The paper presents key assumptions of the mathematical model which describes heat and mass transfer phenomena in a solar sewage drying process, as well as techniques used for solving this model with the Fluent computational fluid dynamics (CFD) software. Special attention was paid to implementation of boundary conditions on the sludge surface, which is a physical boundary between the gaseous phase - air, and solid phase - dried matter. Those conditions allow to model heat and mass transfer between the media during first and second drying stages. Selection of the computational geometry is also discussed - it is a fragment of the entire drying facility. Selected modelling results are presented in the final part of the paper.

In this study, a new laser flash system was proposed for the determination of the thermal conductivity of brown coal, hard coal and anthracite. The main objective of the investigation was to determine the effect of coal rank, composition, physical structure and temperature on thermal conductivity. The solid fuels tested were medium conductors of heat whose determined thermal conductivities were in the range of 0.09 to 0.23 W/(m K) at room temperature. The thermal conductivity of the solid fuels tested typically increased with the rank of coal and the measurement temperature. The results of this study show that the physical structure of solid fuels and temperature have a dominant effect on the fuels' thermal conductivity.

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.

This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser and the falling tube. A numerical analysis of the mass flux and heat transfer coefficient in the steady state has been presented.

Searching for dependance of odour intensity on degree of dillution of basic samples with pure air, samples aromatised with citrus oil and containing difTerent amounts of acetone, ethanol, isopropanol, isoamyl acetate were studied. 192 individual odour intensity assesments of 16 samples were collected. Dependence of odour intensity on acetone concentration determined with chromatographic analysis (110-16500 mg/m3) was defined on the basis of 311 individual odour intensity assessments of 24 samples. The measurements' results were elaborated without initial assumptions concerning character of a psychophisical equation and without initial selection of empirical data. Automatic Networks Designer (Statistica Neural Network, StatSoft) was used. Dependence of odour intensity on concentration was described with logistic function resembling Stevens law within a small concentrations range and Weber-Fechner law within a high concentrations range.

The aim of the article is to compare three literary pictures of the political transformation presented in The impostor (2014) by Javier Cercas, Spis cudzoloznic (1993) by Jerzy Pilch and Sonka (2014) by Ignacy Karpowicz. These novels emphasize their discursive character, thereby revealing that the history is always a narration, not an uninfected series of events. The transformation is shown in conjunction with the theme of cultural memory and imposture.

There is an ongoing debate about the fundamental security of existing quantum key exchange schemes. This debate indicates not only that there is a problem with security but also that the meanings of perfect, imperfect, conditional and unconditional (information theoretic) security in physically secure key exchange schemes are often misunderstood. It has been shown recently that the use of two pairs of resistors with enhanced Johnsonnoise and a Kirchhoff-loop ‒ i.e., a Kirchhoff-Law-Johnson-Noise (KLJN) protocol ‒ for secure key distribution leads to information theoretic security levels superior to those of today’s quantum key distribution. This issue is becoming particularly timely because of the recent full cracks of practical quantum communicators, as shown in numerous peer-reviewed publications. The KLJN system is briefly surveyed here with discussions about the essential questions such as (i) perfect and imperfect security characteristics of the key distribution, and (ii) how these two types of securities can be unconditional (or information theoretical).

These joints are used when the designer and contractor anticipate difficulties during the construction of overlap joints. They were not included in the PN EN 1993‒1‒8 in full scale. Resistance assessment of such joints is presented in accordance with standard rules. The results were compared with the experimental studies carried out at the “Mostostal” Centre; while the former research activities and the legitimacy of the proposed method of assessing the resistance of these joints was confirmed. This is an example of an overlap joint calculation.

On December 6, 2022, Professor Hanna Taborska, an outstanding linguist, Slavicist, distinguished researcher of the Kashubian language, doctor honoris causa of the University of Gdańsk, Righteous Among the Nations passed away at the age of 92. She worked continuously for 58 years at the Institute of Slavic Studies of the Polish Academy of Sciences in Warsaw. She is the author of over 500 scientific publications, including fundamental works in the field of Kashubian and Slavic studies.

In his lecture on Adam Asnyk’s poetry delivered in 1896 Jan Kasprowicz came up with the term endymionism to refer to a relatively small portion of the poet’s work characterized by a tone of extravagant egotism and narcissism. Exemplary for this extravaganza was, according to Kasprowicz, the poem ‘Endymion’. It belongs to a sequence of poems voicing the poet’s trauma after the suppression of the 1863–1864 January Uprising, and is closely connected with the ‘A Dream of the Tombs’, his most opaque and depressive poem. In the Polish literary tradition – from Słowacki’s calling Krasiński the Endymion of poetry, through Norwid and Faleński to a number of Young Poland’s poets (Rydel, Wyspiański, and Lange to mention but a few) – the figure of Endymion marked a situation of the poet being misunderstood or flouted by critics and readers. But with Asnyk’s ‘Endymion’, who, despite the appearance of a lonely dreamer is in fact a guardian of the tombs of heroes who fell in an unequal fight, this mythological figure acquired a new meaning. It became a symbol of loyalty and a noble idealism making no concessions to mundane pragmatism. In the following decades endymionism of that kind would often blend into Parnassianism, a poetic movement committed to the idea of art independent of all practical concerns and obligations.

The paper presents findings of a research project aimed at a reconstruction of the dynamics of biographical experiences of some of those categories of the Polish society’s members whose educational and professional careers have been shaped by the systemic transformation after 1989. The text is an attempt to delineate analytical guidelines for grasping how some components of three types of social order, conceived in terms of premodernity, modernity and postmodernity, interpenetrating each other in the contemporary life of the society, impact its members’ biographical experiences on the level of work, social ties and identity.

This paper investigates the terrain-aliasing effects on geoid determination using different gravimetric reduction schemes. The high resolution of digital terrain model (DTM), if available, should be used for every gravimetric reduction scheme since it can precisely map the details of the terrain. The reduction methods used in this study are the Rudzki inversion method, Helmert's second method of condensation, the residual terrain model (RTM) method, and the Pratt-Hayford (PH) topographic-isostatic reduction technique. The effect of using different DTM grid resolutions of 6", 15", 30", 45", I' and 2' on gravity anomalies and absolute geoid undulations is studied for each of these reduction schemes. A rugged area in the Canadian Rockies bounded by latitude between 49°N and 54°N and longitude between 236°E and 246°E is selected to conduct numerical tests. Our results suggest that a DTM grid resolution of 6" or higher is required for precise geoid determination with an accuracy of a decimetre or higher for any gravimetric reduction method chosen to treat the topographical masses above the geoid in rugged areas. The most precise geoid models obtained in this test are the ones obtained using Rudzki, Helmert, and RTM methods with 6" DTM resolution.

Problems related to power control of low power-output steam turbines are analyzed. These turbines are designed to operate in distributed power generation systems. Principles of automatic control involving a single control valve are presented on the basis of experience gathered with high power-output turbines. Results of simulations of power control for a low power-output turbine are discussed. It has been proven that closing of the control system and an application of a power controller (of optimally selected parameters) improves the object dynamics (shortening of the transition period). At the same time, a lack of such optimization can results in occurrence of undesirable phenomena such as: overshoot in the generator power characteristics, elongation of the response time to disturbance or overshoot of turbine control valves.

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.

Views on the objectives and role of water management have remarkably changed in the last years. The need of a complex water management that would consider all water users including agriculture and natural environment is often underlined. It is pointed out that agriculture and natural environment (including commercial forests) are basic consumers of precipitation water which is not considered in water and economic balances. More and more importance is attributed to the utilisation of waters from catchment basin and to application of non-technical measures of controlling water cycles. A large impact of agro-ecosystems and natural or semi-natural (forests, wetlands) ecosystems on water balance is underlined. This different approach to the problems of water management is expressed e.g. in Water Framework Directive of European Union devoted to surface and ground water protection. The directive attributes a great role to the protection of aquatic and water related ecosystems. More and more often it is realised that the total water resources are equal to the volume of atmospheric precipitation. Water management should involve not only the water in geological aquifers or river channels but also that which is retained in soil profile. Such elements of water balance as spatial distribution, interception, infiltration and recharge of ground water reservoirs, soil retention capacity, surface runoff and evapotranspiration depend largely on land use in a catchment. Through appropriate land use and catchment management, application of rational agro-technical methods, development of small retention, wetland restoration, and hampering water outflow from draining systems one may significantly affect water cycling in a catchment.

Small water resources of Poland, increasing water consumption, climate changes and requirements of environmental protection enforce the implementation of complex methods of water management and search for environmental-friendly methods of limiting economic losses caused by water deficit or excess. Saving water used for economic purposes and agriculture would permit better fulfilment of the needs of natural environment.

The paper proposes an alternative approach to the dissemination of the mass unit in the context of the new definition of the kilogram. Considering the fact that redefinition allows mass to be directly realized at any value, the paper presents a model of the dissemination of mass which can be used for different series in grams, where the measurements are performed in the downward direction, but using 1 g as the reference standard (whose mass value is assumed to be determined after the redefinition using the capacitive or electrostatic techniques). The subdivision method presented (suitable for �� ₁ weights) has as its starting point the approach used by Mihailov-Romanowski for the calibration of series in kilograms which uses an orthogonal system of equations. Thus, according to this method, a solution for obtaining the orthogonality of a system can be the use as defining standard of the ratio between the mass having the highest nominal value in the set and the standard (unit). The results obtained for a set of weights from 10 to 1 g using the subdivision method, in accordance with the Mihailov-Romanowski principle, are validated with those obtained with the multiplication method, where the measurements start from 1 to 10 g, as in the case of the kilogram series. The mass values obtained with both methods are equal, while the estimated uncertainties are slightly different, yet insignificant. The results obtained previously for the same sequence of weights using the traditional dissemination method, where the 1 kg standard is used as reference, are also presented in the paper. The results show that only three weights out of six have a mass value insignificantly different by 1 x 10 ^-4 mg compared to those obtained with the methods presented in this article, but, in terms of uncertainty, there are some differences. The way of disseminating the mass unit presented in this article can be extended to other different sequences of nominal values such as: (5...1) g, (20...1) g, (50...1) g or (500...100) g if the reference standard is 100 g.

The Kibble balance experiment is used to redefine the kilogram as a unit of mass based on the Planck constant. To demonstrate and understand the basic principle of the Kibble balance, the National Institute of Standards (NIS)-Egypt has constructed a prototype Kibble balance that can measure gram-level masses with 0.01% relative uncertainty. Through the construction of this prototype, the challenges can be studied and addressed to overcome the weaknesses of NIS’s prototype. This study presents the design and construction of the prototype Kibble balance. It also focuses on the design and performance of the magnetic system, which is a crucial element of the Kibble balance. Analytical modeling and finite element analysis were used to evaluate and improve the magnet system. Several other aspects were also discussed, including the yoke’s material and enhancing the magnetic profile within the air gap of the magnet system. Over a vertical distance of 30 mm inside the air gap, the magnetic flux density was found to be 0.3 T, and the uniformity was found to be 8 x 10 ^-5.

To increase their competitive advantage in turbulent marketplaces, contemporary manufacturers must show determination in seeking ways to: fulfill buyer orders with quality merchandise; meet deadlines; handle unexpected production disruptions; and lower the total relevant expense. To tackle the abovementioned challenges, this study explores an economic manufacturing quantity (EMQ) model with machine failure, overtime, and rework/disposal of nonconforming items; the goal is to find the best fabrication uptime that minimizes total relevant expenses. Specifically, we consider a production unit with overtime capacity as an operational feature that is linked to higher unit and setup costs. Further, its EMQ-based process is subject to random nonconforming items and failure rates. Extra screening separates the reworkable nonconforming items from scrap, and the rework is executed at the end of each cycle of regular fabrication. The failures follow a Poisson distribution, and a machine repair task starts as soon as a failure occurs; the fabrication of the lot that was interrupted resumes after the repair has been carried out. A decision model is built to capture the characteristics of the problem. Mathematical and optimization processes help in determining the optimal fabrication uptime. A numerical example not only illustrates the applicability of the research outcomes, but also reveals a diverse set of information about the individual or joint influences of deviations in mean-time-to-failure, overtime factors, and rework/disposal ratios linked to nonconforming rates related to the optimal replenishment uptime, total operating expenses, and various cost contributors; this facilitates better decision making.

An attempt was made in the present work to study the compressive strength and microstructure of geopolymer containing high calcium fly ash (HCFA) and silica fume. Concentration of sodium hydroxide solution 8M, 10M, 12M & 14M, liquid to binder ratio 0.5 and sodium hydroxide to sodium silicate ratio 2.5 were selected for the mixes. Geopolymer mortar test results indicated that the mix with 40% silica fume by the weight of HCFA yielded higher compressive strength under ambient curing. The XRD pattern typically shows the major portion of amorphous phase of geopolymer. The existence of C-A-S-H gel, N-A-S-H gel and hydroxysodalite gel products were observed through SEM which developed dense microstructure and thus enhanced strength of HCFA and silica fume geopolymer.

We present the last millennium of history of a peatland located in northern Poland. Our results are based on two replicate monoliths taken from a Baltic raised bog. We applied a high-resolution approach and radio car bon dating to the peat material to obtain a de tailed palaeoenvironmental reconstruction. To reconstruct past peatland moisture, we used three prox ies: testate amoebae, plant macrofossils and pollen. Despite different peat accumulation and extensive hiatus in the formerly studied core, both monoliths show a similar pattern of changes. However, the core from this study provides us with more detailed data on S. fuscum disappear ance which correlates well with the data from the other Baltic bog, S³owiñskie B³oto. Our re search shows that pris tine Bal tic bogs can be dated to AD 1350. Słowiñskie Błoto palaeohydrology confirms AD 1300 as the beginning of the hydrological disturbance. In the case of the Stążki and Słowiñskie Błoto bogs, the Little Ice Age (LIA) is recorded between AD 1500 and AD 1800. However, this climatic change might have been blurred by human impact. In the case of the Baltic bogs, their reference virgin state can be dated to AD 1200. After this date, we observed in creasing human impact and climatic in stability connected with the LIA. However, between AD 1800 and 1900, bogs were wet, most possibly due to climatic forcing. This fact suggests that despite human impact, recent peat deposits can still reflect climate. Our research provided in formation related to the time of existence, location and characteristics of the natural/pristine state. High-resolution peatland palaeoecology is crucial for restoration activities, e.g., rewetting and environmental management. The palaeohydrological context (supported by other proxies) of the last 1000 years provides a reliable answer to the question: ‘To rewet or not to rewet?’

Nine samples of basic (dolerite, gabbro) intrusions collected at Bellsund, South Spitsbergen, have been K−Ar dated. Three dates, between 87.8 and 102.9 Ma, obtained from dolerite sills which intrude Carboniferous and Permian deposits in Van Keulenfjorden point to a Cretaceous age of intrusive activity (Diabasodden Suite). The K−Ar dates obtained from dolerite and gabbro which intrude Upper Proterozoic metasedimentary terrane of Chamber− lindalen form two groups: the dates between 97.1 and 178.6 Ma point to a Mesozoic age of the intrusions (Diabasodden Suite); the dates from a tectonized gabbroid (280.9–402.0 Ma) might point to a Late Palaeozoic age of the intrusion. No K−Ar dates which would indicate a Proterozoic age of the basic intrusions were obtained

Based on the results of CTD measurements (in situ) made during r/v „Oceania" cruises in the Norwegian and Greenland Seas in 1986—1988 selected aspects of termohaline structure and water dynamics of chosen regions of the seas were described. Examples of space-time variations of temperature and salinity fields were presented and water masses geostrophic transport on the limits of the Norwegian Sea (upon the Atlantic Ocean and the Barents Sea) was estimated.