• Journal of Korean Society for Atmospheric Environment
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• v.2 no.3
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• pp.57-63
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• 1986

Atmospheric particulate matter (A.P.M.) was collected on quartz fiber filters from March 1985 to May 1986 according to particle size using Andersen high-volume air sampler, and 6 heavy metals (Fe, Mn, Cu, Ni, Zn, Pb) in these particulates were analyzed by atomic absorption spectrophotometry. The arithmetic mean concentration of A.P.M. was 195.57$\mug/m^3$. The arithmetic mean concentrations of 6 metals (Fe, Mn, Cu, Ni, Zn and Pb) were 3385.04, 1451.67, 897.94, 159.68, 127.14 and 59.49 $ng/m^3$ respectively. The order of heavy metals contributing to A.P.M. was as follows: Fe > Zn > Pb > Cu > Mn > Ni. These heavy metals were devided into 3 groups according to their particle size distribution. The contents of heavy metals belonging to the 1st group (Fe, Mn) were increased with the particle size. On the contrary, the content of Pb belonging to the 2nd group (Pb) was increased with the decrease in the particle size. The heavy metal contents in the 3rd group (Ni, Cu, Zn) were lowest in the particle size range of 2.0-3.3 $\mum$ compared with particles larger or smaller tha this range. The seasonal variation of heavy metal concentration were as follows: Fe and Mn contents were highest in spring, but Ni and Pb contents were highest in winter. Statistical analysis showed that there was a significant correlation between A.P.M. and Fe in coarse particles, meanwhile between A.P.M. and Pb in the case of fine particles.

• Membrane Journal
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• v.33 no.6
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• pp.369-376
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• 2023

In this study, the alternative to the energy-intensive conventional vacuum distillation process, an eco-friendly and energy-efficient pervaporation separation was employed in 1,2 hexane diol/water (HDO/water) mixture. The crosslinked PVA-glutaraldehyde was coated inside the alumina hollow fiber membrane (Al-HF). In the HDO/IPA pervaporation separation, optimization of the membrane concerning PVA/GA ratio, curing temperature, and pervaporation operating condition were performed. In the long-term stability test, the sustainable pervaporation separation performance giving flux in the range of 1.90~2.16 kg/m²h, and water content in permeate was higher than 99.5% (separation factor = 68) was obtained from the PVA/GA (molar ratio = 0.08, curing temperature = 80℃) coated Al-HF membrane from HDO/water (25/75, w/w, %) mixture at 40℃. Therefore, this work provides potential and inspiration for PVA-based membranes to mitigate excessive energy requirements in HDO/water separation by pervaporation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.175-187
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• 2023

Peanuts, also known as groundnuts (Arachis hypogaea L.), are globally recognized as a vital oilseed crop. Peanuts are rich in proteins (e.g., arginine), oils (e.g., oleic acid and linoleic acid), fiber, vitamins (e.g., niacin and tocopherol), and carbohydrates and are consumed worldwide. However, the presence of aflatoxin (AF) has garnered substantial attention since its initial discovery as the causative agent of Tukey's X disease in the United Kingdom in 1960. Among the 18 aflatoxins identified, aflatoxin B₁ (AFB₁) has the highest toxic activity and causes hepatocellular carcinoma. It is classified as Group I by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). The present study was conducted to evaluate aflatoxin B₁ resistance of 102 peanut accessions and select putative aflatoxin B₁-resistant peanut accessions to aflatoxin B₁. One hundred and one Korean germplasms harvested in 2020 were inoculated with A. flavus to identify aflatoxin-resistant cultivars, and the aflatoxin B₁ concentration was measured using an ultra-performance liquid chromatography-photodiode array detector. Twenty-six accessions with aflatoxin B₁ concentrations lower than those of the check plant 55-437 were chosen for the development of aflatoxin-resistant varieties in Korea. As Korean aflatoxin-resistant varieties have not yet been developed, the findings of the present study are expected to provide useful information for the development of aflatoxin-resistant cultivars.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.449-456
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• 2023

Sugar or dextrose increases the cost of production of xanthan gum by Xanthomonas campestris. Brewers' Spent Grain (BSG) was chosen as a source of fermentable sugars. BSG is a significant industrial by-product generated in large quantities from the breweries. Primarily used as animal feed due to its high fiber and protein content, BSG holds great potential as an economically and ecologically sustainable substrate for fermenting biomolecules. This study explores BSG's potential as a cost-effective carbon source for producing xanthan, utilizing Xanthomonas campestris NCIM 2961. An aqueous extract was prepared from BSG and inoculated with the bacterium under standard fermentation conditions. After fermentation, xanthan gum was purified using a standard protocol. The xanthan yield from BSG media was compared to that from MGYP media (control). The fermentation parameters, including pH, temperature, agitation and duration were optimized for maximum xanthan gum yield by varying them at different levels. Following fermentation, the xanthan gum was purified from the broth by alcoholic precipitation and then dried. The weight of the dried gum was measured. The obtained xanthan from BSG under standard conditions and commercial food-grade xanthan were characterized using FTIR. The highest xanthan yields were achieved at 32 ℃, pH 6.0, and 72 h of fermentation at 200 rpm using BSG media. The FTIR spectra of xanthan from BSG media closely resembled that of commercial food-grade xanthan. The results confirm the potential of BSG as a cost-effective alternative carbon source for xanthan production, thereby reducing production costs and solid waste.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.173-180
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• 2009

Very-early strength latex-modified concrete(below ; VES-LMC) was developed for possible early-opening-to-traffic after overlay of bridge deck concrete. The purpose of this study is to analyze the cause of map, transverse and longitudinal cracking in VES-LMC and to provide a control method for minimizing occurrence of cracking. The proposed prevention method against map and transverse cracking was verified by field data. VES cement was modified as the unit cement content was reduced from 390kg/$m^3$ to 360kg/$m^3$. The maximum size of coarse aggregate was increased from 13mm to 19mm. The wire mesh and steel fiber were adopted in concrete mixture. From the results, the proposed prevention method against map and transverse cracking was verified since structural cracking was not occurred until 3 years after overlay.

• Korean Journal of Agricultural Science
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• v.51 no.2
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• pp.239-249
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• 2024

In the assessment of the biosafety of genetically modified (GM) crops, a comparative approach to identifying similarities and differences between transgenic and non-transgenic crops is helpful in identifying potential safety and nutritional issues. In this study, we aimed to compare the nutritional composition of a protopanaxadiol-enhanced genetically modified rice (PPD GM rice) with its non-transgenic counterpart. The nutritional profile of PPD GM rice was assessed against that of the parental rice cultivar 'Dongjin' to ascertain nutritional equivalence. No differences were observed between PPD GM and Non-GM rice cultivar in proximate analysis, mineral content, and amino acid composition. Although significant differences were observed in crude fat, crude protein, total dietary fiber, and some minerals between PPD GM rice and Dongjin, these variances fell within the range suggested by common cultivars (Anmi and Nipponbare) and Organization for Economic Cooperation and Development (OECD) data. Similarly, while some amino acids showed significant differences, these metabolites did not deviate from the OECD range. Principal component analysis (PCA) was conducted using the nutritional analysis data of PPD GM rice and Dongjin. The results revealed that PPD GM rice and Dongjin were grouped according to their respective cultivation years. This suggests that the variability in the nutritional composition of PPD GM rice tends to resemble that of the parental rice cultivar 'Dongjin' rather than being solely attributed to genetic modification. Overall, our findings indicate that the nutritional composition of PPD GM rice is substantially equivalent to that of its non-transgenic counterpart.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.254-261
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• 2014

This study was to assess the effect of sowing mixed legume forage and applying cattle manure on the productivity and feed value of whole-crop barley (WCB) as a representative of winter crops and to estimate feeding capacity of Korean native cattle (Hanwoo) per unit area by defining optimal application level of cattle manure for more fertile soil and manure recycling for the purpose of reduced environmental pollution and efficient production of organic forage contributable to production of organic animal products. Sowing mixed legume forage significantly (p<0.05) increased yields of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) for WCB compared to WCB alone sowing, but there was no difference between mixed sowing treatments. The yields of DM, CP and TDN were significantly (p<0.05) highest in 100~150 kg N/hg. The CP and acid detergent fiber (ADF) contents were highest in mixed sowing with hairy vetch, followed by sowing mixed forage pea and WCB alone (p<0.05). There were no differences in CP and neutral detergent fiber (NDF) contents among cattle manure application levels. As nitrogen application level increased, ADF content increased (p<0.05), but TDN content decreased (p<0.05). Feeding capacity of organic Hanwoo (head/ha) weighing 450 kg of body weight with 400 g of daily gain significantly (p<0.05) increased due to mixed sowing with legume forage, and with increasing application levels of fermented cattle manure, feeding capacity significantly (p<0.05) increased. The results indicate that mixed-sowing of WCB and legume forage not only cut nitrogen application level of fermented cattle manure by over 50 kg per ha but also increased their feed value and productivity, and feeding capacity. This would be contributable to diversity of forage resources as well as production of organic animal product by creating low cost and high quality of forage.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.525-537
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• 2016

This study was aimed to grow organic forage as a prime requirement for organic Hanwoo cattle production over a period of 3 years (2012~2015) in Gyeongbuk region, Korea through mixed cropping of winter fodder barley with legume and application of fermented cattle manure. The effect of barley-legume mixed cropping and application of different levels of fermented cattle manure was studied on forage productivity of whole-crop barley (WCB) and evaluation of feeding capacity of Korean native cattle (Hanwoo) per unit area. The collected data was analyzed using SAS 9.3 software. Barley-legume mixed cropping increased (P<0.05) yields of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) as compared to those of sole WCB as monoculture. Similarly, acid detergent fiber (ADF) contents and relative feed value (RFV) were also higher (P<0.05) in barley-legume mixed sowing forage compared with those of sole WCB as monoculture. In case of manure application, yields of DM, CP and TDN were also found (P<0.05) highest in 100~150 kg N/ha. However, varying cattle manure levels did not influence (P>0.05) CP and neutral detergent fiber (NDF) contents. In response to increasing nitrogen application level, ADF content increased (P<0.05) but TDN content and RFV decreased (P<0.05). The Barley-legume mixed sowing and increasing application levels of fermented cattle manure also significantly enhanced (P<0.05) feeding capacity of organic Hanwoo (head/ha) having 450 kg body weight with 400 g of daily gain. Findings of present study indicated that barley-legume biculture not only cut nitrogen application level of fermented cattle manure by over 50 kg per ha but also increased their feed value and productivity of forage as compared to WCB monoculture. This would be contribution to the diversity of forage resources as well as production of organic animal product by creating low cost and high quality organic forage.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.77-84
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• 2006

This study was conducted to find a system for screening organic resources with 16 species, 62 samples which were selected to randomizing point from city, province and industrial areas in the whole country. Content of organic matters were $65.3%{\sim}98.0%$ in all samples so that they were largely over than 60%, raw material regulation of compost. Concentrations of total nitrogen and total phosphorus were $0.7{\sim}4.8%\;and\;0.8{\sim}5.0$, they could look for effect of the nitrogen and phosphorus supply as a raw material of compost. In case of 8 elements concentrations of heavy metal, they were too high to use as raw materials of compost which were over to regulation limit in Cu, Cr, Ni, and As from fiber industry, Ni from food company and leather industry, and the others are adapt to limit levels. HEM contents fro the highest to $113mg\;kg^{-1}$ from liber industry and PAHs content were the highest to $3,462ug\;kg^{-1}$ from paper-mill manufacture. Distribution of PAHs concentiations were naphthalene>phenanthrene>pyrene>fluoroanthene>acenaphthene. $Microtox{(R)}\;EC_{50}$ values for bioassay were pharmaceutical company>paper-mill manufacture>industrial area sewage sludge>fiber industry>urban sewage sludge>metropolitan sewage sludge. HEM between Zn, Cu, and Ni was significant at the 99% and between Cd was significant at the 95%, Microtox between Hg and BEM significant at the 95%.

• Food Science and Preservation
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• v.23 no.4
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• pp.502-509
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• 2016

The seasonal appearance and the chemical composition characteristics of cladode of Opuntia humifusa were investigated in this study. The minor (horizontal) and major (vertical) axes, the width, and weight of O. humifusa cladode were compared for its appearance features. Moisture, crude protein, ash, fat, color, dietary fiber, mineral, and amino acids contents were measured for the comparison of their chemical composition characteristics. The cladode of O. humifusa harvested in summer showed higher values of minor and major axis, width, and weight than those harvested in winter. According to the results of Hunter color index, cladode of O. humifusa harvested in summer showed the highest lightness level (Hunter L value). In the meanwhile, cladode of O. humifusa harvested in spring showed the highest Hunter a (redness) and b (yellowness) values. Cladode of O. humifusa harvested in summer had the lowest crude protein and crude fat contents, while it showed the highest crude ash content. The total contents of moisture and dietary fiber were significantly greater than summer-harvested cladode of O. humifusa followed by spring- and winter-harvested cladode of O. humifusa. The major mineral content of all seasonal cladode of O. humifusa was $Ca^{2+}$. Glutamic acid and aspartic acid were the major amino acids in all seasonal samples. Contrary, the contents of total amino acids and free amino acids were the lowest in summer-harvested cladode of O. humifusa. Taken together, it was concluded that the appearance and chemical quality of cladode of O. humifusa was versatile depending on the harvesting season.