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Journal of Thermal Analysis and Calorimetry
Authors: L. Benkő, J. Danis, M. Czompo, R. Hubmann, A. Ferencz, G. Jancsó, Z. Szántó, A. Zólyomi, F. Könczöl, Á. Bellyei, E. Rőth, and D. Lőrinczy

Abstract  

Massive bleeding from oesophagus varices presents a life threatening complication of liver cirrhosis. No effective method of treatment is available until now, that would guarantee high grade of patient wellness during the conditioning and investigation phase until the definitive treatment could be introduced. The fact that we have not found any report in the literature about self-expandable metal stents (SEMS) application in acute variceal bleeding had encouraged us to use stents usually used for oesophageal malignancy and furthermore develop a special stent for this individual indication. The aim of this study was to evaluate the tissue response to oesophagus stent designed for stop acute variceal bleeding in animal experiment in compare with another stent used for iatrogenic treatment of different strictures of the oesophagus. Tissue oxygen saturation (StO2) measurement was performed before and after the implantation of the stents. Macroscopic and histological investigations of the stented oesophagus segments were observed after 10 days. Differential scanning calorimeter (DSC) is a well-established method for the demonstration of thermal consequences of local and global conformational changes in biological systems, but it has never been used for the investigation of the oesophagus. According to our results the thermal denaturation of intact oesophagus, its mucosa and muscle fragments revealed significant differences compared to healthy sample in favour of the new stent.

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Abstract  

PHB [poly (3-hydroxybutyrate)], post-consumer soft-drink bottles poly (ethylene terephthalate) PET (herein named PET-R) and PHBPET-R (blends of PHB and PET-R in several compositions) samples were evaluated by differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM) in order to verify their thermal properties and porosity according to amounts of PET-R added the blends. The DSC curve showed that the solvents used to solve the polymer mixture cause changes in the thermal behavior of PET-R films and in PHBPET-R blends. SEM studies of the PHBPET-R blends show that with a gradual mass increase of PET-R, there are gradual increases in the porosity of the films.

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Abstract  

The characterization of samples of painted plasters obtained from the archaeological site of Xochicalco, in Central Mexico, is presented. Elemental concentrations of the painted layers were obtained by using proton induced X-ray emission (PIXE). The main crystalline structures of the samples are identified with the help of X-ray diffraction (XRD), while the microstructure is studied by scanning electron microscopy (SEM). The information resulting from the application of these three techniques is used to achieve more accurate values for the elemental concentrations. Additional data regarding organic components of the paintings was obtained through Fourier transform infrared spectrometry (FTIR). Although the latter results only provided reliable data on inorganic components, they help to clarify the results from XRD and confirm those of SEM.

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Abstract  

The thaumasite form of sulphate attack (TSA) concerns cements and concretes containing limestone and is attributed to the formation of thaumasite. This work deals with the confirmation of thaumasite formation in cement mortars. Three types of cement were examined: Portland cement and Portland limestone cement containing 15 and 30% mass/mass limestone. The specimens were cured at 5C, for 12 months, in a 1.8% MgSO4 solution. The formation of thaumasite was checked and confirmed by XRD, TG and SEM. It was concluded that mortars containing limestone suffer from TSA at low temperature. The combination of XRD, TG and SEM leads to the positive identification of thaumasite and resolves the well known problem of thaumasite and ettringite confusion.

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Abstract  

The dehydration of samples of a Coober Pedy, South Australian sedimentary white opal, displaying play of colour, was investigated using TMA by heating the samples of the specimen to a range of temperatures between room temperature and 1000 at 200C intervals followed by cooling to room temperature. Etched fracture surfaces of the samples were then examined using SEM. The samples showed the typical expansion at low temperature up to 210C before contraction was observed. The contraction of the opals was ascribed to both sintering, supported by morphological change observed in the SEM micrographs, and dehydroxylation of the silanol groups producing silicon-oxygen-silicon bridges resulting in a more dense silica network.

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Journal of Thermal Analysis and Calorimetry
Authors: G. Della Gatta, E. Badea, R. Ceccarelli, T. Usacheva, A. Maši?, and S. Coluccia

Summary  

Environmental impact on parchment was investigated by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Parchments subjected to accelerated ageing and old parchments were compared to evaluate quality and extent of deterioration. Stability of fibrillar collagen within parchment was determined from the changes in thermodynamic parameters associated with thermal denaturation. Parchment surface was characterised, and specific morphological criteria were selected for damage assessment. The thermodynamic and morphological changes of collagen induced by deterioration are discussed, and their correlations are proposed as a means of ranking damage in old parchments.</o:p>

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Abstract  

Poly(d,l-lactide) microspheres with progesterone loadings of 0, 10, 20, 30 and 50% w/w were manufactured using an interrupted solvent evaporation process. Spherical microspheres with loadings close to the theoretical values were produced. The glass transition of the polymer could be identified by a step change in the heat capacity measured by TMDSC. Progesterone was found to plasticise the glass transition temperature at contents of 20% w/w or less. At a 30% loading, cold crystallisation of progesterone was seen indicating that an amorphous form of the drug was present; these microspheres were found to exhibit a pitted surface. TMDSC of the 50% progesterone samples suggested that most of the drug was present as crystals. This was supported by the SEM and PXRD results.

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Abstract  

It was proved that non-destructive and non-sampling methods were used to analyze the composition of the archaeological glasses. Glass has been used in ornaments and decoration in Thailand for thousands of years. In this study, glass bead fragments found from the archaeological site at Khao Sam Kaeo, Chumphon Province, southern Thailand were analyzed by the proton induced X-ray emission spectroscopy (PIXE) and scanning electron microscope coupled with energy dispersive X-ray fluorescence spectroscopy (SEM–EDS). The composition analysis showed that copper was mainly presence as the colorant. Titanium, common impurity in sand, was all present in the glass bead samples. Furthermore, this type of glass almost spread over the various sites in this region that demonstrated the long distance or exchange connections. Finally, PIXE and SEM–EDS have been used to be the efficient techniques to analyze the archaeological objects, especially the glassy materials, to understand their characteristics and how they were produced in ancient times.

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-123. Embryogenesis 82 123 Dubois, T., Dubois, J., Guedira, M., Diop, A. and Vasseur, J. (1992): SEM characterization of an extracellular matrix around somatic pro

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More and more research is dedicated to address the phenomenon of online word-of-mouth (WOM). Concerning electronic WOM, three major underlying motives can be differentiated: opinion seeking, opinion giving and opinion passing (Flynn et al. 1996; Sun et al. 2006). The main aim of the research is to analyse the relationship between these three dimensions and the level of customer satisfaction. The research is based on a representative sample of 1000 respondents living in Hungary. According to the hypothesized Structural Equation Model (SEM), we can conclude that online opinion seeking behaviour has a significant positive impact on levels of customer satisfaction, as well as on opinion giving and opinion passing. This implies that opinion leaders not just share, but also collect enormous amounts of information about products and services and raise their expectations according to feedback. By doing so, their prior expectations are in relation to the true customer value of online stores and products. This means that customer satisfaction — measured using the disconfirmation paradigm — will reach a higher level, so it is advisory for online retailers to encourage customers to give feedback, write reviews, because it will affect the customer satisfaction level in a positive manner.

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