Are mainframes still useful today?

Yes, they are indeed used a lot. Half of server revenues for IBM comes from Mainframe alone. They have excellent reliability and exceptional performance in certain use cases.

Typically they are used where there are huge Input output based operations such as in Banks, Insurance, Warehouse, Flight information etc.

Coming to cost, it costs millions for purchasing a new Mainframe, set it up and kepp them running. You only purchase the hardware, but licence Software and keep paying for it till eternity.

However the usage is going down, seriously going down. They will be in usage for some more time. Career as a Mainframe Developer(if you want to call it that way) is rather limited.

Does yoga helps in reducing facial hair?

facial hair comes due to harmonal imbalance in your body.doing yoga daily helps in reducing facial hair but it takes timethings to be followed to reduce facial hair1.have at least 7hrs sleep2.exercise daily3.avoid dairy products,dairy products increase growth of facial hair4.(important)daily apply turmeric paste before applying it wash your face with warm

What are healthy eating principles?

What has worked for me:No soda, beef, processed meats. Just water, sometimes a glass of milk, coffee, tea.More fresh fish, especially salmon and cod, some poultry. I like bacon occasionally, with our veggie omelets. Moderate amount of protein.Lots of greens-spinach, salad greens, kale, Swiss chard, Asian greens (pac choi, tatsoi, mustard greens). Every day,

Name five devices that convert mechanical energy into electrical energy?

Quora is not a homework cheating service, and five is specific enough to sound like homework. Which you need to do yourself.It would be very rude to ask a volunteer, answering your questions for you, to come up with a specific number, don't you think?if you want to do the work, here are some ideas8c Energy: