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Number of results: 278
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Abstract

Porosity is one of the major defects in aluminum castings, which results is a decrease of a mechanical properties. Porosity in aluminum alloys is caused by solidification shrinkage and gas segregation. The final amount of porosity in aluminium castings is mostly influenced by several factors, as amount of hydrogen in molten aluminium alloy, cooling rate, melt temperature, mold material, or solidification interval. This article deals with effect of chemical composition on porosity in Al-Si aluminum alloys. For experiment was used Pure aluminum and four alloys: AlSi6Cu4, AlSi7Mg0, 3, AlSi9Cu1, AlSi10MgCu1.

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Authors and Affiliations

L. Kucharčík
A. Sládek
M. Brůna
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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

In this paper, the deviation from eutectic composition in boundary layer for eutectic growth is studied by phase-field method. According to a series of artificial phase diagram, the lamellar eutectic growth of these alloy is simulated during directional solidification. At steady state, average growth velocity of eutectic lamella is equal to the pulling velocity. With the increasing of the liquidus slope of β phase, the average composition in boundary layer would deviate from eutectic composition and the deviation increases. The constitutional undercooling difference between both solid phases caused by the deviation increases with the increasing of the deviation. The β phase would develop a depression under the influence of the deviation.

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Authors and Affiliations

Zhixin Tu
Jianxin Zhou
Yajun Yin
Xiaoyuan Ji
Xu Shen
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Abstract

The cement production process is associated with the emission of dust. These are mainly CKD (cement kiln dust) and BPD (by-pass dust), classified as wastes from group 10 – Wastes from thermal processes, subgroups 10 and 13 – wastes from manufacture of cement, lime and plaster and articles and products made from them. Cement kiln dust is a waste of variable composition and properties, which makes it a difficult material to recover. The main directions of recovery presented in the world literature indicate the use of dust from cement kilns in cement, mortar and concrete production, the production of bricks and in order to improve soil quality and wastewater treatment. Factors affecting chemical and phase compositions of dust from cement kilns are the reason why each waste should be analyzed individually. The paper presents the results of the analysis of the cement kiln dust after dedusting cement kilns and two bypass dusts. Analysis of the chemical composition has shown significant concentrations of chlorine, potassium and calcium in all wastes. The content of: Si, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, and Bi has also been confirmed. The analyzed dusts were characterized by the presence of carbonates (calcite, dolomite, and arcanite), quartz, alite, belite, sylvine, anhydrite, and portlandite in their phase composition. The leachates which were characterized by an alkaline reaction. In terms of leachability, high concentrations of chlorine ions in the analyzed dust leachates were confirmed, which significantly limits their use.

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Authors and Affiliations

Alicja Uliasz-Bocheńczyk
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Abstract

An important task for present and future generations is the protection of the national cultural resources. The most attractive architectural objects of historic value include palaces, manors, castles and monasteries. Less attention is paid to educational areas, which apart from the main educational and didactic goal (positive influence on the young person's mind, shaping his personality, social integration) have a great influence on his health, the quality of his life and the shape of his environment. The example of this is the park next to the school complex in Sobieszyn, located in Lublin Voivodeship, Ułęż County. The school complex with its surrounding park established at the end of the 19 th century was given by a will of the Count Kajetan Kanty Kicki, Gozdawa coat of arms, a philantropist and a contemporary owner of Sobieszyn. Localisation of the school, far away from the centre of the village, on the slope of one of the right side tributaries of the Wieprz River – Świnka, makes it an extraordinary place, emphasising the nature values that surround it. Nowadays, the building is still a school- Kajetan Kicki Agriculture School in Sobieszyn.
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Authors and Affiliations

Krystyna Pudelska
Kamila Rojek
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Abstract

This paper presents numerical analyses and a physical experiment on efficiency of different shapes and material composition of piezo actuators on vibration reduction. For this purpose numerical models of a plate clamped on all sides with piezo actuators attached were developed. The elements used were either standard homogeneous elements or the proposed two-part elements with different material composition for inner and outer part of piezo ceramic. Numerical analyses were performed using ANSYS software
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Authors and Affiliations

Jerzy Wiciak
Roman Trojanowski
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Abstract

Physical analysis of the 15-cm top layer of the Rzuno lake bottom sediments showed that their properties changed adequate by depth. They changed from granular structure, in the lakes shallow parts, to amorphic structure, in the lakes deeper parts, from light color to almost black and from loose to gelatinous consistence. Chemical investigation of this lake bottoms sediments showed that their main components is silica (more than 50% of dry matter of sediments), therefore these bottom sediments were classified as silicate sediments. Organic matter was another essential component of these sediments. The content of organic matter increased adequate by depth from 7% to 36%. The investigated sediments exhibited small contents of nitrogen (about 0.6%), with predominance of organic nitrogen. They make up are characterized by small phosphorus contents (about 0.06%), with similar amount of inorganic and organic phosphorus. The content of metals (Ca, Mg, Fe, Al, Mn) was also small in the investigated sediments. Correlation analysis showed that iron ions precipitate phosphate phosphorus from water and accumulate it in sediments. The material deposited in bottom sediments of Rzuno lake in mainly of an autochthonous origin. The chemical composition of bottom sediments of Rzuno lake, as well as its comparison with other lakes, show that this lake is moderately eutrophic.
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Authors and Affiliations

Jan Trojanowski
Janusz Bruski
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Abstract

Wonji Shoa Sugar Estate (WSSE), located in the flood plain of the Awash River (Ethiopia), has been under long-term (>60 years) irrigation, industrial activities and agro-chemical usage. In this study, the hydrochemical properties of ground-water bodies available at WSSE have been characterized for quality compositions. Water samples were collected from groundwater monitoring piezometers distributed in the sugarcane plantation and then analysed for physico-chemical quality parameters (pH, EC,major cations and anions) following standard procedures. Other chemical indices (e.g., total dissolved solids (TDS),total hardness(TH),magnesium absorption ratio(MAR), base exchange (r1), meteoric genesis(r2)) were de-rived from the measured water quality parameters. The compositional variability and groundwater classification has been presented using the Box and Piper plots. The potential sources of minerals were suggested for each of the considered water sources based on their quality characteristics. Both trilinear Piper plot and meteoric genesis index revealed that groundwaterof the area is shallow meteoric water percolation type with a changing of hydrochemical facies and mixing trend. Ground-water of the area, is group 1 (Ca-Mg-HCO3) type, with no dominant cations and HCO3 are the dominant anions. Overall, the study result elucidates that the chemical composition of GW of the area showed spatial variability depending upon the variations in hydrochemical inputs from natural processes and/or anthropogenic activities within the region. The local an-thropogenic processes could be discharges from sugar factory, domestic sewage and agricultural activities.

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Authors and Affiliations

Megersa Olumana Dinka
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Abstract

Although chaetognaths inhabiting polar ecosystems are relatively well known, there are few reports on their functioning in the Antarctic coastal plankton community. The presented results provide the first comprehensive description of population structure of chaetognaths in the neritic zone west of the Antarctic Peninsula. The studies were performed on samples collected in Admiralty Bay, from December 1994 to June 1995. Following six chaetognath species were determined: Eukrohnia hamata, E. bathypelagica, E. fowleri, Pseudosagitta gazellae, P. maxima and Solidosagitta marri. The representatives of Eukrohnia were observed almost throughout the research period, whereas those of Pseudosagitta and Solidosagitta were found only during first four months of our investigation. Eukrohnia hamata showed a strong dominance in respect to abundance (max. 445 ind./1000 m3). The mean abundance of all taxa significantly fluctuated in the study period and across weeks. Generally, all species were represented by the first three maturity stages (I-III), individuals stage IV occurred sporadically, and mature specimens (stage V) were not recorded at all. Morphometric analysis of the most abundant species showed distinct differences in their total length and body proportions. Our findings may suggest that chaetognath populations in Admiralty Bay are migrant, dependent on the inflow of water from the Bransfield Strait, but to prove this statement further, round year study is necessary.
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Authors and Affiliations

Luiza Bielecka
Bartłomiej Jerzak
Ilona Złoch
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Abstract

This paper presents a study of the seismic P−wave velocity and density structure of the lithosphere−asthenosphere system along a 800 km long transect extending from the actively spreading Knipovich Ridge, across southern Spitsbergen to the Kong Karls Land Volcanic Province. The 2D seismic and density model documents 6–8 km thick oceanic crust formed at the Knipovich Ridge, a distinct continent−ocean−boundary (COB), the eastern boundary of the dominantly sheared Hornsund Fault Zone, and the eastern boundary of the Early Cenozoic West Spitsbergen Fold−and−Thrust Belt. The crustal continent−ocean transitional zone has significant excess of density (more than 0.1 g/cm 3 in average), characteristic for mafic/ultramafic and high−grade metamorphic rocks. The main Caledonian suture zone between Laurentia and Barentsia is interpreted based on variations in crustal thickness, velocities and densities. A high velocity body in the lower crust is preferably interpreted in terms of Early Cretaceous magmatism channelled from an Arctic source southwards along the proto−Hornsund zone of weakness. The continental upper mantle expresses high velocities (8.24 km/s) and densities (3.2 g/cm 3 ), which may be interpreted in terms of low heat−flow and composition dominated by dunites. The lower velocities (7.85 km/s) and densities (3.1 g/cm 3 ) observed in the oceanic lithosphere suggest composition dominated by primitive peridotites. The model of mantle allows for successful direct description of subcrustal masses distribution compensating isostatically uneven crustal load. The estimated low value of correlation between density and velocity in the mantle 0.12 kg × s × m −4 suggests that horizontal density differences between oceanic and continental mantle would be dominated by compositional changes.
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Authors and Affiliations

Lech Krysiński
Marek Grad
Rolf Mjelde
Wojciech Czuba
Aleksander Guterch
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Abstract

Physical and chemical properties of Arctic soils and especially the properties of surface horizons of the soils are very important because they are responsible for the rate and character of plant colonization, development of vegetation cover, and influence the rate and depth of thawing of soils and development of active layer of permafrost during summer. The main aim of the present study is to determine and explain the spatial diversity of selected physical and chemical properties of surface horizons of Arctic soils from the non-glaciated Fuglebekken catchment located in the Hornsund area (SW Spitsbergen) by means of geostatistical approach. Results indicate that soil surface horizons in the Fuglebekken catchment are characterized by highly variable physical and chemical properties due to a heterogeneous parent material (marine sediments, moraine, rock debris), tundra vegetation types, and non-uniform influence of seabirds. Soils experiencing the strongest influence of seabird guano have a lower pH than other soils. Soils developed on the lateral moraine of the Hansbreen glacier have the highest pH due to the presence of carbonates in the parent material and a lack or presence of a poorly developed and discontinuous A horizon. The soil surface horizons along the coast of the Hornsund exhibit the highest content of the sand fraction and SiO2. The surface of soils occurring at the foot of the slope of Ariekammen Ridge is characterized by the highest content of silt and clay fractions as well as Al2O3, Fe2O3, and K2O. Soils in the central part of the Fuglebekken catchment are depleted in CaO, MgO, and Na2O in comparison with soils in the other sampling sites, which indicates the highest rate of leaching in this part of the catchment.
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Authors and Affiliations

Wojciech Szymański
Janusz Siwek
Joanna Waścińska
Bronisław Wojtuń
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Abstract

Polymer composite materials based on the Moplen HP400R polypropylene matrix with a filler from walnut shell flour with 30, 40 and 50% content and 200-315 µm and 315-443 µm fraction were produced by the injection method. The effect of filler content was analysed on the processing properties of the composites such as: MFR Melt Flow Rate and the MVR Melt Volume-flow Rate, as well as the temperature of the filler flour decomposition using the TGA thermogravimetric analysis method. The following was also determined: density, hardness, tensile strength and stiffness modulus of elasticity of the materials in question. The obtained composite material was characterised by low density, which increased with the rising filler content. It was found that the applied natural filler has increased the hardness and stiffness modulus of the composite and decreased the tensile strength.

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Authors and Affiliations

A. Włodarczyk-Fligier
M. Polok-Rubiniec
B. Chmielnicki
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Abstract

A method of calculating the deflections of steel plate-concrete composite beams is proposed. In the hybrid work of such beams the properties of reinforced concrete and composite structures are combined. This convention should be followed in considering their ultimate capacity and serviceability limit state. The proposed solution has been verified in experimental studies performed by the authors. Good compatibility of theoretical calculations and experimental results has been obtained. It allows the theoretical solution to be used in the analysis of other cases with parameters different than those of the discussed beams. In the experiments done by the author six beams of total length of 5.20 m and theoretical length of 5,00 m were used. The cross section was rectangular, 0.24 m in width and 0.49 m in height. The steel plate 4.74 m long was 6.10 and 16 mm thick. The diameter of the flexible connectors was 13 mm. Their spacing varied between 80 and 200 mm. Owing to the flexibility of the connectors the interface slip between the steel and concrete parts was included in the theoretical solutions. The results of an in-depth analysis indicate that the deflections of steel plate-concrete composite beams are affected by the compressive strength of concrete and the yield point of steel as well as connectors’ diameter and spacing. This impact varies, that of the yield point of the steel from which the plate is made being the highest.
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Authors and Affiliations

Dawid Kisała
1
Kazimierz Furtak
1
ORCID: ORCID

  1. Department of Bridge and Tunnel Building, Tadeusz Kościuszko Cracow University of Technology, Warszawska 24 St., 31-155 Kraków, Poland
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Abstract

The paper gives coverage to peculiarities of water elements application in landscape compositions created in 19th century by gardener of Dionizy Mikler (Denis McClair) at Volhynia. Being an ambassador of English landscape garden style in this region D. Mikler seamlessly integrated picturesque natural and artificial water components in the garden structure. There are considered the role and ways of interaction of water elements with the landscape compositions by giving examples of Polish landowner´s residences in Gorodok, Mizoch, Mlyniv and Shpaniv.
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Authors and Affiliations

Petro Rychkov
Nataliya Lushnikova
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Abstract

The aim of the study was to determine the effect of adding bio-components in the form of methyl esters of corn oil to the milesPLUS diesel oil on its fractional composition. The corn biofuel was produced in-house by using an own-design GW-200 reactor. The diesel fuel evaporated at temperatures ranging from 162 to 352oC. The addition of 7, 20 and 40% of a bio-component in principle does not affect the deterioration of the starting point distillation temperatures. They affect the temperature at the end of distillation to a greater extent, resulting in temperatures exceeding 360oC.
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Authors and Affiliations

Bolesław Pracuch
Grzegorz Wcisło
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Abstract

The aim of the studies was to evaluate the influence of sowing rate, foliar fertilization (Basfoliar fertilizer 6-12-6) and chemical composition on the mechanical properties of narrow- leaved lupine seeds of cultivars Bojar and Regent. Single seeds were burdened in the direction perpendicular to the parting plane of cotyledons with constant speed 10 mm∙min-1. The crop year and cultivar have significantly differentiated the value of all the analyzed strength parameters of narrow-leaved lupine seeds. The seeds of cultivar Bojar had significantly higher values of all the strength parameters. The designated strength parameters of lupine seeds were negatively correlated with ash content, fiber and protein except for the destructive force. They were also positively correlated with the fat content.
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Authors and Affiliations

Piotr Kuźniar
Wacław Jarecki
Stanisław Sosnowski
Dorota Bobrecka-Jamro
Natalia Matłok
Dagmara Migut
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Abstract

The influence of bean seed surface lipids on infestation of seeds by Acanthoscelides obtectus Say was investigated. The experiments were performed in dual-choice bioassays on three bean varieties: Blanka, Bor and Longina. The collected data for natural and solvent washed seeds concerned the number of ovipositions, embryo mortality, lack of seed-boring activity, dead larvae inside seeds and developed insects. The results clearly indicated that bean seed surface lipids are involved in all infestation stages, and could be used to distinguish resistant and non-resistant varieties of been. Chemical analyses revealed the following groups of surface lipids: wax esters, long chain primary alcohols, n-alkanes, sterols, fatty acids, squalene, aldehydes, monoacylglycerols, ketones and fatty acid esters. Quantitative composition of surface lipids was analysed using selected chemometric procedures to determine correlation with bioactivity. Cluster analysis of surface lipid composition enabled to distinguish resistant and non-resistant varieties. Fatty acids and monoacylglycerols were found to deter bean weevil infestation, while alkan-1-ols acted as attractants.

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Authors and Affiliations

Mariusz Nietupski
Beata Szafranek
Dolores Ciepielewska
Elżbieta Synak
Łucja Fornal
Janusz Szafranek
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Abstract

Cast stainless steel of the Cr-Ni duplex type is used, among others, for the cast parts of pumps and valves handling various chemically

aggressive media. Therefore, the main problem discussed in this article is the problem of abrasion wear resistance in a mixture of SiC and

water and resistance to electrochemical corrosion in a 3% NaCl- H2O solution of selected cast steel grades, i.e. typical duplex cast steel,

high silicon and manganese duplex cast steel, and Cr-Ni austenitic cast steel (type AISI 316L). The study shows that the best abrasion

wear resistance comparable to Ni-Hart cast iron was obtained in the cast duplex steel, where Ni was partially replaced with Mn and N.

This cast steel was also characterized by the highest hardness and matrix microhardness among all the tested cast steel grades. The best

resistance to electrochemical corrosion in 3% NaCl- H2O solution showed the cast duplex steel with high content of Cr, Mo and N. The

addition of Ni plays rather insignificant role in the improvement of corrosion resistance of the materials tested.

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Authors and Affiliations

B. Kalandyk
R. Zapała
M. Starowicz
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Abstract

In the article we were studing the impact of the remelting on transformations in Co-Cr-Mo prosthetics alloy. The TDA curves were analyzed, the microstructure was examined, the analysis of the chemical composition and hardness using the Brinell method was made. It was found that the obtained microstructure of the alloys that we studied do not differ significantly. In all four samples, microscopic images were similar to each other. The volume, size and distribution of the phases remain similar. Analysis of the chemical composition showed that all the samples fall within the compositions provided for the test alloy. Further to this the hardness of the samples, regardless of the number of remeltings did not show any significant fluctuations and remained within the error limit.After analyzing all the results, it can be concluded that the remeltings of the alloys should not have a significant impact on their properties. Secondarily melted alloys can be used for prosthetics works.
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Authors and Affiliations

B. Kacprzyk
G. Gumienny
T. Szymczak
L. Klimek
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Abstract

In this study, cross-section analysis was performed on a novel rotating direct-metal deposition method capable of preliminary surface treatment and damage repair of cylindrical inner walls. The cross-sectional shape, microstructure, and metallurgical composition were analyzed to verify feasibility. No defects such as porosity or cracks were found in the cross section, but asymmetric dilution was observed because of the non-coaxial powder nozzle. Microstructural coarsening was confirmed over a higher dilution area by high-magnification optical microscope images. As the dilution ratio was increased, hard carbides in the dendrite were bulk-diffused into inter-dendrite spaces, and the toughness was lowered by Fe penetration into the deposit. Therefore, the increased laser heat input can be modulated to the typical dilution by decreasing the laser scanning velocity.

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Authors and Affiliations

Byungjoo Choi
Gwang-Jae Lee
Hyun-Ho Yeom
Moon-Gu Lee
Yongho Jeon
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Abstract

Blast furnace and cupola furnace are furnace aggregates used for pig iron and cast iron production. Both furnace aggregates work on very similar principles: they use coke as the fuel, charge goes from the top to down, the gases flow against it, etc. Their construction is very similar (cupola furnace is usually much smaller) and the structures of pig iron and cast iron are very similar too. Small differences between cast iron and pig iron are only in carbon and silicon content. The slags from blast furnace and cupola furnace are very similar in chemical composition, but blast furnace slag has a very widespread use in civil engineering, primarily in road construction, concrete and cement production, and in other industries, but the cupola furnace slag utilization is minimal. The contribution analyzes identical and different properties of both kinds of slags, and attempts to explain the differences in their uses. They are compared by the contribution of the blast furnace slag cooled in water and on air, and cupola furnace slag cooled on air and granulated in water. Their chemical composition, basicity, hydraulicity, melting temperature and surface were compared to explain the differences in their utilization.

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Authors and Affiliations

A. Pribulová
P. Futáš
J. Petrík
M. Pokusová
M. Brzeziński
J. Jakubski
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Abstract

Each bitumen has a slightly different group composition, thus bitumen modifi cation with the SBS copolymer gives slightly different results in each case. Both in the industry and construction prac-tice there is still no simple method available which would allow the evaluation of the impact of SBS content and the group composition of bitumen on the structural and rheological properties of the polymer bitumen mix. The article presents the results of the dynamic viscosity tests of three bitumen types. Based on the analysis of the results obtained, it was found that changes in the rheological properties caused by SBS additive are characteristic for each of the bitumens tested and their chemical and group composition. They are also proportionate to the amount of the modifi er added. In order to have a possibility to measure this impact, three coeffi cients rheologically charac-terizing polymer and bitumen mixes were applied.

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Authors and Affiliations

K. Zieliński

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