• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.160-161
• /
• 2013

Recently, the enviroment problem is serious due to the global warming phenomenon because of the greenhouse gas exhaustion. In addition, the effort to reduce the problem in the situation where the severity of the destruction of environment because of the indiscriminate picking of the that is the raw material of the cement, Accordingly, in the interior of a country, the industrial site using the artificial stone instead of the natural stone is increased. Thus the cement reduction amount of use and substitute material research is the urgent actual condition with the gas emission, which here it is generated in conducting compression molding in the building stone manufacturing process performance degradation phenomenon and fire resistance, and problem of the durability. limestone and aggregate and exhaustion of resource are emphasized is continued. In this research, the fly ash and waste porcelain is applied to the magnesia phosphate composite (MPC) and the characteristic of the artificial stone according to it tries to be looked into.

• Journal of the Korean Society of Visualization
• /
• v.3 no.2
• /
• pp.51-56
• /
• 2005

Acoustic excitations were imposed to coaxial air jet of non-premixed jet flame with hydrogen gaseous injected axially in the center of the flow. The frequencies of excitation were three dominant resonant frequencies at 1L, 2L, 3L. modes including specially 514 Hz (2L-mode) which was estimated theoretically as longitudinal mode of combustor characteristics. The mixing enhancement by acoustic forcing has been investigated quantitatively using PLIF and PIV. The effect of acoustic excitation on combustion process was significant to enhance mixing rate that coincides with specific resonant frequencies. And the behavior of vortex-interaction on flame structure was a good evidence to investigate the phenomenon of shear/mixing layer of fuel-air jet structure. The results obtained in this study concludes that generated streamwise vortex by acoustic excitation has a potential to enhance the mixing rate and abating NOx emissions.

• Journal of computational fluids engineering
• /
• v.11 no.2 s.33
• /
• pp.8-18
• /
• 2006

A CFD benchmark calculation for a steam blowdown test was performed for 30 seconds to develop the methodology of numerical analysis for the thermal mixing between steam and subcooled water. In the CFD analysis, the grid model simulating the sparger and the IRWST pool were developed by the axisymmetric condition and then the steam condensation phenomena by a direct contact was modelled by the so-called condensation region model. Thermal mixing phenomenon in the subcooled water tank was treated as an incompressible flow, a free surface flow between the air and the water, a turbulent flow, and a buoyancy flow. The comparison of the CFD results with the test data showed a good agreement as a whole, but a small temperature difference was locally found at some locations. The commercial CFD code of CFX4.4 together with the condensation region model can simulate the thermal mixing behavior reasonably well when a sufficient number of mesh distribution and a proper numerical method are adopted.

• Journal of the Korean Society of Costume
• /
• v.52 no.8
• /
• pp.73-85
• /
• 2002

Decadence is a phenomenon that people express fear from their inside, so unsound aspects appear in the social culture when the existing society is about to be collapsed. This study covered the cultural and aesthetic meaning and the role of decadence by examining the concept and phenomenon of it and analyzing the real case of expression appeared in the modern fashion. Characteristics of decadent phenomenon were divided into sexual corruption, ideality, cynicism and extreme technique, and decadent expression appeared in the fashion images was examined based on the divided phenomenon. Main results are as fellows. People bring the incidents that animals go through into relief, sticking to animal instinct when the society is on the decline. At that time, sexual decadence becomes remarkable, so voyeurism by exposure in their dress is deepen, revealing abnormal sexual propensity with bisexual tendency and sexual perversion. The real facts and appearance of people are revealed by transforming and distorting bodies for the fear of humans inside suppressed in the fin-de-siecle mood. The sense of alienation and helplessness of people anxious about the future is developed to cynicism expressing the uncertain emotion in their dress, and the formative methods of dismantlement. destruction and abrasion appear to form sickly images in the gloomy and cold mood. The intention of affirmative decadence is realized by mixing heterogeneous styles and producing new things. Extreme decorative technique and gorgeousness are even mysterious and show the highest refinement.

• Fashion & Textile Research Journal
• /
• v.5 no.5
• /
• pp.470-480
• /
• 2003

This study looks upon the borderless phenomenon of genres and at the disintegration of boundaries in fashion, the current 'borderless trend', and analyze modern men's fashion having borderless phenomenon under social changes and disclose current men's fashion. The borderless phenomenon of men's fashion declines traditional image of gender and expresses modern men's images strongly in accordance with social changes: Thus, in modern days, men's images have changed from muscular men having show-off and superiority to women-like men having pearly skin and slender figure. Men's fashion also looked for feminization to let men like make-up, beauty salon, cosmetic surgery and women-like hair style, etc. Men have been also given women's sexy and sensual beauty to put on innerwear as an outerwearization. The Influx and mixing of mutually different cultures is expressed in Hippie, Ethnic, Oriental trends. Mutually opposing country's factors mix so that a new culture is established. Also, the sharing of fashions amongst younger and older generation has occurred for reasons that are similar to the reasons above.

• Advances in concrete construction
• /
• v.17 no.5
• /
• pp.285-292
• /
• 2024

In order to improve the mixing effect of slurry-foam during the preparation of foam concrete, this study takes an SK static mixer as the mixing device, establishes a three-dimensional physical model and a theoretical calculation model, and numerically simulates the effects of different parameters such as foam inlet angle and pipe inner diameter on the mixing of cement slurry and foam under the given boundary conditions, so as to optimize the structure of this mixing device. The results show that when the pipe diameter of the mixer is larger than 60 mm, the phenomenon of backflow occurs in the pipe, which affects the mixing effect. The smaller the pipe diameter, the shorter the distance required to stabilize the cross-sectional average density and density uniformity index. When the foam inlet angle is different, the average density and density uniformity index of the radial cross-section have the same rule of change along the length of the pipeline, and all of them tend to stabilize gradually. At Y = 0.5 m, the average density basically stabilizes at 964 kg/m³ and remains stable until the outlet. At Y = 0.6 m, the density uniformity index basically stabilizes above 0.995 and remains stable until the outlet. Except for the foam inlet position (Y = 0.04 m), the foam inlet angle has little effect on the cross-sectional average density and density uniformity index. Under the boundary conditions given in this study, a pipe diameter of 40 mm, a foam inlet angle of 90°, and a pipe length of 700 mm are the optimal geometries for the preparation of homogeneous foam concrete with a density of 964 kg/m³ in this static mixer.

• Journal of Environmental Science International
• /
• v.11 no.6
• /
• pp.543-551
• /
• 2002

A Numerical simulation on the thermal flow performance was carried out to propose the incinerator type for the domestic refuses and to investigate the design factor and operating conditions. The SSTI(Standard Stoker Type Incinerator) proposed in this study was modified from the type with central f)ow. It has the characteristics of good mixing between refuse and hot combustion gas in primary combustion chamber and between unburned gas inflowing and secondary air jet in secondary chamber. By predictive results, the SSTI was no recirculation zone in secondary chamber so that mixing time was increased with high residence time. It has good characteristics of combustion and low emission. Parametric screening studies have been understood with phenomenon of combustion in incinerator.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1995.04a
• /
• pp.183-188
• /
• 1995

Up to date, high-strength concrete pile which is producing in factory sells in the market. But according to the site and the construction conditions, the system to produce high-strength concrete pile directly in site is utilized in advanced country. Such the production system is the technique phenomenon very disirable in the side of quality control in site and the construction schedule, the time and the cost saving. This study is a fundamental experiment including concrete mixing design, non-autoclave curing method and the optimum condition to produce high-strengh concrete pile in site. As results of this study, High-strength concrete pile in site which target strength is 400kg/ $\textrm{cm}^2$ is able to produce it with optimum curing ciondition(75$^{\circ}C$, 9hr)and mixing design.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.67-70
• /
• 2007

Diesel autothermal reforming has several problems such as carbon deposition in reforming reactor, sulfur poisoning of catalyst, difficulty of aromatics decomposition and mixing problems of reactants(diesel, steam, oxygen). Severe carbon deposition causes the rapid performance degradation of reformer. Carbon deposition is formed from ethylene, carbon precursor. Ethylene was generated at the homogeneous reaction zone of the reactor entrance. This phenomenon is closely linked to the mixing of reactants. In this investigation, we try to minimize the ethylene generation at the reactor entrance atomization technique.

• Journal of Korean Society of Water and Wastewater
• /
• v.21 no.6
• /
• pp.717-726
• /
• 2007

Fully-grown flocs in a mixing tank of membrane filtration with dead-end membrane are ruptured while passing through a pump and the ruptured flocs are aggregated again in a Membrane-Feed-Pipe (MFP). To look at more details, this study tries to relate the reaggregation to a parameter of mixing intensity in MFP, i.e., G-value. The G-value is a function of Reynolds number, pipe diameter, friction factor and average velocity in MFP. To deal with polydispersity condition, we develop a representative particle size called in this study EDPD (Effective Diameter for Polydispersity condition in Dead-end filtration). The experimental results show that as the G-value increases, the EDPD decreases and also the cake resistance increases. Through comparison between EDPD and cake resistance, these results show that cake resistances are controlled by reaggregation phenomenon in MFP. The effect of detention time in MFP, however, does not affect the reaggregation of the broken flocs as G-values are increased.