Search results

Filters

  • Journals
  • Authors
  • Contributor
  • Keywords
  • Date
  • Type

Search results

Number of results: 8
items per page: 25 50 75
Sort by:
Keywords weasels size

Abstract

Dr. Paulina Szafrańska from the PAS Mammal Research Institute in Białowieża explains why weasels range so greatly in size.
Go to article

Abstract

The length of crystalline cones (cc) is proportional to krill body length and this proportion can be described by the equation L cc = L krill x 1.679 + 52.032 ( cc — μm; L krill - mm). By measuring cc one can determine the size of krill with the precision of 2—3 mm. The structure of crystalline cones is not crystal, and the elemental composition includes much of S and Ca. Crystalline cones are often found in the stomach and feces of animals feeding on krill.
Go to article

Abstract

The paper aims at the empirical evaluation of the impact of bank size (as measured by median total assets) on the value relevance of two key accounting variables, i.e. book values of equity and net earnings, in terms of their joint explanatory power in the regression model and the relative responsiveness of bank market values to the changes in those variables. The research is based on the multiple linear regression analysis after controlling for the presence of fixed and random effects. The examined sample covers all domestically-based commercial banks listed on the Warsaw Stock Exchange over the period 1998–2017. The final pooled sample comprises 18 banks and 271 bank-year observations. The findings of the study suggest that the equity investors perceive the joint informational content of book values and earnings of larger banks as more value relevant in comparison to the accounting numbers reported by their smaller peers. The responsiveness of banks’ market values to the changes in each of the explanatory variables seems, however, to be affected by their size in a different way. As expected, book values of equity have turned out to be significantly more informative for smaller banks, whereas the evidence regarding the impact of size on the responsiveness of bank market values to the changes in net earnings is ambiguous. Although larger banks appear to exhibit a higher sensitivity of stock prices to variations in net earnings per share than their smaller peers, the difference between the examined subsamples is not statistically significant.
Go to article

Abstract

The paper includes a summary and a background of long-time research conducted by a research team in the Institute of Electrical Engineering and Computer Science at SilesianUniversity of Technology. The researchwork has principally been related to selected problems in the field of analysis and synthesis of systems aimed at symmetrisation and improvement of some power quality parameters. This paper constitutes a first part of the report on the research. It has been devoted to effective elimination of higher harmonics and reactive power compensation by means of parallel active power filters. The other problem discussed in this paper is related to this issue and it is very important from the economic point of view; it addresses optimal sizing and placement of active power filters in investigated power networks.
Go to article

Abstract

The problem of of the use of fly ash still constitutes a research and exploration area for scientists. This is due to the fact that, 6,000,000 Mg of coal combustion by-products (CCB) are storage on landfills yearly in Poland alone. One of the potential directions of using fly ash is to use it as a substrate in hydrothermal syntheses of mesoporous materials (synthetic zeolites). Zeolites are aluminosilicates with a spatial structure. Due to their specific structure they are characterized by a number of specific properties among others molecular-sieve, ion-exchange and catalytic that can be used in engineering and environmental protection. So far, the synthesis has been carried out using coal combustion by-products such as fly ash or microsphere. The article analyzes whether separation from the fly ash of the appropriate fraction (below 63 μm) will affect the formation of zeolite grains. The syntheses were carried out using class F fly ash and the fraction separated from it, which was obtained by sieving the ash through a 63 μm sieve. Chemical (XRF) and mineralogical (XRD, SEM-EDS) analyzes were carried out for substrates as well as the obtained reaction products. In the case of substrates, the analysis did not show any significant differences between the ash and the separated fraction. However, in products after synthesis (Na-X zeolite with a small amount of Na-P1 zeolite, and small amounts of quartz and unreacted aluminosilicate glass - mullite) higher aluminum and sodium contents were observed from the separated fraction, with a lower calcium and potassium content. A small proportion of illite was observed on the diffraction curve of the zeolite from the fraction. Observations of grain morphology showed no differences in formation. Based on the conducted analyzes, it can be stated that, considering the economics of the synthesis process, the separation of fine fractions from the fly ash does not affect the quality of the synthesis process.
Go to article

Abstract

Experiences of subregional cities in programming of urban renewal. The aim of the article is to analyze and evaluate the experience of selected subregional cities in revitalization programming. At the beginning, the strategic policy of the state towards subregional centers was defined. The guidelines from the National Spatial Development Concept, the National Urban Policy and the Strategy for Responsible Development were pointed out. Then, examine in detail the activities carried out so far in 4 cities, which as a result of the administrative reform in 1999 lost the status of the provincial city, i.e. in Ciechanów, Legnica, Piła and Przemyśl. Current documents have been characterized, in particular, the specificity of areas covered by revitalization has been described. Next, the leading directions of transformations of these areas were presented, resulting from the adopted revitalization policy. This allowed for the formulation of certain generalizations about the specificity of the process of renewal of degraded areas in subregional centers in Poland.
Go to article

Abstract

This article considers designing of a renewable electrical power generation system for self-contained homes away from conventional grids. A model based on a technique for the analysis and evaluation of two solar and wind energy sources, electrochemical storage and charging of a housing area is introduced into a simulation and calculation program that aims to decide, based on the optimized results, on electrical energy production system coupled or separated from the two sources mentioned above that must be able to ensure a continuous energy balance at any time of the day. Such system is the most cost-effective among the systems found. The wind system adopted in the study is of the low starting speed that meets the criteria of low winds in the selected region under study unlike the adequate solar resource, which will lead to an examination of its feasibility and profitability to compensate for the inactivity of photovoltaic panels in periods of no sunlight. That is a system with fewer photovoltaic panels and storage batteries whereby these should return a full day of autonomy. Two configurations are selected and discussed. The first is composed of photovoltaic panels and storage batteries and the other includes the addition of a wind system in combination with the photovoltaic system with storage but at a higher investment cost than the first. Consequently, this result proves that is preferable to opt for a purely photovoltaic system supported by the storage in this type of site and invalidates the interest of adding micro wind turbines adapted to sites with low wind resources.
Go to article

Abstract

The process of enrichment in a jig has usually been described and analysed using particle density as a separation feature. However, a degree of particle loosening in the jig bed is affected by, inter alia, the terminal particle free settling velocity which in turn is affected by the size, density and shape of a particle. Therefore, the terminal particle settling velocity clearly characterises the feed transferred to a jig for the enrichment process. Taking the comprehensive particle geometric (particle size and shape) and physical properties (particle density) into account comes down to the calculation of the terminal particle settling velocity. The terminal particle settling velocity is therefore a complex separation feature which comprises three basic particle features (particle density, size and shape). This paper compares the effects of enrichment of coal fines in a jig, for two cases: when the commonly applied particle density is separation feature and for the particle settling velocity. Particle settling velocities were calculated in the selected three particle size fractions: –3.15+2.00, –10.00+8.00 and –20.00+16.00 mm based on the industrial testing of a jig for coal fines and detailed laboratory tests consisting in determining particle density, projective diameter and volume and dynamic particle shape coefficient. The calculated and drawn partition curves for two variants, i.e. when particle density and particle settling velocity were taken into account as the separation argument in selected particle size fractions, allowed to calculate and compare separation precision indicator. With the use of a statistical test, the assumption on the independence of random variables of the distribution of components included in the distribution of the particle settling velocity as a separation feature during enrichment in a jig was verified.
Go to article

This page uses 'cookies'. Learn more