### MIRCE Science Questions

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### MIRCE Science Questions

Are Drones More Dangerous To Aircarft Than Birds?

The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with an exponential probability distribution, with a mean value of 1000 hours, determine the amount of water pumped during the first 500 hours of continuous operation. In case of the failure of a pump, no additional actions are taken.

For the pump type considered in the above question, determine the amount of water pumped during the first: 2000 and 5000 hours of continues operation.

Why does friction produce a heat?

What is a Post-Maintenance Flight Test ?

How to estimate Total Packaging Cost?

An O-ring is made from an elastomer with equimolar portions of vinylidene fluoride and hexafluoropropylene. Calculate the weight fraction of each polymer.

Estimate the particle size of a wear fragment produced by the adhesive wear of two 1040 steel surfaces under a load of 50 kg with a sliding distance of 5 mm. (Assume the particle to be a hemisphere of diameter *d*.)

Electromagnetic radiation with photon energies greater than 15 eV can damage semiconductors that are used in a communications satellite. Could visible light be a source of this damage?

What are the mechanisms of the Electrical Insulation Failures?

An extremely dis-organised organization operates n different systems numbered from 1 to n, in n different locations. Once a year these systems must be replaced. A central operator obtains a set of new systems and must transfer them to the appropriate locations. The central operator sends the spare systems in a random manner so that each system may find itself in any location. What is the probability that at least one system will be send to the correct address?

Consider a fleet containing m identical systems. In each system there are k identical modules. It is known that n units are failed in the fleet. What is the probability that exactly r k units are failed in the first system?

What are fundamental physical differences between particles and waves?

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In the jargon of maintenance professionals expression “Easter Egging” is frequently used. What does it mean?

Assume that it is known that the number of parts produced in a specific factory during a week is a random variable with mean of 50. a) What is the probability that the next week the number of parts produced will exceed 50?

b) If the variance of weekly production is 25, what is the probability that the next week production will be between 40 and 60?

What is Economic Redundancy?

What is the difference between Correlation and Coincidence?

What is the Nature of Probability Theory?

What is Aerotoxic Syndrome?

What is frangibillity?

What is a Discrete Random variable?

Is weather and climate the same?

What is Anti-core Icing ?

What is Impact of Electromagnetic Phenomena on Aircraft Functionabnility ?

The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with an exponential probability distribution, with a mean value of 1000 hours. The failure of a pump initiates immediate replacement for the pump with an new one. It is expected that the maintenance task taken could be represented with a exponential probability distribution with an expected value of 8 hrs.Determine the amount of water pumped during the first 500 hours of continuous operation and compare the results with the operation of the pump of the same type, considered in the question above, where the failures of the pump has not been rectified.

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What are the main advantages of building a model of a system, process or activity under consideration?

A European producer is to export a packaging machine to a customer in Brazil. The machine is packaged in wooden box of the following internal dimensions: length=7.00 m, width=2.75 m and height=3.00 m. Calculate a required number of desiccant units that should be used in order to for the machine to arrive to Brazil in the functionable state.

The majority of plastic component failures occur in the mid to long term. Even, in normally tough, ductile plastic materials failures are invariable brittle in nature and result in a short service life. What are the most common causes of such brittle failures?

What are mechanisms for formation of plastics?

What are Non Destructive Methods for Corrosion Monitoring?

What is corrosion?

What are the processes of heat transfer?

What is Infrared Thermography?

What are the main differences between inspection and examination as condition monitoring activities?

For a continuously operating machine, does the increase in the number of spare engines: 1) Increases the number of failures of the gearbox? 2) Has no impact on the number of failures of the gearbox? 3) Decreases the number of failures of the gearbox?

What are the differences between linear and dynamic programming?

Under what conditions are the two random variables X and Y independent?

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Functionality and Functionability of machines are: a) The same properties, just different names? b) Not the same, but very similar properties? c) Fundamentally different properties?

As in all chemical reactions, corrosion reactions occur through an exchange of electrons. In electrochemical reactions, the electrons are produced by a chemical reaction in one area, the anode, travel through a metallic path and are consumed through a different chemical reaction in another area, the cathode. In some cases, such as the common dry cell battery, electrochemical reactions can be used to supply useful amounts of electrical current.

What is the generic chemical formula for the corrosion of metals?

Which of the following failure mechanisms the most frequently causes failure of polymers? Biodegradation, Chemical Attack, Diffusion, permeation and migration, Environmental Stress Cracking, Hydrolysis, Physical Ageing, Radiation (ultraviolet radiation most common), Shear damage, Thermo-oxidative degradation

For continuously operating machine, exposed to corrective maintenance policy, the increase in spare parts will: 1.Increase the Number of Failures, 2.Decrease the Number of Failure, 3.Not affect the Number of Failures.

Is the law of conservation of energy true for phenomena related to: 1. Living world? 2. Non-living world? 3. Both worlds?

Are expressions complicated system and complex system: a) Two ways to describe the same entity? b) Two different entities? c) Irrelevant question?

Bahrain Grand Prix is scheduled for 19-21 April 2013. Due to its closeness to the desert Sakhir, Bahrain International Circuit, during last few years recorded only 5 rainy days per year. However, current weather forecast predicts the rain on the racing Sunday. When it actually rains, the weather forecast is accurate 90% of the time. When it doesn't rain, the incorrect forecasts for rain are 10% of the time. What is the probability that it will rain on the next Grand Prix day?

Among some reliability experts the following statement is commonly accepted “To double reliability you just need to double the Mean Time To Failure.” Is this statement: a) Correct? b) Incorrect? c) Meaningless?