I Librarian › Horticulture › Polyethylene › Earth Core › Flatworms › › What is the meaning and definition
Concepts and Meanings Category ›› General
Definitions and meanings of words and expressions Category: General
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I librarian › Definition and Meaning
The term librarian can designate one individual working in a library, ie, it is in charge of it. It is also common that I called it as a librarian.The library is one place where books, bibliographic and audiovisual collections, magazines and newspapers from different periods are stored so they can be consulted by those who so wish.
Meanwhile, the librarian will address, on the one hand, to deploy various techniques and procedures for organizing the material housed in the library and on the other hand to assist people who come to the facility to access information sources, whatever their format.
As has happened with many other professional activities of the librarian was transformed with the passing of the years and went from being mere custodians of books professionals specially trained to organize the material in a library and also to guide users access to thereof, as just noted.
Moreover, the entry of new technologies to business, especially with regard to storage of information, has claimed that those performing the activity of librarians is aggiornen in this regard.
In the aforementioned tasks of a librarian are added: incorporation of new materials, cataloging and classification of them for easy tracking time to locate each documentary piece, removing obsolete material, policy -making work in libraries which display their activity, research, among others.
The task of the library can be deployed in various types of libraries exist: public members of a community; an institution of education, such as in a college or university; in a special library, such it is the case of those for blind or deaf; the library of an enterprise; in the library of Parliament; or a national library, where it collects and stores most of the production literature a nation.
Vocational training of a librarian is carried out in a tertiary institution, with the title Bachelor career in librarianship.
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horticulture › Definition and Meaning
Horticulture is the discipline that deals with the cultivation of vegetables or herbaceous plants and are usually grown in gardens for once reached your ideal stadium to be consumed raw or being part of a culinary preparation.The extent of cultivation of vegetable is because it is a product rich in nutrients and vitamins and as such will provide the body with great nutritional value. It should be noted that in vegetables does not include fruits and cereals.
Meanwhile, they are orchards, those irrigated lands, which are intended primarily for growing vegetables. Irrigation turns out to be a fundamental part of this network since it is responsible for bring to the growing water needs to develop and grow as.
Basically, horticulture activity is integral because it is responsible for implementing a technique to grow plants in gardens but also to introduce improvements in crop and fertilizer to thereby adding in quality and nutritional value of the harvested plants. Another issue which should emphasize horticulture is on environmental conditions that directly affect the results. In this regard hand it shows genetic as essential to develop plants that synthesize molecules that can appropriately be used in combating pests and weeds, among other issues resource.
Meanwhile, the individual who is professionally engaged in this activity is called as a horticulturalist and training takes place in a home for the tertiary level studies. Meanwhile, the working out of these professionals can be really wide as they can be employed in the public or private sphere and deploy their knowledge on the subject in various activities such as farmers who specialize in a particular species, inspect crops, attend as counselor at the time of production of crops in research and also teaching about the matter in any institution educational.
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polyethylene › Definition and Meaning
Polyethylene is a type of polymer that is extendedly used in the manufacture of packaging bags for coating cables, for containers and pipes, among others. This is one of the most common plastics used in the world, especially for the low cost involved.Meanwhile, the polymers are macromolecules which are formed by the union of molecules called monomers smaller. Meanwhile, the polymers can be natural, as in the case of DNA, silk, starch and cellulose, or their synthetic defect, such as nylon, bakelite and polyethylene, which is the polymer of which we now turn continuation.
The polymer it is obtained from a process chemical known as polymerization and the chemical compound ethylene.
It should be noted that depending on the type of polymerization is carried out can be achieved various species of polyethylene.
Meanwhile, during the creation process it is possible to add different substances to the polyethylene that the final product enjoys certain properties. One of the most common is be to bring you a different coloration which naturally has that right in its first stage is translucent.
Furthermore, they will be added different additives will make it a substance antibacterial antioxidant, and fireproofing.
Polyethylene was first synthesized in the late nineteenth century, in 1898 by chemist Hans von Pechmann German origin, accidentally. In the thirties of the last century, two English scientists synthesized with the way we know it today.
As noted above lines, polyethylene is used extendedly and particularly it is employed for manufacturing plastic bags which normally get with purchasing a product in supermarkets or other stores. However, they turn out to be a very serious problem for the environment because the material not being biodegradable pollutes our planet if they are not thrown into a place prepared. They are many years it will take a polythene bag to degrade.
The solution to this problem is the renewable polyethylene obtained from beet, cane sugar or wheat and as such can be recycled.
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Earth Core › Definition and Meaning
The core of the earth is the name that receives the esferacentral and innermost planet earth. Among its main components we find nickel and iron, in a proportion greater and lesser amounts with oxygen and sulfur.The radio has is approximately 3,500 kilometers, an amount that is larger than the planet Mars and its internal pressure is a million times more important than holding the earth 's surface. Its temperature is really high and can reach 6700 °, it is even hotter than the surface having the sun itself, meanwhile, considers that it has to do with the heat that resulted from the collision of the particles when the earth He conformed.
Its outer core is liquid and consists of iron, nickel and other less dense components, while the inner is solid body and also has iron, approximately 70% and 30% nickel, and then other heavy metals appear such as titanium, iridium and lead.
The core of the earth was formed along with this some five billion years ago after the explosion of a supernova. Heavy metals left over crowded disk, revolving around the sun. The core mainly composed of iron and other radioactive elements such as uranium and plutonium and then heat released by gravity heavier materials sank in the middle and lighter floated to the crust. Such process is called planetary differentiation. And this fact is that the core of the earth is composed of iron, nickel, iridium, etc., which are heavy materials as stated above.
It should be noted that when our planet was burning metals that now make up the core suffered an alloy that became a very dense and strong structure and is that the planet Earth is the densest of our system.
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flatworms › Definition and Meaning
The flatworms are a type of worm that are characterized by a flat body unsegmented, ie without vertebrae, and this is that the also called worms planes. Mostly they operate as parasites, ie, parasitizing on other animals. Other distinguishing characteristics are hermaphroditic, the absence of both apparatus respiratory and circulatory and commonly found in fresh water, but it is also plausible, found in the earth but wet characteristics.It should also be noted that some species even have digestive or year, being the digestive tract which is responsible for digestive functions and distribution of nutrients they receive.
Among the best known types include tapeworms and painful. It is estimated that flatworms comprise twenty thousand species.
In the absence of what is called locomotor appendages, flatworms can be mobilized through the vibrations produced by the ciliated epithelium.
A flatworms it distinguishes them in four classes: turbelarios (this type makes a free life, is carnivorous and feed dig to find their food), monogeneans (this variant is found in fish and amphibians), tapeworms and flukes (these two They characterized especially because they often live as parasites of mammals including man). The last three are further characterized by presenting no head.
Tapeworms, meanwhile, are the ones who usually inhabit the man being tapeworm or solitary worm the most common type. The most common form from which the man enters your body is by eating foods that have tapeworm eggs, such as fruits, vegetables and undercooked meat.
There are very characteristic symptoms that allow to notice the presence of tapeworm in humans such as nausea, weight loss, sleep, gastrointestinal pain, lack of appetite and a lot of nervousness.
However, given the serious health consequences that can trigger had as blindness, brain damage and seizures, will require immediate consultation with a professional doctor just feel these symptoms.
Meanwhile, the best way to prevent them is to properly clean food and in the case of meat cooked ingest.
Also, the word flatworm is used to refer to anything related or characteristic of the species platelminta.