MongoDB

 MongoDB is an open source, document-based database management system that does not require a table schema description. MongoDB - classified as NoSQL and uses JSON-like documents and a database schema. If all four previous DBMSs are well known to most IT professionals, then few have heard of MongoDB. But she confidently takes the 5th line in almost all ratings. And as a result, in our ranking, she also occupies the 5th position.

Rod materials

 

Modern materials - fiberglass, carbon fiber and composites - are constantly expanding the possibilities of fishing tackle. They allow you to create tackle that combines the required length, elasticity, strength and low dead weight. Until now, our compatriots can meet bamboo and even wooden rods. But the time of wooden rods is gone, they are not able to compete with modern materials.


What are composite materials? These are materials that are used in various combinations (compositions) of high-strength plastic and fiber materials. Rods are made of fiberglass, carbon fiber, boron fibers, high and low modulus graphite and some other materials.


Nowadays, you can buy a rod for almost every taste: from cheap fiberglass "telescopes" to high-end pole rods made of high modulus graphite. Fiberglass telescopic rods remain in the hobbyist's arsenal due to their low price and satisfactory strength. Their disadvantages are their large (compared to graphite and composites) weight, vulnerability to sunlight, and limited service life.


Carbon fiber rods (the material is a specially processed graphite) must be marked "carbon". They have a high degree of strength, light, with a given degree of elasticity. High-modulus graphite gives greater rigidity, and low-modulus - ductility, flexibility. Carbon fiber rods are durable when properly used. But carbon fiber also has negative properties.


First, they are fragile and require very careful handling. Hitting rocks or flicking a rod with heavy artificial bait can disable this expensive tackle. This will not happen if you handle your rod carefully. Don't throw it at your feet. Before moving from one fishing spot to another, the rod must be disassembled, even if the transition is a short distance. When moving, the rod must be stored in a rigid tube. Freeing yourself from the hook, you can not drag the fishing line with the rod.


Secondly, graphite is an excellent conductor of electricity, so working with such a rod in close proximity to electrical lines of current-carrying structures, as well as in thunderstorm weather, can be very dangerous. Manufacturers usually warn about this by placing a lightning sign on the rod. Any (!) rod during a thunderstorm can be quite a dangerous object. When raised to a vertical position, it attracts an electrical charge, increasing the risk of being struck by lightning. If the rod is marked with a lightning bolt, it is better not to use it during a thunderstorm.