• Journal of the Korean Ceramic Society
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• 제43권12호
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• pp.829-832
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• 2006

In this study, the influence of the magnetic field on ferrite slurry's injection time during the slurry forming process was investigated. The evaluation system of the slurry's injection time under the strong magnetic field was designed with FEM and manufactured. Studied parameters were the applied magnetic field, the input pressure of the slurry, and the supplying tube materials. As the results, the injection time was increased with the external magnetic field strength and rapidly decreased with increasing the input pressure of the slurry. Also the injection time was decreased when the supplying tube was manufactured with the magnetic material having the higher magnetic permeability than the ferrite.

• Journal of The Korean Society of Grassland and Forage Science
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• 제38권3호
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• pp.145-149
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• 2018

The objective of this study was to determine the effect of injection application of pig slurry on ammonia ($NH_3$) and nitrous oxide ($N_2O$) emission from timothy (Phleum pretense L.) sward. The three treatments were applied: 1) only water as a control, 2) pig slurry application by broadcasting, 3) pig slurry application by injection. The pig slurry was applied at a rate of $200kg\;N\;ha^{-1}$. Total $NH_3$ and $N_2O$ emission, expressed as a cumulative amount throughout the measurement time (40 days), was $2.68kg\;NH_3-N\;ha^{-1}$ and $6.58g\;N_2O-N\;ha^{-1}$, respectively, in the control. The injection application of pig slurry decreased total $NH_3$ and $N_2O$ emission by 39.8% and 33.3%, respectively, compared to broadcasting application of pig slurry. The present study clearly showed that injection application exhibited positive roles in reducing N losses through $NH_3$ and $N_2O$ emission.

• Geomechanics and Engineering
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• 제29권4호
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• pp.391-405
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• 2022

A newly proposed grouting simulation method, the sequential diffusion solidification method was introduced into the numerical simulation of combined bi-borehole grouting. The traditional, critical and difficult numerical problem for the temporal and spatial variation simulation of the slurry is solved. Thus, numerical simulation of grouting and blocking of flowing water in karst conduits is realized and the mechanism understanding of the combined bi-borehole technology is promoted. The sensitivity analysis of the influence factors of combined bi-borehole grouting was investigated. Through orthogonal experiment, the influences of proximal and distal slurry properties, the initial flow velocity of the conduit and the proximal and distal slurry injection rate on the blocking efficiency are compared. The velocity variation, pressure variation and slurry deposition phenomenon were monitored, and the flow field characteristics and slurry outflow behavior were analyzed. The interaction mechanism between the proximal and distal slurries in the combined bi-borehole grouting is revealed. The results show that, under the orthogonal experiment conditions, the slurry injection rate has the greatest impact on blocking. With a constant slurry injection rate, the blocking efficiency can be increased by more than 30% when using slurry with weak time-dependent viscosity behavior in the distal borehole and slurry with strong time-dependent viscosity behavior in the proximal borehole respectively. According to the results of numerical simulation, the grouting scheme of "intercept the flow from the proximal borehole by quick-setting slurry, and grout cement slurry from the distal borehole" is put forward and successfully applied to the water inflow treatment project of China Resources Cement (Pingnan) Limestone Mine.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제21권4호
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• pp.593-600
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• 2012

Thixomolding of Mg-alloy is a semi-solid injection molding process utilizing thixotropic phenomenon. Using this process, higher strength, thinner wall section and tighter tolerance without porosity are obtained. It has been applied for production of near-net-shape magnesium component. To design optimal thixomolding process of Mg-alloy part, molding conditions such as slurry temperature, mold temperature and injection time should be determined properly. Selection of these parameters has been dependent upon engineers' experience and intuitiveness. In this paper, to improve mechanical properties of the thixomolded product, optimal selection of process variables such as injection velocity, barrel temperature and die temperature in the process has been studied through microstructural analysis and Taguchi method. Performance of the process is verified through experiments.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제24권4호
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• pp.589-598
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• 2000

A pilot-scale Spray Drying Sorber (SDS) system was set up to evaluate the effect of spray characteristics on the desulfurization yield. The size distribution and the Sauter Mean Diameters of slurry droplets were measured in advance using the optical size measurement system, Malvern 2600. The desulfurization yield of the drying chamber by size was measured for the conditions of inlet gas and spray injection. As a reagent, 10% limestone slurry of $Ca(OH)_2$ was treated with flue gas containing $SO_2$, and the combustion gas analyzer and gas detectors were attached to measure the $SO_2$ concentration. With a flow rate of 144 Nm3/h and a temperature range of $200{\sim}300^{\circ}C$, the experiments were performed for the Stoichiometric Ratio (SR) of 1.0 to 3.0 and droplet mean diameter of 6.5 to $34.3{\mu}m$. In case of smaller spray droplets, the desulfurization efficiency improved due to the increase of total droplet surface area, while the reduction in evaporation time reduced the contact time between the droplets and $SO_2$ gas. In some typical region of droplet diameter, this negative effect, reduction of contact time, became dominant and the desulfurization yield decreases the desulfurization yield in spite of the expansion in absorption area. These results revealed that there exists the optimal size of spray droplets for a given state, which is determined by the compromise between the total surface area of slurry droplets and the evaporation time of droplets. The measurements also indicated that the inlet temperature of flue gas changes the optimal injection condition by varying the driving force for evaporation. The results confirm that the effect of the evaporation time of slurry droplets should be considered in analyzing the desulfurization yield as well as the total surface area, for it is a significant aspect of the correlation with the capabilities of $SO_2$ absorption in wet droplets. In conclusion, the optimal condition of spray can be determined based on these results, which might be applied to design or scale-up of SDS system.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.58-63
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• 1999

Almost all concrete structures have many inevitable cracks for various reasons such as drying shrinkage, heat liberation of cement, fatigues or repeating loads and movements. Conventionally, they are repaired with epoxy materials. The Epoxy resins used by repair materials are different from properties of the base concrete materials such as thermal and mechanical properties - thermal expansion coefficients, bending strength. And the epoxy resin cannot release the water inside the concrete structure and cause corrosion of the steel bars. In this study, before the experiment got launched, we had analyzed cement and slag. Then We blended the two grades of ultra fine cement using high blaine cement and slag. And the cement slurry was produced by water and suprplasticizer to each blended ultra fine cement in various conditions. The slurry produced by each conditions was evaluated with flow properties such as viscosity, dropping time, segregation and observation of dry surface after injection.

• Journal of Korea Foundry Society
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• 제27권4호
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• pp.173-178
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• 2007

The bearing bracket, which has produced by the squeeze casting for the high strength in lightweight part of automobile, was developed by the rheocasting process using the H-NCM slurry. Compared with the squeeze casting, the rheocasting process has some merits such as shortening cycle-time, reducing total weight, and increasing productivity. In this study, partial feeding test was carried out by controlling plunger stroke length and compared with semisolid simulation. Optimal casting parameters such as injection speed and stroke variations were established. Sound products with integral microstructure were obtained by the H-NCM slurry and X-ray analysis also showed the integral condition throughout the entire parts.

• Resources Recycling
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• 제26권6호
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• pp.45-49
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• 2017

Most Waste slurry is produced in the process of silicon manufacturing for semiconductor industry, containing silicon (Si) and silicon carbide (SiC). Waste slurry is simply stored with solidifying by cement or buried. On the other hand, it was suggested in this study that the waste slurry should be used for heating source as supplementary material in steel making process. The waste slurry was refined and pulverized, which was recycled into SiC-based sludge briquette. Chemical composition for SiC-based sludge briquette was analyzed and the feature of heating source was observed in accordance with the injection time and input amount. As a result, SiC-based sludge briquette in terms of low cost and high efficiency had an effect on increasing liquid steel temperature in steel making plants.

• Journal of Korea Foundry Society
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• 제13권6호
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• pp.524-531
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• 1993

Dispersion behaviors of SiC particles and microstructures in Al-2%Si/SiCp composite prepared by Rheo-compocasting were studied with change of fabrication conditions(slurry temperature, agitation time) and additions of Mg($0{\sim}3wt.%$). Also, the microhardness change of matrix, interface and total in composites were examined with additions of Mg($0{\sim}3wt.%$). The dispersion of particles in the composites became relatively homogeneous with increase of Mg additions, agitation time and decrease of slurry temperature. Rate of occupied area by particle in matrix was increased as increase of Mg additions due to improvement of wettability between SiC particle and matrix. A favorable composites were obtained by melting under Ar atmospheric SiCp injection and bottom pouring system. According to the analysis of X-ray diffraction, $Mg_2Si$, $Al_4C_3$, $SiO_2$ and MgO, etc, intermetallic compounds were formed by chemical interreaction at interface of matrix and particles. The microhardness of interface is higher than that of matrix due to more strengthening of above intermetallic compounds. It was considered that the total hardness of the composites is improved by dispersing of SiCp and addition of Mg.

• Journal of Animal Environmental Science
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• 제15권3호
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• pp.217-224
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• 2009

The pig slurry is one of important fertilizer source for production of crops in recent years, but it has many controversial points of utilization such as offensive odor, lack of spread equipment and farmland possession, respectively. This study was carried out in order to remove water pollutants and malodor of pig slurry using biofiltration system. The biofiltration system consists of pig slurry separator, mixing shift and attached blade for sawdust or ricehull, air injection nozzle and outlet for pig slurry and sawdust or ricehull. The characteristics pH, $BOD_5$ (Biochemical Oxygen Demand), $COD_{Mn}$ (Chemical Oxygen Demand), SS (Suspended Solid), T-N (Total Nitrogen), T-P (Total Phosphorus) of the untreated pig slurry used in this study were 7.2, 34,450, 24,604, 71,000, 4,194, $1,631\;ml/{\ell}$, respectively. The $NH_3$ (Ammonia) and $H_2S$(Hydrogen Sulfide) concentration were 70.0, 9.6 ppm, respectively. The initial total microorganisms of pig slurry were $5.0{\times}10^3\;cfu/ml$, and Salmonella, Bacillus were $5.8{\times}10^2$, $1.1{\times}10^3\;cfu/ml$, respectively. The filtration system was very effective on removal of water pollutants of pig slurry. The removal efficiency of the offensive odor of ammonia and hydrogen sulfide in sawdust was higher than those of ricehull. The total microorganisms and bacillus of pig slurry are on the increase by sawdust and ricehull, but Salmonella showed a tendency to decrease in number after that time. Accordingly, the filtration system was very effective to produce a good quality pig slurry.