• Title/Summary/Keyword: 자기 특성

Search Result 6,361, Processing Time 0.029 seconds

The Utilization of the steel converter dust (철강전노 dust의 활용에 관한 연구)

  • 김미성;김민석;김성원;오재현
    • Resources Recycling
    • /
    • v.2 no.2
    • /
    • pp.9-15
    • /
    • 1993
  • In this study, magnetite($Fe_3$$O_4$) from the converter dust of the Kwangyang steel making factory has been recove-red by means of the magnetic separation and the sedimentation column. The magnetite recovered from the dust is used for the preparation of Sr-ferrite instead of hematite. The results obtained in this study as follows : 1. The converter EP dust of the Kwangyang steel making factory are composed of $\alpha$-Fe, ($Fe_3$$O_4$) wustite etc. Magnetite in the converter EP dust is recovered by using sedimentation column and plastic bonding magnet. 2. It was confirmed that Sr-ferrite synthesis could be possible without oxidizing roasting of the magnetite. The steps of Sr-ferrite formation are proposed as follows : I$SrCO_3$ $+Fe_3$O$_4$+1/2(1-X)$O_2$longrightarrow$\alpha$ $-Fe _2$$O_3$ $+SrFeO _3$\ulcorner+$CO_2$II. $5.5\alpha$ $-Fe_2$$O_3$ $+SrFeO_3$\ulcornerlongrightarrowSrFe\ulcornerO\ulcorner+1/2(1/2-X)$O_2$3. By using magnetite from the dust insted of hematite, the hard Sr-ferrite magnet of (B.H)\ulcorner=2.64MGOe in the magnetic characteristics was succesfully prepared.

  • PDF

Synthesis, Potentiometric, Spectral Characterization and Microbial Studies of Transition Metal Complexes with Tridentate Ligand (세자리 리간드의 전이금속 착물에 대한 합성과 전위차 및 분광학적 확인 그리고 미생물학적 연구)

  • Jadhav, S.M.;Munde, A.S.;Shankarwar, S.G.;Patharkar, V.R.;Shelke, V.A.;Chondhekar, T.K.
    • Journal of the Korean Chemical Society
    • /
    • v.54 no.5
    • /
    • pp.515-522
    • /
    • 2010
  • A relation between antimicrobial activities and the formation constants of solid complexes of Cu(II), Ni(II), Co(II), Mn(II) and Fe(III) with tridentate Schiff base ligand, 4-hydroxy-3(1-{2-(benzylideneamino)-phenylimino}-ethyl)-6-methyl-2Hpyran-2-one (HL) derived from o-phenylene diamines, dehydroacetic acid (DHA) and p-chloro benzaldehyde have been studied. The ligand and metal complexes were characterized by elemental analysis, conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, $^1H$-NMR, UV-vis and mass spectra. From the analytical data, the stiochiometry of the complexes was found to be 1:2 (metal:ligand) with octahedral geometry. The molar conductance values suggest the nonelectrolytic nature of metal complexes. The X-ray diffraction data suggests monoclinic crystal system for Ni(II) and orthorhombic crystal system for Cu(II) and Co(II) complexes. The IR spectral data suggest that the ligand behaves as tridentate ligand with ONN donor atoms sequence towards central metal ion. Thermal behavior (TG/DTA) and kinetic parameters calculated by Coats-Redfern method suggests more ordered activated state in complex formation. The protonation constants of the complexes were determined potentiometrically in THF:water (60:40) medium at $25^{\circ}C$ and ionic strength ${\mu}=0.1\;M$ ($NaClO_4$). Antibacterial activities in vitro were performed against Staphylococcus aureu and Escherichia coli. Antifungal activities were studied against Aspergillus Niger and Trichoderma. The effect of the metal ions and stabilities of complexes on antimicrobial activities are discussed.

The study on voluntary satisfaction and voluntary activities of dental hygiene students (치위생과 학생의 자원봉사 만족도와 자원봉사활동에 관한 연구)

  • Park, Young-Nam;Lee, Hye-Jin;Oh, Han-Na
    • Journal of Digital Convergence
    • /
    • v.11 no.11
    • /
    • pp.621-631
    • /
    • 2013
  • This study aimed to investigate that what factors affect the volunteer activities of dental hygiene students and present a plan and problems with devising a program for activating their volunteer activities. A self-administered questionnaire survey was conducted in 265 dental hygiene students in Gwangju from November to December 2012, obtaining the following results: 51.3% of the respondents were freshmen; 74.3% had experience of volunteer activities; and 31.7% had the activities in the field of disabilities. 56.2% were motivated to participate in the activities by 'credit-earning and volunteer activity achievements'. Most of students participated in volunteer activities through clubs. Satisfaction with major-related volunteer activities was associated with higher support by others, higher job perception, higher job adequacy, and higher support by family. To increase satisfaction with major-related volunteer activities of students research is needed to develop systematic education for volunteers, subjects suitable for colleges, and an effective program in order to alter students' perception.

A Survey Study on University Students' Recognition for The Disabled - Focusing on Universities in Chungcheong Province (대학생의 장애인에 대한 인식에 관한 조사연구 - 충청도 대학을 중심으로 -)

  • Jeon, Mi-Young;Lee, Han-Woo
    • Journal of Convergence for Information Technology
    • /
    • v.7 no.5
    • /
    • pp.1-13
    • /
    • 2017
  • It is revealed that there are more registered disabled people in our country who have their disability because of acquired factors such as accidents than because of innate deformity. This phenomenon will continue and the incidence of acquired disability will increase more and more. Even though there is noticeable change, the social recognition toward the disabled is still negative. Particularly, university students are in the early adulthood according to the development of life-cycle, and this is the period that people have diverse social relationships, depart from unified frame and work in various fields, and set up their own thoughts and ideology with knowledge and skills acquired from university education. Therefore, in this study, we are going to search the recognition of the university students, who are in the previous period of entering into the society, toward the disabled, and if they have negative prejudice or attitude against the disabled, we are going to find the ways to improve on their awareness positively. The subjects of the survey were randomly selected among 230 out of total 250 students by visiting thirteen universities in Chungcheong Province, and were analyzed by using SPSS (ver. 18.0) program. T-test and One-way ANOVA were used as analytical methods to look into the difference of analysis of frequency, descriptive statistic, reliability analysis and attitudes for comprehending sociodemographic characteristics of the subjects of the survey. In conclusion, it has to be not a temporary or event-like training, but a training that makes people have positive recognition and attitude towards accurate information, knowledge, human rights, disability, and diversity. This thesis has a limitation to be generalized to the university students all over the country since the region is limited to a certain area.

Social work field training awareness on the impact of the research career (사회복지현장실습이 진로의식에 미치는 영향에 관한 연구)

  • Jeon, Seong-Nam
    • Journal of the Korea Society of Computer and Information
    • /
    • v.19 no.6
    • /
    • pp.119-128
    • /
    • 2014
  • In this study, the social welfare field training course there is a growing awareness as professionals in order to verify the impact was conducted. G-local four-year university study social work majors by sampling 198 people were examined for the purpose, through self - survey was conducted. Materials and analytical methods in order to identify the characteristics of a variable frequency, and technical analysis, T-test, F-test, ANOVA, correlation (correlation), Regression (regression) was used for the SPSS 14.0. The results are as follows. First, the personal factors of the individual physician trainees reflect (${\beta}=.197$), and then the same about Social Welfare satisfaction (${\beta}=.205$) of the Social Welfare majors had significant impact on career identity. Second, the personal factors they chose what to major in social work satisfaction (${\beta}=-.291$), and if you feel you select a parent with a major in Social Work and Social Welfare major students feel the satisfaction of having a significant effect on the level of career decision crazy. Third, individual reflect personal physician factors (${\beta}=.156$) is significantly influenced the behavior of career preparation.

Surface Chemistry in Biocompatible Nanocolloidal Particles (생체 적합한 나노입자와 계면화학)

  • Kim Jong-Duk;Jung Jae Hyun
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.30 no.3 s.47
    • /
    • pp.295-305
    • /
    • 2004
  • Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.

A Study of Oral Health Status and Oral Health Promotion Activities according to the Snack Intake Frequency Change of Some Soldiers Compare to before and after Military Service (일부 군인들의 입대 전후 간식섭취횟수 변화에 따른 구강건강관리실태와 구강건강증진행위에 대한 조사)

  • Cho, Min Jeong;Park, Young Mim
    • Journal of dental hygiene science
    • /
    • v.16 no.1
    • /
    • pp.1-8
    • /
    • 2016
  • The purpose of this study was to find the attitude change for snack by military soldiers before and after entering military service. To investigate oral health status and improving activities, this survey was done for 318 soldiers at Gyeong-gi province Paju city and the results were as follows. After entering military service, the soldiers take more snacks than before and take snacks 2 or more times a day. Both smokers and non-smokers take more snacks after entering military service than before entering. The soldiers did not go dental clinic regularly. But they have lots of interests about oral health. As higher position and older, soldiers restrain themselves to taking sugar contained food, and the elder soldiers showed higher practical character for nutrition intake than younger soldiers. Private soldiers were least practical for brushing after meal and showed the highest level of fulfill for using fluoride contained toothpaste, regular scaling and checkup at dental clinic and flossing.

The Effects of Some Soldiers' Stress on Their Oral Healthcare Practice and Attitudes (일부 군인들의 스트레스가 구강건강실천 및 태도에 미치는 영향)

  • Yoo, Jung-Sook;Kim, Jin;Kim, Ki-Eun
    • Journal of dental hygiene science
    • /
    • v.9 no.4
    • /
    • pp.369-374
    • /
    • 2009
  • The purpose of this study was to survey Korean soldiers' oral healthcare practice and attitudes along with their stress level, and thereby to identify possible correlations among those factors. The survey was conducted from June 11 to Oct. 10, 2008 in G-gun, Chungbuk. province for soldiers. The questionnaire was consisted of the oral healthcare practice and attitude, stress level. As a result, it was found that our respondents scored 3.55 out of possible 9 point in their stress level, which indicated that they had relatively low stress on the whole. According to survey on their oral healthcare practice and attitude depending on their general characteristics, it was found that the higher academic career was associated directly with the more practices of oral healthcare, and nonsmoking group showed more practices of oral healthcare than smoking group. It was found that 'schoolwork and workplace' and 'sexual problem' were critical stress factors on our respondents' oral healthcare attitudes. And it was also found that 'outward appearance complex', 'personality complex', 'conflicts with parents' and 'sexual problem' were critical stress factors on their oral healthcare practices. Since our soldiers' maintenance of their oral healthcare is beneficial to both individual and national aspects, it is necessary for interested parties including dental surgeons to make efforts to develop a promotional program for military dental healthcare project and provide a series of reorientations for soldiers, so that they can have more positive oral healthcare practices and attitudes.

  • PDF

Narratives and Emotions on Immigrant Women Analyzing Comments from the Agora Internet Community(Daum Portal Site) (이주여성에 관한 혐오 감정 연구 다음사이트 '아고라' 담론을 중심으로)

  • Han, Hee Jeong
    • Korean journal of communication and information
    • /
    • v.75
    • /
    • pp.43-79
    • /
    • 2016
  • An increase in the number of immigrants to Korea since the late 1980s' has signified the proliferation of globalization and global capitalism. In Korea, most married immigrants are women, as the culture emphasizes patrilineage and the stability of the institution of marriage, particularly in rural areas. Immigrant women have experienced dual ordeals. The Aogra Internet community in Korea has been one of the most representative sites that has shown the power of communities in cyberspace since 2002, leading the discussion of social issues and deliberative democracy both online and offline. This paper analyzed Koreans' writings (such as long comments) on immigrant women in the Agora community. The analysis revealed the following results: first, immigrant women were referred to using terms related to prostitution, with excessive expression of disgust, which is called a "narrative of identity." Second, anti-multiculturalists called Korean men victims of married immigrant women and expressed hatred toward immigrant women, which is called a "narrative of sacrifice." Third, anti-multiculturalists justified their emotions as just resentment based on ideas of justice, equality, and patriotism, concealing the emotion of disgust, which is called the "narrative of justice, equality." Fourth, antimulticulturalists played roles to spread the emotion of disgust, by repeatedly referring to international marriage fraud and immigrant workers' crimes, which is called "narrative of crime." Fifth, some positive writings on immigrant women were based on empathy(a concept defined in this context by Martha Nussbaum), but they can be analyzed as narratives encouraging cultural integration through the perspective of orientalism. Therefore, comments on immigrant women in the Agora represent a "catch-22" dilemma. To deal with conflicts arising from disgust and violations of human rights, civic education focusing on humanism is needed in this multicultural era.

  • PDF

Studies on the Effect of Picolines on the Stereochemistry of Lanthanide(III) Nitrate Coordination Compounds of 4[N-Furfural)amino]antipyrine Semicarbazone and Antibacterial Activities (4[N-Furfural)amino]antipyrine Semicarbazone의 질산 란탄(III) 배위화합물의 입체화학에 미치는 Picolines의 영향과 항박테리아 활성)

  • Agarwal, Ram K.;Agarwal, Himanshu;Prasad, Surendra;Kumar, Anil
    • Journal of the Korean Chemical Society
    • /
    • v.55 no.4
    • /
    • pp.594-602
    • /
    • 2011
  • The effect of ${\alpha}$-, ${\beta}$- and ${\gamma}$-picolines on the stereochemistry of the coordination compounds of lanthanide(III) nitrates derived from 4[N-(furfural)amino]antipyrine semicarbazone (FFAAPS) has been studied. The general composition of the present coordination compounds is [Ln(FFAAPS)$(NO_3)_3$Pic] (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy or Ho and Pic=${\alpha}$-, ${\beta}$- or ${\gamma}$-picolines). All these coordination compounds have been characterized by elemental analyses, molecular weight, molar conductance, magnetic susceptibility, infrared and electronic spectra. The infrared studies suggest that the FFAAPS behaves as a neutral tridentate ligand with N, N, O donor while ${\alpha}$-, ${\beta}$- or ${\gamma}$-picoline is coordinated to the lanthanide(III) ions via heterocyclic N-atom. Nitrates are bicovalently bonded in these compounds. From the electronic spectral data, nephelauxetic effect (${\beta}$), covalence factor ($b^{1/2}$), Sinha parameter (${\delta}%$) and the covalence angular overlap parameter (${\eta}$) have been calculated. Thermal stabilities of these complexes have been studied by thermogravimetric analysis. The coordination number of lanthanide(III) ions in the present compound is found to be ten. The antibacterial studies screening of the primary ligand FFAAPS and the complexes showed that the present complexes have moderate antibacterial activities.