PURPOSES : This study aims to provide quantitative profile values for the objective evaluation of concrete surface profile (CSP) grades in concrete structures. The main aims are to quantify the CSP grade required for concrete surface pretreatment and proposing a more suitable CSP grade for structural maintenance. METHODS : Initially, the challenges in measuring concrete surface profiles were outlined by analyzing pretreatment work and profile samples of concrete pavements. Theoretical foundations for quantifying concrete surface roughness were established, and regression models including linear regression, cubic regression, and log regression were selected. Additionally, the interquartile range anomaly removal technique was employed to preprocess the data for regression modeling. RESULTS : Concrete CSP profiles were measured through indoor tests, and the measured data were quantified. Linear regression, cubic regression, and log regression models were applied to each CSP grade for comparative analysis of the results. Furthermore, comparative studies were conducted through adhesion strength tests based on the CSP grade. CONCLUSIONS : Our results are expected to establish objective standards for the pretreatment stage of concrete repair and reinforcement. The derived reference values can inform standards for the restoration and reinforcement of concrete structures, thereby contributing to performance improvement. Moreover, our results may serve as primary data for the repair and reinforcement of various concrete structures such as airports, bridges, highways, and buildings.

We established pretreatment method of solidified cement ion-exchange resin samples generated before 2003 in nuclear power plants for measurement of non-volatile radionuclide activity. A microwave digestion system (MDS) with mixed acid (HCl-HNO3-HF-H2O2) was used to dissolve cement and to desorb non-volatile elements such as Ce, Co, Cs, Fe, Nb, Ni, Re, Sr and U from mixed ion-exchange resin. The content of Ce, Co, Fe, Nb, Ni, Re, Sr, U and Cs after pretreatment of cement plus mixed ion-exchange resin was measured by ICP-AES and ICP-MS, respectively. As iron and strontium are also present in cement, their content after dissolving a certain amount of cement was measured by ICP-AES. All elements except Nb were quantitatively recovered. Especially since the Nb recovery was low at 72.0±2.5%, the MDS following addition of the mixed acid to the resin was operated once more for desorbing Nb from it. Finally the recovery of Nb was over 95%. This sample pretreatment method will be applied to solidified cement ion-exchange resin samples generated in nuclear power plants for assessment of radionuclide inventory.

콩나물과 같은 고섬유질 야채류의 동결건조 후 조직감 개선을 위한 전처리 방법을 연구한 결과 예비 열처리와 하 이드로콜로이드 및 당 용액 침지를 조합, 적용시 건조 후 조직수축이 개선되고 복원력이 향상 되었다. 100oC의 0.5%(w/w) 염화나트륨 용액에서 2분간 예비열처리한 다음 0.5% 알긴산나트륨과 1.0% 슈크로오스을 첨가한 상온의 용액에서 60분 교반 침지시 열수 복원 후 전반맛, 식감, 외관 등의 관능 품질이 100oC 물에서 1분간 예비 열처리 한 시료 보다 1.6점이나 더 우수하여 큰 개선 효과를 나타 내었으며, 기계적 측정치에서는 전처리 콩나물 줄기의 경 도값이 0.27 kgf로 가정 조리식의 0.26 kgf와 거의 근접한 수치를 보였다. 이러한 전처리 공정을 대파, 쑥갓, 고사리 등의 다양한 고섬유질 동결건조 야채류에 적용시 관능품질 및 복원력이 향상될 것으로 기대되므로 산업화에서 적용 가능성이 높다고 할 수 있다.

시판중인 여섯 가지 종류의 코이어 자루배지에 세 가지 전처리 방법을 실시하고, 처리 과정에서 생성되는 배액을 분석함으로써 경제적이며 간단하게 칼륨과 나트륨을 제거할 수 있는 전처리 방법을 구명하고자 2차에 걸쳐 실험을 수행했다. 1차 실험에서는 시판중인 코이어 자루 중에서 전처리가 되었고, 농가에 많이 보급된 6가지 배지를 선정하여, 7일간 물로 씻는 처리(W7S0), 물로 3일간 씻고 배양액으로 4일간 씻는 처리(W4S3), 배양액으로 7일간 씻는 처리(W0S7)의 세 가지 전처리를 했다. 2차 실험에서는 Bio Grow와 coco Mix 배지를 대상으로 1차 실험과 동일한 방법으로 재현성을 확인했다. 실험결과 pH의 안정화에 좋은 전처리 방법은 W4S3 처리와 W0S7 처리였다. EC는 세 처리 모두에서 4일차가 되면 공급 EC와 같은 1.0 이하로 안정되었다. 배액의 이온은 W7S0에서는 처리 3~4일 이후에 안정화 되지만 대부분의 이온들이 용탈되어 Ca와 Mg의 부족이 발생했고, 4일 이상을 씻는 것은 물의 낭비로 판단되었다. W0S7에서는 배지의 안정화는 W4S3 처리와 유사했으나 배양액으로 7일간 씻어주는 것은 경제적으로 손실인 것으로 사료된다. 두 가지 배지를 사용한 재현성 실험에서도 비슷한 결과를 보였다. 따라서 농가에서 사용하기에 가장 간단하고 경제적인 전처리 방법은 물로 3일간 씻어준 후 배양액으로 1일간 포수시킨 후에 정식하는 방법으로 사료된다.

This study was attempt to improve the quality of rapid- and low salt-fermented liquefaction of sardine (Sardinops melanoslicta). Effect of pretreatment methods such as water adding, heating, and intermittent NaCl adding on fermented liquefaction of chopped whole sardine were investigated. The divisions of the experimental samples by pretreatment methods were as follows; Sample A (water adding and heating): chopped whole sardine adding 20% water and then adding 3 and 5% NaCl consecutively at the intervals of 3 and 6 hrs during heating for 9 hrs at 50℃ and then fermented at 33℃ for 90 days. Sample B (preheating): chopped whole sardine with 8% NaCl and heating at 50℃ for 9 hrs and then fermented at 33℃ for 90 days. Sample C (control): neither pretreatment methods of water adding nor preheating on chopped whole sardine with 13% NaCl and then fermented at 33℃ for 90 days. Comparison of the appropriate fermentation period, yield of hydrolysate, chemical composition of fermented liquefied products were carried out. The highest content of amino nitrogen appeared at 60 days in the sample A, 75 days in the sample B, and 90 days in the sample C during the fermentation period. The appropriate fermentation period of the sample A was shorten 15 days than the sample B and 30 days than the sample C in the processing of sardine. The product A was lower NaCl (8.5%) and lower histamine content (25mg/100g) than the sample B and C. Possibly, three kinds of pretreatment methods such as water adding, heating, and intermittent NaCl adding, might be recommend as the processing of rapid- and low salt-fermented liquefaction product of chopped whole sardine.

건시의 품질향상을 위하여 국내 유명산지의 건시를 시료로 하여 건시의 제조시험과 품질평가에 관한 기초자료로서 그 품질요소를 조사하였다. 건시의 수분함량은 30-36%였으며, 탄닌함량은 0-20%로 무처리구는 CO2와 alcohol 처리구보다 그 함량이 높게 나타났다. 전당함량은 55-60%였고 그 구성은 glucose와 fructose로 구성되어 있었다. 열풍건조에 의한 건시의 제조는 천일건조보다 그 품질이 전반적으로 우수하였으며 특히 slice 한 제품의 품질은 전과의 경우보다 비교적 우수하였다.

In this study, the COSLIF method for the pretreatment of lignocellulose biomass was employed to overcome the disadvantages of the conventional DA method. When lignocellulose biomass was hydrolyzed by the COSLIF method, dried rice straw produced glucose corresponding to 60.1%, while herbal medicine waste was found in 25.2%. The optimum conditions of the COSLIF method for the pretreatment of biomass were as follows: 84% phosphoric acid, 50oC, and 45 min. The COSLIF method for corn stover showed more lignin-removal characteristics than the DA method. Glucan digestibility in the COSLIF method at a high enzyme dosage was found to be 97% and at least 90% in 12 h and 24 h, respectively, while in the DA method, it was 84% in 72 h. In addition, at a low enzyme dosage, glucan digestibility was 93% in 24 h in the COSLIF method and 60% in 72 h in the DA method. This demonstrates that the COSLIF method is more efficient than the DA method.

This study was conducted to improve the analytical method of siloxanes in biogas. Methanol and hexane were tested as absorption solvents of the impinger absorption method, and also the hexane extraction for pretreatment of sample was evaluated. Manufactured gas contained siloxanes of 50 ppm was completely absorbed by the methanol impinger absorption. The absorption efficiency of biogas containing only 2 ppm, however, was maximum 84%. As the condensate on the first impinger increased, the absorption rate of methanol was decreased. The hexane extraction method of the sample was considered to proper the method of moisture removal. The hexane extraction result showed the high recovery factor and the low relative standard deviation. It is suggested that the suitable choice of solvent and pretreatment is required, as the analysis result of siloxane sample may be differentiated depending on the type of biogas or the sampling point.

Eleuthero(Eleutherococcus senticosus Maxim.) cortex is well known as a herb medicine for tonic. This study was performed to improve the quality of dried E. senticosus cortex. Investigation of quality factor and contents of efficient compounds under different steaming times and drying methods were performed to determine the proper processing and drying conditions of Eleuthero cortex harvested on March in annual stems. The proper steaming time for peeling bark to make high quality Eleuthero cortex took less than 20 mins. Eleutheroside B and E contents among drying methods were significantly different at 5% level DMRT. The 50℃ heat drying was the most advisable condition for drying, when drying and keeping contents of effective compounds.

Hydrogen gas is used as a fuel for the proton exchange membrane fuel cell (PEMFC). Trace amount of carbon monoxide present in the reformate H₂ gas can poison the anode of the PEMFC. Therefore, preferential oxidation (PROX) of CO is essential for reducing the concentration of CO from a hydrogen-rich reformate gas. In this study, conventional Pt/Al₂O₃catalyst was prepared for the preferential oxidation of CO. The effects of catalyst preparation method, additive, and hydrogen on the performances of PROX reaction of CO were investigated. Water treatment and addition of Ce enhanced catalytic activity of the Pt/Al₂O₃ catalyst at low temperature below 100℃.