Experimental Verification of Modal Identification of a High-rise Building Using Independent Component Analysis

Abstract Independent component analysis is one of the linear transformation methods based the techniques for separating blind sources from the output signals of the system. Recently, the method has been analytically applied to the identification of mode shapes and modal responses from the output signal of structures. This study aims to experimentally validate the blind source separation using ICA method and propose a novel method for identification of the modal parameters from the decomposed modal responses. The result of the experimental testing on the three-story steel scale model shows that the mode shapes obtained by ICA method are in good agreement with those by the analytical and peak-picking method in the frequency domain. Based on the robust mathematical model, ICA can calculate the natural frequency and damping ratio effectively using the probability distribution function of the instantaneous natural frequency determined by Hilbert transform of the decomposed modal responses and the change in the output covariance. Finally, the validity of the proposed method paves the way for more effective output-only modal identification for assessment of existing steel-concrete buildings

The Catalysis of Delayed Petroleum Coking

Due to the decreasing crude oil quality (heavier crudes and increasing contaminant concentrations) methods for upgrading residues from the refining process, such as coking, are becoming increasingly important. Delayed coking, a method by which residues are thermally cracked (large heavy molecules broken into smaller lighter molecules), produces liquid products and solid coke which can both be sold for further profit. In order to increase the amount of liquid products produced since they are the most value added product of the coking process catalysts (platinum on 0.5% alumina and nickel (skeletal),molybdenum promoted (1 wt%)) were tested to see how they would affect the process and products. Different ratios of vacuum residue, light gas oil, heavy gas oil, and catalyst were all loaded into a semi-batch reactor which operated under a nitrogen environment at 15 psi. Each ratio of components was tested at 450°C, 475°C, and 500°C. Gas chromatography based on ASTM D2887 was used to analyze gaseous products every 15 minutes during each test and the liquid products at the end. Testing is still ongoing and preliminary results have yet to be obtained. Due to the increased value of liquid products, catalysts and conditions which produce more of those are favored. Further research into these and other catalysts is recommended since residues from different crudes could interact differently with the catalysts

Development of Mental Health Indicators in Korea

Objective: Promoting mental health and preventing mental health problems are important tasks for international organizations and nations. Such goals entail the establishment of active information networks and effective systems and indicators to assess the mental health of populations. This being said, there is a need in Korea develop ways to measure the state of mental health in Korea. Methods: This paper reviews the mental health indicator development policies and practices of seven organizations, countries, and regions: WHO, OECD, EU, United States, Australia, UK, and Scotland. Using Delphi method, we conducted two surveys of mental health indicators for experts in the field of mental health. The survey questionnaire included 5 domains: mental health status, mental health factor, mental health system, mental health service, and quality of mental health services. We considered 124 potential mental health indicators out of more than 600 from indicators of international organizations and foreign countries. Results: We obtained the top 30 mental health indicators from the surveys. Among them, 10 indicators belong to the mental health system. The most important five mental health indicators are suicide rate, rate of increase in mental disorder treatment, burden caused by mental disorders, adequacy of identifying problems of mental health projects and deriving solutions, and annual prevalence of mental disorders. Conclusion: Our study provides information about the process for indicator development and the use of survey results to measure the mental health status of the Korean population. The aim of mental health indicator development is to improve the mental health system by better grasping the current situation. We suggest these mental health indicators can monitor progress in efforts to implement reform policies, provide community services, and involve users, families and other stakeholders in mental health promotion, prevention, care and rehabilitation

Catalysis in Petroleum Coking

The petroleum industry is challenged with the processing of present heavy crudes caused by high composition of sulfur and metals, which lead to a higher yield of unfavorable bottom product as vacuum residue. Vacuum residue is the least valuable fraction of four, such as saturates, aromatics, resins and asphaltenes. However, it can be upgraded to recover more valuable products such as light hydrocarbons. The Delayed Coking process is going to be used to transform the vacuum residue at different experimental conditions. First of all, the behavior of the vacuum residue needs to be analyzed with no additions in feedstock. Secondly, the vacuum residue can be mixed with unhydrogenated and hydrogenated light gas oil at different concentrations. Finally, the addition of different catalysts at various concentrations could be another method to achieve high yield of the desired product. Expected experimental conditions are 475oC for reactor temperature and bimetallic or trimetallic catalysts for the delayed coking process. In this research, 3 different catalysts will be tested in several proportions with respect to the weight of the feedstock material. The recommended feed concentration of light gas oil depends on the molecular structure of the vacuum residue and can be determined only by actual experiment. Based on these experimental conditions, a conclusion about the yield of the light hydrocarbons and ways to improving the process can be drawn

Increasing the Durability of Piezoelectric Impact-based Micro Wind Generator in Real Application

AbstractThe purpose of this study is to increase the durability of piezoelectric impact-based micro wind generator (PIMWG) in real application. Using new PIMWG design, numerical simulation, and experimental comparison analysis, we improved the durability of PIMWGs in real application. The experimental results show that the optimized PIMWG generated 2.4 mW (RMS value), and it did not crack within 40h. In this study, we improved the durability of PIMWGs for real application

All-in-one assembly based on 3D-intertangled and cross-jointed architectures of Si/Cu 1D-nanowires for lithium ion batteries

All-in-one assemblies of separator, electrode and current collector (SECA) for lithium ion batteries are presented by using 1D nanowires of Si and Cu (nwSi and nwCu). Even without binders, integrity of SECA is secured via structural joints based on ductility of Cu as well as entanglement of nwSi and nwCu. By controlling the ratio of the nanowires, the number of contact points and voids accommodating volume expansion of Si active material are tunable. Zero volume expansion and high energy density are simultaneously achievable by the architectureopen0