Ti-6Al-4V ELI (Extra Low Interstitial) alloy have been widely used as alternative to bone due to its excellent biocompatibility, although it still has many problems such as high elastic modulus and toxicity. Therefore, biomaterials with low elastic modulus and non toxic characteristics have to be developed. A novel β Ti-35wt%Nb-7wt%Zr-Calcium pyrophosphate (CPP) composite that is a biocompatible alloy without elemental Al or V was fabricated by spark plasma sintering (SPS) at 1000˚C under 70 MPa using high energy mechanical milled (HEMM) powder. The microstructure and phases of the milled powders and the sintered specimens were studied using SEM, TEM, and XRD. Ti-35wt%Nb-7wt%Zr alloy was transformed from α phase to β phase in the 4h-milled powder by sintering. The sintered specimen using the 4h-milled powder showed that all the elements were distributed very homogeneously and had higher density and hardness. β Ti alloy-CPP composite, which has nanometer particles, was fabricated by SPS using HEMMed powder. During the sintering process, CaTiO3, TixOy, and CaO were formed because of the reaction between Ti and CPP. The Vickers hardness of the composites increases with the increase of the milling time and the addition of CPP. The biocompatibility of the Ti-Nb-Zr alloys was improved by addition of CPP.

Ti-6Al-4V ELI (Extra Low Interstitial) alloy has been widely used as an alternative to bone due to its excellent biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity. Therefore, nontoxic biomaterials with a low elastic modulus should be developed. However, the fabrication of a uniform coating is challenging. Moreover, the coating layer on Ti and Ti alloy substrates can be peeled off after implantation. To overcome these problems, it is necessary to produce bulk Ti and Ti alloy with hydroxyapatite (HA) composites. In this study, Ti, Nb, and Zr powders, which are biocompatible elements, were milled in a mixing machine (24h) and by planetary mechanical ball milling (1h, 4h, and 6h), respectively. Ti-35%Nb-7%Zr and Ti-35%Nb-7%Zr-10%HA composites were fabricated by spark plasma sintering (SPS) at 1000˚C under 70MPa using mixed and milled powders. The effects of HA addition and milling time on the biocompatibility and physical and mechanical properties of the Ti-35%Nb-7%Zr-(10%HA) alloys have been investigated. Ti2O, CaO, CaTiO3, and TixPy phases were formed by chemical reaction during sintering. Vickers hardness of the sintered composites increases with increased milling time and by the addition of HA. The biocompatibilty of the HA added Ti-Nb-Zr alloys was improved, but the sintering ability was decreased.

In case of rectangular lattice dome which shearing rigidity is very small, it has a concern to drop Buckling strength considerably by external force. So, by means of system to increase buckling-strength, there is a method of construction that lattice of dome is one with roof material. In a case like this, shearing rigidity of roof material increases buckling-strength of the whole of structure and can be designed economically from the viewpoint of practice. In case of analysis is achieved considering roof material that adheres to lattice of dame, there is method that considers the rigidity that use effective width frame as method to evaluate rigidity of roof material. therefore, this study is aimed at deciding effective width of roof material united with rectangular lattice dome to evaluate rigidity of roof material by effective width of frame and investigating how much does rigidity of roof material united with lattice of dome increase buckling-strength of the whole of structure according to rise-ratio. Conditions of loading are vertical-type-uniform loading. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems.

Research about spherical shells been applying most usually is achieved by many investigators already and generalized equation has been derived. But, existent research is limited in case that spherical shell's roof rigidity is isotropy or orthotropy, and research that consider periodicity of rigidity-distribution that can happen by doing spherical shell's roof system by lattice system is not gone entirely. The purpose of this paper is applying Galerkin method to spherical shell that model periodicity of roof rigidity distribution that appear by roof lattice form of large space structure and develop structural analysis program that formularize. Rigidity-model of this research selects that of spherical shell which has 2-way grid. In this paper, buckling-strength and deformation distribution of isotopic spherical shell and 2-way grid spherical shell obtained by developed program could confirm the reliability by comparison with result of existent research.

Two way grid single-layer domes are of great advantage in fabrication and construction because of the simple fact that they have only four members at each junction. But, from a point of view of mechanics, the rectangular latticed pattern gives rise to a nonuniform rigidity-distribution in the circumferential direction. If the equivalent rigidity is considered in the axial direction of members, the in-plane equivalent shearing rigidity depends only on the in-plane bending rigidity of members and its value is very small in comparison to that of the in-plane equivalent stretching rigidity. It has a tendency to decrease buckling -strength of dome considerably by external force. But it is possible to increase buckling strength by the use of roofing covering materials connected to framework. In a case like this, shearing rigidity of roofing material increases buckling strength of the overall structure and can be designed economically from the viewpoint of practice. Therefore, the purpose of this paper, in Lamella dome and rectangular latticed dome that are a set of 2-way grid dome, is to clarify the effects of roofing covering materials for increasing of buckling strength of overall dome. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. In case of Lamella domes which have nearly equal rigidity in the direction of circumference, the rigidity of roofing covering materials does not have a great influence on buckling-strength, but in rectangular latticed domes that has a clear periodicity of rigidity, the value of its buckling strength has a tendency to increase considerably with increasing rigidity of roofing covering materials 2. In case of rectangular latticed domes, as rise-span-ratio increases, models which is subjected to pressure -type-uniform loading than vertical-type-uniform loading are higher in the aspects of the increasing rate of buckling- strength according to the rate of shear reinforcement rigidity, but in case of Lamella dome, the condition of loading and rise-span-ratio do not have a great influence on the increasing rate of buckling strength according to the rate of shear reinforcement rigidity.

In Single-layer latticed domes with rectangular network which is composed of ring of circumferential direction and rafter of longitudinal direction, that is, rib domes, if we use the cross-membered junction's method for the advantage in fabrication and construction, the eccentricity is occurred in the nodal point of crossing members. This paper is aimed at investigating the buckling characteristics for the effect of eccentricity according to rise-span ratios and distance of eccentricity. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. The maximum decreasing ratio of buckling strength due to the junction's eccentricity is about 60% in models of this paper. 2. In the increasing ratio of buckling strength for rise-span ratio, that of Type 3 models is larger than that of type 2 models. On the other hand, that of Type 2 mode is larger than that of Type 3 for eccentricity-distance. 3. In the viewpoint of the value of buckling strength, that of Type 2 models is larger than that of type 3 models. The effect of the junction's rigidity on buckling strength is not great for overall models. Therefore if we use the cross-membered junction's method for the advantage in fabrication and construction, the method of Type 2 will have the great advantage of that of Type 3.

본 연구의 목적은 황토의 식이 첨가에 의한 돼지의 성장 특성과 혈중 조성물의 변화를 규명하는 것이다. 총 153마리의 돼지(1주령 자돈 60마리 및 성돈 93마리)를 공시하였다. 자돈군은 일반사료 식이군, 0.5% 황토 + 일반사료 식이군, 1% 황토 + 일반사료 식이군으로 무작위로 3군으로 재배치하였다. 각 군간 증체량을 비교하였을 때 1% 황토가 포함된 사료를 식이한 군에서 일반사료와 0.5% 황토 + 일반사료 투여군에 비해 체중 증가가 관찰되었으나 통계적으로 유의하지는 않았다. 혈액학적 분석을 실시한 결과, 총 백혈구 수, 총 적혈구 수, 헤모글로빈 수, 혈액 중 혈구용적율, 평균 세포용적율, 평균 세포 내 헤모글로빈량, 평균 세포 내 헤모글로빈 농도, 평균 적혈구 폭, 혈소판 수치 등에서 각 군간의 유의한 차이가 없음을 확인하였다. 성돈군은 일반사료 식이군과 1% 황토 + 일반사료 식이군으로 구분하였으며, 혈청학적 분석에서 혈청 알부민의 농도는 1% 황토 + 일반사료 투여군에서 다른 군에 비하여 유의하게 증가하여 있는 것을 확인하였으나(p<0.01), 다른 지표들에서는 유의한 차이를 발견할 수 없었다. 황토가 포함된 사료를 투여한 군에서 획득한 분변의 조지방 함량은 다른 군에 비하여 유의하게 감소하는 것을 확인하였으며(p<0.001), 조단백 함량 및 조회분 함량은 유의한 차이를 보이지 않았다. 도체의 무게와 등지방 두께의 측정 결과 각 군간의 유의한 차이는 발견할 수 없었으나, 도체의 등급 판정 결과 황토를 투여한 군의 도체 등급은 비투여군에 비해 유의하게 등급이 향상된 것을 확인하였다. 이러한 결과는 황토의 식이 첨가는 돼지의 영양소 흡수를 개선시킴으로서 도체의 등급을 향상시키는 것을 확인하였다.

본 연구에서는 도라지 추출물에 대한 세포 독성을 확인하였으며, Aβ에 의한 PC12 세포 독성에 대한 보호효과를 관찰하였다. 또한 도라지 추출물과 도라지 추출물 연양갱을 4주간 강제 경구 투여하여 Morris 수중미로시험에서 도달지점까지의 도달시간이 도라지 추출물 및 도라지 추출물 연양갱 투여에 의해서 모두에서 유의하게 감소하였다. 이와 유사하게 수동회피시험에서도 자극이 있는 어두운 방을 나오는 시간이 도라지 추출물 및 도라지 추출물 연양갱 투여에 의해서 현저하게 감소하였다. 따라서 도라지 추출물 및 도라지 추출물 연양갱은 인지능 개선에 도움을 줄 것으로 생각된다.