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Wyszukujesz frazę "Szymczyk, E." wg kryterium: Autor


Tytuł:
About mechanical joints design in metal - composite structure
Autorzy:
Puchała, K.
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/246795.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mechanical joint
adhesive joint
FEA
aviation
Opis:
Riveting is still one of the main joining methods of thin-walled aircraft structures. Such features as simplicity of implementation, possibility of two different material connection (e.g. metallic with non-metallic ones) and the fact that is it a well-known (reliable) method causes popularity of riveting. The never-ending attempt to obtain as low mass as possible (mainly to reduce fuel consumption) is the reason for using material of high specific strength in the aerospace industry. High strength titanium or aluminium alloys (e.g. 2024T3) and composite laminates (e.g. CFRP or Glare) are examples of such materials. The article deals with methods of connecting various materials. The paper presents advantages and disadvantages of different/selected connection types. Strength prediction and failure modes of mechanical joints are described for metallic as well as for composite components. Composites are complex materials having an anisotropic structure (and anisotropic mechanical properties) leading to various failure mechanisms. Main principles for appropriate joint design of composite laminate panels (laminate configuration and typical/specific geometrical dimensions) are indicated/specified. The bearing failure mechanism is accepted to be a safe progressive one. Mechanism of bearing (generally compressive) load transfer into composite laminates by shear of the matrix is analysed. Some examples of improvement bearing strength of laminates are presented according to literature. On the base of presented examples and bearing load transfer analysis, some conclusions for an appropriate solution of this problem are drawn.
Źródło:
Journal of KONES; 2012, 19, 3; 381-390
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza powierzchni kontaktu w połączniu nitowym
Analysis of contact surface in riveted joints
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/211058.pdf
Data publikacji:
2007
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
naprężenia kontaktowe
MES (metoda elementów skończonych)
analiza fraktograficzna
contact stress
FEM
fractography
Opis:
Celem pracy jest analiza rozkładów naprężeń (w szczególności naprężeń kontaktu) w połączeniu nitowym w aspekcie niszczenia powierzchni nitu i blach wywołanego cyklicznym rozciąganiem zakładkowego połączenia nitowego. Badania przeprowadzono dla próbek konstrukcyjnych wykonanych z cienkich blach aluminiowych połączonych stalowymi nitami. Materiały oraz wymiary próbek zostały dobrane tak, aby podczas cyklicznego rozciągania połączenia wystąpił intensywny fretting oraz kontrolowane niszczenie próbki w wybranej strefie. Wykonano symulacje MES procesu nitowania na prasie oraz obliczenia numeryczne w celu wyznaczenia obciążeń powodujących zerwanie rozciąganego statycznie połączenia i określenia sposobu niszczenia próbki. Przeprowadzono badania statyczne i zmęczeniowe próbek nitowanych oraz analizę fraktograficzną stanu powierzchni połączenia.
The papers deals with the analysis of contact stress fields and inspection of fretting phenomena in the neighbourhood of mating surfaces of the lap riveted joint subjected to cyclic load. The specimens are made of thin aluminium sheets connected by steel rivets. Chosen shape and dimensions of the sample ensures predictable and repetitive failure behaviour. Many undersirable phenomena, like electro-chemical corrosion, occur in a riveted joint due to different material properties of steel and aluminium alloy. This situation causes reduction in fatigue life and it is suitable for observing surface damage. Simulation of a riveting process is performed to obtain post riveting residual stress fields and deformation. Numerical FEM calculations are also carried out to estimate tearing (ultimate) force and to observe the mechanism of the specimen failure. Static and fatigue tests of tensile loaded lap riveted specimens and fractographic (SEM) analysis are performed.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2007, 56, 4; 75-84
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of load transfer into composite structure
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Puchała, K.
Powiązania:
https://bibliotekanauki.pl/articles/118025.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
mechanical joint
adhesive joint
composite material
load transfer
FEA
Opis:
The paper presents advantages and disadvantages of metal foils insertion between composite layers. Composites are complex materials of aniso-tropic structure leading to various failure mechanisms. Mechanism of compressive load transfer into composite laminates by shear of the matrix is analysed. The method of improvement compressive strength of laminates is presented according to literature and analysed for a sele-cted case. Simplified models of a laminate structure modified using various metal foils configurations are analysed with MSC.Marc code. Axial stress in prepreg layers and shear stress in adhesive layers are studied.
Źródło:
Applied Computer Science; 2014, 10, 3; 86-94
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of residual stress fields in the riveted joint
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Derewońko, A.
Powiązania:
https://bibliotekanauki.pl/articles/243089.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
FEM local model
non-destructive testing methods
Opis:
The riveted joints are critical areas of the aircraft structure. The residual stress and strain state appears at the rivet hole after the riveting process and improves fatigue behaviour of the joint. Numerical FE simulations of the upsetting process are carried out using the MARC code. Three-dimensional numerical models are used to determine the resulting stress and strain fields at the countersunk rivet and around the hole. The contact with friction is defined between the mating parts of the joint. Calculations are carried out in an elastic-plastic range. The influence of the rivet geometry, rivet stiffness and the sheet material model on strain and stress states is studied. Non-destructive testing methods like X-ray diffraction, liquid penetrant inspection and visual detection analysis with a UV lamp are used for validation of numerical results. Comparison between numerical and experimental results gives a satisfactory agreement. Numerical simulations allow investigating the influence of imperfections on the strength of the joint.
Źródło:
Journal of KONES; 2007, 14, 2; 465-473
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the efficacy of ofatumumab in patients with chronic lymphocytic leukaemia treated in the Department of Haematooncology and Bone Marrow Transplantation of the Medical University in Lublin - prelimary results
Autorzy:
Wasik-Szczepanek, E.
Szymczyk, A.
Kowal, M.
Nogalski, A.
Hus, M.
Powiązania:
https://bibliotekanauki.pl/articles/2081565.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
chronic lymphocytic leukemia
ofatumumab
monoclonal antibodies
immunotherapy
Opis:
Introduction. Despite significant recent advances in the treatment of chronic lymphocytic leukaemia (CLL), most cases of the disease are still incurable. Treatment with monoclonal antibodies, such as ofatumumab, is one of the new therapeutic options. Objective. Retrospective analysis of the efficacy of ofatumumab in patients with chronic lymphocytic leukaemia (CLL) treated in the Haematooncology and Bone Marrow Transplantation Department of the Medical University of Lublin, Poland, during 2011–2013. Materials and method. The analysis included 5 patients (3 women and 2 men), aged 47–65, with Rai stage II-IV CLL, after a few lines of treatment. Three patients received ofatumumab in monotherapy and 2 patients received ofatumumab in combination with cyclophosphamide (50 mg/day) and dexamethasone (40 mg/day). All patients included in the study were diagnosed with an active form of leukaemia with symptoms such as lymphocytosis or massive lymphadenopathy. Results. All patients responded to the treatment. Within the first 8 weeks of the treatment, levels of white blood cells returned to normal in patients with baseline lymphocytosis (3 patients). An increase in platelet levels was reported in 3 patients. Haemoglobin levels were higher or comparable to the baseline values in all studied patients after the completion of immunotherapy. In the patient with massive lymphadenopathy and hepato- and splenomegaly, the size of the lymph nodes, spleen and liver decreased and neutrophil levels increased. Time of progression was 5–12 months, and in one patient partial remission has been maintained. The treatment was well-tolerated in most cases. Asymptomatic neutropenia and an infection with Candida glabrata were observed. Conclusions. Ofatumumab may be a new and safe therapeutic option for patients with CLL after a few lines of treatment.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 1; 56-59
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakteryzacja geometryczna i mechaniczna skaffoldów ze stopu TI6AL7NB wytworzonych w technologii laserowej mikrometalurgii
Geometrical and mechanical characterization of scaffolds manufactured from TI-6AL-7NB by laser micrometallurgy – SLM
Autorzy:
Szymczyk, P.
Pawlak, A.
Ziółkowski, G.
Dybała, B.
Chlebus, E.
Powiązania:
https://bibliotekanauki.pl/articles/99269.pdf
Data publikacji:
2013
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
skaffold
Ti6Al7Nb
mikrotomografia komputerowa
SLM
scaffold
Ti-6Al-7Nb
computed microtomography
Opis:
Praca przedstawia wyniki badań struktur mikroskaffoldów wytwarzanych ze stopu Ti6Al7Nb, w technologii laserowej mikrometalurgii proszków metali. Opracowana technologia wytwarzania mikrostruktur kratowych, umożliwia produkowanie regularnie porowatych struktur, składających się z porów w kształcie sześcianu z walcowymi belkami wpisanymi w jego krawędzie. Celem badań było opracowanie metodologii oceny i charakteryzacji wytworzonych struktur.
This paper presents the investigation results on Ti6Al7Nb micro scaffold structures, manufactured in metal powder Selective Laser Melting process. Developed technology of manufacturing lattice microstructures, can produce regular porous structure consisting of pores in the shape of a cube with cylindrical beams entered in the edges. The aim of the study was to develop a methodology for the evaluation and characterization of the produced structures.
Źródło:
Aktualne Problemy Biomechaniki; 2013, 7; 157-162
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the dynamic riveting process of a rivet with and without a compensator
Autorzy:
Szymczyk, E.
Slawinski, G.
Jachimowicz, J.
Derewonko, A.
Powiązania:
https://bibliotekanauki.pl/articles/245374.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
mushroom rivet
FEM local model
deformation fields
Opis:
The paper deals with the analysis of deformation of a rivet hole in a riveted joint after the manual dynamic riveting process. For many years, riveting remains a traditional and the most popular method ofjoining in aircraft structures. The residual stress and strain state appear at the rivet hole after the riveting process, which improves the joint's fatigue behaviour. The local finite element models are made with Patran. The rivet and sheets are described using eight-noded, three-dimensional brick elements. The riveting tools consist of four-noded, two-dimensional shell elements. Numerical FE simulations of the upsetting process are carried out using the Ls-Dyna code. The contact with friction is defined between the collaborating parts of the specimen. The results of simulations of the dynamic riveting process of a mushroom rivet with and without a compensator are compared in this paper. Hole deformation of the upper and lower sheet, squeezing force, as well as deformations of the rivet head are analysed. The influence of the compensator on strain and displacement states is studied. Simulation shows that some technological factors may have positive influence on the residual stress fields. Using the rivet with a compensator results in a better rivet hole filling capability. The rivet hole displacement in upper and lower sheets are at the same level. Paper also present manual dynamic riveting process of reverse and standard riveting procedure and model of riveted specimen.
Źródło:
Journal of KONES; 2009, 16, 4; 455-462
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the dynamic riveting process of a rivet with and without a compensator
Autorzy:
Szymczyk, E.
Slawinski, G.
Jachimowicz, J.
Derewonko, A.
Powiązania:
https://bibliotekanauki.pl/articles/245575.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
mushroom rivet
FEM local model
deformation fields
Opis:
The paper deals with the analysis of deformation of a rivet hole in a riveted joint after the manual dynamic riveting process. For many years, riveting remains a traditional and the most popular method of joining in aircraft structures. The residual stress and strain state appear at the rivet hole after the riveting process, which improves the joint's fatigue behaviour. The local finite element models are made with Patron. The rivet and sheets are described using eight-noded, three-dimensional brick elements. The riveting tools consist of four-noded, two-dimensional shell elements. Numerical FE simulations of the upsetting process are carried out using the Ls-Dyna code. The contact with friction is defined between the collaborating parts of the specimen. The results of simulations of the dynamic riveting process of a mushroom rivet with and without a compensator are compared in this paper. Hole deformation of the upper and lower sheet, squeezing force, as well as deformations of the rivet head are analysed. The influence of the compensator on strain and displacement states is studied. Simulation shows that some technological factors may have positive influence on the residual stress fields. Using the rivet with a compensator results in a better rivet hole filling capability. The rivet hole displacement in upper and lower sheets are at the same level. Paper also present manual dynamic riveting process ofreverse and standard riveting procedure and model of riveted specimen.
Źródło:
Journal of KONES; 2009, 16, 3; 415-422
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Strength Analysis of Curved-Root Concept for Compressor Rotor Blade in Gas Turbine
Autorzy:
Wdowiński, W.
Szymczyk, E.
Jachimowicz, J.
Moneta, G.
Powiązania:
https://bibliotekanauki.pl/articles/97975.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
finite element method
turbine engine
rotor disk
rotor blades
blade-disc connection
shape optimization
Opis:
The motivation of the article is fatigue and fretting issue of the compressor rotor blades and disks. These phenomena can be caused by high contact pressures leading to fretting occurring on contact faces in the lock (blade-disk connection, attachment of the blade to the disk). Additionally, geometrical notches and high cyclic loading can initiate cracks and lead to engine failures. The paper presents finite element static and modal analyses of the axial compressor 3rd for the original trapezoidal/dovetail lock geometry and its two modifications (new lock concepts) to optimize the stress state of the disk-blade assembly. The cyclic symmetry formulation was used to reduce modelling and computational effort.
Źródło:
Fatigue of Aircraft Structures; 2017, 9; 137-155
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eksperymentalna i numeryczna analiza procesu instalacji nitu
Experimental and numerical analysis of a rivet installation process
Autorzy:
Korbel, A.
Szymczyk, E.
Skorupa, A.
Powiązania:
https://bibliotekanauki.pl/articles/211311.pdf
Data publikacji:
2013
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
połączenia nitowe
nity lotnicze
siła zakuwania nitu
ekspansja otworu nitowego
naprężenia resztkowe
MES (metoda elementów skończonych)
riveted joints
aircraft rivets
squeeze force
hole expansion
residual stresses
FEM
Opis:
W artykule przedstawiono wyniki badań eksperymentalnych oraz analiz numerycznych MES związane z procesem zakuwania nitu. Analizie poddano stosowane w polskim przemyśle lotniczym nity z łbem kulistym z materiału PA24 oraz blachy ze stopu D16CzATW. Zbadano, jak siła nitowania wpływa na charakterystyczne wymiary zakuwki oraz ekspansję otworu nitowego, a następnie uzyskane wyniki porównano z wynikami analiz MES. Ponieważ dotychczas stosowane metody pomiaru ekspansji otworu mogą być obarczone błędem, opracowano własną metodę pomiaru, cechującą się większą dokładnością. Zbadano, jak przyjęty w analizach MES model materiału nitu wpływa na jakość otrzymywanych wyników. Wykazano, że wierne odtworzenie procesu nitowania w MES wymaga odpowiedniego zdefiniowania modeli materiałowych stosowanych w tych analizach. Ponadto określono wpływ siły zakuwania nitu na rozkład oraz wielkość resztkowych naprężeń promieniowych i obwodowych wokół otworu nitowego.
Experimental results and numerical FE analysis related to the riveting process are considered in the paper. The research has focused on the round head rivet and D16CzATW sheet material used by Polish aircraft manufacturers. The effect of rivet squeeze force on the rivet driven head dimensions and rivet hole expansion was experimentally investigated and the results were compared with the FE results. In view of an insufficient accuracy of hole expansion measurement methods used so far, a novel more accurate measurement technique developed by the present authors has been applied. FE results were obtained for various models of the rivet material. It was shown that an adequate numerical modelling of the rivet installation is conditioned by appropriate assumptions about the constitutive characteristics of the rivet material. The impact of the squeeze force on distributions and values of residual stresses generated by riveting was also determined.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2013, 62, 2; 181-200
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Friction coefficient determination based on the results of ball – on - flat test
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Prasek, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/248003.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
friction coefficient
ball-on-flat test
FFT
Opis:
The interaction of contacting surfaces in relative motion is basic for every engineering design. The transmission of load from one rubbing surface to its mating surface under conditions of dry contact is taken into account. Microlocal or global models of friction are used to describe this phenomenon. In global approach, frictional force is proportional to normal load. A coefficient of external friction depends on the type, shape, and precision of finishing the surfaces of mating elements. The aim of the paper is analysis of a friction coefficient for 2024T3 aluminium alloy during cyclic tangential loading. Experimental tests are carried out on a ball-on-flat wear-testing machine Ducom. Tests of reciprocating friction are carried out using the following friction pairs of specimens: the ball specimen is made of high strength aluminium alloy PA25 and the plane specimen is made of 2024T3 alloy. Finally, graphs of temporary friction coefficients versus time in the form of fluctuated periodical functions are obtained. Two phases of friction are detected. However, during the first stage, the friction coefficient is relatively small while in the second period it rapidly increases and tends to become more irregular. Static and dynamic friction coefficients are estimated. In order to determine the dynamic coefficient the Discrete Fourier Transformation is used. The calculation of the dominant amplitude (corresponding to test frequency) of the studied functions is possible due to this method. An increase of the friction coefficient with an increase of normal load is observed. A cladding layer also causes an increase of friction, especially in the second phase.
Źródło:
Journal of KONES; 2012, 19, 1; 415-422
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of barrier properties of glycol modified poly(ethylene terephthalate) based nanocomposites containing graphene derivatives forms
Poprawa właściwości barierowych nanokompozytów polimerowych opartych na modyfikowanym poli(tereftalanie etylenu) z dodatkiem pochodnych grafenu
Autorzy:
Paszkiewicz, S.
Szymczyk, A.
Pawlikowska, D.
Irska, I.
Piesowicz, E.
Jotko, M.
Lisiecki, S.
Bartkowiak, A.
Sieradzka, M.
Fryczkowski, R.
Kochmańska, A.
Kochmański, P.
Rosłaniec, Z.
Powiązania:
https://bibliotekanauki.pl/articles/946934.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
graphene derivatives forms
glycol-modified poly(ethylene terephthalate)
in situ polymerization
barrier properties
pochodne grafenu
poli(tereftalan etylenu) modyfikowany glikolem cykloalifatycznym
polimeryzacja in situ
właściwości barierowe
Opis:
The development and further studies on several types of graphene nanoplatelets (GNP) have enabled manufacture of electrically conductive and reinforced polymer nanocomposites with enhanced gas barrier performance at extremely low loading. Herein, we present the synthesis process, morphology and gas barrier properties of the glycol modified poly(ethylene terephthalate) (PETG) based nanocomposites. For the first time, we compared how different types of GNPs, at the same nanofiller's content of 0.5 wt %, affect the properties of polymer matrix obtained by in situ polymerization.
Opracowano nanokompozyty polimerowe (PETG) na bazie poli(tereftalanu etylenu) (PET) modyfikowanego glikolem cykloalifatycznym z niewielkim dodatkiem wybranych typów płytek grafenowych (GNP). Zbadano morfologię PETG oraz ich właściwości barierowe. Oceniono wpływ dodatku różnego typu nanopłytek grafenowych na właściwości osnowy polimerowej w nanokompozytach otrzymanych metodą polimeryzacji in situ. Stwierdzono, że otrzymane, wzmocnione nanocząstkami grafenu i elektrycznie przewodzące kompozyty PETG odznaczały się zwiększoną barierowością w stosunku do par i gazów.
Źródło:
Polimery; 2017, 62, 11-12; 868-874
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of sintering temperature and compression speed on properties of hydroxyapatite disks
Wpływ temperatury spiekania i prędkości ściskania na własności krążków hydroksyapatytowych
Autorzy:
Smolina, I.
Szymczyk, P.
Chlebus, E.
Powiązania:
https://bibliotekanauki.pl/articles/98789.pdf
Data publikacji:
2016
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
hydroxyapatite
bioceramics
pellets
dense disks
structure
heat treatment
hydroksyapatyt
bioceramika
pelety
struktura
obróbka cieplna
Opis:
The present article is dedicated to an investigation of a production method of hydroxyapatite (HA) disks with a study of an influence of compression speed (5, 10 and 15 mm/min) and sintering temperature (900˚C and 1200˚C) on structure and properties of those disks. Measurements of density, mass loss and shrinkage as well as scanning electron microscopy (SEM) and light optical microscopy (LM) observations were performed. The aim of this study is to define optimal process parameters, which are applicable for using as a substrate for in vitro experiments.
Niniejszy artykuł poświęcony analizie sposobu krążków hydroksyapatytowych (HA) poprzez ocenę wpływu szybkości ściskania (5, 10 i 15 mm/min) i temperatury spiekania (900˚C i 1200˚C) na strukturę i właściwości krążków. Plan badań zawierał pomiary gęstości, utraty masy i kurczliwości oraz obserwację struktury krążków przy użyciu skaningowej mikroskopii elektronowej (SEM) i mikroskopii optycznej (MO). Celem badań jest określenie optymalnych parametrów procesu do produkcji krążków HA, stosowanych jako podłoże dla eksperymentów in vitro.
Źródło:
Aktualne Problemy Biomechaniki; 2016, 11; 121-126
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ion Implantation and Transient Melting: A New Approach to Formation of Superconducting MgB$\text{}_{2}$ Phases
Autorzy:
Piekoszewski, J.
Kempiński, W.
Stankowski, J.
Prokert, F.
Richter, E.
Stanisławski, J.
Werner, Z.
Szymczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/2041609.pdf
Data publikacji:
2004-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
74.78.-w
Opis:
An attempt to synthesize superconducting MgB$\text{}_{2}$ inter-metallic compound from the liquid state is presented. The process consists of two steps. In the first one, boron ions are implanted into a magnesium substrate. In the second one, the near-surface region of such system is melted by short, intense hydrogen plasma pulses without necessity of annealing in Mg vapor. A magnetically modulated microwave absorption method was used to detect superconducting regions in the obtained MgB$\text{}_{2}$ layer. Percolation between nano-regions (islands) of MgB$\text{}_{2}$ has not been observed. However, a superconducting state of the insulated islands has been experimentally proven with transition temperatures T$\text{}_{C}$ as high as 31 K.
Źródło:
Acta Physica Polonica A; 2004, 106, 6; 861-868
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isolation and characterization of a copalyl diphosphate synthase gene promoter from Salvia miltiorrhiza
Autorzy:
Szymczyk, P.
Skala, E.
Grabkowska, R.
Jelen, A.
Zebrowska, M.
Balcerczak, E.
Powiązania:
https://bibliotekanauki.pl/articles/57296.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The promoter, 5' UTR, and 34-nt 5' fragments of protein encoding region of the Salvia miltiorrhiza copalyl diphosphate synthase gene were cloned and characterized. No tandem repeats, miRNA binding sites, or CpNpG islands were observed in the promoter, 5' UTR, or protein encoding fragments. The entire isolated promoter and 5' UTR is 2235 bp long and contains repetitions of many cis-active elements, recognized by homologous transcription factors, found in Arabidopsis thaliana and other plant species. A pyrimidine-rich fragment with only 6 non-pyrimidine bases was localized in the 33-nt stretch from nt 2185 to 2217 in the 5' UTR. The observed cis-active sequences are potential binding sites for trans-factors that could regulate spatio-temporal CPS gene expression in response to biotic and abiotic stress conditions. Obtained results are initially verified by in silico and co-expression studies based on A. thaliana microarray data.
Źródło:
Acta Societatis Botanicorum Poloniae; 2016, 85, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł

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