Thermal ablative technique

These include mainly thermal ablative techniques such as laser-induced thermotherapy, radiofrequency and microwave ablation, but also chemoembolization as well as selective internal irradiation therapy. 

It is generally acknowledged that DSC is the pre-eminent thermal analysis technique and that it has progressively become the established technique for the study of the thermal behavior of polymeric materials. Conventional DSC correlates thermal power with heat capacity and the integral thereof to energy and entropy. Thus, DSC has been applied to determine heat capacities of a wide range of materials. Conventional DSC is able to determine heat capacity to an uncertainty of 1-2% tmDSC is able to measure this parameter to an uncertainty of less than 1% with reproducible reliability. It is the temperature modulation feature of tmDSC which has confirmed this technique as the most versatile and most reliable of the thermal analysis techniques. Its versatility is further qualified by its ability to characterize the thermal behavior of materials without the need to have a detailed knowledge of the fundamental theoretical principles which underscore the basis of the technique. 

Sometimes thermal analysis techniques must be applied unconventionally if we are to be able to carry out the measurements under conditions close to those of the process being studied. Thus, for example, the calorimetric study of a sample in a sealed cell simulates what happens in a homogeneously heated autoclave. DTA or DSC measurements can also be carried out under a constant pressure of an inert gas or even under supercritical CO2 [112]. Figure 17 presents a scheme for a DTA experiment under supercritical CO2. 

Where kinetic factors are important in studying systems using thermal analysis techniques, then the Arrhenius parameters in theory should be able to be estimated. The Arrhenius equation can be written... 

The LB technique was chosen for covering the spheres because it was shown to provide enhanced thermal stability of many types of proteins in deposited layers (Nicolini et al. 1993, Erokhin et al. 1995, Antolini et al. 1995), which no other technique is able to achieve. Since only the upper protein layer is involved in the catalytic activity, no special attention was paid to check whether the deposited layer is a monolayer or multilayer. However, the samples were thoroughly washed to remove protein molecnles not bound covalently to the sphere surface, since during the functional test these molecules could contribute to the measured apparent catalytic activity. 

How do we decide whether to separate a mixture by gc or hplc In gc, mixtures are examined in the vapour phase, so that we have to be able to form a stable vapour from our mixture, or convert the substances in it to derivatives that are thermally stable. Only about 20% of chemical compounds are suitable for gc without some form of sample modification the remainder are thermally unstable or involatile. In addition, substances with highly polar or ionisable functional groups often show poor chromatographic behaviour by gc, being very prone to tailing. Thus hplc is the better technique for macromolecules, inorganic or other ionic species, labile natural products, pharmaceutical compounds and biochemicals. 

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