Baltic Europe, i.e. the sea and inland hinterland, form a unique macro-regional unit. Strong collaboration links as well as competition in the Baltic Sea Region are an inherent feature of the region from the beginnings of its civilization development. The article shows the forty-year-long Baltic integration process and the Polish scientific contribution to the process. Since 2004, the Baltic has become an internal EU sea. This fact no doubt strengthened cooperation of the countries around the Baltic Sea. In many spheres, these ties take the form of networking. An important stimulus for further integrations is the EU Strategy for the Baltic Sea Region. Political stabilisation and economic development may transform, in a longer time span, the emerging transnational Baltic Europe into a new economic and cultural European centre.

The paper deals with the basic set-up of single-frequency microchip laser - so called Lyot filter configuration. Description of its operation and practical realization is given. Some results obtained for Nd:YAG/KTP microchip laser are presented. The evidences of single-frequency operation and its limits are emphasized. Described construction constitutes the base for building the frequency stabilization of green 532 nm microchip laser.

This paper discusses the transient characteristics of the planar type SOFC cell stack, of which the standard output is 300 W. The transient response of the voltage to the manipulation of an electric current was investigated. The effects of the response and of the operating condition determined by the operating temperature of the stack were studied by mapping a current-voltage (I-V) correlation. The current-based fuel control (CBFC) was adopted for keeping the fuel utilization factor at constant while the value of the electric current was ramped at the constant rate. The present experimental study shows that the transient characteristics of the cell voltage are determined by primarily the operating temperature caused by the manipulation of the current. Particularly, the slope of the I-V curve and the overshoot found on the voltage was remarkably influenced by the operating temperature. The different values of the fuel utilization factor influence the height of the settled voltages. The CBFC has significance in determining the slope of the I-V characteristic, but the different values of the fuel utilization factor does not affect the slope as the operating temperature does. The CBFC essentially does not alter the amplitude of the overshoot on the voltage response, since this is dominated by the operating temperature and its change is caused by manipulating the current.

Methods of reliability engineering allow to anticipate an efficiency both geodetic network and single control points throughout the period of its operating. A reliability assessment of a predicted survey object behaviour produces data useful in optimisation of survey scope. timetable and accuracy. The essentials of reliability approach and procedures of finding of operational reliability characteristics have been presented in the paper. The presented characteristics include: the failure rate function ,i(/), the reliability function R(I) and the random object life F(1). Methods applied in reliability engineering viz. method of complete probability and method of evaluation of raw and parallel reliable structures have been adopted for survey purposes. Besides the standard ones original methods are also presented in the paper. Their concept lies on finding of stability functions and reliability characteristics indicated by means of statistical tests referring to density probability of predicted displacements. Although the presented theory is of general character the main application is focused on levelling networks.

In this paper, we show that the signal sampling operation considered as a non-ideal one, which incorporates finite time switching and operation of signal blurring, does not lead, as the researchers would expect, to Dirac impulses for the case of their ideal behavior.

The paper looks at the issues of operation safety of the national power grid and the characteristics

of the national power grid in the areas of transmission and distribution. The issues of

operation safety of the national transmission and distribution grid were discussed as well as threats

to operation safety and security of the electricity supply related to these grids. Failures in the

transmission and distribution grid in 2017, caused by extreme weather conditions such as: a violent

storm at the night of 11/12.08.2017, hurricane Ksawery on 5–8.10.2017, and hurricane Grzegorz on

29–30.10.2017, the effects of which affected tens of thousands of electricity consumers and led to

significant interruptions in the supply of electricity were presented. At present, the national power

(transmission and distribution) grid does not pose a threat to the operation safety and security of

the electricity supply, and is adapted to the current typical conditions of electricity demand and the

performance of tasks during a normal state of affairs, but locally may pose threats, especially in

extreme weather conditions. A potentially high threat to the operation safety of the national power

grid is closely linked to: age, technical condition and the degree of depletion of the transmission and

distribution grids, and their high failure rate due to weather anomalies. Therefore, it is necessary

to develop and modernize the 400 and 220 kV transmission grids, cross-border interconnections,

and the 110 kV distribution grid (especially in the area of large urban agglomerations), and the MV

distribution grid (especially in rural areas). The challenges faced by the transmission and distribution

grid operators within the scope of investment and operating activities, with a view to avoiding

or at least reducing the scale of grid failures in the case of future sudden high-intensity atmospheric

phenomena, are presented.

Given its high efficiency, low emissions and multiple fuelling options, the solid oxide fuel cells (SOFC) offer a promising alternative for stationary power generators, especially while engaged in micro-combined heat and power (μ-CHP) units. Despite the fact that the fuel cells are a key component in such power systems, other auxiliaries of the system can play a critical role and therefore require a significant attention. Since SOFC uses a ceramic material as an electrolyte, the high operating temperature (typically of the order of 700–900°C) is required to achieve sufficient performance. For that reason both the fuel and the oxidant have to be preheated before entering the SOFC stack. Hot gases exiting the fuel cell stack transport substantial amount of energy which has to be partly recovered for preheating streams entering the stack and for heating purposes. Effective thermal integration of the μ-CHP can be achieved only when proper technical measures are used. The ability of efficiently preheating the streams of oxidant and fuel relies on heat exchangers which are present in all possible configurations of power system with solid oxide fuel cells. In this work a compact, fin plate heat exchanger operating in the high temperature regime was under consideration. Dynamic model was proposed for investigation of its performance under the transitional states of the fuel cell system. Heat exchanger was simulated using commercial modeling software. The model includes key geometrical and functional parameters. The working conditions of the power unit with SOFC vary due to the several factors, such as load changes, heating and cooling procedures of the stack and others. These issues affect parameters of the incoming streams to the heat exchanger. The mathematical model of the heat exchanger is based on a set of equations which are simultaneously solved in the iterative process. It enables to define conditions in the outlets of both the hot and the cold sides. Additionally, model can be used for simulating the stand-alone heat exchanger or for investigations of a semiadiabatic unit located in the hotbox of the μ-CHP unit.

In the paper an algorithm and computer code for the identification of the hysteresis parameters of the Jiles-Atherton model have been presented. For the identification the particle swarm optimization method (PSO) has been applied. In the optimization procedure five design variables has been assumed. The computer code has been elaborated using Delphi environment. Three types of material have been examined. The results of optimization have been compared to experimental ones. Selected results of the calculation for different material are presented and discussed. A novel vector operated one-cycle control matrix rectifier (OCC-MR) is proposed in this paper. Matrix rectifier (MR) is a generalized buck three-phase AC-DC converter with four-quadrant operation capability. MR can also be the front-stage circuit of AC-DC-AC equivalent structure of MC. One-cycle control (OCC) is a nonlinear control technique, which integrates modulation algorithm and control strategy. By applying OCC to current control loop, the OCC-MR achieves balance only in a switching cycle,and realizes unitary input power factor. Furthermore, vector operation of OCC results In minimum switching losses. In order to make up for the insufficiency of OCC on load disturbance suppression, a PID controller is added onto output voltage control to improve load regulation. The OCC-MR features great simplicity, fast dynamic response and good immunity on input disturbance. On the basis of theoretical analysis, a systematic simulation of OCC-MR is implemented by means of Matlab/Simulink. Both static state performance and dynamic state performance of OCC-MR are discussed deeply. The simulation results have proved theoretical analysis of the vector operation of OCC-MR, and the control effects are satisfactory.

Based on mathematical modelling and numerical simulations, a control strategy for a Molten Carbonate Fuel Cell Hybrid System (MCFC-HS) is presented. Adequate maps of performances with three independent parameters are shown. The independent parameters are as follows: stack current, fuel mass flow and compressor outlet pressure. Those parameters can be controlled by external load, fuel valve and turbine-compressor shaft speed, respectively. The control system is purposed to meet many constraints: e.g. stack temperature, steam-to-carbon ratio, compressor surge limitation, etc. The aim is to achieve maximum efficiency of power generated within these constraints. Governing equations of MCFC-HS modelling are given. An operational line of the MCFC-GT system is presented which fulfils several constraints (temperature difference, cell temperature, etc.) The system is able to achieve efficiency of more than 62% even in part-load operation.

This paper presents a position sensorless drive of non salient pole PM synchronous motors for all speeds including zero speed. Using adaptive Lyapunov design a new approach for the design of an observer is developed. The resulting scheme leads to a nonlinear full order observer for the motor states including the rotor speed. Assuming motor parameters known the design achieves stability with guaranteed region of attraction even at zero speed. The control method is made robust at zero and low speed by changing the direct vector current component to a value different from zero. In order to verify the applicability of the method the controller has been implemented and tested on a 800 W motor.

I n t r o d u c t i o n: Hypoplastic left heart syndrome (HLHS) is a congenital heart anomaly that is diagnosed prenatally or postnatally. The prenatal diagnosis leads to limiting the rate of systemic complications in the preoperative period due to optimization of the early therapeutic management.

O b j e c t i v e: The objective of the study is to determine the effect of prenatal diagnostic management of HLHS on the condition of newborns and the frequency of antibiotherapy employment prior to the first stage of surgical treatment.

Me t h o d o l o g y: The study included 95 children with HLHS operated on in the years 2014–2016. The cohort was divided into two groups: newborns with a prenatally diagnosed heart defect (50 children — 52.6%) and neonates with the defect diagnosed after birth (45 children — 47.4%). The data of the patients were analyzed based on their medical records.

R e s u l t s: The mean age of the children upon admission was 3.86 days in the group of patients with the prenatally diagnosed heart defect (PreHLHS) and 7.41 days in the group of newborns without the prenatal diagnosis (PostHLHS) (p = 0.001). In 60% of the PreHLHS group patients (30/50), at least one antibiotic was administered, while in the PostHLHS group, antibiotherapy was employed in 93.3% (42/45) cases (p = 0.001). Bacteriological tests demonstrated pathogen growth in 33 children (36% and 33.3%, respectively), what accounted for 34.7% of the entire cohort. On the average, the first antibiotic was introduced on the 6.55th day of life in the PreHLHS group and on the 2.73th day in the PostHLHS group (p = 0.005). Th e most profound differences in antibiotic employment involved aminoglycosides. The aforementioned type of antibiotic medications was administered to 6% of the children with the prenatal diagnosis and to 17.8% of the children diagnosed postnatally (p = 0.042).

C o n c l u s i o n s: Preoperative antibiotherapy in children with HLHS was employed more frequently than it would be indicated by microbiology tests results. Antibiotics were observed to be introduced more commonly and earlier in the newborns with the postnatally diagnosed congenital heart defect.

The presented paper concerns a novel concept of hybrid piezoelectric motor based on electroactive lubrication principle. Its structure is combined of quasi-static and resonance piezoelectric actuators, synchronizing their work to generate the rotary movement. The hybrid motor topology is compared to the existing piezoelectric motors, regarding its field of applications in embedded systems with very high security requirements. The electroactive lubrication principle is briefly presented with regards to optimization of the hybrid motor. The performance principle of the hybrid motor is described in terms of its working cycle. The assembling process of the prototype hybrid motor is briefly explained with emphasis put on the frequency and impedance tuning of the applied quasi-static and resonance piezoelectric actuators. Next, the hybrid motor power supply system is described and chosen measured performance characteristics are presented. Finally, conclusions concerning the features of the tested prototype hybrid motor and possible solutions of the faced issues, during assembling and testing, are presented.

The operational mineral deposit reconnaissance tends to evaluate its parameters to conduct safe and profitable production. Particular deposit parameters, important from the point of mineral deposit management, are estimated on the basis of observations carried out by mining geological surveys. These observations usually involve sampling, drilling, laboratory analyses and others. The use of fuzzy description to assess the parameters of the mineral deposit was proposed in the paper. In the fuzzy characteristics, an imprecise descriptive description appeared in place of a particular numerical quantity. This approach was used to description of the ore deposit features (metal content, volume, and metal yield) by assigning them specific characteristic functions, whose distributions were based on basic statistical quantities. Characteristic functions can be used to prepare operational strategies for any configuration of required deposit parameters resulting from the production management needs. For this purpose, selected logical operators of fuzzy sets were used. In the next approach to fuzzy modeling, an opportunity to characterize the deposit in a subjective approach was indicated, where the assessment of the deposit parameters is based on rough, in some way, discretionary observation and evaluation. Such model construction enabled the overall assessment of the deposit from the point of view of any parameters. Through the implementation of appropriate inference rules, adequate fuzzy control planes were obtained, which may also be useful in the context of operational mine strategy planning.

In the event of occupational accidents in mining, investors can calculate approximately how much loss will be incurred at the time of the accident. However, in halting mining as a result of occupational accidents or legislation, investors, will perhaps not care about how much of a loss to profits will arise due to the resulting downtime of mining operations. The reason for this is that there is no such halting in mining operation as yet and mining activity is continued. Avoiding halting mines due to occupational accidents and legislation would enable the prevention of unexpected costs resulting from these time losses. The aim of this study was to find out how much the loss of profits resulting from the downtime of mining enterprises due to the aforementioned reasons are in total, and how much the ratio of loss of profits to annual operating costs is on average on an annual basis. To determine the loss of profits and to minimize the accidents in enterprises, permanent supervisors, who are assigned in the enterprises where they are working, were given a survey through the SurveyMonkey program. Of the 235 permanent supervisors who filled out the survey on behalf of the mining enterprises, 58 answered all of the multiple-choice questions examined in the study. These questions were analyzed together according to different mineral groups and differences in mining operation methods. As a result of the analysis, it was determined that the annual loss of profits of mining enterprises resulting from the aforementioned periods of downtime, and the ratio of these values to the annual operating costs constitute a rather significant share. The aim of the article was to raise awareness to have mining companies appropriate more funds for occupational health and safety.

The fact that mines have to be established at the place where they are located without having a chance to choose a location brings out area usage conflicts with areas that need to be protected. In fact, forestlands are most common in these overlapping areas in Turkey. In order to perform mining activities in this overlapping forestlands, mining enterprises in Turkey receive forest land permit fees (FLPF), reforestation fees, rehabilitation fees + security deposit of conformity to the environment (SDCE), and other fees. In order to determine the share of these costs in mining investments and operating costs (OC) and to bring a solution proposal so that these costs do not pose a risk of loss of the investment in the mining enterprises, questions have been asked to mining enterprises within Turkey using the “Survey Monkey” program. The averages of all forest fees determined from the answers are proportioned to the mining investment amounts (MIA) and the annual average OC of each mining company responding to the Survey.

Thus, the distribution criteria of different forest fees that are required to be paid by the mining enterprises in order to carry out mining operations in the forestlands in Turkey and their distribution on the basis of mineral groups were analyzed. In this calculation, it was suggested that all the fees in Turkey should be reduced to a more reasonable degree by suggesting solutions regarding the calculation method envisaged by the FLPF, which has a very high share. Otherwise, the result of these rates shows that the costs of forest land-use for mining stipulated by the legislation in Turkey are quite high compared to other countries, and that the current mining investments can have difficulty in maintaining their economic operability in the presence of these required costs.

A companion robot is capable of performing a variety of activities and thus supporting the elderly and people withdisabilities. It should be able to overcome obstacles on its own, respond to what is happening around it in real-time, andcommunicate with its surroundings. It is particularly important to pay attention to these issues, as a companion robot is likely tobecome a participant in traffic. The aim of the research is to develop a mathematical model that takes into account the use of twonavigation solutions in the companion robot. Thanks to this, it will be possible to use the obtained mathematical relationships tocompare various types of navigation and make a rational choice, enabling the implementation of the assumed activities in aspecific external environment. What is new in this article is the analysis of several navigation methods and the presentation ofresearch carried out in real time using an actual robot.

In this paper, a new set of intuitionistic fuzzy aggregation operators have been introduced under the environment of intuitionistic fuzzy sets (IFSs). For this, firstly focused on some existing aggregation operators and then new operational rules known as Dombi operation have been pro- posed which make the advancement of flexibility behavior with the parameter. Based on Dombi operation laws, some new averaging and geometric aggregation operators namely, intuitionistic fuzzy Dombi weighted averaging, ordered weighted averaging and hybrid weighted averaging operator, classified as IFDWA, IFDOWA and IFDHWA operators respectively and intuitionistic fuzzy Dombi geometric, ordered weighted geometric and hybrid weighted geometric operators, labeled as IFDWG, IFDOWG and IFDHWG operators respectively have been proposed. Further, some properties such as idempotency, boundedness, monotonicity and commutative are investigated. Finally, a multi-attribute decision-making model has been developed for the proposed operators to select the best mutual fund for investment. The execution of the comparative study has been examined with the existing operators in this environment.

Ship management is a topic that has rarely been approached in the modern Polish maritime legal sciences. There are numerous reasons behind the present state of affairs but it seems that the foremost one is, that the focus in political, legal and economic discourse is still on the legal aspects of ship ownership. This trend continues despite the fact that today over 73% of world shipping tonnage is managed by the specialized ship management entities. An economic analysis has proven that year after year Poland was ceasing to be a large ship owning nation, it used to be, and that this trend is unlikely to be reversed in the short and mid-term perspective. Poland may, however, still continue to play a vital role in the world of shipping by becoming a ship management centre. This article aims to introduce the Readers to the selected aspects of ship management operations.

The paper characterizes the status, trends and perspectives of irrigation in Poland after the reforms in agriculture and technology. Irrigation in Poland has supplemental character. It is used in short periods during the growing season and plays an important role in mitigating the effects of drought on crop production. Sub-irrigation from ditches is applied on permanent grasslands, sprin-kling – in field cultivation of arable crops, sprinkling and drip irrigation – in vegetable growing in open areas, micro-jets and drip irrigation systems – in orchards. Drip irrigation and micro-jets sys-tems are also applied in plant cultivation in greenhouses.

Under the economic conditions of Polish agriculture irrigation is often an unprofitable measure. The existing irrigation systems and facilities are only used to a small extent. After changes in the forms of ownership in agriculture, the large-area sprinkling systems were degraded. Small irrigation systems, mainly drip irrigation and micro-sprinkler irrigation, have recently become more common in private farms. Sub-irrigation systems are largely degraded and used only to a small extent if at all. In order to use these systems more effectively, it is necessary to reconstruct and modernize them. In many cases the factor preventing the use of irrigation systems is the deficit of water of required qual-ity and its availability. Besides unfavourable economic conditions, it is one of the main limitations in the development of irrigation in Poland.

Operational Transresistance Amplifier (OTRA) has been a topic of great interest recently. OTRA has proved itself to be an appropriate device for the analog applications. As MOS scaling suffers from various problems, carbon nanotube field effect transistor (CNTFET) has came into light as one of the brightest alternative for FET (Field Effect Transistors) based devices. This work has introduced a new CNTFET based OTRA which is capable of realising inverse low pass filter using two OTRAs and few passive elements. CNTFET based OTRA has been designed and simulated at 10nm technology node. The working ability of the designed model has been conformed using HSPICE simulation. It is compared with conventional CMOS based OTRA. The comparative analysis has revealed improvement in various performance parameters. The paper also presents how change in number of carbon nanotube in CNTFETs in OTRA circuit affects the transresistance gain and input impedance. The optimized results are also discussed to improve transresistance gain and input impedance. The paper also dealt with the realisation of inverse low pass filter using proposed CNTFET based OTRA.

Commonly known DC-AC switching converters are commonly used in compensator branches. One example of this is a static synchronous compensator (STATCOM). It consists of a voltage source converter (VSC) and acts as an inverter with a capacitor as a DC power source. These compensators use the PWM switching scheme or space vector modulation (SVM) method. Both methods require the desired signal to be generated. In some cases, as during the synthesis of self-excited systems or active energy-compensators, it is necessary to perform the desired branch immittance, e.g. negative capacitance, inductance, resistance or irrational impedance. In such cases, it is necessary to control the universal branch on the basis of a formula. This article presents the implementation method for the convolutional type impedance operators.

The paper raises the issue of optimizing the control of the rural low voltage microgrids. Microgrids can operate in a synchronous mode with grids of distribution system operators and in an island mode. We can distinguish two control strategies in microgrids: one approach based on centralized control logic, which is usually used, and another on decentralized control logic. In this paper we decided to present the approach based on the distributed control, combining the efforts of the distributed cooperative control and modified Monte Carlo optimization method. Special attention has been paid to the impact of the order of processing particular devices’ groups on results of optimization calculations. Moreover, different scenarios of behavior of the microgrid control system with respect to the communication loss have been also presented. The influence of the issue of continuity of communication between particular devices’ groups on the possibility of carrying out the optimization process has been investigated. Additionally, characteristics of power loads and generation of electricity from small renewable energy sources appearing in rural areas have been described and the sensitivity of the optimization algorithm to the changes of demanded power values and changes of values of power generated by renewable energy sources has been studied. We analyzed different objective functions which can be used as an optimization goal both in synchronous and island operation modes of microgrid. We decided to intensively test our approach on a sample rural LV microgrid, which is typical in the countryside. The observed results of the tests have been presented and analyzed in detail. Generally, results achieved with the use of proposed distributed control are the same as with the use of centralized control. We think that the approach based on distributed control is promising for practical applications, because of its advantages.