In the constant pursue of the sustainability of socio-industrial systems, the definition of useful, reliable and informative, and at the same time simple and transparent, indicators is an important step for the evaluation of the circularity of the assessed systems. In the circular economy (CE) context, scientific literature has already identified the lack of overarching indicators (social, urban, prevention-oriented, etc.), pointing out that mono-dimensional indicators are not able to grasp the complexity of the systemic, closed-loop, feedback features of CE. In this respect, Emergy accounting is one of the approaches that have been identified as holding the potential to capture both resource generation and product delivery dimensions and therefore to provide an enhanced systems’ evaluation in a CE perspective.
Because of Emergy’s intrinsic definition and its calculation structure, Emergy-based indicators conceptually lend themselves very well to the evaluation and monitoring of circular processes. Additionally, Emergy has the unique feature of enabling the evaluation of systems that are not necessarily only technosphere systems, but also of technological systems which embed nature (techno-ecological systems).
The present paper gives a perspective on a set of Emergy-based indicators that we have identified as suitable to evaluate circular systems, and outlines the different perspective compared to the circularity indicators defined in the “Circularity Indicators Project” launched by the Ellen MacArthur Foundation.
Bioeconomy is an important element of the Polish economy and the basis of bioeconomy is innovative biotechnology. The development of bio-economy (especially in closed circuit) requires modern “bio” technology. The resignation of such elements in the economy as achievements of modern biotechnology – albeit possible – is associated with a significant increase in development costs and the loss of access to innovative technologies that are essential for the today and future economy of the country. It is necessary to gain public acceptance for the emerging market of bioproducts, bioservice and bioprocesses. Legislation ammendment supporting innovation in general, and bio domains in particular, is a necessity. The current state of Polish biotechnology is presented on the basis of detailed studies and published on the website of the Biotechnology Committee of the Polish Academy of Sciences: “Biotechnological centers in Poland – MAP OF POLISH BIOTECHNOLOGY”; on this page you will find as well this report (www.kbiotech.pan.pl).
Analytical relations, describing the electrical fields of cylindrical piezoceramic radiators with circular polarization as a member of the cylindrical systems with the baffle in the inner cavity, using the related fields method in multiply connected regions were obtained. Comparative analysis of the results of numerical experiments performed on the frequency characteristics of the electric field of the radiating systems for different modes of radiation allow to establish a number of subtle effects of the formation of the electric field of radiators.
Steel yielding arch support constructed of V profiles is commonly used to protect galleries and, in some cases, to reinforce or secure a shaft support. For this purpose, a closed, circular-shaped arch support is used, with arches overlapped by clamps that are typical for this type of construction. The support has high resistance to the impact of even (distributed over the entire surface of the support) load, however, as a result of significant deformation associated with a change in the radius of the curvatures, the support shows limited yielding capacity. This is due to the increase in resistance to slide on the locks, resulting from changes in the geometry of the ring caused by the rock mass. This article presents the results of research and analysis concerning the elements of the arch support with notches in arches. The research team tested the effect of the depth and location of the notches of the section’s flanges on the load impacting on the clamp’s bolts and the strength of the roof support. Moreover, the tests covered the influence of the number and location of clamps in a frictional joint on the change in the nature of work and yielding capacity. Finally, the research included both strength tests of the support’s elements, as well as strength analyses based on the finite element method.
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 concept of a Circular Economy assumes that the value of products, materials and resources is to be maintained in the economy for as long as possible to ultimately reduce waste generation to a minimum. In this concept, raw materials are repeatedly put into circulation many times, often passing from one branch of industry to another. So energy, water, metal ores, oil, gas, coal and others, and wherever possible, their replacement with renewable resources (wind and solar energy, natural resources). It is important, and this is the essence of the Circular Economy, the maximum re-use of scarce materials and raw materials from already produced and used products. This concept has found the support of the European Commission and activities in this area will successively be implemented through appropriate legal acts of the European Union. The need to implement solutions in the field of minimizing the consumption of raw materials, materials and energy or reducing waste production is also felt by consumers and industry. The packaging industry is particularly interested in implementing the concept of a Circular Economy. Due to the dynamic growth of the packaging market, which in 2017 reached around EUR 9.6 billion in Poland (data from the Polish Chamber of Packaging) and the increasing amount of post-consumer waste, it is necessary to introduce solutions limiting the consumption of raw materials and energy throughout the product life cycle.
The aim of the article is to present current practices regarding the reduction of the negative impact of packaging on the environment and the indication of directions for the implementation of the Circular Economy concept in the packaging industry.
The circular economy model is based on several priority areas, including biomass and bio-based products. Focusing on them and their use should certainly take their cascading into account use, including how energy from waste from the wood industry is managed. Biomass is one of the most frequently used renewable energy sources in Poland, and in the European Union it satisfies 6% of primary energy. The CE (Circular Economy) model assumes that the reuse, processing and regeneration of a product requires less resources and energy, and is more economical than conventional material recycling, as low quality raw materials. The current model of waste management must take energy recovery into account, without which it is impossible to close the balance sheet of management of many groups of waste. This is also important from the economic point of view. Chemical energy, which is contained in a large part of waste, can be used for energy purposes, including the production of electricity and heat. Reducing the use of raw materials is the most effective environmental approach to solving the waste problem. However, this requires reducing the extraction and consumption of materials, challenging existing production and consumption patterns. In the circular economy model there is a huge difference in approach to recycling leading to new products that create transport and production, new jobs and possible GDP (Gross Domestic Product) growth. The aim of the study is to analyze the use of waste from the wood industry and to present possible solutions for its cascade use, taking the currently implemented circular economy model (CE) into account.
The purpose of this study is to find the value of the discharge coefficient (Cd) on a sieve with a circular perforated plate so that it can be used for application in the field. The method used is to make a physical model test of the screen weir in the laboratory with a width of 40 cm and a length of 797 cm, then the screen is made variations in the diameter of the hole 6, 8, 10 and 12 mm, flowrate Q = 453–4 481 cm3∙s–1 and the slope of the screen θ = 20–45°. The result was quite ef-fective, the sediment did not enter above the screen and did not clog the screen even the catch was quite good about 80% of the screen rods. The discharge coefficient (Cd) is directly proportional to the square value of the number Froude (Fr), the slope of the screen (θ) and the ratio of distance, diameter of the screen (a:d) and inversely proportional to the value of the specific energy square (E). From modelling the average value of the discharge coefficient (Cd) between 0.1–2.75 with NSE = 0.71, MAE = 0 and RMSE = 0.12.
Mining wastes are by-products generated during search, excavation and processing, both physical and chemical, of ores and other minerals. In 2017, wastes from group 01 constituted 60% of total wastes produced in Poland. According to the statistical data, approximately 92% of the waste generated during the excavation and processing of hard coal is economically reused. 30% of this waste used in industry and nearly 70% is used for the reclamation of the degraded industrial areas. At present, there is a tendency in the E uropean Union to shift from a linear economy to the Circular E conomy. The goal is to maintain economical value of the resources, among others, by their reuse in a productive way, which at the same time eliminates waste. One of the industrial branch where the ideals of a Circular E conomy can be implemented is the mining industry. Mining wastes may form one of the sources of anthropogenic minerals, as they belong to alternative aggregates. Deposits of anthropogenic minerals are considered sources of valuable raw materials which guarantee that the products made on their basis will be of high quality. The article presents the results of physico-chemical tests, the leachability of contaminations and phytotoxicity tests carried out on the basis of the selected mining waste in light of a Circular E conomy.
In this work, steady flow-field and heat transfer through a copper-water nanofluid around a rotating circular cylinder, dissipating uniform heat flux, with a constant non-dimensional rotation rate varying from 0 to 5 was investigated numerically using a finite-volume method for Reynolds numbers from the range 10–40. Furthermore, the range of nanoparticle volume fractions considered is 0–5%. The variation of the local and the average Nusselt numbers with Reynolds number, volume fractions, and rotation rate are presented for the range of conditions. The average Nusselt number is found to increase with increasing the nanoparticle volume fractions and decrease with increasing value of the rotation rate.
The theoretical estimation of sound absorption coefficient of a surface may give very different results. This will depend on the type of sound field assumed in the theoretical model used for the estimation of its sound absorption coefficient. Absorption coefficients for normal and diffuse sound fields are widely known, although they may be far from the absorption values given by an absorbing material when it is finally installed inside a room or enclosed space, where a sound field closer to a spherical wavefront is more likely to be found. This work presents a theoretical study, which is addressed at obtaining a mathematical expression to calculate the sound absorption coefficient for a variable range of incidence angles, called αs. The presented method uses a circular sound field incidence as an approximation to a spherical incidence. The estimation of this coefficient αs is based on obtaining the incident and reflected sound fields for a surface located facing a lineal source. The advantage of this calculation method over others lies on its capability to give results for circular, normal and random wave incidence depending on the range of incidence angles considered in the calculation.