본 연구는 학교운동장 굴취 토양(WSSPG)을 모래와 혼합 후 토양개량효과를 조사하여 잔디재배토양으로서 적합성을 조사 함으로써 천연잔디 운동장 조성 시 활용가능성을 평가하기 위해 수행되었다. 처리구는 대조구(모래 100%), WSSPG 5% 처리구 (WSSPG 5% + 모래 95%), WSSPG 10% 처리구(WSSPG 10% + 모래 90%), WSSPG 15% 처리구(WSSPG 15% + 모래 85%), WSSPG 20% 처리구(WSSPG 20% + 모래 80%), WSSPG 30% 처리구(WSSPG 30% + 모래 70%), WSSPG 40% 처리구 (WSSPG 40% + 모래 60%)로 설정하였다. WSSPG 처리 후 pH, EC, CEC등은 증대되었고, 모세관 공극, 비모세관 공극, 총공극 및 포화수리전도도는 감소하였다. WSSPG의 처리량과 토양인자간 조사에서 pH, EC, CEC 및 용적밀도는 정의 상관성 을 나타냈고, 모세관 공극, 비모세관 공극, 총공극 및 포화수리 전도도는 부의 상관성을 나타냈다. 상기 결과를 종합할 때, WSSPG는 토양 화학성을 개선하나 물리성 개선은 미미하였고, WSSPG 처리 후 토양의 물리화학성을 고려할 때, WSSPG의 최대 처리량은 약 5% 정도로 판단되었다.

In this study, we analyzed the structural and mechanical properties of aluminum foams fabricated using aluminum powders of varying sizes and mixtures. The effects of sintering and pore structure at each size on the integrity and mechanical properties of the foams were investigated. Structural characteristics were examined using scanning electron microscopy and micro–computed tomography, while mechanical properties were evaluated through compression testing. The experimental results demonstrated that smaller powder sizes improved foam integrity, reduced porosity and pore size, and resulted in thinner cell walls. In combination, these effects increased compressive strength as the powder size decreased. The findings of this study contribute to the understanding and improvement of the mechanical properties of aluminum foams and highlight their potential for use in a wide range of applications.

This study was conducted to reset the withdrawal time (WT) for amoxicillin (AMX) in pigs as a part of positive list system (PLS) program introduction. Forty-two healthy pigs were orally administered with AMX at doses of 10 mg/kg body weight (BW) (AMX-1, n=20) and 20 mg/kg BW (AMX-2, n=20), twice daily for 5 days, respectively. After the treatment, tissue samples were collected from four pigs at 1, 3, 5, 7 and 14 days post-administration, respectively. Based on a previously established analysis method, residual AMX concentrations in pig tissues were determined using LC-MS/MS. In both AMX-1 and AMX-2 groups, AMX levels in all tissues except fat was below the limit of quantification (LOQ) at one day after the final administration. According to the European Medicines Agency’s guideline on determination of withdrawal periods, the withdrawal periods for AMX-1 and AMX-2 in fat tissue were established as 0 and 2 days, respectively. In conclusion, the estimated WT of AMX in edible tissues of pigs is shorter than the current WT recommendation of 5 days for AMX.