• Analytical Science and Technology
• /
• v.33 no.5
• /
• pp.209-214
• /
• 2020

This study has been carried out to develop a standard method for quantifying of 3 permitted artificial sweeteners (including sodium saccharine, aspartame, acesulfame potassium) contained in foods by HPLC-DAD. A simple and rapid sample pretreatment method was used to remove fat and protein from the test solution with Carrez clearing regent precipitant know to be effective for protein and fat removal. The artificial sweeteners in the test solution purified through sample pretreatment were detected by high performance liquid chromatograph using a Reverse phase C18 column (5 ㎛, 4.6 × 250 mm). The simultaneous quantitative test of 3 kinds of artificial sweeteners can be effectively performed on the high fat emulsified foods containing a large amount of fat. Using the established simultaneous quantitative test method, artificial sweeteners were tested in foods such as dairy products, snacks and chocolate. The results calibration curve showed good linearity with high regression coefficients and the result of recovery test showed satisfactory recoveries within 80~110 %.

• Archives of Plastic Surgery
• /
• v.35 no.1
• /
• pp.96-99
• /
• 2008

Purpose: A meningoencephalocele is a congenital malformation involving herniation of the meninges and cerebral tissue through a defect in the skull. For the patient with frontoethmoidal meningoencephalocele with hypertelorism, the removal of the meningoencephalocele without correction of the combined hypertelorism is not enough for getting a good cosmetic appearance. Correction of the hypertelorism is needed for cosmetic problem. We experienced a case of simultaneous correction of frontoethmoidal meningoencephalocele with hypertelorism. Methods: The meningoencephalocele was removed and the hypertelorism was corrected by central segment technique. The bone defects were filled with autogenous bone dusts. And the nose was reconstructed by a calvarial bone graft. Results: The patient had a good cosmetic appearance without any neurological complications without serious complications. Conclusion: We experienced a case of simultaneous correction of frontoethmoidal meningoencephalocele with hypertelorism. And a brief review of related literatures is given.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.38-43
• /
• 1998

Application of pervaporative extraction of ethanol to simultaneous saccharification and fermentation(SSF) of cellulose was investigated. From batch experiments, optimum cellulose substrate and enzyme loadings were found to be 10% and 15 IFPU/g cellulose, respectively. The cellulose conversion was lowered in fed-batch system due to the ethanol accumulation. The activity of the yeast Saccharomyces uvarum used in this study was significantly reduced at ethanol concentrations above around 40 g/L. From pervaporation experiments using PDMS membrane, ethanol was efficiently separated at 38$^\circ C$ and 10 mmHg of a down stream pressure. The pervaporation unit with 240 cm$^2$ of surface area was combined into the SSF reactor. The continuous removal of ethanol by pervaporation during SSF resulted in an improved cellulose conversion. Within the scope of this experiment, ethanol yields in the pervaporative SSF and simple SSF were 68.3% and 56.6%, respectively. The permeate flux for SSF broth pervaporation was about one-half that for the pervaporation of aqueous ethanol solution. Accordingly, the development of a membrane with higher ethanol selectivity and flux will increase the feasibility of this technology.

• Analytical Science and Technology
• /
• v.11 no.6
• /
• pp.499-504
• /
• 1998

An analytical method for the simultaneous measurement of trace Cu, Sn, and Bi in sea water has been investigated by Inductively Coupled Plasma-Mass Spectrometry. Amberlite IRC-718 resin was used as a solid phase in solid-liquid extraction technique for the removal of matrix interferences such as Na, S, P, and other polyatomic ion species. Recoveries of 99.8% for Cu, 99.6% for Sn, and 97.9% for Bi were obtained for the standard spiked sample. The developed method was applied to analysis of trace metals in sea water.

• Journal of Korean Society on Water Environment
• /
• v.21 no.6
• /
• pp.624-629
• /
• 2005

The purpose of this study is to investigate the performance of nitrogen removal using autotrophic microorganism in the Membrane-Attached Biofilm Reactor (MABR). The treatment system consists of an aerobic MABR (R1) for nitrification and an anaerobic MABR (R2) for hydrogenotrophic denitrification. Oxygen and hydrogen were supplied through the lumen of hollow-fiber membranes as electron acceptor and donor, respectively. In phase Ι, simultaneous organic carbon removal and nitrification were carried out successfully in R1. In phase II, to develop the biofilm on the hollow-fiber membrane surface and to acclimate the microbial community to autotrophic condition, R1 and R2 were operated independently. The MABRs, R1 and R2 were connected in series continuously in phase III and operated at HRT of 8 hr or 4 hr with $NH_4{^+}-N$ concentration of influent, from 150 to 200 mgN/L. The total nitrogen removal efficiency reached the maximum value of 99% at the volumetric nitrogen loading rate of $1.20kgN/m^3{\cdot}d$ in the combined MABR system with R1 and R2. The results in this study demonstrated that the combined MABR system could operate effectively for the removal of nitrogen in wastewater not containing organic materials and can be used stably as a high rate nitrogen removal technology.

• Biomedical Engineering Letters
• /
• v.8 no.4
• /
• pp.365-371
• /
• 2018

Uninterrupted monitoring of multiple subjects is required for mass causality events, in hospital environment or for sports by medical technicians or physicians. Movement of subjects under monitoring requires such system to be wireless, sometimes demands multiple transmitters and a receiver as a base station and monitored parameter must not be corrupted by any noise before further diagnosis. A Bluetooth Piconet network is visualized, where each subject carries a Bluetooth transmitter module that acquires vital sign continuously and relays to Bluetooth enabled device where, further signal processing is done. In this paper, a wireless network is realized to capture ECG of two subjects performing different activities like cycling, jogging, staircase climbing at 100 Hz frequency using prototyped Bluetooth module. The paper demonstrates removal of baseline drift using Fast Fourier Transform and Inverse Fast Fourier Transform and removal of high frequency noise using moving average and S-Golay algorithm. Experimental results highlight the efficacy of the proposed work to monitor any vital sign parameters of multiple subjects simultaneously. The importance of removing baseline drift before high frequency noise removal is shown using experimental results. It is possible to use Bluetooth Piconet frame work to capture ECG simultaneously for more than two subjects. For the applications where there will be larger body movement, baseline drift removal is a major concern and hence along with wireless transmission issues, baseline drift removal before high frequency noise removal is necessary for further feature extraction.

• Korean Chemical Engineering Research
• /
• v.43 no.1
• /
• pp.129-135
• /
• 2005

In this study, we have analyzed the removal efficiencies of $SO_2$ and $SO_2/NO$ by the pulsed corona discharge process and investigated the effects of several process variables on those removal efficiencies systematically. The effects of process variables such as applied voltage, pulse frequency, residence time, and initial concentrations of reactants (NO, $SO_2$, $NH_3$, $H_2O$, and $O_2$) on the removal efficiency were analyzed. As the applied voltage, the pulse frequency or the residence time increases or as the $O_2$ or the $H_2O$ or the $NH_3$ concentration in the inlet feed gas stream increases, the $SO_2$ removal efficiencies and the simultaneous removal efficiencies of $SO_2/NO$ also increase. These experimental results can be used as a basis to design the pulsed corona discharge process to remove $NO_x$ and $SO_x$.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.1
• /
• pp.15-22
• /
• 2003

Treatability tests were conducted using EMC process to study the feasibility of applying this process as recycling-water treatment system in high density seawater aquaculture farm. To study the effect of organic and ammonia nitrogen loading on system performance, hydraulic retention time of reactor was reduced gradually from 12hr to 10min. The conclusions are can be summarized as follows. When the system HRT was reduced from 12hr to 10 min gradually, there was little noticeable change(reduction) in ammonia nitrogen removal efficiencies until 2hr of HRT, however, removal efficiencies were decreased dramatically when the system was operated under the HRT of less than 2hr. In case of organics(COD), there was no dramatic deterioration in removal efficiencies depending on HRT reduction. More than 90% of removal efficiencies were maintained successfully when the system was operated at the HRT of 10 min. In case of system performance depending on media packing ratio in reactor, there was little difference in each reactor performance depending on media packing ratio in reactor when the reactors were operated under the HRT of longer than 1hr, however, differences in reactor performances were considerably evident when the reactors were operated under the HRT of shorter than 1hr. That is, the more reactor was packed, the better reactor performed. When comparing reactor performance among 25%, 50%, 75% packed reactor, it can be judged that media packing ratio more than 50% plays no significant role in increasing reactor performance. For this reason, packing the media less than 50% is more reasonable way in view of economic. Such a tendency well agreed with the variation of ammonia-nitrogen removal efficiencies according to the media packing ratio in reactors at each HRT. Difference in effluent ammonia-nitrogen concentration between 50% media packing reactor and 75% media packing reactor was negligible. When comparing with the results of 25% packing reactor, difference was not so great.

• Journal of Korean Society on Water Environment
• /
• v.25 no.6
• /
• pp.979-983
• /
• 2009

The mean pH of wastewater discharged from the plating process is 2, so a less amount of alkali is required to raise pH 2 to 5. In addition, if sodium sulfite is used to raise pH 5 to 9 in the secondary treatment, caustic soda or slaked lime is not necessary or only a small amount is necessary because sodium sulfite is alkali. Thus, it is considered desirable to use only $FeSO_4{\cdot}7H_2O$ in the primary treatment. At that time, the free cyanide removal rate was highest as around 99.3%, and among heavy metals, Ni showed the highest removal rate as around 92%, but zinc and chrome showed a low removal rate. In addition, the optimal amount of $FeSO_4{\cdot}7H_2O$ was 0.3g/L, at which the cyanide removal rate was highest. Besides, the free cyanide removal rate was highest when pH value was 5. Of cyanide removed in the primary treatment, the largest part was removed through the precipitation of ferric ferrocyanide: $[Fe_4(Fe(CN)_6]_3$, and the rest was precipitated and removed through the production of $Cu_2[Fe(CN)_6]$, $Ni_2[Fe(CN)_6]$, CuCN, etc. Furthermore, it appeared more effective in removing residual cyanide in wastewater to mix $Na_2SO_3$ and $Na_2S_2O_5$ at an optimal ratio and put the mixture than to put them separately, and the optimal weight ratio of $Na_2SO_3$ to $Na_2S_2O_5$ was 1:2, at which the oxidative decomposition of residual cyanide was the most active. However, further research is required on the simultaneous removal of heavy metals such as chrome and zinc.

• Electrical & Electronic Materials
• /
• v.10 no.8
• /
• pp.830-835
• /
• 1997

In this study an experimental investigation has been conducted to remove NOx and SO$_2$simultaneously from a combustion flue gases were consisted of NO-SO$_2$-$CO_2$-$N_2$-O$_2$([NO]o:200ppm and [SO$_2$]o:800ppm) and the injection gases used as radical source gases were NH$_3$-Ar-air and CH$_4$-Ar-air. NOx and SO$_2$removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as SO$_2$, NOx and NO$_2$gas detectors. and SEM images after sampling. The results showed that a significant Nucleating Particle Counter(CNPC) and SEM images after sampling. The results showed that a significant aerosol particle formation was observed during a simultaneous NOx and SO$_2$removal operation in corona radical shower systems. The diameter of aerosol particles was in the range of 0.18 to 3.6${\mu}{\textrm}{m}$ with a maximum fraction of particles at particles diameter of 1${\mu}{\textrm}{m}$. The NOx removal efficiency significantly increased with increasing applied voltage and NH$_3$molecule ratio. The SO$_2$removal efficiency was not significantly effected by applied voltage and slightly increased with increasing NH$_3$molecule ratio. It could be found that it is possible to use CH$_4$for NOx and SO$_2$removal by corona radical shower systems.