• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.165-170
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• 2005

A basic study for the development of a disk type oil skimmer for a tank lorry, compares via experiments to the oil recovery differences by material between the existing oil skimmer disk and several discs which oil adhesion are possible. The experiment results in this study are summarized as follows: In all the disks, the mass of recovery of bunker-A oil was greater than light oil. In light oil, there was nearly no differences in the mass of oil recovery by disk material, but in the case of bunker A oil, recovery efficiency showed big differences depending on the disk materials. For light oil, the differences in the mass of oil recovery per unit of operation time from the initial time zone were hardly shown. However, the mass of recovery of bunker-A oil linearly increased from the initial operation time in all the disks and the increase shaped a slow moving trend as time went on; therefore, the mass of oil recovery per unit of operation time showed differences depending on time. This result shows that oil viscosity has an effect on the disk recovery efficiency. When comparing the mass of pure oil recovery and the mass of water recovery in the total mass of recovery by bunker-A oil, there was no difference in the mass of oil recovery between the window-aluminum material disk and the disks consisting of other materials, but the mass of water recovery of the former was relatively very small. This shows the most ideal result in view of oil recovery efficiency that considers the mass of water recovery. In conclusion, it was found that aluminum is the most advantageous as the material for tank lorry oil skimmer disk.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.690-696
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• 2003

This paper presents the heat recovery performance of water fluidized-bed heat exchanger. Temperature and humidity ratio of waste gas are considered as important parameters in this study. Therefore, the heat recovery rate through water fluidized-bed heat exchanger for exhaust gases with various temperatures and humidity ratios can be estimated from the results of this study. Mass flow ratio (the ratio of mass flow rate of water to that of gas) and temperature of inlet water are also considered as important operating variables. Increase of heat recovery rate can be obtained through either high mass flow ratio or low temperature of inlet water with resultant low recovered temperature. The heat recovery performance with the mass flow ratio of about up to 10 has been investigated. The effect of number of stages of water fluidized-bed on the heat recovery performance has been also examined in this study.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.312-316
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• 2004

Single-well tracer tests, especially push pull tracer tests, are more effective to estimate hydraulic parameters and microbial metabolic activities in terms of duration and cost compared to multi-well tracer tests. However, there are some drawbacks in accuracy, complicated data analysis and uniqueness. These shortages are thought to be derived from the applied conditions which affect mass recovery curve and breakthrough curve. Factors such as extraction rate, resting period, hydraulic conductivity and hydraulic gradient are considered as the major factors determining the mass recovery rate and shape of the breakthrough curve. The results of the sensitivity analysis are summarized as follows: 1) the significant change in concentration of breakthrough curve is obtained when the extraction rate increases. This effect would also be much higher if the hydraulic conductivity is lower; 2) the mass recovery rate decreases with the increase of resting time, and the difference of mass recovery rates for different resting times is inversely proportional to the hydraulic conductivity; 3) the sensitivity values decrease with time. The hydraulic conductivity affects not only the early period, but the later period of the breakthrough curves; 4) The influence of the hydraulic gradient on the breakthrough curves is greater at earlier stage than at later stage. The mass recovery rate is inversely proportional to the hydraulic gradient.

• Journal of Korean Academy of Nursing
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• v.21 no.3
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• pp.281-294
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• 1991

The purpose of this study was to determine the amount of soleus muscle atrophy in rats due to 28 days of decreased activity induced by hindlimb suspension, to observe the restoration of mass and relative muscle weight of the atrophied soleus muscle at day 28 of recovery to control value, and to compare the effect of run training on the mass and relative muscle weight of the atrophied soleus muscle at day 28 of recovery with that of sedentary rats. Adult female Wistar rats were maintained for 28 days with hindlimb suspension. Rats were then assigned randomly to a cage sedentary or running group. Soleus muscle mass and relative muscle weight following hindlimb suspension were compared with a control value. The soleus muscle mass and relative muscle weight of the running and cage sedentary groups following hindlimb suspension were compared with those of a control group. Soleus muscle mass and relative muscle weight of the run training group were compared with those of cage sedentary group. The results obtained were as follows : 1. Soleus muscle mass and relative muscle weight was reduced to 53.28% and 51.11% respectively by hindlimb suspension. 2. Soleus muscle mass and relative muscle weight of the training group t day 28 of recovery was restored to the control value. 3. Soleus muscle mass of the training group was greater than that of the cage sedentary group by 6.6% without statistical significance at day 28 of recovery. 4. Relative soleus muscle weight of the traning group was significantly greater than that of the cage sedentary group by 15.79% From these results, it may be concluded that run training during the posthypokinetic period facilitates the recovery of the atrophied soleus muscle mass of rats.

• Mass Spectrometry Letters
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• v.5 no.1
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• pp.30-33
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• 2014

A solid phase extraction (SPE) method was optimized for the quantitative analysis of perfluorooctanoic acid (PFOA) in serum using hydrophilic-lipophilic balance SPE and LC-MS/MS. Fetal bovine serums spiked with $^{13}C_8$-PFOA before or after SPE were used as test samples for evaluation of the SPE efficiency. Simultaneous evaluation of matrix effects and absolute SPE recovery for $^{13}C_8$-PFOA in serum using different sample pre-treatments and SPE conditions allowed optimization of SPE process efficiency with minimal matrix effect and decent SPE recovery. Introduction of protein precipitation as a sample pre-treatment procedure for serum samples before SPE generally decreased matrix effect in LC-MS/MS analysis and provided more stable recovery of PFOA.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.2
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• pp.73-81
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• 2003

The performance of heat exchanger using oscillating heat pipe (OHP) for low temperature waste heat recovery was evaluated. OHP used in this study was made from low finned copper tubes connected by many turns to become the closed loop of serpentine structure. The OHP heat exchanger was formed into shell and tube type. R-22 and R-141b were used as the working fluids of OHP with a fill ratio of 40 vol.%. Water was used as the working fluid of shell side. As the experimental parameters, the inlet temperature difference between heating and cooling water and the mass velocity of water were changed. The mass velocity of water was changed from 30 kg/$m^2$s to 92 kg/$m^2$s. The experimental results showed that the heat recovery rate linearly increased as the mass velocity and the inlet temperature difference of water increased. Finally, the performance of OHP heat exchanger was evaluated by $\varepsilon$-NTU method. It was found that the effectiveness would be 80% if NTU were about 1.5.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.368-376
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• 2001

Performance of heat exchanger was evaluated to heat exchanger using oscillating heat pipe for waste heat recovery of low temperature. Oscillating heat pipe used in this study was formed to the closed loop of serpentine shapes using copper tubes. Heat exchanger was formed to shell and tube type and composed of low finned tube. R-22 and R-141b were used to the working fluids of tube side and their charging ratio was 40%. And, water was used to the working fluid of shell side. As the experimental parameters, the inlet temperature difference of heating and cooling part of secondary fluid and the mass velocity of secondary fluid were used. The mass velocity of secondary fluid was changed from 90 kg/$m^2s\; to\;190 kg/m^2$s from the experimental results, heat recovery rate was linearly increased to the increment of the mass velocity of secondary fluid and the inlet temperature difference of secondary fluid. Finally, the performance of heat exchanger was evaluated by using $\varepsilon$-NTU method. It was found that NTU was about 1.5 when effectiveness was decided to 80%.

• New & Renewable Energy
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• v.18 no.2
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• pp.82-89
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• 2022

In this study, the exergy characteristics were analyzed, according to the mass flow rate of the propane working fluid and the pressure change in the turbine inlet, for the efficient recovery of cold energy and exhaust heat by the waste energy recovery system applied to the LNG FSRU regasification process. When the turbine inlet pressure and mass flow rate of the Primary Rankine Cycle were kept constant, the exergy efficiency and the net power increased. This occurred as the turbine inlet pressure and the mass flow rate of the working fluid increased in the Secondary Rankine Cycle, respectively, and the maximum values were confirmed. In this regard, the fluctuations in the exergy rate flowing into and out of the system and the exergy rate destroyed by pumps, evaporators, turbines, and LNG heat exchangers (condensers) were examined in detail.

• Journal of the Korean institute of surface engineering
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• v.14 no.4
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• pp.209-214
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• 1981

Electrolytic recovery of gold and silver from diluted solutions has at first been applied nearly 100 years ago. Compared with other recovery techniques electrolytic treatment offers several advantages. But to achieve high space-time yields special constructions of electrolytic cells for improved mass transfer are necessary. Ex-tended cathode surface areas and vigorous agitation are important features. Gold and silver recovery by use of newly developed electrolytic cell constructions - rotating tubular bed reactor and impact rod reactor - has been described. Calculations based on industrial application during several years are confirming that electrolytic recovery of precious metalss from diluted solutions has been operated in a very economic way.

• Environmental Analysis Health and Toxicology
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• v.16 no.3
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.