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Discrete and Continuous Dynamical Systems
No full textThe Restricted Planar Circular 3-Body Problem models the mo- tion of a body of negligible mass under the gravitational influence of two mas- sive bodies, called the primaries, which perform circular orbits coplanar with that of the massless body. In rotating coordinates, it can be modelled by a two degrees of freedom Hamiltonian system, which has five critical points called the Lagrange points. Among them, the point L3 is a saddle-center which is collinear with the primaries and beyond the largest of the two. The papers [3, 4] provide an asymptotic formula for the distance between the one dimensional stable and unstable manifolds of L3 in a transverse section for small values of the mass ratio 0 < μ ≪ 1. This distance is exponentially small with respect to μ and its first order depends on what is usually called a Stokes constant. The non-vanishing of this constant implies that the distance between the invariant manifolds at the section is not zero. In this paper, we prove that the Stokes constant is non-zero. The proof is computer assisted.preprin
Solar Energy
No full textThe exponential increased use of PV panels for energy production would also lead to enormous volumes of PV waste that need to be dealt with in an environmentally responsible manner. In this work we present experimental results for recycling crystalline silicon (c-Si) PV panels using recently developed electrohydraulic shock wave-based fragmentation of PV panels. The electrohydraulic fragmentation process allows for the efficient delamination of the modules and subsequent recovery of almost all valuable materials used in the manufacturing of PV panels, without thermally decomposing the polymers and eliminates creation of any toxic or hazardous waste during the process. We study the impact of the type of panel, size of the feed material and process duration on the quantity and quality of material recovered after the process.sprawozdaniewersja wydawnicz
Renewable Energy
No full textAgricultural digestate is a by–product of biogas plant processes. Its composition is variable and depends on the type of raw feedstock used. Due to its high moisture content the digestate is suitable for hydrothermal
carbonization (HTC). The HTC process is performed in a reactor where the feedstock is heated to a high temperature in an aqueous environment. As a result of the reaction, a solid product, process water and a gaseous
product are generated. The gaseous product is obtained in trace amounts unlike the process water where the amount is significant. The rich in carbon solid product of the HTC process is hydrochar. Hydrochars can be used as an alternative to non–renewable fossil fuels. The aim of this paper was to investigate and characterize hydrochars derived from agricultural digestate at 190 ◦C, 200 ◦C and 210 ◦C and residence times of: 0.5, 1, 1.5,
and 2 h. In addition, the fuel properties and combustion performance supported by an activation energy determination were evaluated. In brief, it was found that a higher temperature and longer residence time produced a more carbonaceous biofuel.innypreprin
Geomatics and Environmental Engineering
No full textThis article is devoted to studying the peculiarities of applying the valuation approach toward assessing the efficiency of agricultural land use. In particular, it was determined that the main link of the valuation approach was the value of the land use. Value is the basis of quantitative correlation under the equivalent exchange, the value of land use can be determined by applying three common approaches: comparison, cost, and income. The authors of the research present a methodology for assessing the value of the right to manage agricultural land use and its efficiency. The work supplies the calculated book value of land use under the actual status of agricultural lands in Ukraine according to the average indicators (in the present research, this was the period of 2017–2021) and the economic market value of land use while considering innovative investments in land improvement that are focused on establishing the more effective use of agricultural lands. It is stated that the valuation approach toward assessing the efficiency of agricultural land use can be used to specify the value of the right to manage land use in the amount of its general value as well as assess its efficiency. The suggested algorithm and statistical indicators were used to calculate the right and efficiency of agricultural land use management for all categories of farms and, particularly, in terms of agricultural enterprises of the different forms of economic activity.Krakówwersja wydawnicz
Quizlet – gra grupowa
No full textCykl: Dasie i Niedasie: https://www.cel.agh.edu.pl/dasie-i-niedasie/film instruktażow
Geology, Geophysics & Environment
No full textWe present an experimental study that explores the feasibility of using the ash from biogenic deposits for laser textural analysis. The results have demonstrated that conducting ash textural analysis without prior chemical treatment can lead to unreliable results. Among other things, this is due to the “contamination” of the ash with aggregates formed by metal oxides and carbonates during ignition ( procedure) in a muffle furnace. Metal oxides and carbonates can create aggregates with silt and clay grains. As a result, the material coarsens, mainly to very coarse and coarse silt fractions. It is illustrated that the ash after has been contaminated with oxides and carbonates of iron (Fe), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), sodium (Na), zinc (Zn), lead (Pb) and copper (Cu). Thus, we suggest a method of using 10% HCl to purify the ash from metal oxides and carbonates (so-called ash purification procedure or APP). The analysis in this paper focuses on the grain size composition of ash, both untreated and HCl-treated. The obtained results have been compared and discussed in detail.Krakówwersja wydawnicz
Composites Part A: Applied Science and Manufacturing
No full textThe growing demand for lightweight and robust materials drives the development of polymer-based and fiber-reinforced composites. Here, using short fibers offers several advantages; however, currently employed methods for producing short fibers, such as homogenization, result in a wide dispersion of dimensions in the produced fibers, which is an undesirable effect in composite materials. In this study, electrospinning is used to produce polymer short fibers directly. This research highlights, for the first time, the differences in the electrospinning process dynamics between short and continuous fibers. By adjusting parameters: voltage and distance, we control dimensions of short fibers below 1 µm in diameter and around 4 µm in length to a few microns in diameter and approximately 14 µm in length. Direct electrospinning of short fibers offers significant advantages, including a narrow size distribution and reproducibility compared to chopped continuous fibers with homogenization.wersja wydawnicz
Opuscula Mathematica
No full textIn this study, we addressed the nonoscillation of th Sturm-Liouville differential equation with a differential operator, which corresponds to a proportional-derivative controller. The equation is a conformable linear differential equation. A Wintner-type nonoscillation theorem was established to be applied to such equations. Using this theorem, we provided a sharp nonoscillation condition that guarantees that all nontrivial solutions to Euler-type conformable linear equations do not oscillate. The main nonoscillation theorems can be proven by introducing a Riccati inequality, which corresponds to the conformable linear equation of the Sturm-Liouville typeKrakówwersja wydawnicz
Studia Humanistyczne AGH
No full textThe aim of this article is to show that referring to the concept of well-being in a broad sense (not only in terms of physical health, but also in an emotional or social sense) is used in food advertising to encourage consumers to purchase food products. However, referring to the idea of wellbeing in food advertising does not necessarily imply building a ‘positive food culture’, that is, one that supports healthy eating habits (Mingay et al., 2021), as it can also be found in advertisements for sweets or fast food. One of the theoretical references used in the article is the concept of food for wellbeing (Block et al., 2011), which complements the hitherto popular food for health concept.Celem artykułu jest pokazanie, że nawiązanie do pojęcia dobrostanu w szerokim rozumieniu (nie tylko w aspekcie zdrowia fizycznego, ale również w sensie emocjonalnym czy społecznym) wykorzystuje się w reklamach żywności, aby zachęcić konsumentów do nabywania produktów spożywczych. Samo odwoływanie się do idei dobrostanu w reklamie żywności nie oznacza jednak budowania „pozytywnej kultury żywieniowej”, to znaczy takiej, która wspiera zdrowe nawyki żywieniowe (Mingay et al., 2021), ponieważ takie nawiązania można znaleźć również w reklamach słodyczy czy jedzenia typu fast food. Jednym z zastosowanych w artykule odniesień teoretycznych jest koncepcja food for wellbeing (Block et al., 2011), która stanowi uzupełnienie popularnej dotychczas koncepcji food for health.Krakówwersja wydawnicz
Mining - Informatics, Automation and Electrical Engineering
No full textGreenhouse gases and their emissions are issues that are being increasingly discussed due to climate change. Next to carbon dioxide, methane is considered one of the most important greenhouse gases. Reducing methane emissions could result in noticeable environmental benefits in a short time. Anthropogenic emissions constitute approximately 60 of total methane emissions and thus solutions to reduce emissions of this gas are most often sought in this sector. The subject of the study is the methane capture system in the “Pniówek” mine, belonging to the Upper Silesian Coal Basin (southern Poland), and the potential for methane management using a trigeneration system. The article discusses the utilization of methane from hard coal mines to reduce its emissions into the atmosphere and as a profitable solution to use the emitted gas. The authors describe a trigeneration system in which methane from the mine is burned in gas engines and used to produce electricity, heat, and cooling energy. This allows for reducing methane emissions into the atmosphere while increasing the efficiency of coal use. The article shows the results of measurements carried out in a hard coal mine in Poland. The presented example indicates the ecological and economic benefits resulting from the use of a trigeneration system.Krakówwersja wydawnicz