• 제목/요약/키워드: residual time

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An experimental study on the comparison of trace amount of sulfonamides detection method in raw milk. (원유중 미량 설파제 검출방법 비교에 대한 실험적 연구)

  • 황원무;이성모;손봉환;이원창
    • Korean Journal of Veterinary Service
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    • v.20 no.1
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    • pp.79-93
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    • 1997
  • The sulfonamide is one of potentiative antimicrobial agents which is being used widely in veterinary medicine for control of several animal diseases such as mastitis as well as for promotion of growth. However, the misusages of sulfonamides in food producing animals, especially cattle produce several considerable problems in human health caused from residues of this antibiotic in milk product. To determine the most effective analytical methods for residual sulfonamides in raw milk, this study was performed comparatively using by some applicable screening detecting method such as TTC, Charm II test (sulfonamides), and Lactek tests (sulfamethazine kit). The positive result from screening tests was confirmed by HPLC method. Milk samples (540 raw milks) were collected from dairy farms. Results of this study are summariezed as follorrs ; 1. All samples (540 raw milks) showed negative response from TTC test, however, 18 raw milks of those samples responded positively to Charm II test. 2. By Lactek test, residual sulfamethazine was detected from 4 raw milks. Fifteen raw milks of 18 samples which were classified as positive one by Charm II test, showed positive response 3. Retention time of sulfonamides added at the level of 100ppb into sklm milk was ranged from 1.55 minute to 23.3 minute. Recovery rates of sulfonamides were variable from 6.7% upto 94.2% depended on the types of sulfonamlde. 4. Single type of sulfonamides was detected from 10 raw milk samples, 2 types of sulfonamides from 3 samples and 3 types from 2 raw milks by HPLC. 5. Sulfonamides was detected in this study were 5 types : 11 samples for sulfisomidine, 5 samples for sulfamethazine, 3 samples for sulfadlmethoxine, 2 samples for sulfathiazole and 1 sample for sulfadiazine. 6. The highest levels of residual sulfonamides was 210.3 ppb of sulfamethazine but the lowest concentration of residue was 2.2 ppb of sulfamethazine and sulfisomidine, respectively. Number of samples detected positively in this experiment were belows : above 100 ppb for 1 sample (4.5%) (sulfamethazine), 50~100 ppb for 4 samples (18.1%) (each 2 samples for sulfamethazine and sulfisomidine, respectively), 25~50 ppb for 6 samples (27.1%) (2 sulfisomidine, each 1 sample for sulfadiazine, sulfadimethoxine, sulfamethazine and sulfathiazole, respectively), 10~25ppb for 3 samples (13.7%) (3 sulfisomidine), and below 10ppb for 8 samples (36.4%) (4 sulfisomidine, 2 sulfadimethoxine and each 1 for sulfamethazine and sulfathiazole).

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Characteristics of Early-Age Restrained Shrinkage and Tensile Creep of Ultra-High Performance Cementitious Composites (UHPCC) (초고성능 시멘트 복합체의 초기 재령 구속 수축 및 인장 크리프 특성)

  • Yoo, Doo-Yeol;Park, Jung-Jun;Kim, Sung-Wook;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.23 no.5
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    • pp.581-590
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    • 2011
  • Since ultra-high performance cementitious composites (UHPCC) not only represents high early age shrinkage strain due to its low water-to-binder ratio (W/B) and high fineness admixture usage but also reduces the cross section of structure from the higher mechanical properties, it generally has more shrinkage cracks from the restraints of formwork and reinforcing bars. In this study, free and restrained shrinkage experiments were conducted to evaluate the suitability of incorporating both expansive admixture (EA) and shrinkage reducing agent (SRA). The test results indi-cated that approximately 40~44% of free shrinkage strain was decreased. Also, the results showed that 35% and 47% of residual tensile stresses were relieved by synergetic effect of SRA and EA, respectively. Residual tensile stresses from ringtest were relaxed by approximately 61% and 64% of elastic shrinkage stresses due to SRA and EA, respectively, because of the tensile creep effect. Therefore, the creep effect should be considered to precisely estimate the restrained shrinkage behavior of concrete structures. The degree of restraint of UHPCC was approximately in the range of 0.78~0.85. The addition of combined EA and SRA showed minute influence on the degree of restraint. However, the effect decreased when thicker concrete ring was used. Tensile creep strains were measured and compared to the predicted values from 4-parametric prediction model considering time dependent restrained forces.

The retrospective study of survival rate of implants with maxillary sinus floor elevation (상악동 거상술을 동반한 상악구치부에 식립된 임플란트 생존율에 대한 후향적 연구)

  • Kim, Beom-Jin;Lee, Jae-Hoon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.2
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    • pp.108-118
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    • 2010
  • Introduction: Maxillary posterior region, compared to the mandible or maxillary anterior region, has a thin cortical bone layer and is largely composed of cancellous bone, and therefore, it is often difficult to achieve primary stability. In such cases, sinus elevation with bone graft is necessary. Materials and Methods: In this research, 121 patients who had implant placement after bone graft were subjected to a follow-up study of 5 years from the moment of the initial surgery. The total survival rate, 5-year cumulative survival rate and the influence of the following factors on implant survival were evaluated; the condition of the patient (sex, age, general body condition), the site of implant placement, diameter and length of the implant, sinus elevation technique, closure method for osseous window, type of prosthesis and opposing teeth. Results: 1. The 5-year cumulative survival rate of total implants was 90.5%, there was no significant difference between sex, age, the site of implant placement, diameter and length of the implant, sinus elevation technique, and the type of opposing teeth. 2. Patients with diabetes mellitus < osteoporosis and smooth-surfaced machined group < hydroxyapatite (HA)-treated group and homogenous demineralized freeze dried allogenic bone (DFDB) bone graft only group had significantly lower survival rate. 3. With less than 4 mm of residual alveolar ridge height, lateral approach without closing the osseous window resulted in a significantly lower survival rate. 4. Restoration of a single implant showed a significantly lower survival rate, compared to cases where the superstructure was joined with several implants in the area. Conclusion: Patients with diabetes or osteoporosis need longer period of time for osseointegration compared to the normal, and the dentists must be prudent when choosing a surface treatment type and the bone graft material. Also, as the vertical dimension of the residual alveolar ridge can influence the result, staged implant placement should be considered when it seems difficult for the implant to gain primary stability from the residual bone with less than 4 mm of vertical dimension. It is recommended to obdurate the bone window and that the superstructure be connected with several impants in the peripheral area.

A GRAVITY STUDY OF THE TRIASSIC VALLEY IN SOUTHERN CONNECTICUT

  • Chang, Chung Chin
    • Economic and Environmental Geology
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    • v.2 no.2
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    • pp.1-35
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    • 1969
  • The structure and geologic history of the Triassic basin in southern Connecticut have been interpreted by using gravimetric data. A gravity survey of 800 gravity stations was made by the U.S. Geological Survey in the southern Connecticut area. The resulting data were reduced by the Bouguer method and then plotted and contoured along with the generalized geology. Residual gravity maps were prepared by different methods to obtain the most plausible agreement with the known geology of the area. Seven gravity profiles across the basin are presented to show the distribution of the Triassic deposits that could produce the measured anomalies. It is concluded that the basin was formed by successive step faulting in the late Triassic period and that the sediments accumulated progressively in this basin. The deepest portion of the basin is located in the middle of the present Triassic belt and reaches a depth of about 2 miles below the surface. The data also appear to indicate the possible source areas for the basalt which at present forms the lava flows, sills, and dikes exposed in the Cheshire and Gaillard regions. The information concerning the tectonic history of the Connecticut Triassic Valley aids considerably in establishing the geologic history of the Appalachians in late Triassic time.

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Effect of Garlic and Onion Juice Addition on the Lipid Oxidation, Total Plate Counts and Residual Nitrite Contents of Emulsified Sausage during Cold Storage (마늘즙 또는 양파즙 첨가가 유화형 소시지의 저장 중 지방 산화, 총 미생물수 및 아질산염잔존량에 미치는 영향)

  • Park, Woong-Yeoul;Kim, Young-Jik
    • Food Science of Animal Resources
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    • v.29 no.5
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    • pp.612-618
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    • 2009
  • The objective of this study was to determine the antioxidant and antimicrobial effects of garlic juice and onion juice in emulsified sausage during cold storage. The sausages were into five groups: control, 1% garlic juice (T1), 3% garlic juice (T2), 1% onion juice (T3), and 3% onion juice (T4). Each sausage type was tested in triplicate and assigned to one of four storage periods: 0, 7, 14 and 21 days. As storage time increased, the presence of garlic juice and onion juice resulted in decreased pH, residual nitrite value, and increased peroxide value, TBARS (thiobarbituric acid reactive substance) values, and total plate counts. The pH value, peroxide value, TBARS, residual nitrite and total plate counts were significantly decreased by the addition of garlic and onion juice relative to the control (p<0.05). Especially, T2 was significantly (p<0.05) more effective in delaying lipid oxidation compared to the other treatment groups. However, no significant difference (p<0.05) was found in total plate counts among all the formulations on day 0. Also, the use of garlic juice resulted in much better antioxidant and antimicrobial effects than the use of onion juice and the control. In conclusion, this study demonstrates that the addition of 3% garlic juice (T2) to emulsified sausages tended to improve antioxidative and antimicrobial effects during storage relative to the other treatment groups.

Analysis of Residual Triflumizole, an Imidazole Fungicide, in Apples, Pears and Cucumbers Using High Performance Liquid Chromatography

  • Khay, Sathya;EI-Aty, A.M. Abd;Choi, Jeong-Heui;Shim, Jae-Han
    • Toxicological Research
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    • v.24 no.1
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    • pp.87-91
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    • 2008
  • The present study was conducted to monitor the level of triflumizole residues in fruits (apple and pear) and vegetable (cucumber) samples in order to assess risk posed by the presence of such residues to the consumer. Triflumizole was applied at a recommended dose rate to apple and pear pulps and to a cucumber sample. The samples were collected at harvesting time following several treatments (three and/or four treatments). Triflumizole was extracted with methanol and re-extracted into dichloromethane. The presence of triflumizole was determined by HPLC with UV detection at 238 nm following the cleanup of the extract by open preparative chromatographic column with Florisil. The versatility of this method was evidenced by its excellent linearity (> 0.999) in the concentration range between 0.2 and 4.0 mg/kg. The mean recoveries evaluated from the untreated samples spiked at two different fortification levels. 0.1 and 0.4 mg/kg, and ranged from 87.5${\pm}$0.0 to 93.3${\pm}$2.6 for the tested fruits and vegetable, respectively, and the repeatability (as relative standard deviation) from three repetitive determinations of recoveries were no larger than 6%. The calculated limit of detection was 0.02 mg/kg and the minimum detectable level of 4 ng for triflumizole was easily detected. When triflumizole was sprayed onto the apple trees three times at 50-40-30 and 40-30-21 days prior to harvesting and four times onto the pear trees at 40-30-21-14 days prior to harvesting, the mean residual amounts of 0.05 and 0.06 mg/kg for apples and pears, respectively, were not detected in all of the treatments. When the cucumber sample was fumigated four times at 7, 5, 3 and 1 day prior to harvesting, the mean residual amount was not detectable. Triflumizole can be used safely when sprayed (wettable powder, 30% active ingredient) and fumigated (10%) 4 times at 14 and 1 day prior to harvesting to protect the fruits and vegetable, respectively.

Estimation of Fugitive Emission Factors of HFC-134a from Scrap Cold Drinking Vending Machine at Use- and Disposal-Phase (음료용 폐자동판매기에서의 HFC-134a 사용 및 폐기단계 탈루배출계수 결정에 대한 연구)

  • Lee, Youngphyo;Kim, Eui-Kun;Kim, Seungdo;Byun, Seokho;Kim, Hyerim;Park, Junho;Lee, Dongwon
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.5
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    • pp.350-355
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    • 2013
  • Little information is available for emission pathway even if HFC-134a that is known as one of the major greenhouse gases has been broadly used in Korea. This paper attempts to clarify the emission characteristics of HFC-134a used for refrigerant of cold drinking vending machines (CDVMs) at the use- and disposal-phase. We measured the residual amounts in the scrap CDVMs of 47 by applying commercial recover for refrigerant. The first-order kinetic model was introduced and the emission rate would be proportional to the remaining quantity of refrigerant. The emission factor at the use-phase was determined indirectly to be $6.9{\pm}0.7$ %/yr within a confidence interval of 95%, using information on residual amount and elapsed operation time at the disposal point. Correspondingly, the annual emission rate of HFC-134a per CDVM was determined to be 11.6 g. The average residual rate of HFC-134a in scrap CDVMs was assessed to be $62.5{\pm}2.2%$, leading to a potential emission amount of 144.8 g per scrap CDVM. The chemical compositions of refrigerants from scrap passenger vehicles are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap passenger vehicles could be reused. During the recovering process of refrigerant, the recovered refrigerant was contaminated by compressor lubricant that accounted for about 30% in weight. It is necessary to separate the refrigerant from the recovered material contaminated by lubricant for recycling and reuse the refrigerant.

Optimization of Synthesis Condition and Determination of Residue for Polyamine Type Flocculant (폴리아민계 고분자 응집제의 합성조건 최적화 및 잔류물분석)

  • Choi, Soo-Young;Park, Lee-Soon;Im, Sung-Hyun;Ryoo, Jae-Jeong;Choi, Sang-June;Hwang, Won-Joo
    • Applied Chemistry for Engineering
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    • v.9 no.7
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    • pp.1043-1046
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    • 1998
  • Aluminium based inorganic flocculants are extensively used in this country in the removal of fine particles present in the raw water for the production of drinking water. These inorganic flocculants, however, have potential hazard of high residual aluminium ions in the treated waters, which is known to be one of the reasons of alzheimer's disease. Inorganic flocculants alone are sometimes incapable of treating water when there are excessive turbidity in the raw water sources due to flooding. A polyamine type polymeric flocculant has long been used to treat raw water in the drinking water production in the European countries and United State of America. The optimum reaction conditions such as mole ratio of epichlorohydrin(EPI) to dimethylamine(DMA), reaction temperature and time for each stage for the pilot scale preparation of polyamine from EPI-DMA was studied in this work. The variation of intrinsic viscosity and flocculating efficiency in the water treatment of the synthesized polyamines were evaluated. The residual materials after polymerization reaction were analyzed by gas chromatography to study the effect of variation of reaction conditions.

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Residues of Thiamphenicol in Blood of Cultured Olive Flounder and Black Rockfish Treated by Single Oral Administration (Thiamphenicol의 단일 경구투여에 따른 넙치와 조피볼락의 혈액내 잔류 분석)

  • JUNG, Sung-Hee;SEO, Jung-Soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.3
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    • pp.692-700
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    • 2016
  • This study was aimed at investigating the residual patterns of thiamphenicol (TP) in the cultured olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes schlegeli) following oral administration. TP concentration were detected by high performance liquid chromatography with UV detector. The recovery rates of TP in serums ranged 77.05~97.23% (olive flounder) and 89.96~97.11% (black rockfish) for the concentration of 0.1, 1.0, $10{\mu}g/mL$, respectively. After single administration of TP (100 mg/kg body weight) by oral route in olive flounder ($700{\pm}50g$, $23{\pm}1.5^{\circ}C$) and black rockfish ($500{\pm}30g$, $23{\pm}1.5^{\circ}C$), the concentration in the serum was determined at 1, 5, 10, 15, 24, 30, 50, 168, 264 and 432 h post-dose. Two-compartment model was applied to analyze in the pharmacokinetics of TP administered to the fishes. In the serum of olive flounder, TP was detected on 10 and 15 hours after treatment were $10.08{\mu}g/mL$ and $10.06{\mu}g/mL$ as maximum level, respectively. In the serum of black rockfish, TP was detected on 15 hours after treatment were $8.88{\mu}g/mL$ as maximum level. Concentrations of TP to the fishes were not measurable at 432 hours (18 days) after treatment in all samples. Similar residual patterns of TP were revealed between the fishes. These results are helpful for estimating withdrawal time of TP which has been already in use for farmed fish treatment.

Substitution Effect of Fossil Fuel using Biomass produced by Forest Treatment (산림 사업지 바이오매스를 이용한 화석연료 대체효과)

  • Son, Yeong Mo;Lee, Kyeong Hak;Seo, Jeong Ho;Kwon, Soon Duk
    • Journal of Korean Society of Forest Science
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    • v.96 no.6
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    • pp.639-643
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    • 2007
  • The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.