Earticle

The properties of porous silicon, such as substrate properties, porosity, thickness, refractive index, surface area, and optical properties of porous silicon were reviewed. Some properties, such as porosity, refractive index, thickness, pore diameter, multi-structures, and optical properties, are strongly dependent on the anodization process parameters. These parameters include HF concentration, current density, anodization time, and silicon wafer type and resistivity.

Various types of smart dust based on photonic crystal exhibiting unique reflectivity were successfully obtained by an electrochemical etching of silicon wafer using square wave currents. Smart dust containing Bragg structure obtained from the sonication of DBR porous silicon film in solution retained its optical reflectivity. Field emission scanning electron micrograph (FE-SEM) was used to measure the size of optically encoded smart dust and its size can be tuned from few hundred nanometers to few microns depending on the duration of sonication. Optical characteristics of smart dust were used to investigate a possible applications such as chemical sensors.

Free-standing multilayer distributed Bragg reflectors (DBR) porous silicon dielectric mirrors, prepared by electrochemical etching of crystalline silicon using square wave currents are treated with polymethylmethacrylate (PMMA) to produce flexible, stable composite materials in which the porous silicon matrix is covered with caffeine-impregnated PMMA. Optically encoded free-standing DBR PSi dielectric mirrors retain the optical reflectivity. Optical characteristics of free-standing DBR PSi dielectric mirrors are stable and robust for 24 hrs in a pH 12 aqueous buffer solution. The appearance of caffeine and change of DBR peak were simultaneously measured by UV-vis spectrometer and Ocean optics 2000 spectrometer, respectively.

In this study, liquid with carbonized artemisia was developed for the first time that can be used as food additives and outside medicinal agents by burning artemisia species such as Artemisia dubia wall, Artemisia capillaris Thunb, Artemisia montana (Nakai) Pamp), Artemisia keiskeana Miq, Leonurus Japonicus Houtt. etc. In addition, edibility of recovered liquid with carbonized artemisia was verified by comparing the contents according to each ingredient with common refined pyroligneous liquid through the analysis of 9 kinds of organic acid by the species of artemisia, methanol and ethanol. Besides, the result of antimicrobial activities on six kinds of food spoilage and food poisoning bacteria observed by paper disc method for liquid with carbonized artemisia indicated that those two liquids showed strong antimicrobial. At the concentration of 1.5 mg/disc, clear zone for S. sonnei and S. aureus, L. monocytogenes was 13~16 mm, and they showed stronger antimicrobial activities than other strain.

Multidrug resistance (MDR) is one of the main obstacles in the chemotherapy of cancer. MDR is associated with the over expression of P-glycoprotein (P-gp), resulting in increased efflux of chemotherapy from cancer cells. Inhibiting Pgp as a method to reverse MDR in cancer patients has been studied extensively, but the results have generally been disappointing. First-generation agents were limited by unacceptable toxicity, whereas second-generation agents had better tolerability but were confounded by unpredictable pharmacokinetic interactions and interactions with other transporter proteins. Third-generation inhibitors have high potency and specificity for P-gp. Furthermore, pharmacokinetic studies to date have shown no appreciable impact on drug metabolism and no clinically significant drug interactions with common chemotherapy agents. Third-generation P-gp inhibitors have shown promise in clinical trials. The continued development of these agents may establish the true therapeutic potential of P-gp-mediated MDR reversal.

Various algorithms and system development are being required to support the advanced decision making of navigation information support system because of a serious loss of lives and property accidents by officer's error like as carelessness and decision faults. Much of researchers have introduced the techniques about the systems, but they hardly consider environmental factors. In this paper, We collect the context information in order to assess the risk, which is considered the various factor of the sailing ship, then extract the features of knowledge context, which is to apply the weight of correlation coefficients among data in context information. We decide the risk after the extract features through the classification and prediction of context information, and compare the value accuracy of proposed method in order to compare efficiency of the weighted value with the non-weighted value. As a result of experience, we know that the method of weight properties effectively reflect the marine environment because the weight accurate better than the non-weighted.

The recent global warming may be estimated to give lots of impacts to the human society and biosphere of influencing climate change included by the natural climate variations through the human activity which can directly and/or indirectly play a major role of total atmospheric composition overall. Therefore it currently appears evidences such as hot wave, typhoon, and biosphere disturbance, etc. over the several regions to be influenced by global warming due to increasing the concentration of greenhouse gases in the atmosphere through inducing forest destruction, fossil fuel combustion, greenhouse gases emission, etc. since industrial revolution era. Through the working group report of IPCC (Intergovernmental Panel on Climate Change) for climate change was analyzed by the individual country's current status and figure out the important issues and problems related to the future trend of climate change science with advanced countries preparedness and research, In this study, the first working group report of IPCC focuses on those aspects of the current understanding of the physical science of climate change that are judged to be most relevant to policymakers. As this report was assessed and analyzed by including the progress of climate change science, the role of climate models and evolution in the treatment of uncertainties. This consists of the changes in atmospheric constituents(both aerosols and gases) that affect the radiative energy balance in the atmosphere and determine the Earth's climate, considering the interaction between biogeochemical cycles that affect atmospheric constituents and climate change, including aerosol/cloud interactions, the extensive range of observations snow available for the atmosphere and surface, for snow, ice, and frozen ground and for the oceans, respectively and changes in sea level, the paleoclimate perspective and assessment of evidence for past climate change and the extension, the ways in which physical processes are simulated in climate models and the evaluation of models against observed climate, the development plans and methods of improving expert and building manpower urgently and R&D fund expansion in detail for climate change science in Korea will be proposed.