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【判断题】Lesson 15 Text A Tor F-1 ADSB originates from Next Gen Air Transportation System and will be applied to air traffic management
A.Y.是
B.N.否
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更多 “【判断题】Lesson 15 Text A Tor F-1 ADSB originates from Next Gen Air Transportation System and will be applied to air traffic managementA.Y.是B.N.否” 相关考题
考题
第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system
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Restrictions occurring in the small orifices(孔) of pneumatic control system components can be caused by ______.A.moisture in the compressed air supplyB.excessive dryness in the compressed air supplyC.pressure surging in the compressed air receiverD.insufficient lubrication of the system components
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In an air conditioning system, moisture is removed from the air by ______.A.filtersB.separatorsC.ducted trapsD.dehumidifiers
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Working conditions in air transportation vary widely, _______ on the occupation.A.depends B.dependable C.depending D.depend
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A cool mass of air heads toward the United States from the upper regions of Canada and Alaska this week according to the National Weather Service.
According to the NWS a mass of cold air will drop from the Arctic regions to Canada and then the upper Midwest next week.
Temperatures across the Midwest will drop into the 60s and 70s-a sharp difference from the 80 degree and 90 degree temperatures from recent weeks. And the relatively cooler air may be felt as far East as New York and Washington
The cool breezes may be a welcome relief this time around but remember the last few times we got hit with Arctic air?
Temperatures in cities including Chicago Cleveland New York and Louisville fell into single-digit and negative territory for long stretches during the harsh winter months of early 2014. But we’re sure you remember
According to the National Weather Service____A. the cool mass of air originates from Canada
B. a mass of cold air will affect both Canada and the U.S
C. the chilly weather is back to the globe
D. only the upper Midwest will be affected by the cool air
考题
资料:We never thought we'd say this, but we'd welcome back some chilly weather.
A cool mass of air heads toward the United States from the upper regions of Canada and Alaska this week, according to the National Weather Service.
According to the NWS, a mass of cold air will drop from the Arctic regions to Canada and then the upper Midwest next week.
Temperatures across the Midwest will drop into the 60s and 70s—a sharp difference from the 80 degree and 90 degree temperatures from recent weeks. And the relatively cooler air may be felt as far East as New York and Washington.
The cool breezes may be a welcome relief this time around, but remember the last few times we got hit with Arctic air?
Temperatures in cities including Chicago, Cleveland, New York, and Louisville fell into single-digit and negative territory for long stretches during the harsh winter months of early 2014. But we're sure you remember.
According to the National Weather Service, ___.A.the cool mass of air originates from Canada
B.a mass of cold air will affect both Canada and the U.S.
C.the chilly weather is back to the globe
D.only the upper Midwest will be affected by the cool air
考题
() is a system of unitized multimodal land transportation of transport by road and rail.A、Land bridgeB、Rail/roadC、PiggybackD、Sea/air
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The modes of transportation include()。A、rail and road transportB、water transportC、pipelinesD、air transport
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ATA100中ATA是什么的缩写?A、Air Transport AssociationB、Air Training AssociationC、Air Traffic Association
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单选题A diesel engine is turned at normal cranking speed, but fails to fireThis can occur from ()A
low lube oil temperatureB
low starting air temperatureC
air in the fuel injectionD
water in the starting air system
考题
单选题Air blowing from the intake air filter of an operating air compressor indicates ().A
broken inlet valvesB
broken discharge valvesC
pulsations in the air distribution systemD
overloading of the air distribution system
考题
单选题In an air conditioning system, moisture is removed from the air by()A
filersB
separatorsC
ducted trapsD
dehumidifiers
考题
单选题A re-heater in an air conditioning system functions to ().A
control inlet air temperatureB
control inlet air volumeC
maintain relative humidity at 15%D
restore conditioned air temperature to a comfortable level
考题
单选题Air or noncondensable gas is removed from a refrigeration system by a ()A
separating chamberB
system of bafflesC
purge valveD
vacuum reducing valve
考题
单选题Restrictions occurring in the small orifices of pneumatic control system components can be used by ()A
moisture in the compressed air supplyB
excessive dryness in the compressed air supplyC
pressure surging in the compressed air receiverD
insufficient lubrication of the system components
考题
单选题Air cocks, usually positioned at the () in a circulating system, is used to get rid of the air in the system.A
bending jointB
expansion tankC
weldD
the highest point
考题
单选题Diesel engine air start system check valves are opened by ()A
an air start camB
cylinder compression pressureC
starting air pressureD
valve springs
考题
单选题If an air compressor is used to supply compressed air to outlets throughout the engine room and on deck of a vessel, the system is known as the ().A
combustion control air systemB
supply air systemC
ships service air systemD
low pressure deck air system
考题
单选题Starting air for auxiliary engines may be taken directly from the main reservoirs or through ().A
an auxiliary reservoirB
a controlling air bottleC
an emergency air compressorD
a main air compressor
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单选题Which of the following methods is normally used to control the temperature of air distributed from individual cooling coils in an air conditioning system using a chilled water circulation system?()A
A room thermostat activates an electric heater at each individual chilled air outlet when necessaryB
Varying the number of passes the air makes across the coilsC
Varying the temperature of the water through the coilsD
Varying the quantity of water flowing through the coils
考题
判断题In international air cargo transportation, Specific Commodity Rates are usually lower than General Cargo Rates.A
对B
错
考题
单选题To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, you should ()A
admit only enough fresh outside air to provide proper ventilationB
reduce the air reheating system loadC
lower the compressor head pressureD
operate the purge recovery unit continuously
考题
单选题Which of the following statements describes the functions of a reservoir used in a hydraulic system?()A
Dissipate heatB
Trap foreign matterC
Separate air from the oilD
All of the above
考题
单选题Pump up the starting air reservoirs to their maximum pressure and ()the air reservoirs and air system.A
openB
closeC
drainD
vent
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单选题A purge recovery system is used in a centrifugal air conditioning or refrigeration system to ()A
purge lube oil from the liquid refrigerantB
recover water purged from the systemC
separate foul gases from the receiverD
purge non-condensable gases without losing refrigerant
考题
单选题In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?()A
noise coming from that air starting valveB
continuous operation of the starting air compressorC
zero air pressure in the air starting systemD
overheated starting air pipe to the cylinder head
考题
单选题If an air compressor is used to supply air primarily to the combustion control system and other pneumatic controllers, the entire system is known as the ().A
control air systemB
forced draft air systemC
supply air systemD
ships service air system
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