• 상하수도학회지
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• 제12권2호
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• pp.115-126
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• 1998

In use of anaerobic bioconversion shellfish wastes present special problems, since the chitinous structures in the shell faction degrade very slowly in an anaerobic environment. Enzymatic pretreatment method was evaluated for improving the anaerobic bioconversion potential of blue crab processing wastes. An enzymatic pretreatment using chitinase enhanced the ultimate methane yield and biodergradation rate constant for total crab solid wastes by 15% and 19% respectively, above those of the untreated wastes. When the enzymatic pretreatment applied to the shell fraction alone, it resulted in increase of 34% in the ultimate methane yield and 38% in the reaction rate. The results indicate that anaerobic bioconversion of these wastes is technically feasible and enzymatic pretreatment will improve the efficiency of the process.

• Environmental Engineering Research
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• 제16권1호
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• pp.11-18
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• 2011

The aim of this research was to introduce a new rapid analysis method (heating of the multi-layer silica gel column/alumina column) for polychlorinated biphenyls in insulating oils, and to compare our new method with the analytical method currently used in Korea. The entire pretreatment procedure was completed within 2 hr, using about only 20 mL of solvents via our rapid analytical method. Furthermore, the pretreatment procedure can always be uniformly performed, regardless of oil type (JIS 1~JIS 7 and KS 1~KS 7). The recovery rates were more than 89%, with relative standard deviations below 6.0%. In conclusion, this rapid analytical method could reduce the pretreatment time and solvent usage by 1/10 and between 1/25 and 1/50, respectively, compared to analytical method currently used in Korea.

• 한국산업보건학회지
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• 제9권2호
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• pp.135-144
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• 1999

The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.

• 유기물자원화
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• 제31권1호
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• pp.27-34
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• 2023

본 연구에서는 버섯 폐배지의 혐기성소화 효율 향상을 위해 수열전처리를 실시하고, 리그노셀룰로오스계 물질의 고온 가수분해 과정에서 생성될 수 있는 중간산물이 기질의 생분해도와 바이오가스 전환 효율에 미치는 영향을 함께 판단하였다. 수열전처리 온도의 범위를 150, 180, 210℃로 설정하였으며, 모든 수열전처리 온도에서 기질의 가용화율이 향상되는 결과를 확인할 수 있었다. 추가적으로, 150℃로 버섯 폐배지를 전처리한 경우에는 혐기성소화 효율에 영향을 미칠 수 있는 C/N 비가 개선되는 효과를 함께 확인하였다. 다만 전처리 온도가 180, 210℃인 경우에는 오히려 150℃로 전처리를 수행한 경우에 비해 메탄 생성량이 저하되는 경향을 보였는데, 이는 리그노셀룰로오스 물질의 중간분해 산물인 퓨란유도체의 형성으로 인해 메탄생성균이 영향을 받은 것으로 판단된다. 결국, 수열전처리를 통해 리그노셀룰로오스계 바이오매스의 가용화율 향상을 통한 메탄 생성 향상을 기대할 수 있으나, 혐기성소화 효율을 저해할 수 있는 중간산물이 생성되지 않는 적정 전처리 온도의 확인과 적용이 중요할 것으로 판단된다.

• Carbon letters
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• 제12권3호
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• pp.167-170
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• 2011

Petroleum pitch-based activated carbons (ACs) were obtained in this work from a combination of pretreatment with different amounts of potassium permanganate ($KMnO_4$) and chemical activation with potassium hydroxide. The surface characteristics of the pitch after the $KMnO_4$ pretreatment were characterized by means of Fourier transform infrared spectroscopy (FT-IR). The structural characteristics of the pitch after the $KMnO_4$ pretreatment were determined by means of X-ray diffraction. The influence of the $KMnO_4$ treatment on the textural properties of the petroleum pitch-based ACs was investigated by means of $N_2$/77K adsorption isotherms. The investigation also involved the use of the Brunauer-Emmett-Teller equation and the Dubinin-Radushkevich method. The FT-IR results show that the pretreatment promotes the formation of surface oxygen functionalities and leads to an increase of the interplanar distance ($d_{002}$) of the functional groups induced between carbon layers. Moreover, the specific surface area of the pitch-based ACs increases in proportion to the amount of $KMnO_4$ pretreatment and reaches its highest value of 2334 $m^2$/g with 2 g of $KMnO_4$ because the surface oxygen groups of the pitch act as an active site during chemical activation.

• 분석과학
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• 제22권2호
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• pp.136-140
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• 2009

AMS (Accelerator Mass Spectrometry)를 이용한 방사성 탄소연대측정법으로 퇴적물 및 토양시료를 측정하기 위한 화학적 전처리법의 유기물 회수율을 개선하기 위하여, 초음파를 이용한 방법을 개발하였다. 일반적으로 널리 쓰이는 부식산 전처리법 중 단계 마다 사용되는 스터링법을 대신하여, 초음파 (ultrasonic)를 사용하고 초음파 출력, 반응 온도, 반응 시간 등 실험조건을 결정하였다. 유기물 함유량이 적어 연대측정이 불가능했던 시료에 대한 탄소 회수율이 6배 향상되어 다량의 시료를 얻기 힘든 연대측정분야에서는 매우 중요한 개선이 이루어졌다. 또한 동일 시료에 대해 초음파법과 스터링법으로 처리한 시료의 연대측정결과를 비교하여 초음파법이 회수율 향상 이외에는 연대측정결과에 영향을 미치지 않음을 확인하여 실용성이 있음을 증명하였다.

• 한국산림과학회지
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• 제78권1호
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• pp.26-29
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• 1989

수목종자(樹木種子)의 포장발아율(圃場發芽率)을 높이는 종자전처리방법(種子前處理方法)을 찾기 위하여, 황벽나무를 비롯한 5수종의 종자(種子)에 대해 종자전처리(種子前處理)에 따른 포장발아율(圃場發芽率)을 조사(調査) 비교(比較)하여 얻은 주요결과(主要結果)는 다음과 같다. 1. 탱자 및 물푸레나무의 포장발아율(圃場發芽率)은 종자전처리간(種子前處理間)에 1% 유의수준(有意水準)에서, 황벽나무는 5% 유의수준(有意水準)에서 각각 통계적(統計的) 유의성(有意性)이 인정(認定)되었으며, 이들 수종(樹種)은 노천이장처리(露天理藏處理)(166 일간(日間)에서 포장발아율(圃場發芽率)이 가장 높았다. 2. 모과나무의 포장발아율(圃場發芽率)은 종자전처리간(種子前處理間)에 1% 유의수준(有意水準)에서 통계적(統計的) 유의성(有意性)이 인정(認定)되었으며, 냉습적처리(冷濕積處理)(110 일간(日間))에서 가장 높았다. 3. 꾸지뽕의 포장발아율(圃場發芽率)은 종자전처리간(種子前處理間)에 5% 유의수준(有意水準)에서 통계적(統計的) 유의성(有意性)이 인정(認定)되지 않았다.

• Journal of Gastric Cancer
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• 제21권2호
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• pp.155-168
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• 2021

Purpose: Previous studies have demonstrated the usefulness of the controlling nutritional status (CONUT) score in nutritional assessment and survival prediction of patients with various malignancies. However, its value in advanced gastric cancer (GC) treated with neoadjuvant chemotherapy and curative gastrectomy remains unclear. Materials and Methods: The CONUT score at different time points (pretreatment, preoperative, and postoperative) of 272 patients with advanced GC were retrospectively calculated from August 2004 to October 2015. The χ² test or Mann-Whitney U test was used to estimate the relationships between the CONUT score and clinical characteristics as well as short-term outcomes, while the Cox proportional hazard model was used to estimate long-term outcomes. Survival curves were estimated by using the Kaplan-Meier method and log-rank test. Results: The proportion of moderate or severe malnutrition among all patients was not significantly changed from pretreatment (13.5%) to pre-operation (11.7%) but increased dramatically postoperatively (47.5%). The pretreatment CONUT-high score (≥4) was significantly associated with older age (P=0.010), deeper tumor invasion (P=0.025), and lower pathological complete response rate (CONUT-high vs. CONUT-low: 1.2% vs. 6.6%, P=0.107). Pretreatment CONUT-high score patients had worse progression-free survival (P=0.032) and overall survival (OS) (P=0.026). Adjusted for pathologic node status, the pretreatment CONUT-high score was strongly associated with worse OS in pathologic node-positive patients (P=0.039). Conclusions: The pretreatment CONUT score might be a straightforward index for immune-nutritional status assessment, while being a reliable prognostic indicator in patients with advanced GC receiving neoadjuvant chemotherapy and curative gastrectomy. Moreover, lower pretreatment CONUT scores might indicate better chemotherapy responses.

• 한국축산식품학회지
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• 제41권2호
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• pp.335-342
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• 2021

Vitamin B12 deficiency may lead to serious health issues in both infants and adults. A simple analytical method involving sample pretreatment with enzyme, followed by cyanide addition under acidic conditions; separation on an immunoaffinity column; and high-performance liquid chromatography (HPLC) was developed for the rapid detection and quantitation of vitamin B12 in powdered milk. Detection limit and powdered milk recovery were determined by quantitative analysis. The limits of detection and quantitation were 2.71 and 8.21 ㎍/L, respectively. Relative standard deviations of the intra-day and inter-day precisions varied in the ranges of 0.98%-5.31% and 2.16%-3.90%, respectively. Recovery of the analysis varied in the range of 83.41%-106.57%, suggesting that the values were acceptable. Additionally, vitamin B12 content and recovery in SRM 1849a were 54.10 ㎍/kg and 112.24%, respectively. Our results suggested that the analytical method, including the sample pretreatment step, was valid. This analytical method can be implemented in many laboratory-scale experiments that seek to save time and labor. Therefore, this study shows that immunoaffinity-HPLC/ultraviolet is an acceptable technique for constructing a reliable database on vitamin B12 in powdered milk containing starch as well as protein and/or fat in high amounts.

• KSBB Journal
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• 제29권4호
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• pp.297-302
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• 2014

The autoclaving assisted by an irradiation pretreatment method was developed without toxic chemicals to produce fermentable sugars for their conversion to bioethanol. In the first step, electron beam irradiation (EBI) of rice straw was performed at various doses. The electron beam-irradiated rice straw was then autoclaved with DI water at $120^{\circ}C$ for 1 h. A total sugar yield of 81% was obtained from 300 kGy electron beam-irradiated rice straw after 72 h of enzymatic hydrolysis by Cellulase 1.5L (70 FPU/mL) and Novozyme-188 (40 CbU/mL). Also, the removal of hemicellulose and lignin was 32.0% and 32.5%, respectively. This result indicates that the environmentally-friendly pretreatment method of rice straw by an electron beam irradiation could be applied for bioethanol production in plant.