Finite fossil fuel resources, as well as the instability of renewable energy production, make the sustainable management of energy production and consumption some of the key challenges of the 21st century. It also involves threats to the state of the natural environment, among others due to the negative impact of energy on the climate. In such a situation, one of the methods of improving the efficiency of energy management – both on the micro (dispersed energy) and macro (power system) scale, may be innovative technological solutions that enable energy storage. Their effective implementation will allow it to be collected during periods of overproduction and to be used in situations of scarcity. These challenges cannot be overestimated - modern science has a challenge to solve various types of problems related to storage, including the technology used or the control/ /management of energy storage. Heat storage technologies, on which research works are carried out regarding both storage based on a medium such as water, as well as storage using thermochemical transformations or phase-change materials. They give a wide range of applications and improve the efficiency of energy systems on both the macro and micro scale. Of course, the technological properties and economic parameters have an impact on the application of the chosen technology. The article presents a comparison of storage parameters or heat storage methods based on different materials with specification of their work parameters or operating costs.
The article presents the possibility of using the Cobb-Douglas production function for planning in a turbulent environment. A case study was carried out – the Cobb-Douglas function was used to examine the condition of the Polish hard coal mining industry and the progress which has been made after undertaking certain activities aimed at increasing the competitiveness of coal companies over recent years. Only the correct and confirmed identification of the causes of irregularities in the production process can allow for the introduction of effective remedies. The effectiveness of the solutions proposed by the author has been confirmed thanks to the simulation during which the impact of the proposed production strategy on the parameters of the CD function was examined. Three variants of production functions models were created and production productivity rates and marginal substitution rates were determined. The results enabled the verification of the progress of restructuring as well as identification of the origin of the observed problems and comparison of the current state with the results of analyses carried out in previous years. Scenarios of possible trend developments for the factors introduced into the function model in order to present remedial measures that could improve the process of hard coal extraction were created. The scenarios were created using the ARIMA class models. Which scenario is the most favourable was determined. A computer program, created by the author, for optimising the level and use of labor resources at the level of the entire coal company has been presented.
In the Fugleberget catchment area (Spitsbergen, Hornsund Fiord region) the growing season lasted 95 days, with growth beginning under the snow. In this time shoots of moss Calliergon stramineum reached a mean length of 19 mm and mean biomass of 0.593 mg dry weight. Annual primary production of moss communities amounts to 220-270 g dry weight per square meter per year. In the first year of destruction the dead plant material lost 30-45% of its initial value, after 10 years only ca 25% of the initial amount of organic matter was left.
This study investigated changes in the real-time measured levels of milk β-hydroxybutyrate according milk yield, lactation number and status of reproduction in dairy cows. A total of 378 cows were selected. According to their reproductive status the cows were classified as belonging to the following groups: Fresh (1 – 44 days after calving. n=43). Open (45 – 65 days after calving. n=78), Inseminated (1 – 35 days after insemination. n=133). Pregnant (35 – 60 days after insemination and pregnant (relatively pregnant) (n=124). The cows were milked with DeLaval milking robot (DeLaval Inc., Tumba, Sweden) in combination with a Herd Navigator (Lattec I/S. Hillerød. Denmark) analyser. We observed that milk β-hydroxybutyrate (BHB) had a tendency of increasing with an increase of lactation number. The average BHB in multiparous cows was 11.111% higher in comparison with primiparous cows (p<0.001). We found higher BHB concentration in the multiparous cows in all reproduction status groups (p<0.001). A strong positive statistically significant (p<0.001) relationship has been found between BHB and the average milk yield within all groups of primiparous cows although we found a statistically unreliable coefficient of correlation (from -0.202 to 0.057) between highest milk yield and BHB in primiparous and multiparous cows.
One of the most important business areas of the company is the management of working capital. Energy companies that produce electricity and heat are the main consumers of steam coal, so their decision concerning stock levels is a major determinant of supply schedules. These decisions depend on legal and technical requirements as well as economic aspects. The seasonality of coal consumption jointly with pre-purchase costs and storage costs has a straight impact on delivery scheduling in a parabolic way. There is a divergence in expectations regarding delivery schedules among the coal market participants (energy, mining, transport companies). The purpose of this article is to present the concept of pricing of steam coal and transport service on the Polish market, assuming the use of price incentives, resulting in delivery scheduling during the year. The article presents selected theoretical content in the field of coal logistics and working capital management in the company, the expectations of the steam coal market participant regarding delivery schedules have been identified. The proposed concept of pricing steam coal and transport service should be discussed further in scientific and expert work.
The region’s development potential is a set of endogenous features that determine the growth of the local economy. It supports the development of knowledge, innovation and eff ective competition on global markets. The publication argues that saturation with potential may not be enough to cause economic growth. The distribution of potential is also important: concentration is its catalyst. The study proposes a method for measuring the concentration of potential. It has also been shown that the size of the regional economy depends on the distribution of potential in the region.
The main purpose of this article is to present an author’s methodology of production levelling and to show the impact of levelling on the time during which the product passes through the process and on staff performance. The article presents the analysis of literature concerning the method of improving the production process, especially taking production levelling into consideration. The authors focussed on the definition and methodologies of production levelling. A diagram of interrelations showing determinants and efficiency measures of production levelling as well as an author’s production levelling methodology have been presented. An example of the implementation of production levelling in one of the departments of a company manufacturing surgical instruments has also been shown. Analysis of the current state, stages of implementation and end effects have been presented. Attention was focussed on the time during which the product passes through the process and on staff performance.
The Silurian Pelplin Formation is a part of a thick, mud-prone distal fill of the Caledonian foredeep, which stretches along the western margin of the East European Craton. The Pelplin Formation consists of organic carbon- rich mudstones that have recently been the target of intensive investigations, as they represent a potential source of shale gas. The Pelplin mudstones host numerous calcite concretions containing authigenic pyrite and barite. Mineralogical and petrographic examination (XRD, optical microscopy, cathodoluminoscopy, SEM-EDS) and stable isotope analyses (δ13Corg, δ13C and δ18O of carbonates, δ34S and δ18O of barite) were carried out in order to understand the diagenetic conditions that led to precipitation of this carbonate-sulfide-sulfate paragenesis and to see if the concretions can enhance the understanding of sedimentary settings in the Baltic and Lublin basins during the Silurian. Barite formed during early diagenesis before and during the concretionary growth due to a deceleration of sedimentation during increased primary productivity. The main stages of concretionary growth took place in yet uncompacted sediments shortly after their deposition in the sulfate reduction zone. This precompactional cementation led to preferential preservation of original sedimentary structures, faunal assemblages and early- diagenetic barite, which have been mostly lost in the surrounding mudstones during burial. These components allowed for the reconstruction of important paleoenvironmental conditions in the Baltic and Lublin basins, such as depth, proximity to the detrital orogenic source and marine primary productivity. Investigation of the concretions also enabled estimation of the magnitude of mechanical compaction of the mudstones and calculation of original sedimentation rates. Moreover, it showed that biogenic methane was produced at an early-diagenetic stage, whereas thermogenic hydrocarbons migrated through the Pelplin Formation during deep burial.
This paper examines highly paid academics – or “top earners” – employed across universities in ten European countries based on a large-scale international survey data of the academic profession. It examines the relationships between salaries and academic behaviors and productivity, as well as the predictors of being an academic top earner. While in the Anglo-Saxon countries the university research mission traditionally pays off at an individual level, in Continental Europe it pays off only in combination with administrative and related duties. Seeking future financial rewards through research does not seem to be a viable strategy in Europe – but seeking satisfaction in research through solving research puzzles is also getting difficult, with the growing emphasis on “relevance” and “applicability” of research. Thus both the traditional “investment motivation” and “consumption motivation” for research are ever-harder to be followed, with policy implications. The primary data come from 8,466 usable cases. This paper examines change processes in Western Europe and in Poland (in a European context) and its main reference point is American higher education scholarship; it is, on the theoretical plane, the founder of the conceptual frameworks to study academic salaries, and, in practical terms, the US science systems heavily draws on European scientific talents.
The article presents research on the relationship between mining and used resources on the example of Gliśno gravel pit. As regards to resources, the following issues were analyzed: employees’ working time, time of running machines, fuel consumption and electricity consumption. The aim of the publication is to examine the dependencies that exist between the analyzed variables. KPI’s (Key Performance Indicators) were calculated for individual resources. The analysis presented in the publication contains data from 2008-2014.
Experiments have been carried out on the influence exerted by Aroclor 1254 upon the photosynthetic production of organic 14C by an assemblage of marine Antarctic diatoms (Thalassiosira sp. 48%, Nitzschia sp. 21%, Chaetoceros sp. 15% and Corethron iriophilum 10%). Samples of various numbers of cells per cm3 of water have been used. Incorporation of 14C02 by the diatoms proved to be proportional to the increased number of cells in the sample only at the lowest levels of concentration in per cm3. Further increase of the level of 14C in diatoms has not been found as number of cells in the sample kept growing. Calculation of brutto photosynthesis has indicated that low concentration of Aroclor 1254 (0,01 to 1 ppm) may stimulate the photosynthetic incorporation of carbon, yet the photosynthetic release of carbon from cells within the photorespiratory process is stimulated to a higher degree. High concentration of Aroclor (1 to 50 ppm) inhibit the brutto assimilation, yet the release of carbon during the photorespiratory process is inhibited to a higher degree. A hypothesis is being considered implying that the relation between the intensity of photosynthesis and intensity of photorespiration may vary according to the rate of concentration of Aroclor.
In the processes of coal mining, preparation and combustion, the rejects and by-products are generated. These are, among others, the rejects from the coal washing and dry deshaling processes as well as the coal combustion by-products (fly ash and slag). Current legal and industry regulations recommend determining the content of mercury in them. The regulations also define the acceptable content of mercury. The aim of the paper was to determine the mercury content in the rejects derived from the coal cleaning processes as well as in the combustion by-products in respect of their utilization. The mercury content in the representative samples of the rejects derived from the coal washing and dry deshaling processes as well as in the coal combustion by products derived from 8 coal-fired boilers was determined. The mercury content in the rejects from the coal washing process varied from 54 to 245 μg/kg, (the average of 98 μg/kg) and in the rejects from the dry deshaling process it varied from 76 to 310 μg/kg (the average of 148 μg/kg). The mercury content in the fly ash varied from 70 to 1420 μg/kg, (the average of 567 μg/kg) and in the slag it varied from 8 to 58 μg/kg (the average of 21 μg/kg). At the moment, in light of the regulations from the point of view of mercury content in the rejects from the coal preparation processes and in the coal combustion by-products, there are no significant barriers determining the way of their utilization. Nevertheless, in the future, regulations limiting the maximum content of mercury as well as the acceptable amount of leachable mercury may be introduced. Therefore, preparing for this situation by developing other alternative methods of using the rejects and by-products is recommended.
The paper presents selected issues related to the development of international coal markets. World consumption of coal dropped for the second year in a row in 2016, primarily due to lower demand from China and the U S. The share of coal in global primary energy consumption decreased to 28%. World coal production accounted to 3.66 billion toe and it was lower by 6.2% when compared to the previous year. More than 60% of this decline took place in China. The decline in global production was more than four times higher than the decrease in consumption. The sufficiency of world resources of coal are estimated at 153 years – that is three times more than the sufficiency of oil and gas resources. After several years of decline, coal prices increased by 77% in 2016. The current spot prices are at the level of $80/t and are close to the 2014 prices. In the European market, after the first half of the year, coal prices reached the level of around 66% higher than in the same period of the last year. The average price in the first half amounted to PLN 12.6/GJ, which is close to the 2012 prices. The share of spot trade in the total purchase amount accounted to approx. 20%. Prices in futures contracts can be estimated on the basis of the Japan-Australia contracts prices and prices in supplies to power plants located in Germany. On average, the prices in supplies to these power plants were higher by approximately 9% in the years 2010–2016 and prices in Australia – Japan contracts were 12% higher than CIF ARA prices in 2017. Global energy coal trade reached about 1.012 billion tonnes in 2016. In 2019, a decline by 4.8% is expected primarily due to the expected reduction in the demand in major importing countries in Asia.
The paper presents a Car Sequencing Problem, widely considered in the literature. The issue considered by the researchers is only a reduced problem in comparison with the problem in real automotive production. Consequently, a newconcept, called Paint Shop 4.0., is considered from the viewpoint of a sequencing problem. The paper is a part of the previously conducted research, identified as Car Sequencing Problem with Buffers (CSPwB), which extended the original problem to a problem in a production line equipped with buffers. The new innovative approach is based on the ideas of Industry 4.0 and the buffer management system. In the paper, sequencing algorithms that have been developed so far are discussed. The original Follow-up Sequencing Algorithm is presented, which is still developed by the authors. The main goal of the research is to find the most effective algorithm in terms of minimization of painting gun changeovers and synchronization necessary color changes with periodic gun cleanings. Carried out research shows that the most advanced algorithm proposed by the authors outperforms other tested methods, so it is promising to be used in the automotive industry.
The essence of advertising lies very often in unusual and surprising juxtapositions of apparently incongruous elements, which nevertheless successfully combine in producing a coherent and understandable message. A vital role is performed by a skillfully engineered context, which allows for simultaneous activation of certain otherwise inconspicuous senses and the construction of novel and attractive connections. Such theoretical proposals as Lemke’s traversals (2001; 2005), Fauconnier and Turner’s Conceptual Blending Theory (1998; 2002) and Kecskes’s Dynamic Model of Meaning (2008) seem to describe many vital aspects of the phenomenon in question. It is in advertising that we often come across the linking of elements by transgressing naturally existing borders between domains which are unrelated, and we are invited to map onto one another different mental spaces on the basis of their salient analogy or identity, and indulge in creative riddle-like exploration of contextual elements in order to reconstruct the intended message. These techniques’ true power lies in their ability to blur the distinction between ‘the real’ and ‘the imagined’ to such an extent that certain irrational but attractive connections, implanted in the minds of the audience, contribute to subsequent decisions in the real world. The present study attempts to uncover the ways in which certain unrelated elements are skillfully brought together in a context which allows for such a juxtaposition in selected Polish TV advertisements for various medicine and health-related products. The method employed is an in-depth content analysis of the material, followed by an attempt to integrate the identified mechanisms with the models of meaning-making mentioned above. The results will hopefully help in better understanding of the ways in which particular components of the context may interact with the message expressed verbally or pictorially in the construction of multilevel meanings in advertising communication.
The insecticidal efficiency of Ag-loaded 4A-zeolite (ZAg) and its formulations with Rosmarinus officinalis essential oil (RO) was evaluated against Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). For comparison, different rates of ZAg (0.25, 0.5, 0.75, and 1 g ⋅ kg–1 wheat) were used solely and in a combination with LC50 concentrations of RO. Mortality was assessed after 7, 14, and 21 days of insect exposure to treated wheat. The progeny production was also evaluated. The use of ZAg accomplished a complete mortality (100%) on S. oryzae and 96.67% on R. dominica as well as 100% mortality of progeny against the two insect species after the longest exposing duration (21 days), at the highest rate (1 g ⋅ kg–1). On the other hand, the complete mortalities of ZAg formulations on S. oryzae were obtained after 14 d of treatment with F1 formulation (0.605 g ⋅ kg–1 RO + 0.25 g ⋅ kg–1 ZAg) and after 7 days with the other tested formulations. In addition, the complete mortality on R. dominica was obtained only by F8 (0.059 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulation after 14 days of treatment. Concerning the efficiency of the examined formulations on the progeny of S. oryzae, F1 (0.605 g ⋅ kg–1 RO + 0.25 g ⋅ kg–1 ZAg) and F2 (0.605 g ⋅ kg–1 RO + 0.5 g ⋅ kg–1 ZAg) formulations recorded 100% mortality. In addition, F3 (0.605 g ⋅ kg–1 RO + 0.75 g ⋅ kg–1 ZAg) and F4 (0.605 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulations suppressed the progeny production. Furthermore, the complete mortality of R. dominica progeny was obtained with F7 (0.059 g ⋅ kg–1 RO + 0.75 g ⋅ kg–1 ZAg) and F8 (0.059 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulations. ZAg, especially its formulations with R. officinalis oil, had potential effects against two stored-product insects. F1 and F8 formulations could be treated efficiently on S. oryzae and R. dominica, respectively.
Coal production in 2018 increased by 3.3% and amounted to 7.81 million tons. Compared to 2010, it increased by 620 million tons. The structure of coal production in the world is very stable in the analyzed period of 2010–2018. Steam coal dominates in production with a share of 77%. Since 1990, the share of coal in the consumption of primary energy carriers has fallen by 3% in the global economy. In the EU, the share of coal in the consumption of primary energy carriers is more than twice lower than in the world, and in 2018 amounted to 13%. BP estimates the sufficiency of coal proven reserves based on 2018 data for the next 132 years. For oil and gas, they are estimated at 51 years. The decline in hard coal production in the European U nion can be dated almost continuously since 1990, which has decreased by 74%. In 2018, 74 million tons of coal were produced in the EU. In 2018, hard coal consumption in EU countries dropped to 226 million tons, i.e. by 20.6%. In 2018, global trade in steam coal amounted to 1.14 billion tons. The situation in China is crucial for the international coal market. The slight change in the import policy of this country significantly affects the situation in international trade in steam coal. In 2019, coal prices (at Newcastle, Richards Bay, ARA ports) dropped by an average of 23 U SD/ton. The average decreases for these three indices were 33%. The prices of steam coal in the forecasts presented in the paper are under pressure of the falling demand.
The article presents current state of the structure of hard coal enrichment plants in Poland, taking the capacity, the range of grain enrichment and the type of equipment used into account. This data were presented in a tabular format for each Polish Coal Company operating on the Polish market. The article was also present simplified: flow sheet of the steam and coking coal enrichment system. Based on the presented data, the planned needs and trends were described in terms of increasing production efficiency, minimizing water consumption and safety of work. A list of research and development works which must be undertaken were also presented as well as factors determining the technological development of the processing plants.
The engine simulations have become an integral part of engine design and development. They are based on approximations and assumptions. The precision of the results depends on the accuracy of these hypotheses. The simplified models of frozen composition, chemical equilibrium and chemical kinetics provide the compositions of combustion products for engine cycle simulations. This paper evaluates the effects of different operating conditions and hypotheses on the exergetic analysis of a spark-ignition engine. The Brazilian automotive market has the highest number of flex-fuel vehicles. Therefore, a flex-fuel engine is considered for simulations in order to demonstrate the effects of these different hypotheses. The stroke length and bore diameter have the same value of 80 mm. The in-cylinder irreversibility is calculated for each case at the closed part of the engine cycle. A comparative analysis of these hypotheses provides a comprehensive evaluation of their effects on exergetic analysis. Higher values of accumulated irreversibility are observed for the oversimplified hypothesis.
The high pressure die casting technology allows the production of complex casts with good mechanical properties, with high production repeatability within narrow tolerance limits. However, the casts are somewhat porous, which may reduce their mechanical properties. There are several recommendations for reducing the porosity of casts, which are aimed at setting the technological parameters of the casting cycle. One of the primary and important ways to reduce the porosity and air entrapment in the melt is a suitable gating system design. Submitted contribution is devoted to assessing the influence of the runner branching geometry on the air entrapment within the cast volume during the filling phase of the casting cycle. Four variants of the gating system for a particular cast are compared with different design of main runner branching. The initial design is based on a real gating system where the secondary runner is connected to the main runner at an angle of 90 °. The modified designs are provided with a continuous transition of the main runner into the secondary ones, with the change in the branching runner radius r1 = 15 mm, r2 = 25 mm and r3 = 35 mm. The air entrapment in the melt is assessed within the cast volume behind the cores, which have been evaluated as a critical points with respect to further mechanical treatment. When designing the structural modification of geometry it was assumed that by branch changing using the radius value r3 = 35 mm, the melt flows fluently, and thus the value of the entrapped air in the volume of the cast will be the lowest. This assumption was disproved. The lowest values of entrapped air in the melt were found in the casts with runner transition designed with radius r1 = 15 mm. The conclusion of the contribution explains the causes of this phenomenon and from a designing point of view it presents proposal for measures to reduce the entrapment of the air in casts.
Final quality of casts produced in a die casting process represents a correlation of setting of technological parameters of die casting cycle, properties of alloy, construction of a die and structure of gating and of bleeding systems. Suitable structure of a gating system with an appertaining bleeding system of the die can significantly influence mechanical and structural properties of a cast. The submitted paper focuses on influence of position of outfall of an gate into the cast on its selected quality properties. Layout of the test casts in the die was designed to provide filling of a shaping cavity by the melt with diverse character of flowing. Setting of input technological parameters during experiment remained on a constant level. The only variable was the position of the gate. Homogeneity represented by porosity f and ultimate strength Rm were selected to be the assessed representative quality properties of the cast. The tests of the influence upon monitored parameters were realized in two stages. The test gating system was primarily subjected to numerical tests with the utilization of a simulation program NovaFlow&Solid. Consequently, the results were verified by the experimental tests carried out with the physical casts produced during operation. It was proved that diverse placement of the gate in relation to the cast influences the mode of the melt flowing through the shaping cavity which is reflected in the porosity of the casts. The experimental test proved correlation of porosity f of the cast with its ultimate strength Rm. At the end of the paper, the interaction dependencies between the gate position, the mode of filling the die cavity, porosity f and ultimate strength Rm.
The article presents the results of research on the finishing of M63 Z4 brass by vibratory machining. Brass alloy was used for the research due to the common use of ammunition elements, cartridge case and good cold forming properties on the construction. Until now, the authors have not met with the results of research to determine the impact of abrasive pastes in container processing. It was found that the additive for container abrasive treatment of abrasive paste causes larger mass losses and faster surface smoothing effects. The treatment was carried out in two stages: in the first stage, the workpieces were deburred and then polished. Considerations were given to the impact of mass of workpieces, machining time and its type on mass loss and changes in the geometric structure of the surface. The surface roughness of machining samples was measured with the Talysurf CCI Lite optical profiler. The suggestions for future research may be to carry out tests using abrasive pastes with a larger granulation of abrasive grains, and to carry out tests for longer processing times and to determine the time after which the parameters of SGP change is unnoticeable.
In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2emission by 90%. In this work the influence of the main parameter of the membrane process – the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.
The purpose of the paper is to present the author’s reflections on the origin and popularity of various approaches to maintenance and improvement of production processes, their terminological consistency, understanding, and practical application of their principles. The author’s reflections are based on his observations made over his many years of activity as a lecturer and consultant in the area of production engineering and management. It was shown that there is a need to make scientists and practitioners aware of the relatively large degree of freedom in defining the scope and way of application of strategies of continuous improvement. The author’s proposal is to refer to all approaches to maintenance and improvement of production processes with the title “Strategies of Efficient Action” and all supporting methods as “Practices of Efficient Action”. Considerations presented in the paper can be useful in more and more efficiently applying the power of TQM, Six Sigma, Lean Manufacturing and other strategies of processes maintenance and improvement in the daily activities of companies.
Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund) and warmer Atlantic water (Kongsfjorden). Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical) of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m-2 y-1 in Kongsfjorden to 216 g C m-2 y-1 in Hornsund, with a dominant component of microplankton (90%) followed by macrophytes and microphytobenthos.