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Microwave-assisted extraction and synthesis studies and the scale-up study with the aid of FDTD simulationDai, Jianming. January 2006 (has links)
No description available.
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Authentication of the Panax genus plants used in Traditional Chinese Medicine (TCM) using Randomly Amplified Polymorphic DNA (RAPD) analysisRinaldi, Catherine January 2007 (has links)
[Truncated abstract] Traditional medicines are used by millions of people throughout the world as their primary source of medical care. A range of materials are in used traditional medicines including plant and animal parts. Even though the traditional medicine trade is estimated to be worth sixty billion dollars annually the trade remains largely unregulated. Unscrupulous practices by vendors to increase their profit margins such as substituting and adulterating expensive material with cheaper varieties go unchecked. This can be dangerous to consumers because some substitutions involve poisonous material. Also, animal parts from endangered species can find their way into traditional medicines, therefore there needs to be a way to identify them in traditional medicines to prosecute poachers. The traditional techniques used for the identification of material used in Traditional Chinese Medicine (TCM) include, morphological, histological, chemical and immunological analysis. However, these techniques have their limitations. This makes applying multiple techniques essential to provide thorough authentication of the material. DNA profiling provides a technique well suited to analysing material used in TCM. DNA profiling is advantageous over other techniques used to authenticate material used in TCM because it requires only a small sample amount, can determine the cultivator, be used on all forms of TCM and potentially distinguish the components of mixtures. ... Therefore, profiles of different species/individual are different and species? can be distinguished. Commercially sold traditional medicines are processed which is likely to degrade the DNA of the sample making extraction and amplification difficult. Here an organic Phenol:Chloroform extraction technique extracted DNA from commercial dried root samples. The extracted DNA was amplifiable using RAPD primers. The RAPD primers used here produced enough polymorphic bands to distinguish different plant species. They were used to distinguish commercial samples that were sold as three different species within the Panax genus, Panax ginseng, Panax quinquefolium and Panax notoginseng and genetically unrelated plant material; Potato and Eleutherococcus senticosus. Liquid samples and mixtures were also profiled with the RAPD primers to determine whether the RAPD primers provide enough distinguishing ability to analyse these forms of TCM. DNA was extracted from the liquid samples, one a ginseng drink and the other an ginseng extractum. However, there was no reliability in the production of PCR products. The analysis of the mixture samples found that not enough polymorphic bands were produced by the RAPD primers used here to identify Panax species within mixtures of two Panax species. While when P. ginseng was mixed with a genetically unrelated sample there was enough polymorphism to differentiate the two samples in the mixture. The results of this research show that RAPD analysis provides a simple and inexpensive technique to begin analysis of materials used in TCM. Using RAPD analysis it is possible to distinguish Panax plant species from each other. However, the RAPD primers used here did not provide enough reproducibility or polymorphism to analyse liquid and mixtures of Panax species plants.
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Microwave-assisted extraction and synthesis studies and the scale-up study with the aid of FDTD simulationDai, Jianming. January 2006 (has links)
The research undertaken in this thesis includes microwave-assisted extraction (MAE), synthesis, and the investigation of the scale-up of the microwave-assisted processes with the numerical aid. / The main goal of this research is to study the various problems associated with the scale-up of the microwave-assisted extraction and synthesis processes. Laboratory studies were carried out to investigate the microwave-assisted extraction of known components from peppermint leaves and American ginseng. Various factors that influence the extraction processes were studied. Microwave-assisted extraction method was compared with conventional heating and room temperature extraction methods on the extraction of ginsenosides from American ginseng. Microwave-assisted extraction method was determined to have higher extraction rate than both room temperature extraction and reflux temperature extraction using hotplate heating indicating that there is acceleration factor in enhancing the extraction rate beyond the temperature influence. / In the study of synthesizing n-butyl paraben, microwave-assisted synthesis was observed to greatly increase the yield of n-butyl paraben in much shorter period of time compared to the classic synthesis method. A transition state theory was proposed to explain this rate enhancement. The study of the synthesis of parabens with different alcohol and the influencing factors on the synthesis of n-butyl paraben yield were also studied. / A visualization method was developed to determine the microwave distribution in a domestic microwave cavity. The method uses gypsum plate as carrier and cobalt chloride as indictor. A simulation program was developed using the finite difference time domain (FDTD) approach and written in C programming language. The program was proved to be very versatile in different type of cavity simulation. Not only cavities with different dimensions and geometrical designs can be simulated, multiple magnetrons and various ways of magnetron placement can also be integrated into the simulation program. The detailed power distribution can be visualized in a 3-D plot, and the power distribution in each layer can be analyzed using the simulation result. The power distribution information will be very useful and necessary before any real equipment development.
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