• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.15-15
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• 1999

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.63-69
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• 2009

New morpholinylcarbonylmethyl-2-phenylimino-1,3-thiazolines 2(X=O) and piperidinylcarbonylmethyl-2-phenylimino-1,3-thiazolines 3(X=C) to which morpholinyl or piperidinyl functional group were introduced at C-4 side chain of the 2-phenylimino-1,3-thiazoline scaffold were synthesized to investigate the effect of NH hydrogen of 2-phenylimino-1,3-thiazoline-4-acetanilide derivatives on the antifungal property against rice blast. Synthesized 30 compounds were screened against 6 kinds of typical plant fungi. Treatment of ketene dimer with chlorine followed by the reaction of morphorine or piperidine without isolation of the intermediate acetoacetylchloride gave $\gamma$-chloro-$\beta$-keto derivatives. These were reacted with thioureas to give morpholinylcarbonylmethyl-2-phenylimino-1,3-thiazolines and piperidinylcarbonylmethyl-2-phenylimino-1,3-thiazolines respectively in good yield (27-98%). The compound 3j, in which two fluorine atoms are substituted at ortho and para position of phenyl group of 2-phenylimino moiety and piperidinyl group is substituted at C-4, showed the highest antifungal activity (100 ppm, 90%). This result suggested that the substituent at C-4 of the 2-phenylimino-1,3-thiazolines may play a supplementary role to show the antifungal activity against rice blast.

• Journal of Life Science
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• v.21 no.3
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• pp.444-450
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• 2011

Perchlorate ($ClO_4^-$) is a contaminant found in surface water and soil/ground water. Autotrophic perchlorate-reducing bacteria (PRB) use hydrogen gas ($H_2$) as an electron donor to remove perchlorate. Since iron corrosion can produce $H_2$, feasibility of autotrophic perchlorate-removal using zero-valent iron (ZVI) was examined in this study using activated sludge that is easily available from a wastewater treatment plant. Batch test showed that activated sludge microorganisms could successfully degrade perchlorate in the presence of ZVI. The perchlorate biodegradation was confirmed by molar yield of $Cl^-$ as perchlorate was degraded. Scanning electron microscope revealed that rod-shaped microorganisms on the surface of iron particles used for the autotrophic perchlorate-removal, suggesting that iron particles could serve as supporting media for the formation of biofilm as well. DGGE analyses revealed that microbial profile of the inoculum (activated sludge) was different from that of biofilm sample obtained from the ZVI-added enrichment culture used for $ClO_4^-$-degradation. A major band of the biofilm sample was most closely related to the class Clostridia.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.873-882
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• 2009

Sonolysis of TCE (Trichloroethylene) was performed in 584 kHz rectangular reactor. At first, the effect of acoustic power and aqueous temperature which are both important factors to operate ultrasound system on sonolysis of TCE were examined under one side irradiation condition. First degradation rate constants of TCE and chloride yields were increased with increasing acoustic power from 100 to 300 W. And increasing the aqeuous temperature resulted in the increase of first degradation rate constants of TCE and the decrease of chloride yield. Sonolysis of TCE was performed under multi ultrasound irradiation conditions that total acoustic power of 300 W was distributed according to the number of irradiation sides. First degradation rate constants of TCE followed the order 4 sides > 3 sides > 1 side > 2 sides (parallel) > 2 sides (orthogonal). When comparing the experimental results under parallel and orthogonal irradiation conditions of 2 sides with 300 and 450 W, first degradation rate constants of TCE were similar, while production rate constants of hydrogen peroxide were more higher at parallel conditions compared to orthogonal conditions.

• Clean Technology
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• v.20 no.1
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• pp.57-63
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• 2014

In this work, we performed the methanation with steam and synthesis gas of a low $H_2/CO$ ratio to develop a process for producing SNG (synthetic natural gas). In this experiment conditions, the water gas shift reaction and the methanation reaction take place at the same time, and insufficient supply of steam might cause the deactivation of the catalyst. Therefore, the reaction characteristics with the amount of steam was performed, and the methanation on syngas containing $CO_2$ of the high concentration were studied. As a result, the temperature in the catalyst bed decreased by the supply of steam, and the methanation and the water gas shift reaction occurred at the same time. Although methane yield slightly decreased at the methanation using syngas containing $CO_2$ of the high concentration, the long-term operation (1,000 h) in the experimental conditions of this study indicates that this condition is suitable for the new commercial scale SNG process.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.36-37
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• 1990

In the past, facile dissolution of cellulose has been hampered by the lack of suitable nondegrading solvents. Recently, this problem has been solved in our laboratory by the discovery of an inexpensive, convenient solvent system, that is the mixture of $NH_3\;and\;NH_4SCN$, for cellulose. Also, the $cellulose/NH_3/NH_4SCN$ solution system has been found to form the anisotropic, i.e., liquid crystalline phase. It is believed that both the cholesterio and the nematic phase occur. This finding has prompted extensive on-going researoh on the formation of the liquid crystalline phase from an inexpensive natural source such as cellulose since the nematic phase is envisioned as an excellent precursor sources for products with desirable properties, for example, high modulus and high strength. This interest naturally leads to a desire to understand the theological properties of the nematic phase so that the transformation of the nematic phase to the solid state with desirable properties can be efficiently accomplished, ;From this point of view, the theological behavior of the $cellulose/NH3_/NH_4SCN$ system has been studied as a function of shear rate and shear stress over a wide range of solvent compositions, cellulose concentration, centrifugation and urea contents, Results indicate that the viscosity decreases with increasing shear rate. A marked shear thinning behavior and a quasi-Newtonian behavior were observed in the low shear rate region and in the high shear rate region, respectively for all solvent compositions. The $cellulose/NH_3/NH_4SCN$ solution system only exhibited the viscosity increase with increasing cellulose concentration and failed to show the viscosity drop generally observed at the point of incipience of liquid crystal formation, This may be due to the gel-like nature of the solution by the association of the rodlike molecules into bundles which may serve as crosslinking points giving the cellulose solution a network structure. Also, simply hydrogen bonding may be so restrictive of molecular mobility that a viscosity drop is blocked. In addition to the above results, yield stress and thixotropy were also observed in the $cellulose/NH_3/NB_4SCN$ solution system which are characteristics of liquid crystal and gel, The results of the effect of centrifugation on viscosity show that viscosity decreases by the application of centrifugation. This may be explained by the change of the piled polydomain structure to the dispersed polydomain structure due to the pressure gradient generated during centrifugation.ation.

• Resources Recycling
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• v.31 no.4
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• pp.12-18
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• 2022

Korea depends on the import of raw materials such as iron ore and coal for the steel industry. These raw materials have a major impact on the cost, productivity, and quality competitiveness in the global steel industry. To secure the competitiveness of steel companies, it is necessary to reduce the country's dependence on raw materials. This can be achieved using byproducts with a high Fe content, which are primarily generated by the steel industry. These byproducts are available in the form of a very fine powder, which can disperse as dust when used directly in plant processes. Dust dispersion has a negative impact on the environment and can lead to the loss of raw materials. To enable the use of a wide range of Fe-containing byproducts, it is necessary to pretreat them in the form of larger aggregates such as pellets and briquettes. There are several methods to achieve such aggregates. There are two ways to produce briquettes: using a hot briquette, which supplies additional heat to produce briquettes, or using a cold briquette, which does not use heat. A method for producing cold briquettes using Fe-containing byproducts was investigated in this study. The yield ratio and briquette strength were examined under various manufacturing conditions.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.59-71
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• 2021

Hybrid hydrothermal carbonization (Hybrid HTC) technology is a proprietary thermochemical process for two or more organic wastes.The reaction time is less than two hours with temperature range 180~250℃ and pressure range 20~40bar. Thanks to accumulation of the carbon of the waste during Hybrid HTC process, the energy value of the solid fuel increases significantly with comparatively low energy consumption. It has also a great volume reduction with odor removal effect so that it is evaluated as the best solid fuel conversion technology for various organic wastes. In this study of the hybrid hydrothermal carbonization, the effect on the calorific value and yield of Cambodian mango waste were evaluated according to changes in temperature and reaction time. Through the study, parameter optimization has been sought with improving energy efficiency of the whole plant. It is decomposed in the Hydro-Carbonation Technology to Generate Gas. At this time, it is possible to develop manufacturing and production technologies such as hydrogen (H₂) and methane (CH₄). Based on the results of the study, a pilot plant (2t/day) has been proposed for future commercialization purpose along cost analysis, mass balance and energy balance calculations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.117-125
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• 2023

In this study, the anti-inflammatory and anti-oxidative activities were compared for the extracts of non-fermented Ligustrum japonicum fruits (LJF) and fermented counterparts. U se of Latilactobacillus curvatus (L. curvatus) and Weissella minor (W. minor), isolated from the Jeju Chromis notata, as fermented strains led to the extracts of LJF-LC and LJF-WM in this experiment. The yield of each fermented extract (LJF-LC and LJF-WM) was 40.5 ~ 46.0%, higher than 29.5% of non-fermented extract (LJF). As a result of an activity experiment using RAW 264.7 macrophages stimulated by lipopolysaccaride (LPS), it was confirmed that LJF-WM, a fermented extract, has an excellent effect of inhibiting NO production in a concentration-dependent manner without cytotoxicity. Upon the screening of DPPH and ABTS⁺ radical scavenging activities, the fermented LJF-LC and LJF-WM showed comparable to the non-fermented LJF. In the study of cell protection effect using HaCaT keratinocytes damaged by hydrogen peroxide (H₂O₂), the fermented LJF-WM indicated protective effect against oxidative stress. In addition, quantitative analysis of a major constituent salidroside by HPLC indicated about 15.6 mg/g for the LJF-LC and 13.9 mg/g for the LJF-WM, which were higher than that of non-fermented LJF (12.0 mg/g). Based on these results, it was suggested that the fermented extract from L. japonicum fruits could be used as a natural cosmetics material with anti-inflammatory and anti-oxidative effects.