• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.349-353
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• 2007

2D SiC fiber-SiC (SiC/SiC) composites were fabricated via slurry infiltration and a stacking process. The effects of the additive composition and content in SiC slurries and the effect of the sintering time on the sintered density and strength of SiC/SiC composites were investigated. A slurry containing $Al_2O_3-Y_2O_3-MgO$ (AYM) additives led to a higher strength compared to a slurry containing $Al_2O_3-Y_2O_3-CaO$ (AYC) additives. The sintered density increased as the sintering time increased and showed a maximum (>98%) at 4 h. In contrast, the flexural strength increased as the sintering time increased and showed a maximum (615 MPa) at 6 h. The relative density and flexural strength increased as the additive content increased.

• The Korean Journal of Food & Health Convergence
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• v.6 no.6
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• pp.1-7
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• 2020

We compared the fermentation of 0 to 4 weeks by manufacturing a rapid low salt-fermented seahorse with a commercial Protamex added to the functional food, Hippocampus abdominalis. We studied amino acid composition, content and major amino acids related to flavor during the fermentation process of salt-fermented seahorse. In the enzyme-free group, it showed little change in the content of non-protein nitrogenous compounds, the content of amino acids and degree of hydrolysis. The Protamex enzyme treatment group was rapidly hydrolyzed in one week of ripening, resulting in increased non-protein nitrogenous compounds content, amino acid content and degree of hydrolysis, and minimal changes in the four weeks. The total amino acid contents ratio showed the highest content of glutamic acid in the enzyme additive group, glycine, alanine, which indicates sweet taste, and serine, the content of glycine, alanine, serine, and lysine, indicating sweet taste, has increased significantly over the enzyme-free group. Twenty species of free amino acid in the four-week of salt-fermented seahorse were detected. It detected 43.0% (6 species) in the enzyme-free group and 63.96% (7 species) in the enzyme additive group.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1723-1725
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• 1999

This paper is the study for piezoelectric properties of PMN-PT-PZ composition for high power piezoelectric device. It needs the properties such as high mechanical quality factor(Qm), high electromechanical coupling coefficient(kp) and high dielectric strain constant$(d_31)$, and the stable electromechanical properties under high vibration level. For acquiring this results, the value of x is changed in 0.1Pb$(Mn_{1/3}Nb_{2/3})O_3$+(0.9-x)$PbZrO_3+xPbTiO_3$ composition to find MPB(morphotropic phase boundary), and the piezoelectric constants is measured by resonance-antiresonance frequency method, based on IRE Standard. Also, it is measured as a function of the amount of additive, $Nb_2O_5$. When the composition is applied to high power device, the electromechanical properties is measured by laser vibrometer to confirm the reliablity under high vibration level. From these results, PMN-PT-PZ composition is shown excellent properties and capacity of application to high power device.

• Analytical Science and Technology
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• v.12 no.6
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• pp.528-533
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• 1999

The total iodine is determined in serum, fresh milk and feed additive by ICP-MS. The preparation involves only a 25-fold dilution with a diluent by direct nebulization in the plasma. The diluent composition is $NH_4OH$(0.5% v/v)+$CH_3OH$(5% v/v) and the abundance of iodine is measured at m/z=127. The calibration curve was linear over the ranges $0-100{\mu}g/L$ with $R^2=0.99$ for iodine. The detection limit of this method is $0.084{\mu}g/L$ for iodine. The relative error range of milk powder SRM in optimum condition is 2.30%-4.73%. The concentration ranges of iodine in the serum, fresh milk, feed additive were $12.4-40.2{\mu}g/L$, < 0.01-3.11 mg/L, < $10^{-7}-2.60g/kg$ respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.2
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• pp.58-66
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• 2012

Brewers grain is a byproduct of beer brewing and consists primarily of grain husks, pericarp, and fragments of endosperm. Although this material is consumed by animals and used as fertilizer, a large amount of brewers grain is simply discarded. Therefore, new methods for utilizing this fibrous resource should be pursued. In this study, we examined the potential utilization of brewers grain as an additive in the paperboard industry by determining the chemical composition of brewers grain and the physical properties of brewers grain powders after grinding with two types of grinders. We found that brewers grain had a lower holocellulose content and higher lignin content and intermediate ash content when compared to other biomass materials, and did not contain any contaminants that would interfere with the papermaking process. Particles had a higher fiber length, less fiber width, and narrower shape factor distribution when ground by a blender type grinder than by a pin crusher type grinder. The blender type grinder was concluded to make regular brewers grain particles appropriate for papermaking.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.126-132
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• 2014

The P-T characteristics of mixed refrigerant in thermostatic expansion valve sensing bulb were studied using R-134a and R-410A refrigerant. The characteristics of mixed refrigerant were investigated according to pressure variation and the variation of composition ratio of R-134A and R-410A in the temperature range of $-15^{\circ}C{\sim}15^{\circ}C$. The Thermodynamic characteristic values of the mixed refrigerants were identified using the characteristic value analysis program of mixed refrigerant(Refrop v9.0, NIST). The P-T characteristics in the case of the mixing ratio of 90:10 for R-410A and R-134A were the same result as R-22. And the physical properties showed similar results with R-22. The Maximum operating pressure(MOP) of mixed refrigerant showed a tendency to decrease with decreasing the mixing ratio of additive gases($N_2$ or He) gases. The characteristics in the case of the mixing ratio of 80:1 for mixed refrigerant and additive gases were the similar result as Reference refrigerant.(R-22 MOP, Sporlan company) In addition $N_2$ and He, both showed the same results. It was able to confirm that a MOP on the thermostatic expansion valve sensing bulb can be maintained by adjusting the mixing ratio of mixed refrigerant gases and additive gases.

• Journal of Powder Materials
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• v.26 no.5
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• pp.405-409
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• 2019

Piezoelectric ceramic specimens with the $Pb(Mg_{1/3}Nb_{2/3})_{0.65}Ti_{0.35}O_3$ (PMN-PT) composition are prepared by the solid state reaction method known as the "columbite precursor" method. Moreover, the effects of the $Li_2O-Bi_2O_3$ additive on the microstructure, crystal structure, and piezoelectric properties of sintered PMN-PT ceramic samples are investigated. The addition of $Li_2O-Bi_2O_3$ lowers the sintering temperature from $1,200^{\circ}C$ to $950^{\circ}C$. Moreover, with the addition of >5 wt.% additive, the crystal structure changes from tetragonal to rhombohedral. Notably, the sample with 3 wt.% additive exhibits excellent piezoelectric properties ($d_{33}=596pC/N$ and Kp = 57%) and a sintered density of $7.92g/cm^3$ after sintering at $950^{\circ}C$. In addition, the sample exhibits a curie temperature of $138.6^{\circ}C$ at 1 kHz. Finally, the compatibility of the sample with a Cu electrode is examined, because the energy-dispersive X-ray spectroscopy data indicate the absence of interdiffusion between Cu and the ceramic material.

• Journal of Powder Materials
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• v.30 no.1
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• pp.13-21
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• 2023

In additive manufacturing, the flowability of feedstock particles determines the quality of the parts that are affected by different parameters, including the chemistry and morphology of the powders and particle size distribution. In this study, the microstructures and flowabilities of gas-atomized heat-resistant alloys for additive manufacturing applications are investigated. A KHR45A alloy powder with a composition of Fe-30Cr-40Mn-1.8Nb (wt.%) is fabricated using gas atomization process. The microstructure and effect of powder chemistry and morphology on the flow behavior are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and revolution powder analysis. The results reveal the formation of spherical particles composed of single-phase FCC dendritic structures after gas atomization. SEM observations show variations in the microstructures of the powder particles with different size distributions. Elemental distribution maps, line scans, and high-resolution XPS results indicate the presence of a Si-rich oxide accompanied by Fe, Cr, and Nb metal oxides in the outer layer of the powders. The flowability behavior is found to be induced by the particle size distribution, which can be attributed to the interparticle interactions and friction of particles with different sizes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.570-575
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• 2001

Three feeding experiments were conducted to investigate the effects of herbs (Obosan-C or Obosan-O) as an additive in formulated diets on growth and body composition of juvenile abalone (Haliotis discus hannai), Three replicate groups of abalone initially average weighing 206 mg, 827 mg and 432 mg were fed the each one of experimental diet containing $0\%\;or\;1\%$ Obosan for 10 (experiment 1), 7 (experiment 2) and 19 weeks (experiment 3), respectively. In addition, an imported commercial diet for abalone was also employed to compare growth performance of juvenile abalone. Weight gain of abalone fed the diet containing Obosan-O was significantly (P<0.05) higher than that of abalone fed the control diet in the experiment 3. Moisture, crude protein and ash contents of soft whole body were not influenced by dietary herbs (P>0.05), whereas crude lipid content of abalone fed the diets containing Obosan-C was significantly (P<0.05) lower than that of abalone fed the control diet in the experiment 2. The results indicate that Obosan-O as an additive in formulated diet can improve body growth of juvenile abalone.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.550-556
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• 2009

This study was designed to evaluate the effects of dietary prebiotic (mannan oligosaccharide = MOS) and probiotic (Saccharomyces cerevisiae = SC) in finishing turkey diets on carcass, cut yield, meat composition and colour. A total of 72 ten-weeksold Big6 male turkey poults were used in the trial. There were eight replicate floor pens per floor with three birds in each. The experiment lasted up to 20 wks of age. The trial was set up as a completely randomized design with 3 dietary treatments. The treatments were: i) negative control (C, no additive); ii) MOS 1 g per kg of diet and iii) SC 1 g per kg of diet (strain SC47, $300{\times}10^{10}$ CFU/kg). Body weight (BW) and feed intake were determined for each of the two week intervals. Twenty-four birds were slaughtered and eviscerated to determine carcass, carcass parts and internal organ weights at 20 wks of age. Meat colour and pH levels were measured 24 h after slaughter. The dietary treatments did not affect BW and average daily gain during the trial (p>0.05). The average daily feed intake and feed conversion ratio of turkey toms fed with MOS were higher than those of control and SC groups during the overall period (p<0.05). The dietary treatments did not affect carcass yield, breast meat, thigh, wing, liver, heart, empty gizzard, intestine, and abdominal fat pad proportions and meat pH, composition and pigmentation (p>0.05). These results suggest that the addition of MOS and SC is not likely to produce any performance or carcass characteristics in finishing turkeys at 10 to 20 wks of age.