• 한국자원식물학회지
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• 제25권6호
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• pp.664-669
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• 2012

The mushroom Coriolusversicolor contains biologically active polysaccharides, most of which belong to the ${\beta}$ glucan group. Diverse physicochemical properties, due to different sources and isolated types of ${\beta}$-glucans, may induce distinct biological activities. Here, we examined the effects of ${\beta}$-glucan from Coriolusversicolor (CVG) on the scavenger receptor B1 (SR-B1) expression and the role of SR-B1 in CVG-induced phagocytosis regulation by using SR-B1-specific shRNA transfected cells. We also examined whether Dectin-1 and CK2 are involved in SR-B1 expression in CVG-treated cells. Our study results showed that CVG increased the SR-B1 expression via Dectin-1 and CK2 in macrophages. However, the inhibition of SR-B1 expression by shRNA did not completely eliminate the effect of CVG on the increase of phagocytosis suggesting that SR-B1 is not essential for CVG-stimulated phagocytosis. This study will contribute to identify CVG's mechanism of action and its use in the development of functional foods.

• 한국안광학회지
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• 제7권2호
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• pp.19-25
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• 2002

$SrO-B_2O_3$ 유리들에 같은 양의 $Al_2O_3$와 $SiO_2$를 첨가한 3성분 SrBAl 유리들과 SrBSi 유리들을 제작하여, $^{11}B$ NMR 방법을 이용하여 4배위 붕소 수인 $N_4$, 대칭적 3배위 붕소 수인 $N_{3S}$ 그리고 비대칭적 3배위 붕소 수인 $N_{3A}$를 얻어 구조를 정량적으로 비교 분석하였다. 두 유리 모두에 대해 $BO_3$ 단위의 경우 $Q_{cc}$=2.74MHz, ${\eta}=0.22$이며, $BO_3{^-}$단위의 경우 $Q_{cc}$=2.54MHz, ${\eta}=0.55$ 그리고 $BO_4$ 단위의 경우 $Q_{cc}$=0.60~0.75MHz, ${\eta}{\approx}0.00$이다. SrBAl 유리계에서는 $R_{1st}$($N_4$ 값의 제1변환점)에서의 유리들의 구조는 tetraborate ($[B_8O_{13}]^{-2}$) 단위들과 1차 변형된 diborate($[B_2Al_2O_7]^{-2}$) 단위들로 구성되어졌으며, $R_{max}$($N_4$ 최대인 R)에서 유리의 구조는 diborate($[B_4O_7]^{-2}$) 단위들, metaborate($[BO_2^{-1}]$) 단위들, 1차 변형된 diborate 단위들, 그리고 2차 변형된 diborate($[B_2Al_2O_8]^{-4}$) 단위들로 구성되어졌다. 그리고 3배위인 $AlO_3$ 단위들은 $BO_3$ 단위들보다 SrO로부터 도입된 산소를 우선적으로 배위하여 4배위인 $AlO_4$ 단위들로 전환되었다. 또한, SrBSi 유리계에서는 Si 원자들은 $R{\leq}0.5$ 영역에서는 붕소 망목구조에 기여하지 않으므로 유리 구조는 $SiO_4$ 단위들로 희석(diluted)된 2성분 SrB 유리계와 같은 구조로 구성되어졌으며, $R{\geq}R_{max}$이상의 영역에서는 SrO로부터 도입된 산소에 의해 $SiO_4$ 단위들이 $BO_3{^-}$ 단위들보다 우선적으로 $SiO_4{^-}$ 단위들로 모두 형성되었다. 그리고 $R_{max}$에서 유리의 구조는 diborate 단위들, metaborate 단위들, loose $BO_4([BO_2]^{-1})$ 단위들, 그리고 $SiO_4{^-}([SiO_{2.5}]^{-1})$ 단위들로 구성되어졌다.

• 한국산업융합학회 논문집
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• 제16권1호
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• pp.1-8
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• 2013

In case that W/B is 20%, 30%, 40% respectively, the effects of additive and shrinkage reducing agent on the autogenous shrinkage for high strengthen concrete through the substitution of FA and SF analysis were obtained as following conclusions. When the ratio of FA increased, the compressive strength of high strengthen concrete is decreased in the early times. As the ratio of SF increase, the compressive strength also increased. Comparing with PC(Portland Cement) for 7 days curing, the strength is 13.8% of FA10 + SR0.5 and 19.2% of FA15 + SR0.5 decreased when W/B is 20%, and 6.1% of SF7.5 + SR0.5, 4.8% of SF15 + SR0.5, the strength are increased. In case that W/B is 30%, 13.1% of FA10 + SR0.5 19.1% of FA15 + SR0.5 the strength is decreased and 4.1% of SF 7.5 + SR0.5, 7.2% of SF15 + SR0.5 the strength are increased. In case of W/B 40%, 4.3% of FA10 + SR0.5, and 8.7% of FA15 + SR0.5, the strength is decreased and 3.3% of SF7.5 + SR0.5, 6.3% SF15 + SR0.5 the strength is increased. When the ratio of SR is 0.5%, autogenous shrinkage strain of OPC concrete appeared $-417{\times}10-6$ in 56days curing, the shrinkage strain is decreased 23.7%. The reducing effects of autogenous shrinkage when the mineral and shrinkage agent are used are the same as ones when only shrinkage agent used.

• Journal of Species Research
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• 제7권2호
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• pp.135-150
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• 2018

Eleven bacterial strains 17SD2_15, 17Sr1_23, 17SD2_13, 17Sr1_31, 17gy_18, 16B15D, 16B02D, 16B04G, 16B01D, 17U4-2 and 17J28-10 assigned to the phylum Proteobacteria were isolated from soil samples collected from Seoul Women's University, in South Korea. The Belnapia species, strain 17SD2_15 was cocci-shaped and pink-colored. The Methylobacterium species, strain 17Sr1_23, 17SD2_13, 17Sr1_31, and 16B15D were short rod-shaped and pink-colored. The Microvirga species, strain 17gy_18, and 16B02D were short rod-shaped and pink-colored. The Oxalicibacterium species, strain 16B04G was short rod-shaped and pink-colored. The Sphingomonas species, strain 16B01D was short rod-shaped and yellow-colored. The Variovorax species, strain 17U4-2 was cocci-shaped and yellow-colored. The Paracoccus species, 17J28-10 was cocci-shaped and orange-colored. Phylogenetic analysis based on 16S rRNA gene sequence showed that strains 17SD2_15, 17Sr1_23, 17SD2_13, 17Sr1_31, 17gy_18, 16B15D, 16B02D, 16B04G, 16B01D, 17U4-2 and 17J28-10 were most closely related to Belnapia soli (with 99.9% similarity), Methylobacterium gregans (99.1%), Methylobacterium isbiliense (99.6%), Methylobacterium oxalidis (99.9%), Microvirga aerilata (98.7%), Methylobacterium aerolatum (99.0%), Microvirga vignae (100.0%), Noviherbaspirillum canariense (100.0%), Sphingomonas desiccabilis (100.0%), Variovorax humicola (99.6%), and Paracoccus acridae (99.1%), respectively. This is the first report of these eleven species in Korea.

• Korean Chemical Engineering Research
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• 제49권5호
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• pp.594-599
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• 2011

분무열분해 공정을 이용하여 $SrAl_2O_4:Eu$ 녹색 형광체를 제조함에 있어 붕소의 치환, 유기첨가제 및 건조 조절제의 사용에 따른 발광 특성을 조사하였다. Al 자리에 붕소를 치환시켜 줌으로써 결정상은 순수해지고 발광강도는 크게 향상됨을 확인하였다. 휘도 측면에서 붕소의 함량은 약 1 at%로 하는 것이 가장 바람직하였다. 유기첨가제의 함량 변화에 따른 $Sr_{0.9}Al_{1.98}B_{0.02}O_4:Eu_{0.1}$ 형광체의 휘도 변화를 조사한 결과 0.2M을 사용했을 때 가장 높은 휘도를 얻었다. 유기첨가제와 함께 건조 조절제로 DMF 0.5M을 함께 사용함으로써 $Sr_{0.9}Al_{1.98}B_{0.02}O_4:Eu_{0.1}$ 형광체의 휘도는 약 172% 향상되었다. XRD 분석 결과에 의하면 사용한 유기첨가제와 DMF의 사용은 $Sr_{0.9}Al_{1.98}B_{0.02}O_4:Eu_{0.1}$ 형광체의 결정상 변화 없이 결정성을 크게 향상시켰다. 유기 첨가제만을 사용할 경우 형광체의 표면적은 커졌지만 DMF를 함께 사용함으로써 현저히 줄어들었다. 따라서 유기첨가제와 DMF를 동시에 사용하여 합성한 형광체의 휘도가 크게 향상된 것은 결정성 증가와 표면적 감소에 기인한 것이라고 결론지었다.

• Bulletin of the Korean Chemical Society
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• 제6권6호
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• pp.344-347
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• 1985

Perovskite type oxides of $SrTiO_3,SrZrO_3,and\;SrTi_{1-x}Zr_xO_3$ have been systematically synthesized at $1250^{\circ}C$and $1550^{\circ}C$ with specimens containing additions of up to x=0.9 of zirconium by solid state reactions and characterized by X-ray diffraction. X-ray diffraction studies showed that the compound $SrTi_{1-x}Zr_xO_3$ has cubic structure. The lattice paramters of $SrTi_{1-x}Zr_xO_3$ solid solutions obey the Vegard's law and fairly large increase in volume can acompany the formation of this solution with increasing Zr content(X). Assuming the lattice constants of perovskite type compounds $A(B_{1-x}B'_x)O_3$where $B_{1-x}B'_x$ is $Ti_{1-x}Zr_x$, to be a linear function of the ionic radii of B and B' ions, the disordered ion pair of $Ti^{4+}$and $Zr^{4+}$ was verified from the lattice constants of a series compounds varying x=0,0.05, 0.25, 0.5, 0.75, 0.9, and 1.0 with known isovalent pairs.

• 한국결정학회지
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• 제12권1호
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• pp.1-4
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• 2001

Single crystals of strontium barium metaborate, Sr/sub 1.36/Ba/sub 1.64/(B₃O/sub 6/)₂, were grown for the first time by the high-temperature-solution-growth technique, and a detailed structure analysis was carried out with the space group R3c. The metaborate (B₃O/sub 6/)/sup 3-/ anion planar groups in the title compound form infinite layers parallel to (001) plane, and Sr and Ba atoms are alternatively placed between the layers and are octahedrally coordinated by six O(2) atoms in the neighbouring anion rings.

• 한국주조공학회지
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• 제38권5호
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• pp.87-94
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• 2018

The effects of Sr and (Ti-B) additives on the tensile properties of AC4A recycled (35% scrap content) aluminum alloys were investigated. An acicular morphology of the eutectic Si phase of as-cast specimens was converted to a fibrous morphology upon the addition of Sr. Moreover, morphology of the Sr modified eutectic Si phase became finer due to a T6 heat treatment. The grain size of the ${\alpha}$-solid solution was decreased by the addition of (Ti-B) additives. Depending on the treatment conditions of the as-cast specimens, i.e., no addition, a Sr addition and a (Ti-B)+Sr addition, the tensile strength levels of the as-cast specimens were 182, 192, and 204MPa, respectively. The corresponding strengths of T6 heat-treated specimens were 293, 308, and 318MPa. Elongations of the as-cast specimens were 2.2, 3.1, and 5.6%, and the corresponding elongations of the T6 heat-treated specimens were 4.6, 6.1, and 7.6%. The percentage of the reduced section area in the tensile specimens was also increased by the Sr and (Ti-B) additives. Sr and (Ti-B) additives changed the microstructure and the distribution of defects in the castings, resulting in an improvement of the tensile properties of AC4A aluminum alloys. According to our test results, recycled (35% scrap content) AC4A aluminum alloy met all of the KS requirements of the tensile strength and elongation values of AC4A aluminum alloy except for the elongation value of the one specimen condition, in this case the as-cast no-addition condition.

• 한국안광학회지
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• 제7권1호
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• pp.57-61
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• 2002

3성분 $SrO-B_2O_3-SiO_2$ 유리들을 R(${\equiv}SrO\;mole%/B_2O_3\;mole%$)과 K(${\equiv}SiO_2\;mole%/B_2O_3\;mole%$)에 의하여 제작하여 유리들의 구조를 적외선 투과(Infrared transmittance), 경도(hardness) 그리고 굴절률(refractive index)을 이용하여 조사하였다. 첫째, 적외선 투과 스펙트럼에 의한 유리구조들의 변화는 R의 증가에 따라 $1200{\sim}1600cm^{-1}$ 영역에서 $BO_3$ 단위구조에 의한 B-O 결합의 신축떨기(stretching vibration)에 의한 흡수 띠의 세기가 감소되어지며, 사면체 구조인 $BO_4$ 단위구조에 의한 B-O 결합의 신축떨기에 의한 흡수 띠의 세기는 $800{\sim}1200cm^{-1}$ 영역에서 변화되어졌다. 그리고 K의 증가에 따라 $BO_3$ 단위구조에 의한 B-O 결합의 신축떨기에 의한 흡수 띠의 세기는 증가되어지며, 사면체 구조인 $BO_4$ 단위구조에 의한 B-O 결합의 신축떨기에 의한 흡수 띠의 세기가 감소하였다. 둘째, 유리들의 경도는 유리 망목구조(network) 내에 형성되어지는 $BO_4$와 $BO_3{^-}$ 단위구조들의 수에 의존하여 각각 증가와 감소하였으며, 굴절률은 SrO량에 크게 의존하였으며 유리 망목구조 내에 형성되어지는 $BO_4$와 $BO_3{^-}$ 단위구조 수에 적게 의존함을 알 수 있었다.

• 한국세라믹학회지
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• 제28권6호
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• pp.471-477
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• 1991

Effects of ZnO, PbO and SiO2 on the grain growth and magnetic properties of Sr-ferrite were investigated. (1) Addition of ZnO to Sr-ferrite increased remanence, but decreased coercivity and maximum energy product. (2) Addition of PbO up to 0.5 wt% increased (B$.$H)max of Sr-ferrite, but addition more than 0.5 wt% decreased (B$.$H)mzx (3) SiO2 addition to the 0.5 wt% PbO doped Sr-ferrite decreased remanence and increased coercivity. The coercivity increase in due to the grain refinement effect of SiO2. But addition of SiO2 more than 0.5 wt% invoked a decrease of coercivity and (B$.$H)max of Sr-ferrite due to abnormal grain growth. Sr-ferrite magnet having maximum energy product of 3.7MGOe was fabricated by using the roasting product of Pyrrhotite.