• Geomechanics and Engineering
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• 제15권5호
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• pp.1091-1100
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• 2018

In this study, the relationships between hydraulic conductivity of GCLs and physico-chemical properties of bentonites were assessed. In addition to four factory manufactured GCLs, six artificially prepared GCLs (AP-GCLs) were tested. AP-GCLs were prepared in the laboratory without bonding or stitching. A total of 20 hydraulic conductivity tests were conducted using flexible wall permeameters ten of which were permeated with distilled deionized water (DIW) and the rest were permeated with tap water (TW). The hydraulic conductivity of GCLs and AP-GCLs were between $5.2{\times}10^{-10}cm/s$ and $3.0{\times}10^{-9}cm/s$. The hydraulic conductivities of all GCLs to DIW were very similar to that of GCLs to TW. Then, simple regression analyses were conducted between hydraulic conductivity and physicochemical properties of bentonite. The best correlation coefficient was achieved when hydraulic conductivity was related with clay content (R=0.85). Liquid limit and plasticity index were other independent variables that have good correlation coefficients with hydraulic conductivity (R~0.80). The correlation coefficient with swell index is less than other parameters, but still fairly good (R~0.70). In contrast, hydraulic conductivity had poor correlation coefficients with specific surface area (SSA), smectite content and cation exchange capacity (CEC) (i.e., R < 0.5). Furthermore, some post-test properties of bentonite such as final height and final water content were correlated with the hydraulic conductivity as well. The hydraulic conductivity of GCLs had fairly good correlation coefficients with either final height or final water content. However, those of AP-GCLs had poor correlations with these variables on account of fiber free characteristics.

• 한국토양비료학회지
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• 제42권3호
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• pp.160-166
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• 2009

We estimated site productivity for unstocked land based on the relationship between site index (i.e., average height of dominant trees at fixed age) and soil physico-chemical properties of Pinus densiflora stands. Site index relates to a direct method of determining a tree's response to a specific environment such as forest soil and climate conditions. We selected 78 sites in 22 P. densiflora stands of central temperate forest zone, and sampled soils for physicochemical analyzing. And 13 properties of soils were statistically treated by stepwise regression. In the degree of contribution of the variables to site index, the highly effective variables in A horizon were OM, clay content, sand content, available $P_2O_5$, and Exch. $Ca^{{+}{+}}$ inorder, and in B horizon T.N., O.M., Soil pH, cation exchange capacity(C.E.C.), and sand content in order. In both A and B horizon of the soil for P. densiflora stands, the variables commonly contributed to the site index were sand content and OM. These results may be useful to provide not only important criteria for establishment of Pinus densiflora stand sespecially in unstocked land but also aguidance for reforestation.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.409-416
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• 2017

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of $6.92{\pm}0.09$. It has spreadability value of $15.04{\pm}0.98g{\cdot}cm/sec$ and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control $Kwell^{(R)}$, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

• 한국식품과학회지
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• 제31권5호
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• pp.1137-1143
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• 1999

볶음참깨 및 참기름 제조시 필요한 기초자료를 마련하기 위하여 볶음온도$(110^{\circ}C{\sim}230^{\circ}C)$변화에 따른 참깨의 물리적 변화 및 화학적 변화를 알아보았다. 볶음참깨의 물리적 특성에 있어서 수분함량, 부피변화, 착유수율, 참깨박함량 및 색도는 $170^{\circ}C$이상에서 유의적으로 변하였고, 참깨박 중의 지방함량 및 단백질함량은 약간 변화하였다. 착유수율과 관능적 특성을 고려할 때 볶음최적온도는 $220^{\circ}C$로 판단된다. Arginine, serine, threonine, lysine, cystine, tyrosine 등의 총아미노산과 대부분의 유리아미노산, 그리고 유리당 중의 sucrose는 $170^{\circ}C$ 및 $190^{\circ}C$ 이상에서 유의적으로 감소하였다. 이러한 당과 아미노산 함량의 감소는 볶음참깨의 갈색색소 및 고소한 맛과 풍미 형성에 중요한 역할을 한 것으로 추측한다. 이러한 반응은 비교적 높은 온도에서 수분이 적고, 기름함량이 많은 식품계에서 당과 아미노화합물의 상호작용에 의한 열분해반응임을 알 수 있었다.

• 한국축산식품학회지
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• 제36권2호
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• pp.267-274
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• 2016

The purposes of this study were to investigate the impacts of concentration levels of whey protein isolate (WPI) and inulin on the formation and physicochemical properties of WPI/inulin nano complexes and to evaluate their potential prebiotic effects. WPI/inulin nano complexes were produced using the internal gelation method. Transmission electron microscopy (TEM) and particle size analyzer were used to assess the morphological and physicochemical characterizations of nano complexes, respectively. The encapsulation efficiency of resveratrol in nano complexes was studied using HPLC while the potential prebiotic effects were investigated by measuring the viability of probiotics. In TEM micrographs, the globular forms of nano complexes in the range of 10 and 100 nm were successfully manufactured. An increase in WPI concentration level from 1 to 3% (w/v) resulted in a significant (p<0.05) decrease in the size of nano complexs while inulin concentration level did not affect the size of nano complexes. The polydispersity index of nano complexes was below 0.3 in all cases while the zeta-potential values in the range of -2 and -12 mV were observed. The encapsulation efficiency of resveratrol was significantly (p<0.05) increased as WPI and inulin concentration levels were increased from 1 to 3% (w/v). During incubation at 37℃ for 24 h, WPI/inulin nano complexes exhibited similar viability of probiotics with free inulin and had significantly (p<0.05) higher viability than negative control. In conclusions, WPI and inulin concentration levels were key factors affecting the physicochemical properties of WPI/inulin nano complexes and had potential prebiotic effect.

• 산업식품공학
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• 제14권3호
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• pp.222-228
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• 2010

감태 분말의 대체량을 0-8%로 달리하여 스펀지 케이크를 제조한 후 물리화학적 및 관능적 품질특성을 측정하고 각 특성사이의 상관관계를 살펴보았다. 감태 분말의 대체 비율이 증가함에 따라 반죽의 비중은 점차적으로 증가하는 경향을 나타내었고, 케이크의 비체적은 감태 분말 대체에 따라 감소하고 굽기 손실은 증가하였다. 부피지수는 감소하는 경향을 보여 감태 분말의 비율이 높아지면 케이크의 부피가 작아짐을 알 수 있다. 밝기는 나타내는 $L^*$값은 유의적으로 감소하였으며(p<0.05), 경도는 점차적으로 증가하였다. 관능검사 결과 감태 분말대체에 따라 대부분의 관능 특성이 뚜렷하게 구분되었다(p<0.05). 한편 상관분석 결과 감태 분말의 대체수준은 $a^*$값과 관능적 경도(firmness)를 제외하고 모든 품질특성과 유의적인 상관관계를 나타내었다(p<0.05, p<0.01 또는 p<0.001).

• 원예과학기술지
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• 제35권4호
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• pp.446-455
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• 2017

본 연구는 참외의 소비자 기반 품질 지표를 제공하기 위하여 이화학적 특성 및 관능 특성을 조사하였다. 참외는 착과 후 20일, 25일, 그리고 30일에 수확하였으며, 각 수확 시기에 따라 부피별로 소, 중, 대를 구분하여 총 9그룹의 특성을 분석하였다. 착과 후 25일 및 30일에 수확된 그룹은 20일에 수확된 그룹에 비하여 CIE $a^*$와 $b^*$값, 그리고 가용성 고형분 함량(SSC)이 높았으며, CIE $L^*$값과 경도는 낮았다. 또한 착과 후 25일 및 30일에 수확된 그룹은 전반적인 기호도가 높았다. 특성간 상관성 분석결과 이화학적 특성(CIE 값, SSC, 산도, 그리고 경도)과 전반적인 기호도는 1% 유의수준에서 상관성이 있었다. 관능 특성 평가결과 수확 시기가 늦을수록 당도와 황색도는 높고 경도는 낮았으며, 이러한 특성은 전반적인 기호도의 증가와 연관이 있었다. 주성분 분석결과 제 1주성분과 제 2주성분은 각각 62.16%와 17.91%의 설명력을 보여주었으며 전체 설명력은 80.07%였다. 제 1주성분 점수의 변화 경향을 활용하여 전반적인 기호도와 직선회귀식을 산출한 결과 $r^2$은 0.87이었다. 본 실험결과 이화학적 특성인 CIE 값과 SSC, pH, SSC/적정 산도(TA) 및 경도와 관능적 품질 특성인 과피의 황색도, 향, 풍미, 단맛, 조직감, 이미, 그리고 태좌부의 상태를 참외의 품질지표로 활용하여 소비자 기호도 예측이 가능하였다.

• 한국작물학회지
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• 제44권4호
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• pp.355-363
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• 1999

The experiments were carried out to elucidate the varietal variation of retrogradation in aged cooked rice and its association with some physicochemical properties of milled rice. The fifteen rice materials were selected from forty-three low-amylose japonica and Tongil-type rice cultivars based on palatability and retrogradation of cooked rice stratified by preliminary sensory evaluation of warm and cooled cooked rice. One japonica glutinous rice variety was included for comparison of retrogradation of cooked rice. The $\alpha$-amylase-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The desirable checking time for evaluating the varietal difference in deterioration of aged cooked rice was four hours after storing in room temperature and two hours after preserving in refrigerator based on the largest coefficients of variations in degree of retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. The retrogadation index represented by the percentage of retrogradation difference between warm and cooled cooked rice to original estimates of warm cooked rice was significantly affected by the degree of retrogradation of cooled cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked nce. The varietal difference in retrogradation of cooked rice can be effectively classified by scatter diagram on the plane of upper two principal components based on some retrogradation properties of cooked rice. The deteriorated structural change in cooled cooked rice by observing through the scanning electron microscope was more conspicuous in the fastly retrograded cooked rice than in the slower one.

• 한국식품영양과학회지
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• 제46권11호
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• pp.1327-1335
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• 2017

본 실험은 카카오 빈의 함량(0, 20, 40, 60%)을 달리하여 쌀가루와 압출성형물을 제조하여 물리화학적인 특성을 관찰하고자 하였다. 공정 조건은 수분 함량 25%, 스크루 회전 속도 200 rpm, 사출구온도 $130^{\circ}C$로 조절하였다. 팽화율은 카카오 빈의 함량이 증가할수록 감소하였다. 밀도와 비길이, 겉보기 탄성계수는 카카오 빈의 함량이 증가함에 따라 증가하였고, 파괴력은 카카오 빈의 함량이 증가할수록 감소하였다. 수분용해지수와 수분흡착지수는 압출성형 공정 후 모두 증가하였다. 카카오 빈의 첨가량이 증가할수록 명도는 감소하였고 적색도는 증가하였으며, 황색도는 무처리구(RAW)에서 카카오 빈이 증가함에 따라 증가하였지만, 압출성형 공정 후 카카오 빈이 증가함에 따라 감소하였다. 색도차는 카카오 빈의 함량이 증가할수록 증가하였다. 페이스트 점도는 카카오 빈의 함량이 증가할수록 모든 조건에서 감소하였으며, 압출성형을 한 모든 실험군과 RAW의 roasted 카카오빈(RC) 첨가군에서 저온최고점도(CPV)를 나타내어 낮은 온도에서도 점성을 나타내는 특성을 보였다. 총 페놀 함량은 non-roasted 카카오 빈(NRC) 첨가군이 RC 첨가군보다 높았으며, DPPH 라디칼 소거능은 압출성형한 NRC 첨가군에서 가장 높게 나타났다. 결론적으로 카카오 빈 첨가가 쌀 카카오의 팽화 특성에 영향을 미치며, 카카오 빈의 총 페놀 함량은 로스팅과 압출성형에 의해 감소하였지만, DPPH 라디칼 소거능은 로스팅을 하지 않고 압출성형 하였을 때 증가하였다.

• KSBB Journal
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• 제13권2호
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• pp.162-167
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• 1998

The adsorption behaviors of two major cellulase components, endo I and exo II, from Trichoderma viride were investigated using $\alpha$-celluloses with different correlation crystallinity index(Cc) as substrates. The adsorption of cellulase enzyme components was significantly affected by the reaction condition and the physicochemical properties of the cellulose. The $\alpha$-cellulose was hydrolyzed in the presence of cellulase for various periods. The correlation crystallinity index of $\alpha$-cellulose increased with increasing the hydrolysis time. The adsorption was apparently found to obey the first-order kinetics, and the adsorption activation energy(Ea) was calculated from the adsorption rate constant(ka). The value of adsorption rate constant for endo I was larger than that of exo II. This means that endo I are adsorbed more rapidly than exo II. With the increase in correlation crystallinity index, the values of the adsorption rate constants for endo I and exo II decreased, respectively. The activation energy for the adsorption of exo II on the cellulose also was larger than that of endo I. Also adsorption activation energy of endo I and exo II increased with an increase in the crystallinity of sample cellulose.