• Journal of Biosystems Engineering
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• v.35 no.3
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• pp.182-188
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• 2010

Post-Harvest processing engineering is a field that studies prevention of the quality change of agricultural products during sorting, packaging, storage, and distribution after harvested. In distribution steps, agricultural products could be damaged by physical force, it is the main reason of low quality and they lost value of commodities. This study was performed to find the vibration characteristics of the peach, and to find the extent of the damage on the peach by fatigue stress. The vibration data was obtained on expressway and the vibration characteristics of peach was used to find the damage on the peach. To analyze the vibration characteristics of peach, the resonance frequency and vibration transmissibility were measured. The resonance frequency of the peach was 167.98 Hz and the transmissibility was 4.06 at resonance point. It was 150 ~ 250 Hz that the transmissibility was more than 1. And the transmissibility in simulated test was measured. When the trasmissibility was more than 1, the range was 15 ~ 65 Hz, and when it was less than 1, the range was 65 ~ 175 Hz. When the transmissibility was about 1, the range was 5 ~ 15 Hz. The damage and the vibration cycle numbers of peaches were compared with input frequency and acceleration. More damage and less cycle number happened in 30 Hz than in 62.5 Hz. The reason was that the transmissibility of 30 Hz was higher and the vibration displacement in lower frequency was more. The more acceleration and cycle number increased, the more the bruising volume of peaches increased. The bruising volume ratio for vibration fatigue was measured according to input acceleration and cycle number. Using measured data, regression models for bruising volume ratio(BVR) was developed as a function of the acceleration(A) and cycle number(CN) as follows. BVR = a * $A^b*$ $(CN)^c$

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.274-278
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• 2004

This study investigates the fatigue characteristics of SM 490 A material specimens for the railway vehicle due to the welding type. The more stress ratio decreases, the more strength of fillet welded specimen decreases. At speciallly, when the stress ratio of TN(Plate with transverse fillet welded rib) specimens decreases 0.5, 0.1, and -0.1, the fatigue limit decreases unifomly. The strength of TN is higher than it of NCN in the compare of fillet welding type, but the strength of NCN(Non load-carrying cruciform fillet welded joint) is higher than it of CN(Load-carrying cruciform fillet welded joint), which these specimens have the rib in the both side. We analysis the strains on the weld positions of the TN specimens during the fatigue test for the investigation of crack initiation and crack growth. In the theses results, we could find the fatigue crack initiation point and time.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.60.2-60.2
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• 2010

We have studied the abundance ratio of HNC and HCN toward the Red MSX Sources (RMS) using HCN (J=1-0), HNC (J=1-0), $H^{13}CN$ (J=1-0), $HN^{13}C$ (J=1-0),and $N_2H^+$ (J=1-0) lines observed with the Mopra 22 m radio telescope. The RMS are massive young stellar objects identified by the MSX satellite data combined with the 2MASS data. HCN and HNC (a geometrical isomer of HCN) are among the most basic interstellar molecules. According to our analysis, the column density of HCN is found to be correlated with that of HNC. Additionally, the [HNC]/[HCN] abundance ratio is sensitive to the core temperature because HNC is depleted in high temperature regions. This result is consistent with the previous results seen in low mass starless or protostellar cores.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.58.2-58.2
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• 2020

We present a method for determining the abundance ratio of nitrogen to iron ([N/Fe]) from low-resolution (R~2000) stellar spectra from large spectroscopic surveys such as Sloan Digital Sky Survey (SDSS) and Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). The basic idea of the method is to match a grid of synthetic spectra with an observed spectrum in the CN band region around 3883 Å. To calibrate our estimate of [N/Fe], we make use of the giants observed in Apache Point Observatory Galaxy Evolution Experiment (APOGEE), which are also observed in the SDSS. This method will be applied to the Galactic halo stars to determine [N/Fe], and the measured nitrogen abundance ratios will be used to investigate the C-N anti-correlation, which is observed in globular clusters, to trace their origin with their kinematic properties.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.6
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• pp.554-565
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• 2002

The purpose of this study is to investigate the effect of raw Cassia tora L. powder added-diets on reducing cadmium accumulation in rats. The experimental animals were Sprague-Dawley family(♂, 4 weeks) which was classified into normal group CN, compared group CS, Cd-added group Cl and groups C2, C3, C4 in which 0.5, 1.0 and 1.5% of the Cassia tora L. powder are added, respectively. The growth rate and food efficiency ratio, and the amounts of accumulated cadmium in rats for S weeks were measured and analyzed. The results are as follows; 1. The rates of weight gain decreased in the order of C3>C2>C4>Cn>Cs>Cl groups, and Cl group to which only cadmium water had been fed was the lowest among them. The correlation between groups Cl and C3 was significantly different at the 1% level. 2. Food efficiency ratio(FER) decreased in the order of C3>C2>Cs>Cn>C4>Cl, and the FERs of C3, C2, CS, CN and C4 are greater than that of Cl by 22.87, 19.59, 18.54, 14.20 and 13.17%, respectively. 3. As for the Cassia tora L. powder-added groups, the amounts of cadmium accumulated in organs and tissues, that is, the brain, heart, spleen, liver, lungs, testicles. kidney, femoral muscle and leg bones were 0.45 $\pm$ 0.04 to 0.83$\pm$0.04, 1.68$\pm$0.02 to 2.16$\pm$0.02, 3.26$\pm$0.05 to 4.62$\pm$0.27, 37.52$\pm$0.09 to 47.71$\pm$0.73, 1.07$\pm$0.10 to 1.66$\pm$0.04, 1.04$\pm$0.06 to 1.24$\pm$0.08, 36.79$\pm$0.20 to 39.61 $\pm$0.53, 0.87$\pm$0.02 to 1.00$\pm$0.02 and 0.65$\pm$0.17 to 1.27 $\pm$ 0.06 $\mu\textrm{g}$/g, respectively. 4. The accumulated Cd content for C4 was the lowest among Cassia tora L. powder-added groups. When the results for C4 are compared with those for Cl, it is observed that each cadmium content accumulated in the brain, heart spleen, liver, lungs, testicles, kidney. femoral muscle and leg bones is dropped by 49.03, 22.56, 36.02, 35.75, 41.75, 36.20, 37.00, 22.77 and 56.67 %, respectively. On the other hand. the accumulated Cd content increased in the order of brain

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.2
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• pp.107-120
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• 2019

In this study, the characteristics of watershed and pollution source were investigated in SoOakcheon located in the upper stream of Daecheong Lake. The Dimension Index method was applied to index various watershed and pollution source data. The influence factors of each pollutant source were derived through correlation analysis between selected index and water quality monitoring data. BOD and COD were significantly influenced by population density and land area ratio, T-N by CN and rice area ratio, and T-P by population density and land area ratio, respectively. The discharge load is often used to establish non-point source countermeasures, but there is a difference between the water load and the water load in the lake or river. Therefore, in order to manage non-point pollution efficiently, it is necessary to analyze influential factors with high correlation with water quality and to manage the relevant factors with priority.

• Geotechnical Engineering
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• v.10 no.4
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• pp.167-180
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• 1994

A series of long term consolidation tests were conducted under loading -unloading and loading(pc) -unloading(p.) -reloading(p,) conditions using reconstituted clay in order to investigate the effect of stress history on secondary consolidation characteristics and the applicability of the secondary consolidation model suggested by Bjerrum to overconsolidated clays. According to the test results, the secondary compression settlement affected by the stress history in the first half of experimental period and the coefficient of secondary compression, C‥‥ is dependent on overconsolidation ratio, OCR(p,1 p.), maBium OCR (p./p.), and unloading duration time. Moreover the coefficient of secondary consolidation in the latter half of experimental period Cn is mainly affected by OCR and it gradually reduces with OCR increment. Finally the comparison of the experimental results with the Bjerrum model indicates that the Bjerrum model can be applied beyond certain range of stress history in the overconsolidated clay.

• Journal of the Korean Chemical Society
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• v.31 no.2
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• pp.162-167
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• 1987

Four component $Ag_2S$-PbS-$PbHAsO_4-Cu_2S$ and three component $Ag_2S$-PbS-$PbHAsO_4$ electrodes have been prepared and evaluated for the direct measurement of monohydrogen arsenate. The 3.0 : 0.5 : 1.0 : 0.25 (mole ratio, $Ag_2S$:PbS:$PbHAsO_4:Cu_2S$) composition is superior in terms of potentiometric response, stability, rapidity of response and reproducibility. Testing was done over the concentration range $10^{-1}$~$10^{-4}M\;HA_SO_4^{2-}$in 0.1F NH4Ac-NH4OH buffer solution at pH 8.50 with constant ionic strength. Interfering ions were $CN^-,\;I^-,\;S^{-2}$ and $Cl^-$.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.517-523
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• 1994

The effects of cure kinetics and mechanism of DGEBA(diglycidyl ether of bisphenol A)/MDA(4,4'-methylene dianiline) with SN(succinonitrile) and HQ(hydroquinone) as an additive and accelerator were investigated. Cure kinetics was evaluated by Kissinger equation and fractional-life method through DSC analysis. The activation energy has hydroxyl group as an accelerator, the activation energy and the starting cure-temperature were lower than those of DGEBA/MDA/SN system. Cure mechanism of those systems was investigated through FT-IR according to the various SN contents. The ratio was SN : HQ = 4 : 1. It has been known that the cure reactions of an epoxy-diamine system are composed of primary amine-epoxy reaction, secondary amino-epoxy reaction and epoxy-hydroxyl group reaction. But in DGEBA/MDA/SN system, primary amino-CN group reaction and CN group-hydroxyl group reaction were added to the above mentioned reactions. These reactions attributed to the long main chain and the low crossliking density. And in DGEBA/MDA/SN/HQ system, hydroxyl group of HQ formed a transition state with epoxide group and amime group and also opened the ring of the epoxide group rapidly, then amino-epoxy reaction took place easily.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.562-569
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• 2016

Recently, Low Impact Development (LID) is being used in Korea to control urban runoff and nonpoint source pollution. In this study, we evaluated the reduction of surface runoff from a study area, as the effect of connecting three bioretention as LID-BMP. Surface runoff and storage volume of bioretention is estimated by the Curve Number (CN) method. In this study, the storage volume of bioretention is divided by the volume of surface runoff and precipitation which directly enters the bioretention. The ratio of captured surface runoff volume to storage volume is highly influenced by the ratio of drainage area to surface area of bioretention. The high bioretention surface area-to-drainage area ratio captures more surface runoff. The ratio of 1.2 captures 51~54% of the total surface runoff, ranging from 5-30cm of bioretention depth; a ratio of 6.2 captures 81~85%. Three connected bioretentions could therefore captures much more runoff volume, ranging from $35.8{\sim}167.3m^3$, as compared to three disconnected bioretentions at their maximum amount of precipitation with non-effluent from the connecting three bioretentions. Hence, connecting LID-BMPs could improve the removal efficiencies of surface runoff volume and nonpoint source pollution.