• Korean Journal of Plant Tissue Culture
• /
• v.28 no.5
• /
• pp.263-271
• /
• 2001

Inoculated anthers of Capsicum annuum L. were subjected to 4 and 32$^{\circ}C$ pretreatment and their influence on the microspore viability, early cytological changes and the induction frequency of microspore embryo was investigated. Viability of freshly isolated microspores was between 62 and 64%. During temperature pretreatment, microspore viability showed a rapid decrease and this tendency enhanced with the 32$^{\circ}C$ pretreatment. Irrespective of temperature pretreatment, microspore viability declined to nearly zero after nine days. Before temperature pretreatment, most of the microspores in anthers were at late uninucleate stage. Several types of multinuclear microspores appeared from the 2 day after culture onwards, together with many degenerated and non-induced microspores. The 32$^{\circ}C$ pretreatment gave higher proportions of embryogenic microspore than other treatment. However, the temperature pretreatment had no clear effect on the frequencies of symmetrical binucleate rnicrospore. The multinucleate grains might originate either by symmetrical or asymmetrical division. After 2 days of pretreatment at 25 and 32$^{\circ}C$ , degenerated microspore increased above 50%. In contrast, during 4$^{\circ}C$ treatment, nucleus of most microspores remained intact for 14 days. The 32$^{\circ}C$ pretreatment produced more embryos than 4$^{\circ}C$ treatment. The most effective period of 32$^{\circ}C$ pretreatment was 4 days. In contrast, effective period of 4$^{\circ}C$ pretreatment was 2 days and longer time had deleterious effect on induction of microspore embryo.

• Journal of the Korean Vacuum Society
• /
• v.2 no.2
• /
• pp.188-198
• /
• 1993

We have developed a technique for growing thin oxides (6~10 nm) by the Last step TCA method. N-channel metal-oxide-semiconductor (n-MOS) capacitor and n-channel metal-oxide-semiconductor field-effect transistor's (MOSFET's) having a gate oxide with chlorine incorporated $SiO_2/Si$ interface have been analyzed by electrical measurements and physical methods, such as secondary ion mass spectrometry (SIMS) and electron spectroscopy for chemical analysis (ESCA). The gate oxide grown with the Last strp TCA method has good characteristics as follows: the electron mobility of the MOSFET's with the Last step TCA method was increased by about 7% and the defect density at the $SiO_2/Si$ interface decreases slightly compared with that with No TCA method. In reliability estimation, the breakdown field was 18 MV/cm, 0.6 MV/cm higher than that of the gate oxide with No TCA method, and the lifetime estimated by TDDB measurement was longer than 20 years. The device lifetime estimated from hot-carrier reliability was proven to be enhanced. As the results, the gate oxide having a $SiO_2/Si$ interface incorporated with chlorine has good characteristics. Our new technique of Last step TCA method may be used to improve the endurance and retention of MOSFET's and to alleviate the degradation of thin oxides in short-channel MOS devices.

• Applied Chemistry for Engineering
• /
• v.10 no.6
• /
• pp.871-875
• /
• 1999

We calculated the characteristics of a phosphoric cation exchanger and studied on an accurately computable method to determine the ion exchange capacity for type of potentiometric titration curve. The ion exchanger was prepared by phosphorylation of a styrene-divinylbenzene copolymer with 4% crosslinking. The ion exchange capacity is 5.7 meq/g. The experimental pK values versus ${\mathit{x}}$ in phosphoric cation exchanger can be expressed as a linear equation. The ${\Delta}pK$ values were obtained from the slope of linear equation. The ${\Delta}pK$ values are the differences of antilogarithms(pK) values of the apparent equilibrium constant at complete and zeroth neutralization of the ion exchanger. Also the experimental pK values at ${\mathit{x}}=0.5$ were accorded well with theoretical data. And when it is titrated with NaOH and $Ba(OH)_2$ solutions, a good agreement between experimental and theoretical pK values for various ${\mathit{x}}$ was seen in all the potentiometric titration curves. We knew that the inflection point of potentiometric titration curve in the case of divalent ions are changed much large than that for monovalent ions. If the relation between g values and ${\partial}pH/{\partial}g$ was plotted to the Lorentz distribution curve, ion exchange capacity can be accurately evaluated.

• Journal of the Korean Society for Library and Information Science
• /
• v.25
• /
• pp.151-183
• /
• 1993

As many Korean libraries has begun to be automated and become a part of the worldwide, open library system, they need a new management. Therefore, the purpose of this paper is to explore the library management in automated libraries and to establish a theory of the library management in information society, The automated libraries could be well explained by the systems theory and the environment of the libraries could be well explained by the contingency theory, The following hypothesis were set to direct this research. 1. As the libraries are automated and become a part of one big, worldwide library system, the libraries interact closely with the environment so that the library and the environment become one. 2. As the libraries are automated and become a part of one big, worldwide library system, the librarians need to work in the environment for the library networks, standardization of cataloging, or government information policy making. 3. As the libraries are automated and become a part of one big, worldwide library system, the librarians only manage the library, The various other library staffs take over the traditional library services directly related to books. The data were gathered from the research done previously, Also the date were collected from the American and Japanese libraries. The findings were as follows: The environment of the library integrated all types of the library services such as school library, university library, etc. And it also integrated all the services of the media centers and the press centers, etc. to library services. And the new library services began in the environment. Librarians worked for these new services. In the library, the librarians distingushed the library system from the environment by planning : mission, goal, objectives, policy, procedures and rules. Library organization became temporary such as forming task forces or matrix or free form. The environment controlled the library. Staffs were controlled by plans or computers. And the professional librarians were controlled by their ability to solve problems raised outside the libraries. Library leaders brought in the technology to the library from its environment. The librarians led the formal and informal organizations so that the staffs cooperated well in their work. And librarians tought the library procedures to the partime workers or the temporary staffs. Participative management and management by objectives were the means of motivating staffs. Budget was based on the ever changing environment. The zero based budget method was applied. Therfore, in the information society, the professional librarians become the able managers in the library and global librarians in the environment.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.35 no.2
• /
• pp.147-155
• /
• 1999

In this study, the stability analysis of a fishing vessel in a seaway was done. The stability analysis is an important item in the ship design, and so the ship registers of each nation constrain the ships to be followed the stability criterion. Stability variation, exciting forces due to wave and wind, and the broaching phenomena cause the capsizing of a ship. In this study, the stability analysis to study of the capsizing of a fishing vessel was performed. The relation between the speed of the ship and the wave length, that makes the encountering frequency vanish, was obtained. It was found that the encountering frequency tend to be zero when the wave whose length and direction are similar to those of ship. In this case, the possibility of dangerous situation becomes high. The calculated restoring arm becomes small when the ship is located near the wave crest. In general, the selected small fishing vessel is better than the large ship with respect to the stability, however the wave height becomes relatively high because of her small length Kim(l994) calculated the stability variation of the large cargo ship, the results of which showed the changes in stability great. But in the selected small fishing vessel in this study, the changes was small in comparison with the larger ship. This reason seems to be the shape of her midship section. In large cargo ships, the block coefficient is large, but that of the fishing vessel is relatively small and the small fishing vessel has chine, therefore the center of buoyancy moves much when the ship is inclined. It is desirable that the dynamic stability analysis for a fishing vessel, whose speed and direction are similar to those of waves, shall be done in the near future.

• Korean Journal of Food Science and Technology
• /
• v.18 no.4
• /
• pp.306-312
• /
• 1986

Color changes of a mixture of 0.8 M glucose, fructose or sucrose and 0.8 M glycine were evaluated by Hunter 'L', 'a', 'b' values during Maillard reaction at the temperature range of $70^{\circ}-100^{\circ}C$. The results suggested the reaction to be devided into three stages. In initial reaction the 'L' and 'a' values decreased slowely, and 'b' rapidly increased to maximum, which were followed by a rapid decrease in 'L' and 'b' and rapid increase in 'a' values at intermediate stage. At final reaction period the both 'L' and 'b' were slowed down in their reduction rate while 'a' decreased rapidly from its maximum point. All of the Hunter values were reached to nea. zero. Linear equations, which can be used for prediction of cole. change in Maillared reaction, of $1/\sqrt{(L_t-L_{\circ})^2\;+\;(a_t-a_{\circ})^2\;+\;(b_t-b_{\circ})^2}\;=\;a(1/t)\;+\;b$ for Hunter values and $1/\sqrt{X\;+\;Y\;+Z}\;=\;a(1/t)\;+\;b$ for CIE tristimulus values were found to have a very high correlation coefficient. Relationships between 'L' and 'a', 'L' and 'b' and 'a' and 'b' were also graphcally compared.

• Applied Biological Chemistry
• /
• v.43 no.1
• /
• pp.39-45
• /
• 2000

The stability of vitamin A, $B_1,\;B_2,\;B_6$, C in aqueous multivitamin solutions was carried out by means of estimation of reaction velocity and the results are described in this paper. The stability of vitamin A, $B_1$ and C due to thermal degradation method in aqueous multivitamin solutions was evaluated at 40, 50, 60 and $70^{\circ}C$ up to 40 days. The shelf-lives of vitamin A, B₁ and C in this preparation, calculated using the Arrhenius equation, were 1493, 449 and 639 days at $25^{\circ}C$ respectively. Examination was made on the effect of initial concentration of vitamin $B_2$$(C_0)$ on light fading of vitamin $B_2$ in aqueous multivitamin solutions and it was found that the fading progressed according to the following formula : $-{\frac {dc}{dt}}=K_c\;{\frac C{C_0}}$ where Kc is apparent light-fading rate constant relate to $C_0$. Photodecomposition of vitamin $B_6$ in aqueous multivitamin solutions was apparently first order kinetics and was stable in polyethylene>brown color>glass container to sunlight. Photodecomposition of vitamin $B_6$ in four seasons also investigated.

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.349-353
• /
• 2008

This study was performed to determine the adherence rates of standard type Salmonella Typhimurium (ST) and wild type Salmonella spp.(WT) in pork after the following contact types and times at $10^{\circ}C$: pork meat (2, 6, 24 hr), conveyer belt (2, 6 hr), stainless steel (2, 6 hr), and cutting board (2, 6 hr). After 6 hr of pork meat to meat fat contact, the adherence rates for ST and WT were approximately 4.21 and 26.87%, respectively, and after 6 hrs of pork meat to red meat contact they were 16.40 and 27.48%, respectively. However, after 24 hr of both types of contact, ST and WT showed 100% adherence rates. The adherence rates for ST after 2 hr and 6 hr of pork meat to conveyer belt contact were 1.34 and 0.60%, respectively, while the adherence rate for WT was 5.14% after 6 hr of contact. After pork meat to stainless steel contact, ST showed adherence rates of zero and 1.59% after 6 and 24 hr of contact, respectively, while the adherence rates for WT ranged from 0.17% after 2 hr to 5.01% after 6 hr. On the other hand, neither ST nor WT offered adherence data following pork meat to cutting board contact. These results suggest that the adherence rates of ST and WT after pork meat to pork meat contact or pork meat to processing surface contact were significantly affected by the contact time and WT presented much higher adherence rates for both types of transmission than ST.

• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.1-9
• /
• 2010

Technology-Based Effluent Limitations (TBELs) is a permit limits for a pollutant that is based on the capability of a treatment technology to reduce the pollutant to a certain concentration. Widely practiced for regulations of industrial wastewater in US, TBELs has been accepted as an effective means that can achieve balanced goals between complete elimination of pollutants discharge and economic feasibility for industries. The review of TBELs application in US and the applicability of TBELs to the domestic industry categories was given in three papers. In the first paper, the development and practices of TBELs in US were reviewed including case studies. The developments of TBELs in US in the four major categories, the metal products & machinery, the petroleum refining, the porcelain enameling and the meat & poultry products were reviewed. The applicability of TBELs to the domestic industrial categories was also assessed. In the second paper, the pollution loads analysis for domestic industrial wastewater was conducted based on risk assessment indicator using Toxic Weighting Factors (TWFs). This is an essential part to determine the priority of TBELs application for the domestic industrial categories. In the last paper, the application of TBELs to the domestic industries was demonstrated through a case-study for the pulp/paper/paperboard category. Direct application of TBELs of US into the Korean regulation system may not be desirable because the specific goals and the environment for the regulations for the two countries may not be identical. For example, unlike US, Korea does not adopt the individual permit system for pollution sources. However, among the unproductive and exhaustive controversies over the uniform regulations regardless of the industrial categories in Korea, the introduction of the principles of TBELs are inevitable and more extensive study for applications of TBELs optimized for Korean regulation system will be necessary.

• Journal of the Korean Wood Science and Technology
• /
• v.38 no.1
• /
• pp.27-35
• /
• 2010

To evaluate the basic characteristics and adsorption properties of commercial wood charcoal, we investigated the proximate analysis, porosimetry analysis, methylene blue adsorption, removal ratios of formaldehyde, and removal ratio of ethylene gas. Fixed carbon contents of traditional black and white charcoal, and mechanical charcoal were 51.8~76.6%, 72.9~84.6%, and 48.5~80.3%, respectively. Refining degrees of the most traditional black charcoal were 9, and those of white charcoal and mechanical charcoals were zero. Specific surface area of traditional black charcoal was 0.1~13.7 $m^2/g$, which was quite lower than that of white charcoal (53.2~372.6 $m^2/g$) and mechanical charcoals (224.3~464.6 $m^2/g$). Also, amounts of methylene blue adsorption were quite lower in black charcoal (0.53~1.97 mg/g) compared with white charcoal (2.68~7.68 mg/g) and mechanical charcoal (11.63~26.10 mg/g). Removal ratios of formaldehyde of the black charcoal were 11.4~26.7%, which is quite similar to white charcoal (17.9~34.9%) and mechanical charcoal (5.5~25.8%). Removal ratios of ethylene gas for traditional black charcoal, traditional white charcoal, and mechanical charcoal were 2.2~43.5%, 21.7~39.1%, 21.7~39.1%, respectively. There was no significant difference in the removal ratios of formaldehyde and ethylene gas among traditional black charcoal, traditional white charcoal, and mechanical charcoal.