• Composites Research
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• v.12 no.3
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• pp.45-54
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• 1999

In this paper, an experimental study on the buckling and postbuckling control of a laminated composite beam with eccentrically embedded SMA wire actuators is performed. For the purpose of enhancing the critical buckling load, buckling control is investigated through the use of reactive moment associated with the shape recovery force of SMA wire actuators. To improve the control authority for the buckling and postbuckling control of the SMA-composite beam, closed-loop control is used. The buckling and postbuckling control behaviours are presented and discussed qualitatively and quantitatively on loaddeflection plots considering the stacking sequence of the laminate, slenderness ratio of the beam and activation conditions of the SMA wire actuators. By maintaining the desired deflection shape with the proper reactive moment, buckling control can be extended to the postbuckling of the SMA-composite beam subjected to an external load.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.19-24
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• 2006

Fatigue crack propagation tests for the brake disc cast iron were conducted for investigating fatigue crack propagation rate(da/dN), crack propagation path and fracture toughness($K_c$) of the material. The threshold stress intensity factor range, ${\Delta}K_{th}$, was found to be about $6MPa{\sqrt{m}}$ at the stress ratio of R = 0.1. Also, fracture toughness value was determined to be $24.7MPa{\sqrt{m}}$. Irregular fatigue fracture surfaces were observed, indicating that fatigue crack growth occurred at the interface between randomly scattered flak graphite and ferrite, where the interfacial strength was relatively weak.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.54-60
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• 2001

A study was conducted to assess the nutritive value of two diets based on a low-energy variety of wheat, RAC C1 and their effects on intestinal mucosal structure and function in broiler chickens. The diets were fed with or without microbial enzyme supplement to male and female broiler chickens. The digesta viscosity was reduced (p<0.001) through supplementation with a microbial enzyme in male and female chicks. Enzyme supplementation also improved the dietary apparent metabolizable energy content (p<0.001) and had slight but non-significant positive effects on chick growth and feed conversion ratio. Intestinal mucosal structure and enzyme function were not affected by microbial enzyme supplement. Male chicks consumed more feeds (p<0.001), attained higher final body weight (p<0.001) and were more efficient at feed utilization (p<0.01) than the female chicks. Except for duodenal villus surface area and ileal protein content, intestinal mucosal structure and enzyme activities were similar between the two sexes and dietary treatment groups. The study showed an improvement in the nutritive value of the diets in the presence of the microbial enzyme supplement.

• Architectural research
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• v.7 no.1
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• pp.39-48
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• 2005

Main objective of this research is to evaluate performance of high-strength concrete (HSC) columns for ductility and strength. Eight one-third scale columns with compressive strength of 69 MPa were subjected to a constant axial load corresponding to 30 % of the column axial load capacity and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement (${\rho}_s=1.58$, 2.25 %), tie configuration (Type H, Type C and Type D) and tie yield strength ($f_{yh}=549$ and 779 MPa). Test results show that the flexural strength of every column exceeds the calculated flexural capacity based on the equivalent concrete stress block used in the current design code. Columns with 42 % higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour, showing a displacement ductility factor (${\mu}_{{\Delta}u}$) of 3.69 to 4.85, and a curvature ductility factor (${\mu}_{{\varphi}u}$) of over 10.0. With an axial load of 30 % of the axial load capacity, it is recommended that the yield strength of transverse reinforcement be held equal to or below 549 MPa.

• Microbiology and Biotechnology Letters
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• v.7 no.2
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• pp.97-102
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• 1979

An actinomycete, AS-568, which produced an inhibitory substance against succinate dehydrogenase of Ehrlich ascites carcinoma and Sarcoma-180 cells of mouse, was isolated. The inhibitory activity was determined by SDI (Succinate Dehydrogenase Inhibition) method. The active substance was specific against carcinoma cells compared to normal cells in mouse; liver, kidney and brain. The inhibitory ratio was about 50％ after one hr treatment at 37$^{\circ}C$ in vitro. Maximal productivity of active substance was recognized by 5 days culture in glucose-asparagine. The active component in cultural liquid was stable in neutral pH range and heat treatment reasonably, add it was recovered from precipitate by ammonium sulfate or non-dialyrable fraction in cellophane membrane as showing the behavior of high molecular substance.

• Wind and Structures
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• v.14 no.2
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• pp.167-186
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• 2011

This paper presents the results of measurements relating to the aerodynamic forces on flat square plates which were allowed to rotate at different speeds about their horizontal axis, by modifying the velocity of the incoming flow. A 1 m square test-sheet and a 0.3 m square test-sheet were fitted with a number of pressure sensors in order to obtain information relating to the instantaneous pressure distribution acting on the test-sheet; a compact gyroscope to record the angular velocity during the rotational motion was also implemented. Previous work on autorotation has illustrated that the angular velocity varies with respect to the torque induced by the wind, the thickness and aspect ratio of the test-sheet, any frictional effects present at the bearings, and the vorticity generated through the interaction between the plate and the wind flow. The current paper sets out a method based on the solution of the equation of motion of a rotating plate which enables the determination of angular velocities on autorotating elements to be predicted. This approach is then used in conjunction with the experimental data in order to evaluate the damping introduced by the frictional effects at the bearings during steady autorotation.

• Environmental Engineering Research
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• v.22 no.3
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• pp.237-244
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• 2017

At present, in India, handling of solid waste has become a major challenge for the municipal authorities. Composting of solid waste, especially organic waste, can be one of the solutions to tackle the issue of handling solid waste. The present study is focused on agitated piles composting of flower waste (FW). Five combinations of FW with dry leaves (DL) and cow dung (CD) were prepared to conduct the study. Significant changes were observed due to the addition of bulking agent. The bulking material helps to reduce the production of leachate and also to maintain the aerobic condition within the piles. The reduction of total organic carbon was 21% in FW composting which increased by 36.48% during the composting of FW on addition of DL and CD. On the 120th day of composting, the pH of pile five (70 kg FW + 20 kg CD + 15 kg DL) was 7.33, electrical conductivity 2.77 mS/cm, total organic carbon 26.9%, total nitrogen 2.2%, and C:N ratio was 12. Appropriate proportion of waste mixture played an important role in providing favorable conditions for the microbial transformation of flower waste to stabilized compost. Finally, FW with the combination of CD and DL was found to be successful during pile composting.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.297-303
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• 2002

Fine particles (d$_{p}$ < 2.5 $\mu$m) were measured using an annular denuder system (ADS) in Chongju. The data set was collected on fifty-eight different days with a 24-hr sampling period from October 27, 1995 through August 25, 1996. Particulate nitrate in the ADS was also measured on teflon and nylon filters in series behind denuders to collect HNO$_3$, HNO$_2$, SO$_2$and NH$_3$. From this study. the mean concentration of particulate nitrate of PM$_{2.5}$ in the ADS were seen with the following order: winter (5.05) ＞fall (4.36) ＞spring (3.92) > summer (1.10 $\mu\textrm{g}$/㎥). Nitrate losses, which calculated from the ratio of nylon filter nitrate to the sum of teflon and nylon filter nitrates, varied in the following manner summer (72.2%) > spring (42.6%) > fall (23.5%)> winter (0.4%). Especially, gaseous nitric acid was dominant at temperature higher than 8$^{\circ}C$ while particulate nitrate was major species in total nitrate below that temperature. This indicates the particulate nitrate loss is strongly correlated rather with ambient temperature.e.e.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.73-76
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• 1998

We give pressure stimulation into organic thin films and detect the induced displacement current. then manufacture a device under the accumulation condition that the state surface pressure is 15[mN/m]. In processing of a device manufacture. We can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/organic thin films(polyimide)/Au, the number of accumulated layers are 31,35, and 41. I-V characteristic of the device is measured from 0[V] to +5[V]. The maximum value of measured current is increased as the number of accumulated layers are decreased. The resistance for the number of accumulated layers, the energy density for an input voltage show desired results, and the insulation of a thin film is better as the interval between electrodes is larger.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.597-600
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• 2002

Electrical properties of $\{(Sr_xCa_{1-x})_{0.95-y-z}Bi_2Pb_{0.05+y}\})Ti_{1.02}O_3$ ceramic were studied as a function of Sr/Ca ratio and Bi, Pb contents. Dielectric properties of specimens with different x, y, z values were explained in terms of ionic polarizability with Molecular Additionally Rules and Clausius-Mosotti equation. For the composition of $\{(Sr_{0.62}Ca_{0.38})_{0.90}Bi_{0.01}Pb_{0.09}\})Ti_{1.02}O_3$ and $\{(Sr_{0.62}Ca_{0.38})_{0.905}Bi_{0.015}Pb_{0.08}\})Ti_{1.02}O_3$, dielectric constant$({\varepsilon}_r)$, quality factor(Q) and temperature coefficient(TC) were 389, 3048, -1490 and 394, 1869, -1340 at 1MHz, respectively.