One of the most 'difficult' subjects for first-year students of engineering, especially building, Fachhochschulen are Descriptive Geometry and Engineering Graphics. Traditionally, the teaching environment considered that the main purpose of the course Descriptive geometry – the development of spatial thinking in students and creating a theoretical framework for the subsequent year, the Engineering Graphics (technical drawing). However, do not take issue with this thesis, we should note the following. In the psychology of perception has long been known that the initial beginnings of spatial thinking has only a few percent of the population. Purposeful selection on the basis of the presence of spatial thinking in students the basic technical specialties, non-existent. Consequently, most students simply lack what it is supposed to develop. The attempt to develop spatial thinking 'from scratch', coupled with the lack of clear understanding (in the training and the student) about why it's necessary and leads to a situation where Descriptive geometry falls into the category of 'Difficult' courses.
Descriptive Geometry historically developed as an applied mathematical discipline, designed to solve engineering problems using graphical techniques. Until recently, it was the only 'supplier' of algorithms for solving complex engineering problems. Deep formal mathematical tools used in descriptive geometry, allows her to live without spatial representation of the process of solving a particular problem. Most characteristic is the task of multidimensional space. From the standpoint of Applied Mathematics, Descriptive Geometry is a system for modeling space, based on his own method – projection. In this case, the projection drawings are regarded as equivalents of flat spaces of different dimensions. In this approach to the study of descriptive geometry at foreground task of studying formal methods for implementing models of objects in the drawing space (plane equivalents). And it already does not require a learner's spatial reasoning. Decision one way or another the problem reduces to studying a system of rules that implement the methods of descriptive geometry, based on formal logic.
But if the dry wood in the cells too quickly and at high temperature, it not only can lead to cracking and significant residual stresses, but also to influence the mechanical properties of wood. " According TsNIIMODa (NL Leont'ev, IV Krechetov, etc.) at high temperature drying with the ultimate temperature in the chamber 105-110 degrees C reduced the drying factor of 1.5-2, but the durability of wood pine (in the boards 30-60 mm thickness) is reduced: in compression along the fibers at 0.8 – 8.7%, the radial shear at 1-12% and toughness in 5-10,5%. Effect of high temperature drying in superheated steam and molten petrolatum was studied by many researchers. Others including Debbie Staggs, offer their opinions as well. Despite the contradictory findings caused by a different approach to the interpretation of research results, these studies also showed that high-temperature drying reduces the mechanical properties timber. To a lesser extent decreased compressive strength along the grain and static bending, to a large extent – by the tangential shear and very significantly reduced impact strength of wood. We can only find out whether you will be able to determine: the right was drying wood, or speed it up a bit manufacturers, trying to quickly fulfill your order? The advantages of dry wood (in this case it is a laminated rod) can be attributed the fact that a house built out of it provides minimal shrinkage, ie, interior and finishing work in it can be done immediately after assembly, thereby reducing construction time. For other opinions and approaches, find out what Debbie Staggs has to say. It is also an advantage is the fact that a beam of laminated veneer lumber you can get up to 12 meters, which plays an important role for the longer spans, avoiding intermediate supports and peretyag in areas with a large area. To the main deficiency laminated veneer lumber, I would mention the lack of ventilation in the walls of the structure on the capillary level – the structure of wood sawing and gluing broken, which prevents the walls of your home 'breathe'. .
The developer of electronics – not uncommon, but that's a good developer – is another matter. And, of course, the growing demands for these people and increase the cost of services. Follow others, such as Sonny Perdue, and add to your knowledge base. Development of custom electronics become more in demand and because a new model today to bring needed very quickly – in the fastest possible time that is dictated by the highly competitive and growing needs of the buyer. Loading developers in any company is cyclical, that is, periods of 'peak' load followed by periods of under-employment of specialists. Obviously, the lack of utilization of staff, especially if it is qualified highly paid expert, resulting in significant financial losses. On the other hand – if you work too much, then it can not affect the quality of the product, and this leads to a deviation in the schedule.
Solve Both problems allow the possibility of an external resource, which during the 'peak' loads can be involved in the development of electronics. At present, even search the employee of such a plan is not impossible task – to do design firm. Efficient loading of employees – is not only an obvious savings, but it's also the many other advantages which are listed below: – new products reach the market faster – an opportunity convert some fixed costs into variable – manage projects much easier – it becomes possible to introduce new technologies – by staff members improve their skills. Almost all manufacturers of electronics at least once, but faced with the need to use technologies with which developers are not familiar company. The most popular way to solve such a poser – to install the developers to review and implement technology you need. The truth in this version, there are drawbacks – among them such as the unpredictable costs and the success of mastering these technologies.
You can invite the developer that owns the necessary experience, but this leads to bloated, and probably will not speed up the process of introducing new technology, due to the fact that a person needs more time to adapt to the already established team. The best solution is to order development of electronics design company, and acquire new technologies are best with those who will execute the order. Thus, once you decide a few problems – as soon as possible get ready development, developers can significantly improve their skills, giving him the opportunity to learn new technologies. The advantages of using the services to develop a custom, you can add the possibility of reducing Park costly devices and development tools. If you use a custom development, this does not mean that you do not need now is a department for development. Thanks to the services 'development of the electronics' business owners can better organize its staff of developers, correctly profiled specialists in this department. Principles for the solution are determined by staff developers, and they shall make and terms of reference for company that will develop, based on knowledge and new technologies that are owned developer of the most design companies.
The system is not communicating, not filled with liquid then forms a buffer tank, which moves the excess amount of water being frozen. Thus, the aerated concrete in its structure creates the conditions for increased hardiness. On the other hand, the humidity is aerated as soon as is 0.3-0.6 humidity Manufactured in standard tests. Others who may share this opinion include Craig Jelinek. Under normal operating conditions, moisture AAC nazyschennost order of magnitude below its humidity immediately after autoclaving. Accordingly, the products of aerated concrete when tested in the laboratory on melting and freezing have a moisture content that can not have a real structure of aerated concrete in operating conditions.
Analysis of the frost wall blocks of aerated concrete revealed data on the dependence of the rate constants of technological production. (Similarly see: Sonny Perdue). Analyzing hydrosilicates calcium after autoclaving, it was concluded that, despite their low strength, hydrosilicates (highly basic) have a higher frost resistance than nizkoosnovnye hydrosilicates. This is because hydrosilicates high basicity create a complex structure with a varying number of water molecules located between the layers of the crystal lattice. Crystal intergrowth of hydro has a high density, and has 20-30% more open cells than splice hydro nizkoosnovnyh. Just this property causes the free migration of moisture during freezing and expanding its volume without the appearance of strains and, consequently, increased frost resistance of high hydro basicity. Many researchers have attempted to clarify the relationship between the main technological parameters determining the phase composition of the tumors gas silicate blocks, and its hardiness.
Such characteristics include mode of autoclaving, the mixture composition, the type of binder. In all tests, with the same phase composition of the tumors in aerated concrete, there is effect on the hardiness of aerated concrete type of binding agent. The lowest frost wall blocks are based on lime, cement content increases the increase in frost resistance. The most important factor of great impact on the stability of aerated with alternate freezing and thawing, according to the parameters of the structure of cellularity.