• Title/Summary/Keyword: UF

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Evaluation of Physicochemical Properties of Muffins Made With Ultrafiltered Sunmul Powder

  • Chung, Hai-Jung;Eom, Kwon-Yong;Kim, Woo-Jung
    • Preventive Nutrition and Food Science
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    • v.11 no.4
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    • pp.333-338
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    • 2006
  • This study was conducted to investigate the quality characteristics of muffins with added ultrafiltered (UF) sunmul powder. Muffins were prepared with four different levels of UF powder (0%, 3%, 5% and 7%) and the physicochemical properties were examined. The volume and specific volume were lower in muffins prepared with UF powder than the control. The incorporation of UF powder in muffin lowered the lightness values but increased the redness values. Rheology testing showed that hardness increased with increasing UF powder and gumminess and brittleness were the highest in the control group and decreased with increasing UF powder. Initial isoflavone content was 2.39$\sim$5.57 mg%, and decreased to 1.81$\sim$4.09 mg% after baking, resulting in 24$\sim$37% reduction in muffin formulations. Scanning electron microscopy showed that the size of the air cells increased with increasing UF powder levels. In sensory evaluation, overall acceptability score was the highest in muffins with 3% added UF powder and no significant difference was observed between control and 7% addition. Therefore, muffins prepared with up to 7% addition of UF powder would be at least as acceptable as control muffins.

Uranium tetrafluoride production at pilot scale using a mercury electrode cell

  • Dides, Munir;Hernandez, Jose;Olivares, Luis
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1909-1913
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    • 2022
  • This work shows the technical feasibility to obtain uranium tetrafluoride through an electrochemical mercury cell. This technique represents a custom scaling-up methodology from our previous studies to obtain UF4 using the dropping mercury electrode cell. The UF4 products were obtained from natural UF6 gas, which was hydrolyzed to obtain a 50 g/L UO2F2 solution. The electrolysis cell was made using a mercury reservoir, to reach UF4 production rates of 1 Kg UF4/day. This custom design allowed a stable UF4 production thanks to the mercury cathode, which do not permit the accumulation of solid products in its surface. The cell was tested using current densities from 5.000 to 17.500 A/m2 and temperatures from 25 to 65 ℃. The maximum current efficiency achieved under these conditions was 80%. The UF4 powders possessed spherical morphology, with diameters between 20 and 80 ㎛. Compared to the SnCl2 precipitation, this process did not allow preferential growth of the precipitates. This improved the compaction of the UF4 - Mg powders mixtures, with densities between 3.0 and 3.5 g/cm3. The purity of the UF4 products was over 98%.

Functional Properties of Sunmul (Soybean Curd Whey) Concentrate by Ultrafiltration (한외여과에 의한 순물 농축액의 기능적 특성)

  • Kim, You-Pung;Eom, Sang-Mi;Chang, Eun-Jung;Kim, Woo-Jung;Oh, Hoon-Il
    • Korean Journal of Food Science and Technology
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    • v.38 no.4
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    • pp.488-494
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    • 2006
  • This study was carried out in order to investigate the feasibility of utilizing concentrated sunmul (soybean curd whey), which is a waste by-product of soybean curd processing, as a functional food ingredient. Sunmul Powder was concentrated by ultrafiltration and spray dried with or without dextrin. Oil adsorption capacity of UF retentate powder was similar to that of ISP (Isolated Soy Protein) and higher than that of sunmul powder, whereas water holding capacity of UF retentate powder was lower than that of ISP. Protein solubility of all types of UF retentate powder was significantly higher than that of ISP at pH 2.0-10.0 with the lowest protein solubility seen at pH 4.0 and solubility increasing as the conditions became more acidic or alkaline. Emulsifying activity indexes of UF retentate powder at pH 2.0-10.0 were not influenced by pH. Emulsion stability of 4% sunmul solution was lowest at pH 4.0, but that of UF retentate powder was higher at acidic pH values and decreased with increasing pH. Foaming capacities of sunmul and UF retentate powder were high at pH 4.0-6.0, but the foam of UF retentate powder disappeared within 20 minutes in all conditions of pH.

Properties of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde to Urea Mole Ratios

  • Park, Byung-Dae
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.67-75
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    • 2007
  • As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.

Treatment of oily wastewater from cold-rolling mill through coagulation and integrated membrane processes

  • Cheng, Xue-Ni;Gong, Yan-Wen
    • Environmental Engineering Research
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    • v.23 no.2
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    • pp.159-163
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    • 2018
  • The feasibility of applying coagulation-integrated microfiltration (MF) as a pretreatment for an ultrafiltration (UF) feed in oily wastewater treatment was investigated. The effects of different coagulants on oil removal rates from wastewater were studied. The maximum oil removal rate of 82% was obtained after coagulation with 130 mg/L of polyaluminium chloride (PAC). UF flux reached $95L/(m^2{\cdot}h)$ with coagulation-integrated MF as pretreatment. This value was 2.5 times higher than that flux obtained without pretreatment. The value of UF flux increased as the transmembrane pressure (TMP) and cross-flow velocity (CFV) of the UF module increased. UF flux gradually increased when TMP and CFV exceeded 0.4 MPa and 3 m/s, respectively, because of concentration polarization and membrane fouling stabilization. Chemical oxygen demand reduction and oil removal rate reached 95.2% and 98.5%, respectively, during integrated membrane processing with a PAC concentration of 130 mg/L, TMP of 0.4 MPa, and CFV of 3 m/s for UF. In addition, sequentially cleaning the fouling membrane with NaOH and $HNO_3$ aqueous solutions caused UF flux to recover to 90%. These encouraging results suggested that the hybrid integrated membrane process-based coagulation and MF + UF are effective approaches for oily wastewater treatment.

Influence of Hydrolytic Degradation on the Morphology of Cured Urea-Formaldehyde Resins of Different Formaldehyde/Urea Mole Ratios

  • Park, Byung-Dae;Jeong, Ho-Won
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.2
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    • pp.179-186
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    • 2011
  • In an effort to understand the hydrolytic degradation process of cured urea-formaldehyde (UF) resins responsible for the formaldehyde emission of wood-based composite panels, this study analyzed the influence of acid hydrolysis on the morphology of cured UF resins with different formaldehyde/urea (F/U) mole ratios such as 1.6, 1.4, 1.2 and 1.0. Field emission-scanning electron microscopy (FE-SEM) was employed to observe both exterior and fracture surfaces on thin films of cured UF resins before and after the etching with hydrochloric acid as a simulation of the hydrolytic degradation process. FE-SEM images showed that the exterior surface of cured UF resin with the F/U mole ratio of 1.0 had spherical structures after the acid hydrolysis while the other cured UF resins were not the case. However, the fracture surface observation showed that all the samples possessed spherical structures in the cured state of UF resins although their occurrence and size decreased as the F/U mole ratio increased. For the first time, we found the spherical structures in cured UF resins of higher F/U mole ratio of 1.4. After the acid hydrolysis, the spherical structures became a much predominant at the fracture surface. These results indicated that the spherical structures in cured UF resinswere much more resistant to the hydrolytic degradation by the acid than amorphous region.

13C-NMR Spectroscopy of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde/Urea Mole Ratios

  • Park, Byung-Dae;Lee, Sang M.;Park, Jong-Young
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.2
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    • pp.63-72
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    • 2008
  • As a part of abating formaldehyde emission of urea-formaldehyde (UF) resin adhesive, this study was conducted to investigate chemical structures of UF resin adhesives with different formaldehyde/urea (F/U) mole ratios, using carbon-13 nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. UF resin adhesives were synthesized at four different F/U mole ratios such as 1.6, 1.4, 1.2, and 1.0 for the analysis. The analysis $^{13}C$-NMR spectroscopy showed that UF resin adhesives with higher F/U mole ratios (i.e., 1.6 and 1.4) had two distinctive peaks, indicating the presence of dimethylene ether linkages and methylene glycols, a dissolved form of free formaldehyde. But, these peaks were not detected at the UF resins with lower F/U mole ratios (i.e., 1.2 and 1.0). These chemical structures present at the UF resins with higher F/U mole ratios indicated that UF resin adhesive with higher F/U mole ratio had a greater contribution to the formaldehyde emission than that of lower F/U mole ratio. Uronic species were detected for all UF resins regardless of F/U mole ratios.

Environment-friendly Adhesives for Fancy Veneer Bonding of Engineered Flooring to Reduce Formaldehyde and TVOC Emissions

  • Kim, Sumin;Kim, Hyun-Joong;Xu, Guang Zhu;Eom, Young Geun
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.58-66
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    • 2007
  • The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring. Urea-formaldehyde (UF)-tannin and melamine-formaldehyde (MF)/PVAc hybrid resin were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. Wattle tannin powder (5 wt%) was added to UF resin and PVAc (30 wt%) to MF resin. These adhesive systems showed better bonding than commercial UF resin with a similar level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial UF resin, UF-tannin and MF/PVAc hybrid resin. By desiccator method, the formaldehyde emission level of UF resin showed the highest but was reduced by replacing with UF-tannin and MF/PVAc hybrid resin. MF/PVAc hybrid satisfied the $E_1$ grade (below $1.5mg/{\ell}$). VOC emission results by VOC analyzer were similar with the formaldehyde emission results. TVOC emission was in the following order: UF > UF-tannin > MF/PVAc hybrid resin.

Preparation of Jeung-Pyun Added with Ultrafiltred Powder of Sunmul (순물의 한외여과(ultrafiltration)막 분리농축분말을 이용한 증편의 제조)

  • Chung, Hai-Jung;Joo, Sin-Youn;Kim, Woo-Jung
    • Korean journal of food and cookery science
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    • v.21 no.5
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    • pp.647-654
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    • 2005
  • This study was conducted to investigate the quality characteristics of Jeung-Pyun prepared with the addition of ultrafiltered(UF) sunmul powder. Jeung-Pyun was prepared with five different levels of UF powder(0%, 0.5%, 1%, 2% and 3%) and the physico-chemical properties were examined. The pH of Jeung-Pyun batters decreased from $4.57{\sim}5.69$ to $4.38{\sim}5.03$ during 4 hours of fermentation at $35^{\circ}C$. The weight of Jeung-Pyun decreased, whereas the volume increased, with increasing UF powder content. Total isoflavone content was $0.41{\sim}2.39\;mg%$ before cooking and increased to $0.77 {\sim}3.80\;mg%$ after cooking. The increase of aglycones was particularly observed after cooking. The incorporation of UF powder in Jeung-Pyun lowered the lightness values but increased the redness and yellowness values. Rheology test showed that hardness was decreased with increasing UF powder amount. The values of gumminess and brittleness were the highest in the control group and decreased with increasing UF powder amount. Scanning electron microscope showed that the size of the air cells decreased with increasing UF powder levels. The results of sensory evaluation showed that there were no significant differences in scores of sweetness and moistness among the samples. Therefore, Jeung-Pyun prepared with UF to 3% addition of UF powder was considered to be as acceptable as Jeung-Pyun prepared without UF power.

Effects of Extraction Method on the Histidine Containing Low Molecular Weight Peptide and Pro-oxidants Contents of Tuna Boiled Extracts (참치자숙액 추출물 중의 히스티딘계 저분자 펩타이드 및 산화촉진물질 함량에 미치는 추출방법의 영향)

  • Kang, Ok-Ju
    • Korean journal of food and cookery science
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    • v.24 no.3
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    • pp.349-357
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    • 2008
  • In an effort to augment extractability of carnosine and anserine at the levels of pro-oxidants such as iron and protein in Tuna boiled extracts(Skipjack, Yellowfin and Bigeye), we assessed the effects of heated and ion exchange chromatography(IEC) and ultrafiltration(UF) using a MW 500 cut-off(500 MWCO). We also evaluated the antioxidant activity of these extracts processed as free radical scavengers and reducing agents. Tuna boiled extracts of dark and ordinary muscle protein and total iron were reduced, whereas carnosine and anserine concentrations and antioxidant activity were increased. The carnosine and anserine concentrations of the ion exchange and permeate UF(IEC-UF) extracts were higher than those observed in the heated and permeate UF(heat-UF), whereas the protein and total iron contents were lower than that observed in the heat-UF. The quantity of carnosine and anserine in ordinary muscle was higher than that detected in dark muscle. HPLC analysis and SDS-PAGE were shown to removes the effect of UF on high molecular weight impurities in the tuna boiled extracts. The major free amino acids(FFAs) from Skipjack, Yellowfin and Bigeye tuna IEC-UF extracts were anserine, histidine and carnosine. These three peptides constituted more than 80~85%. of the detected amino acid. The IEC-UF treated ordinary muscle extracts evidenced the highest levels of DPPH radical scavenging activity and the highest levels of reducing power among the various extracts. The IEC-UF extracts evidenced a DPPH radical scavenging effect equal to that of 1mM ascorbic acid.