• Journal of Welding and Joining
• /
• 제17권2호
• /
• pp.66-75
• /
• 1999

Weld bead quality in tailored blank(TB) is critically affected by edge preparation of sheets. The edge quality of prepared sheets for TB can be classified into straightness and the cross section quality of sheared plane such as a ratio of shear face, shear plane angle, etc. In order to have a good edg quality for butt-welding sheets, precision shearing will be recommended. In this paper, the feasibility of a conventional mechanical shearing as the edge preparation for tailored blanks is studyied. It reveals that fine shearing may not be the unique solution as it is generally accepted. To obtain the good shearing condition with a conventional mechanical shearing, experiments were carried out using Tahuchi method. The major parameters affecting a sheared contour are the clearance between upper blade and lower blade, and shear angle. The optimal shearing condition yields a very good straightness along the entire length of the cut, which gives a butt joint gap less than 10% of the base material thickness. The good cross section of sheared plane is also achieved in the optimal shearing condition such as a ratio of the shear face above 65%, a cross section's shear plane angle above 85%, little burr, which is providing finally good weld beads.

• 분석과학
• /
• 제20권2호
• /
• pp.176-182
• /
• 2007

본 연구는 매트릭스형의 농약 활성물질을 포함하는 서방성 수분 인지제제 및 그의 제조방법에 관한 것이다. 산을 첨가한 커들란 용액에 망목구조를 가진 매트릭스가 형성되며 이 매트릭스에 열처리를 하게 되면 수용성이 없어진다. 본 매트릭스의 망목구조는 수분이 존재조건에서 열리며 건조조건에서는 다시 닫히게 된다. 그러므로 본 서방성 제형시스템에서는 수분이 있는 조건에서만 농약 활성물질이 제형에서 방출된다. 본 서방성 제제에 따른 구성을 이용하면 농약 활성물질의 효과 발현시기를 제어할 수 있고, 약해(藥害) 등의 발생을 경감시킬 수 있다.

• 한국세라믹학회지
• /
• 제40권2호
• /
• pp.132-138
• /
• 2003

출발물질의 종류와 몰비 혼합 방법, 숙성, 결정화 온도와 결정화 시간 등 제올라이트 입자를 합성하는 조건이 FAU 형 제올라이트의 입자크기에 미치는 영향을 연구하였다. 동일한 출발물질이라도 혼합 경로에 따라 생성물의 결정상이 달랐다. 일반적으로 숙성과정을 거친 경우, 특히 숙성온도가 낮은 쪽이 입자 크기가 작았다. 2단계의 혼합겔 제조 방법을 거치는 경우 결정화 기간은 크게 단축되고 입자 크기도 작아졌으나. 1단계에서 제조된 2종의 혼합겔을 모두 숙성하지 않는 경우에는 결정화 시간은 단축되지만, 입자크기는 작아지지 않았다. 액상규산나트륨과 알루민산나트륨, 수산화나트륨을 출발물질로 하여. 저농도와 고농도의 혼합겔을 1차 제조하고, 이 혼합겔을 각각 숙성하고 다시 혼합하여 숙성하는 방법으로 결정화 시간을 단축하고 평균입경 0.4$\mu$m. 비표면적 838 $m^2$/g의 우수한 특성을 가지는 FAU혈 제올라이트를 합성하였다.

• Bulletin of the Korean Chemical Society
• /
• 제32권7호
• /
• pp.2351-2357
• /
• 2011

Three new metal-organic copper(II) complexes, $[Cu(H_2PZTC)_2]_n{\cdot}2nH_2O$ (1), $[Cu(HPZTC){\cdot}2H_2O]_n{\cdot}2nH_2O$ (2), and $Cu_2[(PZHD)(OH)(H_2O)_2]_n$ (3) ($H_3PZTC$ = pyrazine-2,3,5-tricarboxylic acid, $PZHD^{3-}$ = 2-hydroxypyrazine-3,5-dicarboxylate), have been synthesized from $Cu(II)/H_3PZTC$ system under different synthetic conditions, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. In complexes 1 and 2, $H_3PZTC$ ligands loose one and two protons, which were transformed into $H_2PZTC^-$ anion and $HPZTC^{2-}$ dianion under different preparation condition, respectively. Furthermore, two ligands coordinate with Cu(II) cations in different modes, leading to the formation of the different chain structures. In complex 3, $H_3PZTC$ ligand was converted into a new ligand-PZHD by in situ decarboxylation and hydroxylation under a higher pH value than that for complexes 1 and 2. PZHD ligands link the Cu(II) cations to form a 2D layer structure. These results demonstrate that the preparation conditions, including pH value and reaction temperature etc, play an important role in the construction of complexes based on $H_3PZTC$ ligand.

• 한국식품저장유통학회지
• /
• 제14권4호
• /
• pp.394-399
• /
• 2007

본 연구에서는 전두유의 가수분해 조건에 따른 품질 특성을 조사하였다. 그 결과 효소제(KMF-G) 농도가 증가함에 따라 전두유 가수분해물의 당도, 칼슘 내인성, 및 총 유리아미노산 함량은 증가하였으며, SDS-PAGE 분석 결과 단백질의 분자량 변화는 0.20%(w/w)와 0.35%(w/w) 농도에서 유사한 패턴을 나타냈다. 전두유 가수분해물은 효소제(KMF-G) 농도 0.20%(w/w), 가수분해 시간 60분에서 가장 우수하게 나타났다. 전두유 가수분해물을 115, 130 및 $145^{\circ}C$에서 15초간 살균하였을 때 품질변화는 크지 않았다. 이상의 결과 전두유의 가수분해 최적조건은 효소제(KMF-G) 농도 0.20%(w/w), 가수분해 시간 60분으로 설정할 수 있었으며 식품소재로의 다양한 활용이 기대된다.

• 한국전자통신학회논문지
• /
• 제8권7호
• /
• pp.1111-1120
• /
• 2013

본 연구는 고장초를 이용한 입욕제를 개발하고자 천연물질인 어성초, 녹차 및 애엽을 고장초와 혼합하여 완제품 3종류를 만들어서 선호도에 관하여 조사하였다. 향, 색, 맛 및 촉감에서 녹차와 고장초가 높은 선호도를 보였다. 고장초에 첨가할 혼합액에 대한 선호도 조사결과 어성초 50%, 녹차 30% 및 애엽 20% 비율로 만든 혼합액의 선호도가 가장 높았다. 선정된 혼합액을 가지고 고장초와 비율을 달리하여 만든 완성품에 대한 선호도 조사에서 선정된 혼합액이 40%, 고장초 60%를 첨가하여 만든 완성품이 가장 높은 선호도를 보였다. 최종 선정된 완제품 입욕제를 가지고 피부조건 변화에 대해 조사한 결과 높은 만족도를 보였다. 그러므로 고장초를 이용한 입욕제 개발은 피부를 건강하게 해주는 효능이 상승하여, 우수한 입욕제가 될 것으로 판단된다.

• Clinical and Experimental Reproductive Medicine
• /
• 제21권2호
• /
• pp.207-214
• /
• 1994

This study was carried out to develop the methodology of chromosome preparation from blood cultures in mammals which included human, mouse, cattle and pig. For karyotyping, 0.5-5.0ml of peripheral blood were collected and cultured. The satisfactory results were obtained from macroculture and microculture in all species. In culture, the patterns of cell growth were no difference among media except serum concentration and mitogen supplement. The presence of mitogen and fetal bovine serum in medium significantly affected the mitotic index. The optimal culture condition was 37$^{\circ}C$ for 3 days. And the concentration of colcemid and reincubation time also affected the chromosome morphology. In harvest, chromosome patterns were mainly affected on hypotonic treatment which included treated time and temperature, dropwise of fixative solution, and drying after slide preparation.

• 한국표면공학회지
• /
• 제27권3호
• /
• pp.134-142
• /
• 1994

$Al_2O_3$coatings on mild steel substrate by plasma spray process were produced to evaluate microstructural characterization and mechanical properties. As-coated $Al_2O_3$coating samplessd were subjected to two heat treat-ment conditions : ⅰ) annealing under vacuum circumstance, ⅱ) hot press treated condition. The two heat treat-ed coatings were investigated in terms of microhardness, adhesion strength, wear resistance, porosity forma-tion, and microstructures. In the case of the coatings which were subject to preparation step ⅰ, the porosity in the coating was decreased with the increase of temperature ($700^{\circ}C$-$1100^{\circ}C$), and the wear resistance, microhardnesss and adhesion strength were increased with the increase of temperature. On the other hand, in the case of the coatings which were subject to preparation step ⅱ, wear resistance and adhesion strength were improved with the increase of temperature and pressure. Experimental measurements of coatings which were produced by both preparation conditions were enhanced compare to those of as-coated coatings.

• Journal of Welding and Joining
• /
• 제16권5호
• /
• pp.134-141
• /
• 1998

In this study, a fillet size for bending fatigue strength of one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by bending fatigue test with or without edge preparation and burn through, with variation of joint shape. As a result, the following conclusions were obtained. (1) In one side fillet welded T-joint, the larger the leg length, the greater the bending fatigue strength. The increase in bending fatigue strength. (2) One side filet welded T-joint with edge preparation showed higher bending fatigue strength than that with twofold-large leg length and without edge preparation. (3) In one side fillet welded T-joint without edge preparation, both manual welding and automatic welding were carried out with same condition. In this case, automatic welding shoed deeper penetration and more increased horizontal leg length than manual welding, so that automatic welding offers grater bending fatigue strength. (4) For one side fillet welded T-joint without edge preparation, the ratio(h/t) of the leg length (h) and the main plate thickness (t) in which toe crack can occur was 1.2 over. (5) In one side fillet welded T-joint with edge preparation, the burn through led to reduced bending fatigue strength. However, this bending fatigue strength was higher than that of one side fillet welded T-joint without edge preparation and with a larger leg length.

• 한국작물학회지
• /
• 제34권s01호
• /
• pp.26-32
• /
• 1989

The analytic principles of GC and MS were explained in relation to plant hormone analyses and the characteristics of two instruments were compared. The selection of column, condition of measurement and the method of ionization to get a good spectrum were also briefly described. Finally, the pre-treatment of sample by solvent extraction method to remove the unnecessary part of sample and the synthetic method, especially reagents and reaction condition, for the preparation of ether or ester derivative which can be easily vaporized in GC were explained.