Pinus densiflora is a fixed-growth coniferous species that elongates its shoot once a year and finishes growing in early summer. However, it may produce additional shoots in the same year in response to external stimuli, called abnormal shoot growth. This study investigated the effects of open-field summer warming and drought on the abnormal shoot growth of P. densiflora seedlings. In March 2022, two factorial combinations were constructed, including two temperature treatments (control and 4°C increase) and two precipitation treatments (control and drought), with five replicates for each combination. The temperature treatment was performed for 87 days from May 14 to August 8, 2022, and the precipitation treatment was performed for 33 days from May 14 to June 15, blocking 100% of the ambient rainfall. The abnormal shoot occurrence rate and leaf unfolding stages were measured in November, and the shoot and root collar diameter growth rates were calculated by comparing the seedling height and root collar diameter measured in August (after the cessation of treatment) and October (after the end of growing period) with the initial values (i.e., May 2022). The abnormal shoot occurrence rate significantly increased under the warming treatment, showing a 410.6% increase in the warming plots (38.4%) compared to the control plots (7.5%). There was no significant difference in the shoot and root collar diameter growth rate regarding warming and drought treatments. Abnormal shoots may have been affected by high temperatures by inducing early transition to the next ontogenetic stage.

Ice accumulation on Aluminum Conductor Steel Reinforced(ACSR) cable during winter is an important matter in terms of safety, economy, and efficient power supply. In this work, the ice adhesion strengths of ACSR cable oxidized during different periods(7 years oxidized and 15 years oxidized) are evaluated. At first, a plate type dry oxidation standard specimen, whose surface characteristics are similar to those of ACSR cable, is prepared. Dry oxidation standard specimens are heat-treated at 500 °C for 20, 60, and 120 minutes in order to obtain different degrees of oxidation. After the dry oxidation, surface properties are analyzed using contact angle analyzer, atomic force microscopy, spectrophotometer, and gloss meter. The ice adhesion strengths are measured using an ice pull-off tester. Correlations between the surface properties and the ice adhesion strength are obtained through a regression analysis indicating a Boltzmann equation. It is revealed that the ice adhesion strength of 15- year oxidized ACSR cable is approximately 8 times higher than that of ACSR-bare.

The use of continuous welded rail is increasing because of its many advantages, including vibration reduction, enhanced driving stability, and maintenance cost savings. In this work, two different types of continuous welded rails were examined to determine the influence of repeated wheel-rail contact on the crystal structure, microstructure and mechanical properties of the rails. The crystal structure was determined by x-ray diffraction, and the microstructure was examined using optical microscopy and scanning electron microscopy. Tensile and microhardness tests were conducted to examine the mechanical behaviors of prepared specimens taken from different positions in the cross section of both newly manufactured rail and worn rail. Analysis revealed that both the new and worn rail had a mixed microstructure consisting of ferrite and pearlite. The specimens from the top position of each rail exhibited decreased lamella spacing of the pearlite and increased yield strength, ultimate tensile strength and hardness, as compared with those from other positions of the rail. It is thought that the enhanced mechanical property on the top position of the worn rail might be explained by a mixed effect resulting from a directional microstructure, the decreased lamella spacing of pearlite, and work hardening by the repeated wheel-rail contact stress.

천연식물소재 및 한약재 추출제재인 식물추출 혼합제재가 인체내에서 니코틴 분해능에 미치는 영향을 FRCFR5 세포주, Xenopus oocyte, 임상 실험을 통하여 검토하였다. 본 실험은 체내에 잔존하는 니코틴이 식물추출 혼합 제재에 의해 무독한 대사산물인 코티닌으로 분해량이 증가되고 동시에 NNK, NNN, NNA 등과 같은 폐암 유발물질인 니트로사민 유도체 생성 경로가 억제될 것이라는 가정을 전제로 실험을 수행하였다. 본 실험 결과에서 볼 수 있듯이 식물추출 혼합 제재에는 니코틴에서 코티닌으로 전환시키는 대사 활성물질이 함유되어 있다는 사실을 알 수 있으나, 실제로 어떤 유효성분들이 관여하는지 그리고 정확한 작용 기작을 규명하기 위해서는 더 많은 분석 및 생화학적 연구가 앞으로수행되어야 할 것이다. 간세포에서 유래된 FRCFR5 세포주 실험 결과, 니코틴과 식물추출 혼합 제재가 첨가된 배지에서 니코틴과 물을 첨가한 배지보다 니코틴에서 코티닌으로 전환능력이 약 2∼3배 높게 나타났으며, 이러한 결과는 Xenopus oocyte에 직접 주사한 경우와 거의 비슷한 양상을 보였다. 임상실험 결과 식물추출 혼합 제재 음료를 음용하고 담배를 피운 실험군이 물을 음용하고 담배를 피운 대조군에 비해 약 2배 정도 높은 코티닌 함량을 나타내었다. 이는 실험군의 소변 중에 계속적으로 다량의 코티닌이 배출되는 것을 의미하며, 식물추출 혼합 제재 섭취시 체내에 존재하는 니코틴이 코티닌으로 지속적이면서 효과적으로 전환되는 것을 말한다. 이상의 생체 내·외 실험에서 알 수 있듯이 식물추출혼합물은 니코틴에서 코티닌 생성을 약 2배정도 증가 시키는 것을 알 수 있었다.