SYNTHESIS OF THE LOW-FREQUENCY VIBRATION EXCITER

The article is devoted to synthesis of the low-frequency vibration exciter for checking of sensors of acceleration. In many areas of the modern equipment sensors of acceleration working in very low range of frequencies are widely used. For checking and graduation of such sensors the vibration exciter capable to provide rectilinear horizontal harmonic oscillations of the calibrated accelerometer in so low range of frequencies are required. Low frequencies of fluctuations cause the necessity of creation of big amplitudes of movements for ensuring the acceptable values of amplitudes of accelerations. The low-frequency electrodynamic vibration exciter with a magnetic suspension of mobile part which is a component of the National Standard of the vibration movement of the Russian Federation is so far created. However, development of the modern equipment demands expansion of frequency ranges to the area of ultralow frequencies. One of requirements shown to the vibration exciter working in the ultralow range of frequencies is increase in amplitude of horizontal movements of a mobile part as with small amplitudes the speed and acceleration of the harmonious law of the movements proportional according to the frequency of fluctuations and a square of this frequency, will have small amplitude values. One of problems of realization of a control system of the electric drive of the vibration exciter consists in that a mobile part possesses indifferent position of balance. The centre of fluctuations of a mobile part is not defined and can be in any point on magnetic conductor length. That fluctuations had the steady centre in an average point of a magnetic conductor without use of a mechanical spring, the drive is supplied with an additional control system of fluctuations, or a so-called electromagnetic spring.

FACTORS OF EMERGING STATEHOOD IN THE SOUTH-WEST ASIA IN NEOLITHIC – CHALCOLITHIC

It is stated that the process of initial statehood formation occurred in the North Mesopotamia. Also some statements around ascension of sedentariness and pastoralism are revised in the article. Author highlights key problems of population estimations in ancient times of the South-West Asia. New data in the article corrects population estimations by degree. One of the leading themes in the paper is the role of highly mobile part of population in functioning of interregional trade. It is emphasized that Uruk phenomenon is highly overestimated and lacks hard evidence. Author presents new approach of understanding the statehood origin. It is made on the basis of material data and careful review of archaeologic interpretations.

A prospective observational study on prevention of contractures of upper limb following burn

Background: Over 1 lakh people are affected by burn every year in India and 20 thousands of them die per year. Post burn contracture is a common sequele occurring after burn. Upper limb contractures are also occurring more commonly because it is most mobile part of body and likely to be involved in burn. There are many studies on management of post burn contractures but literature about prevention of contracture is little, hence this study was conducted. The aim of this study was to recognise various preventive measures to prevent post burn contractures of upper extremity.Methods: This study was conducted in NSCBM Subharti Medical College and Hospital located in Meerut (North India) from October 2012 to October 2014 in Department of Surgery. It was a prospective observational study consisted of 80 cases who presented as acute burn of upper limb admitted in the hospital.Results: In our study early excision with skin grafting was done in 20 patients (25%) while delayed skin grafting was done in 25 patients (31%) while 35 patients (44%) were managed conservatively. In our study 20 patients reported back with a post burn contracture. The reason found was non-compliance to antideformity splint and physiotherapy.Conclusions: Early surgical management of deep burns, physiotherapy, anti-deformity position and proper splintage can significantly reduce the development of post burn contracture.

TO THE QUESTION ABOUT SPECIAL TYPE OF OCCASIONAL WORDS IN RUSSIAN

The lexical level is the most mobile part of the language system. This mobility is in many respects caused by word-formation mechanisms. In live informal conversation the process of occurrence of new words is continuous and active. The basic part of new words is created according to productive models. The share of occasional ways in word-formation is less. However, it grows, as the occasional way in itself is more expressive and more emphatic. In the work we will pay attention to the words created by means of one of the ways of occasional word-formation.

Deformation of rhyolite lava crust associated with intermittent inner flow of lava: palaeomagnetic evidence

SUMMARY A palaeomagnetic study has been conducted to examine the deformation of thick crusts of rhyolite lava while its inner portions continue to flow. The Sanukayama rhyolite lava, which erupted in the Pleistocene in Kozushima Island, Japan, was chosen as the investigation site because of its well-exposed vertical lithofacies variations classified into three distinct zones (pumiceous, obsidian and crystalline). The targets of this study are the pumiceous and obsidian zones, which constitute the crust of the lava. Thermal demagnetization reveals three remanent magnetization components from the pumiceous and obsidian samples but only a single magnetization component from the inner crystalline rhyolite samples. Alternating field demagnetization is ineffective in isolating the magnetization components in the pumiceous and obsidian samples. The multiple components of remanent magnetization of the crust are interpreted to have been acquired during cooling as thermoremanent magnetizations. We suspect intermittent lava transport of the inner portions, the primary mode of rhyolite lava advancement, to be responsible for the presence of multiple components in pumice and obsidian of the lava crust. When the inner portions of the lava retain mobility to flow out of the crust, the solidified crust of the lava surface below the magnetite Curie temperature remains susceptible to deformation. Analysis of palaeomagnetic directions from the crust allows the deformation of the crust to be described in terms of rotation. Although the mode of rhyolite lava advancement is not well understood, because of its infrequent occurrence, our observations offer an important insight on how the mobile part of the lava is associated with the deformation of the crust during continued lava advance.