LIST OF PERMANENT REVIEWERS

List of Reviewers

MEASUREMENT OF WIND POWER AND ENERGY USING AN ANEMOMETER WITHOUT MOVING PARTS

The paper deals with the application of a newly developed anemometer without moving parts. It is digitized and has built-in electronics that convert the vibrations of two aluminum fixed frames into two digital signals: one, which shows the strength (speed absolute value)) of the wind, and the other, which shows its direction. Both of these signals are used to calculate wind power and energy. Earlier works have shown that the two-bit stochastic digital measurement method overcomes (eliminates) the problem of the offset of the analog adder. The authors of this paper apply this idea to the digital output of the sensor, where the role of the offset of the analog adder is taken over by the integral nonlinearity of the digital output of the anemometer. The first step in this direction is digitally dithering the sensor output. This principle is presented in detail, as well as a rough estimate of the accuracy gain in measuring wind energy. The obtained result shows that the accuracy in measuring wind energy is not worse than the limit accuracy in the case of a cup anemometer that generates sinusoidal voltage.

PRELIMINARY DESIGN OF ANALOG DISCRETE UNIFORM NOISE GENERATOR

The paper presents the basic idea of ​​the construction of an analog discrete uniform noise generator. The source of noise is a carbon resistor, the noise is linearly strongly amplified and limited to around zero. The probability density function (PDF) of the carbon resistor thermal noise in that region is square. By narrowing the symmetric allowable gap (interval) around zero, PDF of the noise approaches a uniform distribution. The factor of deviation from the uniform distribution is correctly and precisely defined. This quantity has been shown to be practically negligible. In addition, the paper discusses the application of the proposed ditheter noise, both in the two-bit and in the multi-bit stochastic digital measurement method (SDMM). It has been shown that noise is more suitable for application in multi-bit SDMM, because it is less sensitive to deviations from the uniform distribution. Commercially available track-and-hold circuits provide at least an order of magnitude wider bandwidth of the described generator compared to the standard solution that uses numerical random number generator and a corresponding D/A converter. However, the realization of such a generator requires hard engineering work, and therefore goes beyond the scope of this paper.

RESONATOR-BASED METERING OF POWER COMPONENTS ACCORDING TO IEEE STANDARD 1459-2010

This paper proposes an accurate and computationally efficient implementation of the IEEE Std. 1459-2010 for power measurements. An implementation is based on digital resonators embedded in a feedback loop. In the first algorithm stage, the unknown signal harmonic parameters are estimated. By this, the voltage and current signals are processed independently on each other. In the second algorithm stage, the unknown power components are estimated (calculated) from based on estimated spectra. To demonstrate the performance of the developed algorithm, computer simulated data and laboratory testing records are processed. Simple LabView implementation, based on point-by-point processing feature, demonstrates techniques modest computation requirements and confirms that the proposed algorithm is suitable for real–time applications.

GUIDE TO CHOOSING THE RIGHT AGRI PHOTOVOLTAIC MOUNTING SYSTEM

The aim of this work is to create a guide for the selection and planning of an agri-photovoltaic mounting system. The mounting systems available on the market were analyzed and those that can be used in agri-photovoltaics were selected. Since there are many mounting systems on the market and there are hardly any technical differences between them, four systems were selected and described in this work. The systems are those that almost every manufacturer offers in a modified form. Three of the four systems are produced by the same manufacturer "ZIMMERMANN PV-Stahlbau GmbH & Co. KG", while the remaining system is produced by the manufacturer "Next2Sun GmbH". Through this collected knowledge about mounting systems, it was possible to create a questionnaire, which was then sent to farmers. The online questionnaire was sent via e-mail to the desired target group throughout Austria. It was sent to as many farmers as possible in order to obtain a large database. The data resulting from the questionnaire made it possible to create a guideline to support technicians in the planning of new Agri-PV systems.

Determination of the Functional Properties of Varieties of New Rice for Africa (NERICA) relevant to its Processing

Flour from rice can be applicable into several types of food, or be used directly as a food substitute, and this can have an impact on the final quality of the product. This aimed to determine the functional properties of some selected NERICA varieties, namely, FARO 44, FARO 52, FARO 57, FARO 60 and FARO 61. Results obtained showed that the functional properties, such as the water absorption capacity (WAC), swelling power, water solubility index (WSI), bulk density, oil absorption capacity (OAC), and the foaming capacity, ranged from 251.74 to 298.51 (%); 7.42 to 8.41 (g/g); 10.01 to 12.27 (%); 0.92 to 1.00 (%); 0.45 to 1.36 (%); and 7.29 to 11.76 (%) respectively. All recorded samples were significantly difference (p < 0.05). FARO 61 recorded highest point of 298.51 (%), and 1.36 (%), in WAC and OAC respectively. While FARO 57 recorded the highest swelling power of 8.41 (g/g). These determined results of the functional properties of NERICA flour samples, will be useful in determining their suitability in food and other relevant industries because the flour samples showed high quality range of functional properties that makes them favourable for such activities.

APPLICATION OF BIOPOLYMER FILMS FOR SUSTAINABILITY OF EDIBLE OILS

Lipid oxidation is a major cause of off-flavors and loss of nutrients in fat-containing foods and oils. The prevention or retardation of those deteriorative reactions of oil during processing and storage is required. Commercially available synthetic packaging materials are causing serious environmental problems due to their non-degradability. To reduce environmental impacts associated with synthetic plastics, biopolymer materials have a great potential to be used instead. Further, biopolymers play an important role in food preservation because of their antioxidant and antimicrobial activities. Packing system comprise of natural active materials can improve shelf life of oil packed, minimize oxidation and improve mechanical, barrier and biological properties of biopolymer films. In this paper, to determine effect of usage biopolymer materials for oil packing, different edible oils and biopolymer materials were observed.

EFFECT OF ELECTROSTATIC FIELD ON SOYBEAN SEED GERMINATION PARAMETARS

The aim of this study was to examine the influence of electrostatic fields on seed vigor, mean rate of germination and coefficient of velocity of germination of five soybean genotypes. Testing was conducted at the Novi Sad Institute of Field and Vegetable Crops on the seeds of five soybean varieties: Sava, NS 2024, NS 1347, NS 3127, and NS Blackstar. The seeds were exposed to different values of direct current (DC) of the following voltage: 0 V (control), 3 V, 6 V and 9 V, to which the seeds were exposed for 0 min (control), 1 min and 3 min. After exposing the seeds to the electric field, the vigour index (VI), mean rate of germination (MGR) and coefficient of velocity of germination (CVG). The results show that the effect of the electrostatic field on seed vigour, mean rate of germination and coefficient of velocity of germination depends on the genotype, voltage and exposure time. The application of DC can be a suitable method for improving vigour index (VI), mean rate of germination (MGR) and coefficient of velocity of germination (CVG). In addition, the results indicate that it is necessary to adjust the DC treatment (voltage and duration of exposure of seeds) to a particular genotype, since inadequate treatments may deteriorate the quality of seeds. Keywords: electrostatic field, vigor index, MGR, CVG, soybean

THE APPLICATION OF IOT SOLUTIONS IN GREENHOUSES WITH THE AIM OF REDUCING ELECTRICAL ENERGY CONSUMPTION

In this paper, we will show a prototype of a system designed based on Internet of Things solutions with the aim of optimizing electrical energy consumption in order to achieve desired conditions for the growth and development of plants located in the greenhouse. The physical parameters that this system monitors are temperature, relative humidity, soil humidity and luminescence levels. In this prototype, we have three measurement nodes with the task of collecting parameter data, processing them and sending resulting data, via wireless communication, to a receiver. The receiver forwards data to the application on PC. The application processes the data and displays it to the end user who can choose to automatically or manually control the devices that are inside of the greenhouse. Systems placed inside the greenhouse are heating, irrigation, lighting and ventilation systems.

NEW METHOD FOR ESTIMATION OF MULTI-HARMONIC POWER SIGNAL PARAMETERS

A systematic analytical procedure for simultaneous estimation of the fundamental frequency, the amplitudes and phases of harmonic waves was proposed in this paper. In order to reduce complexity in the calculation of unknown parameters, a completely new reduced analytical expression is derived, which enabled fast and precise estimation with a small numerical error. Individual sinusoidal components stand out from the input complex-harmonic signal with the filter with a finite-impulse response (FIR) comb filters. The algorithm that is proposed in the operation is based on the application of partial derivate of the processed and filtered input signal, after which it is performed weighted estimation procedure to better estimate the values size of the fundamental frequency, amplitude and the multi-sinusoid signal phase. The proposed algorithm can be used in the signal reconstruction and estimation procedures, spectral processing, in procedures for the identification of the system that is observed, as well as other important signal processing areas. Through the simulation check, the effectiveness of the proposed algorithm was assessed, which confirmed its high performance.