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Number of results: 55
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Abstract

The article presents the results of experiments on a detection system used for detecting signals from a miniature, low-energy micro-electro-mechanical system (MEMS) X-ray source. The authors propose to use a detection based on luminescence phenomena occurring in luminophore and scintillators to record the visual signal on a CMOS/CCD detector. The main part of the article is a review of various materials of scintillators and luminophores which would be adequate to convert low-energy X-ray radiation (E < 25 keV – it is a range not typical for conventional X-ray systems) to visible light. Measurements obtained for different energies, exposure times, and different targets have been presented and analysed.
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Authors and Affiliations

Paweł Urbański 
1
ORCID: ORCID
Tomasz Grzebyk
1
ORCID: ORCID

  1. Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technologyul. Janiszewskiego 11/17, 50-372 Wrocław, Poland
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Abstract

We present spectral emission characteristics from laser-plasma EUV/SXR sources produced by irradiation of < 1 J energy laser pulse on eleven different double stream gas puff targets, with most intense electronic transitions identified in the spectral range from 1 nm to 70 nm wavelength which corresponds to photon energy from 18 eV to 1240 eV. The spectra were obtained using grazing incidence and transmission spectro- graphs from laser-produced plasma emission, formed by the interaction of a laser beam with a double stream gas puff target. Laser pulses with a duration of 4 ns and energy of 650 mJ were used for the experiment. We present the results obtained from three different spectrometers in the wavelength ranges of SXR (1–5.5 nm), SXR/EUV (4–15.5 nm), and EUV (10–70 nm). In this paper, detailed information about the source, gas targets under investigation, the experimental setup, spectral measurements and the results are presented and discussed. Such data may be useful for the identification of adequate spectral emissions from gasses in the EUV and SXR wavelength ranges dedicated to various experiments (i.e. broadband emission for the X-ray coherence tomography XCT) or may be used for verification of magnetohydrodynamic plasma codes.

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Authors and Affiliations

Antony Jose Arikkatt
Przemysław Wachulak
Henryk Fiedorowicz
Andrzej Bartnik
Joanna Czwartos
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Abstract

The article presents an overview and a classification of X-ray detection methods. The main motivation for its preparation was the need to select a suitable and useful method for detecting signals from a currently developed miniature micro-electro-mechanical system (MEMS) X-ray source. The described methods were divided into passive and active ones, among which can be distinguished: chemical, luminescent, thermo-luminescent, gas ionization, semiconductor, and calorimetric methods. The advantages and drawbacks of each method were underlined, as well as their usefulness for the characterisation of the miniature MEMS X-ray source.
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Authors and Affiliations

Paweł Urbański 
1
ORCID: ORCID
Tomasz Grzebyk
1
ORCID: ORCID

  1. Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, ul. Janiszewskiego 11/17, 50-372 Wrocław, Poland
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Abstract

Directionally solidified sample of Fe-Fe3C eutectic alloy were produced under an argon atmosphere in a vacuum Bridgman-type furnace to

study the eutectic growth with v = 167 μm/s pulling rate and constant temperature gradient G = 33.5 K/mm. Since how the growth texture

of eutectic cementite is related to its growth morphology remains unclear, the current study aims to examine this relationship. The technique

such as X-ray diffraction, have been used for the crystallographic analysis of carbide particles in white cast irons.

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Authors and Affiliations

M. Trepczyńska-Łent
T. Szykowny
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Abstract

The paper describes the research on soft X-ray lasers with an active medium created using a gas puff target irradiated

with high-intensity laser pulses. The gas puff target in a form of an elongated gas sheet is produced by pulsed injection of

gas through a slit nozzle using a high-pressure electromagnetic valve. The method of generation of soft X-ray lasers using a

laser-irradiated gas puff target has been developed at the Institute of Optoelectronics. The collaborative experiments were

performed at various laser laboratories using high-intensity laser systems to irradiate the gas puff target and pump the X-ray

laser active medium. Results of these experiments are presented and discussed. Works aimed at increasing the efficiency of

X-ray lasers using a longitudinally irradiated gas puff target are also reviewed.

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Authors and Affiliations

H. Fiedorowicz
A. Bartnik
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Abstract

La0,7Ca0,3MnO3 polycrystalline were synthesized from La2O3, CaO and MnO2 powder mixture using a solid state reaction technique. The compound powders were obtained through the free sintering method at different temperatures and sintering times in order to study the influence of technological conditions on Ca doped La manganites. The most important physical features as structure, microstructure and morphology were described after X-ray diffraction investigation. Photographs of the specimen fractures were taken with SEM (scanning electron microscope) and they revealed high porosity of the tested material and great tendency for its grains to create agglomerates. Influence of doping and technological conditions on lattice parameters were studied by means of Rietvield analysis. The XRD measurements reveal that La0,7Ca0,3MnO3 has orthorhombic symmetry with Pnma space group.

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Authors and Affiliations

M. Bara
J. Dzik
ORCID: ORCID
K. Feliksik
L. Kozielski
B. Wodecka-Duś
ORCID: ORCID
T. Goryczka
ORCID: ORCID
A. Zarycka
M. Adamczyk-Habrajska
ORCID: ORCID
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Abstract

The perovskite type matrix is considered as solidification material for high-level radioactive waste. In this work the perovskite-rutile-type matrix doped by Co, Cs, Nd and Sr which simulate nuclear waste was prepared by sol-gel route. The material was characterized by several methods such as: X-ray diffraction, energy dispersive X-ray spectrometer, and particle induced X-ray emission combined with Rutherford backscattering spectrometry. The analyzes confirmed chemical composition Co-Cs-Nd-Sr- doped perovskite-rutile-type structure. A virtual model of the pellet`s structure was created non-destructively by Roentgen computed micro-tomography. The leaching tests confirmed high chemical resistance of the matrix.

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Authors and Affiliations

T. Smolinski
L. Zhao
M. Rogowski
D. Wawszczak
T. Olczak
M. Brykala
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Abstract

Despite great technological progress scientists still are not capable of ascertaining how many species are there on Earth. Systematic studies are not only time-consuming, but sometimes also significantly impeded by constraints of available equipment. One of the methods for morphology evaluation, which is gradually more often used for taxonomical research is microcomputed tomography. It’s great spatial resolution and ability to gather volumetric data during single acquisition without sectioning specimen are properties especially useful in evaluation of small invertebrates. Nondestructive nature of micro-CT gives possibility to combine it with other imaging techniques even for single specimen. Moreover, in case of rare organisms studies it allows to collect full structural data without fracturing their bodies. Application of proper staining, exposure parameters or specific sample preparation significantly improves quality of performed studies. The following article presents summary of current trends and possibilities of microtomography in morphology studies of small invertebrates.
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Authors and Affiliations

Teresa Nesteruk
Łukasz Wiśniewski
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Abstract

In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe - C alloy was produced. The pulling

rate was v = 83 μm/s (300 mm/h) and constant temperature gradient G = 33,5 K/mm. The microstructure of the sample was examined on

the longitudinal section using an Optical Microscope and Scanning Electron Microscope. The X-ray diffraction and electron backscatter

diffraction technique (EBSD) have been used for the crystallographic analysis of carbide particles in carbide eutectic. The

X-ray diffraction was made parallel and perpendicular to the axis of the goniometer. The EBSD shows the existence of iron carbide Fe3C

with orthorhombic and hexagonal structure. Rapid solidification may cause a deformation of the lattice plane which is indicated by

different values of the lattice parameters. Such deformation could also be the result of directional solidification. Not all of the peaks in

X–ray diffractograms were identified. They may come from other iron carbides. These unrecognized peaks may also be a result of the

residual impurity of alloy.

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Authors and Affiliations

M. Trepczyńska-Łent
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Abstract

The study of liquid crystalline assemblies, with an emphasis on biological phenomena, is now accessible using newly developed microdevices integrated with X-ray analysis capability. Many biological systems can be described in terms of gradients, mixing, and confinement, all of which can be mimicked with the use of appropriate microfluidic designs. The use of hydrodynamic focusing creates well-defined mixing conditions that vary depending on parameters such as device geometry, and can be quantified with finite element modelling.We describe experiments in which geometry and strain rate induce finite changes in liquid crystalline orientation. We also demonstrate the online supramolecular assembly of lipoplexes. The measurement of lipoplex orientation as a function of flow velocity allows us to record a relaxation process of the lipoplexes, as evidenced by a remarkable 4-fold azimuthal symmetry. All of these processes are accessible due to the intentional integration of design elements in the microdevices.

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Authors and Affiliations

H.M. Evans
R. Dootz
S. Köster
B. Struth
T. Pfohl
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Abstract

The technique of electrospinning was employed to fabricate uniform one-dimensional inorganic-organic composite nanofibers at room temperature from a solution containing equal volumes of aluminum 2, 4-pentanedionate in acetone and polyvinylpyrrolidone in ethanol. Upon firing and sintering under carefully pre-selected time-temperature profiles (heating rate, temperature and soak time), high-purity and crystalline alumina nanofibers retaining the original morphological features present in the as-spun composite (cermer) fibers were obtained. Tools such as laser Raman spectroscopy, scanning and transmission electron microscopy together with energy dispersive spectroscopy and selected area electron diffraction were employed to follow

the systematic evolution of the ceramic phase and its morphological features in the as-spun and the fired fibers. X-ray diffraction was used to identify the crystalline fate of the final product.

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Authors and Affiliations

A.-M. Azad
M. Noibi
M. Ramachandran
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Abstract

The article presents an analysis of the change in air voids in asphalt mixtures subjected to fatigue tests at three temperatures of 0°C, 10°C and 25°C. The X-ray computerized tomography imaging method, XCT, was used to identify the air voids in the samples. The research allowed to determine changes in the content of air voids in subsequent fatigue cycles in the sample area. The relationship between air voids volume and the stiffness modulus value was also determined during fatigue for three temperatures. The largest changes were found in samples with notches at 0°C. The analysis of the change in the content of air voids showed that the micro-cracking nucleation processes develop with the number of fatigue cycles. Using the numerical model finite element method we determined the distribution and change in fatigue damage in the extreme areas of the sample during various stages of fatigue. We found clear relationship between the damage and the increased content of air voids.

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Authors and Affiliations

P. Mackiewicz
A. Szydło
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Abstract

Casting porosity is the main factor influencing the fatigue properties of Al-Si alloys. Due to the increasing use of aluminum castings, porosity characterization is useful for estimating their fatigue strength. In principle, a combination of metallographic techniques and statistical pore analysis is a suitable approach for predicting the largest defect size that is critical for the casting. Here, the influence of modifiers and casting technology on the largest pore size population in AlSi7Mg alloy specimens is obtained and discussed adopting the Murakami's approach. However, porosity evaluation is a challenge in the case of microshrinkage pores, which are frequently found in industrial castings. Their complicated morphology prevents a reliable definition of an equivalent defect size based on metallographic techniques. This contribution reports the application of X-ray tomography to the 3D reconstruction of real pores in cast Al-Si alloys and provides insight into the complication of microshrinkage pore sizing by metallography.

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Authors and Affiliations

Stanislava Fintová
Giancarlo Anzelotti
Radomila Konečná
Gianni Nicoletto
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Abstract

This paper presents the results of a study to determine the influence of casting parameters (cooling rate in the casting mould, casting temperature) on the primary structure of Mg-4%Li-1%Ca alloy ingots. The macro- and microstructure analysis of the Mg-4%Li-1%Ca alloy was performed using light and electron microscopy techniques. Microhardness measurements were made for the Mg-4%Li-1%Ca alloy and phase identification in the Mg-4%Li-1%Ca alloy was made using X-ray phase analysis.
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Bibliography

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[2] Bednarczyk, I., Kuc, D. & Mikuszewski, T.(2016). Microstructure and properties of Mg-Li-Re magnesium alloys.Hutnik-WH, 83(8), 321-323. (in Polish).
[3] Bin J. Heng-mei, Y. Rui-hong, L. & Liang, G. (2010). Grain refinement and plastic formability of Mg-14Li-1Al alloy.Transactions of Nonferrous Metals Society of China. 1, 503-507. DOI: 10.1016/s1003-6326(10)60527-4.
[4] Liu, X., Zhan, H., Gu, S., Qu, Z., Wu, R. & Zhang, M. (2011).Superplasticity in a two-phase Mg– 8Li–2Zn alloy processed by two-pass extrusion. Materials Science and Engineering A. 528(19-20), 6157-6162. https://doi.org/10.1016/j.msea.2011.04.073.
[5] Białobrzeski, A., Lech-Grega, M.& Żelechowski, J. (2010). Research on the structure of alloys based on magnesium and lithium with a two-phase α-β and single-phase ß structure.Prace Instytutu Odlewnictwa. L, 17-28. (in Polish).
[6] Zhou, Y., Bian, L., Chen, G. Wang, L. & Liang, W. (2015). Influence of Ca addition on microstructular evolution and mechanical properties of near-eutectic Mg-Li alloys by copper-mold suction casting. Journal of Alloys and Compounds. 664. 85-91. DOI:10.1016/j.jallcom.2015.12.198.
[7] Białobrzeski, A., Saja, K. & Hubner, K. (2007) Ultralightmagnesium-lithiumalloys. Archives of Foundry Engineering. 7(3), 11-16. ISSN(1897-3310).
[8] Jiang, B., Qiu, D., Zhang, M., Ding, P.& Gao, L. (2010). A new approach to grain refinement of an Mg-Li-Al cast alloy. Journal of Alloys and Compounds. 10(1-2), 96-98. DOI:10.1016/j.jallcom.2009.11.066.
[9] Grobner, J., Schmid-Fetzer, R., Pisch, A., Colinet, C., Pavlyuk, V.V., Dmytriv, G.S., Kevorkov, D.G. & Bodak, O.I. (2002). Phase equilibria, calorimetric study and thermodynamic modeling of Mg-Li-Ca alloys. Thermochimica Acta. 389(1-2), 85-94. DOI:10.1016/S0040-6031(01)00842-5.
[10] Song, G.S. &Kral, M.V. (2005) Characterization of cast Mg-Li-Ca alloys. Materials Characterization. (54)4-5, 279-286. DOI: 10.1016/j.matchar.2004.12.001.
[11] Cui, L. Sun, L.R., Zheng, Y. &Li, S. (2018). In vitro degradation and biocompatibility of Mg-Li-Ca alloys – the influence of Li content. Science China Materials, 61(4), 607-618.
[12] Zeng, R.C. Qi, W.C. & Cui, H.Z. (2015). In vitro corrosion of as-extruded Mg-Ca alloys – the influence of Ca concentration. Corrosion Science. 96. 23-31. DOI:10.1016/j.corsci.2015.03.018.
[13] Chang, T., Wang, J., Chu, Ch., Lee, S (2006). Mechanical properties and microstructures of various Mg–Li alloys.Materials Letters.60(27), 3272-3276. DOI 10.1016/j.matlet.2006.03.052.
[14] Li, T., Wu, S.D. Li, S.X. &Li, P.J. (2007).Microstructure evolution of Mg–14% Li–1% Al. alloy during the process of equal channel angular pressing.Materials Science and Engineering A. 460-461, 499-503.DOI10.1016/j.msea.2007.01.108.
[15] Jiang, B., Qiu, D., Zhang, M., Ding, P., Gao, L. (2010). A new approach to grain refinement of an Mg-Li-Al cast alloy. Journal of Alloys and Compounds.492(1-2), 95-98. DOI: 10.1016/j.jallcom.2009.11.066.
[16] Cui, L., Sun, L., Zeng, R., Zheng, Y., Li, S. (2017). In vitro degradation and biocompatibility of, Mg-Li-Ca alloys – the influence of Li content. Science China Materials 7/08, 1-12, DOI: 10.1007/s40843-017-9071-y.
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Authors and Affiliations

Iwona Bednarczyk
1
ORCID: ORCID

  1. Silesian University of Technology, Department of Materials Technology, 40-019 Katowice ul. Krasińskiego 8, Poland
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Abstract

An attempt was made to determine phase composition of commercial aluminium alloys using X-ray diffraction. Samples for phase composition analysis were selected from the group of aluminium alloys covered by the EN 573-3:2013 standard [1]. Representative samples were taken from eight groups of alloys with different chemical composition (at least one sample from each group). The diffraction intensity was measured with a standard X-ray diffractometer in Bragg-Brentano geometry in a way that allowed identification of the weakest diffraction peaks. As a results of the performed research it has been shown that X-ray phase analysis can be used to identify the matrix of aluminium alloys, Si and crystalline intermetallic phases such as Mg2Si, Al93.38Cu6.02Fe24Si16.27, Al4.01MnSi0.74, MgZn2, Al17(Fe3.2Mn0.8)Si2, Al65Cu20Fe15, and Cu3Mn2Al. The detectability limit of the above-mentioned phases is better than 0.5%. The research has also shown that X-ray phase analysis is applicable in the investigation of phase transformations taking place in aluminium alloys.

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Authors and Affiliations

K. Pachut
J. Żelechowski
S. Boczkal
ORCID: ORCID
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Abstract

The aim of this work was to investigate the effect of partial substitution of Mn by Nb on structure and thermomagnetic properties in the (Mn, Nb)-Co-Ge alloy. The master alloys were prepared by arc-melting in an arc furnace with high purity of constituent elements under a low pressure of Ar. The prepared specimens were studied in as-cast state. The X-ray was performed by BRUKER D8 Advance diffractrometer with Cu Kα radiation. The analysis of the XRD pattern revealed coexistence of two orthorhombic phases with different lattice constants. The analysis of the temperature dependence of magnetizaton confirmed the XRD results and showed that produced material manifested two magnetic phase transitions corresponding to detected phases. The values of the Curie temperature were 275 and 325 K. The values of magnetic entropy change ∆SM equaled 3.30 and 2.13 J/(kg K), respectively for recognized phases. Biphase structure of produced material allowed to reach relatively high refigeration capacity 307 J/(kg). Moreover, the analysis of field dependences of magnetic entropy change (∆SM = CBn) allowed to construct temperature dependence of exponent n. The analysis of elaborated n vs. T curve confirmed biphasic structure of produced material.
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Authors and Affiliations

K. Kutynia
1
ORCID: ORCID
P. Gębara
1
ORCID: ORCID
A. Przybył
1
ORCID: ORCID

  1. Czestochowa University of Technology, Institute of Physics, 19 Armii Krajowej Av., 42-200, Częstochowa, Poland
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Abstract

Crystal structure and phase composition of stainless steel substrates (AISI 304 type) was studied and it was found that they adopted the cubic symmetry. The calculated elementary cell parameter for the mayor Fe-Ni phase (weight fraction 99%) was a = 3.593 Å, whereas the mean grain size was <D> = 2932 Å. Morphology of the stainless steel substrate surface was studied with profilometry. Mechanical properties of the stainless steel substrates and stainless steel substrates coated with ceramic layer of barium strontium titanate were studied with microhardness tester. For measurements performed according to the Vickers method the average microhardness was found HV = 189 or HV = 186 for the “in-line” and “mapping” measurement pattern, respectively. The sol-gel method was used to coat the surface of the stainless steel substrate with a thin ceramic layer of the chemical composition Ba0.6Sr0.4TiO3. It was found that the stainless steel substrate covered with sol-gel deposited ceramic coating exhibited the average hardness within the range HV = 217 up to HV = 235 for loading force F = 98 mN and F = 0.98 N, respectively. The Knopp method was also used and it was found that the stainless steel substrate with Ba0.6Sr0.4TiO3 coating exhibited hardness HK = 386.

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Authors and Affiliations

D. Czekaj
A. Lisińska-Czekaj
K. Krzysztofowicz
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Abstract

In the presented work, two multicomponent Cr 25Z 25Co 20Mo 15Si 10Y 5 and Cr 25Co 25Zr 20Mo 15Si 10Y 5 alloys were produced from bulk chemical elements using the vacuum arc melting technique. X-ray diffraction phase analysis was used to determine the phase composition of the obtained materials. Microstructure analysis included scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. The studies revealed the presence of multi-phase structures in both alloys. Elemental distribution maps confirmed the presence of all six alloying elements in the microstructure. The segregation of chemical elements was also observed. Microhardness measurement revealed that both alloys exhibited microhardness from 832(27) to 933(22) HV1.
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Authors and Affiliations

K. Glowka
1
ORCID: ORCID
M. Zubko
1
ORCID: ORCID
K. Piotrowski
1
ORCID: ORCID
P. Świec
1
ORCID: ORCID
K. Prusik
1
ORCID: ORCID
R. Albrecht
1
ORCID: ORCID
D. Stróż
1
ORCID: ORCID

  1. University of Silesia in Katowice, Institute of Materials Engeenering, Chorzów, Poland
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Abstract

Structural biology is concerned with the three-dimensional atomic structure of the molecules of life, proteins and nucleic acids. It was born in mid-1950s with a visionary application of X-ray diffraction to structure determination of protein crystals, and for several decades “structural biology” and “protein crystallography” were synonymous. In the 1980s structural biology received new experimental support from NMR spectroscopy, but a true breakthrough occurred only recently, with the development of atomic-resolution cryo-electron microscopy (cryo- EM), enabling direct visualization of macromolecular objects without the need of growing crystals. The Protein Data Bank (PDB) was created in 1971 with merely seven protein structures known. In mid-1990s the PDB entered an explosive growth phase, ignited by advances of biotechnological methods of protein production and, even more importantly, by widespread use of synchrotrons as extremely powerful X-ray sources. The technological advances did not stop there, and today we have on offer ever more powerful X-ray Free Electron Lasers (XFELs), producing astronomically bright femtosecond X-ray pulses, which allow studying the structure of nanometer-sized crystals or even of single macromolecules. Thanks to all those methodological developments, the PDB holds today over 210,000 experimental macromolecular structures, many of which (such as those related to HIV or SARS-CoV-2) have fundamental importance for medicine as targets for rational drug design. In addition to innovative experimental methodology, structural biology has recently seen a huge progress of artificial intelligence (AI)-based methods of protein structure prediction, capable now of quite accurate divination of the three-dimensional structure for billions of protein sequences in very short time. However, those machine-learning algorithms, such as AlphaFold, recognize patterns that have been seen before, while for truly new sequences and for oligomeric proteins the prediction is still less than certain and needs experimental validation. It appears then that experimental structural biology is not quite dead yet and will remain the main source of reliable novel structural information for the foreseeable future.
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Authors and Affiliations

Mariusz Jaskólski
1 2
ORCID: ORCID

  1. Zakład Krystalografii, Wydział Chemii, Uniwersytet im. Adama Mickiewicza w Poznaniu
  2. Instytut Chemii Bioorganicznej PAN w Poznaniu
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Abstract

Opal can be found in several locations, including America, Tanzania, Brazil, Mexico, East Africa, Indonesia and Australia, which is now the world’s top producer of black opal. One of the most economically valuable gems in the world is the mineraloid opal. In the Rongkong area, opal is found in the host rock of volcanic igneous rock, namely andesite. This study aims to determine the opal mineraloid host-rock’s microstructural characteristics and the elemental and compound content of the opal mineraloid host-rock’s geochemistry in the Rongkong area, Indonesia. The research took three samples in the field as large as hand specimens. The three samples were one host-rock sample and two opal mineraloid samples; the samples were then prepared and analyzed in the laboratory. Laboratory analysis was performed using SEM-EDS, XRF and petrographic analyses. The results of the SEM-EDS test analysis showed that most opal mineraloid carrier rock constituents are aluminum and oxide. This can be seen from the substantial Al and O content. In samples 1 and 2, Al, O, Ca and P with the highest composition of chemical compounds are Al2O3, CaO, and P2O5. The Rongkong opal mineraloid from Limbong Village, Rongkong District, North Luwu Regency, South Sulawesi, based on the results of XRF analysis, contains the chemical compounds SiO2, Al2O3, K2O, Fe2O3, CaO, TiO2, RuO2, SrO, MnO, V2O5, Rb2O, Ag2O and CuO. The content compound that is more dominant in opal mineraloids is SiO2 due to silicate enrichment in the forming of opal mineraloids.
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Authors and Affiliations

Alam B. Thamsi
1
ORCID: ORCID
Agus A. Budiman
1
Emi P. Umar
1
Harwan Harwan
1

  1. Universitas Muslim Indonesia, Indonesia
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Abstract

The composition and structural modification of aluminium alloys influence their strength, tribological properties and structural stability. The phase composition of the structure as well as the characteristics of the elementary cell of each identified phase was established by X-ray diffraction, and the main objective was to determine the compositional phases, microstructure and microcomposition of the alloy. Based on the cyclic voltammograms it can be said that on the OCP interval (+1.5 V… –1.1 V), after the breakthrough potential is an intensification of the anodic process by the pronounced increase of the current density, in these conditions the Al-Si alloy has low values which means that it has a better corrosion resistance.
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Authors and Affiliations

M.G. Minciuna
1 2
ORCID: ORCID
P. Vizureanu
1 2
ORCID: ORCID
B. Jeż
3
ORCID: ORCID
A.V. Sandu
1 2
ORCID: ORCID
M. Nabiałek
3
ORCID: ORCID
D.C. Achitei
1 2
ORCID: ORCID

  1. “Gheorghe Asachi” Technical University of Iasi, Faculty of Materials Science and Engineering, Blvd. Mangeron, No. 51, 700050, Iasi, Romania
  2. Universiti Malaysia Perlis (UniMAP), Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), 01000 Perlis, Malaysia
  3. Czestochowa University of Technology, Faculty of Production Engineering and Materials Technology, Department of Physics, 42-200 Częstochowa, Poland
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Abstract

Short-period 10 monolayers InAs/10ML GaSb type-II superlattices have been deposited on a highly lattice-mismatched GaAs (001), 2° offcut towards <110> substrates by molecular beam epitaxy. This superlattice was designed for detection in the mid-wave infrared spectral region (cut-off wavelength, λcut-off = 5.4 µm at 300 K). The growth was performed at relatively low temperatures. The InAs/GaSb superlattices were grown on a GaSb buffer layer by an interfacial misfit array in order to relieve the strain due to the ~7.6% lattice-mismatch between the GaAs substrate and type-II superlattices. The X-ray characterisation reveals a good crystalline quality exhibiting full width at half maximum ~100 arcsec of the zero-order peak. Besides, the grown samples have been found to exhibit a change in the conductivity.
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Authors and Affiliations

Piotr Martyniuk
1
ORCID: ORCID
Djalal Benyahi
2
ORCID: ORCID

  1. Institute of Applied Physics, Military University of Technology, gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
  2. Laboratoire des Systèmes Lasers, École Militaire Polytechnique, BP 17 Bordj El Bahri, 16111 Algiers, Algeria
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Abstract

The Ag8SnSe6 argyrodite compound was synthesized by the direct melting of the elementary Ag, Sn and Se high purity grade stoichiometric mixture in a sealed silica ampoule. The prepared polycrystalline material was characterized by the X-ray diffraction (XRD), visible (VIS) and near-infrared (NIR) reflection and photoluminescence (PL) spectroscopy. XRD showed that the Ag8SnSe6 crystallizes in orthorhombic structure, Pmn21 space group with lattice parameters: а = 7.89052(6) Å, b = 7.78976(6) Å, c = 11.02717(8) Å. Photoluminescence spectra of the Ag8SnSe6 polycrystalline wafer show two bands at 1675 nm and 1460 nm. Absorption edge position estimated from optical reflectance spectra is located in the 1413–1540 nm wavelength range.

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Authors and Affiliations

Ihor Semkiv
Hryhoriy Ilchuk
Marek Pawlowski
Viktor Kusnezh
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Abstract

This study presents the determination of the content of selected metals (Ba, Ca, Fe, Nb, Rb, Sr, Y, Zn, and Zr) in postglacial deposits from two glacial valleys (Ebbadalen and Elsadalen) in the Petunia Bay (southern Spitsbergen). The aim of the research was to experimentally check the usefulness of the handheld energy dispersive X-ray fluorescence technique in the study of samples from the polar zone, before performing the future field tests. Deposit analyses were performed (in parallel) with two handheld X-ray fluorescence spectrometers from different manufacturers, to investigate the accuracy and reliability of the instruments. The statistical analysis of the results indicated that the measurements carried out with two spectrometers were statistically significantly different, which was probably due to the different calibration characteristics used by the manufacturers. However, the analysis of the spatial distribution of element concentrations using Geographic Information System tools showed that the distribution maps of elements concentrations were similar regardless of the spectrometer used in the analyses.
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Authors and Affiliations

Lidia Kozak
1
Juliana Silva Souza
1
Adam Nawrot
2
Jędrzej Proch
1
Marcin Kaźmierski
3
Agnieszka Zawieja
4
Przemysław Niedzielski
1

  1. Adam Mickiewicz University in Poznań, Faculty of Chemistry, Department of Analytical Chemistry, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
  2. Institute of Geophysics Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warszawa, Poland
  3. Adam Mickiewicz University in Poznań, Faculty of Geographical and Geological Sciences, Bogumiła Krygowskiego 10, 61-680 Poznań, Poland
  4. MEWO S.A., Starogardzka 16, 83-010 Straszyn, Poland

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