scholarly journals Cordierite (2MgO•2Al2O3•5SiO2) synthesis by unconventional methods

2008 ◽  
Vol 2 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Silvana Ianoşev ◽  
Ioan Lazău ◽  
Cornelia Păcurariu ◽  
Antoneta Avramescu
Keyword(s):  
Phase Formation ◽  
Synthesis Methods ◽  
Main Subject ◽  
Blue Colour ◽  
Pale Colour ◽  
Organic Precursors ◽  
Unconventional Methods ◽  
Cordierite Structure ◽  
Magnesium Metasilicate

The cordierite was synthesized by two unconventional methods: 1) the method which uses hydrosilicate precursors and 2) the method which uses organic precursors. Comparison of these synthesis methods with the classical one is the main subject of the presented paper. The influence of Li2O on the cordierite phase formation was investigated too. The results have suggested that the method which uses hydrosilicate precursors provides the SiO2 linkage as magnesium metasilicate, but is not adequate for the cordierite synthesis. Only in the presence of Li2O considerably amount of the ?-cordierite modification was formed, confirming the mineralizing effect of this oxide. In addition, the results have clearly demonstrated that the method which uses organic precursors is suitable for the cordierite synthesis. Thus, even without mineralizer it can be used for the preparation of the almost pure ?-cordierite at 1200?C. Because of that this method was used to obtain pigments with cordierite structure, in which Al3+ was partially substituted with Cr3+ (pink pale colour), and Mg2+ was partially substituted with Co2+ (blue colour).

Structural Effects on Perovskite Phase Formation for PZT Powders Obtained by Polymeric Precursor Method

2018 ◽  
Vol 930 ◽  
pp. 101-106
Author(s):  
Margarete Soares da Silva ◽  
Lucas L. da Silva ◽  
Eliane F. de Souza ◽  
Talita Cuenca Pina Moreira Ramos ◽  
Igor Silva de Sá ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Phase Formation ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Synthesis Methods ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Structural Effects ◽  
Precursor Method

Many synthesis methods are available to obtain a set of specific characteristics for lead zirconate titanate (PZT) piezoelectric ceramic powders. In this work, we have successfully prepared PZT powder samples through the Polymeric Precursor Method with x = 0.6, according the general formula Pb (ZrxTi1-x)O3. The powders were thermally treated from 380 to 550 oC and characterized by Raman spectroscopy and X-ray diffraction (DRX) in order to evaluate the effects of thermal treatment on the phase formation and the crystallization processes. The results obtained by Raman spectroscopy were compared to refined crystal data obtained by Rietveld method, leading to coherent conclusions about the structural effects occurring along the temperature of calcination. It was possible to characterize the tetragonal perovskite phase as predominant phase occurs only after 500 oC, but its crystallinity is already determined by synthesis method. Thus, no ordering process is verified for perovskite as a function of the temperature increasing during thermal treatment, in spite of the continuous pyrochlore-to-perovskite phase transition. The pyrochlore secondary phase starts to vanish before its proper crystallization process, changing the tetragonality of previously formed perovskite phase.

Lead-free BaBi4Ti4O15 ceramics: Effect of synthesis methods on phase formation and electrical properties

2015 ◽  
Vol 41 (1) ◽  
pp. 309-316 ◽  
Author(s):  
J.D. Bobić ◽  
M.M. Vijatović Petrović ◽  
N.I. Ilić ◽  
E. Palaimiene ◽  
R. Grigalaitis ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Phase Formation ◽  
Lead Free ◽  
Synthesis Methods

A. Requirements for Large Domes

1966 ◽  
Vol 27 ◽  
pp. 165-182
Keyword(s):  
Main Subject

In continuing the sessions of the symposium, the main subject this afternoon has to do with domes and their facilities. This, of course, is a very important subject for observatories, because the dome serves much more of a purpose than simply to protect the telescope from wind or rain.

Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

1996 ◽  
Vol 54 ◽  
pp. 1000-1001
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Dark Field ◽  
Nickel Layer ◽  
Multilayer Thin Films ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

Hotspots in Psychology – 2020 Edition

2020 ◽  
Vol 228 (1) ◽  
pp. 1-2
Author(s):  
Michael Bošnjak ◽  
Nadine Wedderhoff
Keyword(s):  
Systematic Reviews ◽  
Research Synthesis ◽  
Synthesis Methods ◽  
Common Denominator ◽  
The Common ◽  
Meta Analyses

Abstract. This editorial gives a brief introduction to the six articles included in the fourth “Hotspots in Psychology” of the Zeitschrift für Psychologie. The format is devoted to systematic reviews and meta-analyses in research-active fields that have generated a considerable number of primary studies. The common denominator is the research synthesis nature of the included articles, and not a specific psychological topic or theme that all articles have to address. Moreover, methodological advances in research synthesis methods relevant for any subfield of psychology are being addressed. Comprehensive supplemental material to the articles can be found in PsychArchives ( https://www.psycharchives.org ).

BKR (BADAN KEAMANAN RAKYAT): Cikal Bakal Tentara Indonesia?

Metahumaniora ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 389
Author(s):  
Widyo Nugrahanto
Keyword(s):  
Armed Forces ◽  
Civil Defense ◽  
The Other ◽  
Main Subject ◽  
Japanese Occupation ◽  
Historical Method ◽  
New Interpretation

AbstrakPenelitian ini berjudul BKR (Badan Kemanan Rakyat):Cikal Bakal Tentara Indonesia?!. Penelitian ini merupakan interpretasi baru tentang cikal bakal TNI, yang umumnya banyak merujuk pada PETA (Pembela Tanah Air). Metode penelitian yang digunakan adalah Metode Sejarah.Metode Sejarah memiliki empat tahapan yaitu Heuristik, Kritik, Interpretasi dan Historiografi.Sumber-sumber penelitian ini menggunakan koran-koran sezaman, majalah sezaman, dan buku. BKR dianggap sebagai cikal bakal TNI didasarkan beberapa sebab. Pertama, atas dasar legalitas formal, PETA telah dibubarkan sehingga BKR adalah satuan militer yang pertama kali dibentuk setelah Indonesia merdeka. BKR selanjutnya melahirkan pembentukan TKR (Tentara Keamanan Rakyat), TKR (Tentara Keselamatan Rakyat), TRI (Tentara Republik Indonesia) dan TNI (Tentara Nasional Indonesia). Kedua, jika PETA dianggap sebagai cikal bakal TNI, maka KNIL dan beberapa satuan keprajuritan diabaikan. Padahal, beberapa bekas perwira KNIL memiliki peran penting di tubuh BKR hingga TNI.Kata kunci: BKR, Tentara, TNIAbstractThe main subject this study is BKR – Indonesian civil defense corps – as origin of Indonesian Military. This study is new interpretation about the origin of TNI (Indonesian National Armed Forces) now. Many opinion refer to PETA as civil defense corps in Japanese occupation era. Study emlpoys a Historical Method, which consists of four stage: Heuristic, Critic, Interpretation, Historiography. The study utilize some sources such as newspaper, magazine, and book. Main finding of this study is PETA had dispersed as legality and formally and BKR was formed as the firts corps after Independence of Indonesia. Futhermore, BKR changed to TKR (Tentara Keamanan Rakyat), TKR (Tentara Keselamatan Rakyat), TRI (Tentara Republik Indonesia) until TNI (Tentara Nasional Indonesia). If PETA is considered as origins of Indonesian Military, then it ignore KNIL – a colonial armed forces – and the other defence corps. Even though the eks KNIL’s officer have important role in military managenment of BKR until TNI.Keywords: BKR, Military, TNI

BKR (BADAN KEAMANAN RAKYAT): Cikal Bakal Tentara Indonesia?

Metahumaniora ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 389
Author(s):  
Widyo Nugrahanto
Keyword(s):  
Armed Forces ◽  
Civil Defense ◽  
The Other ◽  
Main Subject ◽  
Japanese Occupation ◽  
Historical Method ◽  
New Interpretation

AbstrakPenelitian ini berjudul BKR (Badan Kemanan Rakyat):Cikal Bakal Tentara Indonesia?!. Penelitian ini merupakan interpretasi baru tentang cikal bakal TNI, yang umumnya banyak merujuk pada PETA (Pembela Tanah Air). Metode penelitian yang digunakan adalah Metode Sejarah.Metode Sejarah memiliki empat tahapan yaitu Heuristik, Kritik, Interpretasi dan Historiografi.Sumber-sumber penelitian ini menggunakan koran-koran sezaman, majalah sezaman, dan buku. BKR dianggap sebagai cikal bakal TNI didasarkan beberapa sebab. Pertama, atas dasar legalitas formal, PETA telah dibubarkan sehingga BKR adalah satuan militer yang pertama kali dibentuk setelah Indonesia merdeka. BKR selanjutnya melahirkan pembentukan TKR (Tentara Keamanan Rakyat), TKR (Tentara Keselamatan Rakyat), TRI (Tentara Republik Indonesia) dan TNI (Tentara Nasional Indonesia). Kedua, jika PETA dianggap sebagai cikal bakal TNI, maka KNIL dan beberapa satuan keprajuritan diabaikan. Padahal, beberapa bekas perwira KNIL memiliki peran penting di tubuh BKR hingga TNI.Kata kunci: BKR, Tentara, TNIAbstractThe main subject this study is BKR – Indonesian civil defense corps – as origin of Indonesian Military. This study is new interpretation about the origin of TNI (Indonesian National Armed Forces) now. Many opinion refer to PETA as civil defense corps in Japanese occupation era. Study emlpoys a Historical Method, which consists of four stage: Heuristic, Critic, Interpretation, Historiography. The study utilize some sources such as newspaper, magazine, and book. Main finding of this study is PETA had dispersed as legality and formally and BKR was formed as the firts corps after Independence of Indonesia. Futhermore, BKR changed to TKR (Tentara Keamanan Rakyat), TKR (Tentara Keselamatan Rakyat), TRI (Tentara Republik Indonesia) until TNI (Tentara Nasional Indonesia). If PETA is considered as origins of Indonesian Military, then it ignore KNIL – a colonial armed forces – and the other defence corps. Even though the eks KNIL’s officer have important role in military managenment of BKR until TNI.Keywords: BKR, Military, TNI

Evolution of Microclimatic Conditions in Paskov Mine / Ewolucja Warunków Mikroklimatycznych W Kopalni Paskov

2012 ◽  
Vol 57 (4) ◽  
pp. 1045-1055
Author(s):  
Pavel Zapletal ◽  
Pavel Prokop ◽  
Vítězslav Košňovský
Keyword(s):  
Coal Mining ◽  
Mining Activity ◽  
Mining Engineering ◽  
Special Program ◽  
Main Subject ◽  
Coal Basin ◽  
Research Activities ◽  
Microclimatic Conditions ◽  
Technical University

Abstract The main subject of this paper focuses on scientific and research activities conducted in the Institute of Mining Engineering and Safety of the VŠB-Technical University of Ostrava. Cooperation between the VŠB-Technical University of Ostrava and OKD A.S., the only representative of coal mining in the Ostrava-Karviná coal basin, has recently begun to develop again. This paper describes an example discussed in a certain study, which has been undertaken for the Paskov mine, OKD a.s., dealing specifically with the evolution of microclimate parameters in mines that depend on the progress of mining activity at deeper levels over a period of several years. To this end, a special program, aimed at determination of the necessary refrigerating capacity, was established at the VŠB-Technical University of Ostrava.

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