How many times should you use one pair of earplugs before replacing them?
We get asked this a lot. Here is our stock answer: “Foam ear plugs [like those in your picture] are designed to be used once and discarded. Based on feedback from some customers, however, many people do save their foam ear plugs and use them several times. If you choose to re-use disposable foam ear plugs, always make sure to keep them clean between uses by storing them in an appropriate case, and discard them when they get dirty and/or they no longer expand fully after rolling.”That said, the best plan if you are going to use disposable foam ear plugs is to find an inexpensive industrial ear plug so you can afford to use them correctly. The foam ear plugs you find at the drugstore are nearly always just repackaged industrial ear plugs, but at a much higher price. Check out the difference in prices at the two categories that follow:Industrial Foam Ear Plugs in Full Boxes Consumer Packaged Foam Ear Plugs And of course as others have suggested, a reusable ear plug will save you money in the long run. They are not as effective as foam ear plugs, but they are easier to use and they last far longer with proper care. Here too, there is a big difference in the cost of reusable industrial ear plugs and reusable consumer packaged ear plugs:Industrial Reusable Ear Plugs by the Pair (1-50 Pairs) Consumer Packaged Reusable Ear Plugs Be well...and do the right thing.Tom
Why do my ears hurt when I use earphones?
The external ear has an underlying framework of cartilage with a lining called perichondrium. The perichondrium is very sensitive to pressure and bending which is inherent in wearing most earphones. Over the ear phones will take away most of the pressure (this being born by the skull) but will retain moisture around and in the ear which with prolonged use can be a problem in itself. Ultimately, the answer is twofold:experiment with different styles and sizes of earphoneslimit the duration of wear with frequent breaks.
Does super glue stick to rubber? Why or why not?
Depends on if it’s a natural rubber, oil based synthetic rubber or silicone based rubber. It will stick to rubber except the silicone based rubber. The glue is strongest on pulling forces, moderate at bending forces and very weak in sheering forces. Super glue will work for a short while with elastic materials but will eventually fail by sheering forces from rubber stretching and contracting. Most glues will never stick to silicone based synthetic rubbers. Best glues for rubbers are a rubbery solvent based glues formulated for vinyl, fabrics and soft plastics such as Loctite Adhesives
496 Big Block Chevy Engine Build power ratings on the parts i want to use?
You may build it right, but the 502 would have a warranty. If I was building it I would consider going with a good bottom end and blower. That would be awesome. Our mailman done his 454 in his old Chevy and the engine was basically stock other than a good bottom end, heads and his engine produces around 700 hp.
Explain how the chemistry of magma influences the explosiveness of a volcano?
(A) Magma is described as mafic or felsic (and... ultramafic and intermediate, but close enough). Mafic magma contains lots of iron, magnesium, and other heavy elements, with little silica. Because of their nature, these mafic magmas are very fluid (non-viscous) -- basaltic. Felsic rocks have a high silica content (SiO2), along with other light elements. The silica content makes it very viscous. The elements form silicon tetrahedrons (SiO4) that lock into long chains and other rigid structures. This makes it much less inclined to flow, to the point that sometimes it nearly doesn't flow (that's where you get lava domes). (B) If a magma is more fluid, it's able to move around (obviously). If it's viscous, it's resistant to flow. Mafic magma, being silica-poor allows gases to be passed through better than felsic magma. Felsic magma grabs gases and holds onto them, building up enormous pressures. (C) When these two kinds of magma are confined within a volcano, they build up those different pressures due to viscosity and gas content (mafic = not much, felsic = a lot). When a vent opens in an area of mafic magma, the low-viscosity material flows out in relatively thin sheets, with little explosivity. It may flow very far, but it won't explode. This is basically what's happening at Kilauea. On the other hand, felsic magmas will sit inside a mountain and just build up more and more and more intense pressures due to intense viscosity, rigidity, and gas content. Finally, the volcanic edifice (the structure of the mountain) simply cannot take it, and the volcano explodes violently. Mt. St. Helens and Mt. Pinatubo are perfect examples of this activity.
Foot pain that might be Morton's Neuroma?
I've had foot problems for a number of years now. I think it was originally caused by wearing sandals too much. At one time it went away simply by wearing shoes more often. It came back and I had to use a walking cast to make it go away. I've had x-rays and a bone scan done, but everything comes back negative. I suspect it may be Morton's Neuroma. Can anyone help?