Any court, including wooden and plastic must have metal underwater parts. At least – it's mount and engine parts, as a maximum – the case of aluminum, which are very popular in our country for boats boats and yachts. But especially in freshwater and seawater metal parts of the vessel inevitably damaged by galvanic corrosion. And the installation of parts made of stainless steel does not guarantee long-term carefree swimming. The most dangerous so-called local corrosion, which occurs in small areas of the surface, usually very intense, and ends with the destruction of the hull or ship's equipment. But there is a simple solution – the use of anodes.
You do not need to know more school course in chemistry to understand why it is impossible to put the brass or copper fasteners in aluminum housing. In water or in moist air from two metals with different potentials, galvanic cells are formed, a sort of 'battery'. And the more potential difference in metal forming corrosion couple, the more intense destruction of the proceeds of one of them speaker the anode. What kind of metal in the pair will break down due to corrosion? For the answer to find the number of standard electrode potentials of metals. Anode metal will always be with less capacity. And I need it? – think you are, and will, in general, right. Sales to ships, we will meet only two types of anodes – aluminum and zinc. That is enough to answer the question: when to use zinc anodes, and when the aluminum? Aluminium Anodes are better than zinc, protects against corrosion, but also why and quickly destroyed.
The latter is not very important for fresh water, in which corrosion takes place less intensively. Therefore, aluminum anodes are recommended for vessels who attend predominantly in fresh waters. Zinc anodes recommend the use of salt or brackish water. Aluminum anodes are also in the salt water 'eaten up' too quickly. In vessels with fiberglass and wood buildings should be reserved only metal parts. In doing so they must be connected to the anode, either directly or through a copper cable. It should be noted anodes company Vetus. Vetus Zinc anodes are manufactured with the most high quality requirements of the metal (military technical standard of the USA). Otherwise, they are not effective enough. Aluminum anodes are made of aluminum Vetus-indium-zinc alloy. All anodes elaborate form, with a layer of paint on the inner side to protect the colored blocks. The choice of a special attachment comes in the form of rods to weld a steel hull, or special screws for fiberglass and wooden hulls. Anodes for the propeller shaft (axial anodes) are joined perfectly with the shaft and have a unique mounting system, so that work only on the outside.
Pumps can be distinguished by type depending on how the movement of fluid. Thus we can distinguish two main types of pumps: circulating (centrifugal) and volume action. Circulating pumps are movement of fluid through centrifugal force. Pumps that move fluids using this method are called centrifugal pumps. This solution is suitable for moving homogeneous liquids. Pumping equipment volume Use of the forced displacement of the moving portions of fluid from the working chamber in the discharge line, by changing the working volume of the chamber or the mechanical movement of portions of the liquid. Pumps that work on this principle, called volumetric pump action.
Pumps volumetric action does not violate the structure of the fluid. Rotary pump Rotary pump – the general name of forced displacement pumps, which move the fluid motion of rotors, cams / wedges, screws, blades / vanes or similar parts in a fixed housing. Usually necessary in the intake / intake and exhaust valve no. Gear pumps external engagement gear The simplest type of pump with positive displacement, which is caused by a change in the volume of voids between a gears coupled with independent drives. The pump is powerful and inexpensive. In main gear pumps pumping viscous liquids without inclusions. It is necessary that the liquid wets the material of the working chamber and gears. You also need to pay attention to when selecting the type of mechanical seal, which is adjusted for characteristics of the fluid.
As you can see, the design of modern steel doors far removed from their predecessors, welded corners and sheets of iron. They may have transoms, windows (of course, with a special, including and bulletproof, glass) to be one, one and a half and double. Jorge Perez addresses the importance of the matter here. But the basic elements of steel doors remain unchanged: the frame (box) and the case of steel doors. Perhaps even the existence of a rough frame (or kontroramy) fastened by welding to the downtrodden powerful steel pins – bolt. Already a roughing the door frame with screws, which allow to correct its position in space, fixed frame itself. In most domestic models steel door frame is not rough, and the box is connected directly to the wall – with the metal pin it attaches to the doorway and "planted" in the weld.
For all the simplicity steel doors are the mechanism in which each element plays an important role: the blade, and locking system, and the box, and a filler, and appearance – all of them in the complex shaping products, which we appreciate. Cloth steel door housing a steel door consists of one or more steel plates (paintings) and the stiffeners as beams and ribs. In the body of a steel door stiffener can be placed vertically, horizontally, or a combination (in a grid). Used for these steel sections can be of different configurations and have a thickness of 1,5-4 mm. The very same blade steel doors manufactured using frame technology. There are two basic types of frames: made on the basis of rolled mild steel, to the benefits of which include a good load-carrying capacity and impact resistance, made of thin extruded profiles (these steel doors of its good spatial rigidity and lightness).
Why, by demonstrating the historical, social and cultural life of Guarani and therefore, its indisputable value in the Reform Bilingual Education through the Teaching, being-in all cases, our workhorse the subject "grammatical differences between the Guarani and Castilian: contrastive analysis and its impact on education." 1.2. Statement of the Problem The results of the last national census, performed in Paraguay, in 1992, showed that 37% of the population of almost four and a half million inhabitants, is monolingual Guarani, 50% bilingual (Guarani-Castilian) , 7% monolingual Castilian and the remaining 6% speakers of other languages. However, until 1993, education was exclusively in Castilian, including: classes, textbooks and tests, by teachers with tremendous problems of oral communication and written in Castilian. Educational model that perversely helped to keep the majority of people outside of education, it actually reflected in the high rate of illiteracy, school dropouts and repeaters. The effect of still endure today as, according to statistics Ministry of Education and Culture, 67% of the economically active population of Paraguay is illiterate. What is one of the main reasons for this reality? The absence of the Guarani in Education. Paradoxically, today, thanks to bilingual education, that part of education in mother tongue, many native Guarani speaking children achieve democratic and critical learning, which, undoubtedly, the most valuable leads towards the goal of any human being supported freedom of knowledge. But the most important aspect of this fact, it already has and will have a direct and valuable impact, rather than individual development, in socio-economic, cultural and political development.
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