To meet the increased performance and cost requirements of commercial supercapacitor, a N and O self-doped hierarchical porous carbon is fabricated via a green and simple self-activation route utilizing leaves of wild hollyhock as raw materials. Comparing to commercial activated carbon, the reported material exhibits some marked merits, such as simple and green fabrication process, low cost, and superior capacitance performance. The specific surface area of the obtained N and O codoped hierarchical porous carbon arrives 954 m2 g−1, and the content of the self-doped nitrogen and oxygen reaches 2.64 at.% and 7.38 at.%, respectively. The specific capacitance of the obtained material reaches 226 F g− 1 while the specific capacitance of the symmetric supercapacitor arrives 47.3 F g− 1. Meanwhile, more than 90.3% of initial specific capacitance is kept under a current density of 20 A g− 1, and no arresting degradation is observed for capacitance after 5000 times cycle, perfectly demonstrating the excellent cycle and rate capability of the obtained material. The obtained N and O co-doped hierarchical porous carbon are expected to be an ideal substitution for commercial activated carbon.
The structural transformationss of oriented poly(vinyl alcohol) (PVA) fibers impregnated with potassium bisulfate (PBS) were studied in detail on the way from PVA precursor fibers till carbonized at a temperature of 1000 °C fibers. It has been shown that the impregnation of PVA fibers with a sulfur-containing compound (PBS) is an efficient technique to decrease the thermoplasticity of PVA fibers during heat treatment at high temperatures in air and argon and contributes to a high yield of coke residue after heat treatment up to 1000 °C. TMA, TGA, DSC, mass spectrometry, FTIR, Raman spectroscopy, SEM, WAXS and SAXS were used to study the structural transformations of oriented PVA fibers impregnated with PBS at the stages of their preliminary thermal stabilization (215 °C), thermal stabilization (215–400 °C) and carbonization (400–1000 °C). A reaction scheme has been proposed that fully describes carbonization chemistry in the entire studied temperature range. The processing temperature of 215 °C was found to be optimal for preliminary thermal stabilization of PVA fibers impregnated with PBS. The heat treatment in an inert medium can be recommended as the optimal for thermal stabilization of fibers impregnated with PBS. The characteristics of the carbonized PVA fibers, such as strength, modulus and electrical conductivity, were close to the characteristics of commercial cellulose-based carbon fibers yarns.
Nickel nanopowders are obtained by the spark discharge method, which is based on the evaporation of the electrode surface under the action of the discharge current, followed by vapor condensation and the formation of nanoparticles. Nickel electrodes with a purity of 99.99% are used to synthesize the nickel nanoparticles in the setup. Nitrogen is used as the carrier gas with a purity of 99.998%. XRD, TEM, and EDX analyses of the nanopowders are performed. Moreover, HRTEM images with measured interplanar spacings are obtained. In the nickel nanopowder samples, a phase of approximately 90 wt% with an expanded crystal lattice of 6.5% on average is found. The results indicate an unusual process of nickel nanoparticle formation when the spark discharge method is employed.
Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.
Cytochrome P450 1A2 (CYP1A2) is a member of the cytochrome P450 superfamily enzymes in mammals and plays a major role in metabolizing endogenous hormones in the liver. In recent days, CYP1A2 expression has been found in not only the liver but also other tissues including the pancreas and lung. However, little information is available regarding the expression of CYP1A2 in the ovary, in spite of the facts that the ovarian follicle growth and atresia are tightly associated with controls of endocrine hormonal networks. Therefore, the expression of CYP1A2 in the ovaries of prepubertal and pubertal rats was investigated to assess its expression pattern and puberty-related alteration. It was demonstrated that the expression level of CYP1A2 was significantly (p < 0.01) higher in the pubertal ovaries than prepubertal counterparts. At the ovarian follicle level in both groups, whereas CYP1A2 expression was less detectable in the primordial, primary and secondary follicles, the strongly positive expression of CYP1A2 was localized in the granulosa cell layers in the antral and pre-ovulatory follicles. However, the ratio of CYP1A2-positive ovarian follicle was significantly (p < 0.01) higher in the ovary of pubertal group (73.1 ± 3.1%) than prepubertal one (41.0 ± 10.5%). During the Immunofluorescence, expression of CYP1A2 was mainly localized in Fas-positive follicles, indicating the atretic follicles. In conclusion, these results suggested that CYP1A2 expression was mainly localized at the atretic follicular cells and affected by the onset of puberty. Further study is still necessary but we hypothesize that CYP1A2 expresses in the atretic follicles to metabolize residue of the reproductive hormones. These findings may have important implications for the fields of reproductive biology of animals.
The nutritional value and yield of mushrooms depend on the substrate on which it is grown. This study sought to biofortify Pleurotus floridanus with calcium supplements and assess its effect on the yield and calcium levels. The experiment was set up in a 2 × 5 factorial and replicated thrice in a completely randomized design. Two calcium supplements, OML and OMW, were added to two growth media. The examination of total dry weight yield showed that calcium supplements OML and OMW in the sawdust medium containing wheatbran in the ratio 1:10 had a mean value of 4.37 g, which was significantly higher (P < 0.05) than that in the control (1.29 g). However, in the sawdust-only medium, there was no significant difference (p > 0.05) in the application of treatments. No significant difference (p > 0.05) was observed between the calcium types in both growth media. The mineral analysis showed that calcium levels were increased in harvested mushrooms with the addition of calcium OML and OMW to the growth media.
We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet―host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We find that the lens system has a star with mass Mh = 0.55+0.36 -0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62 -2.87 MJup, at a distance of DL = 5.67+1.11 -1.52 kpc. The projected star{planet separation is aㅗ = 3.92+1.10 -1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens{source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.
The effects of supplementing ESP-FM (Erythrobactor sp.), freshwater Chlorella (Chlorella sp.), and baker’s yeast (Saccharomyces cerevisiae) on the nutritional value and mass production of Moina macrocopa, which is used as a live feed for fish fry production, was investigated. Consequently, the effects of feeding the enriched M. macrocopa to the nutritional composition of larval rockfish (Sebastes schlegel) and carp (Cyprinus carpio) was also investigated. Maximum density of M. macrocopa was reached within 15-21 days after inoculation (0.5 to 22 individual/mL), at various temperatures, and either decreased or remained almost constantly thereafter. Protein content and amino acids composition of M. macrocopa were found to be influenced by their respective diets while lipid and ash contents did not considerably change. M. macrocopa fed with baker’s yeast were low in n-3 HUFA content, and those fed on the freshwater chlorella were high in the 18:2n-6 and 18:3n-3 HUFA content, and in cultures treated with ESP-FM were high content in n-3 HUFA. The utilization of M. macrocopa as a substitute fish feed for carp and rockfish showed the enrichment nutritional content.
This essay analyzes the impact of COVID-19 in higher education based on national policies implemented during the current outbreak. Additionally, it enlists and discusses the proposed strategies developed to support higher education in a post-pandemic scenario based on educational and political perspectives.
이전의 스트레스 및 대처 문헌은 효과적인 스트레스 대처 전략이 개인의 복지에 대한 스트레스의 부정적인 영향을 감소시킬 뿐만 아니라 대처가 조직에도 도움이 될 수 있다고 제안한다. 본 연구에서는 노력-보상 불균형이 직원의 잡 크래프팅에 어떠한 영향을 미치는지 알아보고 이 관계에서 직원의 지각이 고용가능성과 조직몰입이 조절역할을 하는지 알아보고자 하였다. 또한, 노력-보상 불균형과 반생산적 과업행동 간 관계를 잡 크래프팅이 매개하는지 알아보고였다. 이를 위하여 본 논문에서는 한국에 종사하는 203명의 직원들을 대상으로 설문조사를 실시하였으며 회귀분석법으로 자료를 분석하였는데, 그 결과는 다음과 같다. 첫째, 노력-보상 불균형이 높을수록 잡 크래프팅이 높아지는 것으로 나타났다. 특히, 노력-보상 불균형과 구조적 직무자원을 증가시키는 행동, 사회적 직무자원을 증가시키는 행동, 그리고 도전적인 직무요구를 증가시키는 행동에 정 (+)의 관계가 있는 것으로 밝혀졌다. 그런데, 노력-보상 불균형과 방해되는 직무요구를 감소시키는 행동에 관계가 없는 것으로 밝혀졌다. 또한 과도위임과 사회적 직무자원을 증가시키는 행동, 도전적인 직무요구를 증가시키는 행동에 정 (+)의 관계가 있는 것으로 밝혀졌다. 둘째, 노력-보상 불균형과 잡 크래프팅 간의 정적 관계는 지각이 고용가능성이 낮을 때보다 높을 때 더 강하게 나타났다. 셋째, 노력-보상 불균형과 잡 크래프팅 간의 정적 관계는 조직몰입이 낮을 때보다 높을 때 더 강하게 나타났다. 넷째, 잡 크래프팅은 노력-보상 불균형과 반생산적 과업행동 간의 관계에서 매개역할을 하는 것으로 나타났다. 추가적으로 해당 연구를 통해 얻어진 결과들을 토대로 연구의 의의 및 한계 점, 향후 연구를 위한 제언 등을 통합적으로 논의하였다.
This study compares the results of a survey of vocabulary learning strategy (VLS) use and perceived helpfulness by Korean university students to the taxonomy of VLS first presented by Schmitt. VLS suggested by previous research by the author and changes in technology since the original taxonomy was compiled were added to Schmitt’s list. The survey was administered online to 135 university students in Korea, primarily of Korean nationality. The results show that reported VLS use is up across the board, and the perceived helpfulness of the majority of VLS is up as well. Technological VLS are widely used for meaning discovery, but used moderately for vocabulary consolidation. Trends in the results are discussed, which suggest that learners rely on a range of VLS rather than a few core VLS. Technological VLS are common among Korean university students, though most still prefer traditional methods. Ramifications for vocabulary teaching and strategy instruction are also discussed, as well as suggestions for further research.
Human sacrifice in the Shang Dynasty (1600 BC – 1046 BC) refers to the practice of killing of human beings in rituals such as slaves, war prisoners as offerings to divine patrons and ancestors. The reason for this is the worship of the ancestors and the sacrifice of slaves to the gods to expand the ranks of their ancestors in another world. This paper aims to demonstrate that the Shang culture was based on human sacrifice to the wife of a king of Shang called Female Ancestors(xianbi 先妣) and the focus of this article is qualified xianbi of enjoying sacrifice in oracle inscriptions of Shang Dynasty. This research shows that xianbi had a quite high status in Shang dynasty, they enjoyed the same species of human sacrifices and animals with male ancestors(xianwang 先王). These results are evidence showing that the status of men and women were equal in the royal system of Shang Dynasty.
Many electronic applications require magnetic materials with high permeability and frequency properties. We improve the magnetic permeability of soft magnetic powder by controlling the shape magnetic anisotropy of the powders and through the preparation of amorphous nanoparticles. For this purpose, the effect of the shape magnetic anisotropy of amorphous Fe-B-P nanoparticles is observed through a magnetic field and the frequency characteristics and permeability of these amorphous nanoparticles are observed. These characteristics are investigated by analyzing the composition of particles, crystal structure, microstructure, magnetic properties, and permeability of particles. The composition, crystal structure, and microstructure of the particles are analyzed using inductively coupled plasma optical emission spectrometry, X-ray diffraction, scanning electron microscopy and focused ion beam analysis. The saturation magnetization and permeability are measured using a vibrating sample magnetometer and an LCR meter, respectively. It is confirmed that the shape magnetic anisotropy of the particles influences the permeability. Finally, the permeability and frequency characteristics of the amorphous Fe-B-P nanoparticles are improved.
The Indonesian Ocean Policy (IOP) is a new milestone in managing its oceans since Indonesia ratified the UNCLOS 35 years ago. Indonesia underwent several paradigm shifts in strengthening ocean governance from 1957 to 2014. This research aims to analyse three paradigm shifts in strengthening ocean governance in Indonesia. The research revealed that the milestone of the first shift was the 1957 Djuanda Declaration, recognised by the UNCLOS in 1982, regarding the concept of an archipelago state, called the ‘ocean space paradigm.’ The second, which occurred in the Reformation period (1998-2014) was called the Ocean Development paradigm, while the third paradigm shift was after President Jokowi launched Indonesia’s vision as a Global Maritime Fulcrum. This third paradigm shift was also associated with the emergence of the IOP, which contributes to national development and pays comprehensive attention to the constellation of relations between the countries in Asia and various initiatives in the region.
Dishwashing tools such as sponges, scourers, and dishcloths are known to harbor dense and diverse microbial communities, including pathogenic bacteria. In this study, the potential of corona discharge plasma jet (CDPJ) as a disinfectant was tested to improve the hygienic quality of dishwashing tools. For the simulation of microbial contamination, selective pathogenic bacteria (Escherichia coli O157:H7, Staphylococcus aureus, and Pseudomonas putida) were inoculated on selected dishwashing tools (dishcloth, sponge, and scourer) at concentrations of 6.55 to 8.77 log CFU/cm 2 . CDPJ generated at 20 kV voltage and 1.5A current was used for decontamination, whereas a sample-to-electrode distance of 25 mm was maintained during the treatment. Following CDPJ treatment for 5 min, the viable counts of E. coli O157:H7, S. aureus, and P. putida were reduced by 4.30-4.56, 3.71-4.78, and 3.50-3.83 log, respectively. The rates of inactivation were varied among the pathogens, decreasing in the order E. coli O157:H7 > S. aureus > P. putida. Among tested kinetic models, namely log-linear, log-linear with shoulder, and Weibull models, the log-linear with shoulder model was found to be the most suitable model to explain the CDPJ inactivation of the pathogens. In conclusion, CDPJ can be used as a potential sanitizing agent for dishwashing tools.
Currently, domestic seaweed production is about 800,000 tons per year, which is the largest seaweed production in the world after China and Japan. However, most seaweeds (Pyropia ssp, Undaria pinnatifida, Saccharina japonica, etc) are consumed in the form of dried products or hot water extracts, and there are many difficulties in developing various products due to difficulties in the manufacturing process. Through the pulsed electric field treatment device, the extraction efficiency can be expected to increase compared to the convectional hot water extraction. Pulsed electric field technology is a non-heating treatment technology in which high-voltage electric energy is processed into cells in the form of pulses, affecting the potential difference of cell membranes, and performing collapse or perforation treatment. In this study, components such as protein and carbohydrate content were extracted by treating Saccharina japonica with PEF, and compared with the hot water extraction method, As a result of experiment at voltages of 0.7 and 1.5㎸ and pulse duration of 5㎲, the crude protein content increased by up to 42% and the sugar content increased by up to 30% compare to the hot water extraction. Higher efficiency results can be expected through optimization of several parameters that may affect the extraction process.