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Number of results: 30
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Abstract

The results and method of measurements of D, H and T carried out at Hornsund in the summer of 1979 are presented. The relative and absolute values of these elements are given in reduction to the Polish magnetic station at Hornsund. An initial evaluation of changes in the magnetic field from 1957 to 1979 is carried out.
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Abstract

This paper presents the results of magnetic mapping carried out in the area of the metamorphic series of Ariekammen and Skoddefjellet. On the basis of qualitative interpretation of measurements a number of anomalous zones were distinguished, whose position can be correlated with local changes in mineralitation and polymetallic ore content in the Fuglebergsletta area. The SE-NW orientation, skew to the almost meridional run of the layers of slates and marbles making up the metamorphic complex, dominates in the course of the anomalous zones.
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Abstract

The paper presents a method of measuring the angle of rotation and twist using a tilted fibre Bragg grating (TFBG) periodic structure with a tilt angle of 6◦, written into a single-mode optical fibre. It has been shown that the rotation of the sensor by 180◦ causes a change in the transmission coefficient from 0.5 to 0.84 at a wavelength of 1541.2 nm. As a result of measurements it was determined that the highest sensitivity can be obtained for angles from 30◦ to 70◦ in relation to the basic orientation. The change in the transmission spectrum occurs for cladding modes that change their intensity with the change in the polarization of light propagating through the grating. The same structure can also be used to measure the twist angle. The possibility of obtaining a TFBG twist by 200◦ over a length of 10 mm has been proved. This makes it possible to monitor both the angle of rotation and the twist of an optical fibre with the fabricated TFBG.
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Abstract

The activity of territorial self-government shaped institutionally during the development process is characterized by a significant scope of care for the financial situation, which determines the efficiency of its functioning. The general availability of public services is a condition for the assessment of the activities of municipalities (powiats, voivodeships). Institutional economy as a real one, takes into account an integrated point of view. The aim of the study is to present the territorial differentiation of the eff ectiveness of communes’ activities in the context of institutional economics and to present the possibility of using a synthetic measure in this process. The synthetic measure of development fluctuated within the limits of 0.30 – Wąchock (Starachowice poviat, urban-rural commune) to 0.41 – Ostrowiec Św. (Ostrowiecki poviat, urban commune) in 2009, 0.32 – Łączna (Skarżysko poviat, rural commune) to 0.40 – Starachowice (Starachowice poviat, municipal commune) in 2015. The results of the analysis confirm the existence of small differences in the assessment of development communes of the Kamienna Basin. This approach allows the assessment of municipalities using one size and allows you to organize the analyzed objects in terms of the considered phenomenon.
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Abstract

The most popular field methods of measurements of raised marine beach altitudes used by geomorphologists are presented. Compared data from clisimeter routes, altimeter routes and from readings from a photogeological map and directly from air photos compose the profiles. Advantages and disavantages of each method are discussed.
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Abstract

On the basis of about 12500 depth measurements of which 6700 were taken from r/v Profesor Siedlecki, 1300 from r/v Polarstern and the remainder from British navigation charts, a bathymetric chart of the Bransfield Strait in the scale 1:500 000 has been prepared. Within the assumed boundaries the total area of the Bransfield Strait covers 65308.6 square kilometres, of which the Western Basin covers 23.5%, Central Basin — 47.3%, and Eastern Basin 29.2%. Capacity of the whole Bransfield Strait amounts to 38451 km3 . The average depth of the Bransfield Strait is 592 m.
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Abstract

Investigations of operating parameters of widely used sand mixers reveal a wide variability range in the values of parameters associated with their power demand. Power efficiency of manufacturing processes has received a great deal of attention lately, which encourages the research efforts to optimise this aspects of operation of machines and installations as well. In the first place these machines and installations have to work properly as a part of the process line- which applies also to moulding sand mixers. Experiments conducted by the authors suggest that the same goal can be achieved at variable energy input levels. To obtain information about the power demands of sand mixers requires the use of highly specialised equipment, methodology and result processing procedures. This study provides a brief characteristic of measurement equipment and results of measurements taken on a unit AG-015 (based on a roller mixer) and a laboratory rotor mixer.
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Abstract

The paper presents selected results of studies connected with modeling of a biological object which could be used for simulation and measurements of the selected human tissues optical transmittance. The studies were performed for transilluminated homogeneous tissue layers as well as for objects consisted of different tissues. During simulations the software built with LabVIEW environment was used. Experimental verification of the model structure was made with spectrophotometry. The presented examples of modeling concern the transmittance spectra for two selected specific objects: the venous blood and muscle tissue analyzed in the wavelength range extending from 360 nm to 900 nm. The implemented model could be used in estimating the content and thickness of particular layers distinguished in a complex object and prediction of their transillumination efficiency.
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Abstract

Four and a half years of African Swine Fever (ASF) in population of free-ranging wild boars and domestic pigs revealed a number of novel insights into the disease epidemiology. Until November 20th, 2018, in total 3048 cases in wild boars and 213 outbreaks in domestic pigs have been confirmed. In spite of low contagiosity as well as low rate of ASF spread in wild boars the disease has an enormous socio-economical impact on the production of pigs in Poland. One of the most important aspects which directly influences the dynamics of ASF spread is the unpredictable hu- man activity. Another important factor responsible for continuous ASF spread is fast recovery of wild boar population in spite of efforts taken by hunters. Assuming our scientific opinion ASF seems to be present in wildlife for the incoming few or several years. Therefore, extraordinary measures should be prepared and undertaken to limit the risk of the occurrence of future out- breaks in domestic pigs. One of the most crucial issues is implementation of strict biosecurity measures in all domestic pigs holdings.
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Abstract

The efficient protection (support reinforcement) of a wall and heading crossing ensures continuity of the production cycle, and that is a quick moving of the scraper conveyor to the wall. Using low or high bolting as a support reinforcement element in wall and heading crossings allows for the elimination of traditional methods of maintaining longwall-gate crossings, and therefore allows for the efficient use high performance modern wall complexes. The paper presents the long underground experience, of the Knurów–Szczygłowice mine of efficient support wall and heading crossing maintenance, which was bolted to the rock mass with the usage of two pairs of bolts, showing full technical and economical usefulness of this support reinforcement method. The article also highlights work safety and the increasingly common usage of endoscopies when specifying the range of crack areas which directly effects the proper choice in number, load-capacity and length of the used bolts. The underground studies the measurements of the reach of the zones of fracturing and roof stratification (using endoscopes and wire type stratification meters) and the laboratory tests (using the test stand) have allowed to determine the safety factor for maintenance of the longwall gangway crossing, directly resulting in the necessity to install additional reinforcement. The value of the safety factor Sbsc-ch greater than 1 is advantageous and safe, and the value less than or equal to 1 can lead to a significant deterioration of the conditions of maintenance of a wall and heading crossing which was bolted.
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Abstract

Meteorological conditions at Arctowski Station during 2013–2017 were presented against the background of regional climate changes, especially air temperature decline. Air temperature, relative air humidity, air pressure, solar radiation, wind speed and direction, snow cover and precipitation were collected with an automatic weather station and manual measurements and were further analysed. The obtained results were compared with data from previous years and with data from other stations located on King George Island. Our observations confirm that the vicinity of Arctowski Station experienced a decrease in air temperature during summer, which supports the hypothesis of regional cooling.
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Abstract

In the paper, presented is a research on effectiveness of absorbing electromagnetic waves at frequency 2.45 GHz by unhardened moulding sands prepared of three kinds of high-silica base and a selected grade of sodium silicate. Measurements of power loss of microwave radiation (Pin) expressed by a total of absorbed power (Pabs), output power (Pout) and reflected power (Pref) were carried-out on a stand of semiautomatic microwave slot line. Values of microwave power loss in the rectangular waveguide filled with unhardened moulding sands served for determining effectiveness of microwave heating. Balance of microwave power loss is of technological and economical importance for manufacture of high-quality casting moulds and cores of various shapes and sizes. It was found that relative density influences parameters of power output and power reflected from samples of moulding sand placed in a waveguide. Absorption expressed by the parameter Pabs is not related to granularity of high-silica base: fine, medium and coarse. It was found that the semiautomatic microwave slot line supports evaluation of effectiveness of microwave absorption on the grounds of power loss measurements and enables statistic description of influence of relative density of the sandmix on penetration of electromagnetic waves in unhardened moulding sands.
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Abstract

The paper attempts to analyze distortions of cast iron and cast steel rings, after heat treatment cycles. The factors influencing distortion are: chemical composition of material, sample geometry, manufacturing process, hardenability, temperature and heat treatment method. Standard distortion tests are performed on C-ring samples. We selected a ring-model, which approximate the actual part, so that findings apply to gear rings. Because distortion depends on so many variables, this study followed strictly defined procedures. The research was started by specifying the appropriate geometry of the samples. Then, the heat treatment was conducted and samples were measured again. The obtained results allow to determine the value of the resulting distortion and their admissibility. The research will be used to evaluate the possibility of using the material to produce parts of equipment operated under extreme load conditions.
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Abstract

Most of sound sources are complex vibroacoustic objects consist of numerous elements. Some coupled vibrating plates of different shapes and sizes can be easily found in urban environments. The main aim of this study is to determine the sound radiation of coupled plates system of practical importance. The investigated vibroacoustic system consist of a thin circular plate coupled with a thick flat baffle with a circular hole. The circular plate has been mounted to the baffle’s hole using screws and two steel rings. The measurement setup was located inside a semi-anechoic chamber to assure the free field conditions. It was necessary to take into account the whole system surface to obtain the radiation efficiency based on the Hashimoto’s method. Such an approach can be troublesome and time-consuming. Therefore, the criterion has been proposed which allows the vibration velocity measurements and calculations to be performed only for the thin plate’s area. An alternative approach has been proposed based on the classical Rayleigh integral formula. Its advantage is a simpler implementation in a computer code. The obtained results have been compared with the theoretical results obtained for the elastically supported circular plate. A good agreement has been obtained at low frequencies.
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Abstract

The paper presents a method for wireless measurement of car wheel air pressure and temperature using the Tire Pressure Monitoring System, or TPMS module - one of the latest safety systems introduced by the automotive industry - with readings taken on a specifically designed test bench. The paper describes the structure and operating principle of the test bench key elements and how they work with the sensors, the TPMS module, and reference instruments, as well as the data format and accuracy of data transmission between TPMS and the host computer. The software designed for an embedded system emulating the real on-board computer allows for observing raw sensor readings and the effect of calibration in two points of the characteristics.
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Abstract

Beamforming is an advanced signal processing technique used in sensor arrays for directional signal transmission or reception. The paper deals with a system based on an ultrasound transmitter and an array of receivers, to determine the distance to an obstacle by measuring the time of flight and – using the phase beamforming technique to process the output signals of receivers for finding the direction from which the reflected signal is received – locates the obstacle. The embedded beam-former interacts with a PID-based line follower robot to improve performance of the line follower navigation algorithm by detecting and avoiding obstacles. The PID (proportional-integral-derivative) algorithm is also typically used to control industrial processes. It calculates the difference between a measured value and a desired set of points, then attempts to minimize the error by adjusting the output. The overall navigation system combines a PID-based trajectory follower with a spatial-temporal filter (beamformer) that uses the output of an array of sensors to extract signals received from an obstacle in a particular direction in order to guide an autonomous vehicle or a robot along a safe path.
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Abstract

An analysis of the influence of inverter PWM speed control methods on the operation of a brushless DC (BLDC) motor was carried out. Field-circuit models of the BLDC motor were developed taking into account rotational speed control by two classic methods: the unipolar H_ON_L_PWM and the bipolar H_PWM_L_PWM. Waveforms of the electrical and mechanical quantities and the motor parameters were computed. The results of the computations were verified by measurements performed on a specially designed test stand. On the basis of the measuredwaveforms of the electrical and mechanical quantities the dependence of the drive system efficiencies and power losses on rotational speed was determined for the two methods of inverter control.
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Abstract

The methane hazard is one of the most dangerous phenomena in hard coal mining. In a certain range of concentrations, methane is flammable and explosive. Therefore, in order to maintain the continuity of the production process and the safety of work for the crew, various measures are taken to prevent these concentration levels from being exceeded. A significant role in this process is played by the forecasting of methane concentrations in mine headings. This very problem has been the focus of the present article. Based on discrete measurements of methane concentration in mine headings and ventilation parameters, the distribution of methane concentration levels in these headings was forecasted. This process was performed on the basis of model-based tests using the Computational Fluid Dynamics (CFD). The methodology adopted was used to develop a structural model of the region under analysis, for which boundary conditions were adopted on the basis of the measurements results in real-world conditions. The analyses conducted helped to specify the distributions of methane concentrations in the region at hand and determine the anticipated future values of these concentrations. The results obtained from model-based tests were compared with the results of the measurements in realworld conditions. The methodology using the CFD and the results of the tests offer extensive possibilities of their application for effective diagnosis and forecasting of the methane hazard in mine headings.
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Abstract

This article, as far as possible based on the available literature, empirical measurements, and data from mesoscale models describes and compares expected wind conditions within the Baltic Sea area. This article refers to aspects related to the design and assessment of wind farm wind resources, based on the author’s previous experience related to onshore wind energy. The consecutive chapters of this publication are going to describe the present state and the presumptions relating to the development of wind energy within the Baltic Sea area. Subsequently, the potential of the sea was assessed using mesoscale models and empirical data from the Fino 2 mast that is located approximately 200 kilometers away from the majority of areas indicated in the Polish marine spatial development plan draft of Poland for offshore wind farm development (Maritime Office in Gdynia 2018). In the chapter describing mesoscale models, the author focused his attention on the GEOS5.12.4 model as the source of Modern-Era Retrospective Analysis for Research and Application 2 data, also known as MERRA2 (Administration National Aeronautics and Space Agency, 28), which, starting from February 2016, replaced MERRA data (Thogersen et al. 2016) and have gained a wide scope of applications in the assessment of pre-investment and operational productivity due to a remarkable level of correlation with in-situ data. Model-specific data has been obtained for eight locations, which largely overlap with the locations of the currently existing offshore wind farms within the Baltic Sea area. A significant part of this publication is going to be devoted to the description of the previously mentioned Fino 2 mast and to the analysis of data recorded until the end of 2014 by using the said mast (Federal Maritime and Hydrographic Agency 2018). The analysis has been carried out by means using scripts made in the VBA programming language, making it easier to work with large chunks of data. Measurements from the Fino 2 mast, together with long-term mesoscale model-specific measurements can be used, to some extent, for the preliminary assessment of wind farm energy yield in the areas designated for the development of renewable energy in the Polish exclusive maritime economic zone (Maritime Office in Gdynia 2018). In the final part of this article, pieces of information on the forecasted Baltic Sea wind conditions, especially within the exclusive economic zone of Poland, are going to be summarized. A major focus is going to be put on the differences between offshore and onshore wind energy sources, as well as on further aspects, which should be examined in order to optimize the offshore wind power development.
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Abstract

Manual measurements of distribution of gas velocity in conduits of flue gas installations using systems with differential pressure sensors of velocity are often performed for the requirements of determining emissions of dust pollutants from industrial process plants to the atmosphere. The aim is to determine an axial velocity profile. Flows in measuring sections are not always coaxial along the run of the duct; they are characterized by different directions of the velocity vector at various measuring points. The determination of actual directions of vectors of local velocities giving a guarantee of an accurate calculation of the axial velocity is often not possible from the technical point of view and the measurement of the velocity is carried out with the parallel setting of the sensor head in relation to the axis and the walls of the conduit. Then the knowledge of the directional sensitivity of the applied velocity sensor allows either to eliminate the axial velocity measurement error or to take it into account by the uncertainty of this measurement. For specific situations of two-dimensional variation of direction of the velocity vector, the directional sensitivity characteristics and in consequence the characteristics of error have been determined for three sensors adopted to tests: a zero pressure dust sampling probe with the anemometric function as an element of the gravimetric dust sampler and comparatively - two commonly used Pitot tubes: types S and L.
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