• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.295-302
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• 2021

Surface modification of recycled plastic film-based aggregates is demonstrated to enhance the interaction between aggregates and cement paste. It is shown that the oxygen(O₂) atmospheric pressure plasma(APP) treatment leads to a drastic increase in hydrophilicity. In case of the plasma treatment at 100W of RF power, 15/4sccm of O₂/Ar flow rate and 30sec of discharging time, the water contact angle on the aggregates surface decreased from 104.5° to 44.0°. In addition, the contact angle of surface modified aggregates kept in air increased with time elapse. Improvement of hydrophilicity can be explained by the formation of new hydrophilic oxygen functional groups which is identified as C-OH, C-O-C, C=O, -COOH by X-ray photoelectron spectroscopy(XPS) analysis and Fourier-transform infrared spectroscopy(FT-IR). Therefore, it can be concluded that the plasma treatment process is an effective method to improve adhesion of the recycled plastic film-based aggregates and cement paste.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.547-555
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• 2009

This study was performed to determine the minimum dose of Poloxamer/Sodium alginate (PX/SA) mixture on preventing intraperitoneal adhesions to evaluate organ toxicity. Twenty five healthy adult mongrel dogs (weighing 4.68${\pm}$1.67 kg) were divided into five experimental groups composed of five dogs respectively; negative control group (NC, non-treated), positive control group (PC, 2% carboxymethyl chitosan solution treated), and experiment 1 group (E1, 0.25 ml PX/SA mixture of abraded area), experiment 2 group (E2, 0.5 ml PX/SA mixture of abraded area), experiment 3 group (E3, 1.0 ml PX/SA mixture of abraded area). Venous blood specimens were collected from all experimental animals for hematologic and biochemical analysis: WBC, fibrinogen, AST, ALT, ALP, BUN and creatinine. The anti-adhesion effect was evaluated using a serosa abrasion model. The denuded ileum was coated with PX/SA mixture, carboxymethyl chitosan solution or neither. The tensile strength of the adhesion site was evaluated with a tensiometer. For histopathological examination, tissue samples of the liver and kidney were collected from all dogs. According to the results, the frequency and tensile strength values for adhesion separation in PX/SA group were significantly lower than those in negative control group (p < 0.05). In E2 group, the tensile strength was significantly decreased in consideration of PX/SA dose. The values of AST, ALT, ALP, BUN and creatinine of the control and the experimental groups showed no statistical differences. No obvious microscopic differences were noted among tissue sections obtained from all groups. The results suggest that PX/SA mixture may be effective on reducing peritoneal adhesion formation in dog and that 0.5 ml PX/SA mixture of abraded area is most effective dose. Moreover, PX/SA mixture was considered not to have toxicity for the liver and the kidney.

• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.51-63
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• 1973

This paper illustrate residual hearing and socio-medical background on the hearing impaired children, 207 comming to Deaf School. attached to Hankuk Social Work College, Taegu, Korea. The survey was performed through interview with their parents and testing by diagnostic audio-meter (TRIO, AS 105 type) at soundproof room from March 10, to November 28, 1973. The results obtained were as follows. 1) The attendance rate of the compulsory primary school was markedly lower tendency in female than male according to directly proportional to prevalence rate of deafness among them. If was showed the deeper gap in the more superior school (middle and high school). 2) Who entered at the suitable age to each school (six years old to primary school, 12 years to middle and 15 years to high) was 11.3%. And who were enrolled in school age to each school (6-11 years for primary. 12-14 years for middle and 15-17 years for high) was 45.9% (43.7% in male, 50.0% in female). 3) As causative disease, congenital case, were 23.6% included of 13.5% of heredity and 10.1% of troubles during pregnancy; the total acquired cases were 47.9%, it was classified as 11.6% of convulsion from any other diseases, 7.7% of measles, 7.7% of other febrile diseases, 3.4% of drug (the most of streptomycin) intoxication, 2.4% of meningitis, 1.5% of epidemic encephalitis and 31.3% of other diseases; and unknown cases were 28.5%. 4) 31.4% of who included congenital cases lost their hearing within six months old, 11.6% in 6-11 months. 9.7% in 1-2 years old and 14.0% in 2-3years old. Consequently we obtained that the most cases 90.0% were lost their hearing within 3 years after birth. 5) According to qualities of hearing leases the most of cases were perceptive, 197(97.5%), only two cases were conductive, and eight cases were mixed. 6) The status of residual hearing according to average grade of hearing loss. $B(=\frac{a+2b+c}{4}$ as table 13) were as follows. Two cases were normal (one was mute and another was severe speach disorder). Ten cases, moderate. Moderately severe cases were 40 (19.3%). Severe cases, 38(18.4%). Scale out, profound cases, 48 (23.3%). And impossible testing cases because that were infantile or had some mental disorder were 69 (33.3%). 7) The using rate of hearing aides was only 12.0%. Among them who had some more residual hearing and could showed hearing effect with hearing aide have used more many proportionary but who were difficult to expect that effect were rare.