Structure-property relations of human and neonatal rat stratum corneum I. Thermal stability of the crystalline lipid structure as studied by X-ray diffraction and differential thermal analysis

1973 ◽  
Vol 304 (2) ◽  
pp. 267-275 ◽  
Author(s):  
G.L. Wilkes ◽  
An-Lac Nguyen ◽  
R. Wildnauer
1972 ◽  
Vol 50 (23) ◽  
pp. 3872-3875 ◽  
Author(s):  
Kim Vo Van ◽  
Fathi Habashi

Anhydrous CU2SO4 was prepared and its X-ray diffraction pattern was established. Differential thermal analysis, thermogravimetric analysis, and X-ray diffraction methods were used to study the effect of heating in different atmospheres. The formation of CU2SO4 as an intermediate in chemical processes has been discussed.


2008 ◽  
Vol 39-40 ◽  
pp. 399-401
Author(s):  
Viliam Pavlík ◽  
Eugen Jóna ◽  
Martina Sapietová ◽  
Soňa Šnircová

The glasses with composition of Li2O . 2 SiO2 . n ZrO2 . n TiO2 (where n = 0; 0.015; 0.031; 0.050; 0.075; 0.1; 0.15; 0.2) were prepared and the relationship between structural and selected parameters of thermal stability vs. crystallization has been studied by differential thermal analysis. Structural analysis was provided by X–ray diffraction. The order of thermal stability vs. crystallization representing of activation energy of studied glass systems which increase with higher addition both oxides. The same order was obtained from the values of XRD. On the comparison the glasses with zero addition titanium dioxide their activation energy was much higher.


1986 ◽  
Vol 1 (3) ◽  
pp. 415-419 ◽  
Author(s):  
R.A. Dunlap ◽  
K. Dini

The structure and thermal stability of rapidly solidified Al-Cr-Si, Al-Mn-Si, Al-Fe-Si, Al-Co-Si, and Al-Ni-Si alloys have been investigated using x-ray diffraction and thermal analysis measurements. Each series of alloys shows a region of stoichiometry that yields icosahedral symmetry and a region that yields an amorphous phase. Thermal and structural properties of these alloys are reported as a function of stoichiometry and quench rate.


2014 ◽  
Vol 32 (3) ◽  
pp. 414-418 ◽  
Author(s):  
Yajun Qi ◽  
Zhiqiang Wang ◽  
Shangru Zhai ◽  
Shuwen Jiang ◽  
Hai Lin

AbstractThe influence of ZnO substitution by 0–12 wt.% Na2O on the properties of ZnO-Sb2O3-P2O5-Na2O glasses has been investigated. The structure and properties of the glasses with the composition of (13.86-x)ZnO-57.93Sb2O3-28.21P2O5−x Na2O (x = 0–12 wt.%) were characterized by infrared spectra (IR), X-ray diffraction and differential thermal analysis (DTA). The results of IR indicated an increase in the intensity of symmetric vibrations of P-O-P bond, which was confirmed by the improvement of water durability with the increasing amount of Na2O in the range of 0–10 wt.%. Substitution of 10 wt.% Na2O led to the weight loss of the glass to 5.93 mg/cm−2 after immersion in deionized water at 50 °C for 24 h. The results of XRD showed that the ability of crystallization decreased, indicating the good thermal stability of the glass. The glass containing 8 wt.% Na2O had the best properties in every respect and might be an alternative to lead based glasses for the applications, providing further composition improvement.


2015 ◽  
Vol 69 (10) ◽  
Author(s):  
Ferooze Ahmad Rafiqi ◽  
Kowsar Majid

AbstractThis paper involves the preparation of polythiophene (PTP) and its composite by the oxidative polymerisation method by using ferric chloride as an oxidant and thiophene monomer. The gadolinium( III) complex obtained by the refluxing technique was used as dopant in the PTP matrix. On the basis of the spectroscopic characterisation, seven-coordinate geometry is proposed for the complex. Conductance measurement confirms the non-selectrolyte nature of complex. The PTP and its composite were subjected to FTIR, X-ray diffraction and scanning electron microscope techniques. The powder X-ray diffraction pattern showed the high crystalline nature of the complex which in turn developed a good degree of crystallinity in the PTP composite. The average particle size was calculated as 4.655 ˚A and 3.737 ˚A for the dopant and PTP composite, respectively, by using Debye Scherrer’s equation. Thermal analysis was performed by thermogravimetric (TG) analysis, differential thermal analysis (DTA) and differential scanning calorimetry (DSC) techniques. The TG, DTA and DSC results were well-correlated. The thermal analysis revealed the high thermal stability of the dopant which in turn improved the thermal stability of the PTP composite, revealing the potential of the composite for high temperature applications.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

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.


Calphad ◽  
2021 ◽  
Vol 73 ◽  
pp. 102258
Author(s):  
František Zelenka ◽  
Jakub Strádal ◽  
Pavel Brož ◽  
Jan Vřešťál ◽  
Jiří Buršík ◽  
...  

Minerals ◽  
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 ◽  
...  

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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