• Computers and Concrete
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• 제29권4호
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• pp.263-278
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• 2022

Limestone calcined clay cement (LC³) is a low carbon alternative to conventional cement. Literature shows that using limestone and calcined clay in LC³ increases the thermal degradation of LC³ pastes and can increase the magnitude of fire risk in LC³ concrete structures. Higher thermal degradation of LC³ paste prompts this study toward understanding the fire performance of LC³ concrete and the associated magnitude of fire risk. For fire performance, concrete prepared using ordinary Portland cement (OPC), pozzolanic Portland cement (PPC) and LC³ were exposed to 16 scenarios of different elevated temperatures (400℃, 600℃, 800℃, and 1000℃) for different durations (0.5 h, 1 h, 2 h, and 4 h). After exposure to elevated temperatures, mass loss, residual ultrasonic pulse velocity (rUPV) and residual compressive strength (rCS) were measured as the residual properties of concrete. XRD (X-ray diffraction), TGA (thermogravimetric analysis) and three-factor ANOVA (analysis of variance) are also used to compare the fire performance of LC³ with OPC and PPC. Monte Carlo simulation has been used to assess the magnitude of fire risk in LC³ structures and devise recommendations for the robust application of LC³. Results show that LC³ concrete has weaker fire performance, with average rCS being 11.06% and 1.73% lower than OPC and PPC concrete. Analysis of 106 fire scenarios, in Indian context, shows lower rCS and higher failure probability for LC³ (95.05%, 2.22%) than OPC (98.16%, 0.22%) and PPC (96.48%, 1.14%). For robust application, either LC³ can be restricted to residential and educational structures (failure probability <0.5%), or LC³ can have reserve strength (factor of safety >1.08).

• 한국초지조사료학회지
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• 제38권3호
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• pp.156-164
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• 2018

Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.

• 한국식생활문화학회지
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• 제35권3호
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• pp.285-293
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• 2020

This study was conducted to monitor the residual pesticides on red pepper powder produced in five regions, which are the major producers of red pepper in Korea, such as Ham-pyeong, An-dong, Yeong-yang, Yeong-gwang, and Cheongyang from 2015 to 2016. Residual pesticides were detected on all samples. Among the 286 pesticides tested, 58 pesticides were detected, with the most frequently detected being chlorfenapyr (93.7%). Twelve types of pesticides (chlorfenapyr, cypermethrin, chlorpyrifos, pyraclostrobin, cyhalothrin, tebuconazole, bifenthrin, deltamethrin, fenvalerate, lufenuron, azoxystrobin, and indoxacarb) were detected in all regions, and 14 types of pesticides were used only in certain regions. An analysis of the residual pesticides showed that none of the pesticides detected exceeded the MRL (Maximum Residue Limits). The Positive List System (PLS) requirements were applied to eight pesticides that had no set MRLs. 0.01 mg/kg (PLS requirements) was exceeded in 12 cases. A comparison of the estimated daily intake (EDI) of pesticides with the acceptable daily intake (ADI) to access their risk revealed %ADI values of 0.001-0.756. Carbofuran showed the highest (0.756%), but most pesticides were below 1%. The results show that residual pesticides in red pepper powder are at safe levels.

• 한국환경과학회지
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• 제16권11호
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• pp.1287-1293
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• 2007

To obtain the risk assessment of hazardous materials in Rehmanniae Radix Preparata, the residual pesticides and heavy metals in samples on the Korea and China are surveyed. Group I ($BHC-{\delta}$, $BHC-{\beta}$, Fenitrothion, Penthoate, Endosulfan-${\alpha}$, Dieldrin, Endosulfan-${\beta}$ and Endosulfan-sulfate), Group II (BHC-${\gamma}$, Aldrin, DDD, DDT-p,p Permethrin and Fenvalerate), Group III(BHC-${\alpha}$, Chlorpyrifos, Tolyfluanid, Captan and DDT-o,p) and Group IV(Quintozene, Vinclozolin, DDE and Chlorfenapyr) could analysed on gas chromatography-ECD for evaluation of residual pesticides. Qualified detection concentration on the GC-ECD are $0.45 ng/g{\sim}2.50 ng/g$. Group I, Group II, Group III and Group IV are not detected in Rehmanniae Radix Preparata on the Korea and China. Concentration of As, Cd and Pb in Rehmanniae Radix Preparata. on the Korea are 3.06%, 7.00% and 5.78% for Korea Food & Drug Administration(KFDA). Concentration of As, Cd and Pb in Rehmanniae Radix Preparata. on the China are 5.16%, 5.33% and 6.50% for Korea Food & Drug Administration(KFDA). The hazardous materials in Rehmanniae Radix Preparata on the Korea and China were verified the safety of the residual heavy metals and pesticides compare with Korea Food & Drug Administration (KFDA) advisory level.

• 한국생산제조학회지
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• 제9권3호
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• pp.76-82
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• 2000

It is well known that during the oxygen cutting process residual thermal stresses are produced in weldment. The local non-uniform heating and subsequent cooling which takes place during any welding process causes complex thermal strains and stresses to finally lead to residual stresses exceed to the yield stress. High tensile stresses combined with applied structural load in the region near the welded joint can given rise to distortion brittle fracture change of the fatigue strength and stress corrosion cracking. The appropriate treatment of the welded component which reduces the peak of he welding residual stresses is believed to lower risk of the fracture during the service of the structure. In this study the impact loading in oxygen cutting frame was applied to reduce the residual stress. After applying the impact loading redistribution of resid-ual stress was measured by cutting method and the effect of fatigue was tested.

• 농약과학회지
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• 제15권1호
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• pp.28-35
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• 2011

안산 및 수원시에서 유통 중인 다류 19품목(감잎차, 국화차, 녹차, 라벤더차, 로즈마리차, 민들레차, 보이차, 뽕잎차, 수국차, 자스민차, 나미향차(찹쌀차), 메밀차, 쑥차, 연화차, 오룡차, 용정차, 장미차, 철관음차, 화과차)을 대상으로 218종의 농약 잔류실태를 조사하였다. 조사대상 65건 중 19건에서 15종(bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon, triazophos)의 농약이 검출돼 23.1%의 검출률을 나타냈다. 검출된 농약의 잔류량은 0.01~1.24 mg/kg으로 대부분 잔류허용기준 이하로 나타났으나 보이차(2006 년산) 1건에서 bifenthrin이 기준치(0.3 mg/kg)를 초과한 것으로 나타났다. 검출된 농약 15종에 대한 위해도를 평가한 결과 EDI/ADI 값은 0.0001~0.0844%로 나타나 다류에 존재하는 잔류농약은 안전한 수준인 것으로 평가되었다.

• 한국환경농학회지
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• 제41권2호
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• pp.95-100
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• 2022

BACKGROUND: This study was aimed to determine characteristics of residues of the soil-treated boscalid and pyraclostrobin within Hylomecon vernalis and to evaluate the risks from intake of the residual pesticides in the crop. METHODS AND RESULTS: The pesticides were treated to soils at two different concentrations, and the plant samples were collected 57 days after seeding. The samples were extracted using the QuEChERS extraction kit (MgSO₄ 4 g, NaCl 1 g). The quantitative methods for boscalid and pyraclostrobin were validated using linearity, recovery, and CV (coefficient of variation). Risk assessment of the pesticides was performed using Korea national nutrition statistics 2019. CONCLUSION(S): The residual levels of boscalid were 0.02-0.05 mg/kg (for the treatment at 6 Kg/10a) and 0.05-0.08 mg/kg (for the treatment at 12 Kg/10a), respectively. The residual concentrations of pyraclostrobin were below the LOQ. The amounts of pesticides were less than Maximum Residue Limits specified by the Korean Ministry of Food and Drug Safety. The maximum hazard indices of boscalid in chwinamul and amaranth for consumers were 0.0075% and 0.1525%, respectively, and it indicates that the risk of the pesticides from the crop is considered to be low.

• 대한의용생체공학회:의공학회지
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• 제44권1호
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• pp.1-10
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• 2023

With the announcement of MEDICAL DEVICE REGULATION 2017/745 (MDR) on April 5 2017, medical device manufacturers shall apply ISO 14971:2019 (3^rd) revised in December 2019. However, there is not much related information and guidance available to medical device manufacturers, especially single use medical device. Risk management process basically follow 5 steps which are Risk Analysis, Risk Evaluation, Risk Control, Evaluation of overall residual risk and post-production activities. The purpose of this study is to provide a guidance of from risk analysis with Failure Mode and Effects Analysis (FMEA) table to overall residual risk evaluation for the single use medical device and to reflect it in a Periodic Safety Update Reports (PSUR) to satisfy with MDR requirements with single use medical device which are widely used and manufactured FDA class 2 or CE class IIb as examples. For this study, single use medical device manufacturer can adopt ISO 14971:2019 in accordance with MDR requirements and it can be extended to the PSUR. But there are still limitations to adopt to the all-single use medical device especially high class, private device and implantable device. So, Competent Authority (CA) shall publish more guidance for the single use medical device.

• 한국해양공학회지
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• 제35권3호
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• pp.203-215
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• 2021

Current industrial practices and approaches are simplified and do not describe the actual behavior of plated elements of offshore topside structures for safety design due to fires. Therefore, it is better to make up for the defective methods with integrated fire safety design methods based on fire resistance characteristics such as residual strength capacity. This study numerically investigates the residual strength of steel stiffened panels exposed to hydrocarbon jet fire. A series of nonlinear finite element analyses (FEAs) were carried out with varying probabilistic selected exposures in terms of the jet fire location, side, area, and duration. These were used to assess the effects of exposed fire on the residual strength of a steel stiffened panel on a ship-shaped offshore structure. A probabilistic approach with a feasible fire location was used to determine credible fire scenarios in association with thermal structural responses. Heat transfer analysis was performed to obtain the steel temperature, and then the residual strength was obtained for the credible fire scenarios under compressive axial loading using nonlinear FEA code. The results were used to derive closed-form expressions to predict the residual strength of steel stiffened panels with various exposure to jet fire characteristics. The results could be used to assess the sustainability of structures at risk of exposure to fire accidents in offshore installations.

• Clinical and Experimental Pediatrics
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• 제50권7호
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• pp.601-605
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• 2007

The cure rate of acute lymphoblastic leukemia (ALL) in children dramatically improved over past 5 decades from zero to about 80%. The main cause of improvement is owing to the development of chemotherapy by multicenter clinical trial of large study groups with the understanding of leukemia biology. Recently, pediatric ALL protocols were applied to the treatment of adolescent and even adult ALL patients. For nearly 30 years, clinical factors have been used to risk-stratify therapy for children with ALL, so that the most intensive therapies are reserved for those patients at the highest risk of relapse. The risk groups of ALL are divided as standard- (low- plus intermediate-), high- and very high-risk group according to the prognostic factors, and treatment results improved by this risk based treatment. The factors used to risk-stratify therapy include age, gender, presenting leukocyte count, immunophenotype, cytogenetic aberrations including ploidy and translocations, and initial response after 1 to 2 weeks of therapy. But treatment efficacy is the most important determinant and can abolish the clinical significance of most, if at all, prognostic factors. Today, in the era of intensive, multiagent regimens, there is increasing evidence that we have reached the limits of prognostic significance of currently applied clinical risk factors in childhood ALL. As the cure rate of ALL is about 80%, introducing new prognostic factors such as new molecular prognostic markers, new methods of assessment about minimal residual disease, and pharmacogenetic study, with the development of stem cell transplantation and molecular targeted therapy are needed to cure residual 20% of childhood ALL patients without short and long term complications.