• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.176-187
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• 1988

Volatile flavor components in the Chinese quince fruits were trapped by simultaneous steam distillation-extraction method, and these were fractionated into the neutral, the basic, the phenolic and the acidic fraction. In the identification of carboxylic acids, the acidic fraction was methylated with diazomethane. Volatile flavor components in these fractions were analyzed by the high-resolution GC and GC-MS equipped with a fused silica capillary column. The total of one hundred and forty-five compounds from the steam volatile concentrate of the Chinese quince fruits were identified: they were 3 aliphatic hydrocarbons, 1 cyclic hydrocarbon, 4 aromatic hydrocarbons, 9 terpene hydrocarbons, 17 alcohols, 3 terpene alcohols, 6 phenols, 21 aldehydes, 7 ketones, 28 esters, 27 acids, 3 furans, 2 thiazoles, 2 acetals, 3 lactones and 9 miscellaneous ones. The greater part of the components except for carboxylic acids were identified from the neutral fraction. The neutral fraction gave a much higher yield than others and was assumed to be indispensable for the reproduction of the aroma of the Chinese quince fruits in a sensory evaluation. According to the results of the GC-sniff evaluation, 1-hexanal, cis-3-hexenal, trans-2-hexenal, 2-methyl-2-hepten-6-one, 1-hexanol, cis-3-hexenol, trans, trans-2, 4-hexadienal and trans-2-hexenol were considered to be the key compounds of grassy odor. On the other hand, esters seemed to be the main constituents of a fruity aroma in the Chinese quince fruits.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.389-394
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• 2003

In order to screen microorganisms producing phopholipase D (PLD) had high transphosphatidylation activity, about 1,000 Actinomycetes strains were isolated from the 63 soil samples, collected over 6 local area in Korea. When the hydrolytic activity in the supernatant was determined, 131 strains produced PLD more than 0.3 U/ml. Among 131 culture broths tested, 23 ones had transphosphatidylation activity higher than 20% and finally one strain (Actinomycetes KF 923), which had highest hydrolytic and transphophadylation activity, was selected. Actinomycetes KF923 showed the highest hydrolytic activity (13 U/ml) and phosphatidylation activity (95%) after 48 h fermentation using the P medium (yeast extract 1%, peptone 1%, glucose 1.5%, glycerol 1%, $CaCo_3$ 0.4%, pH 7.2). PLD was purified from the culture broth of Actinomycetes KF923 and the specific activity of purified PLD was 567 U/mg. The molecular weight of PLD was about 55 kD and the optimum pH and temperature were 6.0 and $60^{\circ}C$, respectively. The stability of PLD toward pH and temperature were high around pH 8.0 and below $40^{\circ}C$. Special metal ions were not necessary to the PLD activity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.649-660
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• 2017

In electronic warfare, the pulse amplitude, one of information of a pulse signal emitted by an enemy, is used for estimating distance from the source and for deinterleaving mixed source signals. An estimate of pulse amplitude is conventionally determined as the maximum magnitude of a Fourier transformed signal within its pulse width which is estimated pre-step in an electronic warfare receiver. However, when frequency modulated signals are received, it is difficult to estimate their pulse amplitudes with this conventional method because the energy of signals is dispersed in frequency domain. In order to overcome this limitation, this paper proposes an enhanced pulse amplitude estimation method which calculates the average power of the received pulse signal in time domain and removes the noise power of the receiver. Simulation results show that even in case the frequency modulated signal is received, the proposed method has the same performance as estimating the pulse amplitude when unmodulated signal is received. In addition, the proposed method is shown to be more robust to an estimation error of pulse width, which affects the estimation performance of pulse amplitude, than the conventional method.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.834-846
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• 2011

The objective of this study is to development of IDFIS system, that are consisted of hydrocyclone, rapid flocculation and inclined settler with chitosan coagulant. As the results of Jar test, a chitosan optimum dosage of 40 mg/L for river sediment, and 5 mg/L for tunnelling wastewater sediment, which these conditions leaves of residual turbidity of less than 5 NTU. Because of the effectiveness of chitosan in removing turbidity was independent on pH, the operation of IDFIS system would be simple. The synthesized turbidity was made with clay particles, river sediment, river suspended sediment, and tunnelling wastewater sediment. Results indicate that the mean overall removal efficiency of turbidity, SS, COD and TP were 98%, 99%, 85% and 95%, respectively. Chitosan is very efficient in removing turbidity in the entire turbidity range examined. IDFIS system would have possibility with compact design, because of the increase of floc size favours the floc settling speed and reduces the settling time.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.949-956
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• 2010

A method for simultaneous removal of nitrogen and phosphate from sewage by elemental sulfur denitrification with membrane bioreactor was proposed, and capacity $10\;m^3$/day of pilot plant was operated for 350 days. This study was investigated to have the effect of denitrification rate and T-P removal with the addition of Alum in Sulfur denitrification Reactor (SDR). The addition of Alum and alkalinity ($NaHCO_3$) in the effluent of MBR was tried to remove simultaneous phosphate and nitrogen in SDR. Characteristics of total nitrogen (T-N) and total phosphate (T-P) removal was compared without and with the addition of Alum as a coagulant. T-N removal without and with the addition of Alum was 92.1% and 87.8%, respectively. And denitrification efficiency was 93.8% and 87.1%, respectively. T-P removal rate was increased to 75.6% in SDR by addition of Alum (2.6~4 mg/L as Al), but T-P removal rate was about 26.7% without the addition of Alum. Therefore, denitrification rate was 6.7% of reduction but T-P removal rate was increased by addition of Alum.

• Resources Recycling
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• v.3 no.3
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• pp.32-49
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• 1994

Hydration process is one of the basic carbonation system. Limestone sludge produced in Pohang Iron & Steel Co., Ltd. We tested for identify of hydration characteristics. The result obtained in this study can be summarized as follows; 1. The classify of limestone sludge is type of ground calcium carbonate(-3mm+325mesh)and the major mineral of calcite, and further more high grade(CaO 51%), fine powder(15~22$\mu\textrm{m}$). 2. Limestone sludge mixed two process sludge, first one is washing process sludge and the other one is wet collect kiln dust. The composition rate is about 8:2. Wet collect kiln dust is major mineral of calcite, too. But the sludge is assumed to one by quick lime, slaked lime and unreacted natural limestone. So, the ideal process is dividing of the washing process sludge and wet collect kiln dust. 3. We manufactured of slaked lime from limestone sludge. To investigate the effect of hydration reactor, the experiments was done with various reactor type as magnetic stirrer, shaking incubator and ultrasonic vibration reactor, respectively. Generally, ultrasonic vibration reactor is excellent hydration for limestone sludge and produced very fine slaked lime powder with ideal distribution. 4. The optimum condition is 10% pulp density, when the manufacture of fine slaked lime powder by ultrasonic vibration reactor. And hydration times to compare the results of the study with ultrasonic vibration reactor of generalized most short time(5~10 min). 5. Finally, the dispersive characteristics of slaked lime powder measured 1~5 $\mu\textrm{m}$ from limestone sludge were compared with those of natural limestone ones(10~20$\mu\textrm{m}$), in order to check applicability of slaked lime with hydration process from limestone sludge.

• Resources Recycling
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• v.25 no.1
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• pp.60-67
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• 2016

A scale-up test with a continuous solvent extraction and electro-winning system was carried out to separate and recover copper from a synthetic sulfuric acid solution (Cu 10.5 g/L, Co 2.0 g/L, Ni 15.0 g/L, Fe 0.2 g/L). The solution was introduced into mixer-settlers with four stages of extraction and two stages of stripping for continuous countercurrent solvent extraction to separate copper from nickel and cobalt. The loading was carried out using 40% LIX 84-I(v/v) as extractant with a phase ratio of A : O = 1 : 1. Meanwhile, the stripping was undertaken at a phase ratio of A : O = 1 : 1.5 using depleted electrolyte containing 35.0 g/L Cu and 180 g/L $H_2SO_4$ as stripping solution. The extraction and stripping efficiencies were found to be 96.7% and 91.0%, respectively. The copper composition of the stripped solution (pregnant electrolyte) was 50.0 g/L Cu with impurities of 25 ppm nickel, 5 ppm cobalt and 3 ppm iron. In the electro-winning process, copper metal of 99.833 purity was yielded with current efficiency of 98.9% and current density of $1.50A/dm^2$.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.477-480
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• 2015

A total number of 100 fecal samples were examined for the presence of Giardia intestinalis infection in dogs using a Giardia ELISA kit (SNAP$^{(R)}$ test, IDEXX Laboratories, Inc., Westbrook, ME). 49 males and 51 females were examined for a G. intestinalis infection in Daejeon and Chungnam area of South Korea. The overall positive rate of G. intestinalis infection was 12.00%. G. intestinalis infection resulted to be more prevalent in males (12.24%) than in females (11.76%), and in symptomatic dogs (18.18%) than in asymptomatic dogs (11.54%). There were no significant differences between the two groups. 19.60% being found in the < 2-year-old group, 4.08% in the over 2 year-old group. $X^2$ analysis revealed a significantly higher prevalence (p < 0.05) in the < 2-year-old group than in the other, and a significantly higher prevalence in dogs kept in a shared kennel (36.00%, p < 0.001). This study is the first survey of G. intestinalis infection prevalence in South Korea according to life style (particularly between dogs kept in a shared kennel and that of dogs kept separately) using an ELISA kit, and this study is expected to provide a useful reference for clinicians and breeders.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.89-94
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• 2013

This study was carried out to calculate the genic values of days for flowering in commercial breeding lines of Korean hot pepper (Capsicum annuum L.). Two breeding lines of pepper '#2132' ($P_1$) early-flowering, and '#1308' ($P_2$) medium-late flowering, and their $F_1$ and $F_2$ generations were used in this study. By using partitioning method (Thseng and Hosokawa, 1971, 1972), it was possible to estimate, from the $F_2$ generations, the number of effective factor pairs differentiating the two parents. It was found out that the two parents were differentiated by two effective factor pairs, A:a and B:b. In the breeding lines used, the inheritance of days to flowering showed that the $F_1$ flowered a little earlier than the earlier flowering parent through the effect of over-dominance. However, $F_2$ flowered earlier or later than both parents through transgressive segregation. Conclusively, the magnitude of genic effects of A-a gene in flowering days was -13.81 days, and B-b gene was -6.73 days. The interaction between the two non-allelic factors using partitioning method was -5.26 days.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3336-3344
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• 2014

The purpose of this study is small scale coagulation module is developed and demonstrated through a lab-scale test. Recent as a sewage treatment rate increases, have heightened the interest in the necessity on the nonpoint source and developing a small processing unit has been increased. Coagulation sedimentation module in this study is additional growth of floc through swirling in the outside zone, reduction of microstructure floc number and the internal settling zone through vertical/level flow complex sedimentation method after the coagulation process precipitation method as an effective high separation efficiency can be divided was also assessed. Coagulation sedimentation module can increase the load factor was 4.4 times compared to conventional clarifier base on the same volume and surface area through vertical/level flow. In this study, this process was selected formation and maintenance of swirling and uniform flow distribution in the internal settling zone as an important design factor, to derive its FLUENT was used to characteristics of the flow model. Through the simulation of swirling, influent velocity, dimensions of external basin, hopper depth of bottom cone was determined and through analysis of velocity distribution, flow distribution detailed specifications are derived like as diameter and number of effluent hole. Lab-scale($120{\ell}/hr$) test results, influent of 300~800 NTU to less than 10 NTU without polymer feeding was able to operate in the 20minutes retention time(surface loading rate $37.3m^3/m^2$-day), and through analysis FLUENT the possibility of using design parameters were derived.