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Abstract  

Instrumental neutron activation analysis was used to perform compositional analysis on more than 200 potsherds from prehistoric ceramic pottery collected in or near the Mimbres Valley in New Mexico. Statistical evaluation of the data was used to identify samples of similar origin. Results indicate that at least two sites within the Mimbres heartland and one in the Upper Gilla Valley existed for the production of the characteristic Classic Mimbres pottery. The composition of the clusters of samples identified are described and the significance of the groupings to the archaeology of the region is discussed.

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Abstract  

A DSC compositional analysis of 3 model binary systems of pharmaceutical significance has been conducted. Mixtures of known selected composition for each of the systems 3,5-dinitrobenzoic acid/benzoic acid, paracetamol/4-aminobenzoic acid and acetylsalicylic/salicylic acid were prepared and analyzed by DSC. The respective compositions derived from applications of the van't Hoff equation were correlated with the corresponding theoretical values and with the corresponding fusion temperatures and fusion enthalpies, obtained from the relevant DSC profiles. Linear correlations were found to exist between the theoretical compositions, fusion temperatures and fusion enthalpies for each of these systems and it is apparent that with suitable calibration procedures, the DSC compositional analysis method can be applied to determine the purity at the 90–95 mole% level. This level is of considerable interest in drug stability studies and has real significance in purity assays of commercial pharmaceutical preparations.

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Abstract  

Conventional thermogravimetric analysis (TG) uses constant heating rates to determine decomposition rates of a material and compositional analysis. Often, the decomposition steps can not be separated clearly enough due to parallel or consecutive reactions. If the reaction rates and the respective activation energies are enough different the TG resolution can be much enhanced by lowering the heating rate during the decomposition steps. The automated discrete adjustment of the heating rate is controlled by a set of parameters, such as threshold values, waiting times and rate factors. This technique, called MaxRes, allows for faster compositional analysis without loss of resolution. The same technique is also applicable to thermomechanical analysis (TMA) if time/temperature dependent events such as softening are to be separated.

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Abstract  

The distribution of nitrogen in plasma deposited silicon nitride films and in commercially produced, hot-pressed bulk material has been determined by the nuclear (proton) track image analysis technique. The nuclear track technique is shown to have the unique capability of sampling large areas (cm2) while providing distribution information on the micro scale (100 m2). Nitrogen over the range of 2 to 40% is determined quantitatively. Spatial distribution and topographical maps are plotted. The overall composition of the material is established by 14 MeV NAA through the determinations of silicon, nitrogen, and oxygen. An application in the micro electronic industry is described.

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Abstract  

The use of ion scattering for surface composition and structure analysis has been reviewed. The extreme surface specificity of this technique has been widely used to obtain qualitative information in a straightforward way, but the occurrence of charge exchange processes, thermal lattice vibrations and multiple scattering have precluded quantitative analysis of experimental data. Examples are quoted to illustrate the progress that has been made in understanding these fundamental processes and in applying this knowledge to the development of the analytical capabilities of the technique.

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Traditional Chinese medicine (TCM) has been widely used in many countries for thousands of years and played an indispensable role in the prevention and treatment of diseases, especially the complicated and chronic ones. However, the application of TCM in diseases is still not fully recognized by people around the world, the main reason is that Chinese herb is a very complex mixture containing hundreds of different components. Thus, it is essential to make quality control and evaluation of TCM. A new quality evaluation method, quantitative analysis of multi-components by single marker (QAMS), was developed to the quality control of alkaloids in TCM, a case study on Radix aconiti lateralis, named Fuzi in Chinese. Six alkaloids, including aconitine, hypaconitine, mesaconitine, benzoylaconine, benzoylmesaconine, and benzoylhypaconine, were selected as main components to evaluate the quality of Radix aconiti lateralis. The feasibility and accuracy of QAMS were checked by the external standard method, and various high-performance liquid chromatographic instruments and chromatographic conditions were investigated to verify its applicability. Using aconitine as the internal reference substance and the content of aconitine was calculated according to relative correction factors by high-performance liquid chromatography. The present results showed that there was no significant difference observed between the QAMS method and the external standard method with the relative average deviations less than 3.0%, and QAMS is an effective way to control the quality of herbal medicines and seems to be a convenient and accurate approach to analyze multi-composition when reference substances are unavailable.

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Abstract  

Results of neutron activation analysis of 100 obsidian specinens from the southern Sierra Madre Occidental are discussed. Two separate peralkaline sources are identified, Huitzila and La Lobera, which are chemically and spatially distinct. Subsequent subdivision of each source into spatial and compositional subgroups suggest separate flows or subsources. Identification of archaeological artifacts which match these sources compositionally suggests that Huitzila and La Lobera were important sources of high quality obsidian which was distributed widely in northern Mesoamerica.

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The main objective of this work was to evaluate the composition, nutritional, physical and rheological properties of wheat flour and dough from genetically modified wheat (Triticum aestivum L.) Hi-Line 111 (GMW) compared to conventional wheat (non-GMW). Analyses were conducted to measure the proximate chemical composition with references to 18 components including total solid, protein, lipids, crude fiber, ash, carbohydrate, minerals, amino acids, and fatty acids. In addition, physical and rheological properties such as water absorption, arrival time, dough development time, stability value, dough weakening value, extensibility of dough, resistance to extension, and ratio of resistance/extensibility were evaluated. The results showed that there were no significant differences between GMW and non-GMW in terms of chemical composition. Results revealed the presence of saturated and unsaturated fatty acids wherein there were no significant differences between GMW and its counterpart in the levels of fatty acids. In addition, there were no significant differences on the levels of amino acids. In addition, there were no significant differences between the GMW and non-GMW in the physical and rheological properties. From these results, it can be concluded that GMW Hi-Line 111 is confirmed to have nearly the composition and rheological properties as non-GMW.

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György Kurtág's music makes extensive musical and extra-musical reference in ways which are often highly personal, yet the instructions which he gives to his performers are very often unclear, ambiguous, or even confusing. Through the examination of a small number of Játékok, centring on the 'Hommage à Tchaikovsky', the author demonstrates the compositional motivations behind some of this music. The discussion covers the use of musical reference and near-quotation, notation and performance physicality. These are also pieces which are situated within a pedagogical framework, and so inspire a particular relationship between the composer and his interpreter. In the 'Hommage à Tchaikovsky', Kurtág's idiosyncratic reinterpretation of the B flat minor Concerto is transformed into a direct engagement with the very physical experience of playing the piano. Through the analysis of complementary works this paper shows how this transmission of personal experience through musical and physical gesture seems crucial to Kurtág's compositional thought.

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Abstract  

An established DTA/T/EGD/GC on-line coupled simultaneous technique and relevant equipment were applied to identify the micro impurity minerals—pyrite and siderite in two kinds of dolomite in air and N2. The proportional five-component mixed minerals (siderite, kaolinite, dolomite, calcite and quartz) and the proportional six-component mixed minerals (pyrite and the above five minerals) were detected in N2 and in air/CO2 (1∶1) separately by applying DTA/EGD/GC and DTA/GC. The experimental results provide the basis for demonstration of the reaction mechanism of thermal decomposition of various gas—solid-phase minerals in N2 and air/CO2. The compositions of six-component mixed minerals can be distinguished individually from the DTA/GC curves; reliable results are obtained.

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