• Korean Journal of Weed Science
• /
• v.17 no.3
• /
• pp.281-287
• /
• 1997

Growth and anatomical responses of rice and barnyardgrass(Echinochloa crus-galli) to oxyfluorfen were examined under various growing conditions in a greenhouse. With foliar application at 0.08kg ai/ha 7 days after seeding or transplanting, oxyfluorfen completely reduced the shoot and root growth of barnyardgrass under all growing conditions. However, oxyfluorfen reduced the growth of direct seeded and transplanted rice by 0~64% and 0~12%, respectively. Phytotoxic effect on rice growth, with respect to plant height and shoot fresh weight, was more pronounced under water(53~63%) than under dry-condition(16~33%), and in broadcast-seeded(34~62%) than in drill-seeded rice(16~33%). Anatomical changes of epidermal and vascular bundle sheath cells of rice leaves were not induced by oxyfluorfen, but mesophyll cells were partially ruptured and total leaf thickness was reduced. Oxyfluorfen, however, constricted and ruptured mesophyll and vascular bundle sheath cells and severely reduced leaf thickness of barnyardgrass under all growing conditions examined. These anatomical changes were more severe under dry- than under water-seeded condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.12
• /
• pp.1075-1080
• /
• 2009

The partial lipid degradation with the saturation of double-bond at the acidogenesis stage is known to help subsequent methanogenesis during anaerobic digestion. Acidogenic reactions in an anaerobic sequencing batch reactor (ASBR) and a continuously stirred tank reactor (CSTR) were carried out to compare their performances. A mixture of two unsaturated (oleate and linoleate) and two saturated (palmitate and stearate) long-chain fatty acids (LCFAs) was used as a model substrate. Biomass retention in the ASBR contributed to the enhanced performance at hydraulic retention time (HRT) below 15 hr. Biomass retention in the ASBR contributed to the enhanced performance compared to CSTR even at shorter HRT. ASBR would be a proper reactor configuration for the acidogenesis of lipid-containing wastewater.

• Clean Technology
• /
• v.23 no.2
• /
• pp.121-132
• /
• 2017

The increase of greenhouse gases and the concern of global warming instigate the development and spread of renewable energy and hydrogen is considered one of the clean energy sources. Hydrogen is one of the most elements in the earth and exist in the form of fossil fuel, biomass and water. In order to use hydrogen for a clean energy source, the hydrogen production method should be eco-friendly and economic as well. There are two different hydrogen production methods: conventional thermal method using fossil fuel and renewable method using biomass and water. Steam reforming, autothermal reforming, partial oxidation, and gasification (using solid fuel) have been considered for hydrogen production from fossil fuel. When using fossil fuel, carbon dioxide should be separated from hydrogen and captured to be accepted as a clean energy. The amount of hydrogen from biomass is insignificant. In order to occupy noticeable portion in hydrogen industries, biomass conversion, especially, biological method should be sufficiently improved in a process efficiency and a microorganism cultivation. Electrolysis is a mature technology and hydrogen from water is considered the most eco-friendly method in terms of clean energy when the electric power is from renewable sources such as photovoltaic cell, solar heat, and wind power etc.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.26 no.1
• /
• pp.74-82
• /
• 2002

The present study is aimed to investigate the effect of the safety hat on the balance of body temperature by observation of the physiological response under hot working environment. The experiment was carried out in a climate chamber of 3$0^{\circ}C$, 50%RH for 70 minutes. To compare the two kinds of safety hat, 5 healthy male subjects worn safety hat without hole (called 'without hole') or safety hat with hole (called 'with hole') according to a randomized cross-over design. The main results of this study are as fellows: Rectal temperature and heart rate were significantly lower level in 'with hole'than in 'without hole'. The mean skin temperature was significantly higher in 'without hole'than in 'with hole'. Blood pressure were significantly low in 'with hole'. Sweat rate which was measured by weight loss before and after experiment was higher in 'without hole'. In subjective ratings, subjects replied more hot, more uncomfortable and more wet, they felt more fatigue in condition of 'without hole'. Work ability which was measured by a grip strength dynamometer was higher in 'with hole'. Safety hat which can be used for safety of the brain in work place is meaningful device of behavioral thermoregulatory response under the hot working environment. The safety hat which is designed for proper ventilation and hygiene can maintain the homeostasis of body temperature by releasing body temperature efficiently.

• Archives of design research
• /
• v.19 no.2 s.64
• /
• pp.121-128
• /
• 2006

The elements to enhance preference in symbol design are mainly related to consumers' response and aesthetic elements. Because certain aesthetic elements in design affect consumers' response and it is actually presented through (the different level of) preference. This study through surveying case studies examines whether a certain aesthetic element in symbol design gives rise to much preference. According to the result of study, high preference in symbolic design depends on high level of Rhythm, Balance, Harmony, Elaboration, Round, Gestalt, Organic, and Artificial/Natural among aesthetic elements. In comparison, it is founded that Simplicity/complexity, Objective/Abstract, depth, and symmetry should be designed at the moderate level, and proportion, repetition of elements be at the low level. Additionally(or Besides) this study makes out that symbol design cases with high preference have shapes from natural material or patterns of traditional culture, while cases with low preference have shapes from geometric figures. On the basis of these results, a guideline of symbol design could De offered(or suggested) to fit preference of consumers. But, this study is mostly concerned with only affect among emotional reactions of consumer in a scope of study, and is considered only in the aspect of form excluding color and texture.

• Environmental Analysis Health and Toxicology
• /
• v.24 no.3
• /
• pp.241-249
• /
• 2009

Heavy metal contaminants on the aquatic environment are of interest because they can have severe effects on economy and public health. Recently, the studies for monitoring of heavy metals try to do on aquatic system to assess safety and health of ecosystem by heavy metals. Thus, biological responses were investigated on Korean fairy shrimp Branchinella kugenumaensis exposed to cadmium (Cd) or copper (Cu) for long-periods (30 days). The survival rate decreased significantly (p<0.05) on B. kugenumaensis exposed to Cd and Cu at all concentrations. Especially, the highest decrease was observed at the relatively high concentration of Cd and Cu (p<0.01) and the response by Cd exposure was at dose-dependent. The growth rates were also decreased significantly (p<0.05) on B. kugenumaensis exposed to Cd and Cu for at all concentrations. Then, the reproduction rate, numbering cyst, was decreased significantly (p<0.01) on B. kugenumaensis after Cd or Cu exposures. Long exposure of the relatively high concentration Cd and Cu can have severe effects on the reproduction, while exposures of Cd and Cu can not have effects on sex ratios of B. kugenumaensis. Additionally, asymmetric telson deformity was only observed after Cd exposure. Therefore, these results suggest that B. kugenumaensis is a sensitive bio-indicator of heavy metal exposure and these biological responses of B. kugenumaensis give important information for long-term monitoring on aquatic ecosystem.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.4
• /
• pp.376-383
• /
• 1988

The effect of dietary methionine level on lipid peroxidation of rats was studied. Rats were fed vitamin E- selenium- deficient diet or diet supplemented with various levels (0.3, 0.6, 0.9%) of methionine. In rat fed MF diet, body weight gain and feed efficiency ratio were decreased compared with those of control rats, but reversed by supplementation with 0.3 and 0.6% methionine. Lipid peroxide levels in plasma and hepatic mitochondrial fraction of MF group rats were significantly higher than those of control rats. However, supplementation with 0.6% methionine modified this increment. GSH-Px activity was decrased to varying degrees in erythrocyte and hepatic mitochondrial fraction from rats fed MF diet. Methionine supplementation did not affect induction of this enzyme activity. Examination of hepatocytes by electronmicroscopy showed that Influence of vitamin E, selenium, and methionine deficiency was mainly characterized by lipid droplets, swollen mitochondria and microvilli destruction. Supplementation with various levels of dietary methionine modified these changes to some extent. The results of this experiment indicated that MF diet causes significant change in lipid peroxide level, GSH-Px activity and morphology of rats which these changes may lessen by supplementation with 0.6% methionine.

• Korean Journal of Veterinary Research
• /
• v.41 no.2
• /
• pp.203-210
• /
• 2001

Here, we compared the effectiveness of 50 MeV($p{\to}RBe^+$) cyclotron fast neutrons versus $^{60}Co$ ${\gamma}$-rays by the apoptotic fragment frequency in both rat peripheral lymphocytes and crypt cells to check a radiobiological endpoint. The incidence of apoptotic cell death was increased in all irradiated groups, and radiation at all doses trigger rapid changes in both crypt cells and peripheral lymphocytes. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for these data of apoptotic fragments frequencies was $y=0.3+(6.512{\pm}0.279)D(r^2=0.975)$ after neutrons, while $y=0.3+(4.435{\pm}0.473)D+(-1.300{\pm}0.551)D^2(r^2=0.988)$ after ${\gamma}$-rays. In addition, $y=3.5+(118.410{\pm}10.325)D+(-33.548{\pm}12.023)D^2(r^2=0.992)$ after ${\gamma}$-rays in rat lymphocytes. A significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic cells with increasing dose. Dose-response curves for high and low linear energy transfer (LET) radiation modalities in these studies were different. The relative biological effectiveness (RBE) value for crypt cells was 1.919. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morphological findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis induction in both crypt cells and peripheral lymphocytes could be a useful endpoint of rat model for studying screening test and microdosimetic indicator to evaluate the biological effects of radiation-induced cell damage.

• The Korean Journal of Zoology
• /
• v.17 no.2
• /
• pp.57-68
• /
• 1974

These experiments were performed in order to study histologically and histochemically on the epithelial cells of gall bladder in Carassius carassius, Bufo bufo gargarizans, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus. The results of the observation were as follows: 1. There were different cell types in the epithelium of gall bladder in each animal and it could not be supported histochemically that the epithelia cells of gall bladder were divided into two cell types of the rod-shaped and barrel-shaped ones. 2. The epithelium of gall bladder in Carassius carassius, Bufo bufo gargarizans, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus was simple columnar epithelium. 3. The eosinophilities of cytoplasm in the epithelial cells of gall bladder were in uniform stronger in the upper portion of nucleus in Carassius carassius, Bufo bufo gargarizans and Natrix tigrina lateralis than its other portions, and in Urloncha striata var. domesticus and Lepus cuniculus var. domesticus existed uniformly in all portions, but there were many non-eosinophilic cells in Bufo bufo gargarizans and many cells that weakly eosinophilic around nucleus in Bos taurus var. domesticus. 4. The periodic acid Schiff's reactivities in the epithelial cells of gall bladder were different in each other and the epithelial cells in PAS reaction were divided into two cell types of the dark and light ones. There presented the light cells of 6.4%, 4.3% and 3.7% of epithelial cell of gall bladder in Carassius carassius, Bufo bufo gargarizans and Urloncha striata var. domesticus for each other, but were not presented in Natrix tigrina lateralis and Bos taurus var. domesticus. 5. The ninhydrin-Schiff-active proteins were much in the epithelial cells of gall bladder in Bos taurus var. domesticus, Carassius carassius, Urloncha striata var. domesticus and Natrix tigrina lateralis in order and were much in epithelial cells in the upper portion of mucosal folds in Carassius carassius, Urloncha striata var. domesticus and Natrix tigrina lateralis, and the ninhydrin-Schiff-active protein of the epithelium of gall bladder in Bufo bufo gargarizans was uniformly distributed. 6. The epithelial cells of gall bladder in Carassius carassius, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus had no stain reactivity or weak stain reactivity to neutral fat and all epithelial cells in Bufo bufo gargarizans had strong stain reactivity, though they were different in quantity of epithelial cell portion. 7. The stain reactivities to RNA and DNA were stronger in the epithelial cells of the upper portion of mucosal fold than in those of other portions.

• Clinical and Experimental Pediatrics
• /
• v.48 no.7
• /
• pp.766-771
• /
• 2005

Purpose : Cysteinyl leukotrienes are important inflammatory mediators in the pathogenesis of asthma; therefore interruption of cysteinyl leukotrienes by leukotriene receptor antagonists improves clinical symptoms in the management of patients with mild to moderate asthma. We evaluated whether clinical response to montelukast, a leukotriene receptor antagonist, in childhood asthma was predicted by genotypes of leukotriene $C_4$ synthase($LTC_4S$) promoter gene polymorphism. Methods : An 8-week prospective, open trial of montelukast was carried out in 161 children with mild to moderate asthma. Genotyping of $LTC_4S$ gene polymorphism was determined by restriction fragment length polymorphism. Results : The distribution of the $LTC_4S$ genotypes AA, AC, and CC was 70.8 percent, 23.6 percent, and 5.6 percent, respectively in asthma group and 74.0 percent, 22.6 percent, and 3.4 percent, respectively in control group. A statistically significant difference in the distribution of $LTC_4S$ genotype was not observed between the asthma and the control groups, and there was no significant difference between the $LTC_4S$ genotype and asthma severity. The responders to montelukast were significantly prevalent in the mild asthma group(P<0.05). There was no significant difference in the distribution of the responders compared to non-responders within genotype in the total asthma group or the moderate asthma group. However, the responsiveness for montelukast was significant difference within genotype for both AA and AC/CC in the mild asthma group : The AA genotype was more included in the responder group(P<0.05). Conclusion : In the mild persistent asthma group, the A allele of $LTC_4S$ polymorphism may be regarded as a predictable factor for clinical response to montelukast. However, LTC4S polymorphism was not significantly associated with the clinical response to montelukast in asthmatic children.