• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.85-95
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• 1998

The broadband ultrasonic transducers have been designed to use in obtaining the broadband echo signals from fish schools in relation to the identification of fish species. The broadening of bandwidth was achieved by attaching double acoustic matching layers on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and to evaluate the performance characteristics, such as the transmitting voltage response(TVR) of transducers. The constructed transducers were tested experimentally and numerically by changing the parameters such as impedances and thicknesses of the head, tail and matching layers, in the water tank. Also, the developed transducer was excited by a chirp signal and the received chirp waveforms were analyzed. According to the measured TVR results, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 7 mm thick and a polyurethane window of 18 mm thick was 7.3 kHz with a center frequency of 38.8 kHz, and the maximum and the minimum values of the TVR in this frequency region were 135.7 dB and 132.7 dB re $1\;{\mu}Pa/V$ at 1 m, respectively. Also, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 11 mm thick and a polyurethane window of 15 mm thick was 6.2 kHz with a center frequency of 38.6 kHz, and the maximum TVR value in the frequency region was 136.3 dB re $1\;{\mu}Pa/V$ at 1 m. Reasonable agreement between the experimental results and the numerical results for the TVR of the developed transducers was achieved. The frequency dependant characteristics of experimentally observed chirp signals closely matched to the measured TVR results. These results suggest that there is potential for increasing the bandwidth by varying other parameters in the transducer design and the material of the acoustic matching layers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.432-438
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• 2016

This study was conducted to investigate the effects of Lespedeza caneata extract on the livers of alcohol-administered mice. The study subjects were divided into a control (Con), alcohol administration (AL), alcohol and Lespedeza Caneata extract 200 mg/kg administration (AL-LC 200), and alcohol and Lespedeza caneata extract400 mg/kg administration (AL-LC 400) group. Distilled water was administrated orally to control and alcohol groups for ten days, while Lespedeza caneata extract was administered orally to alcohol and Lespedeza caneata extract groups for ten days. All experimental groups were fasted for twelve hours seven days after the oral administration, after which distilled water was administered orally to Con five times at twelve-hour intervals. At the same time, 50% ethanol (MERCK, USA) at 10 g/kg concentration was administered orally to AL and AL-LC groups five times at 12-hour intervals. The AST, ALT enzyme activation in blood and histology of the liver were then evaluated. AST and ALT in AL-LC groups were lower than in the AL group. Particularly, the AL-LC 200 and AL-LC 400 groups had significantly lower AST activation than the AL group. Histological results showed that most of the subjects in the AL group had necrosis and deformation in their livers, while fat droplets were accumulated in hepatic cells around the central vein. AL-LC 200 group revealed that a portion of the central vein was swollen, liver cells were expanded, and small fat droplets were accumulated. In the AL-CL 400 group, the central vein was normal and small fat droplets were accumulated in some liver cells. However, most of the liver cells appeared normal in the AL-CL 400 group. These results suggest that the extracts of Lespedeza caneata prevented alcohol induced liver damage in mice and have great potential for use as natural health products.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.91-103
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• 2012

The aim of this study was to develop a rapid and cheap bioassay of four lignans (schisandrin, schisandrin C, the gomisin A and gomisin N) isolated from Schizandra chinensis Baill on seed germination and seedling growth of the radish. Its structure was determined by analysis of MS and NMR spectroscopic data. Radish seeds immersed for 1 hr in the solutions of $10^{-5}M$, $10^{-6}M$ and $10^{-7}M$ of schisandrin, schisandrin C, gomisin A, and gomisin N, seed germination was observed with in 60 hr after all of the treatments. Also, the seeds were germinated faster compared to untreated controls. At early germination stage, 48 hr after the treatment of the lignans, the suppression of germination was observed from all treatments; the suppression due to schisandrin and gomisin A was the highest at the concentration of $10^{-6}M$. The level of suppression increased as the concentration increased in the treatment of schisandrin C and gomisin N. Percent germination of seed after 184 hr was increased 90% at all treatments. For the effects of lignan treatment on seedling growth in radish, the growth of hypocotyl was promoted by gomisin A and gomisin N at all concentrations. Root elongation was significantly promoted by schisandrin and gomisin N at $10^{-5}M$ and $10^{-6}M$, respectively. Fresh and dry weights of the seedlings were high at a low concentration of $10^{-7}M$, but significantly reduced by schisandrin C at a high concentration of $10^{-5}M$. The results of the germination activity and seedling growth of the lignans from S. chinensis suggest their potential use as natural growth regulators.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.101-109
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• 2010

This experiment was designated to investigate the effects of dietary supplementation with various concentrations of oriental herbal natural extract, Galla Rhois (GR), on growth performance and meat quality on broiler chickens. A total of 80 two-day-old broiler chicks were randomly designated to four groups, GR 0% diet (control), GR 0.10%, 0.25%, and 0.50%-treated diet, composed 20 chicks and fed a standard diet supplemented with GR and monitored the growth performance every 5 days during 30 days. Body weight gain (BWG) in all treated groups was increased compared to control group during overall period, showing significant (P<0.05) increase in GR 0.25% and 0.50% independent on concentration, though all group represented a similar level of feed intake (FI) and feed conversion rate (FCR). In analysis of the crude proteins and fatty acid composition in leg and breast meats in control, GR 0.10% and GR 0.50%, there was no significant difference for crude proteins and fatty acid composition in leg meats among 3 groups. Whereas the crude proteins and fatty acid composition in breast meat in GR 0.50% showed significantly higher than those of control (P<0.05). Furthermore, the composition of a-linoleic acid (C18:3n-3) and conjugated linoleic acid, which are known as anticancer and antioxidative fatty acids, are higher than those of control. These results demonstrate that Galla Rhois appears to improve growth performance, feed efficiency and meat quality on broiler chickens, focusing on potential use as a dietary supplement.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2014.10a
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• pp.1-24
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• 2014

This study uses geo-spatial crop modeling to quantify the biophysical impact of weather extremes. More specifically, the study analyzes the weather extreme which affected maize production in the USA in 2012; it also estimates the effect of a similar weather extreme in 2050, using future climate scenarios. The secondary impact of the weather extreme on food security in the developing world is also assessed using trend analysis. Many studies have reported on the significant reduction in maize production in the USA due to the extreme weather event (combined heat wave and drought) that occurred in 2012. However, most of these studies focused on yield and did not assess the potential effect of weather extremes on food prices and security. The overall goal of this study was to use geo-spatial crop modeling and trend analysis to quantify the impact of weather extremes on both yield and, followed food security in the developing world. We used historical weather data for severe extreme events that have occurred in the USA. The data were obtained from the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA). In addition we used five climate scenarios: the baseline climate which is typical of the late 20th century (2000s) and four future climate scenarios which involve a combination of two emission scenarios (A1B and B1) and two global circulation models (CSIRO-Mk3.0 and MIROC 3.2). DSSAT 4.5 was combined with GRASS GIS for geo-spatial crop modeling. Simulated maize grain yield across all affected regions in the USA indicates that average grain yield across the USA Corn Belt would decrease by 29% when the weather extremes occur using the baseline climate. If the weather extreme were to occur under the A1B emission scenario in the 2050s, average grain yields would decrease by 38% and 57%, under the CSIRO-Mk3.0 and MIROC 3.2 global climate models, respectively. The weather extremes that occurred in the USA in 2012 resulted in a sharp increase in the world maize price. In addition, it likely played a role in the reduction in world maize consumption and trade in 2012/13, compared to 2011/12. The most vulnerable countries to the weather extremes are poor countries with high maize import dependency ratios including those countries in the Caribbean, northern Africa and western Asia. Other vulnerable countries include low-income countries with low import dependency ratios but which cannot afford highly-priced maize. The study also highlighted the pathways through which a weather extreme would affect food security, were it to occur in 2050 under climate change. Some of the policies which could help vulnerable countries counter the negative effects of weather extremes consist of social protection and safety net programs. Medium- to long-term adaptation strategies include increasing world food reserves to a level where they can be used to cover the production losses brought by weather extremes.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.383-397
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• 1999

For sites to be investigated, the results of such an investigation can be used in determining foals for cleanup, quantifying risks, determining acceptable and unacceptable risk, and developing cleanup plans t hat do not cause unnecessary delays in the redevelopment and reuse of the property. To do this, it is essential that an appropriately detailed study of the site be performed to identify the cause, nature, and extent of contamination and the possible threats to the environment or to any people living or working nearby through the analysis of samples of soil and soil gas, groundwater, surface water, and sediment. The migration pathways of contaminants also are examined during this phase. Key aspects of cost-effective site assessment to help standardize and accelerate the evaluation of contaminated soils at sites are to provide a simple step-by-step methodology for environmental science/engineering professionals to calculate risk-based, site-specific soil levels for contaminants in soil. Its use may significantly reduce the time it takes to complete soil investigations and cleanup actions at some sites, as well as improve the consistency of these actions across the nation. To achieve the effective site assessment, it requires the criteria for choosing the type of standard and setting the magnitude of the standard come from different sources, depending on many factors including the nature of the contamination. A general scheme for site-specific assessment consists of sequential Phase I, II, and III, which is defined by workplan and soil screening levels. Phase I are conducted to identify and confirm a site's recognized environmental conditions resulting from past actions. If a Phase 1 identifies potential hazardous substances, a Phase II is usually conducted to confirm the absence, or presence and extent, of contamination. Phase II involve the collection and analysis of samples. And Phase III is to remediate the contaminated soils determined by Phase I and Phase II. However, important factors in determining whether a assessment standard is site-specific and suitable are (1) the spatial extent of the sampling and the size of the sample area; (2) the number of samples taken: (3) the strategy of taking samples: and (4) the way the data are analyzed. Although selected methods are recommended, application of quantitative methods is directed by users having prior training or experience for the dynamic site investigation process.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.824-829
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• 2011

In recent years, there has been an increasing public concern about fecal contamination of water, air and agricultural produce by pathogens residing in organic fertilizers such as manure, compost and agricultural by-products. Efforts are now being made to control or eliminate the pathogen populations at on-farm level. Development of efficient on-farm strategies to mitigate the potential risk posed by the pathogens requires data about how the pathogens prevail in livestock manure composts and organic fertilizers. Microbiological analysis of livestock manure composts and organic fertilizers obtained from 32 and 28 companies, respectively, were conducted to determine the total aerobic bacteria count, coliforms, Escherichia coli count and the prevalence of Staphylococcus aureus, Bacillus cereus, Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes, and Cronobacter sakazakii. The total aerobic bacteria counts in the livestock manure composts and organic fertilizers were in the range of 7 to $9log\;CFU\;g^{-1}$ and 4 to $6log\;CFU\;g^{-1}$, respectively. In the livestock manure composts, coliforms and E. coli were detected in samples obtained from 4 and 2 companies, respectively, in the range of 2 to $5log\;CFU\;g^{-1}$ and $2log\;CFU\;g^{-1}$. In the organic fertilizers, coliforms and E. coli were detected in samples obtained from 4 and 1 companies, respectively, in the range of 1 to $3log\;CFU\;g^{-1}$ and $2log\;CFU\;g^{-1}$. In 3 out 32 compost samples, B. cereus was detected, while other pathogens were not detected. In 28 organic fertilizers, no pathogens were detected. The complete composting process can result in the elimination of pathogens in livestock manure compost and organic fertilizer. The results of this study could help to formulate microbiological guidelines for the use of compost in environmental-friendly agriculture. This research provides information regarding microbiological quality of livestock manure compost and organic fertilizer.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.688-694
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• 2021

Turanose is a potential candidate for use as a functional sweetener because of its gentle taste, low calorie, and non-cariogenicity. The aim of this study was to replace sucrose with turanose to produce health-beneficial maesil-cheong. Quality effects of turanose on maesil-cheong were evaluated by determining the contents of free sugars, organic acids, amygdalin, and antioxidant activity. The pH and Brix values of sucrose- and turanose-based maesil-cheong remained at the same level between 2.83 and 3.00 and 54.6-58.6°Bx, respectively, after 90-day storage. Among oxalic, malic, and citric acids, citric acid content was the highest in both maesil-cheong samples. Turanose did not significantly hydrolyze in maesil-cheong, whereas sucrose was completely hydrolyzed to glucose and fructose. Thus, turanose is suitable for the development of acidic maesil-cheong to improve its health promoting effect. Turanose showed product qualities similar to sucrose-based maesil-cheong. Turanose can be used as a functional sweetener or bulking agent in processed foods.

• Journal of Life Science
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• v.31 no.10
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• pp.905-912
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• 2021

In this study, four common food-borne bacteria, namely, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Bacillus subtilis, were targeted via irradiation with 270 nm UV C-LED, 365 nm UV A-LED, 465~475 and 620~630 nm visible-LED, and 850 and 5,000~7,000 nm infrared-LED light. The effect on the growth of each bacterial species was investigated. In the case of 270 nm UV C-LED, all four strains showed inhibitory effects compared with the control group when irradiated for 10 or 30 min. Furthermore, when irradiated with 365 nm UV A-LED for 1 or 3 hr, B. subtilis showed 100% growth inhibition. When irradiated with 465~475 nm visible-LED for 1 hr, all four strains showed no significant difference from the control group but showed significant growth inhibition when irradiated for 3 hr. S. aureus and B. subtilis treated with 620~630 nm visible-LED; S. typhimurium and S. aureus treated with 850 nm infrared-LED; and E. coli, S. typhimurium, and S. aureus treated with 5,000~7,000 nm infrared-LED were confirmed to significantly proliferate compared with the control group. The results of this experiment show the potential of the use of various LED light sources as a food preservation and application technology by examining their effect on the inhibition and growth of food-borne bacteria and by grasping the characteristics of each wavelength.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.548-556
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• 2021

This study was conducted to investigate the applicability of lignocellulosic fiber and coconut shell activated carbon (CSA) for the production of a particulate matter (PM)-reducing air-filter as raw materials to solve the environmental problems of non-woven fabrics. CSA had a good potential to use as a raw material of air-filter for reducing volatile organic compounds as well as noxious metals, and reduction capability of the CSA was 5 times higher than that of wood fiber. Natural adhesives formulated with proteinaceous wastes mostly were applied successfully to fabricate air-filters with the shape of fiberboard. The air-filter fabricated with the minimum target density of 200 kg/m³ and the maximum CSA-content of 40 wt% in fiberboard had a good manageable strength. However, the fiberboard filters was required to make vent-holes for improving an air-permeability of the filters. Size of the CSA particles was adjusted to greater than 2 mesh with the consideration of strength and formability of the fiberboard. Three-layers fiberboard that only wood fiber and the mixture of wood fiber and CSA were formed in the surface and middle layers, respectively, was determined to the optimal condition for the production of air-filters. In addition, traditional Korean paper handmade from mulberry trees (TKP) showed a good PM-reducing property as an air-filter. It is concluded that air-filtering set composed of fiberboard with vent-holes and TKP instead of conventional air-filters made with non-woven fabrics can be used as a filter for reducing the concentrations of PM, VOC and noxious metals existed in indoor and outdoor spaces.