• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.101-111
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• 2014

In this study the effect of heartwood-coating (HCO), vapor-dam (VD), bark-remaining (BR) and bark-remaining-coating (BRC) treatments on the air circulating oven-drying characteristics of Japanese larch hollowed round-post was evaluated. The drying times of the hollowed round-posts for control, VD, HCO and BR specimens were 72, 168, 204 and 240 hours, respectively, from the initial MC to about 8% MC, which was recommended as the indoor in-use MC. The temperature in the hole of the VD specimen was lower than that of wood and the difference between air temperature in the hole and wood temperature became large during drying period. The vapor pressure of air in the hole was higher than that of inside wood for all specimens except VD specimen. The surface checks on all specimens were observed in increasing order of BR, BRC, UC, HCO and VD specimens.

• Environmental Engineering Research
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• v.23 no.3
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• pp.258-264
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• 2018

The objectives of this research were to 1) isolate and identify thermophilic bacteria for food waste treatment; 2) investigate the capability of food waste treatment using Bacillus species; and 3) develop air-dried Bacillus starters for food waste treatment. Five Bacillus species were isolated from food wastes and identified as Bacillus licheniformis (B. licheniformis) G1, Bacillus circulans C2, Bacillus subtilis (B. subtilis) E1, Bacillus vanillea F1, and Bacillus atrophaeus G2 based on 16S rDNA sequencing. Each identified Bacillus and the mixture of Bacillus species were cultivated in the standard food waste at $45^{\circ}C$ for 8 d. Changes in cell count, solid contents, and pH of the food waste were monitored during cultivation. Air-dried Bacillus cell powders were prepared using wheat flour and lactomil as excipients, and the cell count and survival rate were determined. The cell count of B. licheniformis G1 exhibited the highest number among the tested Bacillus (${\sim}10^8CFU/mL$). The greatest reduction in solid contents of food waste was achieved by B. subtilis E1 (22.6%). The mixture of B. licheniformis G1 and B. subtilis E1 exhibited a synergistic effect on the reduction of solid contents. Lactomil was determined as better excipient than wheat flour based on the greatest survival rate of 95%.

• Advances in pediatric surgery
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• v.16 no.2
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• pp.108-116
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• 2010

Air reduction is a safe, effective, and fast initial treatment for pediatric intussusception. There is low dose radiation exposure. Factors affecting outcomes of air reduction were analyzed by reviewing the clinical features and results of treatment. A total of 399 out of 485 patients with pediatric intussusceptions were treated at the Seoul National University Children's Hospital from 1996 to 2009. All of the patients received air reduction as the first line of treatment. Clinical features such as gender, age, seasonal variation, symptoms, signs, types, pathologic leading point, and treatment results including success rate, complication, recurrence, NPO time, and duration of hospitalization were reviewed. The Pearson chi-square, student T-, and logistic regression tests were used for statistical analysis. P-value less than 0.05 was considered to be statistically significant. The prevalent clinical features were: male (65.4 %), under one-year of age (40.3 %), ileocolic type (71.9 %), abdominal pain (85.4 %), and accompanying mesentery lymph node enlargement (2.2 %). The overall success rate for air reduction was 78.4 % (313 of 399 patients), and the perforation rate during reduction was 1.5 %. There were 23 recurrent cases over 21.6 months. All were successfully treated with re-do air reduction. Reduction failures had longer overall NPO times (27.067hrs vs. 43.0588hrs; p=0.000) and hospitalization durations (1.738d vs. 6.975d; p=0.000) compared to the successful cases. The factors affecting success rates were fever (p=0.002), abdominal distension (p=0.000), lethargy (p=0.000) and symptom duration (p=0.000) on univariate analysis. Failure rates were higher in patients with symptom durations greater than 24 hours (p=0.023), and lethargy (p=0.003) on multivariate analysis. Air reduction showed high success rates and excellent treatment outcomes as the initial treatment for pediatric intussusception in this study. Symptom duration and lethargy were significantly associated with reduced success rates.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.474-484
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• 2005

Biological treatment is a promising alternative to conventional air pollution control methods. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing volatile organic compounds and odor compounds. They offer several advantages over traditional technologies such as incineration or adsorption. These include lower treatment costs, absence of formation of secondary pollutants, no spent chemicals, low energy demand and low temperature treatment. The most widely used bioreactor for air pollution control is biofilter, but it has several limitations. In the past years major progress has been accomplished in the development of vapor phase bioreactor, in particular biotrickling filters. Biotrickling filters are more complex than biofilters, but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. While the level of understanding of biotrickling filtration process for VOCs still remains limited, the evident success of biotreatment of VOC in air stimulated the pursue of acitve research. This paper presents fundamental and theoretical/practical aspect of air pollution control in biotrickling filter. Special emphasis is given to the operating parameters and the factors influencing performance for air pollution control in biotrickling filter.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.511-519
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• 2022

In order to develop an air-stripping based remediation process to remove the TOC (Total Organic Carbon) in groundwater around the underground LPG storage cavern, the laboratory scale experiments at various conditions (change of air injection volume and temperature, the application of ultrasonic treatment, etc.) for two types of groundwater (initial TOC concentration of 608 mg/L and 153 mg/L, respectively). From results of experiment, as the air injection rate for stripping into groundwater increased from 2 L/min to 11 L/min and as the air-stripping time increased from 1 hour to 24 hour, the TOC removal efficiency of air-stripping increased. However, the TOC concentration of treated groundwater was higher than the discharge tolerance limit (100 mg/L) even after 24 hour stripping at the maximum air injection rate of 11 L/min. The main compounds of the TOC in groundwater were identified as methanol and propane and the long stripping time (more than 24 hour) was needed to separate the methanol from groundwater because of the affinity between water and methanol. At 20℃ and 4 L/min of air injection, the TOC removal efficiency increased to 59.1% after 24 hour air-stripping. When the temperature of groundwater increased to 30℃ and 40℃, the TOC removal efficiency increased up to 80.0% and 82.8%, suggesting that more than 24 hour air-stripping at 40℃ is needed to lower the TOC concentration to below 100 mg/L and the additional TOC removal process as well as the air-stripping is necessary. When the temperature increased to 60℃ and the ultrasonic treatment was conjugated with the air-stripping, the TOC removal efficiency increased to 87.8% within 5 hour stripping and the final TOC concentration (72.4 mg/L) was satisfied with the TOC discharge tolerance limit. The TOC removal efficiency for groundwater having low TOC concentration (153 mg/L) also showed similar removal efficiency of 89.7% (the final TOC concentration: 18.9 mg/L). Results in this study supported that the air-stripping conjugated with the ultrasonic treatment could remove successfully the TOC in groundwater around the underground LPG strorage cavern.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.4
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• pp.53-60
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• 1991

This study has been performed to investigate into the internal oxidation characteristics of low carbon steel with respect to the added amount of air in nitrogen-propane atmosphere after gas carburizing for various times at $930^{\circ}C$. The results obtained from the experiment are as follows ; (1) Optical micrographs have shown that the internal oxidation is unlikely to occur in the gas atmosphere without air and that oxidized zone in the outer surface layer is formed in the gas atmosphere with air revealing that the depth of oxidized zone increases with increasing the added amount of air. (2) The formation of internally oxidized zone in the outer surface layer has been found to be inhibited as Ni content increases, i. e, the amount of alloying element increases. (3) The depth of oxidation has been measured to increase with almost parabolically gas carburizing time of up to 6 hours.

• Journal of Korean Neurosurgical Society
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• v.42 no.6
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• pp.490-491
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• 2007

Air within the spinal canal called pneumorrhachis has been seen rarely. We report a case showing multiple air pockets in the paraspinal and epidural space with vacuum disc and review pathogenesis and treatment of pneumorrhachis.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.659-666
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• 2011

Although DAF(Dissolved Air Flotation) has been successfully accepted for water and wastewater treatment, the fundamental characteristics of the process have not been fully investigated. Water is saturated with compressed air to dissolve the air into the water at high pressure in saturation tank. Then the water containing dissolved air is released into a floatation tank at a lower pressure, generating micro-bubbles that rise gently through the water and carry the suspended matter to the surface. This study investigated the removal of sewage using automatic mixture type DAF pump and non-powered flotation tank. Characteristics of two devices were compared and analyzed with samples. The results showed that the PAC exhibited higher performance than other coagulants. When air dosage was 2.5ml/l/min, treatment was stable in operation. In the DAF pump with a pressure of 4 atm., the average size of bubbles was 36.2${\mu}m$. Removal efficiency of SS was 80%. At this time removal efficiency of COD was about 80%, of T-N was 30% and T-P was 70% in stable operation. It was concluded that DAF pump system with micro bubble performed higher efficiencies compared to general DAF system for treating wastewater.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.80-86
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• 2023

We report two rare cases of extensive bilateral subcutaneous emphysema that occurred during ordinary dental procedures. An air-driven high-speed handpiece, routinely used in dental procedures may cause subcutaneous emphysema when high pressure air is introduced into the loose connective tissues below the dermal layer. The first case occurred with surgical extraction of the lower third molar. The air introduced into the fascial spaces near the surgical field spread to the contralateral spaces, as well as the neck and chest areas. The second case also showed extensive bilateral subcutaneous emphysema caused by the introduction of compressed air from the handpiece during crown preparation without any invasive procedure. Cases where the emphysema extends beyond the treatment site to involve the contralateral cervicofacial areas have been rarely reported. Predicting the occurrence of subcutaneous emphysema is difficult, so it is important to exercise caution during routine dental treatment. If significant bilateral cervicofacial swelling is suspected to be due to subcutaneous emphysema, prompt diagnosis with securing the patient's airway will be necessary.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.493-501
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• 2004

The principle of vortex tube and cyclone was introduced to enhance the treatment efficiency of waste air streams containing particulate matters, toluene, and others developed by Hangreen Tech, Ltd. and Hoseo Chemical and Industrial Technology R＆D Center. Adsorption, condensation, and/or coagulation could be induced at low temperature zone formed by vortex tube and Joule-Thomson expansion. The pressurized air was introduced at the tangential direction into the cyclone system applied with the coaxial funnel tube. Easily condensible vapors such as toluene. carbon dioxide, and water vapor were adsorbed enforcedly on coagulated or condensed materials which were formed as cores for coagulation or condensation by themselves. These types of coagulation or condensation rates were rapidly promoted as the diameter being growing up. The maximum removal efficiency for carbon dioxide and toluene was achieved to about 87 and 90 percent, respectively. The Joule-Thomson coefficients were increased with the pressure of air injected in the range of the relative humidities between 10% and 30%. An optimum value was observed within the range of the tested temperatures at a fixed pressure. In conclusion. it could be identified that the treatment efficiency would be depended on the pressure of the process air introduced and physical and chemical characteristics of waste air streams containing target materials for a designed system. The final design parameters should be decided depending upon the given system and target materials.