This study quantitatively investigates the effects of internal cavity geometry on the structural safety of high-value aged trees using the finite element method (FEM). Virtual cavities were incorporated into the tree model, and stress responses were analyzed under an extreme wind load condition. The results show that internal cavities significantly increase stress concentration by reducing the effective load-bearing cross-section, with cavity location having a greater influence on structural stability than cavity size. Small cavities located near the outer region of the trunk caused a sharp increase in stress, whereas larger cavities positioned near the center had a limited effect. Structural vulnerability was concentrated in the lower trunk on the leeward side, where wind-induced bending moments are maximized. These findings highlight cavity location as a critical indicator for the safety assessment and management of high-value aged trees.

The experiment was conducted to determine the effects of nitrogen fertilizer levels on seed production of Italian ryegrass (Lolium multiflorum Lam.) in mountainous regions of Gangwon Province. The 'Green Call' variety of Italian ryegrass was sown in Pyeongchang, Gangwon in September 2021. The experiment consisted of three nitrogen application levels (100, 120, and 140 N kg/ha) and was arranged in a randomized complete block design with three replications. Harvest was carried out on June 28. The plant height was tallest in the 140 N kg/ha treatment, but the difference was not statistically significant. Lodging resistance, disease resistance and winter hardiness showed no significant differences among treatments, although severe lodging occurred in all plots. The average spike length was 54.77 cm, with no significant difference among treatments, while the number of seeds per spike was highest in the 100 N kg/ha treatment. Seed yield increased with higher nitrogen levels, with an average of 2,820 kg/ha (based on air-dry weight). The average dry matter content of seeds and straw was 56.70% and 38.80%, respectively, with no significant differences among treatments. The average dry matter yield of residual straw after seed harvest was 4,144 kg/ha, with the highest yield observed in the 120 N kg/ha treatment. Meanwhile, the feed value of the harvested straw did not differ significantly among treatments. The average contents of ADF, NDF, CP, IVDMD, and TDN were 43.04%, 70.63%, 8.65%, 52.77%, and 54.88%, respectively. In conclusion, the optimal nitrogen fertilization level for Italian ryegrass seed production through autumn sowing in the mountainous areas of Gangwon Province was found to be 120 N kg/ha.

This study was conducted to investigate the changes in seed productivity of Italian ryegrass (Lolium multiflorum Lam.) according to harvest time after heading in a mountainous area of Gangwon Province. The Italian ryegrass variety ‘Greencall’ was sown in the fall of 2021 in the Pyeongchang region of Gangwon and harvesting was performed every 10 days from 30 to 60 days after heading.. The treatments consisted of four seed harvest times (30, 40, 50, and 60 days after heading), arranged in a randomized complete block design with three replications. Plant height reached its maximum (93.0 cm) at 30 days after heading and subsequently declined with delayed harvest. Lodging resistance, disease resistance, and winter hardiness did not differ significantly among treatments, but lodging became more severe with time (rated 8∼9). Diseases were also more prevalent in the plots harvested 50 and 60 days after heading. The length of the spike was longest at 40 days after heading (54.33 cm), while the number of seeds per spike was lowest in the 60-day harvest plot (76 seeds/spike). The 1,000-seed weight was highest at 50 days after heading but decreased at 60 days. Seed dry matter content increased with delayed harvest, and dry seed yield increased up to 50 days after heading (3,742 kg/ha) but decreased at 60 days (2,442 kg/ha). The dry matter content of seed straw peaked at 50 days after heading, followed by a slight decline at 60 days, which was attributed to rainfall during the harvest period. Dry matter productivity was highest in the 50-day harvest plot. The feed value of seed straw decreased with delayed harvest, with an average Relative Feed Value (RFV) of 83. In conclusion, the optimal harvest time for fall-sown Italian ryegrass for seed production in the mountainous areas of Gangwon is 50 days after heading.

Carbon nanotube (CNT) fibers were synthesized in this study under a hydrogen atmosphere using the floating-catalyst chemical vapor deposition (CVD) technique. Acetone, ferrocene, and thiophene served as the sources of carbon, catalyst, and promoter, respectively. By adjusting the amount of thiophene, the sulfur molar ratio in the CVD reactor was varied to study its impact on the morphology and composition of the CNT fibers. Raman and TEM analyses showed that the structural properties of the CNTs, especially the production of single-walled CNTs (SWCNTs) with a high Raman IG/ ID ratio of approximately 23.8, can be finely tuned by altering the sulfur content, which also affects the accumulation of spherical carbonaceous particles. Moreover, it was established that the electrical conductivity of the CNT fibers is significantly influenced by their specific components—SWCNTs, multi-walled CNTs (MWCNTs), and spherical carbonaceous particles. The ratios of these components can be adjusted by modifying the molar ratios of catalyst and promoter in the precursor mixture. Remarkably, SWCNTs with enhanced crystallinity were found to substantially improve the electrical conductivity of the CNT fibers, despite the presence of numerous spherical carbon impurities.

For the commercialization of bipolar plates, several properties must be considered together. Electrical conductivity, corrosion resistance, contact resistance, mechanical strength, and light weight are essential evaluation factors, with corrosion resistance and durability being significant for unitized regenerative fuel cells (URFCs), which must operate in electrolysis and fuel cell mode. However, improving both properties is challenging, since corrosion resistance is largely inversely proportional to conductivity. In this study, to improve both properties together, composites composed of Pb and Zn with excellent conductivity and corrosion resistance were prepared with graphite powder and formed as a coating layer on the surface of 304 stainless steel (SS304) and evaluated for electrical conductivity and corrosion resistance. Among the ZnPb/C composites prepared at various ratios, Zn8Pb2/C exhibited the lowest transmittance resistance of 1.566 Ω, and improved electrical conductivity and durability compared to bare SS304.

Because intact FMDV particles (146S) are often unstable in vitro, stabilizing foot-and-mouth disease virus (FMDV) antigens remains a key challenge in studying viral charateristics. Therefore, finding optimal condition to stabilize the FMDV is essential. In this study, we investigated formulations and potentials of several stabilizers such as appropriate buffer, excipients, and storage conditions to enhance the stability of 146S. Inactivated FMDV O-Jincheon (O-JC) was dissolved in various buffer formulations, and stored at 4℃ for two months to evaluate quantity of 146S at every 2-week interval. Among phosphate buffered saline (PBS), Tris buffered saline (TBS), HEPES buffered saline (HBS), and MOPS buffered saline (MBS), PBS showed more effective 146S stabilization that showed 1.3-1.6 fold higher 146S fraction than TBS, HBS, and MBS after storage for 2 weeks. However, constant dissociations of 146S were observed in all formulations at 8 weeks. Compared with other FMDVs, A22 Iraq and SAT-1, in PBS, O-JC proved to be the least stable in PBS. A variety of excipients including carbohydrate, sugar alcohol, cryo-protectant were tested for the capability in protecting O-JC from dissociation. By adding 4-8% sucrose, more than 60% of 146S fractions were maintained at 8 weeks, those were at least 1.8 fold higher than the PBS-only control. Addition of 1% β-cyclodextrin showed synergistic enhancement in O-JC stability. As the results of this study, it could be suggested that the PBS-based buffer together with 4-8% sucrose + 2% sorbitol or 2% sucrose + 2% sorbitol + 1% β-cyclodextrin could help the better stability of the O-JC in vaccine preparation.

In this work, we investigated the photo-degradation performance of MnO2-SiC fiber-TiO2 (MnO2-SiC-TiO2) ternary nanocomposite according to visible light excitation utilizing methylene blue (MB) and methyl orange (MO) as standard dyes. The photocatalytic physicochemical characteristics of this ternary nanocomposite were described by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), photocurrent and cyclic voltammogram (CV) test. Photolysis studies of the synthesized MnO2-SiC-TiO2 composite were conducted using standard dyes of MB and MO under UV light irradiation. The experiments revealed that the MnO2-SiC-TiO2 exhibits the greatest photocatalytic dye degradation performance of around 20 % with MB, and of around 10 % with MO, respectively, within 120 min. Furthermore, MnO2-SiC-TiO2 showed good stability against photocatalytic degradation. The photocatalytic efficiency of the nanocomposite was indicated by the adequate photocatalytic reaction process. These research results show the practical application potential of SiC fibers and the performance of a photocatalyst composite that combines these fibers with metal oxides.

Mathematically modeling photosynthesis helps to interpret gas exchange in a plant and estimate the photosynthetic rate as affected by environmental factors. Notably, the photosynthetic rate varies among leaf vertical positions within a single plant. The objective of this study was to measure the distinct photosynthetic rate of lily (Lilium Oriental Hybrid ‘Casa Blanca’) at the upper, medium, and basal leaf positions. Subsequently, the FvCB (Farquhar-von Caemmerer-Berry) photosynthesis model was employed to determine the parameters of the model and compared it with a rectangular hyperbola photosynthesis model. The photosynthetic rates were measured at different intracellular CO2 concentrations () and photosynthetic photon flux density (PPFD) levels. SPAD values significantly decreased with lowered leaf position. The photosynthetic rates at the medium and basal leaves were lower compared with the upper leaves. FvCB model parameters,  and   , showed no significant difference between the medium and basal leaves. Estimated photosynthetic rates from derived parameters by the FvCB model demonstrated over 0.86 of R2 compared with measured data. The rectangular hyperbola model tended to overestimate or underestimate photosynthetic rates at high  with high PPFD levels or low  with high PPFD levels, respectively, at each leaf position. These results indicated that the parameters of the FvCB model with different leaf positions can be used to estimate the photosynthetic rate of lily.

Salinity stress is a major threat to plant growth and development, affecting crop yield and quality. This study investigated the effects of different salinity levels on photosynthetic responses and bulb growth of Lilium LA hybrid “‘Serrada’.” Plants were irrigated with 1 L of 0, 200, and 400 mM NaCl solutions every two weeks for 14 weeks in a greenhouse. At the end of the cultivation period, the substrate pH decreased, and electrical conductivity increased with increasing salinity. Regardless of salinity levels, the days to flowering and number of flowers were similar among treatments. In contrast, the flower width, plant height, number of leaves, and leaf area decreased with increasing NaCl concentrations. Although there were no differences in the photosystem II (PSII) operating efficiency and maximum quantum yield of PSII, net CO2 assimilation rates (An) and stomatal conductance (gs) were significantly reduced at 200 and 400 mM NaCl solutions compared to the control. At 400 mM NaCl solution, bulb diameter and weight significantly decreased at the end of the experiment. These results suggest that bulb growth inhibition could be attributed to limiting photosynthetic rate and stem growth. This finding suggests that salinity mitigation is necessary to maintain plant growth and photosynthetic capacity in lily cultivation on salt-affected soils.

Recently, it is demonstrate that the invertebrates have a immune memory, called Immune priming (IP). It was partially studied that the IP is mainly regulated by epigenetic modification. Here, to understand the IP on antimicrobial peptides (AMPs) production, we investigated larval mortality and time-dependent expression patterns of AMP genes in T. molitor larvae challenged with E. coli (two-times injection with a one-month interval). Interestingly, the results indicate that the higher and faster expression levels of most AMP genes were detected compared to the non-primed T. molitor larvae. Our results may used to improve the understanding of mechanisms of invertebrate immune memory.

본 연구는 대한민국 울릉도 특산식물인 추산쑥부쟁이(Aster × chusanensis Y.S.Lim, Hyun, Y.D.Kim & H.C.Shin)의 기내 대량증식체계 확립을 위해 시토키닌 계열 식물생장조절 제를 첨가하여 캘러스 및 신초 형성 조건을 구명하고자 수행 하였다. 실험결과, 추산쑥부쟁이의 줄기 절편체에서 캘러스 와 신초가 형성되었다. 캘러스 형성률은 TDZ 3.0mg·L-1처 리구에서 88.9%로 가장 높았고 BAP 3.0mg·L-1와 Zeatin 3.0mg·L-1 처리구는 66.7%, 2iP 3.0mg·L-1 처리구에서는 11.1%였다. 신초 형성률은 모든 처리구에서 77% 이상이고 특히 TDZ처리구와 Zeatin 처리구에서 100%였다. 그러나 TDZ처리구에서는 형성된 신초가 부풀어 오르거나, 잎에 과수 성이 나타나는 등 형태적 기형이 나타났다. Zeatin처리구에 서 발생한 신초는 정상적인 형태를 나타났다. 잎 절편체에서 는 캘러스, 신초가 발생하지 않았으며 절편체가 탈색하며 고 사하는 것을 확인하였다. 종합적으로 추산쑥부쟁이의 캘러 스 및 신초 형성을 위해서는 줄기 절편체를 배양 재료로 이 용하는 것이 효과적으로 확인되었다. 캘러스 유도에는 TDZ 3.0mg·L-1처리가 가장 효과적이었고, 추후 NAA와 같은 옥신 을 함께 첨가하여 증식 효과를 분석하는 연구가 필요할 것이 다. 또한, 신초 유도에도 TDZ 3.0mg·L-1 처리가 효과적이었 으나 장기간, 고농도로 사용할 경우 형태적인 기형이 발생할 수 있어 정상적인 식물생산에 부적합한 것으로 확인되었다. 따라서 형태적 기형이 발생하지 않은 아데닌 유도체형 시토키 닌인 Zeatin을 활용하는 것을 추천한다. 본 연구는 울릉도 특 산식물인 추산쑥부쟁이의 기내 대량증식과 생태계 유지에 필 요한 종 공급을 위한 대량증식 체계 구축을 위한 자료로 활용 할 수 있을 것이다.

Owing to the great demand for portable and wearable chemical sensors, the development of all-solid-state potentiometric ion sensors is highly desirable considering their simplicity and stability. However, most ion sensors are challenged by the penetration of water and gas molecules into ion-selective membranes, causing unstable and undesirable sensing performances. In this study, a hydrophobic ionic liquid-modified graphene (Gr) sheet was prepared using a fluid dynamics-induced exfoliation and functionalization process. The high hydrophobicity and electrical double-layer capacitance of Gr make it a potential solid-state ion-to-electron transducer for the development of potentiometric sodium-ion ( Na+) sensors. The as-prepared Na+ sensors effectively prevented the formation of the water layer and penetration of gas species, resulting in stable and high sensing performances. The Na+ sensors showed a Nernstian sensitivity of 58.11 mV/[Na+] with a low relative standard deviation (0.46), fast response time (5.1 s), good selectivity (K < 10− 4), and good durability. Furthermore, the Na+ sensor demonstrated its feasibility in practical applications by measuring accurate and reliable ion concentrations of artificial human sweat and tear samples, comparable to a commercial ion meter.

A facile and efficient method was developed to prepare highly stretchable and conductive graphene conductors with wrinkled structures by the mechanical stretching and shrinking of elastomeric substrates, in which graphene inks were printed on a prestretched elastomeric substrate. Stretchable and exfoliated graphene inks were prepared by mixing graphite and Ecoflex in a shear-assisted fluid dynamics reactor. The resultant graphene conductor exhibited excellent stretchability at 150% strain and high electrical conductivity of 64 ± 1.2 S m− 1. The resistance of the conductor did not change in bent, twisted, and stretched states. The resistance did not change during 10,000 cycles of stretching/releasing, with a maximum strain of 150%. Based on the graphene conductor, a stretchable conductometric sensor with a two-electrode configuration was fabricated to measure impedance changes at different concentrations of electrolyte ions. This sensor exhibited a good and linear sensitivity curve (298.61 Ω mM− 1, R2 = 0.999) in bent and stretched states.