• Ocean and Polar Research
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• v.29 no.2
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• pp.87-99
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• 2007

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at $0^{\circ},\;6^{\circ}N$, and $10.5^{\circ}N$ along $131.5^{\circ}W$ in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to $171.93\;{\mu}M-C$. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At $6^{\circ}N$, depth-integrated (from surface to 200 m depth) TOC was $337.1\;gC/m^2$, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.468-475
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• 1988

The cloned B. subtilis cdd gene encoding cytidine/2'deoxycytidine deaminase (EC 3.5.4.5) was expressed in the cdd deficient B. subtilis mutant ED40. The gene was isolted from the cdd complementing plasmid pSO21, and inserted into the EcoR1/Pvu1 sites of pGB215-110 ΔB, which is a temperature sensitivie E. coli-B. subtilis shuttle vector. In the transformed B. subtilis ED4O harboring the resulting plasmid pSO100, cdd was expressed at several hundred fold elevated levels, and the cytidine deaminase activity in E. coli containing pSO100 was twice the level in B. subtilis/pSO0100. The Km value for cytidine of the partially purified enzyme is 1.88$\times$10$^{-4}$M at pH 7.0 and the V$_{max}$ = 11.1 $\mu$mol/min/mg of protein. The enzyme was completely inhibited by 0.1M mercaptoethanol and HgCl$_2$. The inhibition by p-chrolomercurybenzoic acid showed a Ki = 5 uM. These results suggest that sulfhydryl reagents block an active site thiol group, and/or disturb the formation of the tetrameic holoenzyme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.227-236
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• 2017

This study attempted to develop and investigate the effects of hair-nourishing cosmetics containing saponin astragaloside from Astragalus membranaceus Bunge on eyebrow growth and development for eventual product development. For this, current use of hair nutrients was investigated in general consumers through a questionnaire survey. A test was conducted for 6 weeks against the same subjects divided into two groups: experimental group with 0.5% saponin astragaloside on the right eyebrow and control group without any astragaloside on the left eyebrow. The results were as follows. In the control group, no significant changes were found in terms of eyebrow length and thickness. In the experimental group with 0.5% saponin astragaloside added, eyebrow length, root, and thickness of the middle area considerably increased. In other words, saponin astragaloside was confirmed an effective natural substance. In addition, subjective assessments such as usability, marketability, and satisfaction assessments supported the usability and market value of saponin astragaloside. Such results reveal that hair-nourishing cosmetics containing saponin astragaloside from Astragalus membranaceus Bunge would be helpful in improving and maintaining eyebrow growth for those concerned about loss and shortening of their eyebrows, showing the potential of product development.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.166-176
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• 2020

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• Ocean and Polar Research
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• v.23 no.2
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• pp.77-95
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• 2001

Temperature, salinity, nutrients, chlorophyll-a, and primary production were measured within the upper 200 m water column in the area around the South Shetland Islands in January, 2000. Surface temperature was relatively high in the Drake Passage north of the South Shetland Islands and low in the northeastern area of the Antarctic Peninsula. In contrast, surface salinity was low in the Drake Passage and increased toward the Antarctic Peninsula, reaching the maximum value in the northeastern area of the Antarctic Peninsula. Surface nutrients were low in the Drake Passage and high in the area near the South Shetland Islands. Surface chlorophyll-a was also low in the Drake Passage and near the Antarctic Peninsula and high in the area of the northern King George Island. The study area could be classified as four geographical zones based on the characteristic shape of the T/S diagrams;the Drake Passage, the Bransfield Strait, the mixed zone, and the Weddell Sea. Each geographical zone showed apparently different physical, chemical, and biological characteristics. Phytoplankton biomass was relatively low in the Drake Passage and the Weddell Sea and high in the Bransfield Strait and the mixed zone. The low phytoplankton biomass in the Weddell Sea could be explained by the low water temperature and deep surface mixing down to 200 m. The high grazing pressure and low availability of iron could be responsible for the low phytoplankton biomass in the Drake Passage.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.753-757
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• 2014

Anode electrode in a microbial fuel cell (MFC) should transfer the receiving electron as well as provide large surface area that can be immobilized microorganisms. Microorganisms' population is one of important factors to improve the current generation and to treat the livestock wastewater by biological treatment. These studies were attempted to investigate if stainless-steel wire skein (SSWS) could be used as anode electrode replacement a graphite felt electrode in microbial fuel cell. For these studies, pretreated livestock wastewater was used diluted to 500 mg/L as COD before use. At this time, the current showed a little difference of about 5% when using each of a SSW and graphite felt (control). There was no significant difference in the current value. The organic removal rate in the microbial fuel cells used graphite felt and SSWS was 82.4% and 88.3%, respectively. The COD removal in the MFC used the SSWS was higher than that of graphite felt. Ammonium nitrogen was showed similar trend in two case all. These results about current generation and organic matter reduction seem possible that SSWS was used to anode electrode. When SSWS is used, the initial investment for system construction is expected to be able to reduce by approximately 1/50.

• Archives of design research
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• v.13 no.1
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• pp.111-120
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• 2000

Certain complex forces are existing at the other side of a canvas. These are visual arrangements and within the arrangement, even the simple combination of dots and lines create more than visual patterns. No matter what form that visual art has taken, it is performed in a certain space and it is constucted with various visual elements. For effective communication, visual elements must form a stable sturcture by extablishing organic relationship among each other. These requires an understanding of the human visual characteristics and psychonology, because human sight senses the same biological and psychological visual elements differently in its force and weight, according to the position within a given space. Although the structure which controls such force and weight exists within a peice of work, it is a internal plan of the work that actually controls the communication through a man\ulcorner psychological reactions towards the horizontal and virtical structures within it. Moreover it is a visual statement that effectively expresses a theme or a message. This thesis has studied visual structures through the analysis of art pieces regarding of these kind of a visual picture plane, characteristics of a picture plane formed by a structure of force existing on the other side of the picture and the theory of visual balance. In addition, the aim of this study is to help designers who deals with visual image works to understand the visual structures and psychological recognitions and to apply these picture plane compositions at their real work by recognizing the psychological power within the construction elements.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.511-514
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• 1997

The objective of this study is to propose a finite element based design of the dental implant replacing unction and shape of natural teeth. For this, geometric actors were varied to investigate stress distribution of the alveolar bone around dental implant. In this study, the results were obtained based on the theory of linear elastic, with geometrically axisymmetric assumption. Geometric actors determining implant shape are ranged as 0.2mm-0.6mm, 0.04mm-0.1mm, 0.46mm-0.84mm or height of thread, radius of curvature of thread, and pitch, respectively. The stresses in the alveolar bone caused by biting force playa major role in determining implant stability. Especially, the stress concentration in the cortical bone causes bone resorption and finally makes the implant unstable. Therefore, the stress distributions were investigated on the side of the alveolar bone focusing on the area of cortical bone. The maximum von Mises stress was found to increase up to 6% as the height of thread increases, while its value was to decrease to 19% when the radius of curvature increase within the assigned ranges. For the variation of pitch, the larger size of pitch results in greater maximum von Mises stress when the length of the implant under consideration is fixed. The existence of the neck below the shoulder did not affect the stress distribution in the region of alveolar bone. However, the stresses on the side of the implant near the neck were found to be different by 20% approximately. Therefore, the neck can provide the stability of the implant against continuing biting movement. As a conclusion, the finite element based study shows a potential in designing the dental implant systematically.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.48-54
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• 2018

In this study, We developed a Ancillary device for child radiography for X-ray of children under 5 years old and verified its effectiveness. Chest X-rays of children younger than 5 years of age were performed by Supine method at the position of Table detector, Short - Source to Image Receptor Distance(SID). Existing Supine and Short -SID imaging methods cause many problems, such as errors in image reading and excessive radiation exposure dose to patients, but the use of an Ancillary device for child radiography(ADCR) solves these problems. A total of 160 children were divided into the Upright group using ADCR and Supine group without ADCR. The chest X-ray image was visually evaluated by two radiologists with reference to the European Commission's List of Quality Criteria for Diagnostic Radiographic Images in Pediatrics. The total score of the qualitative evaluation was 5.15% higher in the chest upright method using ADCR than in the chest supine method without ADCR, and the chest upright method score was higher than that of the chest supine method in items 1 to 7. whether infants have deep inspiration or not, 4.87% higher for item 1, whether infants rotate or not and the degree of tilting, 0% higher for the item 2, the reproduction of image from just above apices of lungs to T12/L1, 0% for the item 3, reproduction of the vascular pattern in central 2/3 of the lungs, 6.92% higher for the item 4, reproduction of the trachea and the proximal bronchi, 12.9% higher for the item 5, visually sharp reproduction of the diaphragm and costo-phrenic angles, 10% higher for the item 6, reproduction of the spine and paraspinal structures and visualisation of the retrocardiac lung and the mediastinum, and 3.65% higher for the item 7. Items 2 and 3 showed no statistically significant differences(P > 0.05), and items 1, 4, 5, 6, and 7 showed statistically significant differences(P < 0.05). In conclusion, Upright method using ADCR in pediatric chest X-ray is considered as a good alternative to existing Supine method.