• Journal of the Korean Applied Science and Technology
• /
• v.27 no.4
• /
• pp.452-460
• /
• 2010

Any theory of liquid should account for interactions between molecules, since molecules in a liquid are close to each other. For this matter statistical-mechanical methodology has been used and various models have been proposed on the basis of this methodology. Among them Kirkwood-Buff solution theory has attracted a lot of interest, because it is regarded as being the most powerful. In this article Kirkwood-Buff solution theory is revisited and its key equations are derived. On the way to these equations, the concepts of pair correlation function, radial distribution function, Kirkwood-Buff integration are explained and implemented. Since complexity of statical mechanics involved in this theory, the equations are applied to one-component systems and the results are compared to those obtained by classical thermodynamics. This may be a simple way for Kirkwood-Buff solution theory to be examined for its validity.

• Journal of Industrial Technology
• /
• v.19
• /
• pp.253-260
• /
• 1999

Two thermodynamic models were used to predict the partial molar volumes of solutes in supercritical carbon dioxide at infinite dilution: (1) the Peng-Robinson equation of state with various mixing rules including those based on $EOS/G^E$ (2) the Kirkwood Buff fluctuation integral with the hard sphere expansion (HSE) method. The Kirkwood-Buff fluctuation integral method, in which an equation of state for pure component and molecular parameters are required, produced better results especially near the critical point than the Peng-Robinson equation of state with the several mixing rules based an $EOS/G^E$. When the $EOS/G^E$ mixing rules were used, poorer results were obtained compared with the classical mixing rule and Kirkwood-Buff model.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.106-111
• /
• 2002

The object of this study is a manufacture of burr die using CAD/CAM systems. Systems are consist of AutoCAD, CAM software and CNC milling machine. CAM software is purpose of G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for networking.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.8 no.1
• /
• pp.71-76
• /
• 2009

In a running blower, there are various exciting forces which can generate noise. The noise of an running industrial fan or blower depends on the structure of a fan, the machining accuracy of each element, and assembled conditions. Many studies have been carried out to reduce the noise of it. In this study, 3-hole buffs are used in pipe of blower to study the influence the number and position of buffs on the noise reduction at inlet and outlet in pipe. Commercial engineering software ANSYS and SYSNOISE were employed to analyze the characteristics and reduction ratio of pressure. It is concluded that optimal position and number of buffs in pipe of blower to show the least reduction ratio of pressure.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.1
• /
• pp.19-24
• /
• 2010

The noise of an running industrial fan or blower depends on the type of a fan, the machining accuracy and assembled conditions of each element, and buffs. Many studies have been carried out to reduce the noise through silencer in blower. In this study, 3 types of buffs which have different hole are employed in pipe of blower to study the influence the number and arrangement of buffs on the noise reduction at inlet and outlet in pipe. Commercial engineering software ANSYS was employed to analyze the characteristics and reduction ratio of pressure. Experimental results shows that optimal one can reduce the reduction ratio of noise as much as 16 percents in the laboratory. Good agreement was found between the analysed ratio of noise reduction and those obtained from the experiments.

• Geomechanics and Engineering
• /
• v.14 no.2
• /
• pp.151-159
• /
• 2018

Annually, the global production of construction aggregates reaches over 40 billion tons, making aggregates the largest mining sector by volume and value. Currently, the aggregate industry is shifting from sand to hard rock as a result of legislation limiting the extraction of natural sands and gravels. A major implication of this change in the aggregate industry is the need for understanding rock fragmentation and energy absorption to produce more cost-effective aggregates. In this paper, we focused on incorporating dynamic rock and soil mechanics to understand the effects of loading rate and water saturation on the rock fragmentation and energy absorption of three different sandstones (Red, Berea and Buff) with different pore sizes. Rock core samples were prepared in accordance to the ASTM standards for compressive strength testing. Saturated and dry samples were subsequently prepared and fragmented via fast and dynamic compressive strength tests. The particle size distributions of the resulting fragments were subsequently analyzed using mechanical gradation tests. Our results indicate that the rock fragment size generally decreased with increasing loading rate and water content. In addition, the fragment sizes in the larger pore size sample (Buff sandstone) were relatively smaller those in the smaller pore size sample (Red sandstone). Notably, energy absorption decreased with increased loading rate, water content and rock pore size. These results support the conclusion that rock fragment size is positively correlated with the energy absorption of rocks. In addition, the rock fragment size increases as the energy absorption increases. Thus, our data provide insightful information for improving cost-effective aggregate production methods.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.221-225
• /
• 2009

Interspecific crossing was conducted to obtain hybrid lilly with better quality of adapting to the unfavorable environment using oriental Lilium spp. as a female parent. Average interspecific crossing rate between oriental and asiatic lines by cut-style pollination was as low as 29%. Although the average germination rate of zygotic hybrid embryo between oriental 'Rodolfa' ${\times}$ asiatic 'Toronto' was increased from 76.6% to 78.3%. on 114 or 1/6 strength MS medium compared to the control, the rate of zygotic embryos formation between oriental 'Farolito' ${\times}$ asiatic 'Buff Pixie' was significantly enhanced up about 86~90% on 1/2 strength MS medium. Meanwhile, germination rate of interspecific hybrid embryo between oriental 'Snow Cristal' ${\times}$ asiatic 'Royal Trinity' showed up 100%. Germination rate of interspecific hybrids slightly increased by addition of $0.5-1.0mg{\cdot}L^{-1}$ GA. Germination rate of zygotic embryos between oriental 'Farolito' ${\times}$ asiatic 'Buff Pixie' and oriental 'Belcanto' ${\times}$ L. callosum was highest on the MS medium containing $0.01mg{\cdot}L^{-1}$ NAA and $0.1mg{\cdot}L^{-1}$ kinetin, as 66.6% and 45.2% respectively.

• Applied Chemistry for Engineering
• /
• v.10 no.5
• /
• pp.718-725
• /
• 1999

In order to investigate the interaction characteristics of poly(dimethylsiloxane) (PDMS) with various solvents such as water, ethanol, and iso-propanol, Inverse Gas Chromatography(IGC) at finite concentration, which is a very fast, accurate, and thus promising technique in thermodynamic study of polymer systems, is employed. By measuring the specific retention volumes of the probes, the interaction parameters are calculated by means of the Flory-Huggins equation. From the results, the interaction parameters of the probes are, as expected due to the hydrophobicity of the polymer, found to be of large positive values (2$2.0{\times}10^{-3}mol/g$. For the linear PDMS, interpretation of the space distribution of molecules is performed by the Kirkwood-Buff-Zimm(KBZ) integrals, which give intuitive information about physical properties. From the KBZ integrals, water does not show the tendency of preferential solvation with the PDMS but formed self-cluster. The larger solvent molecules show a stronger tendency to distribute more randomly in the mixture.

• Korean Journal of Environment and Ecology
• /
• v.33 no.4
• /
• pp.408-421
• /
• 2019

This study estimated and analyzed the incremental profits to compare the imported buff-tailed bumblebees, Bombus terrestris, and their pollination alternatives. A result of the analysis showed that the incremental profit, which is defined as the sales revenue minus the common production cost, was higher when using pollinator insects than when using the artificial pollination and that the incremental costs were lower when using domestic bumblebees or artificial pollination than when using imported bumblebees or honeybees. The incremental profits of each alternative were 46,801 million won for imported bumblebees, 47,170 million won for domestic bumblebees, 46,975 million won for honeybees, and 29,839 million won for artificial pollination. The incremental profit means the accounting profit that can be realized from each alternative. However, not all of the accounting profits can be attributed to pollen-mediated alternatives since they include potential costs such as imputed rent or normal profits. Considering the opportunity costs, which are the potential costs, it appears that the alternative of using imported bumblebees can lead to an economic loss. It means that fruit and vegetable farmers can expect additional economic profits if they choose other alternatives instead of using imported bumblebees.

• Fashion & Textile Research Journal
• /
• v.18 no.3
• /
• pp.289-300
• /
• 2016

This study surveys children's costumes and games from the 11 Genre paintings by Junkeun Kim in the book "Korean Games(Stewart Culin 1858-1929)". The character of the general dress-costumes, games and the culture of life from the late $19^{th}$ century in genre painting of Junkeun Kim are as follows. The study results on the games are as follow. The boy's games are kite-flying, spinning tops, playing shuttlecock with the feet, blindman's buff, yut("Four-Stick Game"). Girl's games are seesaw with board, blindman's buff, marbles. Combined games are mount shoulder, sledge, tightrope walking for men with boy. The strengthen one's body type were seesaw with board, tightrope walking, the compete score type were playing shuttlecock with the feet, marbles and the multi complex type were yut("Four-Stick Game"), kite-flying. Through genre painting in the $19^{th}$ century we know a boy's 'Jeogori 'and 'Ba-ji' were similar to a modern man's and boy's 'Hanbok' with a traditional method of wearing. We believe that the originality of a traditional costume was an unchangeable characteristic. Girl's 'Jeogori' and 'Chi-ma' changed in length and width, and method of wearing; however, the basic shape did not change. The analysis for artist's genre painting which was ordered by a foreigner and the late of $19^{th}$ century's children's costume and game of life culture is useful to match the counters and show how to wear a modern Korean costume used to understand the 'Hanbok' and establish a costume of life.