• Title/Summary/Keyword: liquid additive

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Effects of Air Supply Rate and Eggshell Addition on Liquid Fertilizer Efficiency of Aerobic Stabilized Organic Wastewater Sludge (공기공급량과 계란 껍질 첨가가 유기성 폐수슬러지 액비 비효효과에 미치는 영향)

  • Cheon, Hyo-Chang;Hwang, Eung-Ju;Kim, Sang-Hyoun
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.8
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    • pp.578-582
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    • 2011
  • Aerobic digestion of organic sludge generates stabilized slurry which could be used as a nitrogen-rich liquid fertilizer. In this study, the effects of air supply rate and eggshell addition on the sludge fertilizer efficiency were examined. Sludge from a wastewater treatment plant in a food industry was fed to a lab-scale aerobic digester, and the fertilizer efficiency was assessed by the growth of cucumber. Increase of air supply rate up to 200 mL/L/min enhanced the fertilizer efficiency as well as the nitrification efficiency. The addition of eggshell, a potassium-rich leftover, in fertilizer application was also beneficial to the cucumber growth. A proper control of air supply rate and the use of an inexpensive additive would guarantee the quality of sludge liquid fertilizer.

A Study on the Fabrication of Hollow Glass Sphere by Using a Liquid-mix Precursor (혼합액상 전구체를 이용한 유리 중공구체의 제조에 관한 연구)

  • Lee, Yong Bin;Kim, Ki Do;Kim, Hee Taik
    • Applied Chemistry for Engineering
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    • v.10 no.8
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    • pp.1186-1191
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    • 1999
  • By using a liquid-mix precursor, we prepared the hollow glass spheres(HGS) as an additive of polymer compound which are used in the field of modifier, promoter, filler, and reinforcement. Liquid-mix precursor is a mixture of 40% sodium silicate aqueous solution, boric acid as a insolubilizing agent, and urea as a blowing agent. To obtain the precursor particles which are fed into a gas flame furnae, the above liquid-mix precursor was dried in oven and crushed with ball mill. We assumed the size of precursor particles ($53{\sim}63{\mu}m$, $63{\sim}180{\mu}m$), temperature of furnace($800{\sim}1200^{\circ}C$), and amount of urea(0~30 g) as the parameters affecting on the properties of HGS. As a result mean particle size of HGS increases with increasing the temperature of furnace and the amount of urea and with decreasing the size of precursor particles. Also, we found that incresing the amount of urea is related to a decrease of the crush strength of HGS.

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A Study on Properties of SiC material Fabricated by Liquid Phase Sintering (액상소결법에 의해 제조된 탄화규소 재료의 특성에 대한 연구)

  • Sang-Pill Lee;Jae-Hwan Kwak;Jin-Kyung Lee
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_2
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    • pp.1019-1024
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    • 2023
  • Ceramic materials have excellent material properties such as stability at high temperatures, chemical stability, corrosion resistance, and wear resistance, so they are applicable even in extreme environments of high temperature and pressure. In particular, silicon carbide can be applied in the field of structural ceramics due to its characteristics of high strength, hardness, corrosion resistance, and heat resistance even at high temperatures. In this study, considering the application of silicon carbide materials to next-generation turbines, silicon carbide materials were manufactured using a liquid phase sintering method. When manufacturing liquid phase sintered silicon carbide, sintering additives were added to lower the sintering temperature and densify the material. In Al2O3-SiO2, it was confirmed that the secondary product of the sintering additive was observed as a slightly dark area and was evenly distributed overall, and the fracture surface of Al2O3-SiO2 was in the form of transgranular fracture in which cracks progressed along the crystal plane, and the flexural strength for Al2O3-SiO2 was about 445.6 MPa.

Potency of cashew nut shell liquid in rumen modulation under different dietary conditions and indication of its surfactant action against rumen bacteria

  • Oh, Seongjin;Suzuki, Yasuyuki;Hayashi, Shusuke;Suzuki, Yutaka;Koike, Satoshi;Kobayashi, Yasuo
    • Journal of Animal Science and Technology
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    • v.59 no.11
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    • pp.27.1-27.7
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    • 2017
  • Background: Cashew nut shell liquid (CNSL) is an agricultural byproduct containing alkylphenols that has been shown to favorably change the rumen fermentation pattern only under experimentally fixed feeding conditions. Investigation of CNSL potency in rumen modulation under a variety of feeding regimens, and evidence leading to the understanding of CNSL action are obviously necessary for further CNSL applications. The objective of this study was to evaluate the potency of CNSL for rumen modulation under different dietary conditions, and to visually demonstrate its surfactant action against selected rumen bacteria. Methods: Batch culture studies were carried out using various diets with 5 different forage to concentrate (F:C) ratios (9:1, 7:3, 5:5. 3:7 and 1:9). Strained rumen fluid was diluted with a buffer and incubated with each diet. Gas and short chain fatty acid (SCFA) profiles were characterized after 18 h incubation at $39^{\circ}C$. Monensin was also evaluated as a reference additive under the same conditions. Four species of rumen bacteria were grown in pure culture and exposed to CNSL to determine their morphological sensitivity to the surfactant action of CNSL. Results: CNSL supplementation decreased total gas production in diets with 5:5 and 3:7 F:C ratios, whereas the F:C ratio alone did not affect any gas production. Methane decrease by CNSL addition was more apparent in diets with 5:5, 3:7, and 1:9 F:C ratios. An interactive effect of CNSL and the F:C ratio was also observed for methane production. CNSL supplementation enhanced propionate production, while total SCFA production was not affected. Monensin decreased methane production but only in a diet with a 1:9 F:C ratio with increased propionate. Studies of pure cultures indicated that CNSL damaged the cell surface of hydrogen- and formate-producing bacteria, but did not change that of propionate-producing bacteria. Conclusion: CNSL can selectively inhibit rumen bacteria through its surfactant action to lead fermentation toward less methane and more propionate production. As CNSL is effective over a wider range of dietary conditions for such modulation of rumen fermentation in comparison with monensin, this new additive candidate might be applied to ruminant animals for various production purposes and at various stages.

Study on Sn-Ag-Fe Transient Liquid Phase Bonding for Application to Electric Vehicles Power Modules (전기자동차용 파워모듈 적용을 위한 Sn-Ag-Fe TLP (Transient Liquid Phase) 접합에 관한 연구)

  • Byungwoo Kim;Hyeri Go;Gyeongyeong Cheon;Yong-Ho Ko;Yoonchul Sohn
    • Journal of the Microelectronics and Packaging Society
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    • v.30 no.4
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    • pp.61-68
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    • 2023
  • In this study, Sn-3.5Ag-15.0Fe composite solder was manufactured and applied to TLP bonding to change the entire joint into a Sn-Fe IMC(intermetallic compound), thereby applying it as a high-temperature solder. The FeSn2 IMC formed during the bonding process has a high melting point of 513℃, so it can be stably applied to power modules for power semiconductors where the temperature rises up to 280℃ during use. As a result of applying ENIG surface treatment to both the chip and substrate, a multi-layer IMC structure of Ni3Sn4/FeSn2/Ni3Sn4 was formed at the joint. During the shear test, the fracture path showed that cracks developed at the Ni3Sn4/FeSn2 interface and then propagated into FeSn2. After 2hours of the TLP joining process, a shear strength of over 30 MPa was obtained, and in particular, there was no decrease in strength at all even in a shear test at 200℃. The results of this study can be expected to lead to materials and processes that can be applied to power modules for electric vehicles, which are being actively researched recently.

A study on the analysis of artificial sweeteners in processed foods including emulsified foods by HPLC-DAD

  • Kim, Min-Hee;Lee, Do-Yeon;Ahn, Jang-Hyuk
    • Analytical Science and Technology
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    • v.33 no.5
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    • pp.209-214
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    • 2020
  • This study has been carried out to develop a standard method for quantifying of 3 permitted artificial sweeteners (including sodium saccharine, aspartame, acesulfame potassium) contained in foods by HPLC-DAD. A simple and rapid sample pretreatment method was used to remove fat and protein from the test solution with Carrez clearing regent precipitant know to be effective for protein and fat removal. The artificial sweeteners in the test solution purified through sample pretreatment were detected by high performance liquid chromatograph using a Reverse phase C18 column (5 ㎛, 4.6 × 250 mm). The simultaneous quantitative test of 3 kinds of artificial sweeteners can be effectively performed on the high fat emulsified foods containing a large amount of fat. Using the established simultaneous quantitative test method, artificial sweeteners were tested in foods such as dairy products, snacks and chocolate. The results calibration curve showed good linearity with high regression coefficients and the result of recovery test showed satisfactory recoveries within 80~110 %.

Preparation of PVDF/PEI double-layer composite hollow fiber membranes for enhancing tensile strength of PVDF membranes

  • Yuan, Jun-Gui;Shi, Bao-Li;Ji, Ling-Yun
    • Membrane and Water Treatment
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    • v.5 no.2
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    • pp.109-122
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    • 2014
  • Polyvinylidene fluoride (PVDF) hollow fiber membrane is widely used for water treatment. However, the weak mechanical strength of PVDF limits its application. To enhance its tensile strength, a double-layer composite hollow fiber membrane, with PVDF and polyetherimide as the external and inner layers, respectively, was successfully prepared through phase inversion technique. The effects of additive content, air gap distance, N,N-dimethyl-acetamide content in the inner core liquid, and the temperature of external coagulation bath on the membrane structure, permeation flux, rejection, tensile strength, and porosity were determined. Experimental results showed that the optimum preparation conditions for the double-layer composite hollow fiber membrane were as follows: PEG-400 and PEG-600, 5 wt%; air gap distance, 10 cm; inner core liquid and the external coagulation bath should be water; and temperature of the external coagulation bath, 40 C. A single layer PVDF hollow fiber membrane (without PEI layer) was also prepared under optimum conditions. The double-layer composite membrane remarkably improved the tensile strength compared with the single-layer PVDF hollow fiber membrane. The permeation flux, rejection, and porosity were also slightly enhanced. High-tensile strength hollow fiber PVDF ultrafiltration membrane can be fabricated using the proposed technique.

Mechanical Properties and Microstructure of AlN/W Composites (AlN/W계 복합재료의 기계적 특성과 미세구조)

  • 윤영훈;최성철;박철원
    • Journal of the Korean Ceramic Society
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    • v.33 no.1
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    • pp.83-91
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    • 1996
  • Monolithic AlN and AlN-W composites were fabricated by pressure-less sintering at 190$0^{\circ}C$ under nitrogen atmosphere and the influences of tungsten phase on the microstructure and mechanical properties were investi-gated. In the fabrication of sintered specimen no additive was used. And monolithic AlN showed substantial grain growth and low relative density. AlN-W composites were fully densified and grain growths of matrix were inhibited. The densification behavior of composites were inferred to be achieved through the liquid phase sintering process such as particle-rearrangement and solutino-reprecipitation. Also the oxid phases which is expected to form liquid phases duringsintering process were detected by XRD analysis. As the tungsten volume content increases fracture strength was decreased and fracture toughness was increased. It was suppo-sed that the strength decrease of composites with tungsten content was due to existence of interface phases. The subcritical crack growth behavior was observed from the stress-strain curve of composites. The effect of the secondary phase and interface phases on toughness in crease were studied through observation of crack propagation path and the influence of residual stress on crack propagation was investigated by X-ray residual stress measurement. In the result of residual stress measurement the compressive stress of matrix in composi-test was increased with tungsten volume content and the compressive stress distribution of matrix must have contributed to the inhibition of crack propagation.

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A Study on the Drag Reduction by an Additives in Cylindrical Vertical Tube (수직원형관에서 첨가제에 따른 마찰저항 감소에 관한 연구)

  • Cha, K.O.;Kim, J.G.
    • Solar Energy
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    • v.20 no.2
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    • pp.85-96
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    • 2000
  • When the liquid with the additive of ppm unit of a polymer flows, the pressure drop can be manifestly decreased compared to that of pure liquid: that's the drag reduction. This method is that a small amount of a polymer which doesn't make the transformation of the properties of the working fluid is dissolved into the working fluid, the links of chains of the polymer do a buffer action to the molecules of the working fluid which come out between near the wall of the pipe and the interface, so that the pressure drop is dramatically decreased. When we transport the fluid, therefore, we can save a lot of pumping power, or we can increase the transportation capacity with using the same transportation equipment. But when a polymer solution is also flowing in the fluid transportation system, the degradation which have a very close relation with the phenomena of the drag reduction occurs necessarily. When adding polymer to reduce the drag in two phase flow system, It is impossible to find some studies. This study is focussing on a searching examination for the experimental study considering the mechanical degradation in the closed tow phase system to find out the conditions which could improve the pump capacity.

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YBCO Bulk Superconductors Prepared by Solid-liquid Melt Growth (고액용융성장법을 이용한 YBCO 단결정 제조)

  • Han, Sang-Chul;Lee, Jeong-Phil;Park, Byeong-Cheol;Jeong, Neyon-Ho;Park, Byung-Jun;Jung, Se-Yong;Han, Young-Hee;Sung, Tae-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.10
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    • pp.860-863
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    • 2009
  • YBCO bulks with fine $Y_2BaCuO_5$(Y211) particles have been prepared by the top-seed modified powder melting process method, Solid-Liquid Melt Growth(SLMG), with $Y_2O_3$, $BaCuO_2$ and CuO mixing precursor. By using $Y_2O_3$ instead of $Y_2BaCuO_5$ as precursor, the processing became to be simpler and cheaper than the current powder melting process. The microstructures, trapped field and critical current density of the various conditioned YBCO bulks have been analyzed and the effect of Pt additive was studied. The different trapped magnetic field values of the several samples have been explained in the viewpoint of their microstructures. The fabrication of large-sized YBCO single domain has been conducted.