EEEP 3/2011

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Trichosporon cutaneum R57

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BIOLOGICAL DIVERSITY CONCEPTUAL FRAMEWORK AND THEORETICAL BASIS
Nesho Chipev
Summary. The paper reviews the recent conceptual framework and the theoretical background of the science of biodiversity. The dynamical equilibrium model of biodiversity is presented, emphasising the balance of different processes of increasing and loosing genes and species, changes in the functional characteristics of ecosystems and communities. The role of biodiversity in ecosystem functioning and production of ecosystem services is briefly discussed.
Key words: biodiversity, dynamical equilibrium model, ecosystem functioning

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ARTIFICIAL SPACE LIFE SUPPORT SYSTEMS
Tania Ivanova
Abstract: Long distance manned flights in the future spacecrafts, even to the nearest planet Mars, will be impossible without an onboard artificial self-regenerated biological system, which will guarantee at the beginning at least partially the life of the crew. In these systems will be realized the cycle of biogenic chemical elements, the autonomous air and water purification, as well as the food production. Bulgarian scientists started their work on the design of artificial Biological Life Support System (BLSS) for the manned missions to Mars, as well as for the outer space research labs, long ago in the frame of the Intercosmos program. They took part in the creation of the key element higher plants - an energy gate of BLSS, developing unique scientific instrumentation and biotechnology for conducting long-term experiments with plants in space conditions. The first in the world automated SVET Space Greenhouse for monitoring and control of the environmental parameters was created. In the period 1990-2000 onboard the MIR OS took place experiments with different cultures proving the possibility plants to be used in BLSS and the effectiveness of the design.
Key words: Biological Life Support Systems, SVET Space Greenhouse, Manned Mission to Mars
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STUDIES ON THE FEASIBILITY OF WATER PURIFICATION BY ELECTROCOAGULATION AND ELECTRODESTRUCTION USING ANODIC DISSOLUTION OF ALUMINIUM AND IRON ELECTRODES
Anna Simeonova, Atanas Ivanov
Abstract: The present article examined the potential use of aluminium and iron electrodes for purification of water by electrocoagulation and electrodestruction method. The behavior of the electrodes was investigated in model water suspension (containing bentonite) at different conditions of anodic dissolution. The electrochemical processes were carried out at operating current (I), ranging from 5 to 10 A; current density (J) - 291,38 and 582,7 A/m2; run time (t) - 8, 16 and 24 min. and pollutants concentration 5 and 10 g/dm3. The dissolution of the electrodes was analyzed as well as their role in the synthesis of Cl- ions using NaCl as an electrolyte. The aluminium electrodes exhibited much better dissolution than the iron electrodes which made them more applicable for electrocoagulation. Highest Cl- concentrations (6,217 g/dm3) were measured when using iron electrodes at 5 A operating current, 8 min run time and 5 g/dm3 water pollution which showed that the iron electrodes were more suitable for electrodestruction. When using aluminium electrodes - 50,67 % purification effect was reached by analyzing permanganate index and when using iron electrodes - 62,5 % according to the water color parameter.
Key words: electrocoagulation, electrodestruction, aluminium electrodes, iron electrodes, water purification

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TRICHOSPORON CUTANEUM R57
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GROWTH KINETICS AND DEGRADATION OF TRICHOSPORON CUTANEUM R57 ON PHENOL
Zlatka Alexieva, Maria Gerginova, Nadejda Peneva
Abstract. The object of this study is Trichosporon cutaneum strain R57, which is distinguished by its ability to degrade phenol at high concentrations (1 g/dm3) for a very short time (16-18). Another advantage of the strain is his quick adaptation when switching from glucose to gluconeogenic substrate (phenol and / or acetate), included as a carbon source in the culture medium. The growth and degradation characteristics of Trichosporon cutaneum R57 strain were investigated in different synthetic and complete cultivation media suplemented with phenol. The results showed that the specific growth rate (), and the affinity to the substrate (Ks) with few exceptions, remained similar values. Significant differences occured in the limiting for strain phenol concentration of 1 g/dm3, where theoretically calculated Ks reached about twice as high. This may be due to the high toxicity of phenol and itd effect on the general cells metabolism. Calculation of the maximum rate of substrate utilization (Qmax) in the experiments showed that the values of this parameter is maintained within an order of magnitude 0,17-0,69 h-1, regardless of the conditions of cultivation.The ability of strains to degrade other aromatic compounds gives us reason to believe that the strain has good research skills base to be used in biotechnologies for wastewater treatment.
Key words: Biodegradation, phenol, Haldane kinetics, yeast Trichosporon cutaneum

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MAXIMUM POWER OPERATION OF WOUND ROTOR ASYNCHRONOUS MACHINE FOR WIND GENERATOR
Vladimir Lazarov, Zahari Zarkov, Ludmil Stoyanov, Dimitar Sprirov
Abstract: This paper presents the modeling of wind energy conversion system with the contiguous control system for maximum power extraction from the available wind. A criterion for the control operation estimation is selected and is applied in the simulation to asses the control operation. The correct operation of the developed model and control systems are confirmed by the simulation results.
Keywords: wind generators, maximum power point tracking

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HYDROGEN - ENERGY FOR BULGARIA
Alexander Sadovski
Abstract: The purpose of this work is to identify and present the opportunities for Bulgaria to use hydrogen as an energy source. Today's primary energy sources are mostly non-renewable - coal, oil, natural gas and conventional sources of nuclear energy. There are also renewable sources such as falling water, solar radiation, plants, manure, wind and geothermal sources. Theoretically, all types of energy sources can be used in Bulgaria, but each has its advantages and disadvantages or risks in terms of human health impact, of environmental and economic perspective.
Still many governmental bodies and some of the scientific community underestimated the threat to the ozone layer caused by combustion processes and emissions from thermal power plants (TPPs) and transport. The problem of global warming and the preservation of the ozone layer will encourage Bulgaria to focus efforts and resources for using hydrogen as an energy source.
The Black Sea is the world's largest body of water containing H2S and hydrogen sulfide layer that begins about 200 meters below the surface. The total supply of hydrogen sulfide in the Black Sea is estimated at about 4.6 x 109 tons. Interest in that reserve is manifested by the countries around the Sea - Turkey, Ukraine, Romania, Russia, Bulgaria and Georgia. Methods for extracting hydrogen from hydrogen sulfide are in development. There are concerns that the increase of hydrogen sulfide in the Black Sea may cause huge environmental disaster that can be countered by its reduction and use.
Key words: Energy sources, Hydrogen, Hydrogen sulfide, Ozone, Black Sea, Environmental protection.

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OPPORTUNITY FOR BIOETHANOL PRODUCTION FROM WASTE BREWER'S SPENT GRAIN ( REVIEW)
Ivo Ganchev, Silvia Mileva
Abstract: Brewers spent grain is the main by-product of brewing industry and an attractive lignocellulosic material for bioethanol production since it is one of the most abundant renewable resources. It has several characteristics, such as high cellulose and hemicelluloses content that can be readily hydrolyzed into fermentable sugars. But there occur several challenges and limitations in the process of converting brewers spent grain to ethanol. One of the major challenges in developing technology for bioethanol production from brewers spent grain is selection of an appropriate pretreatment technique. The choice of pretreatment methods plays an important role to increase the efficiency of enzymatic saccharification thereby making the whole process economically viable. The present review discusses the available technologies for bioethanol production using brewers spent grain. 
Keywords: Brewers spent grain; Pretreatment; Enzymatic hydrolysis;Fermentation; Bioethanol 

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COMPARATIVE STUDY OF SOFTWARE SENSORS FOR UNMEASURABLE VARIABLES OF THE ANAEROBIC DIGESTION OF ORGANIC WASTES
Boyko Kalchev, Ivan Simeonov, Nicolai Christov
Abstract. Various deterministic and stochastic software sensors for estimating unmeasurable variables concentrations of bacterial populations and intermediate substrates in the anaerobic digestion of organic wastes, have been designed and characterized by computer simulations. he design has been made on the basis of nonlinear process models of second order, using methane outflow rate as the only online measured quantity. Realistic random and deterministic model parameter perturbations have been taken into account in the study.
Key words: anaerobic digestion, software sensors, comparative study

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INVESTIGATIONS OF FOREST RESEARCH INSTITUTE BAS OF STRUCTURE, DINAMICS AND REGENERATION OF MOUNTAIN FOREST ECOSYSTEMS
Nadezhda Stoyanova
Abstract. In the present paper information of investigations in the stations of Forest Research Institute bay BAS are described. They in the Rila Mts and Stara planina are located. The specific noise of biological investigations from difrent forest ecosystems are described. Finally some conclusions of the work in the mountain forests of FRI BAS stations are given.
Key words: forests, biomass, P. abies, F. sylvatica, A. alba, P. syvestris, Rila and Stara Mts.

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