• Title/Summary/Keyword: basic materials

Search Result 4,554, Processing Time 0.041 seconds

Relationship assessment of the residual antibiotics and the amount of N component by different production stages of liquid fertilizer from livestock manure (가축분뇨 유래 액비 생산단계별 항생제 잔류 농도와 질소 성분 함량과의 상관성 평가)

  • Song-Hee Ryu;Jin-Wook Kim;Young-Kyu Hong;Sung-Chul Kim;Jun-Hyeong Lee;Eun-A Jeong;Chang-Gyu Kim;Young-Man Yoon;Oh-Kyung Kwon
    • Journal of Applied Biological Chemistry
    • /
    • v.66
    • /
    • pp.258-265
    • /
    • 2023
  • After application of veterinary antibiotics, they may be partially metabolized before they are excreted by feces or urine either as unaltered form or as metabolites. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based compost and liquid fertilizer on farmlands and lead to secondary pollution. The objective of this study was to compare the residual concentrations of 6 veterinary antibiotics by different production stages of liquid fertilizer from livestock manure recycling facilities. The relationship between concentration change of the residual antibiotics and the amount of liquid fertilizer component was also assessed. Pre-treatment showed the recovery of 63.4-106.7% at ppb level and the limit of quantification of 0.009-0.037 ㎍/L.As the result of analyzing the relationship between the residual concentrations of antibiotics and the amount of N component in liquid fertilizer by different production stages, the residual concentrations of antibiotics and N tended to decrease as the stabilization period elapsed during the liquid fertilization process. Average concentrations of sulfamethazine in raw materials, middle and final products of liquid fertilizer were 40.85, 26.17, 3.54 ㎍/L, respectively. Those of chlortetracycline decreased from 2.32 to 1.25 ㎍/L. The other 4 antibiotics also showed a decreasing trend by different production stages of liquid fertilizer. The amount of liquid fertilizer component N decreased from 0.21 to 0.096% by production stages of liquid fertilizer. It is considered that the correlation between residual antibiotic concentrations and N content can be applied as basic data for setting antibiotic reduction indicators.

A Study on Improving of Access to School Library Collection through Elementary School Students' DLS Search Behavior Analysis (초등학생의 학교도서관 자료 검색 행태 분석을 통한 독서로DLS의 자료 접근성 향상 방안 고찰)

  • Bongsuk Kang;Jeonghoon Lim
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.58 no.2
    • /
    • pp.317-342
    • /
    • 2024
  • The purpose of this study is to explore ways to improve accessibility to school library materials through analysis of elementary school students' information search behavior in DLS. Accordingly, the DLS search process was recorded for 26 students attempting a DLS search in the school library, and data was collected through a pre-search questionnaire on overall information needs and a post-search questionnaire on the search process and results. As a result of the analysis, satisfaction was found to be low when the main purpose of DLS use was simple leisure reading, when the search time and number of search words were long, and when there were too many search results. Accordingly, it was emphasized that curriculum subject-related metadata elements should be developed and a curriculum subject-specific thesaurus should be built and used to build lists and support user searches. In addition, it was suggested that the basic functions provided in external searches should be included, and a foundation should be laid in terms of resources and curriculum to systematically provide information utilization education to elementary school students who lack the ability to select search terms and judge the suitability of results after the search. It was proposed to provide an integrated search service with external resources and a personalized book recommendation service.

Review on the application of single-shell tunnel in Korea (싱글쉘 터널의 국내 적용에 대한 고찰)

  • Sangpil Lee;Heesang Ha;Donghyun Kim
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.26 no.3
    • /
    • pp.223-242
    • /
    • 2024
  • Single-shell tunnels, introduced to South Korea in the early 2000s, have not been adopted for the main tunnels of roads or railways over the past two decades despite several attempts starting with the Gwangju City Bypass. This reluctance likely arises from concerns about the long-term performance of supporting materials and the absence of relevant criteria and specifications. However, recent progress, including the incorporation of high-strength shotcrete standards and corrosion-resistant rock bolt specifications, alongside equipment and technique enhancements, necessitates a reassessment of single-shell tunnels. While the single-shell tunnel method offers advantages in environmental impact, construction cost and period compared to the conventional NATM, it is crucial to address the challenges, such as limited design and construction experience, incomplete detailed standards, and insufficient construction specifications, through further research and pilot projects. This paper reviewed the basic principles of single-shell tunnel, current application and research status, technical development trends, criteria and specifications, and remaining challenges. It aims to reignite discussions on the feasibility of applying single-shell tunnels in South Korea.

Structural analysis, anti-inflammatory activity of the main water-soluble acidic polysaccharides (AGBP-A3) from Panax quinquefolius L berry

  • Zhihao Zhang;Huijiao Yan;Hidayat Hussain;Xiangfeng Chen;Jeong Hill Park;Sung Won Kwon;Lei Xie;Bowen Zheng;Xiaohui Xu;Daijie Wang;Jinao Duan
    • Journal of Ginseng Research
    • /
    • v.48 no.5
    • /
    • pp.454-463
    • /
    • 2024
  • Background: Panax quinquefolius L, widely recognized for its valuable contributions to medicine, has aroused considerable attention globally. Different from the extensive research has been dedicated to the root of P. quinquefolius, its berry has received relatively scant focus. Given its promising medicinal properties, this study was focused on the structural characterizations and anti-inflammatory potential of acidic polysaccharides from the P. quinquefolius berry. Materials and methods: P. quinquefolius berry was extracted with hot water, precipitated by alcohol, separated by DEAE-52-cellulose column to give a series of fractions. One of these fractions was further purified via Sephadex G-200 column to give three fractions. Then, the main fraction named as AGBP-A3 was characterized by methylation analysis, NMR spectroscopy, etc. Its anti-inflammatory activity was assessed by RAW 264.7 cell model, zebrafish model and molecular docking. Results: The main chain comprised of α-L-Rhap, α-D-GalAp and β-D-Galp, while the branch consisted mainly of α-L-Araf, β-D-Glcp, α-D-GalAp, β-D-Galp. The RAW264.7 cell assay results showed that the inhibition rates against IL-6 and IL-1β secretion at the concentration of 625 ng/mL were 24.83 %, 11.84 %, while the inhibition rate against IL-10 secretion was 70.17 % at the concentration of 312 ng/mL. In the zebrafish assay, the migrating neutrophils were significantly reduced in number, and their migration to inflammatory tissues was inhibited. Molecular docking predictions correlated well with the results of the anti-inflammatory assay. Conclusion: The present study demonstrated the structure of acidic polysaccharides of P. quinquefolius berry and their effect on inflammation, providing a reference for screening anti-inflammatory drugs.

Antioxidative Activity of Aralia elata Shoot and Leaf Extracts (두릅 순 및 잎 추출물의 항산화 효과)

  • Cha, Jae-Young;Ahn, Hee-Young;Eom, Kyung-Eun;Park, Bo-Kyung;Jun, Bang-Sil;Cho, Young-Su
    • Journal of Life Science
    • /
    • v.19 no.5
    • /
    • pp.652-658
    • /
    • 2009
  • The comparative activities of aqueous, ethanol, and methanol extracts from Aralia elata shoot (AES) and leaf (AEL) were tested by in vitro experimental models of linoleic acid peroxidation by thiocyanate and thiobarbituric acid (TBA) methods and scavenging activities of free radicals by DPPH (${\alpha}$,${\alpha}$'-diphenyl-${\beta}$-picrylhydrazyl). In addition, bio-active materials (phenolic compounds and minerals) were also measured. The extract yield of each solvent extracted from AES and AEL was 3.08% and 3.13% in aqueous, 0.58% and 0.66% in ethanol, and 0.81% and 1.73% in methanol, respectively. The highest extract yield was found in the aqueous extract from AEL. Major mineral contents (mg%) of AES and AEL were 575.7 and 759.3 in Ca, 353.5 and 330.0 in K, and 31.3 and 31.0 in Mg, respectively. The highest free radical scavenging activity was found in the aqueous extract by 28.69% at 0.1% additional level from AES and in the methanol extract by 92.36% at 0.1% additional level from AEL. Free radical scavenging activity was stronger in AEL than in AES. In antioxidative activities determined by thiocyanate and TBA methods against lipid peroxidation using linoleic acid, ethanol extracts from AEL showed the highest antioxidative activity at all treatment concentrations. These results may provide the basic data to understand the biological activities of bio-active materials derived from AES and AEL.

A Study about Development of Environment Printing Technology and $CO_2$ (환경 인쇄 기술의 발전과 인쇄물의 $CO_2$ 발생량에 관한 연구)

  • Lee, Mun-Hag
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.30 no.3
    • /
    • pp.89-114
    • /
    • 2012
  • For as to world, the concern about the environment problem is enhanced than any other time in the past because of being 21 century. And the environment problem is highlighted as the world-wide issue. The time of the environment problem intimidates the alive of the mankind and presence of an earth over the time. It becomes the essentiality not being selection in the personal living or the economical viewpoint now to prepare for the climatic modification. As to the company management, the green growth period which it excludes the environment management considering an environment, cannot carry on the company the continued management comes. That is, in the change center of the management paradigm, there is the environment management. Nearly, the greenhouse gas which the publication industry is the environmental toxic material like all industries is generated. The greenhouse gas is ejected in the process of running the manufacturing process and print shop of the various kinds material used as the raw material of the book. Particularly, the tree felling for getting the material of the paper is known to reach the direct influence on the global warming. This study does according to an object it considers and organizes the environment parameter based on this kind of fact as to the publication industry. And it is determined as the reference which is used as the basic materials preparing the case that carbon exhaust right transaction(CAP and TRADE) drawing are enforced in all industries and is sustainable the management of the publication industry and reduces the environmental risk among the company many risk management elements and plans and enforces the publication related policy that there is a value. In the printing publication industry, this study tried to inquire into elements discharging the environmental pollutant or the greenhouse gas. Additionally, in the printed publication production process, it tried to inquire into the effort for an environment-friendly and necessity at the printing paper and the printers ink, regarded as the element discharging the greenhouse gas all kinds of the printing materials, operation of the print shop and all kinds of the machines and recycle process, and etc. These considerations make these industrial field employees aware of the significance about a conservation and environmental protection. They try to give a help in the subsequent study producing quantitatively each environmental parameter emission of green house gas. This makes the calculation of the relative $CO_2$ output reproached ultimately possible. Meanwhile, in a sense, many research protects and improving an environment in connection with the contents of research at the printing publication industrial field is in progress. There will be the voluntary human face that it has to protect an environment but this can not do by the outside factor according to all kinds of environment related law and regulation. Anyway, because of acting on company management as the factor of oppression, the increase of this environment-related correspondence cost could know that the research that the environment loading relates with a procurement and development, environment management system introduction, quality control standard, including, normalizing including a material, and etc. through the part of the effort to reduce the cost low was actively in progress. As to the green growth era, as follows, this paper prescribed the subject and alternative of the print publication industry. It is surrounded by the firstly new digital environment and the generation of the subject. And secondly the printing industry is caused by the point of time when the green growth leaves by the topic which is largest in the global industry and it increases. The printing publication industry has to prepare the bridgehead for the environment-friendly green growth as the alternative for this resolution with first. The support blown in each industry becomes the obligation not being selection. Prestek in which the print publishing was exposed to spend many energies and which is known as the practice of the sustainable print publishing insisted that it mentioned importance of the green printing through the white pages in 2008 and a company had to be the green growth comprised through the environment-friendly activity. The core management for the sustainable printing publication industry presented from Presstack white pages is compacted to 4 words that it is a remove, reduce, recover, and recycle. Second, positively the digital printing(POD) system should be utilized. In the worldwide print out market, the digital printing area stops at the level of 10% or so but the change over and growth of the market of an analog-to-digital will increase rapidly in the future. As to the CEO Jeff Hayes of the Infoland, the offset print referred to that it of the traditional method got old and infirm with the minor phase of the new printing application like the customer to be wanted publication and the print of the digital method led the market. In conclusion, print publishers have to grasp well the market flow in the situation where a digitalization cannot be generalized and a support cannot avoid. And it keeps pace with the flow of the digital age and the recognition about the effort for the development and environment problem have to be raised. Particularly, the active green strategy is employed for the active green strategy.

A Study on Physical Activities in the Teachers' Guidance Manual for the Nuri Curriculum of Four-Year-old Children -Focusing on Pre-service Early-childhood Teachers' Simulated Instruction - (예비유아교사의 모의수업을 통해 본 「4세 누리과정 교사용 지도서 신체활동」 분석)

  • Hong, Kil Hoe;Youn, Hea Ja
    • Korean Journal of Childcare and Education
    • /
    • v.11 no.2
    • /
    • pp.177-200
    • /
    • 2015
  • The purpose of this study is to analyze physical activities in 'Teachers' Guidance Books for the Nuri Curriculum of 4-year-old children' through simulated instruction of pre-service teachers and, through this, to help them better perform physical activities in their field education for early-aged. The subjects of the study were 30 sophomore students in the early-aged children's Education Department in their 2ndsemester of K University located in Gyeonggi-province. For the analysis of physical activities in 'Teachers' Guidance Books for Nuri Curriculum of 4-year-old children', a qualitative study was conducted and data were collected through informal interviews, reflective journals of pre-service teachers and 30 sessions of education assessment sports. The results of the analysis on the physical activities in 'Teachers' Guidance Books for Nuri Curriculum of 4-year-old children' are as follows; first, preliminary teachers of early-aged children understood the major goal of physical activities in 'Teachers' Guidance Books for Nuri Curriculum of 4-year-old children' as 'expressing.' Second, the teachers thought careful analysis is required on media such as 'video, illustration books, sounds, picture materials' presented together with physical activities in 'Teachers' Guidance Books for Nuri Curriculum of 4-year-old children.' Third, teachers pointed out 'activities that were difficult to understand for pre-service early childhood teachers' and 'improperly presented activities different from the title' as errors and problems in the performance of the Nuri Curriculum. Fourth, as for 'points to make improvement on', pre-service early childhood teachers' requested basic physical activities before the actual activities, the provision of proper actual materials, the necessity of active demonstrations of teachers and making a regulation for the situation of physical activities by early-aged children and teachers together. The results of the study illustrate that deep contemplation and judgment is required of the teachers before conducting physical activities of the Nuri Curriculum.

Study on the Silicone Contact Lens Using AA and BMA (AA(Acrylic acid)와 BMA(Butyl methacrylate)를 이용한 실리콘 콘택트렌즈에 관한 연구)

  • Kim, Tae-Hun;Yae, Ki-Hun;Kweon, Young-Seok;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.11 no.3
    • /
    • pp.259-265
    • /
    • 2006
  • We polymerized material of AA(Acrylic acid) and BMA(butyl methacrylate) to make up for the weak points of hydrogel contact lens. The synthesis process of silicone synthesis is as follows. Acrylate-PDMS(Polydimethylsiloxane)-Urethane prepolymer was composed after Diisocynate reacted with HEMA(2-hydroxyethylmethacrylate) under the catalyst and it reacted again with bis(hydroxyalkyl) terminated poly(dimethylsiloxane) with high oxygen transmissibility characteristics. HEMA(2-hydroxyethylmethacrylate) was used to make prepolymer that can be polymerized and the urethane was used to improve elasticity and oxygen transmissibility, copolymerization was performed with conventional hydrogel contact lens materials to make silicone hydrogel contact lens with higher oxygen transmissibility. For manufacturing of contact lens, We added BMA(Butyl methacrylate) with better elasticity and flexibility, and AA(Acrylic acid) with higher moisturizing to used contact lens materials. AIBN (Azobis2-methylpropionitrile) as initiator and EGDMA(Ethylene Glycol Dimethacrylat) as crosslinking agent were used and the lens with higher oxygen transmissibility and better moisturizing were manufactured complying with basic contact lens properties, which have several combination trial of each monomer characteristics. Compounding SN which included SILICONE, HEMA, NVP and EGDMA etc was showed by swelling ratio of 9.38% and water content of 23.7%. SN was showed by swelling ratio of 9.38%, water content of 23.7% and a visible ray transmissibility of 89%. SB which added BMA in the SN was showed by swelling ratio of 12.50%, water content of 18.56% and a visible ray transmissibility of 88%. SAB which added both AA and BMA in the SN was showed by swelling ratio of 8.33%, water content of 12.93% and a visible ray transmissibility of 88%.

  • PDF

Comparison of Cognitive Loads between Koreans and Foreigners in the Reading Process

  • Im, Jung Nam;Min, Seung Nam;Cho, Sung Moon
    • Journal of the Ergonomics Society of Korea
    • /
    • v.35 no.4
    • /
    • pp.293-305
    • /
    • 2016
  • Objective: This study aims to measure cognitive load levels by analyzing the EEG of Koreans and foreigners, when they read a Korean text with care selected by level from the grammar and vocabulary aspects, and compare the cognitive load levels through quantitative values. The study results can be utilized as basic data for more scientific approach, when Korean texts or books are developed, and an evaluation method is built, when the foreigners encounter them for learning or an assignment. Background: Based on 2014, the number of the foreign students studying in Korea was 84,801, and they increase annually. Most of them are from Asian region, and they come to Korea to enter a university or a graduate school in Korea. Because those foreign students aim to learn within Universities in Korea, they receive Korean education from their preparation for study in Korea. To enter a university in Korea, they must acquire grade 4 or higher level in the Test of Proficiency in Korean (TOPIK), or they need to complete a certain educational program at each university's affiliated language institution. In such a program, the learners of the Korean language receive Korean education based on texts, except speaking domain, and the comprehension of texts can determine their academic achievements in studying after they enter their desired schools (Jeon, 2004). However, many foreigners, who finish a language course for the short-term, and need to start university study, cannot properly catch up with university classes requiring expertise with the vocabulary and grammar levels learned during the language course. Therefore, reading education, centered on a strategy to understand university textbooks regarded as top level reading texts to the foreigners, is necessary (Kim and Shin, 2015). This study carried out an experiment from a perspective that quantitative data on the readers of the main player of reading education and teaching materials need to be secured to back up the need for reading education for university study learners, and scientifically approach educational design. Namely, this study grasped the difficulty level of reading through the measurement of cognitive loads indicated in the reading activity of each text by dividing the difficulty of a teaching material (book) into eight levels, and the main player of reading into Koreans and foreigners. Method: To identify cognitive loads indicated upon reading Korean texts with care by Koreans and foreigners, this study recruited 16 participants (eight Koreans and eight foreigners). The foreigners were limited to the language course students studying the intermediate level Korean course at university-affiliated language institutions within Seoul Metropolitan Area. To identify cognitive load, as they read a text by level selected from the Korean books (difficulty: eight levels) published by King Sejong Institute (Sejonghakdang.org), the EEG sensor was attached to the frontal love (Fz) and occipital lobe (Oz). After the experiment, this study carried out a questionnaire survey to measure subjective evaluation, and identified the comprehension and difficulty on grammar and words. To find out the effects on schema that may affect text comprehension, this study controlled the Korean texts, and measured EEG and subjective satisfaction. Results: To identify brain's cognitive load, beta band was extracted. As a result, interactions (Fz: p =0.48; Oz: p =0.00) were revealed according to Koreans and foreigners, and difficulty of the text. The cognitive loads of Koreans, the readers whose mother tongue is Korean, were lower in reading Korean texts than those of the foreigners, and the foreigners' cognitive loads became higher gradually according to the difficulty of the texts. From the text four, which is intermediate level in difficulty, remarkable differences started to appear in comparison of the Koreans and foreigners in the beginner's level text. In the subjective evaluation, interactions were revealed according to the Koreans and foreigners and text difficulty (p =0.00), and satisfaction was lower, as the difficulty of the text became higher. Conclusion: When there was background knowledge in reading, namely schema was formed, the comprehension and satisfaction of the texts were higher, although higher levels of vocabulary and grammar were included in the texts than those of the readers. In the case of a text in which the difficulty of grammar was felt high in the subjective evaluation, foreigners' cognitive loads were also high, which shows the result of the loads' going up higher in proportion to the increase of difficulty. This means that the grammar factor functions as a stress factor to the foreigners' reading comprehension. Application: This study quantitatively evaluated the cognitive loads of Koreans and foreigners through EEG, based on readers and the text difficulty, when they read Korean texts. The results of this study can be used for making Korean teaching materials or Korean education content and topic selection for foreigners. If research scope is expanded to reading process using an eye-tracker, the reading education program and evaluation method for foreigners can be developed on the basis of quantitative values.

소설과 말기 암환자를 통해 본 한국인의 죽음의 의미

  • Jeon, Hye-Won;Kim, Bun-Han
    • Korean Journal of Hospice Care
    • /
    • v.3 no.2
    • /
    • pp.34-54
    • /
    • 2003
  • Every one experiences death one day, however no one can knows exactly what it is because people can not experience death until it comes, it is therefore impossible to judge correctly on the phenomenon of the death. On the whole, man experiences indirect death through the mass communications such as TV drama, fiction, magazine etc because those methods can easily access by every one. In addition to this, people usually acquire the negative awareness of death through the dramatic change of story like dying of cancer for dramatic effect by giving scare and fear to the cancers. The purpose of this study is to provide basic information on the spiritual care that enables the facing death patients to accept death as a part of life and divert hope from scare about after death by comparing and analyzing of two aspects of death meaning I.e, Korean fiction and the end stage cancer patients. Additionally, for medical staff to understand the facing death cancer patients by making to aware patients correctly and provide the better quality of care. The study was performed from September 28, 2002 to February, 28 2003. The materials of this study were collected by direct data obtained from observation, interviews, note and diary of end stage of cancer patients and written materials acquired from Korean contemporary fiction. Participants of this study were 4 end stage cancer patients including 2 lung cancer patients, 1 liver cancer patient and 1 esophagus cancer patient. The methodology used in this study was divided into two types; Huberman & Miles methodology was used for fiction to find and categorize subject, and Colaizzi, one of phenomenological methodology was used for end stage cancer patients to find the major meaning, subject and categorization. 1.The death investigated in the fiction, was found as a progress of negative emotion, acceptance and sublimation, life related subjects in the negative emotion were tenacity for life, anxiety, lingering attachment, responsibility, abandonment and death related subjects were shock, isolation, fear, scare and rejection. Acceptance related subjects were acceptance, destiny, secularism, preparation and arrangement, and sublimation related subjects were sublimation through Christian and Buddhism. 2.The death showed in the participants was negative emotion, acceptance and sublimation, life related subjects were repentance, anxiety, responsibility and hopelessness, and death related subjects were dejection, solitude, anger, fear and scare. The acceptance was a type of religious acceptance that admitted instantly by reaching an understanding with the God, and death was accepted as a progress of preparation, arrangement, acceptance and hope. Sublimation related subjects were Christian sublimation and relief or destiny incurred from self-reflective sublimation through communications and thoughts. 3.The death in view of fiction and participants were positively accepted both death and negative emotion, and the study disclosed the fact that death was sublimated dependent on religion. 4.The progress of negative emotion, acceptance and sublimation was disclosed more complicated and various in the real end stage cancer patients and acceptance only found in the patients on the form of religious acceptance, according to the results compared with fiction and real end stage cancer patients. The death showed in the fiction was standardized, gradated and similar progress with psychological status of Kubler-Ross. However, death in the participants was showed complex and various feelings simultaneously, and sometimes they accepted death positively. The sublimation through religion was found in Buddhism and Christian in the fiction and mostly Christian in the participants due to a number of Hospice patients. It was found that negative emotion various types of death was more found in the participants than fiction. It is therefore necessary to study on the response of death in various types. In the participants death was incurred more systematic and variously, we knew that nursing practice focused on experience of participants is required and reality on death is much profound than we analyzed and presented, lots of situations and reactions should be premised because we can not completely rule out the negligence possibility of care mediation of participants. In caring for the facing death patients, we discovered and confirmed again through this study that the spiritual care should be needed as a mediation method.

  • PDF