Computer-Aided Analysis of Flow in Water Pipe Networks after a Seismic Event

This paper proposes a framework for a reliability-based flow analysis for a water pipe network after an earthquake. For the first part of the framework, we propose to use a modeling procedure for multiple leaks and breaks in the water pipe segments of a network that has been damaged by an earthquake. For the second part, we propose an efficient system-level probabilistic flow analysis process that integrates the matrix-based system reliability (MSR) formulation and the branch-and-bound method. This process probabilistically predicts flow quantities by considering system-level damage scenarios consisting of combinations of leaks and breaks in network pipes and significantly reduces the computational cost by sequentially prioritizing the system states according to their likelihoods and by using the branch-and-bound method to select their partial sets. The proposed framework is illustrated and demonstrated by examining two example water pipe networks that have been subjected to a seismic event. These two examples consist of 11 and 20 pipe segments, respectively, and are computationally modeled considering their available topological, material, and mechanical properties. Considering different earthquake scenarios and the resulting multiple leaks and breaks in the water pipe segments, the water flows in the segments are estimated in a computationally efficient manner.ope

A photonic-crystal optical antenna for extremely large local-field enhancement

We propose a novel design of an all-dielectric optical antenna based on photonic-band-gap confinement. Specifically, we have engineered the photonic-crystal dipole mode to have broad spectral response (Q ~70) and well-directed vertical-radiation by introducing a plane mirror below the cavity. Considerably large local electric-field intensity enhancement ~4,500 is expected from the proposed design for a normally incident planewave. Furthermore, an analytic model developed based on coupled-mode theory predicts that the electric-field intensity enhancement can easily be over 100,000 by employing reasonably high-Q (~10,000) resonators

Stability of wheat germ oil obtained by supercritical carbon dioxide associated with lipase ethanolysis

Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SCCO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1,3-regiospecific lipase at different temperatures (40 to 70°C) to produce diglycerides and monoglycerides containing fatty acid ethyl esters. For determination of stability, wheat germ oil obtained by ethanolysis reactants was characterized by measuring the acid value, peroxide value, free fatty acid contents, thiocyanate method, DPPH radical scavenging effect and rancimat test. The optimized condition of 40°C shows the highest oil stability among the various conditions.Keywords: Supercritical carbon dioxide, wheat germ oil, ethanolysis, immobilized lipases, oil stabilityAfrican Journal of Biotechnology Vol. 12(22), pp. 3570-357

Entrepreneurial orientation, entrepreneurial education and performance

Purpose - Korean economy is demanding to change from an industrial society to an entrepreneurial society. It is asking for a generational change from the preexisting paradigms of such as labor consciousness, the concept of work and company management. Entrepreneurship is one of the key elements that will lead to a successful business performance under highly uncertain business conditions. The purpose of this paper is to examine the relationship between entrepreneurial orientation and business performance. Also, the authors look for the role of entrepreneurship education in the influence of entrepreneurial orientation on financial and nonfinancial business performance. Design/methodology/approach - To accomplish the purpose of this study, the authors carried out a survey targeting nascent entrepreneurs and total early-stage entrepreneurs with less than seven years of experience. Based on the Miller’s (1983) definition, a group of questions for entrepreneurial orientation, similar to Covin and Slevin (1989), were developed. Findings - First, among the subfactors of entrepreneurial orientation, it was clear that innovative progressiveness affected nonfinancial business performance. Second, risk-taking propensity did not influence both financial business performance and nonfinancial business performance. Third, entrepreneurship education had no connection with entrepreneurial orientation or business performance. Practical implications - Nonfinancial business performances are related with long-term goals and growth potential. Innovative proactiveness affects nonfinancial business performance. Thus, entrepreneurs should look for ways to promote their innovative proactiveness. Entrepreneurship education for experienced entrepreneurs is not as effective as that for students. Originality/value - In the authors’ study, survey questionnaires were sent to 200 nascent and total early-stage entrepreneurs searching for business angel investments or entrepreneurship consultants in Korea. A total of 180 entrepreneurs answered the survey questions online. There are not so many valid studies examining the effect of entrepreneurship education for nascent and total early-stage entrepreneurs in Korea