The main goal of the presented work was to determine the relationship between changes in the shape of the derivative curve and the microstructure of Zn-Al-Cu alloys before and after modification. To describe the phenomena that occur in the material during solidification as a result of the modification in the chemical composition, the thermal-derivative analysis method was applied. This method allows to describe and interpret the kinetics of crystallisation of the tested alloys. To describe the morphology and phase composition, light and electron microscopy (SEM, TEM) was also used. The modification of the hypereutectic Zn-Al-Cu alloys with the addition of Ce causes a reduction in the size α' + η eutectics and change in the morphology of the α' phase precipitates from dendritic to “tweed”.
Municipal waste management has been an area of special interest of the European Commission (EC) for many years. In 2018, the EC pointed out issues related to municipal waste management as an important element of the monitoring framework for the transition towards a circular economy (CE), which is currently a priority in the economic policy of the European Union (EU). In the presented monitoring framework, 10 CE indicators were identified, among which issues related to municipal waste appear directly in two areas of the CE – in the field of production and in the field of waste management, and indirectly – un two other areas – secondary raw materials, and competitiveness and innovation. The paper presents changes in the management of municipal waste in Poland in the context of the implementation of the CE assumptions, a discussion of the results of CE indicators in two areas of the CE monitoring framework in Poland (production and waste management), and a comparison of the results against other European countries.
In Poland, tasks related to the implementation of municipal waste management from July 1, 2013 are the responsibility of the municipality, which is obliged to ensure the conditions for the system of selective collection and collection of municipal waste from residents, as well as the construction, maintenance and operation of regional municipal waste treatment installations (RIPOK). The municipality is also committed to the proper management of municipal waste, in accordance with the European waste management hierarchy, whose overriding objective is to prevent waste formation and limiting its amount, then recycling and other forms of disposal, incineration and safe storage. The study analyzed changes in the value of two selected CE indicators, i.e. (1) the municipal waste generation indicator, in the area of production and (2) the municipal waste recycling indicator, in the area of waste management. For this purpose, statistical data of the Central Statistical Office (GUS) and Eurostat were used. Data has been presented since 2014, i.e. from the moment of initiating the need to move to the CE in the EU. In recent years, there has been an increase in the amount of municipal waste generated in Poland as well as in the EU. According to Eurostat, the amount of municipal waste generated per one inhabitant of Poland increased from 272 kg in 2014 to 315 kg in 2017. It should be noted that the average amount of municipal waste generated in Poland in 2017 was one of the lowest in EU, with a European average of 486 kg/person. Poland has achieved lower levels of municipal waste recycling (33.9%) than the European average (46%). The reason for Poland’s worse results in the recycling of municipal waste may be, among others, the lack of sufficiently developed waste processing infrastructure, operating in other countries such as Germany and Denmark, and definitely higher public awareness of the issue of municipal waste in developed countries. Municipal waste management in Poland faces a number of challenges in the implementation of GOZ, primarily in terms of achieving the recycling values imposed by the EC, up to a minimum of 55% by 2025.
The chevkinite group of minerals are REE,Ti-silicates increasingly recognized as widespread accessory phases in a wide range of igneous and metamorphic parageneses. Members of the group are here recorded from five localities in Poland: a two-pyroxene andesite from the Kłodzko-Złoty Stok intrusion, a trachyandesite intrusion north of the Pieniny Mountains, a rapakivi-type granite from the Krasnopol intrusion, an anorthosite from the Suwałki Anorthosite Massif, and nepheline syenite from the Ełk syenite massif. Specific members found are chevkinite-(Ce), perrierite-(Ce) and, potentially, the Al-dominant analogue of perrierite-(Ce). The case is made that chevkinite-group minerals will, through systematic investigation, be found in a wide range of Polish igneous and metamorphic rocks.
This paper proposed a new OFDM scheme called damped zero-pseudorandom noise orthogonal frequency division multiplexing (DZPN-OFDM) scheme. In the proposed scheme, ZPN-OFDM non-zero part is damped to reduce its energy, thus the mutual interference power in-between the data and training blocks with conservative the pseudo-noise conventional properties required for channel estimation or synchronization. The motivation of this paper is the OFDM long guard interval working in wide dispersion channels, whereas a significant energy is wasted when the conventional ZPN-OFDM is used as well as the BER performance is also degraded. Moreover, the proposed scheme doesn’t duplicate the guard interval to solve the ZPN-OFDM spectrum efficiency loss problem. Both detailed performance analysis and simulation results show that the proposed DZPNOFDM scheme can, indeed, offer significant bit error rate, spectrum efficiency and energy efficiency improvement.
Worldwide commercial interest in the production of cerium doped yttrium aluminium garnet (YAG:Ce) phosphors is reflected in the widespread use of white light emitting devices. Despite of the fact that YAG:Ce is considered a “cool phosphor” it is the most important in white LED technology. This article reviews the developed techniques for producing phosphors with superior photoluminescence efficiency, including solid-state reaction, sol-gel and (co)precipitation methods. Also, by co-doping with rare earth elements, a red/blue shift is reached in the spectrum. The characteristics of YAG:Ce phosphors are investigated because the properties of the phosphors are strongly influenced by the synthesis routes and the sintering temperature treatment. After the phase analysis, morphology and emission studies of the phosphors there may be seen the conditions when the transition from the amorphous phase to the crystalline phase appears, when luminescent properties are influenced by the crystalline form, purity, average size of the particles, co-doping and so on.
The paper presents an application of Life Cycle Assessment (LCA) method for the environmental evaluation of the technologies for the fertilizers production. LCA has been used because it enables the most comprehensive identifi cation, documentation and quantifi cation of the potential impacts on the environment and the evaluation and comparison of all signifi cant environmental aspects. The main objective of the study was to assess and compare two technologies for the production of phosphorus (P) fertilizers coming from primary and secondary sources. In order to calculate the potential environmental impact the IMPACT 2002+ method was used. The fi rst part of the LCA included an inventory of all the materials used and emissions released by the system under investigation. In the following step, the inventory data were analyzed and aggregated in order to calculate one index representing the total environmental burden. In the scenario 1, fertilizers were produced with use of an integrated technology for the phosphorus recovery from sewage sludge ash (SSA) and P fertilizer production. Samples of SSA collected from two Polish mono-incineration plants were evaluated (Scenario 1a and Scenario 1b). In the scenario 2, P-based fertilizer (reference fertilizer – triple superphosphate) was produced from primary sources – phosphate rock.
The results of the LCA showed that both processes contribute to a potential environmental impact. The overall results showed that the production process of P-based fertilizer aff ects the environment primarily through the use of the P raw materials. The specifi c results showed that the highest impact on the environment was obtained for the Scenario 2 (1.94899 Pt). Scenario 1a and 1b showed the environmental benefi ts associated with the avoiding of SSA storage and its emissions, reaching -1.3475 Pt and -3.82062 Pt, respectively. Comparing results of LCA of P-based fertilizer production from diff erent waste streams, it was indicated that the better environmental performance was achieved in the scenario 1b, in which SSA had the higher content of P (52.5%) in the precipitate. In this case the lower amount of the energy and materials, including phosphoric acid, was needed for the production of fertilizer, calculated as 1 Mg P2O5. The results of the LCA may play a strategic role for the decision-makers in the aspect of searching and selection of the production and recovery technologies. By the environmental evaluation of diff erent alternatives of P-based fertilizers it is possible to recognize and implement the most sustainable solutions.
An important element of Internet of Things systems (IoT) is wireless data transmission. Narrowband Internet of Things (NB-IoT) and LTE Cat M1 (LTE-M) are the new standards for such transmission intended for LTE cellular networks. Cellular network operators has recently launched such transmission. The article presents the results of measurements of NB-IoT transmission parameters in this network, inside the building and in open urban areas. The main features of the NBIoT system and measuring equipment are briefly discussed.
Many granitic intrusions display evidence of magma mixing processes. The interaction of melts of contrasting composition may play a significant role during their generation and evolution. The Strzegom-Sobótka massif (SSM), located in the Sudetes (SW Poland) in the north-eastern part of the Bohemian Massif of the Central European Variscides, exhibits significant evidence of magma mingling on the macro- and micro-scales. The massif is a composite intrusion, with four main varieties: hornblende-biotite granite (with negligible amount of hornblende) and biotite granite in the western part, and two-mica granite and biotite granodiorite in the eastern part. Field evidence for magma mingling is easily found in the biotite granodiorite, where dark enclaves with tonalitic composition occur. Enclaves range from a few centimeters to half a meter in size, and from ellipsoidal to rounded in shape. They occur individually and in homogeneous swarms. The mixing textures in the enclaves include fine-grained texture, acicular apatite, rounded plagioclase xenocrysts, ocellar quartz and blade-shaped biotite. The most interesting feature of the enclaves is the presence of numerous monazite-(Ce) crystals, including unusually large crystals (up to 500 μm) which have grown close to the boundaries between granodiorite and enclaves. The crystallization of numerous monazite grains may therefore be another, previously undescribed, form of textural evidence for interaction between two contrasting magmas. The textures and microtextures may indicate that the enclaves represent globules of hybrid magma formed by mingling with a more felsic host melt. Chemical dating of the monazite yielded an age of 297±11 Ma.
The manuscript presents the condition of circular economy in Poland in diversified approach: subjective (waste streams, energy), sectoral (construction, wastewater treatment, coal energy), related to the resources (phosphorous and anthropogenic minerals) and considering proper energy management (almost zero energy buildings). The achievements reached in different sectors as well as the requirements towards implementation of CE are presented. The advancement of recycling technologies does not deviate from the global level, in terms of areas specific to Poland. Limiting the exploitation of natural resources and usage of new materials as well as producing more durable products are of CE concern. Also energy and heat recovery in buildings and technological processes (e.g. during wastewater treatment), ways of utilization of combustion by-products and water decarbonization waste are described. The implementation of CE in Poland needs not only research and technical activities, but also the modification of technological processes, the right policy, overcoming crosssectoral barriers, developing legal regulations and support schemes for CE.
At the turn of the twentieth and twenty-first century, the field of Arabic and Islamic studies became enriched by a number of multi-facetted scholarly theories challenging the traditional account on the early centuries of Islam. An author of one of them was the Israeli scholar Yehuda D. Nevo (1932–1992), working in archaeology, epigraphy and historiography. He devoted much of his career to the studying of Arabic rock inscriptions in the Negev desert, as well as to investigating literary and numismatic evidence of nascent Islam. In his theory, the gradual development of the Islamic faith, inspired by Abrahamism with an admixture of Judeo-Christianity, went through a stage of “indeterminate monotheism”. Not earlier than since the end of the second century A.H. one can speak of the formation of the dogmatic pillars of Islam, similar to those we know today. This paper is an attempt to sum up Nevo’s insightful input into the field of modern Islamic & Quranic studies today. Although controversial and unorthodox, many later researchers repeatedly refered to Nevo’s plenty of inspiring theses in their quest for facts on Islamic genesis lost in the maze of time and shifting memory of generations.