• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.1317-1322
• /
• 2001

What changes in the eigen values and eigen functions are produced if the boundary surface S is no longer rigid but has a specific acoustic admittance which may vary from point to point on S. In this paper, changes in eigen values and eigen functions are derived by using Kirchhoff-Helmholtz integral equation. And acoustic potential energy, which is representative measure describing the physical quantity in cavity, is defined. Acoustic potential energy can be divided into primary one and secondary one. Primary one is the acoustic potential energy through unchanged eigen functions, and secondary one is through changed eigen functions. Using these two term, we can find the eigenvalue problem, which gives the control performance when the boundary condition is changed.

• Korean Journal of Weed Science
• /
• v.31 no.3
• /
• pp.240-249
• /
• 2011

The potential of juglone a plant naphthoquinone as a natural herbicide on new target, 7-keto-8-amino pelargonic acid synthetase (KAPAS) in the early step of biotin biosynthesis pathway, was performed in vitro and in vivo. Juglone effectively inhibited KAPAS activities in vitro and the $IC_{50}$ was $9.5{\mu}M$. Foliar application of juglone showed very good herbicidal activity to the eight-tested weed species. Among them, Solanum nigrum was completely controlled at a concentration of $250{\mu}g\;mL^{-1}$ with main symptoms of desiccation or burndown. Digitaria sanguinalis and Aeschynomene indica were also sensitive to juglone treatment. All eight weed species were controlled by 90~100% at a concentration of $500{\mu}g\;mL^{-1}$. However, soil application of juglone to Digitaria sanguinalis did not show any herbicidal symptoms. Cellular leakage from cucumber leaf squares treated with juglone increased depending on the concentrations increased from 6.25 to $100{\mu}M$ after 24 hours incubation with or without light. However, chlorophyll loss in cucumber leaf squares was negligible. Biotin supplements significantly rescued the inhibition of germination rate of Arabidopsis thaliana seeds previously inhibited by the juglone. Our results suggest that the juglone is a possible environmental friendly herbicide candidate with a new target KAPAS inhibiting activity.

• Nano
• /
• v.13 no.11
• /
• pp.1850132.1-1850132.14
• /
• 2018

The direct synthesis of metal-organic frameworks (MOFs) with acidic and basic active sites is challenging due to the introduction of functional groups by post-functionalization method often jeopardize the framework integrity. Herein, we report the direct synthesis of acid-base bifunctional MOFs with tuning acid-base strength. Employing modulated hydrothermal (MHT) approach, microporous MOFs named $UiO-66-NH_2$ was prepared. Through the ring-opening reaction of 1,3-propanesultone with amino group, $UiO-66-NH_2-SO_3H-type$ catalysts can be obtained. The synthesized catalysts were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-HMF conversion. Results revealed the acid-base bi-functional catalyst possessed high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of acid-base bi-functional MOFs for their potential use in catalysis field.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.18 no.1
• /
• pp.19-27
• /
• 1981

The surge motion of a freely-floating sphere in a regular wave is studied within the framework of a linear potential theory. The fluid is assumed to be perfect and only the steady-state harmonic motion in a water of infinite depth is considered. A velocity potential describing the fluid motion is decomposed into three parts; the incident wave potential, the diffraction potential and the radiation potential. In this paper the diffraction potential and the radiation potential are analysed by using multipole expansion method. Upon calculating pressures over the immersed surface of the sphere, the hydrodynamic forces are evaluated in terms of Froude-Krylov, diffraction, added mass and damping forces as functions of the frequency of the incident wave. Finally the frequency dependence of two pertinent parameters, the amplitude ratio and the phase lag between the motion of the sphere and that of the incident wave is derived from the equation of motion. As for numerical results the general tendency of the present calculation shows good agreement with Kim's work who also treated this problem utilizing the Green's function method.

• Journal of Life Science
• /
• v.21 no.11
• /
• pp.1501-1510
• /
• 2011

In recent years novel potential pharmocological candidates have been looked for in animal, seaweed, sponge, fungi and marine bacteria resources. In this study, matrix metalloproteinases (MMPs) that play an important role in metastasis, arthritis, chronic inflammation and wrinkle formation were used as target enzymes to screen therapeutic agents. The inhibitory effects of several marine algae including green algae (5 species), red algae (18 species) and brown algae (4 species) methanolic extracts on MMPs were investigated in human dermal fibroblasts and human fibrosarcoma cell line (HT1080 cells) using gelatin zymography. In human dermal fibroblasts, the inhibition of MMP-2 was observed in Laurencia okamurae, Polysiphonia japonica, Grateloupia lanceolate and Sinkoraena lancifolia of red algae. In contrast, MMP-2 activation was enhanced in Enteromorpha compressa and E. linza of green algae, and Peltaronia bighamiae and Sargassum thunbergii of brown algae. In human fibrosarcoma cells, MMP-9 activation was decreased in the presence of S. thunbergii of brown algae, Polysiphonia japonica in red algae and E. compressa and E. linza of green algae. The interesting finding is that E. compressa and E. linza of green algae, and S. thunbergii of brown algae exhibited a positive effect on MMP-2 in normal cells, but a negative effect on MMP-9 in cancer cell lines. These results suggest that E. compressa and E. linza of green algae, and S. thunbergii of brown algae contain potential therapeutic ingredients for cancer treatment.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.160-165
• /
• 1998

Under the heavy irradiation, when the production and the recombination of interstitials and vacancies are included, the diffusion equations become nonlinear. An effort has been made to arrange an appropriated transformation of these nonlinear differential equations to soluble Poisson's equations, so that analytical solutions for simultaneously calculating the concentrations of interstitials and vacancies in the angular dependent Cottrell's potential of the edge dislocation have been derived from the well-known Green's theorem and perturbation theory.

• Nuclear Engineering and Technology
• /
• v.31 no.2
• /
• pp.151-156
• /
• 1999

Under the heavy irradiation of crystalline materials when the production and the recombination of interstitials and vacancies are included, the diffusion equations become nonlinear. An effort has been made to arrange an appropriate transformation of these nonlinear differential equations to more solvable Poisson's equations, finally analytical solutions for simultaneously calculating the concentrations of interstitials and vacancies in the angular dependent Cottrell's potential of the edge dislocation have been derived from the well-known Green's theorem and perturbation theory.

• The Journal of Industrial Distribution & Business
• /
• v.14 no.5
• /
• pp.19-29
• /
• 2023

Purpose: The hospitality sector is vital to economic development, especially in metropolitan regions, where hotels are a pivotal factor in drawing in leisure and corporate visitors. Despite the potential advantages of urban hotels, there is a gap in empirical studies on the impacts of eco-friendly interior design on hotel appeal and guest behavior. Therefore, this study aims to fill out the research gap. Research design, data and methodology: This study employed a review of the literature systematically as its research design. The study's data collection technique involves exploring peer-reviewed journals through electronic databases like Scopus, and Web of Science. The present author double-checked the quality of instrument for all usable dataset. Results: Prior literature has stated a strong linkage between green interior design in urban hotels and customer behavior and hotel attractiveness. Using environmentally conscious methods, hotels can enhance the quality of their indoor atmosphere, preserve energy and water supplies, and establish a favorable public perception that appeals to environmentally aware consumers, thereby improving their overall experience and contentment. Conclusions: This study concludes that creating indoor spaces with environmental factors in mind could lead to a more enjoyable and beneficial atmosphere for hotel visitors and adopting a sustainability-oriented approach to hotel design and operations could attract potential customers.

• Korean Journal of Social Welfare
• /
• v.48
• /
• pp.7-41
• /
• 2002

This paper analyses the proposals contained in the British Government Green Paper, A New Contract for Welfare: Partnership in Pensions for low paid workers and the potential of the new rules to guarantee a decent income in old age. The UK pension system is a partnership between the State(providing the basic state pension and the SERPS), employers(providing occupational pension scheme) and private pension providers(providing personal pensions). Although the system needs to change, this partnership remains the right foundation. However, the pension Green Paper proposes substantial changes to second tier pension provision in the UK. In particular, the Government plans to replace the SERPS with a new State Second Pension. According to the Green Paper, this will result in "dramatically better pension provision for those earning less than ${\pounds}9,000$ a year" and through increased payments to private pension schemes, will also provide "extra help to those on middle incomes(${\pounds}9,000-{\pounds}18,500$ a year). Therefore, it discusses the general principles inherent in the design of the British pension system and analyses the balance of these principles is represented in the Green Paper. The paper then examines how the Government's proposals protect individuals from a means-tested old age. This paper finds that the Green paper's proposals add up to reinventing a new two-stage basic pension. However, two key features of a such a basic pension package are missing- an 'adequate' level of payment and comprehensive entitlement. Because of these missing principles we argue that the Green Paper's proposals incorporate for the low paid. The income from the basic pension and the secondary pension which is so near the means-tested minimum that little is gained in retirement from a lifetime of work and contribution. Indeed, the shift away from collective provision and the emphasis on individual responsibility will reinforce this inequality, so that many poor will continue to experience poverty in later life.

• Weed & Turfgrass Science
• /
• v.4 no.1
• /
• pp.49-57
• /
• 2015

This research was initiated to analyze the periods of spring green-up and winter leaf discoloration of three ornamental grasses which have potential to be widely used with seed propagation. Two native grasses of Arundinella (Arundinella hirta var. ciliata Koidz), fountaingrass (Pennisetum alopecuroides (L.) Spreng), and switchgrass (Panicum virgatum L.) was tested. Spring green-up were evaluated after one year growth from seed propagation on April 1, 2009. Arundinella started with quick pick of spring green-up during $13^{th}$ to $20^{th}$ of May. Fountaingrass and switchgrass showed relatively slow picks of green-up during $20^{th}$ to $27^{th}$ of May. However, winter leaf discoloration started on swtichgrass and fountaingrass but Arundinella terminated relatively slowly. Swtichgrass showed the pick discoloration during $8^{th}$ to $15^{th}$ of October from the bottom to top parts of the plant. Fountaingrass showed the pick winter discoloration started from bottom to top parts during the $22^{nd}$ to $29^{th}$ of October. However, Arundinella showed relatively slow discoloration from upper to bottom parts during October $29^{th}$ to November $5^{th}$. Arundinella showed a relatively higher ornamental value with 125 days of the complete green period compared than fountaingrass and swtichgrass which maintained approximately 105 days of green period.