To co-fire with commercial LTCC (Low Temperature Co-fired Ceramic) materials at , different contents of were added to the (BZN) ceramics. According to the test results, the cubic phase of BZN was transformed into orthorhombic in all the test materials. phase was formed in test materials with of addition. The phase transformation of cubic BZN was controlled during the synthesis process with excess ZnO content. The Cubic and orthorhombic phases of BZN could coexist and be sintered densely at .

Effect of phase transformation and grain-size variation of hot-pressed cobalt on its dry sliding wear was investigated. The sliding wear test was carried out against glass (83% SiO2) beads at 100N load using a pin-on-disk wear tester. Worn surfaces, cross sections, and wear debris were examined by an SEM. Phases of the specimen and wear debris were identified by an XRD. Thermal transformation of the cobalt from the hcp ε phase to the γ (fcc) phase during the wear was detected, which was deduced as the wear mechanism of the sintered cobalt.

Yttrium aluminum garnet (YAG) powders were synthesized via mechanochemical solid reaction using with three types of aluminum compounds. reacted mechanochemically with all A1 compounds and formed YAM (yttrium aluminum monoclinic), YAG and YAP (yttrium aluminum perovskite) phases depending on the starting materials. The ground samples containing showed the best reactivity, whereas the ground sample containing A100H, which had the largest surface area, exhibited pure YAG after calcination at . The sample containing Al had the least reactivity, producing YAP along with YAG at . The types and grinding characteristics of the starting materials and grinding time are believed to be important factors in the mechanochemical synthesis of YAG.

This study was conducted on the premise that plan types of the public residential houses proposed after the 1945 implicatively showed the developing process of the modern housing. The formal characteristics created through the developing process were analyzed in Micro-Historically. Moreover, by providing a new viewpoint on the changes of the residential houses that occurred around 1945, we tried to provide the fundamental research background for the research on the developing processes of the future housing cultures. The research pursued mainly on the major spaces that became the modern change indices of housing plan changes from the traditional housings in 1940s to the modern housings such as the master bedrooms(An-Bang), kitchen, the main floored-space(Maru), and the secondary bedroom (Kune-Bang). The major experimental subjects are the 87 public residential plan types designed and supplied by the Korea Housing Cooperation in between 1945 and 1970. The study synthesized the developing process of the public residential houses from the traditional residential houses in 1940s through modern situation and intrusion of foreign housing cultures. Following results were derived from the study: First, various and experimental housing plan types had been proposed as public residential houses since 1945. Among them, the plan having the main floored-space(Maru) were the representative type of public residential houses and various series of houses were constructed based on this type. Second, the main floored-space(Maru) type had continued building connection order of the R-M-R that were used in the traditional houses. On the other hand, with decomposition of connecting ring between the main floored-space(Maru) and the kitchen, rationalization of women circulations and introduction of family-centered spaces had been resolved the demands of modern society. It had greate effect on settlement of the current double-row Maru plan type. Third, in Korea most of plan types for the public residential houses were proposed in between 1945 and 1965. Forth, the location of kitchen and relation between Maru and the master bedroom were arranged visually on the corner and center of the rear row with the micro change characteristics of the public residential houses. In this process, the front row was similar with traditional residential houses but the rear row was differentiated and developed with expansion of Maru and Ondol rooms, increase of closet spaces, and introduction of kitchen that divided spaces for sleeping and eating.

유용유전자 도입을 통한 신품종 톨 페스큐를 개발할 목적으로 Agrobacterium을 이용한 효율적인 식물체 재분화 및 형질전환에 미치는 몇 가지 요인을 조사하였다. 성숙종자로부터 유도된 캘러스를 형태에 따라 3가지 type으로 분류하였고 type Ⅱ캘러스는 유백색으로 녹색을 띠며 조직적으로 치밀한 상태이며 식물체로의 재분화효율이 52.6%로 가장 높게 나타났다. 또한 재분화 배지에 AgNO3와 cysteine을 동시에 첨가해 준 경우 무첨가구에 비해 캘러스 유도율은 6.7%, 식물체 재분화율은 12% 씩 각각 증가하였다. 캘러스 type 별 형질전환 효율을 조사한 결과 typeⅡ 캘러스는 58.0%로 가장 높은 형질전환효율을 나타내었다. 형질전환체를 PCR 및 PCR-Southern blot 분석을 실시하여 본 결과 발현벡터의 T-DNA 영역이 형질전환 식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환 시스템은 분자육종을 통한 신품종 톨 페스큐의 개발에 유용하게 이용될 수 있을 것이다.

The anatase particle was facetted at the free surface and a neck formation between the anatase particles prior to the phase transformation occured. This resulted in the severe lattice distortion at the region of the interface near the neck and this can act as the nucleation sites for the phase transformation. The grain growth of rutile particles after the phase transformation grew very fast by the sweeping phenomena of grain boundary. Therfore, It leaded to the microstructure without the rutile phase located in anatase particle.

보의 고유진동수는 보의 동적해석에서 중요한 역할을 한다. 보의 단면이 불규칙적으로 변하는 단형보의 고유진동수 산정은 해석상 복잡하고 어렵다. 이런 단형보의 해석은 주로 다자유도계 해석인 질량집중방법이 널리 사용되지만 이들 해석방법은 요소의 분할수나 계산의 반복수 또는 가정처짐곡선의 정확성 여부에 해석의 정밀성이 좌우된다. 본 연구는 대칭단형 단순보의 등가보 변환 방법과 그에 따른 고유치해석 방법을 제시하였으며 타 문헌의 예제와 여러 모델을 대상으로 그 타당성 및 실용성을 입증하였다.

Through the volume change of Sn in a low-temperature phase transformation, the Sn nanopowder with high, purity, was fabricated by an economic and eco-friendly process. The fine cracks were spontaneously generated. in, Sn ingot, which was reduced to powders in the repetition of phase transformation. The Sn nanopowder with 50 run in size was obtained by the 24th repetitions of phase transformation by low-temperature and ultrasonic treatments. Also, the powder was fabricated by the oxidation of the produced Sn powder to the ingot and milled by the ultrasonic milling method. The nanopowder of 20 nm in size was fabricated after the milling for 180 h

Four different mechanical alloying(MA) processes were employed to fabricate very fine intermetallic compound particles dispersed Al composite materials(MMC) with Al-4at.%Zr composition. Phase transformations including phase stability during MA and heat treatment processes were investigated. Part of Zr atoms were dissolved into Al matrix and part of them reacted with hydrogen produced by decomposition of PCA(methanol) to form hydride during first MA process. These hydrides disappeared when alloy powders were heat treated at . Stable dispersoids with structure were formed by heat treating the mechanically alloyed powders at . On the other hand, metastable dispersoids with structure were formed during first MA of powers with Al-25at.%Zr composition. These metastable dispersoids transformed to stable with structure when heat treated above .

This study provides a descriptive and analytical account of major aspects of urban development and transformation of housing types of Italian Firenze from the 13th century to the 19th century. It is a typo-morphological depiction of urban spatial structure of the extraordinary city, Firenze, the center of Italian Renaissance. And this study has proceeded on the assumption that the evolving form of the urban structure and housing types cannot be understood without reference to the larger context of political, economic, and social life. Based on these backgrounds, the purpose of this study is threefold: to provide a comprehensive discussion of general characteristics of urban spatial structure of Firenze, and to explain the process of formation of working-class neighborhoods by constructing new city wall in later 13th century, and to discuss transformation of housing types of the working-class neighborhood with understanding the mechanism of existence of housing in the newly formed residential neighborhoods. The development of residential neighborhoods was pursued by 'planned' manner through forming square-shaped blocks, and characterized by the subdivision of larger properties into standardized building lots for the construction of houses. On the bases of documentary evidences, several ecclesiastical institutions are identified as the agents of a distinctive type of development. While the institutions did the major role for developing lands, the construction of houses was done by small scale construction agents with moderate amount of properties. The major housing type of working-class neighborhoods of Firenze has been the 'casa a schiera' characterized by the form of narrow front and long depth. The type was generalized by the newly formed middle and working-class of Firenze which grew their body very rapidly, Even though the type assumed very uniform in its fen there were many variations. And through passing time, the casa a schiera developed to be multi-family housing, and the level of variation became deepen. Eventually, transformation of housing type of Firenze was ended by appearance of the 'casa in linea', which was very similar to modern apartment in its spatial organization.

The passivation and oxidation process of tungsten and molybdenum narlopowders, produced by electrical explosion of wires was studied by means of FE-SEM, XPS. XRD, TEM, DIA-TGA and sire distribution analysis. In addition, the phase transformation of W and Mo nanopowders under oxidation in air was investigated. A chemical process is suggested for the oxidation of W and Mo nano-particles after a comprehensive testing of passivated and oxidized powders.