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1

In vitro investigation of the platelet and leukocyte activation on different crystallographic surfaces of silicon carbide

Parlak Zümray V., Zybała Rafał, Labude Norina, Neuss Sabine, Telle Rainer, Schickle Karolina

Engineering of Biomaterials

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2019

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Vol. 22, no. 153 spec. iss.

37

2

Stanisław Zaremba i krystalografia

Pogoda Z.

Kwartalnik Historii Nauki i Techniki

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2015

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R. 60, nr 4

131--137

EN

In the paper we present a little-known episode from the research activities of Stanisław Zaremba in the field of crystallography. We discuss two publications: one of over 470 pages, entitled Sur les fondements de la cristallographie géométrique written together with Stefan Kreutz and published in „Bulletin de l’Académie de Sciences de Cracovie” and Rola przekształceń punktowych przestrzeni w krystalografii included in Poradnik dla samouków.

3

A Review of the Automation of the Czochralski Crystal Growth Process

Winkler J., Neubert M., Rudolph J.

Zeszyty Historyczne Politechniki Warszawskiej

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2014

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z. 16

123--134

EN

On the occasion of the centennial of the invention of the Czochralski crystal growth process by the Polish scientist Jan Czochralski, a review of selected strategies for the automatic control of this process is given. This review provides a sketch of the fundamental challenges of controlling the Czochralski process and the basic concepts of feedback control. Both early and modern approaches to the control of the Czochralski process are described. The discussion focuses on questions related to feed-forward control, feedback control, and state estimation. The presented methods rely on simple mathematical process models in contrast to the finite element model-based approaches typically used in crystal growth process design and analysis. Such mathematical models motivate both the structure and parameters of the chosen controller. A comprehensive list of references to background literature on this topic completes this survey.

4

Transformacje strukturalne w kryształach wywołane reakcjami fotochemicznymi

Turowska-Tyrk I., Bąkowicz J.

Wiadomości Chemiczne

|

2014

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[Z] 68, 5-6

381--402

EN

Structural changes induced in crystals by photochemical reactions were presented. The changes concern: a) the distances between neighbouring reactant molecules and their mutual orientation in the case of intermolecular reactions, b) the distances and angles between fragments of a molecule for intramolecular reactions, c) the position of molecules in crystals, d) geometry of hydrogen bonds, e) cell constants, and f) the content of product molecules in crystals. For most intramolecular reactions, the distances between reactive atoms are constant for a long time in phototransformation and decrease rapidly at its end (Figs. 3 and 5). In the case of intermolecular reactions, the distances between reactive atoms of reactant molecules decrease linearly along with the phototransformation of crystals (Fig. 7). Additionally, unreacted molecules become, to a certain degree, similar to product molecules in terms of their shape (Figs, 4 and 8). Reactant and product molecules do not assume a fixed place in crystals. Product molecules change their orientation towards that of which is observed in a pure product crystal and reactant molecules gradually move away from the position they took in pure reactant crystals. All this has an influence on the geometry of hydrogen bonds existing in crystals (Fig. 9). The above-mentioned structural transformations find their expression in values of cell constants (Fig. 10). The factors influencing the photoreactivity of molecules in crystals were also described. Knowledge of crystal and molecular structures of partly reacted crystals, determined thanks to X-ray structure analysis which is a branch of crystallography, reveals the behaviour of molecules in crystals in which photochemical reactions proceed and helps to understand a pathway of these reactions.

5

Współczesne metody badawcze w określaniu struktur dioksygenaz intradiolowych

Wojcieszyńska D., Hupert-Kocurek K., Sitnik M., Guzik U.

Chemik

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2012

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Vol. 66, nr 12

1346--1351

PL

Dioksygenazy intradiolowe są kluczowymi enzymami szlaku orto rozkładu związków aromatycznych. Ze względu na rodzaj intermediatu, którego pierścień rozszczepiają, enzymy te zaliczane są do trzech klas. Obecnie, dzięki zastosowaniu nowoczesnych metod badawczych takich jak: krystalografia rentgenowska, spektrometria mas, spektroskopia elektronowego rezonansu paramagnetycznego oraz spektroskopia rentgenowska, możliwe jest dokładne poznanie nie tylko ich budowy przestrzennej, ale również wyjaśnienie sposobu wiązania się substratu z ligandami centrum aktywnego oraz poznanie mechanizmu katalizy.

EN

Intradiol dioxygenases are essential enzymes of ortho pathway involved in the decomposition of aromatic compounds. Enzymes are grouped into three classes on account of a type of the intermediate whose ring they cleave. Nowadays, the application of such modern research methods as X-ray crystallography, mass spectrometry, electron paramagnetic resonance spectroscopy, and X-ray spectroscopy creates possibilities for the thorough understanding of their spatial structure as well as for explaining the way of substrate binding with ligands in the active site and learning the catalysis mechanism.

6

Positron trapping in functional spinel-type oxide ceramics.

Klym H., Balitska V., Shpotyuk O. I., Ingram A.

Archives of Materials Science

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2006

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Vol. 27, nr 4

177-187

EN

Positron trapping is studied in functional spinel-type oxide MgAl2O4 and Cu0,4Co0,4Ni0,4Mn1.8O4 ceramics using positron annihilation lifetime spectroscopy. Obtained results are treated in terms of multi-exponential model of positron spectrum involving both positron trapping and ortho-positronium decaying. Crystallographical specifity of spinel structure reflects on the shortest lifetime component, while the middle component corresponds to the vacancy-like defects near boundaries. It is shown that in the cases of humidity-sensitive MgAl2O4 ceramics the positron trapping parameters in defects near grain boundaries occurs more efficiently in water-moistened ceramics.

7

Crystallography of the copper-type shear bands

Paul H.

Archives of Metallurgy

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2002

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Vol. 47, iss. 2

205-215

EN

The microtextural changes within macroscopic shear bands (MSBs) in high purity aluminium and copper single crystals with {112}(111) initial orientation, deformed by channel die compression, have been studied in detail. Systematic measurements of single orientations by SEM/EBSD and TEM/CBED clearly show that the investigated crystals are stable only in a global sense. The occurrence of the first set of MSBs is connected with a local lattice rotation towards the {001}<110> orientation. In particular, this process directs the (111) slip plane, towards a shear plane and the activation of new, highly stressed {111}<101>+{111}<011>->CP{111}<112> slip systems, is documented. The deformed matrix near MSBs represents a relatively more stable behaviour, and the group of the orientations situated near the C{112}<111>-C{4 4 11}<11 11 8> positions describes it.

PL

W pracy analizowano mikrosteksturowe zmiany zachodzące w obszarze makroskopowo obserwowanych pasm ścinania (MSBs), w monokryształach aluminium i miedzi o orientacji wyjściowej {112}<111>, odkształcanych w próbie nieswobodnego ściskania. Pomiary orientacji lokalnych z wykorzystaniem techniki TEM/CBED a zwłaszcza SEM/EBSD, umozliwiajacej konstruowanie map orientacji, tzw. Orientation Imaging Maps (OIM) wskazuja, że badane kryształy są stabilne jedynie w sensie globalnym. Pojawienie się pierwszej rodziny makroskopowych pasm ścinania związane jest z lokalną zmianą orientacji, obserwowaną na figurze biegunowej jako rozmycie w kierunku orientacji {001}<110>. Jednym ze skutków rotacji sieci krystalicznej wewnątrz obszaru pasma, jest zmiana nachylenia płaszczyzny poślizgów współpłaszczyznowych CP(111) w kierunku nałożenia się z płaszczyzna ścinania a także aktywacja operujących na tej plaszczyźnie poślizgów typu: {111}<101>+{111}<011>->CP{111}<112>. Zmiany orientacji obserwowane w obszarach poza pasmem są znacznie mniejsze i mogą być opisane ciągiem położeń: C{112}<111>-D{4 4 11}<11 11 8>.

8

The Ribosome and the Spliceosome Are the True Ribozymes

Giel-Pietraszuk M., Barciszewski J.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 12

1807-1816

EN

Recent advances in ribosome crystallography revealed an atomic resolution structure of the peptidyl-transferase active site. Similarly big progress in biochemical studies of spliceosomes provided a good basis to modify our view concerning functions of these particles. In this review the problem if the ribosomes and the spliceosomes are the ribozymes is discussed.

9

Phase transformations in a Ni-Mo-Cr alloy.

Dymek S., Wróbel M., Dollar M., Blicharski M.

Inżynieria Materiałowa

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2001

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R. XXII, nr 4

305-307

PL

W pracy przedstawiono charakterystykę nadstopu na osnowie niklu, zawierającego 25% Mo i 8% Cr, ze szczególnym uwzględnieniem wpływu obróbek cieplnej i termomechanicznej na przemiany fazowe. Badano próbki przesycane z temperatury 1100 stopni Celsjusza i starzone przy temperaturze 650 stopni Celsjusza: (a) przez 72 godziny (konwencjonalna obróbka cieplna), (b) przez 4000 godzin, (c) przez 4000 godzin a następnie odkształcone plastycznie i wyżarzone przy temperaturze 650 stopni Celsjusza przez kolejne 1000 godzin. Stwierdzono, że konwencjonalne starzenie prowadzi do tworzenia się soczewkowych dyspersyjnych wydzieleń metastabilnej fazy Ni2(Mo,Cr). Starzenie przez 4000 godzin powoduje wzrost tych wydzieleń, bez zmiany typu ich uporządkowania i charakterystyki krystalograficznej. Odkształcenie plastyczne wraz z wyżarzaniem przez 1000 godzin przy temperaturze 650 stopni Celsjusza przyspiesza rozpad fazy Ni2(Mo,Cr) na mieszaninę faz na osnowie Ni3Mo i Ni4Mo.

EN

The paper gives a characteristic of a nickel-based superalloy containing 25 wt. % Mo and 8 wt. % Cr with particular attention to the influence of a thermomechanical and heat treatment on phase transformations. The applied heat treatments are comprised of soaking at temperature 1100 degrees centigrade followed by aging at 650 degrees centigrade at three conditions: conventional aging for 72 hours, prolonged aging for 4000 hours and prolonged aging for 4000 hours followed by cold working and subsequent aging for 1000 hours. The conventional aging led to the formation of lenticular precipitates of the dispersed metastable Ni2(Mo,Cr) phase. The aging for 4000 hours brought about coarsening of the ordered domains without changing their crystallographic and ordering characteristics. The plastic deformation preceded the further aging for 1000 hours accelerated the decomposition of the Ni2(Mo,Cr) phase on the mixture of the Ni3Mo and Ni4Mo-based phases.

10

Crystallographic aspects of the shear bands formation in C-oriented Cu-2%Al single crystals.

Pakul H., Piątkowski A., Jasieński Z., Driver J.H., Pawełek A.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

708-711

EN

High purity Cu-2%Al single crystals with initial C{112}<111> orientation have been deformed by plane strain compression (PSC) at 77K and 293K to develop fine shear bands (SB) in a twin-matrix (T-M) substructure. The microstructural and microtextural changes during deformation have been studied in detail mostly by TEM/CBED method. Local orientations measurements show that the scattering of the original T-M orientations within shear bands inclined at (+/-) 35 degrees is due to the elementary, local rigid lattice rotation around the transverse direction (TD)II<011> axis.

PL

W pracy analizowano metodami mikroskopii elektronowej wpływ umocnionej struktury matryca-bliźniak na proces formowania się pasm ścinania w monokryształach stopu Cu-2%Al, odkształcanych w próbie nieswobodnego ściskania w temperaturze 77K i 293K. W szczególności badania orientacji lokalnych metodą TEM/EBSD pokazały, że rozmycie początkowej orientacji płytek matryca-bliźniak wewnątrz pasm ścinania jest związane z procesem sztywnej rotacji sieci dookoła kierunku poprzecznego TDII<011>.

11

Stability investigations of pure and doped with Cu, Fe and Cr ions lithium niobate single crystals for optical applications

Kaczmarek S.

Biuletyn Wojskowej Akademii Technicznej

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2001

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Vol. 50, nr 6

21-34

EN

The results of investigations of the influence of gamma and proton radiations on absorption, luminescence and birefringence of either pure or Cu, Fe and Cr doped LiNbO₃ single crystals were presented. A method of birefringence dispersion testing on the entire areas of plane-parallel plates of LiNbO₃ crystals has been illustrated by the influence of both types of irradiation on pure and Fe, Cr and Cu-doped LiNbO₃ wafers. It was stated that LN:Cu single crystals show different behavior than other investigated crystals. First of all it exhibits lower susceptibility to ɣ-rays, the absence of 500 nm additional absorption and strong proton susceptibility observed in polarimeter measurements.

PL

W pracy przedstawiono rezultaty badań wpływu promieniowania gamma i protonów na absorpcję, luminescencję i dwójłomność optyczną czystych lub domieszkowanych Cu, Fe i Cr monokryształów LiNbO₃. Na przykładzie płasko-równoległych dużych płytek LiNbO₃ zilustrowano metodę testowania dwójłomności optycznej. Stwierdzono, że monokryształy LiNbO₃:Cu wykazują wyższą odporność na promieniowanie gamma, brak dodatkowej absorpcji w pobliżu 500 nm (biopolarony Nb⁴⁺ - Nb⁴⁺ i wysoką podatność na promieniowanie protonów obserwowaną w badaniach polarymetrycznych.

12

Blue fluorescence of Li₂B₄O₇ glasses doped with rare-earths and transition metal ions

Kaczmarek S., Grinberg M., Wiśniewski K., Koepke C., Majchrowski A., Czuba M.

Biuletyn Wojskowej Akademii Technicznej

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2001

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Vol. 50, nr 8

131-146

EN

Absorption and emission spectra of Cr, Eu and Dy ions in Li₂B₄O₇ glasses melted in oxygen and hydrogen were measured for valency states and excited states analysis. It was stated that the presence of Cr⁶⁺ ion is limited by composition of the starting mixture and atmosphere of the melting and that this ion arises as a Cr⁶⁺O₄ complex. The 308 nm line excites the Li₂B₄O₇:Cr glass within the highest absorption peak which can be ascribed to the following charge transfer transition: Cr⁶⁺O₄(3d⁰2p⁶) -Cr⁵⁺O → (3d¹2p⁵). Under gamma irradiation Cr⁶⁺O₄ complex of 3d(0) configuration can be disintegrated giving additional absorption bands may be (beside self-emission of the glass) responsible for 430 nm emission.

PL

Przeprowadzono pomiary widm absorpcji i emisji szkieł LiB₄O₇ domieszkowanych Cr, Eu oraz Dy w celu dokonania analizy stanów walencyjnych oraz stanów wzbudzonych. Stwierdzono, że obecność jonu Cr⁶⁺ determinowana jest przez skład mieszaniny wyjściowej oraz atmosferę wzrostu i że jon ten występuje w postaci kompleksu Cr⁶⁺O₄. Linia 308 nm lasera excimerowego wzbudza szkło Li₂B₄O₇:Cr do wyżej położonego piku absorpcyjnego, który można opisać jako wynik przejścia typu charge-transfer: Cr⁶⁺O₄ (3d⁰2p⁶-Cr⁵⁺O⁻(3d¹2p⁵). Pod wpływem promieniowania gamma kompleks Cr⁶⁺O₄ o konfiguracji 3d⁰ może zostać rozerwany dając dodatkowe pasma absorpcji charakterystyczne dla centrów Cr³⁺ i Cr⁴⁺ w położeniach tetraedrycznych. Jedno z tych dodatkowych pasm może być odpowiedzialne za emisję 430 nm.

13

Blue fluorescence of LaGaO₃/SrTiO₃ mixed crystals

Kaczmarek S. M., Berkowski M., Czuba M., Aleksiyko R., Fink-Finowicki J., Olesińska W.

Biuletyn Wojskowej Akademii Technicznej

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2001

|

Vol. 50, nr 8

119-129

EN

A series of La₁₋xSrxGa₁₋xTixO₃ solid solution single crystals with x+0,0.04, 0.08 and 0.12 was grown by the Czochralski method and with x=0.01, by the floating zone method. The crystals were grown from the meltwith stoichiometric Ga₂O₃ amount at a growth rate ranging from 2.5 mm/h for pure LaGaO₃ to 1.2 mm/h for x=0.08. Larege, good quality single crystals were grown by the Czochralski method in the concentration range from 0 to 0.04. Thermal analysis proved that the temperature of the first order phase transition observed in pure LaGGaO₃ at 150°C falls to 76°C at x=0.04 and remains almost constant at higher x. The observed fluorescence of ²E-²T₂ transition of Ti³⁺ in the crystals shows two bands centered at about 420 and 447 nm coming from excitation at 314, 340 and 384 nm absorption bands. The fluorescence spectra are strongly polarized.

PL

Metodą Jana Czochralskiego otrzymano szereg kryształów La₁₋xSrGa₁₋xTixO₃ z x=0,04; 0,08 i 0,12 zaś metodą topnienia strefowego z x=0,01. Kryształy otrzymano z roztworu stechiometrycznego Ga₂O₃ z prędkością wzrostu zmieniającą się od 2,5 mm/h dla czystego LaGaO₃ do 1,2 mm/h dla x=0,08. Analiza termiczna wykazała, że temperatura przejścia fazowego pierwszego rzędu obserwowana w czystym LaGaO₃ dla 150°C spada do 76°C dla x=0,04 i pozostaje prawie stała dla większych x. Obserwowana fluorescencja dla przejścia ²T₂-²E jonów Ti³⁺ wykazuje obecność dwóch pasm z maksimum dla 420 i 447 nm, pochodzących od wzbudzeń 314, 340 i 384 nm. Widmo fluorescencji wykazuje silną polaryzację.

14

Tworzywa anortytowe.

Dziubak C., Rećko W.M.

Szkło i Ceramika

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1999

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R. 50, nr 6

19-21

15

The interphase boundary effect on plastic deformation of the austenitic ferritic steel.

Świątnicki W., Kryczkowska J., Grabski M.W.

Inżynieria Materiałowa

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1998

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R. XIX, nr 3

215-218

EN

The influence of interphase boundary crystallography on mechanical properties has been studied in a two-phase austenitic-ferritic steel. This way done by comparing the mechanical behaviour of the steel displaying special orientation relationship (ORs) betweeen phases such as the Kurdiumov-Sachs (KS) and Nishiyama-Wassermann (NW) ones, with the steel exhibiting random misorientations. It was shown, that the steel with large fraction of special ORs exhibits lower hardness and yield strength than the steel with randomly disorientate phases. The mechanical tests performed on examples with different grain size revealed, that the hardness increases with the specific surface of interphase boundaries according to the Hall-Petch relationship.

16

The influence of twinning within shear bands on the recrystallization microtexture.

Paul H., Jasieński Z., Lityńska L., Piątkowski A.

Inżynieria Materiałowa

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1998

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R. XIX, nr 3

496-501

EN

The microstructural and microtexture evolution of cold channel-die compressed and partly annealed cast strips of the 70/30 brass was investigated. Thanks to the application of measurements of individual local orientation it has been shown that within the shear bands (SBs) in the deformed state, two main microstructure components appear: the dominant Goss component G congruents {011}<100> and a weaker S congruents {123}<412> orientation. Nucleation of new grains inside the SBs is associated with the appearance of a family of thin needles of microtwins with near C congruents {112}<111> orientation, and strong retention orientations from the area with the so-called 'recovery twins' in the microtexture of new grains in early recrystallization stages was usually observed.

17

The crystal rotation under in-plane shearing of highly cold-rolled copper and brass.

Kuśnierz J.

Inżynieria Materiałowa

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1998

|

R. XIX, nr 3

492-493

EN

Crystal rotations are considered during in-plane shearing of preliminarly 75% cold rolled Cu and CuZn37 brass sheets. To explain the measured texture, the advantages of model of homogeneous deformation as well as the deformation of individual crystals were taken into consideration.

18

Modern modelling of recrystallization.

Jensen D.J.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

637-644

EN

A new trend in recrystallization modelling is to analyse microstructural and textural changes simultaneously by including orientation aspects of nucleation and of growth in the models. Compared to traditional recrystallization models, which focus on either microstructure or texture, the new models are more realistic and lead to much more precise predictions of specific recrystallization experiments. In the present paper, the various approaches of this modern recrystallization modelling is described and discussed.

19

Microstructure and texture of PM2000 tubes - correlation with multiaxial creep and failure behaviour.

Wasilkowska A., Ratuszek W., Penkalla H.J., Kędzierski Z., Czyrska-Filemonowicz A.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

1187-1190

EN

A relationship between the microstructure and multiaxial creep properties of PM2000 tubes is discussed. The microstructure was investigated by X-ray diffraction, optical metallography, scanning- and transmission electron microscopy (TEM). Creep properties were established at 1000 degrees centigrade under multiaxial loading. The results show a low creep ductility and intergranular failure of tubes at high temperatures, related to the microstructural and mechanical anisotropy. The development of a special pancake grain structure is seen as a factor for increasing the life time of tubes subjected to multiaxial creep.

20

Interpretation of slip behaviour adjacent to (alpha/gamma) phase interfaces at the onset of yielding.

Ryś J.

Inżynieria Materiałowa

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1998

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R. XIX, nr 3

209-214

EN

The compatibility requirement of elastic and plastic strains across the phase interfaces, in the (alpha/gamma) duplex steel bicrystals, results in the occurence of additional internally induced stresses, so-called incompatibility stresses. Structural effects observed along the (alpha/gamma) phase interfaces are due to the incompatibility stresses, which arise from elastic anisotropy and asymetry of plastic flow in component crystals as well as the stress relaxation from dislocation pile-ups in adjacent crystals and the stress distribution in the vicinity of the interfaces.