in adaptive thermogenesis, brown adipose tissue (BAT) may protect from weight gain, insulin resistance/diabetes, and metabolic syndrome. Prior studies have shown contradictory results regarding the influence of thyroid hormone (TH) levels on BAT volume and activity. The aim of this pilot study was to gain further insights regarding the effect of TH treatment on BAT function in adult humans by evaluating the BAT mass and activity prospectively in six patients, first in the hypothyroid and then in the thyrotoxic phase. Methods: The study subjects underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scanning after cold exposure to measure BAT mass and activity while undergoing treatment for differentiated thyroid cancer, first while hypothyroid following TH withdrawal at the time of the radioactive iodine treatment and then three to six months after starting TH suppressive treatment when they were iatrogenically thyrotoxic. Thermogenic and metabolic parameters were measured in both phases. Results: All study subjects had detectable BAT under cold stimulation in both the hypothyroid and thyrotoxic state. The majority but not all (4/6) subjects showed an increase in detectable BAT volume and activity under cold stimulation between the hypothyroid and thyrotoxic phase (total BAT volume: 72.0 ± 21.0 vs. 87.7 ± 16.5 mL, p = 0.25; total BAT activity 158.1 ± 72.8 vs. 189.0 ± 55.5 SUV*g/mL, p = 0.34). Importantly, circulating triiodothyronine was a stronger predictor of energy expenditure changes compared with cold-induced BAT activity. Conclusions: Iatrogenic hypothyroidism lasting two to four weeks does not prevent cold-induced BAT activation, while the use of TH to induce thyrotoxicosis does not consistently increase cold-induced BAT activity. It remains to be determined which physiological factors besides TH play a role in regulating BAT function. PMID:27750020

Variable Cold-Induced Brown Adipose Tissue Response to Thyroid Hormone Status.

PubMed

Gavrila, Alina; Hasselgren, Per-Olof; Glasgow, Allison; Doyle, Ashley N; Lee, Alice J; Fox, Peter; Gautam, Shiva; Hennessey, James V; Kolodny, Gerald M; Cypess, Aaron M

2017-01-01

In addition to its role in adaptive thermogenesis, brown adipose tissue (BAT) may protect from weight gain, insulin resistance/diabetes, and metabolic syndrome. Prior studies have shown contradictory results regarding the influence of thyroid hormone (TH) levels on BAT volume and activity. The aim of this pilot study was to gain further insights regarding the effect of TH treatment on BAT function in adult humans by evaluating the BAT mass and activity prospectively in six patients, first in the hypothyroid and then in the thyrotoxic phase. The study subjects underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scanning after cold exposure to measure BAT mass and activity while undergoing treatment for differentiated thyroid cancer, first while hypothyroid following TH withdrawal at the time of the radioactive iodine treatment and then three to six months after starting TH suppressive treatment when they were iatrogenically thyrotoxic. Thermogenic and metabolic parameters were measured in both phases. All study subjects had detectable BAT under cold stimulation in both the hypothyroid and thyrotoxic state. The majority but not all (4/6) subjects showed an increase in detectable BAT volume and activity under cold stimulation between the hypothyroid and thyrotoxic phase (total BAT volume: 72.0 ± 21.0 vs. 87.7 ± 16.5 mL, p = 0.25; total BAT activity 158.1 ± 72.8 vs. 189.0 ± 55.5 SUV*g/mL, p = 0.34). Importantly, circulating triiodothyronine was a stronger predictor of energy expenditure changes compared with cold-induced BAT activity. Iatrogenic hypothyroidism lasting two to four weeks does not prevent cold-induced BAT activation, while the use of TH to induce thyrotoxicosis does not consistently increase cold-induced BAT activity. It remains to be determined which physiological factors besides TH play a role in regulating BAT function.

Performance evaluation approach for the supercritical helium cold circulators of ITER

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

Vaghela, H.; Sarkar, B.; Bhattacharya, R.

2014-01-29

The ITER project design foresees Supercritical Helium (SHe) forced flow cooling for the main cryogenic components, namely, the superconducting (SC) magnets and cryopumps (CP). Therefore, cold circulators have been selected to provide the required SHe mass flow rate to cope with specific operating conditions and technical requirements. Considering the availability impacts of such machines, it has been decided to perform evaluation tests of the cold circulators at operating conditions prior to the series production in order to minimize the project technical risks. A proposal has been conceptualized, evaluated and simulated to perform representative tests of the full scale SHe coldmore » circulators. The objectives of the performance tests include the validation of normal operating condition, transient and off-design operating modes as well as the efficiency measurement. A suitable process and instrumentation diagram of the test valve box (TVB) has been developed to implement the tests at the required thermodynamic conditions. The conceptual engineering design of the TVB has been developed along with the required thermal analysis for the normal operating conditions to support the performance evaluation of the SHe cold circulator.« less

On the lightweighting of automobile engine components : forming sheet metal connecting rod

NASA Astrophysics Data System (ADS)

Date, P. P.; Kasture, R. N.; Kore, A. S.

2017-09-01

Reducing the inertia of the reciprocating engine components can lead to significant savings on fuel. A lighter connecting rod (for the same functionality and performance) with a lower material input would be an advantage to the user (customer) and the manufacturer alike. Light materials will make the connecting rod much more expensive compared to those made from steel. Non-ferrous metals are amenable to cold forging of engine components to achieve lightweighting. Alternately, one can make a hollow connecting rod formed from steel sheet, thereby making it lighter, and with many advantages over the conventionally hot forged product. The present paper describes the process of forming a connecting rod from sheet metal. Cold forming (as opposed to high energy needs, lower tool life and the need for greater number of operations and finishing processes in hot forming) would be expected to reduce the cost of manufacture by cold forming. Work hardening during forming is also expected to enhance the in-service performance of the connecting rod.

Method and apparatus for selectively controlling the speed of an engine

DOEpatents

Davis, Roy Inge

2001-02-27

A control assembly 12 for use within a vehicle 10 having an engine 14 and which selectively controls the speed of the engine 14 in order to increase fuel efficiency and to effect relatively smooth starting and stopping of the engine. Particularly, in one embodiment, control assembly 12 cooperatively operates with a starter/alternator assembly 20 and is adapted for use with hybrid vehicles employing a start/stop powertrain assembly, wherein fuel efficiency is increased by selectively stopping engine operation when the vehicle has stopped.

Evolution of Residual Stress and Distortion of Cold-Rolled Bearing Ring from Annealing to Quenched-Tempered Heat Treatment

NASA Astrophysics Data System (ADS)

Lu, Bohan; Lu, Xiaohui

2018-02-01

This study investigates the correlation between the residual stress and distortion behavior of a cold-rolled ring from the annealing to quenching-tempering (QT) process. Due to the cold-rolled process, the external periphery of the bearing ring experiences a compressive residual stress. To relieve the residual stress, cold-rolled rings are annealed at 700 °C which is higher than the starting temperature of recrystallization. When cold-rolled rings are annealed at 700 °C for 15 min, the compressive residual stress is reduced to zero and the outer diameter of the annealed ring becomes larger than that of a non-annealed sample, which is unrelated to annealing time. Simultaneously, the roundness and taper deviation do not obviously change compared with those of non-annealed sample. The stress relaxation during the annealing process was attributed to the recovery and recrystallization of ferrite. Annealing has a genetic influence on the following QT heat treatment, wherein the lowest residual stress is in the non-annealed cold-rolled ring. From the annealing to QT process, the deviation of the outer diameter, roundness, and taper increased with annealing time, a large extend than that of non-annealed samples.

Development of Cryogenic Engine for GSLV MkIII: Technological Challenges

NASA Astrophysics Data System (ADS)

Praveen, RS; Jayan, N.; Bijukumar, KS; Jayaprakash, J.; Narayanan, V.; Ayyappan, G.

2017-02-01

Cryogenic engine capable of delivering 200 kN thrust is being developed for the first time in the country by ISRO for powering the upper stage of GSLV Mk-III, the next generation launch vehicle of ISRO capable of launching four tonne class satellites to Geo-synchronous Transfer Orbit(GTO). Development of this engine started a decade ago when various sub-systems development and testing were taken up. Starting with injector element development, the design, realization and testing of the major sub-systems viz the gas generator, turbopumps, start-up system and thrust chamber have been successfully done in a phased manner before conducting a series of developmental tests in the integrated engine mode. Apart from the major sub-systems, many critical components like the igniter, control components etc were independently developed and qualified. During the development program many challenges were faced in almost all areas of propulsion engineering. Systems engineering of the engine was another key challenge in the realization. This paper gives an outlook on various technological challenges faced in the key areas related to the engine development, insight to the solutions and measures taken to overcome the challenges.

Electronic Equipment Cold Plates

DTIC Science & Technology

1976-04-01

using fans or blowers to force the air through the cooling device». ^J^lJ^^i 5!°^ it ia ’«"^"o^ve. nonto«ic. nonfla—able, *nd possesses good ...Techniques GENERAL THERMAL CONTROL SYSTEMS AND THEIR REgUIREMENTS FLON DISTRIBUTION IN MANIFOLDS THE COLD PLATE IA ,! 1 3 S 12 15 33 32 32... IA .1 132 132 132 155 169 179 183 r (1) Air-Cooled Cold Plate No. (2) Air-Cooled Cold Plate No. (3) Air-cooled Cold Plate No. (4) Air-Cooled

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

Instructors who teach outdoors in an environment so cold as to cause injury must satisfy program objectives while avoiding cold injury to themselves and students, help students focus on learning instead of discomfort, and alleviate some students' intense fear of the cold. Dealing with the cold successfully requires a thorough knowledge of:…

Later Start, Longer Sleep: Implications of Middle School Start Times.

PubMed

Temkin, Deborah A; Princiotta, Daniel; Ryberg, Renee; Lewin, Daniel S

2018-05-01

Although adolescents generally get less than the recommended 9 hours of sleep per night, research and effort to delay school start times have generally focused on high schools. This study assesses the relation between school start times and sleep in middle school students while accounting for potentially confounding demographic variables. Seventh and eighth grade students attending 8 late starting schools (∼8:00 am, n = 630) and 3 early starting schools (∼7:23 am, n = 343) from a diverse suburban school district completed online surveys about their sleep behaviors. Doubly robust inverse probability of treatment weighted regression estimates of the effects of later school start time on student bedtimes, sleep duration, and daytime sleepiness were generated. Attending a school starting 37 minutes later was associated with an average of 17 additional minutes of sleep per weeknight, despite an average bedtime 15 minutes later. Students attending late starting schools were less sleepy than their counterparts in early starting schools, and more likely to be wide awake. Later school start times were significantly associated with improved sleep outcomes for early adolescents, providing support for the movement to delay school start times for middle schools. © 2018, American School Health Association.

Temporal prolongation of decreased skin blood flow causes cold limbs in Parkinson's disease.

PubMed

Shindo, Kazumasa; Kobayashi, Fumikazu; Miwa, Michiaki; Nagasaka, Takamura; Takiyama, Yoshihisa; Shiozawa, Zenji

2013-03-01

To unravel the pathogenesis of cold limbs in Parkinson's disease, we evaluated cutaneous vasomotor neural function in 25 Parkinson's disease patients with or without cold limbs and 20 healthy controls. We measured resting skin sympathetic nerve activity, as well as reflex changes of skin blood flow and skin sympathetic nerve activity after electrical stimulation, with the parameters including skin sympathetic nerve activity frequency at rest, the amplitude of reflex bursts, the absolute decrease and percent reduction of blood flow, and the recovery time which was calculated as the interval from the start of blood flow reduction until the return to baseline cutaneous blood flow. The resting frequency of skin sympathetic nerve activity was significantly lower in patients with Parkinson's disease than in controls (p < 0.01). There were no significant differences between the patients and controls with respect to the amplitude of skin sympathetic nerve activity and the absolute decrease or percent reduction of blood flow volume. In the controls, the recovery time (9.4 ± 1.2), which was similar to Parkinson's disease patients without cold limbs (9.0 ± 0.7), while the recovery time ranged (15.7 ± 3.2) in Parkinson's disease patients with cold limbs. Recovery was significantly slower in these patients compared with the other groups (p < 0.05). It is possible that cold limbs might arise due to impaired circulation based on prolonged vasoconstriction by peripheral autonomic impairments, in addition to central autonomic dysfunction in Parkinson's disease.

Mouse strains to study cold-inducible beige progenitors and beige adipocyte formation and function

PubMed Central

Berry, Daniel C.; Jiang, Yuwei; Graff, Jonathan M.

2016-01-01

Cold temperatures induce formation of beige adipocytes, which convert glucose and fatty acids to heat, and may increase energy expenditure, reduce adiposity and lower blood glucose. This therapeutic potential is unrealized, hindered by a dearth of genetic tools to fate map, track and manipulate beige progenitors and ‘beiging'. Here we examined 12 Cre/inducible Cre mouse strains that mark adipocyte, muscle and mural lineages, three proposed beige origins. Among these mouse strains, only those that marked perivascular mural cells tracked the cold-induced beige lineage. Two SMA-based strains, SMA-CreERT2 and SMA-rtTA, fate mapped into the majority of cold-induced beige adipocytes and SMA-marked progenitors appeared essential for beiging. Disruption of the potential of the SMA-tracked progenitors to form beige adipocytes was accompanied by an inability to maintain body temperature and by hyperglycaemia. Thus, SMA-engineered mice may be useful to track and manipulate beige progenitors, beige adipocyte formation and function. PMID:26729601

40 CFR 90.706 - Engine sample selection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine sample selection. 90.706 Section...) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Manufacturer Production Line Testing Program § 90.706 Engine sample selection. (a) At the start of each model year, the small...

Cold Temperatures Increase Cold Hardiness in the Next Generation Ophraella communa Beetles

PubMed Central

Zhou, Zhong-Shi; Rasmann, Sergio; Li, Min; Guo, Jian-Ying; Chen, Hong-Song; Wan, Fang-Hao

2013-01-01

The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China. We hypothesized that the beetle, to be able to track host-range expansion into colder climates, can phenotypically adapt to cold temperatures across generations. Therefore, we questioned whether parental experience of colder temperatures increases cold tolerance of the progeny. Specifically, we studied the demography, including development, fecundity, and survival, as well as physiological traits, including supercooling point (SCP), water content, and glycerol content of O. communa progeny whose parents were maintained at different temperature regimes. Overall, the entire immature stage decreased survival of about 0.2%–4.2% when parents experienced cold temperatures compared to control individuals obtained from parents raised at room temperature. However, intrinsic capacity for increase (r), net reproductive rate (R 0) and finite rate of increase (λ) of progeny O. communa were maximum when parents experienced cold temperatures. Glycerol contents of both female and male in progeny was significantly higher when maternal and paternal adults were cold acclimated as compared to other treatments. This resulted in the supercooling point of the progeny adults being significantly lower compared to beetles emerging from parents that experienced room temperatures. These results suggest that cold hardiness of O. communa can be promoted by cold acclimation in previous generation, and it might counter-balance reduced survival in the next generation, especially when insects are tracking their host-plants into colder climates. PMID:24098666

Altitude Starting Tests of a 1000-Pound-Thrust Solid-Propellant Rocket

NASA Technical Reports Server (NTRS)

Sloop, John L.; Rollbuhler, R. James; Krawczonek, Eugene M.

1957-01-01

Four solid-propellant rocket engines of nominal 1000-pound-thrust were tested for starting characteristics at pressure altitudes ranging from 112,500 to 123,000 feet and at a temperature of -75 F. All engines ignited and operated successfully. Average chamber pressures ranged from 1060 to ll90 pounds per square inch absolute with action times from 1.51 to 1.64 seconds and ignition delays from 0.070 t o approximately 0.088 second. The chamber pressures and action times were near the specifications, but the ignition delay was almost twice the specified value of 0.040 second.

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)

DSN Scheduling Engine

NASA Technical Reports Server (NTRS)

Clement, Bradley; Johnston, Mark; Wax, Allan; Chouinard, Caroline

2008-01-01

The DSN (Deep Space Network) Scheduling Engine targets all space missions that use DSN services. It allows clients to issue scheduling, conflict identification, conflict resolution, and status requests in XML over a Java Message Service interface. The scheduling requests may include new requirements that represent a set of tracks to be scheduled under some constraints. This program uses a heuristic local search to schedule a variety of schedule requirements, and is being infused into the Service Scheduling Assembly, a mixed-initiative scheduling application. The engine resolves conflicting schedules of resource allocation according to a range of existing and possible requirement specifications, including optional antennas; start of track and track duration ranges; periodic tracks; locks on track start, duration, and allocated antenna; MSPA (multiple spacecraft per aperture); arraying/VLBI (very long baseline interferometry)/delta DOR (differential one-way ranging); continuous tracks; segmented tracks; gap-to-track ratio; and override or block-out of requirements. The scheduling models now include conflict identification for SOA(start of activity), BOT (beginning of track), RFI (radio frequency interference), and equipment constraints. This software will search through all possible allocations while providing a best-effort solution at any time. The engine reschedules to accommodate individual emergency tracks in 0.2 second, and emergency antenna downtime in 0.2 second. The software handles doubling of one mission's track requests over one week (to 42 total) in 2.7 seconds. Further tests will be performed in the context of actual schedules.

Change of Martian surface height associated with polar cold spots

NASA Astrophysics Data System (ADS)

Ford, P. G.; Pettengill, G. H.

2003-12-01

For the past 30 years, orbiting microwave radiometers have observed anomalously low emission temperatures during Martian polar winters. While the physical surface temperature cannot drop significantly below 148K---the point at which CO2 starts to condense---radiometric temperatures of 110K or lower at 25μ wavelength are commonly found in isolated ``cold spots'' throughout both northern and southern polar winters. These form roughly circular patches, tens to hundreds of km in diameter, and persist for no more than a few days. Three models have been proposed to account for them: (a) an atmospheric effect that accompanies CO2 snowfall; (b) fresh surface deposits of CO2 snow; or (c) a change in the properties of CO2 slab ice. Following the success of Smith et al.1 in using the MOLA laser altimeter aboard Mars Global Surveyor to directly measure the growth of the winter polar caps, we have applied the same technique to ask whether cold spots are accompanied by a sudden change in surface height. To identify the cold spots, we first examined all polar observations made by the TES radiometer that was co-boresited with MOLA, and made gridded images of ∂ T / ∂ λ , the derivative of the brightness temperature wrt wavelength, 20μ <= λ <= 25μ , over 5o ranges in Ls. A total of 169 cold spots were readily located in the 3 winters (one northern, two southern) during which MOLA operated, and their times of first appearance were noted. We then examined the individual MOLA tracks that crossed these regions from 30 days before, to 30 days after, the cold spot appearances. Three sets of crossing points were assembled: (a) both pairs of tracks were made before the cold spot appearance, (b) both after the appearance, and (c) one before and the other after. For each crossing point, the surface height was interpolated from the 3 nearest altimeter footprints in each of the two tracks. The difference between the resulting pair of heights was averaged over all crossing points, and

Activities of the Institute for Mechanical Engineering

NASA Astrophysics Data System (ADS)

The Institute of Mechanical Engineering (IME) is part of Canada's National Research Council. Its mission is to undertake, support, promote, and disseminate research and development in the mechanical engineering aspects of three vital sectors of the Canadian economy: transportation, resource industries, and manufacturing. The IME achieves its mission by performing research and development in its own facilities; by developing, providing, and transferring expertise and knowledge; by making its research facilities available to collaborators and clients; and by participating in international liaison and collaborative research activities. Six research programs are conducted in the IME: Advanced Manufacturing Technology; Coastal Zone Engineering; Cold Regions Engineering; Combustion and Fluids Engineering; Ground Transportation Technology; and Machinery and Engine Technology. The rationale and major research thrusts of each program are described, and specific achievements in 1991-92 are reviewed. Lists of technical reports and papers presented by IME personnel are also included.

Primary acquired cold urticaria.

PubMed

Lee, Chyh-Woei; Sheffer, Albert L

2003-01-01

Primary acquired cold urticaria (ACU) is the most common type of cold urticaria characterized by rapid onset of pruritic hives, swelling, and possible severe systemic reactions including hypotension and shock after cold exposure. Primary ACU is diagnosed by history of such symptoms, a positive immediate cold-contact stimulation test, and negative laboratory evaluation for underlying systemic disorders. Clinicians should be aware that patients with ACU may be susceptible to life-threatening systemic reactions especially during aquatic activities and that proper patient education is extremely important. This article reviews the clinical presentation, pathogenesis, diagnosis, and management of primary ACU.

Introducing Engineering Design through an Intelligent Rube Goldberg Implementation

ERIC Educational Resources Information Center

Acharya, Sushil; Sirinterlikci, Arif

2010-01-01

Engineering students need a head start on designing a component, a process, or a system early in their educational endeavors, and engineering design topics need to be introduced appropriately without negatively affecting students' motivation for engineering. In ENGR1010 at Robert Morris University, freshmen engineering students are introduced to…

Viral Uncoating Is Directional: Exit of the Genomic RNA in a Common Cold Virus Starts with the Poly-(A) Tail at the 3′-End

PubMed Central

Sedivy, Arthur; Subirats, Xavier; Kowalski, Heinrich; Köhler, Gottfried; Blaas, Dieter

2013-01-01

Upon infection, many RNA viruses reorganize their capsid for release of the genome into the host cell cytosol for replication. Often, this process is triggered by receptor binding and/or by the acidic environment in endosomes. In the genus Enterovirus, which includes more than 150 human rhinovirus (HRV) serotypes causing the common cold, there is persuasive evidence that the viral RNA exits single-stranded through channels formed in the protein shell. We have determined the time-dependent emergence of the RNA ends from HRV2 on incubation of virions at 56°C using hybridization with specific oligonucleotides and detection by fluorescence correlation spectroscopy. We report that psoralen UV crosslinking prevents complete RNA release, allowing for identification of the sequences remaining inside the capsid. We also present the structure of uncoating intermediates in which parts of the RNA are condensed and take the form of a rod that is directed roughly towards a two-fold icosahedral axis, the presumed RNA exit point. Taken together, in contrast to schemes frequently depicted in textbooks and reviews, our findings demonstrate that exit of the RNA starts from the 3′-end. This suggests that packaging also occurs in an ordered manner resulting in the 3′-poly-(A) tail becoming located close to a position of pore formation during conversion of the virion into a subviral particle. This directional genome release may be common to many icosahedral non-enveloped single-stranded RNA viruses. PMID:23592991

Engineers' Non-Scientific Models in Technology Education

ERIC Educational Resources Information Center

Norstrom, Per

2013-01-01

Engineers commonly use rules, theories and models that lack scientific justification. Examples include rules of thumb based on experience, but also models based on obsolete science or folk theories. Centrifugal forces, heat and cold as substances, and sucking vacuum all belong to the latter group. These models contradict scientific knowledge, but…

Heat strain in cold.

PubMed

Rintamäki, Hannu; Rissanen, Sirkka

2006-07-01

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.

Cold atoms as a coolant for levitated optomechanical systems

NASA Astrophysics Data System (ADS)

Ranjit, Gambhir; Montoya, Cris; Geraci, Andrew A.

2015-01-01

Optically trapped dielectric objects are well suited for reaching the quantum regime of their center-of-mass motion in an ultrahigh-vacuum environment. We show that ground-state cooling of an optically trapped nanosphere is achievable when starting at room temperature, by sympathetic cooling of a cold-atomic gas optically coupled to the nanoparticle. Unlike cavity cooling in the resolved-sideband limit, this system requires only a modest cavity finesse and it allows the cooling to be turned off, permitting subsequent observation of strongly coupled dynamics between the atoms and sphere. Nanospheres cooled to their quantum ground state could have applications in quantum information science or in precision sensing.

Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold-sensing

PubMed Central

Kanda, Hirosato; Gu, Jianguo G.

2016-01-01

Except a small population of primary afferent neurons for sensing cold to generate the sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of other primary afferent neurons that are not for cold-sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In the present study we have found that not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (regarded as cold-ineffective neurons) or suppress (regarded as cold-suppressive neurons) their membrane excitability. For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by the increases in action potential (AP) firing numbers and/or reduction of AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. PMID:26709732

Intermediate Volatility Organic Compound Emissions from On-Road Gasoline Vehicles and Small Off-Road Gasoline Engines.

PubMed

Zhao, Yunliang; Nguyen, Ngoc T; Presto, Albert A; Hennigan, Christopher J; May, Andrew A; Robinson, Allen L

2016-04-19

Dynamometer experiments were conducted to characterize the intermediate volatility organic compound (IVOC) emissions from a fleet of on-road gasoline vehicles and small off-road gasoline engines. IVOCs were quantified through gas chromatography/mass spectrometry analysis of adsorbent samples collected from a constant volume sampler. The dominant fraction (>80%, on average) of IVOCs could not be resolved on a molecular level. These unspeciated IVOCs were quantified as two chemical classes (unspeciated branched alkanes and cyclic compounds) in 11 retention-time-based bins. IVOC emission factors (mg kg-fuel(-1)) from on-road vehicles varied widely from vehicle to vehicle, but showed a general trend of lower emissions for newer vehicles that met more stringent emission standards. IVOC emission factors for 2-stroke off-road engines were substantially higher than 4-stroke off-road engines and on-road vehicles. Despite large variations in the magnitude of emissions, the IVOC volatility distribution and chemical characteristics were consistent across all tests and IVOC emissions were strongly correlated with nonmethane hydrocarbons (NMHCs), primary organic aerosol and speciated IVOCs. Although IVOC emissions only correspond to approximately 4% of NMHC emissions from on-road vehicles over the cold-start unified cycle, they are estimated to produce as much or more SOA than single-ring aromatics. Our results clearly demonstrate that IVOCs from gasoline engines are an important class of SOA precursors and provide observational constraints on IVOC emission factors and chemical composition to facilitate their inclusion into atmospheric chemistry models.

Cold-Weather Sports

MedlinePlus

... Videos for Educators Search English Español Cold-Weather Sports KidsHealth / For Teens / Cold-Weather Sports What's in this article? What to Do? Classes ... weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular ...

Feasibility Study of Jupiter Icy Moons Orbiter Permanent Magnet Alternator Start Sequence

NASA Technical Reports Server (NTRS)

Kenny, Barbara H.; Tokars, Roger P.

2006-01-01

The Jupiter Icy Moons Orbiter (JIMO) mission was a proposed, (recently cancelled) long duration science mission to study three moons of Jupiter: Callisto, Ganymede, and Europa. One design of the JIMO spacecraft used a nuclear heat source in conjunction with a Brayton rotating machine to generate electrical power for the electric thrusters and the spacecraft bus. The basic operation of the closed cycle Brayton system was as follows. The working fluid, a heliumxenon gas mixture, first entered a compressor, then went through a recuperator and hot-side heat exchanger, then expanded across a turbine that drove an alternator, then entered the cold-side of the recuperator and heat exchanger and finally returned to the compressor. The spacecraft was to be launched with the Brayton system off-line and the nuclear reactor shut down. Once the system was started, the helium-xenon gas would be circulated into the heat exchangers as the nuclear reactors were activated. Initially, the alternator unit would operate as a motor so as to drive the turbine and compressor to get the cycle started. This report investigated the feasibility of the start up sequence of a permanent magnet (PM) machine, similar in operation to the alternator unit, without any position or speed feedback sensors ("sensorless") and with a variable load torque. It is found that the permanent magnet machine can start with sensorless control and a load torque of up to 30 percent of the rated value.

Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen

DTIC Science & Technology

2002-06-24

comparison of any baryon and antibaryon by almost a factor of CP606, Non-Neutral Plasma Physics IV, edited by F. Anderegg et al. © 2002 American...antiprotons 3 _one-electron .1 eV quantum cyclotron 0.001 K FIGURE 1. Particle energies a million. An improved baryon CPT test (e.g. involving cold...more precise tests of CPT invariance with baryons and leptons than have been realized so far. The pursuit of cold antihydrogen thus began some time ago

Factors associated with efficacy of an ibuprofen/pseudoephedrine combination drug in pharmacy customers with common cold symptoms.

PubMed

Klimek, Ludger; Schumacher, Helmut; Schütt, Tanja; Gräter, Heidemarie; Mueck, Tobias; Michel, Martin C

2017-02-01

The aim of this study was to explore factors affecting efficacy of treatment of common cold symptoms with an over-the-counter ibuprofen/pseudoephedrine combination product. Data from an anonymous survey among 1770 pharmacy customers purchasing the combination product for treatment of own common cold symptoms underwent post-hoc descriptive analysis. Scores of symptoms typically responsive to ibuprofen (headache, pharyngeal pain, joint pain and fever), typically responsive to pseudoephedrine (congested nose, congested sinus and runny nose), considered non-specific (sneezing, fatigue, dry cough, cough with expectoration) and comprising all 11 symptoms were analysed. Multiple regression analysis was applied to explore factors associated with greater reduction in symptom intensity or greater probability of experiencing a symptom reduction of at least 50%. After intake of first dose of medication, typically ibuprofen-sensitive, pseudoephedrine-responsive, non-specific and total symptoms were reduced by 60.0%, 46.3%, 45.4% and 52.8%, respectively. A symptom reduction of at least 50% was reported by 73.6%, 55.1%, 50.9% and 61.6% of participants, respectively. A high baseline score was associated with greater reductions in symptom scores but smaller probability of achieving an improvement of at least 50%. Across both multiple regression approaches, two tablets at first dosing were more effective than one and (except for ibuprofen-sensitive symptoms) starting treatment later than day 2 of the cold was generally less effective. Efficacy of an ibuprofen/pseudoephedrine combination in the treatment of common cold symptoms was dose-dependent and greatest when treatment started within the first 2 days after onset of symptoms. © 2016 The Authors. International Journal of Clinical Practice Published by John Wiley & Sons Ltd.

The Evolution of the Sonobuoy from World War II to the Cold War

DTIC Science & Technology

2014-01-01

airship , the first aircraft intentionally built for ASW.2 After Wilbur and Orville Wright’s first successful airplane flight in December 1903, the...aircraft had to shut down its engines to use the hydrophone, there was reluctance to use this method for fear the aircraft engine would not start again...the sonobuoy would act as the receiver for the echo from the submarine. This mode became known as “Julie” in 1955, when engineers who worked on the

Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Advanced expander cycle engine optimization

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1979-01-01

The performance optimization of expander cycle engines at vacuum thrust levels of 10K, 15K, and 20K lb is discussed. The optimization is conducted for a maximum engine length with an extendible nozzle in the retracted position of 60 inches and an engine mixture ratio of 6.0:1. The thrust chamber geometry and cycle analyses are documented. In addition, the sensitivity of a recommended baseline expander cycle to component performance variations is determined and chilldown/start propellant consumptions are estimated.

Advanced development receiver thermal vacuum tests with cold wall

NASA Technical Reports Server (NTRS)

Sedgwick, Leigh M.

1991-01-01

The first ever testing of a full size solar dynamic heat receiver using high temperature thermal energy storage was completed. The heat receiver was designed to meet the requirements for operation on the Space Station Freedom. The purpose of the test program was to quantify the receiver thermodynamic performance, its operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber with liquid nitrogen cold shrouds and an aperture cold plate to partially simulate a low Earth orbit environment. The cavity of the receiver was heated by an infrared quartz lamp heater with 30 independently controllable zones to produce flux distributions typical of candidate concentrators. A closed Brayton cycle engine simulator conditioned a helium xenon gas mixture to specific interface conditions to simulate various operational modes of the solar dynamic power module. Inlet gas temperature, pressure, and flow rate were independently varied. A total of 58 simulated orbital cycles were completed during the test conduct period. The test hardware, execution of testing, test data, and post test inspections are described.

Avionics Box Cold Plate Damage Prevention

NASA Technical Reports Server (NTRS)

Stambolian, Damon B.; Larchar, Steven W.; Henderson, Gena; Tran, Donald; Barth, Tim

2012-01-01

Problem Introduction: 1. Prevent Cold Plate Damage in Space Shuttle. 1a. The number of cold plate problems had increased from an average of 16.5 per/year between 1990 through 2000, to an average of 39.6 per year between 2001through 2005. 1b. Each complete set of 80 cold plates cost approximately $29 million, an average of $362,500 per cold plate. 1c It takes four months to produce a single cold plate. 2. Prevent Cold Plate Damage in Future Space Vehicles.

Cold acclimation and cognitive performance: A review.

PubMed

Jones, Douglas M; Bailey, Stephen P; Roelands, Bart; Buono, Michael J; Meeusen, Romain

2017-12-01

Athletes, occupational workers, and military personnel experience cold temperatures through cold air exposure or cold water immersion, both of which impair cognitive performance. Prior work has shown that neurophysiological pathways may be sensitive to the effects of temperature acclimation and, therefore, cold acclimation may be a potential strategy to attenuate cold-induced cognitive impairments for populations that are frequently exposed to cold environments. This review provides an overview of studies that examine repeated cold stress, cold acclimation, and measurements of cognitive performance to determine whether or not cold acclimation provides beneficial protection against cold-induced cognitive performance decrements. Studies included in this review assessed cognitive measures of reaction time, attention, logical reasoning, information processing, and memory. Repeated cold stress, with or without evidence of cold acclimation, appears to offer no added benefit of improving cognitive performance. However, research in this area is greatly lacking and, therefore, it is difficult to draw any definitive conclusions regarding the use of cold acclimation to improve cognitive performance during subsequent cold exposures. Given the current state of minimal knowledge on this topic, athletes, occupational workers, and military commands looking to specifically enhance cognitive performance in cold environments would likely not be advised to spend the time and effort required to become acclimated to cold. However, as more knowledge becomes available in this area, recommendations may change. Copyright © 2017 Elsevier B.V. All rights reserved.

Motor starting a Brayton cycle power conversion system using a static inverter

NASA Technical Reports Server (NTRS)

Curreri, J. S.; Edkin, R. A.; Kruchowy, R.

1973-01-01

The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.

PpCBF3 from Cold-Tolerant Kentucky Bluegrass Involved in Freezing Tolerance Associated with Up-Regulation of Cold-Related Genes in Transgenic Arabidopsis thaliana

PubMed Central

Chen, Yu; Xu, Bin; Yang, Zhimin; Huang, Bingru

2015-01-01

Dehydration-Responsive Element Binding proteins (DREB)/C-repeat (CRT) Binding Factors (CBF) have been identified as transcriptional activators during plant responses to cold stress. The objective of this study was to determine the physiological roles of a CBF gene isolated from a cold-tolerant perennial grass species, Kentucky bluegrass (Poa pratensis L.), which designated as PpCBF3, in regulating plant tolerance to freezing stress. Transient transformation of Arabidopsis thaliana mesophyll protoplast with PpCBF3-eGFP fused protein showed that PpCBF3 was localized to the nucleus. RT-PCR analysis showed that PpCBF3 was specifically induced by cold stress (4°C) but not by drought stress [induced by 20% polyethylene glycol 6000 solution (PEG-6000)] or salt stress (150 mM NaCl). Transgenic Arabidopsis overexpressing PpCBF3 showed significant improvement in freezing (-20°C) tolerance demonstrated by a lower percentage of chlorotic leaves, lower cellular electrolyte leakage (EL) and H2O2 and O2 .- content, and higher chlorophyll content and photochemical efficiency compared to the wild type. Relative mRNA expression level analysis by qRT-PCR indicated that the improved freezing tolerance of transgenic Arabidopsis plants overexpressing PpCBF3 was conferred by sustained activation of downstream cold responsive (COR) genes. Other interesting phenotypic changes in the PpCBF3-transgenic Arabidopsis plants included late flowering and slow growth or ‘dwarfism’, both of which are desirable phenotypic traits for perennial turfgrasses. Therefore, PpCBF3 has potential to be used in genetic engineering for improvement of turfgrass freezing tolerance and other desirable traits. PMID:26177510

Miniature Internal Combustion Engine-Generator for High Energy Density Portable Power

DTIC Science & Technology

2008-12-01

Operation on JP-8 from cold startup to steady operation has been demonstrated at the 300 W scale. Miniature engine/generators can be acoustically silenced...design that uses a spring for energy storage . MICE is a high Q system, operating at the resonant frequency of the spring-mass system with very low...development • Demonstrated 94% efficiency of 300 W linear alternator • Demonstrated full operation of MICE generator from cold startup to net power output

Engine System Loads Development for the Fastrac 60K Flight Engine

NASA Technical Reports Server (NTRS)

Frady, Greg; Christensen, Eric R.; Mims, Katherine; Harris, Don; Parks, Russell; Brunty, Joseph

2000-01-01

Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However, with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the new Fastrac engine program, the focus has been to reduce the cost to weight ratio; current structural dynamics analysis practices were tailored in order to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of Fastrac load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are discussed.

Stirling Engine External Heat System Design with Heat Pipe Heater.

DTIC Science & Technology

1986-07-01

Figure 10. However, the evaporator analysis is greatly simplified by making the conservative assumption of constant heat flux. This assumption results in...number Cold Start Data * " ROM density of the metal, gr/cm 3 CAPM specific heat of the metal, cal./gr. K ETHG effective gauze thickness: the

Engineering the Future: The Social Necessity of Communicative Engineers

ERIC Educational Resources Information Center

Ravesteijn, Wim; De Graaff, Erik; Kroesen, Otto

2006-01-01

It is a long and winding road from invention to innovation. Starting from this observation, this paper presents a historical perspective on the capabilities engineers should possess to do their work. The importance of the "communicative competence" involved in creating a social base for innovation is underpinned. We will present a…

Stirling Space Engine Program. Volume 1; Final Report

NASA Technical Reports Server (NTRS)

Dhar, Manmohan

1999-01-01

The objective of this program was to develop the technology necessary for operating Stirling power converters in a space environment and to demonstrate this technology in full-scale engine tests. Hardware development focused on the Component Test Power Converter (CTPC), a single cylinder, 12.5-kWe engine. Design parameters for the CTPC were 150 bar operating pressure, 70 Hz frequency, and hot-and cold-end temperatures of 1050 K and 525 K, respectively. The CTPC was also designed for integration with an annular sodium heat pipe at the hot end, which incorporated a unique "Starfish" heater head that eliminated highly stressed brazed or weld joints exposed to liquid metal and used a shaped-tubed electrochemical milling process to achieve precise positional tolerances. Selection of materials that could withstand high operating temperatures with long life were another focus. Significant progress was made in the heater head (Udimet 700 and Inconel 718 and a sodium-filled heat pipe); the alternator (polyimide-coated wire with polyimide adhesive between turns and a polyimide-impregnated fiberglass overwrap and samarium cobalt magnets); and the hydrostatic gas bearings (carbon graphite and aluminum oxide for wear couple surfaces). Tests on the CTPC were performed in three phases: cold end testing (525 K), engine testing with slot radiant heaters, and integrated heat pipe engine system testing. Each test phase was successful, with the integrated engine system demonstrating a power level of 12.5 kWe and an overall efficiency of 22 percent in its maiden test. A 1500-hour endurance test was then successfully completed. These results indicate the significant achievements made by this program that demonstrate the viability of Stirling engine technology for space applications.

Definition and documentation of engineering processes

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

McDonald, G.W.

1997-11-01

This tutorial is an extract of a two-day workshop developed under the auspices of the Quality Engineering Department at Sandia National Laboratories. The presentation starts with basic definitions and addresses why processes should be defined and documented. It covers three primary topics: (1) process considerations and rationale, (2) approach to defining and documenting engineering processes, and (3) an IDEFO model of the process for defining engineering processes.

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia

PubMed Central

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Sklarin, Nancy T.; Lacouture, Mario E.

2017-01-01

INTRODUCTION The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy cycles. Although not yet reported, improper application procedures could result in undesirable adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. OBJECTIVE To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. MATERIALS AND METHODS We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic, clinical, and histologic characteristics. RESULTS The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions, although mild persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting however, remains unknown. CONCLUSIONS Cold thermal cold injuries are likely an infrequent and preventable AE that may result from improper device application procedures during scalp cooling. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g. permanent alopecia, scarring) are not known. Future prospective studies are needed to further elucidate the risk and standardized delivery methods, and patient/clinical education. PMID:27146710

31. Photographic copy of the Post Engineer drawing (original is ...

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

31. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) concrete dock details, plan number PE 1265.1 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

34. Photographic copy of the Post Engineer drawing (original is ...

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

34. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) electrical riser plan, plan number PE 1268.2 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

29. Photographic copy of the Post Engineer drawing (original is ...

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

29. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) building section & details, plan number PE 1264.2 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

Biomedical engineering and society: policy and ethics.

PubMed

Flexman, J A; Lazareck, L

2007-01-01

Biomedical engineering impacts health care and contributes to fundamental knowledge in medicine and biology. Policy, such as through regulation and research funding, has the potential to dramatically affect biomedical engineering research and commercialization. New developments, in turn, may affect society in new ways. The intersection of biomedical engineering and society and related policy issues must be discussed between scientists and engineers, policy-makers and the public. As a student, there are many ways to become engaged in the issues surrounding science and technology policy. At the University of Washington in Seattle, the Forum on Science Ethics and Policy (FOSEP, www.fosep.org) was started by graduate students and post-doctoral fellows interested in improving the dialogue between scientists, policymakers and the public and has received support from upper-level administration. This is just one example of how students can start thinking about science policy and ethics early in their careers.

Improvements in Cold-Plate Fabrication

NASA Technical Reports Server (NTRS)

Zaffetti, Mark A.; Taddey, Edmund P.; Laurin, Michael B.; Chabebe, Natalia

2012-01-01

Five improvements are reported in cold-plate fabrication. This cold plate is part of a thermal control system designed to serve on space missions. The first improvement is the merging of the end sheets of the cold plate with the face sheets of the structural honeycomb panel. The cold plate, which can be a brazed assembly, uses the honeycomb face sheet as its end sheet. Thus, when the honeycomb panel is fabricated, the face sheet that is used is already part of the cold plate. In addition to reducing weight, costs, and steps, the main benefit of this invention is that it creates a more structurally sound assembly. The second improvement involves incorporation of the header into the closure bar to pass the fluid to a lower layer. Conventional designs have used a separate header, which increases the geometry of the system. The improvement reduces the geometry, thus allowing the cold plate to fit into smaller area. The third improvement eliminates the need of hose, tube, or manifold to supply the cooling fluid externally. The external arrangement can be easily damaged and is vulnerable to leakage. The new arrangement incorporates an internal fluid transfer tube. This allows the fluid to pass from one cold plate to the other without any exposed external features. The fourth improvement eliminates separate fabrication of cold plate(s) and structural members followed by a process of attaching them to each other. Here, the structural member is made of material that can be brazed just as that of the cold plate. Now the structural member and the cold plate can be brazed at the same time, creating a monolithic unit, and thus a more structurally sound assembly. Finally, the fifth improvement is the elimination of an additional welding step that can damage the braze joints. A tube section, which is usually welded on after the braze process, is replaced with a more structurally sound configuration that can be brazed at the same time as the rest of the cold plate.

ILIDS measurements of the evaporation of fuel droplets during the intake and compression strokes in a firing lean burn engine

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

Skippon, S.M.; Tagaki, Y.

1996-09-01

The evaporation of fuel droplets is an important factor in determining the quality of mixture preparation in lean-burn engines, particularly when using open-valve injection timing, which results in large in-cylinder droplet populations. Interferometric Laser Imaging for Droplet Sizing (ILIDS) has been used to measure the in-cylinder droplet size distribution and fuel volume in the droplet phase as a function of crank angle for a typical full boiling range gasoline and three single component fuels with different boiling points: iso-pentane, iso-octane, and xylene, representing the volatilities of the light end, mid-range and heavy ends of a typical gasoline. The measurements weremore » made under firing conditions, with both open and closed valve injection timing, and at two different coolant temperatures, representing simulated cold start and fully warmed up conditions. A specially built single cylinder research engine was used, equipped with a transparent sapphire cylinder to provide all-round sidewall optical access to the cylinder interior. The engine had a four-valve leanburn head, swirl control valve and air-assisted injector. The experimental arrangements for ILIDS in a firing engine, and the optical access engine itself, are discussed in detail. The results showed significant differences in the rates of evaporation of the three fuel components: iso-pentane evaporated fully very early in the induction stroke, iso-octane droplets persisted longer, and xylene droplets persisted to the end of the compression stroke.« less

Orbit Transfer Vehicle (OTV) engine phase A study

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1978-01-01

Requirements for the orbit transfer vehicle engine were examined. Engine performance/weight sensitivities, the effect of a service life of 300 start/shutdown cycles between overalls on the maximum engine operating pressure, and the sensitivity of the engine design point (i.e., thrust chamber pressure and nozzle area ratio) to the performance requirements specified are among the factors studied. Preliminary engine systems analyses were conducted on the stage combustion, expander, and gas generator engine cycles. Hydrogen and oxygen pump discharge pressure requirements are shown for various engine cycles. Performance of the engine cycles is compared.

Familial polymorphous cold eruption.

PubMed

Martin, S; Eastern, J; Knox, J M

1981-02-01

An erythematous, burning papular eruption, constitutional symptoms, fever, and arthropathy developed in a 65-year-old patient after cold exposure. Involvement of other family members occurred in an autosomal dominant pattern. Histopathologic examination of a biopsy specimen revealed telangiectasia and primarily neutrophilic perivascular inflammation, consistent with earlier biopsy reports of this syndrome. Although previously called "familial cold urticaria," this disease is not characterized by urticaria and may be best descriptively termed, "familial polymorphous cold eruption."

Time-of-Day Effects on Metabolic and Clock-Related Adjustments to Cold.

PubMed

Machado, Frederico Sander Mansur; Zhang, Zhi; Su, Yan; de Goede, Paul; Jansen, Remi; Foppen, Ewout; Coimbra, Cândido Celso; Kalsbeek, Andries

2018-01-01

Daily cyclic changes in environmental conditions are key signals for anticipatory and adaptive adjustments of most living species, including mammals. Lower ambient temperature stimulates the thermogenic activity of brown adipose tissue (BAT) and skeletal muscle. Given that the molecular components of the endogenous biological clock interact with thermal and metabolic mechanisms directly involved in the defense of body temperature, the present study evaluated the differential homeostatic responses to a cold stimulus at distinct time-windows of the light/dark-cycle. Male Wistar rats were subjected to a single episode of 3 h cold ambient temperature (4°C) at one of 6 time-points starting at Zeitgeber Times 3, 7, 11, 15, 19, and 23. Metabolic rate, core body temperature, locomotor activity (LA), feeding, and drinking behaviors were recorded during control and cold conditions at each time-point. Immediately after the stimulus, rats were euthanized and both the soleus and BAT were collected for real-time PCR. During the light phase (i.e., inactive phase), cold exposure resulted in a slight hyperthermia ( p  < 0.001). Light phase cold exposure also increased metabolic rate and LA ( p  < 0.001). In addition, the prevalence of fat oxidative metabolism was attenuated during the inactive phase ( p  < 0.001). These metabolic changes were accompanied by time-of-day and tissue-specific changes in core clock gene expression, such as DBP ( p  < 0.0001) and REV-ERBα ( p  < 0.01) in the BAT and CLOCK ( p  < 0.05), PER2 ( p  < 0.05), CRY1 ( p  < 0.05), CRY2 ( p  < 0.01), and REV-ERBα ( p  < 0.05) in the soleus skeletal muscle. Moreover, genes involved in substrate oxidation and thermogenesis were affected in a time-of-day and tissue-specific manner by cold exposure. The time-of-day modulation of substrate mobilization and oxidation during cold exposure provides a clear example of the circadian modulation of physiological and metabolic

Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems.

PubMed

Rix, Laura; de Goeij, Jasper M; Mueller, Christina E; Struck, Ulrich; Middelburg, Jack J; van Duyl, Fleur C; Al-Horani, Fuad A; Wild, Christian; Naumann, Malik S; van Oevelen, Dick

2016-01-07

Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21-40% of the mucus carbon and 32-39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments.

28. Photographic copy of the Post Engineer drawing (original is ...

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

28. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) building section & wall sections, plan number PE 1264.1 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

Cold chain monitoring during cold transportation of human corneas for transplantation.

PubMed

Net, M; Trias, E; Navarro, A; Ruiz, A; Diaz, P; Fontenla, J R; Manyalich, M

2003-08-01

As recommended by international standards the cornea should be maintained in a specific temperature range (2 degrees -8 degrees C) to guarantee its viability. However, there is no standard packaging method to maintain these conditions during transport. Our packaging system is similar to those used by the main eye banks in Spain and elsewhere in Europe. The objective is to monitor the cold chain in the current packaging method to validate the maintenance of temperature within the adequate range for a minimum 24-hour period. The effects of the following variables were studied: number and freezing temperature of the cold packs; air volume in the packaging system; position of the cornea in the packaging system; and the wall section of the container. Exterior temperature was maintained constant at 20 degrees to 24 degrees C. The cold chain was monitored using a device that measures temperature continuously and for which a histogram of temperature variation can be downloaded to a computer for further analysis. When the cold packs were frozen to -40 degrees C or the number of cold packs increased to four, the temperature decreased quickly to 0 degrees C and the transport period was not prolonged. The main objective was to improve isolation by reducing inner air volume, and maintaining the position of the cornea in the container. The currently used cold packaging systems (not frozen, 4 degrees C) do not maintain the temperature within the accepted range for the required distribution period. The improved system maintains the cornea at between 2 degrees C and 6 degrees C for a minimum of 24 hours.

Age and Ethnic Differences in Cold Weather and Contagion Theories of Colds and Flu

ERIC Educational Resources Information Center

Sigelman, Carol K.

2012-01-01

Age and ethnic group differences in cold weather and contagion or germ theories of infectious disease were explored in two studies. A cold weather theory was frequently invoked to explain colds and to a lesser extent flu but became less prominent with age as children gained command of a germ theory of disease. Explanations of how contact with…

Software Development for EECU Platform of Turbofan Engine

NASA Astrophysics Data System (ADS)

Kim, Bo Gyoung; Kwak, Dohyup; Kim, Byunghyun; Choi, Hee ju; Kong, Changduk

2017-04-01

The turbofan engine operation consists of a number of hardware and software. The engine is controlled by Electronic Engine Control Unit (EECU). In order to control the engine, EECU communicates with an aircraft system, Actuator Drive Unit (ADU), Engine Power Unit (EPU) and sensors on the engine. This paper tried to investigate the process form starting to taking-off and aims to design the EECU software mode and defined communication data format. The software is implemented according to the designed software mode.

33. Photographic copy of the Post Engineer drawing (original is ...

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

33. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) electric plan & light fixture schedule, plan number PE 1268.1 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

32. Photographic copy of the Post Engineer drawing (original is ...

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

32. Photographic copy of the Post Engineer drawing (original is located at Fort Hood) compressor, evaporative condenser & unit cooler schedules, plan number PE 1268 - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Guerra, Claudia V; Hidalgo, Ricardo

2013-06-12

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat and fever (usually < 37.8˚C). The widespread morbidity it causes worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched CENTRAL (2012, Issue 12), MEDLINE (1948 to January week 1, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013) and LILACS (1982 to January 2013). Randomised controlled trials (RCTs) of any virus vaccines to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. Disagreements were resolved by discussion or by consulting a third review author. This review included one RCT with 2307 healthy participants; all of them were analysed. This trial compared the effect of an adenovirus vaccine against a placebo. No statistically significant difference in common cold incidence was found: there were 13 events in 1139 participants in the vaccines group and 14 events in 1168 participants in the placebo group; risk ratio (RR) 0.95, 95% confidence interval (CI) 0.45 to 2.02, P = 0.90). No adverse events related to the live vaccine were reported. This Cochrane review has found a lack of evidence on the effects of vaccines for the common cold in healthy people. Only one RCT was found and this did not show differences between comparison groups; it also had a high risk of bias. There are no conclusive data to support the use of

Cold perception and gene expression differ in Olea europaea seed coat and embryo during drupe cold acclimation.

PubMed

D'Angeli, S; Falasca, G; Matteucci, M; Altamura, M M

2013-01-01

FAD2 and FAD7 desaturases are involved in cold acclimation of olive (Olea europaea) mesocarp. There is no research information available on cold acclimation of seeds during mesocarp cold acclimation or on differences in the cold response of the seed coat and embryo. How FAD2 and FAD7 affect seed coat and embryo cold responses is unknown. Osmotin positively affects cold acclimation in olive tree vegetative organs, but its role in the seeds requires investigation. OeFAD2.1, OeFAD2.2, OeFAD7 and Oeosmotin were investigated before and after mesocarp acclimation by transcriptomic, lipidomic and immunolabelling analyses, and cytosolic calcium concentration ([Ca(2+)](cyt)) signalling, F-actin changes and seed development were investigated by epifluorescence/histological analyses. Transient [Ca(2+)](cyt) rises and F-actin disassembly were found in cold-shocked protoplasts from the seed coat, but not from the embryo. The thickness of the outer endosperm cuticle increased during drupe exposure to lowering of temperature, whereas the embryo protoderm always lacked cuticle. OeFAD2 transcription increased in both the embryo and seed coat in the cold-acclimated drupe, but linoleic acid (i.e. the product of FAD2 activity) increased solely in the seed coat. Osmotin was immunodetected in the seed coat and endosperm of the cold-acclimated drupe, and not in the embryo. The results show cold responsiveness in the seed coat and cold tolerance in the embryo. We propose a role for the seed coat in maintaining embryo cold tolerance by increasing endosperm cutinization through FAD2 and osmotin activities. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Paroxysmal cold hemoglobinuria (PCH)

MedlinePlus

... page: //medlineplus.gov/ency/article/000557.htm Paroxysmal cold hemoglobinuria (PCH) To use the sharing features on this page, please enable JavaScript. Paroxysmal cold hemoglobinuria (PCH) is a rare blood disorder in ...

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.

STEM Starts Early: Grounding Science, Technology, Engineering, and Math Education in Early Childhood

ERIC Educational Resources Information Center

McClure, Elisabeth R.; Guernsey, Lisa; Clements, Douglas H.; Bales, Susan Nall; Nichols, Jennifer; Kendall-Taylor, Nat; Levine, Michael H.

2017-01-01

Tomorrow's inventors and scientists are today's curious young children--as long as those children are given ample chances to explore and are guided by adults equipped to support them. "STEM Starts Early" is the culmination of a deep inquiry by the Joan Ganz Cooney Center at Sesame Workshop and New America embarked on an exploratory…

Making the cold Kuiper belt in a planetary instability migration model

NASA Astrophysics Data System (ADS)

Gomes, Rodney S.

2017-06-01

Numerical integrations of the equations of motion of Jupiter, Saturn, three ice cores and a disk of planetesimals are undertaken. Two of the ice planets stand for Uranus and Neptune and a third one is expected to be ejected from the solar system. The planets start in compact cold orbits and each one is in mean motion resonance with its neighbor(s). The disk of planetesimals is placed just outside the outermost planet and is extended to 45 au. Five hundred integrations are done for each of four masses assigned to the disk, which are 25, 30, 35 and 40 Earth masses. The integrations are extended to 100 My. After that, I choose the successful runs in which there are four planets left in closed orbits around the Sun and I separate the good runs among the successful ones, defined by semi-major axes ranges around and not too far from the real ones. Among these good runs, I further choose by visual inspection those that yield an orbital distribution of planetesimals at the Kuiper belt region that resembles the real cold Kuiper belt. I extend these runs to 1 Gy and, after that, to 4.5 Gy. These last integrations for 3.5 Gy are done after replacing the orbits of the planets in the end of the 1 Gy integrations by their current orbits, changing the semi-major axes of the planetesimals so as to keep the same mean motion ratio with Neptune and assigning null masses for the planetesimals. Orbital distributions of the cold Kuiper belt obtained in some of the runs at 4.5 Gy are quite similar to that of the real cold Kuiper belt. The mass in the Kuiper belt region can be dynamically eroded to up to 90% of the original mass. The main conclusion is that the cold Kuiper belt is compatible with a past planetary instability phase even though in some of these runs Neptune's semi-major axis and eccentricity attained values simultaneously larger than 20 au and 0.2 for over 1 My.

Method for reducing peak phase current and decreasing staring time for an internal combustion engine having an induction machine

DOEpatents

Amey, David L.; Degner, Michael W.

2002-01-01

A method for reducing the starting time and reducing the peak phase currents for an internal combustion engine that is started using an induction machine starter/alternator. The starting time is reduced by pre-fluxing the induction machine and the peak phase currents are reduced by reducing the flux current command after a predetermined period of time has elapsed and concurrent to the application of the torque current command. The method of the present invention also provides a strategy for anticipating the start command for an internal combustion engine and determines a start strategy based on the start command and the operating state of the internal combustion engine.

Cold and Cough Medicines

MedlinePlus

... What can you do for your cold or cough symptoms? Besides drinking lots of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

Finalize field testing of cold climate heat pump (CCHP) based on tandem vapor injection compressors

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

Shen, Bo; Baxter, Van D.; Abdelaziz, Omar

2017-03-01

This report describes the system diagram and control algorithm of a prototype air-source cold climate heat pump (CCHP) using tandem vapor injection (VI) compressors. The prototype was installed in Fairbanks, Alaska and underwent field testing starting in 09/2016. The field testing results of the past six months, including compressor run time fractions, measured COPs and heating capacities, etc., are presented as a function of the ambient temperature. Two lessons learned are also reported.

Reusable rocket engine intelligent control system framework design, phase 2

NASA Technical Reports Server (NTRS)

Nemeth, ED; Anderson, Ron; Ols, Joe; Olsasky, Mark

1991-01-01

Elements of an advanced functional framework for reusable rocket engine propulsion system control are presented for the Space Shuttle Main Engine (SSME) demonstration case. Functional elements of the baseline functional framework are defined in detail. The SSME failure modes are evaluated and specific failure modes identified for inclusion in the advanced functional framework diagnostic system. Active control of the SSME start transient is investigated, leading to the identification of a promising approach to mitigating start transient excursions. Key elements of the functional framework are simulated and demonstration cases are provided. Finally, the advanced function framework for control of reusable rocket engines is presented.

Baseline automotive gas turbine engine development program

NASA Technical Reports Server (NTRS)

Wagner, C. E. (Editor); Pampreen, R. C. (Editor)

1979-01-01

Tests results on a baseline engine are presented to document the automotive gas turbine state-of-the-art at the start of the program. The performance characteristics of the engine and of a vehicle powered by this engine are defined. Component improvement concepts in the baseline engine were evaluated on engine dynamometer tests in the complete vehicle on a chassis dynamometer and on road tests. The concepts included advanced combustors, ceramic regenerators, an integrated control system, low cost turbine material, a continuously variable transmission, power-turbine-driven accessories, power augmentation, and linerless insulation in the engine housing.

Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold sensing.

PubMed

Kanda, Hirosato; Gu, Jianguo G

2017-05-01

Aside from a small population of primary afferent neurons for sensing cold, which generate sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of primary afferent neurons not responsible for cold sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In this study we have found that the not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, a cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (cold-ineffective neurons) or suppress their membrane excitability (cold-suppressive neurons). For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by increases in action potential (AP) firing numbers and/or the reduction in AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing, but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. This article is part of the special article series "Pain". © 2015 International Society for Neurochemistry.

Evaluation of Losses Of Cold Energy of Cryogen Products in The Transport Systems

NASA Astrophysics Data System (ADS)

Uglanov, Dmitry; Sarmin, Dmitry; Tsapkova, Alexandra; Burdina, Yana

2017-12-01

At present, there are problems of energy saving in various areas of human life and in power complexes of industrial plants. One possible solution to the problem of increasing energy efficiency is the use of liquefied natural gas and its cold energy. Pipelines for fuel or gas supply in cryogen supply systems have different length depending on the mutual position of storage and cryogen consumption devices relatively to a start construction. Cryogen supply and transport systems include a lot of fittings of different assortment. Reservoirs can be installed on different elevation points. To reduce heat inleak and decrease cold energy of cryogen product different kinds of thermal insulation are used. Cryogen pipelines provide required operation conditions of storage and gasifying systems. The aim of the thermal calculation of cryogen transport and supply systems is to define the value of cryogen heat. In this paper it is shown values of cryogen temperature rise due to heat inleaks at cryogen’s transfer along transport systems for ethane, methane, oxygen and nitrogen were calculated. Heat inleaks also due to hydraulic losses were calculated. Specific losses of cold energy of cryogen product for laminar and turbulent flow were calculated. Correspondences of temperature rise, critical pipeline’s length and Reynolds number were defined for nitrogen, argon, methane and oxygen.

Immersion in Cold-Water Evaluation (ICE) and self-reported cold intolerance are reliable but unrelated measures.

PubMed

Traynor, Robyn; MacDermid, Joy C

2008-09-01

Intolerance to the cold is common following peripheral nerve injury and surgery of the upper extremity. Despite its prevalence, the exact pathophysiology and natural history of this condition are not well understood. Subjective, self-report questionnaires have been created and validated as reliable measures of post-traumatic cold intolerance. The difficulty currently lies in assigning an objective measure to this predominantly subjective phenomenon. The present study evaluated the test-retest reliability of a proposed objective measure of cold intolerance, the Immersion in Cold-water Evaluation (ICE), and its correlation with subjective measures in healthy control subjects. Two age groups were also compared to investigate the effect of age on cold intolerance and temperature recovery. On two separate testing days, subjects completed three health-related questionnaires and submersed their dominant hands in cold water. The temperature of their second and fifth digits was monitored during recovery. Both the objective cold-provocation testing and the subjective self-report questionnaires were highly reliable albeit not significantly correlated. No significant temperature recovery trend was noted between the age groups. Post-traumatic cold intolerance is postulated to have both a vascular and neural etiology among other contributing causes. The protocol studied here was centered predominantly on the former etiology, examining peripheral blood flow and associated temperature recovery. This study established ICE as a reliable means to objectively measure cold response, supplementing information provided by previously validated self-report methods.

Oligomerization as a strategy for cold adaptation: Structure and dynamics of the GH1 β-glucosidase from Exiguobacterium antarcticum B7

NASA Astrophysics Data System (ADS)

Zanphorlin, Leticia Maria; de Giuseppe, Priscila Oliveira; Honorato, Rodrigo Vargas; Tonoli, Celisa Caldana Costa; Fattori, Juliana; Crespim, Elaine; de Oliveira, Paulo Sergio Lopes; Ruller, Roberto; Murakami, Mario Tyago

2016-03-01

Psychrophilic enzymes evolved from a plethora of structural scaffolds via multiple molecular pathways. Elucidating their adaptive strategies is instrumental to understand how life can thrive in cold ecosystems and to tailor enzymes for biotechnological applications at low temperatures. In this work, we used X-ray crystallography, in solution studies and molecular dynamics simulations to reveal the structural basis for cold adaptation of the GH1 β-glucosidase from Exiguobacterium antarcticum B7. We discovered that the selective pressure of low temperatures favored mutations that redesigned the protein surface, reduced the number of salt bridges, exposed more hydrophobic regions to the solvent and gave rise to a tetrameric arrangement not found in mesophilic and thermophilic homologues. As a result, some solvent-exposed regions became more flexible in the cold-adapted tetramer, likely contributing to enhance enzymatic activity at cold environments. The tetramer stabilizes the native conformation of the enzyme, leading to a 10-fold higher activity compared to the disassembled monomers. According to phylogenetic analysis, diverse adaptive strategies to cold environments emerged in the GH1 family, being tetramerization an alternative, not a rule. These findings reveal a novel strategy for enzyme cold adaptation and provide a framework for the semi-rational engineering of β-glucosidases aiming at cold industrial processes.

Breaking the Vicious Start-Stop-Restart Cycle

NASA Technical Reports Server (NTRS)

Singer, Christopher E.

2011-01-01

NASA's history is built on a foundation of can-do strength, while pointing to the Apollo Moon missions in the 1960s and 1970s as its apex a sentiment that often overshadows the potential in store. The chronicle of America s civil space adventure 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 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 briefing will show, U.S. aerospace must confront related workforce development and industrial base issues head on to take space exploration to the next level. This briefing 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.

Atomtronics: Material and Device Physics of Quantum Gases

DTIC Science & Technology

matter physics to electrical engineering. Our projects title Atomtronics: Material and device physics of quantum gases illustrates the chasm we bridged...starting from therich and fundamental physics already revealed with cold atoms systems, then leading to an understanding of the functional materials

Age and ethnic differences in cold weather and contagion theories of colds and flu.

PubMed

Sigelman, Carol K

2012-02-01

Age and ethnic group differences in cold weather and contagion or germ theories of infectious disease were explored in two studies. A cold weather theory was frequently invoked to explain colds and to a lesser extent flu but became less prominent with age as children gained command of a germ theory of disease. Explanations of how contact with other people causes disease were more causally sophisticated than explanations of how cold weather causes it. Finally, Mexican American and other minority children were more likely than European American children to subscribe to cold weather theories, a difference partially but not wholly attributable to ethnic group differences in parent education. Findings support the value of an intuitive or naïve theories perspective in understanding developmental and sociocultural differences in concepts of disease and in planning health education to help both children and their parents shed misconceptions so that they can focus on effective preventive actions.

Vernalizing cold is registered digitally at FLC.

PubMed

Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I; Dean, Caroline; Howard, Martin

2015-03-31

A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor flowering locus C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure.

Vernalizing cold is registered digitally at FLC

PubMed Central

Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I.; Dean, Caroline; Howard, Martin

2015-01-01

A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor FLOWERING LOCUS C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure. PMID:25775579

A&M. TAN607 first floor plan for cold assembly area. Shows ...

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

A&M. TAN-607 first floor plan for cold assembly area. Shows special source vaults, X-ray room, instrument shops, and positions of large machines in component test laboratory. This drawing was re-drawn to show conditions in 1994. Ralph M. Parsons 902-3-ANP-607-A 100. Date of original: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 034-060-00-693-106752 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Design of automatic startup and shutdown logic for a Brayton-cycle 2- to 15-kilowatt engine

NASA Technical Reports Server (NTRS)

Vrancik, J. E.; Bainbridge, R. C.

1975-01-01

The NASA Lewis Research Center is conducting a closed-Brayton-cycle power conversion system technology program in which a complete power system (engine) has been designed and demonstrated. This report discusses the design of automatic startup and shutdown logic circuits as a modification to the control system presently used in this demonstration engine. This modification was primarily intended to make starting the engine as simple and safe as possible and to allow the engine to be run unattended. In the modified configuration the engine is started by turning the control console power on and pushing the start button after preheating the gas loop. No other operator action is required to effect a complete startup. Shutdown, if one is required, is also effected by a simple stop button. The automatic startup and shutdown of the engine have been successfully and purposefully demonstrated more than 50 times at the Lewis Research Center during 10,000 hours of unattended operation. The net effect of this modification is an engine that can be safely started and stopped by relatively untrained personnel. The approach lends itself directly to remote unattended operation.

Cold plasma decontamination of foods.

PubMed

Niemira, Brendan A

2012-01-01

Cold plasma is a novel nonthermal food processing technology that uses energetic, reactive gases to inactivate contaminating microbes on meats, poultry, fruits, and vegetables. This flexible sanitizing method uses electricity and a carrier gas, such as air, oxygen, nitrogen, or helium; antimicrobial chemical agents are not required. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization process. A wide array of cold plasma systems that operate at atmospheric pressures or in low pressure treatment chambers are under development. Reductions of greater than 5 logs can be obtained for pathogens such as Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. Effective treatment times can range from 120 s to as little as 3 s, depending on the food treated and the processing conditions. Key limitations for cold plasma are the relatively early state of technology development, the variety and complexity of the necessary equipment, and the largely unexplored impacts of cold plasma treatment on the sensory and nutritional qualities of treated foods. Also, the antimicrobial modes of action for various cold plasma systems vary depending on the type of cold plasma generated. Optimization and scale up to commercial treatment levels require a more complete understanding of these chemical processes. Nevertheless, this area of technology shows promise and is the subject of active research to enhance efficacy.

Cold medicines and children

MedlinePlus

... ingredient. Avoid giving more than one OTC cold medicine to your child. It may cause an overdose with severe side ... the dosage instructions strictly while giving an OTC medicine to your child. When giving OTC cold medicines to your child: ...

COLD-SAT: An orbital cryogenic hydrogen technology experiment

NASA Technical Reports Server (NTRS)

Schuster, J. R.; Wachter, Joseph P.; Powers, Albert G.

1989-01-01

The COLD-SAT spacecraft will perform subcritical liquid hydrogen storage and transfer experiments under low-gravity conditions to provide engineering data for future space transportation missions. Consisting of an experiment module mated to a spacecraft bus, COLD-SAT will be placed in an initial 460 km circular orbit by an Atlas I commercial launch vehicle. After deployment, the three-axis-controlled spacecraft bus will provide electric power, experiment control and data management, communications, and attitude control along with propulsive acceleration levels ranging from 10(-6) to 10(-4)g. These accelerations are an important aspect of some of the experiments, as it is desired to know the effects that low gravity levels might have on the heat and mass transfer processes involved. The experiment module will contain the three liquid hydrogen tanks, valves, pressurization equipment, and instrumentation. At launch all the hydrogen will be in the largest tank, which has helium-purged MLI and is loaded and topped off by the hydrogen tanking system used for the Centaur upper stage of the Atlas. The two smaller tanks will be utilized in orbit for performing some of the experiments. The experiments are grouped into two classes on the basis of their priority, and include six regarded as enabling technology and nine regarded as enhancing technology.

Gas turbine engine fuel control

NASA Technical Reports Server (NTRS)

Gold, H. S. (Inventor)

1973-01-01

A variable orifice system is described that is responsive to compressor inlet pressure and temperature, compressor discharge pressure and rotational speed of a gas-turbine engine. It is incorporated into a hydraulic circuit that includes a zero gradient pump driven at a speed proportional to the speed of the engine. The resulting system provides control of fuel rate for starting, steady running, acceleration and deceleration under varying altitudes and flight speeds.

Evaluation of heat engine for hybrid vehicle application

NASA Technical Reports Server (NTRS)

Schneider, H. W.

1984-01-01

The status of ongoing heat-engine developments, including spark-ignition, compression-ignition, internal-combustion, and external-combustion engines is presented. The potential of engine concepts under consideration for hybrid vehicle use is evaluated, using self-imposed criteria for selection. The deficiencies of the engines currently being evaluated in hybrid vehicles are discussed. Focus is on recent research with two-stroke, rotary, and free-piston engines. It is concluded that these engine concepts have the most promising potential for future application in hybrid vehicles. Recommendations are made for analysis and experimentation to evaluate stop-start and transient emission behavior of recommended engine concepts.

Ceramic applications in turbine engines

NASA Technical Reports Server (NTRS)

Byrd, J. A.; Janovicz, M. A.; Thrasher, S. R.

1981-01-01

Development testing activities on the 1900 F-configuration ceramic parts were completed, 2070 F-configuration ceramic component rig and engine testing was initiated, and the conceptual design for the 2265 F-configuration engine was identified. Fabrication of the 2070 F-configuration ceramic parts continued, along with burner rig development testing of the 2070 F-configuration metal combustor in preparation for 1132 C (2070 F) qualification test conditions. Shakedown testing of the hot engine simulator (HES) rig was also completed in preparation for testing of a spin rig-qualified ceramic-bladed rotor assembly at 1132 C (2070 F) test conditions. Concurrently, ceramics from new sources and alternate materials continued to be evaluated, and fabrication of 2070 F-configuration ceramic component from these new sources continued. Cold spin testing of the critical 2070 F-configuration blade continued in the spin test rig to qualify a set of ceramic blades at 117% engine speed for the gasifier turbine rotor. Rig testing of the ceramic-bladed gasifier turbine rotor assembly at 108% engine speed was also performed, which resulted in the failure of one blade. The new three-piece hot seal with the nickel oxide/calcium fluoride wearface composition was qualified in the regenerator rig and introduced to engine operation wiwth marginal success.

Garlic for the common cold.

PubMed

Lissiman, Elizabeth; Bhasale, Alice L; Cohen, Marc

2014-11-11

Background Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have six to eight colds per year and adults have two to four.Objectives To determine whether garlic (Allium sativum) is effective for the prevention or treatment of the common cold, when compared to placebo, no treatment or other treatments.Search methods We searched CENTRAL (2014, Issue 7),OLDMEDLINE (1950 to 1965),MEDLINE (January 1966 to July week 5, 2014), EMBASE(1974 to August 2014) and AMED (1985 to August 2014).Selection criteria Randomised controlled trials of common cold prevention and treatment comparing garlic with placebo, no treatment or standard treatment.Data collection and analysis Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data.Main results In this updated review, we identified eight trials as potentially relevant from our searches. Again, only one trial met the inclusion criteria.This trial randomly assigned 146 participants to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily)for 12 weeks. The trial reported 24 occurrences of the common cold in the garlic intervention group compared with 65 in the placebo group (P value < 0.001), resulting in fewer days of illness in the garlic group compared with the placebo group (111 versus 366). The number of days to recovery from an occurrence of the common cold was similar in both groups (4.63 versus 5.63). Only one trial met the inclusion criteria, therefore limited conclusions can be drawn. The trial relied on self reported episodes of the common cold but was of reasonable quality in terms of randomisation and allocation concealment. Adverse effects included rash and odour. Authors' conclusions

Garlic for the common cold.

PubMed

Lissiman, Elizabeth; Bhasale, Alice L; Cohen, Marc

2012-03-14

Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have six to eight colds per year and adults have two to four. To determine whether garlic (allium sativum) is effective for either the prevention or treatment of the common cold, when compared to placebo, no treatment or other treatments. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 4), which includes the Cochrane Acute Respiratory Infections Group Specialised Register, OLDMEDLINE (1950 to 1965), MEDLINE (January 1966 to November week 3, 2011), EMBASE (1974 to December 2011) and AMED (1985 to December 2011). Randomised controlled trials of common cold prevention and treatment comparing garlic with placebo, no treatment or standard treatment. Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data. Of the six trials identified as potentially relevant from our searches, only one trial met the inclusion criteria. This trial randomly assigned 146 participants to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily) for 12 weeks. The trial reported 24 occurrences of the common cold in the garlic intervention group compared with 65 in the placebo group (P < 0.001), resulting in fewer days of illness in the garlic group compared with the placebo group (111 versus 366). The number of days to recovery from an occurrence of the common cold was similar in both groups (4.63 versus 5.63). Only one trial met the inclusion criteria, therefore limited conclusions can be drawn. The trial relied on self reported episodes of the common cold but was of reasonable quality in terms of randomisation and allocation concealment. Adverse effects included rash and

Prevalence of cold-related complaints, symptoms and injuries in the general population: the FINRISK 2002 cold substudy

NASA Astrophysics Data System (ADS)

Raatikka, Veli-Pekka; Rytkönen, Mika; Näyhä, Simo; Hassi, Juhani

2007-05-01

The prevalence of cold-related complaints and symptoms in the general population has remained unknown. As part of the nationwide FINRISK 2002 health survey performed in Finland, 8,723 people aged 25 64 years filled in a questionnaire asking about the number of hours spent weekly in cold air, their sensations during cold exposure, cold-related complaints, symptoms of diseases, and degradation of performance. Cold thermal sensations at +5°C to -5°C were reported by 35% of men and 46% of women. Almost all subjects reported at least some cold-related complaints, most commonly musculoskeletal pain (men 30%, women 27%), followed by respiratory (25% / 29%), white finger (15% / 18%) and episodic peripheral circulation symptoms (12% / 15%). Decreased mental or physical performance in cold was reported by 75% of men and 70% of women, most commonly impairing manual dexterity and tactile sense. With declining temperature, the first symptom to emerge was pain in the elbow or the forearm (at -3°C), followed by increased excretion of mucus from the lungs (-5°C), while most other symptoms appeared only at lower temperatures of -15°C to -20°C. Most symptoms showed little or no association with the weekly duration of exposure, with the exception of cold-induced pain at most sites. Although, in general, Finns are well adapted to the cold climate, the high prevalence of cold-related complaints poses a challenge to the health care system in terms of decreased performance and the possibility that such symptoms predict more serious health effects, such as increased mortality.

Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

PubMed Central

Rix, Laura; de Goeij, Jasper M.; Mueller, Christina E.; Struck, Ulrich; Middelburg, Jack J.; van Duyl, Fleur C.; Al-Horani, Fuad A.; Wild, Christian; Naumann, Malik S.; van Oevelen, Dick

2016-01-01

Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21–40% of the mucus carbon and 32–39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

Climate engineering and space

NASA Astrophysics Data System (ADS)

Schrogl, K.-U.; Summerer, L.

2016-12-01

This article provides a comprehensive look at climate engineering and space. Its starting point is that the States are failing to slow down global warming. The consequences for the environment and the economic and societal burden are uncontested. The priority to maintain the use of fossil resources might soon lead to the implementation of deliberate engineering measures to alter the climate instead of reducing the greenhouse gases. The article describes these currently discussed measures for such climate engineering. It will particularly analyse the expected contributions from space to these concepts. Based on this it evaluates the economic and political implications and finally tests the conformity of these concepts with space law.

Cold-Weather Sports and Your Family

MedlinePlus

... Videos for Educators Search English Español Cold-Weather Sports and Your Family KidsHealth / For Parents / Cold-Weather ... kids while being active. Types of Cold-Weather Sports Skiing, snowboarding, ice skating, and snowshoeing are just ...

Regulatory Networks Controlling Plant Cold Acclimation or Low Temperature Regulatory Networks Controlling Cold Acclimation in Arabidopsis (2011 JGI User Meeting)

ScienceCinema

Thomashow, Mike

2018-02-06

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Mike Thomashow of Michigan State University gives a presentation on on "Low Temperature Regulatory Networks Controlling Cold Acclimation in Arabidopsis" at the 6th annual Genomics of Energy & Environment Meeting on March 23, 2011."

Development of Oxidation Resistant Coatings on GRCop-84 Substrates by Cold Spray Process

NASA Technical Reports Server (NTRS)

Karthikeyan, J.

2007-01-01

GRCop-84, a Cu-CR-Nb alloy, has been developed for rocket engine liner applications. For maximum life additional oxidation protection is required to prevent blanching. NiCrAlY was identified as a suitable coating, and efforts were initiated to develop suitable coating techniques. Cold spray is one technique under consideration. Efforts at ASB Industries to produce dense, adherent coatings are detailed. The work culminated in the production of samples for testing at NASA Glenn Research Center.

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)

Differential expression of the enzymes associated with cold-induced sweetening in long term cold stored potatoes

USDA-ARS?s Scientific Manuscript database

Accumulation of high levels of reducing sugars during cold storage (4-6°C) known as cold-induced sweetening (CIS) is a major post-harvest disorder and is one of the most significant concerns for the potato processing industry. The biochemical process of reducing sugar accumulation during cold stora...

Bacterial spore inactivation induced by cold plasma.

PubMed

Liao, Xinyu; Muhammad, Aliyu Idris; Chen, Shiguo; Hu, Yaqin; Ye, Xingqian; Liu, Donghong; Ding, Tian

2018-04-05

Cold plasma has emerged as a non-thermal technology for microbial inactivation in the food industry over the last decade. Spore-forming microorganisms pose challenges for microbiological safety and for the prevention of food spoilage. Inactivation of spores induced by cold plasma has been reported by several studies. However, the exact mechanism of spore deactivation by cold plasma is poorly understood; therefore, it is difficult to control this process and to optimize cold plasma processing for efficient spore inactivation. In this review, we summarize the factors that affect the resistance of spores to cold plasma, including processing parameters, environmental elements, and spore properties. We then describe possible inactivation targets in spore cells (e.g., outer structure, DNA, and metabolic proteins) that associated with inactivation by cold plasma according to previous studies. Kinetic models of the sporicidal activity of cold plasma have also been described here. A better understanding of the interaction between spores and cold plasma is essential for the development and optimization of cold plasma technology in food the industry.

Mountain Warfare and Cold Weather Operations

DTIC Science & Technology

2016-04-29

military purposes, cold regions are defined as any region where cold temperatures , unique terrain, and snowfall have a significant effect on military...because of the wind’s effect on the body’s perceived temperature . Wet cold leads to hypothermia, frost bite, and trench foot. Wet cold conditions are...combined cooling effect of ambient temperature and wind (wind chill) experienced by their troops (see Figure 1-5). The Environment ATP 3-90.97

Self-recognition in corals facilitates deep-sea habitat engineering

USGS Publications Warehouse

Hennige, Sebastian J; Morrison, Cheryl L.; Form, Armin U.; Buscher, Janina; Kamenos, Nicholas A.; Roberts, J. Murray

2014-01-01

The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no ‘self-recognition’ on a broad species level. This study reveals areas of ‘flawless’ skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of ‘self’ between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Franco, Juan Va; Guerra, Claudia V; Felix, Maria L; Hidalgo, Ricardo; Martinez-Zapata, Maria José

2017-05-18

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat, and fever (usually < 37.8º C). The widespread morbidity caused by the common cold worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. This is an update of a Cochrane review first published in 2011 and previously updated in 2013. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (September 2016), MEDLINE (1948 to September 2016), Embase (1974 to September 2016), CINAHL (1981 to September 2016), and LILACS (1982 to September 2016). We also searched three trials registers for ongoing studies and four websites for additional trials (February 2017). We included no language or date restrictions. Randomised controlled trials (RCTs) of any virus vaccines compared with placebo to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. We resolved disagreements by discussion or by consulting a third review author. We found no additional RCTs for inclusion in this update. This review includes one RCT dating from the 1960s with an overall high risk of bias. The RCT included 2307 healthy participants, all of whom were included in analyses. This trial compared the effect of an adenovirus vaccine against placebo. No statistically significant difference in common cold incidence was found: there were 13 (1.14%) events in 1139 participants in the

Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic

NASA Astrophysics Data System (ADS)

Mohn, Christian; Rengstorf, Anna; White, Martin; Duineveld, Gerard; Mienis, Furu; Soetaert, Karline; Grehan, Anthony

2014-03-01

Observations from numerous cold-water coral locations in the NE Atlantic show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic motions such as trapped waves, freely propagating internal tides and internal hydraulic jumps. In this study, linkages between key abiotic parameters and cold water coral occurrences are explored across entire cold-water coral mound provinces using an integrated modelling and observational approach. The 3-D ocean circulation model ROMS-AGRIF was applied to simulate near-bottom hydrodynamic conditions at three provinces in the NE Atlantic (Logachev mounds, Arc mounds and Belgica mounds) adopting a nested model setup with a central grid resolution of 250 m. Simulations were carried out with a focus on accurate high-resolution topography and tidal forcing. The central model bathymetry was taken from high-resolution INSS (Irish National Seabed Survey) seafloor mapping data. The model was integrated over a full one-year reference period starting from the 1st January 2010. Interannual variability was not considered. Tidal forcing was obtained from a global solution of the Oregon State University (OSU) inverse tidal model. Modelled fields of benthic currents were validated against available independent in situ observations. Coral assemblage patterns (presence and absence locations) were obtained from benthic surveys of the EU FP7 CoralFISH programme and supplemented by data from additional field surveys. Modelled near-bottom currents, temperature and salinity were analysed for a 1-month subset (15th April to 15th May 2010) corresponding to the main CoralFISH survey period. The model results show intensified near-bottom currents in areas where living corals are observed by contrast with coral absence and random background locations. Instantaneous and time-mean current speeds at

Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

USGS Publications Warehouse

Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

2016-01-01

Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

Exhaust gas ignition

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

NONE

1996-04-01

This article describes a system developed for rapid light-off of underbody catalysts that has shown potential to meet Euro Stage III emissions targets and to be more cost-effective than some alternatives. Future emissions legislation will require SI engine aftertreatment systems to approach full operating efficiency within the first few seconds after starting to reduce the high total-emissions fraction currently contributed by the cold phase of driving. A reduction of cold-start emissions during Phase 1 (Euro) or Bag 1 (FTP), which in many cases can be as much as 80% of the total for the cycle, has been achieved by electricalmore » heating of the catalytic converter. But electrically heated catalyst (EHC) systems require high currents (100--200 A) to heat the metallic substrate to light-off temperatures over the first 15--20 seconds. Other viable approaches to reducing cold-start emissions include use of a fuel-powered burner upstream of the catalyst. However, as with EHC, the complexity of parts and the introduction of raw fuel into the exhaust system make this device unsatisfactory. Still another approach, an exhaust gas ignition (EGI) system, was first demonstrated in 1991. The operation of a system developed by engineers at Ford Motor Co., Ltd., Cambustion Ltd., and Tickford Ltd. is described here.« less

Liquid metal cold trap

DOEpatents

Hundal, Rolv

1976-01-01

A cold trap assembly for removing impurities from a liquid metal being provided with a hole between the incoming impure liquid metal and purified outgoing liquid metal which acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly.

Martian (and Cold Region Lunar) Soil Mechanics Considerations

NASA Astrophysics Data System (ADS)

Chua, Koon Meng; Johnson, Stewart W.

1998-01-01

The exploration of Mars has generated a lot of interest in recent years. With the completion of the Pathfinder Mission and the commencement of detailed mapping by Mars Global Surveyor, the possibility of an inhabited outpost on the planet is becoming more realistic. In spite of the upbeat mood, human exploration of Mars is still many years in the future. Additionally, the earliest return of any martian soil samples will probably not be until 2008. So why the discussion about martian soil mechanics when there are no returned soil samples on hand to examine? In view of the lack of samples, the basis of this or any discussion at this time must necessarily be one that involves conjecture, but not without the advantage of our knowledge of regolith mechanics of the Moon and soil mechanics on Earth. The objective of this presentation/discussion is fourfold: (1) Review some basic engineering-related information about Mars that may be of interest to engineers, and scientists - including characteristics of water and C02 at low temperature; (2) review and bring together principles of soil mechanics pertinent to studying and predicting how martian soil may behave, including the morphology and physical characteristics of coarse-grained and fine-grained soils (including clays), the characteristics of collapsing soils, potentials and factors that affect migration of water in unfrozen and freezing/frozen soils, and the strength and stiffness characteristics of soils at cold temperatures; (3) discuss some preliminary results of engineering experiments performed with frozen lunar soil simulants, JSC-1, in the laboratory that show the response to temperature change with and without water, effects of water on the strength and stiffness at ambient and at below freezing temperatures; and (4) discuss engineering studies that could be performed prior to human exploration and engineering research to be performed alongside future scientific missions to that planet.

Careers in biomedical engineering.

PubMed

Madrid, R E; Rotger, V I; Herrera, M C

2010-01-01

Although biomedical engineering was started in Argentina about 35 years ago, it has had a sustained growth for the last 25 years in human resources, with the emergence of new undergraduate and postgraduate careers, as well as in research, knowledge, technological development, and health care.

The cold reading technique.

PubMed

Dutton, D L

1988-04-15

For many people, belief in the paranormal derives from personal experience of face-to-face interviews with astrologers, palm readers, aura and Tarot readers, and spirit mediums. These encounters typically involve cold reading, a process in which a reader makes calculated guesses about a client's background and problems and, depending on the reaction, elaborates a reading which seems to the client so uniquely appropriate that it carries with it the illusion of having been produced by paranormal means. The cold reading process is shown to depend initially on the Barnum effect, the tendency for people to embrace generalized personality descriptions as idiosyncratically their own. Psychological research into the Barnum effect is critically reviewed, and uses of the effect by a professional magician are described. This is followed by detailed analysis of the cold reading performances of a spirit medium. Future research should investigate the degree to which cold readers may have convinced themselves that they actually possess psychic or paranormal abilities.

Cold hardiness in molluscs

NASA Astrophysics Data System (ADS)

Ansart, Armelle; Vernon, Philippe

2003-05-01

Molluscs inhabit all types of environments: seawater, intertidal zone, freshwater and land, and of course may have to deal with subzero temperatures. Ectotherm animals survive cold conditions by avoiding it by extensive supercooling (freezing avoidant species) or by bearing the freezing of their extracellular body fluids (freezing tolerant species). Although some studies on cold hardiness are available for intertidal molluscs, they are scarce for freshwater and terrestrial ones. Molluscs often exhibit intermediary levels of cold hardiness, with a moderate or low ability to supercool and a limited survival to the freezing of their tissues. Several factors could be involved: their dependence on water, their ability to enter dormancy, the probability of inoculative freezing in their environment, etc. Size is an important parameter in the development of cold hardiness abilities: it influences supercooling ability in land snails, which are rather freezing avoidant and survival to ice formation in intertidal organisms, which generally tolerate freezing.

TRPA1 Contributes to Cold Hypersensitivity

PubMed Central

Camino, Donato del; Murphy, Sarah; Heiry, Melissa; Barrett, Lee B.; Earley, Taryn J.; Cook, Colby A.; Petrus, Matt J.; Zhao, Michael; D'Amours, Marc; Deering, Nate; Brenner, Gary J.; Costigan, Michael; Hayward, Neil J.; Chong, Jayhong A.; Fanger, Christopher M.; Woolf, Clifford J.; Patapoutian, Ardem; Moran, Magdalene M.

2010-01-01

TRPA1 is a non-selective cation channel expressed by nociceptors. While it is widely accepted that TRPA1 serves as a broad irritancy receptor for a variety of reactive chemicals, its role in cold sensation remains controversial. Here, we demonstrate that mild cooling markedly increases agonist-evoked rat TRPA1 currents. In the absence of an agonist, even noxious cold only increases current amplitude slightly. These results suggest that TRPA1 is a key mediator of cold hypersensitivity in pathological conditions where reactive oxygen species and pro-inflammatory activators of the channel are present, but likely plays a comparatively minor role in acute cold sensation. Supporting this, cold hypersensitivity can be induced in wild-type but not Trpa1-/- mice by subcutaneous administration of a TRPA1 agonist. Furthermore, the selective TRPA1 antagonist HC-030031 reduces cold hypersensitivity in rodent models of inflammatory and neuropathic pain. PMID:21068322

Actively controlling coolant-cooled cold plate configuration

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

Chainer, Timothy J.; Parida, Pritish R.

Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, formore » example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.« less