• Journal of Environmental Health Sciences
• /
• v.31 no.4 s.85
• /
• pp.309-315
• /
• 2005

Volatile organic compounds (VOCs) and odor materials are major sources of air pollution in Ulsan city, where much chemical plants are located. Therefore, it is necessary to develop a new reactor which can remove VOCs and odor materials effectively and be equipped at the end of pipe easily. A modified reactor (bioscrubber trickling filter, BSTF), which have both characteristics of biofilter and bioscrubber, was developed and tested on its reactivity with several VOCs using two types of media, fiber and activated carbon 4- ceramic(A/C). It was observed that the removal efficiencies of several types of VOCs such as acetaldehyde, ethylalcohol, butanol, diethylamine and triethylamine were up to $95\%$ when they had about 100 ppm of initial concentration and 80 seconds of residence time. Good attachment of microorganisms to both media, where it is thought the reaction efficiency can be determined according to the amount of microorganisms attachment, observed with scanning electron microscopy(SEM). Initial pressure drops of the packed bed with both media were 229 $mmH_2O/m$ at A/C column and 670 $mmH_2O/m$, respectively. However, maximum pressure drop of fiber column during the operation was over 1,647 $mmH_2O/m$. Therefore, it was thought that the fiber material would not suitable to use in the local plant as a packed bed media.

• Microbiology and Biotechnology Letters
• /
• v.48 no.2
• /
• pp.230-235
• /
• 2020

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of bla_TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the KirbyBauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla_TEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla_TEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.

• Applied Biological Chemistry
• /
• v.38 no.3
• /
• pp.259-262
• /
• 1995

Oxidative stabilities of fat in DHA(cis-4,7,10,13,16,19-docosahexaenoic acid)-added dry milk and ordinary dry milk during storage were studied by determining thiobarbituric acid values of samples. Two kinds of milk powder samples were purchased in the local supermarket and $2{\pm}0.05\;g$ of samples were transferred into serum bottles, which were stored under the light or under dark The oxidation of fat in DHA-added milk powder was higher than that of fat in ordinary milk powder and the acceleration was more evident in the presence of light Light and unsaturated fats accelerated synergistically oxidation of milk fat Addition of DABCO(diazabicyclooctane), which is an efficient singlet oxygen quencher, significantly decreased the photooxidation of milk fat This result clearly suggested that singlet oxygen oxidation (Type II reaction) was involved in the system. Deceleration of milk fat oxidation by DABCO was higher in the DHA-added milk powder.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.2
• /
• pp.179-187
• /
• 2013

This case study was conducted to determine the effects of water exercise on the foot pressure distribution (FPD) of persons who have a hemiplegia. A 43-year old female with hemiplegia acquired at the age of 3 years was selected from a local disability program. A 12-week water exercise program (60 min. per session and twice a week) focusing on gait training was developed and implemented as the intervention of this study. A recent product of the Pedar-X (Novel, Germany) was used to measure the FPD of hemiplegic gait before and after the intervention. Variables considered in this study included the average pressure (AP), contact area (CA), maximum pressure (MP), ground reaction force (GRF), and center of pressure (COP). The data collected were analyzed via the descriptive statistics and qualitative analyses on the graphical presentations of the FPD. Results revealed that the AP and CA of the hemiplegic foot was considerably increased before and after the intervention. Similar results were also found in the MP and GRF. Additionally, the graphical route of the COP related to hemiplegic foot was changed in a positive way after the intervention. It can be concluded that water exercise may be beneficial to restore hemiplegic gait. Limitations related to measurement and generalizability are further discussed.

• Korean Journal of Materials Research
• /
• v.30 no.5
• /
• pp.267-271
• /
• 2020

Cerium oxide (ceria, CeO₂) is one of the most wide-spread oxide supporting materials for the precious metal nanoparticle class of heterogeneous catalysts. Because ceria can store and release oxygen ions, it is an essential catalytic component for various oxidation reactions such as CO oxidation (2CO + O₂ 2CO₂). Moreover, reduced ceria is known to be reactive for water activation, which is a critical step for activation of water-gas shift reaction (CO + H₂O → H₂ + CO₂). Here, we apply van der Waals-corrected density functional theory (DFT) calculations combined with U correction to study the mechanism of water chemisorption on CeO₂(111) surfaces. A stoichiometric CeO₂(111) and a defected CeO₂(111) surface showed different water adsorption chemistry, suggesting that defected CeO₂ surfaces with oxygen vacancies are responsible for water binding and activation. An appropriate level of water-ceria chemisorption energy is deduced by vdW-corrected non-local correlation coupled with the optB86b exchange functional, whereas the conventional PBE functional describes weaker water-ceria interactions, which are insufficient to stabilize (chemisorb) water on the ceria surfaces.

• Journal of the Korean Vacuum Society
• /
• v.7 no.2
• /
• pp.104-111
• /
• 1998

The InGaAs/InP quantum wells(QWs) were grown by low pressure metalorganic chemical vapor deposition and the effects of growth interruption steps on their interfacial structures were investigated by measuring photoluminescence spectra. When InP or InGaAs surface was treated under the same group V ambient, the full width at half maximum (FWHM) of the QW peak increased possibly due to the incorporation of impurities during the growth interruption time. When InP surface was treated under $AsH_3$, howerer, the PL peak showed red-shift due to the As-P exchange reaction and the change of FWHM was not remarkable. The effective thickness of InAs interfacial layer formed during $AsH_3$, treatment on the InP surface was calculated to be 1~2 monolayers. In the case of InGaAs treatment under $PH_3$, the PL peak energy and the FWHM increasied. This results suggest that $PH_3$ treatment on the InGaAs surface suppresses the incorporation of As into the subsequent InP layer and the local replacement of As by P occurs simultaneously.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.1
• /
• pp.83-88
• /
• 2013

Progressive collapse is a chain reaction of failures propagating throughout a portion of a structure that is disproportionate to the original local failure. When column members are subjected to unexpected load (compression load), they will buckle if the applied load is greater than the critical load that induces buckling. The post-buckling strength of the columns will decrease rapidly, but if there is enough residual strength, the members will absorb the potential energy generated by the impact load to prevent progressive collapse. Thus, it is necessary to identify the relationship of the load-deformation of a column member in the progressive collapse of a structure up to final collapse. In this study, we carried out nonlinear FEM analysis and based on deflection theory, we investigated the load-deformation relationship of H-section steel columns when both ends were fixed.

• The Journal of Art Theory & Practice
• /
• no.3
• /
• pp.35-50
• /
• 2005

For us, any regional art exist? Almost all art events today take place mostly in Seoul. Concentrating on the reinforcement of its power, the regional art world remains isolated without any connection with the Seoul art community. It is completely closed off from the central art scene. The regional art world seems to consider that more helpful in consolidating its status. It is in real sense suffering the absence of art criticism and art media, lack of an understanding of art and backwardness of art education. Many regional artists are dreaming of moving out from their domain, aspiring to be a member of the central art world. They make an effort to assimilate into a refined, modern style of the central art circle, rather than striving to create works imbued with regionality and locality. As the artists living in the provinces, the characteristics of their district should be above all else reflected in their art. Although they are less informed about the latest trend of culture and art, their art has to be something passionately and obstinately embodying the intrinsic quality of their regions. They have to find a practical solution more positively, instead of merely complaining about the poor condition of the regional art community. There is the need to bring about a turnabout in our awareness that regional art is confined to any limit and cannot be in the center of the entire art world. What' s most significant is to dissolve factionalism and not to depend on school ties or regional networks. As a reaction against authoritarianism, regional art has to put emphasis on attaining its originality. For this, regional art should respect regional tradition, history and background and break away from an old convention of wielding power.

• Journal of Soil and Groundwater Environment
• /
• v.25 no.2_spc
• /
• pp.1-15
• /
• 2020

Monitoring and assessing terminal electron accepting processes (TEAPs) are one of the most important steps to remediate contaminated sites via various in-situ techniques. TEAPs are a part of the microbial respiration reactions. Microorganisms gain energy from these reactions and reduces pollutants. Monitoring TEAPs enables us to predict degradability of contaminants and degradation rates. In many countries, TEAPs have been used for characterization of field sites and management of groundwater wells. For instance, US Environmental Protection Agency (EPA) provided strategies for groundwater quality and well management by applying TEAPs monitoring. Denmark has also constructed TEAPs map of local unit area to develop effective groundwater managing system, particularly to predict and assess nitrogen contamination. In case of Korea, although detailed soil survey and groundwater contamination assessment have been employed, site investigation guidelines using TEAPs have not been established yet. To better define TEAPs in subsurface environments, multiple indicators including ion concentrations, isotope compositions and contaminant degradation byproducts must be assessed. Furthermore, dissolved hydrogen concentrations are regarded as significant evidence of TEAPs occurring in subsurface environment. This review study introduces optimal sampling techniques of groundwater and dissolved hydrogen, and further discuss how to assess TEAPs in contaminated subsurface environments according to several contamination scenarios.

• Clinical and Experimental Pediatrics
• /
• v.62 no.3
• /
• pp.95-101
• /
• 2019

Purpose: Increased apoptosis was recently found in the hypertrophied left ventricle of spontaneously hypertensive rats (SHRs). Although the available evidence suggests that apoptosis can be induced in cardiac cells by various insults including pressure overload, cardiac apoptosis appears to result from an exaggerated local production of angiotensin in adult SHRs. Altered expressions of Bcl associated X (Bax), Bcl-2, chemokine receptor (CCR)-2, monocyte chemoattractant protein (MCP)-1, transforming growth factor $(TGF)-{\beta}1$, phosphorylated extracellular signal-regulated kinases (PERK), and connexin 43 proteins, and kallikrein mRNA were investigated to explore the effects of losartan on the SHR model. Methods: Twelve-week-old male rats were grouped as follows: control (C), SHR (hypertension: H), and losartan (L; SHRs were treated with losartan [10 mg/kg/day] for 5 weeks). Western blot and reverse transcription polymerase chain reaction assays were performed. Results: Expression of Bax, CCR-2, MCP-1, $TGF-{\beta}1$, PERK, and connexin 43 proteins, and kallikrein mRNA was significantly increased in the H group compared to that in the C group at weeks 3 and 5. Expression of Bax, CCR-2, MCP-1, $TGF-{\beta}1$, and connexin 43 proteins and kallikrein mRNA was significantly decreased after losartan treatment at week 5. PERK protein expression was significantly decreased after losartan treatment at weeks 3 and 5. Bcl-2 protein expression was significantly decreased in the H group compared to that in the C group at weeks 3 and 5. Conclusion: Losartan treatment reduced expression of Bax, CCR-2, MCP-1, $TGF-{\beta}1$, PERK, and connexin 43 proteins, and kallikrein mRNA in SHRs, along with decreased inflammation and apoptosis.