• Membrane and Water Treatment
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• v.9 no.4
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• pp.245-253
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• 2018

The aim of this study is to investigate the membrane fouling in a thermophilic membrane bioreactor (TMBR) operated different sludge retention times (SRTs). For this purpose, TMBR was operated at four different SRTs (10, 30, 60 and 100 days). Specific cake resistance (${\alpha}$), cake resistance, gel resistance, total resistance, MFI (modified fouling index) and FDR (flux decrease ratio) were calculated for all SRTs. It was observed that flux in the membrane increases with rising SRT although the sludge concentrations in the TMBR increased. The steady state flux was found to be 31.78; 34.70; 39.60 and 43.70 LMH ($Liter/m^2/h$) for the SRTs of 10, 30, 60 and 100 days respectively. The concentrations of extracellular polymeric substance (EPS) and soluble microbial product (SMP) decreased with increasing SRT. The membrane fouling rate was higher at shorter SRT and the highest fouling rate appeared at an SRT of 10 d. Both the sludge cake layer and gel layer had contribution to the fouling resistance, but the gel layer resistance value was dominant in all SRTs.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.39-46
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• 2004

Waxy maize starches are inherently stable in soluble status and can be chemically modified to improve stability along with heat, acid and shear resistance. This study was carried out to investigate the effect of theological and sensory characteristics of the yellow layer cake made by adding different levels of waxy maize starch as a fat substitute for shortening. By increasing the substitution level of waxy maize starch for shortening, the specific gravity of cake batter increased and the viscosity decreased. The microstructures of cake crumb observed by the scanning electron microscope were not different significantly, and the size of air cells and fat particles also were not substantially decreased by increasing fat substitution level. The texture profile analysis using texture analyzer decreased by increasing the different substituting levels of waxy maize starch. Among various sensory properties, the color value of layer cake increased by increasing the level of waxy maize starch. However, the appearance, flavor, taste, texture and overall preference decreased.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.871-876
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• 2003

Yellow layer cakes were prepared with flour that was partially substituted with mulberry leaf powder (at the levels of 4, 8, 12, 16 and 20%). Batter viscosity increased with increasing substitution levels while specific gravity decreased. The specific volume of the cake increased as batter viscosity increased, except at 20% substitution. Substituting mulberry leaf powder for flour also resulted in decreased lightness and yellowness and increased redness of the cake crumbs. The volume index and uniformity index were not influenced by the addition of mulberry leaf powder, while the symmetry indexes of cakes with 16% and 20% powder were lower than the control. The hardness of cakes substituted with mulberry leaf powder was lower than that of the control during 10 days of storage. Sensory characteristics, including cell size and cell uniformity, were adversely affected with substitution levels of 16% and 20%. The addition of mulberry leaf powder did not influence softness, but affected moistness significantly.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.203-209
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• 2021

The quality characteristics of yellow layer cakes produced by different methods of buckwheat powder addition (0, 10, 20, 30, 40) were investigated. The specific gravity of the dough increased as the amount of buckwheat powder added increased. Regarding the color of the crumb of cake, the L value and b value(yellowness) were lower as the amount of buckwheat powder added increased, but the a value(redness) increased. The cake volume tended to decrease as the amount of buckwheat powder added increased. The cake symmetry index and uniformity index were not significantly different from those of the control group, but the baking loss rate was slightly lower when buckwheat powder was added. The hardness was significantly higher than that of the control as the amount of buckwheat powder added increased. A sensory test showed that the taste had a high score when 20% buckwheat powder was added, and texture and overall acceptance were not significantly different from the control group until 20% buckwheat powder was added. Therefore, when a part of wheat flour is replaced with buckwheat powder to produce a yellow layer cake, it is possible to produce a product with improved cake quality and symbolic characteristics when a buckwheat powder 20% level is added.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.159-166
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• 2020

In this study, the performance and antifouling properties of polysulfone (PSf) and polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) membranes in a membrane bioreactor (MBR) were investigated. The membranes were prepared via phase inversion method, and then characterized by a set of analyses including contact angle, porosity and water flux and applied in a lab-scale MBR system. Soluble microbial product (SMP), extracellular polymeric substance (EPS), FTIR, gel permission chromatography (GPC) and particle size distribution (PSD) analyses were also carried out for MBR system. The results showed that the MBR with PSf membrane had higher hydrophobic organic compounds which resulted in formation of larger flocs in MBR. However, in this MBR had high compressibility coefficient of cake layer was higher (n=0.91) compared to MBR with PVDF/PVP membrane (n=0.8); hence, the fouling was more profound. GPC analysis revealed that compounds with molecular weight lower than 2 kDa are more formed on PSf membrane more than PVDF/PVP membrane. The results of FTIR analysis confirmed the presence of polysaccharide and protein compounds on the cake layer of both membranes which was in good agreement with EPS analysis. In addition, the results showed that their concentration was higher for the cake on PSf membrane.

• Journal of agriculture & life science
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• v.44 no.1
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• pp.51-59
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• 2010

The quality characteristics (specific gravity, viscosity, color, texture and sensory evaluation etc.) of yellow layer cake added with black garlic powder were examined in order to use as a new functional food ingredient of black garlic powder. Specific gravity of cake batters was not affected by addition of black garlic powder. Viscosity (31,315~41,048 cP) of cake batters was increased as the addition level of black garlic powder increased. pH (7.54~6.18) and height (6.14~5.62cm) of cakes were decreased as the addition level of black garlic powder increased. Specific volume of cakes did not show any significant difference except the cake with 15% black garlic powder. In color of cake crust, crumb and batter, lightness (L) and yellowness (b) were decreased as the addition level of black garlic powder increased, while redness (a) was increased. Hardness and adhesiveness of cakes decreased as the addition level of black garlic powder increased Overall acceptability was the highest in yellow layer cake with 5% black garlic powder.

• Food Science and Preservation
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• v.18 no.6
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• pp.830-835
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• 2011

This study was conducted to evaluate the effects of the substitution of flour with young-barley-leaf powder on the quality characteristics of yellow layer cake. The physical properties of the cakes (i.e., viscosity, specific gravity, specific volume, cake index, and color) were measured, and the changes in hardness during the three-day storage at $22^{\circ}C$ were measured. Sensory evaluation was done with five-scale acceptance test. Both the viscosity and specific gravity of the batter were significantly influenced by the substitution. Nonetheless, no significant difference was shown in the specific volumes of the cakes. The volume indices of the cakes containing young-barley-leaf powder were higher than those of the control. The lightness, redness, and yellowness values of the crusts decreased with the addition of young-barley-leaf powder. While the lightness values of the crumbs decreased, the redness and yellowness values increased. The substitution of more than 6% flour with young-barley-leaf powder kept the hardness of the cakes lower than that of the control during the three-day storage. The cakes containing 2, 4, and 6% young-barely-leaf powder showed no significant differences from the control in the acceptance test, except in the crumb color.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.371-380
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• 2004

In the dust separation by using porous filter media, the structure of dust layer deposited on the filter surface of filter medium directly affects the effective filtration. The present study has investigated the specific resistance (K$_2$') of the dust layer and its porosity ($\varepsilon$$_{c}$) for three different filters; FA composite filter, metal fiber filter and stainless filter. The specific resistance (K$_2$') increased and at the same time the cake porosity ($\varepsilon$$_{c}$) decreased with the increase of filtration velocity, possibly due to the compressible effect of dust layer. However, under the low dust concentration, subsequent dust particles would block the open channels through the layer resulting in high specific resistance of the layer. The FA composite filter among three filters was shown to be the most effective filter for dust cake filtration at low filtration velocities less than 0.1 m/s for an approximate dust concentration of 5 g/㎥.

• Membrane Journal
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• v.25 no.3
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• pp.276-286
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• 2015

The effects of relaxation and backwashing on fouling in ultrafiltration were investigated using full-scale membrane bioreactors (MBRs) which operated at a constant flux of 30 LMH. This paper also estimated the feasibility of using intermittent aeration strategies for minimizing the hydraulic resistance to filtration in comparison with the continuous aeration for running MBRs. Multiple cycles of filtration (14.5 min each) and relaxation (0.5 min each) were repeated. Similarly, a backwash was conducted by replacing a relaxation after each filtration cycle for the comparative performance test. The attached cake thickness on the membrane rapidly increased, caused by subsequent no aeration leading to easier combining with gel layer and the formation of heterogeneous layer on the membrane surface. During periodic backwashing, it is expected that gel and thin cake layer might sufficiently be removed by heterogeneous layer. After periodic backwashing, subsequent cake layer formation during time of no aeration was rapid than frequent no aeration, acting as a prefilter and preventing further irreversible fouling. Based on the Pearson correlation analysis, overall period fouling (dTMP/min) and average of all cycles (dTMP/min) were strongly correlated with the on-off period of aeration for operating MBRs.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.220-228
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• 2008

In constructing a slurry trench cutoff wall, a thin but relatively impermeable layer called filter cake can be formed on the excavation surface. The filter cake significantly influences the result of slug test analysis in the cutoff wall. This study is to examine the effect of filter cake on evaluating in situ hydraulic conductivity of the vertical cutoff wall along with slug test analyses. The numerical program Slug_3D was modified to take filter cake into account in the slug test simulation. With consideration of filter cake, the type curve method and the modified line-fitting method were used to reanalyze the case study taken from a landfill site. The previous results achieved by Choi and Daniel (2006b) without consideration of filter cake have been compared with the results in this study. The considerable difference between the two results shows the necessity of considering the filter cake in practice.