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        검색결과 9,767

        1481.
        2021.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, photocatalytic degradation of ammonia in petrochemical wastewater is investigated by solar light photocatalysis. Two-dimensional ultra-thin atomic layer structured MoS2 are synthesized via a simple hydrothermal method. We examine all prepared samples by means of physical techniques, such as SEM-EDX, HRTEM, FT-IR, BET, XRD, XPS, DRS and PL. And, we use fullerene modified MoS2 nanosheets to enhance the activity of photochemically generated oxygen (PGO) species. Surface area and pore volumes of the MoS2-fullerene samples significantly increase due to the existence of MoS2. And, PGO oxidation of MB, TBA and TMST, causing its concentration in aqueous solution to decrease, is confirmed by the results of PL. The generation of reactive oxygen species is detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and the PGO effect increase in the case with modified fullerene. The experimental results show that this heterogeneous catalyst has a degradation of 88.43% achieved through visible light irradiation. The product for the degradation of NH3 is identified as N2, but not NO2−or NO3−.
        4,600원
        1482.
        2021.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, Ni nanoparticle supported by graphene oxide (GO) (Ni-GO) is successfully synthesized through hydrothermal synthesis and calcination, and Cr(VI) is extracted from aqueous solution. The morphology and structure of Ni- GO composites are characterized by scanning electron microscopy (SEM), trans mission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HRTEM) and XRD confirms the high dispersion of Ni nanoparticle after support by GO. Loading Ni on GO can obviously enhance the stability of Ni-GO composites. It can be calculated from TGA that the mass percentage of Ni is about 60.67%. The effects of initial pH and reaction time on Cr(VI) removal ability of Ni-GO are investigated. The results indicate that the removal efficiency of Cr(VI) is greater than that of bared GO. Ni-GO shows fast removal capacity for Cr(VI) (<25 min) with high removal efficiency. Dynamic experiments show that the removal process conforms to the quasi-second order model of adsorption, which indicates that the rate control step of the removal process is chemical adsorption. The removal capacity increases with the increase of temperature, indicating that the reaction of Cr(VI) on Ni-GO composites is endothermic and spontaneous. Combined with tests and characterization, the mechanism of Cr(VI) removal by rapidly adsorption on the surface of Ni-GO and reduction by Ni nanoparticle is investigated. The above results show that Ni-GO can be used as a potential remediation agent for Cr(VI)-contaminated groundwater.
        4,000원
        1483.
        2021.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Composite materials offer distinct and unique properties that are not naturally inherited in the individual materials that make them. One of the most attractive composites to manufacture is the aluminum alloy matrix composite, because it usually combines easiness of availability, light weight, strength, and other favorable properties. In the current work, Powder Metallurgy Method (PMM) is used to prepare Al2024 matrix composites reinforced with different mixing ratios of yttrium oxide (Y2O3) particles. The tests performed on the composites include physical, mechanical, and tribological, as well as microstructure analysis via optical microscope. The results show that the experimental density slightly decreases while the porosity increases when the reinforcement ratio increases within the selected range of 0 ~ 20 wt%. Besides this, the yield strength, tensile strength, and Vickers hardness increase up to a 10 wt% Y2O3 ratio, after which they decline. Moreover, the wear results show that the composite follows the same paradigm for strength and hardness. It is concluded that this composite is ideal for application when higher strength is required from aluminum composites, as well as lighter weight up to certain values of Y2O3 ratio.
        4,000원
        1484.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Today, energy bars are consumed not only as snacks but also as meal replacement foods. Convenience and nutritional supplementation are the main factors accounting for the increasing use of energy bars. Two hundred Chinese customers who attended the China Fisheries & Seafood Exposition in China, and had no inhibitions about consuming cereal bars were selected. The questionnaire was composed of CATA choices that selected both the reasons for liking and disliking four different types of cereal bars, namely topokki flavor (hot pepper paste), seaweed flavor, kimchi flavor, and ginseng flavor cereal bars with 10% of dried anchovy content produced by BadaOne Co. (Seoul, Korea). The purpose of the study was to investigate Chinese consumer’s attitudes and acceptance of different flavored cereal bars containing protein and calciumrich anchovy. For the selected Chinese customers, the acceptance score for the seaweed flavor was the highest, followed by topokki, red ginseng, and kimchi. The acceptance for the topokki flavor was higher than for seaweed for the attributes of color except for general acceptance, flavor, aroma, and texture. The results of the survey showed that the acceptance of kimchi was the lowest, contrary to earlier predictions. The results of the Check All That Apply (CATA) analysis showed that the reasons for liking the seaweed & anchovy flavor were the most diverse, and there was no reason chosen for disliking this flavor. The reasons for liking this flavor were listed as sweet flavor, healthy, seafood flavor, malty flavor, texture, new/unique, and umami. In the case of topokki and kimchi, the reason for disliking the flavor was umami, and in the case of red ginseng, the ginseng flavor was the reason for both likes and dislikes. CA analysis showed that both the flavor and emotional factors were positive for seaweed & anchovy and topokki, but negative for red ginseng. As a result, seaweed & anchovy flavor, which is familiar to the Chinese people, should be the first cereal bar considered for a launch.
        4,000원
        1485.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Three different cats who had chronic kidney disease (CKD) were treated for more than one month with fluid therapy in an animal clinic. Although this long-term treatment and hospitalization, there was no clinical improvement in clinical signs as well as serum biochemical indexes including blood urea nitrogen (BUN), creatinine (CREA), and phosphate (PHOS). All cases were then injected three times with allogeneic stem cells through an intravenous route for treatment on Day 0, 7, and 14 or 30. On the same day, clinical observation and blood tests for serum biochemistry were conducted together. Upon administrating stem cells to the CKD cats, clinical conditions and the indexes of BUN and CREA were clinically improved within normal ranges. Additionally, one of the cats who had the renal cysts presented clinical improvement with showing decreased cysts size than before.
        4,000원
        1486.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        비모란 선인장 ‘Ahwang’ 품종이 2016년에 국립원예특작과 학원에서 육성되었다. 증식력이 우수한 밝은 황색 ‘Ahwang’ 품종 육성을 위해서, 황색 ‘Hwangun’품종을 모본으로, 황색 ‘0930001’ 계통을 부본으로 하여 2012년 6월 25일에 교배하였다. 어린 비모란 선인장을 2014년 이전에 삼각주에 2번 접목하여 계통을 양성하였으며 2014년부터 2016년까지 총 3회에 걸쳐 생육특성을 조사하였다. ‘Ahwang’ 품종의 모구는 편원형 모양에 황색 구색(Y9A)이다. 모구는 평균 8.6개의 능(rip)과 2.7mm의 짧은 직립형 회색 가시를 가지고 있고 혹(tubercle)이 돌출된 형태를 띠고 있다. 10개월 재배 후 ‘Ahwang’ 품종의 구직경은 44.5mm였으며 자구는 평균 26.9개가 생성되었다. ‘Ahwang’ 품종은 모구 능마다 황색의 자구가 3-4개가 착생되었다. 2016년 육성계통 평가회에서 ‘Ahwang’ 품종은 기호도 점수 3.9을 받았다. 이 품종은 2018년 5월 16일 국립종자원에 등록되었으며 식물신품종보호법에 의해 품종보호(등록번호 7193)를 받게 되었다.
        4,000원
        1487.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae is a highly contagious disease that leads to enormous economic losses in pig industry, worldwide. Of the many virulence factors produced by the causative bacterium, ApxA exotoxins have been considered as the most important contributor to the disease. The toxins are classified into four different types; ApxIA, ApxIIA, ApxIIIA and ApxIVA. Uniquely, ApxIVA is expressed across all serotypes of A. pleuropneumoniae only during in vivo infection in pigs. Active research focusing on resolving the precious roles and mechanisms of the toxins is still at its primitive stage. In this study, we report the development of monoclonal antibodies against the two major antigenic epitopes that were characterized in our previous study incorporating the in silico predictions and protein modeling analyses. Recombinant proteins of the selected epitopes were expressed and purified after molecular cloning of the corresponding partial genes in E. coli expression system. Subsequently, we generated hybridomas with lymphoid cells from the rats immunized with the recombinantly expressed proteins of Apx. Consequently, hybridomas exhibiting strong productivity of the monoclonal antibodies were selected for downstream verifications that tested for reactivity and specificity using Western blot and ELISA. Our results strongly suggest the potential application of the monoclonal antibodies developed in this study as useful reagents to further elaborate the mechanism of the A. pleuropneumoniae infection in pig.
        4,000원
        1488.
        2021.06 구독 인증기관 무료, 개인회원 유료
        Jeju Island has been isolated historically from the central government socially, economically and politically as it has own insularity of the closed space and resources. A few cultural aspects for survival have grown in these harsh environments. Especially, Jeju's unique community culture of cooperation at any time was taken place while it kept the family system for guaranteeing the personal self-regularity, so called Kwendang. But the conflicts were seen from 'Kwendang' culture while population inflowed increasingly into Jeju Island today. There is a need to provide political solutions for the social issues arisen from confronting with the central government.
        4,000원
        1489.
        2021.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Even in an era where 8-meter class telescopes are common, small telescopes are considered very valuable research facilities since they are available for rapid follow-up or long term monitoring observations. To maximize the usefulness of small telescopes in Korea, we established the SomangNet, a network of 0.4{1.0 m class optical telescopes operated by Korean institutions, in 2020. Here, we give an overview of the project, describing the current participating telescopes, its scienti c scope and operation mode, and the prospects for future activities. SomangNet currently includes 10 telescopes that are located in Australia, USA, and Chile as well as in Korea. The operation of many of these telescopes currently relies on operators, and we plan to upgrade them for remote or robotic operation. The latest SomangNet science projects include monitoring and follow-up observational studies of galaxies, supernovae, active galactic nuclei, symbiotic stars, solar system objects, neutrino/gravitational-wave sources, and exoplanets.
        4,600원
        1490.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the near-complete genome sequence of the novel reassortant H1N2 influenza A virus strain A/swine/Korea/KS60/2016 is reported. Sequences of the hemagglutinin (HA), neuraminidase (NA), and polymerase basic 2 (PB2) genes were analyzed, revealing that the isolates contain segments from previous Korean swine H1N2 strains. Additionally, the remaining genes of this strain originated from human H1N1 strains in 2009.
        3,000원
        1491.
        2021.06 구독 인증기관 무료, 개인회원 유료
        Salivary glands are exocrine glands that secrete saliva into the oral cavity, and secreted saliva plays essential roles in oral health. Therefore, maintaining the salivary glands in an intact state is required for proper production and secretion of saliva. To investigate a specific signaling pathway that might affect the maintenance of mouse submandibular gland (SMGs), RNA sequencing was performed. In SMGs, downregulated expression patterns of Rho-associated protein kinase (ROCK) signaling pathway-related genes, including Rhoa, Rhob, Rhoc, Rock1, and Rock2, were observed. Gene expression profiling analyses of these genes indicate that the ROCK signaling pathway is a potential signal for SMG maintenance.
        3,000원
        1492.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In addition to physical risks such as electrical, chemical, and mechanic ones in the workplace, psychosocial risks are also raising as an important issue in recent years in connection with human rights and work-life balance policies. The purpose of this study is to confirm the degree of effect of the psychosocial risk management plan at the workplace on workers through logistic regression analysis. Input data for logistic regression analysis is the results of a survey of 4,558 people conducted by the Institute for Occupational Safety and Health were used. There are 9 independent variables, including the change a workplace and confidential counseling, and the dependent variable is whether the worker feels the effect on the psychosocial risk management plan. As a result of this study, changes in work organization, dispute resolution procedures, provision of education program, notification of the impact of psychosocial risks on safety and health, and the persons in charge of solving psychosocial problems are shown effective in reducing worker’s psychosocial risks. This study drives which of the management plans implemented to reduce the psychosocial risk of workers in the workplace are effective, so it can contribute to the development of psychosocial risk management plans in the future.
        4,000원
        1493.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        확산강조 영상은 자기공명영상에서 진단에 매우 중요한 역할을 차지하고 있다. 또한, 높은 b-value를 요구하는 검사가 늘어나는 추세로 확산강조 영상을 얻기 위하여 검사 시간이 길어지게 되며 인공물과 전체적인 신호 감소가 동반하게 된다. 본 연구에서는 확산강조 영상에서 확산 방법을 3스캔 추적 확산강조 영상(3-scan trace diffusion weighted image, tDWI) 에서 DTI의 원리를 적용한 대각선 확산강조 영상(diagonal diffusion weighted image, dDWI)로 변경하여 획득 하였을 때, 두 방법 간의 검사 시간의 단축과 영상을 비교 평가하였다. 농도가 0에서 50%까지 10% 간격인 팬텀을 제작하여 제한된 확산(restrict diffusion)을 단발 스핀에코평면영상(single shot spin echo echo planar, SE-EPI) 기법을 사용하여 검사하였다. 확산 방법을 변경하며 tDWI와 dDWI 검사를 진행하였으며, 획득한 영상을 Image J 프로그램을 이용 하여 농도별 동일한 관심 체적을 설정하여 신호를 측정 후 분석방법은 독립 T-test를 이용하고, 통계적 분석은 SAS를 통해 신호 대 잡음 비와 대조도 대 잡음 비를 비교·분석하였다. p-value 0.05를 기준으로 유의성을 검증하였다. b0를 제외한 b100 이상은 전반적으로 신호 대 잡음 비, 대조도 대 잡음 비가 크며, p-value 0.05 이상으로 나타났다. 확산 방법 간 유의하지 않지만, 전반적으로 dDWI이 tDWI에 비해 평균이 높았다. dDWI 방법이 tDWI에 비해 화질의 변화 없이 검사 시간이 18.35% 단축되는 효과가 있으며, 신호 대 잡음 비와 대조도 대 잡음 비가 소폭 향상된 것으로 나타나 다른 부위의 확산강조 영상을 사용하는 검사에 적용 시 유용할 것으로 사료 된다.
        4,000원
        1494.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cryopreservation is a widely-used efficient means of long-term sperm preservation. However, unlike other types of semen, cryopreserved boar semen has reduced fertility and the efforts continue to optimize post-thawing sperm recovery. In this study, we evaluated the effects of various washing solutions (Hulsen solution, labmade DPBS and commercial DPBS) on post-thawing porcine sperm kinematics (CASA system), viability (SYBR-14/PI) and acrosome integrity (PSA/FITC). We also examined the effect of washing-centrifugation on frozen-thawed semen kinematics. The results indicate that type of washing solution and post-thawing centrifugation alters parameters linked to sperm quality (total motility, progressive motility, viability and acrosome integrity). Significantly higher (p < 0.05) motility and progressive motility were obtained when cryopreserved semen was processed with Hulsen solution. The postthaw percentage of live and intact acrosomal sperm was significantly higher in group 1 (Hulsen solution) as compared to other groups. Following thawing-centrifugation, the results showed significantly higher motility and progressive motility in group 1 than other groups. However, the latter two DPBS groups did not differ statistically. Taken together, Frozen-thawed spermatozoa motility, acrosome integrity and viability can be affected by the type of washing solution used. Moreover, centrifugation of frozenthawed semen has an unfavorable effect on total motility and progressive motility.
        4,000원
        1495.
        2021.06 구독 인증기관 무료, 개인회원 유료
        This study summarizes the recent cutting-edge approaches for dentin regeneration that still do not offer adequate solutions. Tertiary dentin is formed when odontoblasts are directly affected by various stimuli. Recent preclinical studies have reported that stimulation of the Wnt/β-catenin signaling pathway could facilitate the formation of reparative dentin and thereby aid in the structural and functional development of the tertiary dentin. A range of signaling pathways, including the Wnt/β-catenin pathway, is activated when dental tissues are damaged and the pulp is exposed. The application of small molecules for dentin regeneration has been suggested as a drug repositioning approach. This study reviews the role of Wnt signaling in tooth formation, particularly dentin formation and dentin regeneration. In addition, the application of the drug repositioning strategy to facilitate the development of new drugs for dentin regeneration has been discussed in this study.
        4,000원
        1496.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract: Mental health problems leading to depression have become a critical concern due to the growing engagement of people on social media platforms. Several past approaches have been implemented by analyzing the pattern and behaviour of the posts by users on social networking sites. This research study proposed a system for predicting users who may be depressed, based on the characteristics of users who is already affected. A combination of both the tweet-level and the user-level architecture was used to generate a more robust and reliable system where semantic embeddings trained from advanced neural networks were adopted under the tweet-level. SVM with Word2Vec and TF-IDF has been used and yielded an accuracy of 98.14% and recall of 95.63%.
        4,000원
        1497.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Physical activity and exercise is an important step in the journey of a healthy lifestyle. It reduces the risk of developing many diseases like diabetes, cardiovascular diseases, and even cancer. In today’s world, we spend most of our time sitting in front of a computer or mobile phones for work and entertainment. This is one of the leading factors in a lack of physical activities and thus a decrease in the fitness level of many individuals. In this paper, we design a mobile 2D platformer game where progress inside the game world is dependent on physical activity in the real world. The game has two modes namely adventure and story mode. This design can motivate people to lead an active and healthy lifestyle. The physical activity monitoring is done solely through the pedometer of a smartphone held by the user while playing the game. The number of steps walked by the user determines the number of revives inside the adventure mode of the game. There are three levels in the story mode which are unlocked by walking more than a certain number of steps in the real world.
        4,000원
        1498.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated whether a tool such as a game toy can be used as an augmented reality tool, and a system model that can be extended to a game element using wireless communication technology such as Bluetooth and a controllable module. This is an online ship type game using augmented reality technology and wireless communication technology. In addition, the existing game element was extended by applying a smartphone app control module. The existing game method uses the method of playing the game with only limited functions in the same space. This study expands to augmented reality-based games by implementing contents in a way that matches game objects with the grafting of augmented reality technology, and uses various items that emerge as the limit of reality. Therefore, we standardized the size of game objects so that they can be used three-dimension in all spaces on the screen according to the space arrangement such as overlapping prevention, distance, and height, and augmented reality technology was used to allow the game to be played by manipulation of a smartphone. In addition, we propose a system framework-based model that can be applied to various games, and a framework that can implement various augmented reality environments. The augmented reality-based battle game proposed in this study combines a knowledge-based augmented reality system that can be extended to game elements by modularizing the function of a toy through+ a context-aware agent based on context information and an intelligent DB based on domain knowledge.
        4,300원
        1500.
        2021.06 구독 인증기관 무료, 개인회원 유료
        Teacher professional development is critical because teachers play a pivotal role in students' positive learning experience in schools. In particular, teachers' systematic class goal-setting practice is important for their performance outcomes such as effective classroom management and student learning. This study investigates the effects of teachers' engagement in class goal-setting activities using strategies derived from Analysis, Design, Development, Implementation, and Evaluation (ADDIE) framework as a systematic guideline by exploring the relationship among the four variables: teachers' class goal-setting, their partnership with stakeholders, teacher effectiveness, and student satisfaction. By using Process analysis techniques to estimate the dual mediation model on data from 55 elementary school teachers and their 1790 students, the findings indicate the positive relationship between teachers' systematic efforts for their class goal setting and student satisfaction was fully and sequentially mediated by teachers' partnership activities with the stakeholders and perceived teacher effectiveness. The findings propose the importance of teachers' systematic goal-setting strategies in their classes, which can be developed for professional development opportunities leading to successful performance outcomes. The study also highlights the various indirect effects produced by teachers' engagement in class goal setting. The practical implications of the research as well as theoretical contributions for teachers are discussed.
        4,200원