Effect of Heat Treatment on Microstructure and Fracture Behavior of STS304-Zr Alloys for Metal Waste Forms

Three kinds of STS304-Zr alloys were fabricated by varying the Zr content, and their microstructure and fracture properties were analyzed. Moreover, we performed heat treatment to improve their properties and studied their microstructure and fracture properties. The microstructure of the STS304-Zr alloys before and after the heat treatment process consisted of α-Fe and intermetallics: Zr(Cr, Ni, Fe)2 and Zr6Fe23. The volume fraction of the intermetallics increased with an increasing Zr content. The 11Zr specimen exhibited the lowest hardness and fine dimples and cleavage facets in a fractured surface. The 15Zr specimen had high hardness and fine cleavage facets. The 19Zr specimen had the highest hardness and large cleavage facets. After the heat treatment process, the intermetallics were spheroidized and their volume fraction increased. In addition, the specimens after the heat treatment process, the Laves phase (Zr(Cr, Ni, Fe) 2) decreased, the Zr6Fe23 phase increased and the Ni concentration in the intermetallics decreased. The hardness of all the specimens after the heat treatment process decreased because of the dislocations and residual stresses in α-Fe, and the fine lamellar shaped eutectic microstructures changed into large α-Fe and spheroidized intermetallics. The cleavage facet size increased because of the decomposition of the fine lamellarshaped eutectic microstructures and the increase in spheroidized intermetallics.11Yscopuskc

(A) Study of the effect of nonhandicapped peers using milieu language strategies on the handicapped children's social language

장애아동들의 의사소통적 상호작용 기술의 부족은 장애아동의 성장과 발달뿐 아니라, 일반 환경으로의 통합과 또래들의 수용을 어렵게 한다는 인식이 확대되어 오면서, 장애아동 교육 프로그램에서 언어 및 의사소통적 중재가 중요한 영역이 되었다. 특히 아동의 일상 환경에서 자연적인 방법으로 실시되는 언어중재와 효과적인 사회적 상호작용을 위한 또래의 참여는 특수교육의 궁극적 지향점인 장애아동의 사회적 통합을 위한 보다 효과적인 방안으로 인정 받고 있다. 따라서 본 연구에서는 장애아동과 비장애또래아동의 의사소통적 상호작용의 양적·질적 향상을 목적으로 하여, 비장애또래아동에게 환경언어중재전략을 사용하도록 훈련을 제공하고 이러한 전략 사용이 장애아동의 사회적 언어에 미치는 영향을 살펴보았다. 본 연구에는 생활연령 4세 ~ 6세인 세 명의 장애아동과 같은 또래의 비장애아동 세 명이 참여하였다. 중다기초선 설계를 이용하여, 장애아동들과 비장애아동들을 일대일로 짝지은 쌍을 대상으로, 비장애아동들의 환경언어중재전략 사용의 효과를 측정하였다. 비장애아동들은 환경언어중재전략을 사용하도록 훈련받았으며, 훈련과 훈련 후의 중재기간 동안 훈련효과를 검증하기 위한 관찰을 하였다. 관찰은 비장애아동들의 환경언어중재전략의 사용빈도와 대상장애아동들의 사회적 언어 산출에 대해 이루어졌다. 중재효과의 유지를 알아보기 위하여 한달 후 훈련이 시작되기 전의 상황에서 아동들의 행동이 관찰되었다. 본 연구를 통해 얻은 결과는 다음과 같다. 첫째, 환경언어중재전략의 훈련은 비장애또래아동의 전략 사용의 빈도를 증가시켰으며, 이러한 증가는 교사촉진과 강화가 주어지는 실험처치기간 동안 유지되었다. 둘째, 비장애또래아동의 환경 언어중재전략 사용은 대상장애아동의 사회적 언어 사용을 증가시켰다. 이때 자발어와 반응어가 모두 증가되었으며 증가 경향은 아동의 특성에 따라 차이를 보였다. 증가의 경향성과 의사소통적 상호작용은 비장애또래아동과 장애아동의 특성이 상호 영향을 미치는 가운데 각 대상 쌍별로 의사소통적 적응을 보였다. 셋째, 비장애또래아동의 환경 언어중재전략은 대상장애아동이 사용한 사회적 언어의 화용적 기능을 다양화시켰으며, 이 때 장애아동의 언어 활용적 특성과 비장애또래아동의 전략 사용의 특성이 증가의 양상에 영향을 끼쳤다. 넷째, 비장애또래아동에 대한 환경언어중재전략은 한 아동을 제외하고는 시간이 흐른 후에 유지되지 않았으며, 대상장애아동들의 경우 한 장애아동의 사회적 언어는 실험처치기간에 비해 낮은 수준이나 기초선보다 높게 유지되었으며 다른 두 아동의 유지 결과는 일관적이지 않았다. 이상의 결과를 종합하여 볼 때, 본 연구의 중재 방법인 비장애또래아동의 환경언어중재전략 사용은 적어도 본 연구에 참여한 장애아동 세 명과 비장애또래아동들의 의사소통적 상호작용을 증가시키는 데에 효과적이었다고 할 수 있다. 그러나 한달 후의 유지기간 동안 교사촉진과 강화가 제거되었을 때, 비장애또래아동의 환경언어중재전략 사용은 감소 경향을 보였고 한 명의 장애아동을 제외하고는 사회적 언어 사용에 일관된 결과가 나타나지 않아 중재의 효과는 제한적이었다. 따라서 본 연구를 통해 나타난 결과를 기초로 하여, 장애아동과 비장애또래의 의사소통적 상호작용을 증가시키기 위한 중재에서 비장애또래의 훈련이 중요함을 인식할 수 있다. 보다 원활한 의사소통적 상호작용을 위해 장애아동과 비장애아동 모두에 대한 의사소통 및 사회적 기술 훈련이 필요하며, 교사촉진과 강화가 주어지지 않을 때에도 중재의 효과가 유지되며 다른 상황으로도 일반화될 수 있는 효과적인 방안을 모색한다면, 장애아동과 비장애또래의 의사소통 상호작용을 보다 긍정적으로 발달시킬 수 있는 프로그램으로 활용될 수 있을 것이다. 이러한 연구 결과는 장애아동과 비장애아동의 사회적 통합을 위한 하나의 기초자료와 방법론을 제시하는 의미를 가질 수 있을 것이다.;The purpose of this study was to investigate how nonhandicapped peers' milieu language strategies effect on the social language of handicapped children in structured play setting. For this purpose, three pairs of handicapped - nonhandicapped child were selected from an integrated preschool. Using across subjects multiple-baseline design, the frequency of nonhandicapped peers using milieu language strategies and the frequency of the social language use and the pragmatic functions of the target children were measured. During training sessions Nonhandicapped peers were trained to use five milieu language strategies. Teacher prompts and reinforcements were provided to nonhandicapped peers and not to target children. Follow-up observation was implemented one month after withdrawing intervention. The results obtained from the present study are as follows: 1. Milieu language strategies training to the nonhandicapped peers promoted the frequency of using the strategies by the peers, and maintained with teacher prompts and reinforcements.. 2. The nonhandicapped peers' strategies increased the frequency of social language of their target children. Both Initiations and responses were increased. Increasing tendency of the social language was differentiated by individual characteristics. 3. The nonhandicapped peers' strategies improved the pragmatic functions of the social language of the target children. Interactions in each dyad were influenced by each child characteristics. 4. Increasing rate of the strategies and social language were not maintained after withdrawal of intervention except one pair. These results from this investigation suggest that nonhandicapped peer naturalistic communicative interventions could positively influence on the social language of the handicapped children and pragmatic functions of the social language.논문개요 = ⅰ 목차 = ⅳ Ⅰ. 서론 = 1 A. 연구의 필요성 및 목적 = 1 B. 연구 문제 = 5 C. 용어의 정의 = 6 Ⅱ. 이론적 배경 = 8 A. 사회적 의사소통 중재의 배경 = 8 1. 사회적 언어 = 8 2. 화용론(pragmatics)과 언어 중재 = 10 B. 환경적 언어중재 전략 = 15 1. 환경언어중재의 기본 가정 = 16 2. 환경언어중재의 절차 = 17 3. 환경언어중재의 효과 = 20 C. 또래를 매개로 한 중재 = 23 1. 장애 - 비장애 또래 관계 = 23 2. 아동간 언어적 상호작용의 특성 = 27 3. 또래-중개 중재 = 29 Ⅲ. 연구방법 및 절차 = 38 A. 대상 = 38 B. 실험 기간 = 41 C. 환경 = 41 D. 실험 설계 및 실험 조건 = 42 E. 자료수집 및 측정 = 45 F. 자료 분석 = 49 G. 관찰자 신뢰도 = 49 Ⅳ. 연구 결과 = 51 A. 비장애또래아동의 환경언어중재전략 사용 = 51 B. 대상장애아동의 사회적 언어 = 56 C. 사회적 언어의 화용적 기능 종류 및 사용비율 = 60 Ⅴ. 논의 및 제언 = 67 A. 논의 = 67 B. 제한점 및 제언 = 79 참고문헌 = 81 부록 = 96 Abstract = 10

현대 사회의 '소비 인간'에 대한 표현

21세기라는 새로운 밀레니엄의 시작은 우리에게 긍정적인 미래에 대한 기대와 함께, 20세기가 안고 있었던 크고 작은 논쟁과 문제에 대한 무거운 책임까지 지워 주었다. 20세기 말, 자본주의는 그 어느 때보다도 극을 달리면서 인간에게 물질의 풍요로움을 누릴 수 있는 기반을 제공하였다. 그러나 거대한 자본주의의 위력은 물질의 풍요를 담보 삼아, 현대인으로 하여금 인간다움을 상실하고 '소비' 중심의 패러다임 속에 부품과 기계가 되길 강요하고 있다. 본 연구는 거대한 권력으로 자리 잡은, 자본주의에 의해 변질된 현대 사회의 구조와 그 공간을 채우는 현대인을 대상으로 하여 소비 중심의 현대를 진단하고 더 나아가서는 반성과 성찰의 계기를 제공하고자 한다. 본 연구의 방법은 문헌 조사와 작품 제작 및 분석을 병행하였다. 문헌 조사를 통하여 작품의 대상이 되는 현대 사회와 현대인의 특징을 연구하였고 작품의 주요 표현 방법으로 도입된, 오브제와 인체, 블루(Blue)의 상징적 의미에 대해서 관련 작가의 작품 연구에 근거하여 제시하였다. 작품 제작 방법은 인체의 형상을 틀에서 반복적으로 찍어내고, 찍어낸 형상을 Blue로 처리하는 것을 중심으로 하였고 그 밖에 다중적인 표면 처리 방식과 일상의 오브제의 차용과 같은 방법을 도입하여, 다원적으로 작품을 표현하고자 하였다. 작품의 형태는 대부분이 인간의 신체를 단순화하여 표현하였는데 이것은 구조 속에 함몰되어 점점 단순화되어 가는 인간의 폐허화된 정신을 신체 속에 반영하고자 하는데서 비롯되었다. Blue는 작품 전체에 지배적으로 나타나는 색채로서, 비정상적으로 변질되고 왜곡된 현대 사회와 현대인을 비판적으로 인식하고 반성할 수 있는 자성의 계기와 에너지를 제공한다. 본 연구의 작품들에 도입된 다양한 조형적인 표현 방법-Blue의 의미, 단순화된 인체 형상 및 그 형상의 복제, 다양한 표면 처리 방식, 일상 오브제의 차용-들은 소비 중심의 패러다임 속에 함몰된 현대인을 형상화하고 있으며 개인과 구조를 조정하는 패러다임을 반성하고 극복할 수 있는 동기를 부여하는 코드화된 에너지로서 표현되고 있다. ; The opening of the new millenium, the 21th century has given us not only the expectation of better future but also a burden of significant or insignificant issues and problems resulted from the 20th century. At the end of the 20th century, capitalism was in the position with the peak of its prosperity and thrive, pretending to provide human beings with the foundation to enjoy material wealth. Actually, however, the huge power of capitalism has forced people to kick off humanity and to exist as components or machines among the 'consumption-centered paradigm', on the security of material wealth. This study was attempted to diagnose the current consumption- centered society for the structure and people of the contemporary society decayed by capitalism that is settled as mega power, and further to provide an opportunity of introspection upon such trend. For the methodology of this study, literature review and work production/analysis were carried out together. Literature review enabled an investigation into the characteristics of the contemporary society and people which were subjects of the works. Also, the symbolic meanings of object, human body and Blue that were introduced as primary expressions of the works were suggested on the basis of the studies on works of artists concerned. Regarding work production, focused on the blue-painting of shapes of human bodies that were molded repeatedly, multiple surface treatments and substitution of routine objects were introduced to express them into a multi-dimensional work. The shapes of works were expressed mostly through simplification of human bodies, which embodied the exhausted spirits of human beings having gotten limited into certain frames and simplified increasingly. As a predominant color in the overall works, blue offers an introspective opportunity to recognize critically and reflect the contemporary society and people that are decayed and distorted abnormally. The various formative expressions - the meaning of Blue, the simplified shape of human body and their reproduction, the multiple surface treatments, and the substitution of routine object - introduced into works of this study embody the contemporaries who are buried into the consumption- oriented paradigm, which play a role of coded energy as a motive to introspect and overcome the paradigm dominating the structure and people of the contemporary society.논문개요 = vii Ⅰ. 서론 = 1 A. 연구의 목적 = 1 B. 연구의 내용 = 2 C. 연구의 방법 = 2 Ⅱ. 이론적 배경 = 4 A. 현대인과 소비 그리고 소비인간 = 4 B. 미술 속의 산업 오브제 = 6 C. 현대 사회 속의 인간 = 7 D. 블루의 상징적 의미 = 9 Ⅲ. 표현내용 및 방법 = 18 A. 인체의 단순화와 복제 = 18 B. 소비 오브제의 사용 = 19 C. 과포장된 표면 = 20 D. 블루 = 21 Ⅳ. 작품분석 = 24 Ⅴ. 결론 = 45 참고문헌 = 47 ABSTRACT = 4

정상 청자와 인공와우 청자에 있어서 주파수 제한이 어음과 환경음 지각에 미치는 효과

Graduate Program in Speech and Language Pathology/박사Background: Spectral information plays an important role for speech perception as well as environmental sounds. A cochlear implant (CI) can provide extended spectral information compared to conventional hearing aids resulting in improved speech perception by the implantee. However, although the speech sounds depend upon the language of the target speech, CI has been developed and researched primarily in English. The languages around world contain language-universal characteristics as well as language-specific characteristics of perception and production. Korean language is different from English in many aspects, so it might affect the perception performance of CI speech processing mainly developed with English language. It would be worthy to investigate how different frequency-limiting conditions produced by high-pass and low-pass filtering affect sound recognition in normal-hearing (NH) and CI subjects to examine the effect of frequency bands on speech in Korean and environmental sound perception. Objectives: The purposes of this study are first, to find if there is perceptual differences between NH and CI subjects in speech and environmental sounds according to the frequency-limiting conditions, second, how importance of frequency information shows in Korean NH and CI listeners, and third, how the individual phonemes and sounds are recognized in a variety of frequency-limiting conditions. Methods: We conducted vowel and consonant tests in Korean (pronounced by one male and one female speakers) and an environmental sound test for 10 NH and 10 CI subjects in quiet within a variety of frequency-limiting conditions. We used the original sound and frequency band from 100 Hz to 8000 Hz. The band of 100 – 8000 Hz was low-pass and high-pass filtered to derive 28 test conditions for each phoneme and 14 test conditions for each environmental sound per subject. Results: We found a significant interaction effect on sound recognition according to the group, frequency bands, and sound stimuli. There were similarities and differences in recognition pattern between NH and CI group. As for the similarities, first, both group showed better sound recognition as more frequency region was added. Second, as more frequency information introduced, there was more increase of vowel and environmental sound recognition than that of consonant recognition. Third, both groups did not show recognition difference between original sound and 100 – 8000 Hz full band in all the stimuli. Fourth, in the original sound and full band conditions, both groups showed recognition scores as vowel > environmental sound > consonant, in order of performance. Fifth, environmental sound recognition was better than speech recognition in low- and high-pass filtering condition in both groups. Sixth, crossover frequency was occurred around 1500 Hz in all the sound stimuli in both groups. Seventh, in environmental sounds, both groups showed frequency redundancy in almost all the frequency bands. Eighth, on average, both groups recognized vowel /i/ and consonant /h/ best. Ninth, environmental sounds could be divided into the group of sounds which were easily recognized with low frequency or with high frequency and both groups recognized those sounds in a similar pattern. As for dissimilarities, first, CI group got more benefits in vowel recognition than in consonant recognition as frequency information increased and most easily recognized environmental sounds, then vowels and consonants in order. Second, NH group showed difficulty of recognizing phonemes compare to environmental sounds in high-pass filtering whereas CI group showed difficulty of recognizing consonants compare to vowels and environmental sounds in full band + original sound condition. Third, CI group did not utilize frequency cues for consonant recognition as efficient as NH group. Fourth, CI results did not demonstrate perceptual saturation but rather linear increase as more high frequency introduced. Fifth, when we compared full band recognition scores to summation of low-pass and high-pass filtering scores, the NH group showed significant redundancy of frequency at 1500 Hz in vowel and all the cutoff frequency in consonant whereas the CI group did not show redundancy in any cutoff frequency which resulted in no saturation pattern and linearity in recognition with CI speech processing. Sixth, gradient effects confirmed that there were more low frequency information in low-pass filtering and more high frequency information in high-pass filtering for the NH group whereas a reduced and even distribution of frequency information was seen for the CI group across frequency bands. Seventh, CI subjects showed larger individual difference in environmental sound recognition scores, but not in speech sound recognition. Eighth, both phoneme and sound recognition changed according to the frequency bands, and in general, both groups showed a recognition pattern change along formants of vowels; however, the CI group showed varied consonant recognition in a variety of frequency-limiting conditions more than NH group. Ninth, in general, CI group utilized frequency information above 2500 Hz for vowel and consonant recognition and frontal vowels, fricatives, affricates, and alveolars were benefited by it in spite of reduced amount of information about phoneme perception. Discussion: Both groups reflected several perceptual similarities with regard to acoustical characteristics. However, CI group demonstrated different pattern of sound recognition and had difficulty in recognizing different types of sounds with regard to the frequency-limiting conditions. This implies that speech and environmental sound recognition were affected differently from NH group by frequency utilization ability of CI subjects. It seems that 1500Hz brought a significant recognition change in speech for normal Korean listeners, which reflects a speech emphasis in the lower frequency domain in Korean language than English. The CI group also showed crossover around 1500 Hz which show that they recognized specific frequency characteristics of Korean language. With the results that CI users showed linear improvement in sound recognition with increased frequency information. Especially recognition of fricatives, affricates, and alveolars was gradually increased up to 8000 Hz so that we concluded that CI group in this study could utilize frequency information from 100 Hz to 8000 Hz provided by Current CI speech processing and the cues in frequency information conveyed by the device played perceptual role for them. However, we should not overlook the individual differences in recognition according to the frequency bands and individual phonemes and sounds. It is of interest that environmental sound also showed 1500 Hz crossover. On the other hand, environmental sound was revealed to have similar frequency pattern to speech sound in Korean listener and it would be interesting to see if English listeners show the same results to this study. Besides, other factors than the frequency factor in this study seemed to act on the recognition in addition to frequency information in both groups of the subjects. Conclusion: Korean CI listeners utilized 100 – 8000 Hz frequency information to recognize speech and environmental sounds. However, Korean has around 1500 Hz magnitude in speech perception and CI subjects showed different recognition patterns of individual phonemes and sounds with regard to frequency-limiting conditions. With these results, we concluded that CI devices of Koreans users need to be programmed differently and individually to maximize utilization of frequency information in 100 – 8000 Hz as the CI users showed different phoneme and environmental sound recognition according to frequency-limiting conditions. These findings potentially have predictive implications and can be utilized to customize the programming and rehabilitation for individual CI users who use Korean language.restrictio

Fucoidan from Fucus vesiculosus protects against alcohol-induced liver damage by modulating inflammatory mediators in mice and HepG2 cells

Fucoidan is an L-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1, a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-beta1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooxygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or intervention