Si-based anodes are promising alternatives to graphite owing to their high capacities. However, their practical application is hindered by severe volume expansion during cycling. Herein, we propose employing a carbon support to address this challenge and utilize Si-based anode materials for lithium-ion batteries (LIBs). Specifically, carbon supports with various pore structures were prepared through KOH and NaOH activation of the pitch. In addition, Si was deposited into the carbon support pores via SiH4 chemical vapor deposition (CVD), and to enhance the conductivity and mechanical stability, a carbon coating was applied via CH4 CVD. The electrochemical performance of the C/Si/C composites was assessed, providing insights into their capacity retention rates, cycling stability, rate capability, and lithium-ion diffusion coefficients. Notably, the macrostructure of the carbon support differed significantly depending on the activation agent used. More importantly, the macrostructure of the carbon support significantly affected the Si deposition behavior and enhanced the stability by mitigating the volume expansion of the Si particles. This study elucidated the crucial role of the macrostructure of carbon supports in optimizing Si-based anode materials for LIBs, providing valuable guidance for the design and development of high-performance energy-storage systems.
Nanostructured ZnO materials have been studied extensively because of their functional properties. This paper presents a composite material of zinc oxide quantum dots (ZnO QDs) and porous carbon using a one-step carbonization process. The direct carbonization of a metal–organic complex generates mesostructured porous carbon with a homogeneous distribution of ZnO QDs. The structural and morphological properties are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The resulting ZnO QDs@porous carbon composite delivers a high specific capacity of 990 mAh g−1 at 100 mA g−1, 357 mAh g−1 at 2 A g−1, and high reversibility when evaluated as an anode for lithium ion batteries.
Cloned calves derived from somatic cell nuclear transfer (SCNT) have been frequently lost by sudden death at 1 to 3 month following healthy birth. To address whether placental anomalies are responsible for the sudden death of cloned calves, we compared protein patterns of 2 placentae derived from SCNT of Korean Native calves died suddenly at two months after birth and those of 2 normal placentae obtained from AI fetuses. Placental proteins were separated using 2-Dimensional gel electrophoresis. Approximately 800 spots were detected in placental 2-D gel stained with coomassie-blue. Then, image analysis of Malanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between normal and SCNT placentae. In the comparison of normal and SCNT samples, 8 spots were identified to be up-regulated proteins and 24 spots to be down-regulated proteins in SCNT placentae, among which proteins were high mobility group protein HMG1, apolipoprotein A-1 precursor, bactenecin 1, tropomyosin beta chain, H+-transporting ATPase, carbonic anhydrase II, peroxiredoxin 2, tyrosine-rich acidic matrix protein, serum albumin precursor and cathepsin D. These results suggested that the sudden death of cloned calves might be related to abnormal protein expression in placenta.
Acute myocardial infarction (AMI) as an acute form and a catastrophic manifestation of coronary artery disease (CAD) is the major cause of morbidity and mortality worldwide. The prevalence and incidence of myocardial infarction can be influenced by demographic, biological and psychosocial factors, and it is rare in childhood and adolescent years. Contrary to the elderly, where cardiac attack is mainly caused by CAD, exercise-induced cardiac attack is relatively more prevalent in a young adult. We report here on a case of ST-segment elevation myocardial infarction (STEMI) in a young adult during vigorous physical activity and we review the relevant literatures.
Background : For cultivation of varieties of ginseng, the pure line selection method, which is to select the best among those cultivated in farms for pedigree breeding, replicated yield trials and regional adaptation trials before registering as a new variety, is widely used. Although there are 25 registered varieties of ginseng in Korea, the quality of ginseng is declining together with the amount of harvest being decreased by 15 - 20% due to the heat injuries and diseases from the warming & abnormal climate. Thus, the needs for development of disaster-resistant varieties with better chances of surviving through high temperature, salts and disease are increasing. Therefore, this study is to cultivate disaster-resistant varieties among those selected for their disaster tolerance and salt tolerance through regional adaptation trials. Methods and Results : As a result of examining the growth characteristics of the selected 2 - 5 year old varieties used in the study, among the 5-year old crops, Goryeo 4 and Eumseong 5 showed superior growth in both above and below aerial parts, and among the 4-year old crops, Eumseong 11 and Cheonryang showed superior growth while the growth in the below aerial parts were satisfactory in the order of Cheonryang > Eumseong 10 > Eumseong 11 > Eumseong 9. Among the 3-year old crops, the most superior growth in both above and below aerial parts was observed in Eumseong 14 with the weight of the below aerial part, root diameter and taproot length at 13.8 g, 11.8 ㎝ and 6.2 ㎝ respectively. Among the 2-year old crops, Eumseong 10 showed the most superior growth in both above and below aerial parts. Conclusion : Based on the above results, Goryeo 4 and Eumseong 5 among the 5-year old crops, Eumseong 11 among the 4-year old crops, Eumseong 14 among the 3-year old crops and Eumseon 10 among the 2-year old crops showed the most superior growth among the selected varieties. The growth characteristics of both above and below aerial parts in each year will continuously be monitored.
Background : This study was carried out to distribute superior cultivars to farmers by analyzing growth characteristics of ginseng and effectively set the target for breeding by investigating annual agronomic characteristics of ginseng. Methods and Results : As a plant materials, Chunpoong (CP), Yunpoong (YP), Gopoong(GP), Gumpoong (GU) and Sunun (SU) were transplanted in Eumseong (ES), Geumsan (GS) and Yeoncheon (YC) on March 2013. Cultivation and management were conducted on the basis of the standard guidelines. According to stem and petiole by region, YC represent the largest stem diameter, leaf length and petiole length of cultivars, followed by those in ES and those in GS. Leaf growth of cultivars was overall the best in YC. Although CP had long and narrow leaves in all regions, YP and SU had short and narrow leaves. Root weight of all cultivars was the best in YC, but there was no significant differences by them. Growth of CP, YP and GP was generally good in ES. Growth of cultivars was relatively even in GS, but it was poor compared to cultivars which were cultivated in ES and YC. Conclusion : There were considerable differences in root growth of cultivars. However, this results suggest that CP of 4-year-old is produced stably in some regions because it had a small coefficient of variation.
Background : Recently, there is a urgent demand for development of new varieties with enhanced resistance to various biotic/abiotic stresses. In order to develop ginseng varieties with such traits, systematic breeding program and comprehensive field studies are prerequisite. Methods and Results : ‘Cheonmyeong' seeds were collected in 2008 from the farmer field of Buyeo. Physiological investigation and propagation were conducted from 2009 to 2011. It was given the name 'Eumseong No. 8 through the observed yield trial from 2012 to 2013 and local adaptability was carried out from 2014 to 2015. All phenotypes including agronomic characteristics, seed yield, and physiological response to biotic/abiotic stresses were investigated according to the ginseng GAP and UPOV guidelines. Yellow-red leaf and pink berry at maturing stage were observed. The time of emergence, flowering and berry maturity of the ‘Cheonmyeong’ were faster than those of ‘Chunpoong’. Stem length of ‘Cheonmyeong’ was shorter than that of ‘Chunpoong’, whereas stem diameter was thicker than that of ‘Chunpoong’. Main root length was shorter but main root diameter is thicker than that of ‘Chunpoong’. Number of seeds of ‘Cheonmyeong’ was fewer than that of ‘Chunpoong’ but 1,000-seeds weight and stratification rate were higher than those of ‘Chunpoong’. The yield performance of this variety was 661 kg/10 a in local adaptability test for two years, which is 22% higher than that of ‘Chunpoong’. ‘Cheonmyeong’ showed strong resistance to phytophthora blight, mulberry mealybug and nematode and moderate resistance to alternaria blight. ‘Cheonmyeong’ did almost not occur yellow spot of aerial part and rusty skin of root, show moderate resistance at high temperatures. Conclusion : Our study demonstrated that ‘Cheonmyeong’ is an ideal variety with heavier root weight and enhanced stress resistance and contribute will enhance biotic/abiotic stress resistance and increase the farmers' income.
Tissue equivalent proportional counter (TEPC) can measure the Linear Energy Transfer (LET) spectrum and calculate the equivalent dose for the complicated radiation field in space. In this paper, we developed and characterized a TEPC for radiation monitoring in International Space Station (ISS). The prototype TEPC which can simulate a 2 μm of the site diameter for micro-dosimetry has been tested with a standard alpha source (241Am, 5.5 MeV). Also, the calibration of the TEPC was performed by the 252Cf neutron standard source in Korea Research Institute of Standards and Science (KRISS). The determined calibration factor was kf = 3.59×10-7 mSv/R.
The purpose of this study is to explore the concept of a logistics hub, identify key factors and milestones for its development, and give some recommendations and implications to developing countries. For this the countries competing to be Logistics hub in Northeast Asia (NEA), such as South Korea, japan and China, are taken into consideration These countries have under its priority policies the development of a logistics hub vision to become the central area of the region achieving microeconomic and macroeconomic prosperity. Based on the review of the relevant literature, five factors came up as key determinants for the development of a hub project: 1. Logistics services support and infrastructure. 2. Business environment. 3. Economic determinants. 4. Political support and 5. Access to international markets. These are going to be analyzed together with its different variables, using statistical methods.