• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.306-311
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• 2012

This study was performed to evaluate the effects on saccharification and alcohol fermentation, according to the size of the ground rice (12, 20, 35 mesh) and ultra sonication process (15, 30, 60, 120 min). After saccharification of the ground rice samples for 3 h at $60^{\circ}C$, sugar content was observed to be high in the order of cooked ground rice (CGR) > ultrasonicated ground rice (UGR) > ground rice (GR), in all sizes of ground rice. Further, higher sugar content was obtained by increasing the time of ultrasonication process. Almost 90% saccharification of CGR ($11.5^{\circ}Bx$) could be reached up to $10.2^{\circ}Bx$ by ultrasonicating 35 mesh ground rice for 120 min. After alcohol fermentation on the 35 mesh saccharified-UGR for 4 days at $25^{\circ}C$, 16.7% alcohol concentration could be obtained, as high as of CGR (17.2%). After 4 days of alcohol fermentation, UGR showed a lower pH and a higher acidity (pH 4.06-4.17, 0.99-1.1%) than CGR (pH 4.27, 0.75%).

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1791-1793
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• 2003

In order to analyze the dynamic characteristics of ground impedance in large grounding system for lightning and surge protections, a novel method for measuring the ground impedance as a function of frequency was proposed. The experiments were carried out in the grounding system composed of ground rods and mesh grids. The test current was injected by the variable frequency inverter whose frequency is linearly controlled in the range of $5{\sim}500$kHz. The ground impedance and frequency response of the grounding system were mainly caused by the inductive current flowing through grounding conductors over the frequency of 2002. In the combined grounding system of rods and mesh grids, inductive component of ground impedance was significantly decreased. It was fumed out that the grounding system is effective for the surge protection.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.120-125
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• 2011

When we design the grounding grid, dangerous voltage ANSI/IEEE Std. 80 method has been commonly used in the domestic area. However, the suitability of the ground rules for the design environment available. However, the suitability of the ground rules for the design environment available. In this paper, sticks according to the electrode conductor in combination with the mesh in order to design the ground by the IEEE Std.80 was designed. So in this paper, we examined of IEEE Std. 80 touch voltage method marginal utility and we induced for those problems by comparison between IEEE Std. 80 touch voltage value and simulation experimentation value. Furthermore, this paper presents a new design grounding system method that complements the IEEE Std. 80 method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.69-74
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• 2018

In this paper, We investigated the effects of mesh structure variations of meshed ground on MCAA(Microstrip Comb Array Antenna). First, we designed MCAA in 24GHz ISM band and we investigated the variations of the gain and the SLL(Side Lobe Level) of the MCAA as we varied the mesh structure of the meshed ground. We varied two variables, mesh size and unfilled rato, which is defined as no metal area ratio in mesh for the investigation. We investigated two types of MCAA. Those are flat MCAA composed of flat radiator and tapered MCAA composed of tapered radiator. Both the antenna gains of flat MCAA and tapered MCAA are decreased as the unfilled rato increased. However, increase of mesh size made more dramatic decrease in antenna gain than increase of unfilled rato. The antenna SLL showed similar trend. But tapered MCAA affected more severely by variation of mesh size than flat MCAA.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.74-81
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• 2011

A numerical simulation is performed to study the ground effect of a rotating rotor blade on a whirl tower using unstructured overset mesh. The aerodynamic change of the rotor blade by the structure around the whirl tower is also considered. The calculated results showed good agreement with the experiment for the hover performance. The ground effect of the rotor blade is investigated by comparing with the calculated results for the out of ground condition and the results of an analytic model.

• Journal of computational fluids engineering
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• v.17 no.2
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• pp.78-84
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• 2012

Numerical calculations were performed to investigate the influence in aerodynamic characteristics of a rotor system by surrounding structures and the ground effect for the rotor blade on a whirl tower is also investigated. Three dimensional Navier-Stokes simulations were carried out by using unstructured overset mesh technique and parallel computation. The calculated hover performance showed good agreement with the experimental result and showed that the structures around the whirl tower did not affect the aerodynamic characteristics of the blade. The ground effect was studied by comparing with the numerical result for the out of ground condition and the result of an analytic model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.60-66
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• 2010

Mesh grounding electrodes in Korea and abroad are designed as lattice-shaped equidistance grounding grids. In case of a lattice-shaped grounding Grid, however, there is a problem of higher touch voltage at the corner of the grid relative to the center. To overcome this problem, we used oblique-shaped equidistance grounding grid to reduce the area of the corner where mesh voltage occurs. As a result the mesh voltage was reduced. Therefore, this paper suggests the use of oblique-shaped grounding grid instead of the existing lattice-shaped ones. It applied the same grounding design dimensions for both lattice-shaped and oblique-shaped grounding grids, compared and analyzed mesh voltage, GPR, ground resistance, total length of grounding conductor, verified that oblique-shaped grounding grid is superior to the lattice-shaped.

• Food Science and Preservation
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• v.2 no.2
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• pp.269-276
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• 1995

Uncooked rice Tackju was prepared from the groud rice with different particle size such as 12, 20, 35 and 50 mesh, and its characteristics were analysed during the brewing. Reducing sugar and ethanol contents as well as yeast cell counts were the highest in main mash and Tackju prepared from 20 mesh fraction. Especially, reducing sugar content was about. 1.5-2.5 times as much as that obtained from 35 or 50 mesh fraction. The final concentration of ethanol in main mash prepared from 20 mesh fraction was 14.8%(v/v). It was about 1.5%(v/v) higher than the lowest one [13.35%(v/v)] which was prepared from 12 mesh fraction. No significant difference In total acidity was observed. Sensory evaluation revealed 20 or 35 mesh Tackju to be the best in overall preference, especially in sweet and refreshing tastes.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.3
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• pp.139-144
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• 2013

In Korea, where most of the sites are narrow in space and their earth resistivity is relatively high, the spaces between grounding conductors are likely to be designed narrow in order to lower ground resistance and dangerous voltage below to the permitted safety values. In addition, ground nets are in the shape of square or rectangle depending on the location and size of the facilities and ground contact area, and inner conductors are laid out in grids like the pattern of nets. Nevertheless, with the existing designs, the marginal voltage for safety gets higher as the area is extended further outside, in comparison with that of inner mesh grounding, thus causing much difficulty maintaining them equipotential, and there exist limits in the burial, grounding grid design considering the dangerous voltage of muti-layered model in the constrained sites, was studied.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.91-97
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• 2011

In Korea, characterized in most cases by limited area or high earth resistivity, it is likely to design narrow distances between grounding conductors, with a view to keeping ground resistance and touch voltage below the safety margin values. A new grounding method is suggested, making use of double meshes, to lower touch voltage in a confined area, since it is difficult to lay the plugs under the ground with narrow gaps between them on a limited site. For the presentation of a new model, the suggested grounding system has been analyzed and studied in ground resistance, touch voltage and step voltage, using IEEE Std. 80 calculations and computer simulations.