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Number of results: 10
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Abstract

Coal mining activities carried out for 200 years in Upper Silesia have had a negative effect on buildings. T his impact is in all cases related with continuous deformations of the surface and in certain cases with discontinuous deformations (mostly cave-ins), changes in water relations and mining tremors. T he paper presents an evaluation of the impact of a mining activity on a building situated in the Upper Silesian Coal Basin. T he building was affected by continuous deformations and mining tremors. Calculations were made of the values of deformation rates by means of Budryk–Knothe’s theory, which were partly verified on the basis of the results from geodetic measurements. An analysis of the velocity and acceleration of basement vibrations caused by mining-induced tremors was also conducted. T he conclusions included a high consistency between the results obtained on the basis of calculations and the values obtained by means of PGA and PGV measurements. In the case of tremors with the highest energy in the hipocentrum, there an empirical formula allowing for calculation of PGA value in given geological and mining conditions was also proposed. T he application range of the formula mentioned above is obviously limited only to the conditions in consideration. The presented conclusions indicate that at present, sufficiently precise methods, allowing for calculations for practical purposes, not only of deformation indices’ values, but also of PGV and PGA values, presently exist.
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Abstract

Searching and exploring the motives of continuing in the profession may be an important objective of efforts undertaken by researchers and people directly responsible for the organization and quality of work. Identifying the needs and expectations of the employee is an important element of her/his adaptation in the work environment. Because the age of life is one of the factors affecting the perception of the world and work, in this article motives of continuing professional activity in group of special educators are described in the age of life context.
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Abstract

In this paper results of microstructural observations for series of CuZn39Pb2 alloys produced from qualified scraps are presented. The individual alloy melts were differentiated in terms of thermal parameters of continuous casting as well as refining methods and modifications. Structural observations performed by SEM and TEM revealed formation of different types of intermetallic phases including “hard particles”. EDS results show that “hard particles” are enrich in silicon, phosphorus, iron, chromium and nickel elements. Additionally, formation of Al-Fe-Si and Al-Cr in alloy melts was observed as well. It was found that quantity and morphology of intermetallic phases strongly depends upon the chemical composition of raw materials, process parameters, modifiers and refining procedure applied during casting. It was observed that refining process results in very effective refinement of intermetallic phases, whereas modifiers, particularly carbon-based, results in formation of large particles in the microstructure.
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Abstract

The motion planning problem consists in finding a control function which drives the system to a desired point. The motion planning algorithm derived with an endogenous configuration space approach assumes that the motion takes place in an arbitrary chosen time horizon. This work introduces a modification to the motion planning algorithm which allows to reach the destination point in time, which is shorter than the assumed time horizon. The algorithm derivation relies on the endogenous configuration space approach and the continuation (homotopy) method. To achieve the earlier destination reaching a new formulation of the task map and the task Jacobian are introduced. The efficiency of the new algorithm is depicted with simulation results.
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Abstract

The positivity and absolute stability of a class of nonlinear continuous-time and discretetime systems are addressed. Necessary and sufficient conditions for the positivity of this class of nonlinear systems are established. Sufficient conditions for the absolute stability of this class of nonlinear systems are also given.
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Abstract

Short ancestry of the modern citizen of Gdańsk encourages reflection of factors constituting his distinctness. Rapid exchange of population after the World War II disrupted the cultural continuity of Gdańsk society. Despite immense damage, material substance of the city, life environment of both former and new citizens of Gdańsk, turned out to be potentially the only significant bonding element for their identity. With time, the initial national narration was replaced with a favourable overview of the past, which had been previously suppressed and has been escaping the desirable scheme of the Polish identity. Gdańsk inhabitants were accompanied by the city landscape throughout the entire period of changes in consciousness. The landscape, which was erected from ruins in its most prominent attributes, which was undergoing constant spatial changes in the following years, supported the continuity of the emerging common city identity.
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Abstract

The article concerns problems with shaping contemporary housing estates. By analyzing housing structures designed in recent years, the aim was to demonstrate the importance of creating the continuity of public spaces in order to achieve places seen as attractive and presenting features of high quality urban space. Essential for the research is the question about the conditions which should be fulfi lled when creating the ideal residential place which then leads to a series of answers. These included indicating a good location with functional and aesthetic urban/architectural solutions. Environmental issues are important as well. Regardless of whether it is a multi-family dwelling or a single family house, a good neighborhood and its location in a well-connected place with necessary basic services within walking range are important. It is also signifi cant how the public space was shaped and whether a natural network was created. Due to factors such as the specifi city of the structure’s location in the city and diff erent surfaces of designed estates, as well as the variety of residential buildings being constructed, it is often diffi cult to assess them unambiguously. Importantly, this assessment also includes social and economic aspects as well as technical issues. However, by using multi-directional research it can be noted that the forms of public spaces within housing complexes play an important role in the creation of high-quality structures, perceived as attractive not only by the residents.
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Abstract

The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.
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Abstract

The paper analyzes the monthly day equivalent levels, Lday (06–22 h) and night equivalent levels, Lnight (22–06 h) values observed in year 2015 and 2016 for the 70 locations whereby continuous noise monitoring is conducted under the National Ambient Noise Monitoring Network (NANMN). The study exclusively analyzes the ambient noise data acquired for 25 locations in commercial zone, 12 in industrial, 16 in residential and 17 in silence zones. The analysis of (Lday–Lnight) for 70 locations under observations reveals that 10 dB night time adjustment in day-night average sound level descriptor is not appropriate in such a scenario and as such it is recommended to use day-night average sound level and day-eveningnight average sound level descriptors without any 10 dB night time adjustment or 5 dB evening time adjustments. The analysis and conclusions of the present study shall be very useful for developing single value noise descriptor correlating the noise annoyance and health effects in Indian perspectives.
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