On the Risk of Currency Crisis

Traders and investors are often exposed to the currency risk during their market operations. This risk includes the risk of currency crisis. Economists avoid precise defining of such economic disaster in literature, which complicates calculations of the risk of a currency crisis. In this paper, we suggest a few definitions and implications of these definitions - operational measures of the risk of currency crisis as well as empirical examples.Handlowcy i inwestorzy, dokonując transakcji, często są narażeni na ryzyko walutowe. Ryzyko to obejmuje ryzyko kryzysu walutowego. W literaturze przedmiotu ekonomiści unikają jednak precyzyjnego definiowania tego kryzysu, co komplikuje rachunek jego ryzyka. W niniejszym artykule proponujemy pewne definicje oraz wynikające z nich operacyjne miary ryzyka kryzysu walutowego oraz empiryczne przykłady liczbowe.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

Push-Out Method for Micro Measurements of Interfacial Strength in Aluminium Alloy Matrix Composites

The main goal of this work was the evaluation of the interfacial strength of the carbon fibres/aluminium matrix interface dependently on the utilised composite fabrication method, namely high pressure die casting and gas pressure infiltration. In addition, the influence of a Ni-P coating on the C-fibres was investigated. The proposed measurements of the interfacial strength were carried out by means of the “push-out” method. The interfacial strength of the samples fabricated using the high-pressure infiltration method average between 19.03 MPa and 45.34 MPa

Price Inflation of Financial Goods

This paper includes a description of measurement methods of Polish inflation of financial lnstruments and graphic presentation oľ Ume series obtained quarterly from 1993.2 to 2000.3, as Well as economic comments on the results. Inflation of financial instruments is constructed as indices of aggregate returns from those assets. The formulas mentioned above were made °n the well known Laspeyres-type and Paashe-type index basis and applied to Polish financial markets of money, stocks and bonds.Celem artykułu jest omówienie wzorów obliczeniowych tzw. cenowej inflacji finansowych dóbr inwestycyjnych polskiej gospodarki, rozumianych jako indeksy zespołowe zyskowności z tych dóbr, prezentacja graficzna otrzymanych kwartalnych szeregów czasowych tych indeksów za okres 1993.2-2000.3, a także ekonomiczny komentarz do otrzymanych szeregów. Obliczenia dotyczą polskich finansowych rynków pieniądza, akcji i obligacji. W rachunkach wykorzystano znany wzór na indeks Laspeyresa i Paaschego.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

Price Inflation of Financial Goods

This paper includes a description of measurement methods of Polish inflation of financial lnstruments and graphic presentation oľ Ume series obtained quarterly from 1993.2 to 2000.3, as Well as economic comments on the results. Inflation of financial instruments is constructed as indices of aggregate returns from those assets. The formulas mentioned above were made °n the well known Laspeyres-type and Paashe-type index basis and applied to Polish financial markets of money, stocks and bonds.Celem artykułu jest omówienie wzorów obliczeniowych tzw. cenowej inflacji finansowych dóbr inwestycyjnych polskiej gospodarki, rozumianych jako indeksy zespołowe zyskowności z tych dóbr, prezentacja graficzna otrzymanych kwartalnych szeregów czasowych tych indeksów za okres 1993.2-2000.3, a także ekonomiczny komentarz do otrzymanych szeregów. Obliczenia dotyczą polskich finansowych rynków pieniądza, akcji i obligacji. W rachunkach wykorzystano znany wzór na indeks Laspeyresa i Paaschego

ECONOMIC EFFICIENCY OF WEED CONTROL METHODS IN WINTER WHEAT CULTIVATION ON LARGE-SCALE FARMS

In modern agriculture, on large-scale farms using monoculture, reduced tillage and intense chemical protection, the phenomenon of herbicide resistance in weeds is the cause of ecological and economic losses. More and more attempts are made to answer the question about the profitability of reducing agrotechnical treatments and intensifying chemical methods of weed control with a simultaneous intensification of the problem of herbicide resistance in weeds occurring in winter wheat crops, which dominates the structure of cereal sowing in Poland. The main objective of the study was to evaluate the costs of weed control for winter wheat cultivation on large-scale farms where there was no problem of weed resistance and on farms where resistant biotypes were identified. The research was based on a survey conducted among owners of farms cultivating winter wheat in 2019. The collected data were elaborated using basic methods of descriptive statistics and economic analysis. Based on the research results, it was found that with an increase in the area of farms, reduced tillage and monoculture are used more frequently than conventional tillage and crop rotation. At the same time, the commonly used chemical weed control methods are more frequently applied than mechanical ones. Economic efficiency indicators for winter wheat protection against weeds indicate a decrease in this efficiency with an increase in farm size. This is because the larger the farms, the more frequently the occurrence of resistant weed biotypes, which was confirmed by laboratory tests, and farmers more often assumed that such a problem occurred on their farms

ECONOMIC EFFICIENCY OF WEED CONTROL METHODS IN WINTER WHEAT CULTIVATION ON LARGE-SCALE FARMS

In modern agriculture, on large-scale farms using monoculture, reduced tillage and intense chemical protection, the phenomenon of herbicide resistance in weeds is the cause of ecological and economic losses. More and more attempts are made to answer the question about the profitability of reducing agrotechnical treatments and intensifying chemical methods of weed control with a simultaneous intensification of the problem of herbicide resistance in weeds occurring in winter wheat crops, which dominates the structure of cereal sowing in Poland. The main objective of the study was to evaluate the costs of weed control for winter wheat cultivation on large-scale farms where there was no problem of weed resistance and on farms where resistant biotypes were identified. The research was based on a survey conducted among owners of farms cultivating winter wheat in 2019. The collected data were elaborated using basic methods of descriptive statistics and economic analysis. Based on the research results, it was found that with an increase in the area of farms, reduced tillage and monoculture are used more frequently than conventional tillage and crop rotation. At the same time, the commonly used chemical weed control methods are more frequently applied than mechanical ones. Economic efficiency indicators for winter wheat protection against weeds indicate a decrease in this efficiency with an increase in farm size. This is because the larger the farms, the more frequently the occurrence of resistant weed biotypes, which was confirmed by laboratory tests, and farmers more often assumed that such a problem occurred on their farms

Hydrophobic and Anti-Icing Behavior of UV-Laser-Treated Polyester Resin-Based Gelcoats

Ice accumulation on wind turbine blades due to the impact of supercooled water droplets can be reduced by the application of surfaces with anti-icing properties. Hydrophobic surfaces are considered as a promising solution because of their water repellent behavior. In recent years, short-pulsed laser technologies have been developed as an efficient technique to modify the surface properties of materials. However, the anti-icing properties of such surfaces have not yet been validated. In this work, a hybrid modification of polyester resin-based gelcoats was adopted. Laser patterning (LP) was used to produce periodic surface structures on modified unsaturated polyester resin (UPR) substrates. One of the innovations of this research is the utilization of novel purpose-made chemical modifiers for gelcoats. The implementation of linear polymethylhydrosiloxane (PMHS) as a building block is a key improvement in terms of durability and functionality of the coating, since there is an option of introducing not only groups bonding in the polyester into one molecule, but also groups that increase hydrophobicity. The other novelty is a successfully conducted experiment combining such chemical modification with laser texturization of the surface. The influence of the laser energy, pattern shape, and spatial periods on the topographical characteristics and hydrophobicity as well as the anti-icing properties of the produced surfaces were investigated. To characterize the surface topography of the produced structures, scanning electron microscopy (SEM) and profilometer were utilized. Measurements of the wettability parameters (static contact angle and contact angle hysteresis) on the treated surfaces allowed the identification of the influence of wetting behavior and laser parameters on the investigated materials. Anti-icing properties were characterized by ice adhesion (IA) and freezing delay time (FDT) tests. It was found that hybrid modification of unsaturated polyester resin by chemical modifiers and laser treatment increased the hydrophobic and anti-icing properties of polyester gelcoats.This research was funded by National Centre for Research and Development (NCBiR), grant number LIDER/16/0068/L-9/17/NCBR/2018.Peer reviewe

A Wind Tunnel Experimental Study of Icing on NACA0012 Aircraft Airfoil with Silicon Compounds Modified Polyurethane Coatings

Ice formation on the aerodynamic surfaces of an aircraft is regarded as a major problem in the aerospace industry. Ice accumulation may damage parts, sensors and controllers and alter the aerodynamics of the airplane, leading to a range of undesired consequences, including flight delays, emergency landings, damaged parts and increased energy consumption. There are various approaches to reducing ice accretion, one of them being the application of icephobic coatings. In this work, commercially available polyurethane-based coatings were modified and deposited on NACA 0012 aircraft airfoils. A hybrid modification of polyurethane (PUR) topcoats was adopted by the addition of nanosilica and three-functional spherosilicates (a variety of silsesqioxane compound), which owe their unique properties to the presence of three different groups. The ice accretion on the manufactured nanocomposites was determined in an icing wind tunnel. The tests were performed under three different icing conditions: glaze ice, rime ice and mixed ice. Furthermore, the surface topography and wetting behavior (static contact angle and contact angle hysteresis) were investigated. It was found that the anti-icing properties of polyurethane nanocomposite coatings strongly depend on the icing conditions under which they are tested. Moreover, the addition of nanosilica and spherosilicates enabled the reduction of accreted ice by 65% in comparison to the neat topcoat