• Journal of Environmental Science International
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• v.23 no.1
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• pp.97-104
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• 2014

The sludge flotation/thickening apparatus equipped a micro-bubble generating pump was used to investigate micro-bubble generating properties on operational parameters. We evaluated micro-bubble generating properties as results to be operated the apparatus by operational parameters which are pump discharge pressure, air/water ratio(A/W ratio), air flow rate, and water flow rate. Micro-bubble generating efficiencies in pumps without recycling flow and with 50% of recycling flow was found to be very efficient on optimum A/W ratio from 1.06 to 3.62% and optimum A/W ratio from 1.05 to 4.06%, respectively. In condition of 3.6% of A/W ratio, we showed that the apparatus could be generated 36,000 ppm of micro-bubble concentration to be optimum treatment efficiency in sludge thickening process.

• Culinary science and hospitality research
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• v.13 no.3
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• pp.44-53
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• 2007

This study investigated the utilization of pumpkin cream soup mixture of pumpkin P1(sweet pumpkin 25%, pumpkin 75%), and S1(rice flour 100%) and S3(rice powder 50%, glutinous rice powder 50%) as thickening agents showed highest preference for pumpkin cream soup. Rice powder was used in pumpkin cream soup as a thickening agent. Hunter's color marked the lowest value in using group of flour roux, in contrast with the highest value in using glutinous rice powder roux. The results of viscosity were diverse according to the condition of relationships between the percentage of contents flour, rice and glutinous rice control. For the sensory evaluation, parameters such as appearance, color, viscosity and savory taste increased significantly from the control at glutinous rice roux, and overall acceptability marked the lowest result in flour roux control.

• Transactions of Materials Processing
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• v.25 no.4
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• pp.227-234
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• 2016

In the transportation between countries using container, too many empty containers must be transported due to the transportation unbalance. For transportation efficiency, therefore, foldable containers are being developed. Hinge brackets are important parts of foldable containers because great force is applied on the hinges during loading onto and unloading from ships. In this study, the hinge bracket for a foldable container is designed to be made using thick plate or bulk materials to endure the heavy loads. The forming process for the hinge bracket using a thick plate is designed via numerical analysis. First of all, the shape of bracket is designed for the better formability. Bending and successive side wall thickening processes are employed for the forming of the hinge bracket. Maximum thickening that can be achieved in a single stage of forming without a folding defect is determined and three stage of thickening processes are designed.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.743-748
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• 2009

Chemical sludge conditioning is widely used to improve the dewatering efficiency. It is treated with commonly used conditioners, and then thickened and dewatered with a mechanical device. This paper aims to examine the flotation and thickening efficiencies of sewage sludge for conditioning conditions, such as unaerobic storage time, kinds of coagulant and dosages, and flotation conditions, such as sludge concentration and A/S ratio, using an dissolved air flotation apparatus. Experimental results showed that the specific surface area and specific resistance to filtration (SRF) were significantly increased and the flotation and thickening efficiencies were decreased with anaerobic storage time. However, the flotation and thickening efficiencies faintly decreased in sewage sludges conditioned as $Al_2(SO_4)_3$, $Fe_2(SO_4)_3$, and PSO-M. Flotation and thickening efficiencies in conditioned sewage sludge could be sustained up to 96% at A/S ratio of 0.01 mL/mg or over.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.568-574
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• 2004

In order to seek the possibility of using rice flour and potato as thickening agent instead of roux, sensory evaluations of cream soups manufactured from 3 different thickening agents were conducted. The viscosity, moisture and lipid contents, and the color affecting the quality of the soup were investigated. The results were as follows: 1. As thickening agents for 200g of the cream soups, rice flour and potatoes at 20.5 and 20g, respectively, were needed in order to make soup with a similar concentration to that manufactured using 20g of roux. 2. In the sensory tests, the soup made with rice flour had the most preferred overall acceptability, with a significantly preferable taste. The soup made with rice flour had the strongest whiteness and savory taste, but that made with roux had the strongest viscosity and smooth feeling in the mouth feel. There was no difference between the samples with regard to nutty flavor. The whiteness, palatability, viscosity and smooth feel sensory properties were positively correlated with the overall acceptability. Among these properties, the palatability showed the highest correlation (r=0.538) with overall preference. 3. The cream soup made using potatoes as the thickening agent had a $76.20\%$ water content, whereas those made with rice flour and roux had 73.00 and $64.00\%$ respectively The fat content of the cream soup made with roux was $10.24\%$, which was twice as high as those of the rice flour and potato soups. 4. Among the 3 kinds of cream soup, the one made with rice flour had the whitest color.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.6
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• pp.800-808
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• 2005

It is required to propose an alternatives for appropriate sludge treatment owing to persistent construction of sewage treatment plant and increase of sewage sludge quantity. In order to treat sludge more efficiently, the methods which reduce the cost of sludge treatment have been studied such as sludge reduction and conditioning. Especially ozone treatment reduces solid quantity and improves separation of solid-liquid at the same time. Therefore ozone treatment have a positive effect on reduction and stabilization of sludge. So, this study applied ozone to sewage sludge and induced cell destruction of sludge. By comparing with the correlation between thickening and dewatering, and evaluating moisture content and solubilization of cake, this study verificates the effect of process improvement for ozone pre-treatment. In J-STP case, according to ozone dose solid flux increased about 12 times from $1kg/m^2{\cdot}h$ to $12kg/m^2{\cdot}h$. Also this plant were capable to shorten thickening time from 40 minutes to 6~7 minutes. Thus it is expected to reduce volume and retention time of thickener. On pH effect factor, dewatering at pH4 was more than at pH11, $3.05{\times}10^{11}$ and $3.82{\times}10^{11}(m/kg)$. But effect of pH was analogous to ozone, $2.81{\times}10^{11}(m/kg)$. The effect of pH on thickening was similar to law sludge, $0.68(kg/m^2{\cdot}h)$, and the effect of ozone injection on thickening was the biggest, $3.45(kg/m^2{\cdot}h)$. The COD solubilization rate improved from about 5 to 30%. So it is judged that we are able to utilize most solubilized sludge to another sewage treatment plants.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.9-19
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• 1998

Laboratory experiments were carried out to investigate the performance of anaerobic sequencing batch reactor(ASBR) for digestion of a municipal sludge. Each cycle of the ASBR comprised feeding, two-or three-day reaction, one-day thickening, and withdrawal. The reactors were operated at an HRT of 10days and 5days with an equivalent organic loading rate of 0.8-1.54 gVS/l/d, 1.81-3.56 gVS/l/d at 35$\circ$C, respectively. Solids accumulation was remarkable in the ASBR during start-up period, and directly affected by settleable solids in the feed sludge. Floatation thickening occured in the ASBRs, and Solids profiles at the end of thickening step dramatically changed at solid-liquid interface. Slight difference in solids concentrations was observed within thickened sludge bed. Efficiencies through floatation thickening were comparable to that of additional thickening of the completely mixed control reactor. Average solids concentrations in the ASBRs were 2.2-2.6 times higher than that in the control throughout the total operation period. The dehydrogenase activity had a strong correlation with the solids concentration. Organics removals based on clarified effluent of the ASBRs were consistently above 86%. Remarkable increase in equivalent gas production of 27-52% was observed at the ASBRs compared with the control though the control and ASBRs showed similiar effluent quality. Thus, digestion of a municipal sludge was possible using the ASBR in spite of high concentration of solids in the sludge.

• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.77-85
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• 2002

The objective of this study was to evaluate the performances of the ASBR under critical conditions of solid-liquid separation, caused by extremely high solids concentration, for wider application of the ASBR to various wastes. The ASBRs and completely-mixed daily-fed control runs were operated using a municipal mixed sludge at 35$^{\circ}C$ and 55$^{\circ}C$. Conversion of completely-mixed daily-fed reactor to sequencing batch mode and changes in HRT of all ASBRs were easily achieved without adverse effect, regardless of digestion temperature. Solids accumulation was remarkable in the ASBRs, and directly affected by settleable solids concentration of the feed sludge. Noticeable difference in solids-liquid separation was that flotation thickening occurred in the mesophilic ASBRs, while gravity thickening was a predominant solid-liquid separation process in the thermophilic ASBRS. Solids profiles at the end of thickening step dramatically changed at solid-liquid interface, and slight difference in solids concentrations was observed within thickened sludge bed. Organics removals based on subnatant or supernatant after thickening always exceeded 80% in all reactors. Thickened sludge volume and gas production of the ASBRs affected mutually. Gas production increased as thickened sludge accumulated, and continuous gas evolution during thickening could cause thickened sludge to expand or resuspend. Thickened sludge volume exceeding a predetermined withdrawal level resulted in loss of organic solids as well as biomass during withdrawal step, leading to decrease in gas production ind SRT. Such an adverse mutual effect was significant in gravity thickening, while it was not sensitive in flotation thickening. Changes in organic loading had no significant effect on organic removals and gas production after build-up of solids in the ASBRs.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.607-614
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• 2001

Background : Residual pleural thickening is frequently seen following treatment for tuberculous pleurisy, and pleural decortication is performed occasionally in patients with severe residual pleural thickening. However, predictive factors for the development of residual pleural thickening are uncertain at the initial diagnosis of the tuberculous pleurisy. Therefore, the purpose of this study was to identify the associated factors for residual pleural thickening at initial diagnosis. Methods : We separated 63 patients diagnosed as tuberculous pleurisy into two groups; group 1 consisted of patients without residual pleural thickening and group 2 comprised patients with residual pleural thickening at the end of tuberculous pleurisy treatment. We analyzed the clinical characteristics, radiological findings, pleural biopsy and characteristics of pleural fluid between group 1 and group 2. Results : The study population and clinical symptoms of the two groups were not significantly different and the duration of symptoms before treatment and the peripheral WBC were similar between the two groups. The presence of pulmonary tuberculosis, pleural fluid loculation or the amount of pleural effusion sid not differ significantly between the two groups. The incidence of positive AFB staining(group 1 : 8%, group 2 : 38%) and granuloma(group 1 : 30%, group 2: 62%)on pleural biopsy specimens was significantly higher in group 2 than in group 1. Pleural fluid WBC and differential count, adenosine deaminase level, pH, protein level or glucose level did not differ between the two groups. However, group 2 had higher LDH levels ($1370{\pm}208mg/dL$) than group 1 ($860{\pm}71mg/dL$, p<0.05). Conclusion : In tuberculous pleurisy, patients with residual pleural thickening following treatment demonstrated a higher incidence of positive AFB staining and granuloma on the pleural biopsy specimens or higher LDH level in the pleural fluid than patients without residual pleural thickening From these results, we speculate that the amount of tuberculous bacilli and granuloma are probably correlated with residual pleural thickening in the tuberculous pleurisy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.129-130
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• 2009