• Journal of Microbiology and Biotechnology
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• v.7 no.4
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• pp.262-266
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• 1997

To increase the high production of 1-deoxynojirimycin (DNJ) from Streptomyces sp. SID9135, the effect of various carbon sources, nitrogen sources, cationic metal ions, the initial pH of the medium, and agitation speed were investigated. The most effective carbon and nitrogen sources were found to be lactose 2.5% (w/v) and soybean meal 2.0% (w/v), respectively. None of the cationic metal ions examined had any detectable stimulating effect on DNJ production except $Fe^{+2}$ ion. The initial optimum pH for DNJ production ranged from 6-8 and agitation speed was most effective at 400 rpm. In the jar fermentor experiments under optimal culture conditions, the accumulation of DNJ reached about $640{\mu}g$/ml after 5 days of cultivation and the level remained the same for a further two days.

• Journal of the Korean Applied Science and Technology
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• v.23 no.1
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• pp.1-11
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• 2006

The W/O emulsion was formed by mixing hydrophobic nonion surfactants of span 80 and tween 60 with kerosine, and by adding sodium silicate aqueous solution. Precipitating the W/O emulsion by sodium bicarbonate resulted in spherical silica particles. Shape and size distribution of silica particles were observed. The particles were spherical and they have narrow size distribution. Particle sizes were 9.29, 7.39 and $5.73\;{\mu}m$ at homogenizer speed of 2500, 3000, and 3500 rpm, respectively. The particle size was decreased by increasing agitation speed due to the formation of emulsion droplet. At fixed agitation speed, absorbed paraffin oil weight were measured and the $SiO_2/Na_2O$ mole ratio effects on particle size were investigated. Particle size was decreased by increasing the mole ratio of $SiO_2/Na_2O$.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.287-290
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• 2000

To examine effects of agitation and aeration as well as adding of glucose and yeast extract on cell growth and polysaccharide production by Paecilomyces japonica, batch culture was carried out at 5L jar fermenter at $27^{\circ}C$ with the initial pH 7 for 7 days cultivation(innoculum size 2%, working volume 3L). Media compositions(g/L) were 30 glucose, 20 yeast extract, 0.5 $KH_2PO_4$, $0.1\;CuCl_2\;{\cdot}\;2H_2O$. Optimum culture conditions of agitation and aeration in batch culture were 400 rpm and 1.0 vvm, resulting in 23.1 g/L biomass and 2.5 g/L polysaccharide. Additional feeding of glucose and yeast extract with a pulse mode conferred an advantage on cell growth and polysaccharide production with showing the results of 29.2 g/L and 3.3 g/L, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.460-465
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• 2001

To prepare vinegar using concentration apple juice, response surface methodology (RSM) was applied to optimize and monitor the vinegar fermentation properties by two stage fermentation. In the first stage, the optimum conditions for maximum alcohol contents were 18.56。Brix of initial sugar concentration, 61.96 rpm of agitation rate and 67.32 hr of fermentation time. The optimum condition for maximum acidity in the second stage (vinegar fermentation) were 201.53 rpm of agitation rate and 179.42 hr of fermentation time. Malic acid content was the highest and its content little changed during acetic acid fermentation. Lactic acid content increased a little during alcohol fermentation. Acetic acid content apparently increased during acetic acid fermentation.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.471-474
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• 2006

The Mixer is apparatus that help precipitation or an inhomogeneous distribution of various phases to be mixed and that user makes necessary material mixing one or the other. Mainly the mixer which is used from chemical and food industry is very important system in engineering that mixes the material. The inside flow of the mixer under the actual states which put a basis in flow of the fluid is formed rotation of the impeller. The inside flow of impeller will be caused by various reasons change with shape of impeller, number of rotation, mixing material and flow pattern of free surface etc. Also mixer study depended in single-phase flow and experimental research. So the numerical analysis of flow mixing solid-fluid particle is simulated. It is become known, that the case where agitator inside working fluid includes the solid particle the sinkage reverse which the solid particle has decreases an agitation efficiency. From the research which it sees the hazard solid which examines the effect where the change of the sinkage territory which it follows agitation number of revolution and diameter of the particle goes mad to an agitator inside flow distribution - numerical analysis the inside flow distribution of liquid state with Eulerian Two-Phase Method.

• Korean Journal of Biological Psychiatry
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• v.14 no.1
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• pp.48-54
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• 2007

Objectives : This study aimed to examine the relationship between behavioral and psychological symptoms of dementia(BPSD) and patient and caregiver QOL in Alzheimer's disease(AD). Methods : Fifty-one AD patients and their caregivers participated. Measures about patients were Neuropsychiatric Inventory(NPI), Korean version of QOL-Alzheimer's Disease(KQOL-AD), Activities of Daily Living(ADL), Clinical Dementia Rating(CDR), and Korean version-Mini Mental State Examination(K-MMSE). Caregiver QOL was assessed with KQOL-AD and General Health Questionnaire/Quality of Life-12(GHQ/QOL-12). Results : Patient QOL-AD on patient ratings was negatively correlated with appetite/eating change and NPI scores. Patient QOL-AD on caregiver ratings was negatively correlated with hallucinations, depression/dysphoria, and NPI scores. Caregiver QOL assessed by the GHQ/QOL-12 was negatively correlated with agitation/aggression, depression/dysphoria, and NPI scores and was negatively correlated with distress related to agitation/aggression, depression/dysphoria, and NPI scores. Conclusion : BPSD of AD patients was associated with low QOL of both patients and caregivers. Thus, interventions of BPSD were needed to improve both patient and caregiver QOL.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.5
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• pp.658-665
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• 2002

This paper presents a new winding method in electronic descaling (ED) technology. Conventional ED technology Produces an oscillating electric field via Faraday's law to provide the necessary molecular agitation to dissolve mineral ions. However, the proposed method produces an additional agitation force for mineral ions, called Lorentz's force. Experiments were performed using various Renolds numbers. A series of tests was conducted to measure the pressure drop across the test section and the overall heat transfer coefficient as a function of time. In order to accelerate the rate of fouling, artificial hard water, 1000ppm CaCO$_3$, was used throughout the tests. The results show that the new winding method accelerates the collision of the mineral ions, thereby improving the system efficiency. The present study can develope more effective fouling-removing equipment with change of estabishment method of coil.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.342-348
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• 2001

This study was conducted to obtain granular crystalline gypsum that can be used as raw material for plaster boards or cements from waste Plaster board. We could disintegrate preferentially gypsum to gypsum needle in 10${\mu}{\textrm}{m}$ or less size among the contents of waste plaster board (gypsum, paper, fiber, and inorganic material .etc.) by hydration afterwards the dehydration of crushed waste plaster board. In this case, the optimum conditions for minimizing the size of gypsum were dehydration rate of 75%~ 85%, hydration concentration of 10~20%, agitation speed of 250~400rpm, crushing size of 2cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield from under screenings of 325mesh wet screening which followed by the dehydration-hydration process performed in the conditions of dehydration rate of 80%, hydration concentration of 15%, agitation speed of 300rpm, crushing size of 2cm or less. Subsequently, Plate-like Crystalline gypsum of is 151${\mu}{\textrm}{m}$ size and the grade of 99.49% with the Yield of 98.0% from the upper screenings of 270mesh wet screening carried out after the re-crystallization of the recovered gypsum needle slurry.

• Polymer(Korea)
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• v.28 no.2
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• pp.170-176
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• 2004

The effect of reaction conditions on the size and size distribution of superparamagnetic iron oxide coated with siloxane was big investigated by using dynamic light scattering. The hydrogen bond between the hydroxyl groups on tile surface of the magnetite and silanol was confirmed by FT-IR. The size of nanoparticles increased with the reaction temperature, but decreased with monomer contents and agitation speeds. There was not a big difference in size of nanoparticles, prepared by different reaction conditions, but its distribution was in the range of 14∼41nm. All samples exhibited the superparamagnetic nature. The magnetic susceptibility of the nanoparticles increased with the reaction temperature while it decreased with the monomer content and agitation speed.

• KSBB Journal
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• v.5 no.3
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• pp.307-313
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• 1990

A microcomputer-aided fermentation system was constructed for high density fed-batch culture using dissolved oxygen(DO) as a substrate feeding indicator. DO signal was processed prior to aquisition to computer. Agitation speed and oxygen flow rate was changed stepwisely to maintain DO value at a constant level. Agitation speed was controlled by the output signal of D/A converter. Oxygen flow rate was controlled by a flow rate control valve connected to a stepping motor. Substrate was fed with a feeding pump operated by the abrupt increase of DO signal. Methylobacillus sp. SK1 was cultivated to test the system and 16.53g/l of cell density was obtained after 10 hr.