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Number of results: 100
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Abstract

We consider a four-level system with two subsystems coupled by weak interaction. The system is in thermal equilibrium. The thermodynamics of the system, namely internal energy, free energy, entropy and heat capacity, are evaluated using the canonical density matrix by two methods. First by Kronecker product method and later by treating the subsystems separately and then adding the evaluated thermodynamic properties of each subsystem. It is discovered that both methods yield the same result, the results obey the laws of thermodynamics and are the same as earlier obtained results. The results also show that each level of the subsystems introduces a new degree of freedom and increases the entropy of the entire system. We also found that the four-level system predicts a linear relationship between heat capacity and temperature at very low temperatures just as in metals. Our numerical results show the same trend.
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Authors and Affiliations

Oladunjoye A. Awoga
Akpan A. Ikot
Eno E. Ituen
Louis E. Akpabio
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Abstract

Species composition and density of Gastrotricha in bottom sediments were studied, on an annual basis, in the littoral of the mesotrophic Lake Piaseczno (Łęczyńsko-Włodawskie Lakeland). The number of species from spring to autumn remained on the same level (from 24 in spring to 22 in autumn), but in winter in littoral of the lake there were recorded only 8 species. Species diversity expressed by the Shannon index, in spring, summer and autumn was high and amounted 2.86; 2.69 and 2.77 respectively. In winter the value of the index was significantly lower and amounted 1.80. In individual seasons the mean density of Gastrotricha valued from 50 103 indiv. m-2 during winter to 1238 103 indiv. m-2 in spring. The density of Gastrotricha in spring was more than 24 times higher than that winter. There were no significant differences in species diversity Gastrotricha from spring to autumn, although the peak abundance was recorded in the spring. It is necessary to add, that the density of Gastrotricha during the spring peak was one order of magnitude higher from that in summer and autumn. The similarity of the fauna found in winter to the fauna occurring in other seasons, is significantly low, ranging from 24 to 27%. Seasonal changes in amount and diversity of the gastrotrich fauna are probably the result of temperature changes and food availability.
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Authors and Affiliations

Teresa Nesteruk
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Abstract

The research was carried out on species diversity, density and similarity of Gastrotricha living on two species of macrophytes Myriophyllum spicatum L. and Elodea canadensis Michx. in a mesotrophic lake. Gastrotricha occurring on the studied macrophytes were represented by 23 species (21 on M. spicatum L. and 22 on E. canadensis Michx.). Species diversity (expressed by the Shannon index) for the Gastrotricha occurring on the two studied species of macrophytes amounted to 2.70 for M. spicatum L. and 2.81 for E. canadensis Michx., what suggests equal distribution of the gastrotrich species revealed in the studied species of macrophytes. The definite dominants inhabiting the two species of macrophytes were: Heterolepidoderma macrops Kisielewski, 1981, Heterolepidoderma ocellatum (Mečnikow, 1865), Lepidoderma squamata (Dujardin, 1841) and Aspidiophorus squamulosus Roszczak, 1936, and their inclusive percentage participation in the whole gastrotrich fauna for M. spicatum L. and E. canadensis Michx. was 41.8 and 40.3% respectively. The domination structure of the gastrotrich fauna of the two species of macrophytes was similar for each gastrotrich species (G-test, for all p > 0.05). Average density of Gastrotricha inhabiting M. spicatum L. amounted to 588.0 10³ indiv. m-2, and density of Gastrotricha occurring on E. canadensis Michx. amounted to 670.0 10³ indiv. m-2. Statistic analysis based on the Mann-Whitney test showed that differences of the gastrotrich densi-ty on the studied species of macrophytes: M. spicatum L. and E. canadensis Michx. (Z = -1.9282; p = 0.05) are statistically insignificant.
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Authors and Affiliations

Teresa Nesteruk
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Abstract

Euphorbia epithymoides L. population has been the object of research both of the geobotanists as well as the ecologists for the last few year. The purpose of the research is efficient protection of this rare species occupying the scattered stations on Silcsian Upland. Euphorbia epithymoides L. population on the plot in Dąbrowa Górnicza - Sikorka occupies three characteristic habitat types, signed in the study as: I - pits of dump, 11 - flat plots, Ill - larch canopy. Greatest density of individuals occures under larch canopy. However the relation of blooming individuals to barren individuals is more profitable on the flat plot. TI1e spatial structure of investigated population is cluster - random, which is a typical phenomena for the plants with vegetative reproduction. The results we have obtained so far have shown that there arc many blooming individuals on the selected areas, although reproduction of this population occurs by vegetation. The small growth of numerical force of the euphorbia population proves that this species is endangered.
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Authors and Affiliations

Teresa Zaufał
Beata Babczyńska-Sendek
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Abstract

IR spectroscopy, density and ultrasonic velocity measurements have been carried out for aluminum lithium phosphate glasses with and without MoO3. The observed changes in the FTIR spectra of the glasses were related to the modifier/former role of molybdenum ions. The results revealed that the density increases with increasing MoO<sub>3</sub> content, which was attributed to the increase in the compactness and packing of the glass network. The ultrasonic data were analyzed in terms of creation of new bonds of MoO<sub>3</sub> attached to phosphate units. The new bonds increased the average crosslink density and the number of network bonds per unit volume along with a strengthening of the different modes of vibrations which in its turn increased the ultrasonic velocity, the rigidity and hence the elastic moduli of the glasses.

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Authors and Affiliations

Yasser B. Saddeek
S.M. Abo-Naf
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Abstract

The studies were carried out in Wielkopolska region (western Poland) in oat and winter rye cultures. Density and species structure of Thysanoptera were studied. Average density of adult Thysanoptera on oat reached 371.4 individuals/m2, and was higher than on rye, where it reached 107.5 individuals/m2. Limothrips cerealium Haliday was a dominant species on oat as well as on winter rye.

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Authors and Affiliations

Danuta Szeflińska
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Abstract

The article presents the phenomenon of intermediate city defined by Thomas Sieverts in his book titled Zwischenstadt (the title of the English edition: Cities Without Cities). The intermediate city represents — according to the author — a new urban form emerging between historical compact cities. Thomas Sieverts is not enthusiastic about such development, but he believes it to be inevitable. If that was the case we will have to accept it and revise our values. We need to regard the intermediate city not only as a threat but also as a chance for new development and new challenge for planning and urban design. The intermediate city is emerging also in our region — around Krakow. Some elements of the development are discussed — also the ones offering chances for positive changes.
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Bibliography

Dunphy, R. et al. (2004), Developing Around Transit — Strategies and Solutions That Work, Washington D.C.: ULI-the Urban Land Institute.
Sieverts, T. (2003), Cities without Cities — an Interpretation of the Zwischenstadt, London, New York: Spon Press; wydanie niemieckie (2000), Zwischenstadt, Szwajcaria: Birkhauser.
Spyrka, W. (2017), Planowanie korytarzy osiedleńczych w oparciu o sieć transportu zbiorowego — przykład pasma Doliny Raby, praca doktorska, Kraków: Politechnika Krakowska, Wydział Architektury.
Żakowska, L., Bieda, K. (2014), Accessiility as a Criterion for Urban Design of Neighbourhood Areas, Porto: CITA 7 Annual Conference Bridging Implementation Gap.
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Authors and Affiliations

Krzysztof Bieda
1
ORCID: ORCID

  1. Podhalańska Państwowa Uczelnia Zawodowa w Nowym Targu, Instytut Nauk Technicznych
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Abstract

The main theme of this paper is to study two important aspects of precise geoid determination using Helrnerts second method of condensation. This work illustrates via numerical investigations the importance of using actual density information of topographical bulk and the effects that different gravimetric reductions have on gravity interpolation in Helmert geoid computational process, in addition to the commonly used Bouguer scheme. A rugged area in the Canadian Rockies bounded by latitude between 49°N and 54°N and longitude between 236°E and 246°E is selected to carry out numerical investigations. The lateral density information is used in all steps of the Helmert geoid computational process. The Bouguer and residual terrain modelling (RTM) topographic reductions, the Rudzki inversion scheme, and the topographic-isostatic reductions of Pratt-Hayford (PH) and Airy-Heiskanen (AH) are used for gravity interpolation. Results show that the density information should be applied in all steps of the Helmert geoid computational process and that the topographic-isostatic gravimetric reduction schemes like the PH or AH models or the RTM reduction, should be applied for smooth gravity interpolation instead of the commonly used Bouguer reduction scheme for precise Helmert geoid determination.
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Authors and Affiliations

Sujan Bajracharya
Michael G. Sideris
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Abstract

The paper approaches an important issue of the phonological similarity of words, relevant for current research in phonotactics, word recognition, production and acquisition, by analyzing the data collected in an experiment in which 30 native speakers of Polish were asked to provide phonologically similar words to 80 nonwords. The study demonstrates that the uncovered patterns of phonological similarity (segment substitutions, deletions and additions, the use of bigrams, trigrams and quadrigrams, noncontiguous sounds and segment metathesis) go beyond the commonly employed concept of neighbourhood density and point to the need to revise the current approaches to phonological similarity of words. It is argued that the experimental results can be attributed to the considerably more complex phonotactic and morphological structure of Polish than English.

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Authors and Affiliations

Jolanta Szpyra-Kozłowska
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Abstract

It was expected that there would be a relationship between plant density and arrangement within soybean plantations and ground beetles due to changes of abiotic habitat conditions. The aim of this study was to determinate the effect of different plant arrangements of soybean plants on the abundance and species diversity of ground beetles (Coleoptera, Carabidae). The studies were conducted from 2015 to 2017 at the Experimental Research Station, Wrocław, Poland. The occurrence of beetles was examined on soybeans, growing in four different treatments: row spacing of 15 cm or 30 cm, and seeding density of 50 or 90 seeds per m2. The experiment was conducted in a split-plot design in four replicates. Ground beetles were collected with 16 pitfall traps, with one trap in the middle part of each plot. The obtained results show that the general number of ground beetles was similar between the treatments. Some minor effects were found in species number, which was higher in the lower row spacing treatment. Only less abundant species were significantly affected. The most abundant species in all years and treatments were Pseudoophonus rufipes, Harpalus affinis, Calathus fuscipes and Pterostichus melanarius. The abundance of the above-listed common ground beetle species did not differ significantly between treatments.

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Authors and Affiliations

Marcin Cierpisz
Jacek Twardowski
Iwona Gruss
Marcin Kozak
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Abstract

In this study, the effects of heat-treatment conditions of Fe powder compacts on densification, microstructure, strength and magnetic properties were investigated. The prepared Fe powder was compressed in a mold of diameter 20 mm at a pressure of 800 MPa for 30 sec. This Fe powder compact was heat-treated under different atmospheres (air and 90% Ar + 10% H2 and heat-treatment temperatures (300 and 700℃). The Fe powder compacts heat-treated in an Ar+H2 mixed gas atmosphere showed a denser microstructure and higher density than the Fe powder compacts heat-treated in an air atmosphere. Oxygen content in the heat-treatment conditions played a significant role in the improvement of the densification and magnetic properties.
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Authors and Affiliations

Hyo-Sang Yoo
1
ORCID: ORCID
Yong-Ho Kim
1
ORCID: ORCID
Cheol-Woo Kim
1
ORCID: ORCID
Hyeon-Taek Son
1
ORCID: ORCID

  1. Korea Institute of Industrial Technology, Automotive Materials & Components R&D Group, 1110-9 Oryong-dong, Buk-gu, Gwangju 61012, Republic of Korea
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Abstract

Kaolin-based geopolymers are alternatives for producing high-strength ceramics for construction materials. Creating high-performing kaolin ceramics utilizing the regular technique requires a high handling temperature (higher than 1200°C). Thus, the structure and properties such as pore size and distribution are affected at higher sintering temperatures. Along these lines, information with respect to the sintering system and related pore structure is essential for advancing the properties of the previously mentioned materials. This study investigated the microstructure and the density of a kaolin-based geopolymer at various sintering temperatures. The unsintered sample has the highest density of 1610 kg/cm3, while the samples sintered at 1100°C haves the lowest density of 1203 kg/cm3. The result also shows that increasing the sintering temperature to 1100°C resulted in increasing the water absorption of the kaolin-based geopolymer ceramic.
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Authors and Affiliations

M.I.I. Ramli
1
ORCID: ORCID
M.A.A.M. Salleh
1 2
ORCID: ORCID
I.H. Aziz
1
ORCID: ORCID
N.S.M. Zaimi
1
ORCID: ORCID
S.F.M. Amli
1
M.M.A.B. Abdullah
1 2
ORCID: ORCID

  1. Universiti Malaysia Center of Excellence Geopolymer and Green Technology (CEGeoGTech), Perlis, Malaysia
  2. Universiti Malaysia Perlis (UniMAP), Faculty of Chemical Engineering Technology, Malaysia
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Abstract

The paper evaluates the relationship between the selection of the probability density function and the construction price, and the price of the building's life cycle, in relation to the deterministic cost estimate in terms of the minimum, mean, and maximum. The deterministic cost estimates were made based on the minimum, mean, and maximum prices: labor rates, indirect costs, profit, and the cost of equipment and materials. The net construction prices received were given different probability density distributions based on the minimum, mean, and maximum values. Twelve kinds of probability distributions were used: triangular, normal, lognormal, beta pert, gamma, beta, exponential, Laplace, Cauchy, Gumbel, Rayleigh, and uniform. The results of calculations with the event probability from 5 to 95% were subjected to the statistical comparative analysis. The dependencies between the results of calculations were determined, for which different probability density distributions of price factors were assumed. A certain price level was assigned to specific distributions in 6 groups based on the t-test. It was shown that each of the distributions analyzed is suitable for use, however, it has consequences in the form of a final result. The lowest final price is obtained using the gamma distribution, the highest is obtained by the beta distribution, beta pert, normal, and uniform.

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Authors and Affiliations

M. Rogalska
J. Żelazna-Pawlicka
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Abstract

On the basis of observations and markings of Weddell seals in the region of the Admiralty Bay it was estimated that numbers of this species decreased systematically from about 500 to about 100 individuals from December to February. The sex structure of the local population also changed, showing a growing domination of females. Males were observed more often on coastal snow patches, females prevailed on rocky beaches close to the sea. A thesis of an increased nocturnal activity of Weddell seal was confirmed, indicating also a possibility of a two days activity cycle of this species. Synchronized among the individuals of local populations by atmoshperic conditionds.

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Authors and Affiliations

Michał Woyciechowski
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Abstract

Measurements of water temperature and salinity were carried out at 38 oceanographic stations at Admiralty Bay in the period between December 1978 and February 1979. The temperature at the water surface ranged from 0.18°C to 2.81 °C and salinity from 16.40 to 34.16‰. Deeper water temperature decreased and salinity increased ranging at the bottom, at the depth of 480 m, from —0.23°C to 26°C and from 34.51‰ to 34.57‰, respectively. The investigations at the shore and offshore stations showed a marked effect of the run-offs from glaciers causing a considerable decrease in salinity of the thin surface layer of the waters. The main area of the Bay is characterized by high uniformity of water temperature and salinity, which proves that these waters are well mixed.

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Authors and Affiliations

Zygmunt Szafrański
Maciej Lipski
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Abstract

The article describes the idea of a compact city, due to the needs and capabilities of contemporary Polish cities, with an emphasis on the Silesia region. Special attention has been paid to the possibility of increasing the cities’ density and several examples have been shown to present the possibilities of densifying the cities with new housing investments. Also, the article presents the studies that indicate the capacity for the internal development of selected Silesian cities: Katowice and Gliwice. The article ends with the recommendations for cities to become more compact.

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Authors and Affiliations

Agata Twardoch
Tomasz Bradecki
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Abstract

Bayesian VAR (BVAR) models offer a practical solution to the parameter proliferation concerns as they allow to introduce a priori information on seasonality and persistence of inflation in a multivariate framework. We investigate alternative prior specifications in the case of time series with a clear seasonal pattern. In the empirical part we forecast the monthly headline inflation in the Polish economy over the period 2011‒2014 employing two popular BVAR frameworks: a steady-state reduced-form BVAR and just-identified structural BVAR model. To evaluate the forecast performance we use the pseudo real-time vintages of timely information from consumer and financial markets. We compare different models in terms of both point and density forecasts. Using formal testing procedure for density-based scores we provide the empirical evidence of superiority of the steady-state BVAR specifications with tight seasonal priors.

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Authors and Affiliations

Damian Stelmasiak
Grzegorz Szafrański
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Abstract

Cephus fumipennis Eversmann is a key insect pest of wheat crops in Qinghai, China. Its field population densities were surveyed by using both the back-loaded insect vacuum and a sweep net. Mean densities in township-level were calculated and a quantitative relation, ŷ = 0.664 + 0214x, was established between the two sampling methods. The empirical relationship may be applicable in density monitoring and Integrated Pest Management program of the insect.

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Authors and Affiliations

Limin Zhao
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Abstract

Transmission of the electric power is accompanied with generation of low –frequency electromagnetic fields. Electromagnetic compatibility studies require that the fields from sources of electric power be well known. Unfortunately, many of these sources are not defined to the desired degree of accuracy. This applies e.g. to the case of the twisted-wire pair used in telephone communication; already practiced is twisting of insulated high-voltage three phase power cables and single-phase distribution cables as well. The paper presents a theoretical study of the calculation of magnetic fields in vicinity of conductors having helical structure. For the helical conductor with finite length the method is based on the Biot-Savart law. Since the lay-out of the cables is much more similar to a broken line than to strait line, in the paper the magnetic flux densities produced by helical conductor of complex geometry are also derived. The analytical formulas for calculating the 3D magnetic field can be used by a software tool to model the magnetic fields generated by e.g. twisted wires, helical coils, etc.

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Authors and Affiliations

Krzysztof Budnik
Wojciech Machczyński
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Abstract

The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of

stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead

balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the

aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state

was used.

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Authors and Affiliations

M. Korzeniowski
A. Trytek
M. Tupaj
K. Sondej
L. Kozak
M. Mróz
B. Kupiec
A.W. Orłowicz
Z. Cisek
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Abstract

The paper presents results of an analysis of material density distribution in stampings press-moulded in metal dies from raw refractory

materials based on alumina-magnesia-carbon aggregate. The stampings, fabricated on LAEIS HPF 1250 pressing machine, are blanks from

which refractory precast shapes are manufactured by means of drying and firing. Samples for material density evaluation were cut out

from test stampings with the use of diamond-reinforced disc. Density of the material was determined in thirteen layers of stampings

denoted with letters A through M.

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Authors and Affiliations

A.W. Orłowicz
M. Mróz
M. Tupaj
A. Trytek
B. Kupiec
M. Korzeniowski
D. Pająk
K. Sondej
L. Kozak
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Abstract

The conducted work shows and confirms how thermal analysis of grey and ductile iron is an important source for calculating metallurgical data to be used as input to increase the precision in simulation of cooling and solidification of cast iron. The aim with the methodology is to achieve a higher quality in the prediction of macro– and micro porosity in castings. As comparison objects standard type of sampling cups for thermal analysis (solidification module M ≈ 0.6 cm) is used. The results from thermal analysis elaborated with the ATAS MetStar system are evaluated parallel with the material quality (including tendency to external and internal defects) of the tested specimen. Significant temperatures and calculated quality parameters are evaluated in the ATAS MetStar system and used as input to calibrate the density curve as temperature function in NovaFlow&Solid simulation system. The modified data are imported to the NovaFlow&Solid simulation system and compared with real results.

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Authors and Affiliations

P-E. Persson
Z. Ignaszak
H. Fransson
V. Kropotkin
R. Andersson
A. Kump
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Abstract

Al-CuO is a thermite material exhibiting the exothermic reaction only when aluminum melts. For wide spread of its application, the reaction temperature needs to be reduced in addition to the enhancement of total reaction energy. In the present study, a thermite nanocomposite with a large contact area between Al and CuO was fabricated in order to lower the exothermic reaction temperature and to improve the reactivity. A cryomilling process was performed to achieve the nanostructure, and the effect of composition on the microstructure and its reactivity was studied in detail. The microstructure was characterized using SEM and XRD, and the thermal property was analyzed using DSC. The results show that as the molar ratio between Al and CuO varies, the fraction of uniform nanocomposite structure was changed affecting the exothermic reaction characteristics.

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Authors and Affiliations

Minseok Oh
Kwanil Kim
Byungmin Ahn

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