• Journal of Environmental Science International
• /
• v.25 no.5
• /
• pp.737-744
• /
• 2016

For electrolysis process using an insoluble electrode, electrochemical performance was greatly affected by the manufacturing method and procedure, such as the firing temperature, pre-treatment, type of precursor solution, coating method, electrode material, etc. Components of the electrode therein is one of the most important factors in electrochemical reaction. To achieve such characteristics, a appropriate ratio of the electrode material should be carefully chosen. The aim of this research was to apply experimental design method in the optimization of electrode component for the maximum generation of oxidants in electrochemical oxidation process. Mixture design, especially expanded simplex lattice design, in DOME (design of mixture experiments) with Design Expert - commercial software - was used to analyze the data. Analysis of variance (ANOVA) showed a high coefficient of determination ($R^2$) value of 0.9470, thus ensuring a satisfactory adjustment of the $3^{rd}$ order special cubic regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the TRO generation concentration and independent variables(mol ratio of 3 electrode components) in a real unit: TRO generation concentration $(mg/L)=TRO\;conc.=98.25{\times}[Ir]+49.71{\times}[Sn]+95.29{\times}[Sb]-16.91{\times}[Ir]{\times}[Sn]-29.47{\times}[Ir]{\times}[Sb]-22.65{\times}[Sn]{\times}[Sb]+703.19{\times}[Ir]{\times}[Sn]{\times}[Sb]$. The optimized formulation of the 3 component electrode for an high TRO (total residual oxidants) generation was acquired at mol ratio of Ir 0.406, Sn 0.210, Sb 0.384 (desirability d value, 1).

• Journal of Powder Materials
• /
• v.26 no.5
• /
• pp.410-414
• /
• 2019

The hydrogen reduction behavior of the $CuO-SCo_3O_4$ powder mixture for the synthesis of the homogeneous Cu-15at%Co composite powder has been investigated. The composite powder is prepared by ball milling the oxide powders, followed by a hydrogen reduction process. The reduction behavior of the ball-milled powder mixture is analyzed by X-ray diffraction (XRD) and temperature-programmed reduction at different heating rates in an Ar-10%H2 atmosphere. The scanning electron microscopy and XRD results reveal that the hydrogen-reduced powder mixture is composed of fine agglomerates of nanosized Cu and Co particles. The hydrogen reduction kinetics is studied by determining the degree of peak shift as a function of the heating rate. The activation energies for the reduction of the oxide powders estimated from the slopes of the Kissinger plots are 58.1 kJ/mol and 65.8 kJ/mol, depending on the reduction reaction: CuO to Cu and $SCo_3O_4$ to Co, respectively. The measured temperature and activation energy for the reduction of $SCo_3O_4$ are explained on the basis of the effect of pre-reduced Cu particles.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.6
• /
• pp.802-807
• /
• 2022

We investigated the physical properties and color values of surimi mixtures with added natural red pigments from laver Pyropia yezoensis. After adding the natural red pigment from seaweed extract to surimi, the hardness, gumminess, and chewiness of the surimi decreased compared to the negative controls. The L^* color value was lower for the surimi mixture than the negative controls, but the a^* and b^* color values were higher. After cold storage for 7 days, the unheated surimi mixture showed increased firmness, but decreased adhesiveness. Moreover, the gumminess and chewiness of the surimi mixture stored after heating were increased compared to the pre-storage values. These results indicate that seaweed extract pigments may be used as additives for surimi, to increase the color preference, with little effect on the physical properties.

• Analytical Science and Technology
• /
• v.18 no.5
• /
• pp.396-402
• /
• 2005

We try to look for optimum conditions of pre-reductants like L-Cysteine, KI and $FeSO_4$ when analyzing inorganic arsenic by using hydride generation-atomic absorption spectrometry, and run a comparative study of effect in the analysis of them. Also, we separated and analyzed only inorganic arsenic by using $H_2SO_4$-trap to eliminate organic arsenic which are MMA(monomethylarsonate) and DMA(dimethylarsinate). Under the conditions of mixture acid of 1.8 M HCl and 0.08 M $HNO_3$, arsenic standard solution of 20 ppb have more higher absorbance than without adding acid. In case of L-Cysteine, As(V) completely reduces into As(III) when 0.5 g of L-Cysteine is reacted more than 30 mins. in weak acid condition of approximately 0.07 M $HNO_3$ or HCl. In the event of KI, As(V) completely reduces into As(III) when 3 g of KI is reacted more than 1hour in acid condition of 0.8 M $HNO_3$. On the occasion of $FeSO_4$, the inside of tube is blocked by precipitation by mixture reaction of $NaBH_4$ and $Fe^{2+}$, therefore, comparing to other pre-reductants, reproducibility of efficiency of reducing As(V) to As(III) is low. To evaluate the accuracy of the analytical results, we use NIST SRM 1643C Trace Elements in Water ($82.1{\pm}1.2ng/mL$). The results are satisfactory.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.4
• /
• pp.523-530
• /
• 2017

Objective: Two experiments were conducted to evaluate the effects on growth performance, digestibility, and blood metabolites of lambs during pre- and post-weaning period of inclusion of a commercial probiotic (PRO) containing a mixture of two strains of Pediococcus, Pediococcus acidilactici ($1{\times}10^6$ colony-forming unit [cfu]/g) and Pediococcus pentosaceus ($1.3{\times}10^6cfu/g$), with dextrose as the carrier compound compared to a diet based on concentrate mixture and wheat straw. Methods: In exp. 1, 24 male lambs of about $15{\pm}2.6$ d age and initial body weight (BW) of $5.52{\pm}0.6kg$ were randomly allocated into three groups. One group received control diet without additives, and remainders received control diet supplemented with 0.5 or 1 g PRO/lamb/d. Daily feed intake and biweekly BW were recorded. In exp. 2, five lambs, (initial $BW=29.72{\pm}1.15kg$, $age=6.54{\pm}0.32mo$) were used as experimental animals in a digestion trial. They were fed the same diets as in Exp. 1. Results: The supplementation of PRO did not result in any significant differences in milk intake, average daily gain (ADG), or total gain between treatments during the pre-weaning period. Total dry matter intake tended to be greater (p = 0.07) with addition of PRO in the post-weaning diets. During post-weaning phase, the final BW, ADG, total gain, and feed conversion ratio of the lambs receiving PRO treatments tended to be greater ($p{\leq}0.10$) than the control group. Addition of PRO in post-weaning diet decreased ($p{\leq}0.01$) blood urea and cholesterol concentrations. With the exception of ether extract digestibility, all nutrients digestibility were improved with inclusion PRO in the post-weaning diets. Conclusion: Lambs that received PRO in post-weaning diet appeared to show a better performance than lambs in pre-weaning period. Addition of the probiotic in the post-weaning diet trended towards improved dry matter intake, growth performance, feed conversion ratio, and nutrients digestibility.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.10
• /
• pp.1394-1399
• /
• 2001

Influence of pre-weaning nutrition on post-weaning gain was assesses under intensive feeding in Malpura lambs. Thirty six Malpura (15 days old) lambs divided in to 3 equal groups were maintained on high (G1), medium (G2) and low (G3) energy and protein containing creep mixture with free suckling and ad libitum roughage (pala leaves: Ziziphus nummularia) up to 90 days of age. The lambs during post-weaning phase were fed on a 40:60 roughage and concentrate based composite diet to assess their post-weaning growth response. Total dry matter intake in pre-weaning phase was higher (p<0.01) in G3 than G2 and G1 while feed conversion efficiency was better in G1 than G2 and G3. The birth weight, 15 days body weight and weaning weight were however similar in the three groups. The finishing body weight, total body weight gain and average daily gain during post-weaning phase were higher (p<0.01) in G3 than in G1 and G2. The lambs in G3 consumed more (p<0.01) dry matter during post-weaning phase along with better feed conversion efficiency than other two groups. However, the DCP intake/kg body weight gain was higher in G1 than G2 and G3. Digestibility of DM, OM, CP, NDF, ADF and energy were similar among the three groups during post-weaning phase. Percent nitrogen retention as nitrogen intake was higher (p<0.01) in G3 (71.1%) than G1 (67.7%) and G2 (69.7%) during the post-weaning phase of study. The G1, G2 and G3 lambs in post-weaning phase consumed 8.1, 7.7 and 8.1 g DCP and 246.8, 227.2 and 246.1 kcal $DE/kg\;W^{0.75}/d$ and had 84.4, 80.0 and 111.1 g average daily gain, respectively. It is concluded that the lambs fed on low energy and protein containing creep mixture in pre-weaning phase showed improvement in growth during post-weaning phase under optimum feeding regime.

• Journal of Powder Materials
• /
• v.12 no.6 s.53
• /
• pp.447-452
• /
• 2005

The synthesis and consolidation of titanium silicide by electro-discharge-sintering has been investigated. As-received Ti powder was in flaky shape and the mean particle size was $45.0{\mu}m$, whereas the mean particle size of the pre-milled Si powder with angular shape was $8.0{\mu}m$. Single pulse of 2.5 to 5.0 kJ/0.34g-elemental Ti and pre-milled Si powder mixture with the composition of $Ti-37.5at.\%$ Si was applied using $300{\mu}F$ capacitor. The solid with $Ti_5Si_3$ phase has been successfully fabricated by the discharge with the input energy more than 2.5kJ in less than $129{\mu}sec.$ Hv values were found to be higher than $1000kgf/mm^2$. The formation of $Ti_5Si_3$ occurred through a fast solid state diffusion reaction.

• Journal of the Korean Data and Information Science Society
• /
• v.21 no.6
• /
• pp.1289-1303
• /
• 2010

The need for statistical process control to check the performance of a process is becoming more important in chemical and pharmaceutical industries. This study illustrates the method to determine whether a process is in control and how to produce and interpret control charts. In the experiment, a stream of green dyed water and a stream of pure water were continuously mixed in the process. The concentration of the dye solution was measured before and after the mixer via a spectrophotometer. The in-line mixer provided benefits to the dye and water mixture but not for the stock dye solution. The control charts were analyzed, and the pre-mixer process was in control for both the stock and mixed solutions. The R and X-bar charts showed virtually all of the points within control limits, and there were no patterns in the X-bar charts to suggest nonrandom data. However, the post-mixer process was shown to be out of control. While the R charts showed variability within the control limits, the X-bar charts were out of control and showed a steady increase in values, suggesting that the data was nonrandom. This steady increase in dye concentration was due to discontinuous, non-steady state flow. To improve the experiment in the future, a mixer could be inserted into the stock dye tank. The mixer would ensure that the dye concentration of the stock solution is more uniform prior to entering the pre-mixer ow cell. Overall, this would create a better standard to judge the water and dye mixture data against as well.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.5
• /
• pp.1155-1163
• /
• 2011

In this paper, we propose a new pre-processing algorithm applied to depth map to improve the coding efficiency. Now, 3DV/FTV group in the MPEG is working for standard of 3DVC(3D video coding), but compression method for depth map images are not confirmed yet. In the proposed algorithm, after dividing the histogram distribution of a given depth map by EM clustering method based on GMM, we classify the depth map into several layered images. Then, we apply different mean shift filter to each classified image according to the existence of background or foreground in it. In other words, we try to maximize the coding efficiency while keeping the boundary of each object and taking average operation toward inner field of the boundary. The experiments are performed with many test images and the results show that the proposed algorithm achieves bits reduction of 19% ~ 20% and computation time is also reduced.

• Journal of the Korean Society for Heat Treatment
• /
• v.14 no.1
• /
• pp.27-34
• /
• 2001

The effects of pre-heat treatment(Q/T) on microstructure and hardness of STD11 and STD61 tool steel nitrided by micro-pulse plasma were investigated. The quenching temperature for obtaining matrix hardness of STD11 and STD61 steel on range of HRC 50 to HRC 60 desired for machine parts is about $1070^{\circ}C$ and $1020^{\circ}C$ respectively. The hardness of STD11 and STD61 quenched at the temperature was HRC 63 and HRC 56 respectively. The nitrided case depth of STD11 and STD61 nitrided at $550^{\circ}C$ for 5 hours was independent of pre-heat treatment condition and the depth was approximately $100{\mu}m$. However, hardness and compactness of nitrided layer on Q/T treated specimen were higher than the annealed specimen. The case depth increased linearly with the increase of nitriding temperature, however, the hardness of nitrided layer decreased with the increase of temperature. Phase mixture of ${\gamma}-Fe_4N$ and ${\varepsilon}-Fe_{2-3}N$ was detected by XRD analysis in the nitrided layer formed at the optimum nitriding condition. The optimum nitriding temperature was approximately $490^{\circ}C$ which was $10^{\circ}C$ lower than the tempering temperature for preventing softening behavior of STD11 and STD61 matrix during nitriding process and the surface hardness of nitrided layer obtained by optimum pre-heat treatment condition was about Hv1400.