검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 3,043

        261.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Using vocabulary learning strategies allows learners to gain vocabulary autonomously. This study presents data from a self-report survey of Korean university students comparing meaning discovery strategies they employ to comprehend unknown singleword items and unknown idioms. Survey data recorded strategies used by learners, and effectiveness of these strategies measured by rates of correct meaning discovery. The survey revealed that learners relied on context clues, dictionaries, and vocabulary analysis for both idioms and single word vocabulary items with equal effectiveness. Dictionary use was the most effective strategy for correct meaning discovery for both types of vocabulary, although context clues might be a positive factor for idioms but not for single-word items. Data also showed that learners tended to apply strategies methodically rather than heuristically but that methodical application did not necessarily translate into higher rates of correct meaning discovery. Implications for learners and paths for further research are discussed.
        5,400원
        264.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The surface of carbon films deposited with inverted plasma fireballs is analysed in this paper. Measurements were conducted with Raman spectroscopy, atomic force microscopy and nanoindentation. The latter was used to obtain Young’s modulus as well as Martens and Vickers hardness. The roughness of the film was measured by atomic force microscopy and its thickness was measured. It was shown with Raman spectroscopy that the films are homogeneous in terms of atomic composition and layer thickness over an area of about 125 × 125 mm. Furthermore, it was demonstrated that inverted plasma fireballs are a viable tool for obtaining homogeneous, large area carbon films with rapid growth and very little energy consumption. The obtained films show very low roughness.
        4,000원
        265.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ultrasonic method is an alternative to the conventional route to produce structured carbon materials, offering the advantages of synthesis in a short period of time under room temperature. The main objective of this work is to synthesize a sulfonated mesoporous carbon catalyst from a phenolic resin composed of phloroglucinol and formaldehyde. The synthesis was performed by the soft-template method in an ultrasonic processor and the product was subsequently carbonized and sulfonated for application in the esterification model reaction. Functionalization with sulfuric acid of MCS5-6 h sample brought about a decrease in porosity but simultaneously resulted in the generation of functional groups of an acidic nature. The MCS5-6 h catalyst with a sulfonic density of 1.6 mmol g− 1, surface area of 402 m2 g− 1 and pore diameter of 10.6 nm maintained in mesoporous even after acid treatment. MCS5-6 h showed excellent activity in the esterification reaction with 95% oleic acid conversion. The recyclability of MCS5-6 h was satisfactory during five reaction cycles. The present work addressed a promising alternative for the synthesis of carbon catalysts using ultrasound irradiation, thus providing an alternative with a lower cost of time and energy for large-scale production.
        4,600원
        266.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lead sulfide ( PbS ) nanocrystals anchored on nitrogen-doped multiwalled carbon nanotubes ( CNx ) have been synthesized employing an environmentally friendly and inexpensive wet chemistry process. CNx∕PbS composites have been examined by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Theorical ab initio calculations have been developed to determine the samples structural, morphological and optical properties to explain the experimental evidences. The PbS nanoparticles exhibit of 4 nm to 27 nm particle size with a face-centered cubic crystal structure and are homogeneously distributed along the carbon nanotubes. The nitrogen-doped CNTs acts as binding sites for the PbS clusters as ab initio theoretical study suggests.
        4,000원
        267.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanotube fiber is a promising material in electrical and electronic applications, such as, wires, cables, batteries, and supercapacitors. But the problem of joining carbon nanotube fiber is a main obstacle for its practical development. Since the traditional joining methods are unsuitable because of low efficiency or damage to the fiber structure, new methods are urgently required. In this study, the joining between carbon nanotube fiber was realized by deposited nickel–copper doublelayer metal via a meniscus-confined localized electrochemical deposition process. The microstructures of the double-layer metal joints under different deposition voltages were observed and studied. It turned out that a complete and defect-free joint could be fabricated under a suitable voltage of 5.25 V. The images of the joint cross section and interface between deposited metal and fiber indicated that the fiber structure remained unaffected by the deposited metal, and the introduction of nickel improved interface bonding of double-layer metal joint with fiber than copper joint. The electrical and mechanical properties of the joined fibers under different deposition voltages were studied. The results show that the introduction of nickel significantly improved the electrical and mechanical properties of the joined fiber. Under a suitable deposition voltage, the resistance of the joined fiber was 37.7% of the original fiber, and the bearing capacity of the joined fiber was no less than the original fiber. Under optimized condition, the fracture mode of the joined fibers was plastic fiber fracture.
        4,500원
        268.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydroxyl radical (OH radical) is the most harmful free radical amongst the Reactive Oxygen Species (ROS) responsible for numerous diseases of DNA damage like mutagenesis, carcinogenesis and ageing. Therefore, it is important to find a suitable scavenger for OH radical. In the present contribution, we aim to investigate the ability of pristine armchair-SWCNT and B/N/P-doped armchair-SWCNT to scavenge OH radicals using DFT calculations. The calculations reveal that the B/Pdoped armchair-SWCNTs can act as a better scavenger for OH radical compared to pristine armchair-SWCNT but N-doped armchair-SWCNT does not act as a better scavenger for OH radical compared to pristine armchair-SWCNT. Furthermore, the developed scavenger is examined in terms of large-scale availability, biocompatibility, conductivity, stability and reactivity. For both in vivo and in vitro studies, the work is found to useful for enhancing SWCNT as a free radical scavenger.
        4,800원
        269.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서 Nematus tibialis를 국내에서 처음으로 보고한다. 이 종의 사진과 진단, 색 변이, 발육 단계와 분포 등을 제공하였다.
        4,000원
        270.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electro-Fenton (EF) process was first proposed in 1996 and, since then, considerable development has been achieved for its application in wastewater treatment, especially at lab and pilot scale. After more than 25 years, the high efficiency, versatility and environmental compatibility of EF process has been demonstrated. In this review, bibliometrics has been adopted as a tool that allows quantifying the development of EF as well as introducing some useful correlations. As a result, information is summarized in a more visual manner that can be easily analyzed and interpreted as compared to conventional reviewing. During the recent decades under review, 83 countries have contributed to the dramatic growth of EF publications, with China, Spain and France leading the publication output. The top 12 most cited articles, along with the top 32 most productive authors in the EF field, have been screened. Four stages have been identified as main descriptors of the development of EF throughout these years, being each stage characterized by relevant breakthroughs. To conclude, a general cognitive model for the EF process is proposed, including atomic, microscopic and macroscopic views, and future perspectives are discussed.
        5,200원
        271.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, UiO-66-NH2 was synthesized and incorporated with graphene aerosol (UiO-66-NH2/GA) and ethylenediamine functionalized graphene oxide (UiO-66-NH2/GO-NH2). These composites were characterized using infrared spectroscopy, powder X-ray diffraction, ultraviolet–visible light spectroscopy, scanning electron microscope, and energy-dispersive X-ray spectroscopy. UiO-66-NH2/GO-NH2 exhibited 93% adsorption of quinoline in 5 h, UiO-66-NH2 and UiO-66-NH2/GA presented 80.4% and 86.5%, respectively. The high adsorption observed on UiO-66-NH2/GO-NH2 was attributed to the unique electronic properties, and hydrogen bonding between the nitrogen atom of quinoline and NH2- phenyl fragment of UiO-66-NH2, and N–H of ethylenediamine. GO also offered combined strong π–π interactions on its surface, and the oxygen coverage (~ 50%) on GO within the structure is responsible for the formation of strong hydrogen bonds with quinoline. Theoretical calculation suggested that UiO-66-NH2/GO-NH2 presented a more favourable adsorption energy (− 18.584 kcal/ mol) compared to UiO-66-NH2 (− 16.549 kcal/mol) and UiO-66-NH2/GA (− 13.991 kcal/mol). These results indicate that nanocomposites have a potential application in quinoline capture technologies in the process of adsorptive denitrogenation.
        4,600원
        272.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report the use of face mask materials as a carbon precursor for the synthesis of multi- and single-walled carbon nanotubes (CNTs) in an open-loop chemical recycling process. Novel surgical mask precursors were suspended in toluene and injected into a chemical vapor deposition reactor previously optimized for CNT production using liquid injection. The CNTs were collected and characterized using resonant Raman spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) before being turned into fibrils that were tested for electrical conductance. Once confirmed and repeated for statistical accuracy, a CNT-based Ethernet cable was manufactured and tested using iPerf3 for uplink and downlink speeds exceeding broadband standards worldwide. Radial breathing modes from Raman spectroscopy indicate single walled CNTs (SWCNTs) with diameters ranging from 0.8 to 1.55 nm and this matches well with TEM observations of SWCNTs with 1.5 nm diameter. This work pushes the horizon of feedstocks useful for CNT and SWCNT production in particular; this work demonstrates upcycling of materials fated for disposal into materials with positive net value and plenty of real-world applications.
        4,000원
        273.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The conversion of CO2 into solar fuels by photocatalysis is a promising way to deal with the energy crisis and the greenhouse effect. The introduction of oxygen vacancy into semiconductor has been proved to be an effective strategy for enhancing CO2 photoreduction performance. Herein, TiO2- x nanostructures have been prepared by a simple solvothermal method and engineered by the reaction time. With the prolonging of reaction time, the oxygen vacancy signal gradually increases while the band gap becomes narrow for the as-synthesized TiO2- x nanostructures. The results show that the TiO2- x-6 h, TiO2- x-24 h, and TiO2- x-48 h samples have the main product of CH4 (more) and CO (less) for CO2 photoreduction. Among the three oxygen vacancy photocatalysts, the TiO2- x-24 h sample shows the highest CH4 generation rate of 41.8 μmol g− 1 h− 1. On the basis of photo/electrochemical measurements, the TiO2- x-24 h sample exhibits efficient electron–hole separation and charge transfer capabilities, thus allows much more electrons to participate in the reaction and finally promotes the photocatalytic CO2 reduction reaction. It further confirms that the optimization of oxygen vacancy concentration could facilitate the photoinduced charge separation and accordingly improve photocatalytic CO2 conversion.
        4,000원
        274.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bacterial phytopathogen Pectobacterium causes soft rot disease in several vegetable crops globally, resulting in heavy agricultural losses at both the pre and postharvest stages. The present work was carried out to screen Kimchi cabbage genetic resources conserved at the National Agrobiodiversity Center, Rural Development Administration, Korea, for resistance against the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum KACC 21701 over a period of three years (from 2020 to 2022). Infection of the phytopathogen was carried out at four-leaf stage and for each accession, twenty-five plants per germplasm were infected with KACC 21701. Kimchi cabbage cultivars Wangmatbaechu, Seoulbaechu, and CR Kiyoshi were used as control. Seven-days post-infection, the Disease Index (DI) values were manually recorded from zero to four, zero matched perfectly heathy plants and four completely dead plants. The 682 accessions of Kimchi cabbage exhibited varying degrees of disease resistance to KACC 21701 and thirty accessions, exhibiting a DI≤2, were considered for replication studies. During the replication studies, four landrace germplasms (IT102883, IT120036, IT120044, and IT120048) and one cultivar (IT187919) were confirmed to be moderately susceptible to KACC 21701. Results of the preliminary screening as well as replication studies were documented for the all the 682 germplasms. Addition of such information to the passport data of stored germplasms might serve as potential bio-resource for future breeders and researchers to develop resistant varieties or study the mechanisms involved in resistance of plants to such phytopathogen.
        4,000원
        275.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The impact of heat stress (HS) on reproductive performance and its problems in cows remains to be investigated in Bangladesh. The study was, therefore, aimed to evaluate the effect of HS on fertility and reproductive health problems of dairy cows in a selected area of Bangladesh. A total of 1,095 cows from 500 farms were included in this study. The climate-related data were recorded daily basis for every month in a year and temperature-humidity index (THI) values were calculated to determine the level of HS. Concurrently, data on fertility parameters [number of services per conception (NSC), conception rate (CR) and calving to the first service interval (CFSI)], and reproductive problems were collected through a pre-defined questionnaire. The results show that crossbred [Native x Holstein-Friesian, (HF)] cows were more vulnerable (p < 0.05) to a magnitude of HS effects considering physiological parameters of cows [age, body condition score (BCS), parity and milk yield]. Regarding fertility, HS had no effect on NSC, CR and CFSI in both native and crossbred cows (p > 0.05). The findings on the reproductive problems indicate that HS had significant influence on the prevalence of anestrus (χ2 = 21.814, p < 0.05) and retained placenta (χ2 = 24.632, p < 0.05) in cows. Of note, the prevalence of repeat breeding syndrome was 2.5 folds higher in stress condition than in no stress condition. Abortion and dystocia were not influenced by HS. In conclusion, HS does not influence the fertility parameters of cows studied; however, anestrus and retained placenta are likely to occur under HS conditions in cows.
        4,000원
        276.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Reactive oxygen species (ROS) production and F-actin cytoskeleton dynamics play important roles in the survival rate of blastocysts after the vitrifiedwarming process. However, the protective effects of Mito-TEMPO against cryo-injury and viability through F-actin aggregation and mitochondrial-specific ROS production in vitrificated-warmed bovine embryos have not been investigated. The aims of the present study were to: (1) determine the effects of Mito-TEMPO on embryonic developmental competence and quality by F-actin stabilization during in vitro culturing (IVC), and (2) confirm the effects of Mito-TEMPO through F-actin structure on the cryotolerance of vitrification-warming in Mito-TEMPO exposed in vitro production (IVP) of bovine blastocysts. Bovine zygotes were cultured with 0.1 μM Mito-TEMPO treatment for 2 days of IVC. Mito-TEMPO (0.1 μM) exposed bovine embryos slightly improved in blastocyst developmental rates compared to the non-treated group. Moreover, the viability of vitrified-warmed blastocysts from Mito-TEMPO treated embryos significantly increased (p < 0.05, non-treated group: 66.7 ± 3.2% vs Mito-TEMPO treated group: 79.2 ± 5.9%; re-expanded at 24 hours). Mito-TEMPO exposed embryos strengthened the F-actin structure and arrangement in the blastocyst after vitrification-warming. Furthermore, the addition of Mito-TEMPO into the IVC medium enhanced embryonic survival and quality through F-actin stabilization after the vitrification-warming procedure. Overall, our results suggest that supplementing the culture with 0.1 μM Mito- TEMPO improves the embryonic quality and cryo-survival of IVP bovine blastocysts.
        4,000원
        278.
        2022.12 구독 인증기관 무료, 개인회원 유료
        In order to optimising the sea traffic network efficiency, improving the safety of shipping and the protection of the environment, it is useful to model the sea network and its spatio-temporal characteristics of the ship patterns. These maritime patterns could also be an a-priori set of knowledge for the upcoming Maritime Autonomous Surface Ships (MASS) which are starting to navigate our seas with or without remote human controls. The above concepts are crucial and essential elements for defining and understanding the Maritime Situational Awareness (MSA). Nowadays the applied methodologies for modelling the maritime traffic use large scale of database for extracting the patterns. The Knowledge Discovery from Data (KDD), strictly connected with Data Mining (DM) is growing significantly to modelling the behaviour of the vessels in relations to their surroundings. This is just one example that confirms the growing up of the cloud computing usage for maritime applications too. Besides these applications there are also a continuous and fast evolution of the IT services, which more often than not means data centre scale-ups with consequent improve of power consumptions. This paper is a case study based on real world data assessing a multi-objective energy consumption analysis. It is based on the comparison between the traditional air conditioning structures known as Heating, Ventilation and Air Conditioning (HVAC) and the Free Cooling Technique (FCT) in order to reduce the data centre power consumption keeping the same number of computational calculations performed.
        4,000원
        279.
        2022.12 KCI 등재 구독 인증기관·개인회원 무료
        최근 가상현실 기술, AR 기술, 스포츠 센싱 기기가 등장하면서 '메타 유니버 스'라는 개념이 사람들 앞에 나타났다. 현재 메타버스의 대두는 페이스북 창업 자 마크 저커버그가 페이스북을 메타(Meta)로 개명한 것이다. 그는 페이스북을 실제 세계와 매우 유사한 가상 세계에서 스텔스 기기를 착용하도록 요구하는 블록체인 기술과 체감 기술이라고 정의했다. 그것은 일종의 사회활동이기 때문 에 필연적으로 다양한 사회적 관계가 생겨나고, 나아가 이러한 사회관계에 대 한 침해, 즉 위법행위와 범죄행위가 생길 수 있다. 그 중에서도 성범죄는 신체 적 권리뿐만 아니라 피해자의 정신적 이익에도 관여하는 독특한 범죄다. 메타버스(Metaverse)는 특별한 스텔스 장비에 의존해 자연인을 하나의 가상 세계로 끌어들였고, 그곳에서 사람들은 현실세계에 가까운 경험을 즐길 수 있 다. 이 가운데는 사이버 범죄와 유사한 일정한 성적 범죄행위가 존재하기도 하 지만, 성적 범죄행위는 사람의 신체에 대한 의존성이 높기 때문에 메타버스 내 에서 규범화하는 것이 이전의 다른 범죄보다 더욱 어렵다. 현재 중국의 입법은 아직 메타버스 내에서의 범죄에 관한 법규정이 없으며 사이버 범죄에 의한 귀 납이나 사회적 평가와 침해의 사회적 이익관계에 따라 비교적으로 접근하는 다 른 법규정에 의해서만 규제할 수 있다.
        280.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the effects of ImmunoSEB as an immune-booster additive on the performance of broiler chicks. A total of 1150 broiler chickens were randomly allotted to three treatments on the basis of body weight (10 pens per treatment with 40 broilers in each pen): the control (CON), CON + ImmunoSEB 0.025% in feed (SEB25), and CON + ImmunoSEB 0.050% in feed (SEB50). The experiment was conducted for d 42 in three phases (phase 1, d 0–14; phase 2, d 15–28; and phase 3, d 29–42). There were significant differences in the average daily gain (ADG) and feed intake. The ADG at d 14 in the SEB50 treatment was greater than that in the CON treatment. The overall ADG in the SEB50 treatment was greater than that in the CON treatment. During d 0–14, the feed intake of chickens in the SEB50 treatment increased compared to that in the CON treatment. The crude protein and lysine digestibility improved in the SEB25 and SEB50 treatments compared to those in the CON treatment at d 28. Superoxide dismutase concentration significantly increased in the SEB50 treatment compared to that in the CON treatment. The interleukin-1β and tumor necrosis factor-α concentrations were higher in the cecum of chickens in the CON treatment than in the SEB25 and SEB50 treatments. A lower population of E. coli was detected in the ileum and cecum of broilers fed the SEB50 diet compared to those of broilers fed the CON diet. The overall result showed the beneficial effects of using ImmunoSEB at a dose of 0.050% in broiler chickens.
        4,200원