Mathematical model of electromechanical system with variable dissipativity

The article considers the mathematical model of a system of two electric motors. The motors are mounted on hydro mounts with magnetorheological fluid. The viscosity of the magnetorheological fluid changes when applying a magnetic field. The validity of the model is confirmed as the analysis of the balance of power in the steady state with a static load, and analysis of transient process of synchronization shaft at different coefficients of dissipative. The model allows evaluating the electrical energy consumption of electric motor in transient process

Gender Balance of University Professors: European Experience and Its Relevance for Russia

The article compares measures to support female teachers in universities in the UK, Germany and Russia with gender statistics from the OECD. An ambiguous correlation was revealed: the broader the measures to support  female university teachers, the lower their share in higher education. The purpose of the work is to identify the reasons for this relationship. Within the framework of the hypothesis, the following thesis was put forward: high  competition in higher education affects the decrease in the proportion of female teachers and forces the states to introduce a wide range of support tools to achieve gender balance. Comparison of the specifics of the spheres of higher education in the studied countries: R&D expenditures in the field of higher education and the working conditions of teachers (average salary, mobility, a specificity of contracts, hours worked, career opportunities) made it possible to identify the level of competition in universities. The obtained results confirmed the hypothesis about the direct influence of the level of competition on the share of female teachers in higher education. In conclusion, the relevance of the experience of European countries in building a gender balance among university teachers for Russia is considered. It is concluded that significant differences in the specifics of the sphere of higher education in Russia and the studied European countries, as well as the dominant share of female university teachers in our country, are not a sufficient reason for refusing to study foreign experience. On the contrary, the measures taken by the Government and the Ministry of  Education and Science of Russia in recent years, if successfully implemented,  will significantly increase the level of competition in the field of domestic higher education and the issue of gender balance will become relevant. In order to prevent a possible generational gap among female  university teachers and the aggravation of the problem of gender balance in the future, it is necessary to study and adapt foreign experience, avoiding mistakes

Application of mathematical models to optimization of the methane fermentation of fowl dung

We applied mathematical modeling to the optimization of the methane fermentation of dung obtained from the breeding of farm animals in preceding research we carried out/Baykov, 1987, Baykov & Tyravska, 1991/. In the last few years compost is of greater interest as a resource for increasing soil fertility. The conducted research /Baykov, 1987/ indicates that the compost, obtained from the methane fermentation of fowl dung, is a source of biogenic chemical elements in optimal proportions. In the Ordinance for the organic production of plants /Ordinance №22/2001 of the Ministry of Agriculture and Forestry/ it is stated that the manure that can be used is produced from just a few farms. These are the reasons to carry out a research on optimizing the methane fermentation for a little farm, breeding 5000 laying hens without any litter, by applying mathematical modeling

Assessment of the compost from the methane fermentation of litter from broiler production with a view to its utilization in organic plant production

The aim of the present research is to make an ecological assessment of the compost obtained from litter from broiler production /LBP/ according to the requirements of Ordinance №22/2001 for the MRL/Maximum Residue Level/ values of toxic elements and according to the Norms of the Canadian Ministry of Agriculture /2002/ with a view to its utilization in the organic production of plants. This research is necessary because, unlike broiler dung and domestic organic waste, LBP is heterogeneous in content and it includes different sources of cellulose / in Bulgaria hay is the most common as well as some part of the fodder/

ПРОУЧВАНЕ НА ХИМИЧНАТА НЕЕДНОРОДНОСТ НА КАДМИЙ И ОЛОВО В БИОСФЕРАТА - БИОАКУМУЛАЦИЯ НА КАДМИЙ И ОЛОВО В ОРГАНИЗМА НА МЛАДИ ПРЕЖИВНИ ЖИВОТНИ ОТ АНТРОПОГЕННИ ЕКОСИСТЕМИ С ПОВИШЕН ТЕХНОГЕНЕН КЛАРК

The technogenic Clarc of lead (Pb) and cadmium (Cd) from the upper soil layer and the forage plants in an industrially polluted region, so as the Pb and Cd input in the organism of young lambs and kid by the synthesis of secondary biological production have been investigated. For the synthesis of 1 kg secondary production in the organism of lambs, the input of Pb with the food and drinking water is 6.44 mg and 2.46 mg Cd and in the kid- organism- 21.41 mg Pb and 5.29 mg Cd. The obtained production in conditions of increased technogenic Clarc is with higher content of Pb and Cd, according the maximal admissible levels (EC- regulation 466/2001).Изследвани са технологичният кларк на олово и кадмий в горе н слой на почва и фуражи в индустриално замърсен район, както и постъпленията на олово и кадмий в организма на млади агнета и ярета при синтеза на вторична биологична продукция. За синтеза на 1 kg вторична продукция при агнета, постъпленията от фуража и питейната вода са 6,44 mg олово и 2,46 mg кадмий а в организма на яретата – съответно 21,41 mg олово и 5,29 mg кадмий. Получената в условията на повишен техногенен кларк продукция е с по високо съдържание на олово и кадмий спрямо пределнодопустимите концинтрации (EC regulation 466/2001)

ПРОУЧВАНЕ НА ХИМИЧНАТА НЕЕДНОРОДНОСТ НА КАДМИЙ И ОЛОВО В БИОСФЕРАТА - БИОАКУМУЛАЦИЯ НА КАДМИЙ И ОЛОВО В ОРГАНИЗМА НА МЛАДИ ПРЕЖИВНИ ЖИВОТНИ ОТ АНТРОПОГЕННИ ЕКОСИСТЕМИ С ПОВИШЕН ТЕХНОГЕНЕН КЛАРК

The technogenic Clarc of lead (Pb) and cadmium (Cd) from the upper soil layer and the forage plants in an industrially polluted region, so as the Pb and Cd input in the organism of young lambs and kid by the synthesis of secondary biological production have been investigated. For the synthesis of 1 kg secondary production in the organism of lambs, the input of Pb with the food and drinking water is 6.44 mg and 2.46 mg Cd and in the kid- organism- 21.41 mg Pb and 5.29 mg Cd. The obtained production in conditions of increased technogenic Clarc is with higher content of Pb and Cd, according the maximal admissible levels (EC- regulation 466/2001).Изследвани са технологичният кларк на олово и кадмий в горе н слой на почва и фуражи в индустриално замърсен район, както и постъпленията на олово и кадмий в организма на млади агнета и ярета при синтеза на вторична биологична продукция. За синтеза на 1 kg вторична продукция при агнета, постъпленията от фуража и питейната вода са 6,44 mg олово и 2,46 mg кадмий а в организма на яретата – съответно 21,41 mg олово и 5,29 mg кадмий. Получената в условията на повишен техногенен кларк продукция е с по високо съдържание на олово и кадмий спрямо пределнодопустимите концинтрации (EC regulation 466/2001)

Microbiological evaluation of sewage sludge in terms of possibilities of application in soil as a fertilizer

Research was conducted of sewage sludge from wastewater treatment plant for the existence of microorganisms of several major groups, containing pathogenic representatives with epizootological significance (Gram-negative aerobic bacteria, E. coli, Clostridium perfringens, the genera Pseudomonas, Staphylococcus, Enterococcus, fungi, and the total number of microorganisms), in order to assess the environmental safety of the final product. In parallel similar studies were made of fresh and composted cattle manures. A comparison of the results was made with the ready for manuring compost in order to assess the possibilities for the use of sludge for fertilizing. The quantities of microorganisms were given in CFU per 1 g of the investigated material, as well as per 1 g of dry substance for each of them. In our opinion this new approach to the reporting of the results per unit of dry matter of the investigated materials, allows for a more accurate comparison. It was found that the examined sewage sludge from wastewater treatment plant were rich in microorganisms from studied groups and their direct application in soils without prior treatment by aerobic or anaerobic digestion may represent epidemiological danger

Agroecologic valuation of organic waste in different technologies of storage

A study has been conducted, based on three types of fertilizers / cow, pig and bird manure/ and bioshlam /received from clearing station/ that have been storage in different technologies in order to make an agroecologic valuation. The different types of fertilizers and wastewater in different technologies of storage have been analyzed according to the following parameters: Dry matter (DM) ,Organic matter (OM), Organic Carbon (OC), Nitrogen Kjeldahl (N), Nitrogen Ammonium (N -ammonium), Nitrogen nitrate (N- nitrate), Sulfates (SO4) , Calcium Oxide (CaO), Magnesium Oxide (MgO), Patassium (K), P (Phosphorus), pH (H2O) and heavy metals – arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pd), Zinc (Zn). The received results show: variation of the percentage of dry material /from 92,12% to 4,03%/ according to the technology of storage. The way of storage has no essential influence on the content of carbon in the various stable fertilizers, where pig manure has the highest value of nitrogen in all technologies of storage. Near to the recommendable optimal values of C:N is stayed/dry/ and fresh/hard/ in all three fertilizer types. The technology of storage by the different manure types has no influence on the content of heavy metal. Exception can be observed as far as the zinc content in stale /fluid/ pig manure is concerned. High content of dry material can be observed in bioshlam received from clearing station. In both ways of production of variation in the content of dry material the ratio between the biogenic macro elements C:N remains. The free nitrogen forms (N-ammonium and Nnitrate) in bioshlam are higher to other organic waste in both technologies of storage. No values over the critically admissible in bioshlam are observed in both technologies of production