In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, Rf (Resistance of internal contamination) increased rapidly with the increase of UAP, and Rc (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

The physicochemical properties of Korean rice flour cultivars (Saemimyeon [SM], Hanareum No. 4 [HA], and Milyang No. 328 [MY]) with different amylose contents were analyzed and the effects of rice flour blending on their physicochemical property changes were investigated in this study. The swelling power of three different cultivars was similar at 60oC, but MY showed significantly enhanced swelling power at 80oC compared to SM and HA. In the pasting profile, MY showed significantly lower final and break-down viscosities than SM and HA due to its weak granular rigidity. In the case of the 1:1 blending of SM-MY and HA-MY, the measured values of swelling power and solubility were greatly decreased at 80oC, and the setback and final viscosity were significantly increased compared to their predicted arithmetic average values, showing the non-additive effects of blending. For the dynamic viscoelastic properties, SM-MY and HA-MY showed significantly decreased G’ and increased k’ and tanδ, compared to their predicted average values. In conclusion, the selected rice flour blends had non-additive effects on swelling power, solubility, pasting, and dynamic viscoelastic properties. These results showed the feasibility of the rice flour blending to diversify the physicochemical properties of rice flour for better processing suitability.

본 연구의 목적은 폴 멀둔의 시에 나타난 유희적인 비가풍 회상을 두 가지 방식, 즉 어두운 유머와 연상기법을 중심으로 고찰하는 것이다. 멀둔은 어두운 유머를 통해 당대의 존재론적, 역사적, 정치적 위기상황을 보여준다. 그는 심각한 멜랑 콜리 정서만을 유지하지는 않는데, 전통적인 비가에서처럼 화자가 주변 환경과 정서적인 거리를 좁히지 않을 뿐만 아니라, 근대 비가에서처럼 멜랑콜리의 심연에 무력하게 빠지지도 않는다. 멀둔이 보여주는 멜랑콜리와 유머의 특이한 결합은 그가 선택한 미묘한 단어, 암호말, 기표 유희 등의 연상기법을 통해 이뤄지고, 이는 대상과 상황 사이에 긴장을 일으켜 의미화 작용의 한계에 이른다. 멀둔은 20세기 후반 격동기를 애 도하면서 추적 가능한 애도의 감정들이 기표의 유희 속으로 급속히 표류하게 하여 충격적인 역사로부터 유머러스한 거리를 유지한다.

Froude(Fr) 수의 상사성을 통해 문풀의 크기와 유동 속도를 결정할 경우 축척비에 따라 문풀 내부 유동에 대한 Reynolds(Re)수가 크게 달라진다. 즉 같은 Fr 수를 갖는다 할지라도 축척비에 따라 문풀 내부 유동 특성이 달라질 수 있음을 의미한다. 본 연구에서는 같은 Fr 수로 상사되었을 때 축척비가 문풀 내부 유동 특성에 미치는 영향을 분석하기 위해 2차원 수치 해석을 수행하였다. 문풀의 크기가 작을 때 문풀에 작용하는 힘은 매우 주기적인 특성을 보이는 반면 문풀의 크기가 커질수록 주기가 일정하지 않은 교란 특성을 보이기 때문에 과도 응답과 통계적 정상 상태의 응답을 구분하기 어려워진다. 주파수 특성에 있어서도 축척비의 제곱근에 반비례하여 나타나는 주파수 특성(f0.5 ~ 2f1 ~ 2f2.0)은 Fr 수의 상사성에 따른 유동 특성으로 볼 수 있으나, 문풀의 크기가 클 때 매우 낮은 주파수(f2.0=0.07)로 문풀 내부에서 매우 강한 와가 발생하는데 이는 축척비에 따른 영향이다.

YNbO4:Yb3+/Er3+ is synthesized using a solid-state reaction process with a LiCl flux. The effects of the Er/(Yb+Er) ratios (REr) on the up-conversion (UC) and down-conversion (DC) spectra are investigated. The XRD data confirm that the Yb3+ and Er3+ ions are fully substituted for the Y3+ sites. The UC emission spectra activated by 980 nm consists of green and red emission bands, which originate from the Er3+ ions through an energy transfer (ET) process from Yb3+ to Er3+. The UC emission intensity depends on the REr value, and the findings demonstrate that REr ≤ 0.14 is suitable for an effective UC process. The DC emission spectra under 269 nm radiation of the synthesized powders exhibits not only a strong blue emission assigned to the [NbO4]3− niobates, but also green peaks that originate from the Er3+ ions through an ET process between [NbO4]3− and Er3+.

PURPOSES: Current theories for composite structures are too difficult for design engineers for construction. The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the road structures. METHODS: Some laminate orientations have decreasing values of D16, B16, D26 and B26 stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. In order to study the effect of Mx on the equilibrium equations, two cases are considered. Mx term is considered or neglected. RESULTS: Most of the road structures have high aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms. CONCLUSIONS: Most of the road structures have plate aspect ratios higher than 2. It is concluded that, for all boundary conditions, neglecting the longitudinal moment(Mx) terms is acceptable if the aspect ratio (a/b) is equal to or higher than 2. This conclusion gives good guide line for design of the road structures.

We have examined the co-doping effects of 1/2mol% NiO and 1/4mol% Cr2O3 (Ni:Cr=1:1) on the reaction,microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS;Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Ni,Cr-doped ZBS, ZBS(NiCr) varistors werecontrolled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 were detected for all ofcompositions. For the sample with Sb/Bi=1.0, the Pyrochlore was decomposed and promoted densification at lowertemperature by Ni rather than by Cr. A homogeneous microstructure was obtained for all of the samples affected by α-spinel.The varistor characteristics were not dramatically improved (non-linear coefficient, α=5~24), and seemed to formZni..(0.17eV) and Vo.(0.33eV) as dominant defects. From impedance and modulus spectroscopy, the grain boundaries werefound to have been divided into two types, i.e., one is tentatively assigned to ZnO/Bi2O3 (Ni,Cr)/ZnO (0.98eV) and the otheris assigned to a ZnO/ZnO (~1.5eV) homojunction.

Recently, the Ranque-Hilsch vortex tube is widely used for the local cooler of industrial equipment for special purpose. Although many studies on energy extraction in the vortex tube using air as the working fluid have been made so far, a few experimental studies treated solid particles extraction for incompressible fluid. So, an experimental study for the solid particles extraction in the vortex tube(Ranque-Hilsch vortex tube) using the water which is essentially an incompressible fluid is presented. The experiments were carried out with various cold end orifice diameter ratios ranging from 0.25 to 0.70, the input pressure ranging from 1 to 3MPa was considered. The emphasis was given to examine the effect of geometry factors of vortex tube at working fluid(water) for solid particles(Al2O3) extraction. The optimum geometry factor and inlet pressure for the maximum solid particles extraction was found that the smaller cold end orifice diameter ratio and the higher inlet pressure in experimental condition increase.

In the present study, Zr-base metallic glass(MG)/diamond composites are fabricated using a combination of gas-atomization and spark plasma sintering (SPS). The densification behaviors of mixtures of soft MG and hard diamond powders during consolidation process are investigated. The influence of mixture characteristics on the densification is discussed and several mechanism explaining the influence of diamond particles on consolidation behaviour are proposed. The experimental results show that consolidation is enhanced with increasing diamond/Metallic Glass(MG) size ratio, while the diamond fraction is fixed.

In this paper, a best-first branch and bound algorithm based upon the bottom-up approach for the unweighted unconstrained two-dimensional cutting problem is proposed to find the optimal solution to the problem. The algorithm uses simple and effective meth

까치복(Fugu xanthopterus)을 간, 알, 내장, 근육, 정소로 나누어서 얻은 총지질 함량은 간에 81.72%로 가장 많은 지질이 들어 있었으며 그 외 내장, 알, 근육, 정소에는 14.53, 12.63, 0.85, 1.74%로서 근육에서 가장 낮은 지질 수준이 나타났다. 한편 까치복의 간으로부터 독성제거 확인을 하기 위해 1% acetic acid/methanol용액 50ml와 CHCl_3:methanol(0.1% acetic acid)(2:1, v/v)용액 50ml에서 독성을 추출 하였다. 위 두가지 방법 모두에서 지질층에는 mouse test한 결과 무독한 것으로 나타났고 추출한 독성층에는 mouse무게가 가벼운 것이 더 높은 독성치를 나타내어 저항에 약함을 알 수 있었다. 또한 까치복의 부위별 지방산 조성을 GC로 분석한 결과 DHA의 함량이 근육에 32.4%로 가장 높았고, 간과 내장이 지질에도 23.0, 26.7%로 높은 지질수준을 보였으며 정소에는 15.4%로 가장 낮았다. 근육에는 고도 불포화 지방산이 57.4%로 전체 지방산 중 절반이 넘는 높은 함량을 나타내었고 간에도 50.9%의 높은 지질 수준을 보였다. 포화 지방산은 C_16:0가 각 부위마다 높았으며 모노 불포화 지방산은 C_18:1(n-9)가 부위마다 가장 높았음을 알 수 있었다.

본 실험은 양액내 NO3--N : NH4+-N 비율이 잎파(Allium fistulosum L.) 생육 및 품질에 미치는 영향을 알아보고자 실시하였으며, 그 결과는 다음과 같다. 양액내 pH는 NO3--N : NH4+-N 비율이 9:1인 처리구에서는 상승하였고, NO3--N : NH4+-N 비율이 1:1, 1:3인 처리구에서는 하강하는 경향이 있었으나, 3:1 처리구에서는 안정적인 PH를 유지하였다. 외관상 생육은 NO3--N : NH4+-N 비율이 9:1인 처리구에서 가장 양호하였으며, NO3--N : NH4+-N 비율이 1 :3인 처리구에서 가장 저조하였다. 식물체내의 NO3--N의 함량은 양액내의 NO3--N 비율이 높을수록 증가하였다. Pyruvic acid 함량은 생육이 양호한 NO3--N : NH4+-N 비율이 9:1, 3:1인 처리구에서 높았으며, 1:3처리구에서는 낮았다.

야온과 시용질소의 형태를 달리한 양액이 탑채와 백경채의 생육 및 품질에 미치는 영향을 알아보기 위하여 실시한 실험의 결과는 다음과 같다. 1. 탑채, 백경채 모두 야온 15℃ 에서 생육이 왕성하여 생체중이 무거웠으나 건물율과 vitamin C의 함량은 온도가 낮아질수록 증가하였다. 2. 양액의 N형태 비율에 따른 백경채의 생육은 NO3- : NH4+ 의 비가 0 : 8에서만 극히 생육이 저조하고, 다른 처리구에서는 큰 차이가 없었다. 3. 양액내 NO3--N의 함량이 높을수록 vitamin C의 함량이 많고, NH4+-N의 함량이 높을 때는 건물율이 높았다.

This study was performed observe the effect of edible oil on the serum lipid of 0.5% cholesterol-fed rats. In this experiment, male rats of Sprague-Dawley strain were used. The rats were divided into 5groups which were fed differently eigher for 8 weeks : basal diet, 20% sunflower oil diet, 20% soybean oil diet, 20% rapeseed oil diet, 20% coconut oil diet. The followings are the results of this experiment. 1. The total chol., free chol., TG, PL level in the serum were showed tendency of decrease with in creasing of P/S ratios. 2. HDL-chol. level was increased with increasing of P/S ratios but LDL-chol. level was decreased. 3. GOT, GPT, TBA level in the serum were increased with increasing of P/S ratios.