• New & Renewable Energy
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• v.10 no.1
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• pp.20-29
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• 2014

The present study investigated the effects of thermal pre-treatment on the enhancement of anaerobic biodegradability of waste activated sludge at varied TS concentration levels. The activated sludges were thermally oxidized for 30 minutes at $80{\sim}200^{\circ}C$ with varied TS concentrations (2%, 4% and 6%). and then, sludge characteristics, solubilization efficiency and methane production yield of thermally pre-treated sludges were analyzed. The higher the temperature in the thermal pre-treatment, the higher the concentration levels of dissolved matters such as $SCOD_{Cr}$, $NH_4{^+}$ and VFAs, which indicates that the thermal pre-treatment facilitates the hydrolysis and acid fermentation. Furthermore, the solubilization efficiency was increased in proportion to the temperature rise at all TS concentrations and was reached at 68.9%, 55.6% and 53.1%, respectively, at $200^{\circ}C$. In the BMP test of the pre-treated sludges, higher methane production yields were observed as 0.313. 0.314 and $0.299m^3\;CH_4/kg\;VS_{add}$ at the condition of TS 2% ($160^{\circ}C$), 4% ($160^{\circ}C$) and 6% ($180^{\circ}C$), respectively, and degradation rate was increased by 84%, 79% and 65% compared with non-pretreated waste activated sludge. These findings suggest the effectiveness of thermal pre-treatment of waste activated sludge for anaerobic biodegradable process.

• Fibers and Polymers
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• v.6 no.2
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• pp.169-173
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• 2005

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabric properties including low-stress mechanical properties, air permeability and thermal properties, were evaluated. The low-stress mechanical properties were evaluated by means of Kawabata Evaluation System Fabric (KES-F) revealing that the tensile, shearing, bending, compression and surface properties were altered after the LTP treatment. The changes in these properties are believed to be related closely to the inter-fiber and inter-yam frictional force induced by the LTP. The decrease in the air permeability of the LTP-treated wool fabric was found to be probably due to the plasma action effect on increasing in the fabric thickness and a change in fabric surface morphology. The change in the thermal properties of the LTP-treated wool fabric was in good agreement with the above findings and can be attributed to the amount of air trapped between the yams and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric.

• Journal of the Korean Burn Society
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• v.23 no.2
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• pp.64-67
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• 2020

High-intensity focused ultrasound (HIFU) has been regarded as a non-invasive uterine-preserving treatment for women with uterine myoma. Numerous studies have reported that it is a relatively safe and effective treatment for uterine myoma. However, severe complications, such as deep thermal burn injuries, bowel perforation, and bladder injury, were reported on rare occasions. We report a case of a 4th degree burn on the lower abdomen after HIFU treatment for uterine myoma. Physicians must consider the possibility of deep thermal burn injuries when managing uterine myoma with HIFU.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.273-282
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• 2020

PURPOSE. To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS. Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). RESULTS. The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION. Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

• The Journal of Advanced Prosthodontics
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• v.9 no.5
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• pp.364-370
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• 2017

PURPOSE. To explore the influence of different surface conditionings on surface changes and the influence of surface treatments and aging on the bond strengths of composites to non-aged and aged resin nanoceramics. MATERIALS AND METHODS. Rectangular-shaped non-aged and aged (5000 thermocycles) resin nanoceramic specimens (Lava Ultimate) (n=63, each) were divided into 3 groups according to surface treatments (untreated, air abrasion, or silica coating) (n=21). The surface roughness was measured and scanning electron microscopy was used to examine one specimen from each group. Afterwards, the specimens were repaired with a composite resin (Filtek Z550) and half were sent for aging (5000 thermocycles, n=10, each). Shear bond strengths and failure types were evaluated. Roughness and bond strength were investigated by two- and three-way analysis of variance, respectively. The correlation between the roughness and bond strength was investigated by Pearson's correlation test. RESULTS. Surface-treated samples had higher roughness compared with the untreated specimens (P=.000). For the non-aged resin nanoceramic groups, aging was a significant factor for bond strength; for the aged resin nanoceramic groups, surface treatment and aging were significant factors. The failures were mostly adhesive after thermal cycling, except in the non-aged untreated group and the aged air-abraded group, which had mostly mixed failures. Roughness and bond strength were positively correlated (P=.003). CONCLUSION. Surface treatment is not required for the repair of non-aged resin nanoceramic; for the repair of aged resin nanoceramic restorations, air abrasion is recommended.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.2
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• pp.66-73
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• 2022

Partial-hardened hot stamping has been well known to be very effective to absorb more energy in automotive lateral crash. Hardness distribution and dimensional change after partial-hardened hot stamping have been studied to find out effect of thermal deformation of the heated hot stamping die on dimensional accuracy of automotive center pillar. Soft zone of commercial center pillar showed 275~345 in Vickers hardness, indicating bigger non-uniformity which resulted from thermal deformation of heated die. Dimensional changes in soft zone of the commercial center pillar measured by three dimensional scanner were much bigger than that in hard zone. It has been found that hot stamping die compensation considering thermal deformation in soft zone causes a significant decrease in hardness deviation in the soft zone, corresponding to 20 percent of commercial center pillar and subsequently leads to much higher dimensional accuracy.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.477-485
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• 2017

Novel, effective methods to control and prevent spoilage and contamination by pathogenic microorganisms in meat and meat products are in constant demand. Non-thermal pasteurization is an ideal method for the preservation of meat and meat products because it does not use heat during the pasteurization process. Atmospheric pressure cold plasma (APCP) is a new technology for the non-thermal pasteurization of meat and meat products. Several recent studies have shown that APCP treatment reduces the number of pathogenic microorganisms in meat and meat products. Furthermore, APCP treatment can be used to generate nitrite, which is an essential component of the curing process. Here, we introduce the effectiveness of APCP treatment as a pasteurization method and/or curing process for use in the meat and meat product processing industry.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.602-607
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• 2001

Zirconia powder containing 3 mol% yttria (3Y-PSZ) was casted on the cast iron substrate by plasma spraying method. Coated specimens were then heat treated at 500$\^{C}$ in nitrogen plasma. Wear tests were performed on nitrogen heat treated and non heat treated samples at temperatures from 25$\^{C}$ to 600$\^{C}$. Wear results showed that the friction coefficient and the wear loss of both the treated and the non-treated samples showed maximum value at 400$\^{C}$. These results were explained by low temperature thermal degradation due to the monoclinic transformation. Nitrogen plasma treatment significantly improved the tribological performance. The effect of nitrogen heat treatment on tribological behavior was explained by the increased micro-hardness and decreased monoclinic faction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.910-916
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• 2022

The purpose of this study is to evaluate the effect of underwater non-thermal dielectric barrier discharge plasma (DBD plasma) on the sterilization of three types of pathogenic bacteria that cause diseases in freshwater fish and the reduction of a tetracycline antibiotics. This experiment was conducted in the DBD plasma generator, and the voltages used to generate plasma were 11.6 kV and 23.1 kV. The measurement intervals were 0, 1, 5, 10 and 15 min. As a result of DBD plasma treatment, Aeromonas hydrophila, Edwardsiella tarda and Pseudomonas fluorescens were removed 93-99% after 5 min at 23.1 kV, and the tetracycline antibiotics were reduced 70-95% after 15 min at 23.1 kV. In this study, as a result of treating the effluent with DBD plasma at a fish farm where the medicinal bath was conducted with oxytetracycline-HCl (OTC-HCl) products, OTC-HCl decreased by 62% after 10 min at 23.1 kV.

• Journal of Technologic Dentistry
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• v.9 no.1
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• pp.39-49
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• 1987

This study done to evaluate some surface treatment methods in metal coping which can increase the bond strength between porcelain and metal. Therefore this experiment was performed according to the Mc Lean's Theory of bond strength between porcelain and strength between porcelain and metal. In the experiment the author measured respective thermal expansion coefficents in three types of metal(Tallasium, Vera Bond and Rexillium) and Vita Porcelain to get the differences in the coefficents between porcelain and metals. And using insteron testing machine, the author also performed Planar interface shear bond tests on the 45 specimens(15 specimens in oxide surface, rough surface and fine surface treatment methods respectively) to measure bond strength between metal and porcelain. The results Were as follows, 1. The differences in thermal expansion coefficients between three types of metal and Vita procelain: Talladium - $1.2\;10^{-6/0}\;C$, Vera Bond - $1.6\;10^{-6/0}\;C$, Rexillium - $1.9\;10^{-6/0}\;C$. 2. The bond strength in oxide surface on the Shear bond test was the lowest among the treatment methods. 3. There was no significant differences in treatment methods of rough surface of fine surface. 4. In the oxide surface treatment method, there were significant differences(P<0.05)between Vera bond and Rexillium, and between Talladium and Rexillium. 5. In the fine surface treatment, there was a significant difference(P<0.05)between Talladium and Rexillium.