1 If you add music and files to your iPod while you are charging the battery, it will take longer for it to charge. 2  Before using your iPod nano for the first time, it is important that you let it charge for a minimum of three hours. 3  If you do not, you can weaken the battery, giving it a shorter lifespan.
There is also a chance that your black period blood is caused by an infection or STD. Uterus infections can cause blackening as well as many STDs. Women that have sex during their cycle also experience black bleeding because the blood was pushed back into the vagina and can become trapped as a result.
Each hemoglobin protein is made up subunits called hemes, which are what give blood its red color. More specifically, the hemes can bind iron molecules, and these iron molecules bind oxygen. The blood cells are red because of the interaction between iron and oxygen. When the iron is oxygenated(Fe+3), it becomes red. When the iron is deoxygenated(Fe+2), it becomes blue. This is why your veins are blue. When hemoglobin is carrying a lot of oxygen (like when just leaving the lungs), blood is bright red.