for mechanical strenghth
Grounding the metal sheath of a cable helps to protect against electrical shocks and reduces electromagnetic interference. It also provides a path for fault currents to safely dissipate, helping to prevent damage to electrical equipment or fires.
2X - XLPE insulation W - Copper conductor Y - PVC sheath
Metallic sheath is a continuous covering of metal that provides protection against mechanical damage and electromagnetic interference in cables, while armour is an additional layer of metal tape or wires that provides enhanced protection against physical damage such as crushing or rodent attacks. Armour also offers better resistance to environmental factors like moisture and chemicals compared to metallic sheath.
You can use a plastic or a metal sheath. A thermoplastic sheath would be ideal for this situation. It is handy because you can get it in a variety of colors if you want it to blend into the environment.
The sheath in cables provides protection from moisture, chemicals, abrasion, and other environmental factors. It also helps to contain and insulate the inner conductors, ensuring the safety and longevity of the cable.
The purpose of an internal cable routing sheath in a bicycle frame is to guide and protect the cables inside the frame, keeping them secure and preventing them from rattling or getting damaged.
The function of bundle sheath is to facilitate various processes in the plants. Some of the roles include fixation of carbon during photosynthesis and transportation within the plant among others.The bundle sheath separates the vascular bundle from the ground tissue.
You are probably referring to moisture ingress. Moisture ingress into underground electrical cables, particularly high-voltage cables, can act to break down the insulating properties of that cable, and lead to a short circuit. Accordingly, underground cables incorporate a sheath (lead in older cables), which is impervious to moisture ingress, which surrounds the cable cores, and is located beneath the outer armouring. But moisture ingress can occur with all types of electrical equipment, and the manufacturers take steps to prevent this from happening.
tendon sheath
A sheath is a protective covering or casing that surrounds and protects a tool, weapon, or other object. It helps to prevent damage, maintain sharpness, and reduce the risk of accidents.
Myelin sheath never transmits the impulse from one neuron to another. On the contrary these are insulating cells which prevent transmission of nerve impulses.