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Number of results: 45
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Abstract

In recent years, two developments revolutionized the molecular genetics. The first one is an enormously improved technique of the DNA sequencing. It is now possible to obtain in couple of hours and on the low cost, the full sequence of the human genome. The second one is the invention of the CRISPR-Cas technique, which allows the precise manipulations of genomes of living organisms. This technique was already successfully applied to “repair” human genes responsible for hereditary diseases. To some astonishment, applications of genetic engineering to humans does not bring protests of general public, while similar manipulations pf plants genomes are considered an dangerous. In Poland and in some other countries, parliaments introduced an extremely restrictive laws, which in practice makes cultivation of GM plants outside laboratories impossible. This is caused by the ignorance of the general public and by opposition of catholic church which considers genetic modifications of all organisms as contradictory with Gods will. The most common modification of plants is an introduction into their genomes of the single gene from the bacterium Bacillus thuringensis, what make the plant resistant to harmful insects. According to WHO, neither the manipulation mentioned above, nor manipulations of the other kind, do not pose any danger to humans.

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Authors and Affiliations

Piotr Węgleński
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Abstract

Stem cells exist and can do a lot. For several decades, bone marrow and umbilical cord blood transplants containing haematopoietic stem cells have been used in the treatment of blood diseases. Genetic modifications (gene therapy) of such cells help to cure complex immunodeficiencies and severe anaemias. The limbal stem cells taken from the eye and properly multiplied can regenerate the damaged cornea, and the epidermal stem cells help in the treatment of severe burns and some hereditary, severe skin diseases. Promising experimental research is under way on other uses of stem cells. However, these cells are appropriately selected, having real ability to differentiate into specialized cells whose malfunction is the cause of the disease. Therapeutic applications of stem cells are apparently limited to date. Meanwhile, the Internet is full of advertisements for supposedly miraculous treatments for almost any disease. Stem cells have become a modern synonym of the Holy Grail. A wonderful dish, transforming every drink into elixir of health, youth and long life. Stem cells from a single source, e.g., umbilical cord blood, or so-called cells, although without proven properties of stem cells, are offered in commercial private clinics as a panacea for autism, cerebral palsy, spina bifida, eye diseases, amyotrophic lateral sclerosis and dozens other disorders. Without justification for their action in these diseases, without convincing evidence of safety, but for a high fee. This article discusses stem cells and misunderstandings about including any cells among them. It draws attention to the real possibilities and confirmed uses of stem cells and presents the problems, doubts and dangers for patients associated with commercial offers of treatments using “stem” cells. The author cites the positions of scientific institutions and societies warning against premature commercialization of unjustified and potentially dangerous therapies.

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Authors and Affiliations

Józef Dulak
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Abstract

The main contradictions, between hypotheses posed by physical anthropologists or geneticists, and the hypotheses put forward by archaeologists or historians, regarding the origin and spread of the Slavs, concerned and still concern the following: (a) the state and biological dynamics of Slavic populations (the capacity for population expansion) , (b) diversity and biological similarity of various groups living in Central Europe at the end of antiquity and in the early Middle Ages, (c) migration movements and their intensity, (d) directions of migration and their importance in the formation of Slavic “ethnos”. On the basis of the results of anthropological research, it can be concluded that: (a) both in the late antiquity period and in the early Middle Ages, the regional diversity of the populations inhabiting the Odra and Vistula basins was maintained, (b) there was a geographical gradient in the variability of morphological features of the skull from west to east of Europe, (c) populations belonging to the Germanic population and populations living in Scandinavia in the Middle Ages clearly differed in terms of morphological features of the skeleton from the population of Western Slavs inhabiting the Odra and Vistula basin. On the other hand, the emergence of a clear geographical gradient in the variability of morphological features of the skeleton, in late antiquity and in the Middle Ages, in Central Europe, allows to conclude that there were no intense migratory movements and the population exchange between late antiquity and the early Middle (d) results of the skeletal morphological features and state and biological dynamics of the population from the Roman period and the Middle Ages indicate a similar level of adaptation of these groups of people to living conditions. This result does not confirm the thesis put forward by some archaeologists and historians that the cultural system of the Slavs was characterized by poverty and a low level of material culture.

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Authors and Affiliations

Janusz Piontek
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Abstract

This article uses the model of dependency between centers and peripheries of scientific knowledge production to create a theoretical framework for investigating predatory journals. The framework is presented as an alternative to the dominant ways of the problem's characterization. Predatory journals are so far described mostly as a newly emerging phenomenon strongly connected with publishing in Open Access and fraudulent publishers. In this article, I argue that predatory publishers are recognized as illegitimate by the center of knowledge production. This geopolitically situated approach let me look more critically on the ways of assigning this illegitimacy. It also allows me to define the ostensible center and reveal a mechanism for functioning many journals accused of being predatory. The ostensible center is understood as an institution disseminating knowledge that is invisible or illegitimate to the center. However, at the same time some actors see an ostensible center as belonging to the center. The presented terms are analytical tools for further research that might enable us to get a wider picture of a modern global system of knowledge production and point out its antiegalitarian mechanism.

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Authors and Affiliations

Franciszek Krawczyk
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Abstract

In these remarks I do undertake one more time the attempt to answer the following question: what do agnostics really want? This issue is so complicated that even the agnostics themselves had great trouble in delivering the answer. This is also related to these agnostics, such as the recalled here Charles Darwin, Albert Einstein, and Stephen W. Hawking, who belong to the greatest format of scholars. The agnostics are being distanced from, both the atheists and theists. However they do judge differently their views it is important that as well the first as the latter ones may appreciate what stands behind agnosticism and this might be very variable.

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Authors and Affiliations

Zbigniew Drozdowicz
ORCID: ORCID
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Abstract

Professor Jan Gliński was born on 4 April 1933 in Pińsk. He graduated from the Lublin Higher School of Agriculture, where he obtained his Master of Engineering Degree in Agriculture. In 1964, ten years after beginning his work at the School at the Soil Science Department, he was awarded a doctoral degree for his Copper forms in soils of the Łęczyńsko-Włodawskie Lakeland dissertation, and in 1968 he obtained a postdoctoral degree in the field of agricultural sciences on the basis of his thesis Impact of some soil-forming factors on the content and distribution of micronutrients in soil profiles. In 1971 Jan Gliński began his work at the Department of Agrophysics of the Polish Academy of Sciences (PAS) in Lublin. Three years later he was granted the title of associate professor, and in 1980 he was promoted to full professor. Soon he became the head of the Department, and in 1987 the director of the Institute of Agrophysics, Polish Academy of Sciences (in 1986 the Department of Agrophysics, PAS became the Institute of Agrophysics, PAS), the post he held till 2003. Polish Academy of Sciences elected him as a corresponding member in 1991, and in 2002 he became a full member of the Academy. Professor’s scientific achievements consist of over 350 works (i.a. 26 monographs, 220 studies and dissertations, 5 books, 18 patents). His scientific work was focused mainly on the physicochemical soil properties, with particular regard to soil oxidoreductive processes. His soil oxygenation research resulted in two co-authored books: Soil Aeration and its Role for Plants (1985) and Soil Physical Conditions and Plant Roots (1990), published in the US by CRC Press. Professor Gliński was awarded the title of Doctor Honoris Causa from the University of Life Sciences in Lublin (2010) and from the Lviv National Agrarian University in Dublany and the Volodymyr Dahl East-Ukrainian National University (2011). Professor Jan Gliński was a remarkable scientist and scholar, a kind, warm and friendly man, who always stayed willing to serve us with professional advice and support. His colleagues will remember him as their moral and academic authority. Professor died at the age of 86. The funeral service was held on 10 January 2020 at the Lipowa Cemetery in Lublin. Along with the family, numerous representatives of the Polish Academy of Sciences, academic community, local authorities and Professor’s colleagues and friends attended the ceremony.

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Authors and Affiliations

Cezary Sławiński
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Abstract

Stem canker and black scurf of potato (Solanum tuberosum L.) caused by Rhizoctonia solani Kühn are important and epidemic diseases in potato-growing regions worldwide, including Iran. In this study, 120 isolates were retrieved from infected stem canker from six potato- growing regions in Iran (Isfahan, Ardebil, Fars, Hamedan, Kurdestan and Kerman). Out of these, 30 isolates were selected as representatives for genetic and virulence analysis. The isolates were analyzed by one sequence analyzes of the ITS-rDNA region, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR), as well as virulence studies. Based on sequence analysis of the ITS-rDNA region, all 30 isolates were assigned to the anastomosis group (AG) and all were assigned to AG-3 PT. Cluster analysis using the unweighted pair group method with the arithmetic averages (UPGMA) method for both RAPD and ISSR markers revealed that they were divided into three main groups, with no correlation to geographical regions of the isolates. Pathogenicity tests showed that all isolates were pathogenic on potato cv. Agria; however, virulence variability was observed among the isolates. The grouping based on RAPD analysis and virulence variability was not correlated.

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Authors and Affiliations

Mehdi Nasr Esfahani
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Abstract

Ditylenchus destructor is a serious pest of numerous economically important plants worldwide. The population of this nematode species was isolated from the root zone of Ammophila arenaria on a Baltic Sea sand dune. This population’s morphological and morphometrical characteristics corresponded to D. destructor data provided so far, except for the stylet knobs’ height (2.1–2.9 vs 1.3–1.8) and their arrangement (laterally vs slightly posteriorly sloping), the length of a hyaline part on the tail end (0.8–1.8 vs 1–2.9), the pharyngeal gland arrangement in relation to the intestine (dorsal or ventral vs dorsal, ventral or lateral) and the appearance of vulval lips (smooth vs annulated). Ribosomal DNA sequence analysis confirmed the identity of D. destructor from a coastal dune.

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Authors and Affiliations

Renata Dobosz
ORCID: ORCID
Katarzyna Rybarczyk-Mydłowska
Grażyna Winiszewska
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Abstract

Crystals of PbTiO3 and 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 were obtained by the flux growth method whereas crystals of (Na0.5Bi0.5)TiO3 were growth by the Czochralski method. Raman spectroscopy and polarized light microscopy were performed at room temperature. The Raman spectra of 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 shown significant changes comparing to the base materials PbTiO3 and (Na0.5Bi0.5)TiO3. A domain structure was investigated by use polarized light microscopy. Dielectric permittivity measurements were carried out in the temperature range from 20°C to 550°C and a frequency from 1 kHz to 1 MHz. These showed higher dielectric permittivity for the crystals 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 than the source materials PbTiO3 and (Na0.5Bi0.5)TiO3.

The high value of dielectric constant makes it possible to applied 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 as efficient dielectric medium in a capacitors. The small size of the domain structure with the easy possibility of switching by application of an external electric field, give opportunities to apply these materials to FRAM memory applications. Moreover, the high sensitivity of these materials to the surrounding gases e.g. ammonia, chlorine, hydrogen, etc., allows the construction of sensor devices.

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Authors and Affiliations

P. Czaja
ORCID: ORCID
M. Piasecki
M.B. Zapart
J. Suchanicz
K. Konieczny
J. Michniowski
D. Sitko
G. Stachowski
K. Kluczewska-Chmielarz
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Abstract

The development of power industry obligates designers, materials engineers to create and implement new, advanced materials, in which Inconel 617 alloy is included. Nowadays, there are a lot of projects which describe microstructure and properties of Inconel 617 alloy. However, the welded joints from mentioned material is not yet fully discussed in the literature. The description of welded joints microstructure is a main knowledge source for designers, constructors and welding engineers in estimating durability process and degradation assessment for elements and devices with welds of Inconel 617 alloy. This paper presents the analysis and assessment of advanced nickel alloy welded joints, which have been done by tungsten inert gas (TIG). Investigations have included analysis made by light microscope and scanning electron microscope. The disclosed precipitates were identified with Energy Dispersive Spectroscopy (EDS) microanalysis, then it were done X-Ray Diffraction (XRD) phases analysis. To confirm the obtained results, a scanning-transmission electron microscope (STEM) analysis was also performed.

The purpose of the article was to create a comprehensive procedure for revealing the Inconel 617 alloy structure. The methodology presented in this article will be in future a great help for constructors, material specialists and welding engineers in assessing the structure and durability of the Inconel 617 alloy.

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Authors and Affiliations

J. Adamiec
N. Konieczna
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Abstract

The corrosion inhibition behaviour of 1-Ethyl-3-methylimidazolium-methanesulphonate (EMIM[MS]) and 1-Ethyl-3-methylimidazolium acetate (EMIM[Ac]) on API 5L X-52 carbon steel in 2 M HCl was investigated using weight loss, potentiodynamic polarization and electrochemical impedance methods. The corrosion rates of carbon steel decreased in the presence of these ionic liquids. The inhibition efficiencies of the compounds increased with concentration and showed a marginal decrease with a 10°C increase in temperature. Polarization studies showed the compounds to be mixed type inhibitors with stronger anodic character. The adsorption mechanism of both compounds on the metal surface was via physical adsorption and the process obeyed the El-Awardy kinetic-thermodynamic model. The associated activation energy of corrosion and other thermodynamic parameters were calculated to elaborate on the thermodynamics and mechanism of the corrosion inhibition process. EMIM[MS] was found to inhibit the corrosion of carbon steel better than EMIM[Ac] and is attributed to the presence of the highly electronegative sulphur atom in its structure and its larger molecular size.

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Authors and Affiliations

Magdalene Edet Ikpi
Okama Ebri Obono
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Abstract

One of the challenges of modern crystallography of complex systems (complex metallic alloys, proteins, aperiodic crystals and quasicrystals) is to properly describe the disorder in these systems and discuss correctly the refinement results in terms of the structural disorder. In this paper we briefly discuss a new approach to phasons and phonons in quasicrystals and focus on the new theory of phonons in these materials. A newly derived correction factor for phonons in the form of the Bessel function is the approximated way of describing optic modes in the phonon spectra of quasicrystals. It is applied to a real decagonal quasicrystal in the Al-Cu-Rh system with 56/38 atoms per thick/thin structural unit, based on 2092 unique reflections selected from the collected diffraction data, significantly improving the refinement results. The final R-factor value is 7.24%, which is over 0.5% better result comparing to originally reported. We believe our work will open a broader discussion on the disorder in quasicrystals (and other aperiodic systems) and motivate to develop new approaches to treat the diffraction data influenced by different types of disorder in the new way.

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Authors and Affiliations

R. Strzałka
I. Bugański
J. Śmietańska
J. Wolny
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Abstract

A new extraction process suitable for treating refractory CuCo2S4 under atmospheric pressure acidic leaching conditions was investigated. The effect of variables such as oxidant species, liquid-to-solid ratio, leaching time, oxidizing agent and mineral quality ratio, H2SO4 concentration, temperature and sodium chloride concentration on the extraction efficiency of Co, Cu and Fe from CuCo2S4 were investigated. Under optimal conditions including P80-P90 of the sample was d < 0.0074 mm, stirring speed of 400 rpm, leaching time of 8 h with sodium chlorate (NaClO3) and mineral quality ratio of 0.5, 2 mol/L H2SO4, liquid-to-solid ratio of 7, leaching temperature of 90°C and 4 mol/L sodium chloride. The leaching efficiency of Co, Cu, and Fe were nearly 97.08%, 100%, and 92.45%, respectively. Furthermore, the contents of cobalt and copper in leaching residue were all less than 0.4 wt.%, which satisfies the requirements of industrial production.

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Authors and Affiliations

Bo Dong
Jian-Hui Wu
Jun Wu
ORCID: ORCID
Xian-Peng Zhang
Jing-Jun Zhai
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Abstract

2060-T8 Al-Li alloy was friction stir butt welded under natural and water cooling conditions. Microstructures and mechanical properties of the welding joints were mainly compared and discussed. By spraying water on the top surface of stir zone, the grain size was reduced, attributing to the improvement of microhardness. The maximum tensile strength under the water cooling reached 461.1 MPa. The joint fractured at the stir zone due to the thickness reduction and the joint softening. The fracture surface consisted of many dimples with various sizes, indicating the typical ductile fracture. The strategy to apply the low heat input at the welding stage and high cooling rate at the cooling stage during FSW is necessary to obtain a high-quality FSW joint.

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Authors and Affiliations

Lin Ma
ORCID: ORCID
Shiyu Niu
Shude Ji
ORCID: ORCID
Peng Gong
ORCID: ORCID
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Abstract

2-phase composites are often used for high demanding parts that can undergo impact loads. However, most of the papers on dynamic loading concerns layered composites. In our opinion, the impact loads are not considered thoroughly enough. Good examples of 2-phase composites are: (1) a WC/Co cermet or (2) a monolithic ceramic Al2O3/ZrO2. The WC/Co cermet is often modelled as having ductile elasto-plastic Co matrix and ideally elastic WC grains. It is because of very high crushing resistivity of the WC.

In this paper, we present an extension to earlier elaborated models ([44]) with the assumption of ideal elasticity of the grains. The new and general numerical model for high-velocity impact of the 2-phase composites is proposed. The idea of this novelty relies on the introduction of crushability of grains in the composite and thermo-mechanical coupling. The model allows for description of the dynamic response both composite polycrystals made of: (1) 2 different purely elastic phases (e.g. Al2O3/ZrO2) or (2) one elastic phase and the second one plastic (e.g. cermet WC/Co), or (3) 2 elasto-plastic phases with different material properties and damage processes. In particular, the analysis was limited to the cases (2) and (3), i.e. we investigated the WC/Co polycrystal that impacted a rigid wall with the initial velocity equal to 50 m/s.

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Authors and Affiliations

E. Postek
T. Sadowski
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Abstract

The paper presents a method of measuring deformations of cylindrical samples on the testing machine for free tube hydroforming experiments. During experiments a sample made of a thin-walled metal tube is expanded by the internal pressure of the working liquid and additionally subjected to axial compression. This results in a considerable circumferential deformation of the tube and its shortening. Analysis of the load cases and their impact on the deformations can be helpful in determining e.g. tube material properties or general limiting conditions in the tube hydroforming process. In connection with the above, the value of deformations and knowledge of their course during experiment has become one of the most important problems related to the issue described above.

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Authors and Affiliations

H. Sadłowska
Ł. Morawiński
C. Jasiński
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Abstract

The aim of the study was to indicate the influence of consolidation processes on microstructure and selected mechanical properties of powder metallurgy Ti-5Al-5Mo-5V-3Cr alloy, which was produced by blending of elemental powders method. Morphology of the mixture and its ingredients were examined using scanning electron microscopy. The consolidation of powders mixture was conducted using two approaches. The first consisted of the uniaxial hot pressing process, the second included two steps – uniaxial cold pressing process and sintering under argon protective atmosphere. Microstructural analysis was performed for both as-pressed compacts using light microscopy. Additionally, computed tomography studies were carried out, in order to examine the internal structure of compacts. Chosen mechanical properties, such as Vickers hardness and compression strength was also determined and compared. The conducted research proves that the proposed production method leads to obtain materials with no structural defects and relatively low porosity. Moreover, due to the proper selection of manufacturing parameters, favorable microstructures can be received, as well as mechanical properties, which are comparable to conventionally produced material with the corresponding chemical composition.

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Authors and Affiliations

K. Zyguła
ORCID: ORCID
M. Wojtaszek
ORCID: ORCID
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Abstract

Coke oven gas (COG) dome injection in COREX melter gasifier is recognized as one of effective method to reduce the amount of solid fuel used for gasification. In this work, a static model was developed to study the characteristics when COG is injected from dome. The critical bosh gas and critical fuel rate in COREX melter gasifier under different melting rate and coke rate were discussed. The amount of COG injection from dome under the critical fuel rates was studied. The results shows that when the heat of bosh gas reaching the critical value, the decrement of fuel rate decreases with the increase of melting rate and increases with the increase of coke rate. Under the critical fuel rate, the total volume of COG increases with the increase of melting rate and coke rate. After the COG injection, the amount and reduction capacity of the generator gas can meet the needs of reduction in shaft furnace. The findings of this work can be used as a theoretical basis to guide plant operations for COG injection.

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Authors and Affiliations

Mingyin Kou
Heng Zhou
Shengli Wu
Yansong Shen
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Abstract

The ablation casting technology consists in pouring castings in single-use moulds made from the mixture of sand and water-soluble binder. After pouring the mould with liquid metal the mould is destructed (washed out) using a stream of cooling medium, which in this case is water. The process takes place while the casting is still solidifying.

The following paper focuses on testing the influence of the modified ablation casting of aluminum alloy on casts properties produced in moulds with hydrated sodium silicate binder. The authors showed that the best kind of moulding sands for Al alloy casting will be those hardened with physical factors – through dehydration. The analysis of literature data and own research have shown that the moulding sand with hydrated sodium silicate hardened by dehydration is characterized by sufficient strength properties for the modified ablation casting of Al alloys. In the paper the use of microwave hardened moulding sands has been proposed.

The moulds were prepared in the matrix specially designed for this technology. Two castings from the AlSi7Mg alloy were made; one by traditional gravity casting and the other by gravity casting using ablation.

The conducted casts tests showed that the casting made in modified ablation casting technology characterizes by higher mechanical properties than the casting made in traditional casting technology. In both experimental castings the directional solidification was observed, however in casting made by ablation casting, dimensions of dendrites in the structure at appropriate levels were smaller.

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Authors and Affiliations

K. Major-Gabryś
ORCID: ORCID
M. Hosadyna-Kondracka
ORCID: ORCID
S. Puzio
ORCID: ORCID
J. Kamińska
ORCID: ORCID
M. Angrecki
ORCID: ORCID
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Abstract

The paper presents the susceptibility of AE44 magnesium alloy to electrochemical corrosion and stress corrosion cracking (SCC). The evaluation of the intensity of the interaction of the corrosive environment was carried out using the corrosion tests and the Slow Strain Rate Test (SSRT). Corrosion tests performed in 0.1 M Na2SO4 solution (immersion in solution and under cathodic polarization conditions) revealed that the layer of corrosion products was much thicker after immersion test. The results of SSRT showed that the AE44 alloy deformed in the solution was characterized by higher plasticity compared to the alloy deformed in the air after immersion in solution. Moreover, the fractures were characterized by different morphology. In the case of an alloy deformed in the solution under cathodic polarization many microcracks on the fracture were observed, which were not observed in the case of the alloy deformed in the air.

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Authors and Affiliations

M. Sozańska
A. Mościcki
B. Chmiela
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Abstract

The subject of the study concerns the enhancement of corrosion and wear resistance of nitrided 42CrMo4 steel by the formation of zinc phosphate top layer. The present work is aimed at the assessment of the effect of increasing thickness of nitrided layer from approximately 2 µm to 16 µm on the morphology and properties of zinc phosphate coating. XRD analysis showed that along with the increase in the thickness of the nitrides layer, a change in the phase composition was observed. SEM/EDS examination revealed that top layer consists of crystalline zinc phosphate coating. The shape and size of crystals does not significantly depend on a thickness of nitrides layer but corrosion resistance determined by potentiodynamic method in 0.5M NaCl increased with an increase of thickness of a “white layer”. Similarily the wear resistance determined by the 3-cone-roll test was also the highest for 16 µm nitride layer.

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Authors and Affiliations

A. Kapuściński
L. Kwiatkowski
P. Wach
A. Mazurek
R. Diduszko
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Abstract

The aim of this work was to present a method of tissue culture research by measuring the impedance of cells cultured in the presence of nichrome. For this purpose, the Electric Cell-substrate Impedance Sensing system was used with a prototype substrate containing comb capacitors made of nichrome. Magnetron sputtering, photolithography and etching processes were used to produce the thin-film electrodes. In the experimental part, cells of mouse fibroblast cell line L929 were cultured according to the instruction manual in complete medium, under controlled growth conditions. Inoculation of arrays was carried out by 300 microliters per well of cell suspension at ~1.2×105 cells/ml. The results of the monitoring cells behavior in tissue culture indicate good cell viability and proliferative potential.

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Authors and Affiliations

A. Kociubiński
D. Zarzeczny
M. Prendecka
D. Pigoń
T. Małecka-Massalska
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Abstract

The state of the dislocation substructure of meteorite in which the history of phenomena accompanying the meteorite during its passage through the Earth’s atmosphere is recorded remains unused. The main goal of the presented work is a comprehensive analysis of the dislocation structure of the iron meteorite from the Morasko reserve (Poland, Wielkopolska Voivodeship) by TEM methods to determine the conditions and mechanism of its formation. The work is cognitive in the field of phenomena related to the destruction and deformation of the material in extreme conditions: space and terrestrial space. It can also be useful in the research on the creation of the material with specific mechanical properties, as well as a unique reference material for earth experiments with low-temperature deformation, high-speed deformation, recrystallization processes with short thermal pulses and structure relaxation in conditions of very long time periods.

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Authors and Affiliations

W. Osuch
R. Błoniarz
G. Michta
I. Suliga
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Abstract

Liquid forging alias squeeze casting gives the combined advantage of casting and forging. Optimum process parameters are important to get a cost-efficient process. In this study, four materials have been identified, which are extensively used in industries. These materials are commercially pure Al and three Al-alloys namely, 2124, 2218 and 6063. The pouring temperature and the mold temperature is maintained at 700oC and 250oC respectively. The materials were developed at seven pressure variations from 0 to 150 MPa. The effect of the pressure on the microstructures, porosity, and hardness has been reported. The coefficient of solubility is estimated for all materials and a polynomial relationship is found to be the best fit with the applied pressure. The pressure of 100 MPa gives better increment in hardness. The melting point and the freezing coefficient of the materials under study have been determined. A linear relationship between the pressure and the freezing time is deduced. It is observed that the solubility and the freezing coefficients depend on the pressure as well, in addition to the composition and temperature.

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Authors and Affiliations

Vineet Tirth
Amir Arabi

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