Transformations of clay minerals in black earth and red loams of basaltic origin.

The development in the Toowoomba area, Queensland, of red, black, and transitional soil types from basalt is typical of similar processes in many parts of eastern Australia. Systematic samples from this area have been investigated mineralogically by differential thermal analysis, X-ray diffraction, and other methods. Montmorillonite appears to be the clay mineral first formed under present weathering conditions. The further transition to red soils in certain situations is due to partial decomposition of montmorillonite to minerals of the kaolin group by loss of alkalis and iron, the latter being stabilized in the upper horizons as hydrated oxides. Further decomposition of kaolin minerals produces gibbsite. Changes in the nature and amount of clay minerals are thought to correspond with stages in the evolution of basalt soil types.

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The Firing Temperature of Romanesque Brick from Pác

Selected Scientific Papers - Journal of Civil Engineering ◽

10.2478/v10299-012-0009-y ◽

2012 ◽

Vol 7 (2) ◽

pp. 79-86

Author(s):

Rudolf Podoba ◽

Igor Štubňa ◽

Jozefa Lukovičová ◽

Peter Bačík

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

Diffraction Analysis ◽

Firing Temperature ◽

Thermal Analyses ◽

X Ray Diffraction ◽

X Ray ◽

Partial Decomposition ◽

The Church

Abstract A pavement brick taken from a Romanesque part of the church in Pác, in the Trnava County, Slovakia, was investigated by x-ray diffraction analysis (XRD) and thermal analyses as differential thermal analysis (DTA), thermogravimetry (TG) and thermodilatometry (TD). It was found that the brick contained dehydroxylated illitic clay, calcite and quartz. As revealed, dehydroxylation was completely finished and no redehydroxylation was observed. Partial decomposition of calcite was also found. The estimated firing temperature is between 600 °C and 700 °C.

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Identification of pseudoboehmite in mixtures with phyllosilicates

Clay Minerals ◽

10.1180/claymin.1994.029.3.06 ◽

1994 ◽

Vol 29 (3) ◽

pp. 351-359 ◽

Cited By ~ 4

Author(s):

A. Violante ◽

P. M. Huang

Keyword(s):

Electron Microscopy ◽

Thermal Analysis ◽

Transmission Electron Microscopy ◽

Differential Thermal Analysis ◽

Detection Limit ◽

Clay Minerals ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Oriented Samples

AbstractThe influence of kaolinite and montmorillonite on the identification of pseudoboehmite was studied by X-ray diffraction (XRD), differential thermal analysis (DTA), infrared absorption (IR), and transmission electron microscopy (TEM). In the randomly oriented samples containing different proportions of the clay minerals and pseudoboehmite, pseudoboehmite was not easily detectable by XRD even in a sample containing 40% of pseudoboehmite. Preheating of the samples at 110-300°C improved the detection limit to 30%. In samples obtained by mixing suitable amounts of the suspensions of the clay minerals (<2μm)and pseudoboehmite, the identification of pseudoboehmite was even more difficult. In oriented samples, pseudoboehmite was detectable only when present in amounts >30%, at low full-scale counts per second (1000-400 cps), on preheated samples in the presence of kaolinite, or on the samples that were Mg-saturated and solvated with ethylene glycol in the presence of montmorillonite. Identification of pseudoboehmite in the presence of kaolinite or montmorillonite by DTA, IR or TEM failed, even in samples containing 50% pseudoboehmite. In the presence of both kaolinite and montmorillonite (1:1 w/w), the identification of pseudoboehmite became much more difficult than in the presence of either mineral alone. The presence of pseudoboehmite in soils may, thus, be undetectable by standard clay mineralogical analyses.

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PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

SCIENTIA : Jurnal Farmasi dan Kesehatan ◽

10.36434/scientia.v5i1.61 ◽

2016 ◽

Vol 5 (1) ◽

pp. 6

Author(s):

Budi Setiawan ◽

Erizal Zaini ◽

Salman Umar

Keyword(s):

Electron Microscopy ◽

Thermal Analysis ◽

Scanning Electron Microscopy ◽

Fourier Transform ◽

Differential Thermal Analysis ◽

Fourier Transform Infrared ◽

X Ray Diffraction ◽

Poloxamer 188 ◽

X Ray ◽

Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik menggunakan analisis varian satu arah SPSS 17.

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The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

Minerals ◽

10.3390/min11050440 ◽

2021 ◽

Vol 11 (5) ◽

pp. 440

Author(s):

Fabiana Pereira da Costa ◽

Jucielle Veras Fernandes ◽

Luiz Ronaldo Lisboa de Melo ◽

Alisson Mendes Rodrigues ◽

Romualdo Rodrigues Menezes ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Analysis ◽

Differential Thermal Analysis ◽

Chemical Resistance ◽

Mechanical Analysis ◽

Northeastern Brazil ◽

X Ray Diffraction ◽

X Ray ◽

Chemical Agents ◽

Natural Stones

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

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The Roman Ceramics of Salobrena (Granada-Spain) and their Raw Materials

MRS Proceedings ◽

10.1557/proc-267-627 ◽

1992 ◽

Vol 267 ◽

Author(s):

Ana M De Andres ◽

Isabel MuÑOZ

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

Raw Materials ◽

Third Century ◽

Western Coast ◽

X Ray Diffraction ◽

X Ray ◽

The Third ◽

Good Number ◽

Scanning Electron

ABSTRACTNineteen roman ceramic sherds found near Salobreña (Granada, Spain), in the western coast of the Mediterranean Sea, as well as different ceramic clays from the surroundingsare studied. Both clays and ceramic sherds are characterizad by X-ray diffraction and spectrometry, differential thermal analysis, and scanning electron and optical microscopies. A good number of the ceramic pieces, among which some “Terrae Sigillatae”, have a composition similar to that of the local clays and, thus, have been probably manufactured at Salobreña. Only a few of them have a foreign origin. For most of them, the firing temperature was about 800-850 °C, although some have been produced at 900-1000 °C, and some others at 1000-1100 °C. It is concluded that Salobreña appearsto have been an important settlement just in the third century of the Christian era.

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Silica-Kaolin Mix Effect on Evaporative Pattern Castings Surface Roughness

Archives of Foundry Engineering ◽

10.1515/afe-2016-0055 ◽

2016 ◽

Vol 16 (3) ◽

pp. 83-88 ◽

Cited By ~ 1

Author(s):

B.V. Omidiji ◽

R.H. Khan ◽

M.S. Abolarin

Keyword(s):

Thermal Analysis ◽

Surface Roughness ◽

Differential Thermal Analysis ◽

Ratio Method ◽

Gating System ◽

X Ray Diffraction ◽

Pouring Temperature ◽

Material Loss ◽

Refractory Coating ◽

X Ray

Abstract The influence of the refractory coating which is a mixture of silica flour and kaolin on the surface roughness of the plate castings produced using evaporative patterns had been considered in this work. The kaolin was used as a binder and ratio method was employed to form basis for the factorial design of experiment which led to nine runs of experiments. Methyl alcohol at 99% concentration was used as the carrier for the transfer of the coating to the surface of the patterns. Pouring temperature was observed as a process parameter alongside the mix ratios of the coating. Attempts were made to characterize the refractory coating by using two methods; differential thermal analysis (DTA) and X-ray diffraction. Attempt was also made to characterize the casting material. Gating system design was done for the plate casting to determine the correct proportions of the gating parameters in order to construct the gating system properly to avoid turbulence during pouring of liquid metal. A digital profilometer was used to take the measurements of the surface roughness. It was observed that the mix ratio 90% silica flour-10% kaolin produced the lowest value of the surface roughness of the plate castings and had the lowest material loss in the DTA test. The pouring temperature of 650°C produced best casting.

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SOLUBILITY OF GERMANIUM DISELENIDE IN THE Cu3AsSe4

Azerbaijan Chemical Journal ◽

10.32737/0005-2531-2021-4-67-70 ◽

2021 ◽

Vol 0 (4) ◽

pp. 67-70

Author(s):

Z.T. Hasanova ◽

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

Phase Equilibria ◽

Solid Solutions ◽

X Ray Diffraction ◽

X Ray

Differential thermal analysis and powder X-ray diffraction methods were used for phase equilibria studying in the Cu3AsSe4-GeSe2 system. It was established that wide (up to 30 mol.%) solid solutions based on Cu3AsSe4 are formed. GeSe2-rich alloys consist of various heterogeneous mixtures, including phases outside the T–x plane of this section

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