Search results

1

Influence of deposition temperature on amorphous structure of PECVD deposited a-Si:H thin films

100%

Müllerová J., Fischer M., Netrvalová M., Zeman M., Šutta P.

Open Physics

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2011

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vol. 9

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issue 5

1301-1308

EN

The effect of deposition temperature on the structural and optical properties of amorphous hydrogenated silicon (a-Si:H) thin films deposited by plasma-enhanced chemical vapour deposition (PECVD) from silane diluted with hydrogen was under study. The series of thin films deposited at the deposition temperatures of 50–200°C were inspected by XRD, Raman spectroscopy and UV Vis spectrophotometry. All samples were found to be amorphous with no presence of the crystalline phase. Ordered silicon hydride regions were proved by XRD. Raman measurement analysis substantiated the results received from XRD showing that with increasing deposition temperature silicon-silicon bond-angle fluctuation decreases. The optical characterization based on transmittance spectra in the visible region presented that the refractive index exhibits upward trend with increasing deposition temperature, which can be caused by the densification of the amorphous network. We found out that the scale factor of the Tauc plot increases with the deposition temperature. This behaviour can be attributed to the increasing ordering of silicon hydride regions. The Tauc band gap energy, the iso-absorption value their difference were not particularly influenced by the deposition temperature. Improvements of the microstructure of the Si amorphous network have been deduced from the analysis.

2

Numerical Generation of a Fixed Bed Structure

100%

Marek M.

|

vol. 34

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issue 3

347-359

EN

A numerical algorithm is presented for the filling process of a cylindrical column with equilateral cylinders. The process is based on simplified mechanics - the elements are added one by one until the mechanical equilibrium is reached. The final structure is examined with respect to the global and local porosity distribution. Oscillating radial porosity profile is obtained in accordance with experimental data.

3

Structural Aspects of Remelting of the AZ91 Magnesium Alloy Surface Layer

100%

Iwaszko J., Strzelecka M.

Archives of Foundry Engineering

|

2016

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issue 1

4

Degradation of Creep Resistant Ni - Alloy During Aging at Elevated Temperature Part II: Structure Investigations

100%

Kaczorowski M., Skoczylas P., Krzyńska A.

Archives of Foundry Engineering

|

2015

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issue 4

5

Influence of Heat Treatment on Corrosion Resistance of ZnAl40Ti2Cu Alloy

88%

Michalik R.

Archives of Metallurgy and Materials

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2018

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vol. 63

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issue 2

6

Crystallographic and structural characterization of heterometallic platinum clusters Part VIII. Heteronona- and heterodecanuclear clusters

88%

Melník M., Mikuš P., Holloway C. E.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

This review classifies and analyses fifty heteronona- and heterodecanuclear Pt clusters of metal composition: Pt4Ru5, Pt3Ru6, Pt20sr PtRh8, PtAu8; Pt6M4, Pt5M5, Pt4M6, Pt3M2, Pt2M8, PtM9, Pt3Ru6M and PtAu8M. There are nine different heterometals: M = Ru, Au, Ag, Cu, Hg, Os, Rh, Ir and Fe, of which Ru and Au are the most frequent. The clusters crystallize mostly into two crystal classes, monoclinic (74%) and triclinic (18%), and their structures are complex. Three triangular layers of nine metal atoms arranged in the form of a face-shared bioctahedron are common in the series of heterononanuclear clusters. In the series of heterodecanuclear clusters distorted skeletal icosahedrons, where a central platinum atom is surrounded by nine metal atoms, and face (edge) shared (fused) bioctahedral cluster of the metal atoms are the most common. The most frequent ligands are CO and PPh3. The shortest metal-metal bond distances are: 2.540(4) Å (Pt-Fe), 2.580(2) Å (Ru-Ru), 2.584 Å (Pt-Pt) and 2.629(4) Å (Cu-Au). Several relationships between the structural parameters were found and are discussed. Some clusters contain two crystallographically independent molecules within the same crystal and are examples of distortion isomerism.

7

Crystallographic and structural characterization of heterometalic platinum complexes Part X. Heteropolynuclear pt complexes

88%

Melník M., Mikuš P., Holloway C. E.

Open Chemistry

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2015

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vol. 13

|

issue 1

EN

This review covers heteropolynuclear platinum complexes. There are over sixty examples with heterometal atoms as partners including non- transition metals, K, Cs, Mg, Ca, Sr, Tl, Sn, Pb, Zn, Cd, and transition metals: Cu, Ag, Fe, Co, Ni, Rh and Pd. In addition, there are examples for the lanthanides, Eu and Yb. The most common are Ag (x16) and K (x14). The predominant geometries for Pt(II) is square-planar and for Pt(IV) is octahedral. The overall structures are complex. In spite of the wide variety of heterometal atoms partners of platinum, there is “real” Pt-M bonds only with silver, ranging from 2.678 to 2.943(I) Å (ave 2.855 Å). The mean Pt-Pt bond distance is 2.869 Å.

8

Crystallographic and structural characterization of heterometallic platinum clusters. Part IX. Heterooligonuclear Pt clusters

88%

Melník M., Mikuš P., Holloway C. E.

Open Chemistry

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2015

|

vol. 13

|

issue 1

EN

This review classifies and analyzes over thirty heterooligonuclear platinum clusters with a wide variety of metal frameworks, from twelve to forty-four. There are thirteen heterometals (Ge, Sn, Hg, W, Mo, Ru, Rh, Pd, Os, Ni, Cu, Ag, Au) which are the partners of platinum. The clusters mostly crystallize in monoclinic (36,4%) and triclinic (30,3%) crystal classes. Their structures are complex, with platinum most commonly preferring interstitial sites, such as the centroids of icosahedrons. There are examples of distortion isomerism. The most common ligands are CO and PPh3, and it is interesting that the mean Pt-CO and M-CO bond distances are identical at 1.84 Å. In contrast, the mean Pt-μCO and M-μCO are of values of 2.02 and 1.97 Å, respectively, while the Pt-PPh3 and M-PPh3 bond distances are 2.30 and 2.28 Å, respectively. The shortest Pt-Pt, Pt-M (non-transition) and Pt-M (transition) bond distances are 2.559(2) Å, 2.412(2) Å (M = Ge) and 2.510(2) Å (M = Ni).

9

The Influence of Heat Treatment and Chemical Composition on the Structure and Mechanical Properties of Thick-walled Ductile Iron Castings

88%

Trepczyńska-Łent M.

Archives of Foundry Engineering

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2018

|

issue 4

10

The First Post-war Gdynia Downtown Plan

88%

Bańkowska B., Bańkowska B.

Studia KPZK

|

2018

|

vol. 188

11

Numerical Generation of a Fixed Bed Structure

88%

Marek M.

Chemical and Process Engineering

|

2013

|

issue 3

12

The Influence of Pressure Die Casting Parameters on Distribution of Reinforcing Particles in the AlSi11/10% SiC Composite

88%

Pasieka A., Konopka Z.

Archives of Foundry Engineering

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2013

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issue 3

13

The Strengthening of Weight Heavy Alloys During Heat Treatment

88%

Kaczorowski M., Skoczylas P., Krzyńska A., Kaniewski J.

Archives of Foundry Engineering

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2012

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issue 4

14

Oxide Inclusions in Ductile Cast Iron as Starting Materials for Production SiMo Iron Castings

88%

Dyrlaga Ł., Kopyciński D., Guzik E.

Archives of Foundry Engineering

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2021

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issue 3

15

Synthesis and characterization of structural and luminescence properties of blue - green BaAlxOy:Eu2+ phosphor by solution - combustion method

88%

Dejene F., Kebede M.

Open Physics

|

2012

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vol. 10

|

issue 4

977-982

EN

Europium-doped barium aluminate (BaAlxOy:Eu2+) phosphors were obtained at low temperatures (500°C) using the solution - combustion of corresponding metal nitrate-urea solution mixtures. The particle size and morphology and the structural and luminescent properties of the synthesized phosphors were examined by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Electron diffraction spectroscopy (EDS) and photoluminescence (PL). It was found that the change in Ba: Al molar ratios showed greatly influence not only on the particle size and morphology, but also on their PL spectra and crystalline structure. The structure of BaAlxOy nanophosphors changes from a hexagonal Ba2Al10O17 phase for samples with 6:100 molar ratios to a hexagonal BaAl2O4 one with an increase in Ba content. The peak of the emission band occurs at a longer wavelength (around 615 nm) with a decrease in Ba concentration but displays a broad blue-green emission band composed from two emissions with the maximum at 495 and 530nm coming from Eu2+ in two sites for increasing Ba content. The blue-green emission is probably due to the influence of 5d electron states of Eu2+ in the crystal field because of atomic size variation causing crystal defects while the red emission is due to f - f transitions. These findings clearly demonstrate the possibility of fine tuning the colour emission.

16

The Role of CeO₂-Doping of γ-Al₂O₃ on its Structural and Superficial Area

88%

Aribi K., Ghelamallah M., Bellifa A., Bousehaba F.

Acta Physica Polonica A

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2017

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vol. 132

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issue 3

445-447

EN

A series of samples, noted Al_xCe_{1-x} has been prepared by hydrolysis, from γ-Al₂O₃ and CeO₂. These samples were calcined under air at 450, 900 and 1200°C, and then characterized by specific surface area, X-ray diffraction and thermoreduction programmed under H₂. Obtained results show that after calcination at 450 and 900°C, the cerium decreases the surface of alumina. Results of X-ray diffraction and thermoreduction programmed under H₂ experiments showed that the samples are constituted of: γ-Al₂O₃ and CeO₂. The global consumption of hydrogen increase with rate of CeO₂ added. At 1200°C, the sintering of the samples is very important and γ-Al₂O₃ is transformed into the α-phase. The decrease in specific surface area is more accentuated for Al₁Ce₀ sample, since sintering occurs due to the growth in crystallite size. Thermoreduction programmed under H₂ experiments show that reduction of CeO₂ much more accentuated for ceria samples or its decrease can reflect some alterations of the nature of interactions between Al₂O₃ and CeO₂.

17

Influence of Heat Treatments and Ni Content on Properties of Martensitic Stainless Steel

75%

Čamek L., Záděra A., Kaňa V., Myška M.

Archives of Foundry Engineering

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2018

|

issue 2

18

Microstructure and Microhardness of Ti6Al4V Alloy Treated by GTAW SiC Alloying

75%

Bochnowski W.

Archives of Foundry Engineering

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2012

|

issue 2

19

Staminodial Nectary Structure in Two Pulsatilla (L.) Species

75%

Weryszko-Chmielewska E., Sulborska A.

Acta Biologica Cracoviensia s. Botanica

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2011

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vol. 53

|

issue 2

20

Isozymes delta of phosphoinositide-specific phospholipase C and their role in signal transduction in the cell.

75%

Ochocka A.-M., Pawelczyk T.

|

2003

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vol. 50

|

issue 4

1097-1110

EN

Phospholipase C (PLC, EC 3.1.4.11) is an enzyme crucial for the phosphoinositol pathway and whose activity is involved in eukaryotic signal transduction as it generates two second messengers: diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3). There are four major types of phospholipase C named: β, γ, δ and the recently discovered ε, but this review will focus only on the recent advances for the γ isozymes of PLC. So far, four d isozymes (named γ1-4) have been discovered and examined. They differ with regard to cellular distribution, activities, biochemical features and involvement in human ailments.

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Influence of deposition temperature on amorphous structure of PECVD deposited a-Si:H thin films

Numerical Generation of a Fixed Bed Structure

Structural Aspects of Remelting of the AZ91 Magnesium Alloy Surface Layer

Degradation of Creep Resistant Ni - Alloy During Aging at Elevated Temperature Part II: Structure Investigations

Influence of Heat Treatment on Corrosion Resistance of ZnAl40Ti2Cu Alloy

Crystallographic and structural characterization of heterometallic platinum clusters Part VIII. Heteronona- and heterodecanuclear clusters

Crystallographic and structural characterization of heterometalic platinum complexes Part X. Heteropolynuclear pt complexes

Crystallographic and structural characterization of heterometallic platinum clusters. Part IX. Heterooligonuclear Pt clusters

The Influence of Heat Treatment and Chemical Composition on the Structure and Mechanical Properties of Thick-walled Ductile Iron Castings

The First Post-war Gdynia Downtown Plan

Numerical Generation of a Fixed Bed Structure

The Influence of Pressure Die Casting Parameters on Distribution of Reinforcing Particles in the AlSi11/10% SiC Composite

The Strengthening of Weight Heavy Alloys During Heat Treatment

Oxide Inclusions in Ductile Cast Iron as Starting Materials for Production SiMo Iron Castings

Synthesis and characterization of structural and luminescence properties of blue - green BaAlxOy:Eu2+ phosphor by solution - combustion method

The Role of CeO₂-Doping of γ-Al₂O₃ on its Structural and Superficial Area

Influence of Heat Treatments and Ni Content on Properties of Martensitic Stainless Steel

Microstructure and Microhardness of Ti6Al4V Alloy Treated by GTAW SiC Alloying

Staminodial Nectary Structure in Two Pulsatilla (L.) Species

Isozymes delta of phosphoinositide-specific phospholipase C and their role in signal transduction in the cell.