• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.384-387
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• 1999

The residue of imidacloprid in hulled rice and paddy soil was investigated. In laboratory conditions, the degradation of imidacloprid in the soils followed first-order reaction kinetic. The rate of degradation was influenced by soil temperature and soil type. The half-life of imidacloprid at $18-28^{\circ}C$ was 66.7-96.3 days in the heavy clay soil and 56.8-117.5 days in the clay loam soil. Arrhenius activation energy obtained from the temperature experiment was 25.5 KJ/mol in heavy clay soil and 50.3 KJ/mol in clay loam soil. In paddy field, the degradation of imidacloprid was fast during the initial period but the degradation rate was gradually slow. About 10 % of the initial amount remained in the soil 120 day after the application. The residual amount of imidacloprid in rice was below the detection limit, 0.01 ppm. The residue level in rice was lower than MRL 0.05ppm in Korea.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.468-473
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• 2006

This study was conducted to develop pigment of flowers as a food material and the red rose(Rosa hybrida L.) was used for this study. To check the possibility of using the rose pigment as a food additive we have extracted the pigment from rose and examined all the factors (pH, temperature, free sugars, organic acids, metal ions) for stability. The results obtained are as follows: In examining the stability of the pigment, the residue of the pigment noticeably decreased with the increase of the pH and the temperature, and among free sugars (fructose, glucose, sucrose) the addition of fructose made the residue the lowest. With the addition of organic acids the samples exhibited the hyperchromic effect throughout the period of the storage. The pigment residue decreased when the amount of the metal ions increased and especially the Cu$^{2+}$ ion was most destructive.

• YAKHAK HOEJI
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• v.1 no.1
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• pp.4-6
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• 1948

The fruits of Rhus javanica L. distributed widely in Korea were extracted with cold water, the filtered clear liquid was evaporated and from the residue large colorless columns, M.P.about 180.deg., were obtained by recrystallisation from hot water. On being incinerated it left a considerable amount of solid residue consisting of calcium. Its aqueous solution which had a strong acid reaction was acidified with sulfuric acid, the precipitate, CaSO$_{4}$, was filtered off, the filtrate was evaporated and from the residue colorless needles, M.P.98-100.deg., were obtained by treating with alcohol. It was identified to be malic acid by determining the mixed melting points of itself and its p-bromphenacylester with authentic specimens. Thus the original substance was proved to be a kind of Ca-salt of malic acid.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2904-2909
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• 2008

The liquid phase LPG injection (LPLi) system (the 3rd generation technology) has been considered as one of the more promising fuel supply systems for LPG vehicles. To investigate the characteristics of LPG residue in LPLi system, various rubbers were reacted with LPG fuels. The results showed that the residue of a cover rubber in a fuel pump after test increased 10 times higher than that before test. Furthermore, the amount of sulfur, nitrogen species which are considered as main sources in deposit formation in the LPLi fuel injector were also found to be higher than that in original LPG fuel. And these residues made the core parts of LPLi injector such as a neddle and a nozzle, partially worn, which eventually causes a leakage in LPLi injectors.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.248-254
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• 2012

BACKGROUND: In order to elucidate residual characteristics of difenoconazole and thiamethoxam by treatment to sweet persimmons for one year and to generate the data for the maximum residue limit (MRL) establishment for those pesticides in or on sweet persimmon. METHODS AND RESULTS: Systemic fungicide difenoconazole WP (10% a.i.) and systemic insecticide thiamethoxam WG (10% a.i.) were sprayed onto 12~25-years-old sweet persimmons according to its preharvest interval (PHI), respectively, and then fresh sweet persimmons were harvested at 0, 1, 3, 7, 14, 21 days after treatment from pesticide-sprayed plots at each 3 sites. The analytical methods were evaluated to limit of quantification, linearity, specificity, reproducibility and recoveries. The crop samples were extracted with acetone and performed dichloromethane partition process. The extracted samples of difenoconazole were analyzed by GC-ECD and the thiamethoxam extracted samples were analyzed by HPLC with good sensitivity and selectivity of the method. The average recoveries of difenoconazole ranged from 87.5 to 99.5% with the percentage of coefficient variation in the range 4.1~7.6% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg). And the average recoveries of thiamethoxam and clothianidin ranged from 88.8 to 98.9% and 83.2 to 96.6% with the percentage of coefficient variation in the range 3.6~5.0% and 3.8~9.4% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg), respectively. The residue amounts ranges of difenoconazole were 0.2~0.56 mg/kg and the residue amount was decreased below the MRL level, 1.0 mg/kg, after 1 day harvest. The residue amounts ranges of thiamethoxam were 0.08~0.28 mg/kg and the residue amount was decreased below the MRL level, 0.5 mg/kg, after 1 day harvest. And the residue amount of clothianidin was below then 0.03 mg/kg for only one test site of 14 and 28 day samples. CONCLUSION: As a result, the residual amounts of difenoconazole and thiamethoxam were not exceeded the MRL of established criteria for sweet persimmon. The biological half-lives of difenoconazole and thiamethoxam were 13.6, 19.4, 16.3 and 10.0, 15.3, 14.0 days at each three test sites, respectively.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.293-301
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• 2013

This study discusses the feasibility of coffee bean residue as a raw material of medium-density fiberboard (MDF). In this relation, the effect of coffee bean residue known as an absorbent material on the physical and mechanical properties of MDF manufactured at its different addition level. Coffee bean residue which is a by-product of coffee mill and large amount of waste left over after processing for instant coffee was added at the level of 3, 6, and 9% on dry basis and urea formaldehyde resin was used as the adhesive. The MDF made with mixture of wood fiber and coffee bean residue was tested for physical and mechanical properties as well as formaldehyde emission. The bending strength and internal bonding strength of the MDF made with mixture of wood fiber-coffee bean residue were higher than that of the KS standard in randomized mat structure type, but not in layered mat structure type. Also, the physical properties of MDF made with mixture of wood fiber-coffee bean residue showed a considerable improvement in thickness swelling over the commercial MDF. More importantly, the formaldehyde emission rate of MDF made with mixture of wood fiber-coffee bean residue met the KS standard and was close to that of commercial MDF. These results showed the feasibility of coffee bean residue as a raw material for the production of environmentally-friendly MDF. Additional works on adhesive-coffee bean compatibility, improvement of moisture absorption effect and reduction the formaldehyde emission rate by carbonization of coffee bean residue may be required.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.453-461
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• 2009

Killifish (Oryzias latipes) were exposed to an organophosphate pesticide, pirimiphos-methyl, in a flow-through system to determine the bioconcentration factor (BCF) following GLP (Good Laboratory Practice). This study was conducted at two different concentrations (1 and $10\;{\mu}$g/L) of $^{14}C$-labeled pirimiphos-methyl for 28 days uptake and 14 days depuration according to the OECD 305 test guideline. The $BCF_{ss}$ for total radioactive residues in whole fish were 1,251 and 1,277 for low and high concentrations, respectively. The $BCF_k$ based on the uptake and depuration rate constants were 1,200 for both low and high concentrations. During the depuration phase, the accumulated test substance was rapidly depurated from fish. Greater than 95% of the residue at steady-state was depurated after 2 days. Although the measured BCF values were high, pirimiphos-methyl could be evaluated as a low risk from bioaccumulation by aquatic organisms due to the short depuration period and low amount of bound residue (1.5%). We suggest that in evaluating bioaccumulation, not only the BCF should be considered, but also depuration time and bound residue in aquatic organisms give an indication of the potential environmental risks.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.3
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• pp.162-168
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• 1991

Iterbicide resduc. cauicd ~rljul-y to ovcrsown pasture grasses \\hen herbicide appliccl for use in pasturc est;~blish~nt~nt lo gro~vth contro! ol n;rtivc ~r ~:cds and shrubs. 'l'hih L~sperirnel~t was conducted to cv;lluati. (he herbicidr residue anti its ph!:totosical ~riiiuence on the growth of introtluccd pasturts species. Esperimcmtal soils was treated with buthitlazolc, ~ o d l ~ l m chlorate, glyphosatc. U-46 anti paraquat each at twt) applici~tion rates. Lhcf~1i.s glowl~mlc~ including othrr pasture grasses and le~urnes were evaluatrd for tolerance to herbicide. IIerbicide residue in the amount ot injury caused to introduced pasture grasses was found in order of buthidazole, sodium chlorate, U-46 and glyphosate. Euthidazole was not available for use in pasture establishment because of their long persist of toxic herbicide residues. A great stand redl~ction of subseq ~ ~ c n t oversown pastures was also observed In sodium chlorate treatment. However, normal vegetative stand and grass production was obtained, when thc pasture grasses seeded 45-60 days later herbicide treatments. Glyphosate did not affect subsequent oversown pasture species in both grasses and legumes. fistuccr arundinc~cea and Pou pratensis were the most tolerant pasture species to herbicide residue while 7'rzfi,lium pyatense and Medicugo suti~u showed a wsceptible response regardless of herbicide.

• Journal of Haehwa Medicine
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• v.22 no.1
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• pp.129-143
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• 2013

This study was conducted to investigate the residue amount of pesticide on the 41 medicinal herbs in Daejeon area. This study was carried out to monitor the current status of pesticide residues in commercial medicinal herbs for sale of food use in 2012. It was performed using GC/ECD, GC/NPD, HPLC to analyze pesticides residues. Residues of 283 pesticides were analyzed by a simultaneous multiresidue method in 41 medicinal herbs being on sale in Daejeon. The medicinal herbs detected pesticides in 10 of 41 cases, showed a detection rate of 24.39%. The medicinal herbs which exceed the maximum residue limit were five cases as Cnidii Rhizoma, Osterici Radix, Artemisiae Capillaris Herba, Zizyphi Fructus and Alismatis Rhizoma. And pesticide residue of Cnidii Rhizoma and Alismatis Rhizoma exceeds the limit standard presented in only medicine use of KFDA. The residual pesticides which had the high detection rate were Chlopyrifos, Tebuconazole and Endosulfan in the detection of medicinal herbs. For further research, standards of Pesticide Residues in medicinal herbs should be added and more research of pesticide residues in medicinal herbs required. And standards of pesticide residues in medicinal herbs should be applied equally as medicines and food.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.407-411
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• 2010

ALC was fabricated using cement, lime and quartzite by hydrothermal reaction. ALC has low strength and brittleness on account of inner pores. The studies for resolving these problems were driven by many researchers. Among these researches, the controls of quartzite fineness have been studied for unsuitable properties of ALC. This study experimented with variation of 90 ${\mu}m$ residue for obtain good physical properties. It was found that 90 ${\mu}m$ residue influenced on physical properties of ALC. The lower amount of 90 ${\mu}m$ residue, the higher compressive and bending strength. But the continuing decrease of 90 ${\mu}m$ residue did not cause the increase of strength. In order to application of these results in process, the states of process and hydrothermal products will be considered.