• 한국생물공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.904-909
• /
• 2005

To optimize the removal of free fatty acid in crude vegetable oil, response surface methodology was applied to determine the effects of five level-four factors and their reciprocal interactions on removal of free fatty acid. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, catalyst amount and methanol amount. A statistical model predicted that the highest removal yield of free fatty acid was 99.8%, at the following optimized reaction conditions: a reaction temperature of 64.99$^{\circ}C$, a reaction time of 36.20 mins., an catalyst amount of 13.01% (w/v), and a methanol amount of 15% (v/v). Using these optimal factor values under experimental conditions in three independent replicates, the average removal yield was well within the value predicted by the model.

• Parasites, Hosts and Diseases
• /
• v.58 no.2
• /
• pp.135-145
• /
• 2020

Infections caused by Trichomonas vaginalis in humans are one of the main public health problems caused by sexually transmitted diseases. Objective of this study was to evaluate potential biological activity of the medicinal plant Argemone mexicana (Mexican poppy) on T. vaginalis. Methanolic extracts of the stems and leaves of A. mexicana, and different fractions were prepared with solvents of different polarities. The extracts and functional groups were detected containing sterols, triterpenes, quinones, flavonoids and, alkaloids. Extracts from both the stems and leaves of A. mexicana inhibited the growth of T. vaginalis with half-maximal inhibitory concentration value of 70.6 and 67.2 ㎍/ml, respectively. In the active fractions, the most abundant compounds were berberine and jatrorrhizine, with presumed antiparasitic activity.

• Korean Journal of Environmental Biology
• /
• v.39 no.1
• /
• pp.32-38
• /
• 2021

Cyanobium is a genus of picoprokaryotic cyanophytes, which includes species worldwide. The present study investigated the morphology, ultrastructure, and molecular phylogeny of the unrecorded genus Cyanobium Rippka & Cohen-Bazire 1983 and species Cyanobium gracile Rippka & Cohen-Bazire 1983. A C. gracile culture from a freshwater sample collected from the Adongji pond was established by single-cell isolation. Morphological data were analyzed using light and transmission electron microscopy. C. gracile lives as solitary cells without gelatinous envelopes and is ovate, oval, or shortly rod-shaped. Thylakoids are laid along the cell walls, with three thylakoid membranes parallel to each other. Nucleoplasm was observed in the center of the cell. Molecular phylogeny performed with data from 16S small subunit ribosomal DNA gene (SSU rDNA) sequences showed that the three strains of C. gracile, including the type strain (PCC6307) and a newly recorded strain (Adong101619), formed a distinct clade with a high supporting value (maximum-likelihood=100, pp=1.00). Based on morphology and molecular data, we report the newly recorded C. gracile in Korea.

• Polymer(Korea)
• /
• v.31 no.1
• /
• pp.1-7
• /
• 2007

In this study, the sulfonated ion exchange fiber was synthesized by $Co^{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) increased with increasing the total dose and showed the highest value at 50 v/v% styrene monomer. And also, the degree of sulfonation (DS) increased with increasing the DG and reaction temperature. DS showed the maximum value at 20 min. Ion exchange capacity and swelling ratio of ion exchange fibers increased with increasing the DS and their maximum values were 4.76 meq/g and 23.5%, respectively. Ammonia adsorption increased as increasing the ammonia concentration and ion exchange capacity and remained constant over 10 cycles.

• Journal of Korea Multimedia Society
• /
• v.9 no.12
• /
• pp.1588-1595
• /
• 2006

In this paper, we proposed a liver extracting procedure for computer aided liver diagnosis system. Extraction of liver region in an abdominal CT image is difficult due to interferences of other organs. For this reason, liver region is extracted in a region of interest(ROI). ROI is selected by the window which can measure the distribution of Hounsfield Unit(HU) value of liver region in an abdominal CT image. The distribution is measured by an existential probability of HU value of lever region in the window. If the probability of any window is over 50%, the center point of the window would be assigned to ROI. Actually, liver region is not clearly discerned from the adjacent organs like muscle, spleen, and pancreas in an abdominal CT image. Liver region is extracted by the watershed segmentation algorithm which is effective in this situation. Because it is very sensitive to the slight valiance of contrast, it generally produces over segmentation regions. Therefore these regions are required to merge into the significant regions for optimal segmentation. Finally, a liver region can be selected and extracted by prier information based on anatomic information.

• The Korean Journal of Physiology and Pharmacology
• /
• v.15 no.6
• /
• pp.371-382
• /
• 2011

We performed experiments using Aplysia neurons to identify the mechanism underlying the changes in the firing patterns in response to temperature changes. When the temperature was gradually increased from $11^{\circ}C$ to $31^{\circ}C$ the firing patterns changed sequentially from the silent state to beating, doublets, beating-chaos, bursting-chaos, square-wave bursting, and bursting-oscillation patterns. When the temperature was decreased over the same temperature range, these sequential changes in the firing patterns reappeared in reverse order. To simulate this entire range of spiking patterns we modified nonlinear differential equations that Chay and Lee made using temperature-dependent scaling factors. To refine the equations, we also analyzed the spike pattern changes in the presence of potassium channel blockers. Based on the solutions of these equations and potassium channel blocker experiments, we found that, as temperature increases, the maximum value of the potassium channel relaxation time constant, ${\tau}_n(t)$ increases, but the maximum value of the probabilities of openings for activation of the potassium channels, n(t) decreases. Accordingly, the voltage-dependent potassium current is likely to play a leading role in the temperature-dependent changes in the firing patterns in Aplysia neurons.

• Korean Journal of Ichthyology
• /
• v.12 no.4
• /
• pp.223-229
• /
• 2000

Phylogenetic relationships between 8 species Korean loaches (Cobitidae) were investigated by comparing mitochondrial cytochrome b gene sequences. However our results are in accordance with finding observed using other morphological studies, new interesting interspecific variation in Korean loaches were found. Orthrias and Lefua appeared to be paraphyletic in Cobitidae observed. Their sequence divergence value was agreed with interfamilic sequence divergences between Cobitidae and Cyprinidae ranged from 0.184 to 0.272. Otherwise, the present results support that two species of Iksookimia and Cobitis melanoleuca were early diverged respectively. And another remarkable result was sequence divergence between Misgurnus anguillicaudatus from China and M. anguillicaudatus from Yongdok, Korea. That was 0.099, which was interspecific value. Also the phylogenetic location of some Iksookimia species was suggested as the cobitid intergeneric hybrid origin.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.533-536
• /
• 2007

The LiDAR data structure has the potential for modeling in three dimensions because the LiDAR data can represent voxels with z value under certain defined conditions. Therefore, it is possible to classify the physical damaged degree of vegetation by forest fire as using the LiDAR data because the physical loss of canopy height and width by forest fire can be relative to an amount of points reached to the ground through the canopy of damaged forest. On the other hand, biological damage of vegetation by forest fire can be explained using the NDVI (Normalized Difference Vegetation Index) which show vegetation vitality. In this study, we graded the damaged degree of vegetation by forest fire in Yangyang-Gun of South Korea using the LiDAR data for physical grading and digital aerial photograph including Red, Green, Blue and Near Infra-Red bands for biological grading. The LiDAR data was classified into 2 classes, of which one was Serious Physical Damaged (SPD) and the other was Light Physical Damaged (LPD) area. The NDVI was also classified into 2 classes which are Serious Biological Damaged (SBD) and Light Biological Damaged (LBD) area respectively. With each 2 classes ofthe LiDAR data and NDVI, the damaged area by forest fire was graded into 4 degrees like damaged class 1,2,3 and 4 grade. As a result of this study, 1 graded area was the broadest and next was the 3 grade. With this result, we could know that the burned area by forest fire in Yangyang-Gun was damaged rather biologically because the NDVI in 1 and 3 grade appeared low value whereas the LiDAR data in 1 and 3 grade included light physical damage like the LPD.

• Korea-Australia Rheology Journal
• /
• v.17 no.2
• /
• pp.63-69
• /
• 2005

The stability of low-speed spinning process exhibiting spinline flow-induced crystallization (FIC) with no neck-like spinline deformation has been investigated using the method of linear stability analysis. Effects of various process conditions such as fluid viscoelasticity and the spinline cooling on the spinning stability have been found closely related to the development of the spinline crystallinity. It also has been found that the FIC makes the system less stable or more unstable than no FIC cases when the spinline crystallinity reaches its maximum possible value, whereas the FIC generally stabilizes the system if the crystallinity doesn't reach its maximum value on the spinline. It is believed that the destabilizing effect of the FIC on low-speed spinning when the crystallinity is fully developed on the spinline is due to the reduction of the real spinning length available for deformation on the spinline. On the other hand, the increased spinline tension caused by the FIC when the maximum crystallinity is not reached on the spinline and thus no reduction in the spinning length occurs, makes the sensitivity of spinline variables to external disturbances smaller and hence stabilizes the system. These linear stability results are consistent with the findings by nonlinear transient simulation, as first reported by Lee et al. (2005b).

• Journal of Korean Academy of Nursing
• /
• v.7 no.1
• /
• pp.80-87
• /
• 1977

The present study was undertaken to find the factors affecting academic achievement in a nursing school. 172 students were selected for this study and were divided into higher & lower 12 percent. Tools & measures used for this study were the interest test, personality test, test of self-concept, test of adjustment & school achievement. The major findings obtained from this study were as follows : 1. Factors affecting school achievement except intellectuality were thus : 1) Artistic interest, literary interest, scientific interest biological & scientific interest -physical affected the academic achievement . 2) Sociability, reasonability, depression & refractiveness affected the academic achievement. 3) Self criticism, total positive self-score, & personal self - score affected the academic achievement. 4) Adjustment to school, personal economics, health & value Morality affected the academic achievement. 2. Correlation between school achievement & interest, personality, self-concept or adjustment in the higher 81 lower group were thus; 1) There was a significant relationship between academic achievement & the following: artistic interest, scientific interest-biological, scientific interest-physical, out-door interest, refractiveness, sociability, responsibility, depression, self satis faction- score, personal self -score, social self - score, self behavior score, adjustment to school, health & values morality in the higher group. 2) There were no significant factors related with academic achievement in the lower group. 3. Difference or difference in relationship between higher & lower group in the interest, personality, self-concept & adjustment were as follows, : 1) There was a significant difference between higher & lower group in artistic -interest. literary interest, scientific interest-biological , out-door interest, sociability, depression, refractiveness, self criticism, total positive self score, personal self score, adjustment to school, personal economics, health & values morality. 2) There was a significant difference in relationships between higher & lower group in artistic interest, scientific interest, scientific 3) There was a significant difference in relationships between higher 8E lower group in artistic interest, scientific interest -biological, out -door interest , sociability, responsibility, refractiveness, depression, self identity score, self satisfaction score, adjustment to school, health, personality & value morality.