Hiking equipment
According to Tom Brown, the basic plan for survival is in the order of shelter (including clothing), water, fire, and food. Cody Lundin writes about the "Rule of 3s"; this relates to human survival without basics: three minutes without air, three hours without shelter, three days without water, or three weeks without food.
Nanotechnology for water purification
Water is the most essential element to every life on this Earth. It’s a substance composed of the chemical elements hydrogen and oxygen. Water has always played a prominent role in human civilization. A sufficient supply of safe drinking water is one of the important requirement for a healthy life, but waterborne diseases plays a deadly role in creating large numbers of deaths in many parts of the world. All living things require water to grow and reproduce their own kind. Water is a tasteless and odorless liquid at room temperature. Water is the only substance that occurs naturally as a solid in the form of ice, a liquid and a gas which is in the form of water vapor. Water covers 71% of the entire Earth surface. The amount of water in this world isn't diminishing, but the demand is steadily increasing. Scientists believe that the world's population, will double by 2050. In addition to this, the amount of fresh water that is clean and safe to drink is steadily decreasing because of pollutants. So, people are in need of drinking water in its purest form. There are plenty of water purifiers available in the market which use different techniques like boiling, filtration, distillation, chlorination, sedimentation and oxidation. Currently nanotechnology plays a vital role in water purification techniques. In nanotechnology, nano membranes are used with the purpose of softening the water and removal of contaminants such as physical, biological and chemical contaminants. There are variety of techniques in nanotechnology which uses nano particles for providing safe drinking water with a high level of effectiveness. Some techniques have become commercialized.