Search Results

You are looking at 1 - 10 of 4,089 items for :

Clear All

Abstract  

To study the corrosion resistance of metals and alloys, an analysis system needs to be able to simulate the harsh environments to which these materials are subjected. The system must also collect data from metal and alloy samples at elevated temperatures over long periods of time (typically days). Thermogravimetric analyzers (TGs) are well accepted systems for both corrosion studies and long-term elevated temperature studies. However, until now, TGs could conduct either corrosion studies or long-term studies, but not both. This paper presents a TG system specifically designed to satisfy the requirements of long-term corrosion resistance studies of metals and alloys.

Restricted access

Abstract  

Theoretical models for the melting of solids are inadequate because relatively little is known about the structures of liquids formed and the factors that control this phase transformation. In the present analysis of fusion phenomenon, usually considered to be a physical change, it is pointed out that, for many solids (e.g., metals and some simple ionic salts) melting involves the redistribution of primary valence bonds. Accordingly, this review includes examination some more chemical aspects of the controls of melting. The available data show that enthalpy and density changes during liquefaction and solidification of the metallic elements and of the alkali halides are small. From quantitative consideration of these values, it is concluded that ordered packing arrangements of atoms, ions, or molecules, comparable with those of crystals, must be extensively retained into the melt. The energy and molar volume changes on melting are too small to allow significant departure, in the liquid, from the regular, efficient space-filling arrays that characterize crystalline solids. The set/liq model for melting (dynamic equilibria between alternative ordered structures) is proposed to account for the properties of the liquid. A detailed and critical comparison of melting with solid state decompositions considers the kinetics and the mechanisms of the changes that occur during the supply/removal of energy to/from the melt/crystal contact interface. Other relevant aspects of melting are discussed including the factors that determine the magnitudes of the melting points of individual solids.

Restricted access

–Baran-Çelik 2013 O. Tekin Baran-Çelik : Corpus Ponderum Antiquorum et Islamicorum . Turkey. 2: Istanbul Archaeological Museums. Greek, Roman, Byzantine and Islamic Weights in the Department of Metal Objects (Turkish Institute of Archaeology). Istanbul 2013

Restricted access

Metal complexes of fenoterol drug

Preparation, spectroscopic, thermal, and biological activity characterization

Journal of Thermal Analysis and Calorimetry
Authors: M. Soliman, Gehad Mohamed and Eman Mohamed

that were required for pharmacokinetic studies. Fig. 1 Structure of FEN·HBr drug However, in this work, metal chelates of Mn(II), Cr(III), Co(II), Ni(II), Cu(II), and Zn

Restricted access

. 129–138. Biró, B. et al., 1998. Toxicity of field applied heavy metal salts to the rhizobial and fungal microsymbionts of alfalfa and red clover. Agrokémia és Talajtan. 47. 265– 277

Restricted access

. Journal of Environmental Management 2005 Trefry LH, Parsley BJ. Heavy metal transport from the Mississippi river to the Gulf

Restricted access
Pollack Periodica
Authors: Alex Szakál, Gerhard Krexner, Andreas Grill, György Káli, Márton Markó and László Cser

Spittle J. A. Preferred orientations in cast metals, Materials Science and Technology , Vol. 21, No. 5, 2005, pp. 546–550. Spittle J. A

Restricted access

can be created as desired. The facility to synthesize complexes with various hydrophobic chains and head group (metal ions) provides great flexibility in tailoring the amphiphiles to have specific physical architecture and chemical functionalities. It

Restricted access
Acta Alimentaria
Authors: I. Mohammadpour, R. Ahmadkhaniha, M. Zare Jeddi and N. Rastkari

. KHAN , R. , SRIVASTAVA , R. , ABDIN , M. , MANZOOR , N. ( 2013 ): Effect of soil contamination with heavy metals on soybean seed oil quality . Eur. Food Res. Technol. , 236 , 707 – 714

Restricted access

issue as sewage sludge is often highly contaminated with organic pollutants and heavy metals. Consequently, the amount of sewage sludge thermally treated (mono- or co-incineration and subsequent disposal of the ashes) significantly increased in the last

Restricted access