• Environmental Engineering Research
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• v.24 no.4
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• pp.591-599
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• 2019

To convert sewage sludge to energy, drying-gasification characteristics during microwave heating were studied. During the gasification of carbon dioxide, the main products were gas, followed by char, and tar in terms of the amount. The main components of the producer gas were carbon monoxide and hydrogen including a small amount of methane and light hydrocarbons. They showed a sufficient heating value as a fuel. The generated tar is gravimetric tar, which is total tar. As light tars, benzene (light aromatic tar) was a major light tar. Naphthalene, anthracene, and pyrene (light polycyclic aromatic hydrocarbon tars) were also generated, but in relatively small amounts. Ammonia and hydrogen cyanide (precursor for NO_x) were generated from thermal decomposition of tar containing protein and nitrogen in sewage sludge. In the case of sludge char, its average pore diameter was small, but specific area, pore volume, and adsorption amounts were relatively large, resulting in superior adsorption characteristics.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1103-1105
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• 2002

H-ZSM-5 and γ-alumina were treated with formaldehyde and sodium carbonate. The treatment increased the amounts of weak acid sites, removing strong acid sites. The maximum temperature of weak acid sites in their ammonia TPD spectra shifted in the direction of high temperature. The modified H-ZSM-5 and g-alumina were mixed with the methanol synthesis catalyst to perform dimethyl ether synthesis from syn-gas. The modified catalysts showed better selectivity to dimethyl ether, minimizing the reforming reaction to carbon dioxide. The maximum yield of 53.3% to dimethyl ether was achieved under the reaction conditions of 54.4 atm, 523 K, and the feed rate of 4500 Lhr-1 .gcat-1.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.622-632
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• 2020

Phenylalanine ammonia-lyase (PAL) catalyzes the reversible deamination of phenylalanine to cinnamic acid and ammonia. Algae have been considered as biofactories for PAL production, however, biochemical characterization of PAL and its potency for myristicin biotransformation into MMDA (3-methoxy-4, 5-methylenedioxyamphetamine) has not been studied yet. Thus, PAL from Anabaena flos-aquae and Spirulina platensis has been purified, comparatively characterized and its affinity to transform myristicin was assessed. The specific activity of purified PAL from S. platensis (73.9 μmol/mg/min) and A. flos-aquae (30.5 μmol/mg/min) was increased by about 2.9 and 2.4 folds by gel-filtration comparing to their corresponding crude enzymes. Under denaturing-PAGE, a single proteineous band with a molecular mass of 64 kDa appeared for A. flos-aquae and S. platensis PAL. The biochemical properties of the purified PAL from both algal isolates were determined comparatively. The optimum temperature of S. platensis and A. flos-aquae PAL for forward or reverse activity was reported at 30℃, while the optimum pH for PAL enzyme isolated from A. flos-aquae was 8.9 for forward and reverse activities, and S. platensis PAL had maximum activities at pH 8.9 and 8 for forward and reverse reactions, respectively. Luckily, the purified PALs have the affinity to hydroaminate the myristicin to MMDA successfully in one step. Furthermore, a successful method for synthesis of MMDA from myristicin in two steps was also established. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to track the product formation.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.53-56
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• 2015

In this study, investigated the synthesis method of p-Phenylenediamine (PPD) by amination of p-Diiodobenzene (PDIB) under supercritical ammonia and CuI catalyst conditions. We examined the effects of various process variables (e.g., reaction temperature, pressure, amount of ammonia inserted, amount of catalyst inserted, and reaction time) on the production yield of PPD by analyzing the Gas Chromatography (GC). The experimental results demonstrated that PPD was not produced under non-catalyst conditions, and PPD production yield increased with increasing temperature, pressure, amount of catalyst inserted, and reaction time. However, for the reaction temperature case, it was found that $200^{\circ}C$ was the optimal temperature, because thermal degradation of PPD occurred above $250^{\circ}C$. In addition, we confirmed the structure of PPD and the bonding characteristics of the amine group via FT-IR and H-NMR analysis.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.896-904
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• 2011

The features of the capture reaction of $CO_2$ by ammonia solution have been investigated along with the effect of temperature on the reaction based upon computer program-utilizing calculation and thermodynamic estimation. The stable region of $CO{_3}^{2-}$ was observed to increase with temperature and the change of the stable region of $CO{_3}^{2-}$ with temperature was greater than the temperature variation of the stable region of other carbonate species. The distribution diagram for $NH_4{^+}-NH_3$ system was constructed and the rise of temperature resulted in the decrease of the stability of $NH_4{^+}$ ion, which was thought to be due to the endothermic nature of its acidic dissociation. Considering the introduction of $Ca^{2+}$ ion in the carbon capture reaction by $NH_4{^+}$, the temperature was observed to be important in the determination of the order of reaction between carbonate ion and these cations. The removal process of $CO_2$ gas by ammonia solution was presumed to occur in open system and the temperature variations of the concentration of carbonate system species along with their total concentration were calculated for the proper control and design of the real process.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.274-278
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• 2020

Pig slurry (PS) is the most applicable recycling option as an alternative organic fertilizer. The application of pig slurry has the risk of air pollution via atmospheric ammonia (NH3) and nitrous oxide (N2O) emission. The zeolite has a porous structure that can accommodate a wide variety of cations, thus utilizing for the potential additive of deodorization and gas adsorption. This study aimed to investigate the possible roles of zeolite in mitigating NH3 and N2O emission from the pig slurry applied to the maize cropping. The experiment was composed of three treatments: 1) non-N fertilized control, 2) pig slurry (PS) and 3) pig slurry mixed with natural zeolite (PZ). Both of NH3 and N2O emission from applied pig slurry highly increased by more than 3-fold compared to non-N fertilized control. The NH3 emission from the pig slurry was dominant during early 14 days after application and 20.1% of reduction by zeolite application was estimated in this period. Total NH3 emission through whole period of measurement was 0.31, 1.33, and 1.14 kg ha-1. Nitrous oxide emission in the plot applied with pig slurry was also reduced by zeolite treatment by 16.3%. Significant increases in forage and ear yield, as well as nutrient values were obtained by pig slurry application, while no significant effects of zeolite were observed. These results indicate that the application of zeolite and pig slurry efficiently reduces the emission of ammonia and nitrous oxide without negative effects on maize crop production.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.1
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• pp.71-81
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• 2020

Enclosed pig house are creating an environment with high concentrations of gas and dust. Poor conditions in pig farms reduce pig weight and increase disease and accidents for livestock workers. In the pig house, the high concentration of harmful gas may cause asphyxiation accidents to workers and chronic respiratory disease by long-term exposure. As pig farm workers have been aging and feminized, the damage to the health of the harsh environment is getting serious, and real-time monitoring is needed to prevent the damage. However, most of the measuring devices related to humidity, harmful gas, and fine dust except temperature sensors are exposed to high concentrations of gas and dust inside pig house and are difficult to withstand for a long time. The purpose of this study is to develop an wearable based device to monitor the hazardous environment exposed to workers working in pig farms. Based on the field monitoring and previous researches, the measurement range and basic specifications of the equipment were selected, and wearable based device was designed in terms of utilization, economic efficiency, size and communication performance. Selected H₂S and NH₃ sensors showed the average error of 5.3% comparing to standard gas concentrations. The measured data can be used to manage the working environment according to the worker's location and to obtain basic data for work safety warning.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.95-103
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• 2017

A lot of hazardous materials have been used for product processing and utility plant. Many accidents including toxic release, fire and explosions occur in the ammonia related facility and plant. Various safety and environment management program including PSM, SMS, ORA etc. are being implemented for risk management and accident prevention in the production industry. Also much study and research have been carried about risk assessment of accident scenario in the academic and research area. In this paper, firstly risk level was assessed by using a typically used KORA program and LOPA PFD method for the selected ammonia unloading and storage facility. And then risk reduction measures for the risk assessed facility were studied in 3 aspects and some measures were proposed. Those Risk Reduction measures are including a leak detection and emergency isolation, water spray, dilution tank, dike and trench, scattering protection in hardware impovement aspect, and a applicable risk criteria, conditional modifier for existing LOPA PFD, alternative supporting modeling program in risk estimation methodology aspect, and last RBPS(Risk Based Process Safety) program, re-doing of process hazard analysis, management system compliance audit in managerial activity aspect.

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.125-132
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• 2015

The Far Infrared Ray (FIR) is part of the natural energy as light spectrum of sunlight. Human can disentangle the colors within visible ray, but FIR is invisible to human sight because it has longer wavelength than visible ray. The effect of using FIR on broiler performance, blood biochemical profiles and fecal gas emission from litter. Day-old semi-broiler chicks (Ross ♂ ${\times}$ Hyline ♀) were obtained and assigned to eight pens, 2 replicates of white and green color LED light, and with FIR on each color light, in a 20L:4D of lighting program. The body weight gain and feed efficiency were tend to improve under the green color than white color, which were increased by exposing to FIR on both color light. Emission of ammonia and lower hydrocarbons from litter were not different from each color but there was a decrease by exposing to FIR regardless of light color. The level of blood aspartate aminotransferase (AST) tends to be decreased under green color than white color, and this tendency becomes more pronounced as exposing to FIR. Therefore significantly increased under white color without FIR than green color with FIR (P<0.05). The levels of albumin and immunoglobulin were not different from each color but there was an increase by exposing to FIR regardless of light color. In conclusion, exposing to Far Infrared Ray (FIR) when broiler raising, there is potential to increase broiler performance because of improvement of bioactivity and raising environment.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.273-277
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• 2006

Purpose : The prevalence of Reye syndrome has decreased since late 1980's. But we report that recently there were concentrative attacks of Reye syndrome after acute enteritis during the neonatal period. Methods : Clinical symptoms and laboratory results(quantitative organic acid analysis, routine chemistry, arterial blood gas analysis, serum ammonia) of seven patients admitted at the Samsung Medical Center, Sanggye Paik Hospital, Wonju Christian Hospital and Chuncheon Sacred Heart Hospital, referred from Jan. 2005 to Apr. 2005, were analysed retrospectively. The major clinical symptoms were derived from the patients' clinical records sended with urine samples and quantification of organic acids were done with gas chromatography and mass spectrometry. Results : The mean age of seven cases is 18 days and the major preceding symptoms were gastrointestinal symptoms(vomiting, diarrhea, refusal to feeding). The major clinical symptoms were clouded conciousness, repiratory difficulty, vomiting, seizures, and diarrhea. One patient died; that patient's serum ammonia was twenty times higher than normal. Conclusion : The seven patients were neonates. Reye syndrome has been known to be closely related with upper respiratory infections as a preceding disease and to internal use of aspirin, but in our study, the major preceding disease of the seven cases was gastrointestinal infection and none of these used aspirin.