Spark ignition gasoline and compression ignition diesel engines differ in how they supply and ignite the fuel. In a spark ignition engine, the fuel is mixed with air and then inducted into the cylinder during the intake process. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion.
1 If your skin is too sensitive, dilute tea tree oil with some baby shampoo. Add 10-20 drops of tea tree oil to 1/2 cup of baby shampoo. Use this daily to wash your scalp and hair till you get rid of itchy scalp.  You can even massage diluted tea tree oil to your scalp.
Massage the gel into your scalp and leave it for ten minutes, then rinse before shampooing or co-washing as usual. You can also use aloe vera juice to the same end. For a lighter pre-shampoo treatment, mix aloe vera juice, coconut milk and wheat germ oil.IY Conditioner. 1  Cut the aloe vera leaf from the stem upward. 2  Use a spoon to remove all the gel. 3  Apply it to damp hair, starting at the scalp and working your way down to the ends. 4  Wrap your hair in a warm, damp towel and let the treatment sink in for at least 15 minutes.