• 한국환경과학회지
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• 제15권5호
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• pp.485-491
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• 2006

In the aqueous solutions the dephosphorylations of isopropyl phenyl-4-nitrophenyl phosphinate(IPNPIN) mediated by hydroxide$(OH^{\theta})$ and o-iodosobenzoate$(IB^{\theta})$ ions ate relatively slow, because of hydrophobicity of the substrate, and however it appears that $OH^{\theta}$ is inherently better nucleophile than $IB^{\theta}$, which is more soft ion. On the other hand, in cetyltrimetyiammonium bromide(CTABr) solutions which contain cationic micelles, the dephosphorylations of IPNPIN mediated by $OH^{\theta}$ or $IB^{\theta}$ ate very accelerated to 120 or 100,000 times as compared with those in the aqueous solutions. The values of pseudo first order rate constants reach a maximum with increasing. Such rate maxima are typical of micellar catalysed bimolecular reactions and the rise in rate constant followed by a gradual decrese is characteristic of reactions of hydrophobic substrates. In the cationic micellar solutions of CTABr, $IB^{\theta}$ accelerates the reactions much more than that $OH^{\theta}$ does. The reason seems that $IB^{\theta}$ which is more hydrophobic and soft ion than $OH^{\theta}$ is more easily moved into the Stern layer of the CTABr micelles than $OH^{\theta}$. In the anionic micellar solutions of sodium dodecyl sulfate(SDS), the dephosrhorylations of IPNPIN ate slower than those in aqeous solutions. It means that $OH^{\theta}$ or $IB^{\theta}$ cannot easily move and approach to the Stern layer of the micelle in which almost all the hydrophobic substrate are located and which has a negative circumstance.

• 한국환경복원기술학회지
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• 제27권1호
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• pp.45-54
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• 2024

This study developed a model to evaluate the co-benefits and trade-off effects between biodiversity and carbon storage capacity based on the implementation locations of nature-based solutions. The model aims to propose optimal implementation locations by using the conceptual idea of edge effects for carbon storage and connectivity for biodiversity. The co-benefits were considered by simultaneously taking into account two effects rather than a single effect. Trade-off effects were observed among optimal plans through a comparison of benefits. The NSGA-II multi-objective optimization algorithm was utilized, confirming the identification of Pareto-optimal solutions. The implementation patterns of Pareto-optimal solutions for green areas were examined. This study holds significance in proposing optimal locations by evaluating various co-benefits and trade-off effects of nature-based solutions. By advancing models based on this evaluation framework, it is anticipated that the assessment of co-benefits and trade-off effects among various benefits of nature-based solutions, such as climate change mitigation, enhancement of biodiversity, and provision of ecosystem services, can be accomplished.

• 산경연구논집
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• 제15권6호
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• pp.9-15
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• 2024

Purpose: The primary aim of this study is to investigate the current issues in the leisure sports tourism and propose viable solutions based on a comprehensive review of existing literature. The specific objectives are to: (1) Identify the key challenges facing the leisure sports tourism industry. (2) Analyze the impact of these challenges on the industry's growth and sustainability. (3) Review and synthesize existing research to propose evidence-based solutions. Research design, data and methodology: The preliminary search yielded an extensive list of articles. These articles underwent a rigorous screening process based on their titles and abstracts. The inclusion criteria were: (1) studies focused specifically on the leisure sports tourism industry, (2) empirical research providing data on the identified issues, and (3) peer-reviewed journal articles. Results: The leisure sports tourism industry faces several pressing issues requiring effective solutions to ensure sustainability and growth. This section provides four critical solutions addressing the identified challenges: environmental sustainability, infrastructure and facility management, seasonality and economic impact, and health and safety concerns. Conclusions: The findings highlight several actionable solutions to the current issues faced by the leisure sports tourism industry. This industry can achieve a more stable and sustainable growth trajectory by addressing environmental sustainability, infrastructure and facility management, seasonality, and health and safety concerns.

• 한국환경과학회지
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• 제17권6호
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• pp.671-677
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• 2008

We studied to determine quantitatively the radical species generated from humic acid (HA) solutions by irradiation(>400 mn). The formation of radical species from HA solutions was investigated with ESR spectroscopy. We gave ESR spectrum with g-value 2.0048 and line width 0.559mT, coincided with those of the semiquinone radical. 0.1 mg/L HA solution generated the radicals of $1.2{\times}10^{-6}M$, increased with increasing HA concentration. Also, pH and ionic strength effect of the amount of the semiquinone radical generate from HA solution. In this study, we have found that the singlet oxygen affects the semiquinone radicals generation in HA solution.

• 기술혁신연구
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• 제13권1호
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• pp.141-167
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• 2005

The purpose of this study is to present the model of performance in new product R&D project team, from the perspective of the problem solving. The quality and commitment of the problem solutions in R&D project team depend on the team's cognitive diversity and affective acceptance. The higher cognitive diversity is, the higher quality of solutions is. And more affective acceptance is, more commitment to the problem solving is. The environmental maturity of team, and quality and commitment of problem solutions in R&D project teams are supposed to relate to the performance of research and development.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권2호
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• pp.131-136
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• 1999

The solubility of H2S is an important parameter for modeling H2S absorption. Since the direct measurement of H2S solubility in aqueous amine solutions is impossible, this work initially attempted to develop an H2S analogy method, however, this was unsuccessful. Consequently, H2S solubilities were measured in aqueous amines which were completely protonated with HCI over a temperature range of 25-60℃. The solvents investigated in this work included 0-50% aqueous solutions of methyldiethanolamine and diethanolamine. Thereafter, a new empirical correlation was developed that can predict Henry's constant for H2S using only the solubility of H2S in water and t도 molecular weight of the aqueous solvent.

• Structural Engineering and Mechanics
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• 제38권5호
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• pp.549-571
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• 2011

This paper presents analytical solutions for skewed thick plates under transverse loading that have previously been unreported in the literature. The thick plate solution is obtained in a framework of an oblique coordinate system. The governing equation is first derived in the oblique coordinate system, and the solution is obtained using deflection and rotation as partial derivatives of a potential function developed in this research. The solution technique is applied to three illustrative application examples, and the results are compared with numerical solutions in the literature and those derived from the commercial finite element analysis package ANSYS 11. These results are in excellent agreement. The present solution may also be used to model skewed structures such as skewed bridges, to facilitate efficient routine design or evaluation analyses, and to form special elements for finite element analysis. At the same time, the analytical solution developed in this research could be used to develop methods to address post-buckling and dynamic problems.

• Structural Engineering and Mechanics
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• 제30권5호
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• pp.593-602
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• 2008

This paper presents a new linearization algorithm to find the periodic solutions of the Duffing equation, under harmonic loads. Since the Duffing equation models a single degree of freedom system with a cubic nonlinear term in the restoring force, finding its periodic solutions using classical harmonic balance (HB) approach requires numerical integration. The algorithm developed in this paper replaces the integrals appearing in the classical HB method with triangular matrices that are evaluated algebraically. The computational cost of using increased number of frequency components in the matrixbased linearization approach is much smaller than its integration-based counterpart. The algorithm is computationally efficient; it only takes a few iterations within the region of convergence. An example comparing the results of the linearization algorithm with the "exact" solutions from a 4th order Runge- Kutta method are presented. The accuracy and speed of the algorithm is compared to the classical HB method, and the limitations of the algorithm are discussed.

• The Plant Pathology Journal
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• 제18권5호
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• pp.284-287
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• 2002

The antifungal activity of super reductive water (SRW) against plant pathogenic fungi was examined to extend its application to integrated pest management (IPM) for plant diseases. Diluted solutions ($\times$1/10, $\times$1/25, and $\times$1/50) of SRW inhibited fungal growth of kiwifruit soft rot pathogen, Diaporthe actinidiae, in a concentration dependent manner, When kiwifruits were inoculated on wounds with mycelium blocks, stock and diluted solutions successfully inhibited the disease development. In addition to the high pH of the SRW, fungistatic activity was also considered as the cause of the antifungal effect against the pathogen. Whereas conidial germination of Magnaporthe grisea was not affected by the diluted SRW solutions, appressorium formation was significantly inhibited in a concentration dependent manner, With little harmfulness to human health and environment SRW could be used to control plant pathogenic fungi, particularly appressorium-forming fungal pathogens.

• Environmental Engineering Research
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• 제11권6호
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• pp.303-310
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• 2006

The aim of this study is to assess the applicability of sericite in wastewater treatment particularly the removal of two important heavy metal toxic ions viz., Cu(II) and Pb(II) from aqueous solutions. The batch type experiments showed that sericite is found to be one of useful natural sorbent for the removal of these two cations from aqueous solutions and it is also to be observed that with the increase in sorptive concentration amount of metal uptake increases and the concentration dependence data obtained are fitted well for the Langmuir adsorption isotherm rather than Freundlich adsorption model. Further, the Langmuir monolayer adsorption capacity is found to be $1.674\;mg\;g^{-1}$ for Cu(II) and $4.697\;mg\;g^{-1}$ for Pb(II). Kinetic studies enabled, an apparent equilibria can be achieved between soild/solution interface within ca 10 mins for Cu(II) and ca 90 mins for Pb(II). Moreover, the removal behavior of sericite for these two metal ions is greatly influenced by solution pH.