• Comparing the Effectiveness/Robustness of Gammatone and LP Methods with the direct use of FFT

    pg(s) 60-62

    In this paper we evaluate the growth of Automatic Speech Recognition systems in respect to the various forms of spectral analysis ways used. A straightforward analysis of platter and Gammatone filter banks used for spectral analysis compared with the direct use of FFT spectral values is taken into account. This analysis was supported understanding the effectiveness of existing Automatic Speech Recognition systems that are specifically targeted on platter and Gammatone filter banks compared with FFT spectral values. We discover that warping the FFT spectrum directly, instead of using filter bank averaging, provides an additional precise approximation to the sensory activity scales. Direct use of FFT spectral values are even as effective as using either Gammatone or Linear Prediction filter banks, as long as the feature extracted from the FFT spectral values takes into consideration a Gammatone or platter like frequency scale. Computing speech signals using FFT or filter bank spectral features and utilizing a method supported by a sliding block of spectral features, is shown to be simpler in terms of ASR accuracy.

  • Efficiency and loss analysis of main steam condenser from nuclear power plant at various loads and ambient temperatures

    pg(s) 56-59

    This paper presents exergy analysis of the main steam condenser, which operates in nuclear power plant. The analysis is performed in four main condenser operating regimes (loads) for a variety of the ambient temperatures. It is found that the main steam condenser has the lowest exergy destruction (equal to 72091.56 kW) and the highest exergy efficiency (equal to 66.66%) at the lowest observed ambient temperature (5 °C) and for the highest of four observed loads. Also, it is noted that an increase in the ambient temperature from 20 °C to 25 °C (two the highest observed ambient temperatures) significantly decreases main steam condenser exergy efficiency for about 21%, regardless of the observed load.

  • Retrofit of an electric motor driving a shuttleless weaving grapple machine

    pg(s) 50-55

    In specific energy saving measures, special attention is paid to driving technologies, as electric drives account for two thirds of industrial energy consumption. Paper deals with appropriate selection of electric motor with higher efficiency for shuttleless weaving grapple machine in order to retrofitting the electric drive. Such machines are not single pieces, but are always a certain set of a given production company. Once electricity consumption is reduced by investing in energy-saving engines, this can be the basis for intelligent and efficient energy management, accurate predictions of electricity consumption for future periods, which ultimately leads to increased energy efficiency of manufacturing enterprises.and systems.

  • Impedance matching analysis of magnetic resonance coupled power transfer system

    pg(s) 46-49

    Remote Electric Vehicles (EV) charging could become a viable alternative to cable systems. This paper is dedicated to the ana lysis of the Strongly Coupled Magnetic Resonance (SCMR) serial-to-serial topology aimed at establishing the impedance matching and obtains the maximum efficiency and power transfer coefficient. The research was done by using a model of equivalent circuits, experimental investigation and finite-element modeling of the mutual inductance. Upon generalizing the results obtained from the analytical and experimental research as well as 3D modelling of magnetic fields using Comsol Multiphysics, the interrelationships between internal resistance of voltage source and load resistance, characteristic and loss resistances as well as the distance between coils (the strength of magnetic coupling) necessary to ensure maximum efficiency and power transfer coefficient were established. The results of exp erimental research and modelling of the active power transfer coeff icient were presented.

  • Мathematical analysis of an electrical circuit

    pg(s) 25-26

    There are some research about mathematical analysis of electrical circuits. In time when the scientists are in a deep search of invention new alternative ways for producing renewable energy, mathematic postulates and analysis can help optimize the const ruction of electrical circuits and prevent lost of energy. By themselves, the electrical schemas that represent Electrical circuits are a combination of interconnected electronical elements (components). According to the characteristics of the elements of Electrical schemas they are divided into the following groups: Passive and Active, Linear and Nonlinear, Bipolar and Multipolar. In our research we are going to switch from high to low power and vice versa, so we are going to us the abilities of diodes that switch from on to off state. The different values of low and high power of the electrical circuit will be represented programmatically with a cross-platform application – Arduino Integrated Development Environment and programmable language C++.

  • Investigation of hollow ceramic structures by contactless computer-tomographic nondestructive method

    pg(s) 21-24

    This article deals with the study of the cavity of ceramic constructional elements for the construction of beehives and carriers for electric furnace heaters. Unlike the traditional practice of performing tomography studies to determine the structure and harmful defects in the interior and surface of specimens, in the present studies, the non-destructive non-contact method is used to assess the nature and volume of deliberate fulfilled cavities in ceramic specimens. The role of well-shaped and regulated cavities is to reduce the coefficient of thermal conductivity in the hives to the inside, and in the carriers for heaters to the outer walls of the furnace, i.e. heat loss. The cavity samples are obtained from an aqueous dispersed colloidal system based on patent-protected quartz glass-ceramics by the “pouring” method. The obtained structural details are fireproof, thermally stable and with high physical and mechanical characteristics. They are composed of amorphous SiO2, mullite and cristobalite. The study of the cavity at different beam depths was performed using a NIKON XTH 225 device, and the data processing Volume Graphic, My VGL.

  • Optimization of flat solar collector based on the principle of entropy

    pg(s) 18-20

    This article describes the entropy method optimization based on the approach of minimal increase of entropy in the thermodynamic system. Here is presented the experimental set up of flat plate solar collector with liquid as working medium, effective absorber area of the collector 1,4 m2, absorber plate of aluminum, copper pipes and selective coating. A comparative analysis is conducted between the efficiency of a theoretical model of nonisothermal solar collector and the efficiency obtained by measuring the physical model of a solar collector. Results show a general trend of growth the collector efficiency due to the reduction of irreversibility of the represented processes.

  • Automation of drilling and blasting passport formation with intelligent algorithms

    pg(s) 14-17

    This article is devoted to the problem of a passport for drilling and blasting operations formation, taking into account the main
    characteristics. At most mining enterprises, this process is a manual calculation that leads to errors due to human factor and increases the
    time it takes to generate drilling and blasting passport, and, as a consequence, the time for drilling and blasting.
    The proposed solution is an automated complex that bases its calculations on the data of the cross-section mines shape, the dimensions of
    the height and width of the mine and the cross-sectional area in the tunnel, the fortress on the scale of prof. M.M. Protodyakonov and the
    thickness of the host rocks. All geometrical parameters of tunnel face are obtained automatically based on laser scanning. For further
    calculations, intelligent algorithms are used, implemented using deep learning neural networks (with python tensorflow library). It is worth
    noting that the final decision on the acceptance of the drilling and blasting passport is made by the person in charge. The result of using the
    proposed system is automatically generated passport of drilling and blasting operations, including its alternative variations (due to the
    passport chosen by the person in charge, the system will receive feedback to further improvement of the system algorithm).

  • Seasonal dynamics of plant sediment microbial fuel cell efficiency in a moderate continental climate zone

    pg(s) 10-13

    Plant sediment microbial fuel cells (PSMFC) transform solar energy in an environmentally friendly and efficient way. Their integration in constructed wetlands allows the generation of electricity in parallel wastewater treatment. The work of plant sediment microbial fuel cells is influenced by a number of factors, such as environmental conditions, vegetation type, hydraulic retention time, water flow, the presence of heavy metals and other contaminants in the treated water and others. The purpose of this study is to establish the seasonal dynamics of the effectiveness of PSMFC in Moderate continental climate zone. Seasonal changes in environmental conditions have a significant impact on the generation of energy from the PSMFC in regions with moderate continental climate. With the best electrical parameters the cell is characterized in spring and summer. They are significantly lower in autumn and winter. The effectiveness of PSMFC, both as a treatment facility and as electricity generation is directly related to the vegetation period of the planted vegetation and the effectiveness of the photosynthesis, which are a function of the intensity of the light, the duration of the sunshine and the average daily temperatures.

  • Experimental investigation of a hybrid pv-t system under Albania’s climate conditions

    pg(s) 230-232

    Photovoltaic thermal system (PV-T) converts sunlight into electricity and heat simultaneously. The overall efficiency of these systems is higher than the efficiencies of PV panels and solar collectors together. In Albania energy production from photovoltaic systems has been promoted in the recent years. Albania’s Mediterranean climate conditions are very favourable for investment in renewable energy systems. In this study a stand-alone 280 W PV-T panel is considered with respect to thermal analysis of the system. The panel is installed at the terrace of the building University in Tirana, Albania. The aim of this work is to present the temperature profile of the panel, since there is a correlation between efficiency and temperature. In order to analyse the temperature distribution on the panel surface a series of experiments are carried out. Temperature variation vs. time for different water flow rate was performed. The inlet and outlet water temperature profile is drawn in this article.

  • Study of sound absorption and reflection coefficients and thermal conductivity of porous composite material obtained from household glass waste and burnt rice grains husks

    pg(s) 227-229

    The coefficients of sound absorption and reflection in the frequency range up to 2 kHz, here respectively 0.2 and 08, as well as the coefficient of thermal conductivity, here below 0.027, of a new porous composite material were studied. The material was obtained from ground household glass waste and rice grains husks burned at temperature from 4000C to 7000C. The results show that the material has good sound reflectivity and low thermal conductivity, which makes it suitable for the manufacture of modules for thermal and sound insulation.

  • Off-grid hybrid PV configuration’s role to supply internet access points antenna in remote areas. Case study: “Ostren i vogël – trebisht” villages, Bulqiza district, Albania

    pg(s) 218-226

    As a result of the global pandemic situation COVID-19 many rural areas in Albania are suffering and will more especially the lack of internet services have engaged in development and cultivation of knowledge in the education sector, responsible in building a safer and more caring community. Even more Albania is indexed as a European country that still continue to experience the lowest rate userpenetration of internet especially in remotes areas. Despite its widespread use in urban areas, a very significant portion of the rural population still isn’t connected to the internet. Immigration of the population from rural toward more urbanized areas and lack of reliable electricity supply and infrastructure are the main problems that hinder investors to offer internet services in remote regions. The performance analysis of a solar PV power plant is important aspect as far as concern with technology and economic analysis. Due to seasonal variation standalone system can’t provide a continuous power supply. Therefore, in recent years PV energy systems that combine solar energy and other conventional conversion units are becoming promising more popular, efficient to fulfill load demand and representing a cost-effective technology.