The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics. Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points. Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.
The paper is devoted to explication of one of the advantages of heat and electricity cogeneration, rarely considered in technical literature. Usually attention is paid to the fact that heat losses of the heat distribution network are less severe in the case of cogeneration of heat in comparison with its separate production. But this conclusion is also true in other cases when the internal consumption of heat is significant. In this paper it has been proved in the case of two examples concerning trigeneration technology with an absorption chiller cooperating with a combined heat and power (CHP) plant and CHP plant integrated with amine post-combustion CO2processing unit. In both considered cases it might be said that thanks to cogeneration we have to do with less severe consequences of significant demand of heat for internal purposes.
Several human studies have reported that capsaicin has anti-pruritic effects. Moreover, sever- al concentrations of topical capsaicin have been used to alleviate itch. The aim of this study was to investigate the anti-pruritic effect of capsaicin against histamine-induced pruritus compared with that of topical steroid or vehicle in 15 healthy beagles. Fifteen dogs were divided into three groups (n = 5 each), and treated topically with one of the following on the left side of the neck: capsaicin, positive control (steroid), or negative control (vehicle). Each treatment was performed twice daily for 8 days. All dogs were injected with histamine intradermally before treatment and on the 2nd, 4th, 6th, and 8th days of the treatment to evoke itch. Pruritus, wheal, and erythema intensity were assessed at each evaluation; cutaneous temperature was also recorded. On the final day, skin biopsy was conducted for histopathological evaluation for all dogs. The severity of pruritus was lesser in the capsaicin-treated group compared with the negative control group on day 8 (p<0.05). In the capsaicin and steroid groups, wheal size, erythema index, and cutaneous temperature also decreased compared with pretreatment. Histopathological evaluation showed that the capsaicin-treated group had a higher number of inflammatory cells in the dermis com- pared to the vehicle control group; however, the steroid-treated group showed less severe inflam- matory reactions than the vehicle control group. These results suggest that capsaicin cannot reduce inflammation but may play a helpful role in reducing pruritus in dogs.
The paper presents an analysis of the influence of the energy generated from renewable sources on an improvement in the energy efficiency of public utility building and households. It also presents the current state of the technologies for the production of electricity from renewable sources, as well as their share in the national power supply system. The conducted analysis concerns both micro, as well as large systems generating electricity. Systems generating power from renewable sources are gaining in popularity. With an increasing awareness in the society of the beneficial influence that renewable power generating systems have on the environment, as well as the support in form of various programs offering subsidies for the construction of new systems, power generation from renewable sources is becoming increasingly popular and common. Although the renewable energy systems are still not widely considered to be a profitable solution, systems using renewable sources of energy are positively perceived and treated as a new trend in the construction of multi or single-family residential buildings. The increasing share of the renewable energy in the national power supply system significantly reduces the demand for energy produced from conventional sources. This obviously translates into a reduced consumption of primary energy, for example, fossil fuels, and, in turn, leads to the reduced exploitation of natural resources, thus contributing to the protection of the natural environment. A reduced consumption of fossil fuels also means a significant reduction in environmental pollution during their processing into electricity or heat. Actions aiming at improving energy efficiency and reducing final energy consumption are being undertaken by many countries all over the world, and by the European Union. In 2012, the European Parliament and the Council issued Directive 2012/27/EU obliging the Member States to initiate actions aiming at a reduction in the consumption of final energy by 1.5% a year. The paper presents the current status of generation of energy from renewable sources during the last 13 years. The ways for using energy from the renewable sources to improve the energy efficiency of facilities were also discussed.
Empathy and psychopathy seem to be two distant extremes, which only differ, with nothing similar. Therefore, the question that seems to be surprising is whether such a theoretical perspective is justified. Empathy exerts significant influence on social relationships and is associated with moral development, whereas psychopathy seems to be an opposite phenomenon, as it is associated with the lack of deep interpersonal bonds and the violation of legal norms. As studies from various disciplines and scientific areas indicate, such concepts as behavioral effectiveness, morality or altruism might help explain the complex nature of the interrelationship between psychopathy and empathy. The authors tried to explore and describe the complexity of the two presented concepts in the light of the conducted research, and the resulting theoretical and empirical implications.
Research suggests that placebo can reduce the misinformation effect. We aimed to examine for the first time whether placebo administered in the guise of caffeine can reduce the misinformation effect. One hundred and twenty -three healthy volunteers were randomly assigned to four groups in a 2 Placebo (Present, Not Present) × 2 Narrative (Misleading, Correct) study design. Participants from placebo groups drank 100 ml of placebo solution. They were told that it was water mixed with caffeine which could positively influence their memory. After three minutes, they watched a short movie clip as an original event and read a narrative with misleading details or correct details as a postevent information; they then completed a 22 -item, two -alternative forced -choice questionnaire. The results reveal that the misinformation effect occurred. Although participants in the placebo with misinformation group scored better than participants who did not drink placebo and read the narrative containing misleading details, the difference was not statistically significant. Thus, it is concluded that placebo might not be enough to reduce the misinformation effect when it is administered in the guise of caffeine.
The paper presents an analysis of the sustainable development of electricity generation sources in the National Power System (NPS). The criteria to be met by sustainable power systems were determined. The paper delineates the power balance of centrally dispatched power generation units (CDPGU), which is required for the secure work of the NPS until 2035. 19 prospective electricity generation technologies were defined. They were divided into the following three groups: system power plants, large and medium combined heat and power (CHP) plants, as well as small power plants and CHP plants (distributed sources). The quantities to characterize the energy effectiveness and CO2 emission of the energy generation technologies analyzed were determined. The unit electricity generation costs, discounted for 2018, including the costs of CO2 emission allowance, were determined for the particular technologies. The roadmap of the sustainable development of the generation sources in the NPS between 2020 and 2035 was proposed. The results of the calculations and analyses were presented in tables and figure
In the current study, twenty lambs, aged 4 months, half male and half female, were classified into four groups, with five in each group. The experimental three groups of lambs were given intravenous (IV), intramuscular (IM) and subcutaneous (SC) administrations of recombinant ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs was given normal saline injections in the same way. After administrations, blood samples were collected from the tested animals at different time points post injection, and the serum titers of roIFN-τ were measured using cytopathic effect (CPE) inhibition bioassay. The results of calculating pharmacokinetic (PK) parameters using DAS software showed that the PK characteristics of roIFN-τ through IV injection conformed to the two-compartment open model, whose half-life of distribution phases (T1/2α) was 0.33±0.034 h and the elimination half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM injection and SC injection of roIFN-τ conformed to the one compartment open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively, together with an elimination half life(T1/2β) of 9.11±0.76 h and 7. 43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and 1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM administration reaches 73.57%, which is greater than that of SC administration (53.43%). These results indicate that the drug administration effect can be preferably obtained following a single dose IM administration of the roIFN-τ aqueous preparation. This study will facilitate the clinical application of roIFN-τ as a potential antiviral agent in future work.
The aim of the article is to examine the specific properties of language actions in terms of their moral evaluation. The author starts from the question whether responsibility for words has the same meaning as responsibility for a physical action. In her analysis, the author deliberates whether in both cases the same rules and criteria are applicable. Referring to the classical theory of speech acts proposed by John L. Austin, who introduced a fundamental division into constative and performative utterances and went on to distinguish illocutionary effects from perlocutionary consequences of speech acts, the author investigates how far a subject is responsible for the words he uses.
Clusters belong to the regional innovation system, which led to the formulation and implementation of the cluster-based policy in many countries. The positive impact of clusters on the competitiveness of regions was confirmed by empirical studies. Absence of clusters means retardation in a regional development. The implementation of cluster policy supporting coopetition into the scope of principled regional policy assumptions seems urgent. In this way effective conditions for the formation of growth poles around industries specific for a given region will be developed and, consequently, the economic specialization of individual regions will be achieved. Observation of the benefits resulting from the functioning of clusters in the region, taking into account their possible negative impact, will allow to determine the specificity of regional development policy based on clusters. These problems indicated above are the subject of this study, based on the Polish and foreign literature available on the subject employing the desk research method.
Internalization of external economic effects on urban sprawl affected areas. An example of the Krakow Metropolitan Area, The study is a discussion on economic externalities, with particular emphasis on technological effects. Attention is also paid to the problem of internalization of economic external effects caused by movement (transport) in areas affected by the urban sprawl process. The research was conducted for all communes of the Krakow Metropolitan Area (KOM), as a result of which the value of: directly incurred financial losses and the value of lost time generated by the necessity of commuting and return in the space of KOM were presented.
The instability characteristics of a dielectric fluid layer heated from below under the influence of a uniform vertical alternating current (AC) electric field is analyzed for different types of electric potential (constant electric potential/ electric current), velocity (rigid/free) and temperature boundary conditions (constant temperature/heat flux or a mixed condition at the upper boundary). The resulting eigenvalue problem is solved numerically using the shooting method for various boundary conditions and the solution is also found in a simple closed form when the perturbation heat flux is zero at the boundaries. The possibility of a more precise control of electrothermal convection (ETC) through various boundary conditions is emphasized. The effect of increasing AC electric Rayleigh number is to hasten while that of Biot number is to delay the onset of ETC. The system is more stable for rigid-rigid boundaries when compared to rigid-free and least stable for free-free boundaries. The change of electric potential boundary condition at the upper boundary from constant electric potential to constant electric current is found to instill more stability on the system. Besides, increase in the AC electric Rayleigh number and the Biot number is to reduce the size of convection cells.
Over the past few years, a great deal of research has been conducted concerning the mathematical skills of children after the first stage of education. In my report, I present a selection of results from this research in order to illustrate the most typical didactical effects of the style in which mathematical education is performed in our schools. Comparing some detailed results from research in a number of chosen fields, I also try to assess whether or not, and how, the level of schoolchildren’s skills has changed in the recent years.
The category of expectation constitutes an important element of reflection in many scientific disciplines focusing on man. it is treated in both the categories of expectations inscribed in large social projects (e.g. of utopian nature) and individual expectations which build human daily routine. The article is divided into two parts. in the first, the issues of interpersonal expectations, analysed in the perspective of social psychology and sociology, will be undertaken. what will be explored here are the problems of defining the notion of expectation and the problems of expectations at school, which will be exemplified by the pygmalion effect. The first part is completed with some considerations on the meaning of expectation in sociology, the role of expectations in interaction, and the relations between expecting and social order. In the second part, the author focuses on the issues of expectations inscribed in utopian projects (“great expectations”). pedagogical utopias and relations between utopias and popularization of normative (formal) or informal pedagogies are subjected to analysis. The author makes here some references to the concept of post-materialistic society, attempting to elicit relations between this type of society and popularization of nonformal pedagogies.
This paper deals with the modelling of traction linear induction motors (LIMs) for public transportation. The magnetic end effect inherent to these motors causes an asymmetry of their phase impedances. Thus, if the LIM is supplied from the three-phase symmetrical voltage, its phase currents become asymmetric. This effect must be taken into consideration when simulating the LIMs’ performance. Otherwise, when the motor phase currents are assumed to be symmetric in the simulation, the simulation results are in error. This paper investigates the LIM performance, considering the end-effect induced asymmetry of the phase currents, and presents a comparative study of the LIM performance characteristics in both the voltage and the current mode.
The purpose of this paper is to focus on the loss separation of non-grain-oriented electrical steels used for speed-variable rotating electrical machines. The impact of laser-cutting, used in prototype manufacturing and of flux density harmonics, occurring locally in the lamination, on the loss distribution is studied in detail. Iron losses occurring under operation can physically be separated in different loss components. In this paper, a frequency-based loss model with parameters identified for single-sheet tester specimens, cut in strips of different widths, is therefore used. Moreover, a time-domain approach considers loss distributions occurring from higher harmonics. Hysteresis losses having high sensitivity to cut edge effects are calculated by the well-known Jiles-Atherton model adapting the frequency-based loss parameters. The model is validated by free-curve measurements at a single-sheet tester. It has been shown that the studied elliptical hysteresis model becomes inaccurate particularly for specimens with small strip widths with similar dimensions as teeth of electrical machine laminations. The incorrect mapping of losses occurring from minor hysteresis loops due to higher harmonics is concluded. The results showconsequently that both, the impact of a cut edge effect and local distributions of flux density harmonics need to be considered in terms of accurate iron loss prediction of electrical machine design.
This paper describes the weather conditions on the NE coast of Sørkappland (South Spitsbergen) during August 2005, and considers them in the context of the general synoptic situation over the North Atlantic . A comparison of local climates features for the East and West coast of southern Spitsbergen shows that the general atmospheric circulation and direct solar radiation in summer are the decisive factors affecting weather on the East coast. Foehn effects were observed during the study period. In the East, these were triggered by the westerly cyclonic situation and, in the West, by the easterly. The differences in the intensity of foehn effects may be explained by a specific relief of the Sørkappland peninsula.
The aim of this article is to defi ning problems occurring in the spatial management system, including those independent of subsequent legislative changes. The process of adopting decisions to be viable and socially equitable and execute the requirements of spatial order and sunstainable development requires fundamental changes. The study draws a conclusion – important in the context of subsequent research activities – that the varied application of development decisions in diff erent municipalities is also the result of not preparing a large part of the representatives of municipalities for specifi c spatial activities.
Scientific output analysis in Poland takes place in many ways: by use both central and local databases. The article discusses the contents and bibliometric functions of the most important bibliographic databases, i.e. “People of science”, Polish Scientific Bibliography and employeers local registration system Expertus. The authors evaluate these tools from the perspective of the ability to make comparisons of the effectivity of individual researchers as well as to stimulate the development of scientific careers. As alternative solution relative to the analytical spectrum of all external tools, the authors present own application that allows visualization of scientific achievements. According authors’ observation, the Scientific Visualiser can enrich the individual information space of the contemporary scientist. Dedicated application certainly facilitates the evaluation of the publication activity, increases an awareness of updating of the bibliographic data, helps in discovering the relationship between the research fields, inspires to broaden intelectual horizons and cooperation networks. From another side, it can also be a tool supporting administration activities, such as: employees evaluation, promotion proceedings, accreditation, experts selection, distribution of funds.
Transverse effective thermal conductivity of the random unidirectional fibre-reinforced composite was studied. The geometry was circular with random patterns formed using random sequential addition method. Composite geometries for different volume fraction and fibre radii were generated and their effective thermal conductivities (ETC) were calculated. Influence of fibre-matrix conductivity ratio on composite ETC was investigated for high and low values. Patterns were described by a set of coordination numbers (CN) and correlations between ETC and CN were constructed. The correlations were compared with available formulae presented in literature. Additionally, symmetry of the conductivity tensor for the studied geometries of fibres was analysed.
The cohesion and internal friction angle were characterized as quadratic functions of strain and were assumed to follow the Mohr-Coulomb criterion after the yield of peak strength. These mechanical parameters and their variations in post-peak softening stage can be exactly ascertained through the simultaneous solution based on the data points of stress-strain curves of triaxial compression tests. Taking the influence of the fault into account, the variation of strata pressure and roadway convergence with coal advancement, the temporal and spatial distribution of axial bolt load were numerically simulated by FLAC3D (Fast Lagrangian Analysis of Continua) using the ascertained post-peak mechanical parameters according to the cohesion weakening and friction strengthening model. The change mechanism of axial load of single rock bolt as abutment pressure changes was analyzed, through the comparison analysis with the results of axial bolt load by field measurements at a coal mine face. The research results show that the simulated results such as the period of main roof weighting, temporal and spatial distribution of axial bolt load are in accordance with field measurement results, so the validity of the numerical model is testified. In front of the working face, the front abutment pressure increases first and then decreases, finally tends to be stable. A corresponding correlation exists between the variation of axial bolt load and rock deformation along the bolt body. When encountered by a fault, the maximum abutment pressure, the influential range of mining disturbance and the roadway convergence between roof and floor before the working face are all increased. In the roadways along the gob, axial bolt loads on the side of the working face decrease, while the other side one increases after the collapse of the roof. As superficial surrounding rock mass is damaged, the anchoring force of rock bolts will transfer to inner rock mass for balancing the tensile load of the bolts.
Entries in steeply pitching seams have a more complex stress environment than those in flat seams. This study targets techniques for maintaining the surrounding rock mass stability of entries in steep seams through a case study of a steep-seam entry at a mine in southern China. An in-depth study of the deformation and instability mechanisms of the entry is conducted, employing field measurement, physical simulation experiment, numerical simulation, and theoretical analysis. The study results show that the surrounding rock mass of the entry is characterised by asymmetrical stress distribution, deformation, and failure. Specifically, 1) the entry deformation is characterised by a pattern of floor heaving and roof subsidence; 2) broken rock zones in the two entry walls are larger than those in the roof and floor, and the broken rock zone in the seam-floor side wall is larger than that in the seam-roof side wall; 3) rock bolts in the middle-bottom part of the seam-floor side wall of the entry are prone to failure due to tensile stress; and 4) rock bolts in the seam-roof side wall experience relatively even load and relatively small tensile stress. Through analysis, disturbances were found to occur in both temporal and spatial dimensions. Specifically, in the initial mining stage, the asymmetrical rock structure and stress distribution cause entry deformation and instability; during multiple-seam multiple-panel mining operations, a wedge-shaped rock mass and a quasi-arc cut rock stratum formed in the mining space may cause subsidence in the seam-floor side wall of the entry and inter-stratum transpression, deformation, and instability of the entry roof and floor. The principles for controlling the stability of the surrounding rock mass of the entry are proposed. In addition, an improved asymmetrical coupled support structure design for the entry is proposed to demonstrate the effective control of entry deformation.
The arc suppression coil determines whether it can effectively extinguish the arc when it is grounded in the neutral non-effective grounding system. An artificial grounding test is an importantway to verify its performance. In this study, 13 substations with the 10 kV system in the Ningxia areawere selected and considered. Based on the artificial single-phase grounding test, the residual current, the compensation current and the off-resonance degree were measured in the arc suppression coil, and the performance of the arc suppression coil in the 10 kV system was verified. The experimental results show that the error of arc suppression coil automatic measurement is large, the off-resonance degree is large, the resistive component in the compensation current is excessive, the harmonic component exists in the compensating current and capacitive current. To solve these problems, this paper puts forward the corresponding countermeasures for reference.