• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.230-240
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• 2015

An IOM sampler equipped with glass fiber filter has been recently utilized instead of solid adsorbent, which was used to measure the inhalation exposure of agricultural operator to pesticides. The aim of this study is to validate the efficacy of an IOM sampler by measuring the trapping efficiency and breakthrough using kresoxim-methyl water-dispersible granule and fenthion emulsifiable concentrate. On LC-MS/ MS, minimum detection level was 12.5 pg and method limit of detection was 5.0 ng/mL. Good linearity ($R^2$ > 0.999) for matrix matched standards was obtained. Recoveries of pesticides from glass fiber filter were 102-109% (kresoxim-methyl) and 97-104% (fenthion) while those from XAD-2 resin were 94-98% (kresoxim methyl) and 93-100% (fenthion). Trapping efficiency test was performed with personal air pumps and IOM sampler (glass fiber filter) connected with solid adsorbent (XAD-2 resin) with two types of formulation (solid and liquid) which were diluted by standard rate and sprayed to IOM sampler. Those pesticides were trapped only in glass fiber filter without any breakthrough to solid adsorbent. After spiking of pesticides to glass fiber filter, breakthrough test was carried out with IOM sampler (glass fiber filter) which was connected with solid adsorbent. As a results, 87-101% of kresoxim-methyl and 96-105% of fenthion remained in spiked glass fiber filter, however, no pesticides were detected in second glass fiber filter and solid adsorbent. In conclusion, IOM sampler which equipped with glass fiber filter can be applied widely for pesticide inhalation exposure study since it has good trapping efficiency and adsorption capacity, regardless of the solid or liquid formulation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.3
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• pp.85-102
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• 1979

In spite of the expansion of population as well as the improvement of living standard, the sugar consumption in Korea depends totally upon the imported sugar with no domestic production. In order to solve this current problem, the author carried out series of experiments and investigations in Daegwanryeong area best suitable for sugar beet cultivation to determine the good varieties, cultivation method, distribution of cultivation area. Thus, it is expected that the result of investigation make a small contribution to the enterprise or production.

• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.277-288
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• 2005

Perlite, a hydrated volcanic glass, occurs mainly as a bed-like body, and is distributed intermittently along the unconformity surface between the Beomgockri Group and its lower formations, viz. Janggi Group. The perlite is intimately associated with surrounding pumiceous welded tuff and rhyodacites in space and time. Compared to the typical perlite, the perlite is rather silica-poor and impure, and thus, includes lots of phenocrysts and rock fragments. Nearly the perlite is compositionally rather close to a pitchstone than a perlite in water contents. Petrographic comparison between perlite and associated volcanic to volcaniclastic rocks indicates that pumiceous welded tuff and rhyodacite seem to be Protolith of the Perlite. A Zr/$TiO_{2}$-Nb/Y diagram and field occurrence of perlite and their protolithic rocks also conforms the above interpretation. Kn addition, remnant vesicles in perlite strongly reflect that the precursor of perlitic glass appeared to be pumice fragment as well as volcanic glass. The perlite was diagenetically formed by way of a pervasive water-rock interaction at the deposition of the Manghaesan Formation in lacustrine environment. During perlitization, $SiO_{2}$ and alkali tend to be consistently depleted. Preexisting system of the Beomgockri Group based on the perlite formation should be corrected, because the perlite was formed diagenetically without lateral persistence in its occurrence.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.350-357
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• 2014

We studied on pesticide residue and pest control effect when using various types of sprayers on paprika cultivation. Additionally, a test was conducted to optimize chemical content per unit area in condition of optimum pest control. Two types of sprayer were tested (three times) on paprika cultivation which was divided into seven sections. Blind spots were also examined using a water sensitive paper when spraying chemical pesticide, remote controlled sprayer were confirmed to be not effective in terms of its spraying capacity. However, a U-shaped sprayer was confirmed that it sprayed enough on all the parts of a plant in green house including the blind spots. Additionally, it does not exceed the minimum residue limits on the all parts of pesticides residue conditions. When using remote controlled sprayer, water sensitive paper were changed to blue color (82.5% and 81.2%) in terms of controlling Bemisia tabaci and Aphis gossypii based on the two spraying manners. 53.0% and 42.6% of control effect were shown on the fair parts of the plants. However, on the poor parts on which pesticides were not well-sprayed, thus, not-remained, more number of pests increased. Meanwhile, on farming that only one type of pesticide has been used, resistance pests present with very low control effect, even though sufficient amount of pesticide was well-sprayed. On the test of the optimum amount of spraying per a unit area, which shows no differences in the two cases of using 5L and 2.5L of chemical pesticides on 9 plants of paprika that has 81.8% and 84.5% control effect, respectively.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.39-44
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• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.84-89
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• 2017

This study was carried out to investigate residue dissipation of fluquinconazole and flusilazole in field-sprayed tomatoes during greenhouse cultivation and processing. The test pesticide, fluquinconazole+flusilazole 8.5 (7+1.5)% SC, was sprayed onto the tomatoes growing in a greenhouse according to Korea preharvest intervals and then samples were collected on 0 (3 hours after spraying), 1, 3, 5 and 7 days after last application for decline test. For processing test, tomatoes collected at harvest on 5 day after last application were processed to puree and juice. Limits of quantitation of fluquinconazole and flusilazole were 0.005 mg/kg in both tomatoes and their processed products. Recoveries for validation of the analytical methods for fluquinconazole and flusilazole in tomatoes and their processed products ranged from 74.8 to 97.5%. Biological half-lives of fluquinconazole and flusilazole in tomatoes under greenhouse conditions found to be 5.2 and 6.4 days, respectively. Average persistent residue levels of fluquinconazole and flusilazole were 37.34 and 79.53% after washing, 8.95 and 28.75% in filtrates after boiling, 3.58 and 14.66% in puree, and 3.34 and 13.52% in juice, respectively. These results indicated that the test pesticide residues on tomatoes could be largely removed through washing and boiling.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.283-296
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• 2012

Allergic contact dermatitis (ACD) is an inflammatory skin disease and regarded as a prototype of T-cell mediated delayed-type hypersensitivity reactions. Poly-${\gamma}$-glutamic acid (PGA) is a biodegradable polymer that is produced by Bacillus subtilis. This study was performed to assess the effects of PGA in a canine model of ACD. ACD was induced on the back of dogs induced by sensitization and repeated application by 2,4-dinitro-1-chlorobenzene (DNCB). Topical treatment of PGA was applied once a day for 12 days and skin biophysical parameters including transepidermal water loss (TEWL), skin hydration, skin pH, skin thickness and erythema index, were measured every two days during experimental periods. Histopathology and immunohistochemistry were performed to evaluate the antiinflammatory effect. In skin biophysical parameters, TEWL, skin hydration, skin thickness and erythema index were significantly increased, with a maximum increase appeared on day 2 (p < 0.05). On the other hand, skin pH was significantly decreased, with a maximum decrease appeared on day 2 (p < 0.01). After the completion of PGA treatment, skin biophysical parameters were significantly reached those of baseline in a time-dependent manner (p < 0.05). In histopathology, marked increases of epidermal thicknesses were induced after DNCB challenge with numerous inflammatory cell infiltrations and edematous changes, decreases of connective tissue occupied regions in dermis. In addition, marked increases of cytokine - tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$)-immunoreactivities in the dermis and of apoptotic markers - caspase-3 and PARP-immunoreactivities in the epidermis were observed in DNCB-PBS control as compared with intact control, respectively (p < 0.01). It means, the ACD and related apoptotic changes were induced by DNCB in the present study. However, these ACD induced by DNCB and related apoptosis in epidermis were significantly inhibited by treatment of PGA treated skin, the decreases of infiltrated inflammatory cells and related decreases of pro-inflammatory cytokine immunoreactivities were also observed (p < 0.01). Based on these findings, PGA may have anti-inflammatory and alleviatory effects in the allergic contact dermatitis.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.119-128
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• 2015

The purpose of this study is to understand the effects of obesity and stress on oral disease in Korean adults by using the data of the Fifth Korea National Health and Nutrition Examination Survey. The subjects of this study are 4,627 adults at the age of 19 to 64, and the data were analyzed by using SPSS Windows ver.18.0. The results are as follows: Obesity was higher in men and the age of 40 to 64 than the other. And the group with lower education or lower income level tended to show significantly higher obesity (p<0.05). As for stress, women, the age of 19 to 39 and the subjects with higher academic career tended to indicate significantly higher stress (p<0.05). As for the effects of obesity on oral disease, there were no significant difference between body mass index (BMI) or waist-hip ratio (WHR) and oral disease but there was statistically significant difference between stress and temporomandibular joint disorder (TMD) (p<0.05). Even when the subjects with stress were obese or abdominally obese, there was no significant difference in oral disease (p>0.05). As to correlation among variables, there were correlations between BMI and WHR, stress and TMD, masticatory problems and periodontal disease or TMD (p<0.05). About the effects of general characteristics, obesity, and stress on oral disease, age was the variable influencing TMD, and age and abdominal obesity were the variables influencing masticatory problems (p<0.05). In this society, the environment surrounding individuals is fairly complex, and the concept of health including quality of life has more complex meaning than in the past. Various factors are influencing obesity and stress, and they are also influencing oral health and behaviors. Accordingly, it will be needed not only to make efforts to reduce obesity and stress but also to employ approaches from different perspectives to improve oral health.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.226-245
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• 2019

Beopjusa Gwaebultaeng (Large Buddhist Painting), designated as Treasure No. 1259, was painted in 1766 and featured Yeorae (Buddha) at the center in the style of a single figure. It is the longest existing buddhist painting and was created by Duhun, a painter who was representative of 18th century Korean artists. His other remaining work is Seokgayeorae Gwaebultaeng (1767) in Tongdosa Temple. Considering their same iconography, they are assumed to have used the same underdrawing. Duhun had a superb ability to maintain a consistent underdrawing, while most painters changed theirs within a year. The Beopjusa painting carries significance because it was not only painted earlier than the one in Tongdosa, but also indicates possible relevance to the royal family through its records. Beopjusa Temple is also the site of Seonhuigung Wondang, a shrine housing the spirit tablet of Lady Yi Youngbin, also known as Lady Seonhui. Having been built only a year before Beopjusa Gwaebultaeng was painted, it served as a basis for the presumption that it has a connection to the royal family. In particular, a group of unmarried women is noticeable in the record of Beopjusa painting. The names of some people, including Ms. Lee, born in the year of Gyengjin, are recorded on the Bonginsa Temple Building, the construction of which Lady Yi Youngbin and Princess Hwawan donated money to. In this regard, they are probably court ladies related to Lady Yi Youngbin. The connection of Beopjusa Gwaebultaeng with the royal family is also verified by a prayer at the bottom of the painting, reading "JusangJusamJeonhaSumanse (主上主三殿下壽萬歲, May the king live forever)." While looking into the historical characteristics of this art, this study took an approach based on scientific analysis. Damages to Beopjusa Gwaebultaeng include: bending, folding, wrinkles, stains due to moisture, pigment spalling, point-shaped pigment spalling, and pigment penetration to the lining paper at the back. According to the results of an analysis of the painting pigments, white lead was used as a white pigment, while an ink stick and indigo were used for black. For red, cinnabar and minium were used independently or were combined. For purple, organic pigments seem to have been used. For yellow, white lead and gamboge were mixed, or gamboge was painted over white lead, and gold foil was adopted for storage. As a green pigment, atacamite or a mixture of atacamite and malachite was used. Azurite and smalt were used separately or together as blue pigments.

• Resources Recycling
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• v.28 no.5
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• pp.60-67
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• 2019

A valuable metal recovery from waste resources such as spent rechargeable secondary batteries is of critical issues because of a sharp increase in the amount of waste resources. In this context, it is necessary to research not only recycling waste lithium-ion batteries (LIBs), but also reusing valuable metals (e.g., Li, Co, Ni, Mn etc.) recovered from waste LIBs. In particular, the lithium hydroxide ($LiOH{\cdot}xH_2O$), which is of precursors that can be prepared by the recovery of Li in waste LIBs, can be reused as a catalyst, a carbon dioxide absorbent, and again as a precursor for cathode materials of LIB. However, most studies of recycling the waste LIBs have been focused on the preparation of lithium carbonate with a recovery of Li. Herein, we show the preparation of high purity lithium hydroxide powder along with the precipitation process, and the systematic study to find an optimum condition is also carried out. The lithium carbonate, which is recovered from waste LIBs, was used as starting materials for synthesis of lithium hydroxide. The optimum precipitation conditions for the preparation of LiOH were found as follows: based on stirring, reaction temperature $90^{\circ}C$, reaction time 3 hr, precursor ratio 1:1. To synthesize uniform and high purity lithium hydroxide, 2-step precipitation process was additionally performed, and consequently, high purity $LiOH{\cdot}xH_2O$ powder was obtained.