• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.5
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• pp.1-8
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• 2010

Clients require easy to use of product and operating and industry safety according to the change of a market and a factory. For overcoming it, this paper developed controller of take-out robots that take high speed and superprecision and supplement a week point as use the system based on network. development controller classify teaching pendant and center server PC. Center server PC service the information about all process to supervisor. Teaching pendant is the bridge that service various faculties such as control, user recognition, metallic pattern operation to the user using injection molding. The controller development for taking out injection molded body classify software and hardware. The development of software is divided into three step which is application program, user interface and device driver. the simple device driver is not classified and included in application program. The hardware induce the touch panel and wireless network and construct the effective process control and internet connection. The inject ion cycle of existing system was five second but advanced system has the inner four cycle, process efficiency and product operation through wireless network.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.425-430
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• 1994

The effect of inhibitors and catalysts in the synthesis of 2-hydroxyethyl methacrylate(2-HEMA) was studied. As catalysts, triethylamine(TEA), $FeCl_3{\cdot}6H_2O$, $Cu(NO_3)_2{\cdot}2H_2O$, $AlCl_3$, $Na_2Cr_2O_7$were selected. p-Methoxyphenol (PMP) of aq. $NaNO_3$ solution was used as an inhibitor in polymerization. in aq. $NaNO_3$ inhibitor system, triethylamine (TEA), $FeCl_3{\cdot}6H_2O$, and $Na_2Cr_2O_7$, showed good catalytic effects. When p-methoxyphenol(PMP) was used as a polymerization inhibitor, the reaction was very sluggish and noneffective because the metal ion such as $Fe^{3+}$ or $Cr^{6+}$ was reduced by PMP. On the contrary, when aq. $NaNO_3$ was used as an inhibitor in polymerization, the reaction was very fast without deactivation of the metal catalysts.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.877-885
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• 2013

A seawater pipe of the engine room in the ships is being surrounded with severely corrosive environments caused by fast flowing of the seawater, containing aggressive chloride ion and high conductivity etc.. Therefore, the leakage of the seawater from its pipe have been often occurred due to its local corrosion by aggressive chloride ions. Subsequently, its leakage area is usually welded by AC shielded metal arc welding with various electrodes. In this study, when the sea water pipe is welded with several types of electrodes such as E4301, E4311, E4313 and E4316, a difference of the corrosion resistance on the welding metal zones was investigated using an electrochemical method, observing microstructure, measuring polarization behaviors and hardness. The weld metal zone welded with E4313 electrode exhibited the lowest value of hardness compared to other weld metal zones. In addition, its zone indicated also the best corrosion resistance than those of other weld metal zones. Furthermore, all of the weld metal zones revealed a relatively better corrosion resistance than those of the base metal zones. and also showed higher hardness than the base metal zones.

• Journal of the Korean Applied Science and Technology
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• v.7 no.1
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• pp.93-105
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• 1990

Semicarbazone formation of nine monosubstituted benzaldehydes was studied kinetically in 20% methanol buffer solution at 15, 25, 35, and $45^{circ}C$. The rate of p-nitrobenzaldehyde semicarbazone formation is 2.7 times as fast as that of benzaldehyde, while p-hvdroxybenzaldehyde is 3.6 times as slow as that of benzaldehyde. Activation energies for p-chlorobenzaldehyde, benzaldehyde, p-methylbenzaldehyde, p-methoxybenzaldshyde, p-hydroxybenzaldehyde, and p-dimethylaminobenzaldehyde semicarbazone formation are calculated as 5.80, 6.19, 6.57, 7.06, 8.03, and 6.46 kcal/mol respectively. It is concluded from the effect of ionic strength that the reaction is affected by not ions but neutral molecules involving hydrogen bonding between oxygen atom of carbonyl group and hydrogen atom of acid-catalyst, and concerted attack of the necleophilic reagent, free base on carbonyl compound. Also, the effect of solvent composition is small in 20% and 50% methanol (and ethanol) aqueous solutions. The ${\rho}-{\sigma}$ plots for the rates of semicarbazone formation at pH 7.1 show a linear ${\rho}-{\sigma}$ relationship (${\rho}=0.14l$, in contrast to that at pH 2.75 and pH 5.4 corresponding to ${\rho}-{\sigma}$ correlations reparted by Jencks. The rate of semicarbazone formation at pH 5.4 show a relationship which is convex upward, resulting in a break in the curve but at pH 2.75, slight difference from a linear relationship. As a result of studying citric acid catalysis, second-order rate constants increase linearly with citric acid concentration and show a 2 times increase as the catalyst concentration is varied from 0.025 to 0.1 mol/1 at pH 2,9, but slight increase at pH 5.3. The rate-determining step is addition below pH 5 but is dehydration between pH 5 and 7. Conclusively, the rate-determining step of the reaction changes from dehydration to addition in respect to hydrogen ion activity near pH 5. The ortho: para rate ratio of the hydroxybenzaldehydes for semicarbazone formation is about 17 at $15^{\circ}C$. It is concluded that the results constitute strong evidence in favor of greater stabilization of p- than o-hydroxybenzaldehyde by substituent which donate electrons by resonance and is due to hydrogen bonding between the carbon-bound hydrogen of the-CHO group and the oxygen atom of the substituent.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.33-43
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• 2013

A bacterium producing a fibrinolytic enzyme was isolated from Cheonggukjang. The bacterium was identified as a strain of Bacillus amyloliquefaciens by 16S rDNA analysis and designated as B. amyloliquefaciens HC188. The optimum culture medium appeared to be one containing 0.5% (w/v) maltose and 0.5% (w/v) soytone. Bacterial growth in the optimal medium at $37^{\circ}C$ reached the stationary phase after 27 h of incubation and the fibrinolytic enzyme showed optimum activity at 24 h. The enzyme was purified by 20-80% ammonium sulfate precipitation, CM Sepharose fast flow ion exchange chromatography, and Sephacryl S-200HR column chromatography. Its specific activity was 38359.3 units/mg protein and the yield was 5.5% of the total activity of the crude extracts. The molecular weight was 24.7 kDa and the amino acids of the N-terminal sequence were AQSVPYGVSQIKAPA. The fibrinolytic enzyme activity had an optimum temperature of $40^{\circ}C$ and an optimum pH of 8.0, and the enzyme was stable in the ranges $20-40^{\circ}C$ and pH 6.0-8.0. Enzyme activity was increased by $Ca^{2+}$ and $Co^{2+}$ but inhibited by $Cu^{2+}$, EDTA, and PMSF. It is suggested that the purified enzyme is a metallo-serine protease.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.75-80
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• 1979

Ammonium desorption from 16 soils treated with $(NH_4)_2HPO_4$ solution (2000 ppm $NH_4$) was investigated by seven extractions with 0.01M $CaCl_2$. 1. There were 2 to 4 steps alternately appeared with fast and slow mode. 2. Desorption equation, log y=b-ax where y is desorption amount, b a constant indicating adsorption maximum, a retention constant, and x extraction number, was held for each step. 3. Desorption rate (100${\times}$desorption / adsorption) was 65% for the average of 15 soils, maximum 87% in Gimcheon series, minimum 32% in Samgag series. Yongho series (a peat soil) showed 156% indicating the release of large quantity of indigenous soil ammonium. 4. Desorption rate was negatively correlated with initial adsorption and in this relation the tested soils were classified into 3 groups. 5. The cumulative desorption curve was approaching almost to maximum in all tested soils with seven extractions. The final retention amount, ranged from 25% of CEC (Gimhae series) to 502% (Samgag Series). 6. Amount and rate of desorption did not have any significant relation with Langmuir adsorption maxima of ammonium, CEC and contents of clay, available phosphorus and organic matter. 7. The above results may indicate that adsorption and desorption of ammonium is closely related with iron, aluminum silicate and adsorption and desorption characteristics of accompanied anions.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.29-33
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• 2020

The objective of this study was to develop a fast and accurate method of variety discrimination and geographical discrimination origin of Korean angelica (Korean variety, Angelica gigas Nakai) by using TDU-GC/MS. Two peaks of decursin and decursinol, which are coumarin derivatives were identified in the range of Total Ion Chromatogram (TIC) RT 26.9-27.2 of the Korean angelica by GC/MS analysis at the time of condensation in a refrigerated condensation system after thermal desorption of sample extracts. In case of Chinese angelica (Chinese variety), ligustilide peak was detected at the RT 17.2. In order to investigate the difference of volatile components according to the geographical origin of Korean variety, the mass spectra were measured by TDU-GC/MS at the range of m/z 40-400 amu. The TIC of domestic cultivation and Chinese cultivation of the Korean variety, Angelica gigas Nakai showed the same tendency as a whole. However, in partial scans of TIC, two peaks detected at 15.54 and 16.05 of RT showed different peak patterns between Korean angelica (Korean variety) cultivated in Korea and in China. The ratio of Peak A (RT 15.54) and B (RT 16.05) was 0.0-0.2 for domestic cultivation and 0.5-2.8 for Chinese cultivation, confirming the possibility of discriminating origin by comparing the TIC peak pattern of TDU-GC/MS.

• Journal of Conservation Science
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• v.29 no.4
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• pp.297-309
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• 2013

Iron objects become corroded at fast speed from the moment when they are excavated, so it is needed to control corrosion through processes of conservation treatment. However, re-corrosion mostly takes place in excavate iron objects, although they have already gone through the process of conservation treatment, and it is more difficult to carry out the second conservation treatment of re-corroded excavated iron objects than the first conservation treatment, and it requires a longer period of time to treat them as well. In this study, aims to discover factors of re-corrosion by scientifically analyzing corrosion products generated during the process of storage after the process of conservation treatment. The finished on conservation treatment of the iron artifacts, which were unearthed from three ancient site in Gyeongju by using the same conservation method between 2002 and 2009, re-corrosion condition observed on the packaging-iron artifacts. Focused on 9 target forged iron artifacts among them, this study analyzed the physical changes by mass measurement, naked-eye and microscopic observations and the chemical changes by SEM-EDS, XRD, IC and ICP analysis. The results show that the yellowish brown corrosion products formed on the facing surface of part dropped from the artifacts had different associated forms but acicular shape. In addition, the acicular shape became clearer as the color changed from red to yellowish brown. According to the process when the conservation treatment was completed, the mass of the artifacts increased in proportion to the corrosion products and the chloride ion ($Cl^-$) concentration had a tendency to increase relatively. ${\beta}$-FeOOH (akaganeite) was confirmed in the XRD analysis for the corrosion products of all the collected samples. As a result of ICP analysis, $Na^+$ and $Ca^{2+}$ components were confirmed.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.653-658
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• 2016

In this work, we developed a synthetic method for preparing one-dimensional $MnO_2$ nanowires through a hydrothermal method using a mixture of $KMnO_4$ and $MnSO_4$ precursors. As-prepared $MnO_2$ nanowires had a high surface area and porous structure, which are beneficial to the fast electron and ion transfer during electrochemical reaction. The microstructure and chemical structure of $MnO_2$ nanowires were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller measurements. The electrochemical properties of $MnO_2$ nanowire electrodes were also investigated using cyclic voltammetry and galvanostatic charge-discharge with a three-electrode system. $MnO_2$ nanowire electrodes showed a high specific capacitance of 129 F/g, a high rate capability of 61% retention, and an excellent cycle life of 100% during 1000 cycles.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.294-302
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• 2015

BACKGROUND: Chemical accidents have increased owing to chemical usage, human error and technical failures during the last decades. Many countries have organized supervisory authorities in charge of enforcing related rules and regulations to prevent chemical accidents. A very important part in chemical accidents has been coping with comprehensive first aid tool. Therefore, the present research has provided information with the initial applications concern to the rapid analysis of hazardous material using instruments in vehicle of field mode after chemical accidents. METHODS AND RESULTS: Mobile measurement vehicle was manufactured to obtain information regarding field assessments of chemical accidents. This vehicle was equipped with four instruments including gas chromatography with mass spectrometry (GC/MS), Fourier Transform Infrared Spectroscopy (FT-IR), Ion Chromatography (IC), and UV/Vis spectrometer (UV) to analyses of accident preparedness substances, volatile compounds, and organic gases. Moreover, this work was the first examined the evaluation of applicability for analysis instruments using 20 chemicals in various accident preparedness substances (GC/MS; 6 chemicals, FT-IR; 2 chemicals, IC; 11 chemicals, and UV; 1 chemical) and their calibration curves were obtained with high linearity ( r ² > 0.991). Our results were observed the advantage of the high chromatographic peak capacity, fast analysis, and good sensitivity as well as resolution. CONCLUSION: When chemical accidents are occurred, the posted measurement vehicle may be utilized as tool an effective for qualitative and quantitative information in the scene of an accident owing to the rapid analysis of hazardous material.